Hydraulic Optimization Design And Internal Flow Characteristics Research Of The Vane Submersible Sewage Pump

In recent years,with the increasing efforts of the state in energy conservation and emission reduction,various industries are striving to improve efficiency and reduce energy consumption.Submersible sewage pump is widely used,and it is of great significance to improve the operation efficiency of the pump.In this paper,the performance of vane submersible sewage pump is optimized and studied based on CFD technology,The main research contents and creative achievements of this paper are as follows:1.By analyzing the research status at home and abroad,the optimization parameters of impeller are determined: blade outlet angle,wrap angle difference between front cover plate and back cover plate streamline,and blade inlet axial surface angle;optimization parameters of spiral case: section shape and base circle diameter.2.Compared with the impeller of vane submersible sewage pump with speed of281,18 schemes were determined by orthogonal experiment.The head and efficiency of each scheme were obtained by CFD simulation calculation.The correlation between head,efficiency and optimization parameters was analyzed.The results show that the lift is directly proportional to the axial angle and outlet angle,and inversely proportional to the wrap angle difference Δβ,among which the head is proportional to the outlet angle The efficiency is directly proportional to the axial angle and inversely proportional to the difference between the outlet angle and the wrap angle,among which the correlation with the outlet angle is the largest and that with the axial plane angle is the least.3.Based on the optimal impeller hydraulic model,the volute section shape and base circle diameter are optimized,and three kinds of volute section shapes are designed and simulated by CFD.The results show that the section shape of the volute has little influence on the head.The trapezoidal volute has the highest efficiency at the rated flow point and the lowest efficiency at the large flow point.The rectangular volute has the highest efficiency at the small flow point and large flow point,and the efficiency at the rated flow point is the highest at the rated flow point The efficiency of flow point is the lowest.The calculation results of three kinds of volutes with different base circle diameters show that the diameter of base circle has little influence on external characteristics within a certain range,and properly increasing the diameter of base circle can improve the ability of sewage pump to transport large particles.4.The pressure pulsation analysis of the optimized model shows that: the unsteady excitation caused by static and dynamic interference is mainly concentrated in the low frequency band,and the fluctuating energy at the blade frequency is dominant;the fluctuating energy near the impeller outlet is much higher than that at other positions of the volute;in the low frequency range,the excitation frequency appears at the measuring points of the volute,and the internal flow is uneven.The effect of particle diameter on impeller wear and external characteristics of submersible sewage pump was studied.The influence of particle size on liquid and solid flow was mastered,and the distribution of solid particles in the channel was analyzed.5.The performance test of the prototype is completed.The efficiency of the optimized submersible sewage pump is more than 75%,which is about 5% higher than that of the original model;the vibration speed under the rated condition is 1.28mm/s,which meets the standard requirements.