管道附件影响的管道声发射信号衰减特性

Attenuation characteristics of pipeline acoustic emission signal considering the influence of pipeline accessories

摘要:

以包含多种附件的液体和气体管道为对象，开展复杂结构管道声发射信号的衰减特性研究。通过采集不同流量压力下管道本体的声发射信号，分析其幅值衰减规律，并用DB8小波包与快速傅里叶变换(FFT)研究管道声发射信号成分变化。通过采集阀门、法兰、流量计等6种管道附件前后的声发射信号并分析衰减规律，发现对声发射信号衰减影响最大的管道部件为电磁流量计。之后重点分析了法兰上螺栓连接紧固程度对信号幅值和频率成分的影响，实验结果表明，螺栓紧固程度越高，声发射信号衰减越小。本文的相关研究结论对工程中进行输油或输气管道进行声发射检测时的传感器布设决策具有集成化的参考价值。

Abstract:

The attenuation characteristics of Acoustic Emission(AE) signals in liquid and gas pipelines with complex structures are studied. By collecting acoustic emission signals of pipe body under different flow pressures, the amplitude attenuation law is analyzed, and the composition changes of pipe acoustic emission signals are studied by DB8 wavelet packet and Fast Fourier Transform(FFT). Through collecting acoustic emission signals before and after valve, flange, flow meter and other six kinds of pipeline accessories and analyzing attenuation law, it is found that electromagnetic flow meter is the pipeline component that has the greatest influence on the attenuation of acoustic emission signals. Then, the effect of fastening degree of bolt connection on signal amplitude and frequency components is analyzed. The results show that the higher the fastening degree of bolt, the lower the signal attenuation. The relevant research conclusions of this paper have integrated reference value and guiding significance for the sensor layout decision of acoustic emission detection of oil or gas pipelines in engineering.