二氧化碳和富氧空气对甲烷与乙烯燃烧的影响

利用碳氢燃烧实验台，研究了二氧化碳和富氧空气对甲烷、乙烯层流燃烧火焰的特性影响，分析了不同气氛下火焰结构特性和温度分布规律. 结果表明，随氧浓度从21%增加到50%(j)，甲烷、乙烯火焰高度下降70%，火焰温度和亮度同时增加，且发光区域呈向下收缩趋势；相同氧浓度下，乙烯火焰亮度高于甲烷. 随CO2浓度由0增加到20%(j)，火焰高度增加28%，各高度处火焰边缘温度平均下降290℃，中心温度平均下降132℃. 火焰亮度降低，由黄色变为暗黄色，底部亮度更低，CO2浓度超过20%(j)后，火焰出现悬浮状态，最终被吹熄.

Effects of CO2 and Oxygen-enriched Air on Combustion of Methane and Ethylene

The effect of dilution gas addition is an important topic in the field of gaseous fuel combustion. In the present study, the effects of CO2 addition and oxygen enrichment on the characteristics of laminar coflow methane and ethylene diffusion flames were investigated experimentally. The shape and temperature distribution of the flames under different atmospheres were analyzed. With the increase of oxygen concentration from 21% to 50%(j), the height decreased by about 70% for both flames, while the flame temperature and brightness increase. Under the same oxygen concentration, the brightness of the ethylene flame is higher than that of the methane flame. With the increase of CO2 concentration from 0 to 20%(j), the flame height increased by 28%, and the average edge temperature of the flame at each height decreased by 290℃, and the centerline temperature decreased by 132℃. The flame brightness is reduced from yellow color to dull yellow, and the visible flame base sligts down towards the burner rim. When the CO2 concentration is more than 20%(j), the flame will be lifted, and eventually blown out.