Temperature control performance of high thermal conductivity metal foam/paraffin composite phase change material: An experimental study

Abstract

Phase change material (PCM) has been widely used in the temperature control system of electrical devices. The temperature control effect greatly depends on the thermal conductivity and melting enthalpy of PCM. The purpose of this study is to prepare metal foam/paraffin composite PCM (MFPCM) with high thermal conductivity and melting enthalpy, and experimentally investigate the effects of metal foam structure on the temperature control performance of MFPCM embedded in vertical square cavity. Firstly, the directional compression method was used to change the pore structure of metal foam and improve the directional thermal conductivity of MFPCM. The test results show that when the compression rate of metal foam is 0.2, the thermal conductivity of MFPCM increases by 23.3% compared with traditional MFPCM, while the melting enthalpy only decreases by 7.5%. On this basis, the temperature control performance of MFPCM was tested experimentally, and a two-stage metal foam filled model with gradient porosity was established. The experimental results show that the presence of metal foam can greatly enhance the temperature control effect, especially for the metal foam after directional compression. In addition, the filling model with porosity increase along heat flow direction can play a better role in improve temperature control effect of MFPCM, and the average heating surface temperature at 1000 W/m2 is 45.2 ℃.