JP2015079565A - Fuel cell stack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress deterioration due to heat as much as possible, by preventing occurrence of a heat spot reliably, on the downstream side of an H flow type cooling medium flow path.SOLUTION: In a fuel cell stack 10, a plurality of fuel cells 12 are stacked. Between a first separator 24 and a third separator 30, which constitute respective fuel cells 12 and are adjacent to each other, a cooling medium flow path 52 is formed. In a second cooling medium flow path 52B that is a part of the cooling medium flow path 52, a plurality of corrugated flow path grooves 52b are provided between corrugated protrusions 52a. The flow path width of a corrugated flow path grooves 52bm on the central side in the flow path width direction is set wider than the corrugated flow path grooves 52b on both sides in the flow path width direction.

Description

  The present invention relates to a fuel cell stack having a fuel cell in which an electrolyte membrane / electrode structure provided with electrodes on both sides of an electrolyte membrane and a separator are stacked, and a plurality of the fuel cells are stacked.

  For example, in a polymer electrolyte fuel cell, an electrolyte membrane / electrode structure in which an anode electrode is disposed on one side of an electrolyte membrane made of a polymer ion exchange membrane and a cathode electrode is disposed on the other surface side ( MEA). The electrolyte membrane / electrode structure constitutes a power generation cell sandwiched between separators. A fuel cell is usually incorporated in a fuel cell electric vehicle as an in-vehicle fuel cell stack, for example, by stacking a predetermined number of power generation cells.

  In the fuel cell, a fuel gas channel for flowing fuel gas to the anode electrode and an oxidant gas channel for flowing oxidant gas to the cathode electrode are provided in the plane of the separator. On the other hand, between the separators adjacent to each other, a cooling medium flow path for flowing the cooling medium is provided along the surface direction of the separator.

  In the fuel cell, a so-called fuel gas communication hole through which fuel gas flows through the stacking direction, an oxidant gas communication hole through which oxidant gas flows, and a cooling medium communication hole through which a cooling medium flows are provided. Internal manifold type fuel cell is adopted. The fuel gas communication hole has a fuel gas inlet communication hole and a fuel gas outlet communication hole, the oxidant gas communication hole has an oxidant gas inlet communication hole and an oxidant gas outlet communication hole, and the cooling medium communication hole has The cooling medium inlet communication hole and the cooling medium outlet communication hole are provided.

  As this type of internal manifold type fuel cell, for example, a fuel cell stack disclosed in Patent Document 1 is known. In this fuel cell stack, a pair of cooling medium inlet communication holes and a pair of cooling medium outlet communication holes are formed in one side of the separator facing each other in the stacking direction and are distributed to the respective sides to flow the cooling medium. A hole is provided.

  In the above configuration, after the cooling medium is supplied from the pair of upper and lower or left and right cooling medium inlet communication holes to the cooling medium flow path in the direction close to each other, the cooling medium is horizontally or along the cooling medium flow path. It circulates in the vertical direction. The cooling medium is further dispersed in a direction away from each other in the vertical direction or the horizontal direction, and then discharged to the pair of cooling medium outlet communication holes. Hereinafter, this cooling medium flow path configuration is also referred to as an H flow type cooling medium flow path.

  As described above, in the H flow type cooling medium flow path, the pair of cooling medium inlet communication holes and the pair of cooling medium outlet communication holes are provided separately. For this reason, a cooling medium can be uniformly and reliably supplied with respect to the whole H flow type cooling medium flow path. Therefore, it is possible to make the humidity environment uniform over the entire power generation region, and efficient power generation is performed well.

Republished WO2010 / 082589

  In said patent document 1, the separator 1 shown in FIG. 9 is provided, for example. The separator 1 is formed with a pair of cooling medium inlet communication holes 2a, 2a and a pair of cooling medium outlet communication holes 2b, 2b penetrating in the stacking direction. A cooling medium flow path 3 is formed in the plane of the separator 1, and the cooling medium flow path 3 extends in the direction of an arrow h (for example, a horizontal direction).

