Study For Tank Helium Pressurization System In Start-Up Process

In a spacecraft propulsion system, helium gas was used to pressurize for propellant tank through control the tank pressure. Due to the special requirements of spacecraft, the start-up process of pressurization system was particularly complex, more variable factors, and especially important for engine. Therefore, we must developed its systematic studies of simulation analysis and testing, in order to obtain reasonable parameter configuration, and to guarantee a reliable system working.In the paper, it mainly researched some parameters changing rules in the start-up process of helium pressurization system, include the pressure of propellant tank gas-cushion (or in the membrane), and the pressure before the engine isolation valve. On the basis of the law, through rational design of system parameters, enhanced pressurization system stability, and ensured reliable engine working.Firstly, in this research, introduced the composition of the helium pressurization system and its working principle, and analyzed emphatically its start-up process. Secondly, used AMESim, Nastran software to simulate and analyze the pressurization system and it's key components, such as pressure regulator, reducer, and metallic membrane etc. It mastered the influence of the relevant system parameters on starting characteristic, and brought some pertinent improvements. Finally, it accomplished lots of testing studies, include the regulator's pressure characteristics test, flow characteristics test, the system simulation test of starting characteristic, the engine hot test, etc. Through the comparative analysis of simulation results, it acquired the performance parameters of the pressurization system and its key components, proved the rationality of the system design parameters and the reliability of the system working. KEY WORDS: Pressurization System, Start-up process, Pressure...