填充床储热系统作为一种重要的储热方式,填充材料的物性以及储热温度对其性能有显著影响。为了获得详细的影响规律,本文使用局部非热平衡模型对高温固体颗粒填充床内的气固两相对流换热过程开展了数值模拟,研究了不同颗粒材料(岩石、氧化铝、碳化硅)、储热温度(600 K、900 K、1200 K)对蓄放热过程中床层内温度分布、压力损失、蓄热效率、放热功率、循环?效率的影响。模拟结果表明,碳化硅体积比热容最高,对应的填充床储热系统的蓄热量、蓄热效率、循环?效率也最高。当储热温度从600 K分别提升到900 K和1200 K时,蓄热效率分别提升了约2%和3%,放热功率提升一倍和两倍,?效率提升38% - 70%和55% - 100%。该研究结果将为高温固体颗粒填充床储热系统的设计提供重要参考。

The packed bed storage system is an important thermal energy storage method, and both physical properties of the filling material and heat storage temperature have significant effects on system’s performance. To find out the specific influence rules, the convective heat transfer process between gas and solid phases in a granular packed bed was numerically analyzed by using non-thermal equilibrium model. To compare the effects of different particle materials (rock, Al2O3, SiC) and different heat storage temperatures (600 K, 900 K, 1200 K) on the performance of heat storage system, the temperature distribution in the packed bed, air pressure loss, heat charging efficiency, heat discharging power and exergy efficiency during heat storage and release cycle were analyzed. The results showed that the heat storage capacity, heat charging efficiency and cycle exergy efficiency of SiC particle packed bed were all the highest due to the largest volume specific heat capacity of SiC. Besides, the heat charging efficiency was increased by about 2% and 3%, the heat discharging power was doubled and increased by two times, and the exergy efficiency was increased by 38% - 70% and 55% - 100%, respectively, when the thermal storage temperature is increased from 600 K to 900 K and 1200 K. The numerical results will provide the reference for the design of heat storage system of high temperature solid particle packed bed.

TK512