SOFC hot box components

• US 9,941,525 B2
• Filed: 01/20/2015
• Issued: 04/10/2018
• Est. Priority Date: 01/06/2011
• Status: Active Grant

• Current Assignee: Bloom Energy Corporation
• Original Assignee: Bloom Energy Corporation
• Inventors: Perry, Martin, Krishnan, Navaneetha, Basu, Nilanjana, Ramanan, Ram
• Primary Examiner(s): Jelsma, Jonathan
• Assistant Examiner(s): KEKIA, OMAR M
• Application Number:
  US14/600,450
• Publication Number:
  US 20150140457A1
• Time in Patent Office: 1,176 Days
• Field of Search: 429408
• 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 fuel cell system, comprising:

a hot box;

fuel cell stacks located in the hot box;

a cathode recuperator heat exchanger located in the hot box;

an anode cooler heat exchanger; and

a cathode exhaust steam generator comprising a steam generator coil located in the hot box between an inner lid and an outer lid of the cathode recuperator heat exchanger, wherein the steam generator coil is positioned horizontally below the anode cooler heat exchanger,

wherein the steam generator coil is located in one horizontal plane and comprises a straight tube, a partially corrugated tube or a fully corrugated tube.

2. The fuel cell system of claim 1, wherein:

the steam generator coil comprises a spiral coil or one or more coils comprising at least one U-turn; and

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 the cathode exhaust stream exiting the cathode recuperator.

3. The fuel cell system of claim 2, wherein the steam generator coil is supported by a horizontal baffle plate which is configured to force a fuel cell stack cathode exhaust stream to pass around the steam generator coil to enhance flow uniformity across the coil.

4. The fuel cell system of claim 3, wherein the baffle plate is configured to force cathode exhaust stream travelling in a substantially vertical direction from the cathode recuperator to flow in a substantially horizontal direction in the steam generator.

5. The fuel cell system of claim 4, wherein the steam generator is configured to force the cathode exhaust stream to flow in an inward radial direction around the steam generator coil.

6. The fuel cell system of claim 3, further comprising support ribs configured to hold the steam generator coil in place.

7. The fuel cell system of claim 2, further comprising a horizontal portion of an air inlet conduit located below the steam generator coil.

8. The fuel cell system of claim 7, further comprising:

an anode tail gas oxidizer (ATO);

a vertical portion of the air inlet conduit in the cathode recuperator heat exchanger located below the steam generator coil;

a vertical portion of an ATO exhaust conduit in the cathode recuperator heat exchanger located below the steam generator coil; and

a hollow cylinder shaped single corrugated plate or sheet which separates the vertical portion of the air inlet conduit from the vertical portion of the ATO exhaust conduit, and which is located below the steam generator coil.

9. The fuel cell system of claim 8, further comprising:

an inlet portion of the ATO exhaust conduit which connects an air exhaust inlet of the cathode recuperator heat exchanger to an output of the ATO; and

a cathode exhaust conduit which connects an air exhaust output of the fuel cell stacks to an air exhaust inlet of the ATO.

10. The fuel cell system of claim 9, wherein the cathode exhaust stream exiting the outlet of the cathode recuperator heat exchanger comprises a combusted cathode exhaust stream.

11. A fuel cell system, comprising:

a hot box;

fuel cell stacks located in the hot box;

a cathode recuperator heat exchanger located in the hot box;

an anode cooler heat exchanger; and

a cathode exhaust steam generator comprising a steam generator coil located in the hot box between an inner lid and an outer lid of the cathode recuperator heat exchanger,

wherein the steam generator coil is positioned horizontally below the anode cooler heat exchanger, and

wherein the steam generator coil is supported by a horizontal baffle plate which is configured to force a fuel cell stack cathode exhaust stream to pass around the steam generator coil to enhance flow uniformity across the coil.