Shape-stabilized phase change material convective melting by considering porous configuration effects

Abstract

Phase change material (PCM) encapsulation within a porous medium, known as the shape-stabilized PCM (SS-PCM), is a kind of novel technique for maintaining the PCM during the melting process and improving the conductive heat transfer. However, the performance of the SS-PCM in thermal energy storages and slurries is highly dependent on the thermophysical properties of PCM and the stabilizer’s structure. In this state-of-art study, the convective melting within a circular porous region, as a representative for an embedded PCM particle, is investigated. The main characteristic parameters of SS-PCM, including porosity, permeability, effective thermal conductivity and latent heat of fusion, have been under scrutiny by developing enthalpy-based Lattice-Boltzmann code. The results revealed that the Rayleigh-Benard convection can be shaped at powerful flow circulation that has a significant impact on the melting trend and time. Moreover, improving the thermal conductivity by using highly conductive porous material is reasonable up to a certain optimum point depending on the application. Meanwhile, the porosity of the stabilizer and latent heat capacity of the PCM have shown an inverse impact on the melting performance. They are the main factors in changing heat transfer mechanism, between conduction and convection, and heat storage model, between sensible and latent.