JP2020053265A - Fuel cell stack and porous body channel plate - Google Patents

Abstract

To provide a fuel cell stack and a porous body channel plate capable of suppressing a decrease in power generation efficiency of a fuel cell.SOLUTION: A space between a second separator 60 and a frame member 40 is sealed by a seal unit 60a. Between a side edge of a gas channel unit 51 and the seal unit 60a, a shielding unit 59 for shielding a space between the second separator 60 and a power generation unit 11 is provided.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a fuel cell stack and a porous body flow path plate constituting a part of a single cell of the fuel cell stack.

The polymer electrolyte fuel cell includes a fuel cell stack configured by stacking a plurality of single cells (for example, see Patent Document 1).
The single cell described in Document 1 includes a membrane electrode assembly, a pair of separators sandwiching the membrane electrode assembly in the thickness direction, and a pair of porous members provided between the membrane electrode assembly and the pair of separators. A body channel plate is provided. The membrane electrode assembly is one in which an electrolyte membrane is sandwiched between a pair of electrodes in a thickness direction thereof, and constitutes a power generation unit of a fuel cell.

  The porous flow path plate has a mesh-shaped gas flow path portion in which a plurality of irregularities are alternately arranged. The portion defined by the membrane electrode assembly and the irregularities functions as a flow path for a fuel gas or an oxidizing gas.

  In the single cell, a fuel gas supply manifold for supplying a fuel gas and a fuel gas discharge manifold for discharging the fuel gas are provided in a plane direction with the power generation unit interposed therebetween. A plurality of connection flow paths that connect the fuel gas supply manifold and the gas flow path portion of the porous flow path plate are provided in parallel in the single cell.

  Further, the single cell is provided with an oxidizing gas supply manifold for supplying an oxidizing gas, and an oxidizing gas discharge manifold for discharging the oxidizing gas, with the power generation unit interposed therebetween in the plane direction. In the single cell, a plurality of connection flow paths that connect the oxidant gas supply manifold and the gas flow path of the porous flow path plate are provided in parallel.

  The fuel gas supplied through the fuel gas supply manifold flows into the gas flow path of the porous flow path plate through the connection flow path, and flows into the anode side of the power generation unit when flowing toward the fuel gas discharge manifold.

  The oxidizing gas supplied through the oxidizing gas supply manifold flows into the gas flow path of the porous flow path plate through the connection flow path, and flows toward the oxidizing gas discharge manifold when the gas flows toward the cathode of the power generation section. Flows into.

Then, power generation is performed by an electrochemical reaction between the fuel gas and the oxidant gas in the power generation unit.
The fuel gas and the oxidizing gas after passing through the flow path of the porous flow path plate are respectively discharged through the fuel gas discharging manifold and the oxidizing gas discharging manifold.

JP 2008-108573 A

  By the way, since the gas flow path portion of the porous flow path plate has a mesh shape in which a plurality of irregularities are alternately arranged, a fuel gas or an oxidizing gas flowing through the gas flow path portion (hereinafter collectively referred to as a reaction gas) is used. Flows out to the side of the porous flow channel plate, that is, a so-called side flow occurs. Since such by-passed reaction gas does not contribute to power generation, the power generation efficiency of the fuel cell may be reduced.

  An object of the present invention is to provide a fuel cell stack and a porous flow channel plate that can suppress a decrease in power generation efficiency.

  A fuel cell stack for achieving the above object has a power generation unit having a membrane electrode assembly, a frame member surrounding an outer periphery of the power generation unit, a pair of separators sandwiching the power generation unit and the frame member, and A fuel cell stack comprising a plurality of unit cells each including at least one of the separators described above and the porous body flow path plate having a mesh-shaped gas flow path section through which a reactant gas flows, provided between the power generation unit. Wherein the gap between the separator and the frame member in which the porous body flow path plate is provided between the power generation unit and the frame member are sealed by a seal part, and a side edge of the gas flow path part and Between the seal part, a shielding part for shielding between the separator and the power generation part is provided.

