Double cut design of horizontal phase change heat storage device: experimental and numerical study

Latent heat thermal energy storage (LHTES) systems are used to store heat efficiently and reliably. However, the thermal performance of LHTES systems is often limited by their shape. This study aims to improve the heat transfer efficiency of horizontal LHTES storage units through shape optimization by systematically investigating three resection designs: bottom-crosscut, sidecut, and a novel double-cut. The influence of three cutting methods on their thermal performance is studied through experimental analysis and numerical simulation. The double-cut design enhances natural convection in the upper LHTES unit while minimizing the refractory area at the bottom, addressing the critical challenge of uneven heat distribution. The results show that compared with the ring type, the complete melting time distribution of LHTES with the three cutting methods is reduced by 73.93 %, 47.41 %, and 77.22 %, and the average Nusselt number (Nu‾) is increased by 154.71 %, 69.46 %, and 179.52 %, respectively. Due to the better thermal performance of the three cutting methods, the geometrical parameters of the double-cut LHTES are optimized by response surface method (RSM). The optimized configuration reduces the melting time by 81.88 % compared to the ring type and 28.96 % compared to the original double-cut design, significantly enhancing heat transfer efficiency. This study provides valuable design insights and theoretical basis for improving the thermal performance of LHTES systems.