- Email: [email protected]
A review of material and coatings in solar collectors
Materials Today: Proceedings xxx (xxxx) xxx
Contents lists available at ScienceDirect
Materials Today: Proceedings journal homepage: www.elsevier.com/locate/matpr
A review of material and coatings in solar collectors R. Suresh Isravel ⇑, S. Saravanan, V. Vijayan Department of Mechanical Engineering, K. Ramakrishnan College of Technology, Trichy 621112, India
a r t i c l e
i n f o
Article history: Received 22 May 2019 Accepted 17 June 2019 Available online xxxx Keywords: Reflector Receivers Selective coating Absorbtance Reflectance
a b s t r a c t Performance improvement of the solar thermal power generation systems can be improved by the choosing the suitable materials and the coatings of the reflectors and receiver. The conventional reflector such as glass and the advanced reflector such as polymers based reflectors are discussed. The coating used in this types of Reflectors for the coatings for the protection from the dirt and corrosion are mentioned. Receiver of the solar collector should have the high specular absorbtance. To improve the absorbtance solar selective coatings have been used by the researchers. Ó 2019 Elsevier Ltd. All rights reserved. Peer-review under responsibility of the scientific committee of the International Conference on Recent Trends in Nanomaterials for Energy, Environmental and Engineering Applications
1. Introduction
2. Materials and coatings in Reflector
Energy is the important requirement for the developing the economy of the country. Nowadays the availability of the fossil fuels were diminishing gradually. So the energy Engineers are concentrating more on the renewable energy resources such as solar and wind energy. Energy generation using solar power is classified into two methods such as solar thermal power generation and solar photo voltaics. These two methods have their own advantage and disadvantage [1]. India is blessed with a very vast solar power. Most of the places of the country receive the sunlight about 300 days. Direct normal Irradiance value of the sunshine is 4– 6.5 kWh/m2/day. There are four types of concentrating solar power technologies available globally; they are Parabolic trough collector, parabolic dish, Linear Fresnel collector and solar tower system. The concept of this system is different but the materials used in these systems are same [2]. Two main things in the concentrating solar power technologies is the Reflector and receiver. Numerous materials have been investigated for use as coatings in Reflector and Receiver. In order to produce one or more desirable properties including: anti-reflection, better transmission, reducing build-up of organic dirt, resistance to abrasion, resistance to oxidation or corrosion and solar selective absorption [7] (Fig. 1).
The Glass mirrors are the best baseline reflectors for the solar parabolic collector because it has high reflectance, durability and degradation of reflectivity is modest over the concentrator life time. But the limitations of the glass mirrors include weight, fragility and expensive in terms of cost. To overcome these limitations, manufacturers can use the polymer mirrors because it is flexible, low weight and less expensive. But polymer mirrors have the limited lifetime (Fig. 2). The above two mentioned mirrors are the basic types of reflectors. The technology advancements in manufacturing of reflectors resulted in advanced reflector materials. They are Directly Deposited Reflector Material, Silvered Teflon Reflector Material, Polymer MultiLayer Reflector Material (Fig. 3). Directly Deposited Reflector Material- the order of different the layers are Top coat, Reflective layer, Levelizing layer, Substrate. This types of reflector reduces the need of the lamination and adhesives. Silvered Teflon Reflector Material-The advantages of such a mirror include the fact that TeflonTM is an inherently weatherable and nonhygroscopic material, has good barrier properties, and exhibits a low surface energy which may reduce soil retention. Polymer MultiLayer Reflector Material the order of different the layers Si3N4 and-or PML – Ag – Polymer Multi layer – Substrate. The advantage of this type is it has high production capacity thereby reduces the production cost. One of the most promising ways to reduce the cost of solar mirrors is to metallize an appropriate and inexpensive substrate mate-
⇑ Corresponding author. E-mail address: [email protected] (R. Suresh Isravel).
https://doi.org/10.1016/j.matpr.2019.06.644 2214-7853/Ó 2019 Elsevier Ltd. All rights reserved. Peer-review under responsibility of the scientific committee of the International Conference on Recent Trends in Nanomaterials for Energy, Environmental and Engineering Applications
Please cite this article as: R. Suresh Isravel, S. Saravanan and V. Vijayan, A review of material and coatings in solar collectors, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.06.644
2
R. Suresh Isravel et al. / Materials Today: Proceedings xxx (xxxx) xxx
Fig. 1. Parabolic trough collector [1].
