摘要
通过保持压缩比和燃烧室容积不变,应用计算流体力学(CFD)软件建立燃烧室三维数值模型并耦合CHEMKIN,以正庚烷-正丁醇-多环芳香烃-甲苯简化机理作为正丁醇-柴油混合燃料燃烧化学反应动力学机理,研究不同径深比燃烧室对正丁醇-柴油低温燃烧不同燃烧阶段碳烟前驱物A4(C16H10)生成的影响.结果显示,燃烧室径深比对正丁醇-柴油混合燃料燃烧压力和放热率影响较小,对A4的生成历程影响较大.在燃烧初期,A4主要分布在燃烧室凹坑、侧壁和活塞顶,燃料高温裂解产生的中间基团C2H2和C3H3在A4的生成过程中起关键作用.径深比较小时,局部高温使A4的生成量较多,径深比较大时,温度分布均匀,A4生成量少.在燃烧末期,A4的生成集中在燃烧室凹坑,且随着径深比的增加,A4的生成量呈现先增加后减小的趋势.
The combustion model of engine was built by using the computational fluid dynamics （CFD） software cou- pled with CHEMK1N, the n-heptane-n-butanol-PAH-toluene reduced mechanism was used as n-butanol-diesel blend fuel combustion chemical reaction kinetics mechanism, and then the effect of the diameter-depth ratio of chambers with the same compression ratio and chamber volume on the formation of soot precursors A4 （C16H10） at different n- butanol-diesel blend fuel combustion stages was studied. Results indicate that diameter-depth ratio has a small effect on in-cylinder pressure and heat release rate, but has a great effect on A4 formation. At the initial combustion stage, A4 is mainly produced in the piston bowl, on the combustion chamber wall and on the top of piston, and C2H2 and C3H3 as the fuel pyrolysis products play a key role in A4 formation. When the diameter-depth ratio gets smaller, more A4 is produced due to the local high temperature in the cylinder. When the diameter-depth ratio gets bigger, less A4 is produced because of the temperature uniformity in the cylinder. At the end of combustion, A4 is mainly produced in the piston bowl, and as the diameter-depth ratio increases, A4 formation increases first and then decreases.
出处
《燃烧科学与技术》
EI
CAS
CSCD
北大核心
2014年第2期106-114,共9页
Journal of Combustion Science and Technology
基金
国家自然科学基金资助项目(51076033)
广西研究生教育创新计划资助项目(GXU11T32545)
关键词
燃烧室形状
正丁醇-柴油
碳烟前驱物
combustion chamber geometry
n-butanol-diesel
soot precursor
