Leak localization approaches for gas pipelines using time and velocity differences of acoustic waves

2019 ◽  
Vol 103 ◽  
pp. 1-8 ◽  
Author(s):  
Cuiwei Liu ◽  
Zhaoxue Cui ◽  
Liping Fang ◽  
Yuxing Li ◽  
Minghai Xu
Author(s):  
Cuiwei Liu ◽  
Yuxing Li ◽  
Qihui Hu ◽  
Wuchang Wang ◽  
Yazhen Wang ◽  
...  

Natural gas is a vital energy carrier which can serve as an energy source, which is extremely vulnerable to leakages from pipeline transportation systems. The required ignition energy is low. Although the safety of natural gas pipelines has been improved, the average economic loss of natural gas accidents, including leaks, is large. To solve these problems, an acoustic leak localization system is designed and researched for gas pipelines using experiments with methods proposed according to different application situations. The traditional method with two sensors installed at both ends can be improved by a newly proposed combined signal-processing method, which is applied for the case that it is necessary to calculate the time differences with data synchronicity. When the time differences cannot be calculated accurately, a new method based on the amplitude attenuation model is proposed. Using these methods, the system can be applied to most situations. Next, an experimental facility at the laboratory scale is established, and experiments are carried out. Finally, the methods are verified and applied for leak localization. The results show that this research can provide a foundation for the proposed methods. The maximum experimental leak localization errors for the methods are −0.592%, and −7.62%. It is concluded that the system with the new methods can be applied to protect and monitor natural gas pipelines.


Measurement ◽  
2019 ◽  
Vol 134 ◽  
pp. 54-65 ◽  
Author(s):  
Cuiwei Liu ◽  
Yuxing Li ◽  
Liping Fang ◽  
Minghai Xu

2015 ◽  
Vol 35 ◽  
pp. 236-246 ◽  
Author(s):  
Cui-wei Liu ◽  
Yu-xing Li ◽  
Yu-kun Yan ◽  
Jun-tao Fu ◽  
Yu-qian Zhang

2019 ◽  
Vol 14 (3) ◽  
pp. 157-164
Author(s):  
V.Sh. Shagapov ◽  
E.V. Galiakbarova ◽  
Z.R. Khakimova

Evolution of pressure perturbations propagating in pipeline filled with gas-and-drop medium representing “wet” methane at temperature below dew point and having damaged section, in form of extended narrowing of channel due to hydrate plug, is investigated. Hydrate formation is due to the presence of water (or its vapours) and gas, the components of which dissolve in water under certain conditions form a solid phase. Hydrate deposits help to reduce the cross-country capacity of gas pipelines and therefore their detection is a pressing task. It is proposed to solve the problem using acoustic methods. For this purpose mathematical model of propagation of acoustic waves in long-wave range in gas-and-droplet medium is considered. The horizontal pipeline appears semi-pointed, the solution is sought in the form of a harmonic wave. Wave is one-dimensional, having small amplitude of oscillations. Based on dispersion equations, dependence of phase velocity and attenuation coefficient on frequency of acoustic wave disturbance and on volume content of suspended phase (water droplets) are built. In the high frequency region, the attenuation coefficient increases with the volume content. The formulas for reflection and passage coefficients are derived taking into account pipeline narrowing due to hydrate deposits. The results of numerical calculations illustrating the dynamics of pulse signals depending on the thickness of the gas hydrate on the inner wall of the pipeline are presented. Calculations are based on forward and backward Fourier transformations and the use of software. It is established that the greater the hydrate deposit on the wall in thickness, the greater the amplitude of the returned reflected signal.


2000 ◽  
Vol 122 (07) ◽  
pp. 66-68 ◽  
Author(s):  
Paul Sharke

This article describes use of photoacoustics by automakers to track and tackle leakage problems. Photoacoustics uses momentary heat from a light source to excite acoustic waves. Laser Imaging Systems of Punta Gorda, FL, developed the idea of photoacoustic leak detection. Dowling worked with Ford in developing leak localization as part of a team that was put together by the National Center for Manufacturing Sciences. Once a leak is sensed, a technique originally developed for a US Navy underwater acoustics program deploys to pinpoint its place. Vertical location is known already. Vacuum Instrument and Laser Imaging Systems are building the alpha prototype now.


Author(s):  
Zewei Zhang ◽  
Leixia Zhang ◽  
Ming Fu ◽  
Didem Ozevin ◽  
Hongyong Yuan

Author(s):  
Aline Barbosa Figueiredo ◽  
Renan Martins Baptista ◽  
Felipe Bastos de Freitas Rachid ◽  
Gustavo Cesar Rachid Bodstein

Author(s):  
Kemining W. Yeh ◽  
Richard S. Muller ◽  
Wei-Kuo Wu ◽  
Jack Washburn

Considerable and continuing interest has been shown in the thin film transducer fabrication for surface acoustic waves (SAW) in the past few years. Due to the high degree of miniaturization, compatibility with silicon integrated circuit technology, simplicity and ease of design, this new technology has played an important role in the design of new devices for communications and signal processing. Among the commonly used piezoelectric thin films, ZnO generally yields superior electromechanical properties and is expected to play a leading role in the development of SAW devices.


1998 ◽  
Vol 77 (5) ◽  
pp. 1195-1202
Author(s):  
Andreas Knabchen Yehoshua, B. Levinson, Ora

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