叶片安放角对蜗壳式轴流泵反转作透平的性能影响

为了利用轻化工行业中低压头、大流量的液体余压能，以国内某企业生产的一台比转速为900的PLK XII型蜗壳式轴流泵为研究对象，分别在叶片安放角为12°、14°、16°时，使用ANSYS Fluent进行数值模拟定常计算，以探究不同叶片安放角对蜗壳式轴流泵反转作液力透平性能的影响。基于泵及透平的最优效率点，得到不同叶片安放角下泵与液力透平的流量换算系数K_Q、扬程换算系数K_H、效率换算系数K_η和轴功率换算系数K_P。根据计算结果可知:叶片安放角为12°时，K_Q=1.31、K_H=1.22、K_η=0.92、K_P=1.05；叶片安放角为14°时，K_Q=1.22、K_H=1.68、K_η=0.94、K_P=1.12；叶片安放角为16°时，K_Q=1.06、K_H=1.86、K_η=0.97、K_P=1.23。研究结果表明:随着叶片安放角的增大，蜗壳轴流泵在泵和透平工况下最优效率点的扬程、流量和效率均逐渐增大；增大叶片安放角可以增加泵工况叶轮进口流速均匀度；随着叶片安放角增大，透平叶轮进口前的蜗壳流道内的流态变得更好，隔舌处流速的分布更加均匀。

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.