Method for operating an internal combustion engine with an emission control system

Patent metadata

Field	Value
Publication number	US-9322351-B2
Application number	US-201013148060-A
Country	US
Kind code	B2
Filing date	Jan 26, 2010
Priority date	Feb 6, 2009
Publication date	Apr 26, 2016
Grant date	Apr 26, 2016

Abstract

A method for operating an internal combustion engine comprising an emission control system that includes at least one catalytic and/or filter-effective emission control component. In conjunction with a cold start and/or a warm-up of the internal combustion engine, the internal combustion engine is operated using a cold start engine operation process having predefined values for predefined operating parameters of the internal combustion engine. An amount of hydrocarbons (HC) stored in one or more of the at least one emission control component is estimated, and the cold start engine operation process is activated when the estimation indicates that the amount of stored HC exceeds a predefined maximum amount of stored HC.

First claim

The invention claimed is:

1. A method for operating an internal combustion engine with an exhaust gas cleaning system that includes at least one catalytic or filter-effective exhaust gas cleaning component, where, in connection with a cold start or a warm-up of the internal combustion engine, the internal combustion engine is operated with a cold start engine operation method for heating up the exhaust gas cleaning component, the cold start engine operation method having predefined values for predefined internal combustion operation variables, comprising:
estimating an HC storage amount of hydrocarbons stored in one or more of the at least one exhaust gas cleaning component; and
activating the cold start engine operation method when the estimate indicates that the HC storage amount exceeds a predefined HC storage amount limit value, wherein the cold start engine operation method comprises
controlling operation of the internal combustion engine using predefined values for internal combustion engine operation variables to produce heated exhaust gas,
providing the heated exhaust gas to the at least one exhaust gas cleaning component, wherein the at least one exhaust gas cleaning component is heated by the heated exhaust gas, wherein predefined values for the internal combustion engine operation variables produce a heating gradient of the heating of the at least one exhaust gas cleaning component in a predefined desorption temperature range that falls below a predefined heating gradient maximum value, and

wherein the predefined desorption temperature range is where a desorption of hydrocarbons stored in the exhaust gas cleaning component takes place and is below a start-up temperature of the heated at least one exhaust gas cleaning component.

2. The method according to claim 1 , wherein the cold start engine operation method is activated with a cold start with outer temperatures of minus 10° C. or less.

3. The method according to claim 1 , wherein the heating gradient is less than 20° C. per minute in a desorption temperature range of 50° C. to 150° C.

4. The method according to claim 1 , wherein the heating gradient maximum value results in an emission concentration of hydrocarbons emitted to the environment that is below a maximum concentration of hydrocarbons, wherein the maximum concentration of hydrocarbons corresponds to a concentration below a concentration that produces visible white smoke.

5. The method according to claim 1 , wherein the estimate of the HC storage amount is based on an operation duration of the internal combustion engine with a temperature continuously falling below a predefined first threshold temperature for at least one exhaust gas cleaning component that is dominant with regard to a smoke-causing HC desorption.

6. The method according to claim 1 , wherein a fraction of an HC storage capacity (κ) of the at least one exhaust gas cleaning component or an exhaust gas cleaning component being dominant with regard to a smoke-causing HC desorption is predefined as HC storage amount limit value.

7. The method according to claim 6 , wherein a value of 30% or less is predefined as the fraction of the HC storage capacity (κ).

8. The method according to claim 1 , wherein the cold start engine operation method is deactivated after reaching a predefined second threshold temperature for at least one of the exhaust gas cleaning components or an exhaust gas cleaning component being dominant with regard to a smoke-causing HC desorption.

9. The method according to claim 4 , wherein the cold start engine operation method is deactivated after reaching a predefined second threshold temperature for at least one of the exhaust gas cleaning components or an exhaust gas cleaning component being dominant with regard to a smoke-causing HC desorption.

10. The method according to claim 5 , wherein the cold start engine operation method is deactivated after reaching a predefined second threshold temperature for at least one of the exhaust gas cleaning components or an exhaust gas cleaning component being dominant with regard to a smoke-causing HC desorption.

11. The method according to claim 1 , wherein a multiple injection of fuel into one or several cylinder combustion chambers of the internal combustion engine is performed with an activated cold start engine operation method that comprises a first pilot injection, a second pilot injection following the first pilot injection and a main injection following the second pilot injection within one working cycle of the respective cylinder, wherein
the first pilot injection occurs in a crank angle range of larger than 20 degrees before an upper dead center in a compression stroke of the respective cylinder,
the second pilot injection occurs at a point after the start of a heat releasing conversion of fuel injected by the first pilot injection, and
the main injection occurs at a point after the start of a heat releasing conversion of fuel injected by the second pilot injection.

12. The method according to claim 8 , wherein a multiple injection of fuel into one or several cylinder combustion chambers of the internal combustion engine is performed with an activated cold start engine operation method that comprises a first pilot injection, a second pilot injection following the first pilot injection and a main injection following the second pilot injection within one working cycle of the respective cylinder, wherein
the first pilot injection occurs in a crank angle range of larger than 20 degrees before an upper dead center in a compression stroke of the respective cylinder,
the second pilot injection occurs at a point after the start of a heat releasing conversion of fuel injected by the first pilot injection, and
the main injection occurs at a point after the start of a heat releasing conversion of fuel injected by the second pilot injection.

13. The method according to claim 9 , wherein a multiple injection of fuel into one or several cylinder combustion chambers of the internal combustion engine is performed with an activated cold start engine operation method that comprises a first pilot injection, a second pilot injection following the first pilot injection and a main injection following the second pilot injection within one working cycle of the respective cylinder, wherein
the first pilot injection occurs in a crank angle range of larger than 20 degrees before an upper dead center in a compression stroke of the respective cylinder,
the second pilot injection occurs at a point after the start of a heat releasing conversion of fuel injected by the first pilot injection, and
the main injection occurs at a point after the start of a heat releasing conversion of fuel injected by the second pilot injection.

14. The method according to claim 10 , wherein a multiple injection of fuel into one or several cylinder combustion chambers of the internal combustion engine is performed with an activated cold start engine operation method that comprises a first pilot injection, a second pilot injection following the first pilot injection and a main injection following the second pilot injection within one working cycle of the respective cylinder, wherein
the first pilot injection occurs in a crank angle range of larger than 20 degrees before an upper dead center in a compression stroke of the respective cylinder,
the second pilot injection occurs at a point after the start of a heat releasing conversion of fuel injected by the first pilot injection, and
the main injection occurs at a point after the start of a heat releasing conversion of fuel injected by the second pilot injection.

Assignees

• Koch Thomas
• Massner Alexander
• Traebert Anke
• Daimler Ag

Inventors

• Koch Thomas
• Massner Alexander
• Traebert Anke

Classifications

• F02D41/064

  at cold start (F02D41/067 takes precedence) · CPC title

• F01N2250/12

  absorption or adsorption, and catalytic conversion · CPC title

• Y02T10/44

  Cross-Sectional Technologies · mapped topic

• Y02T10/26

  Cross-Sectional Technologies · mapped topic

• F02D41/403

  with pilot injections · CPC title