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 NO, 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.