Investigations on transient thermal performance of phase change materials embedded in metal foams for latent heat thermal energy storage

A feasibly numerical model based on enthalpy-porosity and local thermal non-equilibrium is proposed to explore the transient heat transfer characteristics of phase change materials (PCMs) embedded in metal foams during charging process. Parametric analysis elaborates effects of various parameters on thermal performance of PCMs. Heat transfer and storage performances are further conducted from the perspectives of transient temperature. Results indicate that metal foams are capable of boosting melting rate of PCMs and phase change heat transfer is dominated through thermal conduction with obviously weakened natural convection. Metal foams with less thermal conductivity lead to lower temperature differences between metal foams and PCMs and more uniform temperature distributions of PCMs embedded in metal foams are developed over pure PCMs case. The complete melting times of PCMs can be shorten by approximately of 55.03%, 54.75% and 49.58%, when incorporated in metal foams and superiorities are even more obvious under lower porosity, larger pore density or higher heat flux. Greatest results in profiles and contours of temperature difference correspond well to mushy zones of phase transitions. Thermal energy is primarily reserved in PCMs in the form of latent heat. In conclusion, this paper is expected to be explicitly beneficial to broaden phase change energy storage applications.