Exhaust gas treatment device, method for processing exhaust gas, and motor vehicle

Patent metadata

Field	Value
Publication number	US-9562454-B2
Application number	US-201214240772-A
Country	US
Kind code	B2
Filing date	Aug 8, 2012
Priority date	Aug 25, 2011
Publication date	Feb 7, 2017
Grant date	Feb 7, 2017

Abstract

The invention relates to an exhaust-gas treatment device for processing exhaust gas from a combustion aggregate, especially a diesel engine. Moreover, the present invention relates to a method for processing exhaust gas from a combustion aggregate by means of selective catalytic reaction, and it also relates to a motor vehicle in which the method according to the invention is implemented or which has the exhaust-gas treatment device according to the invention. It is provided that the exhaust-gas treatment device comprises an exhaust-gas system and, arranged in it, an oxidation catalyst, a reduction catalyst for selective catalytic reduction, and a particle filter, whereby the oxidation catalyst is arranged upstream from the reduction catalyst and the reduction catalyst is arranged upstream from the particle filter. The reduction catalyst ( 50 ) is arranged in the exhaust-gas system ( 20 ) so far upstream in the direction of flow ( 23 ) of the exhaust gas that the heat of the exhaust gas passing the reduction catalyst ( 50 ) is sufficient to bring the reduction catalyst ( 50 ) to the operating temperature.

First claim

The invention claimed is:

1. An exhaust-gas treatment device for processing exhaust gas from a combustion aggregate, the exhaust-gas treatment device comprising:
an exhaust-gas system having arranged therein an oxidation catalyst, a reduction catalyst configured for selective catalytic reduction and having a metering module configured for metered introduction of a reducing agent, and a particle filter, the metering module having a cooling unit through which a cooling medium flows,
wherein the oxidation catalyst is arranged upstream from the reduction catalyst and the reduction catalyst is arranged upstream from the particle filter,
wherein the reduction catalyst is arranged in the exhaust-gas system upstream in a direction of flow of the exhaust gas such that heat of the exhaust gas passing the reduction catalyst is sufficient to bring the reduction catalyst to an operating temperature,
wherein the exhaust-gas treatment device further comprises a low-pressure exhaust-gas return means having a cooling element flow-connected to the cooling unit of the metering module of the reduction catalyst such that the cooling medium from the cooling element of the low-pressure exhaust-gas return means cools the metering module.

2. The exhaust-gas treatment device for processing exhaust gas according to claim 1 , wherein the exhaust gas passing the reduction catalyst still retains at least 40% of a temperature that the exhaust gas has immediately after combustion in the combustion aggregate.

3. The exhaust-gas treatment device for processing exhaust gas according to claim 1 , wherein the exhaust gas passing the reduction catalyst still retains at least 80% of a temperature that the exhaust gas has immediately after the combustion in combustion aggregate.

4. The exhaust-gas treatment device for processing exhaust gas according to claim 1 , wherein the reduction catalyst is arranged on a connecting module that connects the oxidation catalyst to the particle filter.

5. The exhaust-gas treatment device for processing exhaust gas according to claim 4 , wherein the connecting module has a housing through which the exhaust gas can flow and which serves as a housing for the reduction catalyst.

6. The exhaust-gas treatment device for processing exhaust gas according to claim 1 , wherein the reduction catalyst is arranged on the particle filter.

7. A method for processing exhaust gas from a combustion aggregate by means of selective catalytic reduction via a metering module configured for metered introduction of a reducing agent, comprising:
providing, in an exhaust-gas system, an oxidation catalyst upstream from a reduction catalyst configured for selective catalytic reduction, wherein the reduction catalyst is located upstream from a particle filter,
using heat of the exhaust gas passing the reduction catalyst to heat the reduction catalyst to an operating temperature
cooling the metering module via a cooling element of a low-pressure exhaust-gas return means, the cooling element of the low-pressure exhaust-gas return means being flow-connected to a cooling unit of the metered module of the reduction catalyst such that the cooling medium from the cooling element of the low-pressure exhaust-gas return means cools the metering module.

8. The method for processing exhaust gas according to claim 7 , wherein only heat of the exhaust gas passing the reduction catalyst is used to bring the reduction catalyst to the operating temperature.

9. The method for processing exhaust gas according to claim 7 , wherein the reducing agent is injected directly into the particle filter or into a module which flow-connects the oxidation catalyst to the particle filter.

10. A motor vehicle system comprising an exhaust-gas treatment device for processing exhaust gas from a combustion aggregate, the exhaust-gas treatment device comprising:
an exhaust-gas system having arranged therein an oxidation catalyst, a reduction catalyst configured for selective catalytic reduction and having a metering module configured for metered introduction of a reducing agent, and a particle filter, the metering module having a cooling unit through which a cooling medium flows,
wherein the oxidation catalyst is arranged upstream from the reduction catalyst and the reduction catalyst is arranged upstream from the particle filter,
wherein the reduction catalyst is arranged in the exhaust-gas system upstream in a direction of flow of the exhaust gas such that heat of the exhaust gas passing the reduction catalyst is sufficient to bring the reduction catalyst to an operating temperature,
wherein the exhaust-gas treatment device further comprises a low-pressure exhaust-gas return means having a cooling element flow-connected to the cooling unit of the metering module of the reduction catalyst such that the cooling medium from the cooling element of the low-pressure exhaust-gas return means cools the metering module.

11. The motor vehicle system according to claim 10 , wherein the reduction catalyst is arranged above an underbody of a motor vehicle.

Assignees

• Sprute Jörg
• Volkswagen Ag

Inventors

• Sprute Jörg

Classifications

• F01N3/035

  with catalytic reactors · CPC title

• F02M26/30

  Connections of coolers to other devices, e.g. to valves, heaters, compressors or filters; Coolers characterised by their location on the engine · CPC title

• F02M26/15

  in relation to engine exhaust purifying apparatus · CPC title

• F01N13/0097

  the purifying devices are arranged in a single housing · CPC title

• F01N3/10 Primary

  by thermal or catalytic conversion of noxious components of exhaust · CPC title