多相变材料蓄热器蓄热特性数值模拟研究

Numerical Simulation of Thermal Energy Storage Characteristics of Multiple Phase Change Materials

本文基于单蓄热介质套管式蓄热器蓄热过程中换热流体沿流向的温度分布特点,提出了多相变材料套管式蓄热器,并采用数值模拟的方法研究了该蓄热器的蓄热过程特性,分析了蓄热过程中换热流体沿流向的温度变化特性,蓄热材料的熔化及温度分布特性。与单蓄热介质(切片石腊)相比,多相变材料(切片石腊和石蜡C16)蓄热器换热流体出口温度降低了38%,且达到相同液相率时其蓄热时间缩短了15%。结果表明,在蓄热时,相变材料的熔化温度随换热流体温度降低而相应降低将有利于提高蓄热速率、增大单位时间内的蓄热能力。

Based on the temperature distribution of heat transfer fluid along the direction of the fluid flow in the thermal energy storage container with a single Phase Change Material（PCM）, a thermal energy storage container of multiple phase change material is proposed. The characteristics of heat transfer during the thermal energy storage process are investigated by using numerical method. The variation of some physical parameters with time are analyzed during thermal energy storage process, such as the temperature of heat transfer fluid, the temperature of multiple phase change material, and the percentage of liquid formation. The outlet temperature of heat transfer fluid of multiple phase change material decreases 38% compared with single phase change material, and the thermal energy storage time decreases 15%at the same percentage of liquid formation. The results show that the decrease of melting temperature of phase change material along the direction of heat transfer fluid flow is helpful to decrease the time of thermal energy storage and increase the thermal storage capacity per unit time.