Effect of Ethanol-Gasoline Blends on Combustion and Emissions of a Passenger Car Engine at Part Load Operations

摘要

Alcohols are preferred choice of alternative fuel for gasoline engines to tackle the problems associated with nation’s energy security and environmental pollution. Ethanol can be used as a sole fuel or gasoline blending component for use in spark ignition engines. BIS Specification 2796: 2013 permitted to blend 10% ethanol in gasoline and the concentration may be further increased in coming years in India. Research on combustion of ethanol blended gasoline on modern gasoline engine is highly desirable. This paper highlights the experimental investigation carried out on the latest generation multipoint fuel injection system passenger car engine fueled with ethanol-gasoline blends in a climatic controlled test cell to study the in-cylinder combustion, performance and emission characteristics. Part load tests at regular speed intervals were conducted using ethanol blends. Combustion duration decreased with increase in engine load and speed for the all test fuels. Longer burn duration was observed with ethanol blends compared to neat gasoline at various load and speed conditions. Negligible changes peak pressure and cumulative heat release were observed among the fuel blends. Lower specific energy consumption for ethanol blends compared to neat gasoline at lower load and/or speed conditions whereas this effect is negligible at higher load/speed conditions. In general, gaseous emission reduced with increase in ethanol percentage in the blends. E20 blends reduced the CO emissions upto 15%; HC emissions upto 20% and NOx emissions upto 45% at various load and speed conditions. Better reduction in HC emission was achieved at higher speed conditions for the all load conditions. Ethanol as blending component for gasoline improved the combustion and thereby enhanced the engine performance and reduced the exhaust emissions.