Distributed optical fiber polarization sensor based automatic early warning system of intelligent pipeline

Abstract

The invention relates to a distributed optical fiber polarization sensor based automatic early warning system of an intelligent pipeline, comprising lasers, polarization controllers, OBPFs (Optical Bandpass Filter), circulators, polarizers, sensor fiber and photodetectors. In a first light path, a light signal emitted by the laser (with the central wavelength of lambda2) enters the sensor fiber through the circulator C1 and sequentially passes through the circulator C2, the polarization controller PC2, the filter (with the central wavelength of lambda2) and the polarizer P2 to be detected by the photodetector PIN2. In a second light path, a signal is outputted by the laser (with the central wavelength of lambda1) to the circulator C2, enters the sensor fiber and sequentially passes through the circulator C1, the polarization controller PC1, the filter (with the central wavelength of lambda1) and the polarizer P1 to be detected by the photodetector PIN1, and the photodetector converts the light signal into an electric signal and transmits the electric signal to a digital signal processing subsystem. The invention has low cost and high safety and reliability, early positions and early warns the damage activities of an oil gas pipeline, is suitable for long-distance monitoring and has optical application prospects in the automatic monitoring field of the oil gas pipeline.

Description

technical field [0001] The invention belongs to the technical field of long-distance and distributed optical fiber sensing, in particular to an intelligent pipeline automatic warning system based on distributed optical fiber polarization sensors. Background technique [0002] Oil and gas resources, as important energy sources and raw materials for many chemical products, play a pivotal role in many aspects such as national life, industrial and agricultural production, and national defense construction. Due to its high reliability and low transportation cost, the pipeline transportation system has been widely used in oil, natural gas and other industrial sectors as a safe and economical transportation method. This has caused huge economic losses, which makes the automatic monitoring technology of oil and gas pipelines more and more important. [0003] At present, the relatively mature pipeline leakage detection technology at home and abroad can be roughly divided into two ca...

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) The monitoring distance is short; (4) OTDR is more suitable for detecting static loss and slowly changing disturbances, and cannot detect transient disturbances

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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