斜式轴流泵装置出水流道偏流特性研究

斜式轴流泵是大流量低扬程提水领域的一种典型泵型,但其在某些工况下存在严重偏流问题,是影响斜式轴流泵站安全稳定运行的工程难题和关键科学问题。本文以浙江盐官泵站15°斜式轴流泵装置模型为研究对象,通过模型试验和数值模拟方法对装置内部瞬态流动特性进行研究,分析了不同流量工况下内部流动特征及偏流产生的原因,提出了解决偏流问题的抑制措施。研究结果表明:顺水流方向出水流道隔墩左侧流量高于右侧,最优流量工况下偏流比达2.33,有70%的流量从左侧流道流出;出水流道内的偏流是因水流在剩余环量的影响下发生偏转,通过弯管段时产生的;在出水流道弯管段设置偏流抑制措施可有效改善出水流道内部流态,抑制偏流的发生。本文研究成果已经应用到盐官泵站装置原型上,并得到了很好的应用,从而为解决大型斜式轴流泵站偏流问题,保证泵站安全稳定运行提供了参考。

Flow deviation in the discharge passage of a slanted axial-flow pump system

Slanted axial-flow pump is a typical type of pump in the field of high flow and low lift, but it has a serious flow deviation problem on some operating conditions. The deviation phenomenon affects the efficiency and instability of pumping stations. In this paper, the model of 15-degree slanted axial flow pump in Zhejiang Yanguan pump station is taken as the research object. The transient flow characteristics in the device are studied through model test and numerical simulation. The characteristics of internal flow under different flow conditions and the causes of flow deviation are analyzed, and the inhibition measures to solve the problem of flow deviation are put forward. The results show that the left flow rate of the outlet flow pier is higher than the right flow rate in the downstream flow direction, and the flow deviation ratio reaches 2.33 under the optimal flow condition. 70% of the flow rate flows out from the left flow channel. The deflection of the water flow in the outlet passage is caused by the deflection of the water flow through the bend section under the influence of residual ring volume. It can effectively improve the internal flow state of the outlet flow passage and restrain the occurrence of the bias by setting the bias suppression measures in the bend section of the outlet flow passage. The research results have been applied to the prototype device of Yanguan pump station and achieved good effect, which provides good references for solving the bias problem of large-scale slanted axial-flow pump station and ensuring the safe and stable operation of the pump station.