SOOT LOAD ESTIMATION DURING IDLE OR LOW LOAD

• US 20170159535A1
• Filed: 12/02/2015
• Published: 06/08/2017
• Est. Priority Date: 12/02/2015
• Status: Active Grant

• Current Assignee: Cummins Emission Solutions Inc.
• Original Assignee: Cummins Emission Solutions Inc.
• Inventors: Wang, Weiwen, Hall, Tony J., Lei, Yinghuan, Wilhelm, Daniel D.
• Granted Patent: US 10,273,858 B2
• Time in Patent Office: Days
• 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 13/008 Mounting or arrangement of exhaust sensors in or on exhaust apparatus sensor arrangements for engine control F02D41/1439
• CPC Class Codes: F01N 13/009 having two or more separate purifying devices arranged in series
• CPC Class Codes: F01N 2560/08 the means being a pressure sensor
• CPC Class Codes: F01N 2570/14 Nitrogen oxides
• CPC Class Codes: F01N 2610/02 the substance being ammonia or urea
• CPC Class Codes: F01N 2900/0416 using the state of a sensor, e.g. of an exhaust gas sensor
• CPC Class Codes: F01N 2900/08 said parameters being related to the engine
• CPC Class Codes: F01N 2900/1606 Particle filter loading or soot amount
• CPC Class Codes: F01N 3/021 by means of filters
• CPC Class Codes: F01N 3/206 Adding periodically or continuously substances to exhaust gases for promoting purification, e.g. catalytic material in liquid form, NOx reducing agents F01N3/2066 takes precedence
• CPC Class Codes: F01N 3/2066 Selective catalytic reduction [SCR]
• CPC Class Codes: F01N 9/00 Electrical control of exhaust gas treating apparatus monitoring or diagnostic devices for exhaust-gas treatment apparatus F01N11/00; conjoint electrical control of two or more combustion engine functions F02D43/00
• CPC Class Codes: F01N 9/002 of filter regeneration, e.g. detection of clogging
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A system can include an engine, an aftertreatment system with a particulate filter, and a controller. The controller is configured to compare a time value since a last delta pressure soot load estimate process to a predetermined time threshold. Responsive to the time value being greater than or equal to the predetermined time threshold, the controller decreases a flow threshold value to a lower flow threshold value. If the flow amount is greater than or equal to the lower flow threshold value, then the controller activates a delta pressure soot load estimation process. A combined soot load estimate is then calculated using a delta pressure soot load estimation of the delta pressure soot load estimate process responsive to the lower flow threshold value.

Claims

1. A system comprising:

an engine;

an aftertreatment system including a particulate filter; and

a controller configured to;

receive engine operating conditions for the engine;

compare the engine operating conditions to one or more engine operating threshold values;

compare a time value since a last delta pressure soot load estimate process to a predetermined time threshold;

decrease a flow threshold value to a lower flow threshold value responsive to the time value being greater than or equal to the predetermined time threshold;

compare a flow amount to the lower flow threshold value;

activate a delta pressure soot load estimation process responsive to determining the flow amount is greater than or equal to the lower flow threshold value; and

calculate a combined soot load estimate using a delta pressure soot load estimation of the delta pressure soot load estimate process responsive to the lower flow threshold value.

2. The system of claim 1, wherein the engine operating conditions comprise an engine operating time, and wherein the one or more engine operating threshold values comprise a predetermined engine time threshold value.

3. The system of claim 2, wherein the predetermined engine time threshold value is at least 5 hours.

4. The system of claim 1, wherein the engine operating conditions comprise an engine revolutions per minute, and wherein the one or more engine operating threshold values comprise a predetermined engine revolutions per minute threshold value.

5. The system of claim 1, wherein the controller is further configured to:

increase a flow amount in the aftertreatment system responsive to the time value being greater than or equal to the predetermined time threshold.

6. The system of claim 5, wherein increasing the flow amount in the aftertreatment system comprises closing an exhaust gas recirculation valve.

