球团竖炉气固流动与焙烧过程耦合的三维数值模拟

基于欧拉多相流模型,建立了球团竖炉气固流动与焙烧过程耦合的三维数理模型,其中气相采用标准k-e湍流模型,固相采用颗粒动理学模型,化学反应采用氧化动力学模型.对不同工况下的焙烧过程进行三维数值模拟计算,探讨了不同操作参数对竖炉炉温和焙烧产物Fe2O3产率的影响规律.结果表明,竖炉炉温和焙烧产物Fe2O3的产率对入炉烟温、入炉烟气量和冷却风量均存在最大需求值,分别为1 400 K,65.6 t/h,7.8×104 m3/h.达到最大需求值前,炉温和Fe2O3的产率均随入炉烟温、入炉烟气量和冷却风量的增加而增加.超过最大需求值后,竖炉炉温随入炉烟温、冷却风量的增加而降低,随入炉烟气量的增加变化不大;Fe2O3的产率随入炉烟温、入炉烟气量的增加而降低,随冷却风量的增加而增加.

Three-dimensional numerical simulation of gas-solid flow and roasting process coupling in pelletizing shaft furnace

Based on the Eulerian multiphase flow model,the three-dimensional numerical model of gas-solid flow and roasting process coupling in pelletizing shaft furnace is established.The gas phases is modeled with the k-e turbulent model;the particle is modeled with the kinetic theory of the granular flow model;the chemical reaction is modeled with the oxidation kinetics model.The roasting processes for different operating conditions are simulated to discuss the effects of the operating parameters on the temperature of the furnace and the yield of Fe₂O₃.The results show that there are maximum requirement values for the flue gas temperature entering the shaft furnace,the amount of flue gas entering the shaft furnace and the amount of cold air entering the shaft furnace,and the values are 1400K,65.6t/h,7.8×104m3/h,respectively.Before reaching the maximum values,the temperature of the furnace and the yield of Fe₂O₃ increases with the increase of the flue gas temperature,the amount of flue gas and the amount of cold air.In excess of the maximum values,the temperature of the furnace decreases with the increase of the flue gas temperature and the amount of cold air,and has little changes with the increase of the amount of flue gas.The yield of Fe₂O₃ decreases with the increase of the flue gas temperature and the amount of flue gas,and increases with the increase of the amount of cold air.