Electromagnetic Thermal Coupling Field Analysis Of Electromagnetic Heating Process For Hot-drawing Huge Gas Collector

Gas collector is a key component of natural gas long-distance transmission;it plays an important role in the field of petrochemical industry.It is an significant task of pipe processors to ensure that the gas collector can be used safely.Because of its comprehensive performance is better than that of the welded gas collector,hot-drawing gas collector can be used in high pressure gas pipeline.Large gas collector should be heated to 900? when drawing,and the heating methods are mostly flame heating at present.This heating method has many disadvantages,such as high labor costs,slow heating rate,low safely factor and large labor intensity.To solve this series of problems from the root and improve the working environment of workers,a new heating method should be sought.With the development of science and technology,electromagnetic heating process has been widely used in the field of mechanical processing,which has the characteristics of high efficiency,cleanness and high safe factor.Therefore,this subject carried out research on electromagnetic heating process,which based on electromagnetic field theory and heat conduction theory,and the means of combining theoretical simulation and experimental verification is adopted.The specific research contents are as follows:1.Based on the basis principle of electromagnetic heating,the distribution of eddy current on the workpiece during heating is analyzed.The required frequency range of power supply is determined according to the main parameters of main pipe of the gas collector.The process of electromagnetic field in metal is discussed.The composition of energy loss during electromagnetic heating and its influence on the temperature distribution are analyzed.2.Based on the Maxwell electromagnetic theory and unstable conduct theory,the field equations of vortex regions and non-eddy current regions are established,respectively;boundary conditions responding to the equations are given.The way to solve three dimensional nonlinear electromagnetic field and temperature field is pointed out.3.Inductors are designed for the electromagnetic heating process of pipes with specific size.The electromagnetic thermal coupling field is simulated through the means of combining different parameters such as current,frequency and heating time.Finally,a suitable parameter combination is obtained.4.Through the comparison of experiment and simulation results,the rationality of the parameters of the simulation results and the design of inductor are verified.