Performance study on multiple phase change materials heat storage system during melting process based on entransy theory

摘要

There is a good application prospects in improving the performance for the heat storage system with Multiple phase change materials (PCMs). This article aims to evaluate the performance of multiple PCMs with reasonable PCM proportion from the perspective of entransy. A two-dimensional mathematical model of phase change heat storage unit is established, and verified experimentally. Two indicators, entransy dissipation rate and dissipation factor, are proposed with entransy theory to evaluate the heat storage performance. The influence of the PCM proportions, heat transfer flow (HTF) inlet temperature and flow rate on the performance are explored. Results indicate that the multiple PCMs with the PCM proportion of 2/3/4 is the most optimal. And with the increase of HTF inlet temperature and flow rate, the dissipation factor decreases at first and then increases. So there is also an optimal HTF inlet temperature and flow rate, which is 343 K and 0.0005 m/s respectively. The present research has guiding value for the performance improvement of the device using multiple PCMs.