Fig. 3. Structure of Metalized polymer reflectors [5].
dioxide and water. This exclusive property of TiO2 has led to use in the reflector of the concentrating solar power system [7]. Reflectance is increased from 0.4 to 0.6 for solar collector black paint with nickel coating. Nickel nanoparticle was deposited by electrodeposition method [13]. Reflectivity is compared for chrome plate 316(L) and aluminium composite panel. Results showed that aluminum composite panel has high reflectivity [20]. 3. Materials and coatings in Receiver Fig. 2. Linear Fresnel collector [1].
rial such as a polyethylene terephthalate (PET) film and then overcoat the reflector with an abrasion-resistant, durable, protective top layer. Cost of the solar reflectors can be eliminated by using low cost substrate material such as polyethylene terephthalate and then overcost the reflector with the abrasion- resistant top layer [2]. Basically three layers are present in the solar reflectors they are Reflector material, substrate material and structural support. Reflector material should have good specular reflectance which is defined as the degree to which a mirror is capable of transferring directed radiation to a target receiver surface. Microroughness of a mirror surface can result in scattering (loss) of light. Conventionally glass mirrors are used but Metallized polymer reflector materials is less expensive than the glass mirrors. Solar coatings were used in reflectors to protect the reflectors from the corrosion, dirt and from the reflection losses. Silver and aluminium coating has been given to the reflectors of the concentrating solar power technologies because they have the higher reflectivity of 88% and 98% respectively. To protect this layer from the corrosions sacrificial copper anode is coated. To address the soiling and cleaning issues of concentrating solar power technologies Titanium dioxide (TiO2) in has photocatalytic properties. Photons with energies greater than the band gap of TiO2 create electron-hole pairs which in the presence of air can speed up or catalyse the conversion of organic matter to carbon
The absorbtance of the Aluminium solar receiver was improved by C/NiO coatings has been deposited by the spray coating technique. Results show that absorbtance has been increased upto 90%. This type of reflector will be used for the low cost domestic water heating system [6]. Light absorption property of the receiver depends on the electronic structure and wave length of the light coming from the sun. The design process of selecting solar coating of the solar thermal power system is much more complicated than the design of the anti reflection coating and the dirt protection coating. The solar selective coating should be chemically and structurally stable for the variable range of the temperatures, should have comply the rules of the local administration, low cost and it should have good adhesion to the receiver tubes. Solar selective coatings are classified into: intrinsic; semiconductor-metal; multi-layer; cermets or metal-dielectric composite materials; and finally textured surfaces [7]. High entropy alloys may be used for frame of solar collector since it has intense strength and hardness and superior corrosion resistance [9].Si02 Nanoparticle is synthesized by sol-gel technique. This can be used for the preparation of nanofluid for the improvement of heat transfer in the solar collector [10]. Aluminium carbide reinforced with silicon carbide and titanium can be used as the supporting frame in solar collector[11].Analysed the parameters for improving the surface finish because good surface finish is needed for solar collectors[12]. Black chrome coating has high absorbtance when compared to matt black painting and black nickel-chrome painting[14]. Iron sheet and black ABRO spray
Please cite this article as: R. Suresh Isravel, S. Saravanan and V. Vijayan, A review of material and coatings in solar collectors, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.06.644
R. Suresh Isravel et al. / Materials Today: Proceedings xxx (xxxx) xxx
to have the highest absorbtance when compared with blackboard paint and commercial black paint[15]. Mild steel absorber tube is coated with nickel and chromium and it is found that mild steel coated with nickel has higher absorbtance[16]. Simulation software was used for the estimate the selectivity of the coatings for solar collectors[17].Black chrome, Black Nickel, Black cobalt, Thickness-sensitive spectrally selective (TSSS) paint coatings and Black-colored CuFeMnO4 spinel powders are the various coatings used in the receiver side of solar parabolic trough collector[18]. Computer-aided design software was used modeling a solarselective coating composed of materials stable at high temperature[19]. 4. Conclusion In this review articles the reflector and the receiver of the concentrating solar power systems have been discussed. Different types of coatings materials used in the reflectors for the purpose of protection of the solar collector and for the improvement of the optical performance of the collector is listed. Also the materials available for the reflectors as well as the receivers are also listed. Then the advance solar collectors used in industries and the solutions the for preventing the accumulation of the dust in the solar collectors have been discussed. References [1] Rajesh Kumar, J. Mat Sci. Mech. Eng. (JMSME) 2 (6) (2015) 41–44. [2] Jibran Khan, H. Mudassar, Arsalan, Renew. Sust. Energy Rev. 55 (2016) 414– 425.
