Fuel cell system

Patent metadata

Field	Value
Publication number	US-10374241-B2
Application number	US-201515741711-A
Country	US
Kind code	B2
Filing date	Jul 8, 2015
Priority date	Jul 8, 2015
Publication date	Aug 6, 2019
Grant date	Aug 6, 2019

Abstract

The present invention comprises a plurality of fuel cells connected to each other in series, and a reformer configured to reform raw fuel, wherein reformed fuel by the reformer is supplied to a first stage of the plurality of fuel cells, and the fuel cell on the first stage is provided with a methane reaction suppressing function which suppresses reaction of methane included in the reformed fuel to a larger extent than at least one fuel cell on a second and later stages. Suppressing temperature drop due to endothermic reaction in the fuel cell on the first stage can improve the efficiency of electric power generation of the fuel cell system having the plurality of fuel cells arranged in series.

First claim

The invention claimed is:

1. A fuel cell system, comprising:
a plurality of fuel cells connected to each other in series; and
a reformer configured to reform raw fuel, wherein
reformed fuel by the reformer is supplied to a first stage of the plurality of fuel cells,
at least one fuel cell in the first stage is provided with a methane reaction suppressing function which suppresses reaction of methane included in the reformed fuel more than at least one fuel cell in a second stage, and
the at least one fuel cell in the first stage has an electrode with a smaller area in which fuel and oxidizer react than that of the at least one fuel cell in the second stage.

2. A fuel cell system, comprising:
a plurality of fuel cells connected to each other in series; and
a reformer configured to reform raw fuel, wherein
reformed fuel by the reformer is supplied to a first stage of the plurality of fuel cells,
at least one fuel cell in the first stage is provided with a methane reaction suppressing function which suppresses reaction of methane included in the reformed fuel more than at least one fuel cell in a second stage,
each of the at least one fuel cell in the first stage and the at least one fuel cell in the second stage includes fuel poles configured to form a three-phase interface, and
a thickness of the fuel poles of the at least one fuel cell in the first stage is less than a thickness of the fuel poles of the at least one fuel cell in the second stage such that the methane reaction suppressing function of the at least one fuel cell in the first stage suppresses reaction of methane included in the reformed fuel more than the at least one fuel cell in the second stage.

3. The fuel cell system according to claim 1 , wherein the at least one fuel cell in the first stage includes a proton conductive material as a material of fuel poles such that the at least one fuel cell in the first stage has the methane reaction suppressing function.

4. The fuel cell system according to claim 1 , wherein
the at least one fuel cell in the first stage includes a proton conductive material as a material of an electrolyte such that the at least one fuel cell in the first stage has the methane reaction suppressing function.

5. The fuel cell system according to claim 1 , wherein
the at least one fuel cell in the second stage is provided with a later-stage methane reaction suppressing function which suppresses reaction of methane included in the reformed fuel, and
the later-stage methane reaction suppressing function is weaker in terms of a function of suppressing reaction of methane than the methane reaction suppressing function of the at least one fuel cell in the first stage.

6. The fuel cell system according to claim 5 , further comprising at least one fuel cell in a third stage after the second stage, wherein
the at least one fuel cell in the third stage is provided with a third-stage methane reaction suppressing function which suppresses reaction of methane included in the reformed fuel,
the third-stage methane reaction suppressing function is weaker in terms of a function of suppressing reaction of methane than the later-stage methane reaction suppressing function.

7. The fuel cell system according to claim 1 , wherein
a discharged fuel reformer configured to reform discharged fuel discharged from a fuel cell of a preceding stage is provided between each pair of the plurality of fuel cells.

8. The fuel cell system according to claim 1 , wherein
the raw fuel is hydrocarbon-based or alcohol-based liquid fuel.

9. The fuel cell system according to claim 1 , further comprising
a discharged fuel circulator configured to supply, in a circulating manner, the reformer with fuel containing water discharged from a fuel cell located in a last stage of the plurality of fuel cells.

10. The fuel cell system according to claim 8 , wherein
the alcohol-based liquid fuel contains water.

11. The fuel cell system according to claim 2 , wherein
the at least one fuel cell in the first stage includes a proton conductive material as a material of the fuel poles such that the at least one fuel cell in the first stage has the methane reaction suppressing function.

12. The fuel cell system according to claim 2 , wherein
the at least one fuel cell in the first stage includes a proton conductive material as a material of an electrolyte such that the at least one fuel cell in the first stage has the methane reaction suppressing function.

13. The fuel cell system according to claim 2 , wherein
the at least one fuel cell in the second stage is provided with a later-stage methane reaction suppressing function which suppresses reaction of methane included in the reformed fuel, and
the later-stage methane reaction suppressing function is weaker in terms of a function of suppressing reaction of methane than the methane reaction suppressing function of the at least one fuel cell in the first stage.

14. The fuel cell system according to claim 13 , further comprising at least one fuel cell in a third stage after the second stage, wherein
the at least one fuel cell in the third stage is provided with a third-stage methane reaction suppressing function which suppresses reaction of methane included in the reformed fuel,
the third-stage methane reaction suppressing function is weaker in terms of a function of suppressing reaction of methane than the later-stage methane reaction suppressing function.

15. The fuel cell system according to claim 2 , wherein
a discharged fuel reformer configured to reform discharged fuel discharged from a fuel cell of a preceding stage is provided between each pair of the plurality of fuel cells.

16. The fuel cell system according to claim 2 , wherein
the raw fuel is hydrocarbon-based or alcohol-based liquid fuel.

17. The fuel cell system according to claim 2 , further comprising
a discharged fuel circulator configured to supply, in a circulating manner, the reformer with fuel containing water discharged from a fuel cell located in a last stage of the plurality of fuel cells.

18. The fuel cell system according to claim 16 , wherein
the alcohol-based liquid fuel contains water.

Assignees

• Nissan Motor

Inventors

• Yaguchi Tatsuya
• Kamijo Motohisa

Classifications

• H01M8/2425

  High-temperature cells with solid electrolytes · CPC title

• H01M8/1213

  characterised by the electrode/electrolyte combination or the supporting material · CPC title

• H01M4/8652

  as mixture · CPC title

• H01M2004/8684

  Negative electrodes · CPC title

• H01M8/249

  comprising two or more groupings of fuel cells, e.g. modular assemblies · CPC title