SCR aftertreatment system maintenance inducement method

• US 9,626,812 B2
• Filed: 12/04/2014
• Issued: 04/18/2017
• Est. Priority Date: 06/07/2012
• Status: Active Grant

• Current Assignee: Cummins Incorporated
• Original Assignee: Cummins Incorporated
• Inventors: See, Tung-King, Niehus, W. Patrick, Griffith, Brett D.
• Primary Examiner(s): Tran, Binh Q
• Application Number:
  US14/560,355
• Publication Number:
  US 20150088362A1
• Time in Patent Office: 866 Days
• Field of Search: 60274, 60286, 60295, 60297, 60301, 60303
• 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 2550/02 Catalytic activity of catalytic converters
• CPC Class Codes: F01N 2550/05 Systems for adding substances into exhaust
• CPC Class Codes: F01N 2570/14 Nitrogen oxides
• CPC Class Codes: F01N 2610/02 the substance being ammonia or urea
• CPC Class Codes: F01N 2610/1406 Storage means for substances, e.g. tanks or reservoirs
• CPC Class Codes: F01N 2900/1814 Tank level
• CPC Class Codes: F01N 2900/1818 Concentration of the reducing agent
• CPC Class Codes: F01N 3/208 Control of selective catalytic reduction [SCR], e.g. dosing of reducing agent
• CPC Class Codes: G07C 5/0808 Diagnosing performance data testing of vehicles G01M17/00; testing of electrical installation on vehicles G01R31/005
• CPC Class Codes: G07C 5/0825 using optical means
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

Systems and methods are disclosed that relate to an SCR aftertreatment system and incentives/inducements for an operator/user to maintain the SCR aftertreatment in compliance with operating requirements and/or regulations. An engine is operationally coupled to at least one of a DEF tank and an SCR aftertreatment system. An inducement signal value is determined in response to a threshold value being obtained relating to at least one of the DEF tank level indication, a DEF quality indication, and an SCR aftertreatment system malfunction indication. The inducement signal value initiates at least one derate value of the engine to incentivize or induce the operator to have the aftertreatment system maintained and avoid or prevent out-of compliance operation of the SCR aftertreatment system.

Claims

1. A method for providing a selective catalytic reduction (SCR) system maintenance incentive, comprising:

interpreting an SCR aftertreatment system malfunction indication associated with at least one of a DEF tank and an aftertreatment system operationally coupled to an engine;

determining an inducement signal value when the SCR aftertreatment system malfunction indication obtains a threshold value; and

derating the engine in response to the inducement signal value.

2. The method of claim 1, wherein the threshold value for the SCR aftertreatment system is an elapse of a predetermined amount of time since the SCR aftertreatment system malfunction indication.

3. The method of claim 1, wherein derating the engine comprises utilizing an inducement schedule that includes an initial derate value, a secondary derate value, and a final derate value, wherein the derate value increases, in order, from the initial derate value to the secondary derate value to the final derate value.

4. The method of claim 3, wherein the initial derate value comprises at least one of a torque derate value and a speed derate value.

5. The method of claim 3, wherein the final derate value comprises at least one of an engine shutdown operation, an engine forced idle operation, a limp-home mode, and a restart limitation.

6. The method of claim 5, wherein the restart limitation comprises limiting the engine to a predetermined number of restart events in response to the final derate value.

7. The method of claim 3, wherein at least one of the initial derate and the secondary derate comprises a ramped derate.

8. The method of claim 3, further comprising allowing at least one operator derate override during derating the engine.

9. The method of claim 8, wherein the final derate value does not allow the operator derate override.

10. The method of claim 1, wherein derating the engine further comprises at least one of a ramped derate and a derate schedule.

11. The method of claim 10, wherein the ramped derate comprises a percentage derate per minute value.

12. The method of claim 11, wherein the percentage derate per minute value is 1% per minute.

13. The method of claim 1, further comprising allowing at least one operator derate override during derating the engine.

14. The method of claim 1, further comprising:

interpreting at least one of a diesel exhaust fluid (DEF) tank level indication and a DEF quality indication; and

determining the inducement signal value when the SCR aftertreatment system malfunction indication and at least one of the DEF tank level indication and the DEF quality indication obtains the threshold value.

15. The method of claim 14, wherein the DEF tank level indication is a continuous DEF tank level indication.

16. The method of claim 14, wherein the DEF quality indication is a binary quality value.

17. The method of claim 14, wherein the threshold value for the DEF tank level indication is a threshold tank fill level and the inducement signal value is determined when the DEF tank level indication is below the threshold tank fill level.

18. The method of claim 14, wherein the threshold value for the DEF quality indication is an elapse of a predetermined amount of time since a poor DEF quality indication.

