Evaluation and optimization of melting performance for a latent heat thermal energy storage unit partially filled with porous media

In this paper, melting performance of phase change materials (PCMs) in a horizontal concentric–tube thermal energy storage (TES) unit was numerically investigated with consideration of natural convection. Porous media were employed to enhance the thermal response of PCMs. Performances of different porous configurations were compared to optimize the location of porous insert, and the optimal filling ratio of porous insert was determined based on a new criterion proposed in this study, which is called TES rate density. This new criterion was proved to be effective to comprehensively evaluate the melting performance, including melting time, TES capacity, and total mass of materials. Furthermore, the effects of pore size and porous materials were discussed. The results showed that partially locating the porous media in the lower part has the best enhancement on melting performance of PCM and the optimal filling height ratio of porous media is 0.7. In this case, the TES rate density can be significantly increased by more than 6 times compared with the none-porous case. More importantly, compared with the full-porous case, 3% better comprehensive performance with about 28% less porous material can be achieved. Porous insert with high thermal conductivity, large pore size, and high porosity is recommended to enhance the melting performance of PCMs. From the point of view of practical utilization of the porous material, silicon carbide is recommended due to its relatively high conductivity, chemical inertness and low cost.

[1]  L. Wei,et al.  Amplified charge and discharge rates in phase change materials for energy storage using spatially-enhanced thermal conductivity , 2016 .

[2]  Chang Xu,et al.  Numerical investigation on porous media heat transfer in a solar tower receiver , 2011 .

[3]  D. Delaunay,et al.  Industrial waste heat recovery using an enhanced conductivity latent heat thermal energy storage , 2016 .

[4]  Cho Lik Chan,et al.  GPU accelerated numerical study of PCM melting process in an enclosure with internal fins using lattice Boltzmann method , 2016 .

[5]  Gonzalo Diarce,et al.  Design and feasibility of high temperature shell and tube latent heat thermal energy storage system for solar thermal power plants , 2016 .

[6]  Zhigen Wu,et al.  Experimental and numerical study on the effective thermal conductivity of paraffin/expanded graphite composite , 2014 .

[7]  Y. Tao,et al.  Lattice Boltzmann simulation on phase change heat transfer in metal foams/paraffin composite phase change material , 2016 .

[8]  Peng Zhang,et al.  Melting heat transfer characteristics of a composite phase change material fabricated by paraffin and metal foam , 2017 .

[9]  Y. Qiu,et al.  Non-uniform characteristics of solar flux distribution in the concentrating solar power systems and its corresponding solutions: A review , 2016 .

[10]  Ming Li,et al.  Heat transfer characteristics of a molten-salt thermal energy storage unit with and without heat transfer enhancement , 2015 .

[11]  R. Mahajan,et al.  Forced Convection in High Porosity Metal Foams , 2000 .

[12]  Peilun Wang,et al.  Numerical investigation of PCM melting process in sleeve tube with internal fins , 2016 .

[13]  A. Elgafy,et al.  Numerical Study for Enhancing the Thermal Conductivity of Phase Change Material (PCM) Storage using High Thermal Conductivity Porous Matrix , 2005 .

[14]  Kun Wang,et al.  Thermodynamic analysis and optimization of a molten salt solar power tower integrated with a recompression supercritical CO2 Brayton cycle based on integrated modeling , 2017 .

[15]  Yong Li,et al.  Characterization and thermal performance of nitrate mixture/SiC ceramic honeycomb composite phase change materials for thermal energy storage , 2015 .

[16]  C. Zhang,et al.  Highly stable graphite nanoparticle-dispersed phase change emulsions with little supercooling and high thermal conductivity for cold energy storage , 2017 .

[17]  L. Cabeza,et al.  Lithium in thermal energy storage: A state-of-the-art review , 2015 .

[18]  Subrata Sengupta,et al.  Effect of porosity of conducting matrix on a phase change energy storage device , 2016 .

[19]  Wei Yuan,et al.  Experimental investigation on the thermal performance of a heat sink filled with porous metal fiber sintered felt/paraffin composite phase change material , 2016 .

[20]  G. Ziskind,et al.  Melting in a vertical cylindrical tube: Numerical investigation and comparison with experiments , 2010 .

[21]  Changying Zhao,et al.  A review of solar collectors and thermal energy storage in solar thermal applications , 2013 .

