漏损管网中瞬态压力变化规律的研究

Variation of Transient Pressure in Leaking Water Pipe Network

瞬态压力在管网中的传播关系到管网运行的安全。设计并建立了一套供水管网模拟试验装置,用以分析不同管道形式、漏点尺寸和初始流速三者对管内瞬态压力波传播的影响。试验管道采用直径为50mm的镀锌钢管,通过关闭阀门引起瞬态压力波,采用压力传感器监测瞬态压力波动。结果表明,瞬态压力与漏点尺寸呈负相关关系,漏点的设置对管内瞬态压力有调节作用;上、下游均存在支管可有效削弱管内瞬态压力的峰值和谷值,仅上游存在支管时效果次之,在有漏点的情况下,下游存在支管反而对主管内瞬态压力的正压起到叠加作用;瞬态压力波的特征值随着初始流速的增大而增大。

Transient pressure in water pipe network is known to affect the safety management of pipelines operation. A set of simulation test device was constructed, in order to study the coupling relationship between three independent variables ( pipeline form, leakage size and initial velocity) and the transient pressure in pipelines. The diameter of galvanized steel pipe was designed as 50 mm and a pressure sensor was used to monitor the transient pressure which was manually made by suddenly closing the valve. The results indicated that the transient pressure had a negative correlation with the size of leakage. The location of leakage played a regulatory role in transient pressure changes. In terms of the position of dendritic pipes, when the pipelines had dendritic pipes in both upstream and downstream, it enjoyed the highest effectiveness to weaken the in-pipe positive and negative waves, followed by the pipeline with only dendritic pipe in upstream. However, when there were leakages, the pipelines with dendritic pipes in downstream might increase the positive pressure. Besides, the eigenvalues of the transient pressure increased as the initial velocity increased?