油气管道特殊缺陷的漏磁信号识别方法

针对油气管道特殊缺陷的识别问题,分析了凸形缺陷和凹形缺陷的漏磁信号产生机理.以补板代表凸形缺陷,采用COMSOL有限元仿真软件建立管道补板与凹形缺陷漏磁检测模型,对其漏磁信号分布特点进行仿真计算.搭建管道漏磁内检测永磁励磁实验平台,结果表明:管道上补板(凸形缺陷)漏磁信号特点呈先减小后增大变化趋势,轮廓呈凹形分布;管道上凹形缺陷漏磁信号特点呈先增大后减小变化趋势,轮廓呈凸形分布.通过信号分布特点可准确识别补板缺陷,实验结果与理论分析具有很好的一致性.

Recognition method of magnetic flux leakage signal for special defect of oil and gas pipeline

Aiming at the recognition problem of special defect of oil and gas pipeline, the mechanism of magnetic flux leakage signal of convex and concave defects was analyzed. By using the patch plate instead of convex defect, the magnetic flux leakage detection model for the patch plate and concave defect was established with COMSOL finite element simulation software, and the distribution characteristics of magnetic flux leakage signal were simulated and calculated. A permanent magnet excitation experimental platform for the internal detection of magnetic flux leakage of pipeline was established. The experimental results show that the characteristics of magnetic flux leakage signal of patch plate(convex defect)decreases at first and then increases, and the profile is concave; the characteristics of magnetic flux leakage signal of concave defect increases at first and then decreases, and the profile is convex. According to the signal distribution characteristics, the defect on the patch plate can be accurately recognized, and the experimental results is consistent with theoretical analysis.