Numerical investigation on enhancing phase change material thermal response through optimized fin design

This research presents a comprehensive numerical analysis on the thermal performance of the phase change material (PCM)-based thermal energy storage (TES) system associated with the concave- and convex-shaped fins under the influence of conduction-only and natural convection regimes. Seven various cases including an unfinned base case and varied finned geometries were investigated to assess their influence on the phase change behavior, static temperature behavior, heat flux, and total energy storage efficiency. The conduction study discovered the slow heat penetration and restricted PCM melting when there is no fluid motion, whereas the thermal performance of the system was improved under natural convection currents. It was revealed from various investigating parameters like liquid fraction, temperature distribution, heat flux, and overall energy storage capacity that case 7 (four-arc convex fins) possessed the maximum thermal efficiency in both conduction and convection regimes, making a 33 times improvement in the energy storage capacity and a reduction of 75% in the total charging time as compared to the base case. These outcomes emphasize the importance of the optimized fin geometry and convection current in the thermal enhancement of TES system, making it more suitable for advanced high-demand energy storage applications like industrial waste heat recovery and solar thermal applications.