油气管道特殊部件的漏磁检测信号特征分析

Feature analysis on magnetic flux leakage detection signal for special parts of oil and gas pipeline

针对油气管道特殊部件的结构特点,分析了管道磁化后产生的磁场特征.基于管道漏磁内检测原理及麦克斯韦方程,采用Comsol有限元仿真软件对管道特殊部件与缺陷进行仿真,以漏磁信号轴向分量B_x所占的通道个数、B_x正负峰值出现的先后顺序、B_x幅值以及轴向长度作为分析判别管道特殊部件与缺陷的依据,对管道特殊部件上存在缺陷的整体漏磁信号B_x分量进行特征分析,缺陷信号B_x在补板信号B_x内侧且极性相反时视为补板缺陷.结果表明,该方法在判别管道特殊部件存在缺陷方面具有一定的可行性.

Aiming at the structural characteristics of special parts of oil and gas pipeline,the characteristics of magnetic field generated after the magnetization of pipeline were analyzed.Based on the pipeline magnetic flux leakage inner inspection principle and Maxwell equation,the Comsol finite element simulation software was used to perform the simulation for the special parts and defects of pipeline.In addition,the channel number occupied by the axial component B_x of magnetic flux leakage signal,the appearing sequence of positive and negative peak B_x values,the B_x amplitude and axial length were taken as the basis for analyzing and distinguishing the special parts and defects of pipeline.The feature analysis on the B_x component of total magnetic flux leakage signal under the condition of existing the defects in the special parts of pipeline was carried out.When the defect signal was in the inner side of reinforcing plate signal and the polarity was opposite,the defect signal was regarded as a reinforcing plate defect.The results show that the proposed method has certain feasibility in the defect identification of special parts of pipelines.