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Thermal and Fluid Characteristics of a Latent Heat Thermal Energy Storage Unit
Available online at www.sciencedirect.com
ScienceDirect Energy Procedia 104 (2016) 425 – 430
CUE2016-Applied Energy Symposium and Forum 2016: Low carbon cities & urban energy systems
Thermal and fluid characteristics of a latent heat thermal energy storage unit Xiaohu Yanga,b, Yang Lia, Zhao Luc, Lianying Zhanga, Qunli Zhangd, Liwen Jina* a
Group of the Building Energy & Sustainability Technology, School of Human Settlements and Civil Engineering, Xi’an Jiaotong University, Xi’an 710049, China. b MOE Key Lab for Multifunctional Materials and Structures, Xi'an Jiaotong University, Xi'an 710049, China. c School of Energy and Power Engineering, Xi’an Jiaotong University, Xi’an 710049, China. d Beijing Municipal Key Lab of Heating, Gas Supply, Ventilating and Air Conditioning Engineering, Beijing University of Civil Engineering and Architecture, Xicheng District, Beijing 100044, China.
Abstract
Latent heat thermal energy storage (LHTES) is a promising way to smooth the discrepancy between energy supply and demand, and it is now becoming increasingly significant in the heating and cooling of buildings. However, the low thermal conductivity of the available PCMs require more efficient configuration of LHTES system in reducing the melting time. In order to evaluate the dynamic thermal performances of LHTES unit in shell and tube heat exchanger, the two-HTF-passage configuration and single-pass configuration are numerically investigated. The results show that the central and annular injection in two-HTF-passage configuration has little influence on the transient melting interface location and temperature in the PCM domain and both can effectively enhance the phase change heat transfer, but the HTF tube injection in single-pass configuration shows a significantly poor performance. © 2016 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license © 2016 The Authors. Published by Elsevier Ltd. (http://creativecommons.org/licenses/by-nc-nd/4.0/). Selection peer-review of under responsibility of CUE Peer-reviewand/or under responsibility the scientific committee of the Applied Energy Symposium and Forum, CUE2016: Low carbon cities and urban energy systems. Keywords: Latent heat thermal energy storage; thermal performances; shell and tube; two-HTF-passage; single-pass
1. Introduction
* Corresponding author. Tel.: +86-29-8339-5127; fax: +86-29-8339-5127. E-mail address: [email protected].
1876-6102 © 2016 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of the scientific committee of the Applied Energy Symposium and Forum, CUE2016: Low carbon cities and urban energy systems. doi:10.1016/j.egypro.2016.12.072
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Xiaohu Yang et al. / Energy Procedia 104 (2016) 425 – 430
One of the major noticeable challenges in the near future will be to find new resources to replace the fossil fuels. At present, by improving energy efficiency can bring various benefits to meet environmental requirements concerning CO2 emission and atmospheric pollution. A lot of researches are dedicating to the efficient application of renewable energy and waste heat recovery. Thermal energy storage (TES) is a proven efficient way to smooth the discrepancy between energy supply and demand, and becoming increasingly significant in the heating and cooling of buildings. In particular, latent heat thermal energy storage (LHTES) is a promising way to store thermal energy. As a matter of fact, using a phase change material (PCM) is quite attractive due to high storage density and relatively constant heat transfer fluid (HTF) temperature [1]. Several PCMs have been identified as latent heat storage media for low and high temperature. Paraffin is the most suitable for solar energy storage in the hot water supply of building [2]. There were plenty of investigations on the thermal performances of the LHTES systems with different configurations and operational conditions. Akgün et al. [3] analyzed the influence of the Reynolds number of HTF and the Stefan number on the melting and solidification characteristics of paraffin in a shell-and-tube LHTES system. The results indicated the Stefan number showed a greater effect on the melting time than the Reynolds number. Li and Wu [4] numerically simulated the dynamical thermal performances of shell and tube TES units. They found that the full melting/solidification time can be shortened at least 14% by using the extended fins. Belusko et