Exploratory investigation of a new thermal energy storage system with different phase change materials having distinct melting temperatures

This paper presents the experimental investigation of the new thermal energy storage system comprising of different PCMs. Three PCMs having different melting temperatures are used to investigate the performance of the system and water is used as a heat transfer fluid (HTF). Spherical AISI 304 L capsules of 55 mm diameter were used to encapsulate the phase-change material. The whole system was operated between different temperature ranges, and HTF (heat transfer fluid) flow was varied from 2 liters/min to 6 liters/min. The temperature inside the bed was continuously monitored using LABVIEW express during the charging and discharging procedures. The effect of inlet temperature and HTF flow rate on the performance of the system was also assessed in the experimental work. The study demonstrates that there is a decrease in the charging time of the packed bed from 28% to 14% when flow rate is increased from 2 liters/min to 6 liters/min. Moreover, the energy efficiency also increases by the increase in mass flow rate. It was also found that there is a decrease in exergy efficiency with the increase in mass flow rate.