空气过剩系数对瓦斯燃烧器燃烧和NO_x排放性能影响的三维模拟计算

THREE DIMENSION SIMULATION CALCULATION FOR THE INFLUENCE OF AIR EXCESS COEFFICIENCY ON THE GAS BURNER COMBUSTION AND THE NO_X EXHAUST FEATURE

以某公司一种瓦斯燃烧器为几何模型,对燃烧器和稳焰锥附近的复杂结构未作简化,以实际瓦斯气为燃料,用标准的k-ε湍流模型、双δPDF气相燃烧模型和蒙特卡洛辐射传热模型对燃烧器的流动及燃烧性能进行全尺寸数值模拟,得到燃烧器内温度分布、火焰长度和NOx浓度分布,计算结果表明空气过剩系数对火焰温度、火焰长度和NOx的生成量具有显著的影响,NO的生成量主要与温度分布和氧气浓度的分布有关。

Taking one type of gas burner in a certain company as the geometry model,without simplified the complicated situation nearby the burner and the stable flame cone, taking actual gas as the fuel, by the use of standard k- εturbulence model,double δPDF gas phase combustion model and Montecalo radiant heat transfer model, the full size numerical value simulation on burner flow and combustion property was carried out. The temperature distribution in burner, the flame length, and NOx concentration distribution were obtained. The calculation result denoted that: the influence of air excess coeffi-ciency on flame temperature, flame length and the amount of NOx resultant were very obvious. The amount of NOx resultant was mainly relevant to temperature distribution and oxygen concentration distribution.