Magnetic Flux Leakage Detection Mathematical Model Of Permanent Magnet Ferromagnetic Loops

Along with our country economic level in recent years,the rapid increase of the national energy demand also increases day by day,the pipeline transport of energy security also nots allow to ignore.The energy complex pipeline distribution in our country,has the characteristics of long distance,connecting the time long,detection efficiency and quality of the pipes produced a great test.Have a common cause of pipeline defects such as corrosion,scratches,deformation,in a variety of pipeline defect detection method,the magnetic flux leakage testing in terms of efficiency,safety,cost is particularly prominent advantages.In magnetic flux leakage detection device,mainly for permanent magnet excitation on pipe material,there is a magnetic circuit calculation,the optimization design and permanent magnet geometry size,between permanent magnet and the pipe materials,permanent magnet excitation speed impact on excitation effect problem,to solve these problems to improve the efficiency of the magnetic flux leakage testing and improve the precision of the results have certain help.The magnetic field is modeled by the magnetic flux leakage method based on the principle of magnetic flux leakage and the Maxwell equations.The relationship between the working point and geometrical dimensions of the permanent magnet and the excitation effect of the steel plate is obtained.The magnetic field strength of a certain point in the air and its two aspects of the impact;permanent magnet and ferromagnetic material between the material affect the effect of excitation to discuss several common materials on the excitation effect of the excitation process,the excitation device and ferromagnetic materials(Pipe),can allow some part of the value of the lift,you can also use other non-ferromagnetic material as the excitation device,when no steel brush when the center of the magnetic field strength should be stronger than the magnetic field when the steel strength;for permanent magnets The magnetization characteristics of electromagnetically energized steel plate are the same as those of permanent magnet excitation.The electromagnet effect is optimized by using COMSOL simulation software instead of permanent magnet.According to the model of permanent magnet excitation steel plate,the effect of permanent magnet geometry on the magnetization of the steel plate and the analysis of the magnetization effect of the permanent magnet magnets were carried out respectively.Theresults show that the change of the excitation area affects the excitation effect of the steel plate,and the larger the area,the better the excitation effect.After the parameters of the electromagnet are optimized,the magnetic flux density distribution and the permanent magnet The distribution of the excitation source is the same.By designing the appropriate electromagnet excitation source(including the number of turns and the current value),the magnetization effect of the permanent magnet excitation can be realized with the same geometric parameters,and the permanent magnet excitation is calculated by the relevant parameters of the electromagnet The mathematical model of the most simple magnetic circuit and the magnetic field distribution of the steel plate defect.The design of the permanent magnet excitation source,including the improvement of the efficiency of magnetic flux leakage detection,permanent magnet magnetization optimization and geometric design,can be helpful for several aspects of the permanent magnet magnetic circuit.