Based On Acoustic Emission Technology Of Pipeline Corrosion And Leak Detection Research

Pipeline as a carrier of the transport medium, has realized automatic control, high-efficiency transportation because of its cost saving, security, small footprint, uninterrupted nature, large volume, etc. While providing convenience, long track laying and harsh environment may cause inefficient inspection. Also, most transport medium is inflammable, explosive and toxic. Pipelines may leak if there are corrosion, aging, man-made vandalism or other factors, which may damage the national economy and life safety.Therefore, studying ways to real-time monitoring and detection of pipeline and discovering abnormal defects of pipeline has raised attention around the world. Acoustic emission technology is a new detection technology with on-line dynamic characteristics, which has a good engineering application value to find the early defects and improve the detection efficiency, and has good engineering application value.This thesis analyzed experimental data by software from the aspect of dynamic monitoring, aiming at transportation carrier, pipeline corrosion and dynamic monitoring of leakage. Corrosion of X60 pipeline steel were analyzed as well as the typical acoustic emission signals of pipeline leakage platform, the feasibility of using acoustic emission technology to monitor the security state was also discussed.The corrosion of X60 pipeline steel in 10% Fe Cl 3· 6H2 O solution was online monitored by using acoustic emission(AE) technique. AE signal was processed by the combination of signal characteristic parameter analysis, waveform analysis and wavelet analysis. Change disciplinarian and feature of AE signal in different stages were also analyzed. It is showed that, X60 corrosion process in 10% Fe Cl 3· 6H2 O solution can be divided into initial corrosion s tage, accelerated corrosion stage and stable corrosion stage. AE signals types are different in different stages. The differences also exist in signal spectrum and energy proportion. The frequency changes from low to high, then to low frequency. The combin ation of three methods can be used for the identification of different corrosion stages so that to supply the basis for safety evaluation of X60 pipeline steel corrosion.Aiming at the situation due to fail to find early defects, pipeline leak experiment simulation platform was built. This thesis analyzed the influence factors of AE signal of pipeline leakage and preliminary positioning technology. The relationship among propagation distance, aperture leakage, pressure and AE signal was also studied. And the location of pipeline leakage was realized through correlation analysis. The results show that AE signal spectrum amplitude present attenuation along with the increase of propagation distance; With the increase of pressure, the energy and amplitude of leakage signal increased, frequency extended from low frequency to high frequency; With the increase of aperture, high frequency components gradually reduced, low frequency components have obvious distribution; The energy ratio decomposed by the wavelet can be used as the characteristic value of the signal differences to judge the spectrogram. It is easy to locate the leakage position by cross-correlation analysis because of the close sensor spacing.