针对油气长输管道外壁缺陷影响管道安全运行的问题,提出了一种基于动生涡流磁场的无损检测方法。借助ANSYS Electronics有限元分析软件分析了管道表面缺陷参数、检测速度与动生涡流磁场之间的关系,发现在不同管道表面缺陷参数下,动生涡流磁场会根据缺陷形状、尺寸的差异反馈出不同的磁感应强度信号,缺陷尺寸越大,信号反馈越强烈;随着检测速度的提高,动生涡流的磁感应强度逐渐增大,但整体变化趋势基本一致。根据工程实际研制了基于动生涡流磁场的管道无损检测试验装置,开展了试验研究,得到了与仿真相同的规律性结果,从而验证了该技术的可行性,表明动生涡流磁场无损检测方法能够对管道缺陷进行精准定位与辨别。

As the outer defects of long-distance oil and gas transmission pipelines affect the safe operation of the pipelines, a nondestructive testing method based on motion-induced eddy current (MIEC) magnetic field is proposed. With the help of ANSYS Electronics finite element analysis software, the relationship between pipe surface defect parameters, detection speed and the MIEC magnetic field is analyzed. The results show that under different pipe surface defect parameters, the MIEC magnetic field will induce different magnetic flux density signals according to the difference of defect shape and size. The larger the defect size is, the stronger the signal induction is. With the increase of detection speed, magnetic flux density of MIEC will gradually increase and its overall change trend is basically the same. According to the engineering practice, a pipeline nondestructive testing device based on MIEC magnetic field is developed and experimental research is carried out. The feasibility of this technology is verified as the experimental results have the same trend with the finite element simulation results. It can be concluded that the MIEC magnetic field nondestructive testing method can achieve accurate location and identification of pipeline defects.