不同加湿模式下甲烷湍流燃烧特性数值模拟

为研究水蒸气对甲烷燃烧的影响,基于简化的24步甲烷气相反应动力学机理,通过数值模拟的方法研究了在助燃空气和燃料中分别添加同体积的水蒸气对甲烷同轴湍流扩散火焰流场、组分浓度分布及污染物生成的影响,重点分析了中间产物OH基团对燃烧温度、污染物生成的影响.结果 表明:添加水蒸气后,两种加湿方式下整体燃烧室温度均降低,燃料预混水蒸气燃烧方式下降低幅度较大;该模式下对控制污染物排放效果优于空气预混水蒸气,最后基于燃烧稳定性和控制污染物排放确定了一种最优的蒸汽燃料预混比例为71.4％ CH4/28.6％ H2O.

Numerical simulation of methane turbulent combustion characteristics under different humidification modes

In order to study the effect of water vapor on methane combustion, based on the simplified 24-step gas phase reaction kinetics mechanism of methane, the method of numerical simulation was used to study the effect of adding the same volume of water vapor to combustion-supporting air and fuel on the methane coaxial turbulent diffusion flame. The influence of flow field, component concentration distribution and pollutant generation, focusing on the influence of intermediate product OH group on combustion temperature and pollutant generation. The results show that: after adding water vapor, the temperature of the overall combustion chamber is reduced under the two humidification methods, and the reduction is greater under the fuel premixed water vapor combustion mode; this mode has better pollutant emission control effect than air premixed water vapor. Finally, based on combustion stability and pollutant emission control, an optimal steam-fuel premix ratio is determined to be 71.4%CH4/28.6%H2O.