Abstract: A technique concerning a pressure-relief-throttle with double-pressure-control is presented in spatial cryogenic phase-change refrigeration for systematic pressure control in cold shield system of spacecraft. The valve can realize the function of controlling double pressure, pressure relieving and throttling. A 3-D model is established for flow-field simulation and a real experimental model is manufactured in terms of the simulated result. The numerical simulation and experimental results show that the valve meets the requirement of double pressure control when the heat flux changes outside of cold shield in space. The valve can efficiently throttle the saturated vapor, vapor-liquid phase and saturated liquid, and can stop the vapor-liquid phase flow or solidification of refrigerant with variation of pressure at outlet outside of cold shield. The valve can throttle cryogenic flow and improve the efficiency of refrigeration, decrease quantity of refrigerant refilling and reduce the accelerating load of launch.

Key words: Cold-shield system, Liquid nitrogen, Pressure-relief-throttle valve, Two-pressure control