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Applications of nanofluids in photovoltaic thermal systems: A review of recent advances
Journal Pre-proof Applications of nanofluids in photovoltaic thermal systems: A review of recent advances Naseem Abbas, Muhammad Bilal Awan, Mohammed Amer, Syed Muhammad Ammar, Uzair Sajjad, Hafiz Muhammad Ali, Nida Zahra, Muzamil Hussain, Mohsin Ali Badshah, Ali Turab Jafry
PII: DOI: Reference:
S0378-4371(19)31440-2 https://doi.org/10.1016/j.physa.2019.122513 PHYSA 122513
To appear in:
Physica A
Received date : 6 April 2019 Revised date : 3 May 2019 Please cite this article as: N. Abbas, M.B. Awan, M. Amer et al., Applications of nanofluids in photovoltaic thermal systems: A review of recent advances, Physica A (2019), doi: https://doi.org/10.1016/j.physa.2019.122513. This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
© 2019 Published by Elsevier B.V.
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Highlights 1. Influence of configurations and geometries in PV/T systems. 2. Influence of nanoparticle type, size, volume fraction and concentration ratio.
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3. Effective parameters for Nano fluids applications in PV/T systems.
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4. Summary of application of Nano fluids as a coolant in photovoltaic systems.
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Applications of nanofluids in photovoltaic thermal systems: A
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review of recent advances
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Naseem Abbas a, b, Muhammad Bilal Awan b, Mohammed Amer c, *1, Syed Muhammad Ammar d,
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Uzair Sajjad c, Hafiz Muhammad Ali e, *2, Nida Zahra f, Muzamil Hussain g, Mohsin Ali Badshah , and Ali Turab Jafry h
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a
School of Mechanical Engineering, Chung Ang University, Seoul 06974, Republic of Korea
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b
Department of Mechanical Engineering, University of Central Punjab, Lahore 54000, Pakistan
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c
Department of Mechanical Engineering, National Chiao Tung University, Hsinchu, Taiwan
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d
Division of Mechanical Design Engineering, Chonbuk National University, Jeonju, Jeonbuk
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54896, Republic of Korea
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e
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Technology, Taxila, 47050, Pakistan
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Department of Physics, Government College University, Faisalabad 38000, Pakistan
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g
Department of Polymer Engineering and Technology, University of the Punjab, Lahore 54000,
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Pakistan
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h
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and Technology, Swabi 23640, Pakistan
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Department of Mechanical Engineering, Ghulam Ishaq Khan Institute of Engineering Sciences
*1 [email protected] *2 [email protected]
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Department of Mechanical and Aeronautical Engineering, University of Engineering and
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Abstract
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The aim of this study is to present a critical review of the impact of nanofluids on the
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performance enhancement of PV/T systems. The review has analyzed the effects of nanoparticle
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type, size, volume fraction and concentration ratio on the performance of PV/T systems.
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Furthermore, the type of base-fluid, flow channels, and flow types have also been studied
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comprehensively in relation to nanofluids characteristics and properties. Results have shown that
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the inclusion of nanofluid enhances the overall efficiency of the PV/T systems. It has been
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concluded that the organic fluids are better base fluids than water, and nanofluids with better
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thermal conductivity enhance the maximum efficiency once optimum size, volume fraction and
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correct concentration ratio of nanofluid are selected. Moreover, straight microchannel and the
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addition of Fe3O4, SiC and TiO2 nanofluids with low concentration ratio provides better
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efficiency and flexibility. The motive beyond that is the micro-channels turbulent flow occurs at
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low Reynolds number. Accordingly, maximum efficiency can be obtained at higher velocity
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laminar flows. Increasing the velocity to higher ranges of turbulent flow doesn’t allow proper
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time for heat transfer and can cause clustering of nanoparticles. The observations of this review
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are proposed to PV/T systems and it is helpful for the thermal system design practitioners
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towards achieving high efficiency in any thermal system.
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Keywords: Nanofluids; Photovoltaics; Thermal; Applications.
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1. Introduction
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Photovoltaic (PV) and photovoltaic thermal (PVT) systems have been the pivotal part in the
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transition towards energy sustainability. However, their low efficiency offers hurdles in their
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usage as sustainable devices. Cooling of PV systems and low heat carrying capacity of PVT
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systems is considered a major reason for the low efficiency of these systems. Positively, modern
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research on nanofluids has ensured rapid advancement in enhancing heat transfer in energy
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systems. Figure 1 shows a typical schematic diagram of the PV/T system.
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Figure 1. A schematic diagram of a typical PV/T system.
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A nanofluid is a mixture of nanoparticles with a base fluid. The performance of nanofluid is a
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function of its material, size, base fluid, thermal conductivity, geometry, and so on. Nanoparticles
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are characterized by their high surface area to volume ratio. The surface area of one gram of
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some nanoparticles can be assumed to be as large as a football stadium [1]. Because of having a
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higher surface area than the base fluid and having a small size, it possesses superior thermal
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conductivity, smooth flow, and stability [2, 3]. Furthermore, nanofluids have higher heat transfer
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properties than traditional heat transfer fluids [4]. On the other hand, long term stability is
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considered the most significant characteristic for effective utilization of nanofluids since they
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interact with each other during motion. This interacts drives to a particle clustering due to strong
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attractive forces the nanoparticles have. Under the force of gravity, these nanoparticles form
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large clusters and alter the flow stability. This phenomenon shrinks the system thermal
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performance and blocks the channels. Hence, selection and manufacturing of nanoparticles
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require long term stability test of nanoparticles. Major stability tests of nanoparticles include
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Zeta potential measurement method, sedimentation, and centrifugation method, UV–Visible
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Spectroscopy Analysis and Dynamic Light Scattering (DLS) Method. These methods do not only
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afford the stability of nanoparticles but also offer a measuring scale to increase the stability of
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the nanoparticle.
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PV and PVT systems both are carbon neutral resources of energy for producing electrical and
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thermal energy, respectively. PVT system converts solar energy into thermal energy by storing
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heat in the working fluid and then provided it for thermal applications [5]. Techno-economic
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characteristic of PVT collectors depends upon the base fluid, absorber material, collector length,
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fluid flow parameters, collector depth, module type, sun tracking, tube spacing and diameter,
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glazing characteristics, shading factor, solar irradiance and working of fluid type [6-17].
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Optimizing these parameters increase the thermal efficiency (useful thermal energy/total solar
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irradiance in kJ/m2), electrical efficiency (useful electricity produced/total solar irradiance in
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kW/m2) and overall efficiency (portion of energy in the form of sunlight that can be converted
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via photovoltaics into electricity) of these systems.
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Photovoltaic (PV) system are used to provide output electrical energy when solar energy is being
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employed [18, 19]. An efficient PV system should possess some vital characteristics such as
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better cooling system, the exact location of the module, system and load synchronization and
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choice of solar tracking in the system [20]. The absorbed energy by solar irradiation in an
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efficient system exceeds 50% [21]. The increased temperature due to the absorbed energy results
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in many problems like cell temperature increment and low electrical efficiency [22]. The
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efficiency of a PV system is very critical to its working temperature. Irradiation increases surface
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temperature; however, it decreases the electrical efficiency [23-25]. For a better understanding of
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the PV systems function, it is important to analyze the input source. PV cells utilize solar
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irradiations with photon energy greater than the band gap of PV cells to produce electricity. The
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remaining energy is converted into waste heat increases the temperature of the PV cell. The
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increased temperature may result in the decrease of open circuit voltage (Voc), output energy and
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fill factor to about 2-2.3 mV/°C, 0.4-0.5%/°C and 0.1-0.2%/°C, respectively [26].
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Previous research analyzes the effect of heat on the performance of PV and PVT systems.
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Chander et al. [27] experimentally investigated the effect of temperature on the behavior of the
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mono-crystalline solar cell. The experiments were done at 550 W/m2 light intensity and the cell
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temperature of 25-60 °C. The efficiency decreased with the increase in cell temperature. Cuce et
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al. [28] did experimentation to investigate the effect of PV cell on the light intensity and
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temperature. They concluded that the performance can be readily improved by decreasing the PV
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cell temperature. Radziemska [29] concluded from his experimental study that output power of
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solar cell could decrease to about 0.4% as a result of a temperature increase of 1 K (Kelvin).
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Similarly, the effect of temperature on the efficiency of PV cells and fuel cells has been studied
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by many investigators [30-43]. Research on PVT systems has indicated that heat capturing
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process can be enhanced by varying the thermo-physical properties of base fluid [44]. Research
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proved that nanoparticles are the best candidate for enhancing the heat transfer characteristic of
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any base fluid for any PV/T system [45-58]. Some current studies related to using of nanofluids,
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prediction of their thermal performance and analysis of their heat transfer were reported [59-71]
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where this research could be a beneficial and expand to other systems [72-75].
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This review is a hand for researchers who are looking for nanoparticles to use in PV system since
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it gives the effect of almost each practically used nanoparticle for PV systems. In essence,
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enhancing PV and PVT systems efficiency obliges enhancing the heat transfer. A detailed review
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has been reported for the cooling of the PV system and efficiency enhancement of PVT systems
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by using nanofluids in the current research. Each chapter explains the latest research of PV/T
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system performance enhancement presented in terms of flow conditions (laminar/turbulent), base
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fluid, flow channels, and nanoparticle characteristics and properties.
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2. Influence of configurations and geometries in PV/T systems
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Nanofluids usage in PV/T systems cannot be arbitrary. They must be used with a proper
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configuration and with an optimum geometry to extract the maximum output from such up-
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gradation. Table 1 provides a detailed review of the effect of flow channel geometry and
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nanofluid concentration on the performance of various PV/T systems.
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Table 1. Types of channels configurations used for effective cooling with reference to
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nanofluids.
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Nanofluid (concentration)
Electrical efficiency
Thermal efficiency
Overall efficiency
Single rectangular (2 mm & 4 mm thickness) (Over the cell)
MgO-water. 10 nm size. (0.020.1 wt%)
14.7% (2 mm) 14 % (4 mm)
47.2 % (2 mm) 32 % (4 mm)
61.9 % (2 mm) 46 % (4 mm)
Chandrasekar et al. [77] (2013)
Porous mm)
Al2O3 and CuO in water (0.1 wt%)
9.7% (Al2O3) 9.5% (CuO) 10.4 (Water)
11% CuO 17% Al2O3 30% Water
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Xu and Kleinstreuer [78] (2014)
Single rectangular
5% Al2O3-water
11%
59%
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AlOOH.xH2O 0.01 wt%
27%
Comparative values
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[76]
media
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Karami and Rahimi. [79] (2014)
Microchannels (rectangular, 1.8×0.5×240 mm3)
Karami and Rahimi [80] (2014)
Straight rectangular (5×3.5×245 mm3) Helical mm2)
(5×3.5
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Geometry and type (thickness)
Investigator (Year)
AlOOH.xH2O 0.1 wt%
20.57% Straight 37.67% Helical
Comparative values
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Fe3O4-water (3 wt% - with and without magnetic field)
7.23%
68.42%
76% 79%
Sheet and Tube
Sardarabadi et al. [56] (2014)
Sheet and Tube
SiO2/Water (1 and 3 wt% )
9.01% 9.75%
69.2% 72.1%
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Michael and Iniyan [53] (2015)
Rectangular (2 mm)
CuO (0.05 vol%)
6%
45.76%
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Said et (2015)
Sheet and Tube
TiO2/water vol%)
-
-
76%
Microchannel
Al2O3/water
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Ghadiri et al. [52] (2015)
[81]
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Lelea et al. [82] (2015)
(0.1
Saroha et al. [83] (2015)
Rectangular (Above and below)
AgNPs AuNPs
and
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-
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Noghrehabadi et al. [84] (2016)
Conical
SiO2/water (1% mass fraction)
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62%
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Sardarabadi and Passandideh-Fard [85] (2016)
Sheet and tube
Al2O3, TiO2, and ZnO (2 wt%)
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-
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Al-Shamani et al.
Serpentine
SiC
13.52%
68.21%
81.73%
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Electrical efficiency
Thermal efficiency
Overall efficiency
(rectangular)
Rejeb et al. [87] (2016)
Sheet and tube
Al2O3 and Cu (0.1 – 0.4 wt%)
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46.69% (Al2O3) 76.87% (Cu)
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Radwan et al. [88] (2016)
Microchannel (rectangular)
Al2O3/water, SiC/water
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Sharaf and Orhan [89] (2016)
Rectangular (Minichannel)
Al2O3/water Al2O3/synthetic oil
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-
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Soltani et al. [90] (2017)
Sheet and tube
SiO2/water Fe3O4/water (0.5% mass ratio)
14.9%
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Al-Waeli et al. [91] (2017)
Sheet and tube
Al-Waeli et al. [92] (2017)
Serpentine (PCM)
Hasan et al. [93] (2017)
Jet Impingement
Sardarabadi et al. [94] (2017)
Serpentine (PCM)
Yazdanifard et al. [95] (2017)
Sheet and tube (CPV/T)
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Nanofluid (concentration)
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Geometry and type (thickness)
Al2O3, CuO and SiC (0.5 – 4% vol. fraction)
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SiC
13.7%
72%
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SiC
12.75%
85%
97.75%
ZnO
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Investigator (Year)
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TiO2
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Geometries in Table 1 can be mainly categorized as a single rectangular channel, sheet and tube,
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micro-channel, and serpentine channel.
Rectangular Channel:
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For a single rectangular channel, Michael and Iniyan [53] used CuO nanoparticles in a PV/T
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system. In comparison to water, the nanofluid improved the thermal efficiency of the solar
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thermal collector. However, a reduction in electrical efficiency was observed which attributed to
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the need for a redesign of the heat exchanger for the higher nanofluid heat transfer rate. In
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another study, a numerical analysis of high-concentration PV/T system for a constant flow rate
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mode was performed. Simulation results showed that a greater number of channels leads to a
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good performance at a slight expense of pumping power [89]. Additionally, in the mini-channel
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rectangular heat extractor, Al2O3/synthetic oil nanofluid was found unfavorable against pure
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water and Al2O3/water.
Microchannel:
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Karami and Rahimi [79] used water-based Boehmite (AlOOH.xH2O) nanofluid in rectangular
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microchannels to observe its cooling effect. The nanoparticles decreased the average temperature
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as compared to the pure water case. Yet, increasing the concentration from 0.01 to 0.3 wt% gave
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a weaker cooling performance and electrical efficiency. In another attempt, they investigated the
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effect of geometry by comparing straight rectangular channels and helical channels configuration
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[80]. The Boehmite nanofluid showed same results in performing reducing the average
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temperature of the PV cell and increasing the thermal and electrical performance compared to
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water. The helical configuration demonstrated a superior performance due to high bending
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sections number that is always causing a disruption in its thermal boundary layer and high
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thermal efficiency of the system by the end of the way. Furthermore, the helical geometry
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required less pumping power as compared to the straight one; making the channel geometry an
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important parameter for cooling performance of PV/T systems. Lelea et al. [82] used water with
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Al2O3 in a microchannel to study the effects of Reynolds number. At low Reynolds number, the
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maximum temperature reduced by using nanofluids. However, for Re>1000, the difference was
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negligible. Radwan et al. [88] compared Al2O3/water and SiC/water with water in a rectangular
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microchannel for a low concentrated photovoltaic-thermal system (LCPV/T). Nanofluids
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achieved a higher thermal performance in comparison with water, with SiC/water attaining a
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higher reduction in cell temperature than Al2O3/water. Higher concentration (threshold value)
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and the lower Reynolds number achieved better electrical performance. The friction of nanofluid
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increased with increasing both the Reynolds number and volume fraction of nanoparticles.
Sheet and tube:
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Sardarabadi et al. [56] demonstrated the effect of adding SiO2/water nanofluids in a sheet and
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tube collector. Thermal and overall efficiencies improved compared to water via using
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nanoparticles as well as by increasing their concentration from 1 wt% to 3 wt%. Ghadiri et al.
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[52] investigated the effect of using ferrofluids in a sheet and tube system under constant and
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alternating magnetic fields. Their results indicated a vast improvement in the overall
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performance compared to the water and an additional increment in efficiency through using an
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alternating magnetic field. In another study, TiO2 nanoparticles also improved thermal
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performance as well as the overall energy and exergy efficiency of the system [85]. A detailed
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comparison revealed that TiO2/water and ZnO/water nanofluids performed better in terms of
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electrical efficiency than Al2O3/water and water in a sheet and tube collector. Moreover,
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ZnO/water was found to have better thermal performance compared to TiO2/water and
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Al2O3/water. Rejeb et al. [87] demonstrated that pure water performed better than ethylene glycol
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as the base fluid. In addition, Cu/water was found to possess the best thermal and electrical
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efficiency in comparison with Al2O3/water. Soltani et al. [90] studied the effect of five different
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cooling methods which included natural, forced, water, SiO2/water nanofluid, and Fe3O4 /water
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nanofluid cooling on a hybrid photovoltaic/thermoelectric (PV/TE) system. Liquid cooling
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showed better results for total power in comparison with air. Both nanofluids outperformed water
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with SiO2/water yielding a slightly higher power production than Fe3O4 /water. Al-Waeli et al.
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[94] used a copper tubing mesh welded to a copper plate and used Al2O3, CuO, and SiC
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nanoparticles in water. Among the three nanofluids, SiC showed higher stability and thermal
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conductivity for the PV/T system. Yazdanifard et al. [95] numerically investigated the effects of
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various geometrical parameters such as pipe length, diameter, concentration ratio, as well as the
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use of TiO2 nanofluids in laminar and turbulent regime in a concentrating-PV/T system using a
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parabolic trough collector. The simulation results showed improvement in cooling performance
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with nanofluids in the laminar flow regime. However, the efficiency decreases in the turbulent
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flow regime which conflicts with the results of turbulent flow without using nanofluids.
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Serpentine:
A study on the serpentine channel in a rectangular cross-section was carried out by Al-Shamani
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et al. [86] who examined TiO2, SiO2, and SiC as nanofluids in water. The released results
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showed that SiC has the highest electrical, thermal and overall efficiency followed by TiO2/water
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and SiO2/water. Al-Waeli et al. [94] proposed a new configuration by utilizing paraffin wax
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mixed with SiC nanoparticles as a phase change material (PCM). They filled it in a rectangular
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tank with copper tubing containing SiC/water nanofluid flowing through them. Their unique
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setup displayed a significant improvement on the acquired thermal, electrical, and overall
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performance of the system compared to the other PV/T systems. The nanoparticles improved the
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thermal performance in both nanofluids as well as the paraffin wax. In a similar attempt,
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Sardarabadi et al. [54] used ZnO/water nanofluid and determined the cooling efficiency for the
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PV/T alone, PV/T with fluid, and PV/T with PCM system. The results demonstrated a higher
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overall exergy efficiency for PCM/nanofluid based collector system making it a suitable option
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for improving the cooling in PV/T systems.
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Other configurations:
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Cui et al. [76] applied the flow of nanofluid above the PV cell. The results exposed a reduction in
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transmittance of nanofluids with an escalation in mass fraction and film thickness and hence
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decreasing the electrical output compared to PV cells. Despite this, the thermal efficiency of the
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system increased resulting in a much higher overall efficiency due to the conservation of heat
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and electricity. Saroha et al. [83] used silver and gold nanoparticles flowing into primary and
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secondary channels acting as coolant (flow below PV cell) and an optical filter (flow above PV
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cell), respectively. The results revealed an improvement in the thermal and electrical efficiencies
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in the PV/T hybrid collector. A similar configuration for a PV/T hybrid system with two designs
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of separate and double-pass channels was numerically investigated by Hassani et al. [55]. It
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showed that separate channels for nanofluids outperformed the connected channel design.
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Another effective way of cooling PV modules was investigated by Chandrasekar et al. [7] using
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passive cooling with the help of cotton wick structures in the form of a serpentine shape channel.
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The cooling effect of water was higher in comparison with nanofluids of Al2O3/water and
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CuO/water. This deterioration in thermal performance was due to the aggregation of
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nanoparticles within the porous fibers which caused a reduction in the capillary force necessary
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for the fluid movement. A conical solar collector was experimentally investigated by
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Noghrehabadi et al. [77] using SiO2/water nanofluid. It was shown that the nanofluid had a
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slightly better thermal performance than water with higher thermal efficiencies for higher flow
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rates. Hasan et al. [55] used a jet impingement to analyze their cooling performance with
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different nanofluids. Their results indicated the highest electrical and thermal efficiencies for
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SiC/water nanofluid followed by TiO2/water, SiO2/water, and water respectively.
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From the above literature review and Table 1, it can be reasonably concluded that straight
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microchannel offers the best performance as compared to all other channels. Though some
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channels have better efficiency than the straight microchannel, they are difficult to manufacture
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and are not cost effective. Yet, for best cost-effective performance straight microchannel is
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preferable. Moreover, SiC performs much better than other aforementioned nanoparticles.
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Although PCM inclusion increases the efficiency of the system, cost-effectiveness must be
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considered before integrating PCM with the PVT system.
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3. Influence of nanoparticle type in PV/T systems
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Different kinds of nanoparticles behave differently in PV/T systems. Nanoparticle thermo-
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physical properties (thermal diffusivity, conductivity, size, etc.) greatly impact their performance.
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PV/T systems majorly nanoparticles are divided into two categories; Metals and Metal oxides-
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based nanoparticles.
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For cooling purposes, thermal conductivity is considered as a major performance indicator.
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Table 2 shows the thermal conductivities of most abundantly used nanoparticles in PV/T
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systems. Increasing the nanoparticle thermal conductivity increases performance. However, it is
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not the only parameter for selection of the nanoparticle.
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Material
Silver (Ag) / 425
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Copper (Cu) / 398 Nanoparticles
Gold (Au) / 315 Aluminum (Al) / 273 Iron (Fe) / 80
Metal Oxides / Thermal Conductivity (W/m⸳K)
Others / Thermal (W/m⸳K) Diamond(C1) [103]
/
2320
Cupric Oxide (CuO) / 77 [98]
Graphite(C2) [104]
/
2000
Alumina (Al2O3) / 40 Zinc Oxide [100]
(ZnO)
[99]
Conductivity
/ 29
Titanium Oxide (TiO2) /8.4 [101] Iron Oxides (Fe3O4) / 7 [102]
Carbon [105]
Nano
Silicon [106]
Carbide
Bohemite [107]
Tubes(CNTs)/2000
(SiC)
/
280
(γ-AlO(OH))
/
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The purpose of using nanoparticles in PV/T systems is to increase their thermal efficiency.
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Therefore, the selected nanoparticles for PV/T system must have better thermal conductivity,
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thermal diffusivity, and viscosity. They must possess the ability to increase the thermo-physical
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properties of the base fluid. Furthermore, base fluid plays an essential part in increasing the
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thermal efficiency of any PV/T system. Table 3 shows that using glycol is a good option
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compared to water. Whereas, some oils have better efficiency than both water and ethylene
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glycol.
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Table 3 clearly shows that nanoparticles are mostly used with water and ethylene glycol with a
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very low concentration and small size. Research has shown that gold (Au), silver (Ag) and
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copper (Cu) metals perform better than other metals due to their higher conductivities. Table 3
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shows that metal oxides are best-suited nanoparticles for any application considering their
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effectiveness and suspension characteristics. Among metal oxides, copper oxide (CuO) and iron
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oxides (Fe3O4, Fe2O3) perform better than other types of nanoparticles [108, 109]. Modern
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research has also shown that carbon-based nanoparticles are also very effective, especially
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silicon carbide (SiC). Silicon carbide (SiC) is the best suited for enhancing the thermal efficiency
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of any system [110]. Modified nanoparticles like bohemite, digenite have made their mark in
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thermal systems. On the other hand, a lot of research needs to be done before considering them
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as a replacement of conventional nanoparticles.
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Thermal properties are not enough for selecting nanoparticles for PV/T applications. Physical
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geometry is an extremely important parameter for enhancing the thermal performance of any
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system. Chen et al. [111] investigated three different sizes (25, 33 and 40 nm) of Au-based
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nanofluid and found that the best suited among them was 33 nm sized particles. Filho et al. [112]
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proved that large size particles form clusters reduces the sunlight entrance in the system and
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reduces the efficiency of the system. Consequently, an optimum size must be considered for any
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particle to avoid clustering. Sokhansefat et al. [113] concluded that the performance of any
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nanoparticle also depends upon its volume fraction. Hence, selecting the volume percentage for
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any nanoparticle must consider as well. They performed experiments on two different volume
272
percentages (1 and 5 %) of alumina. They found that increasing the concentration will raise
273
efficiency from 5 to 15%. However, after a specific value, there was a decline in the performance
274
of the system. This makes his argument stronger for that any nanofluid will perform best only
275
under certain conditions. Lee at al. [114] performed the same research on the same nanoparticle
276
and found that increasing the volume fraction from 0.01 to 0.3% will the efficiency of the
277
system.
278
Table 3. Nanoparticle effect on different system’s thermal performance.
