Phase-change materials for storing heat extracted from heat pump condensers

This study aims to investigate the storage of heat from a heat pump's condenser in a well-insulated cylindrical tank filled with spherical capsules containing a phase-change material (PCM). Using a detailed physical model and the enthalpic method, the system's operation and phase change phenomena are simulated. The impact of various operational parameters, such as condenser power, water flow rate, storage volume, and PCM type, is examined. The results reveal that increasing condenser power significantly reduces the PCM loading time, achieving a 66 % reduction within the 5 kW to 15 kW power range. Additionally, decreasing the water flow rate enhances storage efficiency by 15 % when the flow rate drops from 2.3 m3/h to 1 m3/h. The use of a PCM with a melting temperature of 44 degrees C is deemed more suitable for the system compared to other options.