Research On Leak Detection And Location Method Based On Flow Signal

As a transportation tool for natural gas,crude oil and other chemical raw materials,pipelines will inevitably leak due to corrosion,geological disasters,third-party construction and other reasons.The operating characteristics of pumps,compressors,etc.,the complexity of the conveying conditions,the length of the station spacing,and the propagation attenuation characteristics of the leakage signal propagating in the medium inevitably lead to the occurrence of false negatives and false alarms,resulting in economic losses.And ecological pollution.Therefore,the study of accurate and reliable leak detection and location methods has important theoretical significance and application value.The essence of pipeline leakage is the loss of medium.Compared with the detection variables such as negative pressure wave and sound wave used in pipeline leak detection,the flow signal can more realistically and essentially reflect the leakage condition.Non-leakage conditions such as pumping,pressure regulating,and valve operation during canning will not cause loss of pipeline media,but will greatly affect the detection variables such as pressure and sound waves,thus seriously affecting underreporting and false positives.happened.Therefore,the flow signal is more suitable for leak detection of pipes.However,due to the relatively slow change of flow signal caused by leakage and the accuracy of flowmeter detection,flow-based leak detection technology is not as widely used as negative pressure wave method and acoustic wave method,and there is no application example of flow-based leak location.In view of the above problems,this paper studies the leak detection and location method based on flow signal.From the perspective of signal energy distribution,the frequency domain energy distribution characteristics of the flow leakage signal and the normal signal are analyzed and compared.For the above characteristics,the filtering effects,advantages and disadvantages of different signal filtering methods on the flow leakage signal are compared,and the most suitable one is found.Traffic signal enhancement method.Based on this,a leak detection and localization method based on the expected leak detection sensitivity is proposed.The technical problem of the false alarms caused by the change of operating conditions is based on the essential characteristics of upstream and downstream flow signals during pipeline leakage.A method for improving the reliability of leak detection by leak signal homology testing.Based on the flow signal leakage detection and positioning method,a long-term continuous operation test was carried out under the conditions of the working conditions,and the test was tested by multiple simulated leaks.The field test results show that the leak detection method based on flow signal proposed in this paper can accurately and reliably identify the leakage signal under different working conditions under the premise of the expected leak detection sensitivity,which has higher detection sensitivity and lower.The false alarm rate;the signal leakage signal after signal enhancement,combined with the delay cross-correlation technology,can accurately locate the leak point.