title: Study of Miller timing on exhaust emissions of a hydrotreated vegetable oil (HVO)-fueled diesel engine.
abstract: The effect of intake valve closure (IVC) timing by utilizing Miller cycle and start of injection (SOI) on particulate matter (PM), particle number and nitrogen oxide (NOx) emissions was studied with a hydrotreated vegetable oil (HVO)-fueled nonroad diesel engine. HVO-fueled engine emissions, including aldehyde and polyaromatic hydrocarbon (PAH) emissions, were also compared with those emitted with fossil EN590 diesel fuel. At the engine standard settings, particle number and NOx emissions decreased at all the studied load points (50%, 75%, and 100%) when the fuel was changed from EN590 to HVO. Adjusting IVC timing enabled a substantial decrease in NOx emission and combined with SOI timing adjustment somewhat smaller decrease in both NOx and particle emissions at IVC -50 and -70 degrees CA points. The HVO fuel decreased PAH emissions mainly due to the absence of aromatics. Aldehyde emissions were lower with the HVO fuel with medium (50%) load. At higher loads (75% and 100%), aldehyde emissions were slightly higher with the HVO fuel. However, the aldehyde emission levels were quite low, so no clear conclusions on the effect of fuel can be made. Overall, the study indicates that paraffinic HVO fuels are suitable for emission reduction with valve and injection timing adjustment and thus provide possibilities for engine manufacturers to meet the strictening emission limits.
authors.affiliation: Aerosol Physics Laboratory, Department of Physics, Tampere University of Technology, Tampere, Finland. juha.heikkila@tut.fi
authors.forename: Juha
authors.initials: J
authors.lastname: Heikkilä
authors.forename: Matti
authors.initials: M
authors.lastname: Happonen
authors.forename: Timo
authors.initials: T
authors.lastname: Murtonen
authors.forename: Kalle
authors.initials: K
authors.lastname: Lehto
authors.forename: Teemu
authors.initials: T
authors.lastname: Sarjovaara
authors.forename: Martti
authors.initials: M
authors.lastname: Larmi
authors.forename: Jorma
authors.initials: J
authors.lastname: Keskinen
authors.forename: Annele
authors.initials: A
authors.lastname: Virtanen
mesh_terms: D000393:Air Pollutants; D056804:Biofuels / Q000032:analysis; D004736:Energy-Generating Resources; D005742:Gasoline; D009589:Nitrogen Oxides; D052638:Particulate Matter; D010938:Plant Oils / Q000737:chemistry*; D001335:Vehicle Emissions / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D056804:Biofuels; D005742:Gasoline; D009589:Nitrogen Oxides; D052638:Particulate Matter; D010938:Plant Oils; D001335:Vehicle Emissions