Experimental study on thermal performance of phase change heat storage device with rectangular shell structure

To solve the imbalance between energy supply and demand, it is necessary to explore the heat exchange performance of large-scale phase change heat storage devices in line with engineering applications. Based on the principle of low-cost enhanced heat transfer, a shell and tube phase change heat storage device with a rectangular shell with annular fins was designed in this paper. Using paraffin as phase change material (PCM) and water as heat transfer fluid (HTF). The effects of different flow rates and inlet temperature on the temperature distribution, heat, power, and efficiency of phase change materials during melting and solidification were studied experimentally. It is found that when the flow rate is 4 L/min, the total heat release was 61.06 MJ and the minimum heat release rate was 81.23%. The increase in flow rate and inlet temperature will shorten the heat storage time. The influence of inlet temperature on the heat storage time is more obvious than flow rate. Along with the raise of flow rate the shortening range of heat storage time decreases gradually. Additionally, the increase of the flow rate not only causes the enhancement of the heat storage and release power, but also results in the reduction of the average efficiency. Therefore, to improve the heat exchange speed in practical application, priority should be given to changing the inlet temperature.