Thermal performance of copper foam/paraffin composite phase change material

Phase change materials are promising options for thermal energy storage and thermal energy devices. However, their low thermal conductivity lowers their charging and discharging rate. In this paper, copper foam was utilized to enhance the thermal performance of the paraffin. A visible experimental device was built to investigate the melting behavior of paraffin with and without copper foam. The effect of the heating position on the thermal performance of copper foam/paraffin composite phase change material (CPCM) was also discussed. The heat transfer characteristics including solid-liquid interface development, temperature distribution and wall temperature of the heater were tested and recorded. In addition, a numerical model was established using one-temperature volume averaging method to analyze the melting process of the CPCM. The experimental results showed that the total melting time of the CPCM was 20.5% shorter than that of pure paraffin, and the CPCM heated at the top melted slowest and reached the biggest temperature difference in the three heating conditions, so the effect of natural convection on the melting process of the CPCM could not be neglected. A two dimensional numerical simulation was also performed to analyze the melting behavior of CPCM, and the numerical results were well consistent with the experimental data.