Daimler Chrysler Ag

Daimler Ag

Daimler-benz Ag

Stefan Kurze

Thomas Liebscher

Norbert Ruzicka

Friedrich Wirbeleit

Bernd Krutzsch

Markus Paule

Walter Boegner

Arno Nolte

Christian Goerigk

Hans-Hubert Hemberger

Joachim Schommers

Anton Kerckhoff

Klaus Allmendinger

Holger Adler

Michael Lenz

Ulrich Merten

Dirk Becker

Oliver Erlenmayer

Andreas Hasert

Frank Duvinags

Andreas Roll

In a method for operating an exhaust-gas cleaning unit of a diesel engine including a particle filter and a nitrogen oxide storage device arranged upstream of the particle filter, wherein sulfur regeneration of the nitrogen oxide storage device is performed periodically at raised exhaust gas temperatures and, in certain phases, with a rich exhaust gas composition, and also soot regeneration of the particle filter is performed at raised exhaust gas temperatures with a lean exhaust gas composition, at least some of the sulfur regeneration and the soot regeneration phases are performed in a combined soot and sulfur regeneration phase, and for the sulfur regeneration, at least temporarily, a rich exhaust-gas composition with a temperature higher than the temperature of the lean exhaust gas composition is provided for the soot regeneration of the particle filter.

Method of operating an exhaust gas cleaning unit with particle filter and nitrogen oxygen store

The invention relates to a method for operating a diesel engine in which an air ratio (&#x3bb;) of the fuel which is to be burnt and of the combustion air supplied is set by a control unit () according to predetermined values. When a value () which is predetermined as a switching criterion is recorded, the control unit () switches to a special operating mode for regeneration of a catalytic converter () and sets the fuel/air ratio according to predetermined values for this operating mode. To achieve more effective regeneration of the catalytic converter, according to the invention it is provided that at least one afterinjection, which is separated in time from a main injection, of fuel which is also to be burnt takes place in the special operating mode.

Method for operating a diesel engine

A process and apparatus for reducing the nitrogen oxide content in oxygen-containing emissions is provided, particularly for internal-combustion engines, particularly of diesel engines and directly injecting Otto engines for motor vehicles. The nitrogen oxides contained in the exhaust gas are reduced by a suitable reducing agent, such as hydrogen or hydrocarbons, on a DENOX catalyst. For achieving an improved conversion rate for the nitrogen oxides, a combination of hydrogen and hydrocarbons are used as reducing agents. In different operating ranges of the internal-combustion engine only hydrogen, only hydrocarbons, or hydrogen and hydrocarbons are added. Preferably, for this purpose, the quantity of supplied hydrogen or hydrocarbons is reduced or increased with an increasing engine load and/or catalyst temperature and/or rotational engine speed.

Process and apparatus for reducing nitrogen oxides in engine emissions

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Markgröningen, Germany

Stefan Kurze