Fuel water vapor replenishment system for a fuel cell

• US 20030162067A1
• Filed: 02/20/2003
• Published: 08/28/2003
• Est. Priority Date: 02/20/2002
• Status: Abandoned Application

• Current Assignee: Bloom Energy Corporation
• Original Assignee: Bloom Energy Corporation
• Inventors: McElroy, James F.
• Application Number:
  US10/368,425
• Publication Number:
  US 20030162067A1
• Time in Patent Office: Days
• US Class Current: 429/26
• CPC Class Codes: H01M 2008/1293 Fuel cells with solid oxide electrolytes
• CPC Class Codes: H01M 2250/00 Fuel cells for particular applications; Specific features of fuel cell system
• CPC Class Codes: H01M 2250/40 Combination of fuel cells with other energy production systems
• CPC Class Codes: H01M 2250/405 Cogeneration of heat or hot water
• CPC Class Codes: H01M 2300/0074 Ion conductive at high temperature
• CPC Class Codes: H01M 8/0247 characterised by the form characterised by a channel configuration H01M8/0258
• CPC Class Codes: H01M 8/028 Sealing means characterised by their material
• CPC Class Codes: H01M 8/04007 related to heat exchange
• CPC Class Codes: H01M 8/04022 Heating by combustion
• CPC Class Codes: H01M 8/04111 using a compressor turbine assembly
• CPC Class Codes: H01M 8/04141 by water containing exhaust gases
• CPC Class Codes: H01M 8/04291 Arrangements for managing water in solid electrolyte fuel cell systems H01M8/04119 takes precedence
• CPC Class Codes: H01M 8/0662 Treatment of gaseous reactants or gaseous residues, e.g. cleaning
• CPC Class Codes: Y02B 90/10 Applications of fuel cells in buildings
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y10S 429/901 Fuel cell including means for utilization of heat for unrelated application, e.g. heating a building

Abstract

A system contains a solid oxide fuel cell stack and an enthalpy wheel or at least two adsorbent beds. The enthalpy wheel or the adsorbent beds transfer product water vapor from a fuel cell stack anode exhaust to a fuel cell stack fuel supply.

Claims

1. A system comprising:

a solid oxide fuel cell stack; and

an enthalpy wheel which transfers product water vapor from a fuel cell stack anode exhaust to a fuel cell stack fuel supply.

2. The system of claim 1, wherein a rotational speed of the enthalpy wheel controls an amount of water vapor provided into the fuel supply.

3. The system of claim 1, wherein up to 90% of the product water vapor is transferred to the fuel supply.

4. The system of claim 1, wherein a hydrocarbon fuel is steam reformed into a hydrogen rich stream within the anode structure of the solid oxide fuel cells of the fuel cell stack.

5. The system of claim 1, further comprising:

a hydrocarbon fuel inlet into the enthalpy wheel;

a heat exchanger which heats the water vapor containing fuel supply with heat from the anode exhaust;

a first conduit between the enthalpy wheel and a first heat exchanger inlet;

a second conduit between a first heat exchanger outlet and the anode inlet;

a third conduit between the anode exhaust and a second heat exchanger inlet; and

a fourth conduit between a second heat exchanger outlet and the enthalpy wheel.

6. The system of claim 5, wherein all heat transferred to the fuel supply is through the enthalpy wheel and the heat exchanger.

7. The system of claim 1, wherein no boiler is used to provide water vapor into the fuel supply during stead state operation of the system.

8. The system of claim 1, further comprising a boiler adapted to provide additional water vapor into the fuel supply.

9. A system comprising:

a solid oxide fuel cell stack; and

at least two adsorbent beds which transfer product water vapor from a fuel cell stack anode exhaust to a fuel cell stack fuel supply.

10. The system of claim 9, further comprising:

a hydrocarbon fuel inlet into the at least two adsorbent beds;

a first valve which switches fuel input between a first and a second adsorbent bed;

a heat exchanger which heats the water vapor containing fuel supply with heat from the fuel cell stack anode exhaust;

a first conduit connecting the first adsorbent bed and a first heat exchanger inlet or a first heat exchanger outlet;

a second conduit connecting the second adsorbent bed and the first heat exchanger inlet or the first heat exchanger outlet;

at least one second valve which provides a fluid path between the first adsorbent bed and the first heat exchanger inlet in a second position and between the first adsorbent bed and the first heat exchanger outlet in a first position and which provides a fluid path between the second adsorbent bed and the first heat exchanger outlet in the second position and between the second adsorbent bed and the first heat exchanger inlet in the first position;

a third conduit between a second heat exchanger outlet and the anode inlet; and

a fourth conduit between the anode exhaust and a second heat exchanger inlet.

11. The system of claim 9, further comprising a reformer located between a fuel inlet and the solid oxide fuel cell stack.

12. A system comprising:

a solid oxide fuel cell stack; and

a first means for transferring product water vapor from a fuel cell stack anode exhaust to a fuel cell stack fuel supply.

13. The system of claim 12, further comprising a second means for transferring heat from the fuel cell stack anode exhaust to the fuel cell stack fuel supply.

14. A method of hydrating fuel provided into a solid oxide fuel cell stack, comprising:

providing a hydrocarbon fuel into an anode input of solid oxide fuel cell stack; and

transferring product water vapor from a fuel cell stack anode exhaust into a fuel cell stack fuel supply.

15. The method of claim 14, further comprising transferring heat from the fuel cell stack anode exhaust into the fuel cell stack fuel supply to provide the entire supply of water vapor and heat for the fuel supply to operate the solid oxide fuel cell stack.

16. The method of claim 15, wherein an enthalpy wheel is used to transfer the product water vapor into the fuel supply.

17. The method of claim 16, wherein a heat exchanger is used to transfer the heat from the anode exhaust into the fuel supply.

18. The method of claim 16, further comprising controlling a rotation speed of the enthalpy wheel to control an amount of water vapor added to the fuel supply.

19. The method of claim 18, wherein up to 90% of the water vapor from the anode exhaust is transferred to the fuel supply.

20. The method of claim 14, further comprising:

providing the fuel supply through a first adsorbent bed to transfer at least one of water and water vapor into the fuel supply; and

providing the anode exhaust into a second adsorbent bed to store at least one of water and water vapor in the second adsorbent bed.

21. The method of claim 20, further comprising:

providing the fuel supply through the second adsorbent bed to transfer at least one of water and water vapor into the fuel supply; and

providing the anode exhaust into the first adsorbent bed to store at least one of water and water vapor in the second adsorbent bed.