JP2013012334A - Fuel cell stack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel cell stack that reduces pressure drop in a manifold as far as possible with a simple configuration and that allows a cooling medium to be circulated smoothly and reliably.SOLUTION: A fuel cell stack 10 includes a first end plate 18a that is provided with a cooling medium supply manifold 50 and a cooling medium discharge manifold 52. The cooling medium supply manifold 50 has: a pair of supply manifold sections 54a and 54a that communicate with a pair of cooling medium supply communication holes 30a and 30a of the first end plate 18a, respectively; and a supply connection section 56a that connects upper sides of the pair of supply manifold sections 54a and 54a. On an inner wall surface of at least one of the supply manifold sections 54a, a sloping portion 60c is provided that smoothly slopes from a straight portion 60a through a curved portion 60b.

Description

  The present invention relates to a fuel cell stack in which an electrolyte / electrode structure provided with a pair of electrodes on both sides of an electrolyte and a separator are stacked, and rectangular end plates are disposed at both ends in the stacking direction.

  For example, in a polymer electrolyte fuel cell, an electrolyte membrane / electrode structure (MEA) in which an anode side electrode and a cathode side electrode are disposed on both sides of an electrolyte membrane made of a polymer ion exchange membrane is provided by a pair of separators. The unit cell is sandwiched. This type of fuel cell is usually used as an in-vehicle fuel cell stack, for example, by stacking a predetermined number of unit cells.

  In this type of fuel cell stack, a fuel gas supply communication hole and a fuel gas discharge communication hole for flowing fuel gas through the unit cell in the stacking direction, an oxidant gas supply communication hole for flowing oxidant gas, and In many cases, a so-called internal manifold type fuel cell is provided which includes an oxidant gas discharge communication hole, a cooling medium supply communication hole for flowing a cooling medium, and a cooling medium discharge communication hole.

  As a technique related to the internal manifold fuel cell, for example, Patent Document 1 is known. This Patent Document 1 relates to a fuel cell stack in which an electrolyte / electrode structure provided with a pair of electrodes on both sides of an electrolyte and a separator are stacked, and rectangular end plates are disposed at both ends in the stacking direction. is there.

  A pair of cooling medium supply communication holes and a pair of cooling medium discharge communication holes are provided on the two long sides facing each other of the fuel cell stack so as to communicate with each other in the stacking direction. The one end plate is connected to a pair of manifold portions communicating with at least one of the pair of cooling medium supply communication holes or the pair of cooling medium discharge communication holes, and the pair of manifold portions is connected to the long side. And a connecting portion whose width dimension is set to be smaller than the dimension of the pair of manifold portions.

  Accordingly, an increase in pressure loss of the cooling medium flowing into the manifold can be effectively suppressed, and the cooling medium can be supplied and distributed to the fuel cell smoothly and uniformly.

JP2011-54425A

  The present invention has been made in connection with this type of internal manifold fuel cell. In particular, the pressure loss in the manifold can be reduced as much as possible, and the cooling medium can be smoothly and uniformly supplied to the fuel cell. It is an object of the present invention to provide a fuel cell stack that can be made to operate.

  The present invention relates to a fuel cell stack in which an electrolyte / electrode structure provided with a pair of electrodes on both sides of an electrolyte and a separator are stacked, and rectangular end plates are disposed at both ends in the stacking direction.

  In this fuel cell stack, a pair of cooling medium supply communication holes and a pair of cooling medium discharge communication holes through which the cooling medium is circulated are respectively connected to the two long sides facing each other in the fuel cell stack. And are provided.

  The one end plate includes a pair of supply manifold portions that are communicated with the pair of cooling medium supply communication holes and that are long along two sides, and a supply connection portion that connects the pair of supply manifold portions. In addition, provided on the inner wall surface of at least one supply manifold section is an inclined portion that smoothly inclines from a straight portion via a curved portion.

  Further, in this fuel cell stack, one end plate communicates with the cooling medium discharge communication hole and is connected to the pair of discharge manifold portions that are long along two sides and the pair of discharge manifold portions. It is preferable that a connecting portion is provided, and an inclined portion that smoothly inclines from a straight portion via a curved portion is provided on the inner wall surface of at least one discharge manifold portion.

