Bundesanstalt für Materialforschung und-Prüfung (BAM), Unter den Eichen 87, 12205 Berlin, Germany.
Sensors (Basel). 2018 Aug 28;18(9):2841. doi: 10.3390/s18092841.
In the presented work, the potential of fiber-optic distributed acoustic sensing (DAS) for detection of small gas pipeline leaks (<1%) is investigated. Helical wrapping of the sensing fiber directly around the pipeline is used to increase the system sensitivity for detection of weak leak-induced vibrations. DAS measurements are supplemented with reference accelerometer data to facilitate analysis and interpretation of recorded vibration signals. The results reveal that a DAS system using direct fiber application approach is capable of detecting pipeline natural vibrations excited by the broadband noise generated by the leaking medium. In the performed experiment, pipeline vibration modes with acceleration magnitudes down to single μg were detected. Simple leak detection approach based on spectral integration of time-averaged DAS signals in frequency domain was proposed. Potential benefits and limitations of the presented monitoring approach were discussed with respect to its practical applicability. We demonstrated that the approached is potentially capable of detection and localization of gas pipeline leaks with leak rates down to 0.1% of the pipeline flow volume and might be of interest for monitoring of short- and medium-length gas pipelines.
在本工作中，研究了光纤分布式声学传感（DAS）在检测小口径天然气管道泄漏（<1%）方面的潜力。通过将传感光纤直接缠绕在管道上，可以增加系统对检测弱泄漏引起的振动的灵敏度。DAS 测量结果补充了参考加速度计数据，以方便分析和解释记录的振动信号。结果表明，使用直接光纤应用方法的 DAS 系统能够检测到由泄漏介质产生的宽带噪声激发的管道自然振动。在进行的实验中，检测到加速度幅度低至单个μg 的管道振动模式。提出了一种基于频域中时间平均 DAS 信号的频谱积分的简单泄漏检测方法。讨论了所提出的监测方法的潜在优势和局限性，以及其在实际应用中的适用性。我们证明，该方法有可能检测和定位泄漏率低至管道流量的 0.1%的天然气管道泄漏，并可能对短中和中长天然气管道的监测具有重要意义。
