Solid oxide fuel cell system

• US 9,666,885 B2
• Filed: 08/30/2012
• Issued: 05/30/2017
• Est. Priority Date: 09/15/2011
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Fuel Cell Systems Inc. (LG Corporation)
• Inventors: Bozzolo, Michele, Balestrino, Cristiano
• Primary Examiner(s): Siddiquee, Muhammad
• Application Number:
  US14/342,952
• Publication Number:
  US 20140242483A1
• Time in Patent Office: 1,734 Days
• CPC Class Codes: H01M 2008/1293 Fuel cells with solid oxide electrolytes
• CPC Class Codes: H01M 2250/402 Combination of fuel cell with other electric generators
• CPC Class Codes: H01M 8/04014 Heat exchange using gaseous fluids; Heat exchange by combustion of reactants
• CPC Class Codes: H01M 8/04097 with recycling of the reactants H01M8/04119, H01M8/04104 take precedence
• CPC Class Codes: H01M 8/04111 using a compressor turbine assembly
• CPC Class Codes: Y02B 90/10 Applications of fuel cells in buildings
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

A solid oxide fuel cell system (10) comprises a solid oxide fuel cell stack (12) and a gas turbine engine (14). The solid oxide fuel cell stack (12) comprises a plurality of solid oxide fuel cells (16). The gas turbine engine (14) comprises a compressor (24) and a turbine (26). The compressor (24) supplies oxidant to the cathodes (22) of the fuel cells (16) via an oxidant ejector (60) and the oxidant ejector (60) supplies a portion of the unused oxidant from the cathodes (22) of the fuel cells (16) back to the cathodes (22) of the fuel cells (16) with the oxidant from the compressor (24). The fuel cell system (10) further comprises an additional compressor (64), an additional turbine (66), a cooler (70) and a recuperator (72). The compressor (24) supplies oxidant via the cooler (70) to the additional compressor (64) and the additional compressor (64) supplies oxidant to the oxidant ejector (60) via the recuperator (72). The solid oxide fuel cell stack (12) supplies exhaust gases to the turbine (26) and the turbine (26) supplies the exhaust gases through the recuperator (72) to heat the oxidant flowing through the recuperator (72).

Claims

1. A solid oxide fuel cell system comprising a solid oxide fuel cell stack and a gas turbine engine, the solid oxide fuel cell stack comprising at least one solid oxide fuel cell, each solid oxide fuel cell comprising an electrolyte, an anode and a cathode, the gas turbine engine comprising a compressor and a turbine arranged to drive the compressor, the compressor being arranged to supply oxidant to the cathode of the at least one solid oxide fuel cell via an oxidant mixer, wherein the cathode is arranged to supply a first portion of any unused oxidant to a combustor, the anode of the at least one solid oxide fuel cell is arranged to supply a first portion of any unused fuel to the combustor and the combustor is arranged to supply at least a portion of the combustor exhaust gases to the turbine, and wherein the cathode is arranged to supply a second portion of any unused oxidant to the oxidant mixer without passing through the combustor, the oxidant mixer being arranged to supply the second portion of the unused oxidant from the cathode of the at least one solid oxide fuel cell back to the cathode of the at least one solid oxide fuel cell with the oxidant from the compressor, wherein the solid oxide fuel cell system further comprises an additional compressor and an additional turbine arranged to drive the additional compressor, the compressor being arranged to supply oxidant to the additional compressor, the additional compressor being arranged to supply oxidant to the oxidant mixer and the solid oxide fuel cell stack being arranged to supply exhaust gases to the turbine, and wherein the oxidant mixer is an oxidant ejector, and wherein the solid oxide fuel cell system further comprises a cooler and a recuperator, the compressor being arranged to supply oxidant via the cooler to the additional compressor, the additional compressor being arranged to supply oxidant to the oxidant mixer via the recuperator, the solid oxide fuel cell stack being arranged to supply exhaust gases to the turbine and the turbine being arranged to supply the exhaust gases through the recuperator to heat the oxidant flowing through the recuperator.

