Effect of compression ratio on exhaust emissions and performance of a methanol-fueled single-cylinder engine

Conference · Tue Jan 01 04:00:00 EST 1980 · SAE Prog. Technol.; (United States)

OSTI ID:6872897

Brinkman, N D

One of the reasons methanol is considered an attractive alternative fuel for automobiles is its high octane quality, which may allow the use of high compression ratio (CR) engines. To evaluate compromises between engine efficiency and exhaust emissions, a methanol-fueled single-cylinder engine was run at CR's from 8 to 18. At each CR, engine speed and airflow were constant at 1200 rpm and about half throttle, respectively; equivalence ratio (phi) was varied from 0.7 to 1.1; and spark timing was varied from best power (MBT) to 10/sup 0/ retarded. Knock was observed only at CR = 18 with MBT spark timing. Increasing CR from 8 to 18 while maintaining MBT spark timing increased efficiency about 16%, but also increased NO/sub x/ and unburned fuel (UBF) emissions. Some previous studies have reported decreased NO/sub x/ emissions with increased CR, possibly because MBT spark timing was not maintained. Results of this study indicate that constant NO/sub x/ emissions can be maintained by retarding spark timing while increasing CR to improve efficiency. Retarding spark timing, however, only marginally reduced UBF emissions. Vehicle tests are necessary to define the optimum CR for methanol fueling because exhaust emission trends and knocking tendency may be different than those observed with this single-cylinder engine.

• OSTI ID: 6872897
• Conference Information: Journal Name: SAE Prog. Technol.; (United States) Journal Volume: 19
• Country of Publication: United States
• Language: English

Related Subjects

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10 SYNTHETIC FUELS
33 ADVANCED PROPULSION SYSTEMS
330701 -- Emission Control-- Nitrogen Oxides
330800* -- Emission Control-- Alternative Fuels
AIR POLLUTION ABATEMENT
ALCOHOL FUELS
CHALCOGENIDES
CHEMICAL REACTIONS
COMBUSTION
DATA
ENGINES
EXHAUST GASES
EXPERIMENTAL DATA
FLUIDS
FUELS
GASEOUS WASTES
GASES
HEAT ENGINES
INFORMATION
INTERNAL COMBUSTION ENGINES
METHANOL FUELS
NITROGEN COMPOUNDS
NITROGEN OXIDES
NUMERICAL DATA
OPERATION
OXIDATION
OXIDES
OXYGEN COMPOUNDS
PERFORMANCE
PERFORMANCE TESTING
POLLUTION ABATEMENT
SPARK IGNITION ENGINES
SYNTHETIC FUELS
TESTING
THERMOCHEMICAL PROCESSES
WASTES