3
[5] Gary Jorgensen National Renew Energy Lab 1617, Cole Boulevard Golden, CO 80401. [6] Georgios Polizos, Kyle Winter, Michael J. Lance, Harry M. Meyer, Beth L. Armstrong, Daniel A. Schaeffer, John T. Simpson, Scott R. Hunter, Panos G. Datskos, App. Surf. Sci. 292 (2014) 563–569. [7] Carol Atkinson, Chris L. Sansom, Heather J. Almond, Chris P. Shaw, Renew. Sust. Energy Rev. 45 (2015) 113–122. [9] A.M. Rameshbabu, P. Parameshwaran, V. Vijayan, R. Panner, J. Mech. Behav. Mater. 26 (2017) 127–132. [10] S. Saravanan, A. Godwin Antony, V. Vijayan, M. Loganathan, S. Baskar, Int. J. Mech., Eng. Technol. 1 (2019) 785–790. [11] A. Godwin Antony, V. Vijayan, S. Saravanan, S. Baskar, M. Loganathan, Int. J. Mech., Eng. Technol. 9 (2018) 681–691. [12] S. Dinesh, A. Godwin Antony, K. Rajaguru, V. Vijayan, Mech. Mech. Eng. 21 (2017) 17–28. [13] J. El Nady, A.B. Kashyout, Sh. Ebrahim, M.B. Soliman, Alexandria Eng. J. 55 (2) (2016) 723–729. [14] Alibakhsh Kasaeian, Samaneh Daviran, Reza Danesh, Azarian Int. J. Renewable Energy Res.-IJRER 6 (2016) 15–20. [15] Fana Filli, Petros Gebray, Ashenafi Kebedom, Momona Ethiopian J. Sci. 10 (1) (2018) 1–14. [16] P. Sundaram, R. Senthil, Indian J. Sci. Tech. 9 (47) (2016) 1–5. [17] N. El-Mahallawy, M.R.A. Atia, A. Khaled, M. Shoeib, Mater. Res. Exp. 5 (4) (2018) 046402. [18] P.S. Ladgaonkar, A. Patil Abhishek, A.M. Patil, Int. J. Eng. Sci. Res. Technol. 3 (4) (2014) 6005–6008. [19] C.E. Kennedy, H. Price, Proceedings of ISEC2005 Int Solar Energy Conference , 2005, Orlando, Florida USA. [20] Ahmet Çag˘lar, Proceedings of the 2nd World Congress on Mechanical, Chemical, and Material Engineering (MCM’16) Budapest, 2016 HTFF 152-(1-5).
Further reading [3] Atul Sharma, Renew. Sust. Energy Rev. 15 (2011) 1767–1776. [4] Gary Jorgensen, Tom Williams, Tim Wendelin, Nat Renew Energy Lab 1617, Cole Blvd. Golden, CO 80401 USA. [8] K.T. Roro, N. Tile, B. Yalisi, M. De Gama, T. Wittes, T. Roberts, A Forbes World renew energy congress 2011-Sweden 8-13 may 2011.
