The Research On Infrasonic Sensor And Its Leak Detection System For Oil And Gas Pipelines

At present,Safety is an important problem facing the oil and gas pipeline transportation.With the recent instrumentation technology, modern signal processing technology and the continuous development of computer technology,detection system has become more and more common based on pipeline leak.This article applied the infrasound wave leak detection of oil and gas pipeline leak detection technology, the main work is as follows:1. According to the mathematical model of acoustic excitation on oil and gas pipeline leakage, pipeline leakage from pressure curve and amplitude frequency curve is available, the signal produced at the moment the pipeline leakage of burst signal,leakage continuous phase signal belongs to continuous signals,and the leak acoustic signal energy is mainly concentrated in the low frequency part.According to the characteristics of acoustic model, based on the investigation of a large number of domestic and foreign literature, the leakage acoustic wave propagation form in the pipeline is divided into surface wave and fluid wave, and then the research of oil and gas pipeline leak detection system for infrasound wave.The system consists of sound acquisition module, data processing module leakage, and expounds the operating principle.2. Based on the leakage characteristics of infrasound wave, design the conditioning circuit and power circuit of infrasonic sensor,completing the conversion of current/voltage about infrasonic sensor signal,and signal filtering function. Designing the function of applying the PCI acquisition card for analog data conversion of AID and PC transmission.3. The real-time data analysis and processing of domestic long distance natural gas pipeline, the wavelet analysis method of multi-scale decomposition, the field data de-noising, improve the signal to noise ratio, then the following treatment is more accurate.Using time difference methods to locate the leak of the pipeline,building a leak positioning model based on time delay measurement,Select the adjacent two site, at the same time data related to the results to determine the time delay, and the leak point detection point position is obtained according to the positioning model.comparing the original data delay analysis result, wavelet de-noising signal delay analysis results with the field alarm leak location, concluding that the experimental method is feasible,the original signal of the wavelet de-noising for the result of delay analysis can improve the precision of the system positioning.