Adaptive Reductant Dosing And Emission Control Strategies

• US 20080306631A1
• Filed: 06/11/2007
• Published: 12/11/2008
• Est. Priority Date: 06/11/2007
• Status: Active Grant

• Current Assignee: Southwest Research Institute
• Original Assignee: Southwest Research Institute
• Inventors: Huang, Yiqun
• Granted Patent: US 7,991,533 B2
• Time in Patent Office: Days
• US Class Current: 700/271
• CPC Class Codes: B01D 2251/2062 Ammonia
• CPC Class Codes: B01D 2251/2067 Urea
• CPC Class Codes: B01D 2258/012 Diesel engines and lean burn gasoline engines
• CPC Class Codes: B01D 53/9431 Processes characterised by a specific device
• CPC Class Codes: B01D 53/9495 Controlling the catalytic process
• CPC Class Codes: F01N 11/00 Monitoring or diagnostic devices for exhaust-gas treatment apparatus , e.g. for catalytic activity safety, indicating or supervising devices for internal combustion engines F02B77/08; testing of machines G01M13/00
• CPC Class Codes: F01N 2570/14 Nitrogen oxides
• CPC Class Codes: F01N 2610/02 the substance being ammonia or urea
• CPC Class Codes: F01N 2900/0421 using an increment counter when a predetermined event occurs
• CPC Class Codes: F01N 2900/0422 measuring the elapsed time
• CPC Class Codes: F01N 2900/08 said parameters being related to the engine
• CPC Class Codes: F01N 2900/102 Travelling distance
• CPC Class Codes: F01N 2900/1808 Pressure
• CPC Class Codes: F01N 2900/1814 Tank level
• CPC Class Codes: F01N 3/208 Control of selective catalytic reduction [SCR], e.g. dosing of reducing agent
• 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

The present disclosure relates to a method or apparatus for controlling reductant dosing level introduced to a selective catalytic reduction device. The method or apparatus may determine available reductant and determine a distance to a source of reductant. This may be followed by adjusting a reductant dosing level based upon the available reductant and the distance to the reductant source. The apparatus may be installed in a vehicle and may also regulate in-cylinder emission control variables to reduce NOx emissions.

Claims

1. A controller comprising:

a control unit capable of controlling a reductant dosing level introduced to a selective catalytic reduction catalyst wherein said control unit is capable of determining available reductant and a distance to a source of reductant;

wherein said control unit is capable of adjusting said reductant dosing level based upon said available reductant and said distance to a source of reductant;

wherein said controller is capable of implementing a by-pass mode with zero reductant dosing and counting the number of times the controller was previously in said by-pass mode with zero reductant dosing; and

wherein said controller is capable of determining if the number of times the controller was in said by-pass mode has exceeded a previously determined value.

2. The controller of claim 1 wherein said control unit is capable of in-cylinder emission control of one or more of the following:

injection timing, amount or temperature of exhaust gas recycling, amount or temperature of air flow, fuel mass, compression ratio, boost pressure or combustion temperature.

3. The controller of claim 1 wherein said control unit is capable of estimating reductant consumption and determining whether or not said available reductant is sufficient to maintain said estimated reductant consumption for said distance to said source of reductant.

4. The controller of claim 1 wherein said control unit is capable of estimating reductant consumption and determining that said available reductant is insufficient to maintain said estimated reductant consumption for said distance to said source of reductant and reduces said reductant dosing level.

5. The controller of claim 4 wherein said controller is capable of adjusting one or more of the following:

injection timing, amount or temperature of exhaust gas recycling, amount or temperature of air flow, fuel mass, compression ratio, variable valve actuation timing, boost pressure or combustion temperature, wherein said adjusting is based upon said reduced dosing level.

6. The controller of claim 1 wherein said controller is capable of determining if said available reductant is less than a predetermined level and said controller is capable of adjusting one or more of the following:

injection timing, amount or temperature of exhaust gas recycling, amount or temperature of air flow, fuel mass, compression ratio, variable valve actuation timing, boost pressure or combustion temperature at zero reductant dosing.

9. The controller of claim 1 wherein said controller is capable of implementing a timer for a given time period and said controller is capable of further adjusting one or more of the following:

injection timing, amount or temperature of exhaust gas recycling, amount or temperature of air flow, fuel mass, compression ratio, variable valve actuation timing, boost pressure or combustion temperature for said time period.