Please cite this article as: R. Suresh Isravel, S. Saravanan and V. Vijayan, A review of material and coatings in solar collectors, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.06.644
Contents lists available at ScienceDirect
Materials Today: Proceedings journal homepage: www.elsevier.com/locate/matpr
A review of material and coatings in solar collectors R. Suresh Isravel ⇑, S. Saravanan, V. Vijayan Department of Mechanical Engineering, K. Ramakrishnan College of Technology, Trichy 621112, India
a r t i c l e
i n f o
Article history: Received 22 May 2019 Accepted 17 June 2019 Available online xxxx Keywords: Reflector Receivers Selective coating Absorbtance Reflectance
a b s t r a c t Performance improvement of the solar thermal power generation systems can be improved by the choosing the suitable materials and the coatings of the reflectors and receiver. The conventional reflector such as glass and the advanced reflector such as polymers based reflectors are discussed. The coating used in this types of Reflectors for the coatings for the protection from the dirt and corrosion are mentioned. Receiver of the solar collector should have the high specular absorbtance. To improve the absorbtance solar selective coatings have been used by the researchers. Ó 2019 Elsevier Ltd. All rights reserved. Peer-review under responsibility of the scientific committee of the International Conference on Recent Trends in Nanomaterials for Energy, Environmental and Engineering Applications
1. Introduction
2. Materials and coatings in Reflector
Energy is the important requirement for the developing the economy of the country. Nowadays the availability of the fossil fuels were diminishing gradually. So the energy Engineers are concentrating more on the renewable energy resources such as solar and wind energy. Energy generation using solar power is classified into two methods such as solar thermal power generation and solar photo voltaics. These two methods have their own advantage and disadvantage [1]. India is blessed with a very vast solar power. Most of the places of the country receive the sunlight about 300 days. Direct normal Irradiance value of the sunshine is 4– 6.5 kWh/m2/day. There are four types of concentrating solar power technologies available globally; they are Parabolic trough collector, parabolic dish, Linear Fresnel collector and solar tower system. The concept of this system is different but the materials used in these systems are same [2]. Two main things in the concentrating solar power technologies is the Reflector and receiver. Numerous materials have been investigated for use as coatings in Reflector and Receiver. In order to produce one or more desirable properties including: anti-reflection, better transmission, reducing build-up of organic dirt, resistance to abrasion, resistance to oxidation or corrosion and solar selective absorption [7] (Fig. 1).
The Glass mirrors are the best baseline reflectors for the solar parabolic collector because it has high reflectance, durability and degradation of reflectivity is modest over the concentrator life time. But the limitations of the glass mirrors include weight, fragility and expensive in terms of cost. To overcome these limitations, manufacturers can use the polymer mirrors because it is flexible, low weight and less expensive. But polymer mirrors have the limited lifetime (Fig. 2). The above two mentioned mirrors are the basic types of reflectors. The technology advancements in manufacturing of reflectors resulted in advanced reflector materials. They are Directly Deposited Reflector Material, Silvered Teflon Reflector Material, Polymer MultiLayer Reflector Material (Fig. 3). Directly Deposited Reflector Material- the order of different the layers are Top coat, Reflective layer, Levelizing layer, Substrate. This types of reflector reduces the need of the lamination and adhesives. Silvered Teflon Reflector Material-The advantages of such a mirror include the fact that TeflonTM is an inherently weatherable and nonhygroscopic material, has good barrier properties, and exhibits a low surface energy which may reduce soil retention. Polymer MultiLayer Reflector Material the order of different the layers Si3N4 and-or PML – Ag – Polymer Multi layer – Substrate. The advantage of this type is it has high production capacity thereby reduces the production cost. One of the most promising ways to reduce the cost of solar mirrors is to metallize an appropriate and inexpensive substrate mate-
⇑ Corresponding author. E-mail address: [email protected] (R. Suresh Isravel).
https://doi.org/10.1016/j.matpr.2019.06.644 2214-7853/Ó 2019 Elsevier Ltd. All rights reserved. Peer-review under responsibility of the scientific committee of the International Conference on Recent Trends in Nanomaterials for Energy, Environmental and Engineering Applications
Please cite this article as: R. Suresh Isravel, S. Saravanan and V. Vijayan, A review of material and coatings in solar collectors, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.06.644
2
R. Suresh Isravel et al. / Materials Today: Proceedings xxx (xxxx) xxx
Fig. 1. Parabolic trough collector [1].
