Transient generation in pipe networks for leak detection

Abstract

Inverse transient analysis is known to be a powerful approach for leak detection and calibration of friction factors in pressurised pipes. In order to use inverse transient analysis, a transient state is generated in the system by opening or closing a regulating valve. This excitation and its location in a pipe network significantly influence the success of inverse-transient-analysis-based methods; this issue is the focus of this work. The paper defines a mathematical programming model to produce rapid transient variations in the system subject to allowable high and low pressures. The transient generation point in the network, the time interval and the magnitude of the excitation are decision variables. Using the method of characteristics, a numerical model is developed to analyse transients and evaluate the objective function. Based on genetic algorithms, an optimisation solver is developed to solve the problem. To demonstrate the efficiency of the method, a water distribution network of 34 pipes (with unknown friction factors) and 22 junctions (with unknown leaks) is defined and analysed. The results show that the proposed method makes a remarkable contribution to the success of applied inverse transient analysis.