VD真空精炼脱氢和脱氮过程的三维数值模拟

Three Dimensional Numerical Simulation for Denitrogenation and Dehydrogenation in Vacuum Degasser

基于质量、动量守恒计算了真空脱气装置内流场,并结合反应热力学和动力学理论建立了真空精炼过程中脱氢、脱氮与流场耦合的三维数学模型,研究了不同工艺参数对VD脱氢和脱氮过程的影响。结果表明:钢包内流场对脱气过程中氢和氮浓度空间分布具有明显影响;脱氢和脱氮速率随底吹气量的增加而增大,终点氢和氮浓度随底吹气量的增加而减小;在实际生产中,应在避免发生卷渣的前提下合理选择吹气量;不同底吹方式对脱氢和脱氮过程影响明显,其中偏心底吹效果优于中心底吹,双底吹效果最好。

The flow field was computed on the base of mass and momentum conservation.Based on the reaction thermodynamics and kinetics,a three-dimensional mathematical model on the dehydrogenation and denitrogenation process coupled with flow field in vacuum degasser was developed to investigate the effect of different technical parameters on the dehydrogenation and denitrogenation during vacuum degassing process.The numerical results indicate that the flow field in ladle has a great effect on the distributions of nitrogen and hydrogen concentration.With the increasing bottom blowing gas rate,the dehydrogenation and denitrogenation rates increase,while the terminal nitrogen and hydrogen concentrations decrease.The gas flow rate should be chosen on the premise of avoiding slag entrapment in practical production.The different bottom blowing mode has a great effect on the dehydrogenation and denitrogenation process.And the double bottom blowing is the most effective method for dehydrogenation and denitrogenation,the eccentric bottom blowing has a better effect than the centric bottom blowing.