  According to this configuration, the seal between the separator in which the porous body flow path plate is provided between the power generation unit and the frame member is sealed by the seal unit. Further, a shielding portion for shielding between the separator and the power generation portion is provided between the side edge portion of the gas flow passage portion and the seal portion. For this reason, it is possible to suppress the side flow of the reaction gas between the side edge of the gas flow path and the seal. Therefore, a decrease in the power generation efficiency of the fuel cell can be suppressed.

In the fuel cell stack, it is preferable that the shielding portion is provided between both the side edge portions of the gas flow passage portion and the sealing portion.
According to this configuration, it is possible to suppress the side flow of the reaction gas on both sides of the gas flow path. Therefore, a decrease in the power generation efficiency of the fuel cell can be further suppressed.

In the above fuel cell stack, it is preferable that the shielding section is formed integrally with the gas flow path section.
According to this configuration, since the shielding portion is formed integrally with the gas flow passage portion, it is not necessary to separately provide the gas flow passage portion and the shielding portion. Therefore, the manufacture of the fuel cell stack and the fuel cell is facilitated.

  In the above fuel cell stack, it is preferable that the power generation unit includes a pair of gas diffusion layers sandwiching the membrane electrode assembly, and a leading edge of the shielding unit abuts on the gas diffusion layer.

  According to this configuration, since the leading edge of the shielding portion is in contact with the gas diffusion layer sandwiching the membrane electrode assembly, the reaction gas flowing to the side of the gas flow path portion is located outside the gas diffusion layer. The reactant gas no longer flows, and reaches the gas diffusion layer that contributes to power generation. Therefore, a decrease in the power generation efficiency of the fuel cell can be further suppressed.

  In the fuel cell stack, it is preferable that the shielding portion is inclined so as to be more distant from the gas flow path portion from the separator side toward the power generation portion side in the stacking direction of the single cells.

  The shielding portion is inclined so as to be more distant from the gas flow path portion as the shielding portion moves from the separator side toward the power generation portion side in the stacking direction of the single cells. Thereby, the reaction gas flowing to the side of the gas flow path portion flows along the inner surface of the shielding portion, and is easily guided to the gas diffusion layer. Therefore, a decrease in the power generation efficiency of the fuel cell can be further suppressed.

  In addition, the porous body flow path plate for achieving the above object has a mesh-shaped gas flow path portion through which a reaction gas flows, and a power generation section having a membrane electrode assembly and having an outer periphery surrounded by a frame member. In the porous flow path plate constituting a part of the single cell of the fuel cell stack by being sandwiched by the separator, a side edge of the gas flow path portion shields between the separator and the power generation section. The shielding part to be formed is integrally formed.

  According to this configuration, the shielding portion that shields the space between the power generation unit and the separator is integrally formed at the side edge of the gas passage portion of the porous body passage plate. For this reason, the side flow of the reaction gas from the side edge of the gas flow path to the side can be suppressed. Therefore, a decrease in the power generation efficiency of the fuel cell can be suppressed.

Further, according to the above configuration, it is not necessary to separately provide the porous body flow path plate and the shielding portion, and therefore, the fuel cell stack, and eventually the fuel cell, can be easily manufactured.
In the porous flow channel plate, the shielding portion may be inclined so as to be more distant from the gas flow channel portion toward the power generation portion side from the separator side in the thickness direction of the porous flow channel plate. Is preferred.

  According to this configuration, the shielding portion is inclined so as to be more distant from the gas flow passage portion from the separator side toward the power generation portion side in the thickness direction of the porous flow passage plate. Thereby, the reaction gas flowing to the side of the gas flow path portion flows along the inner surface of the shielding portion, and is easily guided to the gas diffusion layer. Therefore, a decrease in the power generation efficiency of the fuel cell can be further suppressed.

  ADVANTAGE OF THE INVENTION According to this invention, the fall of the electric power generation efficiency of a fuel cell can be suppressed.

