The Analysis Of Cavitation And Pressure Fluctuation In Double Suction Centrifugal Pump

Double suction centrifugal pump is widely used in various fields because of its high lift,large flow,good dynamic balance performance and cavitation resistance.Compared with the single suction centrifugal pump,double suction centrifugal pump cavitation performance is better,but in the actual work process,the double suction pump cavitation phenomenon still occurs.At the same time,the pressure pulsation problem in pump work will not only cause the vibration and noise of the pump body,the pump will seriously affect the fluid flow,thus affecting the performance of the pump head and efficiency,stable operation and even destroy the system,reduce the service life of the equipment.Therefore,it is of great significance to fully understand the cavitation performance and pressure pulsation characteristics of double suction centrifugal pump.This article analysis the double suction pump from the following two aspects:First,simulate the double suction pump’s cavitation performance under different conditions.With the decline of the pump’s inlet total pressure,impeller blade suction front edge first to form a low pressure zone and extended gradually to the direction of the impeller outlet,and the distribution area of low pressure in different leaves in the channel is not uniform;the cavitation vapor first appeared at the inlet position,near the front cover.The cavitation degree in front cover is significantly greater than the back cover;Having a significant relationship of the head’s down with the cavitation vortex,the energy loss caused by vortex is the main factor of the sharp decline of head.Second,design four different angles of the staggered impeller and simulated them under unsteady calculation condition.Analysis the pressure changes in the behavior of a calculation cycle from the time domain and frequency domain on the monitoring point,found that the pressure pulsation frequency in the pump volute main the blade passing frequency and its harmonics.The amplitude of pressure fluctuation of double suction pump decrease the and pulsation frequency increase when the impellers staggered 45 degrees,the double suction pump impeller optimum stagger angle is 45 degrees,and verified the conclusion from the fluid flow aspect.