Fig. 3. Structure of Metalized polymer reflectors [5].
dioxide and water. This exclusive property of TiO2 has led to use in the reflector of the concentrating solar power system [7]. Reflectance is increased from 0.4 to 0.6 for solar collector black paint with nickel coating. Nickel nanoparticle was deposited by electrodeposition method [13]. Reflectivity is compared for chrome plate 316(L) and aluminium composite panel. Results showed that aluminum composite panel has high reflectivity [20]. 3. Materials and coatings in Receiver Fig. 2. Linear Fresnel collector [1].
rial such as a polyethylene terephthalate (PET) film and then overcoat the reflector with an abrasion-resistant, durable, protective top layer. Cost of the solar reflectors can be eliminated by using low cost substrate material such as polyethylene terephthalate and then overcost the reflector with the abrasion- resistant top layer [2]. Basically three layers are present in the solar reflectors they are Reflector material, substrate material and structural support. Reflector material should have good specular reflectance which is defined as the degree to which a mirror is capable of transferring directed radiation to a target receiver surface. Microroughness of a mirror surface can result in scattering (loss) of light. Conventionally glass mirrors are used but Metallized polymer reflector materials is less expensive than the glass mirrors. Solar coatings were used in reflectors to protect the reflectors from the corrosion, dirt and from the reflection losses. Silver and aluminium coating has been given to the reflectors of the concentrating solar power technologies because they have the higher reflectivity of 88% and 98% respectively. To protect this layer from the corrosions sacrificial copper anode is coated. To address the soiling and cleaning issues of concentrating solar power technologies Titanium dioxide (TiO2) in has photocatalytic properties. Photons with energies greater than the band gap of TiO2 create electron-hole pairs which in the presence of air can speed up or catalyse the conversion of organic matter to carbon
The absorbtance of the Aluminium solar receiver was improved by C/NiO coatings has been deposited by the spray coating technique. Results show that absorbtance has been increased upto 90%. This type of reflector will be used for the low cost domestic water heating system [6]. Light absorption property of the receiver depends on the electronic structure and wave length of the light coming from the sun. The design process of selecting solar coating of the solar thermal power system is much more complicated than the design of the anti reflection coating and the dirt protection coating. The solar selective coating should be chemically and structurally stable for the variable range of the temperatures, should have comply the rules of the local administration, low cost and it should have good adhesion to the receiver tubes. Solar selective coatings are classified into: intrinsic; semiconductor-metal; multi-layer; cermets or metal-dielectric composite materials; and finally textured surfaces [7]. High entropy alloys may be used for frame of solar collector since it has intense strength and hardness and superior corrosion resistance [9].Si02 Nanoparticle is synthesized by sol-gel technique. This can be used for the preparation of nanofluid for the improvement of heat transfer in the solar collector [10]. Aluminium carbide reinforced with silicon carbide and titanium can be used as the supporting frame in solar collector[11].Analysed the parameters for improving the surface finish because good surface finish is needed for solar collectors[12]. Black chrome coating has high absorbtance when compared to matt black painting and black nickel-chrome painting[14]. Iron sheet and black ABRO spray
Please cite this article as: R. Suresh Isravel, S. Saravanan and V. Vijayan, A review of material and coatings in solar collectors, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.06.644
R. Suresh Isravel et al. / Materials Today: Proceedings xxx (xxxx) xxx
to have the highest absorbtance when compared with blackboard paint and commercial black paint[15]. Mild steel absorber tube is coated with nickel and chromium and it is found that mild steel coated with nickel has higher absorbtance[16]. Simulation software was used for the estimate the selectivity of the coatings for solar collectors[17].Black chrome, Black Nickel, Black cobalt, Thickness-sensitive spectrally selective (TSSS) paint coatings and Black-colored CuFeMnO4 spinel powders are the various coatings used in the receiver side of solar parabolic trough collector[18]. Computer-aided design software was used modeling a solarselective coating composed of materials stable at high temperature[19]. 4. Conclusion In this review articles the reflector and the receiver of the concentrating solar power systems have been discussed. Different types of coatings materials used in the reflectors for the purpose of protection of the solar collector and for the improvement of the optical performance of the collector is listed. Also the materials available for the reflectors as well as the receivers are also listed. Then the advance solar collectors used in industries and the solutions the for preventing the accumulation of the dust in the solar collectors have been discussed. References [1] Rajesh Kumar, J. Mat Sci. Mech. Eng. (JMSME) 2 (6) (2015) 41–44. [2] Jibran Khan, H. Mudassar, Arsalan, Renew. Sust. Energy Rev. 55 (2016) 414– 425.