al. [5-6] investigated the effect of boundary condition and latent fraction with different tube configurations in the tube-in-tank arrangements, and found that the counterflow arrangement was best suited for extracting latent energy while the single pass arrangement was best suited for extracting sensible energy. Zhang et al. [7] found that encapsulating molten salt with nickel foam to enhance the effective thermal conductivity of the PCM can improve the performance of LHTES system by developing an experimental system and a 3D numerical model of shell and tube configuration. Fornarelli et al. [8] examined the melting process in a shell and tube geometry. They highlighted natural convective played a major role in enhancing heat transfer and shorten the time needed to charge the LHTES tank. Most of existing LHTES systems adopted the shell and tube configurations. However, the flow regime of HTF is usually single-pass, and the backflow regime of two-HTF-passage arrangement has not been fully evaluated. The present study shows a numerical simulation of the melting process of PCM (paraffin RT35) in the two-HTF-passage and single-pass latent heat thermal energy storage unit, taking into account the presence of the natural convection. The 2D axisymmetric models of LHTES units are established, and the dynamical thermal performances of LHTES units with diverse geometric configurations are investigated. 2. Numerical simulation The studied configuration was a PCM-water heat exchanger with three coaxial cylinders, as shown in Fig. 1 (b) and (c). The radius of inner cylinder (R0) is 7.5 mm, and the middle (R1) and outer (R3) ones are 24.5 and 32 mm respectively. All tubes had thickness of 2.5 mm and the total length of LHTES unit (h) was 400 mm. The space between the inner and middle cylinders was filled with PCM RT35, whose thermo-physical properties were list in Table 1. To examine the effect of flow configuration of a LHTES unit, different flow injection patterns (central injection in Fig. 1(b) and annular injection in Fig. 1(c)) were compared, with single flow passage as the basis (see Fig.1 (d)). The average injection velocity was kept constant at 0.01m/s, corresponding to a Reynolds number lower 2300 inside the HTF tube and annulus. Therefore, the flow can be considered to be laminar. In order to simulate the melting process of the PCM according the axial symmetry of the LHTES unit, 2D axisymmetric CFD simulation was carried out. The PCM (solid phase) and the wall were initially at
427
Xiaohu Yang et al. / Energy Procedia 104 (2016) 425 – 430
20 ć, and all the thermo-physical properties of the PCM were independent with temperature except the density for liquid PCM where Boussinesq assumption was made for simulation. The solution was thought to be converged when the residuals of all the governing equations were less than 10-6. Table 1 Thermo-physical properties of PCM (Paraffin RT35) 35
Melting temperature (ć) Latent heat (KJ·Kg-1)
157
Density (Kg·m-3)
Solid/liquid -1
-1
Special heat capacity (KJ·Kg ·K )
Solid/liquid
880/760 1.8/2.4
Thermal conductivity (W·m-1·K-1)
0.2
Kinematic viscosity (m2·s-1)
3.3×10-6
Fig. 1. Studied configurations and computational domain: (a) size diagram of two-HTF-passage configuration; (b) two-HTF-passage configuration with HTF central injection; (c) two-HTF-passage configuration with HTF annular injection; (d) single-pass configuration with top injection
3. Results and discussions The present research undertook the study of three cases, the first and second of which were two-HTFpassage configurations with HTF tube injection shown in Fig. 1 (b) and (c), while the comparison base was the single-pass configuration with HTF tube injection shown in Fig. 1 (d). All of cases were under same operation conditions. 3.1. Validation of numerical model To validate the computational model of phase change in the present study, the simulation based on the experimental conditions [9] was performed for a vertical concentric tube heat exchanger shown in Fig. 1 (d) incorporating an organic PCM (RT35) with a melting point 35ć and HTF (water). The temperature evolution at one radial position in the D section during the charge process with top HTF tube injection
428
Xiaohu Yang et al. / Energy Procedia 104 (2016) 425 – 430
was plotted in Fig. 2(a). The continuous line represented the numerical results, while the plenty of dots denoted the experimental data; see Fig. 2(b). A good agreement between numerical and experimental data can be noted, confirming the feasibility of the computational models developed in the present study.
