Abstract
Exhaust Gas Recirculation (EGR) system has become a popular way for reducing NOX level in internal combustion engine. Both reducing NOX and improving fuel consumption simultaneously are important in meeting government regulations and social needs. In order to reduce NOX emission further, cooled EGR system is one of the most effective techniques in diesel engine. In the present study, experiments with engine dynamometer have been carried on the characteristics which improve the heat exchange effectiveness of EGR cooler with the surface area change. The results show that the heat exchange effectiveness of four-step EGR cooler is the worst among 3 type of EGR cooler due to the smallest surface area. In case of six-step EGR cooler, the heat exchange effectiveness is over 100% due to latent heat off, however, condensed water of exhaust gas increases the fouling and decreases the heat exchange effectiveness. The authors conclude that the five-step EGR cooler has the optimum surface area because it has higher heat exchange effectiveness than that of four-step EGR cooler and less fouling of Particulate Matter (PM) than that of six-step EGR cooler, respectively.
Keywords: Diesel Engine, EGR Cooler, Heat Exchange Effectiveness, NOX, Particulate Matter (PM), fouling