Auto-pressurization Control System Of Hydrogen Oxygen Engine Test Stand

Rocket engine is the most important subsystem of launch vehicle. It directly determined the performance and cost of the whole vehicle. During the research of new launch vehicle, most countries adopted LH2/L0X or LOX/kerosene as nontoxic and non-pollutant propellant for the hardcore of launch vehicle-large engines. On account of nontoxic, high combustion enthalpy and propulsive efficiency, it becomes one of the develop current to use LH2/LOX engine for core stages of large launch vehicle.During rocket engine developing process, it must use propellant delivery system on test stand, preferring instead to remain pressurization feed system to supply propellant to the engine. The propellant delivery system consists of propellant delivery pipeline and auto-pressurization system. By controlling pressure of gas willow, the auto-pressurization system could ensure input pressure of turbo pump. In addition, by adjusting the auto-pressurization system according to the test task demand, technical parameters in different conditions could be obtained, thereby examining rocket engine performance. Due to the complex mass and heat transfer process affected by adiabatic capability, environment and pressurant temperature, pressurization pressure and time, the pressurization system must have a high degree of precision and reliability.The dissertation analyses the auto-pressurization system of rockets and test stand. Then it analyses the overall and subsystem of pressurization system. Depending on the application the mathematical model is established, basing on the major devices. So the controller can be designed when the transfer function is got by simplifying the mathematical model. Using the control theory of PID, the dissertation gets the PID controller of the hydrogen system and the oxygen system. The effect gotten by the Matlab is perfect. When all is complete, the dissertation design the auto-pressurization system basing on advance devices and control technology, and the reliability of the system is high. Combining with the previous numerical simulation and practical experience, the parameters is tuned. And, it is adjusted during the test of engines. At last, a high control precision is gotten.This dissertation uses some methods to meet the requirement of reliability, such as power redundancy which can switch in zero seconds; closed-loop control with double solenoid valves and flow regulator, at the same time the hole plate is redundant; Profibus field bus technology which can increase the degree of integration. These have greatly enhanced the reliability of the system.