On the In-Pipe Measurements of Acoustic Signature of Leaks in Water Pipelines

Identification and localization of leaks in water pipelines using acoustic methods have been utilized for many years. Most of the existing acoustic leak detection techniques rely on external measurements of sound emitted from the turbulent jet of water escaping the pipe. Direct acoustic measurements via hydrophones, which travel inside the pipe with the flow, have been recently addressed as a viable complementary leak detection technique. This paper presents an experimental investigation that addresses the feasibility and potential of inpipe acoustic measurements for leak detection. An experimental water pipe circuit was constructed to permit different line pressures, flow rates and leak sizes. The leak acoustic signature was acquired at different proximities from the leak port for variations of the line parameters. The acquired acoustic signals are processed and analyzed to access the feasibility and point out the limitations of invoking in-pipe measurements for leak detection.

A non-linear multiple-model state estimation scheme for pipeline leak detection and isolation

Model-based monitoring schemes are known to have a great potential in detection and localization of leaks in pipelines. Fluid flow in pipelines is characterized by a system of non-linear-coupled partial differential equations. Since state estimation can provide the basis for real-time monitoring of fluid flow in pipelines, a suitable numerical scheme is employed to formulate the problem in state-space form, which enables the development of state estimation techniques. A modified extended Kalman filter (MEKF) in conjunction with feed forward computations to anticipate the leak magnitude provides the core of the adaptive multimodel state estimation technique used in this paper. Numerical simulation results show that the developed state estimation scheme effectively detects and locates small leaks in pipelines within a short time duration.