Thermal transport process of metal foam/paraffin composite (MFPC) with solid-liquid phase change: An experimental study

Abstract

In this work, thermal transport process of open-cell metal foam/paraffin composite (MFPC) with solid-liquid phase change is experimentally investigated. The benchmark data including planar visualized phase and temperature fields of MFPC as well as temperature variations at critical inner positions are obtained by using photography and infrared technique together with thermocouples, respectively. The phase transition process of MFPC and influences of porous foam structure (featured by porosity and pore density) have been analyzed in detail, concerning both heat transfer characteristics and thermal control performance. It is revealed that the foam structure parameters influence evidently the thermal diffusion and convection in MFPC, which further have crucial impacts on the phase change evolution and thermal transport, leading to distinct phase interface shapes and phase change rates, as well as different temperature distributions in the phase change unit and its adjacent heating source. By decreasing foam porosity or pore density, it can result in evident influences, including: (1) enhancing the thermal diffusion in MFPC; (2) strengthening the local thermal non-equilibrium between foam matrix and paraffin; (3) expediting the propelling of phase interface; and (4) improving the phase change synchronism and temperature uniformity of paraffin. Moreover, it is preferred to apply the MFPC with a lower enough porosity and a relatively higher pore density for maintaining a low-temperature heating condition and uniform temperature distribution in heat-generating devices needing suitable thermal management. This work gives both benchmark data and physical characteristics related to phase change of MFPC, which is beneficial to better application of MFPC, ensuring both high performances of thermal transport and thermal control.