Experimental Study on the Heat Transfer of Metal Foam Filled in Paraffin

In this study, the thermal performance of paraffin saturated open cell metal foam was experimentally investigated by tracking the heated surface and internal temperatures. The effects of metal foam and natural convection on heat transfer in paraffin were discussed. The results showed that the heat conduction played a dominant role for the case of top heating. For the case of bottom heating, the natural convection in liquid paraffin led to the quicker phase change interface movement and more uniform internal temperature. Meanwhile, the temperature of heated surface was controlled in a small range in the phase change-convection zone. The inclusion of metal foam greatly improved the thermal conductivity of paraffin but suppressed the liquid nature convection. The former resulted in the slower temperature rising of heated surface and quicker phase change interface movement. The latter led that the phase change zone can be divided into the phase change-conduction zone and phase change-convection zone for the bottom heating. The enhanced heat conduction due to the fill of metal foam played a dominant role in the heat transfer of paraffin.