烟气循环烧结过程料层温度及NOx排放模拟模型

 为了研究烟气循环条件影响料层的热状态及减排机理,依据烟气循环烧结过程主要反应的热力学和动力学、气-固传热规律以及气体流体力学,建立了烟气循环烧结料层温度及NO_x排放的数值模拟模型。试验验证结果表明,模型计算的料层温度、气体组分(O₂、CO、NO)等与试验检测值吻合较好,料层温度及NO排放浓度相对误差在±5%以内;根据模拟模型分析可知,烟气循环烧结中影响NO排放的主要因素是烟气循环中O₂和CO浓度,随着O₂浓度的降低和CO浓度的上升,燃料氮氧化反应速率明显下降,NO-CO还原反应速率升高,烟气中NO平均排放浓度降低。

Numerical simulation model of temperature and NOx emission in flue gas circulating sintering process

In order to study the influence of flue gas circulation conditions on the thermal state and emission reduction mechanism of the material layer, the heat transfer law of gas-solid and the gas flow mechanics, a numerical simulation model of bed temperature and NO_x emission of flue gas circulation sintering is established and verified by experiments, which based on the thermodynamics and kinetics of main reactions in flue gas circulating sintering process. The results show that the simulated temperature and gas composition(O₂、CO、NO)are in good agreement with the experimental values, and the relative error distribution of material layer temperature and NO emission concentration is within ±5%. According to the analysis of simulation model, the main factors affecting the NO emission in flue gas recirculating sintering are the concentration of O₂ and CO. With the decreasing of the concentration of O₂ and the increasing of CO, the reaction rate of fuel N oxidation decreases significantly, the reduction rate of NO-CO increases, and the average emission concentration of NO in flue gas decreases.