基于正交试验的双P型辐射管三级燃烧器低NOx仿真

为降低双P型辐射管NOx 排放,运用扩散式分段燃烧的低NOx 均匀化燃烧技术,设计一种辐射管三级燃烧器,对其进行数值模拟,经过验证模型可靠.对燃烧器结构及运行参数进行正交试验和单因素研究.研究表明：空气预热温度、空气分级配比和空气过剩系数对出口NOx 排放浓度有显著的影响,相互无交互作用；一次风量由10%增大到20%时NOx 生成量由65.2×10-6增加到108.2×10-6,一次风量增加到30%以上时出口NOx 体积分数增加速率趋缓；空气预热温度每增加100益,最高燃烧温度增加约50益,排放气体中NOx 体积分数由50.9×10-6以22%、23.2%、25.3%、27.2%、27.3%和29.5%的速率增加；随空气过剩系数增加,出口NOx 体积分数由82×10-6呈22.1%、1.9%、2.1%、24%和2.5%的波动增长趋势.

Numerical simulation of low NO x emission three-stage burners for double-P type radiant tubes based on orthogonal test

A kind of three-stage burner for double-P type radiant tubes was designed by using diffusion-type low-NOx-burning technology. Numerical simulation was performed to verify the model. The structure and operation parameters of the burner were ana-lyzed by orthogonal test and single factor analysis. The research results show that air preheating temperature, air staged proportion and excess air coefficient have significant effect on the outlet NOx emission concentration without mutual interaction. When the primary air increases from 10% to 20%, the amount of NOx increases from 65. 2í10 -6 to 108. 2í10 -6; but when the primary air increases to more than 30%, the outlet NOx concentration increase rate decreases. The maximum combustion temperature increases about 50℃with each increase in air preheating temperature of 100℃, and the NOx emission concentration increases from 50. 9í10 -6 at the rates of 22%, 23. 2%, 25. 3%, 27. 2%, 27. 3% and 29. 5%. With the increase of excess air coefficient, the outlet NOx concentration in-creases from 82í10 -6 at the rates of 22. 1%, 1. 9%, 2. 1%, 24% and 2. 5%.