Au
Fe
Al2O3
TiO2
Size (nm)
Fraction (vol %)
Water Water Acetone
<10 26 80
.01-.05 0.5-2.0 0.04
Thermal Improvement (%) 41 [116] 22 [118] 18 [120]
Ethylene Glycol
80
0.5
15 [122]
80
0.5
4.7 [3]
0.1 0.5 3 7.5 0.9 5 4 5 5.5 0.2
4 [122] 12 [122] 27 [122] 52 [128] 15 [130] 60 [109] 20 [108] 26.5 [133] 25 [135] 46 [137]
5
12-18 [139]
Water Kerosene Water Kerosene
80 80 80 100 <100 36 18.6 210 <100 20 90210 13 6.7 10 155
2 6.3 5 1
48 [141] 300 [143] 200 [145] 34 [147]
15-22 [148]
Water
<100
1.1-4.4
22 [149]
85.1 [150]
EG
30
1
12.4 [151]
Fraction (vol %)
Water Water Water Ethylene Glycol (EG)
<100 <100 35
0.3-0.9 0.25-1 .01-1
100500
0.1-1.0
15 [121]
Water
21
0.00026
48 [123]
<100 17 <100 20 10 98 10 9 28 10 6501000 15 20 21 21 2040 50-
N/A 0.18 0.011 0.55 0.55 0.01 .1-0.55 2-10 3-8 0.5-1.8
20-25 [124] 63 [125] 14 [126] 11-33 [127] 18 [129] 5 [131] 18 [132] 29 [116] 41 [134] 32 [136]
0.5-4
20 [138]
Water
0.5-5 4 0.2 0.2
30 [140] 23 [142] <10 [144] 6-11 [146]
0.7-1 0.025
Water Water Water EG EG Water EG Water Water / EG Water Transformer Oil Water Water DI Water Water Oil Water
al
Ag
Base Fluid
Size (nm)
urn
Type
Thermal Improvement (%) 30 [115] 10 [117] 10-80 [119]
Base Fluid
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Type
Cu
Al
CuO
ZnO
Fe3O4
Engine Oil Water Water EG Water Water Water EG EG EG Water
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C2
300 35 30 65 600 N/A 115
CNTs 0.01 1.36 3 wt% 4 0.1 1 wt%
25 [152] 36 [154] 88.9 [91] 22.9 [156] 10 -20 [157] 29 [159]
γAlO(OH) C1
Water EG Water Water Water Water
10 30 10 5-10 10 <10
0.84 1 0.1 wt% .01 wt% 3 wt% 0.9 wt%
23-31 [153] 12.7 [155] 37.67 [80] 27 [79] 10.8 [158] 10.95 [160]
of
SiC
Water Oil Water EG Water Water
Based on Table 3, it can be concluded that nanoparticle selection can only be beneficial if
281
optimum size and concentration is well-thought-out. Moreover, any nanoparticle selection must
282
be linked with its thermo-physical properties by keeping in mind its life and cost. Lastly,
283
research has proved that metal oxides are best suited for PV/T applications but the ease of
284
manufacturing SiC can also be adopted for PV/T applications as it offers almost similar results
285
like metal oxides. Hence, metal oxides and SiC are preferable.
286
4. Effective parameters for nanofluids applications in PV/T systems
287
Nanofluids as coolant show variable performance with respect to different parameters associated
288
with the properties of nanofluids and PV/T systems. Details are discussed below with reference
289
to the previous research works.
290
4.1. Velocity
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Figure 2. Solar cell temperature (Tsc) variation relation with wind velocity (Vw) at different
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geometric concentration ratios (CR) [88].
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Velocity is one of the most effective parameters for shaping the heat transfer efficiency of any
295
system. Convective heat transfer is directly linked with the velocity of the system. Increasing the
296
velocity increases the Reynolds number that makes fluid turbulent after some specific increase in
297
velocity. The performance of PV/T system depends upon two velocities, air passing over the
298
panel and the coolant, flowing for the purpose of cooling, inside the system. Figure shows that
299
as the wind velocity increases over the panel, the temperature of the panel decreases resulting in
300
an increase of the system’s performance.
301
Whereas, Figure is a clear indication of the effect of a velocity increasing (Reynolds number)
302
on the cell temperature. At high geometric concentration ratio, solar cells show an increase in
303
efficiency of the system via increasing nanofluid’s velocity, but this trend is almost constant at a
304
low concentration ratio. The graph also shows that volume concentration is not affecting the
305
system’s efficiency when it increased from 1% to 4%. In addition, SiC-water is presenting better
306
performance than water and Al2O3 nanofluid based system. Therefore, it is better to use
307
nanoparticles at high geometric concentration ratios compared to low concentration ratios.
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Figure 3. Solar cell temperature variation at different velocities (Reynolds number) with varying
311
CR and different nanofluids at (a) 1 vol% nanoparticle (b) 4 vol% nanoparticle [88].
312 313
Figure 4 and Figure 5 indicates that the best performance from nanofluids can be achieved at
314
higher velocities, but those velocities must be in the range of low turbulent Reynolds number or
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in the laminar region. Laminar flow of nanoparticles with low velocity does not have a
316
considerable effect on the performance of the system and cause clustering of nanoparticles. The
317
same tendency will be for too high velocities. It can be concluded from the available data that the
318
velocity of nanoparticles-based coolant must be high. On the other hand, it should not be high
319
enough to make flow extreme turbulent as high velocity laminar or slightly turbulent flow. This
320
provides a better particle suspension and a better heat transfer rate that helps to increase the
321
efficiency of the PV/T systems.
322
4.2. Concentration/volume fraction
323
Another important factor to determine the effectiveness of any nanofluid is its volume fraction or
324
concentration ratio. Figure and Figure 5 show that at low Reynolds number and low volume
325
fraction, the efficiency of the system increases. As the volume fraction exceeds a specific
326
amount, the effect on panel cooling is almost constant. Again, SiC-based coolant has better
327
performance than the Al2O3 based coolant and systems with lower geometric concentration ratios
328
has better efficiency than the higher concentration ratio systems.
329
Straight channel and helical channels were employed with Boehmite nanofluid to observe the
330
efficiency of PV cells. The volume fraction of 39.70% and 53.76% of 0.1 wt% were used for
331
helical and straight channels respectively. The efficiency of the PV cells enhanced by 20.57%
332
and 37.67% for the straight and helical channels. In the case of helical channels, the temperature
333
decrease by nanofluid is too high if compared to the base fluid as shown in Fig. 5.
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Figure 4. Solar Cell temperature variation for different volume fractions of nanoparticles at
339
varying Reynolds numbers (a) CR=10 (b) CR=20 (c) CR=40 [88, 161, 162].
340 341
Similarly, the concentration ratio of nanofluids also has a positive impact on the heat removal in
342
the PV/T systems. Figure
343
performance when it has a concentration of 0.1%. System performance is low when the
344
concentration is in the 0.0x range. correspondingly, when the concentration increased from 0.1%
345
to 0.5%, the efficiency of the system doesn’t show any positive impact. As a result, it is crucial to
346
select effective concentration ratio of any nanoparticle for using it as a coolant.
347
A detailed comparison is presented from some previous studies in Fig. 6. It indicates that with
348
the increase in volume fraction, system conductivity enhances which has a positive impact on the
349
efficiency of the system. Yet, this fraction should be tested before using nanoparticles in any
350
system. If the concentration ratio increases from a certain limit, it will start to have a negative
351
impact on the efficiency of the system. Furthermore, it will offer nanoparticle suspension issues.
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shows that the Boehmite based coolant system has the best
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352 (a) water.
(b) Boehmite 0.01% wt.
354 355
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(c) Boehmite 0.1% wt.
(d) Boehmite 0.5% wt.
Figure 5. The temperature gradient of cooling and without cooling with different weight
357
concentrations of Boehmite using different channels [80].
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359
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358
360
Figure 6. Comparison of variation of thermal conductivity of nanoparticle with respect to (a)
361
Nanoparticle fraction (b) Temperature [78, 116, 161, 162].
362 363
Paul et al. [123] measured the thermal conductivity enhancement of Au based nanofluid by
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varying the particle concentration and particle size. The enhancement was found thru increasing
365
the concentration and decreasing the particle size. The maximum enhancement in thermal
366
conductivity was recorded at particle size 21 nm and volume fraction 0.00026 with 48%. The
367
response to enhancement is shown in Figure . In another study [147], only 28% enhancement in
368
thermal conductivity was reported for both Au and carbon nanotubes composite water-based
369
nanofluid. Besides, only 15% enhancement was recorded with the addition of Au nanoparticles
370
in water-based carbon nanotubes composite nanofluids. The variation in enhancement as
371
compared to many other studies may be attributed to the additional stabilizer, synthetic
372
conditions and distribution of nanoparticles.
373
Hong et al. [129] prepared an ethylene glycol-based Fe nanofluids from monocrystalline powder.
374
The dispersion improved when using sonication with high-powered pulses. The nonlinear
375
response of thermal conductivity as a function of volume fraction was observed and a maximum
376
18% enhancement was reported. The results were compared with Cu nanofluids as shown in
377
Figure . The improved conductivity of Fe nanofluids than Cu nanofluids was observed thanks to
378
more effective thermal-transport ability of Fe nanofluids.
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(b)
Figure 7. Thermal conductivity enhancement percentage of gold water based nanofluid (a) with
384
a variation of volume fraction (b) with a variety of particle size at 0.00026 volume fraction [78].
385 386 387
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Figure 8. Thermal conductivity of Fe and Cu nanofluids at different volume fractions [82].
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Any increase in the volume fraction will lead to high enhancement in the thermal conductivity of
389
CuO nanofluids. Liu [128] investigated the performance of ethylene-based CuO nanofluids by
390
changing the volume fraction. The normalized viscosity and thermal conductivity data are shown
391
in Figure . In thermal conductivity ratio, ke is the thermal conductivity of CuO nanofluids and kf
392
is the thermal conductivity of the base fluid. In viscosity ratio, µe is the viscosity of CuO
393
nanofluids and µf is the viscosity of the base fluid. The response is almost in a linear manner
394
because of the decent dispersion and stable suspension of CuO nanoparticles in ethylene glycol.
395
The maximum enhancement in thermal conductivity was achieved by 22.4% at 5% volume
396
fraction. The 22% enhancement in thermal conductivity at 4% volume fraction has been reported
397
for ethylene glycol-based CuO nanofluids [148]. Furthermore, 17% enhancement has been
398
recorded at 4% volume fraction for deionized water based CuO nanofluids [149]. The difference
399
in results is due to the variation in the specific surface area of nanoparticles. The enhanced
400
thermal conductivity of ethylene glycol based ZnO nanofluid was reported by Yu et al. [147].
401
The thermal conductivity response with volume fraction is shown in Figure 10. Thermal
402
conductivity enhancement as a function of volume fraction for ZnO-EG nanofluid [87].
403
. Lee [135] concluded that ZnO nanofluids exhibited temperature dependence at higher
404
concentration while viscosity didn’t show dependence on temperature and increased with volume
405
fraction. The shape of nanoparticle offered a significant effect on the thermal conductivity
406
enhancements.
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407 (a)
410 411 412
(b)
Figure 9. Heat transfer enhancement of Cu nanofluids as a function of volume fraction (a)
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thermal conductivity data (b) viscosity data [163].
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413 414
Figure 10. Thermal conductivity enhancement as a function of volume fraction for ZnO-EG
415
nanofluid [87].
al
416 Fe3O4 and TiO2 nanofluids have almost the same properties as ZnO nanofluids. Their
418
performance can be enhanced by changing the shape and size of nanoparticles and using
419
surfactants. The values of enhancement of thermal performance of these oxides nanofluids are
420
reported in the given data sheet. Dramatic enhancement in thermal conductivity has been
421
reported for kerosene-based Fe3O4 nanofluid under the magnetic field influence along the heat
422
flow direction. The maximum enhancement was observed 300% at 6.3% volume fraction. The
423
increase in thermal conductivity was due to the formation of the chain-like structure under
424
magnetic field when dipolar interaction energy enhanced from thermal energy. The heat transport
425
becomes more effective through the chainlike aggregates of nanoparticles. The magnetic field
426
effect on thermal conductivity is shown in Figure .
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Yang et al. [148] used the graphite nanofluids to measure the convective heat transfer coefficient
428
for tube heat exchanger. The significant increase in heat transfer coefficient and the thermal
429
conductivity was observed at low weight fraction. The 22% enhancement in heat transfer
430
coefficient and 50% enhancement in the conductivity was observed at 2.5% weight fraction and
431
at 50 °C temperature. The graphite nanofluids have been used in solar collector to enhance the
432
absorptions of solar radiations. Results of this study showed that it can be possible to absorb
433
more than 50% of incident irradiation energy by using graphite nanofluids with 0.000025%,
434
volume fraction, while pure water solar collector can only absorb around 27% of incident
435
irradiation energy as shown in Figure .
436
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427
437
Figure 2. The thermal conductivity ratio (ke/kf) and the percentage of enhancement as a function
438
of the external magnetic field at different volume fractions of Fe3O4 [164].
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439 440
Figure 3. The absorbed energy of solar radiation for different graphite nanofluids [118].
441 4.3. Size
443
A comprehensive experimental study [77] was conducted to investigate the enhancement in the
444
thermal conductivity for the metallic and oxides based nanofluids. The effect of suspension
445
temperature on thermal conductivity with various particle volume fractions, particle sizes and the
446
base fluid was presented. Increasing the particle size and volume fraction drove to a good
447
enhancement. The thermal conductivity enhancement of Al2O3 nanoparticles in base fluid water
448
with suspension temperature at varying nanoparticle size and volume fraction is presented in Fig.
449
13. The thermal conductivity of the nanoparticles in base fluid ethylene glycol was relatively
450
higher than the base fluid water due to the improved dispersion. The metallic nanoparticles were
451
found to give higher enhancement than oxides nanoparticles. Figure 14 presents a comparison of
452
thermal conductivity enhancement of Cu and Al nanofluids at 1% volume fraction and 80 nm
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nanoparticle size. The conductivity of Cu nanofluid was found higher than Al nanofluid due to
454
the higher value of thermal conductivity.
of
18
150 nm/0.5% 150 nm/1% 150 nm/2% 150 nm/3% 45 nm/0.5% 45 nm/1% 45 nm/2% 45 nm/3% 11 nm/0.5% 11 nm/1% 11 nm/2% 11 nm/3%
15
p ro
12
9
6
3
Pr e-
Enhancement in Thermal Conductivity (%)
453
0 20
30
40
50
o
Temperature ( C)
455
457
and particle sizes [3].
urn
20
al
Figure 4. Enhancement in thermal conductivity of Al2O3 nanofluid at different volume fractions
Enhancement in Thermal Conductivity (%)
456
Jo
15
458 459 460
Water-Cu Ethylene Glycol-Cu Water-Al Ethylene Glycol-Al
10
20
30
40
50
o
Temperature ( C)
Figure 5. Comparison of Cu and Al nanofluid at 1% volume fraction and 80 nm particle size [3].
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The nanoparticle size must be within the optimum range for better suspension and better heat
462
transfer in the coolant system. Figure shows that increasing the nanoparticle size will decrease
463
the heat transfer rate due to uneven suspension. As evidential from Figure , the optimum
464
nanoparticle size provides better heat flux. Thus, nanoparticle size selection must be carefully
465
monitored to avoid any efficiency loss in the system. Furthermore, any nanoparticle size used
466
within the mentioned range is better than using base fluid alone.
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Figure 6. Nanoparticle size effect on heat transfer [165].
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467
469 470
Figure 7. Nanoparticle size effect on heat flux and heat transfer [166].
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471 Zaoui et al. [35] compared the heat transfer rate of silver nanofluid in a closed-loop oscillating
473
heat pipe with check valves (CLOHP/CV) with pure water. The best heat flux was achieved at a
474
90˚ inclination angle, 25 aspect ratio and 60 °C operating temperature with 0.5% w/v
475
concentration of silver nanofluid. A 10% improvement in the heat flux was recorded in case of
476
silver nanofluid as compared to pure water. Variation in the heat flux at different concentrations
477
and operating temperature is shown in Figure . The study contradicts with another previous
478
research [146], as heat flux response with a variety of nanoparticles concentration is different in
479
both cases. In this case, the heat flux was increased with increase in concentration owing to using
480
of CLOHP/CV. As the heat flux of CLOHP/CV is dependent on the working fluid viscosity limit,
481
the viscosity of the working fluid will increase at higher concentration of nanoparticles. This
482
makes it difficult to produce bubbles and produce a large friction resistance causing liquid slug
483
obstruction. Therefore, silver concentration can be increased to a limited point in order to
484
enhance the heat flux of CLOHP/CV. The particle size of Ag nanoparticles for this study was less
485
than 100 nm. The heat transfer performance of Ag nanofluid in heat pipe was investigated in
486
terms of thermal resistance using 10 nm and 35nm sizes of Ag nanoparticles. It was found that
487
the thermal resistance of the heat pipe containing 10 nm and 35 nm nanoparticles was 52% and
488
81% lower as compared to DI-water respectively as shown in Figure [37]. In such a case,
489
increasing particle size causes thermal resistance reduction which will enhance the thermal
490
conductivity. The presence of nanoparticles smooths the fluid temperature gradient and reduce
491
the boiling limit due to the increase in conductance and heat resistance reduction.
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492
Figure 8. The operating temperature effect on the heat transfer rate of CLOHP/CV at 25 aspect
494
ratio [35].
495 496
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497 498
(b)
499
Figure 9. The measured value of thermal resistance of heat pipe with nanofluid (a) at 1 ppm (b)
500
at 10 ppm [37].
al
501 4.4. Base fluid
503
Water is the most commonly used base fluid with nanoparticles since it offers better suspension
504
properties and reasonable heat transfer. Yet, organic fluids show better suspension and heat
505
transfer than water. It is preferable to employ water where heat transfer removal can be
506
compromised. However, for high efficiency and sensitive equipment, organic fluids offer
507
outstanding performance. For an economic system, using water as a base fluid is a better option
508
than any other fluid.
509
Increasing the nanoparticles volume fraction will increase the thermal conductivity of nanofluids,
510
while higher concentration enhances the viscosity. This enhancement in thermal conductivity at
511
higher concentration depends on the temperature due to the aggregation and clustering of
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502
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nanoparticles. In general, heat transfer improves by increasing the nanoparticle size and by
513
having highly thermally conductive nanoparticles. This might be due to the difference in surface
514
area per unit volume of the nanoparticles. Enhanced nanofluids performance was observed by
515
increasing the nanofluids specific surface area. Highly thermally conductive nanomaterial was
516
not always found to be the best in improving the thermal transport property of the fluids for
517
suspension. The results variation was also observed due to the difference in synthetic processes,
518
connectivity of nanoparticle, microstructure, experimental techniques, testing conditions and
519
dispersion quality of the nanoparticles. The quite enhancement in conductivity was observed in
520
the case of metallic nanofluids as compared to oxides nanofluids. Oxides nanofluids are good for
521
bountiful long-time stability of suspension which gives a significant improvement. Non-metallic
522
nanoparticles fluids have also great potential in thermal photovoltaic applications. Carbides
523
nanofluids and nano-composite based nanofluids enhance thermal performance. The complete
524
data is simplified in Table 3 that is useful for the selection of nanofluids for different
525
applications.
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5. Summary of application of nanofluids as a coolant in photovoltaic systems
528
Table 4 represents the advantages of using nanofluids as a coolant in different types of
529
photovoltaic systems.
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Table 4. Applications of nanofluids as a coolant in photovoltaic systems. Study Type
Flow Regime
Nano Fluid Type/ Application
Concentration / Size
System Configuration
Mittal et al. [167] (2013)
Numerical
Laminar
Ag-water & Cuwater / Spectral filter + Coolant
0.0043 vol% & 0.01937 vol% / 10 nm & 10 nm
CPV/T
Both Nano temperature thermal effic
Faizal et al. [168] (2013)
Numerical
Laminar
CuO, SiO2, TiO2, and Al2O3 with water/ Coolant
0.02 wt% to 0.032 wt% for all /
PV/T
Nanofluids specific he efficiency. Compared nanofluid efficiency.
Karami et al. [80] (2014)
Experimental
Laminar + Turbulent
Boehmite Coolant
/
0.01,0.1, 0.5 wt% / 5-10 nm
PV/T
Boehmite is than water better perfor
Xu et al. [78] (2014)
Numerical
Turbulent
Al2O3-water Coolant
/
0-4 vol% / 38.4 nm
CPV/T absorber Plate
Cell efficien volume fract
DeJarnette et [169] (2015)
Numerical
Laminar
Plasmonic / Spectral Filter + Coolant
Variable
CPV/T
Plasmonic n filters. They prov nanoparticle
Siddharth et al. [170] (2015)
Numerical + Experimental
Laminar
Ag-water & Auwater / Coolant
0.00019 vol% & 0.00025 vol% / 5 nm each
PV/T
Both nanofl performance system and more efficie
Said et. al. [163] (2015)
Numerical
Laminar
TiO2-water Coolant
0.1, 0.3 vol%
PV/T
Nanofluids efficiency o positive imp Pressure dr nanofluids u
urn
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Pr e-
Researcher (Year)
Jo
al.
/
Conclusive
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Study Type
Flow Regime
Nano Fluid Type/ Application
Concentration / Size
System Configuration
Michael et al. [53] (2015)
Experimental
Laminar
CuO-water Coolant
/
0.05 vol% / 75 nm
PV/T
CuO-water efficiency efficiency as as a coolant.
Lelea et (2015)
Numerical
Laminar
Al2O3-water Coolant
/
1,3,5 vol% / 28, 47 nm
CPV/T
In this spec constant pum better than w
Matin et al. [52] (2015)
Experimental
Laminar
Fe3O4-water Coolant
/
1, 3 wt%
PV/T
System effi usage of ferr The efficie introducing
Sharaf et al. [89] (2016)
Numerical
Al2O3-water & Al2O3-synthetic oil / Coolant
15-40 nm
CPV/T
Al2O3-synth thermal per water.
Laminar
Al2O3-water, TiO2water & and ZnOwater / Coolant
All with separate 0.2 wt% / 20 nm, 10-30 nm & 1025 nm
Sheet and Tube PV/T
In terms of showed lagg other two a best among Thermal ef dependent o electrical eff
et
al.
al
Experimental + Numerical
Jo
Sardarabadi [54] (2016)
[82]
Laminar + Turbulent
urn
al.
Pr e-
Researcher (Year)
Conclusive
Hassani et al. [55] (2016)
Numerical
Laminar
Ag–water & Agtherminol VP / Spectral Filter + Coolant
0.001-1.5 Vol% & 0.0002,0.003 vol% / 10 nm & 10 nm
CPV/T
Increasing t range will in case of Si an For concent thermal nan separate cha channels.
Shamani et al. [86] (2016)
Experimental
Turbulent
SiC-water, TiO2water & SiO2water / Coolant
0 – 2 wt%
PV/T
SiC-based performance
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Study Type
Flow Regime
Nano Fluid Type/ Application
Concentration / Size
System Configuration
Khanjari et al. [171] (2016)
Numerical
Laminar
Ag-water & Al2O3water / Coolant
0-12 vol% / 50 nm
Sheet & Tube PV/T
Ag based performance As volume indicated a (energy + ex
Radwan et al. [88] (2016)
Numerical
Laminar
Al2O3-water SiC-water Coolant
& /
0-4 vol% / 20 nm
CPV/T
SiC based Al2O3. High efficie help of nan compared to pumping w efficiency.
Hassani et al. [172] (2016)
Numerical
CNTs–water & Ag-water / Coolant
0.1 vol% & 0.001 vol% / 15 nm & 10 nm
PV/T
Nanofluid b efficiency a simple PV a
al
Pr e-
Researcher (Year)
urn
Laminar
Conclusive
[173]
Experimental
Laminar
Cu9S5 – oleylamine / Spectral Filter
22.3, 44.6, 89.2 ppm / 60.2 nm
CPV/T
Heat to E dependent o Anti-reflecti increasing sy
Noghrehabadi et al. [174] (2016)
Experimental
Laminar
SiO2-water Coolant
1 wt%
CPV/T
Nanofluids i At high ir system didn to nanofluid
Laminar
Al2O3 and Cu with water and ethyl Glycol / Coolant
0.1,0.2 and 0.4 wt%
PV/T
Cu-water co efficiency co with ethyl efficiency w Thermal and the same con
Jo
An et al. (2016)
Oussama et al. [87] (2016)
Numerical
/
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Study Type
Flow Regime
Nano Fluid Type/ Application
Concentration / Size
System Configuration
Al-Waeli et al. [92] (2017)
Experimental
Laminar
Nano SiC-paraffin wax / Coolant
0-5 mass%
PV/T
Nanofluids e of the system helped to ke the reasonab
Farideh et al. [95] (2017)
Numerical
Laminar + Turbulent
TiO2-water Coolant
/
0-4 vol%
CPV/T & PV/T
Nanofluids flow regime Nanofluids CPVT system TiO2 is an increase the systems.
