ABSTRACT
This paper deals with the use of an Exhaust Gas Re-circulation (EGR) system on a given Spark Ignition engine for studying the performance and emission characteristics. For various openings of EGR-Valve, experiments are carried out on a set of loads varying from 0 to 15 percent of engine loads at a cruising speed of 3500rpm. The results when compared with those obtained from the same engine without EGR system, show nearly a 10 percent fuel savings when 4.8 percent of exhaust gas was recirculated. Also, fall in engine friction by 8% leads to a marginal 2% improvement in engine power. The exhaust gas emission contents like carbon monoxide and unburned hydrocarbons are reduced from 5.3 percent and 1530 parts per million to 3.21 percent and 640parts per million respectively for the above position of the EGR valve. An energy conservation study using neat ethanol as a fuel to replace gasoline shows a remarkable reduction of engine emission by three and half times with respect to the above emission values. In other words, EGR system for gasoline operation and neat ethanol (without EGR) as an eco-friendly substitute to gasoline fuel curtail engine emissions by 40 to 50 per cent.
