Enhancing the characteristics of the heat transfer of paraffin wax (RT65) as PCM (Phase Change Material) is required to be used in energy storage system. Carbon Foam matrix (CF20) and other Multi Walls Carbon Nano Tubes (MWCNTs) additives have been recently used on the research and applications levels for this enhancement. Quantitate evaluation of the thermal conductivity enhancement due to these additives have not been addressed. In the present work, experimental investigation for predicting correlations for the thermal conductivities of CF20 infiltrated either with RT65 as a PCM or RT65/MWCNTs composite as thermal conductivity enhancer have been conducted for different percentages of MWCNTs and temperatures. The results showed that (i) the reduction of CF20 thermal conductivity due to RT65 infiltration can be regained by the addition of MWCNTs to RT65, and (ii) the enhancement in the thermal conductivity of RT65-MWCNTs composite and CF20 + RT65-MWCNTs structure increases with increasing the MWCNTs percentage and decreasing the sample temperature. Correlations of thermal conductivity of RT65/MWCNTs and CF20 + RT65/MWCNTs are deduced in terms of the MWCNTs percentage and temperature. The correlations prediction was compared with the present experimental data and a fair agreement has been obtained. |
