Experimental study on improving the rapid response performance of modular latent thermal energy storage by topological fins

This study employs a density-based topology optimization method to design latent thermal energy storage modules integrated with topological fin structures. The modules were fabricated through additive manufacturing and tested on a visualized test rig, focusing primarily on its discharging performance. The designed latent thermal energy storage modules contain a heat transfer surface area of 1.73 m², with a rated thermal storage capacity and thermal output power of 1.1 kWh and 2.0 kW, respectively. The topology fin configuration significantly improves the thermal storage and release efficiency of the phase change material. The thermal storage tests conducted at a temperature of 72.3 °C and a flow rate of 6 LPM, which demonstrated a volumetric thermal storage density of 145.3 kWh·m⁻³. At an inlet temperature of 11.3 °C and flow rate of 8 LPM, the average thermal output power is 2.309 kW, with a corresponding volumetric output power density of 305.0 kW·m⁻³. The maximum round-trip efficiency is 92.1 %. The results indicate that once the structure of the latent thermal energy storage system is finalized, the ability to regulate the average thermal output power through adjustments in heat transfer fluid temperature and flow rate becomes limited, with a maximum adjustment range of only 30 % observed in this study. Consequently, the structural design of the latent thermal energy storage system plays a critical role in optimizing its performance.