Research On Non-invasive Leakage Detection Method For Dangerous Hazardous Chemicals Transportation Pipeline

Due to pipeline aging,construction defects,corrosion and drilling and other reasons,hazardous chemicals transport pipeline leakage have occurred,and resulted in disastrous consequences.Hazardous chemicals has toxic,corrosive,explosive characteristics and other characteristics.The existing methods with the damage to the welding structural damage and other hidden dangers of pipeline,are not applicable to hazardous chemicals transport pipeline leak detection.Therefore,it is very important valuable to study hazardous chemicals transport pipeline leak detection with high detection sensitivity,leak precise positioning and leakage estimation.In this paper,a non-intrusive leak detection method for hazardous chemicals transport pipeline based on WSN is proposed.The machinery of wireless acoustic sensor nodes with data compression and synchronous sampling are designed and fabricated.The method of detecting abnormal signals is proposed base on the Quasi-Gaussian statistical characteristics of the acoustic signal by the interval division,the standard deviation of the background signal and the SNR of the interval signal.By setting the abnormal signal SNR threshold,the direct extraction of the abnormal signal is realized.Based on the acoustic propagation attenuation,dual sensor signal amplitude ratio method,sensor reference experiment method and three sensor signal amplitude leakage positioning method are proposed.The application conditions,advantages and disadvantages of the three positioning methods are analyzed and compared.A feature extraction method of leak acoustic signal is proposed to establish a leakage aperture estimation model based on SVM.In the laboratory environment,a gas-liquid dual-use pipeline platform to simulate leakage test is built,and the acoustic signal acquisition system based on WSN is completed.The experiments are carried out to verify the sensitivity of the leaky acoustic signal extraction method,the amplitude of three nodes signal leakage positioning method and the leak aperture identification leak aperture to estimate leakage method base on SVM.The experimental results show that the new proposed method for non-intrusive hazardous chemicals transport pipeline can accurately identify the leakage signal.This method has the high short-distance pipeline leakage point positioning accuracy,the high leakage aperture recognition accuracy and the good generalization ability.