Combustion Features and Emissions of a DI-Diesel Engine with Air Path Optimization and Common Rail Fuel Injection 981931
Emission and performance parameters of a medium size, and medium speed D.I. diesel engine equipped with a Miller System, a new developed High Pressure Exhaust Gas Recirculation System (HPEGR), a Common Rail (CR) system and a Turbocharger with Variable Turbine Geometry (VTG) have been measured and compared to the standard engine. While power output, fuel consumption, soot and other emissions are kept constant, nitric oxide emissions could be reduced by 30 to 50% depending on load and for the optimal combination of methods.
Heat release rate analysis provides the reasons for the optimised engine behaviour in terms of soot andNOx emissions: The variable Nozzle Turbocharger helps deliver more oxygen to the combustion process (less soot) and lower the peak gas temperature (less NOx). The flexible common rail system delivers higher injection pressures and thus more intense fuel-air mixing (less soot), while allowing later combustion phasing for the same bsfc and thus lower peak temperatures (less NOx).
Therefore the combination of flexible air and fuel paths yields a synergistic optimisation of engine operation in global terms.
Citation: Boulouchos, K. and Stebler, H., "Combustion Features and Emissions of a DI-Diesel Engine with Air Path Optimization and Common Rail Fuel Injection," SAE Technical Paper 981931, 1998, https://doi.org/10.4271/981931. Download Citation