Abstract
Keywords Fuel-Injection, Injection-Nozzle, Diesel-Engine, Emission, Fuel-Consumption
Abstract In the development of future medium duty and heavy duty diesel engines a major issue is the reduction of the emission of nitrogen oxides and Particulate Matter. The further decrease of the emission limits (e.g. EPA2007 and EPA2010, Euro 5, Japan 05) require new, advanced approaches. An emphasis in the development of new diesel engines is therefore the design of engine concepts in order to obtain these exhaust limit values while maintaining a good engine efficiency. Examples are concepts with cooled EGR, particulate filter, Denox catalysts, Nox adsorber catalysts as well as combinations of these subsystems.
The injection system of direct injecting diesel engines has an important role regarding the fulfillment of demands after low pollutant emissions and high engine efficiency. Dependent on the engine concept the injection system must be able to provide different injection pressure and mixture formation processes, so that the potential of the respective engine concept can be used completely.
The paper points out the requirements regarding functionality of the fuel injection system in dependency on the different engine concepts and shows which concepts concerning fuel injection systems were developed so far in order to fulfill these requirements. These injection concepts or systems are described briefly and evaluated regarding the fulfilment of the future requirements. It is also shown, which effects of details of the injection nozzle design on mixture formation are to be considered.