Field Measurements of Gasoline Direct Injection Emission Factors: Spatial and Seasonal Variability

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• 作者：Naomi Zimmerman ; Jonathan M. Wang ; Cheol-Heon Jeong ; Manuel Ramos ; Nathan Hilker ; Robert M. Healy ; Kelly Sabaliauskas ; James S. Wallace ; Greg J. Evans
• 刊名：Environmental Science & Technology
• 出版年：2016
• 出版时间：February 16, 2016
• 年：2016
• 卷：50
• 期：4
• 页码：2035-2043
• 全文大小：509K
• ISSN：1520-5851

文摘

Four field campaigns were conducted between February 2014 and January 2015 to measure emissions from light-duty gasoline direct injection (GDI) vehicles (2013 Ford Focus) in an urban near-road environment in Toronto, Canada. Measurements of CO₂, CO, NO_x, black carbon (BC), benzene, toluene, ethylbenzene-xylenes (BTEX), and size-resolved particle number (PN) were recorded 15 m from the roadway and converted to fuel-based emission factors (EFs). Other than for NO_x and CO, the GDI engine had elevated emissions compared to the Toronto fleet, with BC EFs in the 73rd percentile, BTEX EFs in the 80–90th percentile, and PN EFs in the 75th percentile during wintertime measurements. Additionally, for three campaigns, a second platform for measuring PN and CO₂ was placed 1.5–3 m from the roadway to quantify changes in PN with distance from point of emission. GDI vehicle PN EFs were found to increase by up to 240% with increasing distance from the roadway, predominantly due to an increasing fraction of sub-40 nm particles. PN and BC EFs from the same engine technology were also measured in the laboratory. BC EFs agreed within 20% between the laboratory and real-world measurements; however, laboratory PN EFs were an order of magnitude lower due to exhaust conditioning.