A Study On Urban Drainage Systems Modeling And Control Method

Urban drainage mainly focus on the treatment of urban wastewater, such as the collection, transmission, purification and using of the emissions of urban sewage, industrial wastewater, rainfall runoff and the others. Urban drainage was an important symbol of weighing the standard of modern city and the most important foundation establishment of ensuring the city's normal running, it was named by"One of the City Life System", the delay or failure of any part may result in the paralysis of the entire system.The urban sewage treatment plant has developed rapidly, and the requirements of emission standards have also increasingly become stringent, which has played a key role to improve the water environment. However, in our country, there existed universally some problems at present, the maintaining of the pipe network and pumps, the schedule of the production, the distribution of wastewater and the flood's prevention were still operated by people's experience. There were some dangerous situations because of the lower of automation and the disadvantage of monitoring, such as wastewater's overflow and emergency capacity for disaster weather. It's an important problem on realizing the Urban Drainage Integrated Automation System, improving the efficiency of urban drainage's running, reducing the pollution of letting into environment directly and supplying the warning and decision's information for resisting the disaster.This paper takes urban drainage pipe network as the research object, aiming at establishing numerical model and the state space model of urban drainage system, and achieving the automatic control of the drainage system. In order to provide reference to the analysis of running state and real-time control study of urban drainage system. At the same time, the pipe network hydraulic model could be used to the accurate simulation of the operating conditions for various working conditions, such as rain and scheduling program, and it also could be used for water resource's scheduling, disaster assessment and flood warning. This paper mainly focuses on the modeling of urban drainage pipe network, and the specific can be divided into three parts:Firstly, this paper takes water motion state of drainage network as the research object, uses Preissmann implicit difference scheme to disperse the model, and establish a numerical model of the drainage system according to the pipe network hydraulic model.Secondly, from the point of the pipe network hydraulic model, this paper uses Taylor series and finite difference method to do the discrete model, and established the state space model of urban drainage system combined with the network operating conditions. Besides, combining with the actual situation of pipe network, the paper designs state feedback control to design the system with observer running feedback controller, in order to control the water level and flow of the urban pipe network, and making the sewage water level inside the pipe reach a stable state.Finally, aiming at the channel leakage in urban drainage system, the paper analyzes the motion of wastewater in the pipe network when the leakage occurred. Combined with the Saint-Venant equations, an improved form of Saint-Venant equations was given based on the leakage model, then a stability analysis was conducted for the model, and the state feedback controller was designed for the system.