Research On Optimal Design And Wear Characteristics Of Single-stage Double-suction Centrifugal Pump

Centrifugal pumps can not only transport clean water,but also transport sandy water.In recent years,due to the rapid development of the domestic economy,urbanization,and the vigorous development of large-scale water conservancy facilities,the demand for pumps has increased sharply.Single-stage double-suction centrifugal pumps are widely used in domestic production and life due to their large flow and high head.Compared with the international first-class level,my country’s single-stage double-suction centrifugal pump has problems such as lower efficiency.At the same time,due to the transportation of sandy water,it causes certain wear and tear on the flow-through components in the single-stage double-suction centrifugal pump.This affects the service life of the pump to a certain extent.In view of the problems faced by the above-mentioned single-stage double-suction centrifugal pump,the results of this paper are as follows:(1)For the relatively low efficiency of a single-stage double-suction centrifugal pump with a rated flow of 3220 m~3/h,a head of 23 m,a speed of 990 r/min,and a specific speed of 230,without changing the volute,Take the six parameters of the inlet and outlet placement angle,wrap angle of the blade,inlet and outlet diameter of the blade and the number of blades as the six factors of the orthogonal test,and select different test levels for each factor to complete the orthogonal test.Design,study the influence of various factors on the efficiency of single-stage double-suction centrifugal pumps.Through the analysis of the orthogonal test results,the order of the influence of various factors on the efficiency of the single-stage double-suction centrifugal pump,from large to small,is the inlet placement angle of the blade middle streamline,the blade outlet placement angle,the blade wrap angle,and the impeller inlet.Diameter,impeller outlet diameter,number of blades.At the same time,the optimal design plan was determined:β1=12.9°,β2=24°,(?)=96°,Dj=363 mm,D2=480 mm,Z=6.Comparing the optimized model with the original design model,it is found that the pump efficiency at the design operating point is 1.2%higher than the original design model.(2)The solid particles in the extension section of the inlet and outlet and the impeller are approximately evenly distributed,while the particle distribution of the pressurized water chamber is mainly concentrated on the outside of the pressurized water chamber due to the effect of inertia.After entering the impeller flow channel,when the flow is small,the number of particles on the pressure surface is reduced to a certain extent compared with the suction surface of the blade.With the increase of the flow rate,the particles in the impeller flow channel gradually approach the pressure surface of the blade,and the solid particles are distributed approximately uniformly in the middle flow channel area of the single-stage double-suction centrifugal pump impeller.(3)When the operation of the pump is stable,the wear of the blade is mainly concentrated on the front edge of the blade and the interface between the pressure surface and the rear half of the suction surface of the blade and the front and rear cover plates of the impeller.The smaller the particle size of the sand,the more uniform the wear of the blade;at the same time,as the radius of the sand gradually increases,the wear rate of the impeller is relatively reduced.(4)When solid particles enter the pump,the wear rate of each part of the blade quickly reaches a stable state after a short time.When the flow rate increases,the wear rate reaches a stable state faster.When the flow is small,the wear of the impeller is mainly concentrated on the front cover of the impeller;when the flow is large,the wear of the impeller is gradually concentrated on the pressure surface of the blade and the rear cover.