3
[5] Gary Jorgensen National Renew Energy Lab 1617, Cole Boulevard Golden, CO 80401. [6] Georgios Polizos, Kyle Winter, Michael J. Lance, Harry M. Meyer, Beth L. Armstrong, Daniel A. Schaeffer, John T. Simpson, Scott R. Hunter, Panos G. Datskos, App. Surf. Sci. 292 (2014) 563–569. [7] Carol Atkinson, Chris L. Sansom, Heather J. Almond, Chris P. Shaw, Renew. Sust. Energy Rev. 45 (2015) 113–122. [9] A.M. Rameshbabu, P. Parameshwaran, V. Vijayan, R. Panner, J. Mech. Behav. Mater. 26 (2017) 127–132. [10] S. Saravanan, A. Godwin Antony, V. Vijayan, M. Loganathan, S. Baskar, Int. J. Mech., Eng. Technol. 1 (2019) 785–790. [11] A. Godwin Antony, V. Vijayan, S. Saravanan, S. Baskar, M. Loganathan, Int. J. Mech., Eng. Technol. 9 (2018) 681–691. [12] S. Dinesh, A. Godwin Antony, K. Rajaguru, V. Vijayan, Mech. Mech. Eng. 21 (2017) 17–28. [13] J. El Nady, A.B. Kashyout, Sh. Ebrahim, M.B. Soliman, Alexandria Eng. J. 55 (2) (2016) 723–729. [14] Alibakhsh Kasaeian, Samaneh Daviran, Reza Danesh, Azarian Int. J. Renewable Energy Res.-IJRER 6 (2016) 15–20. [15] Fana Filli, Petros Gebray, Ashenafi Kebedom, Momona Ethiopian J. Sci. 10 (1) (2018) 1–14. [16] P. Sundaram, R. Senthil, Indian J. Sci. Tech. 9 (47) (2016) 1–5. [17] N. El-Mahallawy, M.R.A. Atia, A. Khaled, M. Shoeib, Mater. Res. Exp. 5 (4) (2018) 046402. [18] P.S. Ladgaonkar, A. Patil Abhishek, A.M. Patil, Int. J. Eng. Sci. Res. Technol. 3 (4) (2014) 6005–6008. [19] C.E. Kennedy, H. Price, Proceedings of ISEC2005 Int Solar Energy Conference , 2005, Orlando, Florida USA. [20] Ahmet Çag˘lar, Proceedings of the 2nd World Congress on Mechanical, Chemical, and Material Engineering (MCM’16) Budapest, 2016 HTFF 152-(1-5).
Further reading [3] Atul Sharma, Renew. Sust. Energy Rev. 15 (2011) 1767–1776. [4] Gary Jorgensen, Tom Williams, Tim Wendelin, Nat Renew Energy Lab 1617, Cole Blvd. Golden, CO 80401 USA. [8] K.T. Roro, N. Tile, B. Yalisi, M. De Gama, T. Wittes, T. Roberts, A Forbes World renew energy congress 2011-Sweden 8-13 may 2011.
Please cite this article as: R. Suresh Isravel, S. Saravanan and V. Vijayan, A review of material and coatings in solar collectors, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.06.644