天地差异性对低温保险阀压力点影响研究

Differentia Analysis between Space and Ground on Cryogenic Safety Valve

针对低温保险阀飞行工况相比地面试验工况附加压力偏高0.02~0.03 MPa的现象,通过开展低温保险阀出口管路的流场仿真,提出了保险阀出口管路中的超音速流动及激波现象;在此基础上,通过连通管感知压力对保险阀压力点影响的定量分析及低温保险阀的天地差异性分析,认为低温保险阀压力点对连通管感知压力异常敏感,并当保险阀打开后,连通管感知出口管路中的气体压力,将使得保险阀压力点发生上漂/下漂;对于飞行工况,仿真结果表明,飞行工况连通管感知压力约0.02 MPa,使保险阀压力点发生上漂0.02 MPa,有效解释了多个型号低温保险阀飞行工况中附加压力偏高的现象。

The cryogenic safety valve's discharge pressure is 0.02~0.03 MPa more than the pressure in ground test.By the simulation of the safety valve opening,the results show that connection pipe pressure influences the safety valve dischanrge pressure remarkably.When the safety valve opens,connection pipe pressure will change because of the gas from the safety valve,the pressure change will affect the safety valve's discharge pressure.When the safety valve works in the space,connection pipe pressure will be more 0.02 MPa than the ground because of shock wave.This is the reason why the cryogenic safety valve's discharge pressure is 0.02~0.03 MPa more than the pressure in ground test.