轴流式止回阀在长距离高扬程输水泵站工程中的水锤防护研究

Research on the Water Hammer Protection of the Axial Flow Check Valve in the Long-distance and High-lift Water Pumping Stations

针对长距离高扬程泵站在事故停泵后,导致输水系统沿线发生水柱分离及瞬态高压等严重水锤现象,基于瞬变流理论及特征线法,结合水柱分离数学模型,推导了轴流式止回阀边界条件,并建立输水工程系统的数学模型。针对工程实例中应用轴流式止回阀的防护措施防护效果进行数值模拟。通过对轴流式止回阀不同装设位置的工况进行数值模拟,并对管线瞬态压力的变化进行比较,得到在长距离高扬程泵站管线中轴流式止回阀宜布置在管线的中后段,且停泵后易产生弥合高压水锤的位置的结论,对应用轴流式止回阀作为长距离高扬程输水系统的泵站水锤防护措施提供了新思路。

At long-distance and high-lift pumping stations,serious phenomena of the water hammer such as water column separation and transient pressure along pipelines of water conveyance systems when pumps stop due to failures.In view of this,based on the theory of fluid transients and the method of characteristics,with a mathematical model of water column separation,this paper deduces boundary conditions for axial flow check valves and builds a mathematical model of the water conveyance system.For the application of axial flow check valves in engineering projects,measures and effects of protection are modeled numerically.Moreover,the working conditions at different installation positions of the axial flow check valve are numerically simulated.After that,the comparison of changes in the transient pressure of the pipeline shows that the axial flow check valve shall be set in the middle and rear sections of the pipeline at the long-distance high-lift pumping station.What’s more,it is also concluded that the position of closing the high-pressure water hammer can be produced after pump stopping.Hence,applying the axial flow check valve as the water hammer protection of the pumping station has a new idea for the long-distance highlift water conveyance system.