Study On Calculation Model Of Water Hammer In Urban Water Supply Pipe Network

China’s urbanization process has entered into the depth stage from the shallow stage, in order to cope with the process of urbanization, the scale of urban water supply network system and the scope of water supply gradually expanded. A part of the old pipe network has been built for thirty or forty years, there has been a serious leakage of water and other phenomena, and the continuous occurrence of tube explosion accident, not only caused a lot of waste water resources, but also for the daily life of urban residents caused great security risks, these accidents are mainly caused by water hammer. Pipeline water hammer is a technical problem that needs to be solved urgently in the design process of water supply network. In this paper, based on the previous research results of hydraulic transition process of water hammer, the paper focuses on the harm of water hammer and the protective measures.The main contents and conclusions of this paper are as follows:1.Describes the basic equations of water hammer calculation and method of characteristic computerized solution principle.2.Analysis and research of the pipeline water hammer calculation with various boundary conditions and calculation model, and the hydraulic calculation model of different pipeline connecting point of water supply network is established.3.For single source network and dual water supply network were established water hammer protection measures of stopping the pump off water hammer and the non cutoff water hammer calculation model, and the water supply pipe network calculation program, and explain the process of programming.4.Combined with engineering example of pipeline under different source locations and different water number and different terrain elevation of water hammer hydraulic transition process pump stopping calculation and analysis, and studied a variety of water pipe network conditions under different conditions of water hammer characteristics.5.When water is close to the central region, the network terrain elevation difference is small, the water supply network system stop pump water hammer of pipe network system safety of smaller and smaller.6.Single source to stop the accident of pump dual water supply system due to water pumping station adjustment pressure tower role in water hammer protection than the single water source water supply system more favorable, so the dual water supply system stop pump water hammer harm small compared to that of the single water supply system.7.Dual water supply pipe network occurs, stop the pump cutoff water hammer in bridge sites usually in the transfer of the two water service area, namely flow occurrence node mutations. While the single water water hammer pump stops cavities place usually in the network area near the control point.8.The key is to eliminate water hammer protection network disconnection water hammer, also need to pay attention to stabilizing exhaust pipe system. Bi directional pressure regulating tower has a good effect to eliminate negative pressure, and then combined with a certain amount of air valve will have a good effect on the elimination of water hammer pipe network system. The water outlet of the water pump should be installed in the slow closing check valve, valve closing procedures should be optimized.9.The selection, calculation and optimization of different water hammer protection measures of dual water supply network are carried out with the engineering examples, explore the optimal method of water hammer protection scheme, optimal water hammer protection measures are obtained.