Multistage Blade Outlet Edge And Radial Diffuser Structure For Numerical Study Of The Influence Of The Centrifugal Pump Performance

Centrifugal pump as a kind of widely used mechanical impeller, there are a large number of scholars in the operation process of vibration, noise, low operation efficiency and the pressure pulsation problem has carried on the related research and made a lot of progress. However, the pressure pulse of centrifugal pump and the guide blade is large, and the problems of the axial force are still present.In this paper, a single-stage single-suction centrifugal pump with radial guide vane impeller exit edge Angle respectively 0°, 5°,10°,15°, 20°, numerical simulation of the hydraulic efficiency and intensity of pressure pulsation in centrifugal pump to improve the effect of the optimal dip Angle. To force on the impeller outlet side tilt retrofit rear axle change sharply, the model based on the optimum tilt Angle of the axial force balance modification methods, and tilted blade outlet edge after retrofit centrifugal pump pressure pulsation amplitude are still high, to continue to reduce the impeller outlet and the pressure pulsation of dynamic and static junction, is all vanes were selected for radial blade height coefficient is 0.8, 0.6, 0.4, for the study of modification.Simulation of each model was discovered that (1) blade outlet side tilt after retrofit: small flow rate increases as the blade outlet edge Angle, under the pump lift drop rate increase gradually,big flow increases as the blade outlet edge Angle, under the pump of Mr. Cheng increased gradually after reduction. Blade outlet edge Angle is 15 0 on the impeller hydraulic efficiency and pressure pulsation intensity to improve the effect of the optimal, Rated conditions after retrofit efficiency 0.41%, up 0.92% 1.13Q flow under the head and the efficiency of 0.53%, the impeller performance curve is smoother, the pressure pulse intensity of the model pump decreased by 11.1%. (2) Blade axial force balance: Changes to 15 0 Angle model pump impeller outlet side cover plate diameter, Reducing the diameter of the front plate can lower the axial force of the vane shaft without affecting the hydraulic performance of the pump. Increase rear cover diameter can also achieve the goal of balance of axial force, but the affect of the impeller outlet flow, small amplitude decrease hydraulic performance of pump; (3) Radial positive lobe variant: To 15°obliquity model pump to select different guide under plate height is to continue the study found that selecting rational is guide under plate height can continue to reduce the intensity of pressure pulsation in the model pump. When the high coefficient of the positive leaf blade was 0.6, the average pressure intensity of the monitoring point was lowest, and the decrease was 11.0% before the change. But decreasing the height of the leaf blade will narrow the efficient area of the centrifugal pump and decrease the diffusing pressure of the radial guide.