Improved Lifting Design Method And Internal Flow Field Calculation Of Axial Flow Pump Impeller

Axial flow pump has been widely used in various fields of the national economy. It will have an important effect on the development of the national economy and energy saving to improve its research and design level. In order to improve its efficiency and reliability and enlarge its working condition range, thorough research on the internal flow of the axial flow pump must be done. In view of this, further study on lifting design method which is the traditional design method of the axial flow pump has been done. -Considering the influence of the boundary layer flow and the wheel rim clearance flow, improved lifting design method has been proposed. Hydraulic calculation and design of the ZWXB axial flow pump impeller has been done by programming of the two methods. Taking ZWXB1200 axial flow pump for granted, we have done the internal flow field analysis and numerical calculation of the designed hydraulic model with CFD. The result shows that the performance index of the hydraulic model designed by improved lifting design method is better than another. After considering the mutual interference among actual flow of blade tip near the enclosure,wheel hub and annular boundary layer flow of the static enclosure and boundary layer flow of the rotating blade surface and clearance flow between blade top and enclosure,lengthening ante version twist shape of the axial flow pump impeller' blade tip and blade root designed by improved lifting design method is adopted. The development of the annular boundary layer of the enclosure and wheel hub surface and the separation of the upper boundary layer of blade's lower pressing have been controlled effectively. The load of the blade tip and the influence of the clearance flow have also been decreased. The shape of the blade is closer to the actual situation. Secondary flow between blades and the effect of various vortexes on the flow are also improved. The result of the flow numerical calculation shows that the efficiency of the axial flow pump impeller blade designed by improved lifting design method is higher 1.5 percent averagely in each working condition than another. Calculation of the flow of the axial flow pump impeller blade wheel rim clearance has also been done. The 1.5 mm and 2.5 mm clearance have been selected. Its flow and the effect of the clearance change on impeller performance have been studied. Distribution law of velocity and pressure of the impeller in each working condition has also been obtained.It shows that the model of axial flow pump designed by improved lifting design method is correct. It provides new design concept and method of axial flow pump.