FIG. 2 is an exploded perspective view showing a configuration of a single cell of the fuel cell stack according to one embodiment of the fuel cell stack. The perspective view showing a part of porous body channel board of the embodiment. Sectional drawing which shows the edge part in the width direction of the fuel cell stack of the embodiment. The side view which shows typically a mode that a base material is roll-formed by the roll forming apparatus of the embodiment. Sectional drawing which shows a mode that a base material is roll-formed by the roll forming apparatus of the embodiment. It is a figure which shows the manufacturing process of the porous body flow path board of a modification, (a) is a figure which shows the process of arrange | positioning the base material roll-formed in the shaping | molding die, (b) is a figure which shows the base material by a shaping | molding die. The figure which shows the process which presses.

Hereinafter, an embodiment will be described with reference to FIGS.
As shown in FIG. 1, the fuel cell stack of the present embodiment constitutes a polymer electrolyte fuel cell, and has a structure in which a plurality of unit cells 10 each having a substantially rectangular plate shape in a plan view are stacked. ing. The single cell 10 includes a membrane electrode gas diffusion layer assembly (hereinafter, MEGA 30) constituting the power generation unit 11, a first separator 20 and a second separator 60 that sandwich the MEGA 30 in the thickness direction, and The porous body flow path plate 50 provided between the MEGA 30 and the second separator 60 is provided.

  The MEGA 30 is fitted inside a frame member 40 made of a resin material such as an epoxy resin. Each of the frame member 40, the first separator 20, and the second separator 60 has a substantially rectangular plate shape in a plan view, and has the same outer dimensions. The frame member 40 is sandwiched between the first separator 20 and the second separator 60 in the thickness direction.

The first separator 20 is arranged on the anode side of the power generation unit 11. Further, the second separator 60 is arranged on the cathode side of the power generation unit 11.
The porous flow path plate 50 has a substantially rectangular shape in a plan view, and has a mesh-shaped gas flow path portion 51 through which an oxidizing gas flows (see FIG. 2). The porous flow path plate 50 is disposed such that two pairs of parallel sides of the gas flow path 51 and two pairs of parallel sides of the single cell 10 are parallel to each other.

Hereinafter, the direction along the long side of the rectangle of the single cell 10 is referred to as the longitudinal direction X, and the direction along the short side of the rectangle is referred to as the width direction Y.
<Single cell 10>
As shown in FIG. 1, in a single cell 10, a fuel gas supply manifold 12 for supplying a fuel gas (for example, hydrogen gas) and a fuel gas discharge manifold 13 for discharging the fuel gas generate electric power in the surface direction of the single cell 10. It is provided with the portion 11 interposed therebetween. More specifically, the fuel gas supply manifold 12 is located at one end side in the longitudinal direction X (right side in the figure) and at one end side in the width direction Y (upper side in the figure). Further, the fuel gas discharge manifold 13 is located on the other end side in the longitudinal direction X (left side in the figure) and on the other end side in the width direction Y (lower side in the figure).

  In the single cell 10, an oxidizing gas supply manifold 14 that supplies an oxidizing gas (for example, air) and an oxidizing gas discharge manifold 15 that discharges the oxidizing gas sandwich the power generation unit 11 in the plane direction of the single cell 10. It is provided in. More specifically, the oxidizing gas supply manifold 14 is located at the other end in the longitudinal direction X (left side in the figure) and at one end in the width direction Y (upper side in the figure). The oxidizing gas discharge manifold 15 is located at one end in the longitudinal direction X (right side in the figure) and at the other end in the width direction Y (lower side in the figure).

  Further, the single cell 10 is provided with a cooling water supply manifold 16 for supplying cooling water and a cooling water discharge manifold 17 for discharging cooling water with the power generation unit 11 interposed therebetween in the surface direction of the single cell 10. More specifically, the cooling water supply manifold 16 is located between the fuel gas supply manifold 12 and the oxidizing gas discharge manifold 15 in the width direction Y. The cooling water discharge manifold 17 is located between the fuel gas discharge manifold 13 and the oxidizing gas supply manifold 14 in the width direction Y.

Each of the manifolds 12 to 17 penetrates the single cell 10 (the first separator 20, the frame member 40, and the second separator 60).
Next, each configuration of the single cell 10 will be described in detail.

