Study On The Matching Relation Between Impeller And Guide Vane Of Multistage Centrifugal Pump

The low specific speed centrifugal pump has the characteristics of small flow and high lift,which makes the pump efficiency generally low.matching relations of impeller and guide blade have an impact on the performance of the pump,So the matchi ng relation between both needs to be considered in the design of the pump.Optimizing the matching of impeller and guide blade by the theoretical analysis and numerical calculation improve the performance of the pump and get simultaneously the optimal matching between them in this paper about Multistage Segmental Centrifugal Pump of 100×80(G)TDF10GM.First of all,hydraulic calculation of the original impeller and guide blade is carried out according to the speed coefficient method.Low specific speed centr ifugal pump have itself efficiency low,easy overload and hump,the area ratio principle is used to reconsider the throat area of the guide vane.The original type pump is calculated by the steady calculation result and making the test to verify the reliability of numerical simulation.Analyzing the relationship of number Z,import settling Angle and inlet throat plane width of a3 about guide blade finally determine the throat area of the guide vane inlet by changing the value of a3.Then changing based dia meter of guide blade to optimize the gap of T between the outer diameter on the impeller and the based diameter.Finally,the performance of the pump has been improved when the Y is 0.434 and T2 is 6mm,the efficiency of the four stage model pump is increased by 4.5%,the pump head has almost no change and the shaft power is reduced.The internal flow of the pump and the static pressure distribution on the blade face were studied under different design conditions,The matching of the impeller and the guide vanes clearly affects the flow of the whole flow passage.Increasing the inlet area and clearance of T will reduce the static pressure of the blade working face with flow gradually increasing,which shows that the circulation of impeller is more smooth,and further reveals that the matching of the two is an important factor affecting the performance of the pump.Considering the matching relation of area ratio and clearance,relation formula is deduced about the throat area of the single inlet and based diameter of the guide vane and impeller diameter which could avoid the error caused by traditional velocity coefficient method design.The research results of this paper have certain guiding significance for the design of this pump type.