Multi-Scale Modeling in Solid–Liquid Phase Change Conjugate Heat Transfer for Thermal Energy Storage Applications

Abstract

Latent heat thermal energy storage is essential for handling the intermittent issue of solar energy due to its large energy storage density. However, the phase change materials usually suffer from the drawback of low thermal conductivity, significantly hindering the latent heat thermal energy storage efficiency. Facing this challenge, several heat transfer enhancement technologies are developed to ameliorate the thermal response of phase change materials. Even though the charging and discharging processes of latent heat thermal energy storage systems could be accelerated by high thermal conductive extended fins, porous media, and nanoparticles, there exists a trade-off effect between the enhanced heat transfer rate and the reduced energy storage capacity. Under this situation, the heat transfer process inside latent heat thermal energy storage units needs to be carefully optimized. Due to the advantages of high flexibility and low cost, numerical modeling plays an indispensable role in clarifying thermal behavior during latent heat thermal energy storage. In this chapter, we firstly highlight multi-scale numerical methods and their coupling schemes for solid–liquid phase change conjugate heat transfer including molecular dynamics simulation, lattice Boltzmann method, and finite volume method. Then, applications of multi-scale modeling techniques in latent heat thermal energy storage are briefly provided.