This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Evaluating the Performance of a Conventional and Hybrid Bus Operating on Diesel and B20 Fuel for Emissions and Fuel Economy
ISSN: 0148-7191, e-ISSN: 2688-3627
Published April 14, 2020 by SAE International in United States
This content contains downloadable datasetsAnnotation ability available
With ongoing concerns about the elevated levels of ambient air pollution in urban areas and the contribution from heavy-duty diesel vehicles, hybrid electric vehicles are considered as a potential solution as they are perceived to be more fuel efficient and less polluting than their conventional engine counterparts. However, recent studies have shown that real-world emissions may be substantially higher than those measured in the laboratory, mainly due to operating conditions that are not fully accounted for in dynamometer test cycles. At the U.S. EPA National Fuel and Vehicle Emissions Laboratory (NVFEL) the in-use criteria emissions and energy efficiency of heavy-duty class 8 vehicles (up to 36280 kg) can be evaluated under controlled conditions in the heavy-duty chassis dynamometer test. The present study evaluated the performance of a conventional bus and a hybrid bus for emissions and fuel economy under representative test cycles (including cold start and hot start conditions) with Diesel (#2) and Biodiesel (B20) fuel. The conventional bus was equipped with a Cummins ISL 8.3L engine and a Diesel Particulate Filter (DPF) and Diesel Oxidation Catalyst (DOC) aftertreatment, while the hybrid bus had a Cummins ISB 6.7L engine with a Selective Catalytic Reduction (SCR), DPF and DOC aftertreatment. Generally, the hybrid bus showed higher fuel economy (lower CO2 emissions) as compared to the conventional bus for both cold start and hot start test cycles. However, NOx emissions were observed to be somewhat higher for the hybrid bus over the cold start test cycle. In general, lower emissions were observed for both bus configurations when operating on B20 over diesel fuel, while fuel economy was comparable. To confirm these trends on in-use vehicles and to understand if chassis dynamometer testing accounts for real world operation appropriately, some initial results from on-road testing of the buses are reported for comparison purposes.
CitationPillai, R., Brusstar, M., Boehman, A., and Ludlam, S., "Evaluating the Performance of a Conventional and Hybrid Bus Operating on Diesel and B20 Fuel for Emissions and Fuel Economy," SAE Technical Paper 2020-01-1351, 2020, https://doi.org/10.4271/2020-01-1351.
Data Sets - Support Documents
|Unnamed Dataset 1|
|Unnamed Dataset 2|
|Unnamed Dataset 3|
- Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2017 June 11, 2019 https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas-emissions-and-sinks-1990-2017
- Public Transportation’s Role in Responding to Climate Change https://www.transit.dot.gov/sites/fta.dot.gov/files/docs/PublicTransportationsRoleInRespondingToClimateChange2010.pdf
- Bass , E. and Alfermann , T. The Influence of Idle, Drive Cycle and Accessories on the Fuel Economy of Urban Hybrid Electric Buses - Chassis Dynamometer Tests SAE Technical Paper 2003-01-3438 October 2003 https://doi.org/10.4271/2003-01-3438
- Nix , A.C. , Sandoval , J.A. , Wayne , W.S. , Clark , N.N. , and Mckain , D.L. Fuel Economy and Emissions Analysis of Conventional Diesel, Diesel-Electric Hybrid, Biodiesel and Natural Gas-Powered Transit Buses December 2011 https://doi.org/10.2495/sdp110741
- Bari , S. Performance, Combustion and Emission Tests of a Metro-Bus Running on Biodiesel-ULSD Blended (B20) Fuel Applied Energy 124 35 43 2014 https://doi.org/10.1016/j.apenergy.2014.03.007
- Hallmark , S.L. , Wang , B. , and Sperry , R. Comparison of On-Road Emissions for Hybrid and Regular Transit Buses Journal of the Air & Waste Management Association 63 10 1212 2013 https://doi.org/10.1080/10962247.2013.813874
- Burton , J. , Walkowicz , K. , Sindler , P. , and Duran , A. In-Use and Vehicle Dynamometer Evaluation and Comparison of Class 7 Hybrid Electric and Conventional Diesel Delivery Trucks SAE International Journal of Commercial Vehicles 6 2 545 554 2013 https://doi.org/10.4271/2013-01-2468
- Russell , R.L. , Johnson , K. , Durbin , T. , Chen , P.P. et al. Emissions, Fuel Economy, and Performance of a Class 8 Conventional and Hybrid Truck SAE Technical Paper 2015-01-1083 2015 https://doi.org/10.4271/2015-01-1083
- Xu , G. , Li , M. , Zhao , Y. , and Chen , Q. Study on Emission Characteristics of Hybrid Buses under Driving Cycles in a Typical Chinese City Advances in Mechanical Engineering 9 10 168781401772823 2017 https://doi.org/10.1177/1687814017728238
- Geng , W. , Lou , D. , Xu , N. , Tan , P. , and Hu , Z. Chassis Dynamometer and On-Road Evaluations of Emissions from a Diesel-Electric Hybrid Bus SAE Technical Paper 2017-01-0984 2017 https://doi.org/10.4271/2017-01-0984
- Jain , S. and Kumar , L. Fundamentals of Power Electronics Controlled Electric Propulsion Power Electronics Handbook 2018 1023 1065
- Heywood , J.B. Internal Combustion Engine Fundamentals New York McGraw-Hill Education 2018