  A pair of cooling medium inlet communication holes 2a, 2a communicate with the inlet side of the cooling medium flow path 3 via the inlet connection paths 4a, 4a. A pair of cooling medium outlet communication holes 2b, 2b communicate with the outlet side of the cooling medium flow path 3 via outlet connection paths 4b, 4b.

  Meanwhile, in the separator 1, the cooling medium supplied to the cooling medium flow path 3 from the pair of cooling medium inlet communication holes 2 a and 2 a has a flow rate at the center in the width direction of the cooling medium flow path 3. It tends to be less than the flow rate on both sides in the width direction of the path 3. For this reason, the so-called heat spot 5 where the cooling medium is difficult to flow, the cooling performance is lowered, and the temperature is higher than the surroundings, in particular, at the downstream side of the central portion in the width direction of the cooling medium flow path 3 is a certain position May occur. Thereby, there exists a problem that electrolyte membrane and an electrode structure are easy to deteriorate with a heat | fever, and durability falls.

  The present invention solves this type of problem and reliably prevents heat spots from being generated on the downstream side of the H flow type cooling medium flow path, and suppresses heat degradation as much as possible. An object is to provide a possible fuel cell stack.

  A fuel cell stack according to the present invention includes a fuel cell in which an electrolyte membrane / electrode structure provided with electrodes on both sides of an electrolyte membrane and a rectangular separator are stacked, and a plurality of the fuel cells are stacked. . Between the separators adjacent to each other, there is formed a cooling medium flow path through which the cooling medium flows along the longitudinal direction of the separator surface, and the cooling medium flow path is formed on the inlet side of the cooling medium flow path. A pair of cooling medium inlet communication holes are provided across the direction. On the other hand, a pair of cooling medium outlet communication holes are provided on the outlet side of the cooling medium flow path so as to sandwich the cooling medium flow path in the flow path width direction.

  In the fuel cell stack, at least one separator is formed with a plurality of protrusions protruding toward the other separator in contact with each other, and a cooling medium flow path is constituted by a plurality of flow path grooves provided between the protrusions. Has been. The channel width of the channel groove arranged on the center side in the channel width direction is set wider than the channel width of the channel groove arranged on both ends in the channel width direction.

  In this fuel cell stack, the separator is preferably composed of a metal separator. It is preferable that a reaction gas flow channel for allowing the fuel gas or the oxidant gas to flow along the separator surface is formed on the back surface side of the cooling medium flow channel as the back surface shape of the cooling medium flow channel.

  According to the present invention, in the plurality of flow channel grooves constituting the cooling medium flow channel, the flow channel width of the flow channel groove disposed on the center side in the flow channel width direction is disposed on both ends of the flow channel width direction. It is set wider than the channel width of the channel groove. For this reason, the flow rate of the cooling medium flowing through the flow channel disposed on the center side in the flow channel width direction is larger than the flow rate of the cooling medium flowing through the other flow channel grooves. Therefore, it is possible to reliably prevent the heat spot from being generated on the downstream side of the center portion in the width direction of the H flow type cooling medium flow path, and to suppress deterioration due to heat as much as possible.

1 is an exploded perspective view of a main part of a fuel cell constituting a fuel cell stack according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view of the fuel cell stack taken along line II-II in FIG. 1. FIG. 3 is a cross-sectional view of the fuel cell stack taken along line III-III in FIG. 1. It is front explanatory drawing of the 2nd separator which comprises the said fuel cell. It is explanatory drawing of one surface of the 3rd separator which comprises the said fuel cell. It is explanatory drawing of the other surface of the said 3rd separator. It is a principal part disassembled perspective explanatory drawing of the fuel cell which comprises the fuel cell stack which concerns on the 2nd Embodiment of this invention. It is the VIII-VIII sectional view taken on the line of the said fuel cell stack in FIG. It is front explanatory drawing of the separator which comprises the fuel cell stack of patent document 1. FIG.

