Effect of enhancement in metal foam pore density on heat transfer of phase-change materials

• Published in: International communications in heat and mass transfer 2023-05, Vol.144, p.106750, Article 106750
• Main Authors: Wang, Zilong, Sun, Xiangxin, Zhu, Mengshuai, Zhu, Liucan, Zhang, Hua, Dou, Binlin, Wu, Weidong, Szymczak, Piotr, Wu, Rui
• Format: Article
• Language: English
• Subjects: Copper foam; Enhancement of heat transfer; Phase change materials; Pore density; Thermal storage performance
• ISSN: 0735-1933; 1879-0178
• DOI: 10.1016/j.icheatmasstransfer.2023.106750

To explore the effect of metal foam(MF)pore density on the melting and heat transfer of phase-change materials(PCMs), a semi-cylindrical visualization experimental setup was established to experimentally study copper MFs with different pore densities coupled with paraffin wax. The results showed that as pore density increases, the melting time of the composite PCMs decreases compared to that of pure paraffin wax by 11.5%, 16.2% and 18.1% for pore densities of 5, 20, and 30 PPI, respectively. Composite PCMs with a pore density of 30 PPI exhibited fastest melting and lowest maximum temperature difference during melting. Considering the relative thermal energy storage(TES) capacity and relative TES rate, composite PCMs with a pore density of 30 PPI exhibited optimal overall thermal storage performance. Furthermore, heat conduction was the primary means of thermal transmission during the melting of the bottom paraffin. However, the melting of the upper paraffin was nevertheless influenced by natural convection, Hence, as pore size decreased, the influence on the weakening of natural convection became more significant. The results of the study provide guidance for the optimal design of latent heat storage devices for semi-cylinders. •The metal foam's pores are smaller the more effectively it transfers heat.•The copper foam with a 30 PPI pore density exhibited the best thermal storage performance.•The natural convection effect was less noticeable as pore size decreased.•The rate of heat storage increased as pore density continued to rise.