基于有限元的油气管道漏磁检测器励磁结构影响分析

Influence Analyzing on Finite Element Based Excitation Structure of Oil&Gas Pipeline Magnetic Flux Leakage Detector

设计长输管道漏磁内检测器时,因管径尺寸限制,其励磁结构尺寸往往会受磁饱和强度、检测灵敏度、通过能力等多重因素限制。为分析励磁结构对缺陷漏磁场的影响,建立了不同管道尺寸参数的三维有限元分析模型,计算出不同励磁结构尺寸下缺陷漏磁场径向磁通量密度分布曲线。得出永磁铁厚度、永磁铁宽度,两磁极间距对缺陷漏磁场分布的影响规律,为励磁结构的优化设计提供必要的理论基础。

During design of pipeline magnetic flux leakage internal detector, due to the limit of pipe diameter, the excitation structure size will be affected by multiple factors such as the intensity of magnetic saturation, the detection sensitivity, the accessibility, etc. To analysis the influence of excitation structure to magnetic field leakage of the defect, a three-dimensional finite element analysis model of different size parameters of pipe is constructed, and the radial magnetic flux density distribution curve of magnetic field leakage of the defect is calculated for different excitation structure size. The influence regulation on the distribution of defect magnetic field leakage of the width, thickness of permanent magnets, and the distance between two poles are obtained. Necessary theoretical basis for optimal design of magnetization structure is provided.