APPARATUS, SYSTEM, AND METHOD FOR ENHANCING SOOT FILTER PROTECTION

• US 20080034738A1
• Filed: 08/11/2006
• Published: 02/14/2008
• Est. Priority Date: 08/11/2006
• Status: Active Grant

• Current Assignee: Cummins Filtration Incorporated (Cummins Incorporated)
• Original Assignee: Fleetguard, Inc. (Cummins Incorporated)
• Inventors: Singh, Nishant, Wilhelm, Daniel D.
• Granted Patent: US 7,500,358 B2
• Time in Patent Office: Days
• US Class Current: 60/295
• 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 2610/02 the substance being ammonia or urea
• CPC Class Codes: F01N 2610/03 the substance being hydrocarbons, e.g. engine fuel
• 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 3/0842 Nitrogen oxides
• CPC Class Codes: F01N 3/103 Oxidation catalysts for HC and CO only
• CPC Class Codes: F01N 9/002 of filter regeneration, e.g. detection of clogging
• CPC Class Codes: F01N 9/005 using models instead of sensors to determine operating characteristics of exhaust systems, e.g. calculating catalyst temperature instead of measuring it directly
• CPC Class Codes: F02B 37/18 by bypassing exhaust from the inlet to the outlet of turbine or to the atmosphere
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

An apparatus, system, and method are disclosed for enhancing protection of a soot filter. The method enhances soot filter protection by interpreting a baseline regeneration scheme, estimating whether a set of current soot filter conditions indicate that a regeneration is occurring, and setting an engine operating indicator if an internal combustion engine is operating such that a threshold amount of soot is being generated. The method may continue with incrementing a first counter based on the baseline regeneration scheme and the engine operating indicator, and activating a regeneration request indicator when the first counter reaches a first threshold. The method may further include incrementing a second counter when the regeneration request indicator is active, where the incrementing value for the second counter is based on whether a regeneration is occurring. The method may further include deactivating the regeneration request indicator when the second counter reaches a second threshold.

Claims

1. An apparatus for enhancing soot filter protection, the apparatus comprising:

an operating detection module configured to set an engine operating indicator if an internal combustion engine is operating such that a threshold amount of soot is being generated;

a regeneration-start timing module configured to increment a first counter based on the engine operating indicator, and to set a regeneration request indicator when the first counter reaches a first threshold;

a regeneration-stop timing module configured to increment a second counter based on the set regeneration request indicator, and to reset the regeneration request indicator when the second counter reaches a second threshold; and

a regeneration request module configured to request a regeneration event based on the regeneration request indicator.

2. The apparatus of claim 1, further comprising a baseline regeneration module configured to interpret a baseline regeneration scheme, wherein the regeneration-start timing module is further configured to increment the first counter based on the baseline regeneration scheme.

3. The apparatus of claim 1, wherein the first counter comprises a first timer, and wherein the second counter comprises a second timer.

4. The apparatus of claim 2, further comprising a secondary protection module configured to use a sensor-based soot load estimate if:

the baseline regeneration scheme comprises a mixed soot load estimate comprising a model and a sensor; and

the sensor-based soot load estimate indicates a higher soot loading than the mixed soot load estimate comprising a model and a sensor.

5. The apparatus of claim 4, wherein using a sensor-based soot load estimate comprises one of overriding soot load estimate value and setting a sensor trust factor to a relatively high value.

6. The apparatus of claim 1, further comprising a regeneration estimation module configured to estimate whether a set of current soot filter conditions indicate that a regeneration is occurring, wherein the regeneration-start timing module is further configured to increment the first counter with a first negative value when the regeneration estimation module estimates a regeneration is occurring, and to increment the first counter with a first positive value when the regeneration estimation module estimates a regeneration is not occurring.

7. The apparatus of claim 6, wherein the first negative value comprises a value calculated from the set of current soot filter conditions.

8. The apparatus of claim 6, wherein the regeneration-start timing module is further configured to initialize the first counter such that an elapsed time is relatively short for the first time the regeneration-start timing module sets the regeneration request indicator.

9. The apparatus of claim 6, wherein the regeneration-start timing module is further configured to initialize the first counter such that an elapsed time is relatively long for the first time the regeneration-start timing module sets the regeneration request indicator.

10. The apparatus of claim 6, wherein the set of current soot filter conditions comprise a threshold oxygen level, and a peripheral temperature estimate.

11. The apparatus of claim 10, wherein the set of current soot filter conditions further comprise a peripheral soot concentration estimate.

