连续油管缺陷综合检测传感器的磁路设计

为了在现场能同时检测连续油管金属截面损耗缺陷 (LMA)和连续油管局部缺陷 (LF)两类磁特性完全不同的缺陷 ,做了连续油管缺陷综合检测传感器的磁路设计。传感器的励磁源选择具有较高性价比的钕铁硼永磁体NdFeB ,选用多回路励磁方式。为了获得较好的缺陷检测信号的信噪比 ,经过对磁路的理论计算和磁化曲线的分析 ,提出连续油管检测时磁场强度应选在磁化曲线的近饱和区。磁路尺寸参数设计时 ,磁轭和极靴的尺寸应尽量小 ,但又不能进入饱和区

Magnetic circuit design of integrated sensors for coiled tubing defects inspection

To inspect simultaneously the loss of metallic cross sectional area and localized fault of a coiled tubing, the magnetic circuit of an integrated sensor is designed. NdFeB permanent magnet with high cost performance is selected as the excitation source of the sensor, and multiloop excitation mode is adopted. Theoretical calculation of the magnetic circuit is made, and the magnetic curve is analyzed. To obtain good signal to noise performance in the defect inspection, it is proposed that the magnetic field intensity should be located near the saturation region of the magnetic curve. In designing the parameters of the magnetic path, the sizes of the magnetic yoke and the pole shoe should be as small as possible, but not in the saturation region.