Pipeline leakage location method based on cross-correlation

Abstract

The invention discloses a pipeline leakage location method based on cross-correlation. The method is implemented on the basis of the following detection device: two sensors are mounted on a to-be-detected pipeline and are acceleration sensors or hydrophones; each sensor is connected with a data acquisition unit which is used for synchronously acquiring leak acoustic signals transmitted in a fluiddue to pipeline leakage. The method comprises the following steps: acquiring leak acoustic time-domain signals picked by the two sensors, and calculating a cross power spectral density function; weighting the cross power spectral density function, performing inverse Fourier transform to obtain a cross-correlation function, acquiring time delay estimation corresponding to a peak value of the cross-correlation function, and accordingly, reversely deriving the distance between a leak point and a first sensor with a location formula. According to the method, filtering processing is not needed forsensor signals, the influence of reflection can be eliminated effectively, and pipeline leakage can be located more accurately under complicated working conditions.

Description

technical field [0001] The invention relates to the field of pipeline transportation, in particular to a method for locating leakage of urban water supply pipelines under complex working conditions, and in particular to a method for locating pipeline leakage based on cross-correlation. Background technique [0002] With the acceleration of urbanization and population increase, the demand for water resources continues to increase. In the planning, construction and operation management of my country's urban water supply pipeline network, there are common problems such as corrosion and aging of underground infrastructure, lack of pipeline information, excessive traffic load and man-made damage, backward monitoring and operation management methods, etc., resulting in frequent pipeline leakage. Pipeline leakage usually accounts for more than 70% of the total water loss, causing direct and indirect energy, economic losses and safety hazards; secondly, the current construction of c...

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Problems solved by technology

However, this method has three problems in the actual pipeline leakage location that are difficult to solve: first, when detecting non-metallic pipelines, low water pressure, deep buried pipelines and other working conditions, the accuracy of leak location is not high, and even misjudgment; Second, it is usually necessary to predict the prior knowledge of leakage sound and background noise, and select the non-dispersive frequency band where leakage sound dominates (document [1]: Y.Gao, M.J.Brennan, P.F.Joseph, J.M.Muggleton, O.Hunaidi, A model of the correlation function of leak noise in buried plastic pipes, Journal of Sound and Vibration 277 (1-2) (2004) 133-148.), first filter the signal picked up by the sensor, but it is difficult to obtain this prior knowledge in practice The third is when the leakage sound generates reflections of sound waves at the branches and nodes of the pipeline (document [2]: Y.Gao, M.J.Brennan, P.F.Joseph, On the effect of reflections on time delay estimation for leak detection in buried plastic water pipes, Journal of Sound and Vibration 325(3)(2009)649-663.), the location of leaks will be inaccurate

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