SOFC Hot Box Components

• US 20120196194A1
• Filed: 01/05/2012
• Published: 08/02/2012
• Est. Priority Date: 01/06/2011
• Status: Active Grant

• Current Assignee: Bloom Energy Corporation
• Original Assignee: Bloom Energy Corporation
• Inventors: Perry, Martin, Weingaertner, David, Basu, Nilanjana, Petrucha, Michael, Lyle, William David, Gottmann, Matthias, Krishnan, Navaneetha
• Granted Patent: US 8,563,180 B2
• Time in Patent Office: Days
• US Class Current: 429/410
• CPC Class Codes: F28D 9/0018 without any annular circulation of the heat exchange media
• CPC Class Codes: F28D 9/0025 the conduits being formed by zig-zag bend plates
• CPC Class Codes: F28F 9/02 Header boxes; End plates
• CPC Class Codes: H01M 2008/1293 Fuel cells with solid oxide electrolytes
• CPC Class Codes: H01M 2300/0074 Ion conductive at high temperature
• CPC Class Codes: H01M 8/0297 Arrangements for joining electrodes, reservoir layers, heat exchange units or bipolar separators to each other H01M8/0271 takes precedence
• CPC Class Codes: H01M 8/04007 related to heat exchange
• CPC Class Codes: H01M 8/04022 Heating by combustion
• CPC Class Codes: H01M 8/04052 Storage of heat in the fuel cell system
• CPC Class Codes: H01M 8/04067 Heat exchange or temperature measuring elements, thermal insulation, e.g. heat pipes, heat pumps, fins
• CPC Class Codes: H01M 8/04074 Heat exchange unit structures specially adapted for fuel cell
• CPC Class Codes: H01M 8/04097 with recycling of the reactants H01M8/04119, H01M8/04104 take precedence
• CPC Class Codes: H01M 8/04268 Heating of fuel cells during the start-up of the fuel cells
• CPC Class Codes: H01M 8/0618 Reforming processes, e.g. autothermal, partial oxidation or steam reforming
• CPC Class Codes: H01M 8/0662 Treatment of gaseous reactants or gaseous residues, e.g. cleaning
• CPC Class Codes: H01M 8/12 operating at high temperature, e.g. with stabilised ZrO2 electrolyte
• CPC Class Codes: H01M 8/24 Grouping of fuel cells, e.g. stacking of fuel cells
• CPC Class Codes: H01M 8/2425 High-temperature cells with solid electrolytes
• CPC Class Codes: H01M 8/243 Grouping of unit cells of tubular or cylindrical configuration
• CPC Class Codes: H01M 8/2432 Grouping of unit cells of planar configuration
• CPC Class Codes: Y02E 60/50 : Fuel cells

Abstract

Various hot box fuel cell system components are provided, such as heat exchangers, steam generator and other components.

Claims

1. A heat exchanger, comprising:

a top enclosure comprising a finger plate or end cap;

a bottom enclosure comprising a finger plate or end cap; and

a corrugated sheet between the top and bottom enclosure;

wherein the heat exchanger is configured such that a first fluid flows on one side of the corrugated sheet and a second fluid flows on an opposite side of the corrugated sheet.

2. The heat exchanger of claim 1, wherein:

the top and the bottom enclosure each comprise a finger plate;

the heat exchanger comprises an anode cooler heat exchanger for a solid oxide fuel cell system;

the first fluid comprises a fuel exhaust from a solid oxide fuel cell stack; and

the second fluid comprises an air inlet for the solid oxide fuel cell stack.

3. The heat exchanger of claim 1, wherein:

the top and the bottom enclosure each comprise an end cap;

the heat exchanger comprises an anode cooler heat exchanger for a solid oxide fuel cell system;

the first fluid comprises a fuel exhaust from a solid oxide fuel cell stack; and

the second fluid comprises an air inlet for the solid oxide fuel cell stack.

4. The heat exchanger of claim 1, wherein:

one of the top and bottom enclosures comprises a finger plate and the other one of the top and bottom enclosures comprises an end cap;

the heat exchanger comprises an anode cooler heat exchanger for a solid oxide fuel cell system;

the first fluid comprises a fuel exhaust from a solid oxide fuel cell stack; and

the second fluid comprises an air inlet for the solid oxide fuel cell stack.

