Cavitation Characteristics Analysis of a Reciprocating Cryogenic Pump During Fluid Inlet Process Based on Computational Fluid Dynamics Simulation

Abstract Reciprocating cryogenic pumps can effectively enhance the energy efficiency of power systems. However, cavitation phenomenon caused by pressure drops can severely compromise the safety and reliability of the pump. In this regard, this study attempts to illustrate the inlet cavitation characteristics of a reciprocating liquid nitrogen pump based on computational fluid dynamics (CFD) simulations. The cavitation behavior under different inlet pressures, gas contents, and subcooling conditions is also discussed. It is found that under saturated inlet conditions, severe cavitation occurs in both the intake region and the cylinder, and the vapor volume fraction varies by up to 5.86% under different inlet pressures. Subsequently, it is displayed that the vapor volume fraction inside the cylinder is nearly independent of the inlet gas content. Furthermore, increasing the inlet subcooling gradually reduces the effect of cavitation, and at approximately 3 K subcooling, the cylinder is expected to remain in a pure-liquid state. This paper provides insights into the inlet cavitation characteristics to elucidate the actual suction progress of reciprocating cryogenic liquid nitrogen pumps and offers guidance for cavitation suppression.