Experimental Study of Phase Change Process of the Paraffin as a PCM with Copper Foam and Iron Wool

Paraffin waxes are widely used as commercial organic heat storage phase changes (PCM) for many applications due to their suitable properties. Significant heat from fusion, nonpoisonous and stable properties, no phase separation, and the phase process result in a small volume change. Meanwhile, they are subject to low thermal conductivity. The thermal conductivity of PCMs can be increased by different techniques such as the use of dispersion of particles or nanomaterials with high conductivity in PCM and the use of metal foams. The use of nanoparticles has such disadvantages as high cost and particle deposition after various cycles. Hence, in this study, some experiments were carried out to investigate the effect of porous media like copper foam and iron wool as the filler instead of nanomaterials on improving the heat conductivity of PCM. The results show that the porous foam increases the heat transfer and during the charging operation, the temperature of the porous plate wall increases continuously at the same rate as the paraffin. At 2400 s, the temperature of pure PCM, iron wool, and copper foam reaches 67.3, 72.5, and 73.27℃, respectively. The optimal mode is the one in which the copper absorber plate is connected to the copper foam, thus reducing the charging time by 600 s compared to pure PCM and saving 75% of energy. Connecting the copper absorber plate to the iron wool has a good thermal performance and stores 70.83% of energy. Thus, iron wool has an acceptable performance and is suitable for storage systems.