Shohreh et al. [90]
Numerical
SiO2-water Fe3O4-water Coolant
& /
N/A
PV/TE
Both nanofl thermal and water nanof 4% better in to Fe3O4-wa than water a
al
Pr e-
Researcher (Year)
urn
Laminar
Conclusive
Numerical
Laminar
Al2O3, CuO and SiC with water / Coolant
0.5, 1, 2, 3, and 4 vol%
PV/TE
SiC nanopar in terms of nanoparticle than Al2O3.
Husam et al. [93] (2017)
Experimental
Laminar
TiO2-water, SiO2water & SiC-water / Coolant
1 wt% for each
PV/T
SiC perform nanofluids b on the effici a decrease in With the in the efficienc
Dudul et al. [175] (2017)
Numerical + Experimental
Laminar
CuO-water Coolant
N/A
PV/T
Use of nano by 14.5 °C. Electrical e whereas exe
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Al-Waeli et al. [91] (2017)
/
Flow Regime
Nano Fluid Type/ Application
Concentration / Size
System Configuration
Numerical + Experimental
Laminar
Al2O3-water Coolant
0.1-0.5 wt%
PV/T
The tracking increase the factor of mo The increas efficiency w started to de The optimu was selected
Experimental
Laminar + Turbulent
TiO2 in water polyethylene glycol mixture & Al2O3 in watercetyltrimethylamm onium bromide mixture / Coolant
(0.01, 0.05 and 0.1) wt.%
PV
Al2O3 usage than any oth The flow rat 5000 mL/m rate, better c Increasing increased t increased t system.
Laminar
ZnO-water Coolant
/
0.2 wt%
PV/T
When nano PV/T system material (PC 9%, wher efficiencies respectively.
Laminar
Al2O3-water Coolant
/
(1 & 6) vol%
CPV
Nanofluids more than However, sy Transfer. Combination would giv performance Both exergy considerably
Hussein et al. [176] (2017)
Munzer et al. [177] (2017)
urn
al.
Experimental
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et
Srivastava et [178] (2017)
al.
Numerical
/
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Study Type
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Researcher (Year)
Sardarabadi [54] (2017)
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of
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Conclusive
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It is clear from the literature review that nanofluids are effective in increasing the thermal, electrical and overall efficiencies of the system. Comparisons of different nanoparticles
of
performance showed that Al2O3 is not a much effective nanofluid. Overall performance and working conditions for nanofluids can be summarized as follows:
System efficiency can be enhanced further by controlling the nanofluid concentration, but
p ro
optimum test condition must run on the system before choosing a nanofluid concentration for that specific system.
Nanofluids perform much better in high-velocity laminar flow compared to turbulent flow
Pr e-
since laminar flow provides a better suspension of nanoparticles.
The effectiveness of nanofluids can be enhanced further by using synthetic oils as base fluids.
Increasing the flow rate has a positive impact on the nanofluids to a specific limit. I increase the flow rate after that limit will decrease the efficiency of the system. Therefore, it is strongly recommended to select the optimum flow rates for nanofluids. Nanofluids as coolants behave differently in different climates. The climate must consider
al
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before choosing any nanofluid for cooling applications. Nanoparticle size is another important parameter for judging the effectiveness of nanofluid. Different sizes of nanoparticles behave differently at different flow rates and temperatures. Mostly, the response is random when it comes to the size of the nanoparticles with a velocity
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of the coolant.
6. Conclusions
A comprehensive review of nanoparticle’s application in photovoltaic (PV) cooling has been done in the current study. The effect of almost each practically used nanoparticle for PV systems has been critically observed. Nanoparticle properties (type, size, volume fraction and
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concentration) in relation with base fluid, flow channels, and flow types have been analyzed. It has been observed that base fluids like ethylene glycol and kerosene must be selected for best
of
performance. Results have shown that nanofluid with better thermal conductivity enhances the maximum efficiency where optimum size, volume fraction and correct concentration ratio of
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nanofluid is selected. The concentration ratio of nanoparticle must be as low as possible and volume fraction (%) must be below 0.5%. Care must be taken in the selection of correct volume fraction as higher volume fraction results a clustering of nanoparticle possess the negative effect on the system's performance. Results have shown that straight microchannel is preferred but for
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extremely sensitive applications, helical channels can also be selected. Out of all the studied nanoparticles, Fe3O4, SiC, and TiO2 nanoparticles presented the maximum efficiency enhancement. As indicated in the parametric studies, micro-channels turbulent flow occurs at low Reynolds number. For obtaining the maximum efficiency, the high-velocity laminar flow must be selected. Hense, at higher ranges of Reynolds number time, it is hard to remove heat from the PV
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system. This leads to even negative effect on the system performance and can cause clustering
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problem. This case is applicable for low speed flows as well.
7. Future Works
There is no compact mathematical model to study the effect of nanoparticle on thermal system
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performance considering different variables such as nanoparticle properties and nanofluid characteristics. Research is needed in this regard. Moreover, research is also needed to study the effect of nanofluid usage on lifetime enhancement of thermal systems.
Acknowledgments This research was supported by School of Mechanical Engineering, Chung Ang University,
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Republic of Korea and Department of Mechanical Engineering, University of Central Punjab, Pakistan.
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Nomenclature
closed-loop oscillating heat pipe with check valves
CR
geometric concentration ratio
DLS
dynamic light scattering
EG
ethylene glycol
fv
graphite nanofluid concetration [%]
h
heat transfer coefficient [W m-2 K-1]
ke
Thermal conductivity of the nanofluid [W m-1 K-1]
kf
thermal conductivity of the base fluid [W m-1 K-1]
LCPV/T
low concentrated photovoltaic-thermal system
µe
viscosity of nanofluids [m2 s-1]
µf
viscosity of base fluid [m2 s-1]
PCM
phase change material
PV
photovoltaic
PVT
photovoltaic thermal
PV/T
photovoltaic/ photovoltaic thermal
Q q
Pr e-
al
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PV/TE
p ro
CLOHP/CV
hybrid photovoltaic/thermoelectric heat transfer rate [W] heat flux [W m-2]
R
thermal resistance [ºC W-1]
RH
relative humidity, dimensionless, in %
solar cell temperature [ºC]
UV
ultraviolet
Voc
open circuit voltage
vol%
volume concentration [%]
Vw
wind velocity [m/s]
wt%
weight percent (concentration) [%]
nanofluids
f
base fluid
o
base fluid
oc
open circuit
sc
solar cell
w
wind
[1]
G. Boyle, Renewable energy: power for a sustainable future, Oxford University Press, 1996.
S. Murshed, K. Leong, C. Yang, Investigations of thermal conductivity and viscosity of
Jo
[2]
urn
References
al
e
Pr e-
subscript
p ro
Tsc
of
Journal Pre-proof
nanofluids, International Journal of Thermal Sciences, 47(5) (2008) 560-568. [3]
M. Chandrasekar, S. Suresh, A.C. Bose, Experimental investigations and theoretical determination of thermal conductivity and viscosity of Al2O3/water nanofluid, Experimental Thermal and Fluid Science, 34(2) (2010) 210-216.
[4]
Gaganpreet and S. Srivastava, Viscosity of nanofluids: particle shape and fractal
Journal Pre-proof
aggregates, Physics and Chemistry of Liquids, 53(2) (2015) 174-186. [5]
A.N. Al-Shamani, S. Mat, M.H. Ruslan, A.M. Abed, K. Sopian, Numerical study on the
of
characteristics of a specially designed rectangular tube absorber photovoltaic thermal collector (PVT), WSEAS Transactions on Environment and Development, 11 (2015) 23-
[6]
p ro
28.
A. Elbreki, M. Alghoul, A. Al-Shamani, A. Ammar, B. Yegani, A.M. Aboghrara, M. Rusaln, K. Sopian, The role of climatic-design-operational parameters on combined PV/T
(2016) 602-647. [7]
Pr e-
collector performance: a critical review, Renewable and Sustainable Energy Reviews, 57
J. Zhao, Y. Song, W.-H. Lam, W. Liu, Y. Liu, Y. Zhang, D. Wang, Solar radiation transfer and performance analysis of an optimum photovoltaic/thermal system, Energy Conversion and Management, 52(2) (2011) 1343-1353.
[8]
A. Tiwari and M. Sodha, Performance evaluation of hybrid PV/thermal water/air heating
B. Agrawal and G. Tiwari, Life cycle cost assessment of building integrated photovoltaic
urn
[9]
al
system: a parametric study, Renewable energy, 31(15) (2006) 2460-2474.
thermal (BIPVT) systems, Energy and Buildings, 42(9) (2010) 1472-1481. [10] B. Huang, W. Ding, Y. Huang, Long-term field test of solar PV power generation using one-axis 3-position sun tracker, Solar Energy, 85(9) (2011) 1935-1944. G. Tiwari, R. Mishra, S. Solanki, Photovoltaic modules and their applications: a review on
Jo
[11]
thermal modelling, Applied energy, 88(7) (2011) 2287-2304. [12] J. Tonui and Y. Tripanagnostopoulos, Performance improvement of PV/T solar collectors with natural air flow operation, Solar energy, 82(1) (2008) 1-12. [13] R. Koech, H. Ondieki, J. Tonui, S. Rotich, A steady state thermal model for
Journal Pre-proof
photovoltaic/thermal (PV/T) system under various conditions, Int. J. Sci. Technol. Res, 1(11) (2012) 1-5.
of
[14] A.N. Al-Shamani, S. Mat, M. Ruslan, A.M. Abed, K. Sopian, Effect of New Ellipse Design on the Performance Enhancement of PV/T Collector: CDF Approach,
p ro
International Journal of Environment and Sustainability, 5(2) (2016).
[15] A.C. Gladen, J.H. Davidson, S.C. Mantell, The effect of a thermotropic material on the optical efficiency and stagnation temperature of a polymer flat plate solar collector, Journal of solar energy engineering, 137(2) (2015) 021003.
Pr e-
[16] A.M. Do Ango, M. Medale, C. Abid, Optimization of the design of a polymer flat plate solar collector, Solar Energy, 87 (2013) 64-75.
[17] G. Chen, K. Shestopalov, A. Doroshenko, P. Koltun, Polymeric materials for solar energy utilization: a comparative experimental study and environmental aspects, Polymer-Plastics Technology and Engineering, 54(8) (2015) 796-805.
al
[18] G.T. Wrixon, A.-M.E. Rooney, W. Palz, Renewable energy-2000, Springer Science &
urn
Business Media, 2012.
[19] I. Mahbubul, Preparation, Characterization, Properties, and Application of Nanofluid, William Andrew, 2018.
[20] K.S. Karimov, M. Saqib, P. Akhter, M. Ahmed, J. Chattha, S. Yousafzai, A simple photo-
Jo
voltaic tracking system, Solar energy materials and solar cells, 87(1-4) (2005) 49-59. [21] A.K. Suresh, S. Khurana, G. Nandan, G. Dwivedi, S. Kumar, Role on nanofluids in cooling solar photovoltaic cell to enhance overall efficiency, Materials Today: Proceedings, 5(9) (2018) 20614-20620. [22] R. Saidur, K. Leong, H. Mohammad, A review on applications and challenges of
Journal Pre-proof
nanofluids, Renewable and sustainable energy reviews, 15(3) (2011) 1646-1668. [23] R. Vaillon, L. Robin, C. Muresan, C. Ménézo, Modeling of coupled spectral radiation,
and mass transfer, 49(23-24) (2006) 4454-4468.
of
thermal and carrier transport in a silicon photovoltaic cell, International journal of heat
p ro
[24] Y. Assoa, C. Menezo, G. Fraisse, R. Yezou, J. Brau, Study of a new concept of photovoltaic–thermal hybrid collector, Solar energy, 81(9) (2007) 1132-1143. [25] E. Skoplaki and J.A. Palyvos, On the temperature dependence of photovoltaic module
(2009) 614-624.
Pr e-
electrical performance: A review of efficiency/power correlations, Solar energy, 83(5)
[26] C.S. Solanki, Solar photovoltaics: fundamentals, technologies and applications, PHI Learning Pvt. Ltd., 2015.
[27] S. Chander and A. Purohit, A. Sharma, S. Nehra, M. Dhaka, A study on photovoltaic
(2015) 104-109.
al
parameters of mono-crystalline silicon solar cell with cell temperature, Energy Reports, 1
urn
[28] E. Cuce and P.M. Cuce, T. Bali, An experimental analysis of illumination intensity and temperature dependency of photovoltaic cell parameters, Applied Energy, 111 (2013) 374382.
[29] E. Radziemska, The effect of temperature on the power drop in crystalline silicon solar
Jo
cells, Renewable energy, 28(1) (2003) 1-12. [30] T.T. Chow, A review on photovoltaic/thermal hybrid solar technology, 87(2) (2010) 365379.
[31] E. Radziemska and C. Science, Thermal performance of Si and GaAs based solar cells and modules: a review, 29(5) (2003) 407-424.
Journal Pre-proof
[32] A. Sacco, L. Rolle, L. Scaltrito, E. Tresso, C.F. Pirri, Characterization of photovoltaic modules for low-power indoor application, 102 (2013) 1295-1302. .
eneses- odr gue , P.P. Horley, J. Gonzalez-Hernandez, Y.V. Vorobiev, P.N. Gorley,
of
[33]
Photovoltaic solar cells performance at elevated temperatures, 78(2) (2005) 243-250.
p ro
[34] A. Orioli and A. Di Gangi, A procedure to calculate the five-parameter model of crystalline silicon photovoltaic modules on the basis of the tabular performance data, 102 (2013) 1160-1177.
[35] F. Zaoui, A. Titaouine, M. Becherif, M. Emziane, A. Aboubou, A combined experimental
modules, 75 (2015) 373-380.
Pr e-
and simulation study on the effects of irradiance and temperature on photovoltaic
[36] D. Vittorini, N. Castellucci, R. Cipollone, Heat recovery potential and electrical performances in-field investigation on a hybrid PVT module, 205 (2017) 44-56. [37] M. Al-Addous, Z. Dalala, C.B. Class, F. Alawneh, H. Al-Taani, Performance analysis of
al
off-grid PV systems in the Jordan Valley, 113 (2017) 930-941.
urn
[38] U. Sajjad, M. Amer, H.M. Ali, A. Dahiya, N. Abbas, Cost effective cooling of photovoltaic modules to improve efficiency, (2019) 100420. [39] S. Alrwashdeh, Technology, Comparison among Solar Panel Arrays Production with a Different Operating Temperatures in Amman-Jordan, 9(6) (2018) 420-429.
Jo
[40] S.M. Ammar, N. Abbas, S. Abbas, H.M. Ali, I. Hussain, M.M. Janjua, U. Sajjad, A. Dahiya, M. Transfer, Condensing heat transfer coefficients of R134a in smooth and grooved multiport flat tubes of automotive heat exchanger: An experimental investigation, 134 (2019) 366-376. [41] T. Taner, Energy and exergy analyze of PEM fuel cell: A case study of modeling and
Journal Pre-proof
simulations, Energy, 143 (2018) 284–294. [42] T. Taner, Fundamentals of Renewable Energy and Applications Alternative Energy of the Fuel Cell Water
anagement, 5(3) (2015) 3–6.
of
Future : A Technical Note of PE
[43] T. Taner, The Micro-Scale Modeling by Experimental Study in PEM Fuel Cell, J. Therm.
p ro
Eng., 3 (5) (2017) 1515–1526.
[44] A. Ibrahim et al., Hybrid Photovoltaic Thermal (PV/T) Air and Water Based Solar Collectors Suitable for Building Integrated Applications, Solar Energy Research Institute, University Kebangsaan Malaysia, 43600, Bangi, Selangor, Malaysia, 5(5) (2009) 618-624.
(2010) 5179-5187.
Pr e-
[45] E. Sani et al., Carbon nanohorns-based nanofluids as direct sunlight absorbers, 18(5)
[46] K.V. Wong, O. D. Leon, Applications of nanofluids: current and future, 2 (2010) 519659. [47] M. Sardarabadi et al., S. Cells, Experimental study of using both ZnO/water nanofluid and phase change material (PCM) in photovoltaic thermal systems, 161 (2017) 62-69.
al
[48] A.H. Al-Waeli et al., An experimental investigation of SiC nanofluid as a base-fluid for a
urn
photovoltaic thermal PV/T system, 142 (2017) 547-558. [49] H.A. Hasan, K. Sopian, A.H. Jaaz, A.N. Al-Shamani, Experimental investigation of jet array nanofluids impingement in photovoltaic/thermal collector, 144 (2017) 321-334. [50] A.N. Al-Shamani, K. Sopian, H. Mohammed, S. Mat, M.H. Ruslan, A.M. Abed,
Jo
Enhancement heat transfer characteristics in the channel with Trapezoidal rib–groove using nanofluids, 5 (2015) 48-58. [51] S.M. Ammar, N. Abbas, S. Abbas, H.M. Ali, I. Hussain, M.M. Janjua, Experimental investigation of condensation pressure drop of R134a in smooth and grooved multiport flat tubes of automotive heat exchanger, M. Transfer, 130 (2019) 1087-1095.
Journal Pre-proof
[52] M. Ghadiri, M. Sardarabadi, M. Pasandideh-fard, A. Moghadam, Experimental investigation of a PVT system performance using nano ferrofluids, Energy Conversion
of
and Management, 103 (2015) 468-476. [53] J.J. Michael and S. Iniyan, Performance analysis of a copper sheet laminated photovoltaic
p ro
thermal collector using copper oxide–water nanofluid, 119 (2015) 439-451. [54] M. Sardarabadi, M. Hosseinzadeh, A. Kazemian, M. Passandideh-Fard, Experimental investigation of the effects of using metal-oxides/water nanofluids on a photovoltaic thermal system (PVT) from energy and exergy viewpoints, 138 (2017) 682-695.
Pr e-
[55] S. Hassani, R.A. Taylor, S. Mekhilef, R. Saidur, A cascade nanofluid-based PV/T system with optimized optical and thermal properties, 112 (2016) 963-975. [56] M. Sardarabadi and M. Passandideh-Fard, S.Z.J Heris, Experimental investigation of the effects of silica/water nanofluid on PV/T (photovoltaic thermal units), 66 (2014) 264-272. [57] S. Jaisankar, T. Radhakrishnan, K. Sheeba, Experimental studies on heat transfer and
al
friction factor characteristics of forced circulation solar water heater system fitted with
urn
helical twisted tapes, 83(11) (2009) 1943-1952. [58] C. Guo, J. Ji, W. Sun, J. Ma, W. He, Y. Wang, Numerical simulation and experimental validation of tri-functional photovoltaic/thermal solar collector, 87 (2015) 470-480. [59] F. Mebarek-Oudina and O. D. Makinde, Numerical Simulation of Oscillatory MHD
Jo
Natural Convection in Cylindrical Annulus: Prandtl Number Effect, Defect Diffus. Forum, 387 (2018) 417–427. [60] M. Alkasassbeh, Z. Omar, F. Mebarek-Oudina, J. Raza, and A. Chamkha, Heat transfer study of convective fin with temperature-dependent internal heat generation by hybrid block method, Heat Transf. - Asian Res., no. November 2018 (2019) 1225–1244.
Journal Pre-proof
[61] F. Mebarek-Oudina, Numerical modeling of the hydrodynamic stability in vertical annulus with heat source of different lengths, Eng. Sci. Technol. an Int. J., 20(4) (2017) 1324–
of
1333. [62] F. Mebarek-Oudina, Convective heat transfer of Titania nanofluids of different base fluids
135–147.
p ro
in cylindrical annulus with discrete heat source, Heat Transf. - Asian Res., 48(1) (2019)
[63] J. Reza, F. Mebarek-Oudina, and O.D. Makinde, MHD Slip Flow of Cu-Kerosene Nanofluid in a Channel with Stretching Walls Using 3-Stage Lobatto IIIA Formula, Defect
Pr e-
Diffus. Forum, 387 (2018) 51–62.
[64] P. Anand Kumar Lam and K. A. Prakash, Effect of Magnetic Field on Natural Convection and Entropy Generation in Al2O3/Water Nanofluid-Filled Enclosure With Twin Protruding Heat Sources, J. Therm. Sci. Eng. Appl., 9(2) (2017) 024502. [65] A. J. Chamkha and F. Selimefendigil, Forced convection of pulsating nanofluid flow over
al
a backward facing step with various particle shapes, Energies, 11(11) (2018) 1–19.
urn
[66] A. Chamkha and F. Selimefendigil, Numerical Analysis for Thermal Performance of a Photovoltaic Thermal Solar Collector with SiO2-Water Nanofluid, Appl. Sci., 8(11) (2018) 2223.
[67] F. Selimefendigil and H. F. Öztop, Forced convection and thermal predictions of pulsating
Jo
nanofluid flow over a backward facing step with a corrugated bottom wall, Int. J. Heat Mass Transf., 110 (2017) 231–247. [68] F. Selimefendigil, H. F. Öztop, and A. J. Chamkha, Analysis of mixed convection of nanofluid in a 3D lid-driven trapezoidal cavity with flexible side surfaces and inner cylinder, Int. Commun. Heat Mass Transf., 87 (2017) 40–51.
Journal Pre-proof
[69] F. Selimefendigil, H. F. Öztop, and N. Abu-Hamdeh, Mixed convection due to rotating cylinder in an internally heated and flexible walled cavity filled with SiO2-water
of
nanofluids: Effect of nanoparticle shape, Int. Commun. Heat Mass Transf., 71 (2016) 9– 19.
p ro
[70] F. Selimefendigil and H. F. Öztop, Corrugated conductive partition effects on MHD free convection of CNT-water nanofluid in a cavity, Int. J. Heat Mass Transf., 129 (2019) 265– 277.
[71] F. Selimefendigil and H. F. Öztop, Modeling and optimization of MHD mixed convection
Pr e-
in a lid-driven trapezoidal cavity filled with alumina–water nanofluid: Effects of electrical conductivity models, Int. J. Mech. Sci., 136 (2018) 264–278. [72] M. Amer and C.C. Wang, Review of defrosting methods, Renewable and Sustainable Energy Reviews, 73 (2017) 53-74.
[73] M. Amer and C.C. Wang, Review of active defrosting methods in refrigeration systems
al
(2016).
urn
[74] M. Amer and C.C. Wang, Review of passive defrosting surface methods in refrigeration systems (2015).
[75] M. Amer, M.R. Chen, M.C. Lu, and C.C. Wang, An experimental study of plastic heat exchangers applicable for dehumidification (2018).
Jo
[76] Y. Cui and Q. Zhu, Study of photovoltaic/thermal systems with MgO-water nanofluids flowing over silicon solar cells, in: 2012 Asia-Pacific Power and Energy Engineering Conference, IEEE, 2012, pp. 1-4. [77] M. Chandrasekar, S. Suresh, T. Senthilkumar, Passive cooling of standalone flat PV module with cotton wick structures, Energy Conversion and Management, 71 (2013) 43-
Journal Pre-proof
50. [78] Z. Xu, C. Kleinstreuer, Concentration photovoltaic–thermal energy co-generation system
of
using nanofluids for cooling and heating, Energy Conversion and Management, 87 (2014) 504-512.
p ro
[79] N. Karami, M. Rahimi, Heat transfer enhancement in a hybrid microchannel-photovoltaic cell using Boehmite nanofluid, M. Transfer, 55 (2014) 45-52.
[80] N. Karami, M. Rahimi, Heat transfer enhancement in a PV cell using Boehmite nanofluid, Management, 86 (2014) 275-285.
Pr e-
[81] Z. Said, M. Sabiha, R. Saidur, A. Hepbasli, N. Rahim, S. Mekhilef, T. Ward, Performance enhancement of a flat plate solar collector using titanium dioxide nanofluid and polyethylene glycol dispersant, 92 (2015) 343-353.
[82] D. Lelea, D.G. Calinoiu, G. Trif-Tordai, A.E. Cioabla, I. Laza, F. Popescu, The hybrid nanofluid/microchannel cooling solution for concentrated photovoltaic cells, in: AIP
al
Conference Proceedings, AIP, 2015, pp. 122-128.
urn
[83] S. Saroha, T. Mittal, P.J. Modi, V. Bhalla, V. Khullar, H. Tyagi, R.A. Taylor, T.P. Otanicar, Theoretical analysis and testing of nanofluids-based solar photovoltaic/thermal hybrid collector, 137(9) (2015) 091015. [84] A. Noghrehabadi, E. Hajidavalloo, M. Moravej, Experimental investigation of efficiency
Jo
of square flat-plate solar collector using SiO2/water nanofluid, Case Studies in Thermal Engineering, 8 (2016) 378-386. [85] M. Sardarabadi and M. Passandideh-Fard, Experimental and numerical study of metaloxides/water nanofluids as coolant in photovoltaic thermal systems (PVT), Solar Energy Materials and Solar Cells, 157 (2016) 533-542.