[22]  L. Cabeza,et al.  Experimental evaluation of commercial heat exchangers for use as PCM thermal storage systems , 2009 .

[23]  Wei-Biao Ye,et al.  Numerical simulation on phase-change thermal storage/release in a plate-fin unit , 2011 .

[24]  Peng Zhang,et al.  Preparation and thermal characterization of paraffin/metal foam composite phase change material , 2013 .

[25]  Alan Henderson,et al.  A comparative study of thermal behaviour of a horizontal and vertical shell-and-tube energy storage using phase change materials , 2016 .

[26]  D. Banerjee,et al.  Enhanced thermal properties of SiO2 nanocomposite for solar thermal energy storage applications , 2015 .

[27]  Peiwen Li,et al.  Application of phase change materials for thermal energy storage in concentrated solar thermal power plants: A review to recent developments , 2015 .

[28]  B. W. Webb,et al.  ANALYSIS OF HEAT TRANSFER DURING MELTING OF A PURE METAL FROM AN ISOTHERMAL VERTICAL WALL , 1986 .

[29]  Ming-Jia Li,et al.  Thermal analysis of solar central receiver tube with porous inserts and non-uniform heat flux , 2017 .

[30]  Ya-Ling He,et al.  Preparation and thermal properties characterization of carbonate salt/carbon nanomaterial composite phase change material , 2015 .

[31]  W. Tao,et al.  The impact of concrete structure on the thermal performance of the dual-media thermocline thermal storage tank using concrete as the solid medium , 2014 .

[32]  Zhengguo Zhang,et al.  Metal foam embedded in SEBS/paraffin/HDPE form-stable PCMs for thermal energy storage , 2016 .

[33]  Experimental investigation of a thermal storage system using phase change materials , 2016 .

[34]  Hamid Ait Adine,et al.  Numerical analysis of the thermal behaviour of a shell-and-tube heat storage unit using phase change materials , 2009 .

[35]  K. Nithyanandam,et al.  Computational Studies on Metal Foam and Heat Pipe Enhanced Latent Thermal Energy Storage , 2014 .

[36]  Chie Gau,et al.  Melting and Solidification of a Pure Metal on a Vertical Wall , 1986 .

[37]  Peng Zhang,et al.  Experimental and numerical investigation of a tube-in-tank latent thermal energy storage unit using composite PCM , 2017 .

[38]  Wenhua Yu,et al.  Phase change material with graphite foam for applications in high-temperature latent heat storage systems of concentrated solar power plants , 2014 .

[39]  Ya-Ling He,et al.  Effects of natural convection on latent heat storage performance of salt in a horizontal concentric tube , 2015 .

[40]  Z. Khan,et al.  A review of performance enhancement of PCM based latent heat storage system within the context of materials, thermal stability and compatibility , 2016 .

[41]  Zhaowen Huang,et al.  Thermal property measurement and heat storage analysis of LiNO3/KCl – expanded graphite composite phase change material , 2014 .

[42]  N. Araki,et al.  Measurement of thermophysical properties of molten salts: Mixtures of alkaline carbonate salts , 1988 .

[43]  Ming-Jia Li,et al.  Optimization of porous insert configurations for heat transfer enhancement in tubes based on genetic algorithm and CFD , 2015 .

[44]  Ya-Ling He,et al.  Numerical study on thermal energy storage performance of phase change material under non-steady-state inlet boundary , 2011 .

[45]  Changying Zhao,et al.  A numerical investigation of heat transfer in phase change materials (PCMs) embedded in porous metals , 2011 .

[46]  Chao Xu,et al.  Dynamic thermal performance analysis of a molten-salt packed-bed thermal energy storage system using PCM capsules , 2014 .

[47]  Yanping Yuan,et al.  Effect of installation angle of fins on melting characteristics of annular unit for latent heat thermal energy storage , 2016 .

[48]  Chao Xu,et al.  Cyclic behaviors of the molten-salt packed-bed thermal storage system filled with cascaded phase change material capsules , 2016 .

[49]  Changying Zhao,et al.  Experimental investigations of porous materials in high temperature thermal energy storage systems , 2011 .

[50]  Orhan Aydin,et al.  Effect of eccentricity on melting behavior of paraffin in a horizontal tube-in-shell storage unit: An experimental study , 2014 .

[51]  N. Kousha,et al.  Effect of inclination angle on the performance of a shell and tube heat storage unit – An experimental study , 2017 .