面向管道安全监测的R-OTDR分布式光纤测温系统

针对长距离管道存在潜在泄漏及火灾等问题,提出了基于后向自发拉曼散射效应和光时域反射原理(R-OTDR)的分布式光纤温度检测方法用于管道安全监测.理论上分析了该方法在管道泄漏方面的检测原理,设计了R-OTDR分布式光纤温度监测系统,采用累加平均融合小波降噪的方法在改善系统测量精度的同时保证了系统实时性.在实验室中对系统性能进行测试,结果表明,系统检测距离可达10 km,测温量程-25℃～+200℃,测温精度±1℃,定位精度≤2 m,响应时间<3 s.同时在管道铺设现场进行了模拟实验,结果表明,该系统能够实现管道沿线温度的监测并准确定位,满足管道沿线泄漏和火灾的监测需求.

Distributed Optical Fiber Temperature Measurement System for Pipeline Safety Monitoring based on R-OTDR

Aiming at the potential leakage and fire issues in long-distance pipeline,a distributed optical fiber tem-perature detection method based on backscattered spontaneous Raman scattering and Optical Time Domain Reflecto-metry( R-OTDR) is proposed for pipeline safety monitoring. The principle of the method in pipeline leakage was the-oretically analyzed,and the R-OTDR distributed optical fiber temperature monitoring system was designed,a method of ensemble averaging in conjunction with wavelet transform was adopted to improve the measurement accuracy while ensuring the real-time performance of the system. The system performance was tested in the lab. The results indicate that with a total length of 10 km of sensing fiber,a temperature measure bound of-25℃～+200℃,a tem-perature accuracy of ±1 ℃,a positioning accuracy of no more than 2 m and a fast response time of less than 3 s have been achieved. At the same time,a simulation experiment is carried out in the pipeline laying site,the result shows that the system can monitor the temperature along the pipeline and accurately locate the fault position,which indicates that the system can meet the leakage and fire monitoring demands.