Real-world fuel consumption, fuel cost and exhaust emissions of different bus powertrain technologies

Rodman Oprešnik, Samuel (author), Seljak, Tine (author), Vihar, Rok (author), Gerbec, Marko (author), Katrašnik, Tomaž (author)

Air quality in urban areas is strongly influenced by exhaust emitted by the public transport fleet. The aim of this study was to analyze benefits in the fuel consumption, fuel costs and exhaust emissions when replacing baseline diesel fueled EURO III city buses by the compressed natural gas (CNG)-fueled EURO V buses and by hydraulic series hybrid diesel-fueled EURO V buses. Real-world measurements were performed on the regular bus route to access realistic energy consumption and exhaust emissions. Instantaneous gaseous emission (CO$_2$, CO, NO$_x$ and THC) were measured together with the instantaneous PM$_{10}$ mass emission. Innovativeness of the presented approach thus arises from the systematic comparison of different powertrain technologies under real-world drive cycles and measuring time traces of not only gaseous but also of PM$_{10}$ mass emissions. Furthermore, lumped cycle averaged emissions are interpreted and explained by typical powertrain performance parameters and exhaust emission time traces. Cumulative results indicate that application of the CNG fueled buses does not necessary reduce CO$_2$ emissions compared to diesel-fueled buses whereas reduction in fuel costs is evident. Additionally, it is shown that hybrid operation of the hydraulic series hybrid diesel-fueled bus resulted in higher fuel consumption due to poorly optimized hybrid topology and control strategy. Furthermore, analyses of the time traces point out inadequate lambda control of CNG-fueled buses and nucleation mode-based particle number emissions during deceleration.

• Language: English
• Keywords: bus powertrain technologies, instantaneous gaseous and PM$_{10}$ mass emissions, real-world driving cycles
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2018
• Number of pages: 20 str.
• Numbering: Vol. 11, iss. 8, art. 2160
• PID: 20.500.12556/RUL-106465
• UDC: 621.43(045)
• ISSN on article: 1996-1073
• DOI: 10.3390/en11082160
• COBISS.SI-ID: 16192027
• Publication date in RUL: 25.02.2019

Record is a part of a journal

• Title: Energies
• Shortened title: Energies
• Publisher: Molecular Diversity Preservation International
• ISSN: 1996-1073
• COBISS.SI-ID: 518046745

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.
• Licensing start date: 18.08.2018

Secondary language

• Language: Slovenian
• Keywords: tehnologije avtobusnih pogonskih sklopov, trenutni plinski in PM$_{10}$ izpusti, vozni cikel v realnem svetu

Projects

• Funder: EC - European Commission
• Funding programme: FP7
• Project number: 218954
• Name: CIVITAS ELAN Mobilising citizens for vital cities Ljubljana - Gent - Zagreb - Brno - Porto
• Acronym: ELAN