催化燃烧对均质压燃发动机燃烧特性影响的数值模拟

通过运用DETCHEM软件包,对甲烷在催化剂Rh表面的详细反应机理进行了分析,结果表明数值模拟结果与实验数据相当吻合;通过耦合DETCHEM软件包及CHEMKIN软件包中的SENKIN模块,对活塞顶涂有催化剂铑的均质压燃(HCCI)发动机的燃烧过程进行了数值计算,建立了单区和多区模型．利用单区模型分析了催化燃烧对HCCI发动机着火时刻的影响,同时讨论了催化燃烧对燃烧过程中主要化学组分浓度变化的影响,结果表明催化燃烧会使HCCI发动机着火时刻提前;利用多区模型分析了催化燃烧对HCCI发动机的未燃碳氢化合物(UHC)、氮氧化合物(NOx)排放的影响,结果表明催化燃烧能降低UHC的排放,但会提高NOx的排放．

Numerical Simulation of the Influences of Catalytic Combustion on HCCI Engine Combustion Characteristics

The detailed reaction mechanism of methane on rhodium was analyzed by using DETCHEM package. Comparisons between numerical simulation and experiments show good agreement. By coupling the DETCHEM package and the SENKIN code of CHEMKIN chemical kinetics package, the combustion process of HCCI (homogeneous charge compression ignition) engine whose piston face was coated with catalyst was simulated. The single-zone and multi-zone models were built. The influences of the catalytic combustion on the ignition timing of the HCCI engines were analyzed and the influences of catalytic combustion on the concentration of the main chemical species were discussed. The results show that catalytic combustion can advance the ignition timeing. The influences of catalytic combustion on UHC and NOx emissions of the HCCI engine were analyzed by the multi-zone model. The results show that catalytic combustion can decrease the emissions of UHC, while increases the emissions of NOx.