Influence of EGR on Combustion and Exhaust Emissions of Heavy Duty DI-Diesel Engines Equipped with Common-Rail Injection Systems
At the Internal Combustion Engines and Combustion Laboratory of the Swiss Federal Institute of Technology in Zurich we are currently developing low emission strategies for heavy duty diesel engines that engine manufacturers can implement to meet stringent emissions regulations. The technologies being studied include high-pressure fuel injection (with common-rail injection system), multiple injection strategies (with pilot or post injections), turbo charging, exhaust gas recirculation (cooled EGR), oxygenated fuels and the optimization of the air management system. This paper focuses on the effects of exhaust gas recirculation (cooled EGR) in combination with very high injection pressure. Measurements were carried out on a heavy-duty diesel single-cylinder research engine equipped with a modern common rail fuel injection. The engine investigations were conducted in different operating points in the engine map covering wide speed and load ranges.