Simulation, Localization And Control Techniques For Major Leakage Accident Of Municipal Water Supply Network

Urban water supply system has the characteristics of large-scale, wide distribution and concealment. It is often difficult to detect the major leakage accident when it happens in water supply network. So it brings serious risks for people lives and social wealth. Water supply industry has been troubled by techniques of identifying and locating the major accidents for a long time. Many research institutions and companies are conducting research on related technologies. But because of large investment and low precision, the study is still on the stage of theoretical research, and it is difficult to be used directly into practical applications.Techniques of GIS, SCADA and Simulation for dynamic management of water supply network have been introduced at the beginning of the paper. Concept methods, establishing process and application on network accident with examples have been introduced. These kinds of technique lay the foundation for locating the major accident.In the third chapter, characteristic of pressure changes under the circumstances in emergencies has been analyzed in detail. And hydraulic model has been setup in this case. Using detail model, assessment has been done for the pressure changes at all the SCADA pressure points due to pipe burst. Through the example analysis, characteristic information database for major leakage accident in water supply network has been established.In the fourth chapter, analysis has been focused on discrimination of the accident, the accident point positioning technology, and two-step method of accurately positioning the accident points has been proposed. First step is to use BP neural network intelligent to recognize accident area. At the beginning, the leakage accident characteristic database has been used to do the learning and training for BP neural network, and establish the nonlinear relationship between accident area and pressure variation at SCADA pressure points. And then use the pressure change at SCADA points as known conditions to predict the location of the accident area. Second step is to use the detail hydraulic model to identify the suspicious accident points by statistical method. And also leakage volume has been calculated by golden section method.In the last section of the paper, several critical techniques of water supply system leakage accident control have been discussed, like DMA, pressure management and network risk evaluation model. Theories, principles and process have been presented, and risk evaluation based on statistical analysis and fault tree analysis methods have been proposed. Through the active preventive measures, frequency of major accidents will be reduced. At last, leakage control strategy and practice are discussed according to the actual water supply network of one city.