Variable PCM Density-based Numerical Model for Packed Bed Latent Heat Thermal Energy Storage

Abstract

This work focuses on developing a numerical model for packed bed latent heat thermal energy storage with cylindricalshaped encapsulation of phase change material (PCM). A local thermal non-equilibrium model with a porous media approach is developed. The effect of shrinkage and expansion of PCM during melting and solidification are considered. The PCM density is modelled as the function of melt fraction, liquid and solid density of PCM. The latent heat part of PCM is modelled using the enthalpy-porosity approach. The flow of heat transfer fluid (HTF) over the cylindrical particles is considered a cross-flow arrangement. In this numerical modelling, three equations for HTF (mass, momentum and energy) and one energy equation for PCM and storage tank wall are solved. The main purpose was to develop a computationally efficient model that can capture and incorporate the shrinkage and expansion effect of PCM while melting and solidification.