Robert Boschgmbh

Stefan Scherer

Frank Schweizer

Tobias Pfister

Andreas Pfaeffle

Wolfgang Klenk

Holger Ziegler

Simone Neuberth

Markus Gloeckle

Matthias Loehr

Herbert Schoemig

Stefan Forthmann

Rolf-Dieter Koch

Gerd Hartmann

Andreas Schaffrath

Albrecht Schwaderer

Wolfram Faas

Christian Covini

A method for monitoring a nitrogen oxide storage catalytic converter (NSC) in the exhaust gas duct of an internal combustion engine which is operated at least temporarily in a lean fashion, wherein during a lean mode of the internal combustion engine nitrogen oxides from the exhaust gas are stored by the nitrogen oxide storage catalytic converter, wherein during a regeneration phase of the nitrogen oxide storage catalytic converter the internal combustion engine is operated in a rich fashion, and as a result the nitrogen oxides stored in the nitrogen oxide storage catalytic converter are removed, and wherein an exhaust gas component or exhaust gas characteristic variable which is characteristic of the profile of the regeneration is detected during the regeneration phase by means of an exhaust gas probe.

Method and device for monitoring a nitrogen oxide storage catalytic converter

A method is presented for controlling an internal combustion engine (), which includes an exhaust gas system () having an exhaust gas aftertreatment component () that temporarily stores exhaust gas constituents and can be regenerated, wherein an expected value for a temperature of the exhaust gas aftertreatment component () is formed as a function of an increase in temperature, which arises as a result of exothermal reactions during the duration of an operating mode (BA) of the internal combustion engine () which is set for the regeneration of said exhaust gas aftertreatment component (), wherein the expected value is compared with an upper threshold value (T_max) and the control of said internal combustion engine () is changed when the threshold value (T_max) is exceeded, such that an expected value formed while taking the changed control into account does not exceed said threshold value (T_max). The method is thereby characterized in that a direction of change of a current temperature of said exhaust gas aftertreatment component () is taken into account when forming the expected value.

Method for controlling an internal combustion engine in connection with an exothermal regeneration of an exhaust gas aftertreatment component

A method for operating an exhaust system of an internal combustion engine, wherein nitrogen oxide (NO) is reduced by use of a SCR catalytic converter and wherein the ageing state of the SCR catalytic converter is monitored, characterized in that during a temporally limited phase having a high proportion of nitrogen oxide (NO) in the exhaust gas, a conversion of said SCR catalytic converter is acquired and evaluated and the ageing state of said SCR catalytic converter is suggested therefrom.

Method for operating an exhaust system of an internal combustion engine

The invention concerns a procedure to determine the sulfur removal of a NOstorage catalytic converter in an exhaust gas aftertreatment system of an internal combustion engine, whereby conditions, in which a surplus of the reducing agent is generated in the internal combustion engine, are adjusted in the internal combustion engine for the sulfur removal, whereby a SOremoval amount is determined in a SOremoval calculation using a model from the reducing agent flow and from additional operating parameters of the internal combustion engine. In so doing, dynamic effects during the desulferization of the NOstorage catalytic converter can be better taken into account for the SOremoval calculation; and in so doing, the subsequent effect of the NOstorage catalytic converter on the reduction of the nitrogen oxides in the exhaust gas can be more accurately predicted, which makes the process management more streamlined and consequently more fuel efficient.

[object Object]

The invention relates to a method for regenerating an emission control system of an internal combustion engine, comprising a storage catalytic converter, a first exhaust gas probe being situated in an exhaust gas tract upstream of the storage catalytic converter and a second exhaust gas probe being situated in a second exhaust gas tract downstream of the storage catalytic converter. A first output signal of a first exhaust gas probe and a second output signal of a second exhaust gas probe are supplied to an engine management system and the storage catalytic converter is regenerated by being exposed to a reductant in a regeneration phase. If the quantity of reductant is controlled by the engine management system during the regeneration phase, whereby said system detects the quantity of reductant that is present downstream of the storage catalytic converter by means of the second output signal of the second exhaust gas probe situated downstream of said converter, the charging of reductant can be significantly reduced with respect to an optimised dosage. Excess consumption of fuel or reductant as a result of the regeneration of the storage catalytic converter is minimised. In addition, the method improves the emission values, thus significantly contributing to the maintenance of emission limits.

Method and device for regenerating an emission control system

The disclosure concerns a procedure for the regeneration of a particle filter and the desulfurization of a NOstorage catalytic converter in an exhaust gas aftertreatment system of an internal combustion engine. The disclosed procedure allows for the necessary heating energy and fuel consumption required to completely or partially regenerating the particle filter to be significantly reduced. Furthermore, an increase in efficiency of the NOstorage catalytic converter results, because the process reduces the average sulfur absorption on account of a greater frequency of desulfurization phases. In so doing, the NOemissions after the NOstorage catalytic converter can further be reduced.

A procedure is introduced to operate a diesel engine, which has a catalytic converter with three-way conversion characteristics. The procedure is characterized thereby, in that if the engine rotational speed increases without in the process exceeding an engine rotational speed threshold value and the engine's load is greater than a load threshold value, the diesel engine is operated in such a manner that the diesel engine alternately generates an oxidizing and a reductive exhaust gas atmosphere before the catalytic converter. Additionally a control unit is introduced, which controls the sequence of the procedure.

Procedure and control unit to operate a diesel engine

A method is described for operating an internal combustion engine, in particular of a motor vehicle. In the method, a lean air/fuel mixture is burned in a combustion chamber; nitrogen oxides contained in the exhaust gas are stored in an accumulator-type catalytic converter; a storage efficiency, with which the accumulator-type catalytic converter stores the nitrogen oxides contained in the exhaust gas, is ascertained; and the storage efficiency is ascertained as a function of an instantaneous space velocity of the exhaust gases in the accumulator-type catalytic converter. Two efficiencies are ascertained at least as a function of the temperature of the accumulator-type catalytic converter and a space velocity. One of the two efficiencies is ascertained for a great space velocity, and the other efficiency is ascertained for a small space velocity. The storage efficiency is ascertained as a function of the instantaneous space velocity from the two efficiencies.

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Stuttgart, Germany

Stefan Scherer