中文摘要：

结合山西中部某引黄工程，采用流体力学的基本原理和特征线法，在泵出口安装两阶段关闭蝶阀和沿管线布设空气阀联合防护措施下，针对输水系统事故停泵引起的水锤问题进行水力过渡分析和计算，得出管线沿程水锤压力和泵出口断面压力变化过程线。结果表明，泵出口安装两阶段关闭蝶阀对高扬程、长距离管道的水锤防护效果较明显，合理控制快慢关时间及角度能有效降低水击压力、机组倒转和倒泄流量。通过调整空气阀的布设位置、口径及进出流量系数，得出在空气阀流入流量系数为0．975、流出流量系数为0．650、口径为450 mm下的水力过渡过程，管路中最大负压水头控制在-1．6 m以内。可见，沿管线合理布置空气阀能有效降低管道负压。

英文摘要：

Aimed at the problem of water hammer caused by accidental Pump-stop in pressurize water supply systems,using the fluid dynamics the-ory and characteristics method and combining with a Yellow River diversion project in the center of Shanxi,the paper calculated and analyzed the hydraulic transient process under the conditions of protective measures of installing two-stage closed butterfly valve and air valve. The pressure enve-lope of water hammer along the pipeline and the pressure change process of pump outlet cross-section were obtained simultaneously. The numerical results show that the present water hammer protections to the long pipeline system are effective. The water hammer pressure,the unit upside down and inverted vent flow can be effectively reduced by controlling the two stage valve closing time and closing angle. According to the adjusting posi-tion of air valve,the caliber of the valve and inflow and outflow coefficient to control the negative pressure. It is found that the parameters combina-tion in which air valve inflow coefficient is 0. 975,outflow coefficient 0. 65 and caliber 450 mm is suitable for the pumping station. The pipeline maximum negative pressure head control is within -1. 6 m. This shows that the negative pressure of the pipe can be effectively reduced by rational arrangement of the air valve.