  As shown in FIGS. 1 to 3, the fuel cell stack 10 according to the first embodiment of the present invention is mounted on, for example, a fuel cell electric vehicle (not shown). In the fuel cell stack 10, a plurality of fuel cells 12 are stacked in the horizontal direction (arrow A direction) with the electrode surface in an upright posture. Note that the fuel cell stack 10 may be configured by stacking a plurality of fuel cells 12 in the direction of gravity (arrow C direction).

  The fuel cell 12 includes a first separator 24, a first electrolyte membrane / electrode structure (MEA) 26 a, a second separator 28, a second electrolyte membrane / electrode structure (MEA) 26 b, and a third separator 30.

  The first separator 24, the second separator 28, and the third separator 30 are constituted by, for example, a steel plate, a stainless steel plate, an aluminum plate, a plated steel plate, or a vertically long metal plate that has been subjected to anticorrosion surface treatment on its metal surface. Is done. The first separator 24, the second separator 28, and the third separator 30 have a rectangular planar shape, and are formed into a concavo-convex shape by pressing a metal thin plate into a wave shape. The first separator 24, the second separator 28, and the third separator 30 may be constituted by, for example, a carbon separator instead of the metal separator.

  The first electrolyte membrane / electrode structure 26a and the second electrolyte membrane / electrode structure 26b include, for example, a solid polymer electrolyte membrane 32 in which a thin film of perfluorosulfonic acid is impregnated with water. The solid polymer electrolyte membrane 32 is sandwiched between the anode electrode 34 and the cathode electrode 36. The anode electrode 34 constitutes a step MEA having a smaller planar dimension than the cathode electrode 36, but is not limited to this. For example, the anode electrode 34 may have a larger planar dimension than the cathode electrode 36, or may have the same planar dimension as the cathode electrode 36.

  The anode electrode 34 and the cathode electrode 36 have a gas diffusion layer (not shown) made of carbon paper or the like, and an electrode catalyst layer (not shown). In the electrode catalyst layer, porous carbon particles having a platinum alloy supported thereon are uniformly applied to the surface of the gas diffusion layer. The electrode catalyst layer is formed on both surfaces of the solid polymer electrolyte membrane 32, for example.

  An oxidant gas inlet communication hole 38a and a fuel gas outlet communication hole 40b are provided at one edge of the long side direction (arrow B direction) of the fuel cell 12 so as to communicate with each other in the arrow A direction. The oxidant gas inlet communication hole 38a supplies an oxidant gas, for example, an oxygen-containing gas. The fuel gas outlet communication hole 40b discharges fuel gas, for example, hydrogen-containing gas.

  The other end edge of the fuel cell 12 in the long side direction (arrow B direction) communicates with each other in the arrow A direction to discharge the fuel gas inlet communication hole 40a for supplying fuel gas and the oxidant gas. The oxidant gas outlet communication hole 38b is provided.

  A pair of cooling medium inlet communication holes 42a for supplying a cooling medium is provided on one end of both ends of the long side of the fuel cell 12 which are opposed to each other in the direction of arrow A. A pair of cooling medium outlet communication holes 42b for discharging the cooling medium is provided on the other end of both ends of the long side of the fuel cell 12 facing each other.

  The cooling medium inlet communication holes 42a and 42a are distributed to the long sides on both sides in the direction of arrow C, close to the oxidant gas inlet communication hole 38a and the fuel gas outlet communication hole 40b. The cooling medium outlet communication holes 42b and 42b are respectively arranged close to the oxidant gas outlet communication hole 38b and the fuel gas inlet communication hole 40a and distributed to the long sides on both sides in the direction of arrow C.