7. The system of claim 5, wherein increasing the flow amount in the aftertreatment system comprises increasing an engine revolutions per minute.

8. The system of claim 7, wherein increasing the engine revolutions per minute occurs during a power take off regeneration process.

9. The system of claim 8, wherein the power take off regeneration process includes modifying the engine revolutions per minute to a first value for a first period of time and modifying the engine revolutions per minute to a second value for a second period of time after the first period of time.

10. The system of claim 1, wherein the controller is further configured to decrement the lower flow threshold value over time.

11. The system of claim 1, wherein the controller is further configured to:

activate a regeneration process for the particulate filter based on a soot load estimate of the delta pressure soot load estimation process.

12. A method for intrusively increasing exhaust flow to update a delta pressure soot load estimate process comprising:

comparing a time value since a last delta pressure soot load estimate process to a predetermined time threshold;

decreasing a flow threshold value to a lower flow threshold value responsive to the time value being greater than or equal to the predetermined time threshold;

increasing a flow amount in an aftertreatment system of the engine responsive to the time value being greater than or equal to the predetermined time threshold;

comparing the increased flow amount to the lower flow threshold value;

activating a delta pressure soot load estimation process responsive to determining the increased flow amount is greater than or equal to the flow threshold value; and

calculating a combined soot load estimate using a delta pressure soot load estimation of the delta pressure soot load estimate process responsive to the lower flow threshold value.

13. The method of claim 12, wherein decreasing the flow threshold value is based on an engine operating time.

14. The method of claim 12, wherein decreasing the flow threshold value is based on an engine revolutions per minute.

15. The method of claim 12, wherein increasing the flow amount in the aftertreatment system comprises closing an exhaust gas recirculation valve.

16. The method of claim 12, wherein increasing the flow amount in the aftertreatment system comprises increasing an engine revolutions per minute.

17. The method of claim 16, wherein increasing the engine revolutions per minute occurs during a power take off regeneration process.

18. The method of claim 12, further comprising:

activating a regeneration process for a particulate filter based on the combined soot load estimate.

19. An apparatus comprising a controller including:

a mass-based soot load rate circuit configured to determine a mass-based soot load estimate for a particulate filter of an aftertreatment system;

a delta pressure soot load estimation circuit configured to determine a delta pressure soot load estimate for the particulate filter of the aftertreatment system;

a combined soot load estimate circuit configured to determine a combined soot load estimate for the particulate filter of the aftertreatment system based on the mass-based soot load estimate and the delta pressure soot load estimate; and

a low flow soot operations circuit configured to;

compare a time value since a last delta pressure soot load estimate to a predetermined time threshold;

decrease a flow threshold value to a lower flow threshold value responsive to the time value being greater than or equal to the predetermined time threshold;

increase a flow amount in the aftertreatment system of the engine responsive to the time value being greater than or equal to the predetermined time threshold;

compare the increased flow amount to the lower flow threshold value;

activate a delta pressure soot load estimation process of the delta pressure soot load estimation circuit responsive to determining the increased flow amount is greater than or equal to the lower flow threshold value; and

calculate a combined soot load estimate using a delta pressure soot load estimation of the delta pressure soot load estimate process responsive to the lower flow threshold value.

20. The apparatus of claim 19, wherein decreasing the flow threshold value is based on an engine operating time.

21. The apparatus of claim 19, wherein decreasing the flow threshold value is based on an engine revolutions per minute.

22. The apparatus of claim 19, wherein increasing the flow amount in the aftertreatment system comprises closing an exhaust gas recirculation valve.

23. The apparatus of claim 19, wherein increasing the flow amount in the aftertreatment system comprises increasing an engine revolutions per minute during a power take off regeneration process.

24. The apparatus of claim 19, wherein the low flow soot operations circuit is further configured to periodically decrement the lower flow threshold value.

25. The apparatus of claim 19, wherein the predetermined time threshold value is at least 5 hours.