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Modifying Diesel Engine Operating Parameters to Reduce Emissions.

Marshall WF; Hurn RW
NTIS: PB 204 154 :14 pages
The effect of engine parameters on exhaust emissions from two diesel engines was studied experimentally. Fuel-injection characteristics and intake air conditions were considered as parameters influencing the emissions. Emphasis was placed on the effect of parameter variations on nitrogen oxide (nox) emissions, because diesels generally emit very low levels of carbon monoxide (co) and unburned hydrocarbons. Emissions other than nox were at lowest levels when the engines were adjusted for best performance. Nox emissions can be diminished somewhat through variation in fuel-injection characteristics, but there generally are penalties in emissions of CO, smoke, and unburned hydrocarbons or in engine performance. Temperature and composition of intake air have a significant effect on nox emissions. Levels of nox are reduced by recirculating the exhaust gas or by adding water to the intake air stream. However, the rate of water added or exhaust gas recirculated must be limited to prevent the degradation of engine performance and increased emissions of CO and smoke. At high exhaust recirculation rates, levels of CO and smoke were increased such that it was necessary to derate the engine and also to use a catalytic system for oxidation of carbon monoxide
Publication Date
Document Type
IH; Report of Investigation;
Fiscal Year
NTIS Accession No.
NTIS Price
Identifying No.
RI 7579
Source Name
NTIS: PB 204 154
Page last reviewed: December 10, 2021
Content source: National Institute for Occupational Safety and Health Education and Information Division