Filling copper foam partly on thermal behavior of phase-change material in a rectangular enclosure

The copper foam is widely applied to improve the heat transfer performance of Phase-Change Material (PCM) used in Latent Thermal Energy Storage (LTES) system, but it will occupy the certain PCM place, resulting in the heat storage density reduction. To justify the contribution of copper foam and then explore the suitable volume fraction, a rectangular enclosure filled with PCM was built with 8 kinds of filling ratios of copper foam for comparison. A two-dimensional numerical simulation considering the two-temperature equation was built and validated by experimental results with the commonly employed evaluation parameters including the liquid fraction, temperature response rate, heat flux and heat storage capacity. Results showed the higher the volume fraction, the larger the improved thermal performance. The copper foam had a larger influence in the solidification process than in the melting process. Melting and solidification times were reduced by 93.32% and 97.63% for the volume fractions of 4.783% and 10.00%, respectively, compared to pure PCM. And the contribution efficiency of unit volume fraction was analyzed on melting and solidification time, temperature response rate, average heat flux and heat storage capacity under different volume fractions for the application reference.