Thermal Performance Analysis of Phase Change Material Based Thermal Energy Storage

The study presents an experimental analysis of the thermal performance of a high energy density phase change material (PCM)-based thermal energy storage (TES) prototype (PCM TES). The PCM TES is designed for use in heating and domestic hot water preparation systems within a temperature range of 40–60 °C. Charging and discharging experiments were conducted using an experimental setup, and several parameters were analysed, including heat transfer fluid (HTF) temperature and mass flow rate, PCM temperature, PCM charging and discharging time, heat transfer rate of the heat exchanger, and stored and released thermal energy. The experiment showed that during the charging process, at a mass flow rate of 0.1 kg/s and an average inlet temperature of hot water of 72 °C, the heat transfer rate decreased from 20.9 kW to 3.4 kW, with an average of 9.3 kW. During the discharging process, at a mass flow rate of 0.1 kg/s and an average cold water inlet temperature of 16 °C, the heat transfer rate decreased from 19.2 kW to 2.2 kW, with an average of 10.6 kW. The amount of heat absorbed and released in the PCM temperature range of 20–70 °C was 7.48 kWh, and the duration of the charging and discharging was 48 min and 37 min 49 s, respectively.