摘要
轴流泵叶轮室进口水流的流态对大型低扬程泵站水泵的安全、稳定和高效运行具有很大的影响。采用模型试验方法和三维湍流流动数值模拟方法,分别研究了轴流泵泵段装置叶轮室进口和立式轴流泵装置叶轮室进口的流态,得到以下主要结论:(1)叶轮室进口流态与水泵运行工况密切有关;(2)在正常运行工况范围内,叶轮室进口水流基本上为轴向流动,无预旋现象;(3)在小流量工况运行时,叶轮室进口的外圈水流出现与叶轮转动方向相同的预旋流动,但内圈水流仍向叶轮室方向流动,而中圈的水流则在预旋流动与轴向流动两种状态之间摆动;(4)轴流泵叶轮室进口在小流量工况发生预旋现象是泵内发生"二次回流"的内特性表现,水泵性能曲线出现马鞍形区则为其外特性表现。
The flow pattern at the inlet of impeller chamber of axial-flow pump has a great influence on the operation of large-scale low-head pumping station.In this work,numerical and experimental methods were used to study this flow for safe,stable and efficient operation,and the conclusions were summarized as follow.（1） The flow pattern is determined by operating condition.（2） Under normal condition,the flow direction is basically along the axial direction of the inlet and no pre-swirl flow exists.（3） Under low flow rate,a pre-swirl flow in the impeller rotating direction appears in the outer ring region of the inlet section,while the inner ring flow keeps in the axial direction toward the impeller.The flow in the middle ring switches between the two regimes,pre-swirl flow and axial flow.（4） This pre-swirl of low flow rate is an indicator of special internal features caused by a second backflow inside the pump.These features and the second backflow are often indicated by a saddle shape on the performance curve.
出处
《水力发电学报》
EI
CSCD
北大核心
2012年第1期213-219,225,共8页
Journal of Hydroelectric Engineering
关键词
水力机械
轴流泵
叶轮室进口
模型试验
数值模拟
预旋
hydraulic machinery
axial flow pump
inlet of impeller chamber
scale model test
numerical simulation
pre-swirl
