| With the development of modern metallurgical craft, people need to understand and describe all kinds of fluids flow’s phenomenon during the metallurgical course urgenly. But it is difficult to measure directly for high-temperature environment in metallurgical industry, and get enough information and data about flowing field reliably. Computational Fluid Dynamics is the product which combine with Modern Hydrodynamics、Value Mathematics and Computer Science, its essential feature is numerical simulation and computer experiment. With the rapid development of computer technology and relevant software, CFD technology have offered a new method and possibility for research fluid flow phenomenon in metallurgy process thoroughly.Core strengthening smelting technology of TSL is the rapid process of heat and mass transfer through immersion top blown lance stirring bath three phases, so as to achieve significant energy-saving effect. But blindly emphasizes high intensified smelting will lead smelting furnace lining life of low, spray gun and other key equipment wear, improper injection operation even serious accidents caused by the slag foaming. Numerical simulation study on heat and mass transfer process and the use of CFD technology to the molten pool smelting blowing stirring, to investigate the effect of injection speed, depth of the bath flow and bath splash damage to the furnace wall is very necessary. In this paper, taking A company of Yunnan copper lsasmelt furnace top blown bath hot mixing process as the research object, mainly from the two aspects of computational fluid dynamics simulation and water model experiment was carried out to study the work of the following aspects:First, through in the VOF theory framework of two phase surface tension and wall function is considered, to achieve a single bubble in a viscous fluid, free floating single droplet free falling impact free surface, three dimensional numerical simulation of unsteady multi bubble floatation and fusion in the liquid, and the results are verified with the classical literature and the water model experiment phenomenon, for further study of bubble laid solid foundation in the process of strengthening stirring strong nonlinear behavior rules. After completing the above simulation behavior of single bubble and single of droplet, using the RNG κ-ε model and Geo-Reconstruct geometry reconstruction method to achieve the coupling unsteady flow and heat transfer of two-phase interface， establish two-dimensional top blown bath of multiphase flow and heat transfer coupled model, and compare the results with the classic paper and water model experiment phenomenon was verified, and obtains the influence law of top blowing bubbles, floating and fracture behavior of the stirring effect; The above two top model is extended to3D space, combined with3D ISA furnace body mesh with high quality, building thermal model top blown bath ratio ISA submerged, using the QUICK discretization scheme and based on the pressure implicit splitting operator (Pressure Implicit with Splitting of Operators) pressure velocity coupling scheme to ensure stable and convergence process, get ISA3D blown hot bath temperature field, flow field calculation results, compared to the flow rate and nozzle depth mixing effect and the temperature field in the furnace the effect of the distribution of the bath, get the optimization of operating parameters with theoretical guidance for practical production;From the angle of multiphase flow deformation mechanism of bubble free finish rising water, that the difference between the upper and lower surface of bubbles and bubble boundary under the action of the upward jet is the main factor leading to bubble bottom sag deformation and eventually split, the changes of velocity and deformation rule of the single bubble free floating from the two aspects of the simulation simulation and water model experiment. The condition of the boundary conditions and calculation results into the corresponding dimensionless number, the summary of findings:in the middle range of Reynolds number (5<Re<100) and relatively high Bond number (20<Bo<50), the bottom is the basic form of the depression of the bubble; bubble bottom observation, found that the Reynolds number is low, the bottom edge of the circle, and increases with Reynolds number, edge sharpened up.The effects that the quantity of flow affects the temperature distribution are more sensitive than gun insertion depth. Large flow stirring on the bath is more intense, the temperature rise was more uniform way in bore. While the nozzle depth increase can cause the near wall temperature rise speed, road bore center and near wall region of the temperature difference between the larger, is not conducive to prolong the life of furnace lining.For the calculation of unsteady three-dimensional flow, heat transfer, the key section of physical quantity weighted average value and standard deviation of the same three-dimensional physical field combining with the analysis method helps to more accurately describe the regularity reflected simulation process. The equivalent surface and the specific section physical quantity weighted average method can be used to determine the three-dimensional transient multiphase flow evaluation method of mixing degree. |
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