基于质谱分析的航天器工质原位检漏技术研究

Leak DetectionIn-Situ of Spacecraft Facilities Containing Liquid Media with Mass Spectroscopy:An Experimental Study

航天器推进系统、热控系统、环控系统及流体回路系统有严格的泄漏指标要求,基于质谱分析的检漏方法存在本底信号干扰及重复性较差等难点,建立了工质原位检漏方法的理论模型,分析了质谱室直接进样与分流进样的特点,确定了分流进样的技术方案;通过试验,获得了大气环境取样条件下质谱室工作压力与本底信号的关系;同时,通过氦气、氪气、氙气等标准漏孔重复性试验获得了工质气体校准系数与本底信号的关系,并验证了系统检漏灵敏度满足航天器检漏要求。

The influence of the direct and bypass gas-sampling modes on leak detection in-situ,with mass spectroscopy in atmospheric environment,of the spacecraft facilities,including the propelling/thermal/environment control units and fluid media loops,was experimentally investigated.First,the direct and bypass sampling modes of tracer gases were mathematically modeled and theoretically analyzed.Second,the dependence of He,Kr,Xe and CF4 background pressures on the leak-detector chamber pressure was repeatedly measured to improve the stability and sensitivity.Third,the bypass sampling mode was found to outperform the direct sampling mode.And finally,the calibration coefficients with relation to the background signal were derived by repeatedly evaluating in bypass sampling mode the standard leaks of He,Kr and Xe tracers.The sensitivity of the newly-developed in-situ leak detection technique was estimated to be better than 1.0×10-8 Pa·m3/s,meeting the stringent requirements for leak detection of spacecraft.