5. The heat exchanger of claim 2, wherein:

the top enclosure comprises a top finger plate;

the bottom enclosure comprises a bottom finger plate;

the corrugated sheet comprises a cylindrical metal sheet;

the top finger plate comprises a hollow ring shaped plate having finger shaped extensions which extend into the inner portion of the ring;

the bottom finger plate comprises a hollow ring shaped plate having finger shaped extensions which extend into the inner portion of the ring; and

the top and bottom finger plates are offset from each other by one corrugation, such that fingers of the top finger plate cover every one either inward or outward facing recesses in the corrugated sheet, and fingers of the bottom finger plate cover every other one of the inward or outward facing recesses in the corrugated sheet.

6. The heat exchanger of claim 2, wherein:

the first side of the corrugated sheet is in fluid communication with a fuel exhaust conduit which is connected to the fuel exhaust of the solid oxide fuel cell stack and in fluid communication with an exhaust conduit from an anode recuperator heat exchanger; and

the second side of the corrugated sheet is in fluid communication with an air inlet stream conduit.

7. A cathode recuperator uni-shell comprising a monolithic assembly comprising a single cylindrical corrugated fin plate;

a top enclosure comprising a finger plate or end cap; and

a bottom enclosure comprising a finger plate or end cap;

wherein the cathode recuperator uni-shell is configured so that a first fluid flows on one side of the single cylindrical corrugated fin plate and a second fluid flows on an opposite side of the single cylindrical corrugated fin plate.

8. The cathode recuperator uni-shell of claim 7, wherein the top and the bottom enclosure each comprise a finger plate.

9. The cathode recuperator uni-shell of claim 7, wherein the top and the bottom enclosure each comprise an end cap.

10. The cathode recuperator uni-shell of claim 7, wherein one of the top and bottom enclosures comprises a finger plate and the other one of the top and bottom enclosures comprises an end cap.

11. The cathode recuperator uni-shell of claim 8, wherein:

the top enclosure comprises a top end cap;

the bottom enclosure comprises a bottom end cap;

wherein the top end cap and the bottom end cap are configured to force the first fluid and the second fluid to make a non-zero angle turn before flowing along the single cylindrical corrugated fin plate.

12. The cathode recuperator uni-shell of claim 11, wherein the non-zero angle turn comprises a turn of about 90 degrees from radial flow direction to an axial flow direction with respect to the cathode recuperator uni-shell having a cylindrical shape.

13. The cathode recuperator uni-shell of claim 7, further comprising a steam generator located above the cathode recuperator uni-shell.

14. The cathode recuperator uni-shell of claim 13, wherein the steam generator is located between an inner lid and an outer lid of the cathode recuperator uni-shell or in an exit plenum of the cathode recuperator.

15. The cathode recuperator uni-shell of claim 13, wherein the steam generator comprises a steam generator coil, the steam generator coil is in fluid communication with a cathode exhaust outlet of the cathode recuperator to allow conversion of water to steam in the coil using heat of a stack cathode exhaust stream exiting the outlet of the cathode recuperator.

16. The cathode recuperator uni-shell of claim 15, wherein the steam generator coil is supported by a baffle plate.

17. A fuel cell system, comprising:

a hot box;

a fuel cell stack located in the hot box; and

at least one uni-shell heat exchanger located in the hot box, the at least one uni-shell heat exchanger comprising a roughly cylindrical corrugated sheet process gas separator, wherein peaks and valleys of the cylindrical corrugated sheet process gas separator are aligned parallel to an axial direction of the cylindrical corrugated sheet process gas separator.

18. The system of claim 17, wherein:

the heat exchanger is configured to allow a hotter process gas and a cooler process gas to flow on respective opposing surfaces of the gas separator; and

the hotter process gas stream is configured to provide convective heat transfer to the gas separator, conductive heat transfer through a thickness of the gas separator, and convective heat transfer from the gas separator to the cooler process gas stream.

19. The system of claim 17, wherein:

the at one uni-shell heat exchanger comprises a roughly cylindrical anode cooler uni-shell heat exchanger and a roughly cylindrical cathode recuperator uni-shell heat exchanger;

the anode cooler is configured to allow substantially axial fuel cell stack anode exhaust stream and air inlet stream entry into the anode cooler; and

the cathode recuperator is configured to allow substantially non-axial ATO exhaust stream and the air inlet stream entry into the cathode recuperator.

20. A fuel cell system comprising:

at least one fuel cell stack or column; and

a cathode recuperator heat exchanger in which an air inlet stream to the at least one fuel cell stack or column is heated by an air exhaust stream from the at least one fuel cell stack or column;

wherein the air inlet stream outlet of the cathode recuperator heat exchanger is located adjacent to any one or more points in a middle portion of the fuel cell stack or column, such that the air inlet stream exiting the cathode recuperator is directed towards a middle portion of the at least one fuel cell stack or column.