  Further, in this fuel cell stack, the pair of supply manifold portions are arranged in a vertically long manner, and the supply connection portion is connected to the upper portion of the pair of supply manifold portions, and at least one supply manifold portion is provided. It is preferable that an inclined portion is provided at the lower corner of the inner wall surface.

  Furthermore, in this fuel cell stack, the pair of supply manifold portions are arranged in a vertically long manner, and the supply connection portion is connected to the lower portion of the pair of supply manifold portions, and at least one supply manifold is provided. It is preferable that the inclined portion is provided in an upper corner portion of the inner wall surface of the portion.

  Further, in this fuel cell stack, the pair of supply manifold portions are disposed in a long length in the vertical direction, and the supply connection portion is connected to the central portion of the pair of supply manifold portions, and at least one supply manifold is provided. It is preferable that inclined portions are respectively provided in the lower corner portion and the upper corner portion of the inner wall surface of the portion.

  According to the present invention, an inclined portion that smoothly inclines from a straight portion through a curved portion is provided on the inner wall surface of one supply manifold portion. Therefore, the pressure loss of the cooling medium flowing in one supply manifold portion can be reduced as much as possible, and the distribution of the cooling medium to the pair of cooling medium supply communication holes is improved satisfactorily. This makes it possible to supply and circulate the cooling medium smoothly and uniformly to the fuel cell with a simple configuration.

1 is a schematic perspective explanatory view of a fuel cell stack according to a first embodiment of the present invention. 2 is an exploded perspective view of a fuel cell constituting the fuel cell stack. FIG. It is front explanatory drawing of the said fuel cell stack. It is side surface explanatory drawing of the said 1st end plate. It is a figure which compares the pressure loss of each manifold part of a comparative example and 1st Embodiment. FIG. 5 is a schematic perspective explanatory view of a fuel cell stack according to a second embodiment of the present invention. It is front explanatory drawing of the said fuel cell stack. It is a schematic perspective view of a fuel cell stack according to a third embodiment of the present invention. It is front explanatory drawing of the said fuel cell stack. It is front explanatory drawing of the fuel cell stack which concerns on the 4th Embodiment of this invention.

  As shown in FIG. 1, the fuel cell stack 10 according to the first embodiment of the present invention includes a fuel cell 12, and the plurality of fuel cells 12 are arranged in a horizontal direction (arrow A direction) or a vertical direction (arrow C direction). ) Are stacked on each other.

  The first terminal plate 14a, the first insulating plate 16a and the first end plate 18a are stacked at one end in the stacking direction of the fuel cell 12, while the second terminal plate 14b and the second insulating plate are stacked at the other end in the stacking direction. 16b and the second end plate 18b are stacked.

  The first end plate 18 a and the second end plate 18 b configured in a rectangular shape are integrally clamped and held by a plurality of tie rods 19 extending in the arrow A direction. Note that the fuel cell stack 10 may be integrally held by a box-shaped casing (not shown) including the first end plate 18a and the second end plate 18b as end plates.

  As shown in FIG. 2, the fuel cell 12 includes an electrolyte membrane / electrode structure 20 sandwiched between first and second separators 22 and 24. The first and second separators 22 and 24 are made of, for example, a metal separator such as a steel plate, a stainless steel plate, an aluminum plate, or a plated steel plate in addition to a carbon separator.

  An oxidation for supplying an oxidant gas, for example, an oxygen-containing gas, to the upper edge of the fuel cell 12 in the direction of arrow C (the gravitational direction in FIG. 2) communicates with each other in the direction of arrow A which is the stacking direction. The agent gas supply communication holes 26a and the fuel gas supply communication holes 28a for supplying a fuel gas, for example, a hydrogen-containing gas, are arranged in the arrow B direction (horizontal direction).

  The lower end edge of the fuel cell 12 in the direction of arrow C communicates with each other in the direction of arrow A, and the oxidant gas discharge communication hole 26b for discharging the oxidant gas, and the fuel gas discharge for discharging the fuel gas. The communication holes 28b are arranged in the arrow B direction.

  A pair of cooling medium supply communication holes 30a for supplying a cooling medium and a pair of cooling for discharging the cooling medium are provided at both end edges (two sides on the long side) of the fuel cell 12 in the arrow B direction. For example, the medium discharge communication holes 30b are provided on the upper and lower sides, respectively. The pair of cooling medium supply communication holes 30a have the same opening area, while the pair of cooling medium discharge communication holes 30b have the same opening area. Each of the cooling medium supply communication holes 30a and each of the cooling medium discharge communication holes 30b may be divided into two or more vertically.

