Experimental investigation of the impacts of various parameters on thermal energy storage and release behavior of paraffin-based phase change materials

Abstract

This study experimentally investigates the charging and discharging patterns of the paraffin-based phase change materials (PCM) in a shell and tube thermal energy storage system under varying operating conditions. The effects of heat transfer fluid temperature, flow rate, and system orientation were systematically assessed. The results demonstrate that system orientation and other parameters have a significant impact on thermal performance, influencing both phase change duration and energy recovery characteristics. Melting time varied between 49 and 177 min, while solidification time ranged from 397 to 680 min under various operating conditions. Although the total stored energy remained within a relatively narrow range from 225 kJ to 283 kJ. On the other hand, the recoverable energy time improved by up to 20% for inclined and vertical configurations compared to the horizontal orientation. Moreover, thermographic and visual analysis showed more detailed physical behavior of the PCM during its melting and solidification process, providing more insights into the underlying heat transfer mechanisms.