TY - JOUR
T1 - Real Driving NOx Emissions from Euro VI Diesel Buses
AU - Söderena, Petri
AU - Nylund, Nils Olof
AU - Pettinen, Rasmus
AU - Mäkinen, Reijo
N1 - Funding Information:
The authors would like to acknowledge HSL, Trafi, HSY, City of Helsinki and TØI for the support to the Euro VI city buses emissions field-monitoring project. Definitions/Abbreviations CNG Compressed natural gas DOC Diesel oxidation catalyst DPF Diesel particulate filter EAT Exhaust aftertreatment EU European Union ISC In-service conformity HSL Helsinki region transport JRC Joint Research Centre NO x Nitrogen oxides RDE Real-driving emissions SCR Selective catalytic reduction SEMS Sensor emissions measurement system PM Particulate matter PEMS Portable emissions measurement system WHVC World harmonized vehicle cycle WHTC World harmonized transient cycle
Publisher Copyright:
© 2018 SAE International. All Rights Reserved.
Copyright:
Copyright 2019 Elsevier B.V., All rights reserved.
PY - 2018
Y1 - 2018
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=85056894640&partnerID=8YFLogxK
U2 - 10.4271/2018-01-1815
DO - 10.4271/2018-01-1815
M3 - Article in a proceedings journal
AN - SCOPUS:85056894640
SN - 0148-7191
VL - 2018
JO - SAE Technical Paper Series
JF - SAE Technical Paper Series
M1 - 2018-01-1815
T2 - SAE 2018 International Powertrains, Fuels and Lubricants Meeting, FFL 2018
Y2 - 17 September 2018 through 19 September 2018
ER -