Effect of EGR on Performance and Emission Characteristics of Natural Gas Fueled Diesel Engine

In diesel engines, it is difficult to reduce both smoke and NOx simultaneously. An experimental study was conducted to determine the performance and exhaust emission characteristics of a commercial single cylinder, natural aspirated, air cooled DI diesel engine. The system was modified to work on either dual fuel or diesel alone. The objective of this work is to investigate the possibility of decreasing the exhaust emissions and to determine the performance parameters. At part loads, the dual fuelled operation suffers from higher CO and unburnt hydrocarbon emissions. This is mainly due to overall lean mixture and incomplete combustion because of small quantity of pilot fuel. To resolve these problems, the effects of cooled EGR were investigated. The experimental results show that the application of EGR reduces substantially NOx, CO and smoke. Results indicate that performance parameters are comparable with baseline diesel operation.