Effect of Internal Fins on the Melting Behavior and Energy Storage in Latent Heat Systems

This study presents a comparative numerical analysis of two latent heat thermal energy storage (LHTES) systems: a basic cylindrical configuration and an enhanced model incorporating internal fins. Both systems utilize phase change materials (PCM) as the storage medium and are equipped with U-shaped internal heat transfer mbes for the circulation of heat transfer fluid (HTF). The thermal charging process was simulated using COMSOL Multiphysics by solving the coupled Navier—Stokes and heat transfer equations under transient conditions. Natural convection at the outer surface was also considered to account for ambient heat exchange. The simulations investigated the temperature evolution, fluid flow dynamics, melting behaviour, phase transition characteristics, and thermal energy storage capacity of both configurations. Results indicate that the presence of internal fins significantly improves heat transfer within the PCM domain, leading to faster melting rates and enhanced thermal storage performance. The finned LHTES demonstrated a more uniform temperature distribution and higher melting fraction over time, confirming the effectiveness of conductive enhancement structures. These findings provide valuable insights for the optimization of PCM-based thermal storage systems, particularly for applications requiring rapid energy charging and efficient heat management.