不同冷凝段温度下液氢脉动热管实验研究

Experimental Study on a Hydrogen Pulsating Heat Pipe Under Different Condenser Temperatures

脉动热管是一种高效的传热元件,可用于将低温制冷机冷头的有限冷量分配到更大的面积、传输到更远的距离。本文采用一台两级GM制冷机作为氢工质脉动热管的冷源,测试脉动热管在不同冷凝段温度下的传热性能,实验中充液率为28%@19K。不控制冷凝段温度(实验A)和将冷凝段温度控制在19 K(实验B)的实验结果表明实验A中的脉动热管在每个热负荷下都有更小的温差和更大的有效热导率。固定热负荷,控制冷凝段温度从16.5 K逐步增加到24 K(实验C),结果表明在此充液率和热负荷下,有效热导率随着冷凝段温度的升高而近似线性增加。在本研究的三组实验工况下,氢脉动热管正常运行范围内,冷凝段温度越高,有效热导率越高。

Pulsating heat pipe is an efficient heat transfer device to extend the cooling capacity of a cryocooler to a wider area and a longer distance. In this paper, the heat transfer performance of a hydrogen pulsating heat pipe under different condenser temperatures is studied. The filling ratio is 28%@19 K. The results show that when the condenser temperature is not controlled, the pulsating heat pipe has smaller temperature differences and larger effective thermal conductivities compared with the case that the condenser temperature controlled at 19 K. In the experiment when the condenser temperature is increased from 16.5 K to 24 K stepwisely while the heat load remains fixed, the effective thermal conductivity increases almost linearly with the increase of the condenser temperature. In the experiments, within the normal operation range of the hydrogen pulsating heat pipe, the higher the condenser temperature, the higher the effective thermal conductivity.