The HSDI Diesel engine contributes substantially to the decrease of fleet fuel consumption thus to the reduction of CO2 emissions. This results in the rising market acceptance which is supported by desirable driving performance as well as greatly improved NVH behavior. In addition to the above mentioned requirements on driving performance, fuel economy and NVH behavior, continuously increasing demands on emissions performance have to be met.
From today's view the Diesel particulate trap presents a safe technology to achieve the required reduction of the particle emission of more than 95%. However, according to today's knowledge a further, substantial NOx engine-out emission reduction for the Diesel engine is counteracts with the other goal of reduced fuel consumption.
To comply with current and future emission standards, Diesel engines will require DeNOx technologies. The NH3-SCR and Lean NOx-Trap (LNT) technologies are currently the most promising solutions to meet stringent NOx standards. While the NH3-SCR shows benefits considering fuel consumption penalty, the usage of an additional reduction component is considered as a backdraw.
Introduction of DeNOx technologies in combination with DOC/DPF application requires a detailed and thorough analysis of exhaust system layout at the very beginning of the engine development. To define the appropriate technology for different applications, modeling and simulation of emission and fuel consumption are mandatory.
This paper will discuss the simulation results for aftertreatment components such as DOC, DPF, SCR and LNT and the impact of different exhaust system layouts on emission reduction.