锅炉燃烧及NO_x生成特性的数值仿真

Simulation of Combustion and NO_x Formation Process on Boiler

针对煤燃烧排放NOx污染物造成污染,为了能准确地预测NOx的生成及提出更有效的控制NOx排放的措施,提出建立了煤粉锅炉的三维物理模型,并将炉膛分区域进行合理的网格划分。应用涡团耗散概念(EDC)模型耦合对化学反应机理对炉膛内煤粉的流动、燃烧及NOx的生成特性进行研究,炉内各组分的浓度分布与NOx的生成分布存在很强的对应关系,采用EDC模型耦合反应动力学机理进行仿真。结果表明方法可以很好地反映NOx的生成特性。可以较为准确地模拟NOx的生成特性,可准确预测和有效控制NOx的排放,为优化设计提供了理论基础。

In order to accurately predict the formation of NOx from microscopic and make a more effective method of controlling NOx emissions,a three-dimensional physical model of pulverized-coal boiler was built up and the furnace was divided into regions for Meshing.Using eddy dissipation concept（EDC） model,the three-dimensional simulation of the flow and combustion process of pulverized-coal and the process of NOx formation were coupled with detailed chemical kinetic mechanism.Simulation results and actual operating conditions basically consistent test results,which shows that the method can well reflect the characteristics of NOx formation.Simulation results show that NOx formation has close relation with the concentration of each species,and the model using EDC coupling reaction mechanisms can more accurately simulate the formation of NOx characteristics,This microcosmic analysis laid a good theoretical foundation for the control and systematic optimal design of NOx emission.