Research on the heat storage and optimization of the heat transfer performance of a phase change heat storage heat exchanger based on flow heat transfer

Conserving energy, reducing emissions, and efficiently utilizing energy have become common global goals in the post-carbon era. Thermal storage technology can effectively solve the contradiction between thermal energy supply and demand in terms of time and intensity while avoiding energy waste, thus improving the efficiency of energy utilization. This study analyzes the influence of factors such as fin shape, thickness, quantity, and phase change material (PCM) filling thickness on the heat storage and transfer performance of a phase change heat storage heat exchanger (PC-HS-HE) through a combination of simulations and experimental methods. A geometric model was established that includes serpentine tubes and serrated fins, with paraffin wax used as the PCM filling the space between the tubes and fins. Through COMSOL simulation analysis, it was found that serrated fins could significantly enhance the heat exchange efficiency compared to flat fins by about 3.27%. The height and quantity of fin teeth also have an impact on heat exchange performance, but too many fins can hinder external heat dissipation. The optimization of PCM filling thickness indicated that thinner PCM layers (70 mm) have a faster thermal response speed than thicker ones, but they also have a more limited thermal storage capacity. Based on the simulation results, an experimental platform was built to verify the thermal storage and release characteristics of the PC-HS-HE. The experiment shows that the heat exchanger exhibits significant improvement in heat exchange efficiency within the paraffin temperature range of 310–349 K. The study ultimately determined the optimal structure for the PC-HS-HE: five serrated fins with a tooth height of 1.6 mm and a PCM filling thickness of 70 mm. This structural design can achieve rapid PCM heating and stable heat release from thermal storage materials, making it suitable for scenarios requiring heating at a constant temperature. This study analyzes the influence of factors such as fin shape, thickness, quantity, and phase change material (PCM) filling thickness on the heat storage and transfer performance of a phase change heat storage heat exchanger (PC-HS-HE) through a combination of simulations and experimental methods. A geometric model was established that includes serpentine tubes and serrated fins, with paraffin wax used as the PCM filling the space between the tubes and fins. Through COMSOL simulation analysis, it was found that serrated fins could significantly enhance the heat exchange efficiency compared to flat fins by about 3.27%. The height and quantity of fin teeth also have an impact on heat exchange performance, but too many fins can hinder external heat dissipation. The optimization of PCM filling thickness indicated that thinner PCM layers (70 mm) have a faster thermal response speed than thicker ones, but they also have a more limited thermal storage capacity. Based on the simulation results, an experimental platform was built to verify the thermal storage and release characteristics of the PC-HS-HE. The experiment shows that the heat exchanger exhibits significant improvement in heat exchange efficiency within the paraffin temperature range of 310–349 K. The study ultimately determined the optimal structure for the PC-HS-HE: five serrated fins with a tooth height of 1.6 mm and a PCM filling thickness of 70 mm.