Urban Water Supply Networks Leak Detection Methods And Applied Research

Water supply pipeline leak detection has always puzzled water supply industry. At present, many enterprises and sci-tech research institutes are studying pipeline leak detection technology, whereas encounter difficulties of high investment, complex computing, low precision and low benefit.This system is integrated in Jinan Water Supply Control System Reconstruction project. The thesis aims to study and design a simple, convenient, maneuverable pipeline leak detection method with low investment so as to reduce cost and increase benefit for the enterprises. When making the design, not only the precision and sensitivity, but also the simplicity, speed and economy should be taken into account. Complexity of technology should be up to actual application. This is a major start point when planning system design.The water supply pipeline leak detection system, as this thesis designs, mainly focuses on R & D of single straight pipe leak detection model. On the basis, analyze the relations between the pipelines of the pipe network and study water supply pipeline leak detection method using hydraulic model so as to build up application system for water supply pipeline leak detection. In the thesis, many works are done, including leak detection computing, system hardware & software design and experimental data analysis.There are two steps to detect leakage. The first step is to study the operation state of the pipeline. That is the basis of the thesis studies. Study of pipeline operational state is based on pipeline hydraulics. The study objects are opposite single straight pipes which are made of different materials, different service time anddiameters. Pipe resistance coefficient is used to reflect pipeline operational state. When studying pipeline operational state, the system evades uncertain factors that may influence the changes of the resistance coefficient and reckons simple and measurable methods to calculate the resistance coefficient of the pipeline. The second step is to find out the leakage position. After ascertaining the operation state of the pipeline, analyze the pipeline parameters of the system according to the alarms of next analog parameter and calculate with known pipeline resistance coefficient so as to finally make sure the leakage point.Data analysis and computing proves that this system meets the precision requirement to certain degree. Besides, as the design requires, the system is economic and practical.The novelty of the system is mainly incarnated in the system computing and realization method. When computing the pipeline resistance coefficient, we skillfully evade the uncertain factors that may influence the changes of pipeline resistance coefficient and work out the coefficient with simple and measurable methods. As a result, the complex pipeline resistance coefficient becomes simple and measurable, and the precision is improved. With regard to realization method, we use two steps to constitute pipeline leak detection system so that the system has simple computing method, strong maneuverability and turns to be economic and practical.This system realizes the objective, that' s to build up water supply pipeline leak detection system using simple and practical method with low investment. The aimed system is quite economic and practical, with high price ratio and strong maneuverability, reaching the objectives of water supply enterprises for automation reformation. To build up such a system can help the operators andadministrators to qualitatively and quantitatively know the operational state of the pipeline under different working conditions. In case of accident, it can help operators to make rapid responds to exactly point out the valves in the pipelines that should be closed for purpose of maintenance and rush repair. Therefore, the system should have high values in practical sense.