Diesel exhaust control during limp-home mode

• US 20080141658A1
• Filed: 12/14/2006
• Published: 06/19/2008
• Est. Priority Date: 12/14/2006
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Brown, David B.
• Granted Patent: US 7,992,377 B2
• Time in Patent Office: Days
• US Class Current: 60/285
• CPC Class Codes: F01N 11/002 the diagnostic devices measuring or estimating temperature or pressure in, or downstream of the exhaust apparatus
• CPC Class Codes: F01N 13/009 having two or more separate purifying devices arranged in series
• CPC Class Codes: F01N 2250/02 filtering and catalytic conversion
• CPC Class Codes: F01N 2560/06 the means being a temperature sensor
• CPC Class Codes: F01N 2610/03 the substance being hydrocarbons, e.g. engine fuel
• CPC Class Codes: F01N 2610/1406 Storage means for substances, e.g. tanks or reservoirs
• CPC Class Codes: F01N 3/021 by means of filters
• CPC Class Codes: F01N 3/2033 using a fuel burner or introducing fuel into exhaust duct
• CPC Class Codes: F01N 3/36 Arrangements for supply of additional fuel
• CPC Class Codes: F02B 1/12 with compression ignition with fuel-air charge ignited by compression ignition of an additional fuel F02B7/00
• CPC Class Codes: F02B 3/06 with compression ignition compression ignition engines using air or gas for blowing fuel into compressed air in cylinder F02B13/02
• CPC Class Codes: F02D 2041/227 Limping Home, i.e. taking specific engine control measures at abnormal conditions
• CPC Class Codes: F02D 2200/0802 Temperature of the exhaust gas treatment apparatus
• CPC Class Codes: F02D 2200/701 Information about vehicle position, e.g. from navigation system or GPS signal
• CPC Class Codes: F02D 41/0002 Controlling intake air
• CPC Class Codes: F02D 41/024 to increase temperature of the exhaust gas treating apparatus
• CPC Class Codes: F02D 41/22 Safety or indicating devices for abnormal conditions in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809
• CPC Class Codes: F02D 41/3035 a mode being the premixed charge compression-ignition mode
• CPC Class Codes: Y02A 50/20 Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies
• CPC Class Codes: Y02T 10/40 : Engine management systems

Abstract

A method of extending emissions performance of an exhaust after-treatment system of a vehicle that includes a dosing agent includes determining a level of a dosing agent source, selectively entering a limp-home mode based on the level and monitoring a catalyst temperature during said limp-home mode. Operation of an engine is regulated to increase the catalyst temperature when the catalyst temperature is less than a threshold catalyst temperature during the limp-home mode.

Claims

1. An exhaust after-treatment system for a vehicle including a dosing agent that is selectively injected into an exhaust from a dosing agent supply, comprising:

a first module that determines a level of a dosing agent source; and

a second module that monitors a catalyst temperature during a limp-home mode; and

a third module that selectively initiates said limp-home mode based on said level and that regulates operation of an engine to increase said catalyst temperature when said catalyst temperature is less than a threshold catalyst temperature during said limp-home mode.

2. The exhaust after-treatment system of claim 1 wherein said third module regulates operation of said engine by throttling said engine.

3. The exhaust after-treatment system of claim 1 wherein said third module regulates operation of said engine by adjusting an air flow of said engine.

4. The exhaust after-treatment system of claim 1 wherein said third module regulates operation of said engine by adjusting a fueling rate of said engine.

5. The exhaust after-treatment system of claim 1 wherein said third control module regulates operation of said engine to post-inject fuel into said exhaust upstream of said catalyst.

6. The exhaust after-treatment system of claim 5 wherein said post-injecting occurs when said catalyst temperature is greater than said threshold catalyst temperature.

7. The exhaust after-treatment system of claim 1 wherein said catalyst temperature is monitored based on a catalyst temperature sensor signal.

8. The exhaust after-treatment system of claim 1 wherein said catalyst temperature is monitored based on a catalyst temperature model.

9. A method of extending emissions performance of an exhaust after-treatment system of a vehicle that includes a dosing agent, comprising:

determining a level of a dosing agent source;

selectively entering a limp-home mode based on said level;

monitoring a catalyst temperature during said limp-home mode; and

regulating operation of an engine to increase said catalyst temperature when said catalyst temperature is less than a threshold catalyst temperature during said limp home mode.

10. The method of claim 9 wherein said regulating includes throttling said engine.

11. The method of claim 9 wherein said regulating includes adjusting an air flow of said engine.

12. The method of claims 9 wherein said regulating includes adjusting a fueling rate of said engine.

13. The method of claim 9 further comprising post-injecting fuel into exhaust upstream of said catalyst.

14. The method of claim 13 wherein said post-injecting occurs when said catalyst temperature is greater than said threshold catalyst temperature.

15. The method of claim 9 wherein said catalyst temperature is monitored based on a catalyst temperature sensor signal.

16. The method of claim 9 wherein said catalyst temperature is monitored based on a catalyst temperature model.

17. A method of extending emissions performance of an exhaust after-treatment system of a vehicle that includes a dosing agent, comprising:

determining a level of a dosing agent source;

selectively entering a limp-home mode based on said level;

monitoring a catalyst temperature during said limp-home mode;

regulating operation of an engine to increase said catalyst temperature when said catalyst temperature is less than a threshold catalyst temperature during said limp home mode;

selectively post-injecting fuel into exhaust upstream of said catalyst; and

regulating operation of an engine in accordance with a limp-home mode strategy when said catalyst temperature is greater than said threshold catalyst temperature.

18. The method of claim 17 wherein said regulating includes throttling said engine.

19. The method of claim 17 wherein said regulating includes adjusting an air flow of said engine.

20. The method of claims 17 wherein said regulating includes adjusting a fueling rate of said engine.

21. The method of claim 17 wherein said post-injecting occurs when said catalyst temperature is greater than said threshold catalyst temperature.

22. The method of claim 17 wherein said catalyst temperature is monitored based on a catalyst temperature sensor signal.

23. The method of claim 17 wherein said catalyst temperature is monitored based on a catalyst temperature model.