Integrated Diesel System Achieving Ultra-Low Urban and Motorway NOₓ Emissions on the Road

Authors

Dr. J. Demuynck, C. Favre MSc, D. Bosteels MSc MBA, AECC, Brussels; G. Randlshofer, IPA, Munich;
Dr.-Ing. F. Bunar, Dipl.-Ing. J. Spitta, Dipl.-Ing. O. Friedrichs, A. Kuhrt MEng, Dr.-Ing. M. Brauer, IAV GmbH, Berlin

Year

2019

Print Info

Fortschritt-Berichte VDI, Reihe 12, Nr. 811

Summary

The paper discusses the technical approach to meet Euro 6d Real-Driving Emissions (RDE) requirements and beyond, with a particular focus on reducing diesel NO_x emissions in urban and motorway driving situations. Novel technology aspects of the diesel powertrain are an RDE-optimized aftertreatment system layout to improve both low- and high-load deNO_x
performance and a 48V P0 hybrid system. An additional key element of the powertrain concept is the advanced model-based deNO_x control strategy.
The first part of the paper provides a brief summary of Euro 6d and possible post-Euro 6 RDE requirements. Based on this, the technology strategy for the powertrain and aftertreatment architecture is derived. Challenges for the related control functions are discussed as well. The optimized exhaust aftertreatment layout combines Lean NO_x Trap (LNT) and Selective Catalytic Reduction (SCR) technologies. For maximum low load deNO_x performance, the close-coupled SCR, consisting of an additional slice upstream of an SCR coated on DPF (SDPF), is assisted by an LNT. High load conditions are covered by a dual
SCR system with twin AdBlue® dosing. The P0 48V electric motor supports the NO_x control in addition to ensuring good driving performance and fuel efficiency. A smart and advanced control strategy is implemented to ensure optimal interaction between all components.
The second part of the paper focusses on experimental data from PEMS measurements of a demonstrator car on public roads and on the chassis roller test bench. The RDE tests investigated cover a wide range of driving conditions. Special attention is paid to the robustness of the emission performance under urban and motorway driving conditions.
Finally, further possible technology and system evolutions are discussed.