Gas pipeline leakage acoustic emission positioning method

Abstract

The invention discloses a gas pipeline leakage acoustic emission positioning method, and relates to the technical field of gas pipeline fault diagnosis. According to the gas pipeline leakage acoustic emission positioning method, leakage points can be positioned by detecting gas pipeline leakage acoustic emission, detection signals collected by sensors are subjected to cross-spectrum Gaussian window processing, single and small-dispersion modal compositions in leakage source signals are extracted, and the position of a leakage source can be positioned through a cross-correlation function of the sensors. By the adoption of the positioning method, multi-modal guided wave interference is reduced, positioning errors of the leakage source are lowered, positional accuracy of the leakage source is improved, and working efficiency of gas pipeline maintenance is also improved. According to the positioning method, a LabVIEW development platform is adopted for designing a gas pipeline leakage acoustic emission detecting and positioning virtual system, the selected single modal compositions can be extracted by selecting window parameters, and therefore operation is easy and applicability is high.

Description

technical field [0001] The invention belongs to the technical field of gas pipeline fault diagnosis, in particular to an acoustic emission positioning method for gas pipeline leakage. Background technique [0002] As a fuel, natural gas is favored by countries all over the world because of its high calorific value and cleanness. my country's "Twelfth Five-Year Plan" points out that it is necessary to increase natural gas consumption, accelerate the construction of natural gas pipelines across the country, and by 2015 more than 95% of cities will use natural gas. Natural gas is a flammable, explosive and toxic gas. Once a pipeline leak occurs, it will threaten people's lives and property. Therefore, timely detection and location of natural gas pipeline leakage is of great significance to the sustainable development of society. [0003] At present, natural gas pipeline leakage detection methods mainly include in-pipe detection ball method, optical fiber sensor detection meth...

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Problems solved by technology

Wu Yinfeng, Pei Liying and others proposed to use wavelet transform to extract the high-energy mode of gas pipeline leakage for correlation time-delay positioning. This method uses the measured sound velocity for positioning, and more than 3 sensors are required to detect leakage signals; Rewerts et al. Dispersion characteristics of propagation, analysis of the leakage signal is composed of multiple modes of guided waves, and the single mode of the signal is extracted by performing time-frequency transformation and time-space transformation on the acoustic emission signal detected at both ends of the leakage source. Correlation analysis of modal signals theoretically achieves accurate location of leakage acoustic emission sources, but this method of modal extraction needs to obtain acoustic emission signals within the range of ±Δ near the two detection points, that is, each detection point at both ends of the leakage source in actual location At least two sensors are required to collect signals at the same time in the vicinity; Jiao Jingpin, He Cunfu, etc., based on the modal extraction algorithm of Rewerts et al., according to the principle that the guided wave waveform received by a certain sensor can determine the propagation waveform at any position, using two sensors Acoustic emission single-mode positioning is achieved by picking up the leak signal, but the experimental results show that for the liquid-filled pipeline leakage, the relative positioning error is mostly more than 4% at different detection distances within 40m, and the maximum is 13%, and the positioning error is relatively large

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