Engine-Aftertreatment in Loop Modeling for Heavy Duty Truck Emissions Control

Zhiming  Gao, ORNL

Engine-Aftertreatment in Loop Modeling for Heavy Duty Truck Emissions Control

 Zhiming Gao, Dean Deter, David E. Smith, and Josh Pihl

Abstract: An engine-aftertreatment in loop modeling was developed to evaluate tailpipe emissions and fuel consumption of heavy duty trucks powered by a commercial 2010-compliant 15-L diesel engine. The engine model was developed based on steady-state engine maps and dynamic correction factors for accounting for recent engine history. These correction factors were modeled as dynamic first-order lags associated with heat-up or cool-down of major engine components and the rate at which excess heat is being added to the engine from combustion or lost to the surroundings. The aftertreatment train model consists of DOC, DPF and SCR catalysts to account for CO/HC/NOx/PM emissions controls required by EPA regulation standards. By locating the DPF upstream of the SCR catalyst, chances for passive regeneration of the DPF are increased, thereby potentially reducing the need to expend extra fuel for DPF regeneration. The integrated engine and aftertreatment models are capable of understanding the interactions among the fuel efficiency, emissions control, power demand (including auxiliary loads) for HD trucks. Both the engine and aftertreatment models have been well calibrated with our VSI lab data measured over a HD engine FTP cycle. The Engine-Aftertreatment in Loop Modeling can be used to explore the technical path of maximizing the benefits of conventional truck and truck hybridization through the integration of multiple power demand reduction technologies. In the presentation, we will provide the simulated fuel economy and tailpipe emissions of the conventional and hybrid long-haul trucks.