Heating Strategies for Efficient Combined Inductive and Convective Heating of Profiles

In this paper, an experimental and numerical study of a novel heating strategy is shown for thin profiled workpieces using induction and convective heating at the same time. A characteristic of induction heating is its potential for achieving efficient local heating due to the direct conversion of electromagnetic fields to thermal energy. One disadvantage of this is the high temperature gradients that occur on the workpiece and, therefore, the uneven distribution. This is even more significant for thin workpieces or workpieces made out of sheet metal due to the lighter mass and, therefore, less conduction away from the heating zone. This paper presents the idea of combining induction heating with convection to obtain a more even distribution of the temperature but with considerable energy savings compared to pure convective heating. The combination of both heating methods has been analysed both experimentally and numerically with different geometries. The multiphysic simulation included both the induction heating and also the convective heat transfer for temperature-dependent material properties. The results of the simulations and the experiments were in good agreement, and both showed that there is a huge potential for energy savings when convective heating is supported by induction heating (up to 53%). This study provides a reference for future industrial applications for heating sheet metal workpieces, e.g., for drying paint.