Permanent magnet linear induction heating device: new topology enhancing performances

Abstract

Purpose This work aims to study a new design of linear permanent magnet transverse flux induction heating devices of nonmagnetic parallelepipedic workpiece. In these topologies, the permanent magnet inductor produces a static magnetic field, and the workpiece to be heated is subjected to a linear movement. To study the magnetothermal process, a new analytical coupling method between the magnetic and thermal phenomena is developed. This analytical model described in this study takes into account the variation of the physical properties of the heated workpiece. The analytical results are compared with good agreement to those issued from finite elements simulations, as well as those issued from measurements on an actual prototype. Design/methodology/approach The research methodology is based on analytical development of coupled problem, including the electromagnetic and thermal boundary problems. A strongly coupled magneto-thermal analytical model is developed; the time dependent magnetic problem is first solved by using the separation of variables method to evaluate the induced currents in the nonmagnetic plate and the resulting power density loss distribution. The plate temperature profile is then obtained, thanks to strong involvement of this magnetic model in a new analytical thermal model based on a synergy of separation of variables method and Green’s function transient regime analysis method. Findings The results show that an efficient transient magneto-thermal analytical model was developed allowing fast analysis of permanent magnet induction heater for deep heating of parallelepipedic workpieces. Developed model allows also fast and precise simulations of nonlinear and transient magneto-thermal phenomena for different types of permanent magnet induction heating devices. Practical implications The developed magneto-thermal analytical model can be used for fast designing of permanent magnet linear induction heating devices for moving parallelepipedic nonmagnetic workpiece. Originality/value A new analytical coupled model, including the electromagnetic and transient thermal boundary problem with additional algebraic equations and taking into account the nonlinearity, has been developed. The developed model accuracy was validated with a permanent magnet linear induction heating device. Developed coupled analytical model allows fast analysis and designing of such permanent magnet linear induction heating devices.

Transient quasi-3D magneto-thermal analytical solution in PM induction heating device

“…However, this effect is not discussed in the case of x direction due to the sufficient length of the workpiece helping to neglect the xdirection end effect. The induced heating power density calculation using the 2D magnetodynamic model developed in (Abdi et al, 2018), has a lack of accuracy due to the non-consideration of the eddy currents flowing in the x-direction (Pluk et al, 2014). Therefore, in this paper, a solution based on the correction of the induced power density is proposed.…”

“…In terms of Green's function, the general solution of ( 9) can be represented, in the whole domain X of the workpiece, by the following expression (Rudnev et al, 2003;Abdi et al, 2018):…”

“…We give heir more details for determination of the correction coefficient given by ( 7). The normal magnetic flux density, created by permanent magnets inductor is given by (Abdi et al, 2018):…”

2d Hybrid Magnetic Model Calculation in Axisymmetric Device

“…Induction heating is widely used in many industrial applications, surface heat, treatment and core heating [1,2]. The well-known principle is based on the fact that any stationary conductor placed in a variable magnetic field is flowed by eddy currents creating Joule losses [3][4][5].…”

“…The well-known principle is based on the fact that any stationary conductor placed in a variable magnetic field is flowed by eddy currents creating Joule losses [3][4][5]. Another induction heating process is to move the conductive plate in a static magnetic field [2,5].…”