组合式相变材料吸热器热性能研究

针对NASA 2kW高温相变吸热器采用单-熔点的相变材料出现的问题，提出了由3种相变温度不同的相变材料组成的组合PCM吸热器模型，建立了相应的物理模型，给出了数值求解方法，计算了换热管最大温度、工质出口温度、换热管总PCM熔化率等结果。并与单一PCM换热管吸热器进行了比较分析，说明采用组合PCM换热管可以很好地提高吸热器的性能，减少工质温度被动、减少吸热器质量。计算结果可用于指导吸热器的设计。

ANALYSIS OF THERMAL PERFORMANCE FOR A COMBINED HEAT RECEIVER OF MULTI-PHASE CHANGE MATERIALS

Aiming at the problems caused by employing the single melt point phase change material in heat receiver for the NASA 2 kW solar dynamic power system, this paper presents a practically easy to carry-out PCM receiver model composed of three different phase change temperature material together with a corresponding physical model and gives a method fornumerical solute by which the maximal temperature for heat transfer , working fluid exit temperature, liquid PCM fraction of the total heat transfer tube in whole are calculated and compared with those getten from the single PCM heat receiver. The results show it is possible to promote receiver performance, to reducethe fluctuation of working fluid temperature and the weight of heat receiver. All results of the calculation can be used to guide the heat receiver design.