The Research On Modeling Method Of Water Supply Network Under The Accident Conditions

Urban water supply system is one of the essential infrastructure of the city, which has large investment,high operating costs,management and maintenance difficulties.It is a large,complex and diversified engineering system for water supply to modern cities and enterprises. Its emergency directly threatens urban public safety. Comprehensively and systematically acquiring the state of water network operation in emergency, analyzing the effect after emergency to the nomal operation,scientific and reasonable in water supply dispatching,research on security of water supply becomes even more important.In view of the present situation of water supply systems research on the accident conditions and significance, here improved the traditional hydraulic calculation method and put forward pressure dependent-demand hydraulic analysis method, analysis the research result using different simulation methods under the accident conditions of the water supply systems, Which based on the micro-hydraulic model of zhengzhou, the main conclusions are as follows:(1) Traditional hydraulic calculation method of node flow and pressure is the independent variables, but the actual water supply system in the flow of the node by the influence of the node pressure, in this paper, we consider the node of the pressure and flow dynamic relations, improve the traditional hydraulic calculation method, put forward pressure dependent-demand hydraulic analysis method, which involves the key parameters of demand pressure correlation index and user services required head, demand pressure correlation index of0.5, according to user’s requirements of the practical system head service standard setting water pressure.(2) Through the case study and application example analysis and contrast, traditional hydraulic calculation shows that the method is not suitable for pressure under poor plumbing hydraulic calculation, the traditional analysis method is easier to cause confusion results. Through the engineering example analysis shows that, the pressure dependent-demand hydraulic analysis method can effectively under the condition of the pipe network for accident hydraulic analysis, including the results of the simulation results with pressure the rate of matching94.38%, flow simulation results and the measured value the rate of matching96.59%.(3) Pressure dependent-demand hydraulic analysis method can reasonably accurate analysis insufficient water pressure hydraulic pipe network due to a fire, pipe rupture and pipe network construction.so that management can effectively evaluate the effects of the accidents,issue accurate effects of the accidents to increase the water supply quality and emergency response capability.