Journal Pre-proof
[86] A.N. Al-Shamani, K. Sopian, S. Mat, H.A. Hasan, A.M. Abed, M.H. Ruslan, Experimental studies of rectangular tube absorber photovoltaic thermal collector with various types of
of
nanofluids under the tropical climate conditions, Energy Conversion and Management, 124 (2016) 528-542.
p ro
[87] O. Rejeb, M. Sardarabadi, C. Ménézo, M. Passandideh-Fard, M.H. Dhaou, A. Jemni, Numerical and model validation of uncovered nanofluid sheet and tube type photovoltaic thermal solar system, Energy Conversion and Management, 110 (2016) 367-377. [88] A. Radwan, M. Ahmed, S. Ookawara, Performance enhancement of concentrated
Pr e-
photovoltaic systems using a microchannel heat sink with nanofluids, Energy Conversion and Management, 119 (2016) 289-303.
[89] O.Z. Sharaf and M.F. Orhan, Thermodynamic analysis and optimization of denselypacked receiver assembly components in high-concentration CPVT solar collectors, Energy Conversion and Management, 121 (2016) 113-144.
al
[90] S. Soltani, A. Kasaeian, H. Sarrafha, D. Wen, An experimental investigation of a hybrid
urn
photovoltaic/thermoelectric system with nanofluid application, Solar Energy, 155 (2017) 1033-1043.
[91] A.H. Al-Waeli, M.T. Chaichan, H.A. Kazem, K. Sopian, Comparative study to use nano(Al2O3, CuO, and SiC) with water to enhance photovoltaic thermal PV/T collectors,
Jo
Energy Conversion and Management, 148 (2017) 963-973. [92] A.H. Al-Waeli, K. Sopian, M.T. Chaichan, H.A. Kazem, A. Ibrahim, S. Mat, M.H. Ruslan, Evaluation of the nanofluid and nano-PCM based photovoltaic thermal (PVT) system: An experimental study, Energy Conversion and Management, 151 (2017) 693-708. [93] H.A. Hasan, K. Sopian, A.H. Jaaz, A.N. Al-Shamani, Experimental investigation of jet
Journal Pre-proof
array nanofluids impingement in photovoltaic/thermal collector, Solar Energy, 144 (2017) 321-334.
of
[94] M. Sardarabadi, M. Passandideh-Fard, M.-J. Maghrebi, M. Ghazikhani, Experimental study of using both ZnO/water nanofluid and phase change material (PCM) in
p ro
photovoltaic thermal systems, Solar Energy Materials and Solar Cells, 161 (2017) 62-69. [95] F. Yazdanifard, E. Ebrahimnia-Bajestan, M. Ameri, Performance of a parabolic trough concentrating photovoltaic/thermal system: effects of flow regime, design parameters, and using nanofluids, Energy Conversion and Management, 148 (2017) 1265-1277.
Pr e-
[96] M. Alghoul, M. Sulaiman, B. Azmi, M.A. Wahab, Review of materials for solar thermal collectors, Anti-Corrosion methods and materials, 52(4) (2005) 199-206. [97] B.C. Gates, J.R. Katzer, G.C. Schuit, Chemistry of catalytic processes, McGraw-Hill College, 1979.
[98] Y.-j. Hwang, J. Lee, C. Lee, Y. Jung, S. Cheong, C. Lee, B. Ku, S. Jang, Stability and
al
thermal conductivity characteristics of nanofluids, Thermochimica Acta, 455(1-2) (2007) 70-74.
urn
[99] J. Shackelford and C. William, Materials Science and Engineering Handbook (3rd Edition), in Taylor & Francis (2001). [100] S.H. Kim, S.R. Choi, D. Kim, Thermal conductivity of metal-oxide nanofluids: particle
Jo
size dependence and effect of laser irradiation, Journal of Heat Transfer, 129(3) (2007) 298-307.
[101] M. Mehrali, E. Sadeghinezhad, M.M. Rashidi, A.R. Akhiani, S.T. Latibari, M. Mehrali, H.S.C. Metselaar, Experimental and numerical investigation of the effective electrical conductivity of nitrogen-doped graphene nanofluids, Journal of Nanoparticle Research,
Journal Pre-proof
17(6) (2015) 267. [102] G.A. Slack, Thermal Conductivity of MgO, Al2O3, Mg Al2O4, and Fe3O4 Crystals from 3°
of
to 300° K, Physical Review, 126(2) (1962) 427. [103] J.A. ean, Lange’s handbook of chemistry 15th ed, in, McGraw-Hill, New York, 1999.
p ro
[104] S. Choi, Z. Zhang, W. Yu, F. Lockwood, E. Grulke, Anomalous thermal conductivity enhancement in nanotube suspensions, Applied physics letters, 79(14) (2001) 2252-2254. [105] A.A. Balandin, Thermal properties of graphene and nanostructured carbon materials, Nature Materials, 10(8) (2011) 569.
Pr e-
[106] R. Wei, S. Song, K. Yang, Y. Cui, Y. Peng, X. Chen, X. Hu, X. Xu, Thermal conductivity of 4H-SiC single crystals, Journal of Applied Physics, 113(5) (2013) 053503. [107] . Ota, M. Mizutani, K. Kido, T. Kawai, H. Kihou, High thermal conductive boehmite and method for manufacturing same, in, Google Patents, 2015. [108] S. Lee, S.-S. Choi, S. Li, and, J. Eastman, Measuring thermal conductivity of fluids
al
containing oxide nanoparticles, Journal of Heat transfer, 121(2) (1999) 280-289.
urn
[109] J. Eastman, U. Choi, S. Li, L. Thompson, S. Lee, Enhanced thermal conductivity through the development of nanofluids, MRS Online Proceedings Library Archive, 457 (1996). [110] H. Ali, T. Miqdam, A. Hussein, H. Abdulrasool, A. Najah, experimental investigation of SiC nanofluid as a base-fluid for a photovoltaic thermal PV/T system, Energy conversion
Jo
and management, 2017.
[111] M. Chen, Y. He, J. Zhu, D.R. Kim, Enhancement of photo-thermal conversion using gold nanofluids with different particle sizes, Energy conversion and management, 112 (2016) 21-30. [112] E.P. Bandarra Filho, O.S.H. Mendoza, C.L.L. Beicker, A. Menezes, D. Wen, Experimental
Journal Pre-proof
investigation of a silver nanoparticle-based direct absorption solar thermal system, Energy Conversion and Management, 84 (2014) 261-267.
of
[113] T. Sokhansefat, A. Kasaeian, F. Kowsary, Heat transfer enhancement in parabolic trough collector tube using Al2O3/synthetic oil nanofluid, Renewable and Sustainable Energy
p ro
Reviews, 33 (2014) 636-644.
[114] J.-H. Lee, K.S. Hwang, S.P. Jang, B.H. Lee, J.H. Kim, S.U. Choi, C.J. Choi, Effective viscosities and thermal conductivities of aqueous nanofluids containing low volume
2651-2656.
Pr e-
concentrations of Al2O3 nanoparticles, Int. J. of Heat and Mass Transfer, 51(11-12) (2008)
[115] L. Godson, B. Raja, D.M. Lal, S. Wongwises, Experimental investigation on the thermal conductivity and viscosity of silver-deionized water nanofluid, Experimental Heat Transfer, 23(4) (2010) 317-332.
[116] H.A. Mintsa, G. Roy, C.T. Nguyen, D. Doucet, New temperature dependent thermal
al
conductivity data for water-based nanofluids, Int. J. of thermal sciences, 48(2) (2009) 363-
urn
371.
[117] S. Wannapakhe, S. Rittidech, B. Bubphachot, O. Watanabe, Heat transfer rate of a closedloop oscillating heat pipe with check valves using silver nanofluid as working fluid, Journal of Mechanical Science and Technology, 23(6) (2009) 1576-1582.
Jo
[118] Q. Li, Y.-M. Xuan, Flow and Heat Transfer Performances of Nanofluids Inside Small Hydraulic Diameter Flat Tube, Journal of Engineering Thermophysics, 25(2) (2004) 305307.
[119] S.-W. Kang, W.-C. Wei, S.-H. Tsai, S.-Y. Yang, Experimental investigation of silver nanofluid on heat pipe thermal performance, Applied Thermal Engineering, 26(17-18) (2006)
Journal Pre-proof
2377-2382. [120] D. Zhou, Heat transfer enhancement of copper nanofluid with acoustic cavitation,
of
International Journal of Heat and Mass Transfer, 47(14-16) (2004) 3109-3117. [121] P. Sharma, I.-H. Baek, T. Cho, S. Park, K.B. Lee, Enhancement of thermal conductivity of
p ro
ethylene glycol based silver nanofluids, Powder Technology, 208(1) (2011) 7-19. [122] H.E. Patel, T. Sundararajan, S.K. Das, An experimental investigation into the thermal conductivity enhancement in oxide and metallic nanofluids, Journal of Nanoparticle Research, 12(3) (2010) 1015-1031.
Pr e-
[123] G. Paul, T. Pal, I. Manna, Thermo-physical property measurement of nano-gold dispersed water based nanofluids prepared by chemical precipitation technique, Journal of colloid and interface science, 349(1) (2010) 434-437.
[124] C. Tsai, H. Chien, P. Ding, B. Chan, T. Luh, P. Chen, Effect of structural character of gold
(2004) 1461-1465.
al
nanoparticles in nanofluid on heat pipe thermal performance, Materials Letters, 58(9)
urn
[125] H.-T. Chien, C.-I. Tsai, P.-H. Chen, P.-Y. Chen, Improvement on thermal performance of a disk-shaped miniature heat pipe with nanofluid, in: Fifth International Conference on Electronic Packaging Technology Proceedings, 2003. ICEPT2003., IEEE, 2003, pp. 389391.
Jo
[126] H.E. Patel, S.K. Das, T. Sundararajan, A. Sreekumaran Nair, B. George, T. Pradeep, Thermal conductivities of naked and monolayer protected metal nanoparticle based nanofluids: Manifestation of anomalous enhancement and chemical effects, Applied Physics Letters, 83(14) (2003) 2931-2933. [127] K. Sinha, B. Kavlicoglu, Y. Liu, F. Gordaninejad, O.A. Graeve, A comparative study of
Journal Pre-proof
thermal behavior of iron and copper nanofluids, Journal of Applied Physics, 106(6) (2009) 064307.
of
[128] M.-S. Liu, M.C.-C. Lin, C. Tsai, C.-C. Wang, Enhancement of thermal conductivity with Cu for nanofluids using chemical reduction method, Int. J. of Heat and Mass Transfer,
p ro
49(17-18) (2006) 3028-3033.
[129] T.-K. Hong, H.-S. Yang, C. Choi, Study of the enhanced thermal conductivity of Fe nanofluids, Journal of Applied Physics, 97(6) (2005) 064311.
IL (US), 1999.
Pr e-
[130] J. Eastman, Novel thermal properties of nanostructured materials, Argonne National Lab.,
[131] M.H. Esfe, S. Saedodin, S. Wongwises, D. Toghraie, An experimental study on the effect of diameter on thermal conductivity and dynamic viscosity of Fe/water nanofluids, Journal of Thermal Analysis and Calorimetry, 119(3) (2015) 1817-1824. [132] K. Hong, T.-K. Hong, H.-S. Yang, Thermal conductivity of Fe nanofluids depending on
al
the cluster size of nanoparticles, Applied Physics Letters, 88(3) (2006) 031901.
urn
[133] W. Yu, H. Xie, L. Chen, Y. Li, Investigation of thermal conductivity and viscosity of ethylene glycol based ZnO nanofluid, Thermochimica Acta, 491(1-2) (2009) 92-96. [134] X. Wang, X. Xu, S.U. S. Choi, Thermal conductivity of nanoparticle-fluid mixture, Journal of thermophysics and heat transfer, 13(4) (1999) 474-480.
Jo
[135] G.-J. Lee, C.K. Kim, M.K. Lee, C.K. Rhee, S. Kim, C. Kim, Thermal conductivity enhancement of ZnO nanofluid using a one-step physical method, Thermochimica Acta, 542 (2012) 24-27.
[136] J.-Y. Jung, H.-S. Oh, H.-Y. Kwak, Forced convective heat transfer of nanofluids in microchannels, in: ASME 2006 International Mechanical Engineering Congress and
Journal Pre-proof
Exposition, American Society of Mechanical Engineers, 2006, pp. 327-332. [137] H.M. Ali, H. Ali, H. Liaquat, H.T.B. Maqsood, M.A. Nadir, Experimental investigation of
of
convective heat transfer augmentation for car radiator using ZnO–water nanofluids, Energy, 84 (2015) 317-324.
p ro
[138] C. Choi, H. Yoo, J. Oh, Preparation and heat transfer properties of nanoparticle-intransformer oil dispersions as advanced energy-efficient coolants, Current Applied Physics, 8(6) (2008) 710-712.
[139] J. Jeong, C. Li, Y. Kwon, J. Lee, S.H. Kim, R. Yun, Particle shape effect on the viscosity
(2013) 2233-2241
Pr e-
and thermal conductivity of ZnO nanofluids, International journal of refrigeration, 36(8)
[140] S. Murshed, K. Leong, C. Yang, Enhanced thermal conductivity of TiO2—water based nanofluids, International Journal of thermal sciences, 44(4) (2005) 367-373. [141] L.S. Sundar, M.K. Singh, A.C. Sousa, Investigation of thermal conductivity and viscosity
al
of Fe3O4 nanofluid for heat transfer applications, International communications in heat
urn
and mass transfer, 44 (2013) 7-14.
[142] K. Leong, R. Saidur, T. Mahlia, Y. Yau, Performance investigation of nanofluids as working fluid in a thermosyphon air preheater, International Communications in Heat and Mass Transfer, 39(4) (2012) 523-529.
Jo
[143] J. Philip, P. Shima, B. Raj, Enhancement of thermal conductivity in magnetite based nanofluid due to chainlike structures, Applied Physics Letters, 91(20) (2007) 203108. [144] P. Naphon, L. Nakharintr, Nanofluid jet impingement heat transfer characteristics in the rectangular mini-fin heat sink, Journal of Engineering Physics and Thermophysics, 85(6) (2012) 1432-1440.
Journal Pre-proof
[145] A. Gavili, F. Zabihi, T.D. Isfahani, J. Sabbaghzadeh, The thermal conductivity of water base ferrofluids under magnetic field, Experimental Thermal and Fluid Science, 41 (2012)
of
94-98. [146] W. Duangthongsuk, S. Wongwises, Heat transfer enhancement and pressure drop
p ro
characteristics of TiO2–water nanofluid in a double-tube counter flow heat exchanger, International Journal of Heat and Mass Transfer, 52(7-8) (2009) 2059-2067. [147] W. Yu, H. Xie, L. Chen, Y. Li, Enhancement of thermal conductivity of kerosene-based Fe3O4 nanofluids prepared via phase-transfer method, Colloids and Surfaces A:
Pr e-
Physicochemical and engineering aspects, 355(1-3) (2010) 109-113. [148] Y. Yang, Z.G. Zhang, E.A. Grulke, W.B. Anderson, G. Wu, Heat transfer properties of nanoparticle-in-fluid dispersions (nanofluids) in laminar flow, International Journal of Heat and Mass Transfer, 48(6) (2005) 1107-1116.
[149] D.J. Faulkner, D.R. Rector, J.J. Davidson, R. Shekarriz, Enhanced heat transfer through
al
the use of nanofluids in forced convection, in: ASME 2004 International Mechanical
urn
Engineering Congress and Exposition, American Society of Mechanical Engineers, 2004, pp. 219-224.
[150] S. Ladjevardi, A. Asnaghi, P. Izadkhast, A. Kashani, Applicability of graphite nanofluids in direct solar energy absorption, Solar Energy, 94 (2013) 327-334.
Jo
[151] M.-S. Liu, M.C.-C. Lin, I.-T. Huang, C.-C. Wang, Enhancement of thermal conductivity with carbon nanotube for nanofluids, International Communications in Heat and Mass Transfer, 32(9) (2005) 1202-1210. [152] Z. Luo, C. Wang, W. Wei, G. Xiao, M. Ni, Performance improvement of a nanofluid solar collector based on direct absorption collection (DAC) concepts, International Journal of
Journal Pre-proof
Heat and Mass Transfer, 75 (2014) 262-271. [153] D. Wen, Y. Ding, Effective thermal conductivity of aqueous suspensions of carbon
of
nanotubes (carbon nanotube nanofluids), Journal of Thermophysics and Heat Transfer, 18(4) (2004) 481-485.
p ro
[154] B. Wang, X. Wang, W. Lou, J. Hao, Thermal conductivity and rheological properties of graphite/oil nanofluids, Colloids and Surfaces A: Physicochemical and Engineering Aspects, 414 (2012) 125-131.
[155] H. Xie, H. Lee, W. Youn, M. Choi, Nanofluids containing multiwalled carbon nanotubes
Pr e-
and their enhanced thermal conductivities, Journal of Applied Physics, 94(8) (2003) 49674971.
[156] X. Li, C. Zou, X. Lei, W. Li, Stability and enhanced thermal conductivity of ethylene glycol-based SiC nanofluids, Int. J. Heat and Mass Transfer, 89 (2015) 613-619. [157] K.M. Kim, Y.S. Jeong, I.G. Kim, I.C. Bang, Comparison of thermal performances of
al
water-filled, SiC nanofluid-filled and SiC nanoparticles-coated heat pipes, International
urn
Journal of Heat and Mass Transfer, 88 (2015) 862-871. [158] P. Gunnasegaran, M.Z. Abdullah, M.Z. Yusoff, R. Kanna, Heat transfer in a loop heat pipe using diamond-H2O Nanofluid, Heat Transfer Engineering, 39(13-14) (2018) 1117-1131. [159] M. Ghanbarpour, N. Nikkam, R. Khodabandeh, M.S. Toprak, Improvement of heat
Jo
transfer characteristics of cylindrical heat pipe by using SiC nanofluids, Applied Thermal Engineering, 90 (2015) 127-135. [160] T.S. Aun, M.Z. Abdullah, P. Gunnasegaran, Influence of low concentration of diamond water nanofluid in loop heat pipe, Int. J. Heat Technol, 35 (2017) 539-548. [161] S. Sargunanathan, A. Elango, S.T. Mohideen, Performance enhancement of solar
Journal Pre-proof
photovoltaic cells using effective cooling methods: A review, Renewable and Sustainable Energy Reviews, 64 (2016) 382-393.
of
[162] T. Ho, S.S. Mao, R. Greif, Improving efficiency of high‐concentrator photovoltaics by cooling with two‐phase forced convection, International Journal of Energy Research,
p ro
34(14) (2010) 1257-1271.
[163] Z. Said, M. Sabiha, R. Saidur, A. Hepbasli, N. Rahim, S. Mekhilef, T. Ward, Performance enhancement of a flat plate solar collector using titanium dioxide nanofluid and polyethylene glycol dispersant, Journal of Cleaner Production, 92 (2015) 343-353.
Pr e-
[164] M. Sheikholeslami, M. Rashidi, D. Ganji, Effect of non-uniform magnetic field on forced convection heat transfer of Fe3O4–water nanofluid, Computer Methods in Applied Mechanics and Engineering, 294 (2015) 299-312.
[165] K. Anoop, T. Sundararajan, S.K. Das, Effect of particle size on the convective heat transfer in nanofluid in the developing region, International Journal of Heat and Mass
al
Transfer, 52(9-10) (2009) 2189-2195.
urn
[166] Y. Hu, H. Li, Y. He, Z. Liu, Y. Zhao, Effect of nanoparticle size and concentration on boiling performance of SiO2 nanofluid, Int. J. Heat and Mass Transf, 107 (2017) 820-828. [167] T. Mittal, S. Saroha, V. Bhalla, V. Khullar, H. Tyagi, R.A. Taylor, T.P. Otanicar, Numerical study of solar photovoltaic/thermal (PV/T) hybrid collector using nanofluids, in: ASME
Jo
2013 4th international conference on micro/nanoscale heat and mass transfer, American Society of Mechanical Engineers, 2013, pp. V001T002A007-V001T002A007. [168] M. Faizal, R. Saidur, S. Mekhilef, M. Alim, Energy, economic and environmental analysis of metal oxides nanofluid for flat-plate solar collector, Energy Conversion and Management, 76 (2013) 162-168.
Journal Pre-proof
[169] Z. Xu, C. Kleinstreuer, Computational analysis of nanofluid cooling of high concentration photovoltaic cells, Journal of Thermal Science and Engineering Applications, 6(3) (2014)
of
031009. [170] S. Ravikumar, Elementary assessments and simulations based proposals for new heat
internal condensing flows, 2015.
p ro
transfer correlations and flow regime maps for annular/stratified regime of shear driven
[171] Y. Khanjari, F. Pourfayaz, A. Kasaeian, Numerical investigation on using of nanofluid in a
(2016) 263-278.
Pr e-
water-cooled photovoltaic thermal system, Energy Conversion and Management, 122
[172] S. Hassani, R. Saidur, S. Mekhilef, R.A. Taylor, Environmental and exergy benefit of nanofluid-based hybrid PV/T systems, Energy Conversion and Management, 123 (2016) 431-444.
[173] W. An, J. Wu, T. Zhu, Q. Zhu, Experimental investigation of a concentrating PV/T
al
collector with Cu9S5 nanofluid spectral splitting filter, Applied Energy, 184 (2016) 197-
urn
206.
[174] A. Noghrehabadi, E. Hajidavalloo, M. Moravej, An experimental investigation on the performance of a symmetric conical solar collector using SiO2/water nanofluid, Transp Phenom Nano Micro Scales, 5(1) (2016) 23-29.
Jo
[175] D. Das, P. Kalita, Performance Improvement of a Novel Flat Plate Photovoltaic Thermal (PV/T) System Using Copper Oxide Nanoparticle—Water as Coolant, in: International Conference on Nano for Energy and Water, Springer, 2017, pp. 97-104. [176] H. Hussein, A. Numan, A. Abdulmunem, An Experimental Investigation on the Performance Enhancement of Photovoltaic/Thermal Panel Using a Tracking System and
Journal Pre-proof
Nanofluid (Al2O3), Engineering and Technology Journal, 35(5 Part (A) Engineering) (2017) 493-508.
of
[177] M.S. Ebaid, A.M. Ghrair, M. Al-Busoul, Experimental investigation of cooling photovoltaic (PV) panels using (TiO2) nanofluid in water-polyethylene glycol mixture and
and Management, 155 (2018) 324-343.
p ro
(Al2O3) nanofluid in water-cetyltrimethylammonium bromide mixture, Energy Conversion
[178] S. Srivastava, K. Reddy, Simulation studies of thermal and electrical performance of solar
213.
Figure captions
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linear parabolic trough concentrating photovoltaic system, Solar Energy, 149 (2017) 195-
A schematic diagram of a typical PV/T system.
Figure 2
Solar cell temperature (Tsc) variation relation with wind velocity (Vw) at different geometric concentration ratios (CR) [88].
Figure 3
Solar cell temperature variation at different velocities (Reynolds number) with varying CR and different nanofluids at (a) 1 vol% nanoparticle (b) 4 vol% nanoparticle [88].
Figure 4
Solar Cell temperature variation for different volume fractions of nanoparticles at varying Reynolds numbers (a) CR=10 (b) CR=20 (c) CR=40 [88, 161, 162].
Figure 5
The temperature gradient of cooling and without cooling with different weight concentrations of Boehmite using different channels [80].
Figure 6
Comparison of variation of thermal conductivity of nanoparticle with respect to (a) Nanoparticle fraction (b) Temperature [78, 116, 161, 162].
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Figure 1
Figure 7
Thermal conductivity enhancement percentage of gold water based nanofluid (a) with a variation of volume fraction (b) with a variety of particle size at 0.00026 volume fraction [78].
Figure 8
Thermal conductivity of Fe and Cu nanofluids at different volume fractions [82].
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Heat transfer enhancement of Cu nanofluids as a function of volume fraction (a) thermal conductivity data (b) viscosity data [163].
Figure 10
Thermal conductivity enhancement as a function of volume fraction for ZnOEG nanofluid [87].
Figure 11
The thermal conductivity ratio (ke/kf) and the percentage of enhancement as a function of the external magnetic field at different volume fractions of Fe3O4 [164].
Figure 12 Figure 13
The absorbed energy of solar radiation for different graphite nanofluids [118]. Enhancement in thermal conductivity of Al2O3 nanofluid at different volume fractions and particle sizes [3].
Figure 14
Comparison of Cu and Al nanofluid at 1% volume fraction and 80 nm particle size [3].
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Figure 9
Nanoparticle size effect on heat transfer [165].
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Figure 15
Nanoparticle size effect on heat flux and heat transfer [166]. The operating temperature effect on the heat transfer rate of CLOHP/CV at 25 aspect ratio [35].