  An oxidant gas flow path 32 communicating with the oxidant gas supply communication hole 26a and the oxidant gas discharge communication hole 26b is provided on the surface 22a of the first separator 22 facing the electrolyte membrane / electrode structure 20.

  A fuel gas passage 34 communicating with the fuel gas supply communication hole 28a and the fuel gas discharge communication hole 28b is provided on the surface 24a of the second separator 24 facing the electrolyte membrane / electrode structure 20.

  A cooling medium that connects the cooling medium supply communication hole 30a and the cooling medium discharge communication hole 30b between the surface 22b of the first separator 22 and the surface 24b of the second separator 24 constituting the fuel cells 12 adjacent to each other. A flow path 36 is provided. Each cooling medium supply communication hole 30a and the cooling medium flow path 36 communicate with each other via a communication path 38a, and each cooling medium discharge communication hole 30b and the cooling medium flow path 36 communicate with each other via a communication path 38b. To do.

  The first seal member 40a is integrally or individually provided on the surfaces 22a and 22b of the first separator 22, and the second seal member 40b is integrally formed on the surfaces 24a and 24b of the second separator 24. Or individually.

  The electrolyte membrane / electrode structure 20 includes, for example, a solid polymer electrolyte membrane 42 in which a perfluorosulfonic acid thin film is impregnated with water, and a cathode side electrode 44 and an anode side electrode 46 that sandwich the solid polymer electrolyte membrane 42. With.

  The cathode side electrode 44 and the anode side electrode 46 are uniformly coated on the surface of the gas diffusion layer with a gas diffusion layer (not shown) made of carbon paper or the like and porous carbon particles carrying a platinum alloy on the surface. And an electrode catalyst layer (not shown) formed. The electrode catalyst layers are formed on both surfaces of the solid polymer electrolyte membrane 42.

  As shown in FIG. 1, on the outer surface side of the first end plate 18a, a cooling medium supply manifold 50 is provided on the upper side, and a cooling medium discharge manifold 52 is provided on the lower side. The cooling medium supply manifold 50 and the cooling medium discharge manifold 52 have a substantially U-shape that opens downward.

  For example, the cooling medium supply manifold 50 may be provided on the first end plate 18a side, while the cooling medium discharge manifold 52 may be provided on the second end plate 18b side, for example. Moreover, the structure opposite to the above may be sufficient.

  As shown in FIGS. 1 and 3, the cooling medium supply manifold 50 includes a pair of supply manifold portions 54a and 54a communicating with the pair of cooling medium supply communication holes 30a and 30a of the first end plate 18a, and the pair of supplies. The supply connection part 56a which connects the upper part side of the manifold parts 54a and 54a, and the width dimension W1 along a long side direction (arrow C direction) is set smaller than the dimension of said pair of supply manifold parts 54a and 54a. With.

  The supply manifold portions 54a and 54a have a rectangular parallelepiped shape that is long along the long side direction (arrow C direction) of the first end plate 18a. On one supply manifold portion 54a, a cooling medium supply pipe 58a extending outside the first end plate 18a is provided separately (or integrally). The cooling medium supply pipe 58a communicates with a cooling medium supply unit (not shown).

  As shown in FIG. 4, the cooling medium supply pipe 58a is inclined at a lower end portion of one supply manifold portion 54a by a predetermined angle θ ° (for example, 10 ° to 40 °) from the vertical direction to the horizontal direction. Connected. The cooling medium supply pipe 58a supplies the cooling medium into one supply manifold portion 54a from obliquely below.

  As shown in FIG. 3, the inner wall surface of the supply manifold portion 54a is provided with an inclined portion 60c that smoothly inclines from the straight portion 60a via the curved portion 60b. The inclined portion 60c may be configured by a curved surface, or may be configured by a flat surface. The same applies to each inclined portion described below.

  The cooling medium supply communication hole 30a is provided outwardly in the supply manifold portion 54a, and the inclined portion 60c is formed at an inner corner below the inner wall surface of the supply manifold portion 54a (to other supply manifold portions 54a). Provided at the opposite corners). The inclined portion 60c is preferably provided on the inner wall surface of at least one supply manifold portion 54a to which the cooling medium supply pipe 58a is connected.

