离心泵复合叶轮短叶片偏置设计研究

Research on Design for Splitting Vanes of Compound Centrifugal Pump Impeller

对离心泵叶轮进行偏置短叶片设计既能够避免叶轮进口过度排挤,又能够解决叶轮出口流道扩散严重的问题,因而是改善低比转速离心泵性能的有效方法。为了研究短叶片水力设计方法,首次提出了以叶轮流道内不出现回流区域为目标建立的叶片数计算公式,进而确定了叶片型线的设计方法以及短叶片的偏置设计准则,为短叶片偏置设计提供了精确的数学基础。最后,对一台比转速为47的复合叶轮离心泵,在不同短叶片偏置设计参数下进行了试验,试验验证表明,文章中提出的计算公式可以指导设计。

Splitting vanes can both avoid jam in the inlet of the impeller for too many vanes and the severedivergence of the flow passage in the outlet of the impeller for too few vanes. Therefore it is the effective wayto improve the performance of low specific speed centrifugal pump. In order to research the hydraulic designmethod of splitting vanes, for the first time puts forward the computation method for blade number on the basisthat negative velocity should not come into being in the flow passage. And then, the design formulae for theblade geometry and the criterion for restricting splitting vanes are proposed which is the accurate mathematicalformulae for the complex impeller design. An example with specific speed 47 is examined by the equationsmentioned above and the results show that the theory is completely agreed with the test results.