Effect of contact thermal resistance and skeleton thermodynamic properties on solid-liquid phase change heat transfer in porous media: A simulation study

Abstract

Phase change materials (PCMs) have the potential for heat storage and release, but low thermal conductivity limits their wide application in thermal systems. This work proposes a mathematical model to simulate the freezing process of water in porous media. Unlike traditional methods that solve for two temperatures in different materials, the hybrid finite element method computes a single temperature satisfying the jump on the interface. The effect of contact thermal resistance and skeleton parameters on solid-liquid phase change heat transfer was investigated. This model was validated by experiments in reference. Results show that increased contact thermal resistance decreases temperature gradient, phase interface deflection and freezing rate. Specifically, with contact thermal resistance of 0.0001 K/W, 0.0005 K/W, and 0.001 K/W, freezing rates decrease by 36.4 %, 52.35 %, and 54.14 %, respectively, compared to the case without resistance. Although the contact thermal resistance reduced the temperature gradient, it stabilized the phase change process. Moreover, higher thermal conductivity of the skeleton enhances the freezing rate. However, after a certain value is reached, the rate increases only marginally. Skeletons with lower density and specific heat capacity are favorable to enhancing phase change heat transfer.