  As shown in FIGS. 1 and 3, the cooling medium discharge manifold 52 includes a pair of discharge manifold portions 54b and 54b communicating with the pair of cooling medium discharge communication holes 30b and 30b of the first end plate 18a, and the pair of discharges. The upper and lower sides of the manifold portions 54b and 54b are connected to each other, and the width W2 along the long side direction (arrow C direction) is set to be smaller than the size of the pair of discharge manifold portions 54b and 54b. With.

  The discharge manifold portions 54b and 54b have a rectangular parallelepiped shape that is long along the long side direction (arrow C direction) of the first end plate 18a. A cooling medium discharge pipe 58b extending to the outside of the first end plate 18a is provided separately (or integrally) on one discharge manifold section 54b positioned diagonally to the one supply manifold section 54a. The cooling medium discharge pipe 58b extends in the horizontal direction (arrow A direction) from the central portion of the one discharge manifold portion 54b.

  As shown in FIG. 3, an inclined portion 62c that smoothly inclines from the straight portion 62a through the curved portion 62b is provided on the inner wall surface of the discharge manifold portion 54b. The cooling medium discharge communication hole 30b is provided so as to be biased outward in the discharge manifold portion 54b, and the inclined portion 62c is formed at an inner corner below the inner wall surface of the discharge manifold portion 54b (to other discharge manifold portions 54b). Provided at the opposite corners). The inclined portion 62c is preferably provided on the inner wall surface of at least one discharge manifold portion 54b to which the cooling medium discharge pipe 58b is connected.

  Although not shown, the second end plate 18b is provided with manifolds corresponding to the oxidant gas supply communication hole 26a, the oxidant gas discharge communication hole 26b, the fuel gas supply communication hole 28a, and the fuel gas discharge communication hole 28b. It is done.

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

  First, in the second end plate 18b, an oxidant gas such as an oxygen-containing gas is supplied to the oxidant gas supply communication hole 26a, and a fuel gas such as a hydrogen-containing gas is supplied to the fuel gas supply communication hole 28a.

  Further, as shown in FIG. 1, in the first end plate 18a, a cooling medium such as pure water, ethylene glycol, or oil is supplied into the cooling medium supply manifold 50 from the cooling medium supply pipe 58a. A part of the cooling medium is supplied to the cooling medium supply communication hole 30a from one supply manifold part 54a provided with the cooling medium supply pipe 58a, and the remaining part of the cooling medium passes through the supply connecting part 56a. The other supply manifold portion 54a supplies the coolant supply passage 30a.

  For this reason, as shown in FIG. 2, the oxidant gas is introduced into the oxidant gas flow path 32 of the first separator 22 from the oxidant gas supply communication hole 26a. The oxidant gas moves in the direction of arrow C (the direction of gravity) along the oxidant gas flow path 32 and is supplied to the cathode side electrode 44 of the electrolyte membrane / electrode structure 20.

  On the other hand, the fuel gas is introduced into the fuel gas flow path 34 of the second separator 24 from the fuel gas supply communication hole 28a. The fuel gas moves along the fuel gas flow path 34 in the direction of gravity (arrow C direction) and is supplied to the anode side electrode 46 of the electrolyte membrane / electrode structure 20.

  Therefore, in the electrolyte membrane / electrode structure 20, the oxidant gas supplied to the cathode side electrode 44 and the fuel gas supplied to the anode side electrode 46 are consumed by an electrochemical reaction in the electrode catalyst layer to generate power. Is done.

  Next, the oxidant gas consumed by being supplied to the cathode side electrode 44 of the electrolyte membrane / electrode structure 20 is discharged in the direction of arrow A along the oxidant gas discharge communication hole 26b. The fuel gas supplied to and consumed by the anode side electrode 46 of the electrolyte membrane / electrode structure 20 is discharged in the direction of arrow A along the fuel gas discharge communication hole 28b.

  On the other hand, the cooling medium supplied to the two cooling medium supply communication holes 30 a and 30 a is introduced into a cooling medium flow path 36 formed between the first separator 22 and the second separator 24. This cooling medium moves in the direction of arrow C to cool the electrolyte membrane / electrode structure 20, and then passes from the two cooling medium discharge communication holes 30 b, 30 b to the pair of discharge manifold portions 54 b, 54 b of the cooling medium discharge manifold 52. Discharged.

