Abstract
Abstract
According to the future Euro VI standards, the NOx emissions for heavy duty engine have to be drastically reduced while maintaining very low particulate emissions. Two stage turbocharger, high EGR rate, high injection pressure should lead to an important reduction of nitrogen oxides keeping low the particulate emissions without any penalty in CO2 emissions comparable to current motorisations. The "non conventional" combustion process as HCCI, HPC, LTC offer also an attractive potential.
In response to challenge that the Diesel engine faces, IFP has developed a combustion system which is able to achieve near zero particulates and NOx emissions while maintaining the performance of D.I Diesel engine. This “dual mode” approach named NADITM (Narrow Angle Direct Injection) consists of applying Homogeneous Charge Compression Ignition at part load condition and switches to conventional Diesel combustion to reach high and full load requirements.
This paper presents the latest developments of the NADITM concept on a 1.3 L single cylinder heavy duty engine, and the associated improvements regarding HPC (Highly Premixed Combustion) operating range, CO and HC emissions, fuel consumption and combustion noise. At full load, the NADITM system is consistent with present Diesel performances with a slight increase in fuel consumption and smoke level.
The challenge is now to extend "zero-NOx" range while minimizing the need in term of intake pressure and EGR rate to be able to present this concept as an alternative approach to conventional combustion focusing Euro VI.