Effect of porosity and pore density of copper foam on thermal performance of the paraffin-copper foam composite Phase-Change Material

Abstract

Latent thermal energy storage was widely used in many thermal engineering, but the low thermal conductivity of Phase-Change Material (PCM) limited the thermal storage efficiency seriously. Filling metal foam has been an effective way to enhance the heat transfer due to its capability to improve the overall heat conduction effectively. To optimize the thermal performance of the paraffin-metal foam composite PCM, this study analyzed the influence laws of porosity and pore density of copper foam. A two-dimensional numerical model considering two-temperature non-equilibrium equation was built and validated by published results, while the four parameters including the liquid fraction, the temperature response rate, the heat flux, and heat storage capacity were evaluated. The results showed reducing the porosity could improve the thermal behavior of composite PCM especially between 92% and 98%, but it would reduce the heat storage capacity of about 22.3 kJ per the 2% increased porosity. The recommended porosity was 92%. Moreover, increasing pore density could also enhance the thermal behavior of the composite PCM, especially between 5PPI and 15PPI, and it had no influence on the heat storage capacity.