Investigation of morphological characteristics of concentric tube thermal energy storage

Abstract

This study focuses on the heat transfer intensification of concentric tube type thermal energy storage (TES). The collective influence of aspect ratio (ratio of length to diameter of the tube) and number of fins is investigated. The validation of mathematical model adopted in this research is performed by experimental results available in the literature. To optimize thermal energy storage, first an optimal aspect ratio investigated. And then, optimal number of fins is obtained. Thermal energy storage with combined optimal configuration is then compared with the concentric tube thermal energy storage without fins. Results are compared based on the amount of liquid fraction available after 120 minutes of charging and discharging. It was found that with an increasing aspect ratio, liquid fraction also increased, but up to the aspect ratio of 11. Afterwards, an increased aspect ratio showed insignificant change in the liquid fraction. Similarly, liquid fraction in case of charging was increased with increasing the number of fins up to 8. Afterward, an increased number of fins showed insignificant change in the liquid fraction. Liquid fraction of the optimized thermal energy storage was increased by 100% for case of charging and decreased by 35% for the case of discharging as compared to the thermal energy storage without fins.