| Detecting small leaks in time can prevent the accident from getting worse,which plays an extremely important role in safe pipeline transportation.The negative pressure wave method is widely used in pipeline leak detection in my country because of its simplicity and high efficiency,but its effect on small leak detection is not good.In order to improve the detection ability of the negative pressure wave method for small leaks,two methods for enhancing the SNR of weak signals are proposed.One is a new pipeline leak detection method based on the improved fast differential signal adaptive initialization integration algorithm(IFD-AI).This method first reviews and analyzes the advantages and disadvantages of the fast difference algorithm;on this basis,in order to further improve the signal-to-noise ratio of small leaks and the robustness of the leak monitoring system,an integral algorithm with adaptive initialization is proposed;The other is a leak detection method based on a bistable stochastic resonance model.This method uses the improved Max-Min normalization to apply the non-periodic stochastic resonance model to the negative pressure wave leakage detection to improve the signal-to-noise ratio of the leakage signal.Next,in order to improve the location accuracy of small leaks,this paper proposes the use of historical data reverse estimation of wave velocity and the principle of feature matching to estimate the wave velocity at the time of leakage in real time。In addition,considering that the leaked signal does not necessarily obey the Gaussian distribution,a multi-scale resampling mutual information method is proposed to solve the positioning time difference.The application of actual leakage test data shows that the proposed method can detect the leakage rate is about 0.3%;the false alarm rate is significantly reduced;and the positioning accuracy is improved.All of those verify the effectiveness and practicability of the proposed method. |
PDF Full Text Request