Research On The Influence Of Matching Relationship Between Inducer And Impeller On The Performance Of High-Speed Centrifugal Pump

High-speed centrifugal pumps are widely used in aviation,ships,petrochemical and other industries,but due to the high speed of the pump and the special medium,there are problems such as low pump efficiency and cavitation.In this paper,the highspeed centrifugal pump produced by a domestic company was selected as the research object,the performance parameters of the pump were Qv=8.48m3?h,the head H=580m,the speed n=31590r/min,and the medium was water.Firstly,the numerical simulation of the model is carried out,and it is found that the numerical simulation results of the head-efficiency change curve with flow rate are basically consistent with the experimental results,which proves the feasibility of the numerical simulation method.Then,several schemes for the axial distance and timing position of the induction wheel and impeller are studied.Firstly,by changing the axial distance between the induction wheel and the impeller of the high-speed centrifugal pump,the flow state between the upstream induction wheel of the high-speed centrifugal pump and the downstream impeller is optimized,a method for defining the axial distance between the induction wheel and the impeller of the high-speed centrifugal pump is proposed,and five schemes are designed.By comparing the energy characteristics and cavitation performance of highspeed centrifugal pumps with five schemes,the optimal axial distance between the induction wheel and the impeller of the model pump is 8mm,which lays a solid foundation for subsequent research.Secondly,the main overflow component in the centrifugal pump is the main impeller,and the circumferential placement position of the front induction wheel is also an important factor in the flow state in the main impeller.Based on the optimal axial distance between the induction wheel and the impeller,four schemes were designed according to the angle between the blades of the front induction wheel of the high-speed centrifugal pump,and the internal flow characteristics of the high-speed centrifugal pump were studied by numerical simulation,and finally the optimal circumferential placement angle of the pre-induction wheel of the high-speed centrifugal pump was 30°.Finally,the optimal axial distance between the induction wheel and the impeller and the optimal circumferential position of the front induction wheel are combined to obtain the optimal high-speed centrifugal pump model.Due to the high speed requirements of high-speed centrifugal pumps,the cavitation problem of centrifugal pumps is the most worthy of attention in the actual operation process.Through the cavitation simulation of high-speed centrifugal pump,the energy analysis of the internal flow field is carried out based on the entropy production theory,and the vortex viscosity characteristics and turbulent kinetic energy distribution of the internal flow field are analyzed in detail.In summary,through the analysis of the axial distance between the front induction wheel and the impeller,the circumferential placement position of the front induction wheel and the cavitation energy characteristics of the high-speed centrifugal pump,the installation position of the pre-induction wheel of the high-speed centrifugal pump is finally obtained,in order to provide a certain reference for the on-site installation designers of the high-speed centrifugal pump.