Method for operating an exhaust gas cleaning system arranged in the exhaust line of an internal combustion engine, and exhaust gas cleaning system

Patent metadata

Field	Value
Publication number	US-11814997-B2
Application number	US-202217661129-A
Country	US
Kind code	B2
Filing date	Apr 28, 2022
Priority date	Oct 30, 2019
Publication date	Nov 14, 2023
Grant date	Nov 14, 2023

Abstract

A method for operating an exhaust-gas purification system which is arranged in the exhaust system of an internal combustion engine, and an exhaust-gas purification system, are described. In the method, a combination of electrical catalytic converter heating measures with internal combustion engine catalytic converter heating measures is implemented, whereby particularly fast and inexpensive heating of a catalytic converter is achieved. The corresponding exhaust system preferably has, in an exhaust-gas flow direction, firstly a support catalytic converter and then a heated catalytic converter.

First claim

What is claimed is:

1. A method for operating an exhaust-gas purification system arranged in an exhaust system of an internal combustion engine, the method comprising:
providing a support catalytic converter;
providing a catalytic converter;
providing a heated catalytic converter positioned between the support catalytic converter and the catalytic converter, the heated catalytic converter configured to preheat the catalytic converter causing the catalytic converter to reach its light-off temperature before a starting of the internal combustion engine;
electrically heating the heated catalytic converter before the starting of the internal combustion engine;
operating the internal combustion engine, before the starting thereof, as an air pump by:
increasing circulation between an outlet valve and an inlet valve, and
drawing air back into a combustion chamber and/or air is discharged into an intake tract,
wherein the increase in circulation and the drawing air cause the catalytic converter to reach the light-off temperature; and

thereafter starting the internal combustion engine,
wherein during the air pump operating mode, the internal combustion engine is controlled such that there is an increased valve overlap between outlet valves and inlet valves.

2. The method of claim 1 , further comprising:
reducing an intake pipe pressure during the air pump operating mode and of the internal combustion engine.

3. The method of claim 1 , further comprising:
reducing a rotational speed of the internal combustion engine during the air pump operating mode.

4. The method of claim 1 , further comprising:
closing a throttle flap of the internal combustion engine further during the air pump operating mode.

5. The method of claim 1 , wherein the heated catalytic converter preheats a three-way catalytic converter.

6. An exhaust-gas purification system arranged in an exhaust system of an internal combustion engine, the exhaust-gas purification system comprising, in an exhaust-gas flow direction:
a support catalytic converter;
a catalytic converter; and
a heated catalytic converter positioned between the support catalytic converter and the catalytic converter, the heated catalytic converter configured to preheat the catalytic converter causing the catalytic converter to reach its light-off temperature before a starting of the internal combustion engine, the exhaust-gas purification system configured to execute a method comprising:
electrically heating the heated catalytic converter before the starting of the internal combustion engine;
operating the internal combustion engine, before the starting thereof, as an air pump;
thereafter starting the internal combustion engine; and
bringing the catalytic converter above the light-off temperature of the catalytic converter before the starting of the internal combustion engine by way of the internal combustion engine being controlled, during its air pump operating mode, such that air is drawn back into a combustion chamber and/or air is discharged into an intake tract,

wherein the internal combustion engine is controlled, during the air pump operating mode, such that there is an increased valve overlap between outlet valves and inlet valves.

7. The exhaust-gas purification system of claim 6 , wherein the method further comprises:
reducing an intake pipe pressure during the air pump operating mode and of the internal combustion engine.

8. The exhaust-gas purification system of claim 6 , wherein the method further comprises:
reducing a rotational speed of the internal combustion engine during the air pump operating mode.

9. The exhaust-gas purification system of claim 6 , wherein the method further comprises:
closing a throttle flap of the internal combustion engine further during the air pump operating mode.

10. The exhaust-gas purification system of claim 6 , wherein the heated catalytic converter preheats a three-way catalytic converter.

Assignees

• Vitesco Tech Gmbh

Inventors

• Achleitner Erwin
• Arlt Tino
• Kleiner Florian
• Haft Gerhard

Classifications

• F01N3/2013 Primary

  using electric or magnetic heating means · CPC title

• F01N3/101

  Three-way catalysts · CPC title

• F01N3/2093 Primary

  Periodically blowing a gas through the converter, e.g. in a direction opposite to exhaust gas flow or by reversing exhaust gas flow direction · CPC title

• F01N2240/16

  an electric heater, i.e. a resistance heater · CPC title

• F01N2430/10

  by modifying inlet or exhaust valve timing · CPC title