10. The controller of claim 1 wherein said controller is located in a vehicle.

7. (canceled)

8. (canceled)

11. A method of controlling reductant dosing level introduced to a selective catalytic reduction device comprising:

determining available reductant;

determining a distance to a source of reductant;

adjusting a reductant dosing level based upon said available reductant and said distance to a source of reductant;

implementing a by-pass mode with zero reductant dosing and counting the number of times the controller was previously in said by-pass mode with zero reductant dosing; and

determining if the number of times previously in said by-pass mode has exceeded a previously determined value.

12. The method of claim 11 further comprising:

adjusting one or more of the following;

injection timing, amount or temperature of exhaust gas recycling, amount or temperature of air flow, fuel mass, compression ratio, variable valve actuation timing, boost pressure or combustion temperature.

13. The method of claim 11 further comprising:

estimating a reductant consumption;

determining whether said reductant is sufficient to maintain said reductant consumption for said distance to said source of reductant.

14. The method of claim 11 further comprising:

estimating a reductant consumption;

determining whether said available reductant is sufficient to maintain said estimated reductant consumption for said distance to said source of reductant; and

reducing said reductant dosing level when said available reductant is insufficient to maintain said estimated reductant consumption for said distance to said source of reductant.

15. The method of claim 14 further comprising adjusting one or more of the following:

injection timing, amount or temperature of exhaust gas recycling, amount or temperature of air flow, fuel mass, compression ratio, variable valve actuation timing, boost pressure or combustion temperature, based upon said reduced dosing level.

16. The method of claim 11 further comprising:

determining if said available reductant is less than a predetermined level; and

adjusting one or more of the following;

injection timing, amount or temperature of exhaust gas recycling, amount or temperature of air flow, fuel mass, compression ratio, variable valve actuation timing, boost pressure or combustion temperature, at zero reductant dosing.

19. The method of claim 11 further comprising:

initiating a timer for a given time period; and

further adjusting one or more of the following;

injection timing, amount or temperature of exhaust gas recycling, amount or temperature of air flow, fuel mass, compression ratio, variable valve actuation timing, boost pressure or combustion temperature, at zero reductant dosing for said period.

17. (canceled)

18. (canceled)

20. An article comprising a storage medium having stored thereon instruction that when executed by a machine result in the following operations:

determining available reductant;

determining a distance to a source of reductant;

adjusting a reductant dosing level based upon said available reductant and said distance to said source of reductant;

implementing a by-pass mode with zero reductant dosing and counting the number of times the controller was previously in said by-pass mode with zero reductant dosing; and

determining if the number of times previously in said by-pass mode has exceeded a previously determined value.

21. The article of claim 20, wherein said instructions that when executed by said machine result in the following additional operations:

adjusting one or more of the following;

injection timing, amount or temperature of exhaust gas recycling, amount or temperature of air flow, fuel mass, compression ratio, variable valve actuation timing, boost pressure or combustion temperature.

22. The article of claim 20, wherein said instructions that when executed by said machine result in the following additional operations:

estimating a reductant consumption;

determining whether said reductant is sufficient to maintain said reductant consumption for said distance to said source of reductant.

23. The article of claim 20, wherein said instructions that when executed by said machine result in the following additional operations:

estimating a reductant consumption;

determining whether said available reductant is sufficient to maintain said estimated reductant consumption for said distance to said source of reductant; and

reducing said reductant dosing level when said available reductant is insufficient to maintain said estimated reductant consumption for said distance to said source of reductant.

24. The article of claim 23 wherein said instructions that when executed by said machine result in the following additional operations:

adjusting one or more of the following;

injection timing, amount or temperature of exhaust gas recycling, amount or temperature of air flow, fuel mass, compression ratio, variable valve actuation timing, boost pressure or combustion temperature upon said reduced dosing level.

25. The article of claim 20, wherein said instructions that when executed by said machine result in the following additional operations:

determining if said available reductant is less than a predetermined level; and

adjusting one or more of the following;

injection timing, amount or temperature of exhaust gas recycling, amount or temperature of air flow, fuel mass, compression ratio, variable valve actuation timing, boost pressure or combustion temperature, at zero reductant dosing.

28. The article of claim 20, wherein said instructions that when executed by said machine result in the following additional operations

initiating a timer for a given time period;

and

further adjusting one or more of the following;

injection timing, amount or temperature of exhaust gas recycling, amount or temperature of air flow, fuel mass, compression ratio, variable valve actuation timing, boost pressure or combustion temperature, at zero reductant dosing for said period.

26. (canceled)

27. (canceled)