| 초록 |
Computer methods with simplified mathematical models in conjunction with empirical model parameters can be efficiently practiced into an optimization of a diesel aftertreatment system. Components of prime interests are diesel particulate filter, diesel oxidation catalyst and de-NOx catalytic converter. de-NOx, de-PM, and de-HC processes in each part are individually modeled, formulated and then combined into an integrated analysis procedure for a unified simulation of the diesel emission aftertreatment. The model is empirically tuned and validated with comprehensive engine and laboratory data. The effects of emission species and space velocity on the NOx and soot reductions are parametrically investigated. A lowered NO2/NOx ratio due to PM oxidation in DPF contributes to promote the NOx reduction by SCR at intermediate gas temperatures. NOx reduction is inert to the PM oxidation at high temperatures. Rate of PM trapping strongly depends on temperature and NOx concentration. |
