组合相变材料储热系统的储热速率研究

STUDY ON CHARGING AND DISCHARGING RATES OF LATENT HEAT THERMAL ENERGY STORAGE SYSTEMS EMPLOYING MULTIPLE PHASE CHANGE MATERIALS

建立了组合式柱内封装相变材料熔化—固化循环相变储热系统的物理模型 ,用有限差分法进行了数值模拟求解。结果表明 ,与采用单一相变材料的传统储热系统相比 ,在给定相变材料组合方式和传热流体进口温度条件下 ,传热流体流量存在最佳值 ;选用三种石蜡作相变材料和水作传热流体的模拟计算结果表明 ,相变速率可提高 15 %— 2 5 %左右。

This paper proposed a physical model of cyclical melting freezing phase change processes of latent heat storage system employing multiple phase change materials(PCM)encapsulated in horizontal staggered tubes.The finite difference method was used to simulate the dynamic phase change processes.Compared with the traditional latent heat storage systems using single kind of PCM,the heat transfer fluid exists an optimum flow rate,which is corresponding to the minimum phase change time.Calculation results demonstrated that the charging and discharging rates can be increased by 15%-25% by using three types of paraffin waxes as PCMs.