<First separator 20>
As shown in FIGS. 1 and 3, the first separator 20 is made of a metal plate such as stainless steel and has a substantially rectangular plate shape. The MEGA 30 is in contact with the center of the first separator 20. The frame member 40 is in contact with a portion of the first separator 20 on the outer peripheral side from the center.

  At the center of the first separator 20, a plurality of groove-shaped fuel gas flow paths 21 extending along the longitudinal direction X are arranged in parallel in the width direction Y. Between the fuel gas supply manifold 12 and the fuel gas flow path 21 in the first separator 20, a plurality of fuel gas supply flow paths 22 connecting the fuel gas supply manifold 12 and the fuel gas flow path 21 are formed in the width direction Y. It is juxtaposed. Further, between the fuel gas flow path 21 and the fuel gas discharge manifold 13, a plurality of fuel gas discharge flow paths 23 connecting the fuel gas flow path 21 and the fuel gas discharge manifold 13 are arranged in parallel in the width direction Y. ing.

  As shown in FIG. 3, a plurality of groove-shaped cooling water passages 24 are formed on a surface of the first separator 20 opposite to the fuel gas passage 21. The cooling water passages 24 are formed one by one in the portion between the fuel gas passages 21 adjacent to each other in the width direction Y, and are connected to the cooling water supply manifold 16 and the cooling water discharge manifold 17. In FIG. 1, the illustration of the cooling water channel 24 is omitted.

<MEGA30>
As shown in FIG. 3, the MEGA 30 includes a membrane electrode assembly (hereinafter, MEA 31), and an anode-side gas diffusion layer 32 and a cathode-side gas diffusion layer 33 that sandwich the MEA 31. The MEGA 30 has a substantially rectangular shape in plan view.

The MEA 31 includes an electrolyte membrane 34 having proton conductivity, and an anode-side electrode catalyst layer 35 and a cathode-side electrode catalyst layer 36 sandwiching the electrolyte membrane 34.
Each electrode catalyst layer 35, 36 carries a catalyst (for example, platinum) for promoting an electrochemical reaction of the reaction gas in the power generation unit 11.

  Each of the gas diffusion layers 32 and 33 is for diffusing the reaction gas in the plane direction of the MEA 31 and is formed of a material having gas permeability and conductivity such as carbon paper or carbon cloth.

<Second separator 60>
As shown in FIGS. 1 and 3, the second separator 60 is made of a metal plate material such as stainless steel and has a substantially rectangular plate shape. The second separator 60 has a flat central portion 61. The porous body channel plate 50 is in contact with the central portion 61. In addition, a portion of the second separator 60 on the outer peripheral side from the central portion 61, more specifically, on a portion on the outer peripheral side of each of the manifolds 12 to 17, a rectangular annular seal portion projecting toward the frame member 40. 60a are integrally formed. The seal portion 60 a seals between the second separator 60 and the frame member 40 by being in contact with the frame member 40.

  The second separator 60 is provided with a plurality of groove-shaped oxidizing gas supply flow paths 62 that connect the oxidizing gas supply manifold 14 and the edge 50 a of the gas flow path 51. The plurality of oxidizing gas supply channels 62 are connected over the entire width 50 of the edge 50a.

  Further, the second separator 60 is provided with a plurality of groove-shaped oxidizing gas discharge channels 63 that connect the edge portion 50 b of the gas channel portion 51 and the oxidizing gas discharge manifold 15. The plurality of oxidizing gas discharge channels 63 are connected over the entire width of the edge portion 50b in the width direction Y.

<Porous body flow path plate 50>
As shown in FIGS. 2 and 3, the porous body flow path plate 50 includes a mesh-shaped gas flow path 51 having a substantially rectangular shape in a plan view, and side edges on both sides in the width direction Y of the gas flow path 51. A shielding portion 59 extending from the side edge portion 50c and shielding the space between the second separator 60 and the power generation portion 11 is provided between the side edge portion 50c and the sealing portion 60a of the second separator 60. FIG. 2 shows only one shielding portion 59 in the width direction Y.