(a)
(b)
Fig. 2. (a) Scheme of the experimental LHTHS unit and thermocouple position; (b) comparison of the experimental results and numerical solution for charge with top HTF injection
3.2. Melting front
Xiaohu Yang et al. / Energy Procedia 104 (2016) 425 – 430
Fig. 3. Temporal evolution of melting fronts: (a) two-HTF-passage configuration with HTF tube injection; (b) two-HTF-passage configuration with HTF annulus injection; (c) single-pass configuration with HTF tube injection
Fig. 3 demonstrated the temporal evolution of the melting front in the PCM domain after 300s, 1200s, 2000s, 2500s and 3000s successively. Initially, the melting interface was almost flat and moved in a radial direction. With melting fraction increasing, the natural convection in the melt phase (liquid paraffin) was triggered on, where inclined melting interface formed. Nevertheless, Case (a) and (b) showed a similar tendency that the rapidly declining melting front moved from the top to the bottom until the PCM was completely melted. The inclined moving pattern was only obviously found in Case (c) due to the one-side heating (Fig. 3(c)). This indicated that local natural convection dominated the heat transfer in the melted phase, further enhancing the phase change process for a single pass unit. As for the two-HTF-passage configuration, heat conduction was the governing heat transfer mechanism even in the melted domain for double heating faces significantly suppressed the local natural convection. Even so, the fully charging time for the two-HTF-passage configuration was much shorter than single pass unit. This can be further verified through analyzing their temperature history (the same point in PCM domain) as shown in Fig. 4. To compare the injection pattern, central and annular injection for the same two-HTF-passage unit was examined. There seemed little difference in transient melting interface (see Fig. 3(a) and (b)) and the temperature history curve was collapsed (see Fig. 4), as well. This indicated that engineers may conveniently choose either central or annular injection for a LHTES heat exchanger without any doubt.
Fig. 4. Temporal evolution of temperature for different LHTES units
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Xiaohu Yang et al. / Energy Procedia 104 (2016) 425 – 430
4. Conclusion In this paper, Numerical simulations of the melting process in a two-HTF-passage configuration and a single-pass configuration of the LHTES unit have been investigated. The numerical model is validated by comparison with experimental results. The temporal evolution of melting front and temperature in the PCM domain are compared in three different cases. The inclined melting interface was observed for single passage unit due to the onset of local natural convection; while heat conduction dominates the phase change heat transfer process. The numerical results also show that the HTF tube injection and annulus injection in two-HTF-passage configuration have little influence on the melting process of PCM and both can effectively charge the PCM, but the HTF tube injection in single-pass configuration shows a significantly poor performance. It is therefore convenient for engineers to choose either central or annular injections for designing the phase change heat exchanger. Acknowledgements This work was supported by the National Natural Science Foundation of China (51506160), China Post-Doctoral Science Foundation Project (2015M580845, 2016T90916), and the Beijing Key Lab of Heating, Gas Supply, Ventilating and Air Conditioning Engineering (NR2015K01 & NR2016K01). References [1] Liu M, Saman W, Bruno F. Review on storage materials and thermal performance enhancement techniques for high temperature phase change thermal storage systems. Renewable and Sustainable Energy Reviews, 2012, 16(4): 2118-2132. [2] Yang XH, Lu TJ, Kim T. Temperature effects on the effective thermal conductivity of phase change materials with two distinctive phases. International Communcations in Heat and Mass Transfer, 2011, 38: 1344–1348. [3] Akgün M, Aydın O, Kaygusuz K. Thermal energy storage performance of paraffin in a novel tube-in-shell system. Applied Thermal Engineering, 2008, 28(5): 405-413. [4] Li Z, Wu Z G. Analysis of HTFs, PCMs and fins effects on the thermal performance of shell–tube thermal energy storage units. Solar Energy, 2015, 122: 382-395. [5] Belusko M, Tay N H S, Liu M, et al. Effective tube-in-tank PCM thermal storage for CSP applications, Part 1: Impact of tube configuration on discharging effectiveness. Solar Energy, 2015. [6] Belusko M, Tay N H S, Liu M, et al. Effective tube-in-tank PCM thermal storage for CSP applications, Part 2: Parametric assessment and impact of latent fraction. Solar Energy, 2015. [7] Zhang P, Ma F, Xiao X. Thermal energy storage and retrieval characteristics of a molten-salt latent heat thermal energy storage system. Applied Energy, 2016, 173: 255-271. [8] Fornarelli F, Camporeale S M, Fortunato B, et al. CFD analysis of melting process in a shell-and-tube latent heat storage for concentrated solar power plants. Applied Energy, 2016, 164: 711-722. [9] Longeon M, Soupart A, Fourmigué J F, et al. Experimental and numerical study of annular PCM storage in the presence of natural convection. Applied Energy, 2013, 112: 175-184.
Biography Dr. Jin Liwen obtained his Ph.D. from Nanyang Technological University of Singapore and then worked at National University of Singapore. He is currently a professor working at Xi’an Jiaotong University, China. His research interests include building energy analysis, solar heat/cold storage and heat transfer in microchannels.
