南水北调中线自流式加压泵站泵后负压分析

采用了AFT impulse3．0构建了南水北调中线上惠南庄泵站的管网模型，并对泵站过渡过程进行详细计算和分析后，发现对于大流量的管线按照自流形式布置的泵站，泵站掉电过程中并未产生正压水锤，泵后水流流速大，掉电后容易在泵后形成比较大的负压，且在备用泵后的盲管端更易产生较大的负压，采用空气阀对泵后负压的控制比较有限，有效的方法是加大泵的转动惯量。

Waterhammer in Long Distance Gravity Water Delivery Systems

In this paper,the waterhammer problem is carefully studied in a long distance gravity water delivery project. The negative pressures always exist in the pipes next to the outlet of the pumps,especially the stand-up pumps,to increase the inertias of the pump system is an effective way to solve the negative pressure problems to some extent. Some problems of theoretical discussion and practical processing related to the computer-based numerical computing of water hammer caused by offstream of pumping assemblies are described in this paper. The scopes involved are boundary condition equations, simplification of pipe-networks and section of calculating, parameters set-up of pump and valves, patterns of water rupture of water flow and valve movement in water hammer status.