Study On The Oil Pipeline Leak Detection System Based On Distributed Fiber Temperature Sensing

According to characteristics of 3-high type crude (high pour point, high wax content and high viscosity) of our country, so it needs heating transportation. Combined with advantages of fiber sensing and distributed optical fiber temperature sensor which can multipoint measure with large range. This article takes distributed optical fiber temperature sensor as centre, studied the technology of leakage detection of oil pipeline and designed the system of detection. The primary studies are as follows:Firstly, fundamental theoretical research of fiber sensing based on backscattering. Studied Raman backscattering using the theory of traditional optical and Quantum Mechanics, introduced mechanism of distributed optical fiber temperature sensing, the relationship of temperature demodulation, and optical time domain reflection technology.Then, according to the practical application of the detection of oil pipeline leakage, studied the key technology of distributed optical fiber temperature sensing system., analyzed the wavelength and power of pulsed laser, optimal avalanche gain of APD, noise of amplifier circuit and so on, separated weak scattered light using 1×3 WDM for Raman backscattering, selected temperature calibration area and determined the paving location of fiber alone pipeline.It mainly studied the signal processing technology of distributed optical fiber sensing. Applied index weighted average algorithm and wavelet de-noising algorithm to process signal, used the wavelet entropy to extract the threshold adaptively, simulated the algorithm and the result is good.Finally, the software of leakage detection system of oil pipeline was designed. Adopted advanced technology of computer and database to design the software based on virtual instrument technology. It has good man-machine interaction.