• SAE-2005-01-0126

NOx and N2O formation in HCCI Engines

Authors: Per Amneus, Fabian Mauss*, Markus Kraft, Andreas Vressner, and Bengt Johansson

Reference: SAE Paper 2005-01-0126


Calculations using homogeneous and stochastic reactor models were performed in order to find an explanation to observed properties of NOx HCCI engines. It was found that for moderate NOx levels, N2O reactions play an important role in the NOx formation. Further, the high proportions of NO2 found in from some HCCI engines is due to high temperature inhomogeneities, poor mixing and slow overall combustion. N2O is often emitted from HCCI combustion. The levels of NOx in the exhausts are highly sensitive to temperature; however N2O has a weak negative dependence on temperature. While fuel rich operation naturally leads to high temperatures and thus high NOx levels; once the temperature effects are decoupled the fuel rich conditions themselves has a favorable effect on low-NOx engine operation.

Access options

Associated Themes:
  Theme icon Theme icon Theme icon

*Corresponding author:
Address: Universität Cottbus Lehrstuhl für Thermodynamik / Thermische Verfahrenstechnik
Website: Personal Homepage