Abstract The latent heat thermal energy storage system (LHTES) utilizes phase change material (PCM) to store energy. The non-uniformity in heat transfer between heat transfer fluid (HTF) and PCM along the height of the widely used vertical cylindrical shell and tube type storage tank causes a reduced thermal performance of the storage. Hence, in the present work, a passive heat transfer enhancement technique is proposed through a novel funnel shaped configuration of the shell and tube LHTES to achieve more uniform temperature distribution in the PCM as compared to the cylindrical shell and tube LHTES. Additionally, longitudinal fins are introduced in the HTF tube further to enhance the heat transfer between HTF and PCM. A numerical model is developed using the enthalpy-porosity technique to analyze the phase change phenomenon. The thermal performance of the funnel LHTES is evaluated using the first and second law of thermodynamics. The funnel LHTES with the lateral shell surface tilting up to a height of 250 mm shows higher melt fraction and energy efficiency by 11.5% and 66.6%, respectively compared to the cylindrical LHTES. The latent heat content of the funnel LHTES with a shell tilt height of 250 mm during the charging and discharging period is improved by 1.72 and 1.11 times, respectively than that of the cylindrical LHTES. A significant improvement in the rate of solidification of PCM during the discharging process is obtained with the funnel LHTES.

中文翻译：

---

一种新型漏斗形壳管潜热蓄热系统的性能研究

摘要 潜热蓄热系统（LHTES）利用相变材料（PCM）来储存能量。沿广泛使用的立式圆柱壳管式储罐的高度，传热流体 (HTF) 和 PCM 之间的传热不均匀导致储罐的热性能降低。因此，在目前的工作中，与圆柱形壳管 LHTES 相比，通过壳管 LHTES 的新型漏斗形配置提出了一种被动传热增强技术，以在 PCM 中实现更均匀的温度分布。此外，在 HTF 管中引入了纵向翅片，以进一步增强 HTF 和 PCM 之间的热传递。使用焓-孔隙率技术建立数值模型来分析相变现象。使用热力学第一定律和第二定律评估漏斗 LHTES 的热性能。与圆柱形 LHTES 相比，侧壳表面倾斜至 250 mm 高度的漏斗 LHTES 显示出更高的熔体分数和能量效率，分别提高了 11.5% 和 66.6%。外壳倾斜高度为250 mm的漏斗LHTES在充电和放电期间的潜热含量分别比圆柱形LHTES提高了1.72和1.11倍。使用漏斗 LHTES 可显着提高放电过程中 PCM 的凝固速率。与圆柱形 LHTES 相比，侧壳表面倾斜至 250 mm 高度的漏斗 LHTES 显示出更高的熔体分数和能量效率，分别提高了 11.5% 和 66.6%。外壳倾斜高度为250 mm的漏斗LHTES在充电和放电期间的潜热含量分别比圆柱形LHTES提高了1.72和1.11倍。使用漏斗 LHTES 可显着提高放电过程中 PCM 的凝固速率。与圆柱形 LHTES 相比，侧壳表面倾斜至 250 mm 高度的漏斗 LHTES 显示出更高的熔体分数和能量效率，分别提高了 11.5% 和 66.6%。外壳倾斜高度为250 mm的漏斗LHTES在充电和放电期间的潜热含量分别比圆柱形LHTES提高了1.72和1.11倍。使用漏斗 LHTES 可显着提高放电过程中 PCM 的凝固速率。