  As shown in FIG. 1, the cooling medium discharged to one discharge manifold portion 54b is directly discharged to the outside via the cooling medium discharge pipe 58b. The cooling medium discharged to the other discharge manifold portion 54b flows into the one discharge manifold portion 54b through the discharge connection portion 56b, and is then discharged to the outside through the cooling medium discharge pipe 58b.

  In this case, in the first embodiment, as shown in FIG. 3, an inclined portion 60c that smoothly inclines from the straight portion 60a through the curved portion 60b is provided on the inner wall surface of at least one supply manifold portion 54a. ing. The cooling medium supply communication hole 30a is provided outwardly in the supply manifold portion 54a, and the inclined portion 60c is provided in an inner corner below the inner wall surface of the supply manifold portion 54a.

  Therefore, the pressure loss of the cooling medium flowing in the supply manifold portion 54a can be reduced as much as possible, and the distribution of the cooling medium to the pair of cooling medium supply communication holes 30a is improved. Thereby, it is possible to obtain an effect that the cooling medium can be supplied and distributed to the fuel cell smoothly and uniformly with a simple configuration.

  In the first embodiment, in addition to the other supply manifold portion 54a, the pair of discharge manifold portions 54b and 54b are configured similarly to the one supply manifold portion 54a. For this reason, there are advantages that the pressure loss inside the manifold is reduced and the distribution of the cooling medium is improved. In each embodiment described below, only the supply manifold portion side will be described, but the same effect can be obtained.

  Therefore, Comparative Example 1 in which the inner wall surfaces of the pair of supply manifold portions 54a and the pair of discharge manifold portions 54b are formed in a rectangular shape, and the inclined portions 60c on the inner wall surfaces of the pair of supply manifold portions 54a and the pair of discharge manifold portions 54b, Each pressure loss was detected using the first embodiment provided with 62c. The result is shown in FIG.

  Thereby, in 1st Embodiment, the result that the pressure loss inside a manifold reduced significantly compared with the comparative example was obtained. Moreover, the distribution of the cooling medium with respect to the pair of cooling medium supply communication holes 30a is better in the first embodiment than in the comparative example.

  FIG. 6 is a schematic perspective explanatory view of a fuel cell stack 70 according to the second embodiment of the present invention.

  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. Similarly, in the third and subsequent embodiments described below, detailed description thereof is omitted.

  The fuel cell stack 70 includes a cooling medium supply manifold 72 and a cooling medium discharge manifold 74 provided on the outer surface side of the first end plate 18a. The cooling medium supply manifold 72 and the cooling medium discharge manifold 74 have a substantially H shape.

  The cooling medium supply manifold 72 is an abbreviation of a pair of vertically long supply manifold portions 76a, 76a communicating with the pair of cooling medium supply communication holes 30a, 30a of the first end plate 18a, and the pair of supply manifold portions 76a, 76a. A supply connecting portion 78a that connects the intermediate positions and has a width dimension along the long side direction (arrow C direction) is set smaller than the pair of supply manifold portions 76a and 76a. One supply manifold portion 76a is provided with a cooling medium supply pipe 80a extending to the outside of the first end plate 18a.

  The cooling medium supply pipe 80a is connected to the central portion of the one supply manifold portion 76a so as to incline from the stacking direction outward in the horizontal direction (on the side opposite to the supply connection member 78a side). The cooling medium supply pipe 80a supplies the cooling medium into one supply manifold portion 76a from an oblique side.

  As shown in FIG. 7, an inclined portion 82c that smoothly inclines from the straight portion 82a through the curved portion 82b is provided on the inner wall surface of the supply manifold portion 76a. The cooling medium supply communication hole 30a is provided to be biased outward in the supply manifold portion 76a, and the inclined portion 82c is formed on each inner corner portion below the inner wall surface and above the inner wall surface of the supply manifold portion 76a (other (Upper and lower corners facing the supply manifold portion 76a). It is preferable that the inclined portion 82c is provided on the inner wall surface of at least one supply manifold portion 76a to which the cooling medium supply pipe 80a is connected.

