A heat pump in the aerospace industry can significantly reduce the area of radiator by elevating the rejection temperature. Especially for a Lunar base, the heat pump can improve the heat rejection capability of the thermal control system to adapt the high-temperature environment. However, gravity on the Lunar (about 1/6 g) may have an adverse impact on a gas-oil separator of the heat pump, and solving this problem is the key for a heat pump used on Lunar base. At present, the gas-oil separator all based on gravity separation theories, the researches under low or micro gravity were blank. In this work, a gravity separation model based on a single-particle principle was built, and the effects of the vapor velocity, the oil droplet initial velocity, and the oil droplet diameter were investigated under normal gravity. Then the variations of the separation efficiency under Lunar gravity were discussed and the numerical calculation results showed that the separation efficiency was reduced when the vapor velocity or droplet initial velocity increased in a certain height of the separator whenever under normal or Lunar gravity. Particularly, the separation efficiency under Lunar gravity was reduced from 99% to 55% than it under normal gravity.

航空航天业中的热泵可通过提高排出温度来显着减小散热器的面积。特别是对于月球基地，热泵可以提高热控制系统的排热能力，以适应高温环境。但是，月球上的重力（约1/6 g）可能会对热泵的气油分离器产生不利影响，解决此问题是月球底座上使用的热泵的关键。目前，油气分离器均基于重力分离理论，在低重力或微重力下的研究尚属空白。在这项工作中，建立了基于单粒子原理的重力分离模型，并研究了在正常重力下蒸汽速度，油滴初始速度和油滴直径的影响。然后讨论了月球重力作用下分离效率的变化，数值计算结果表明，在正常或月球重力作用下，当蒸汽速度或液滴初始速度在一定高度的分离器中升高时，分离效率都会降低。特别是，月球重力下的分离效率比正常重力下的分离效率从99％降低到55％。