基于Φ-OTDR的光纤准分布式氢泄漏监测

Optical Fiber Quasi-distributed Hydrogen Leakage Monitoring Based onΦ-OTDR

为了有效监测氢气管道的氢泄漏,该文提出了一种基于相位敏感光时域反射仪(Φ-OTDR)的准分布式氢泄漏实时在线监测系统。首先去除单模光纤包层,接着在去除包层的光纤表面采用化学镀膜法镀上对氢气敏感的钯膜,其次在钯膜表面涂上一层疏水溶胶,然后将涂覆有疏水溶胶的氢敏光纤安装在聚四氟乙烯槽中,最后采用Φ-OTDR分布式氢传感系统对氢气管道氢泄漏进行监测。结果表明,光纤Φ-OTDR分布式氢传感系统能准确地对氢气管道周界氢浓度的微小变化做出快速响应,响应时间为60 s,位置分辨率达到50 mm,氢气浓度检测下限达到1000×10-6。研究结果表明,基于光纤Φ-OTDR的测量系统能对长距离、大范围内的氢气管道氢泄漏进行准确检测。

To effectively monitor the hydrogen leakage of hydrogen pipeline,a quasi-distributed real-time online hydrogen leakage monitoring system based on-OTDR is proposed in this paper.First,the cladding of the single-mode fiber was removed,and then the hydrogen-sensitive palladium film was coated on the surface of fiber without cladding by using the chemical coating method to response the hydrogen,thereafter,the hydrophobic sol was coated on the palladium film.Second,the hydrophobic sol coated fiber was installed in the PTFE channel.Finally,the hydrogen leak of the hydrogen pipeline was monitored by using theΦ-OTDR distributed hydrogen sensing system.The results show that the optical fiberΦ-OTDR distributed hydrogen sensing system can accurately respond to small changes in hydrogen concentration around the hydrogen pipeline.The response time was 60 s,the position resolution was 50 mm,and the lower limit of detection for hydrogen concentration was 1000×10-6.The research results show that the measurement system based on optical fiberΦ-OTDR can accurately detect hydrogen leaks in hydrogen pipelines over a long distance and large range.