Numerical simulation of heat transfer during ladle holding period

The temperature control during ladle holding period has a significant effect on the continuous casting process. Using ANSYS software, a three-dimensional heat transfer model of ladle was established for transient simulation. The influences of 4%, 6% and 8% refining slag thickness on the velocity field and temperature field in molten steel and temperature distribution through ladle wall were studied. During the simulation, the two-phase flow model (steel-slag) was adopted as well as the variation of slag viscosity was used as a function of temperature, combined convection and radiation boundary conditions were applied to slag-air outface and refractory exterior surface. The results show that circulation of velocity field and heat loss in molten steel can be effectively weakened by increasing slag thickness, but it will aggravate thermal stratification of molten steel. The heat dissipation power of molten steel on sidewall and steel-slag interface is dominant, accounting for about 90%. When the thickness of slag layer increases from 4% to 6% and continues to 8%, the heat dissipation power of steel-slag interface decreases by 17.42% and 19.96%, respectively.