供氧模式对载人航天器气压控制的影响分析

载人航天器气压控制系统主要负责控制密封舱内氧分压和总压满足指标要求,承担长期载人任务的载人航天器通常配备电解制氧系统用于维持密封舱内氧分压水平。文章建立了一种载人航天器密封舱气压控制系统仿真分析模型,利用该模型分析对比了氧气瓶供氧和电解制氧供氧2种模式对应的密封舱氧分压和总压变化规律。结果表明,驻留24 h内,氧气瓶供氧模式对应的氧分压单调下降;电解制氧供氧模式对应的氧分压并非单调下降,而是取决于供氧速率与乘员代谢耗氧间的关系,且氧分压变化范围要远小于氧气瓶供氧模式。驻留60 d内,电解制氧供氧模式对应的氧分压在上下限间的变化周期以及总压的变化周期要明显长于氧气瓶供氧模式。为避免空气温度的影响,氧分压和总压的控制范围应比允许范围窄。

The effect of oxygen supply mode on air pressure control of manned spacecraft

The air control system in a manned spacecraft is used to control theoxygen partial pressure and the air pressure of the pressurized cabin within the index range. In the manned spacecraft for a long-term crew staying, the water electrolysis system is usually used to control the oxygen partial pressure of the pressurized cabin. A simulation model of the air pressure control system of the pressurized cabin in the manned spacecraft is proposed. Using this model, the varying trends of the oxygen partial pressure and the air pressure related to the two oxygen supply modes of the water electrolysis system and the oxygen cylinder are compared and analyzed. According to the results, when the staying period is 24 h, the oxygen partial pressure related to the oxygen supply by the oxygen cylinder keeps declining, which is different from that related to the oxygen supply by the water electrolysis system. The varying trend of the oxygen partial pressure related to the oxygen supply by the water electrolysis system is determined by the oxygen supply flux and the crew metabolic oxygen consumption; meanwhile, the varying range of the oxygen partial pressure related to the oxygen supply by the water electrolysis system is dramatically smaller than that related to the oxygen supply by the oxygen cylinder. When the staying period is 60 d, the varying cycle of the oxygen partial pressure and the air pressure related to the oxygen supply by the water electrolysis system is dramatically longer than that related to the oxygen supply by the oxygen cylinder. In order to avoid the influence of the air temperature, the control range of the oxygen partial pressure and the air pressure should be narrower than the allowable range.