The Research Of Pipeline Internal Detection Based On Pulsed Eddy Current

Pipeline transportation has become one of the most economical and security way to transport oil, natural gas, chemical raw material, coalbed methane and etc. Affected by the environment around, pipeline prone to corrosion defects during the process of working. Therefore, regularly test of the pipeline is the main way to ensure the security of oil and gas pipelines. As one branch of non-destructive testing technology, pulsed eddy current testing technology is getting more and more attention in recent years, and has been more widely applied in the field of pipeline inspection.In this paper describes the history and current situation of domestic and international researches about pulsed eddy current testing techniques firstly, introduces the working principle and theoretical basis of pulsed eddy current testing. And then, a set of pulsed eddy current technology pipeline detection system has been designed based on the principles and theoretical bases of pulsed eddy current detection, which were introduced before, then collected experimental data after a series of experiments conducted in a test pipeline with a few artificial defects, processed and analyzed the experimental data. The detection system including the hardware experimental platform and the software platform, the software for data acquisition and analysis. The hardware experimental platform has four main components, pulse signal generating unit, power amplifier circuit, probe section (including the excitation coil and the sensor) and the data collection module. Among them, the signal generator section adopts the Direct Digital Frequency Synthesis, which is popular in recent years. Data acquisition part using NI USB-6218capture card, taking advantage of Altium Designer, Protues, Multisim and other auxiliary simulation software, in order to complete simulation for all aspects of the hardware circuit and to determine the parameters. Finally, the collection and processing of data, mainly based on the Lab VIEW platform, performs the following functions:data collection, filtering by software, storage data, process and analysis data, and etc.In this paper, tested pipe with artificial defects was detected by the designed detection system. Voltage amplitude changes obviously at the defects of pipeline through analyzing the collected detection data, and the changes of the amplitude vary in different depth of the defects. This shows that the detection system has sufficient sensitivity for the detection of pipe’s surface defects, and can complete the related detection work. Then, prove the feasibility of the design of this project.