  The surface 24a of the first separator 24 facing the first electrolyte membrane / electrode structure 26a has a wave-shaped (or linear) first fuel gas that communicates the fuel gas inlet communication hole 40a and the fuel gas outlet communication hole 40b. A flow path 44 is formed. The first fuel gas channel 44 has a plurality of wavy convex portions 44a protruding toward the surface 24a, and a plurality of wavy flow channel grooves 44b are formed between each wavy convex portion 44a. The wavy flow channel grooves 44b are arranged in the direction of arrow C.

  The first fuel gas channel 44 extends in the direction of arrow B, and an inlet buffer portion 46a and an outlet buffer portion 46b each having a plurality of embosses are provided in the vicinity of the inlet and the outlet thereof. The surface 24a has a plurality of supply connection passages 48a for communicating the fuel gas inlet communication hole 40a and the inlet buffer portion 46a, and a plurality of discharge connection passages 48b for communicating the fuel gas outlet communication hole 40b and the outlet buffer portion 46b. It is formed. Lids 50a and 50b are disposed as bridge portions on the supply connection path 48a and the discharge connection path 48b.

  A first cooling medium flow path 52A, which is a part of the cooling medium flow path 52 that connects the cooling medium inlet communication hole 42a and the cooling medium outlet communication hole 42b, is formed on the surface 24b of the first separator 24. The back surface shape of the first coolant flow path 52 </ b> A is the shape of the first fuel gas flow path 44. First cooling medium flow path 52A extends along the direction of arrow B.

  As shown in FIG. 4, the surface 28 a of the second separator 28 facing the first electrolyte membrane / electrode structure 26 a has a wave shape that connects the oxidant gas inlet communication hole 38 a and the oxidant gas outlet communication hole 38 b ( Alternatively, a linear first oxidant gas flow path 54 is formed. The first oxidant gas flow channel 54 has a plurality of wavy convex portions 54a protruding toward the surface 28a, and a plurality of wavy flow channel grooves 54b are provided between the wavy convex portions 54a.

  An inlet buffer portion 56a and an outlet buffer portion 56b are provided near the inlet and the outlet of the first oxidant gas flow channel 54. The surface 28a has a plurality of supply connection passages 58a communicating the oxidant gas inlet communication hole 38a and the inlet buffer portion 56a, and a plurality of discharge connection passages communicating the oxidant gas outlet communication hole 38b and the outlet buffer portion 56b. 58b is formed.

  As shown in FIG. 1, the surface 28b of the second separator 28 facing the second electrolyte membrane / electrode structure 26b has a wave shape (or a straight line) that connects the fuel gas inlet communication hole 40a and the fuel gas outlet communication hole 40b. Shaped second fuel gas flow path 60 is formed. The second fuel gas flow channel 60 has a plurality of wavy convex portions 60a protruding toward the surface 28b, and a plurality of wavy flow channel grooves 60b are provided between the wavy convex portions 60a. The back surface shape of the second fuel gas channel 60 is the shape of the first oxidant gas channel 54.

  The second fuel gas flow channel 60 extends in the direction of arrow B, and an inlet buffer portion 62a and an outlet buffer portion 62b each having a plurality of embosses are provided in the vicinity of the inlet and the vicinity of the outlet. The surface 28b has a plurality of supply connection passages 64a communicating the fuel gas inlet communication hole 40a and the inlet buffer portion 62a, and a plurality of discharge connection passages 64b communicating the fuel gas outlet communication hole 40b and the outlet buffer portion 62b. Is formed. Lids 66a and 66b are disposed as bridge portions in the supply connection path 64a and the discharge connection path 64b.

  As shown in FIG. 5, the surface 30a of the third separator 30 facing the second electrolyte membrane / electrode structure 26b has a wave shape that communicates the oxidant gas inlet communication hole 38a and the oxidant gas outlet communication hole 38b ( Alternatively, a second oxidant gas flow path 68 having a linear shape is formed. The second oxidant gas flow path 68 has a plurality of wavy convex portions 68a protruding to the surface 30a side, and a plurality of wavy flow channel grooves 68b are provided between the wavy convex portions 68a. The wavy convex portion 68am disposed on the center side in the flow path width direction (arrow C direction) is set wider than the wavy convex portion 68a disposed on both ends in the flow width direction (and all other than the central side). .

