【摘要】 针对多孔焦炭颗粒富氧气氛中燃烧时,反应气体在颗粒孔结构中的扩散传质,内外表面上氧化还原的化学反应,孔隙结构变化等这些过程的分析,建立了以改进的随机孔模型为基础的物理和数学模型。研究了在不同浓度、温度下焦炭颗粒燃烧时,孔内化学反应速率、反应气体内扩散浓度和颗粒转化率等参数随内径的变化特性。结果表明,在研究工况的过渡控制区(1 200 K),氧化反应速率比还原反应速率高达3个数量级,随着氧浓度的增加,颗粒内部转化率变化率的拐点内移。更多还原

【Abstract】 For analyzing the combustion of porous char particle in oxy-fuel atmosphere,considering these processes about the reaction gas diffusion and mass transfer in the particle-hole structure,chemical reactions on the outer and inner surfaces and the pore structure changes and so on,a physical and mathematical equation basised on an improved random pore model were established. the chemical reaction rate in pores,the reaction gas diffusion concentration,particle conversion rate and other parameters characteristics along with inner diameter changing were studied,when the single-char particle is burning at a different concentration and temperature. The results show that in this studied conditions of transitional control area( 1 200 K),the oxidation reaction rate is higher 3 orders of magnitude than the reduction reaction rate,and with the increase of oxygen concentration,the changing of char particle internal conversion rate ’s inflection point moved inside. Therefore,a reasonable oxygen concentration ’s choice in transitional control combustion zone for char particle burnout have a major impact.更多还原