Influence of cavitation on inducer and return channels of LNG pump

Cryogenic centrifugal submersible pump is a core equipment that pressurizes and transports fluid with the centrifugal force generated from impeller’s rotation. Problems like cavitation and surging, attributed to the working fluid and multistage structural characteristics, negatively affect the lifespan, noise, vibration, and performance of the pump. Therefore, this study develops a pump for a general-purpose specific-speed liquified natural gas fuel-supply system. The internal flow characteristics and performance prediction were analyzed using a commercial computational fluid dynamics analysis software. The numerical analysis results demonstrated that the average head varied across all conditions, where cavitation was absent within the inducer. NPSHre was determined at a cavitation coefficient of about 1.07 and head reduction of 97 %. It was confirmed that the swirl component generated at the trailing edge had a negative effect on the impeller when the flow passed through the inducer region. Upon analyzing the existing model, we identified the problems and discussed the future research directions for improving the pump performance.