Effect of copper foam fin shapes on the thermal performance of spherical encapsulated Phase-Change Material (PCM) in packed-bed latent heat storage system

Adding copper foam fin (CFF) to encapsulated phase change material (PCM) significantly enhances heat transfer performance. The CFF incorporation improves the thermal characteristics of spherically encapsulated PCMs, particularly in terms of shorter charging and discharging times, increased heat release and storage capacities, and enhanced natural convection during phase transitions. This study investigates the influence of different CFF shapes on the thermal performance of spherical encapsulated PCMs used in a Packed-Bed Latent Heat Storage (PBLHS) system. Three types of CFF-encapsulated PCMs (Z-aligned, XZ-aligned, and XYZ-aligned) were experimentally analyzed to evaluate their effects on heat transfer rates, phase-change times, thermal storage, and release capacities. The results indicate that the heat transfer performance of the PCMs improved substantially with an increase in the number of fins. Specifically, the CFF-encapsulated PCMs demonstrated the most significant enhancement, reducing the charging time to 2300s and the discharging time to 12000s compared to non-finned PCMs. Additionally, the heat storage capacity increased by 76.8%, and the release capacity increased by 181.0%. The presence of CFFs promotes better natural convection during the melting process and ensures effective heat transfer during solidification. Furthermore, the optimized CFF shape significantly improves fin efficiency without excessively reducing the PCM fill rate. These findings suggest that optimizing the CFF shape enhances both heat transfer and storage performance, making the CFF-enhanced PCM system highly suitable for applications such as solar thermal storage and waste heat recovery.