Simulations of the Fuel Economy and Emissions of Hybrid Transit Buses over Planned Local Routes

Journal Article · Wed Jan 01 00:00:00 EST 2014 · SAE International Journal of Commercial Vehicles

DOI:https://doi.org/10.4271/2014-01-1562· OSTI ID:1129607

Gao, Zhiming ^[1]; LaClair, Tim J ^[1]; Daw, C Stuart ^[1]; Smith, David E ^[1]; Franzese, Oscar ^[1]

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1. ORNL

We present simulated fuel economy and emissions city transit buses powered by conventional diesel engines and diesel-hybrid electric powertrains of varying size. Six representative city drive cycles were included in the study. In addition, we included previously published aftertreatment device models for control of CO, HC, NOx, and particulate matter (PM) emissions. Our results reveal that bus hybridization can significantly enhance fuel economy by reducing engine idling time, reducing demands for accessory loads, exploiting regenerative braking, and shifting engine operation to speeds and loads with higher fuel efficiency. Increased hybridization also tends to monotonically reduce engine-out emissions, but trends in the tailpipe (post-aftertreatment) emissions involve more complex interactions that significantly depend on motor size and drive cycle details.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 1129607
• Journal Information: SAE International Journal of Commercial Vehicles, Vol. 7, Issue 1; ISSN 1946-3928
• Country of Publication: United States
• Language: English