Integrated solid oxide fuel cell mechanization and method of using for transportation industry applications

• US 6,562,496 B2
• Filed: 04/30/2001
• Issued: 05/13/2003
• Est. Priority Date: 05/01/2000
• Status: Expired due to Term

• Current Assignee: Bayerische Motoren Werke AG
• Original Assignee: Delphi Technologies, Inc. (Aptiv PLC), Bayerische Motoren Werke AG
• Inventors: Noetzel, John G., Shaffer, Steven R., Schumann, David R., DeMinco, Christopher M., Grieve, M. James, Haller, James M., Vavonese, Catherine C., Keegan, Kevin R., Simpkins, Haskell, Mukerjee, Subhasish, Haltiner, Karl J. Jr., Faville, Michael T., Armstrong, Donald J., Husted, Harry L., Kammerer, Juergen T., OʼBrien, John F.
• Primary Examiner(s): Chaney, Carol
• Assistant Examiner(s): Scaltrito, Donald V.
• Application Number:
  US09/845,531
• Publication Number:
  US 20020025458A1
• Time in Patent Office: 743 Days
• Field of Search: 429/12, 429/13, 429/17, 429/19, 429/26, 429/29, 429/30, 429/34
• US Class Current: 429/423
• CPC Class Codes: H01M 2008/1293 Fuel cells with solid oxide electrolytes
• CPC Class Codes: H01M 8/04014 Heat exchange using gaseous fluids; Heat exchange by combustion of reactants
• CPC Class Codes: H01M 8/04089 of gaseous reactants
• CPC Class Codes: H01M 8/04268 Heating of fuel cells during the start-up of the fuel cells
• CPC Class Codes: H01M 8/0612 from carbon-containing material
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

A method of starting a solid oxide fuel cell system is disclosed. The method comprises pressurizing a main plenum to a first pressure. The main plenum comprises a first supply of fuel, blowers, and air control valves. The first supply of fuel and a first supply of air are directed to a preheated micro-reformer. A heated pre-reformate is created in the micro-reformer and discharged from the micro-reformer to a main reformer. The main reformer is preheated with the heated pre-reformate. A second supply of fuel and a second supply of air are introduced to the main reformer. A heated main reformate is created in the main reformer and directed to a waste energy recovery assembly. A cathode supply is heated in the waste energy recovery system and then directed to a solid oxide fuel cell stack in order to heat the solid oxide fuel cell stack. Methods of transitioning, operating, shutting down, and maintaining in standby mode are also disclosed. A solid oxide fuel cell mechanization for a transportation vehicle is also disclosed.

Claims

1. A method of starting a solid oxide fuel cell system, comprising:

pressurizing a main plenum to a first pressure, wherein said main plenum comprises a first supply of fuel, blowers, and air control valves;

directing said first supply of fuel and a first supply of air to a preheated micro-reformer;

creating a heated pre-reformate in said micro-reformer;

discharging said heated pre-reformate from said micro-reformer to a main reformer;

preheating said main reformer with said preheated pre-reformate;

introducing a second supply of fuel and a second supply of air to said main reformer;

creating a heated main reformate in said main reformer;

directing said heated main reformate to a waste energy recovery assembly;

heating a cathode supply in said waste energy recovery system; and

directing said heated cathode supply to heat said solid oxide fuel cell stack.

2. The method of claim 1, wherein said solid oxide fuel cell stack is at an ambient temperature of about −

40°

C. to about 50°

C., and is heated to a temperature of up to about 120°

C.

3. The method of claim 1, further comprising directing said heated pre-reformate and said heated main reformate through a reformate control valve.

4. The method of claim 1, further comprising electrically preheating said micro-reformer.

5. The method of claim 1, further comprising monitoring said heated main reformate with a sensor selected from the group consisting of pressure sensors, temperature sensors, and combinations comprising at least one of the foregoing sensors.

6. The method of claim 1, further comprising directing said heated pre-reformate and said heated main reformate through said waste energy recovery assembly to said solid oxide fuel cell stack.