  In the vicinity of the inlet and the outlet of the second oxidant gas flow path 68, an inlet buffer part 70a and an outlet buffer part 70b are provided. The surface 30a has a plurality of supply connection passages 72a communicating the oxidant gas inlet communication hole 38a and the inlet buffer portion 70a, and a plurality of discharge connection passages communicating the oxidant gas outlet communication hole 38b and the outlet buffer portion 70b. 72b.

  As shown in FIG. 6, a second cooling medium flow path 52 </ b> B that is a part of the cooling medium flow path 52 is formed on the surface 30 b of the third separator 30. The second cooling medium flow channel 52B has a plurality of wavy convex portions 52a protruding toward the surface 30b, and a plurality of wavy flow channel grooves 52b are provided between the wavy convex portions 52a. The second cooling medium flow path 52B is configured as the back surface shape of the third separator 30 in which the second oxidant gas flow path 68 is formed, and the wavy convex portion 52a is the back surface shape of the wavy flow channel groove 68b. The channel groove 52b has a back surface shape of the wavy convex portion 68a.

  In the second cooling medium flow channel 52B, the flow channel width t1 of the wavy flow channel groove 52bm disposed on the central side in the flow channel width direction is the wavy flow channel groove 52b (other than the central side) disposed on both ends in the flow channel width direction. Is set wider than the channel width t2 of other wave-like channel grooves 52b (t1> t2). The wavy flow channel groove 52bm is not limited to one, and a plurality of wavy flow channel grooves 52bm may be provided.

  A pair of cooling medium inlet communication holes 42 a are provided on the inlet side of the cooling medium flow path 52 with the cooling medium flow path 52 sandwiched in the flow path width direction. On the outlet side of the cooling medium flow path 52, a pair of cooling medium outlet communication holes 42b are provided with the cooling medium flow path 52 sandwiched in the flow path width direction.

  The surface 30 b is provided with a supply connection path 74 a that communicates the cooling medium inlet communication hole 42 a with the inlet side of the cooling medium flow path 52. The supply connection path 74a is provided near the fuel gas outlet communication hole 40b. The surface 30 b is provided with a discharge connection path 74 b that communicates the cooling medium outlet communication hole 42 b with the outlet side of the cooling medium flow path 52. The discharge connection path 74b is provided near the oxidant gas outlet communication hole 38b.

  As shown in FIG. 1, a first seal member 76 is integrally formed on the surfaces 24 a and 24 b of the first separator 24 around the outer peripheral edge of the first separator 24. A second seal member 78 is integrally formed on the surfaces 28 a and 28 b of the second separator 28 around the outer peripheral edge of the second separator 28. A third seal member 80 is integrally formed on the surfaces 30 a and 30 b of the third separator 30 around the outer peripheral edge of the third separator 30.

  Examples of the first seal member 76, the second seal member 78, and the third seal member 80 include EPDM, NBR, fluororubber, silicone rubber, fluorosilicone rubber, butyl rubber, natural rubber, styrene rubber, chloroprene, or acrylic rubber. A sealing member having elasticity such as a sealing material, a cushioning material, or a packing material is used.

  The operation of the fuel cell stack 10 configured as described above will be described below.

  As shown in FIG. 1, an oxidant gas such as an oxygen-containing gas is supplied to the oxidant gas inlet communication hole 38a, and a fuel gas such as a hydrogen-containing gas is supplied to the fuel gas inlet communication hole 40a. The Further, a cooling medium such as pure water, ethylene glycol, or oil is supplied to the pair of cooling medium inlet communication holes 42a and 42a.