As shown in a partially enlarged manner in FIG. 2, the gas flow path portion 51 of the porous flow path plate 50 includes a plurality of flat portions 52 in a shape of a flat bar extending along the longitudinal direction X.
The gas flow path portion 51 has a first convex portion 53 protruding toward the MEGA 30 with respect to the flat portion 52 and a first concave portion 54 protruding toward the second separator 60 with respect to the flat portion 52. The convex portions 53 and the first concave portions 54 are provided with first wavy portions 55 which are alternately arranged in the longitudinal direction X to form a wavy shape.

  The gas flow path 51 has a second convex portion 56 protruding toward the MEGA 30 with respect to the flat portion 52 and a second concave portion 57 protruding toward the second separator 60 with respect to the flat portion 52. The convex portions 56 and the second concave portions 57 are provided alternately in the longitudinal direction X, and include a second wavy portion 58 having a wavy shape.

The first wavy portions 55 are arranged on both sides of the flat portion 52 in the width direction Y. The second wavy portion 58 is arranged on the side of the first wavy portion 55 opposite to the flat portion 52.
The top surfaces of the projections 53 and 56 are in contact with the cathode-side gas diffusion layer 33 of the MEGA 30. The surfaces of the concave portions 54 and 57 opposite to the bottom surface are in contact with the second separator 60 (see FIG. 3).

  The first convex portion 53 of the first wavy portion 55 and the second concave portion 57 of the second wavy portion 58 are adjacent to each other in the width direction Y, and the first concave portion 54 of the first wavy portion 55 and the second wavy portion 58 The first wavy portion 55 and the second wavy portion 58 are adjacent to each other in the width direction Y such that the two convex portions 56 are adjacent to each other in the width direction Y.

  The shielding portion 59 extends from the side edge portion 50c of the first concave portion 54 of the first wavy portion 55 located on the outermost side in the width direction Y, and extends in the thickness direction of the porous body flow path plate 50 (the vertical direction in FIG. 3). In (), it is inclined so as to be more distant from the gas flow path 51 as it goes from the second separator 60 side to the power generation unit 11 side. The leading edge of the shielding portion 59 is in contact with the cathode-side gas diffusion layer 33.

The flat portion 52, the first wavy portion 55, the second wavy portion 58, and the shielding portion 59 are connected to each other at portions adjacent to each other in the width direction Y.
The oxidizing gas flows through the flow path formed between the gas flow path 51 and the MEGA 30, while the fuel gas and the oxidizing gas flow through the flow path formed between the gas separator 51 and the second separator 60. The water produced by the electrochemical reaction with water flows.

Such a porous body flow path plate 50 is formed by roll-forming a substrate made of a stainless steel plate or the like by a roll forming apparatus 70 described later.
Next, a method of manufacturing the porous body flow path plate 50 by the roll forming apparatus 70 will be described.

  As shown in FIGS. 4 and 5, the roll forming device 70 includes a first roll 72 that rotates integrally with the first shaft 71, and a second roll 76 that rotates integrally with the second shaft 75. I have. The first shaft 71 and the second shaft 75 are arranged parallel to each other. That is, the first roll 72 and the second roll 76 are arranged such that their outer peripheral surfaces face each other. Note that the first roll 72 and the second roll 76 are configured to rotate in mutually opposite directions.

  As shown in FIG. 5, the first roll 72 has a structure in which a plurality of blade bodies 73 are stacked in the axial direction. On the outer peripheral surface of each blade body 73, a plurality of cutting blades 73a are protruded at intervals in the circumferential direction. The blade bodies 73 adjacent to each other are fixed to the first shaft 71 at positions shifted from each other by a predetermined pitch in the circumferential direction so that the respective cutting blades 73a are not adjacent to each other in the axial direction.

  The second roll 76 has a structure in which a plurality of blade bodies 77 are stacked in the axial direction. A plurality of cutting blades 77a are provided on the outer peripheral surface of each blade body 77 at intervals in the circumferential direction. The blade bodies 77 adjacent to each other are fixed to the second shaft 75 at positions shifted from each other by a predetermined pitch in the circumferential direction such that the respective cutting blades 77a are not adjacent to each other in the axial direction.

