Leak location in gas pipelines using cross-time-frequency spectrum of leakage-induced acoustic vibrations
Leak location in gas pipelines using cross-time-frequency spectrum of leakage-induced acoustic vibrations
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DOI：
10.1016/j.jsv.2014.04.018
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发表时间：
2014-08-18
影响因子：
4.7
通讯作者：
Mu, Yanhua
中科院分区：
文献类型：
--
作者：
Li, Shuaiyong;Wen, Yumei;Mu, Yanhua
在管道泄漏检测中，基于相关性的定位方法得到了广泛的应用。实际上，由于气体泄漏引起的声波的色散，声速是频率变化的，因此该假设不被支持。本文针对声速随频率变化的气体泄漏声波，提出了一种基于交叉时频谱的定位方法。在该方案中，CTFS是通过一维傅里叶变换的时域卷积核函数之间的相关域和瞬时互相关的两个空间上分开收集的声学信号的泄漏的两侧。然后，到达时间差（TDOA）和相应的频率信息的同时提取时，CTFS达到最大值。所得的峰值频率被用来在线确定频率相关的声速结合已知的色散曲线的气体泄漏引起的主导模式。最后，利用时差法和频率相关声速法实时确定气体泄漏位置，代替恒定声速法。因此，对于所提出的方案，恒定声速不再是先决条件。实验结果表明，与常用的基于相关性的定位方法相比，该方法的平均相对定位误差降低了6倍。(C)2014爱思唯尔有限公司版权所有。
The correlation-based location methods are widely used in leak detection of the pipelines assuming that the acoustic speed has been known and constant. In practice, the acoustic speed is frequency-varying due to the dispersions of gas-leak-induced acoustic waves, and thus the assumption is not supported. In this work, a location scheme based on cross-time-frequency spectrum (CTFS) is intended for the gas-leak-induced acoustic waves with frequency-varying acoustic speed. In the scheme, the CTFS is obtained by the one-dimensional Fourier transform of the time domain convolution between the kernel function in correlation domain and the instantaneous cross-correlation of the two spatially separately collected acoustic signals on either sides of a leakage. Then, the time difference of arrival (TDOA) and the corresponding frequency information are extracted simultaneously when the CTFS reaches the maximum value. The resulting peak frequency is used to online determine the frequency-dependant acoustic speed in combination with the known dispersive curve of gas-leak-induced dominated mode. Finally, the gas leakage is located by the TDOA and the frequency-dependant acoustic speed of real-time determination instead of constant acoustic speed. Consequently, for the proposed scheme, the constant acoustic speed is no longer a prerequisite. The proposed scheme has been experimentally validated in leak detection of gas pipelines and results demonstrate that the average relative location errors are reduced by six times compared with the commonly used correlation-based location method. (C) 2014 Elsevier Ltd. All rights reserved.