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

Abstract

Natural or hydrogen gas is a vital energy carrier, which can serve as an energy source and is extremely vulnerable to leakages from pipeline transportation systems. Although the safety of natural gas pipelines has improved, the average economic loss of natural gas accidents including leakages is high. Most present acoustic methods are based on the time differences between two sensors installed at both ends of the pipeline. To achieve leak localization, traditional methods using two sensors installed at both ends can be improved by a newly proposed combined signal processing method that calculates time differences more accurately. Based on the combined signal processing method, a new method is designed based on velocity differences, in which the two sensors are installed at the same end within a smaller distance. In this situation the velocity differences must be considered because the time differences between the two sensors can be calculated accurately, even when the distance between the two sensors is small. An experimental facility in a laboratory is established and experiments are carried out. Finally, the methods are verified and applied to leak localization. The results provide a foundation for the proposed methods. The maximum experimental leak localization errors for the methods are −0.59 and 1.48%. It is concluded that the system with the new methods based on the time and velocity differences can be applied to protect and monitor natural gas pipelines.