  As shown in FIGS. 6 and 7, the cooling medium discharge manifold 74 includes a pair of discharge manifold portions 76b and 76b communicating with the pair of cooling medium discharge communication holes 30b and 30b of the first end plate 18a, and a pair of the discharges. A discharge connecting portion 78b that connects substantially intermediate positions of the manifold portions 76b and 76b and has a width dimension along the long side direction (arrow C direction) set smaller than the pair of discharge manifold portions 76b and 76b. .

  The discharge manifold section 76b is provided with a cooling medium discharge pipe 80b extending outward from the first end plate 18a at a position diagonal to the cooling medium supply pipe 80a. The cooling medium discharge pipe 80b extends in the horizontal direction (stacking direction) from the central portion of one discharge manifold portion 76b.

  As shown in FIG. 7, an inclined portion 84c that smoothly inclines from the straight portion 84a through the curved portion 84b is provided on the inner wall surface of the discharge manifold portion 76b. The cooling medium discharge communication hole 30b is provided so as to be biased outward in the discharge manifold portion 76b, and the inclined portion 84c is formed on each inner corner portion below the inner wall surface and above the inner wall surface of the discharge manifold portion 76b (other discharge holes). (Both upper and lower corners facing the manifold portion 76b). The inclined portion 84c is preferably provided on the inner wall surface of at least one discharge manifold portion 76b to which the cooling medium discharge pipe 80b is connected.

  In the second embodiment configured as described above, as shown in FIG. 7, a cooling medium supply pipe 80a is connected to the central portion of one supply manifold portion 76a, and the inner wall surface of the supply manifold portion 76a is below. And the inclination part 82c is each provided in each inner corner | angular part above an inner wall surface.

  Therefore, the pressure loss of the cooling medium flowing in the supply manifold portion 76a can be reduced as much as possible, and the distribution of the cooling medium to the pair of cooling medium supply communication holes 30a is improved satisfactorily. Thereby, with the simple configuration, it is possible to supply and circulate the cooling medium smoothly and uniformly to the fuel cell, and the same effects as in the first embodiment can be obtained.

  FIG. 8 is a schematic perspective explanatory view of a fuel cell stack 90 according to the third embodiment of the present invention.

  The fuel cell stack 90 includes a cooling medium supply manifold 92 and a cooling medium discharge manifold 94 provided on the outer surface side of the first end plate 18a. The cooling medium supply manifold 92 and the cooling medium discharge manifold 94 have a substantially U-shape that opens upward.

  The cooling medium supply manifold 92 includes a pair of vertically-shaped supply manifold portions 96a and 96a communicating with the pair of cooling medium supply communication holes 30a and 30a of the first end plate 18a, and lower portions of the pair of supply manifold portions 96a and 96a. A supply connecting portion 98a that connects the sides and has a width dimension along the long side direction is set to be smaller than the pair of supply manifold portions 96a and 96a. In one supply manifold portion 96a, a cooling medium supply pipe 100a extending outside the first end plate 18a is provided separately (or integrally).

  The cooling medium supply pipe 100a is connected to the upper end portion of one supply manifold portion 96a so as to be inclined from the vertical direction to the horizontal direction. The cooling medium supply pipe 100a supplies the cooling medium into one supply manifold portion 96a from obliquely above.

  As shown in FIG. 9, an inclined portion 102c that smoothly inclines from the straight portion 102a through the curved portion 102b is provided on the inner wall surface of the supply manifold portion 96a. The cooling medium supply communication hole 30a is provided so as to be biased outward in the supply manifold portion 96a, and the inclined portion 102c is formed at an inner corner (above the other inner surface of the supply manifold portion 96a). Provided at the opposite corners). The inclined portion 102c is preferably provided on the inner wall surface of at least one supply manifold portion 96a to which the cooling medium supply pipe 100a is connected.

  As shown in FIGS. 8 and 9, the cooling medium discharge manifold 94 includes a pair of discharge manifold portions 96b and 96b communicating with the pair of cooling medium discharge communication holes 30b and 30b of the first end plate 18a, and a pair of the discharges. A discharge connecting portion 98b that connects lower portions of the manifold portions 96b and 96b and has a width dimension along the long side direction set smaller than the pair of discharge manifold portions 96b and 96b is provided.

