轴流泵装置导叶出口水流速度环量对出水流道水力损失的影响

摘要

为了定量研究大型泵装置导叶出口水流的速度环量对出水流道水力性能的影响,提出了泵装置导叶出口断面水流的速度环量定量表示方法和平均角速度的测量方法,分别采用数值计算和模型试验的方法研究了导叶出口水流的剩余环量对虹吸式出水流道和直管式出水流道水力损失的影响.结果表明:导叶出口水流的环量对出水流道水力损失的影响较为明显,存在使出水流道水力损失最小的最优环量,虹吸式和直管式出水流道的最优环量分别为0.972和1.308 m2/s；虹吸式出水流道和直管式出水流道最优环量时的水力损失计算值较零环量时的水力损失计算值分别小0.126和0.180 m.研究结果不仅有助于改进低扬程泵装置出水流道的优化水力设计,同时对改进轴流泵导叶的优化水力设计也有重要意义.%In order to study influence of the velocity circulation at the guide vane outlet on the hydraulic performance of outlet conduit for a large pump system quantitatively, the methods to calculate velocity circulation and to measure the average angular velocity for the flow at the guide vane outlet of the pump system were put forward, the influence of circulation on the hydraulic losses of both siphon and straight outlet conduit were studied numerically and experimentally. The results indicated that the hydraulic loss of the outlet conduit was obviously influenced by the circulation at the guide vane outlet. There was an optimum circulation for the hydraulic loss of the outlet conduit to be minimized, the optimum circulation for siphon and straight outlet conduit was 0.972 and 1.308 m2/s respectively. The hydraulic losses calculated of the siphon and straight conduit under the condition of the optimal circulation were respectively lower 0.126 and 0.180 m than those under the condition of zero circulation. This study above could be helpful to optimal hydraulic design both for outlet conduit and guide vane of an axial-flow pump.