小流量下多级离心泵首级导叶内部流动性能分析

Inner Flow Performance Analysis of First-stage Guide Vane in Multistage Centrifugal Pump with Low Mass Flow

采用标准模型对多级导叶式清水离心泵的内部流场进行了数值模拟,对首级导叶内部流动规律进行了分析。结果表明,性能曲线的预测值与实验值趋势基本一致;在小流量工况下,内部流动局部紊乱,个别导叶流道内出现较大的旋涡流,叶轮与导叶之间、导叶头部偏向叶轮方向和叶轮末端边缘处存在小范围低压区,在反导叶部分流道内出现较大的涡流,可通过减小工质进入的冲角及改变叶片几何型线即延长动能向压力能转换过程等措施加以改善,为水泵的优化设计提供理论依据。

The standard model was adopted to simulate the inner flow field of multistage centrifugal pump and the inner-flow regularity of the first-stage guide vane＇ was analyzed to show that, the predicted value of the performance curves complies with the experimental values basically; and as for the low mass flow, the centrifugal pump＇ s internal flow becomes disorder partly and larger vortex flows can be found in some guide vane flow passages, including small low pressure areas in the impeller blade＇ s marginal area, between the impeller and the guide vane and in the head face of guide vane. As for the larger vortex found in some flow channels of return guide vanes, having the working medium reduced in the angle of attack and the blade＇ s geometric shape modified can solve it to provide theoretical basis for optimal design of the water pump.