Looking at new concepts for ultra-low emission Diesel combustion system

The possibility to obtain, in the medium period, internal combustion engines with emissions close to the equivalent electrical zero emission vehicles (EZEV) has pushed numerous Centres of Research to investigate on innovative concepts of combustion. The Istituto Motori has patented, in the course of the year 2001, an innovative concept of combustion for the Diesel engines able to approach at low load conditions the EZEV limits. The combustion concept that as been patented belongs to the so-called “mixed” category that is it refers to a process in which the goal of low flame temperatures (necessary for the control of nitrogen oxides) is obtained acting both on the dilution of mixture and on its homogenisations.In the present paper the main characteristics of the new diesel combustion process are described and the principal constraints relative to technological feasibility of this concept are outlined.