Mechanism and method of combined fuel reformer and dosing system for exhaust aftertreatment and anti-idle SOFC APU

• US 20060174608A1
• Filed: 02/07/2005
• Published: 08/10/2006
• Est. Priority Date: 02/07/2005
• Status: Active Grant

• Current Assignee: International Engine Intellectual Property Company, LLC (Volkswagen AG)
• Original Assignee: Eaton Corp. (Wisconsin) (Eaton Corporation PLC.)
• Inventors: McCarthy, James Edward Jr., Bevan, Karen Evelyn, Hu, Haoran, Singh, Vishal, Yan, Jiyang, Radhamohan, Subbaraya, Reuter, Johannes W.
• Granted Patent: US 7,213,397 B2
• Time in Patent Office: Days
• US Class Current: 60/286
• CPC Class Codes: B01D 53/90 Injecting reactants
• CPC Class Codes: B01D 53/9431 Processes characterised by a specific device
• CPC Class Codes: B01D 53/96 Regeneration, reactivation or recycling of reactants
• CPC Class Codes: B60L 58/33 by cooling
• CPC Class Codes: B60L 58/34 by heating
• CPC Class Codes: B60L 58/40 for controlling a combination of batteries and fuel cells
• CPC Class Codes: F01N 2240/30 a fuel reformer
• CPC Class Codes: F01N 3/0871 Regulation of absorbents or adsorbents, e.g. purging by electrically controlling the supply of combustible mixture or its constituents only F02D41/0235
• CPC Class Codes: F01N 3/20 specially adapted for catalytic conversion F01N3/22 takes precedence; Methods of operation or control of catalytic converters
• 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: F02N 11/04 the motors being associated with current generators
• CPC Class Codes: F02N 11/0814 comprising means for controlling automatic idle-start-stop
• CPC Class Codes: F02N 2200/061 Battery state of charge [SOC]
• CPC Class Codes: H01M 16/006 of fuel cells with rechargeable batteries
• CPC Class Codes: H01M 2250/20 Fuel cells in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: H01M 2250/40 Combination of fuel cells with other energy production systems
• CPC Class Codes: H01M 8/0618 Reforming processes, e.g. autothermal, partial oxidation or steam reforming
• CPC Class Codes: H01M 8/12 operating at high temperature, e.g. with stabilised ZrO2 electrolyte
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y02T 10/12 : Improving ICE efficiencies
• CPC Class Codes: Y02T 10/40 : Engine management systems
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 90/40 : Application of hydrogen technology to transportation, e.g. using fuel cells

Abstract

The invention relates to a power generation system with a continuously operating fuel reformer. Preferably, the fuel reformer is either off, warming up, or operating with an essentially constant fueling rate. Some of the reformed fuel is intermittently used to regenerate a NOx trap that treats the exhaust of an internal combustion engine. Any reformed fuel not used for other purposes is supplied to a fuel cell. The fuel reformer does not shut down between NOx trap regeneration cycles except when the engine is also shut down. The invention substantially eliminates issues of reformer response time as they relate to NOx trap regeneration.

Claims

1. A power generation system, comprising:

an internal combustion engine configured to drive an axle and operational to produce exhaust;

a NOx trap operational to extract NOx from the exhaust;

a fuel reformer operational to produce reformate; and

a fuel cell configured to receive at least a portion of the reformate and use it to generate electrical power;

wherein the system is configured to regenerate the NOx trap using a portion of the reformate; and

the system is configured for the fuel reformer to operate in such a way that NOx trap regeneration can always commence on demand whenever the power generation system is operating steadily after warm-up without the need to first change operation of the reformer in response to the demand.

2. The power generation system of claim 1, the system is not configured to supply the reformate to the engine.

3. The power generation system of claim 1, wherein the system is configured to by default supply the reformate to the fuel cell, diverting a portion of the reformate from the fuel cell to the NOx trap as needed for regeneration and the diversions occur without significantly modifying operational settings for the fuel reformer.