ScienceDirect Energy Procedia 104 (2016) 425 – 430
CUE2016-Applied Energy Symposium and Forum 2016: Low carbon cities & urban energy systems
Thermal and fluid characteristics of a latent heat thermal energy storage unit Xiaohu Yanga,b, Yang Lia, Zhao Luc, Lianying Zhanga, Qunli Zhangd, Liwen Jina* a
Group of the Building Energy & Sustainability Technology, School of Human Settlements and Civil Engineering, Xi’an Jiaotong University, Xi’an 710049, China. b MOE Key Lab for Multifunctional Materials and Structures, Xi'an Jiaotong University, Xi'an 710049, China. c School of Energy and Power Engineering, Xi’an Jiaotong University, Xi’an 710049, China. d Beijing Municipal Key Lab of Heating, Gas Supply, Ventilating and Air Conditioning Engineering, Beijing University of Civil Engineering and Architecture, Xicheng District, Beijing 100044, China.
Abstract
Latent heat thermal energy storage (LHTES) is a promising way to smooth the discrepancy between energy supply and demand, and it is now becoming increasingly significant in the heating and cooling of buildings. However, the low thermal conductivity of the available PCMs require more efficient configuration of LHTES system in reducing the melting time. In order to evaluate the dynamic thermal performances of LHTES unit in shell and tube heat exchanger, the two-HTF-passage configuration and single-pass configuration are numerically investigated. The results show that the central and annular injection in two-HTF-passage configuration has little influence on the transient melting interface location and temperature in the PCM domain and both can effectively enhance the phase change heat transfer, but the HTF tube injection in single-pass configuration shows a significantly poor performance. © 2016 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license © 2016 The Authors. Published by Elsevier Ltd. (http://creativecommons.org/licenses/by-nc-nd/4.0/). Selection peer-review of under responsibility of CUE Peer-reviewand/or under responsibility the scientific committee of the Applied Energy Symposium and Forum, CUE2016: Low carbon cities and urban energy systems. Keywords: Latent heat thermal energy storage; thermal performances; shell and tube; two-HTF-passage; single-pass
1. Introduction
* Corresponding author. Tel.: +86-29-8339-5127; fax: +86-29-8339-5127. E-mail address: [email protected].
1876-6102 © 2016 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of the scientific committee of the Applied Energy Symposium and Forum, CUE2016: Low carbon cities and urban energy systems. doi:10.1016/j.egypro.2016.12.072
426
Xiaohu Yang et al. / Energy Procedia 104 (2016) 425 – 430
One of the major noticeable challenges in the near future will be to find new resources to replace the fossil fuels. At present, by improving energy efficiency can bring various benefits to meet environmental requirements concerning CO2 emission and atmospheric pollution. A lot of researches are dedicating to the efficient application of renewable energy and waste heat recovery. Thermal energy storage (TES) is a proven efficient way to smooth the discrepancy between energy supply and demand, and becoming increasingly significant in the heating and cooling of buildings. In particular, latent heat thermal energy storage (LHTES) is a promising way to store thermal energy. As a matter of fact, using a phase change material (PCM) is quite attractive due to high storage density and relatively constant heat transfer fluid (HTF) temperature [1]. Several PCMs have been identified as latent heat storage media for low and high temperature. Paraffin is the most suitable for solar energy storage in the hot water supply of building [2]. There were plenty of investigations on the thermal performances of the LHTES systems with different configurations and operational conditions. Akgün et al. [3] analyzed the influence of the Reynolds number of HTF and the Stefan number on the melting and solidification characteristics of paraffin in a shell-and-tube LHTES system. The results indicated the Stefan number showed a greater effect on the melting time than the Reynolds number. Li and Wu [4] numerically simulated the dynamical thermal performances of shell and tube TES units. They found that the full melting/solidification time can be shortened at least 14% by using the extended fins. Belusko et al. [5-6] investigated the effect of boundary condition and latent fraction with different tube configurations in the