Potential of Highly Integrated Exhaust Gas Aftertreatment for Future Passenger Car Diesel Engines

Authors

Dr. C. Severin, F. Bunar, Dr. M. Brauer, M. Diezemann, W. Schultalbers, G. Buschmann, M. Kratzsch, K. Blumenröder, IAV GmbH, Berlin / Gifhorn

Year

2017

Print Info

Fortschritt-Berichte VDI, Series 12, No 802

Summary

This paper describes the potential of close-coupled exhaust gas aftertreatment concepts for passenger car diesel engines in conjunction with new options for turbocharging and hybridization. In the course of simulation studies and engine tests, the potential for reducing CO₂ and pollutant emissions was analyzed and evaluated in the WLTC and in a low-load driving cycle. In the concept study, various exhaust gas turbocharger (TC) layouts were compared with exhaust gas aftertreatment (EAT) components in close-coupled position. A variant with a simple TC bypass, variants with diesel oxidation catalyst (DOC) upstream of and in the bypass to the TC as well as an extreme variant with DOC+SCRF upstream of the TC were compared with a EU-6 base. The experimental studies were carried out on an EU-6-R4-2.0l engine from a D-segment vehicle and are also used for validating the 1-D simulation model. In the 1-D simulation, the use of an electric compressor and hybridization was evaluated as a possible way of compensating for potential performance drawbacks with EAT upstream of the TC. The extreme variant with DOC+SCRF upstream of the TC shows the best results for NOx emissions. Consumption is also shown to be significantly improved when including hybridization which is necessary to compensate for the performance drawbacks. The life cycle assessment for a full hybrid vehicle with diesel engine also shows a very good CO₂ balance with fossil energy sources, similar to the level of an electric vehicle with EU-27 electricity mix. Discussion of the purchasing and running costs for the diesel drive in the passenger car now remains. On the path to the intelligent powertrain, this paper describes concepts and technologies for minimizing emissions and maximizing efficiency.