Effects of Fuel Properties on Particle Number and Particle Mass Emissions from Lean and Stoichiometric Gasoline Direct Injection Engine Operation

Journal Article · Tue Apr 02 00:00:00 EDT 2019 · SAE Technical Paper Series

DOI:https://doi.org/10.4271/2019-01-1183· OSTI ID:1807776

Bock, Noah ^[1]; Jeon, Joonho ^[2]; Kittelson, David ^[2]; Northrop, William ^[2]

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1. Univ. of Minnesota-Twin Cities, MN (United States); University of Minnesota - Twin Cities
2. Univ. of Minnesota-Twin Cities, MN (United States)

Engine-out particle size distributions and soot mass emissions were measured from a gasoline direct injection (GDI) engine fueled by seven different gasoline formulations. Additionally, particle size distributions were simultaneously measured downstream of a catalyzed gasoline particulate filter (GPF) to determine the size resolved filtration efficiency. Stoichiometric, lean homogeneous, and lean stratified combustion modes were studied at four steady-state engine conditions. The particulate matter (PM) Index was calculated for each fuel as a function of the double bond equivalent and vapor pressure of the fuel components. There was generally poor correlation between particle number (PN)/PM mass emissions and the PM Index for steady state stoichiometric conditions with clean injectors, which emitted low particle concentrations. However, under high-load lean homogeneous conditions, there was good correlation between PN/PM mass emission and the PM Index, with the exception that the high ethanol content fuel produced significantly higher PM emissions than the other fuels. Under lean stratified conditions, most fuels produced similar particle size distributions and concentrations with the exception that the E50 fuel produced significantly lower concentrations than the other fuels. These results demonstrate the profound sensitivity of particle emissions from high ethanol content fuel to engine operating conditions. Additionally, these results show the predominant factor influencing particle formation is charge mixture formation, which fuel properties influence, but not as significantly as engine conditions. Here, the GPF reduced the tailpipe particle number concentrations by 60 - 95% and showed evidence of passive regeneration under higher load lean engine conditions (Temp>400°C, Lambda>1.3). Total PN filtration efficiencies ranged from ~60 % with a clean filter to greater than 95% with as little as 25 mg/L of soot loaded on the filter with a most penetrating particle size (MPPS) between 100 and 150 nm. The GPF results show that GPF regeneration can be achieved with the added fuel efficiency benefit of lean operation.

• Research Organization: Univ. of Minnesota, Minneapolis, MN (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Transportation Office. Vehicle Technologies Office
• Grant/Contract Number: EE0007217
• OSTI ID: 1807776
• Journal Information: SAE Technical Paper Series, Journal Name: SAE Technical Paper Series Vol. 2019; ISSN 0148-7191
• Publisher: SAE International
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
Emissions
Energy conservation
Fuel economy
Gasoline
Particulate filters
Particulate matter (PM)
Pressure