Localization of Transient Events Threatening Pipeline Integrity by Fiber-Optic Distributed Acoustic Sensing

• Published in: Sensors (Basel, Switzerland) Vol. 19; no. 15; p. 3322
• Main Authors: Hussels, Maria-Teresa, Chruscicki, Sebastian, Arndt, Detlef, Scheider, Swen, Prager, Jens, Homann, Tobias, Habib, Abdel Karim
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 29-07-2019; MDPI
• Subjects: Acoustic propagation; Acoustic waves; Acoustics; Artificial intelligence; Cables; condition monitoring; Deflagration; Detonation; distributed acoustic sensing (DAS); distributed vibrations sensing (DVS); Elastic waves; Feasibility studies; Fiber optics; fiber-optic sensing; gas explosion; Gas explosions; Gas mixtures; Gas pipelines; Industrial plants; Localization; Machine learning; Monitoring systems; Optical fibers; pipeline integrity; Pipes; Sensors; Stress concentration; Structural failure; Transducers; Vibration; Wave propagation; Germany; pipeline integrity; condition monitoring; fiber-optic sensing; gas explosion; distributed vibrations sensing (DVS); distributed acoustic sensing (DAS)
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s19153322

Pipe integrity is a central concern regarding technical safety, availability, and environmental compliance of industrial plants and pipelines. A condition monitoring system that detects and localizes threats in pipes prior to occurrence of actual structural failure, e.g., leakages, especially needs to target transient events such as impacts on the pipe wall or pressure waves travelling through the medium. In the present work, it is shown that fiber-optic distributed acoustic sensing (DAS) in conjunction with a suitable application geometry of the optical fiber sensor allows to track propagating acoustic waves in the pipeline wall on a fast time-scale. Therefore, short impacts on the pipe may be localized with high fidelity. Moreover, different acoustic modes are identified, and their respective group velocities are in good agreement with theoretical predications. In another set of experiments modeling realistic damage scenarios, we demonstrate that pressure waves following explosions of different gas mixtures in pipes can be observed. Velocities are verified by local piezoelectric pressure transducers. Due to the fully distributed nature of the fiber-optic sensing system, it is possible to record accelerated motions in detail. Therefore, in addition to detection and localization of threatening events for infrastructure monitoring, DAS may provide a powerful tool to study the development of gas explosions in pipes, e.g., investigation of deflagration-to-detonation-transitions (DDT).