400 t／h煤粉锅炉分级送风低NO_x燃烧数值模拟

Numerical Simulation of Low NO_x Combustion with Staged-Air in a 400 t/h Pulverized Coal-Fired Boiler

利用商业软件Fluent6．1对天生港电厂400 t/h燃煤锅炉分级送风低NOx改造进行数值模拟,给出原工况以及4种预改造工况下炉膛内的温度场和NOx的浓度分布,通过比较其降低NOx排放的效果、机械未完全燃烧损失q4、出口烟温等因素,预测分级风改造中的风量配比等问题．将其结果与实际运行结果进行比较,发现采用分级送风可降低NOx排放,降幅可达30％以上,NOx排放浓度的预测值与实际测量值基本相符,因此,该方法可以作为锅炉燃烧器低NOx改造的预测工具．

Using the Fluent6.1 software, the 400 t/h pulverized coal-fired boiler restructured by staged combustion to reduce the NO, release was simulated. Temperature, velocity and NOx distribution of the old project and four new projects are given. By comparing the rates of reducing NOx, q4 and exit gas temperature, conclusions can be drawn about air quantum, the high of burn-out wind position. Finally by comparing the results of numerical simulations with the practical projects, the method is proven to be valid and useful in simulating the low NOx restructuring boiler.