Research On The Theory And Technology Of Pulsed Eddy Current Pipeline Detection Method

Since twentieth Century fifty years Chinese first long oil and gas pipelines--XinjiangKaramay oil pipeline, gas pipeline construction in China has made considerable progress inoil long distance of60years. In recent years, China’s oil and gas pipeline generally haveclose to the maximum service life, frequent accidents in order to ensure the safe operationof buried pipeline, need to be examined for its repair. In the detection of pipeline in eddycurrent testing technology has been widely used, and the eddy current testing technique todetect defects in the surface of the pipe has high sensitivity and resolution. Eddy currentdetection technology incentive by pulse signals can be realized on the pipeline in serviceinspection, plays a key role in the daily maintenance in pipeline.In this paper, the pipeline for object detection, the eddy current testing system oftransmission pulse excitation was analyzed by COMSOL finite element simulation, bychanging the parameters in the simulation to simulate various conditions of simulationresults. The main research of the pipe eddy current detection technology pulse excitation,and the design of the experiment platform, using the ALtium Designer software to designthe hardware circuit diagram. Detection system is composed of signal generating circuit, apower amplification circuit, probe, post amplifier circuit and data acquisition module. Theprobe is a central loop device, composed of a detection coil and excitation coil. Accordingto the system design, the pipeline for processing defects and no defect detection, analysisof peak value of induced electromotive force is obtained, and compared the magnitude ofthe peak value, through the acquisition of the induced electromotive force detection coil.LabVIEW software written in the acquisition process, acquisition, display and the storageof the induced electromotive force on the coil signal detection. Put forward the method bycomparing the induced electromotive force peak value to real-time detection of thepipeline.Through the pipeline design of pulsed eddy current excitation detection system underthe induction electromotive force defect and non defect analysis shows that: the pulsededdy current testing method can detect the defects of pipeline in real time, so as to prove the feasibility of the method, effectiveness.