长输水管道尾部保水堰的水力特性试验研究

Hydraulic experiments on long water supply pipelines connected to overflow weirs

在长距离输水管路出口设置溢流堰可以有效控制水击和防止管路脱空。为了分析该结构在非恒定流情况下的工作特性,设计水力模型试验对突然断水情况的水流特性进行观察测试,通过测试结果建立优化设计的方法和准则。试验表明:长管道水体的惯性力作用可能引起衔接池的水位跌落和波动,从而导致管路进气和水流拍打管口,通过增加溢流堰的高度或扩大衔接池的面积可以避免这一现象。

Overflow weir is used to control water hammer and prevent air entrainment in long supply pipelines. A hydraulic model was developed to analyze the unsteady flow of a water supply system with long pipelines and an overflow weir. The water level fluctuations in the inlet surge tank were simulated in model tests. Design criteria were developed from empirical data. The results show that the inertia of the pipe flow is the primarily influence on the water level fluctuations, which lead to air entrainment and hydraulic flap at the pipeline inlet. The fluctuations can be controled by increasing the inlet tank area and the weir height.