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Numerical Simulation Of Particle Field And Material Layer Gas Permeability In Iron Ore Powder Sintering Process

Posted on:2020-06-11Degree:MasterType:Thesis
Country:ChinaCandidate:H P CaoFull Text:PDF
GTID:2381330602461172Subject:Power Engineering and Engineering Thermophysics
Abstract/Summary:PDF Full Text Request
The sintering process of iron ore powder is a complex multi-field coupled thermal process.It contains a variety of physical and chemical reactions and multi-stage process operation processes.It is the key upstream process in iron and steel production.In the context of economic strategy transformation in the New Era,it is an important task for Chinese steel industry to combine the development trend of intelligent manufacturing and improve the level of intelligent production.Modeling and Simulation of sintering process is an important way to reduce energy consumption and economic costs and improve the level of intelligent production.In this paper,the particle field of the sintering process is selected as the analysis object,and sintering process is modeled and simulated from the macroscopic and microscopic perspectives based on sintering process mechanism.A numerical modeling framework process model was used to characterize the sintering process in this study.It based on models such as turbulence model,porous medium model,internal heat source model,and pore variation model.The refinement of the model is achieved by using a method of local non-thermal balance of double mesh and user-defined functions.The sinter layer was divided into 5 layers according to its height.Under the premise that the fuel,flux and moisture were distributed along the height direction,the temperature field,velocity field and gas permeability of the layer under the typical particle field were studied.The main contents are as follows:(1)A set of baseline models and 5 sets of control models were constructed for comparative analysis.The heat of the baseline model,model ? and model ? increased gradually,which indicates that the granular field structure has a continuous upper to lower particle size distribution from fine to coarse.It will be more conducive to maintaining the high temperature state of the material layer and producing obvious heat storage capacity.The change of the apparent porosity of the grain size field obviously determines the change trend of the internal flow field of the material layer.(2)Combining the fitting formula with the Ergun equation to set the flow resistance coefficient,the particle field permeability formed by the different porosity and particle size distribution of the six experimental models is explored.The intermediate development process of the baseline model and the model I negative pressure is moderate,the particle field structure is a continuous upper and lower coarse particle size distribution,or It is the same particle size distribution in the upper and lower parts,and its gas permeability is more stable in the inteirmediate process,and the calculation results are analyzed in combination with experimental data.(3)Combining Fluent and EDEM to carry out coupling calculation,set 4 simulation models,simulate the flow field distribution of different grain size fields of cold sintered layer particles,and analyze the influencing factors of the results.In this paper,the influence of different particle field states on the sintering process in the height direction of the sintered layer is analyzed from the particle size of the particle field.The temperature,velocity and gas permeability of several typical particle fields are simulated and evaluated.It can provide ideas for reasonable distribution structure and research methods,which has certain reference guidance for sintering production practice.
Keywords/Search Tags:Iron ore powder sintering, particle field, numerical simulation, porous medium, gas permeability
PDF Full Text Request
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