Experimental analysis of latent heat thermal energy storage system using encapsulated multiple phase-change materials

The current study aims to improve the energy storage capability of the thermal energy storage system by utilizing multiple phase-change materials. In this regard, a new thermal energy storage system has been studied when multiple phase-change material with different melting temperatures are employed. In this study, three-set, each having 70 encapsulated phase-change materials, are arranged horizontally in the order of decreasing melting temperature for the charging cycle and increasing melting temperature in the case of discharging cycle. Water is employed as heat transfer fluid, and the SAE 304 spherical capsule with a diameter of 60 cm is used to encapsulate the phase-change material. The arrangement showed an excellent thermal response for input parameters such as inlet temperature, flow rate. Further, it was observed that as the heat transfer fluid flow rate increases from 1 litres per minute (LPM) to 5 LPM, the melting and solidification time decreases from 10% to 30% and 14% to 28%, respectively. It was also noticed that as the flow rate increases, exergy and overall efficiency decreases.