tube-in-tank arrangements, and found that the counterflow arrangement was best suited for extracting latent energy while the single pass arrangement was best suited for extracting sensible energy. Zhang et al. [7] found that encapsulating molten salt with nickel foam to enhance the effective thermal conductivity of the PCM can improve the performance of LHTES system by developing an experimental system and a 3D numerical model of shell and tube configuration. Fornarelli et al. [8] examined the melting process in a shell and tube geometry. They highlighted natural convective played a major role in enhancing heat transfer and shorten the time needed to charge the LHTES tank. Most of existing LHTES systems adopted the shell and tube configurations. However, the flow regime of HTF is usually single-pass, and the backflow regime of two-HTF-passage arrangement has not been fully evaluated. The present study shows a numerical simulation of the melting process of PCM (paraffin RT35) in the two-HTF-passage and single-pass latent heat thermal energy storage unit, taking into account the presence of the natural convection. The 2D axisymmetric models of LHTES units are established, and the dynamical thermal performances of LHTES units with diverse geometric configurations are investigated. 2. Numerical simulation The studied configuration was a PCM-water heat exchanger with three coaxial cylinders, as shown in Fig. 1 (b) and (c). The radius of inner cylinder (R0) is 7.5 mm, and the middle (R1) and outer (R3) ones are 24.5 and 32 mm respectively. All tubes had thickness of 2.5 mm and the total length of LHTES unit (h) was 400 mm. The space between the inner and middle cylinders was filled with PCM RT35, whose thermo-physical properties were list in Table 1. To examine the effect of flow configuration of a LHTES unit, different flow injection patterns (central injection in Fig. 1(b) and annular injection in Fig. 1(c)) were compared, with single flow passage as the basis (see Fig.1 (d)). The average injection velocity was kept constant at 0.01m/s, corresponding to a Reynolds number lower 2300 inside the HTF tube and annulus. Therefore, the flow can be considered to be laminar. In order to simulate the melting process of the PCM according the axial symmetry of the LHTES unit, 2D axisymmetric CFD simulation was carried out. The PCM (solid phase) and the wall were initially at
427
Xiaohu Yang et al. / Energy Procedia 104 (2016) 425 – 430
20 ć, and all the thermo-physical properties of the PCM were independent with temperature except the density for liquid PCM where Boussinesq assumption was made for simulation. The solution was thought to be converged when the residuals of all the governing equations were less than 10-6. Table 1 Thermo-physical properties of PCM (Paraffin RT35) 35
Melting temperature (ć) Latent heat (KJ·Kg-1)
157
Density (Kg·m-3)
Solid/liquid -1
-1
Special heat capacity (KJ·Kg ·K )
Solid/liquid
880/760 1.8/2.4
Thermal conductivity (W·m-1·K-1)
0.2
Kinematic viscosity (m2·s-1)
3.3×10-6
Fig. 1. Studied configurations and computational domain: (a) size diagram of two-HTF-passage configuration; (b) two-HTF-passage configuration with HTF central injection; (c) two-HTF-passage configuration with HTF annular injection; (d) single-pass configuration with top injection
3. Results and discussions The present research undertook the study of three cases, the first and second of which were two-HTFpassage configurations with HTF tube injection shown in Fig. 1 (b) and (c), while the comparison base was the single-pass configuration with HTF tube injection shown in Fig. 1 (d). All of cases were under same operation conditions. 3.1. Validation of numerical model To validate the computational model of phase change in the present study, the simulation based on the experimental conditions [9] was performed for a vertical concentric tube heat exchanger shown in Fig. 1 (d) incorporating an organic PCM (RT35) with a melting point 35ć and HTF (water). The temperature evolution at one radial position in the D section during the charge process with top HTF tube injection
428
Xiaohu Yang et al. / Energy Procedia 104 (2016) 425 – 430
was plotted in Fig. 2(a). The continuous line represented the numerical results, while the plenty of dots denoted the experimental data; see Fig. 2(b). A good agreement between numerical and experimental data can be noted, confirming the feasibility of the computational models developed in the present study.