A plurality of blade bodies are laminated on both ends of the first roll 72 in the axial direction, and a first blade body group 74 is provided in which the outer diameter is gradually reduced as the blade body is positioned outward in the axial direction. Have been.
Further, a plurality of blade bodies are laminated at both ends in the axial direction of the second roll 76, and the second blade body group 78 in which the outer diameter increases stepwise as the blade body is positioned outside in the axial direction. Is provided. In FIG. 5, only one end in the axial direction of the roll forming apparatus 70 is shown, but the other end has a shape obtained by inverting the one end, and a duplicate description will be omitted. .

Next, a method of manufacturing the porous body flow path plate 50 by the roll forming apparatus 70 will be described.
As shown in FIG. 4, first, a base material 150 made of a metal plate material is supplied between the first roll 72 and the second roll 76 by a transport device (not shown). Then, as shown in FIG. 5, the gas passage portion 51 having a mesh shape is formed in the base material 150 by the rotating blades 73 and 77 of the first roll 72 and the second roll 76. 1 step). Further, at this time, gas passes between the blade body groups 74 and 78 at the side ends where the gas flow path 51 is not formed on both sides of the base material 150 in the width direction (direction orthogonal to the conveyance direction). The shielding part 59 extending stepwise from the flow path part 51 to the side is formed (the above is the second step).

In this manner, the porous flow channel plate 50 having the gas flow channel 51 and the shielding portion 59 is manufactured.
The operation of the present embodiment will be described.

  As shown in FIG. 1, the fuel gas supplied to the fuel gas supply manifold 12 flows into the fuel gas passage 21 through the fuel gas supply passage 22 of the first separator 20. Then, the fuel gas reaches the anode-side gas diffusion layer 32 of the power generation unit 11 when flowing toward the fuel gas discharge manifold 13.

  The oxidizing gas supplied through the oxidizing gas supply manifold 14 flows into the gas flow path 51 of the porous flow path plate 50 through the oxidizing gas supply flow path 62 of the second separator 60. The oxidizing gas reaches the cathode-side gas diffusion layer 33 of the power generation unit 11 when flowing toward the oxidizing gas discharge manifold 15.

Then, power generation is performed by an electrochemical reaction between the fuel gas and the oxidizing gas in the power generation unit 11.
The fuel gas is discharged from the fuel gas discharge channel 23 through the fuel gas discharge manifold 13. The oxidizing gas is discharged from the oxidizing gas discharge channel 63 through the oxidizing gas discharge manifold 15.

  Here, as shown in FIG. 4, in this embodiment, the porous body flow path plate 50 is provided with the shielding portion 59 located between the side edge portion 50 c of the gas flow portion 51 and the seal portion 60 a of the second separator 60. have. Therefore, the side flow of the oxidizing gas between the side edge portion 50c and the seal portion 60a is suppressed.

The effect of the present embodiment will be described.
(1) The seal between the second separator 60 and the frame member 40 is sealed by a seal portion 60a, and between the side edge of the gas flow passage portion 51 and the seal portion 60a, the second separator 60 and the power generator A shielding portion 59 that shields the space from the portion 11 is provided.

According to such a configuration, the above operation is achieved, so that a decrease in the power generation efficiency of the fuel cell can be suppressed.
(2) The shielding portion 59 is provided between both side edge portions 50c of the gas flow passage portion 51 and the seal portion 60a.

According to such a configuration, it is possible to suppress the side flow of the reaction gas on both sides of the gas flow path 51. Therefore, a decrease in the power generation efficiency of the fuel cell can be further suppressed.
(3) The shielding part 59 is formed integrally with the gas flow path part 51.

  According to such a configuration, since the shielding portion 59 is formed integrally with the gas passage portion 51, it is not necessary to separately provide the gas passage portion 51 and the shielding portion 59. Therefore, the manufacture of the fuel cell stack and the fuel cell is facilitated.

  (4) The power generation unit 11 includes the anode-side gas diffusion layer 32 and the cathode-side gas diffusion layer 33 sandwiching the MEA 31, and the leading edge of the shielding unit 59 is in contact with the cathode-side gas diffusion layer 33.

