镍铁矿热炉熔炼过程中的多物理场耦合

Multi-physical field coupling in smelting processes of ferronickel submerged arc furnace

建立了一个三维多物理场耦合模型,揭示矿热炉运行过程中电磁、温度、化学反应间的相互作用机理该模型不仅将电磁理论、多相流动、传热、还原反应整合到统一的计算框架中,还通过用户自定义函数(UDFs)将电弧热、焦耳热和化学反应热加入到能量方程源项中研究了不同电极插入深度下的熔池温度分布,并分析了熔池不同位置处的还原反应量结果表明:随着电极插入深度的增加,熔池温度不断升高在磁场作用下,熔池底部温度分布均匀熔池区内氧化镍比铁氧化物还原更彻底,而坩埚区内镍铁氧化物均被彻底还原当电极插入深度为21m和22m时,有助于提高炉料温度,适用于升温阶段当电极插入深度为20m时,炉料温度和铁氧化物的还原量更为均衡,适用于稳定熔炼阶段。

A three-dimensional multi-physical field coupled model is developed to reveal the interaction mechanism among electromagnetic,temperature and chemical reaction during the operation of submerged arc furnace.This model not only integrates electromagnetic theory,multi-phase flow,heat transfer and reduction reaction into a unison computational framework,but also adds the arc heat,Joule heat and reaction heat into the source term of the energy equation by user-defined functions(UDFs).The temperature distribution of molten bath under different electrode insertion depths is investigated and the reduction reaction degree at different regions of molten bath is analyzed.The results show that the temperature of molten bath increases with increasing electrode insertion depth.Under the influence of the magnetic field,the temperature distribution at the bottom of the molten bath becomes more uniform.The nickel oxide is more completely reduced in the molten bath than iron oxide,while both nickel and iron oxides are completely reduced in the crucible zone.When the electrode insertion depth is 2.1 m and 2.2 m,it helps to increase the furnace charge temperature and is suitable for the heating stage.When the electrode insertion depth is 2.0 m,the temperature of the charge and the reaction amount of iron oxide are more balanced,which is suitable for a stable melting stage.