Figure 18
The measured value of thermal resistance of heat pipe with nanofluid (a) at 1 ppm (b) at 10 ppm [37].
Tables captions
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Figure 16 Figure 17
Types of channels configurations used for effective cooling with reference to nanofluids.
Table 2
Various nanoparticles thermal conductivities at 25 °C.
Table 3
Nanoparticle effect on different system’s thermal performance.
Table 4
Applications of nanofluids as a coolant in photovoltaic systems.
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PII: DOI: Reference:
S0378-4371(19)31440-2 https://doi.org/10.1016/j.physa.2019.122513 PHYSA 122513
To appear in:
Physica A
Received date : 6 April 2019 Revised date : 3 May 2019 Please cite this article as: N. Abbas, M.B. Awan, M. Amer et al., Applications of nanofluids in photovoltaic thermal systems: A review of recent advances, Physica A (2019), doi: https://doi.org/10.1016/j.physa.2019.122513. This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
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Highlights 1. Influence of configurations and geometries in PV/T systems. 2. Influence of nanoparticle type, size, volume fraction and concentration ratio.
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3. Effective parameters for Nano fluids applications in PV/T systems.
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4. Summary of application of Nano fluids as a coolant in photovoltaic systems.
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Applications of nanofluids in photovoltaic thermal systems: A
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review of recent advances
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Naseem Abbas a, b, Muhammad Bilal Awan b, Mohammed Amer c, *1, Syed Muhammad Ammar d,
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Uzair Sajjad c, Hafiz Muhammad Ali e, *2, Nida Zahra f, Muzamil Hussain g, Mohsin Ali Badshah , and Ali Turab Jafry h
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a
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1
a
School of Mechanical Engineering, Chung Ang University, Seoul 06974, Republic of Korea
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b
Department of Mechanical Engineering, University of Central Punjab, Lahore 54000, Pakistan
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c
Department of Mechanical Engineering, National Chiao Tung University, Hsinchu, Taiwan
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d
Division of Mechanical Design Engineering, Chonbuk National University, Jeonju, Jeonbuk
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6
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54896, Republic of Korea
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e
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Technology, Taxila, 47050, Pakistan
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f
Department of Physics, Government College University, Faisalabad 38000, Pakistan
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g
Department of Polymer Engineering and Technology, University of the Punjab, Lahore 54000,
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Pakistan
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h
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and Technology, Swabi 23640, Pakistan
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Department of Mechanical Engineering, Ghulam Ishaq Khan Institute of Engineering Sciences
*1 [email protected] *2 [email protected]
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Department of Mechanical and Aeronautical Engineering, University of Engineering and
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Abstract
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The aim of this study is to present a critical review of the impact of nanofluids on the
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performance enhancement of PV/T systems. The review has analyzed the effects of nanoparticle
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type, size, volume fraction and concentration ratio on the performance of PV/T systems.
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Furthermore, the type of base-fluid, flow channels, and flow types have also been studied
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comprehensively in relation to nanofluids characteristics and properties. Results have shown that
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the inclusion of nanofluid enhances the overall efficiency of the PV/T systems. It has been
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concluded that the organic fluids are better base fluids than water, and nanofluids with better
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thermal conductivity enhance the maximum efficiency once optimum size, volume fraction and
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correct concentration ratio of nanofluid are selected. Moreover, straight microchannel and the
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addition of Fe3O4, SiC and TiO2 nanofluids with low concentration ratio provides better
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efficiency and flexibility. The motive beyond that is the micro-channels turbulent flow occurs at
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low Reynolds number. Accordingly, maximum efficiency can be obtained at higher velocity
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laminar flows. Increasing the velocity to higher ranges of turbulent flow doesn’t allow proper
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time for heat transfer and can cause clustering of nanoparticles. The observations of this review
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are proposed to PV/T systems and it is helpful for the thermal system design practitioners
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towards achieving high efficiency in any thermal system.
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Keywords: Nanofluids; Photovoltaics; Thermal; Applications.
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1. Introduction
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Photovoltaic (PV) and photovoltaic thermal (PVT) systems have been the pivotal part in the
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transition towards energy sustainability. However, their low efficiency offers hurdles in their
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usage as sustainable devices. Cooling of PV systems and low heat carrying capacity of PVT
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systems is considered a major reason for the low efficiency of these systems. Positively, modern
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research on nanofluids has ensured rapid advancement in enhancing heat transfer in energy
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systems. Figure 1 shows a typical schematic diagram of the PV/T system.
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Figure 1. A schematic diagram of a typical PV/T system.
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A nanofluid is a mixture of nanoparticles with a base fluid. The performance of nanofluid is a
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function of its material, size, base fluid, thermal conductivity, geometry, and so on. Nanoparticles
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are characterized by their high surface area to volume ratio. The surface area of one gram of
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some nanoparticles can be assumed to be as large as a football stadium [1]. Because of having a
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higher surface area than the base fluid and having a small size, it possesses superior thermal
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conductivity, smooth flow, and stability [2, 3]. Furthermore, nanofluids have higher heat transfer
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properties than traditional heat transfer fluids [4]. On the other hand, long term stability is
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considered the most significant characteristic for effective utilization of nanofluids since they
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interact with each other during motion. This interacts drives to a particle clustering due to strong
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attractive forces the nanoparticles have. Under the force of gravity, these nanoparticles form
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large clusters and alter the flow stability. This phenomenon shrinks the system thermal
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performance and blocks the channels. Hence, selection and manufacturing of nanoparticles
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require long term stability test of nanoparticles. Major stability tests of nanoparticles include
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Zeta potential measurement method, sedimentation, and centrifugation method, UV–Visible
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Spectroscopy Analysis and Dynamic Light Scattering (DLS) Method. These methods do not only
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afford the stability of nanoparticles but also offer a measuring scale to increase the stability of
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the nanoparticle.
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PV and PVT systems both are carbon neutral resources of energy for producing electrical and
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thermal energy, respectively. PVT system converts solar energy into thermal energy by storing
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heat in the working fluid and then provided it for thermal applications [5]. Techno-economic
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characteristic of PVT collectors depends upon the base fluid, absorber material, collector length,
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fluid flow parameters, collector depth, module type, sun tracking, tube spacing and diameter,
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glazing characteristics, shading factor, solar irradiance and working of fluid type [6-17].
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Optimizing these parameters increase the thermal efficiency (useful thermal energy/total solar
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irradiance in kJ/m2), electrical efficiency (useful electricity produced/total solar irradiance in
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kW/m2) and overall efficiency (portion of energy in the form of sunlight that can be converted
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via photovoltaics into electricity) of these systems.
87
Photovoltaic (PV) system are used to provide output electrical energy when solar energy is being
88
employed [18, 19]. An efficient PV system should possess some vital characteristics such as
89
better cooling system, the exact location of the module, system and load synchronization and
90
choice of solar tracking in the system [20]. The absorbed energy by solar irradiation in an
91
efficient system exceeds 50% [21]. The increased temperature due to the absorbed energy results
92
in many problems like cell temperature increment and low electrical efficiency [22]. The
93
efficiency of a PV system is very critical to its working temperature. Irradiation increases surface
94
temperature; however, it decreases the electrical efficiency [23-25]. For a better understanding of
95
the PV systems function, it is important to analyze the input source. PV cells utilize solar
96
irradiations with photon energy greater than the band gap of PV cells to produce electricity. The
97
remaining energy is converted into waste heat increases the temperature of the PV cell. The
98
increased temperature may result in the decrease of open circuit voltage (Voc), output energy and
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fill factor to about 2-2.3 mV/°C, 0.4-0.5%/°C and 0.1-0.2%/°C, respectively [26].
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Previous research analyzes the effect of heat on the performance of PV and PVT systems.
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Chander et al. [27] experimentally investigated the effect of temperature on the behavior of the
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mono-crystalline solar cell. The experiments were done at 550 W/m2 light intensity and the cell
103
temperature of 25-60 °C. The efficiency decreased with the increase in cell temperature. Cuce et
104
al. [28] did experimentation to investigate the effect of PV cell on the light intensity and
105
temperature. They concluded that the performance can be readily improved by decreasing the PV
106
cell temperature. Radziemska [29] concluded from his experimental study that output power of
107
solar cell could decrease to about 0.4% as a result of a temperature increase of 1 K (Kelvin).
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Similarly, the effect of temperature on the efficiency of PV cells and fuel cells has been studied
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by many investigators [30-43]. Research on PVT systems has indicated that heat capturing
110
process can be enhanced by varying the thermo-physical properties of base fluid [44]. Research
111
proved that nanoparticles are the best candidate for enhancing the heat transfer characteristic of
112
any base fluid for any PV/T system [45-58]. Some current studies related to using of nanofluids,
113
prediction of their thermal performance and analysis of their heat transfer were reported [59-71]
114
where this research could be a beneficial and expand to other systems [72-75].
115
This review is a hand for researchers who are looking for nanoparticles to use in PV system since
116
it gives the effect of almost each practically used nanoparticle for PV systems. In essence,
117
enhancing PV and PVT systems efficiency obliges enhancing the heat transfer. A detailed review
118
has been reported for the cooling of the PV system and efficiency enhancement of PVT systems
119
by using nanofluids in the current research. Each chapter explains the latest research of PV/T
120
system performance enhancement presented in terms of flow conditions (laminar/turbulent), base
121
fluid, flow channels, and nanoparticle characteristics and properties.
122
2. Influence of configurations and geometries in PV/T systems
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Nanofluids usage in PV/T systems cannot be arbitrary. They must be used with a proper
124
configuration and with an optimum geometry to extract the maximum output from such up-
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gradation. Table 1 provides a detailed review of the effect of flow channel geometry and
126
nanofluid concentration on the performance of various PV/T systems.
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Table 1. Types of channels configurations used for effective cooling with reference to
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nanofluids.
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Nanofluid (concentration)
Electrical efficiency
Thermal efficiency
Overall efficiency
Single rectangular (2 mm & 4 mm thickness) (Over the cell)
MgO-water. 10 nm size. (0.020.1 wt%)
14.7% (2 mm) 14 % (4 mm)
47.2 % (2 mm) 32 % (4 mm)
61.9 % (2 mm) 46 % (4 mm)
Chandrasekar et al. [77] (2013)
Porous mm)
Al2O3 and CuO in water (0.1 wt%)
9.7% (Al2O3) 9.5% (CuO) 10.4 (Water)
11% CuO 17% Al2O3 30% Water
-
Xu and Kleinstreuer [78] (2014)
Single rectangular
5% Al2O3-water
11%
59%
-
AlOOH.xH2O 0.01 wt%
27%
Comparative values
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al.
[76]
media
(7
Karami and Rahimi. [79] (2014)
Microchannels (rectangular, 1.8×0.5×240 mm3)
Karami and Rahimi [80] (2014)
Straight rectangular (5×3.5×245 mm3) Helical mm2)
(5×3.5
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Geometry and type (thickness)
Investigator (Year)
AlOOH.xH2O 0.1 wt%
20.57% Straight 37.67% Helical
Comparative values
-
Fe3O4-water (3 wt% - with and without magnetic field)
7.23%
68.42%
76% 79%
Sheet and Tube
Sardarabadi et al. [56] (2014)
Sheet and Tube
SiO2/Water (1 and 3 wt% )
9.01% 9.75%
69.2% 72.1%
-
Michael and Iniyan [53] (2015)
Rectangular (2 mm)
CuO (0.05 vol%)
6%
45.76%
-
Said et (2015)
Sheet and Tube
TiO2/water vol%)
-
-
76%
Microchannel
Al2O3/water
-
-
-
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Ghadiri et al. [52] (2015)
[81]
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Lelea et al. [82] (2015)
(0.1
Saroha et al. [83] (2015)
Rectangular (Above and below)
AgNPs AuNPs
and
-
-
-
Noghrehabadi et al. [84] (2016)
Conical
SiO2/water (1% mass fraction)
-
62%
-
Sardarabadi and Passandideh-Fard [85] (2016)
Sheet and tube
Al2O3, TiO2, and ZnO (2 wt%)
-
-
-
Al-Shamani et al.
Serpentine
SiC
13.52%
68.21%
81.73%
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Electrical efficiency
Thermal efficiency
Overall efficiency
(rectangular)
Rejeb et al. [87] (2016)
Sheet and tube
Al2O3 and Cu (0.1 – 0.4 wt%)
-
46.69% (Al2O3) 76.87% (Cu)
-
Radwan et al. [88] (2016)
Microchannel (rectangular)
Al2O3/water, SiC/water
-
-
-
Sharaf and Orhan [89] (2016)
Rectangular (Minichannel)
Al2O3/water Al2O3/synthetic oil
-
-
-
Soltani et al. [90] (2017)
Sheet and tube
SiO2/water Fe3O4/water (0.5% mass ratio)
14.9%
-
-
Al-Waeli et al. [91] (2017)
Sheet and tube
Al-Waeli et al. [92] (2017)
Serpentine (PCM)
Hasan et al. [93] (2017)
Jet Impingement
Sardarabadi et al. [94] (2017)
Serpentine (PCM)
Yazdanifard et al. [95] (2017)
Sheet and tube (CPV/T)
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Al2O3, CuO and SiC (0.5 – 4% vol. fraction)
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SiC
13.7%
72%
-
SiC
12.75%
85%
97.75%
ZnO
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Investigator (Year)
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TiO2
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Geometries in Table 1 can be mainly categorized as a single rectangular channel, sheet and tube,
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micro-channel, and serpentine channel.
Rectangular Channel:
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For a single rectangular channel, Michael and Iniyan [53] used CuO nanoparticles in a PV/T
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system. In comparison to water, the nanofluid improved the thermal efficiency of the solar
135
thermal collector. However, a reduction in electrical efficiency was observed which attributed to
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the need for a redesign of the heat exchanger for the higher nanofluid heat transfer rate. In
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another study, a numerical analysis of high-concentration PV/T system for a constant flow rate
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mode was performed. Simulation results showed that a greater number of channels leads to a
139
good performance at a slight expense of pumping power [89]. Additionally, in the mini-channel
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rectangular heat extractor, Al2O3/synthetic oil nanofluid was found unfavorable against pure
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water and Al2O3/water.
Microchannel:
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Karami and Rahimi [79] used water-based Boehmite (AlOOH.xH2O) nanofluid in rectangular
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microchannels to observe its cooling effect. The nanoparticles decreased the average temperature
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as compared to the pure water case. Yet, increasing the concentration from 0.01 to 0.3 wt% gave
146
a weaker cooling performance and electrical efficiency. In another attempt, they investigated the
147
effect of geometry by comparing straight rectangular channels and helical channels configuration
148
[80]. The Boehmite nanofluid showed same results in performing reducing the average
149
temperature of the PV cell and increasing the thermal and electrical performance compared to
150
water. The helical configuration demonstrated a superior performance due to high bending
151
sections number that is always causing a disruption in its thermal boundary layer and high
152
thermal efficiency of the system by the end of the way. Furthermore, the helical geometry
153
required less pumping power as compared to the straight one; making the channel geometry an
154
important parameter for cooling performance of PV/T systems. Lelea et al. [82] used water with
155
Al2O3 in a microchannel to study the effects of Reynolds number. At low Reynolds number, the
156
maximum temperature reduced by using nanofluids. However, for Re>1000, the difference was
157
negligible. Radwan et al. [88] compared Al2O3/water and SiC/water with water in a rectangular
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microchannel for a low concentrated photovoltaic-thermal system (LCPV/T). Nanofluids
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achieved a higher thermal performance in comparison with water, with SiC/water attaining a
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higher reduction in cell temperature than Al2O3/water. Higher concentration (threshold value)
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and the lower Reynolds number achieved better electrical performance. The friction of nanofluid
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increased with increasing both the Reynolds number and volume fraction of nanoparticles.
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Sardarabadi et al. [56] demonstrated the effect of adding SiO2/water nanofluids in a sheet and
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tube collector. Thermal and overall efficiencies improved compared to water via using
166
nanoparticles as well as by increasing their concentration from 1 wt% to 3 wt%. Ghadiri et al.
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[52] investigated the effect of using ferrofluids in a sheet and tube system under constant and
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alternating magnetic fields. Their results indicated a vast improvement in the overall
169
performance compared to the water and an additional increment in efficiency through using an
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alternating magnetic field. In another study, TiO2 nanoparticles also improved thermal
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performance as well as the overall energy and exergy efficiency of the system [85]. A detailed
172
comparison revealed that TiO2/water and ZnO/water nanofluids performed better in terms of
173
electrical efficiency than Al2O3/water and water in a sheet and tube collector. Moreover,
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ZnO/water was found to have better thermal performance compared to TiO2/water and
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Al2O3/water. Rejeb et al. [87] demonstrated that pure water performed better than ethylene glycol
176
as the base fluid. In addition, Cu/water was found to possess the best thermal and electrical
177
efficiency in comparison with Al2O3/water. Soltani et al. [90] studied the effect of five different
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cooling methods which included natural, forced, water, SiO2/water nanofluid, and Fe3O4 /water
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nanofluid cooling on a hybrid photovoltaic/thermoelectric (PV/TE) system. Liquid cooling
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showed better results for total power in comparison with air. Both nanofluids outperformed water
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with SiO2/water yielding a slightly higher power production than Fe3O4 /water. Al-Waeli et al.
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[94] used a copper tubing mesh welded to a copper plate and used Al2O3, CuO, and SiC
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nanoparticles in water. Among the three nanofluids, SiC showed higher stability and thermal
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conductivity for the PV/T system. Yazdanifard et al. [95] numerically investigated the effects of
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various geometrical parameters such as pipe length, diameter, concentration ratio, as well as the
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use of TiO2 nanofluids in laminar and turbulent regime in a concentrating-PV/T system using a
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parabolic trough collector. The simulation results showed improvement in cooling performance
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with nanofluids in the laminar flow regime. However, the efficiency decreases in the turbulent
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flow regime which conflicts with the results of turbulent flow without using nanofluids.
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Serpentine:
A study on the serpentine channel in a rectangular cross-section was carried out by Al-Shamani
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et al. [86] who examined TiO2, SiO2, and SiC as nanofluids in water. The released results
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showed that SiC has the highest electrical, thermal and overall efficiency followed by TiO2/water
194
and SiO2/water. Al-Waeli et al. [94] proposed a new configuration by utilizing paraffin wax
195
mixed with SiC nanoparticles as a phase change material (PCM). They filled it in a rectangular
196
tank with copper tubing containing SiC/water nanofluid flowing through them. Their unique
197
setup displayed a significant improvement on the acquired thermal, electrical, and overall
198
performance of the system compared to the other PV/T systems. The nanoparticles improved the
199
thermal performance in both nanofluids as well as the paraffin wax. In a similar attempt,
200
Sardarabadi et al. [54] used ZnO/water nanofluid and determined the cooling efficiency for the
201
PV/T alone, PV/T with fluid, and PV/T with PCM system. The results demonstrated a higher
202
overall exergy efficiency for PCM/nanofluid based collector system making it a suitable option
203
for improving the cooling in PV/T systems.
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Other configurations:
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Cui et al. [76] applied the flow of nanofluid above the PV cell. The results exposed a reduction in
206
transmittance of nanofluids with an escalation in mass fraction and film thickness and hence
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decreasing the electrical output compared to PV cells. Despite this, the thermal efficiency of the
208
system increased resulting in a much higher overall efficiency due to the conservation of heat
209
and electricity. Saroha et al. [83] used silver and gold nanoparticles flowing into primary and
210
secondary channels acting as coolant (flow below PV cell) and an optical filter (flow above PV
211
cell), respectively. The results revealed an improvement in the thermal and electrical efficiencies
212
in the PV/T hybrid collector. A similar configuration for a PV/T hybrid system with two designs
213
of separate and double-pass channels was numerically investigated by Hassani et al. [55]. It
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showed that separate channels for nanofluids outperformed the connected channel design.
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Another effective way of cooling PV modules was investigated by Chandrasekar et al. [7] using
216
passive cooling with the help of cotton wick structures in the form of a serpentine shape channel.
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The cooling effect of water was higher in comparison with nanofluids of Al2O3/water and
218
CuO/water. This deterioration in thermal performance was due to the aggregation of
219
nanoparticles within the porous fibers which caused a reduction in the capillary force necessary
220
for the fluid movement. A conical solar collector was experimentally investigated by
221
Noghrehabadi et al. [77] using SiO2/water nanofluid. It was shown that the nanofluid had a
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slightly better thermal performance than water with higher thermal efficiencies for higher flow
223
rates. Hasan et al. [55] used a jet impingement to analyze their cooling performance with
224
different nanofluids. Their results indicated the highest electrical and thermal efficiencies for
225
SiC/water nanofluid followed by TiO2/water, SiO2/water, and water respectively.
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From the above literature review and Table 1, it can be reasonably concluded that straight
227
microchannel offers the best performance as compared to all other channels. Though some
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channels have better efficiency than the straight microchannel, they are difficult to manufacture
229
and are not cost effective. Yet, for best cost-effective performance straight microchannel is
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preferable. Moreover, SiC performs much better than other aforementioned nanoparticles.
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Although PCM inclusion increases the efficiency of the system, cost-effectiveness must be
232
considered before integrating PCM with the PVT system.
233
3. Influence of nanoparticle type in PV/T systems
234
Different kinds of nanoparticles behave differently in PV/T systems. Nanoparticle thermo-
235
physical properties (thermal diffusivity, conductivity, size, etc.) greatly impact their performance.
236
PV/T systems majorly nanoparticles are divided into two categories; Metals and Metal oxides-
237
based nanoparticles.
238
For cooling purposes, thermal conductivity is considered as a major performance indicator.
239
Table 2 shows the thermal conductivities of most abundantly used nanoparticles in PV/T
240
systems. Increasing the nanoparticle thermal conductivity increases performance. However, it is
241
not the only parameter for selection of the nanoparticle.
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242 Table 2. Various nanoparticles thermal conductivities at 25 °C. Metals [96, 97] / Thermal Conductivity (W/m⸳K)
urn
Material
Silver (Ag) / 425
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Copper (Cu) / 398 Nanoparticles
Gold (Au) / 315 Aluminum (Al) / 273 Iron (Fe) / 80
Metal Oxides / Thermal Conductivity (W/m⸳K)
Others / Thermal (W/m⸳K) Diamond(C1) [103]
/
2320
Cupric Oxide (CuO) / 77 [98]
Graphite(C2) [104]
/
2000
Alumina (Al2O3) / 40 Zinc Oxide [100]
(ZnO)
[99]
Conductivity
/ 29
Titanium Oxide (TiO2) /8.4 [101] Iron Oxides (Fe3O4) / 7 [102]
Carbon [105]
Nano
Silicon [106]
Carbide
Bohemite [107]
Tubes(CNTs)/2000
(SiC)
/
280
(γ-AlO(OH))
/
11
244 245
The purpose of using nanoparticles in PV/T systems is to increase their thermal efficiency.
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Therefore, the selected nanoparticles for PV/T system must have better thermal conductivity,
247
thermal diffusivity, and viscosity. They must possess the ability to increase the thermo-physical
248
properties of the base fluid. Furthermore, base fluid plays an essential part in increasing the
249
thermal efficiency of any PV/T system. Table 3 shows that using glycol is a good option
250
compared to water. Whereas, some oils have better efficiency than both water and ethylene
251
glycol.
252
Table 3 clearly shows that nanoparticles are mostly used with water and ethylene glycol with a
253
very low concentration and small size. Research has shown that gold (Au), silver (Ag) and
254
copper (Cu) metals perform better than other metals due to their higher conductivities. Table 3
255
shows that metal oxides are best-suited nanoparticles for any application considering their
256
effectiveness and suspension characteristics. Among metal oxides, copper oxide (CuO) and iron
257
oxides (Fe3O4, Fe2O3) perform better than other types of nanoparticles [108, 109]. Modern
258
research has also shown that carbon-based nanoparticles are also very effective, especially
259
silicon carbide (SiC). Silicon carbide (SiC) is the best suited for enhancing the thermal efficiency
260
of any system [110]. Modified nanoparticles like bohemite, digenite have made their mark in
261
thermal systems. On the other hand, a lot of research needs to be done before considering them
262
as a replacement of conventional nanoparticles.
263
Thermal properties are not enough for selecting nanoparticles for PV/T applications. Physical
264
geometry is an extremely important parameter for enhancing the thermal performance of any
265
system. Chen et al. [111] investigated three different sizes (25, 33 and 40 nm) of Au-based
266
nanofluid and found that the best suited among them was 33 nm sized particles. Filho et al. [112]
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proved that large size particles form clusters reduces the sunlight entrance in the system and
268
reduces the efficiency of the system. Consequently, an optimum size must be considered for any
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particle to avoid clustering. Sokhansefat et al. [113] concluded that the performance of any
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nanoparticle also depends upon its volume fraction. Hence, selecting the volume percentage for
271
any nanoparticle must consider as well. They performed experiments on two different volume
272
percentages (1 and 5 %) of alumina. They found that increasing the concentration will raise
273
efficiency from 5 to 15%. However, after a specific value, there was a decline in the performance
274
of the system. This makes his argument stronger for that any nanofluid will perform best only
275
under certain conditions. Lee at al. [114] performed the same research on the same nanoparticle
276
and found that increasing the volume fraction from 0.01 to 0.3% will the efficiency of the
277
system.