  According to such a configuration, since the leading edge of the shielding portion 59 is in contact with the cathode-side gas diffusion layer 33, the reaction gas flowing to the side of the gas flow path portion 51 is located outside the cathode-side gas diffusion layer 33. The reaction gas does not flow sideways, and reaches the cathode-side gas diffusion layer 33 that contributes to power generation. Therefore, a decrease in the power generation efficiency of the fuel cell can be further suppressed.

(5) The shielding part 59 is inclined so as to be more distant from the gas flow path part 51 from the second separator 60 side toward the power generation part 11 side in the stacking direction of the single cells 10.
According to such a configuration, the oxidant gas flowing to the side of the gas flow path 51 flows along the inner surface of the shielding portion 59, so that the oxidizing gas is easily guided to the cathode-side gas diffusion layer 33. Therefore, a decrease in the power generation efficiency of the fuel cell can be further suppressed.

  (6) In the first step, the gas flow path 51 is formed in the base 150 made of a metal plate by the roll forming apparatus 70. In the second step, the roll forming device 70 forms a shielding portion 59 extending in a stepwise manner from the gas flow path 51 to the side end of the base material 150 where the gas flow path 51 is not formed. did.

According to such a method, an effect similar to the effect (1) can be obtained. Further, the porous body flow path plate 50 can be manufactured by the same roll forming apparatus 70.
This embodiment can be implemented with the following modifications. The present embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.

  -The shape of the shielding part 59 of the porous body flow path plate 50 is not particularly limited as long as it shields between the second separator 60 and the power generation part 11. In addition, for example, a shielding unit having an inclined surface that is inclined so as to be more distant from the gas flow path unit 51 from the second separator 60 toward the power generation unit 11 may be used. Further, a shielding portion extending from the side edge portion 50c of the gas flow path portion 51 along the stacking direction of the single cells 10 may be used. In this case, the shielding portion having the inclined surface may be formed by bending a side end of the base material 150, or as shown in FIGS. 6A and 6B. 80 may be used.

  As shown in FIG. 6A, the molding die 80 includes a fixed die 81 on which the porous body flow path plate 50 is placed, and a movable die 85 that can advance and retreat with respect to the fixed die 81. The fixed die 81 has a contact portion 82 to which the lower surface of the gas flow path portion 51 contacts, and a holding portion 83 for holding the lower surface of the shielding portion 59. The movable die 85 includes an abutting portion 86 to which the upper surface of the gas flow path portion 51 abuts, a pressing portion 87 for pressing the upper surface of the shielding portion 59, and a shearing portion 88 for shearing the tip of the shielding portion 59. Have. When forming a shielding part using such a forming die 80, first, the porous flow path plate 50 is placed on the fixed die 81. Next, the movable mold 85 is lowered with respect to the fixed mold 81. Accordingly, the lower surface of the shielding portion 59 is held by the holding portion 83 and the upper surface is pressed by the pressing portion 87. Then, the shield portion 59 extending stepwise is press-formed to form a flat shield portion 159 having an inclined surface 159a. At this time, the tip portion 59a of the shielding portion 59 is sheared by the shearing portion 88. At this time, the gas flow path portion 51 where the contact portion 82 of the fixed die 81 and the contact portion 86 of the movable die 85 contact each other is not deformed by the descent of the movable die 85.

  The first step of forming the gas flow path 51 of the porous flow path plate 50 and the second step of forming the shielding part 59 can be performed separately. That is, the second step may be performed using a device other than the roll forming device 70, such as a bending machine.

  In the porous body flow path plate 50 of the present embodiment, the gas flow path section 51 and the shielding section 59 are integrally formed, but the porous body flow path plate 50 is provided between the second separator 60 and the power generation section 11. A shielding part separate from the flow path plate may be provided.

-The leading edge of the shielding portion 59 may be in contact with the frame member 40.
-The shielding part 59 may be inclined so that it may be located on the side of the gas flow path part 51 from the power generation part 11 side toward the second separator 60 side.

  The shielding portion is not limited to the one formed integrally with the gas passage portion 51 of the porous body passage plate 50. In addition, for example, a protrusion protruding from the second separator 60 toward the power generation unit 11 is provided at a portion inside the seal portion 60a of the second separator 60 in the width direction Y, and the protrusion functions as a shielding portion. It may be.