4. The power generation system of claim 1, wherein the system is the fuel reformer is configured to operate according to settings that are not designed to change significantly between periods of regenerating the NOx trap and periods wherein the NOx trap is not being regenerated.

5. The power generation system of claim 1, further comprising an electric motor configured to drive the axle.

6. The power generation system of claim 5, further comprising a battery storage system and-wherein the power generation system is configured to deliver power to the electric motor in a manner that limits the accumulation of energy in the battery storage system.

7. The power generation system of claim 5, wherein the system is configured to automatically shut down the internal combustion engine while continuing to drive the axle during periods when power demands can be met without the engine.

8. The power generation system of claim 1, wherein the system is configured to startup and shutdown the fuel reformer, but to otherwise operate the fuel reformer with a fueling rate that is essentially constant.

9. A vehicle comprising the power generation system of claim 1.

10. The vehicle of claim 9, further comprising an accelerator pedal, wherein the system is configured to automatically shutdown the engine when an operator removes his foot from the accelerator pedal.

11. A method of operating a power generation system comprising an internal combustion engine, a fuel reformer, a NOx trap, and a fuel cell, comprising:

operating the fuel reformer at least whenever the engine is running, except optionally while the engine is warming up;

using the reformed fuel to power the fuel cell and thereby produce a significant amount of power;

intermittently regenerating the NOx trap by redirecting a portion of the reformed fuel from the fuel cell to the NOx trap;

wherein throughout periods between startup and shutdown of the fuel reformer the fuel reformer is operated with an essentially constant fueling rate.

12. The method of claim 11, wherein the engine is shutdown rather than idled.

13. The method of claim 11, wherein the reformer fueling rate does not vary substantially as the NOx trap is intermittently regenerated.

14. The method of claim 11, wherein the fuel reformer is operated at an essentially constant fueling rate whenever the fuel reformer is warmed up and operating.

15. The method of claim 11, wherein the power generation system further comprises an electric drive and the method further comprises selectively delivering power to the electric drive to avoid accumulation of excess electrical energy during prolong periods of fuel reformer and fuel cell operation.

16. The method of claim 11, wherein the power generation system further comprises an electric drive and a battery system and the method comprises selectively engaging the electric drive in response to a charge level in the battery system.

17. The method of claim 16, wherein the electric drive is engaged upon the battery system exceeding a determinate charge level.

18. The method of claim 16, wherein the electric drive is disengaged when the battery system falls below a determinate charge level.

19. The method of claim 11, wherein the power generation system further comprises a battery system and the fuel reformer is not shutdown unless the engine is off and the battery system has at least a determinate level of charge.

21. A method of operating a vehicle having a power generation system, comprising operating the power generation system according to the method of claim 11.

22. The method of claim 21, wherein the fuel reformer and fuel cell provide sufficient energy for cabin heating and other electrical demands of the vehicle while the engine is stopped.

23. The method of claim 21, wherein the fuel reformer is operated at an essentially constant fueling rate whenever the fuel reformer is warmed up and being supplied with fuel.

20. (canceled)

24. A method of operating a fuel reformer mounted on a vehicle having an internal combustion engine that produces exhaust, a pollution control device that treats the exhaust, and a fuel cell, comprising:

operating the fuel reformer to produce reformate;

providing the reformate to the pollution control device as needed; and

sending reformate in excess of other needs to the fuel cell;

wherein the fuel reformer is operated in such a way that NOx trap regeneration can commence on demand without the need to first change operation of the reformer in response to the demand as long as the engine is not shut down.

25. The method of claim 24, wherein the fuel reformer operates at an essentially constant rate.

26. The method of claim 24, further comprising automatically starting the fuel reformer to provide reformate to the fuel cell to produce power to charge a battery system whenever fuel is available and the battery system charge falls below a determinate level.

27. The method of claim 24, wherein none of the reformate is supplied to the engine.