Abstract

This project aims at the experimental investigation of the effects of hot and cold Exhaust gas recirculation (EGR) methods on emissions and efficiency of the engine. This experiment is conducted in single cylinder, 4-stroke, direct injection diesel engine. A heat exchanger arrangement is provided for obtaining different EGR methods. The performance parameters were studied with and without exhaust gas recirculation of different methods with 10%, 15% and 20% of EGR. The recycled exhaust gas lowers the oxygen concentration in the combustion chamber and increases the temperature of intake charge which lowers the flame temperature and leads to lower NOx formation. Experimental results shows that the cold EGR is much effective than the hot and intermediate EGR for the reduction of NOx emission. The increase in temperature of EGR gases causes the combustion temperature which leads to increase in formation of NOx. By increasing the cooled EGR rates reduces the emissions more significantly.