Distributed optical fibre oil gas conveying pipeline early early-warning system based on polarization detection

Abstract

The invention relates to a polarization-based early warning system of a distributed optical fiber oil transporting pipeline, which comprises a laser. A forward-propagating optical signal sent from a laser is input from a first port of a polarization beam splitter, and output from a second port to sensing optical fiber connected with a Faraday polariscope. The forward-propagating optical signal is reflected by the Faraday polariscope, and becomes a backward-propagating optical signal after the polarization state of the signal rotates 90 DEG. The backward-propagating optical signal is input from the second port of the polarization beam splitter, and output from a third port to a photoelectric detector. The changed electrical signal is transmitted to a digital signal processing subsystem. The early warning system can position a sensing line perturbing point according the time information of electric power change so as to output alarm and positioning information. The early warning system has the advantages of low cost, high safety and reliability. Furthermore, the early warning system can early position and warn against acts of sabotage to the oil transporting pipeline.

Description

【Technical field】: [0001] The invention belongs to the technical field of long-distance and distributed optical fiber sensing, in particular to an early warning system for distributed optical fiber oil and gas pipelines based on polarization detection. 【Background technique】: [0002] As a safe and economical transportation method, the pipeline transportation system has been widely used in oil, natural gas and other industrial sectors. However, in recent years, oil pipelines have been drilled and stolen from time to time, causing huge economic losses. This makes oil and gas pipelines Automatic monitoring technologies are becoming increasingly important. [0003] At present, the relatively mature pipeline leakage detection technologies at home and abroad can be roughly divided into two categories: internal detection and external detection, including internal detection methods: magnetic flux leakage detection, ultrasonic detection, eddy current detection, camera and video dete...

AI Technical Summary

Problems solved by technology

At present, OTDR technology is relatively mature, and there are corresponding products on the market, but there are still some shortcomings for long-distance pipeline leakage monitoring: (1) The design of the sensor is troublesome and the cost performance is low; (2) It is not sensitive to small leaks; (3) short monitoring distance

However, since the optical phase is very sensitive to environmental changes, the optical fiber sensing system based on interferometry puts forward high requirements for the later signal processing, both in terms of algorithm and hardware implementation, and there is no relatively mature solution or solution in the market. product

[0008] Through the analysis of the above-mentioned existing technologies, it can be found that all technologies can only alarm and locate after leakage, which belongs to post-event anti-theft, and cannot provide early warning when criminals commit crimes

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