基于双膜蒸馏的尿残液水分回收技术研究

Research on Water Recovery from Urine Brine Through Double-Membrane Distillation

针对载人航天环控生保系统尿处理残液进一步处理处置难度大的问题,开发了间接加热气扫式双膜蒸馏技术,以完成尿残液中的水分回收和减量化处理,考察不同膜组合、吹扫气体条件(温度、湿度和流量)等对蒸馏速率的影响,并探究了双膜蒸馏过程和膜污染情况。结果表明,质子膜对双膜组合蒸馏速率影响大于疏水膜,试验获得较优的吹扫气体条件为30℃,30%RH;双膜蒸馏能去除尿残液中99%以上的无机盐和有机物,吹扫气体质量和回收冷凝水水质良好;随着蒸馏过程的进行,尿残液中的无机盐和有机物在材料表面结晶、沉积,尿残液水分回收过程分为快速蒸馏和慢速蒸馏2个阶段。在此基础上,完成了尿残液双膜蒸馏在轨验证与应用的技术流程设计。

To realize water recovery and volume reduction in urine residue that was produced as a byproduct in environmental control and life support system during manned spaceflight,an indirect heated gas sweep double-membrane distillation technology was developed and the effects of membrane combination and purge gas conditions(temperature,humidity and flow)on the distillation rate were investigated.Moreover,the distillation process and membrane contamination characteristics were studied.The results showed that the proton membrane had a greater influence on the distillation rate of the double-membrane combination than that of the hydrophobic membrane,and the test obtained a better purge gas condition of 30℃,30%RH.Double membrane distillation could remove more than 99%of inorganic salts and organic matter in the urine brine,and the quality of the purge gas and the recovered condensate was good.Inorganic and organic substances would crystallize and deposit on the surface of the material along with the distillation process,dividing the water recovery process into two stages of fast distillation and slow distillation.On this basis,a technical scheme for the on-orbit verification and application of urine brine double-membrane distillation technology was designed.