Systems and methods for managing ammonia slip with a heater

Patent metadata

Field	Value
Publication number	US-12372019-B2
Application number	US-202218554710-A
Country	US
Kind code	B2
Filing date	Apr 11, 2022
Priority date	Apr 12, 2021
Publication date	Jul 29, 2025
Grant date	Jul 29, 2025

Abstract

Systems and methods for controlling and managing ammonia slip are provided. A method includes: receiving, by a controller, data regarding operation of an exhaust aftertreatment system; determining, by the controller, that a condition for ammonia slip is present based on the data regarding operation of the exhaust aftertreatment system; determining, by the controller, that a condition for ammonia storage is present based on the data regarding operation of the exhaust aftertreatment system; and, commanding, by the controller, a heater to activate and warm a component of the exhaust aftertreatment system to reduce the stored amount of ammonia.

First claim

What is claimed is:

1. A method comprising:
receiving, by a controller, data regarding operation of an exhaust aftertreatment system;
determining, by the controller, that a condition for ammonia slip is present based on the data regarding operation of the exhaust aftertreatment system;
determining, by the controller, that a condition for ammonia storage is present based on an engine fueling rate exceeding a transient threshold; and
commanding, by the controller, a heater to activate and warm a component of the exhaust aftertreatment system to reduce a stored amount of ammonia, the component being an Ammonia Slip Catalyst (ASC).

2. The method of claim 1 , wherein the condition for ammonia slip is at least one of a sensed amount of system-out NOx exceeding a sensed amount of engine-out NOx or a sensed amount of ammonia exceeding an ammonia slip threshold.

3. The method of claim 1 , further comprising determining an amount of ammonia storage based on at least one of a sensed amount of engine-out NOx, a sensed amount of system-out NOx, a dosing rate of diesel exhaust fluid, an exhaust flow rate, or a sensed temperature of the exhaust aftertreatment system,
wherein the condition for ammonia slip is the determined amount of ammonia storage exceeding an ammonia slip threshold.

4. The method of claim 1 , wherein the determination that the condition for ammonia storage is present is further based on a sensed temperature of the ASC being below a threshold value.

5. The method of claim 1 , wherein the heater is integrated into the ASC.

6. A system comprising:
an exhaust aftertreatment system including a heater; and
a controller coupled to the exhaust aftertreatment system, the controller configured to:
receive data regarding operation of the exhaust aftertreatment system;
determine that a condition for ammonia slip is present based on the data regarding operation of the exhaust aftertreatment system;
determine that a condition for ammonia storage is present based on an engine fueling rate exceeding a transient threshold; and
command the heater to activate and warm a component of the exhaust aftertreatment system to reduce a stored amount of ammonia, the component being an Ammonia Slip Catalyst (ASC).

7. The system of claim 6 , wherein the condition for ammonia slip is at least one of a sensed amount of system-out NOx exceeding a sensed amount of engine-out NOx or a sensed amount of ammonia exceeding an ammonia slip threshold.

8. The system of claim 6 , wherein the controller is further configured to:
determine an amount of ammonia storage based on at least one of a sensed amount of engine-out NOx, a sensed amount of system-out NOx, or a sensed temperature of the exhaust aftertreatment system,
wherein the condition for ammonia slip is the determined amount of ammonia storage exceeding an ammonia slip threshold.

9. The system of claim 6 , wherein the determination that the condition for ammonia storage is present is further based on a sensed temperature of the ASC being below a threshold value.

10. The system of claim 6 , wherein the transient threshold is a predefined high fueling rate threshold for a predefined period of time.

11. The system of claim 10 , wherein the heater is integrated into the ASC.

12. A non-transitory computer-readable storage medium comprising computer-readable instructions stored thereon that, when executed by a processor of a controller, causes the controller to perform operations comprising:
receiving data regarding operation of an exhaust aftertreatment system, the data including at least one of (i) a sensed amount of engine-out NOx and a sensed amount of system-out NOx or (ii) a sensed amount of ammonia in an exhaust gas stream;
determining that a condition for ammonia slip is present based on (i) the sensed amount of system-out NOx exceeding a sensed amount of engine-out NOx, or (ii) the sensed amount of ammonia in the exhaust gas stream exceeding a threshold;
determining that a condition for ammonia storage is present based on an engine fueling rate exceeding a transient threshold; and
commanding a heater to activate to warm a component of the exhaust aftertreatment system based on the condition for ammonia slip being present, the component being an Ammonia Slip Catalyst (ASC).

13. The non-transitory computer-readable medium of claim 12 , wherein determining the condition for ammonia storage comprises:
receiving data regarding an amount of fueling into an engine coupled to the exhaust aftertreatment system; and
determining that the amount of fueling into the engine exceeds a predefined threshold as a prerequisite for commanding the heater to activate.

14. The non-transitory computer-readable medium of claim 12 , wherein the operations further comprise:
receiving data regarding a temperature of the component of the exhaust aftertreatment system; and
commanding the heater to deactivate based on the temperature exceeding a predefined threshold temperature.

15. The non-transitory computer-readable medium of claim 12 , wherein the heater is integrated into the ASC.

16. The non-transitory computer-readable medium of claim 12 , wherein the operations further comprise:
determining that a current temperature of the component is less than a target temperature of the component by more than a threshold value, and commanding the heater to activate at a first power level; or
determining that the current temperature of the component is less than the target temperature of the component by less than the threshold value, and commanding the heater to activate at a second power level less than the first power level.

Assignees

• Cummins Inc

Inventors

• Luo Jinyong
• Qiu Lu
• Schmidt David
• Song Xiaobo
• Song Yuying
• Yuan Ying

Classifications

• F01N2900/04

  Methods of control or diagnosing · CPC title

• F01N2610/02

  the substance being ammonia or urea · CPC title

• F01N2550/22

  of electric heaters for exhaust systems or their power supply · CPC title

• F01N2550/03

  of sorbing activity of adsorbents or absorbents · CPC title

• F01N2240/16

  an electric heater, i.e. a resistance heater · CPC title