278
Table 3. Nanoparticle effect on different system’s thermal performance.
Au
Fe
Al2O3
TiO2
Size (nm)
Fraction (vol %)
Water Water Acetone
<10 26 80
.01-.05 0.5-2.0 0.04
Thermal Improvement (%) 41 [116] 22 [118] 18 [120]
Ethylene Glycol
80
0.5
15 [122]
80
0.5
4.7 [3]
0.1 0.5 3 7.5 0.9 5 4 5 5.5 0.2
4 [122] 12 [122] 27 [122] 52 [128] 15 [130] 60 [109] 20 [108] 26.5 [133] 25 [135] 46 [137]
5
12-18 [139]
Water Kerosene Water Kerosene
80 80 80 100 <100 36 18.6 210 <100 20 90210 13 6.7 10 155
2 6.3 5 1
48 [141] 300 [143] 200 [145] 34 [147]
15-22 [148]
Water
<100
1.1-4.4
22 [149]
85.1 [150]
EG
30
1
12.4 [151]
Fraction (vol %)
Water Water Water Ethylene Glycol (EG)
<100 <100 35
0.3-0.9 0.25-1 .01-1
100500
0.1-1.0
15 [121]
Water
21
0.00026
48 [123]
<100 17 <100 20 10 98 10 9 28 10 6501000 15 20 21 21 2040 50-
N/A 0.18 0.011 0.55 0.55 0.01 .1-0.55 2-10 3-8 0.5-1.8
20-25 [124] 63 [125] 14 [126] 11-33 [127] 18 [129] 5 [131] 18 [132] 29 [116] 41 [134] 32 [136]
0.5-4
20 [138]
Water
0.5-5 4 0.2 0.2
30 [140] 23 [142] <10 [144] 6-11 [146]
0.7-1 0.025
Water Water Water EG EG Water EG Water Water / EG Water Transformer Oil Water Water DI Water Water Oil Water
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Ag
Base Fluid
Size (nm)
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Type
Thermal Improvement (%) 30 [115] 10 [117] 10-80 [119]
Base Fluid
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Type
Cu
Al
CuO
ZnO
Fe3O4
Engine Oil Water Water EG Water Water Water EG EG EG Water
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C2
300 35 30 65 600 N/A 115
CNTs 0.01 1.36 3 wt% 4 0.1 1 wt%
25 [152] 36 [154] 88.9 [91] 22.9 [156] 10 -20 [157] 29 [159]
γAlO(OH) C1
Water EG Water Water Water Water
10 30 10 5-10 10 <10
0.84 1 0.1 wt% .01 wt% 3 wt% 0.9 wt%
23-31 [153] 12.7 [155] 37.67 [80] 27 [79] 10.8 [158] 10.95 [160]
of
SiC
Water Oil Water EG Water Water
Based on Table 3, it can be concluded that nanoparticle selection can only be beneficial if
281
optimum size and concentration is well-thought-out. Moreover, any nanoparticle selection must
282
be linked with its thermo-physical properties by keeping in mind its life and cost. Lastly,
283
research has proved that metal oxides are best suited for PV/T applications but the ease of
284
manufacturing SiC can also be adopted for PV/T applications as it offers almost similar results
285
like metal oxides. Hence, metal oxides and SiC are preferable.
286
4. Effective parameters for nanofluids applications in PV/T systems
287
Nanofluids as coolant show variable performance with respect to different parameters associated
288
with the properties of nanofluids and PV/T systems. Details are discussed below with reference
289
to the previous research works.
290
4.1. Velocity
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Figure 2. Solar cell temperature (Tsc) variation relation with wind velocity (Vw) at different
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geometric concentration ratios (CR) [88].
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Velocity is one of the most effective parameters for shaping the heat transfer efficiency of any
295
system. Convective heat transfer is directly linked with the velocity of the system. Increasing the
296
velocity increases the Reynolds number that makes fluid turbulent after some specific increase in
297
velocity. The performance of PV/T system depends upon two velocities, air passing over the
298
panel and the coolant, flowing for the purpose of cooling, inside the system. Figure shows that
299
as the wind velocity increases over the panel, the temperature of the panel decreases resulting in
300
an increase of the system’s performance.
301
Whereas, Figure is a clear indication of the effect of a velocity increasing (Reynolds number)
302
on the cell temperature. At high geometric concentration ratio, solar cells show an increase in
303
efficiency of the system via increasing nanofluid’s velocity, but this trend is almost constant at a
304
low concentration ratio. The graph also shows that volume concentration is not affecting the
305
system’s efficiency when it increased from 1% to 4%. In addition, SiC-water is presenting better
306
performance than water and Al2O3 nanofluid based system. Therefore, it is better to use
307
nanoparticles at high geometric concentration ratios compared to low concentration ratios.
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Figure 3. Solar cell temperature variation at different velocities (Reynolds number) with varying
311
CR and different nanofluids at (a) 1 vol% nanoparticle (b) 4 vol% nanoparticle [88].
312 313
Figure 4 and Figure 5 indicates that the best performance from nanofluids can be achieved at
314
higher velocities, but those velocities must be in the range of low turbulent Reynolds number or
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in the laminar region. Laminar flow of nanoparticles with low velocity does not have a
316
considerable effect on the performance of the system and cause clustering of nanoparticles. The
317
same tendency will be for too high velocities. It can be concluded from the available data that the
318
velocity of nanoparticles-based coolant must be high. On the other hand, it should not be high
319
enough to make flow extreme turbulent as high velocity laminar or slightly turbulent flow. This
320
provides a better particle suspension and a better heat transfer rate that helps to increase the
321
efficiency of the PV/T systems.
322
4.2. Concentration/volume fraction
323
Another important factor to determine the effectiveness of any nanofluid is its volume fraction or
324
concentration ratio. Figure and Figure 5 show that at low Reynolds number and low volume
325
fraction, the efficiency of the system increases. As the volume fraction exceeds a specific
326
amount, the effect on panel cooling is almost constant. Again, SiC-based coolant has better
327
performance than the Al2O3 based coolant and systems with lower geometric concentration ratios
328
has better efficiency than the higher concentration ratio systems.
329
Straight channel and helical channels were employed with Boehmite nanofluid to observe the
330
efficiency of PV cells. The volume fraction of 39.70% and 53.76% of 0.1 wt% were used for
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helical and straight channels respectively. The efficiency of the PV cells enhanced by 20.57%
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and 37.67% for the straight and helical channels. In the case of helical channels, the temperature
333
decrease by nanofluid is too high if compared to the base fluid as shown in Fig. 5.
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Figure 4. Solar Cell temperature variation for different volume fractions of nanoparticles at
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varying Reynolds numbers (a) CR=10 (b) CR=20 (c) CR=40 [88, 161, 162].
340 341
Similarly, the concentration ratio of nanofluids also has a positive impact on the heat removal in
342
the PV/T systems. Figure
343
performance when it has a concentration of 0.1%. System performance is low when the
344
concentration is in the 0.0x range. correspondingly, when the concentration increased from 0.1%
345
to 0.5%, the efficiency of the system doesn’t show any positive impact. As a result, it is crucial to
346
select effective concentration ratio of any nanoparticle for using it as a coolant.
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A detailed comparison is presented from some previous studies in Fig. 6. It indicates that with
348
the increase in volume fraction, system conductivity enhances which has a positive impact on the
349
efficiency of the system. Yet, this fraction should be tested before using nanoparticles in any
350
system. If the concentration ratio increases from a certain limit, it will start to have a negative
351
impact on the efficiency of the system. Furthermore, it will offer nanoparticle suspension issues.
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352 (a) water.
(b) Boehmite 0.01% wt.
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(c) Boehmite 0.1% wt.
(d) Boehmite 0.5% wt.
Figure 5. The temperature gradient of cooling and without cooling with different weight
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concentrations of Boehmite using different channels [80].
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Figure 6. Comparison of variation of thermal conductivity of nanoparticle with respect to (a)
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Nanoparticle fraction (b) Temperature [78, 116, 161, 162].
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Paul et al. [123] measured the thermal conductivity enhancement of Au based nanofluid by
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varying the particle concentration and particle size. The enhancement was found thru increasing
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the concentration and decreasing the particle size. The maximum enhancement in thermal
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conductivity was recorded at particle size 21 nm and volume fraction 0.00026 with 48%. The
367
response to enhancement is shown in Figure . In another study [147], only 28% enhancement in
368
thermal conductivity was reported for both Au and carbon nanotubes composite water-based
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nanofluid. Besides, only 15% enhancement was recorded with the addition of Au nanoparticles
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in water-based carbon nanotubes composite nanofluids. The variation in enhancement as
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compared to many other studies may be attributed to the additional stabilizer, synthetic
372
conditions and distribution of nanoparticles.
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Hong et al. [129] prepared an ethylene glycol-based Fe nanofluids from monocrystalline powder.
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The dispersion improved when using sonication with high-powered pulses. The nonlinear
375
response of thermal conductivity as a function of volume fraction was observed and a maximum
376
18% enhancement was reported. The results were compared with Cu nanofluids as shown in
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Figure . The improved conductivity of Fe nanofluids than Cu nanofluids was observed thanks to
378
more effective thermal-transport ability of Fe nanofluids.
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(b)
Figure 7. Thermal conductivity enhancement percentage of gold water based nanofluid (a) with
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a variation of volume fraction (b) with a variety of particle size at 0.00026 volume fraction [78].
385 386 387
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Figure 8. Thermal conductivity of Fe and Cu nanofluids at different volume fractions [82].
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Any increase in the volume fraction will lead to high enhancement in the thermal conductivity of
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CuO nanofluids. Liu [128] investigated the performance of ethylene-based CuO nanofluids by
390
changing the volume fraction. The normalized viscosity and thermal conductivity data are shown
391
in Figure . In thermal conductivity ratio, ke is the thermal conductivity of CuO nanofluids and kf
392
is the thermal conductivity of the base fluid. In viscosity ratio, µe is the viscosity of CuO
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nanofluids and µf is the viscosity of the base fluid. The response is almost in a linear manner
394
because of the decent dispersion and stable suspension of CuO nanoparticles in ethylene glycol.
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The maximum enhancement in thermal conductivity was achieved by 22.4% at 5% volume
396
fraction. The 22% enhancement in thermal conductivity at 4% volume fraction has been reported
397
for ethylene glycol-based CuO nanofluids [148]. Furthermore, 17% enhancement has been
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recorded at 4% volume fraction for deionized water based CuO nanofluids [149]. The difference
399
in results is due to the variation in the specific surface area of nanoparticles. The enhanced
400
thermal conductivity of ethylene glycol based ZnO nanofluid was reported by Yu et al. [147].
401
The thermal conductivity response with volume fraction is shown in Figure 10. Thermal
402
conductivity enhancement as a function of volume fraction for ZnO-EG nanofluid [87].
403
. Lee [135] concluded that ZnO nanofluids exhibited temperature dependence at higher
404
concentration while viscosity didn’t show dependence on temperature and increased with volume
405
fraction. The shape of nanoparticle offered a significant effect on the thermal conductivity
406
enhancements.
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(b)
Figure 9. Heat transfer enhancement of Cu nanofluids as a function of volume fraction (a)
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thermal conductivity data (b) viscosity data [163].
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Figure 10. Thermal conductivity enhancement as a function of volume fraction for ZnO-EG
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nanofluid [87].
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418
performance can be enhanced by changing the shape and size of nanoparticles and using
419
surfactants. The values of enhancement of thermal performance of these oxides nanofluids are
420
reported in the given data sheet. Dramatic enhancement in thermal conductivity has been
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reported for kerosene-based Fe3O4 nanofluid under the magnetic field influence along the heat
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flow direction. The maximum enhancement was observed 300% at 6.3% volume fraction. The
423
increase in thermal conductivity was due to the formation of the chain-like structure under
424
magnetic field when dipolar interaction energy enhanced from thermal energy. The heat transport
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becomes more effective through the chainlike aggregates of nanoparticles. The magnetic field
426
effect on thermal conductivity is shown in Figure .
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Yang et al. [148] used the graphite nanofluids to measure the convective heat transfer coefficient
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for tube heat exchanger. The significant increase in heat transfer coefficient and the thermal
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conductivity was observed at low weight fraction. The 22% enhancement in heat transfer
430
coefficient and 50% enhancement in the conductivity was observed at 2.5% weight fraction and
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at 50 °C temperature. The graphite nanofluids have been used in solar collector to enhance the
432
absorptions of solar radiations. Results of this study showed that it can be possible to absorb
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more than 50% of incident irradiation energy by using graphite nanofluids with 0.000025%,
434
volume fraction, while pure water solar collector can only absorb around 27% of incident
435
irradiation energy as shown in Figure .
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Figure 2. The thermal conductivity ratio (ke/kf) and the percentage of enhancement as a function
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of the external magnetic field at different volume fractions of Fe3O4 [164].
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Figure 3. The absorbed energy of solar radiation for different graphite nanofluids [118].
441 4.3. Size
443
A comprehensive experimental study [77] was conducted to investigate the enhancement in the
444
thermal conductivity for the metallic and oxides based nanofluids. The effect of suspension
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temperature on thermal conductivity with various particle volume fractions, particle sizes and the
446
base fluid was presented. Increasing the particle size and volume fraction drove to a good
447
enhancement. The thermal conductivity enhancement of Al2O3 nanoparticles in base fluid water
448
with suspension temperature at varying nanoparticle size and volume fraction is presented in Fig.
449
13. The thermal conductivity of the nanoparticles in base fluid ethylene glycol was relatively
450
higher than the base fluid water due to the improved dispersion. The metallic nanoparticles were
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found to give higher enhancement than oxides nanoparticles. Figure 14 presents a comparison of
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thermal conductivity enhancement of Cu and Al nanofluids at 1% volume fraction and 80 nm
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nanoparticle size. The conductivity of Cu nanofluid was found higher than Al nanofluid due to
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the higher value of thermal conductivity.
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150 nm/0.5% 150 nm/1% 150 nm/2% 150 nm/3% 45 nm/0.5% 45 nm/1% 45 nm/2% 45 nm/3% 11 nm/0.5% 11 nm/1% 11 nm/2% 11 nm/3%
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6
3
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0 20
30
40
50
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Temperature ( C)
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and particle sizes [3].
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Figure 4. Enhancement in thermal conductivity of Al2O3 nanofluid at different volume fractions
Enhancement in Thermal Conductivity (%)
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458 459 460
Water-Cu Ethylene Glycol-Cu Water-Al Ethylene Glycol-Al
10
20
30
40
50
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Temperature ( C)
Figure 5. Comparison of Cu and Al nanofluid at 1% volume fraction and 80 nm particle size [3].
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The nanoparticle size must be within the optimum range for better suspension and better heat
462
transfer in the coolant system. Figure shows that increasing the nanoparticle size will decrease
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the heat transfer rate due to uneven suspension. As evidential from Figure , the optimum
464
nanoparticle size provides better heat flux. Thus, nanoparticle size selection must be carefully
465
monitored to avoid any efficiency loss in the system. Furthermore, any nanoparticle size used
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within the mentioned range is better than using base fluid alone.
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Figure 6. Nanoparticle size effect on heat transfer [165].
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Figure 7. Nanoparticle size effect on heat flux and heat transfer [166].
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471 Zaoui et al. [35] compared the heat transfer rate of silver nanofluid in a closed-loop oscillating
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heat pipe with check valves (CLOHP/CV) with pure water. The best heat flux was achieved at a
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90˚ inclination angle, 25 aspect ratio and 60 °C operating temperature with 0.5% w/v
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concentration of silver nanofluid. A 10% improvement in the heat flux was recorded in case of
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silver nanofluid as compared to pure water. Variation in the heat flux at different concentrations
477
and operating temperature is shown in Figure . The study contradicts with another previous
478
research [146], as heat flux response with a variety of nanoparticles concentration is different in
479
both cases. In this case, the heat flux was increased with increase in concentration owing to using
480
of CLOHP/CV. As the heat flux of CLOHP/CV is dependent on the working fluid viscosity limit,
481
the viscosity of the working fluid will increase at higher concentration of nanoparticles. This
482
makes it difficult to produce bubbles and produce a large friction resistance causing liquid slug
483
obstruction. Therefore, silver concentration can be increased to a limited point in order to
484
enhance the heat flux of CLOHP/CV. The particle size of Ag nanoparticles for this study was less
485
than 100 nm. The heat transfer performance of Ag nanofluid in heat pipe was investigated in
486
terms of thermal resistance using 10 nm and 35nm sizes of Ag nanoparticles. It was found that
487
the thermal resistance of the heat pipe containing 10 nm and 35 nm nanoparticles was 52% and
488
81% lower as compared to DI-water respectively as shown in Figure [37]. In such a case,
489
increasing particle size causes thermal resistance reduction which will enhance the thermal
490
conductivity. The presence of nanoparticles smooths the fluid temperature gradient and reduce
491
the boiling limit due to the increase in conductance and heat resistance reduction.
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Figure 8. The operating temperature effect on the heat transfer rate of CLOHP/CV at 25 aspect
494
ratio [35].
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Figure 9. The measured value of thermal resistance of heat pipe with nanofluid (a) at 1 ppm (b)
500
at 10 ppm [37].
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501 4.4. Base fluid
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Water is the most commonly used base fluid with nanoparticles since it offers better suspension
504
properties and reasonable heat transfer. Yet, organic fluids show better suspension and heat
505
transfer than water. It is preferable to employ water where heat transfer removal can be
506
compromised. However, for high efficiency and sensitive equipment, organic fluids offer
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outstanding performance. For an economic system, using water as a base fluid is a better option
508
than any other fluid.
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Increasing the nanoparticles volume fraction will increase the thermal conductivity of nanofluids,
510
while higher concentration enhances the viscosity. This enhancement in thermal conductivity at
511
higher concentration depends on the temperature due to the aggregation and clustering of
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nanoparticles. In general, heat transfer improves by increasing the nanoparticle size and by
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having highly thermally conductive nanoparticles. This might be due to the difference in surface
514
area per unit volume of the nanoparticles. Enhanced nanofluids performance was observed by
515
increasing the nanofluids specific surface area. Highly thermally conductive nanomaterial was
516
not always found to be the best in improving the thermal transport property of the fluids for
517
suspension. The results variation was also observed due to the difference in synthetic processes,
518
connectivity of nanoparticle, microstructure, experimental techniques, testing conditions and
519
dispersion quality of the nanoparticles. The quite enhancement in conductivity was observed in
520
the case of metallic nanofluids as compared to oxides nanofluids. Oxides nanofluids are good for
521
bountiful long-time stability of suspension which gives a significant improvement. Non-metallic
522
nanoparticles fluids have also great potential in thermal photovoltaic applications. Carbides
523
nanofluids and nano-composite based nanofluids enhance thermal performance. The complete
524
data is simplified in Table 3 that is useful for the selection of nanofluids for different
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applications.
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5. Summary of application of nanofluids as a coolant in photovoltaic systems
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Table 4 represents the advantages of using nanofluids as a coolant in different types of
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photovoltaic systems.
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Table 4. Applications of nanofluids as a coolant in photovoltaic systems. Study Type
Flow Regime
Nano Fluid Type/ Application
Concentration / Size
System Configuration
Mittal et al. [167] (2013)
Numerical
Laminar
Ag-water & Cuwater / Spectral filter + Coolant
0.0043 vol% & 0.01937 vol% / 10 nm & 10 nm
CPV/T
Both Nano temperature thermal effic
Faizal et al. [168] (2013)
Numerical
Laminar
CuO, SiO2, TiO2, and Al2O3 with water/ Coolant
0.02 wt% to 0.032 wt% for all /
PV/T
Nanofluids specific he efficiency. Compared nanofluid efficiency.
Karami et al. [80] (2014)
Experimental
Laminar + Turbulent
Boehmite Coolant
/
0.01,0.1, 0.5 wt% / 5-10 nm
PV/T
Boehmite is than water better perfor
Xu et al. [78] (2014)
Numerical
Turbulent
Al2O3-water Coolant
/
0-4 vol% / 38.4 nm
CPV/T absorber Plate
Cell efficien volume fract
DeJarnette et [169] (2015)
Numerical
Laminar
Plasmonic / Spectral Filter + Coolant
Variable
CPV/T
Plasmonic n filters. They prov nanoparticle
Siddharth et al. [170] (2015)
Numerical + Experimental
Laminar
Ag-water & Auwater / Coolant
0.00019 vol% & 0.00025 vol% / 5 nm each
PV/T
Both nanofl performance system and more efficie
Said et. al. [163] (2015)
Numerical
Laminar
TiO2-water Coolant
0.1, 0.3 vol%
PV/T
Nanofluids efficiency o positive imp Pressure dr nanofluids u
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/
Conclusive
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Study Type
Flow Regime
Nano Fluid Type/ Application
Concentration / Size
System Configuration
Michael et al. [53] (2015)
Experimental
Laminar
CuO-water Coolant
/
0.05 vol% / 75 nm
PV/T
CuO-water efficiency efficiency as as a coolant.
Lelea et (2015)
Numerical
Laminar
Al2O3-water Coolant
/
1,3,5 vol% / 28, 47 nm
CPV/T
In this spec constant pum better than w
Matin et al. [52] (2015)
Experimental
Laminar
Fe3O4-water Coolant
/
1, 3 wt%
PV/T
System effi usage of ferr The efficie introducing
Sharaf et al. [89] (2016)
Numerical
Al2O3-water & Al2O3-synthetic oil / Coolant
15-40 nm
CPV/T
Al2O3-synth thermal per water.
Laminar
Al2O3-water, TiO2water & and ZnOwater / Coolant
All with separate 0.2 wt% / 20 nm, 10-30 nm & 1025 nm
Sheet and Tube PV/T
In terms of showed lagg other two a best among Thermal ef dependent o electrical eff
et
al.
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Experimental + Numerical
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Sardarabadi [54] (2016)
[82]
Laminar + Turbulent
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Pr e-
Researcher (Year)
Conclusive
Hassani et al. [55] (2016)
Numerical
Laminar
Ag–water & Agtherminol VP / Spectral Filter + Coolant
0.001-1.5 Vol% & 0.0002,0.003 vol% / 10 nm & 10 nm
CPV/T
Increasing t range will in case of Si an For concent thermal nan separate cha channels.
Shamani et al. [86] (2016)
Experimental
Turbulent
SiC-water, TiO2water & SiO2water / Coolant
0 – 2 wt%
PV/T
SiC-based performance
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Study Type
Flow Regime
Nano Fluid Type/ Application
Concentration / Size
System Configuration
Khanjari et al. [171] (2016)
Numerical
Laminar
Ag-water & Al2O3water / Coolant
0-12 vol% / 50 nm
Sheet & Tube PV/T
Ag based performance As volume indicated a (energy + ex
Radwan et al. [88] (2016)
Numerical
Laminar
Al2O3-water SiC-water Coolant
& /
0-4 vol% / 20 nm
CPV/T
SiC based Al2O3. High efficie help of nan compared to pumping w efficiency.
Hassani et al. [172] (2016)
Numerical
CNTs–water & Ag-water / Coolant
0.1 vol% & 0.001 vol% / 15 nm & 10 nm
PV/T
Nanofluid b efficiency a simple PV a
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Researcher (Year)
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Laminar
Conclusive
[173]
Experimental
Laminar
Cu9S5 – oleylamine / Spectral Filter
22.3, 44.6, 89.2 ppm / 60.2 nm
CPV/T
Heat to E dependent o Anti-reflecti increasing sy
Noghrehabadi et al. [174] (2016)
Experimental
Laminar
SiO2-water Coolant
1 wt%
CPV/T
Nanofluids i At high ir system didn to nanofluid
Laminar
Al2O3 and Cu with water and ethyl Glycol / Coolant
0.1,0.2 and 0.4 wt%
PV/T
Cu-water co efficiency co with ethyl efficiency w Thermal and the same con
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An et al. (2016)
Oussama et al. [87] (2016)
Numerical
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Study Type
Flow Regime
Nano Fluid Type/ Application
Concentration / Size
System Configuration
Al-Waeli et al. [92] (2017)
Experimental
Laminar
Nano SiC-paraffin wax / Coolant
0-5 mass%
PV/T
Nanofluids e of the system helped to ke the reasonab
Farideh et al. [95] (2017)
Numerical
Laminar + Turbulent
TiO2-water Coolant
/
0-4 vol%
CPV/T & PV/T
Nanofluids flow regime Nanofluids CPVT system TiO2 is an increase the systems.