19. The method of claim 14, wherein:

determining the inducement signal value includes determining when the threshold value of the at least one of the DEF tank level indication, the DEF quality indication, and the SCR aftertreatment system malfunction indication obtains a first threshold value, a second threshold value, and a third threshold value; and

derating the engine includes utilizing an inducement schedule that includes inducement signal values with an initial derate value at the first threshold value, a secondary derate value at the second threshold value, and a final derate value at the third threshold value that increase in an amount of derate, in order, from the initial derate value to the secondary derate value to the final derate value.

20. The method of claim 19, wherein the first threshold value is a first time period since the DEF quality indication, the second threshold value is a second time period after the first time period, and the third threshold value is a third time period after the second time period.

21. The method of claim 20, further comprising providing a warning of poor DEF quality upon interpreting the DEF quality indication.

22. The method of claim 19, wherein the first threshold value is a first time period following the SCR aftertreatment system malfunction indication, the second threshold value is a second time period, after the first time period, and the third threshold value is a third time period after the second time period.

23. The method of claim 22, further comprising providing a warning of SCR aftertreatment system malfunction upon interpreting the SCR aftertreatment malfunction indication.

24. The method of claim 19, wherein the first threshold value is a first DEF tank level that is less than the DEF tank level indication, the second threshold value is a second DEF tank level that is less than the first DEF tank level, and the third threshold value is a time period after the DEF tank level indication reaches the second threshold value.

25. The method of claim 24, wherein the second DEF tank level corresponds to an empty DEF tank.

26. The method of claim 25, wherein the time period ranges from about 2 minutes to one hour.

27. A system, comprising:

an internal combustion engine including an exhaust system for receiving an exhaust gas produced by the internal combustion engine;

a selective catalytic reduction (SCR) aftertreatment system connected to the exhaust system for treating nitrous oxide emissions in the exhaust gas;

a diesel exhaust fluid (DEF) tank connected to the exhaust system to provide DEF to the SCR aftertreatment system;

an SCR aftertreatment system indicator configured to detect an SCR system malfunction; and

a controller configured to determine an inducement signal value in response to the at least one of the DEF level indicator, the DEF quality indicator, and the SCR aftertreatment system indicator obtaining a threshold value, the controller further being configured to derate the engine in response to the inducement signal value.

28. The system of claim 27, wherein the controller is configured to derate the engine according to an inducement schedule that includes an initial derate value, a secondary derate value, and a final derate value, wherein the derate value increases, in order, from the initial derate value to the secondary derate value to the final derate value.

29. The system of claim 27, wherein the initial derate value comprises at least one of a torque derate value and a speed derate value.

30. The system of claim 28, wherein the final derate value comprises at least one of an engine shutdown operation, an engine forced idle operation, a limp-home mode, and a restart limitation.

31. The system of claim 27, further comprising:

at least one of;

a DEF level indicator configured to detect a level of DEF in the DEF tank; and

a DEF quality indicator configured to detect a quality of the DEF, and

wherein the controller is configured to determine the inducement signal value in response to the SCR aftertreatment system indicator and the at least one of the DEF level indicator and the DEF quality indicator obtaining the threshold value.

32. The system of claim 31, wherein the controller is configured to determine the inducement signal value when the threshold value of the at least one of the DEF tank level indicator, the DEF quality indicator, and the SCR aftertreatment system malfunction indicator obtains a first threshold value, a second threshold value, and a third threshold value, the controller further being configured to derate the engine according to an inducement schedule having inducement signal values that include an initial derate value at the first threshold value, a secondary derate value at the second threshold value, and a final derate value at the third threshold value that increase in an amount of derate in order, from the initial derate value to the secondary derate value to the final derate value.

33. The system of claim 32, wherein the first threshold value for the DEF quality indication is a first time period since the DEF quality indicator indicates a poor DEF quality, the second threshold value is a second time period after the first time period, and the third threshold value is a third time period after the second time period.

34. The system of claim 33, wherein the controller is configured to provide a warning signal before the first time period upon indication of poor DEF quality.

35. The system of claim 32, wherein the first threshold value for the SCR aftertreatment system malfunction indication is an elapse of a first time period since the SCR aftertreatment system malfunction indication, the second threshold value is an elapse of a second time period after the first time period, and the third threshold value is an elapse of a third time period after the second time period.

36. The system of claim 35, wherein the controller is configured to provide a warning signal before the first time period upon indication of SCR aftertreatment system malfunction.

37. The system of claim 32, wherein the first threshold value for the DEF tank level indication is a first DEF tank level, the second threshold value is a second DEF tank level that is less than the first DEF tank level, and the third threshold value is an elapse of a time period after the DEF tank level indication reaches the second threshold value.

38. The system of claim 37, wherein the controller is configured to provide a warning signal before the DEF tank level indication obtains the first DEF tank level.