12. The apparatus of claim 1, further comprising a regeneration estimation module configured to estimate whether a set of current soot filter conditions indicate that a regeneration is occurring, wherein the regeneration-stop timing module is further configured to increment the second counter with a second positive value when the regeneration estimation module estimates a regeneration is occurring, and to increment the second counter with a second negative value when the regeneration estimation module estimates a regeneration is not occurring.

13. The apparatus of claim 12, wherein the second positive value comprises a value calculated from the set of current soot filter conditions.

14. The apparatus of claim 12, wherein the set of current soot filter conditions comprise a threshold oxygen level, and a peripheral temperature estimate.

15. The apparatus of claim 14, wherein the set of current soot filter conditions further comprise a peripheral soot concentration estimate.

16. A computer program product comprising a computer readable medium having computer usable program code programmed to enhance soot filter protection, the programming product having operations comprising:

interpreting a baseline regeneration scheme;

estimating whether a set of current soot filter conditions indicate that a regeneration is occurring;

setting an engine operating indicator if an internal combustion engine is operating such that a threshold amount of soot is being generated;

incrementing a first counter based on the baseline regeneration scheme and the engine operating indicator;

setting a regeneration request indicator when the first counter reaches a first threshold;

incrementing a second counter when the regeneration request indicator is active, wherein the increment value for the second counter is based on whether a regeneration is occurring; and

resetting the regeneration request indicator when the second counter reaches a second threshold.

17. The computer program product of claim 16, further comprising resetting the regeneration request indicator when the regeneration request indicator is active, a regeneration is not occurring, and a specified period of time elapses.

18. The computer program product of claim 16, further comprising performing a diagnostic test when the regeneration request indicator is set, wherein performing a diagnostic test comprises at least one member selected from the group consisting of:

checking a fuel doser operation;

checking a catalytic component for an expected temperature rise; and

verifying a soot filter expected soot loading based on an observed temperature rise and the set of current soot filter conditions.

19. The computer program product of claim 16, further comprising initializing the first counter such that an elapsed time is relatively short for the first time the regeneration request indicator is set.

20. The computer program product of claim 16, further comprising initializing the first counter such that an elapsed time is relatively long for the first time the regeneration request indicator is set.

21. The computer program product of claim 16, wherein the set of current soot filter conditions comprise a soot filter temperature threshold and an oxidizing agent threshold, wherein the oxidizing agent comprises one of nitrogen oxide and oxygen.

22. The computer program product of claim 16, wherein the increment value for the second counter is further based on the set of current soot filter conditions.

23. The computer program product of claim 22, wherein the set of current soot filter conditions comprises at least one member selected from the group consisting of the soot filter temperature, the soot filter periphery temperature, a soot loading estimate, and an oxidizing agent concentration, wherein the oxidizing agent comprises one of nitrogen oxide and oxygen.

24. A system for enhancing soot filter protection, the system comprising:

an internal combustion engine;

an aftertreatment system fluidly coupled to the internal combustion engine, the aftertreatment system comprising a soot filter;

a soot filter protection tool comprising at least one of a protective regeneration timer and a protective soot estimator;

wherein the protective regeneration timer comprises an operating detection module configured to set an engine operating indicator if an internal combustion engine is operating such that a threshold amount of soot is being generated, a regeneration-start timing module configured to increment a first counter based on the engine operating indicator, and to set a regeneration request indicator when the first counter reaches a first threshold, a regeneration-stop timing module configured to increment a second counter based on the set regeneration request indicator, and to reset the regeneration request indicator when the second counter reaches a second threshold, and a regeneration request module configured to request a regeneration event based on the regeneration request indicator; and

wherein the protective soot estimator comprises a secondary protection module configured to use a sensor-based soot load estimate if the baseline regeneration scheme comprises a mixed soot load estimate comprising a model and a sensor and the sensor-based soot load estimate indicates a higher soot loading than the mixed soot load estimate comprising a model and a sensor.

25. The system of claim 24, wherein the protective regeneration timer further comprises a regeneration estimation module configured to estimate whether a set of current soot filter conditions indicate that a regeneration is occurring, wherein the regeneration-stop timing module is further configured to increment the second counter with a second positive value when the regeneration estimation module estimates a regeneration is occurring, and to increment the second counter with a second negative value when the regeneration estimation module estimates a regeneration is not occurring.

26. The system of claim 25, wherein the internal combustion engine comprises an engine controller configured to communicate with the soot filter protection tool, and wherein the engine controller is further configured to provide at least one of a mixed soot load estimate, and upstream conditions related to the set of current soot filter conditions to the soot filter protection tool.