  The oxidant gas is introduced into the first oxidant gas flow path 54 of the second separator 28 and the second oxidant gas flow path 68 of the third separator 30 from the oxidant gas inlet communication hole 38a. The oxidant gas moves in the arrow B direction (horizontal direction) along the first oxidant gas flow path 54 and is supplied to the cathode electrode 36 of the first electrolyte membrane / electrode structure 26a. Further, the remaining oxidant gas moves in the direction of arrow B along the second oxidant gas flow path 68 and is supplied to the cathode electrode 36 of the second electrolyte membrane / electrode structure 26b.

  On the other hand, the fuel gas moves in the horizontal direction (in the direction of arrow B) along the first fuel gas flow path 44 of the first separator 24 from the fuel gas inlet communication hole 40a, and the anode of the first electrolyte membrane / electrode structure 26a. It is supplied to the electrode 34. The remaining fuel gas moves in the direction of arrow B along the second fuel gas channel 60 of the second separator 28 and is supplied to the anode electrode 34 of the second electrolyte membrane / electrode structure 26b.

  Therefore, in the first electrolyte membrane / electrode structure 26a and the second electrolyte membrane / electrode structure 26b, the oxidant gas supplied to the cathode electrode 36 and the fuel gas supplied to the anode electrode 34 are converted into the electrode catalyst layer. Power is generated by being consumed by electrochemical reaction.

  Next, the oxidant gas supplied and consumed to the cathode electrodes 36 of the first electrolyte membrane / electrode structure 26a and the second electrolyte membrane / electrode structure 26b is moved along the oxidant gas outlet communication hole 38b by the arrow A. Circulate in the direction. The fuel gas supplied and consumed by the anode electrode 34 of the first electrolyte membrane / electrode structure 26a and the fuel gas supplied and consumed by the anode electrode 34 of the second electrolyte membrane / electrode structure 26b are fuel gas. It flows in the direction of arrow A along the outlet communication hole 40b.

  On the other hand, the cooling medium supplied to the pair of upper and lower cooling medium inlet communication holes 42 a is formed between the first separator 24 constituting one fuel cell 12 and the third separator 30 constituting the other fuel cell 12. The cooling medium flow path 52 is introduced.

  The cooling medium supplied to the cooling medium flow path 52 from each cooling medium inlet communication hole 42a, 42a once flows along the direction of arrow C (the direction of gravity). The cooling medium further moves in the direction of arrow B (horizontal direction) to cool the first electrolyte membrane / electrode structure 26a and the second electrolyte membrane / electrode structure 26b. This cooling medium moves outward in the direction of arrow C, and is then discharged into the pair of cooling medium outlet communication holes 42b and 42b. This is a so-called H flow type coolant flow path.

  In this case, in the first embodiment, as shown in FIGS. 3 and 6, the second cooling medium flow path 52 </ b> B is provided with a plurality of wavy flow channel grooves 52 b between the plurality of wavy convex portions 52 a. And the channel width t1 of the wavy channel groove 52bm arranged on the center side in the channel width direction is set wider than the channel width t2 of all other wavy channel grooves 52b including both ends of the channel width direction. Has been. For this reason, the flow rate of the cooling medium flowing through the wavy flow channel groove 52bm is larger than the flow rate of the cooling medium flowing through all other wavy flow channel grooves 52b.

  Accordingly, it is possible to reliably prevent the heat spot from being generated on the downstream side of the center portion in the width direction of the H flow type cooling medium flow path 52, and to suppress deterioration due to heat as much as possible. Thereby, the effect that deterioration of the 1st electrolyte membrane and electrode structure 26a and the 2nd electrolyte membrane and electrode structure 26b by heat | fever can be suppressed as much as possible is acquired.

  In the first embodiment, the fuel cell 12 is composed of three separators and two MEAs, and employs a so-called thinning cooling structure in which no cooling medium flow path is provided in the fuel cell 12. However, the present invention is not limited to this. For example, so-called cell-cooled fuel cells in which one MEA is sandwiched between two separators can be used. The same applies to the second embodiment described below.

