This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Real Driving NOx Emissions from Euro VI Diesel Buses
ISSN: 0148-7191, e-ISSN: 2688-3627
Published September 10, 2018 by SAE International in United States
This content contains downloadable datasetsAnnotation ability available
Since 2013, Euro VI heavy-duty on-road vehicles have been on the market in the Europe. Regulated exhaust emissions, including nitrogen oxides and particulate matter, have been cut down to a very low level, independent of fuel (diesel or natural gas). Multiple research papers have shown that the regulated emissions from the Euro VI and US 2010 heavy-duty on-road vehicles tested on chassis dynamometers really deliver emission levels which correspond the type approval requirements, independent of the test cycle used.
In-service conformity (ISC), which is included in the Euro VI legislation, requires heavy-duty on-road engine manufacturers to test and prove their engines to comply with the emission legislation during the engine in-use period. The measurements are carried out in the field using PEMS (Portable Emission Measurement System) equipment. This kind of testing, depicting real-world emissions is the final stage to confirm low real-life emissions.
Although there is evidence that the exhaust aftertreatment systems of Euro VI heavy-duty on-road engines work well on an average, there is only a limited data of city buses covering their functionality over longer operation periods, especially not at lower ambient temperatures. Especially reduction of nitrogen oxides in the SCR-system (Selective Catalytic Reduction) is sensitive to SCR catalyst operation temperature, and also to impurities transferred from engine oil or fuel.
This paper present results of a unique combination of chassis dynamometer measurements, on-road PEMS measurements and continuous NOx-emission monitoring during operation in winter condition from four Euro VI diesel city buses operating in the Helsinki metropolitan area.
Based on the research done, four Euro VI city buses monitored and measured during the project showed decreased NOx conversion rate and increased tailpipe NOx emissions when operating in ambient temperatures below 0 °C. Especially in ambient temperatures below −10 °C, the continuous monitoring showed dramatically increased tailpipe NOx concentrations.
CitationSöderena, P., Nylund, N., Pettinen, R., and Mäkinen, R., "Real Driving NOx Emissions from Euro VI Diesel Buses," SAE Technical Paper 2018-01-1815, 2018, https://doi.org/10.4271/2018-01-1815.
Data Sets - Support Documents
|[Unnamed Dataset 1]|
|[Unnamed Dataset 2]|
|[Unnamed Dataset 3]|
|[Unnamed Dataset 4]|
- Johnson, K.C., Durbin, T.D., Cocker, D.R., Miller, W.J. et al., “On-Road Comparison of a Portable Emission Measurement System with a Mobile Reference Laboratory for Heavy-Duty Diesel Vehicle,” Atmospheric Environment 43:2877-2883, 2009, doi:10.1016/j.atmosenv.2009.03.019.
- Bougher, T., Khalek, I., Laroo, C., and Bishnu, D., “Determination of the PEMS Measurement Allowance for PM Emissions Regulated under the Heavy-Duty Diesel Engine In-Use Testing Program,” SAE Int. J. Engines 5(3), 2012, doi:10.4271/2012-01-1250.
- Giechaskiel, B., Clairotte, M., Valverde, V., and Bonnel, P., “Real Driving Emissions: 2017 Assessment of Portable Emissions Measurement Systems (PEMS) Measurement Uncertainty,” JRC Technical Reports, 2018, doi:10.2760/127122.
- Nylund, N., Karvonen, V., Kuutti, H., and Laurikko, J., “Comparison of Diesel and Natural Gas Bus Performance,” SAE Technical Paper 2014-01-2432, 2014, doi:10.4271/2014-01-2432.
- VTT’s database on transit bus emissions, (2017), In Finnish. http://www.transsmart.fi/files/439/Rakebus_2017_Projektin_loppuraportti.pdf.
- Mizushima, N., Kawano, D., Ishii, H., Takada, Y. et al., “Evaluation of Real-World Emissions from Heavy-Duty Diesel Vehicle Fueled with FAME, HVO and BTL Using PEMS,” SAE Technical Paper 2014-01-2823, 2014, doi:10.4271/2014-01-2823.
- Mäkinen, R., Nylund, N., Erkkilä, K., Saikkonen, P. et al., “Bus Fleet Operation on Renewable Paraffinic Diesel Fuel,” SAE Technical Paper 2011-01-1965, 2011, doi:10.4271/2011-01-1965.
- Nylund, N., Laurikko, J., Kytö, M., Aakko-Saksa, P., “Uudet dieselmoottorin biopolttoainevaihtoehdot,” In Finnish, 2017, VTT-R-02415-17.