基于平均频谱的储油罐罐底腐蚀声发射特征分析

Acoustic Emission Characteristics of Tank Bottom Corrosion Based on Average Spectrum

针对声发射(AE)罐底检测过程中传统分析方法无法准确判断储油罐罐底腐蚀区域腐蚀程度的问题,提出了基于平均频谱的储油罐罐底腐蚀声发射特征分析方法,用于判断储油罐罐底板腐蚀类型.该方法利用平均值原理,分别求出罐底板不同腐蚀区域的平均频谱,再通过傅里叶逆变换得到该区域的平均波形,以此来表征腐蚀区域占主导地位的声发射信号特征.为了验证分析方法的有效性,进行了现场储油罐检测实验,实验过程中应用护卫传感器屏蔽罐内噪声干扰.实验结果表明,护卫传感器可以有效屏蔽大量罐内噪声信号,使定位结果更加准确.应用护卫传感器所得到的定位结果与开罐检测结果基本一致.在获得准确的声发射定位结果的前提下,应用基于平均频谱的分析方法,可以有效识别不同腐蚀类型,进而准确判断出罐底腐蚀程度.

The traditional acoustic emission（AE） test methods cannot identify the corrosion condition of tank bottom precisely.In response to this problem,an analysis method for AE signals from the bottom of the tank corrosion regions based on the average spectrum was presented to identify the corrosion types of tank bottom.With probability theory,the average spectrum and waveform of each corrosion region are obtained respectively,which represent characteristics of the AE signals generated by the dominant corrosion behavior.In order to verify the validity of the proposed method,field experiment of tank inspection was carried out.The results show that guard sensors can effectively shield a large amount of extraneous noise signals from inside the tank,so that the location prediction results from AE are more accurate.AE test results are consistent with tank internal inspection data.It is verified that,with accurate AE location results,the analysis method based on average spectrum can achieve identification of corrosion type and corrosion condition of tank bottom effectively and precisely.