Numerical investigations of the influences of valve spool structure on the eccentric jet flow characteristic in high-pressure angle valves

High-pressure angle valves have suffered from eccentric jet flow characteristic in the diffuser pipe section due to the inherent structures and throttling effect. The eccentric jet flow will continuously scour the valve body and lead to washout on the side wall of the valve seat, largely impacting the valve service life and safety. With regard to this issue, this paper has conducted a numerical characterization study to investigate the influences of valve spool structures including the prototype, parallel and spherical spools on the eccentric jet flow in the first diffuser pipe section of a high-pressure angle valve. Results show that the parallel and spherical valve spool structures can achieve a lower pressure difference across the pipe section than the prototype spool structure, while the spherical spool has shown the minimum pressure difference in the first diffuser pipe section. Moreover, compared with the prototype and parallel spools, separated flows are distributed more uniformly on both side walls in the first diffuser pipe section for the valve with the spherical spool. The relative uniformly distributed separation vortexes makes the high-speed mainstream along the pipe center line and can successfully mitigate the eccentric jet flow. The motivation of this work is to reveal the influencing mechanisms of spool structures on the eccentric jet characteristic in high-pressure angle valves and provide useful guidelines for advanced angle valve design with low erosion and long service life.