叶轮外径对混流泵作透平性能的影响

为了研究混流泵作透平工况下,叶轮外径对性能的影响,以混流泵为模型,通过试验验证了CFD方法的有效性.基于BladeGen设计了160,170,180 mm这3种叶轮外径的混流泵水力模型, 并通过数值分析研究了3种叶轮外径下,混流泵作透平工况下的外特性,水力损失分布及内部流场分布.结果表明:随着叶轮外径的不断增大,混流泵作透平的高效点逐渐向大流量区域移动,高效点的扬程、轴功率及效率都随之增加;大流量区域内,扬程迅速降低,轴功率下降变缓,效率有所上升;总水力损失与叶轮部分的水力损失显著减少;蜗壳部分的水力损失变化不明显;叶轮入口处的旋涡区域逐渐减小,蜗壳出口与叶轮入口之间存在的间隙流体逐渐减小,从而引起该部分水力损失逐渐减小;压力分布更加均匀.

Influence of impeller diameter on mixed flow pump as turbine

In order to research the performance and concentration of the impeller diameter of mixed flow pump as turbine, a mixed flow pump was set as a model. First, the CFD method was verified by using the experiment. Then, three different impeller diameters of 160,170 and 180 mm were built through BladeGen. Finally, the numerical simulation is used to make an analysis of hydraulic characteristics, loss distribution and internal flow field distribution under these three different impeller diameters. The results show that with the increase of impeller diameter, the high efficiency point moves gradually to the large flow area, and the corresponding head, shaft power and efficiency of the high efficiency point increase. In the large flow area, the head decreases rapidly, the shaft power decreases and the efficiency increases, while the total hydraulic loss and the hydraulic loss of the impeller part decrease significantly; the hydraulic loss change in the volute part is not obvious; the vortex area of the impeller inlet gradually decreases; the gap fluid between the volute and impeller entrance gradually decrease, which causes the hydraulic loss in the part decreases gradually.