Characterizing NOₓ emissions from diesel trucks with tampered aftertreatment systems and its implications for identifying high emitters

Reducing the differences between real-world and certificated NOₓ emission levels is an important element of in-use emission surveillance programs. Therefore, investigating the characteristics of the vehicles which have much higher NOₓ emissions (i.e., high-emitters) and determining a reasonable cut-off point to identify high-emitters with a low false detection rate is important. In this study, six diesel trucks were tested under different aftertreatment conditions. The results showed that the discrepancies of fuel-specific NOₓ emissions between vehicles with functioning and tampered selective catalytic reduction (SCR) systems occur mainly from medium- to high-speed modes. This is because the SCR systems were at low conversion efficiencies when the exhaust temperature was low, including cold-start and urban creep conditions. By using binary classification, the authors selected fuel-specific NOₓ cut-off points for high-emitters from China V and China VI diesel trucks. The false detection rate of high-emitters can decrease by 33 % and 95 %, if only NOₓ emissions from medium- to high-speed modes were used for the chosen cut-off points, respectively. This work highlights the importance of in-use emission compliance programs. It also suggests that high-emitters can be more accurately identified at medium- to high-speed modes if using instantaneous emission data.

• Record URL:
  • https://doi.org/10.1016/j.scitotenv.2024.170378
• Record URL:
  • http://www.sciencedirect.com/science/article/pii/S0048969724005138
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/00489697
• Supplemental Notes:
  • © 2024 Published by Elsevier B.V. Abstract reprinted with permission of Elsevier.
• Authors:
  • Tian, Miao
  • He, Liqiang
  • Peng, Di
  • Fu, Mingliang
  • Ma, Shuai
  • Mu, Jinsong
  • Yu, Quanshun
  • Wang, Jia
  • Yin, Hang
  • Wang, Junfang
• Publication Date: 2024-3-20

Language

• English

Media Info

• Media Type: Web
• Features: References;
• Pagination: 170378
• Serial:
  • Science of the Total Environment
  • Volume: 917
  • Issue Number: 0
  • Publisher: Elsevier
  • ISSN: 0048-9697
  • Serial URL: http://www.sciencedirect.com/science/journal/00489697

Subject/Index Terms

• TRT Terms: Classification; Diesel engine exhaust gases; Diesel trucks; Emission control systems; Nitrogen oxides; Tampering
• Identifier Terms: China 5 (Standard : China); China 6 (Standard : China)
• Geographic Terms: China
• Subject Areas: Environment; Highways; Vehicles and Equipment;

Filing Info

• Accession Number: 01915321
• Record Type: Publication
• Files: TRIS
• Created Date: Apr 17 2024 9:30AM