Design and experimental investigation of topology-optimized fin structures for enhanced heat transfer in latent heat thermal energy storage units

In order to enhance the heat exchange rate between the heat transfer fluid and the phase change material (PCM), the placement of fins in the latent heat thermal energy storage (LHTES) unit is an effective means. To this end, this paper introduces a novel fin structure that can evolve along the optimization process using a topology optimization strategy, aiming to optimize the spatial layout of the fins and maximize the thermal performance of the LHTES unit. The numerical results demonstrate that the topological fins (TOF) outperform the conventional rectangular fins (CF) in effectively enhancing the temperature and liquid phase fraction of the PCM. Following this, the TOF was fabricated using selective laser melting and tested in an experimental platform containing three types of LHTES units to examine its thermal properties. The findings from the experiments indicate that the TOF exhibits superior thermal performance and can achieve a more uniform heat exchange with the PCM. Specifically, under the heat storage and release conditions of 90 degrees C-60 degrees C, the heat transfer efficiency of the TOF unit is enhanced by 57.8 % compared to that of the finless unit, and by 25.26 % compared to that of the CF unit. Similarly, under the heat storage and release conditions of 85 degrees C-65 degrees C, the heat transfer efficiency of the TOF unit is improved by 67.54 % compared to the finless unit, and by 22.84 % compared to the CF unit. Consequently, in engineering applications, LHTES units equipped with TOF can achieve faster heat storage and release, and exhibit greater responsiveness to load changes in the energy system.