一种新的直线型Sagnac光纤干涉仪管道泄漏检测系统及其定位技术

研制了一种基于Sagnac干涉仪的直线型分布式光纤传感器,可实时进行管道泄漏检测与定位。利用法拉第旋转镜将传统Sagnac干涉仪的环形结构改为直线型结构,使其适用于各种复杂管道的布放。推导了泄漏信号引起的光信号相位变化表达式;分析了该干涉仪应用于泄漏检测的原理及其泄漏源定位方法,并在泄漏点距法拉第旋转镜为4.020 km处进行了泄漏有无及定位的研究。实验结果表明,该系统很好地检测到泄漏源的有无,又较准确地确定了泄漏源位置且最大定位误差小于118 m。

A New Pipeline Leakage Detection System Based on Linear Optical Fiber Sagnac Interferometer and Its Location Technology

A linear distributed optical fiber sensor based on the principle of Sagnac interferometer is developed to detect pipeline leakage and locate leakage point in real-time.The traditional Sagnac interferometer is converted into in-line structure by using a Faraday rotator mirror,and the in-line structure is applied easily in perplexing pipelines.The representation of phase change caused by leakage is formulated for optic signal.The measuring principle and leaking source location method for the detection system are analyzed.An experiment is designed to detect leaking source and locate leaking source,and the leak is produced at 4.020 km from Faraday rotator mirror.The results verify that the system can realize leaking source detection and location accurately and the largest location error is less than 118 m.