2. A solid oxide fuel cell system as claimed in claim 1 wherein the compressor is arranged to supply a portion of the oxidant via the cooler to the additional compressor and the compressor is arranged to supply a portion of the oxidant to the additional turbine.

3. A solid oxide fuel cell system as claimed in claim 1 wherein the recuperator is arranged to supply a portion of the oxidant supplied by the additional compressor to the oxidant mixer and the recuperator is arranged to supply a portion of the oxidant supplied by the additional compressor to the additional turbine.

4. A solid oxide fuel cell system as claimed in claim 1 wherein the cooler is arranged to supply a portion of the oxidant supplied by the compressor to the additional compressor and the cooler is arranged to supply a portion of the oxidant supplied by the compressor to the additional turbine.

5. A solid oxide fuel cell system as claimed in claim 1 wherein the combustor is arranged to supply a portion of the combustor exhaust gases to the turbine.

6. A solid oxide fuel cell system as claimed in claim 5 wherein the combustor is arranged to supply the portion of the combustor exhaust gases to a first flow path through a heat exchanger and the oxidant mixer is arranged to supply the second portion of the unused oxidant from the cathode of the at least one solid oxide fuel cell back to the cathode of the at least one solid oxide fuel cell with the oxidant from the compressor through a second flow path through the heat exchanger.

7. A solid oxide fuel cell system as claimed in claim 6 wherein the additional compressor is arranged to supply oxidant to an additional mixer via the recuperator, the combustor is arranged to supply the combustor exhaust gases to the additional mixer, the additional mixer is arranged to supply oxidant and the combustor exhaust gases to the first flow path through the heat exchanger.

8. A solid oxide fuel cell system as claimed in claim 7 wherein the heat exchanger is arranged to supply a first portion of the combustor exhaust gases and oxidant leaving the first flow path through the heat exchanger to the combustor and the heat exchanger is arranged to supply a second portion of the combustor exhaust gases and oxidant leaving the first flow path through the heat exchanger to the turbine.

9. A solid oxide fuel cell system as claimed in claim 7 wherein the additional mixer is an additional ejector.

10. A solid oxide fuel cell system as claimed in claim 1 wherein the additional compressor is a fan or a blower.

11. A solid oxide fuel cell system comprising a solid oxide fuel cell stack and a gas turbine engine, the solid oxide fuel cell stack comprising at least one solid oxide fuel cell, each solid oxide fuel cell comprising an electrolyte, an anode and a cathode, the gas turbine engine comprising a compressor and a turbine arranged to drive the compressor, the compressor being arranged to supply oxidant to the cathode of the at least one solid oxide fuel cell via an oxidant mixer, the oxidant mixer being arranged to supply a portion of the unused oxidant from the cathode of the at least one solid oxide fuel cell back to the cathode of the at least one solid oxide fuel cell with the oxidant from the compressor through a heat exchanger, wherein the solid oxide fuel cell system further comprises an additional compressor and an additional turbine arranged to drive the additional compressor, the compressor being arranged to supply oxidant to the additional compressor, the additional compressor being arranged to supply oxidant to the oxidant mixer and the solid oxide fuel cell stack being arranged to supply exhaust gases to the turbine, wherein the cathode is arranged to supply a portion of the unused oxidant directly into the oxidant mixer without passing through a combustor, wherein the oxidant mixer is an oxidant ejector, and wherein the solid oxide fuel cell system further comprises a cooler and a recuperator, the compressor being arranged to supply oxidant via the cooler to the additional compressor, the additional compressor being arranged to supply oxidant to the oxidant mixer via the recuperator, the solid oxide fuel cell stack being arranged to supply exhaust gases to the turbine and the turbine being arranged to supply the exhaust gases through the recuperator to heat the oxidant flowing through the recuperator.