Hussels Maria-Teresa, Chruscicki Sebastian, Arndt Detlef, Scheider Swen, Prager Jens, Homann Tobias, Habib Abdel Karim
Bundesanstalt für Materialforschung und -prüfung (BAM), Unter den Eichen 87, 12205 Berlin, Germany.
Sensors (Basel). 2019 Jul 29;19(15):3322. 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).
管道完整性是关乎工业厂房和管道的技术安全、可用性及环境合规性的核心问题。一种状态监测系统，能够在实际结构失效（例如泄漏）发生之前检测并定位管道中的威胁，尤其需要针对诸如管壁受到冲击或压力波在介质中传播等瞬态事件。在当前工作中，研究表明，光纤分布式声学传感（DAS）结合光纤传感器合适的应用几何结构，能够在快速时间尺度上追踪管道壁中传播的声波。因此，对管道的短时间冲击能够以高保真度进行定位。此外，识别出了不同的声学模式，并且它们各自的群速度与理论预测结果吻合良好。在另一组模拟实际损伤场景的实验中，我们证明了能够观测到管道中不同气体混合物爆炸后产生的压力波。速度由局部压电压力传感器进行验证。由于光纤传感系统具有完全分布式的特性，能够详细记录加速运动。因此，除了用于基础设施监测中检测和定位威胁事件外，DAS还可能成为研究管道中气体爆炸发展过程（例如爆燃到爆轰转变（DDT）的研究）的有力工具。
