A Parametric Investigation of Melting Process within a Porous Medium under Local Thermal Non-Equilibrium Condition Using Lattice Boltzmann Method

Document Type : Research Article

Authors

Department of Engineering, University of Zanjan, Zanjan, Iran

Abstract

The use of a porous medium with a high conductivity improves the rate of heat transfer in latent energy storage systems. This paper investigates the melting of the phase change material inside a porous medium under the local thermal non-equilibrium condition with the lattice Boltzmann method. Results examine the effect of Rayleigh number, porosity ratio, pore size, and Sparrow number on the liquid fraction and position of the melting front. Results show that by increasing the pore diameter, the interface of the two phases tends to bend but the liquid fraction decreases. Also, it is found that the difference between the liquid fraction in the presence and absence of natural convection for Ra<106, is less than 5%. Nonetheless, by increasing the Rayleigh number to 108, this difference at Fo=0.003 is more than 14% and at Fo=0.006 will reach more than 31%. Furthermore, in Ra=108 and for small Sparrow numbers, this difference is small and intensifies with increasing the Sparrow number. Also, by reducing the Darcy number, natural convection is weakened and it can be ignored for Da<10-4. It is shown that in small Darcy numbers Da=10-4, the deviation from the pure conduction is always increased by Sparrow number, and for larger Darcy numbers Da=10-2, this deviation has a maximum value of 53% at Fo=0.003 and 84% at Fo=0.006.

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Main Subjects


[1] F. Agyenim, N. Hewitt, P. Eames, M. Smyth, A review of materials, heat transfer and phase change problem formulation for latent heat thermal energy storage systems (LHTESS), Renewable and sustainable energy reviews, 14(2) (2010) 615-628.
[2] M. Gaeini, S. Shaik, C. Rindt, Characterization of potassium carbonate salt hydrate for thermochemical energy storage in buildings, Energy and Buildings, 196 (2019) 178-193.
[3] M. Nakhchi, J. Esfahani, Improving the melting performance of PCM thermal energy storage with novel stepped fins, Journal of Energy Storage, 30 (2020) 101424.
[4] C. Nie, S. Deng, J. Liu, Effects of fins arrangement and parameters on the consecutive melting and solidification of PCM in a latent heat storage unit, JOURNAL OF ENERGY STORAGE, 29 (2020).
[5] S. Rostami, M. Afrand, A. Shahsavar, M. Sheikholeslami, R. Kalbasi, S. Aghakhani, M.S. Shadloo, H.F. Oztop, A review of melting and freezing processes of PCM/nano-PCM and their application in energy storage, Energy, 211 (2020) 118698.
[6] L. Yang, J.-n. Huang, F. Zhou, Thermophysical properties and applications of nano-enhanced PCMs: An update review, Energy Conversion and Management, 214 (2020) 112876.
[7] A. Ghahremannezhad, H. Xu, M.R. Salimpour, P. Wang, K. Vafai, Thermal performance analysis of phase change materials (PCMs) embedded in gradient porous metal foams, Applied Thermal Engineering, 179 (2020) 115731.
[8] R. Mabrouk, H. Dhahri, H. Naji, S. Hammouda, Z. Younsi, Lattice Boltzmann simulation of forced convection melting of a composite phase change material with heat dissipation through an open-ended channel, International Journal of Heat and Mass Transfer, 153 (2020) 119606.
[9] Y. Tao, Y. You, Y. He, Lattice Boltzmann simulation on phase change heat transfer in metal foams/paraffin composite phase change material, Applied Thermal Engineering, 93 (2016) 476-485.
[10] M. Jourabian, A.A.R. Darzi, D. Toghraie, O. ali Akbari, Melting process in porous media around two hot cylinders: Numerical study using the lattice Boltzmann method, Physica A: Statistical Mechanics and its Applications, 509 (2018) 316-335.
[11] D. Gao, Z. Chen, D. Zhang, L. Chen, Lattice Boltzmann modeling of melting of phase change materials in porous media with conducting fins, Applied Thermal Engineering, 118 (2017) 315-327.
[12] D. Gao, Z. Chen, Lattice Boltzmann simulation of natural convection dominated melting in a rectangular cavity filled with porous media, International Journal of Thermal Sciences, 50(4) (2011) 493-501.
[13] D. Gao, F.-B. Tian, Z. Chen, D. Zhang, An improved lattice Boltzmann method for solid-liquid phase change in porous media under local thermal non-equilibrium conditions, International Journal of Heat and Mass Transfer, 110 (2017) 58-62.
[14] W. Minkowycz, A. Haji-Sheikh, K. Vafai, On departure from local thermal equilibrium in porous media due to a rapidly changing heat source: the Sparrow number, International journal of heat and mass transfer, 42(18) (1999) 3373-3385.
[15] D. Gao, Z. Chen, L. Chen, A thermal lattice Boltzmann model for natural convection in porous media under local thermal non-equilibrium conditions, International Journal of Heat and Mass Transfer, 70 (2014) 979-989.
[16] C. Wang, M. Mobedi, F. Kuwahara, Analysis of local thermal non-equilibrium condition for unsteady heat transfer in porous media with closed cells: Sparrow number, International Journal of Mechanical Sciences, 157 (2019) 13-24.
[17] M. Esapour, A. Hamzehnezhad, A.A.R. Darzi, M. Jourabian, Melting and solidification of PCM embedded in porous metal foam in horizontal multi-tube heat storage system, Energy conversion and management, 171 (2018) 398-410.
[18] Q. Liu, X.-B. Feng, X.-L. Wang, Multiple-relaxation-time lattice Boltzmann model for convection heat transfer in porous media under local thermal non-equilibrium condition, Physica A: Statistical Mechanics and its Applications, 545 (2020) 123794.
[19] A. Amiri, K. Vafai, Analysis of dispersion effects and non-thermal equilibrium, non-Darcian, variable porosity incompressible flow through porous media, International journal of heat and mass transfer, 37(6) (1994) 939-954.
[20] G. Zhao-Li, Z. Chu-Guang, S. Bao-Chang, Non-equilibrium extrapolation method for velocity and pressure boundary conditions in the lattice Boltzmann method, Chinese Physics, 11(4) (2002) 366.
[21] X. He, S. Chen, G.D. Doolen, A novel thermal model for the lattice Boltzmann method in incompressible limit, Journal of computational physics, 146(1) (1998) 282-300.