A new method for location leak in long-distance pipeline

For the long-distance pipeline based mainly on frictionalhead loss, it is necessary to locate the leak point after the leak appears.The researchers have developed many methods for position leak during thepast of a few years, such as pressure gradient method, inverse transientmethod, etc. These methods have their respective advantages anddisadvantages for long-distance pipeline. The pressure gradient method issuitable to the pipeline of hydraulic grade line varied linearly. The leaklocation in the inverse transient method is firstly assumed. Therefore, anew method for location of the leakage points has been developed with thecombination of the pressure gradient method and the inverse transient methodin this paper. In this scheme, the coefficients of the friction resistancebefore and after the leakage points, and the coefficients of the leakageflow, are taken as the optimizing control variables, and the difference ofwater head between the calculated values by waterhammer equations and themeasured values at measured sites are utilized as the objective function.The coefficients of the friction resistance before and after the leakagepoints are optimized through the genetic algorithm, based on which theiterative method is used to locate the leakage points.To verify the new method, the experiment in a water pipe with a length of48.775m and a diameter of 53mm was set up in the hydraulics laboratory ofDalian University of Technology. The pipeline is made of iron pipe, and isconnected to the pump at the upstream end and the water flume at thedownstream end. The error value of mean location in this method is about4%, compared with the experimental data. The experimental results showthat the method is quite feasible and efficient to locate the leak inlong-distance pipeline.