高压管汇冲蚀缺陷脉冲涡流检测数值分析

Numerical Analysis of Pulsed Eddy Current Testing for Erosion Defects of High-pressure Manifold

压裂作业中长周期运行的高压管汇在恶劣工况下极易产生冲蚀损伤,高压管汇的在线检测对保障安全生产尤为重要。为此,针对高压管汇冲蚀缺陷,基于脉冲涡流检测技术,采用Maxwell软件对高压管汇下表面缺陷检测模型进行数值模拟,分析磁感应强度矢量法向和切向分量,探究冲蚀缺陷脉冲涡流检测规律。研究结果表明:一定条件下,脉冲涡流检测高压管汇冲蚀缺陷时,激励电流为1.5 A,激励频率为500 Hz,线圈内径为10 mm时具有较高灵敏度;对于不同角度冲蚀缺陷,可根据差分信号梯度云图中的亮斑形状获得缺陷形状信息;法向检测信号差值与缺陷半径和缺陷深度呈三次多项式关系;线圈中设置铁芯可增加检测信号幅值,一定范围内,铁芯半径对检测效果影响较小。所得结论可为高压管汇冲蚀缺陷脉冲涡流检测装置的研制提供参考。

In fracturing operation, erosional damage easily occurs in high-pressure manifold running for a long time under bad working conditions, and the online testing of high-pressure manifold is particularly important to ensure safe production.Based on pulsed eddy current testing technology, the Maxwell software was used to conduct numerical simulation on the undersurface defect testing model of high-pressure manifold, analyze the normal and tangential components of magnetic induction intensity vector, and explore the pulsed eddy current testing law of erosion defect of high-pressure manifold.The study results show that under certain conditions, when the excitation current is 1.5 A, the excitation frequency is 500 Hz, and the inner diameter of the coil is 10 mm, the pulsed eddy current testing for erosion defect of high-pressure manifold has higher sensitivity.For different angles of erosion defects, the defect shape information can be obtained based on the bright spot shape in the gradient cloud chart of differential signals.The difference of normal testing signal has a cubic polynomial relationship with defect radius and defect depth.Setting iron core in the coil can increase the amplitude of the testing signal, and within a certain range, the radius of the iron core has little effect on the testing results.The conclusions provide reference for the development of pulsed eddy current testing device for erosion defects of high-pressure manifold.