The Computation Research Of The Cutoff And Non-cutoff Suddenly Pump-stopping Hammer In The Single Water Source Urban Water Supply Pipe Network

The water supply network was the product of human culture progress and urbanizd accumulation housing.It was one of the most important infrastructures in modernized city. At the same time, it was the important symbol of the the urban society and the economic development modernization level. Along with the development of society and the acceleration of urbanization, the people's life standards enhanced day by day, and the request of safety water supply of the water supply network increased higher and higher. However, the bursting and exposing accident of urban water supply network occurred frequently. At present, the harm of water hammer in the long distance water distribution project received more and more attention, at the same time, its analysis and calculation are more and more further. However, regarding to the reason of tube explosion in the water supply network, mostly blamed the outside influences, but the study about the exhausting buchang caused the water hammer harm was really few. This paper based on the continuum transient theory already the research results which obtains, mainly analyzes the harm of the cut-off and closing water hammer and the its protective measures in water supply network.1. On the basis of the summarized of the air-liquid two-phase flow, exposed the basic principle and the method of the water hammer--the characteristic curve equation and finite difference's compatibility equations. And based on this, according to equipment's concrete performance, designs the appropriate boundary condition.2. When the pipeline pressure is reduced to the saturation water vapor pressure, the water will vaporize so that a continuous water column separation occurs, followed by separation of the water column to bridge, and then the generation of water hammer of cavities collapsing causes a huge pressure rising in pipes, as is the water hammer of cavities collapsing. This article established two mathematical model, which was the cutoff water hammer and the non-cutoff water hammer due to power failure, carries on the analysis and comparison to them, and through calculating and conparing the pressor water hammer of concrete examples, obtains the reasonable computation model.3. This article based on the predecessor research results of the water hammer in the long distance water distribution project, elaborated briefly the establishment of water power transient process's computational procedure in the single water source water supply pipe network, preposes in both establishment process similarities and differences.4. Combined with the engineering practice, carrying on the VC++language programming and simulation operation to the single source water supply network stop the pump water hammer, compared to different schemes, finally gives the best water hammer protective measure of single water source water supply pipe network..The research provided the reference value and salutary lesson for the water hammer protection measures of single water source water supply pipe network, simultaneously it also has far-reaching influence on optimizing urban water supply network protection measures of water hammer.