Analysis of the Dynamic Characteristics of the Pump Valve System of an Ultra-High Pressure Liquid Hydrogen Reciprocating Pump

Abstract

This paper developed a 3D physical model of the hydraulic end of a high-pressure liquid hydrogen reciprocating pump to research the dynamic characteristics of the pump valve system. Based on dynamic mesh technology, we analyzed the coupling characteristics of pump valve and plunger motion and spool force considering the leakage model, closure model of valve gap, and compressibility of liquid hydrogen. Further, we analyzed the effect of the spring stiffness and preload force on the laws of motion of the pump valve. Finally, a liquid hydrogen pressurization test was conducted to revise the simulation model and verify the accuracy of the simulation. The results of the simulation and test show that the simulation method in this paper can simulate the liquid hydrogen pressurization process more accurately and obtain the motion law of the suction and discharge valves. Both the suction and discharge valves have an opening hysteresis angle of about 40°, and there is a strong coupling relationship between the spool motion and the piston motion and forces. The greater the preload force of the suction valve, the more obvious the oscillation effect of the suction valve. As the preload of the discharge valve increases, the opening hysteresis angle of the discharge valve increases significantly and the closing hysteresis angle decreases. The results of the research can provide some useful reference for the design of pump valves of high-pressure liquid hydrogen reciprocating pumps.