不凝气体对航天器两相热控设备性能的影响

不凝气体(NCG)是影响航天器两相热控系统性能和寿命的关键因素之一。文章总结了NCG产生的机理,即材料相容性、物理吸附与脱附,以及空间极端环境下工质的分解;介绍了NCG对航天器传统热管、环路热管和重力驱动两相流体回路热性能的潜在危害,包括工作温度升高、总热导减小、启动困难,甚至引起运行失效;从工程应用角度,提出了NCG问题的抑制措施,如对于环路热管,可加装半导体致冷器,对于两相流体回路,可增大储液器体积或减少工质充装量。

Effect of Non-condensable Gas on Performances of Two-phase Thermal Control Devices for Spacecraft

NCG （non-condensable gas） is one of the main causes affecting the thermal performance and lifespan of the two-phase thermal control devices in spacecraft.The mechanisms of NCG generation is summarized,including materials compatibility,physical adsorption and desorption,and breakdown of the working fluid due to extreme space environment.The adverse effects of the NCG on the performance of the heat pipe,loop heat pipe and loop thermosyphon are also introduced,such as increasing the operating temperature,decreasing the total thermal conductance,difficulty in startup and operating failure.Moreover,from the point of the applications,some suppression measures for the NCG effect are proposed.For instance,a thermoelectric converter can be installed at the reservoir of the loop heat pipe so that the volume and the inventory of the loop thermosyphon can increase and decrease respectively.