Study On The Radial Force Characteristics Of Single-blade Submersible Sewage Pump

The single-blade submersible sewage pump is widely used in municipal engineering,sewage treatment plant,sewage pumping station and so on,through large diameter,anti-clogging and anti-winding ability.The non-axisymmetric arrangement of impeller blades leads to excessive radial force and uneven bearing force,short maintenance period and high cost,which greatly limits the development of the industry.Therefore,this paper conducts an in-depth study on the problem of the radial force of the rotor system of single-blade submersible sewage pump,and the specific research contents and achievements are as follows:1.The design parameters were determined and the hydraulic design of single blade impeller and supporting volute was designed.Based on the orthogonal test method,3 sets of variables were selected,and 9 experimental schemes were designed,and the hydraulic efficiency of the optimized impeller was 59.8%.2.Aiming at the unbalanced quality of rotor system of single blade submersible sewage pump,the method of parametric modeling and virtual prototype simulation technology is used to balance the quality.After the balancing test of original impeller and balanced impeller,the results are basically the same,which shows that this method has high precision,short period and low cost.3.Based on full hexahedron structured grid of single blade diving sewage pump for the unsteady flow field calculation,the external characteristic of the single blade diving sewage pump forecasting curve and flow characteristics,successfully captured singleblade impeller of secondary flow and vortex phenomenon,internal flow disorder,and found a small flow conditions and large flow condition of internal flow field structure of physics has been obviously improved.4.According to the results of the hydraulic design for structure design,prototype test and modification,the prototype of the flow and head the measured curve,compared with the numerical analysis,verify the accuracy of numerical calculation.5.Based on the above simulation method,the unsteady calculation of the whole flow field is carried out,and the pressure pulsation law of different points in the pump is analyzed.According to the analysis of time-domain map,the pressure pulsation is obviously periodicity,and the peaks and valleys in one cycle correspond to the number of leaves in the impeller.Based on the Fourier transform,the frequency domain characteristics are obtained,and the pulsation amplitude of each point in the blade frequency is the largest.6.According to the results of unsteady numerical calculation,the radial force of impeller is tracked,and the radial force of the impeller is oval,indicating that the radial force is constantly changing in one cycle.In the range of 0.8Q~1.2Q,the hydraulic radial force of impeller increases with the increase of flow.According to the analysis of the hydraulic radial force vector of impeller,the three feature points of the maximum,minimum and mutation are selected,and the relative position of the direction and the impeller in the same working condition is basically unchanged.7.In the design condition,the hydraulic radial force of the impeller rotation in one cycle is averaged.In the reverse direction of the hydraulic radial force,the impeller is added to the weight,and the centrifugal force generated by the unbalanced mass after the counterweight is equal to the average.Static analysis was performed on mass balanced impeller and weighted impeller,and loading hydraulic force and the quality of their respective forces,found that the weighted impeller stress and deformation is reduced,decreases in the radial force on the bearing,which shows that through the impeller unbalanced quality and control the phase angle,can offset part of the hydraulic radial force in rotor system.