Method for exhaust gas aftertreatment, and exhaust gas aftertreatment system
AssigneeVitesco Technologies GmbH
InventorGerhard Haft
Life of this patent
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Abstract
A method for exhaust gas aftertreatment in a gasoline engine and an exhaust gas aftertreatment system are provided. In the method, two catalytic converters arranged in the exhaust gas tract of the gasoline engine are operated in different states. A first three-way catalytic converter is operated in a slightly low-oxygen range, and a second three-way catalytic converter is operated in a slightly oxygen-rich range. Secondary air is furthermore blown into the exhaust gas tract between the two three-way catalytic converters. It is thereby possible to reduce the output of emissions of the gasoline engine to a great extent. An exhaust gas aftertreatment system is likewise explained.
Claims11
A method for exhaust gas aftertreatment in a gasoline engine, the method including:
- operating a first three-way catalytic converter arranged in an exhaust gas tract of the gasoline engine in a slightly low-oxygen range;
- operating an NOx sensor arranged in the first three-way catalytic converter;
- operating a second three-way catalytic converter arranged downstream thereof in the exhaust gas tract of the gasoline engine in a slightly oxygen-rich range;
- and
- blowing secondary air into the exhaust gas tract between the first and second three-way catalytic converters;
- wherein the NOx sensor is used as an NH3 sensor in order to implement control of the first three-way catalytic converter in the slightly low-oxygen range (slightly rich range).
An exhaust gas aftertreatment system for a gasoline engine, the exhaust gas aftertreatment system comprising:
- an exhaust gas tract;
- a first three-way catalytic converter arranged in the exhaust gas tract;
- an NOx sensor arranged in the first three-way catalytic converter;
- a second three-way catalytic converter arranged downstream thereof in the exhaust gas tract;
- and
- a device for blowing secondary air into the exhaust gas tract between the first and second three-way catalytic converters;
- wherein the NOx sensor is used as an NH3 sensor in order to implement control of the first three-way catalytic converter in the slightly low-oxygen range (slightly rich range).
Dependencies are inferred from the claim text.