(a)
(b)
Fig. 2. (a) Scheme of the experimental LHTHS unit and thermocouple position; (b) comparison of the experimental results and numerical solution for charge with top HTF injection
3.2. Melting front
Xiaohu Yang et al. / Energy Procedia 104 (2016) 425 – 430
Fig. 3. Temporal evolution of melting fronts: (a) two-HTF-passage configuration with HTF tube injection; (b) two-HTF-passage configuration with HTF annulus injection; (c) single-pass configuration with HTF tube injection
Fig. 3 demonstrated the temporal evolution of the melting front in the PCM domain after 300s, 1200s, 2000s, 2500s and 3000s successively. Initially, the melting interface was almost flat and moved in a radial direction. With melting fraction increasing, the natural convection in the melt phase (liquid paraffin) was triggered on, where inclined melting interface formed. Nevertheless, Case (a) and (b) showed a similar tendency that the rapidly declining melting front moved from the top to the bottom until the PCM was completely melted. The inclined moving pattern was only obviously found in Case (c) due to the one-side heating (Fig. 3(c)). This indicated that local natural convection dominated the heat transfer in the melted phase, further enhancing the phase change process for a single pass unit. As for the two-HTF-passage configuration, heat conduction was the governing heat transfer mechanism even in the melted domain for double heating faces significantly suppressed the local natural convection. Even so, the fully charging time for the two-HTF-passage configuration was much shorter than single pass unit. This can be further verified through analyzing their temperature history (the same point in PCM domain) as shown in Fig. 4. To compare the injection pattern, central and annular injection for the same two-HTF-passage unit was examined. There seemed little difference in transient melting interface (see Fig. 3(a) and (b)) and the temperature history curve was collapsed (see Fig. 4), as well. This indicated that engineers may conveniently choose either central or annular injection for a LHTES heat exchanger without any doubt.
Fig. 4. Temporal evolution of temperature for different LHTES units
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Xiaohu Yang et al. / Energy Procedia 104 (2016) 425 – 430
4. Conclusion In this paper, Numerical simulations of the melting process in a two-HTF-passage configuration and a single-pass configuration of the LHTES unit have been investigated. The numerical model is validated by comparison with experimental results. The temporal evolution of melting front and temperature in the PCM domain are compared in three different cases. The inclined melting interface was observed for single passage unit due to the onset of local natural convection; while heat conduction dominates the phase change heat transfer process. The numerical results also show that the HTF tube injection and annulus injection in two-HTF-passage configuration have little influence on the melting process of PCM and both can effectively charge the PCM, but the HTF tube injection in single-pass configuration shows a significantly poor performance. It is therefore convenient for engineers to choose either central or annular injections for designing the phase change heat exchanger. Acknowledgements This work was supported by the National Natural Science Foundation of China (51506160), China Post-Doctoral Science Foundation Project (2015M580845, 2016T90916), and the Beijing Key Lab of Heating, Gas Supply, Ventilating and Air Conditioning Engineering (NR2015K01 & NR2016K01). References [1] Liu M, Saman W, Bruno F. Review on storage materials and thermal performance enhancement techniques for high temperature phase change thermal storage systems. Renewable and Sustainable Energy Reviews, 2012, 16(4): 2118-2132. [2] Yang XH, Lu TJ, Kim T. Temperature effects on the effective thermal conductivity of phase change materials with two distinctive phases. International Communcations in Heat and Mass Transfer, 2011, 38: 1344–1348. [3] Akgün M, Aydın O, Kaygusuz K. Thermal energy storage performance of paraffin in a novel tube-in-shell system. Applied Thermal Engineering, 2008, 28(5): 405-413. [4] Li Z, Wu Z G. Analysis of HTFs, PCMs and fins effects on the thermal performance of shell–tube thermal energy storage units. Solar Energy, 2015, 122: 382-395. [5] Belusko M, Tay N H S, Liu M, et al. Effective tube-in-tank PCM thermal storage for CSP applications, Part 1: Impact of tube configuration on discharging effectiveness. Solar Energy, 2015. [6] Belusko M, Tay N H S, Liu M, et al. Effective tube-in-tank PCM thermal storage for CSP applications, Part 2: Parametric assessment and impact of latent fraction. Solar Energy, 2015. [7] Zhang P, Ma F, Xiao X. Thermal energy storage and retrieval characteristics of a molten-salt latent heat thermal energy storage system. Applied Energy, 2016, 173: 255-271. [8] Fornarelli F, Camporeale S M, Fortunato B, et al. CFD analysis of melting process in a shell-and-tube latent heat storage for concentrated solar power plants. Applied Energy, 2016, 164: 711-722. [9] Longeon M, Soupart A, Fourmigué J F, et al. Experimental and numerical study of annular PCM storage in the presence of natural convection. Applied Energy, 2013, 112: 175-184.
Biography Dr. Jin Liwen obtained his Ph.D. from Nanyang Technological University of Singapore and then worked at National University of Singapore. He is currently a professor working at Xi’an Jiaotong University, China. His research interests include building energy analysis, solar heat/cold storage and heat transfer in microchannels.