-The shielding part may be formed only on one side in the width direction Y of the gas flow path part 51.
-Instead of the 1st separator 20 arrange | positioned at the anode side of the electric power generation part 11, the porous body flow plate and the separator similar to the porous body flow plate 50 and the 2nd separator 60 arrange | positioned at the cathode side are employ | adopted. You can also.

  The shape of the gas flow path portion 51 of the porous flow path plate is not limited to the shape illustrated in the present embodiment, and may be changed to a gas flow path portion having a known shape.

  DESCRIPTION OF SYMBOLS 10 ... Single cell, 11 ... Power generation part, 12 ... Fuel gas supply manifold, 13 ... Fuel gas discharge manifold, 14 ... Oxidant gas supply manifold, 15 ... Oxidant gas discharge manifold, 16 ... Cooling water supply manifold, 17 ... Cooling Water discharge manifold, 20 first separator, 21 fuel gas passage, 22 fuel gas supply passage, 23 fuel gas discharge passage, 24 cooling water passage, 30 MEGA, 31 MEA, 32 anode Side gas diffusion layer, 33 ... cathode side gas diffusion layer, 34 ... electrolyte membrane, 35 ... anode side electrode catalyst layer, 36 ... cathode side electrode catalyst layer, 40 ... frame member, 50 ... porous material flow path plate, 50a ... edge Part, 50b ... edge part, 50c ... side edge part, 51 ... gas flow path part, 52 ... flat part, 53 ... first convex part, 54 ... first concave part, 55 ... first corrugated part, 56 ... second convex part Part, 57 2nd concave part, 58 ... 2nd wavy part, 59 ... shielding part, 59a ... tip part, 60 ... 2nd separator, 60a ... seal part, 61 ... central part, 62 ... oxidant gas supply channel, 63 ... oxidant Gas discharge channel, 70: roll forming device, 71: first shaft, 72: first roll, 73: blade, 73a: cutting blade, 74: first blade group, 75: second shaft, 76: first 2 rolls, 77 ... blade body, 77a ... cutting blade, 78 ... second blade body group, 80 ... molding die, 81 ... solid type, 82 ... contact part, 83 ... holding part, 85 ... movable type, 86 ... contact Contact portion, 87: pressing portion, 88: shearing portion, 150: base material, 159: shielding portion, 159a: inclined surface.

Claims (7)

A power generation unit having a membrane electrode assembly, a frame member surrounding the outer periphery of the power generation unit, a pair of separators sandwiching the power generation unit and the frame member, and a portion between at least one of the pair of separators and the power generation unit. Provided, the porous body flow path plate having a mesh-shaped gas flow path portion for flowing the reaction gas,
Between the separator and the frame member provided with the porous body flow path plate between the power generation unit is sealed by a seal portion,
Between the side edge portion of the gas flow path portion and the seal portion, a shielding portion that shields between the separator and the power generation portion is provided.
Fuel cell stack. The shielding portion is provided between both the side edge portion of the gas flow path portion and the seal portion,
The fuel cell stack according to claim 1. The shielding portion is formed integrally with the gas flow passage portion,
The fuel cell stack according to claim 1. The power generation unit includes a pair of gas diffusion layers sandwiching the membrane electrode assembly,
The leading edge of the shielding portion is in contact with the gas diffusion layer,
The fuel cell stack according to claim 1. The shielding portion is inclined so as to be more distant from the gas flow path portion toward the power generation portion side from the separator side in the stacking direction of the single cells,
The fuel cell stack according to claim 4. It has a mesh-shaped gas flow path through which the reaction gas flows, has a membrane electrode assembly, and is sandwiched between a power generation unit and a separator whose outer periphery is surrounded by a frame member. In the porous channel plate constituting the part,
A shielding portion that shields between the separator and the power generation unit is integrally formed on a side edge of the gas flow path unit.
Porous channel plate. The shielding portion is inclined so as to be more distant from the gas flow passage portion toward the power generation portion side from the separator side in the thickness direction of the porous body flow passage plate,
The porous channel plate according to claim 6.

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