Research On Optimal Design Of Transverse Flux Induction Heater And The Coupled Field Analysis Method

The moving strip is heated continuously by the joule heat which is caused by magneticflux in the transverse flux induction heating (TFIH) process. Compared with longitudinalflux induction heating equipments, the transverse flux induction heating equipments haveconsiderable advantages, due to the need of lower frequencies, less reactive power, and theinductor’s geometry which not encircling the work piece, is particularly suitable forcontinuously processes. The main disadvantage of TFIH is the resulting inhomogeneoustemperature distribution on the surface of the strip cross-section at the inductor outlet,which limit its industrial application. In this paper, the coupled field of transverse fluxinduction heating is analyzed, and the inductor is optimized.The FEM numerical mathematic analysis models of eddy current field and temperaturefield in the transverse flux induction heating are established at first； then theelectromagnetic-thermal coupling field simulations of TFIH inductors with rectangularshape coil and diamond shape coil are obtained. The temperature distributions of prototypewith diamond shape coil agree with the numerical simulation results.Comparing the simulations of different coil shape, the impacts of the coil structureparameters of the coil outside of the yoke, the coil width, the diameter of coil, the corner,the intersecting length between the coil projection and the strip edge on the temperaturedistribution of the strip at inductor outlet are analyzed.Referring to the coil structure factors, a hexagon coil shape is presented. Thesimulations have confirmed positively the feasibility of the proposed coil shape in obtainingthe inhomogeneous temperature distribution. Then the electromagnetic force is simulated inthe process of induction heating. Through the analysis of the influence of electromagneticforce on strip, it provides accurate reference on the design of transverse flux inductionheating equipment.Due to the material properties change with the temperature, and the strip has velocity,the coupling process of transverse flux induction heating is complex. To simplify thecalculation, an improved simulation method for moving strip of TFIH considering materialproperty variation is proposed.