关键词: 液体火箭发动机, 高温环境, 热控组件, 推进剂汽化, 工作性能, 脉冲冲量

Abstract: In order to investigate the working capability of liquid rocket engine under the high temperature environment on the lunar surface, the high-altitude simulation hot fire test of a 120N bipropellant rocket engine using hypergolic propellants was car-ried out. The thermal control assembly and proportion integration derivative control device were used to control the heating and insulation of the propellant supply lines and solenoid valve housing. The effects of the insulation at normal atmospheric temperature and 80~135℃ on the steady-state and pulse working performance of the engine ignition were investigated. The feasibility of discharging the vaporized propellant through the long-pulse ignition procedure after insulation was verified. The test results show that the engine can operate in both steady state and pulsed mode under all high temperature conditions, with comparable steady-state working performance after stabilization. The start-up response time based on thrust measurement is significantly longer than that under normal atmospheric temperature conditions, and returns to normal level at shutdown. Affected by the combined effect of propellant density and nitrogen tetroxide gas-liquid flow state, the first impulse thrust impulse at 30ms pulse width relative to the normal atmospheric temperature condition is 80%, 66%, 31%, 16% and 17% at holding temperatures of 80°C, 90°C, 105°C, 120°C and 135°C, respectively. When the pulse width is less than or greater than the start-up response time, the deviation value of thrust impulse compared with normal atmospheric temperature gradually decreases with increasing pulse width. The 7 sets of 128ms pulse width can basically drain the vaporized propellant in the propellant supply lines, and the engine pulse working performance returns to normal level after the exhaust procedure.

Key words: liquid rocket engine, high temperature environment, thermal control assembly, propellant vaporization, working performance, pulse impulse value