分布式光纤管道泄漏检测及预警技术灵敏度分析

Sensitivity Analysis of the Distributed Optical Fiber Pipeline Leakage Detection and Pre-Warning Technology

针对管道安全存在的问题,提出了一种基于Mach-Zehnder光纤干涉仪原理的分布式光纤管道泄漏检测及预警技术,利用与管道同沟敷设的光缆中的3条单模光纤构成分布式光纤微振动传感器检测管道沿线的振动信号,可以有效地检测管道沿线所发生泄漏和异常事件.分析和研究了检测系统的测试灵敏度影响因素,并采用不同光缆结构和埋设方式对检测系统的检测灵敏度进行测试.实验结果表明,该检测技术可以检测到1m范围内的人工挖掘信号,在气体管道压力不小于0.2MPa的条件下,可以检测到0.4m3/min的气体管道泄漏.

Aiming at the issue of pipeline safety, a new distributed optical fiber pipeline leakage detection and pre-waming technology based on Mach-Zehnder optical fiber interferometer was proposed. In this detection system, an optical cable was laid along the pipeline in the same ditch and three single mode optical fibers in the optical cable were used to build up the distributed micro-vibrant measuring sensor in order to detect the vibrant signals led by leakage or other abnormal events efficiently. The factors influencing measuring sensitivity were analyzed and the measuring sensitivities of the different structures of optical cable and embedment ways were tested. The results show that by using the new technology the signal of the manual excavation in the 1 m scope can be detected and the gas leakage of 0.4 m3/min can be detected in the condition that the pressure of the gas pipe is no less than 0.2 MPa.