Paired-IRF Method for Detecting Leaks in Pipe Networks

Abstract

Pipeline leak detection is critical for targeted maintenance and water loss reduction within water distribution systems. This paper proposes a hydraulic transient, impulse response function (IRF)–based, signal analysis approach for leak detection in water pipelines and networks. In the proposed approach, continuous pressure signals are sent into the pipeline, where pressure responses are measured by two transducers (separated by a distance) located close to the generator. Given this setup, a signal analysis methodology was theoretically derived to extract the major components of the deconvolution between these two measured pressure traces. The result shows that the deconvolution consists of a pair of IRFs of the pipeline with opposite signs and a time shift associated with the distance between the transducers. Hereon, they are referred to as a paired IRF. A leak is shown to induce a pair of pulses on the paired-IRF trace. With the paired IRF obtained, the leak can be localized by analyzing the occurrence times of the leak-induced paired pulses. Numerical verification was undertaken in both a single pipe and a pipe network using the pipeline pressure responses simulated by the method of characteristics. The leaks in the pipelines were successfully detected using the new approach. Experimental verification was conducted on a laboratory copper pipeline with a leak simulated by a discharge orifice. The proposed method was found to accurately localize the leak even with the pressure waves contaminated by realistic background pressure fluctuations and noise. The numerical and experimental cases demonstrate that the novel paired-IRF method is applicable to pipe networks, robust to system interference, and able to deal with realistic background pressure fluctuations and noise.