Coupled Three Dimensional Numerical Simulation Study Of Molten Steel’s Flow And Heat Transfer And Solidification In Slab Continuous Casting Mold

In this paper, the slab in cross-section of 1600 mm × 230 mm is used for the research object, and the fluid simulation software FLUENT14.0 is taken as a simulation platform. Based on the Finite Volume Method of numerical analysis, a three-dimensional mathematical model of the flow field in continuous casting slab mold is established. In the flow field model,high Reynolds number realizable k-ε turbulence model and VOF multiphase flow model is used to consider turbulence characteristics of the flow and the molten steel slag layer. Then,based on the reasonable parameters determined from the flow field simulation, a three-dimensional coupled model of flow, heat transfer and solidification is built.The model takes the heat transfer of casting direction into account, and use the low Reynolds number turbulence model to simulate turbulent characteristics among the coupling mold.In the Coupled model, the wide face and the narrow face of the slab have different nonlinear heat density function. Within a slab, the solid-liquid two-phase region is seen as a porous medium, and takes the influence of thermal buoyancy into consideration.The analysis of flow field show that:Casting speed, inclination of nozzle outlet and insertion depth of nozzle have a greater impact on the level fluctuation, while the width of nozzle outlet and groove depth of nozzle bottom have less affect. The casting speed is maintained at 1.0-1.2m / min; Nozzle insertion depth is elected at160mm; Nozzle exit angle choose down 10 ℃ to 15 ℃; When height of nozzle oulet is set up at 60 mm without change, the width of the nozzle outset should be maintained at 50-60mm; Outlet groove depth is set up at 30 mm.All of these will get a more reasonable flow field. The coupled simulation analysis of flow, heat transferand solidfication shows that when the shell thickness of slab mold outlet meet the principles of metallurgy, casting speed should be selected in 1.0-1.2m / min, while the cooling water of wide and narrow face should be maintained at 3200 L/min and 310.5 L/min. Under the premise of great slab quality, Increasing the cooling intensity when it is in high casting speeds, can improve production efficiency effectively.Rationalization of the flow field can reduce slag rolling into liquid steel and is conducive to inclusion float. Reasonable flow field and the reasonable set of heat transfer boundary will both promote the rational distribution of temperature, and thereby improve the slab internal heat transfer, and definitively improve the internal slab quality. So in this paper, the simulation analysis of flow,heat transfer and solidfication provides theoretical guidance to improve the process of continuous casting and the quality of the slab.