Development Of Small High Speed Diesel Engines With Direct injection For Low Emissions 885152
The small, high speed turbocharged IVECO 8140.21 diesel engine with direct injection has been produced in large numbers since 1985. DI engines as used in small transporters performed very well and a reduction in fuel consumption between 15-20 % relative to the IDI engines have been realised and the fuel saving compared to gasoline engines are in the region of 30 to 40 %.
In the meantime, European countries have announced emission standards for such vehicles. For example, Switzerland has issued severe emission standards for light duty vehicles with a gross vehicle weigth below 3500 kg that are to be enforced by October 1990, which cannot be achieved without the availability of a fully developed particulates filter technology.
In this paper, the state of development of a small high speed diesel engine with regard to emissions is presented. Achievements with improved combustion systems and techniques to assist the optimisation of the combustion process are described. Improvements so far achieved, resulted in an increased rated power of 15 % relative to the present production engine while the NOx -emissions could be reduced substantially.
Results achieved with electronic control of the fuel injection system are promising but not sufficient in order to accomplish very low particulates levels. Reference is also made to measures for the reduction of combustion noise.