Study On The Impact Of Gas Containing Cavities Collapsing Water Hammer Boosting Based On Exhaust

Water is the foundation of human survival and development,it has an irreplaceablerole on the formation of human civilization and development of human society. Waterresource is abundant in our country, but the per capita of water volume is scarce, especiallyin recent years,The distribution of water resources is uneven, our country is facing a hugecrisis of water resources. In order to solve these problems, long distance inter-basin andlong distance water conveyance project is gradually increasing in recent years. Whilecut-out bridge in long distance water conveyance project and from which the occurrence ofwater hammer brings great harm on the pipe security system. In order to protect the safetyof water conveyance pipeline operation system better, water hammer is intensively studiedin recent years.Bridge formation and cavity movement regularity upon the water hammer occurrenceis analyzed in this thesis, including the regularity of the production, movement and mutualtransformation rule of gas and liquid two phase flow in the six kinds of flow pattern.Through the characteristic line method for computer programming calculation, based on allkinds of boundary conditions in the pipeline, the different ways of exhaust influence onwater conveyance pipeline water hammer pressure are discussed, influence of differentexhaust pipe exhaust ultimately depends on the block in the pipe bridge effect of inhibitingor eliminate water hammer pressure is also pointed out in the thesis.By analyzing the pipeline operation of transient process under different workingconditions, it is concluded that using constant speed buffering exhaust valve to exhaust pipeis the most effective way of exhausting at present, and at the same time in the practicalengineering in two-way regulating tower under the collocation with constant speedbuffering exhaust valve is ensured that the water hammer pressure when the water hammeraccident occurs shall not exceed the pipeline pressure value, therefore guarantee the safetyof pipeline operation.