Summary: The objective of the project is to promote CO2 reduction via improved powertrain efficiency, with the goal to overcome known limitations while maintaining the potential for implementation under high volume production by the end of this decade. The technical objectives are to demonstrate 15% improvement in fuel economy. Chalmers is involved in a sub-project concerning high efficiency Diesel engines for long haul trucks. Our task is to explore the potential of new combustion concepts (e.g. Partially Pre-mixed Combustion/Low Temperature Combustion). The primary goal of the task is to study the effects of various injection, EGR, and charging strategies using unconventional valve timings in order to assess how a “high efficiency combustion concept” can be realized and controlled. Particular attention will be given to EGR strategies. The robustness of the various solutions will be considered. For the experiments a heavy duty single cylinder engine equipped with a fully flexible valve system will be used. For simulations, GT-Power and KIVA 4/OpenFoam will be used.
The figure below shows rate of heat release obtained by GT-Power and KIVA 4 simulations for two different intake valve timings. One can see that ignition delay times were increased when later IVC timing was used, and a larger part of the charge was burned in a premixed mode. Temperature reduction before ignition helps in reducing NOx emissions especially for 25% EGR cases, while soot emissions decrease due to more premixed combustion with a later IVC timing.
The project includes 16 partners.
Calculated rate of heat release curves with 25% EGR for IVC 0 aBDC (baseline) and late IVC 100 aBDC cases at 50 % load and 1200 rpm (A50).