太阳能热发电用高温相变蓄热器的数值模拟

Numerical simulation of high-temperature phase transition thermal energy storage container for solar thermal power generation applications

对采用单级相变材料(PCM)蓄热的太阳能热发电用高温相变蓄热器的蓄热过程进行了数值模拟。得到了采用单级蓄热时熔化过程中PCM温度和液相率随时间的变化曲线及不同时刻液相率的分布云图。通过对曲线和云图的分析,在保证蓄热量的前提下,提出了采用3种PCM级联蓄热的高温相变蓄热器的设计方案,并对其蓄热性能进行了模拟。结果表明,采用级联蓄热的方案减小了蓄热的总时间,且有效地降低了单级蓄热末期"死区"对蓄热性能的影响,使PCM的液相率分布更加均匀,为太阳能热发电用高温相变蓄热器的优化设计提供了理论依据。

The heat storage process of the high temperature thermal energy storage container using single-stage PCM for solar thermal power generation is numerically simulated. The change curves of the PCM＇s temperature and liquid rate over time during the single-stage thermal stage melting process and its cloud distributions of the liquid rate at different time have been obtained. Through the analysis of the curves and cloud figures, in the premise of ensuring the heat accumulation amount, three kinds of PCM cascade regenerative high temperature thermal energy storage container design schemes are derived and simulated on their regenerative performance. The result indicates that the cascade heat storage schemes greatly reduce the total heat stor- age time and the ＂dead zones＂ effects effectively on the performance of heat storage during the single-stage regenerative terminal stage, which can make the PCM liquid rate distribution to be more uniform. It provides the theoretical basis for the optimization design of the high temperature phase change thermal energy storage container for solar thermal power generation applications.