Experimental analysis of latent thermal energy storage systems based on pure and copper-foam-loaded PCMs

In this work a commercial paraffin PCM (RT35) characterized by a solid-liquid phase change temperature Ts-l = 29 ÷ 36 °C and a low thermal conductivity λ = 0.2 W/m K is experimentally tested submitting it to charging/discharging cycles. The paraffin is contained in a case with a rectangular base and heated from the top thanks to an electrical resistance. The aim of this research is to show the benefits that a 95% porous copper metal foam can bring to a PCM-based system simply loading it, thanks to the consequent strong thermal conductivity increase. The experimental results highlight the positive effects of the copper foam presence such as the heat conduction improvement throughout the system and a significant reduction in time for the complete melting of the PCM. In addition, the experimental data highlight that in the copper-foam-loaded PCM the maximum temperature reached during the heating process is lower than 20 K respect to the test with pure PCM, imposing the same heat flux on the top.