预混天然气小尺度燃烧特性的CFD研究

运用计算流体力学（CFD）二维模型研究预混天然气在小尺度空间内燃烧及墙壁的导热系数、外部的热损对燃烧特性的影响。研究表明，墙壁的导热系数和外壁面的热损直接影响着火焰的点燃、稳定及氮氧化物的生成。对于预混气体。仅存在一个很小的流速区间能维持通道内的燃烧。最后分析了轴向及径向的温度梯度对燃烧器的影响，找到了在模拟条件下最佳的热力条件，并以此达到优化小尺寸燃烧器的目的。

A CFD (Computational Fluid Dynamics) Study of the Small-scale Combustion Characteristics of Premixed Natural Gas

A CFD(computational fluid dynamics) two-dimensional model was employed to study the combustion of premixed natural gas in a small-scale space and the impact of wall heat-conductivity factor and outer wall heat loss on the combustion characteristics.The results of the study indicate that the wall heat conductivity factor and the outer-wall heat loss have a direct influence on the ignition and stability of the flame and the formation of NO_x.As for the premixed natural gas there exists only a zone of very small flow velocity,which can maintain combustion in a channel.Finally,the impact of axial and radial temperature gradient on a combustor was analyzed and,an optimum thermodynamic condition under simulated circumstances has been identified,thereby making it possible to achieve the aim of optimizing a small-sized combustor.