摘要
针对油库管道的泄漏诊断问题,利用管道泄漏声发射信号非平稳的特点,提出了基于HHT时-频熵的声发射管道泄漏诊断方法。该方法采用Hilbert-Huang变换分析管壁声发射信号,求得信号的HHT谱,将HHT时-频平面划分为等面积的时-频块,运用信息熵的计算方法,求得时-频块内所包含能量的信息熵,通过对比信息熵的大小判断管道有无泄漏。采用3组模拟信号作为仿真对象,求取HHT时-频熵,其大小与理论分析相符,验证了该方法的有效性。用模拟管道进行输水实验,分别对距离泄漏孔2.0 m和14.8 m的管壁声发射信号进行分析,判断管道是否泄漏,实验表明该方法可以准确诊断管道有无泄漏。
In order to detect the leakage of pipeline within tankfarm, this paper puts forward an acoustic emission pipeline leakage diagnosis technique based on time-frequency entropy of HHT, considering the instability of acoustic emission signal from the leakage of pipeline. This technique adopts Hilbert-Huang Transform to analyze the acoustic emission signal of pipe wall and then obtain the HHT spectrum of signal. The HHT time-frequency plane is divided into equal area timefrequency blocks, with the calculation method of information entropy, the information entropy of the energy contained in each time-frequency block is obtained. Then, the information entropies are compared to define whether there is leakage in pipeline. Three sets of analog signal are regarded as the simulation object to calculate the time-frequency entropy of HHT. The obtained value agrees with the theoretical analysis, which verifies the effectiveness of this technique. Simulated pipeline is used for water transportation experiment. The AE signals of pipelines with a distance of 2.0 m and 14.8 m from leakage are analyzed to determine leakage. Experimental results show that this technique can accurately detect pipeline leakage.
出处
《油气储运》
CAS
北大核心
2016年第3期250-253,258,共5页
Oil & Gas Storage and Transportation
关键词
时频熵
HHT谱
管道泄漏
声发射
time-frequency entropy
HHT spectrum
pipeline leakage
acoustic emission
