高冰点热管工作特性实验研究及在“嫦娥四号”探测器上的应用

Experimental study of operation properties of high freezing point heat pipe and the application in Chang’e-4 lunar probe

文章针对月球探测器设备月昼高效传热和月夜阻断传热需求,设计了一种以八氟环丁烷为工质的开关式高冰点槽道热管,对其常温下传热性能及启动特性开展了地面实验研究。结果表明:热管工作温度35~55℃范围内的最大传热量大于40 W;工作在35~55℃温度范围、传热量为25 W时,蒸发段测点与冷凝段测点温差小于5℃;在相同传热量情况下,工作温度越高,传热温差越小;管体与水平面夹角分别为10°、30°两种情况下,热管均能在90 s内正常启动。该热管已在“嫦娥四号”探测器中得到成功应用。探测器地面热平衡试验和在轨数据表明,高冰点热管在月昼高温工况传热效果良好,月夜低温工况热管工质冻结、可以实现设备保温,确保了探测器相关设备在轨的高性能工作。

Based on the requirement for the high-efficiency heat transfer in the moon day and the blocking of the heat transfer on the moon night,a high-freezing-point axially grooved switch heat pipe is designed by using the octafluorocyclobutane(C4F8)as the working medium.The ground experiments are carried out for its heat transfer characteristics at the normal temperature and for its startup mechanism at the(1/6)g gravitation.It is shown that the heat transfer capacity of the heat pipe exceeds 40 W in the working temperature range of 35~55℃,with a temperature difference of less than 5℃at 25 W between the evaporation zone and the condensation zone;the temperature difference decreases with the increase of the working temperature under the same amount of the heat transfer;the heat pipe can startup successfully within 90 s with an inclination to the horizontal plane at either 10°or 30°.This type of heat pipes have been applied in the China’s Chang’e-4 lunar probe.The results of the ground thermal balance test and the on-orbit operation show that the heat pipe can achieve an efficient heat transfer under the high temperature working condition during the lunar day period,and with a good insulation as a consequence of the freezing working medium under the low temperature working condition during the lunar night period.