催化燃烧对HCCI发动机着火点、燃烧性能及排放的影响

对甲烷在催化剂铑(Rh)表面的反应机理进行了分析。通过修改CHEMKIN软件包中的SENKIN模块,对活塞顶涂有催化剂的HCCI发动机的燃烧过程进行了数值计算,建立了单区、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,结果表明在控制HCCI发动机着火时刻方面催化燃烧有其他方式所没有的优势;利用多区模型分析了催化燃烧对HCCI发动机的燃烧性能及HC、CO、NOx排放的影响,结果表明催化燃烧对燃烧效率、着火持续期有较大的影响,同时能降低HC、CO的排放,但会提高NOx的排放。

Influences of Catalytic Combustion on Ignition Timing, Combustion Capability and Emissions of HCCI Engine

The detailed reaction mechanism of methane on rhodium catalyst was examined.By amending the SENKIN code of CHEMKIN chemical kinetics package,the combustion process of homogeneous charge compression ignition(HCCI) engine whose piston surface was coated with catalyst(rhodium and platinum) was numerically investigated.A single-zone model and a multi-zone model were developed.The effects of catalytic combustion on the ignition timing were analyzed through the single-zone model.The results show that the catalysis has some advantages over other means on controlling the ignition timing of the HCCI engine.The effects of catalytic combustion on combustion capability and the emissions of HC,CO and NOx of the HCCI engine were analyzed through the multi-zone model.The results show that the combustion efficiency and the ignited duration time are affected and the emissions of HC and CO are decreased,while the emissions of NOx are elevated by the catalytic combustion.