New leak-localization approaches for gas pipelines using acoustic waves

Natural or hydrogen gas is a vital energy carrier that can serve as an energy source but is extremely vulnerable to leakage from pipeline transportation systems. The required ignition energy for these gases is low. Methane, which is a far more potent greenhouse gas than CO2, is partly sourced from natural gas leaks. Although the safety of natural gas pipelines has been improved, the average economic loss due to natural gas accidents, including leaks, is large. To solve these problems, an acoustic leak-localization system is designed and researched for gas pipelines via experiments using four methods proposed for 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 in cases where it is necessary to calculate the time differences with data synchronicity. For cases where data synchronicity cannot be ensured, a new method is designed based on velocity differences-involving the installation of two sensors at the same end separated by a small distance-is designed. When the time differences cannot be calculated accurately, two new methods based on the amplitude attenuation model are proposed, which include the two aforementioned methods of sensor installation. Using these four methods, the system can be applied to most situations. Next, a laboratory-scale experimental facility is established, and experiments are performed with the same leakage point. Finally, the methods are verified and applied for leak-localization. The results provide a foundation for the proposed methods. The maximum experimental leak-localization errors for the four methods are -0.59%, -2.44%, 1.83%, and -11.68%. By using these novel methods, the system can be applied to protect and monitor natural gas pipelines. (C) 2018 Elsevier Ltd. All rights reserved.