中俄天然气管线的光纤预警系统数据处理方法

光纤管道安全光纤预警系统是基于瑞利相干分布式光纤振动传感系统(DVS),以与管道同沟敷设的通信光缆作为传感器,全天候实时监测管道周围土壤震动,可以实时监测土壤的振动数据,一旦发生危害管道安全的破坏事件,系统能第一时间感知.在中俄天然气管道东线,系统长期运行在低温环境下,灵敏度降低,亟须新的数据处理方法提高系统灵敏度.以信噪比作为灵敏度衡量标准,分析当前普遍使用的差分算法的优势和劣势.建立数学模型,得到差分算法提高信号信噪比的条件.通过MATLAB仿真,得到信号频率分布范围与最佳差分方式对应表格.提出一种新的灵敏度提升算法流程,对不同频率分布的信号均起到最佳的灵敏度提升效果,克服了原差分方式的劣势.现场试验表明,采用新算法后信噪比有明显提高.

Data Processing Method of Pipeline Fiber Forewarning System for Russian-Chinese Gas Pipelines

The pipeline fiber forewarning system is used as a sensor to monitor the soil vibration around the pipeline in a real-time and all-weather communication cable. The soil vibration data can be monitored in real time. In the event of safety threat to the pipeline, the system can perceive at the very beginning of the activity. In the east line of the Russian-Chinese gas pipeline, the sensitivity of the system has been reduced by the long-term operation at low temperatures, and new data processing methods are urgently needed to improve the sensitivity of the system. Signal-to-noise ratio (SNR) is used as the sensitivity criterion to analyze the advantages and disadvantages of the current universal difference algorithm. A mathematical model is established to analyse the signal-to-noise ratio of the signal by the difference algorithm. Through MATLAB simulation, the corresponding table of the signal frequency distribution range and the best difference method are obtained. A new sensitivity enhancement algorithm is proposed, which can improve the sensitivity of different frequency distribution signals and overcome the disadvantage of the original difference method. The field test shows that the SNR of the new algorithm is improved obviously.