7. A method of transitioning a solid oxide fuel cell system to normal operating conditions, comprising:

operating a main reformer to produce a reformate;

directing said reformate in a first stream and second stream to a waste energy recovery assembly;

catalytically combusting said first stream of said reformate in said waste energy recovery assembly;

producing thermal energy in said waste energy recovery assembly to heat said second stream of said reformate and a supply of air;

directing said second stream of said reformate and said supply of air to a solid oxide fuel cell stack; and

heating said solid oxide fuel cell stack to a temperature of about 600°

C. or greater.

8. The method of claim 7, further comprising directing said reformate through a reformate control valve.

9. The method of claim 7, wherein said solid oxide fuel cell stack is at a temperature of about 120°

C. or greater and is heated to a temperature of about 600°

C. to about 1,000°

C.

10. The method of claim 9, wherein said solid oxide fuel cell stack is heated to about 650°

C. to about 800°

C.

11. A method of operating a solid oxide fuel cell system, comprising:

directing a supply of reformate from a waste energy recovery assembly to a solid oxide fuel cell stack;

using said supply of reformate and a supply of air in said solid oxide fuel cell stack;

producing electrical energy in said solid oxide fuel cell stack;

harnessing said electrical energy;

sensing a condition of said reformate; and

adjusting said supply of reformate and/or said supply of air, based upon said condition, to meet a demand by a vehicle for said electrical energy.

12. The method of claim 11, wherein said condition is selected from the group consisting of temperature, pressure sensor, gas content, and combinations comprising at least one of the foregoing conditions.

13. A method of shutting down a solid oxide fuel cell system, comprising:

maintaining a supply of air to a solid oxide fuel cell stack and at least one thermal enclosure;

decreasing a supply of reformate to said solid oxide fuel cell stack;

stopping said supply of reformate after an anode oxidation period has passed; and

stopping said supply of air to said solid oxide fuel cell stack.

14. The method of claim 13, further comprising maintaining said supply of reformate at a sufficient flow to prevent anode oxidation during said anode oxidation period.

15. The method of claim 13, wherein said solid oxide fuel cell stack is to about 200°

C. or less.

16. The method of claim 13, further comprising cooling a system enclosure with said supply of air to a temperature of about 45°

C. or less.

17. The method of claim 13, further comprising exhausting stored thermal energy through a waste energy recovery assembly with said supply of air.

18. A method of operating a solid oxide fuel cell system, comprising:

directing a supply of reformate and a supply of air to a solid oxide fuel cell stack;

operating said solid oxide fuel cell stack;

reducing said supply of reformate and said supply of air to said solid oxide fuel cell stack; and

maintaining said solid oxide fuel cell stack at a standby temperature of about 400°

C. to about 600°

C.

19. The method of claim 18, further comprising transitioning said solid oxide fuel cell system from said standby temperature to an operating of about 600°

C. or less based upon a vehicle load request.

20. A solid oxide fuel cell mechanization for a transportation vehicle, comprising:

a solid oxide fuel cell stack;

a reformer system disposed in fluid communication with said solid oxide fuel cell stack, wherein said reformer system comprises a main reformer and a micro-reformer;

a waste energy recovery assembly disposed in fluid communication with said solid oxide fuel cell stack and said reformer system;

a system enclosure disposed around said solid oxide fuel cell stack, said waste energy recovery assembly, and said reformer system;

a thermal management system disposed within said system enclosure, wherein said thermal management system comprises a main plenum and an insulation plenum enclosing a chamber, said chamber comprising said solid oxide fuel cell stack, said reformer system, and said waste energy recovery system; and

a process air supply disposed in fluid communication with said thermal management system.

21. The mechanization of claim 20, wherein said micro-reformer and said main reformer are partial oxidation reformers.

22. The mechanization of claim 20, wherein said insulation plenum comprises an active porous insulation.

23. The mechanization of claim 20, further comprising a plenum bulkhead disposed in contact with said main plenum and said insulation plenum.

24. The mechanization of claim 20, further comprising a main blower, air control valves, and an actuator in said main plenum.

25. The mechanization of claim 20, further comprising an enclosure lid cooling air passage in thermal communication with said main plenum.

26. The mechanization of claim 20, further comprising a reformate control valve in fluid communication with said reformer system.