  As shown in FIGS. 7 and 8, in the fuel cell stack 90 according to the second embodiment of the present invention, a plurality of fuel cells 92 are stacked in the horizontal direction in a standing posture. The same components as those of the fuel cell stack 10 according to the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  The fuel cell 92 includes a first separator 94, a first electrolyte membrane / electrode structure 26 a, a second separator 28, a second electrolyte membrane / electrode structure 26 b, and a third separator 30. The first separator 94 is provided with a first fuel gas flow path 44 on a surface 94a facing the first electrolyte membrane / electrode structure 26a. The first fuel gas channel 44 has a plurality of wavy convex portions 44a protruding toward the surface 94a, and a plurality of wavy flow channel grooves 44b are provided between the wavy convex portions 44a.

  The wavy convex portions 44am arranged on the center side in the flow channel width direction (arrow C direction) are set wider than the wavy convex portions 44a arranged on both ends of the flow channel width direction. In the first coolant flow path 52A, which is the back surface shape of the first fuel gas flow path 44, as shown in FIG. 8, the back surface shape (the wavy flow path groove) of the wavy convex portion 44am is in the stacking direction with the wavy flow path groove 52bm. Overlap. For this reason, the cross-sectional area of the wavy flow channel groove 52bm disposed on the center side in the flow width direction of the cooling medium flow channel 52 is larger than that of the wavy flow channel groove 52b disposed in the other part.

  Thereby, in 2nd Embodiment, it can prevent more reliably that a heat spot generate | occur | produces in the downstream of the width direction center part of the H flow type cooling-medium flow path 52. FIG. Therefore, it is possible to suppress deterioration of the first electrolyte membrane / electrode structure 26a and the second electrolyte membrane / electrode structure 26b due to heat as much as possible, and the same effects as those of the first embodiment described above. Is obtained.

DESCRIPTION OF SYMBOLS 10, 90 ... Fuel cell stack 12, 92 ... Fuel cell 24, 28, 30, 94 ... Separator 26a, 26b ... Electrolyte membrane and electrode structure 32 ... Solid polymer electrolyte membrane 34 ... Anode electrode 36 ... Cathode electrode 38a ... Oxidation Agent gas inlet communication hole 38b ... Oxidant gas outlet communication hole 40a ... Fuel gas inlet communication hole 40b ... Fuel gas outlet communication hole 42a ... Cooling medium inlet communication hole 42b ... Cooling medium outlet communication hole 44, 60 ... Fuel gas flow path 44a , 44am, 52a, 54a, 60a, 68a, 68am ... Wave-like convex portions 44b, 52b, 52bm, 54b, 60b, 68b ... Wave-like channel grooves 52, 52A, 52B ... Cooling medium channel 54, 68 ... Oxidant gas flow Road 76, 78, 80 ... seal member

Claims (2)

A fuel cell in which an electrolyte membrane / electrode structure provided with electrodes on both sides of an electrolyte membrane and a rectangular separator are stacked, and a plurality of the fuel cells are stacked, and between the adjacent separators A cooling medium flow path for circulating the cooling medium along the longitudinal direction of the separator surface is formed, and a pair of cooling medium is sandwiched in the flow path width direction on the inlet side of the cooling medium flow path. In the fuel cell stack, a medium inlet communication hole is provided, and a pair of cooling medium outlet communication holes are provided on the outlet side of the cooling medium flow path so as to sandwich the cooling medium flow path in the flow width direction. And
At least one of the separators is formed with a plurality of convex portions projecting toward the other separator side in contact with each other, and the cooling medium flow path is constituted by a plurality of flow path grooves provided between the convex parts. With
The channel width of the channel groove arranged on the center side in the channel width direction is set wider than the channel width of the channel groove arranged on both ends of the channel width direction. Fuel cell stack. The fuel cell stack according to claim 1, wherein the separator is formed of a metal separator,
A reaction gas channel for allowing a fuel gas or an oxidant gas to flow along the separator surface is formed on the back side of the cooling medium channel as a back surface shape of the cooling medium channel. stack.

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