Research On The Methods Of Hydraulic Calculation And Water Quality Analyses Of Urban Water Supply Network

Water supply, which provides necessary conditions to the production and living of a city, is the nucleus of a city. The water supply pipe network is a very complex systematic engineering. With the civilian's increasing requirement of the water quality and quantity, and with the continuously enlarged water supply scale, using computer to accomplish the dynamic analysis and simulation of water supply , thus understanding the present situation of city pipe network, and acquiring its operating data information in time is indispensable for a city's pipe network design and scientific management.In this thesis, it is analyzed and researched hydraulic calculation and water quality in water distribution network, and established those calculation models on the basis of former research achievements. The models are simulated dynamically by using EPANET software of the U.S. Environmental Protection Agency's research program. The dynamic simulation can accomplish these functions about design of water supply network, network calculation, dynamic simulation, change parameter, query information, database manage and continual monitoring.In this thesis, it is analyzed and researched the method of hydraulic calculation and used the method of node pressure to calculate the nonlinear hydraulic model of water distribution network. The result shows good correspondence with the method of Hardy Cross data. A series of analyses are performed to examine the effects of the change of pipe roughness coefficients and system reliabilities.the change rule of water quality in distribution network is studied. The thesis introduces the conventional first-order model to describe chlorine decay in water supply system based on water quality analysis. According to the decay model, we simulate the change rule of chlorine decay in the urban water supply condition by using EPANET software. The modeling outcome shows good correspondence with observed field data. It can get the influence of water quality on the basis of the node age of water, the change of nodal demands and pipe roughness coefficients of the network. By continual water quality monitoring, these models can ensure that residual chlorine satisfies the water quality standard.