快速闸门断流的轴流泵起动过程三维数值模拟

针对轴流泵机组起动过程的研究是泵站安全稳定运行研究的重要环节。为了准确捕捉轴流泵机组在起动过渡过程中的动态特性,建立轴流泵机组的全流道三维模型,采用三维CFD计算软件Fluent,利用基于有限体积法的动网格技术,配合VOF多相流模型对快速闸门断流的轴流泵机组起动过程进行了三维瞬态数值模拟,获得了轴流泵机组起动过渡过程中的流态变化及外特性参数的变化规律。闸门开启时间为60s时,机组起动扬程在12s时达到最大值2.76m,为运行扬程的1.28倍。减小快速闸门开启时间能够降低机组最大起动扬程,但同时会加剧回流及闸门处的水流撞击。计算结果表明:动网格技术结合VOF多相流模型可以较好的应用于快速闸门断流的轴流泵机组起动过渡过程数值模拟中,其结果可为泵站水力设计及轴流泵机组的过渡过程研究提供参考。

Numerical simulation of starting process of axial flow pump with quick-stop gate

Research on the starting process of the axial flow pump is a very important part of the research on pump stations. In order to capture accurately the dynamic characteristics of an axial flow pump in the starting process, a three-dimensional geometrical model of the full passage was established. The CFD software Fluent, the dynamic mesh technology based on finite volume method, and the VOF multiphase flow model were all used to conduct three-dimensional transient numerical simulation of the axial flow pump, from which the variation patterns of external characteristic parameters were obtained. When the opening time of the gate was 60 s, the maximum head was 2.76 m at 12 s, which was 1.28 times of the rated head. Less starting time of the gate led to a lower starting head, but it aggravated the back-flow. The results showed that the dynamic mesh technology can be used in 3D numerical simulation of the starting transition process of an axial flow pump with a quick-stop gate. The results can help optimize the hydraulic parameters of pump stations and can be used as a reference for the research of the transition process of axial flow pump units.