The Research On The Protection Of Water Hammer In High-lift, Multi-fluctuations And Long Distance Pipeline

With the development of the economy, the water resources, which people require are incread day by day. In order to solve the sharp contradiction between supply and demand of water resources, long distance and large-scale water delivery cascade pumping stations are begin to be built. In order to guarantee security of the running of the water supply system to prevent the water-supply systems from causing water hammer accidents when transient phenomenon taken place in pipe. Tt is necessary to make water hammer analysis, predict and simulate the occurrence of water hammer accidents and diffuse law at each kind of the operating mode. According to actual characteristic of pumping system, the reasonable, effectively and economic measure of preventing water hammer is designed.In long pipe line, especially high-lift, multi-undulate pipeline, the difficulty of prevention water hammer is most difficult. Therefore, the actual project needs this aspect of the technology eager. And this was studied in this article.1,Each kind of air-liquid two-phase flow patterns in pipeline and the relations of the transformation among the flow patterns were expounded .Also the mathematical models of air-liquid two-phase flow were summarized. According to above set the request to the pipeline exhaust technology.2,The origin and position of the gas in the pipeline were elaborated. The work principle, the performance and the good and bad points of each discharge valve were analyzed and compared.3,The protective measures of the water hammer in high-lift, multi- fluctuations long distance pipeline were illustrated. The cut-off water hammer in pipeline protective was analyzed. According to the cavity medium as well as the pattern of closing, the cut-off and closing water hammer was classified and the analyzed by closing and press rising. On the basis of project, the choosing steps of protection plan of high-lift, multi- fluctuations pipeline system were proposed.4,The basic mathematical model of water hammer computation was established. And the formula and the application condition of each kind of boundary condition in high-lift, multi-fluctuations pipeline were put forward. The boundary condition used presently of the exhaust valve was revised5,Take the protection and optimization of water hammer of the pipeline in Yulin and Dalian as the example. Through the calculation, the protection measures of cut-off flow were compared. The closure and the operation of water pump were optimized. According to calculation, the different performance of different discharge valve in the protection processs of water hammer was verifyied. According to the calculation, the discharge valve with constant speed and cushion function is the basic protective measure of cut-off and closing water hammer in the high-lift, multi- fluctuations and long distance pipeline...