镁颗粒在CO2中的点火燃烧特性试验

摘要

A Xe-lamp ignition and combustion setup was designed,and a series of experiments of single magnesium particle ig-nition and combustion in CO2 were conducted,with the help of a high resolution and high speed image formation system.During the ignition and combustion,the structure of particle and flame was observed directly and clearly.The results indicate that the process of ignition and combustion of a single magnesium particle consists of metal melting,surface chemical reaction,oxide film fracture,mag-nesium gas ejecting and gas phase combustion.And combustion fluctuation was also observed during the combustion process.Environ-mental pressure would affect the particle ignition temperature,which increases the rising environmental pressure.The combustion pro-duction takes the shape of a hollow sphere,being covered by white magnesium oxide on the surface,and black carbon filled in the inner layer.%利用自行设计的氙灯点火燃烧试验装置,采用高分辨率高速成像系统,开展了单个镁颗粒在CO2 气体氛围中的点火燃烧试验研究,直接观察到了镁颗粒点火燃烧过程中颗粒和火焰形态. 试验结果表明,镁颗粒在CO2 中的点火燃烧经历了颗粒熔化、表面化学反应、氧化层破裂、镁蒸气喷射、气相燃烧等物理化学过程,颗粒燃烧过程伴有脉动燃烧现象;环境压强对颗粒表面氧化层疏松度有一定影响,进而会影响到颗粒的点火温度,压强越大,颗粒点火温度越高;燃烧产物是中空的多孔球壳状物质,且外层为白色氧化镁,内层为黑色碳.