TVD格式数值模拟四通管阀门关闭特性研究

Research on the Characteristic of Closed Valves in Four-way Pipes with TVD Scheme

水击问题是管道输水中重要的安全问题,管网水击直接制约着管道输水技术的发展。正确进行四通管水击及其影响分析并采取适当控制措施对管网安全运行有重要意义。将TVD格式运用到四通管阀门关闭特性对水击过程影响的研究中,对其阀门关闭规律及组合关闭方式进行模拟,以期遴选出使得水击压力不影响管网安全运行的关阀模式。由模拟结果可以看出:两阶段直线关阀方式优于加速曲线和直线关闭方式,可操作性强,两阀门同时直线关闭方式优于一个或两个阀门瞬时关闭方式,产生水击压强最小且衰减最快,可分别作为保证四通管在瞬变工况下安全运行的阀门关闭模式和组合关阀方式,进而为四通管乃至管网在瞬变工况下的安全运行和管理提供理论依据和参考。

The water hammer problem is an important safety problem in the pipeline system. The water hammer of pipe networks restricts thedevelopment of technology for water pipeline directly. It has a significant impact on the safe operation of pipe networks if we make a correct a-nalysis of the water hammer in a four-way pipe and take appropriate control measures. This paper studies the influence of valve closing char-acteristics on the water hammer process in a four-way pipe with TVD scheme. To select the valve mode in which condition water hammer doesnot affect the safe operation of the pipeline networks, the valve closure laws and composition of the law-off mode are simulated as well. Theresults indicate that the two-stage shut-off mode is superior to linear acceleration curve off mode and straight line mode, with strong operabili-ty, two valves simultaneously linear-off mode is better than one or both valves closed instantaneously mode, producing the smallest and fastestattenuation water hammer pressure. They can respectively be used as the appropriate valve closing mode and combination valve off modewhich can guarantee safe operation of four-way pipes in transient flow conditions. The conclusion provides a theoretical basis and reference tothe four-way pipe and the safe operation and management of pipe networks under transient conditions.