Diesel exhaust control during limp-home mode

• US 7,992,377 B2
• Filed: 12/14/2006
• Issued: 08/09/2011
• Est. Priority Date: 12/14/2006
• Status: Expired due to Fees

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Brown, David B.
• Primary Examiner(s): Denion; Thomas E
• Assistant Examiner(s): Carton; Michael
• Application Number:
  US11/639,370
• Publication Number:
  US 20080141658A1
• Time in Patent Office: 1,699 Days
• Field of Search: 602/86, 602/95, 602/99, 603/00, 603/16
• US Class Current: 60/286
• 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 source, comprising:

a first module that determines a level of said dosing agent within said dosing agent source,

wherein said dosing agent includes ammonia;

a second module that selectively generates a signal when said vehicle is at a predetermined location and an engine is started; and

a third module that reduces vehicle performance when said level is less than a first predetermined level, said level is greater than a second predetermined level, and said signal is not generated, that regulates operation of said engine to increase a selective catalytic reduction (SCR) catalyst temperature when said SCR catalyst temperature is less than a predetermined temperature while said vehicle performance is reduced, and that disables said engine when said level is less than said second level and said signal is generated.

2. The exhaust after-treatment system of claim 1 wherein said third module operates said engine in a pre-mixed charge combustion ignition (PCCI) mode when said level is less than said first predetermined level, said level is greater than said second predetermined level, and said signal is not generated.

3. The exhaust after-treatment system of claim 1 wherein said third module transitions operation of said engine from a first mode to a second mode when said level is less than said first predetermined level, said level is greater than said second predetermined level, and said signal is not generated, and

wherein output nitrogen oxides (NOx) and particulate matter amounts are less during operation in said second mode than during operation in said first mode.

4. The exhaust after-treatment system of claim 1 wherein said second module generates said signal when a difference between first and second fuel levels is greater than a predetermined amount,

wherein said first fuel level is before said engine is started, and

wherein said second fuel level is one of when and after said engine is started.

5. The exhaust after-treatment system of claim 1 wherein said second module generates said signal when a difference between first and second oil levels is greater than a predetermined amount,

wherein said first oil level is before said engine is started, and

wherein said second oil level is one of when and after said engine is started.

6. The exhaust after-treatment system of claim 1 wherein said second module selectively generates said signal based on a change in an oil parameter.

7. The exhaust after-treatment system of claim 6 wherein said oil parameter is electrical impedance of said oil.

8. The exhaust after-treatment system of claim 1 wherein said second module generates said signal based on a second signal from a global positioning system (GPS).

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 said dosing agent within a dosing agent source,

wherein said dosing agent includes ammonia;

selectively generating a signal when said vehicle is at a predetermined location and an engine is started;

reducing vehicle performance when said level is less than a first predetermined level, said level is greater than a second predetermined level, and said signal is not generated;

regulating operation of an engine to increase a selective catalytic reduction (SCR) catalyst temperature when said SCR catalyst temperature is less than a predetermined temperature while said vehicle performance is reduced; and

disabling said engine when said level is less than said second level and said signal is generated.

10. The method of claim 9 wherein said regulating includes operating said engine in a pre-mixed charge combustion ignition (PCCI) mode when said level is less than said first predetermined level, said level is greater than said second predetermined level, and said signal is not generated.

11. The method of claim 9 wherein said regulating includes transitioning operation of said engine from a first mode to a second mode when said level is less than said first predetermined level, said level is greater than said second predetermined level, and said signal is not generated, and

wherein output nitrogen oxides (NOx) and particulate matter amounts are less during operation in said second mode than during operation in said first mode.

12. The method of claim 9 wherein said generating includes generating said signal when a difference between first and second fuel levels is greater than a predetermined amount,

wherein said first fuel level is before said engine is started, and

wherein said second fuel level is one of when and after said engine is started.

13. The method of claim 9 wherein said generating includes generating said signal when a difference between first and second oil levels is greater than a predetermined amount,

wherein said first oil level is from before said engine is started, and

wherein said second oil level is from one of when and after said engine is started.

14. The method of claim 9 wherein said generating includes generating said signal based on a change in an oil parameter.

15. The method of claim 14 wherein said oil parameter is an electrical impedance of said oil.

16. The method of claim 9 wherein said generating includes generating said signal based on a second signal from a global positioning system (GPS).