Integrated leakage detection and localization model for gas pipelines based on the acoustic wave method

• An integrated leakage detection and localization model for gas pipelines based on the acoustic wave method is proposed.
• An improved gas pipeline leak localization scheme that considers the dynamic change of sound and gas velocity is proposed.
• An improved wavelet double-threshold de-noising method for acoustic signal with random noise is proposed.
• Different pipework condition acoustic signals are distinguished by the least squares support vector machine.

With the development of natural gas transportation systems, major accidents can result from internal gas leaks in pipelines that transport high-pressure gases. Leaks in pipelines that carry natural gas result in enormous financial loss to the industry and affect public health. Hence, leak detection and localization is a major concern for researchers studying pipeline systems. To ensure the safety and improve the efficiency of pipeline emergency repair, a high-pressure and long-distance circular pipe leakage simulation platform is designed and established by similarity analysis with a field transmission pipeline, and an integrated leakage detection and localization model for gas pipelines is proposed. Given that the spread velocity of acoustic waves in pipelines is related to the properties of the medium, such as pressure, density, specific heat, and so on, this paper proposes a modified acoustic velocity and location formula. An improved wavelet double-threshold de-noising optimization method is also proposed to address the original acoustic wave signal collected by the test platform. Finally, the least squares support vector machine (LS-SVM) method is applied to determine the leakage degree and operation condition. Experimental results show that the integrated model can enhance the accuracy and precision of pipeline leakage detection and localization.