Simulation Analysis Of Leakage Magnetic Field Of Tube Defect And Detector Design

Tubular heating furnace is a conventional kind of oil heating equipment,which is used for heating the flowing oil in the furnace tube with the flame and the high-temperature smoke generated by the combustion of the fuel in the hearth as the heat source.Because of high heat-transfer capability and convenient management,they have been widely used in the field of petroleum and petrochemical.But because of the high temperature condition of the furnace tube and the oil transported in the tube,it was easy to cause the wall corrosion of the tube,therefore,the heating furnace tube was easy to produce corrosion failure in the production process.how to conduct a scientific and effective non-destructive testing of the furnace has become an important issue..In this paper,one kind of the furnace tube-?102×8mm is studied in the magnetic detection technology,and the structure of the magnetic flux leakage detector was designed by finite element simulation and other methods.Aim at the heating furnace tube of ?102×8mm,and based on the rules of magnetic flux leakage,the straight pipe section model and the elbow model were established in ANSYS,the finite element software.Also the defects in the straight pipe and the elbow were constructed,and the magnetic flux leakage of virtual defects on the model were simulated and analyzed.Under the condition of the same magnetic structure,the difference of magnetic flux leakage of defects in the different pipe segments was compared.By changing the number of segments of the multi-stage armature,contrast and analyse the difference of magnetic leakage of defect in finite element software.Also in the finite element software,by controlling the variable method,the difference between the leakage fluxes generated by the different shapes of the furnace tube was simulated and analyzed.The influence of a single parameter on the characteristics of the leakage flux component at the defect was studied,by changing a single parameter-the diameter,the depth of the corrosion of the defect,the height of the air gap and the extraction.Combined with the results of calculation and simulation in the finite element software,the magnetic flux leakage testing device for the heating furnace tube of ?102×8mm was developed,and the magnetization mechanism of the device can simultaneously meet the defect detection of the straight pipe section and the elbow part of the heating furnace tube of?102×8mm.The sizes of the magnetization mechanism were calculated and optimized combined with the theoretical data of finite element simulation.Also with the help of Solidworks,three-dimensional drawing software,the other hardware devices on the magnetic flux leakage detector model in this scheme were designed.Finally,it can meet the requirements of magnetic flux leakage testing.