Effect of Blade Placement Angle on Performance of Volute Axial Flow Pump Reverse Turbine

In order to utilize the liquid residual pressure energy of medium and low pressure head and large flow in light chemical industry, a PLK XII volute axial flow pump with specific speed of 900 produced by a domestic enterprise was taken as the research object. Now, when the blade placement Angle is 12°, 14° and 16° respectively, ANSYS Fluent is used for numerical simulation and steady-state calculation to explore the influence of different blade placement angles on the hydraulic turbine performance of volute axial flow pump inversion. Based on the optimal efficiency points of the pump and turbine, the flow conversion coefficient K_Q, head conversion coefficient K_H, efficiency conversion coefficient K_η and shaft power conversion coefficient K_P are obtained under different blade emplacement angles. According to the calculation results, when the blade placement Angle was 12°, K_Q=1.31, K_H=1.22, K_η =0.92 and K_P=1.05. When the blade placement Angle was 14°, K_Q=1.22, K_H=1.68, K_η=0.94, and K_P=1.12. When the blade placement Angle was 16°, K_Q=1.06, K_H=1.86, K_η=0.97, and K_P=1.23. The results show that with the increase of blade placement Angle, the head, flow and efficiency of the optimal efficiency point of the volute axial flow pump increase gradually under pump and turbine conditions. Increasing the blade placement Angle can increase the impeller inlet velocity uniformity in pump working condition. As the blade placement Angle increases, the flow pattern in the volute runner before the inlet of the turbine impeller becomes better, and the distribution of velocity at the tongue is more even.