SELECTIVE CATALYST REDUCTION HEAT MANAGEMENT METHOD AND SYSTEM

• US 20150285174A1
• Filed: 04/08/2014
• Published: 10/08/2015
• Est. Priority Date: 04/08/2014
• Status: Active Grant

• Current Assignee: Komatsu America Corporation (Komatsu)
• Original Assignee: Komatsu America Corporation (Komatsu)
• Inventors: Scott, David J.
• Granted Patent: US 9,458,782 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: F01N 2430/00 Influencing exhaust purification, e.g. starting of catalytic reaction, filter regeneration, or the like, by controlling engine operating characteristics
• CPC Class Codes: F01N 3/2066 Selective catalytic reduction [SCR]
• CPC Class Codes: F01N 3/208 Control of selective catalytic reduction [SCR], e.g. dosing of reducing agent
• CPC Class Codes: F02D 2041/026 using an external load, e.g. by increasing generator load or by changing the gear ratio
• CPC Class Codes: F02D 41/021 Introducing corrections for particular conditions exterior to the engine conjoint control of vehicle sub-units for propelling the vehicle B60W30/18
• CPC Class Codes: F02D 41/0245 by increasing temperature of the exhaust gas leaving the engine
• 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

Abstract

The heat provided to a vehicle based SCR system may be managed by purposely increasing the load placed on the vehicle'"'"'s engine such that the engine'"'"'s exhaust gas temperature remains above a predetermined level. The energy generated by the extra load placed on the engine may be dissipated through an energy absorption device. The need for extra engine load may be anticipated to ensure adequate heat is provided to the SCR throughout various operating conditions.

Claims

1. A method for providing adequate heat to a selective catalyst reduction system located in a vehicle with an engine and a selective catalyst reducer (SCR), the method comprising:

sensing a temperature indicative of the gas temperature at an inlet of the SCR;

determining whether the gas temperature at the inlet of the SCR is at a first predetermined minimum temperature;

determining the engine load required for current vehicle operation;

calculating a first increased engine load required to increase the gas temperature at the inlet of the SCR to at least the first predetermined minimum temperature;

calculating a first excess engine load by comparing the engine load required for current vehicle operation to the first increased engine load;

adjusting the engine load to the first increased engine load;

discarding the first excess engine load through a power absorption device.

2. The method of claim 1, further comprising:

determining a haul cycle of the vehicle, wherein the haul cycle includes a plurality of segments;

anticipating a future need for a raised engine load based on the upcoming segments in the haul cycle, wherein at least one segment of the haul cycle calls for the raised engine load, wherein the raised engine load occurs above a second predetermined temperature of the gas at the inlet of the SCR;

calculating a second increased engine load required to increase the gas temperature at the inlet of the SCR to at least the second predetermined temperature;

calculating a second excess engine load by comparing the first increased engine load to the second increased engine load;

adjusting the engine load to the second increased engine load before the vehicle reaches the haul cycle segment that calls for the raised engine load;

discarding the second excess engine load through a power absorption device.

3. The method of claim 2, wherein an odometer reading of the vehicle is used to anticipate a future need for a raised engine load.

4. The method of claim 2, wherein a time period that the vehicle has been in the haul cycle is used to anticipate a future need for a raised engine load.

5. The method of claim 2, wherein an energy output of the engine over time is used to anticipate a future need for a raised engine load.

6. The method of claim 1, further comprising:

determining a payload located in the vehicle;

anticipating a future need for a raised engine load based on the payload located in the vehicle, wherein the raised engine load is needed when the payload located in the vehicle reaches a predetermined payload level, wherein the raised engine load occurs above a second predetermined temperature of the gas at the inlet of the SCR;

calculating a second increased engine load required to increase the gas temperature at the inlet of the SCR to at least the second predetermined temperature;

calculating a second excess engine load by comparing the first increased engine load to the second increased engine load;

adjusting the engine load to the second increased engine load before the payload located in the vehicle reaches the predetermined payload level;

discarding the second excess engine load through a power absorption device.

7. The method of claim 1, further comprising:

determining whether the engine is operating at the first increased engine load;

determining whether the gas temperature at the inlet of the SCR is above the first predetermined minimum temperature;

calculating a second increased engine load required to decrease the gas temperature at the inlet of the SCR to the first predetermined minimum temperature, wherein the second increased engine load is lower than the first increased engine load;

calculating a second excess engine load by comparing the first increased engine load to the second increased engine load;

adjusting the engine load to the second increased engine load;

discarding the second excess engine load through a power absorption device.

8. The method of claim 1, wherein the power absorption device is selected from a group consisting of brakes, electronic energy storage devices, batteries, flywheels, hydraulic systems, retarding grids, and combinations of the foregoing.

9. The method of claim 1, wherein the first predetermined temperature relates to a minimum gas temperature required for SCR performance.

10. The method of claim 2, wherein the second predetermined temperature relates to a minimum gas temperature indicative of improved engine responsiveness.

