Thermal Characteristics of Temperature Distribution of Plate Phase Change Energy Storage Unit

Abstract To analysis the temperature distribution of the plate-type phase change energy storage unit, a series of simulation was carried out to investigate the heat storage/release process in a plate phase change material (PCM) heat storage unit, the PCM channel number of which is 39, the plate spacing is 0.01 m, the air channel is 40 with its plate spacing of 0.003 m, and the unit length is total of 1.62 m. The simulation used Fluent Enthalpy method, and the results show that during the whole heat storage process, PCM is melted step by step along the fluid flow direction. In the initial stage of heat storage, the temperature difference is relatively large between the PCM side and the fluid side, and also the corresponding heat transfer rate is. With the heat storage time, the temperature mentioned above gradually shrinks, and the heat transfer inside the system gradually shifts from the lateral direction to the radial direction. In the later stage for heat storage, the temperature difference between the PCM and the fluid decreases gradually with the increase of PCM temperature locally, and then the heat transfer rate of the whole system decreases gradually. As well, the air heating rate accelerates with the increase of heat storage rate under different speed conditions, and relatively the average PCM temperature in the initial stage increases faster than that in the later stage of heat storage.