Shohreh et al. [90]
Numerical
SiO2-water Fe3O4-water Coolant
& /
N/A
PV/TE
Both nanofl thermal and water nanof 4% better in to Fe3O4-wa than water a
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Researcher (Year)
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Laminar
Conclusive
Numerical
Laminar
Al2O3, CuO and SiC with water / Coolant
0.5, 1, 2, 3, and 4 vol%
PV/TE
SiC nanopar in terms of nanoparticle than Al2O3.
Husam et al. [93] (2017)
Experimental
Laminar
TiO2-water, SiO2water & SiC-water / Coolant
1 wt% for each
PV/T
SiC perform nanofluids b on the effici a decrease in With the in the efficienc
Dudul et al. [175] (2017)
Numerical + Experimental
Laminar
CuO-water Coolant
N/A
PV/T
Use of nano by 14.5 °C. Electrical e whereas exe
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Al-Waeli et al. [91] (2017)
/
Flow Regime
Nano Fluid Type/ Application
Concentration / Size
System Configuration
Numerical + Experimental
Laminar
Al2O3-water Coolant
0.1-0.5 wt%
PV/T
The tracking increase the factor of mo The increas efficiency w started to de The optimu was selected
Experimental
Laminar + Turbulent
TiO2 in water polyethylene glycol mixture & Al2O3 in watercetyltrimethylamm onium bromide mixture / Coolant
(0.01, 0.05 and 0.1) wt.%
PV
Al2O3 usage than any oth The flow rat 5000 mL/m rate, better c Increasing increased t increased t system.
Laminar
ZnO-water Coolant
/
0.2 wt%
PV/T
When nano PV/T system material (PC 9%, wher efficiencies respectively.
Laminar
Al2O3-water Coolant
/
(1 & 6) vol%
CPV
Nanofluids more than However, sy Transfer. Combination would giv performance Both exergy considerably
Hussein et al. [176] (2017)
Munzer et al. [177] (2017)
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Experimental
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Srivastava et [178] (2017)
al.
Numerical
/
Pr e-
Study Type
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Researcher (Year)
Sardarabadi [54] (2017)
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Conclusive
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It is clear from the literature review that nanofluids are effective in increasing the thermal, electrical and overall efficiencies of the system. Comparisons of different nanoparticles
of
performance showed that Al2O3 is not a much effective nanofluid. Overall performance and working conditions for nanofluids can be summarized as follows:
System efficiency can be enhanced further by controlling the nanofluid concentration, but
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optimum test condition must run on the system before choosing a nanofluid concentration for that specific system.
Nanofluids perform much better in high-velocity laminar flow compared to turbulent flow
Pr e-
since laminar flow provides a better suspension of nanoparticles.
The effectiveness of nanofluids can be enhanced further by using synthetic oils as base fluids.
Increasing the flow rate has a positive impact on the nanofluids to a specific limit. I increase the flow rate after that limit will decrease the efficiency of the system. Therefore, it is strongly recommended to select the optimum flow rates for nanofluids. Nanofluids as coolants behave differently in different climates. The climate must consider
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before choosing any nanofluid for cooling applications. Nanoparticle size is another important parameter for judging the effectiveness of nanofluid. Different sizes of nanoparticles behave differently at different flow rates and temperatures. Mostly, the response is random when it comes to the size of the nanoparticles with a velocity
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of the coolant.
6. Conclusions
A comprehensive review of nanoparticle’s application in photovoltaic (PV) cooling has been done in the current study. The effect of almost each practically used nanoparticle for PV systems has been critically observed. Nanoparticle properties (type, size, volume fraction and
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concentration) in relation with base fluid, flow channels, and flow types have been analyzed. It has been observed that base fluids like ethylene glycol and kerosene must be selected for best
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performance. Results have shown that nanofluid with better thermal conductivity enhances the maximum efficiency where optimum size, volume fraction and correct concentration ratio of
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nanofluid is selected. The concentration ratio of nanoparticle must be as low as possible and volume fraction (%) must be below 0.5%. Care must be taken in the selection of correct volume fraction as higher volume fraction results a clustering of nanoparticle possess the negative effect on the system's performance. Results have shown that straight microchannel is preferred but for
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extremely sensitive applications, helical channels can also be selected. Out of all the studied nanoparticles, Fe3O4, SiC, and TiO2 nanoparticles presented the maximum efficiency enhancement. As indicated in the parametric studies, micro-channels turbulent flow occurs at low Reynolds number. For obtaining the maximum efficiency, the high-velocity laminar flow must be selected. Hense, at higher ranges of Reynolds number time, it is hard to remove heat from the PV
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system. This leads to even negative effect on the system performance and can cause clustering
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problem. This case is applicable for low speed flows as well.
7. Future Works
There is no compact mathematical model to study the effect of nanoparticle on thermal system
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performance considering different variables such as nanoparticle properties and nanofluid characteristics. Research is needed in this regard. Moreover, research is also needed to study the effect of nanofluid usage on lifetime enhancement of thermal systems.
Acknowledgments This research was supported by School of Mechanical Engineering, Chung Ang University,
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Republic of Korea and Department of Mechanical Engineering, University of Central Punjab, Pakistan.
of
Nomenclature
closed-loop oscillating heat pipe with check valves
CR
geometric concentration ratio
DLS
dynamic light scattering
EG
ethylene glycol
fv
graphite nanofluid concetration [%]
h
heat transfer coefficient [W m-2 K-1]
ke
Thermal conductivity of the nanofluid [W m-1 K-1]
kf
thermal conductivity of the base fluid [W m-1 K-1]
LCPV/T
low concentrated photovoltaic-thermal system
µe
viscosity of nanofluids [m2 s-1]
µf
viscosity of base fluid [m2 s-1]
PCM
phase change material
PV
photovoltaic
PVT
photovoltaic thermal
PV/T
photovoltaic/ photovoltaic thermal
Q q
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PV/TE
p ro
CLOHP/CV
hybrid photovoltaic/thermoelectric heat transfer rate [W] heat flux [W m-2]
R
thermal resistance [ºC W-1]
RH
relative humidity, dimensionless, in %
solar cell temperature [ºC]
UV
ultraviolet
Voc
open circuit voltage
vol%
volume concentration [%]
Vw
wind velocity [m/s]
wt%
weight percent (concentration) [%]
nanofluids
f
base fluid
o
base fluid
oc
open circuit
sc
solar cell
w
wind
[1]
G. Boyle, Renewable energy: power for a sustainable future, Oxford University Press, 1996.
S. Murshed, K. Leong, C. Yang, Investigations of thermal conductivity and viscosity of
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[2]
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References
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of
Journal Pre-proof
nanofluids, International Journal of Thermal Sciences, 47(5) (2008) 560-568. [3]
M. Chandrasekar, S. Suresh, A.C. Bose, Experimental investigations and theoretical determination of thermal conductivity and viscosity of Al2O3/water nanofluid, Experimental Thermal and Fluid Science, 34(2) (2010) 210-216.
[4]
Gaganpreet and S. Srivastava, Viscosity of nanofluids: particle shape and fractal
Journal Pre-proof
aggregates, Physics and Chemistry of Liquids, 53(2) (2015) 174-186. [5]
A.N. Al-Shamani, S. Mat, M.H. Ruslan, A.M. Abed, K. Sopian, Numerical study on the
of
characteristics of a specially designed rectangular tube absorber photovoltaic thermal collector (PVT), WSEAS Transactions on Environment and Development, 11 (2015) 23-
[6]
p ro
28.
A. Elbreki, M. Alghoul, A. Al-Shamani, A. Ammar, B. Yegani, A.M. Aboghrara, M. Rusaln, K. Sopian, The role of climatic-design-operational parameters on combined PV/T
(2016) 602-647. [7]
Pr e-
collector performance: a critical review, Renewable and Sustainable Energy Reviews, 57
J. Zhao, Y. Song, W.-H. Lam, W. Liu, Y. Liu, Y. Zhang, D. Wang, Solar radiation transfer and performance analysis of an optimum photovoltaic/thermal system, Energy Conversion and Management, 52(2) (2011) 1343-1353.
[8]
A. Tiwari and M. Sodha, Performance evaluation of hybrid PV/thermal water/air heating
B. Agrawal and G. Tiwari, Life cycle cost assessment of building integrated photovoltaic
urn
[9]
al
system: a parametric study, Renewable energy, 31(15) (2006) 2460-2474.
thermal (BIPVT) systems, Energy and Buildings, 42(9) (2010) 1472-1481. [10] B. Huang, W. Ding, Y. Huang, Long-term field test of solar PV power generation using one-axis 3-position sun tracker, Solar Energy, 85(9) (2011) 1935-1944. G. Tiwari, R. Mishra, S. Solanki, Photovoltaic modules and their applications: a review on
Jo
[11]
thermal modelling, Applied energy, 88(7) (2011) 2287-2304. [12] J. Tonui and Y. Tripanagnostopoulos, Performance improvement of PV/T solar collectors with natural air flow operation, Solar energy, 82(1) (2008) 1-12. [13] R. Koech, H. Ondieki, J. Tonui, S. Rotich, A steady state thermal model for
Journal Pre-proof
photovoltaic/thermal (PV/T) system under various conditions, Int. J. Sci. Technol. Res, 1(11) (2012) 1-5.
of
[14] A.N. Al-Shamani, S. Mat, M. Ruslan, A.M. Abed, K. Sopian, Effect of New Ellipse Design on the Performance Enhancement of PV/T Collector: CDF Approach,
p ro
International Journal of Environment and Sustainability, 5(2) (2016).
[15] A.C. Gladen, J.H. Davidson, S.C. Mantell, The effect of a thermotropic material on the optical efficiency and stagnation temperature of a polymer flat plate solar collector, Journal of solar energy engineering, 137(2) (2015) 021003.
Pr e-
[16] A.M. Do Ango, M. Medale, C. Abid, Optimization of the design of a polymer flat plate solar collector, Solar Energy, 87 (2013) 64-75.
[17] G. Chen, K. Shestopalov, A. Doroshenko, P. Koltun, Polymeric materials for solar energy utilization: a comparative experimental study and environmental aspects, Polymer-Plastics Technology and Engineering, 54(8) (2015) 796-805.
al
[18] G.T. Wrixon, A.-M.E. Rooney, W. Palz, Renewable energy-2000, Springer Science &
urn
Business Media, 2012.
[19] I. Mahbubul, Preparation, Characterization, Properties, and Application of Nanofluid, William Andrew, 2018.
[20] K.S. Karimov, M. Saqib, P. Akhter, M. Ahmed, J. Chattha, S. Yousafzai, A simple photo-
Jo
voltaic tracking system, Solar energy materials and solar cells, 87(1-4) (2005) 49-59. [21] A.K. Suresh, S. Khurana, G. Nandan, G. Dwivedi, S. Kumar, Role on nanofluids in cooling solar photovoltaic cell to enhance overall efficiency, Materials Today: Proceedings, 5(9) (2018) 20614-20620. [22] R. Saidur, K. Leong, H. Mohammad, A review on applications and challenges of
Journal Pre-proof
nanofluids, Renewable and sustainable energy reviews, 15(3) (2011) 1646-1668. [23] R. Vaillon, L. Robin, C. Muresan, C. Ménézo, Modeling of coupled spectral radiation,
and mass transfer, 49(23-24) (2006) 4454-4468.
of
thermal and carrier transport in a silicon photovoltaic cell, International journal of heat
p ro
[24] Y. Assoa, C. Menezo, G. Fraisse, R. Yezou, J. Brau, Study of a new concept of photovoltaic–thermal hybrid collector, Solar energy, 81(9) (2007) 1132-1143. [25] E. Skoplaki and J.A. Palyvos, On the temperature dependence of photovoltaic module
(2009) 614-624.
Pr e-
electrical performance: A review of efficiency/power correlations, Solar energy, 83(5)
[26] C.S. Solanki, Solar photovoltaics: fundamentals, technologies and applications, PHI Learning Pvt. Ltd., 2015.
[27] S. Chander and A. Purohit, A. Sharma, S. Nehra, M. Dhaka, A study on photovoltaic
(2015) 104-109.
al
parameters of mono-crystalline silicon solar cell with cell temperature, Energy Reports, 1
urn
[28] E. Cuce and P.M. Cuce, T. Bali, An experimental analysis of illumination intensity and temperature dependency of photovoltaic cell parameters, Applied Energy, 111 (2013) 374382.
[29] E. Radziemska, The effect of temperature on the power drop in crystalline silicon solar
Jo
cells, Renewable energy, 28(1) (2003) 1-12. [30] T.T. Chow, A review on photovoltaic/thermal hybrid solar technology, 87(2) (2010) 365379.
[31] E. Radziemska and C. Science, Thermal performance of Si and GaAs based solar cells and modules: a review, 29(5) (2003) 407-424.
Journal Pre-proof
[32] A. Sacco, L. Rolle, L. Scaltrito, E. Tresso, C.F. Pirri, Characterization of photovoltaic modules for low-power indoor application, 102 (2013) 1295-1302. .
eneses- odr gue , P.P. Horley, J. Gonzalez-Hernandez, Y.V. Vorobiev, P.N. Gorley,
of
[33]
Photovoltaic solar cells performance at elevated temperatures, 78(2) (2005) 243-250.
p ro
[34] A. Orioli and A. Di Gangi, A procedure to calculate the five-parameter model of crystalline silicon photovoltaic modules on the basis of the tabular performance data, 102 (2013) 1160-1177.
[35] F. Zaoui, A. Titaouine, M. Becherif, M. Emziane, A. Aboubou, A combined experimental
modules, 75 (2015) 373-380.
Pr e-
and simulation study on the effects of irradiance and temperature on photovoltaic
[36] D. Vittorini, N. Castellucci, R. Cipollone, Heat recovery potential and electrical performances in-field investigation on a hybrid PVT module, 205 (2017) 44-56. [37] M. Al-Addous, Z. Dalala, C.B. Class, F. Alawneh, H. Al-Taani, Performance analysis of
al
off-grid PV systems in the Jordan Valley, 113 (2017) 930-941.
urn
[38] U. Sajjad, M. Amer, H.M. Ali, A. Dahiya, N. Abbas, Cost effective cooling of photovoltaic modules to improve efficiency, (2019) 100420. [39] S. Alrwashdeh, Technology, Comparison among Solar Panel Arrays Production with a Different Operating Temperatures in Amman-Jordan, 9(6) (2018) 420-429.
Jo
[40] S.M. Ammar, N. Abbas, S. Abbas, H.M. Ali, I. Hussain, M.M. Janjua, U. Sajjad, A. Dahiya, M. Transfer, Condensing heat transfer coefficients of R134a in smooth and grooved multiport flat tubes of automotive heat exchanger: An experimental investigation, 134 (2019) 366-376. [41] T. Taner, Energy and exergy analyze of PEM fuel cell: A case study of modeling and
Journal Pre-proof
simulations, Energy, 143 (2018) 284–294. [42] T. Taner, Fundamentals of Renewable Energy and Applications Alternative Energy of the Fuel Cell Water
anagement, 5(3) (2015) 3–6.
of
Future : A Technical Note of PE
[43] T. Taner, The Micro-Scale Modeling by Experimental Study in PEM Fuel Cell, J. Therm.
p ro
Eng., 3 (5) (2017) 1515–1526.
[44] A. Ibrahim et al., Hybrid Photovoltaic Thermal (PV/T) Air and Water Based Solar Collectors Suitable for Building Integrated Applications, Solar Energy Research Institute, University Kebangsaan Malaysia, 43600, Bangi, Selangor, Malaysia, 5(5) (2009) 618-624.
(2010) 5179-5187.
Pr e-
[45] E. Sani et al., Carbon nanohorns-based nanofluids as direct sunlight absorbers, 18(5)
[46] K.V. Wong, O. D. Leon, Applications of nanofluids: current and future, 2 (2010) 519659. [47] M. Sardarabadi et al., S. Cells, Experimental study of using both ZnO/water nanofluid and phase change material (PCM) in photovoltaic thermal systems, 161 (2017) 62-69.
al
[48] A.H. Al-Waeli et al., An experimental investigation of SiC nanofluid as a base-fluid for a
urn
photovoltaic thermal PV/T system, 142 (2017) 547-558. [49] H.A. Hasan, K. Sopian, A.H. Jaaz, A.N. Al-Shamani, Experimental investigation of jet array nanofluids impingement in photovoltaic/thermal collector, 144 (2017) 321-334. [50] A.N. Al-Shamani, K. Sopian, H. Mohammed, S. Mat, M.H. Ruslan, A.M. Abed,
Jo
Enhancement heat transfer characteristics in the channel with Trapezoidal rib–groove using nanofluids, 5 (2015) 48-58. [51] S.M. Ammar, N. Abbas, S. Abbas, H.M. Ali, I. Hussain, M.M. Janjua, Experimental investigation of condensation pressure drop of R134a in smooth and grooved multiport flat tubes of automotive heat exchanger, M. Transfer, 130 (2019) 1087-1095.
Journal Pre-proof
[52] M. Ghadiri, M. Sardarabadi, M. Pasandideh-fard, A. Moghadam, Experimental investigation of a PVT system performance using nano ferrofluids, Energy Conversion
of
and Management, 103 (2015) 468-476. [53] J.J. Michael and S. Iniyan, Performance analysis of a copper sheet laminated photovoltaic
p ro
thermal collector using copper oxide–water nanofluid, 119 (2015) 439-451. [54] M. Sardarabadi, M. Hosseinzadeh, A. Kazemian, M. Passandideh-Fard, Experimental investigation of the effects of using metal-oxides/water nanofluids on a photovoltaic thermal system (PVT) from energy and exergy viewpoints, 138 (2017) 682-695.
Pr e-
[55] S. Hassani, R.A. Taylor, S. Mekhilef, R. Saidur, A cascade nanofluid-based PV/T system with optimized optical and thermal properties, 112 (2016) 963-975. [56] M. Sardarabadi and M. Passandideh-Fard, S.Z.J Heris, Experimental investigation of the effects of silica/water nanofluid on PV/T (photovoltaic thermal units), 66 (2014) 264-272. [57] S. Jaisankar, T. Radhakrishnan, K. Sheeba, Experimental studies on heat transfer and
al
friction factor characteristics of forced circulation solar water heater system fitted with
urn
helical twisted tapes, 83(11) (2009) 1943-1952. [58] C. Guo, J. Ji, W. Sun, J. Ma, W. He, Y. Wang, Numerical simulation and experimental validation of tri-functional photovoltaic/thermal solar collector, 87 (2015) 470-480. [59] F. Mebarek-Oudina and O. D. Makinde, Numerical Simulation of Oscillatory MHD
Jo
Natural Convection in Cylindrical Annulus: Prandtl Number Effect, Defect Diffus. Forum, 387 (2018) 417–427. [60] M. Alkasassbeh, Z. Omar, F. Mebarek-Oudina, J. Raza, and A. Chamkha, Heat transfer study of convective fin with temperature-dependent internal heat generation by hybrid block method, Heat Transf. - Asian Res., no. November 2018 (2019) 1225–1244.
Journal Pre-proof
[61] F. Mebarek-Oudina, Numerical modeling of the hydrodynamic stability in vertical annulus with heat source of different lengths, Eng. Sci. Technol. an Int. J., 20(4) (2017) 1324–
of
1333. [62] F. Mebarek-Oudina, Convective heat transfer of Titania nanofluids of different base fluids
135–147.
p ro
in cylindrical annulus with discrete heat source, Heat Transf. - Asian Res., 48(1) (2019)
[63] J. Reza, F. Mebarek-Oudina, and O.D. Makinde, MHD Slip Flow of Cu-Kerosene Nanofluid in a Channel with Stretching Walls Using 3-Stage Lobatto IIIA Formula, Defect
Pr e-
Diffus. Forum, 387 (2018) 51–62.
[64] P. Anand Kumar Lam and K. A. Prakash, Effect of Magnetic Field on Natural Convection and Entropy Generation in Al2O3/Water Nanofluid-Filled Enclosure With Twin Protruding Heat Sources, J. Therm. Sci. Eng. Appl., 9(2) (2017) 024502. [65] A. J. Chamkha and F. Selimefendigil, Forced convection of pulsating nanofluid flow over
al
a backward facing step with various particle shapes, Energies, 11(11) (2018) 1–19.
urn
[66] A. Chamkha and F. Selimefendigil, Numerical Analysis for Thermal Performance of a Photovoltaic Thermal Solar Collector with SiO2-Water Nanofluid, Appl. Sci., 8(11) (2018) 2223.
[67] F. Selimefendigil and H. F. Öztop, Forced convection and thermal predictions of pulsating
Jo
nanofluid flow over a backward facing step with a corrugated bottom wall, Int. J. Heat Mass Transf., 110 (2017) 231–247. [68] F. Selimefendigil, H. F. Öztop, and A. J. Chamkha, Analysis of mixed convection of nanofluid in a 3D lid-driven trapezoidal cavity with flexible side surfaces and inner cylinder, Int. Commun. Heat Mass Transf., 87 (2017) 40–51.
Journal Pre-proof
[69] F. Selimefendigil, H. F. Öztop, and N. Abu-Hamdeh, Mixed convection due to rotating cylinder in an internally heated and flexible walled cavity filled with SiO2-water
of
nanofluids: Effect of nanoparticle shape, Int. Commun. Heat Mass Transf., 71 (2016) 9– 19.
p ro
[70] F. Selimefendigil and H. F. Öztop, Corrugated conductive partition effects on MHD free convection of CNT-water nanofluid in a cavity, Int. J. Heat Mass Transf., 129 (2019) 265– 277.
[71] F. Selimefendigil and H. F. Öztop, Modeling and optimization of MHD mixed convection
Pr e-
in a lid-driven trapezoidal cavity filled with alumina–water nanofluid: Effects of electrical conductivity models, Int. J. Mech. Sci., 136 (2018) 264–278. [72] M. Amer and C.C. Wang, Review of defrosting methods, Renewable and Sustainable Energy Reviews, 73 (2017) 53-74.
[73] M. Amer and C.C. Wang, Review of active defrosting methods in refrigeration systems
al
(2016).
urn
[74] M. Amer and C.C. Wang, Review of passive defrosting surface methods in refrigeration systems (2015).
[75] M. Amer, M.R. Chen, M.C. Lu, and C.C. Wang, An experimental study of plastic heat exchangers applicable for dehumidification (2018).
Jo
[76] Y. Cui and Q. Zhu, Study of photovoltaic/thermal systems with MgO-water nanofluids flowing over silicon solar cells, in: 2012 Asia-Pacific Power and Energy Engineering Conference, IEEE, 2012, pp. 1-4. [77] M. Chandrasekar, S. Suresh, T. Senthilkumar, Passive cooling of standalone flat PV module with cotton wick structures, Energy Conversion and Management, 71 (2013) 43-
Journal Pre-proof
50. [78] Z. Xu, C. Kleinstreuer, Concentration photovoltaic–thermal energy co-generation system
of
using nanofluids for cooling and heating, Energy Conversion and Management, 87 (2014) 504-512.
p ro
[79] N. Karami, M. Rahimi, Heat transfer enhancement in a hybrid microchannel-photovoltaic cell using Boehmite nanofluid, M. Transfer, 55 (2014) 45-52.
[80] N. Karami, M. Rahimi, Heat transfer enhancement in a PV cell using Boehmite nanofluid, Management, 86 (2014) 275-285.
Pr e-
[81] Z. Said, M. Sabiha, R. Saidur, A. Hepbasli, N. Rahim, S. Mekhilef, T. Ward, Performance enhancement of a flat plate solar collector using titanium dioxide nanofluid and polyethylene glycol dispersant, 92 (2015) 343-353.
[82] D. Lelea, D.G. Calinoiu, G. Trif-Tordai, A.E. Cioabla, I. Laza, F. Popescu, The hybrid nanofluid/microchannel cooling solution for concentrated photovoltaic cells, in: AIP
al
Conference Proceedings, AIP, 2015, pp. 122-128.
urn
[83] S. Saroha, T. Mittal, P.J. Modi, V. Bhalla, V. Khullar, H. Tyagi, R.A. Taylor, T.P. Otanicar, Theoretical analysis and testing of nanofluids-based solar photovoltaic/thermal hybrid collector, 137(9) (2015) 091015. [84] A. Noghrehabadi, E. Hajidavalloo, M. Moravej, Experimental investigation of efficiency
Jo
of square flat-plate solar collector using SiO2/water nanofluid, Case Studies in Thermal Engineering, 8 (2016) 378-386. [85] M. Sardarabadi and M. Passandideh-Fard, Experimental and numerical study of metaloxides/water nanofluids as coolant in photovoltaic thermal systems (PVT), Solar Energy Materials and Solar Cells, 157 (2016) 533-542.
