湿空气扩散燃烧火焰结构特性研究

利用二维粒子成像速度仪(PIV)对钝体燃烧器中的甲烷／湿空气扩散燃烧的速度场进行测量,考察其火焰的结构特性及其内部流动状况。通过对湿空气燃烧流场与普通燃烧流场的对比分析表明,湿空气燃烧情况下,两种燃烧状态的火焰(回流燃烧火焰和中心射流主导火焰)相互转换的燃空速度比(γ)值要比普通燃烧的小;湿空气燃烧使得喷嘴后的同流空气的速度降低,空气的回流作用减弱,燃料更容易冲出回流区,火焰的稳定性能变差。

CHARACTERISTICS OF NON-PREMIXED FLAME STRUCTURE IN HUMID AIR COMBUSTION

The two-dimensional velocity fields of methane/air diffusion flame wear measured successfully using 2D particle image velocimetry (PIV) in a disc bluff-body burner, and the characteristics of flame structures and flow fields were investigated in both humid air combustion and non-humid air combustion. The experimental results show that the classical fuel-jet to annular air flow velocity ratio of transition between recirculation zone flame and central-jet dominated flame is lower under the humid air combustion than that the no-humid air combustion; comparing with the no-humid air combustion, the annular co-flow air velocity behind the nozzle exit in humid air combustion is decreased observably and the recirculation intension of humid air is declined obviously, accordingly the fuel-jet penetrates recirculation bubble easier and the humid air flame is inevitable more unstable.