储液器在被动式热交换下环路热管的热性能研究

Study on Thermal Performance of Loop Heat Pipe with Passive Heat Exchange for Accumulator

环路热管是应用于航天器、航空器、舰船等设备的新型换热器件,热性能是评价环路热管的主要性能参数。通过试验和系统级数值模拟研究了当储液器处于自然对流的被动式热交换时,环路热管在不同冷源温度下的温度分布特性和换热性能,说明环路热管总热阻和冷凝器利用率受冷源温度的影响规律。环路热管存在可变热导和固定热导区:在可变热导区,环路热管总热阻随热负荷的增大迅速减小,而升高冷源温度有助于降低总热阻;进入固定热导区后,总热阻则趋于稳定。蒸发器换热系数随着热负荷的增大先增大后减小,但其变化幅度在冷源温度较高时明显减弱。

The loop heat pipe is a new-fashioned heat exchanger applied in spacecraft,and thermal performance is the main performance parameter of a LHP.Experimental and systematic numerical study are conducted on the temperature distribution and heat transfer property in the loop heat pipe under different condenser temperatures,when the reservoir is in the passive mode of heat exchange,i.e.the natural convection.The paper also discusses the effect of the condenser temperature on the total thermal resistance of the loop heat pipe and the utilization ratio of the condenser.The loop heat pipe has both variable and fixed conductance mode.In the variable conductance mode,the total thermal resistance of the LHP decreases rapidly with increased heat load and increased condenser temperature.In the fixed conductance mode,the total thermal resistance tends to be stable.The heat transfer coefficient of the evaporator firstly increases and then decreases with increased heat load,but this variation range is reduced when the condenser temperature is high.