11. A method for maintaining engine load and for providing adequate heat to a selective catalyst reduction system located in a vehicle with an engine and a selective catalyst reducer (SCR), the method comprising:

determining a haul cycle of the vehicle, wherein the haul cycle includes a plurality of segments;

anticipating a future need for an increased engine load based on the upcoming segments in the haul cycle, wherein at least one segment of the haul cycle will result in a gas temperature at the inlet of the SCR falling below a predetermined minimum temperature;

calculating an increased engine load required to increase the gas temperature at the inlet of the SCR to at least the predetermined minimum temperature;

determining the engine load required for current vehicle operation;

calculating an excess engine load by comparing the engine load required for current vehicle operation to the increased engine load;

adjusting the engine load to the increased engine load before the vehicle reaches the haul cycle segment that will result in a gas temperature at the inlet of the SCR falling below the predetermined minimum temperature;

discarding the excess engine load through a power absorption device.

12. The method of claim 11, wherein the power absorption device is selected from a group consisting of brakes, electronic energy storage devices, batteries, flywheels, hydraulic systems, retarding grids, and combinations of the foregoing.

13. The method of claim 11, wherein the predetermined temperature relates to a minimum gas temperature required for SCR performance.

14. The method of claim 11, wherein the predetermined temperature relates to a minimum gas temperature indicative of improved engine responsiveness.

15. A selective catalyst reduction heat management system located in a vehicle with an engine, the system comprising:

a sensor configured to determine a temperature indicative of the gas temperature at the inlet of a selective catalyst reducer (SCR);

an SCR controller in communication with the sensor, the SCR controller configured to;

determine whether the gas temperature at the inlet of the SCR is at a first predetermined minimum temperature;

calculate a first increased engine load required to increase the gas temperature at the inlet of the SCR to at least the first predetermined minimum temperature;

a drive system controller in communication with the SCR controller, the drive system controller configured to;

determine an engine load required for current vehicle operation;

calculate a first excess engine load by comparing the engine load required for current vehicle operation to the first increased engine load;

adjust the engine load to the first increased engine load;

a power absorption device in communication with the drive system controller and connected to the engine, wherein the power absorber device is configured to discard the first excess engine load.

16. The selective catalyst reduction heat management system of claim 15, further comprising:

a haul cycle associated with the vehicle, wherein the haul cycle includes a plurality of segments;

wherein the SCR controller is configured to;

anticipate a future need for a raised engine load based on the upcoming segments in the haul cycle, wherein at least one segment of the haul cycle calls for the raised engine load, wherein the raised engine load occurs above a second predetermined temperature of the gas at the inlet of the SCR;

calculate a second increased engine load required to increase the gas temperature at the inlet of the SCR to at least the second predetermined temperature;

wherein the drive system controller is configured to;

calculate a second excess engine load by comparing the first increased engine load to the second increased engine load;

adjust the engine load to the second increased engine load before the vehicle reaches the haul cycle segment that calls for the raised engine load;

wherein the power absorption device is configured to discard the second excess engine load.

17. The selective catalyst reduction heat management system of claim 15, further comprising:

a payload sensor in communication with the SCR controller, wherein the payload sensor is configured to determine the payload located in the vehicle;

wherein the SCR controller is configured to;

anticipate a future need for a raised engine load based on the payload located in the vehicle, wherein the raised engine load is needed when the payload located in the vehicle reaches a predetermined payload level, wherein the raised engine load occurs above a second predetermined temperature of the gas at the inlet of the SCR;

calculate a second increased engine load required to increase the gas temperature at the inlet of the SCR to at least the second predetermined temperature;

wherein the drive system controller is configured to;

calculate a second excess engine load by comparing the first increased engine load to the second increased engine load;

adjust the engine load to the second increased engine load before the payload located in the vehicle reaches the predetermined payload level;

wherein the power absorption device is configured to discard the second excess engine load.

18. The selective catalyst reduction heat management system of claim 15, wherein the SCR controller is configured to:

determine whether the gas temperature at the inlet of the SCR is above the first predetermined minimum temperature;

calculate a second increased engine load required to decrease the gas temperature at the inlet of the SCR to the first predetermined minimum temperature, wherein the second increased engine load is lower than the first increased engine load;

wherein the drive system controller is configured to;

determine whether the engine is operating at the first increased engine load;

calculate a second excess engine load by comparing the first increased engine load to the second increased engine load;

adjust the engine load to the second increased engine load;

wherein the power absorption device is configured to discard the second excess engine load.

19. The selective catalyst reduction heat management system of claim 15, wherein the power absorption device is selected from a group consisting of brakes, electronic energy storage devices, batteries, flywheels, hydraulic systems, retarding grids, and combinations of the foregoing.

20. The selective catalyst reduction heat management system of claim 15, wherein the first predetermined temperature relates to a minimum gas temperature required for SCR performance.

21. The selective catalyst reduction heat management system of claim 16, wherein the second predetermined temperature relates to a minimum gas temperature indicative of improved engine responsiveness.

22. The selective catalyst reduction heat management system of claim 16, wherein an odometer reading of the vehicle is used to anticipate a future need for a raised engine load.

23. The selective catalyst reduction heat management system of claim 16, wherein a time period that the vehicle has been in the haul cycle is used to anticipate a future need for a raised engine load.

24. The selective catalyst reduction heat management system of claim 16, wherein an energy output of the engine over time is used to anticipate a future need for a raised engine load.