摘要
对管道泄漏声发射信号进行传播特性研究,可以为工程上进行传感器布设和采集参数确定提供参考依据.介质类型、压力、流量与泄漏孔径对产生的泄漏声发射信号幅值影响较大,对泄漏声发射信号传播衰减规律无影响.泄漏介质为气体时,产生的声发射信号幅值较大;随着压力的增加,泄漏声发射信号幅值增大;随着泄漏孔径的增大,泄漏声发射信号幅值先变大后变小.应用FFT变换和小波包分解等理论方法,分析泄漏声发射信号在传播过程中经过法兰、阀门时的频率变化特征.研究结果表明：泄漏声发射信号经过法兰后,主要引起信号幅值衰减,衰减值为11～15 dB,而信号频率分布变化不大.泄漏声发射信号经过阀门后不仅信号幅值衰减27～35 dB,且信号的高频成分（187.5～312.5 kHz）也出现较大幅度的衰减.
The research on propagation characteristics of acoustic emission signals of pipeline leak can provide an important basis to the location determination of sensors and the parameters acquisition in pipeline projects.Medium type,pressure,flowrate and leak size have significant impacts on the amplitude of acoustic emission signals of leak,but no effect on propagation attenuation pattern of acoustic emission signal of leak.Gas leak generates a high amplitude acoustic emission signals,and the amplitude of acoustic emission signals from leak increases as pressure increases.With the increase of leak size,the amplitude of acoustic emission signals of leak rises first and declines later.By using FFT conversion and wavelet packet decomposition theory,the paper analyzes the variation characteristics of frequency when the signals pass through flange and valves during propagation.The results show that signals amplitude attenuation,about 11 to 15 dB,will happen when acoustic emission signals pass through flange,while little change occurs in signal frequency distribution.After acoustic emission signals of pipeline leak pass through the valve,not only the amplitude of the signals attenuates by 27 to 35 dB,but also the high-frequency components see a substantial attenuation （from 187.5 kHz to 312.5 kHz）.（2 Tables,7 Figures,10 References）
出处
《油气储运》
CAS
2013年第10期1141-1145,共5页
Oil & Gas Storage and Transportation
基金
国家科技重大专项"高含硫气田集输系统安全控制技术--高含硫气田集输设备风险检测与维护技术研究"
2008ZX05026-01
关键词
声发射
管道泄漏检测
信号衰减
小波包分解
传播规律
acoustic emission
pipeline leak detection
signal attenuation
wavelet packet decomposition
propagation pattern
