Optimum Design Of Tangent Pump Based On Orthogonal Test

Because of the tangent pump performance advantage in curves between flow rate with head is relatively flat and reliable work,Tangent pump gradually applied in industrial,spaceflight and fire fileld.The research on tangent pump is gradually from the normal speed to the high speed,making the tangent pump has wider application range and field.The WG211-10 tangent pump produced by one certain company is selected as the research object.The external character is experiments of the model pump are done in pump test bench and the test data are recorded,curves between flow rate with head and efficiency are drawn,and the change trend of the curves are observed.CFD method is used to simulate the flow field of the model pump,The simulation results are compared with the experimental results to guarantee the simulated results are reliable.Based on this,changes of flow fields in the tangent pump and key geometric parameters which influence on performances of tangent pump are studied;For tangent pump produced by China,efficiency has a big difference with tangent pump produced by foreign countries.By using methods of experiment and orthogonal method,and the tangent pump is built to optimally design the WG211-10 tangent pump,to improve the efficiency.Simulation results are as follows.1?The internal flow fields of the model tangent pump were simulated and results showed that studying the velocity fields,a large number of were found in the passages of impeller,which is one of the most important causes to make the efficiency of the tangent pump become lower.Vortices can be reduced by changing the structure of the impeller and the blade.And efficiency of tangent pump can be improved.For example,the long straight blade was chequered with the long and short blades.2?By changing the different throat diameters to study the effects of throat area on the tangent pump performance.The throat area was determined the maximum flow rate Q_max in the tangent pump.The throat area is larger,the maximum flow rate Q_max is higher;And efficiency was affected by the throat area of tangent pump.If the design flow rate is near the cutting off flow rate,The pump has a higher efficiency when the throat area is 10 mm.3?Flow coefficient is one of the most important design parameters to design tangent pump.the efficiency is higher and the flow rate is near the cut-off flow rate,I think that the value of flow coefficient should be in the range from 0.75 to 0.8.4?Space between the impeller blades with the volute of the tangent pump has a certain influence on the performance.Space1.2mm?1.8mm,?3mm is selected and then,And the smaller the space is,the higher the efficiency is.During operating period,the shaft may become bending.The space becoming too small will cause the contact of the impeller and the volute,affecting the normal operation of the pump.So the space 2mm is more appropriate.5?The main geometric parameters of the impeller and volute are analyzed,The orthogonal experiment was carried out by selecting the impeller outer diameter D₂,the outlet width of the blade b₂,the blade angle ? and the diameter of the volute throat D_d The optimal scheme is obtained by the design formulas and design experience: Impeller diameter D₂,outlet width of the blade b₂,dip angle of the blade ?,throat diameter D_d.The final plan for the prototype production,Comparison and analysis of the internal flow field and the characteristic curve of the optimal pump and the original pump.There are a large number of vortices in the flow passage between the original impeller blades,After the optimization of the pump,it is found that the vortex disappears or the vortex area decreases between the impeller blades.we can get that under the design condition,head of the optimized pump is 223 m,efficiency is 43.3% and shaft power is 14.4k W.Compared with the prototype tangent pump,the head increased by 2m,the efficiency increased by 1.3% and the shaft power reduced by 0.58 k W.It achieved the optimized design.