Analysis Of Sediment Erosion On Impeller And Blade Optimization In A Double-suction Centrifugal Pump

With large flow and high head,double-suction centrifugal pump is widely used in irrigation pump station engineering along The Yellow River.However,pump is designed to work under clear water.When operating in sand-laden water,the impingement of particles can lead to serious sediment erosion on the flow passage components of the pump,such as impeller,seal ring and pump shell,which can arouse the hydraulic performance degradation of the pump,shorten the maintenance cycle and service life of the pump,posing a threat to the safe and stable operation of the pump station.Therefore,it is of great significance to analyze the abrasive wear characteristics of double suction centrifugal pump and put forward the corresponding anti-wear measures.In this paper,CFD method is adopted to study the erosion characteristics of blades in double suction centrifugal pump,and a bionic blade with convex domes is proposed to improve erosion resistance of the blade surfaces.The main work of this paper is as follows:First,the Euler-Lagrangian two-phase flow model was used to simulate the motion of the solid-liquid two-phase flow in a double-suction centrifugal pump and blade erosion rates were predicted using the Discrete Phase Impact Model(DPM).The effects of five different particle sizes(0.02 mm,0.04 mm,0.12 mm,0.2375 mm,0.4725 mm)on the erosion characteristics of the prototype blades were studied.The results showed that under different particle size conditions,the outlet section of blades suffers serious silt erosion.With the particle size increases,erosion on the leading edge of blades becomes more serious,but erosion on pressure side and suction side reduces first and then increases.The erosion position predicted by the numerical simulation is basically consistent with the erosion location measured by the impeller erosion test,which indicates that the erosion model used in this paper is reliable.Second,a bionic blade with convex domes was proposed and the erosion characteristics of bionic blades under the various conditions with five different particle sizes(0.02 mm,0.04 mm,0.12 mm,0.2375 mm,0.4725 mm)was studied.The result shows that the bionic blades have better anti-erosion characteristics compared with the prototype blades.Besides,the effects of three different heights(1.0 mm,1.5 mm,2.0 mm)on anti-erosion characteristics of bionic blades were explored.The results show that the bionic blades with three different-height convex domes show good erosion resistance characteristics and the maximum erosion rate of the pressure surface decreases with the height of the convex domes.