Journal Pre-proof
[86] A.N. Al-Shamani, K. Sopian, S. Mat, H.A. Hasan, A.M. Abed, M.H. Ruslan, Experimental studies of rectangular tube absorber photovoltaic thermal collector with various types of
of
nanofluids under the tropical climate conditions, Energy Conversion and Management, 124 (2016) 528-542.
p ro
[87] O. Rejeb, M. Sardarabadi, C. Ménézo, M. Passandideh-Fard, M.H. Dhaou, A. Jemni, Numerical and model validation of uncovered nanofluid sheet and tube type photovoltaic thermal solar system, Energy Conversion and Management, 110 (2016) 367-377. [88] A. Radwan, M. Ahmed, S. Ookawara, Performance enhancement of concentrated
Pr e-
photovoltaic systems using a microchannel heat sink with nanofluids, Energy Conversion and Management, 119 (2016) 289-303.
[89] O.Z. Sharaf and M.F. Orhan, Thermodynamic analysis and optimization of denselypacked receiver assembly components in high-concentration CPVT solar collectors, Energy Conversion and Management, 121 (2016) 113-144.
al
[90] S. Soltani, A. Kasaeian, H. Sarrafha, D. Wen, An experimental investigation of a hybrid
urn
photovoltaic/thermoelectric system with nanofluid application, Solar Energy, 155 (2017) 1033-1043.
[91] A.H. Al-Waeli, M.T. Chaichan, H.A. Kazem, K. Sopian, Comparative study to use nano(Al2O3, CuO, and SiC) with water to enhance photovoltaic thermal PV/T collectors,
Jo
Energy Conversion and Management, 148 (2017) 963-973. [92] A.H. Al-Waeli, K. Sopian, M.T. Chaichan, H.A. Kazem, A. Ibrahim, S. Mat, M.H. Ruslan, Evaluation of the nanofluid and nano-PCM based photovoltaic thermal (PVT) system: An experimental study, Energy Conversion and Management, 151 (2017) 693-708. [93] H.A. Hasan, K. Sopian, A.H. Jaaz, A.N. Al-Shamani, Experimental investigation of jet
Journal Pre-proof
array nanofluids impingement in photovoltaic/thermal collector, Solar Energy, 144 (2017) 321-334.
of
[94] M. Sardarabadi, M. Passandideh-Fard, M.-J. Maghrebi, M. Ghazikhani, Experimental study of using both ZnO/water nanofluid and phase change material (PCM) in
p ro
photovoltaic thermal systems, Solar Energy Materials and Solar Cells, 161 (2017) 62-69. [95] F. Yazdanifard, E. Ebrahimnia-Bajestan, M. Ameri, Performance of a parabolic trough concentrating photovoltaic/thermal system: effects of flow regime, design parameters, and using nanofluids, Energy Conversion and Management, 148 (2017) 1265-1277.
Pr e-
[96] M. Alghoul, M. Sulaiman, B. Azmi, M.A. Wahab, Review of materials for solar thermal collectors, Anti-Corrosion methods and materials, 52(4) (2005) 199-206. [97] B.C. Gates, J.R. Katzer, G.C. Schuit, Chemistry of catalytic processes, McGraw-Hill College, 1979.
[98] Y.-j. Hwang, J. Lee, C. Lee, Y. Jung, S. Cheong, C. Lee, B. Ku, S. Jang, Stability and
al
thermal conductivity characteristics of nanofluids, Thermochimica Acta, 455(1-2) (2007) 70-74.
urn
[99] J. Shackelford and C. William, Materials Science and Engineering Handbook (3rd Edition), in Taylor & Francis (2001). [100] S.H. Kim, S.R. Choi, D. Kim, Thermal conductivity of metal-oxide nanofluids: particle
Jo
size dependence and effect of laser irradiation, Journal of Heat Transfer, 129(3) (2007) 298-307.
[101] M. Mehrali, E. Sadeghinezhad, M.M. Rashidi, A.R. Akhiani, S.T. Latibari, M. Mehrali, H.S.C. Metselaar, Experimental and numerical investigation of the effective electrical conductivity of nitrogen-doped graphene nanofluids, Journal of Nanoparticle Research,
Journal Pre-proof
17(6) (2015) 267. [102] G.A. Slack, Thermal Conductivity of MgO, Al2O3, Mg Al2O4, and Fe3O4 Crystals from 3°
of
to 300° K, Physical Review, 126(2) (1962) 427. [103] J.A. ean, Lange’s handbook of chemistry 15th ed, in, McGraw-Hill, New York, 1999.
p ro
[104] S. Choi, Z. Zhang, W. Yu, F. Lockwood, E. Grulke, Anomalous thermal conductivity enhancement in nanotube suspensions, Applied physics letters, 79(14) (2001) 2252-2254. [105] A.A. Balandin, Thermal properties of graphene and nanostructured carbon materials, Nature Materials, 10(8) (2011) 569.
Pr e-
[106] R. Wei, S. Song, K. Yang, Y. Cui, Y. Peng, X. Chen, X. Hu, X. Xu, Thermal conductivity of 4H-SiC single crystals, Journal of Applied Physics, 113(5) (2013) 053503. [107] . Ota, M. Mizutani, K. Kido, T. Kawai, H. Kihou, High thermal conductive boehmite and method for manufacturing same, in, Google Patents, 2015. [108] S. Lee, S.-S. Choi, S. Li, and, J. Eastman, Measuring thermal conductivity of fluids
al
containing oxide nanoparticles, Journal of Heat transfer, 121(2) (1999) 280-289.
urn
[109] J. Eastman, U. Choi, S. Li, L. Thompson, S. Lee, Enhanced thermal conductivity through the development of nanofluids, MRS Online Proceedings Library Archive, 457 (1996). [110] H. Ali, T. Miqdam, A. Hussein, H. Abdulrasool, A. Najah, experimental investigation of SiC nanofluid as a base-fluid for a photovoltaic thermal PV/T system, Energy conversion
Jo
and management, 2017.
[111] M. Chen, Y. He, J. Zhu, D.R. Kim, Enhancement of photo-thermal conversion using gold nanofluids with different particle sizes, Energy conversion and management, 112 (2016) 21-30. [112] E.P. Bandarra Filho, O.S.H. Mendoza, C.L.L. Beicker, A. Menezes, D. Wen, Experimental
Journal Pre-proof
investigation of a silver nanoparticle-based direct absorption solar thermal system, Energy Conversion and Management, 84 (2014) 261-267.
of
[113] T. Sokhansefat, A. Kasaeian, F. Kowsary, Heat transfer enhancement in parabolic trough collector tube using Al2O3/synthetic oil nanofluid, Renewable and Sustainable Energy
p ro
Reviews, 33 (2014) 636-644.
[114] J.-H. Lee, K.S. Hwang, S.P. Jang, B.H. Lee, J.H. Kim, S.U. Choi, C.J. Choi, Effective viscosities and thermal conductivities of aqueous nanofluids containing low volume
2651-2656.
Pr e-
concentrations of Al2O3 nanoparticles, Int. J. of Heat and Mass Transfer, 51(11-12) (2008)
[115] L. Godson, B. Raja, D.M. Lal, S. Wongwises, Experimental investigation on the thermal conductivity and viscosity of silver-deionized water nanofluid, Experimental Heat Transfer, 23(4) (2010) 317-332.
[116] H.A. Mintsa, G. Roy, C.T. Nguyen, D. Doucet, New temperature dependent thermal
al
conductivity data for water-based nanofluids, Int. J. of thermal sciences, 48(2) (2009) 363-
urn
371.
[117] S. Wannapakhe, S. Rittidech, B. Bubphachot, O. Watanabe, Heat transfer rate of a closedloop oscillating heat pipe with check valves using silver nanofluid as working fluid, Journal of Mechanical Science and Technology, 23(6) (2009) 1576-1582.
Jo
[118] Q. Li, Y.-M. Xuan, Flow and Heat Transfer Performances of Nanofluids Inside Small Hydraulic Diameter Flat Tube, Journal of Engineering Thermophysics, 25(2) (2004) 305307.
[119] S.-W. Kang, W.-C. Wei, S.-H. Tsai, S.-Y. Yang, Experimental investigation of silver nanofluid on heat pipe thermal performance, Applied Thermal Engineering, 26(17-18) (2006)
Journal Pre-proof
2377-2382. [120] D. Zhou, Heat transfer enhancement of copper nanofluid with acoustic cavitation,
of
International Journal of Heat and Mass Transfer, 47(14-16) (2004) 3109-3117. [121] P. Sharma, I.-H. Baek, T. Cho, S. Park, K.B. Lee, Enhancement of thermal conductivity of
p ro
ethylene glycol based silver nanofluids, Powder Technology, 208(1) (2011) 7-19. [122] H.E. Patel, T. Sundararajan, S.K. Das, An experimental investigation into the thermal conductivity enhancement in oxide and metallic nanofluids, Journal of Nanoparticle Research, 12(3) (2010) 1015-1031.
Pr e-
[123] G. Paul, T. Pal, I. Manna, Thermo-physical property measurement of nano-gold dispersed water based nanofluids prepared by chemical precipitation technique, Journal of colloid and interface science, 349(1) (2010) 434-437.
[124] C. Tsai, H. Chien, P. Ding, B. Chan, T. Luh, P. Chen, Effect of structural character of gold
(2004) 1461-1465.
al
nanoparticles in nanofluid on heat pipe thermal performance, Materials Letters, 58(9)
urn
[125] H.-T. Chien, C.-I. Tsai, P.-H. Chen, P.-Y. Chen, Improvement on thermal performance of a disk-shaped miniature heat pipe with nanofluid, in: Fifth International Conference on Electronic Packaging Technology Proceedings, 2003. ICEPT2003., IEEE, 2003, pp. 389391.
Jo
[126] H.E. Patel, S.K. Das, T. Sundararajan, A. Sreekumaran Nair, B. George, T. Pradeep, Thermal conductivities of naked and monolayer protected metal nanoparticle based nanofluids: Manifestation of anomalous enhancement and chemical effects, Applied Physics Letters, 83(14) (2003) 2931-2933. [127] K. Sinha, B. Kavlicoglu, Y. Liu, F. Gordaninejad, O.A. Graeve, A comparative study of
Journal Pre-proof
thermal behavior of iron and copper nanofluids, Journal of Applied Physics, 106(6) (2009) 064307.
of
[128] M.-S. Liu, M.C.-C. Lin, C. Tsai, C.-C. Wang, Enhancement of thermal conductivity with Cu for nanofluids using chemical reduction method, Int. J. of Heat and Mass Transfer,
p ro
49(17-18) (2006) 3028-3033.
[129] T.-K. Hong, H.-S. Yang, C. Choi, Study of the enhanced thermal conductivity of Fe nanofluids, Journal of Applied Physics, 97(6) (2005) 064311.
IL (US), 1999.
Pr e-
[130] J. Eastman, Novel thermal properties of nanostructured materials, Argonne National Lab.,
[131] M.H. Esfe, S. Saedodin, S. Wongwises, D. Toghraie, An experimental study on the effect of diameter on thermal conductivity and dynamic viscosity of Fe/water nanofluids, Journal of Thermal Analysis and Calorimetry, 119(3) (2015) 1817-1824. [132] K. Hong, T.-K. Hong, H.-S. Yang, Thermal conductivity of Fe nanofluids depending on
al
the cluster size of nanoparticles, Applied Physics Letters, 88(3) (2006) 031901.
urn
[133] W. Yu, H. Xie, L. Chen, Y. Li, Investigation of thermal conductivity and viscosity of ethylene glycol based ZnO nanofluid, Thermochimica Acta, 491(1-2) (2009) 92-96. [134] X. Wang, X. Xu, S.U. S. Choi, Thermal conductivity of nanoparticle-fluid mixture, Journal of thermophysics and heat transfer, 13(4) (1999) 474-480.
Jo
[135] G.-J. Lee, C.K. Kim, M.K. Lee, C.K. Rhee, S. Kim, C. Kim, Thermal conductivity enhancement of ZnO nanofluid using a one-step physical method, Thermochimica Acta, 542 (2012) 24-27.
[136] J.-Y. Jung, H.-S. Oh, H.-Y. Kwak, Forced convective heat transfer of nanofluids in microchannels, in: ASME 2006 International Mechanical Engineering Congress and
Journal Pre-proof
Exposition, American Society of Mechanical Engineers, 2006, pp. 327-332. [137] H.M. Ali, H. Ali, H. Liaquat, H.T.B. Maqsood, M.A. Nadir, Experimental investigation of
of
convective heat transfer augmentation for car radiator using ZnO–water nanofluids, Energy, 84 (2015) 317-324.
p ro
[138] C. Choi, H. Yoo, J. Oh, Preparation and heat transfer properties of nanoparticle-intransformer oil dispersions as advanced energy-efficient coolants, Current Applied Physics, 8(6) (2008) 710-712.
[139] J. Jeong, C. Li, Y. Kwon, J. Lee, S.H. Kim, R. Yun, Particle shape effect on the viscosity
(2013) 2233-2241
Pr e-
and thermal conductivity of ZnO nanofluids, International journal of refrigeration, 36(8)
[140] S. Murshed, K. Leong, C. Yang, Enhanced thermal conductivity of TiO2—water based nanofluids, International Journal of thermal sciences, 44(4) (2005) 367-373. [141] L.S. Sundar, M.K. Singh, A.C. Sousa, Investigation of thermal conductivity and viscosity
al
of Fe3O4 nanofluid for heat transfer applications, International communications in heat
urn
and mass transfer, 44 (2013) 7-14.
[142] K. Leong, R. Saidur, T. Mahlia, Y. Yau, Performance investigation of nanofluids as working fluid in a thermosyphon air preheater, International Communications in Heat and Mass Transfer, 39(4) (2012) 523-529.
Jo
[143] J. Philip, P. Shima, B. Raj, Enhancement of thermal conductivity in magnetite based nanofluid due to chainlike structures, Applied Physics Letters, 91(20) (2007) 203108. [144] P. Naphon, L. Nakharintr, Nanofluid jet impingement heat transfer characteristics in the rectangular mini-fin heat sink, Journal of Engineering Physics and Thermophysics, 85(6) (2012) 1432-1440.
Journal Pre-proof
[145] A. Gavili, F. Zabihi, T.D. Isfahani, J. Sabbaghzadeh, The thermal conductivity of water base ferrofluids under magnetic field, Experimental Thermal and Fluid Science, 41 (2012)
of
94-98. [146] W. Duangthongsuk, S. Wongwises, Heat transfer enhancement and pressure drop
p ro
characteristics of TiO2–water nanofluid in a double-tube counter flow heat exchanger, International Journal of Heat and Mass Transfer, 52(7-8) (2009) 2059-2067. [147] W. Yu, H. Xie, L. Chen, Y. Li, Enhancement of thermal conductivity of kerosene-based Fe3O4 nanofluids prepared via phase-transfer method, Colloids and Surfaces A:
Pr e-
Physicochemical and engineering aspects, 355(1-3) (2010) 109-113. [148] Y. Yang, Z.G. Zhang, E.A. Grulke, W.B. Anderson, G. Wu, Heat transfer properties of nanoparticle-in-fluid dispersions (nanofluids) in laminar flow, International Journal of Heat and Mass Transfer, 48(6) (2005) 1107-1116.
[149] D.J. Faulkner, D.R. Rector, J.J. Davidson, R. Shekarriz, Enhanced heat transfer through
al
the use of nanofluids in forced convection, in: ASME 2004 International Mechanical
urn
Engineering Congress and Exposition, American Society of Mechanical Engineers, 2004, pp. 219-224.
[150] S. Ladjevardi, A. Asnaghi, P. Izadkhast, A. Kashani, Applicability of graphite nanofluids in direct solar energy absorption, Solar Energy, 94 (2013) 327-334.
Jo
[151] M.-S. Liu, M.C.-C. Lin, I.-T. Huang, C.-C. Wang, Enhancement of thermal conductivity with carbon nanotube for nanofluids, International Communications in Heat and Mass Transfer, 32(9) (2005) 1202-1210. [152] Z. Luo, C. Wang, W. Wei, G. Xiao, M. Ni, Performance improvement of a nanofluid solar collector based on direct absorption collection (DAC) concepts, International Journal of
Journal Pre-proof
Heat and Mass Transfer, 75 (2014) 262-271. [153] D. Wen, Y. Ding, Effective thermal conductivity of aqueous suspensions of carbon
of
nanotubes (carbon nanotube nanofluids), Journal of Thermophysics and Heat Transfer, 18(4) (2004) 481-485.
p ro
[154] B. Wang, X. Wang, W. Lou, J. Hao, Thermal conductivity and rheological properties of graphite/oil nanofluids, Colloids and Surfaces A: Physicochemical and Engineering Aspects, 414 (2012) 125-131.
[155] H. Xie, H. Lee, W. Youn, M. Choi, Nanofluids containing multiwalled carbon nanotubes
Pr e-
and their enhanced thermal conductivities, Journal of Applied Physics, 94(8) (2003) 49674971.
[156] X. Li, C. Zou, X. Lei, W. Li, Stability and enhanced thermal conductivity of ethylene glycol-based SiC nanofluids, Int. J. Heat and Mass Transfer, 89 (2015) 613-619. [157] K.M. Kim, Y.S. Jeong, I.G. Kim, I.C. Bang, Comparison of thermal performances of
al
water-filled, SiC nanofluid-filled and SiC nanoparticles-coated heat pipes, International
urn
Journal of Heat and Mass Transfer, 88 (2015) 862-871. [158] P. Gunnasegaran, M.Z. Abdullah, M.Z. Yusoff, R. Kanna, Heat transfer in a loop heat pipe using diamond-H2O Nanofluid, Heat Transfer Engineering, 39(13-14) (2018) 1117-1131. [159] M. Ghanbarpour, N. Nikkam, R. Khodabandeh, M.S. Toprak, Improvement of heat
Jo
transfer characteristics of cylindrical heat pipe by using SiC nanofluids, Applied Thermal Engineering, 90 (2015) 127-135. [160] T.S. Aun, M.Z. Abdullah, P. Gunnasegaran, Influence of low concentration of diamond water nanofluid in loop heat pipe, Int. J. Heat Technol, 35 (2017) 539-548. [161] S. Sargunanathan, A. Elango, S.T. Mohideen, Performance enhancement of solar
Journal Pre-proof
photovoltaic cells using effective cooling methods: A review, Renewable and Sustainable Energy Reviews, 64 (2016) 382-393.
of
[162] T. Ho, S.S. Mao, R. Greif, Improving efficiency of high‐concentrator photovoltaics by cooling with two‐phase forced convection, International Journal of Energy Research,
p ro
34(14) (2010) 1257-1271.
[163] Z. Said, M. Sabiha, R. Saidur, A. Hepbasli, N. Rahim, S. Mekhilef, T. Ward, Performance enhancement of a flat plate solar collector using titanium dioxide nanofluid and polyethylene glycol dispersant, Journal of Cleaner Production, 92 (2015) 343-353.
Pr e-
[164] M. Sheikholeslami, M. Rashidi, D. Ganji, Effect of non-uniform magnetic field on forced convection heat transfer of Fe3O4–water nanofluid, Computer Methods in Applied Mechanics and Engineering, 294 (2015) 299-312.
[165] K. Anoop, T. Sundararajan, S.K. Das, Effect of particle size on the convective heat transfer in nanofluid in the developing region, International Journal of Heat and Mass
al
Transfer, 52(9-10) (2009) 2189-2195.
urn
[166] Y. Hu, H. Li, Y. He, Z. Liu, Y. Zhao, Effect of nanoparticle size and concentration on boiling performance of SiO2 nanofluid, Int. J. Heat and Mass Transf, 107 (2017) 820-828. [167] T. Mittal, S. Saroha, V. Bhalla, V. Khullar, H. Tyagi, R.A. Taylor, T.P. Otanicar, Numerical study of solar photovoltaic/thermal (PV/T) hybrid collector using nanofluids, in: ASME
Jo
2013 4th international conference on micro/nanoscale heat and mass transfer, American Society of Mechanical Engineers, 2013, pp. V001T002A007-V001T002A007. [168] M. Faizal, R. Saidur, S. Mekhilef, M. Alim, Energy, economic and environmental analysis of metal oxides nanofluid for flat-plate solar collector, Energy Conversion and Management, 76 (2013) 162-168.
Journal Pre-proof
[169] Z. Xu, C. Kleinstreuer, Computational analysis of nanofluid cooling of high concentration photovoltaic cells, Journal of Thermal Science and Engineering Applications, 6(3) (2014)
of
031009. [170] S. Ravikumar, Elementary assessments and simulations based proposals for new heat
internal condensing flows, 2015.
p ro
transfer correlations and flow regime maps for annular/stratified regime of shear driven
[171] Y. Khanjari, F. Pourfayaz, A. Kasaeian, Numerical investigation on using of nanofluid in a
(2016) 263-278.
Pr e-
water-cooled photovoltaic thermal system, Energy Conversion and Management, 122
[172] S. Hassani, R. Saidur, S. Mekhilef, R.A. Taylor, Environmental and exergy benefit of nanofluid-based hybrid PV/T systems, Energy Conversion and Management, 123 (2016) 431-444.
[173] W. An, J. Wu, T. Zhu, Q. Zhu, Experimental investigation of a concentrating PV/T
al
collector with Cu9S5 nanofluid spectral splitting filter, Applied Energy, 184 (2016) 197-
urn
206.
[174] A. Noghrehabadi, E. Hajidavalloo, M. Moravej, An experimental investigation on the performance of a symmetric conical solar collector using SiO2/water nanofluid, Transp Phenom Nano Micro Scales, 5(1) (2016) 23-29.
Jo
[175] D. Das, P. Kalita, Performance Improvement of a Novel Flat Plate Photovoltaic Thermal (PV/T) System Using Copper Oxide Nanoparticle—Water as Coolant, in: International Conference on Nano for Energy and Water, Springer, 2017, pp. 97-104. [176] H. Hussein, A. Numan, A. Abdulmunem, An Experimental Investigation on the Performance Enhancement of Photovoltaic/Thermal Panel Using a Tracking System and
Journal Pre-proof
Nanofluid (Al2O3), Engineering and Technology Journal, 35(5 Part (A) Engineering) (2017) 493-508.
of
[177] M.S. Ebaid, A.M. Ghrair, M. Al-Busoul, Experimental investigation of cooling photovoltaic (PV) panels using (TiO2) nanofluid in water-polyethylene glycol mixture and
and Management, 155 (2018) 324-343.
p ro
(Al2O3) nanofluid in water-cetyltrimethylammonium bromide mixture, Energy Conversion
[178] S. Srivastava, K. Reddy, Simulation studies of thermal and electrical performance of solar
213.
Figure captions
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linear parabolic trough concentrating photovoltaic system, Solar Energy, 149 (2017) 195-
A schematic diagram of a typical PV/T system.
Figure 2
Solar cell temperature (Tsc) variation relation with wind velocity (Vw) at different geometric concentration ratios (CR) [88].
Figure 3
Solar cell temperature variation at different velocities (Reynolds number) with varying CR and different nanofluids at (a) 1 vol% nanoparticle (b) 4 vol% nanoparticle [88].
Figure 4
Solar Cell temperature variation for different volume fractions of nanoparticles at varying Reynolds numbers (a) CR=10 (b) CR=20 (c) CR=40 [88, 161, 162].
Figure 5
The temperature gradient of cooling and without cooling with different weight concentrations of Boehmite using different channels [80].
Figure 6
Comparison of variation of thermal conductivity of nanoparticle with respect to (a) Nanoparticle fraction (b) Temperature [78, 116, 161, 162].
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Figure 1
Figure 7
Thermal conductivity enhancement percentage of gold water based nanofluid (a) with a variation of volume fraction (b) with a variety of particle size at 0.00026 volume fraction [78].
Figure 8
Thermal conductivity of Fe and Cu nanofluids at different volume fractions [82].
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Heat transfer enhancement of Cu nanofluids as a function of volume fraction (a) thermal conductivity data (b) viscosity data [163].
Figure 10
Thermal conductivity enhancement as a function of volume fraction for ZnOEG nanofluid [87].
Figure 11
The thermal conductivity ratio (ke/kf) and the percentage of enhancement as a function of the external magnetic field at different volume fractions of Fe3O4 [164].
Figure 12 Figure 13
The absorbed energy of solar radiation for different graphite nanofluids [118]. Enhancement in thermal conductivity of Al2O3 nanofluid at different volume fractions and particle sizes [3].
Figure 14
Comparison of Cu and Al nanofluid at 1% volume fraction and 80 nm particle size [3].
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Figure 9
Nanoparticle size effect on heat transfer [165].
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Figure 15
Nanoparticle size effect on heat flux and heat transfer [166]. The operating temperature effect on the heat transfer rate of CLOHP/CV at 25 aspect ratio [35].
Figure 18
The measured value of thermal resistance of heat pipe with nanofluid (a) at 1 ppm (b) at 10 ppm [37].
Tables captions
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Figure 16 Figure 17
Types of channels configurations used for effective cooling with reference to nanofluids.
Table 2
Various nanoparticles thermal conductivities at 25 °C.
Table 3
Nanoparticle effect on different system’s thermal performance.
Table 4
Applications of nanofluids as a coolant in photovoltaic systems.
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Table 1