This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Development of a Cold Start Fuel Penalty Metric for Evaluating the Impact of Fuel Composition Changes on SI Engine Emissions Control
ISSN: 0148-7191, e-ISSN: 2688-3627
Published April 03, 2018 by SAE International in United States
This content contains downloadable datasetsAnnotation ability available
The U.S. Department of Energy’s Co-Optimization of Fuels and Engines initiative (Co-Optima) aims to simultaneously transform both transportation fuels and engines to maximize performance and energy efficiency. Researchers from across the DOE national laboratories are working within Co-Optima to develop merit functions for evaluating the impact of fuel formulations on the performance of advanced engines. The merit functions relate overall engine efficiency to specific measurable fuel properties and will serve as key tools in the fuel/engine co-optimization process. This work focused on developing a term for the Co-Optima light-duty boosted spark ignition (SI) engine merit function that captures the effects of fuel composition on emissions control system performance. For stoichiometric light-duty SI engines, the majority of NOx, NMOG, and CO emissions occur during cold start, before the three-way catalyst (TWC) has reached its “light-off” temperature. This light-off temperature depends on the exhaust composition, which changes with fuel formulation. Thus, the time to achieve light-off, and therefore the cold start emissions, depends on fuel composition. Since the time to reach light-off must be minimized to meet emissions regulations, modern vehicles employ cold start strategies that intentionally release fuel energy into the engine exhaust to heat the TWC above the light-off temperature as quickly as possible. The fuel penalty associated with catalyst heating during cold start provides a link between fuel properties, emissions performance, and engine efficiency. This paper describes the derivation of the Co-Optima SI engine merit function term for emissions control, which is based on the cold start fuel penalty for catalyst heating and the catalytic light-off temperature for a particular fuel composition. It also discusses the process used for extracting cold start fuel penalties from chassis dynamometer data sets previously collected at ORNL. The form of the merit function term is simple, but it is only intended as a starting point for comparing the potential impacts of changes in fuel formulation on emissions control system performance.
CitationPihl, J., Thomas, J., Sinha Majumdar, S., Huff, S. et al., "Development of a Cold Start Fuel Penalty Metric for Evaluating the Impact of Fuel Composition Changes on SI Engine Emissions Control," SAE Technical Paper 2018-01-1264, 2018, https://doi.org/10.4271/2018-01-1264.
Data Sets - Support Documents
|Unnamed Dataset 1|
- Kessels , J. , Foster , D. , and Bleuanus , W. Fuel Penalty Comparison for (Electrically) Heated Catalyst Technology Oil & Gas Science and Technology - Revue D IFP Energies Nouvelles 65 1 47 54 2010 10.2516/ogst/2009078
- Rodriguez , J. and Cheng , W. Cycle-By-Cycle Analysis of Cold Crank-Start in a GDI Engine SAE Int. J. Engines 9 2 2016 10.4271/2016-01-0824
- Anderson , J. , Rask , E. , Lohse-Busch , H. , and Miers , S. A Comparison of Cold-Start Behavior and its Impact on Fuel Economy for Advanced Technology Vehicles SAE Int. J. Fuels Lubr. 7 2 427 435 2014 10.4271/2014-01-1375
- Rodriguez , J. and Cheng , W. 9 2 2016 10.4271/2016-01-0827
- Thomas , J. , West , B. , Huff , S. 10.2172/1185964
- Theiss , T. , et al 2016 10.2172/1286966
- Kang , S. , Nam , S. , Cho , B. , Nam , I.-S. et al. Effect of Speciated HCs on the Performance of Modern Commercial TWCs Catalysis Today 231 3 14 2014 10.1016/j.cattod.2013.11.032
- U.S. DRIVE Advanced Combustion and Emission Control Technical Team Low Temperature Aftertreatment Working Group https://cleers.org/low-temperature-protocols 2017