Fuel cell stack

Patent metadata

Field	Value
Publication number	US-2015349354-A1
Application number	US-201314654987-A
Country	US
Kind code	A1
Filing date	Nov 8, 2013
Priority date	Dec 26, 2012
Publication date	Dec 3, 2015
Grant date	—

Abstract

A fuel cell stack has a stacked plurality of single cells. Each of the single cells has a membrane electrode assembly, and a pair of separators sandwiching the membrane electrode assembly therebetween. A cooling fluid channel where a cooling fluid flows is formed between adjacent single cells. The fuel cell stack further comprises a displacement absorbing member disposed in the cooling fluid channel to absorb a displacement between the single cells. The displacement absorbing member comprises a channel flow resistance reduction structure that reduces a channel flow resistance of the cooling fluid channel against the cooling fluid.

First claim

1 .- 15 . (canceled)

16 . A fuel cell stack, comprising:
a stacked plurality of single cells, wherein each of the single cells comprises:
a membrane electrode assembly, and
a pair of separators sandwiching the membrane electrode assembly therebetween,
wherein a cooling fluid channel where a cooling fluid flows is formed between adjacent single cells, wherein the fuel cell stack further comprises a displacement absorbing member disposed in the cooling fluid channel to absorb a displacement between the single cells, and wherein the displacement absorbing member comprises a channel flow resistance reduction structure that reduces a channel flow resistance of the cooling fluid channel against the cooling fluid.

17 . The fuel cell stack according to claim 16 ,
wherein the channel flow resistance reduction structure reduces the channel flow resistance by reducing a projected area of the displacement absorbing member projected in a flow direction of the cooling fluid in an arbitrary location in the flow direction.

18 . The fuel cell stack according to claim 16 ,
wherein the channel flow resistance reduction structure reduces the channel flow resistance by preventing vortex flow of the cooling fluid.

19 . The fuel cell stack according to claim 17 ,
wherein the channel flow resistance reduction structure reduces the channel flow resistance by preventing vortex flow of the cooling fluid.

20 . The fuel cell stack according to claim 16 ,
wherein a surface of the separators facing the cooling fluid channel has an uneven cross-sectional shape that continues in the flow direction of the cooling fluid, and wherein the displacement absorbing member is configured such that a contacting part in contact with a separator moves in an in-plane direction according to a deformation in a thickness direction, and is disposed so that a moving direction of the contacting part corresponds to the flow direction of the cooling fluid.

21 . The fuel cell stack according to claim 17 ,
wherein a surface of the separators facing the cooling fluid channel has an uneven cross-sectional shape that continues in the flow direction of the cooling fluid, and wherein the displacement absorbing member is configured such that a contacting part in contact with a separator moves in an in-plane direction according to a deformation in a thickness direction, and is disposed so that a moving direction of the contacting part corresponds to the flow direction of the cooling fluid.

22 . The fuel cell stack according to claim 18 ,
wherein a surface of the separators facing the cooling fluid channel has an uneven cross-sectional shape that continues in the flow direction of the cooling fluid, and
wherein the displacement absorbing member is configured such that a contacting part in contact with a separator moves in an in-plane direction according to a deformation in a thickness direction, and is disposed so that a moving direction of the contacting part corresponds to the flow direction of the cooling fluid.

23 . The fuel cell stack according to claim 19 ,
wherein a surface of the separators facing the cooling fluid channel has an uneven cross-sectional shape that continues in the flow direction of the cooling fluid, and wherein the displacement absorbing member is configured such that a contacting part in contact with a separator moves in an in-plane direction according to a deformation in a thickness direction, and is disposed so that a moving direction of the contacting part corresponds to the flow direction of the cooling fluid.

24 . The fuel cell stack according to claim 16 ,
wherein the displacement absorbing member comprises a base plate and a number of spring functional parts arranged on one surface of the base plate, and wherein the spring functional parts have a cantilever structure comprising a fixed proximal end fixed on the base plate and a free tip end.

25 . The fuel cell stack according to claim 24 ,
wherein the spring functional parts are formed by lancing the base plate.

26 . The fuel cell stack according to claim 25 ,
wherein the spring functional parts are formed by lancing the base plate, in which blank areas are formed along a periphery of the spring functional parts.

27 . The fuel cell stack according to claim 24 ,
wherein the channel flow resistance reduction structure comprises at least either an opening or a cutout formed in an area from the free end to the fixed end of the spring functional parts.

28 . The fuel cell stack according to claim 27 ,
wherein the channel flow resistance reduction structure is formed between the free end and the fixed end of the spring functional parts.

29 . The fuel cell stack according to claim 27 ,
wherein the spring functional parts has a width that decreases with a location from the fixed end to the free end.

30 . The fuel cell stack according to claim 24 ,
wherein the displacement absorbing member is disposed so that the free end of the spring functional parts faces toward a downstream of the flow direction of the cooling fluid.

31 . The fuel cell stack according to claim 30 ,
wherein the opening and the cutout as the channel flow resistance reduction structure are composed of a curved line.

32 . The fuel cell stack according to claim 24 ,
wherein the displacement absorbing member comprises the spring functional parts that have different shapes according to a location in the cooling fluid channel.

33 . The fuel cell stack according to claim 32 ,
wherein the displacement absorbing member comprises the spring functional parts that are disposed so that a channel size of the cooling fluid channel is decreased in both side areas thereof in the flow direction of the cooling fluid.

34 . The fuel cell stack according to any one of claims 24 ,
wherein the displacement absorbing member comprises the spring functional parts that are disposed at different intervals between adjacent spring functional parts according to a location in the cooling fluid channel.

35 . The fuel cell stack according to claim 30 ,
wherein the channel flow resistance reduction structure is a pathway formed between the spring functional parts of the displacement absorbing member.

Assignees

• Nissan Motor
• Nhk Spring Co Ltd

Inventors

• Fukuyama Yosuke
• Iritsuki Keita
• Terada Yusuke
• Tajima Norihiro

Classifications

• F28D9/005

  the plates having openings therein for both heat-exchange media · CPC title

• F28F2265/26

  for allowing differential expansion between elements · CPC title

• F28F2240/00

  Spacing means · CPC title

• F28D2021/0043

  for fuel cells · CPC title

• H01M8/0265

  the reactant or coolant channels having varying cross sections · CPC title