管道磁聚焦瞬变电磁技术设计与实现

为克服瞬变电磁法检测埋地管道时局部腐蚀分辨率低、抗干扰能力差的缺点,利用磁信号聚焦技术对其进行改进。首先,给出矩形载流线圈磁场空间分布的计算公式;并利用改进的遗传算法对线圈阵列进行了设计。根据实际检测需求,设计了一种由三线圈组成的阵列。仿真结果表明阵列60%以上能量聚集于半径0.5 m的圆形区域内。阵列激励磁场测量结果表明,其聚集斑半径小于0.7 m,与传统瞬变电磁检测仪相比极大提高了管道局部腐蚀分辨率。

The Design and Implementation of Magnetic Focusing Transient Electromagnetic Method

In order to overcome the disadvantage of transient electromagnetic (TEM) for detect the buried metal pipe such as the lower local corrosion resolutions and anti-interference ability, a new method of focusing magnetic field signal has been provided. At first, this paper deduces the formula of calculating the spatial distribution of rectangular current-carrying coil excitation. And then, the magnetic focusing coil array has been designed using the improved genetic algorithm. We design a array with three coils, the results of simulation show that above 60% energy excited by the array focus on a circle region which radius is less than 0.5m. The magnetic measurement results show that the radius of the focused region exciting by the array is less than 0.7m. The results also imply that the array improve the local corrosion resolution compared with the traditional transient electromagnetic instrument.