Performance of suspended finned heat pipes in high-temperature latent heat thermal energy storage

This study presents a thermal network model for evaluating heat transfer enhancement in a high-temperature latent heat storage unit incorporating finned heat pipes. The objective of this heat enhanced latent heat storage system was to improve the thermal performance of concentrating solar power plants. In this proposed design, finned heat pipes are used in the heat storage unit as effective heat spreaders. The finned heat pipes are kept in suspension and are adjacent to the heat transfer channel in order to increase the overall heat conductance of the phase change material (PCM). The feasibility of the proposed design was established by conducting experimental measurements of the solidification process. The results have shown that the performance was significantly improved by adding finned heat pipes, especially at the later stage of PCM solidification. The performance enhancement was quantified based on heat pipe effectiveness. It was found that the effectiveness of the twelve-heat pipe configuration reached 2.4 after 5 h of simulated operation. In addition, a preliminary system sizing was conducted in order to estimate the system size required for 50 MW electrical power output.