Modeling of a thermo-electromagneto-hydrodynamic problem in continuous casting tundish with channel type induction heating

Abstract

A mathematical model has been developed to understand the electromagnetic phenomena, heat transfer and molten steel flow in a continuous casting tundish with channel-type induction heating. Maxwell equations are first solved using the finite element method to determine the electromagnetic force and joule heating. Then, the Navier-Stokes equations and energy conservation equation are also solved with the electromagnetic force and joule heating as a source term, respectively. The two-equation RNG κ-ε model is used to represent the turbulent mixing. Additionally, the tracer distribution is determined by solving a scale transport equation. The coupled flow field, temperature distribution and concentration distribution are solved by the finite volume method. A non-isothermal water model experiment is performed to observe significantly buoyancy driven flow in the tundish with induction heating. The results indicate that a current loop would be formed by the induced current through the two channels. The electromagnetic force points to the center of the channel generating a pinch effect on molten steel. As skin effect and proximity effect, the electromagnetic force as well as the joule heating in the region closer to the induction coil is greater than that in another region. Therefore, spiral recirculation would occur in the channels when molten steel flows through. After flows through the channels, the molten steel lifts upward under the effect of buoyancy. The heat loss of molten steel can be compensated effectively by the joule heating, and the temperature distribution become more uniform in the continuous casting tundish with induction heating. © 2014 ISIJ.