  The discharge manifold portion 96b is provided with a cooling medium discharge pipe 100b extending outside the first end plate 18a at a position diagonal to the cooling medium supply pipe 100a. The cooling medium discharge pipe 100b extends in the horizontal direction (stacking direction) from the central portion of one discharge manifold portion 96b.

  As shown in FIG. 9, an inclined portion 104c that smoothly inclines from the straight portion 104a through the curved portion 104b is provided on the inner wall surface of the discharge manifold portion 96b. The cooling medium discharge communication hole 30b is provided so as to be biased outward in the discharge manifold portion 96b, and the inclined portion 104c is formed on the inner corner portion above the inner wall surface of the discharge manifold portion 96b (to other discharge manifold portions 96b). Provided at the opposite corners). The inclined portion 104c is preferably provided on the inner wall surface of at least one discharge manifold portion 96b to which the cooling medium discharge pipe 100b is connected.

  In the third embodiment configured as described above, the cooling medium supply pipe 100a is connected to the upper portion of one supply manifold portion 96a, and the inner corner portion above the inner wall surface of the supply manifold portion 96a is inclined. A portion 102c is provided.

  Therefore, the pressure loss of the cooling medium flowing in the supply manifold portion 96a can be reduced as much as possible, and the distribution of the cooling medium to the pair of cooling medium supply communication holes 30a is improved. As a result, it is possible to obtain the same effects as those of the first and second embodiments described above, such that the cooling medium can be supplied and distributed to the fuel cell smoothly and uniformly with a simple configuration.

  FIG. 10 is a schematic perspective explanatory view of a fuel cell stack 110 according to the fourth embodiment of the present invention.

  In the fuel cell stack 110, a cooling medium supply manifold 112 and a cooling medium discharge manifold 114 are arranged vertically on the outer surface side of the first end plate 18a.

  The cooling medium supply manifold 112 includes a pair of supply manifold portions 116a and 116a communicating with the pair of cooling medium supply communication holes 30a and 30a of the first end plate 18a, and an upper side of the pair of supply manifold portions 116a and 116a. And a supply connecting portion 118a to be connected.

  The supply manifold portions 116a and 116a have a rectangular parallelepiped shape that is long along the long side direction (arrow C direction) of the first end plate 18a. One supply manifold portion 116a is provided with a cooling medium supply pipe 58a extending outside the first end plate 18a.

  The inner wall surface of the supply manifold portion 116a is provided with an inclined portion 120c that smoothly inclines from the straight portion 120a through the curved portion 120b. The cooling medium supply communication hole 30a is provided inwardly in the supply manifold portion 116a, and the inclined portion 120c is provided in an outer corner below the inner wall surface of the supply manifold portion 116a. The inclined portion 120c is preferably provided on the inner wall surface of one supply manifold portion 116a to which at least the cooling medium supply pipe 58a is connected.

  The cooling medium discharge manifold 114 includes a pair of discharge manifold portions 116b and 116b communicating with the pair of cooling medium discharge communication holes 30b and 30b of the first end plate 18a, and an upper side of the pair of discharge manifold portions 116b and 116b. And a discharge connecting portion 118b to be connected.

  The discharge manifold portions 116b and 116b have a rectangular parallelepiped shape that is elongated along the long side direction (arrow C direction) of the first end plate 18a. A cooling medium discharge pipe 58b extending to the outside of the first end plate 18a is provided in one discharge manifold section 116b located diagonally to the one supply manifold section 116a.

  The inner wall surface of the discharge manifold portion 116b is provided with an inclined portion 122c that smoothly inclines from the straight portion 122a through the curved portion 122b. The cooling medium discharge communication hole 30b is provided inwardly in the discharge manifold portion 116b, and the inclined portion 122c is provided in an outer corner below the inner wall surface of the discharge manifold portion 116b. The inclined portion 122c is preferably provided on the inner wall surface of one discharge manifold portion 116b to which at least the cooling medium discharge pipe 58b is connected.

  In the fourth embodiment configured as described above, an inclined portion 120c that smoothly inclines from the straight portion 120a via the curved portion 120b is provided on the inner wall surface of the supply manifold portion 116a. The cooling medium supply communication hole 30a is provided inwardly in the supply manifold portion 116a, and the inclined portion 120c is provided in an outer corner below the inner wall surface of the supply manifold portion 116a.

  Therefore, the pressure loss of the cooling medium flowing in the supply manifold portion 116a can be reduced as much as possible, and the distribution of the cooling medium to the pair of cooling medium supply communication holes 30a is improved satisfactorily. Accordingly, the same effects as those of the first to third embodiments described above can be obtained, such as allowing the cooling medium to be supplied and distributed to the fuel cell smoothly and uniformly with a simple configuration.

  In the first to fourth embodiments, the cooling medium discharge pipes 58b, 80b, and 100b are configured to extend in the horizontal direction, but are not limited thereto. For example, the cooling medium discharge pipes 58b, 80b, and 100b may be configured similarly to the cooling medium supply pipes 58a, 80a, and 100a, respectively.

DESCRIPTION OF SYMBOLS 10, 70, 90, 110 ... Fuel cell stack 12 ... Fuel cell 18a, 18b ... End plate 20 ... Electrolyte membrane electrode assembly 22, 24 ... Separator 26a ... Oxidant gas supply communication hole 26b ... Oxidant gas discharge communication hole 28a ... Fuel gas supply communication hole 28b ... Fuel gas discharge communication hole 30a ... Cooling medium supply communication hole 30b ... Cooling medium discharge communication hole 32 ... Oxidant gas flow channel 34 ... Fuel gas flow channel 36 ... Cooling medium flow channel 38a, 38b ... Communication passage 42 ... Solid polymer electrolyte membrane 44 ... Cathode side electrode 46 ... Anode side electrodes 50, 72, 92, 112 ... Cooling medium supply manifolds 52, 74, 94, 114 ... Cooling medium discharge manifolds 54a, 76a, 96a, 116a ... Supply manifold portions 54b, 76b, 96b, 116b ... Discharge manifold portions 56a, 78a, 98 , 118a ... supply connection portions 56b, 78b, 98b, 118b ... discharge connection portions 58a, 80a, 100a ... cooling medium supply piping 58b, 80b, 100b ... cooling medium discharge piping 60a, 62a, 82a, 84a, 102a, 104a, 120a , 122a ... straight parts 60b, 62b, 82b, 84b, 102b, 104b, 120b, 122b ... curved parts 60c, 62c, 82c, 84c, 102c, 104c, 120c, 122c ... inclined parts

Claims (5)

A fuel cell stack in which an electrolyte / electrode structure provided with a pair of electrodes on both sides of an electrolyte and a separator are stacked, and rectangular end plates are disposed at both ends in the stacking direction,
A pair of cooling medium supply communication holes and a pair of cooling medium discharge communication holes through which the cooling medium is circulated and respectively communicated in the stacking direction are provided on the two opposite long sides of the fuel cell stack,
One end plate communicates with the pair of cooling medium supply communication holes, and has a pair of supply manifold portions elongated along the two sides,
A supply connecting portion for connecting the pair of supply manifold portions;
Is provided,
A fuel cell stack, wherein an inclined portion that smoothly inclines from a straight portion through a curved portion is provided on an inner wall surface of at least one supply manifold portion. 2. The fuel cell stack according to claim 1, wherein the one end plate communicates with the cooling medium discharge communication hole and has a pair of discharge manifold portions elongated along the two sides;
A discharge connecting portion that connects the pair of discharge manifold portions;
Is provided,
A fuel cell stack, wherein an inclined portion that smoothly inclines from a straight portion through a curved portion is provided on an inner wall surface of at least one discharge manifold portion. 3. The fuel cell stack according to claim 1, wherein the pair of supply manifold portions are elongated in the vertical direction,
The supply connecting part is connected to the upper part of the pair of supply manifold parts,
The fuel cell stack, wherein the inclined portion is provided at least in a lower corner portion of an inner wall surface of the one supply manifold portion. 3. The fuel cell stack according to claim 1, wherein the pair of supply manifold portions are elongated in the vertical direction,
The supply connecting portion is connected to a lower portion of the pair of supply manifold portions,
The fuel cell stack, wherein the inclined portion is provided at least in an upper corner portion of an inner wall surface of the one supply manifold portion. 3. The fuel cell stack according to claim 1, wherein the pair of supply manifold portions are elongated in the vertical direction,
The supply connecting portion is connected to a central portion of the pair of supply manifold portions,
The fuel cell stack, wherein the inclined portions are provided at least in a lower corner portion and an upper corner portion of an inner wall surface of the one supply manifold portion.