Separator for fuel cell and fuel cell stack

Abstract

The present application relates to a separator for fuel cell and a fuel cell stack. The separator (33) for fuel cell has a refrigerant flow path (66) formed between a first metal separator plate (30) and a second metal separator plate (32). First communication holes (106a, 114a) formed by an outer peripheral wall (96s1, 99s1) of a communication hole sealing protrusion (96a, 96b, 99a, 99b) surrounding an air removal communication hole (94) and a refrigerant discharge communication hole (98) formed through in a separator thickness direction, and second communication holes (106b, 114b) formed by an inner peripheral wall (96s2, 99s2) are located at positions deviated from each other in an extension direction of a first internal passage (97) or a second internal passage (101).

Description

TECHNICAL FIELD

[0001] The present application relates to a separator for fuel cells and a fuel cell stack. BACKGROUND

[0002] In recent years, as a vehicle for mitigating adverse effects on the global environment, a fuel cell vehicle (FCV) using hydrogen as a fuel has attracted attention. The fuel cell vehicle supplies air (containing oxygen) and hydrogen gas as a fuel gas to a fuel cell. The fuel cell vehicle travels using electric power generated by the fuel cell to drive a motor. Therefore, the fuel cell vehicle does not emit carbon dioxide (CO2), NOx, SOx, and the like like a gasoline vehicle, and only emits water, and is an environmentally friendly vehicle.

[0003] For example, Patent Literature 1 discloses a fuel cell stack provided with a separator for fuel cells. The separator for fuel cells is configured by joining two metal separator plates in a state of facing each other. A reaction gas flow path for flowing a fuel gas or an oxidant gas, that is, a reaction gas is formed on one side surface of each metal separator plate. A refrigerant flow path is formed between the two metal separator plates.

[0004] An air removal communication hole and a refrigerant discharge communication hole are formed through each metal separator plate in a separator thickness direction. In addition, a protruding portion that protrudes toward a direction opposite to the refrigerant flow path is integrally formed with each metal separator plate.

[0005] The protruding portion includes a sealing protrusion, two communication hole sealing protrusions, and two connection protrusions. The sealing protrusion prevents the reaction gas from leaking. One of the communication hole sealing protrusions surrounds the air removal communication hole. The other of the communication hole sealing protrusions surrounds the refrigerant discharge communication hole. One end of each of the connection protrusions is connected to the sealing protrusion. The other end of each of the connection protrusions is connected to an outer peripheral wall of each of the communication hole sealing protrusions.

[0006] A passage that protrudes toward the air removal communication hole is provided to an inner peripheral wall of the one of the communication hole sealing protrusions. A passage that protrudes toward the refrigerant discharge communication hole is provided to an inner peripheral wall of the other of the communication hole sealing protrusions. The air removal communication hole and the refrigerant discharge communication hole each communicate with an inner space of the sealing protrusion via an inner space of the passage, an inner space of the communication hole sealing protrusion, and an inner space of the connection protrusion. That is, a first communication hole for communicating the inner space of the communication hole sealing protrusion with the inner space of the connection protrusion is formed in the outer peripheral wall of the communication hole sealing protrusion. A second communication hole for communicating the inner space of the communication hole sealing protrusion with the inner space of the passage is formed in the inner peripheral wall of the communication hole sealing protrusion. The first communication hole and the second communication hole are located at positions facing each other.

[0007] In the state where the fuel cell separator described above is assembled to the fuel cell stack, the fuel cell separator is applied with a compression load in the separator thickness direction. At this time, the inner peripheral wall and the outer peripheral wall of the communication hole sealing protrusion elastically deform, and a reaction force is generated at the protruding end surface of the communication hole sealing protrusion. Thereby, the inside and the outside of the portion surrounded by the communication hole sealing protrusion are sealed.

[0008] Prior Art Documents

[0009] Patent Documents

[0010] Patent Document 1: Japanese Patent No. 6499247 SUMMARY

[0011] Problems to be Solved by the Invention

[0012] In the above-described conventional technology, the first communication hole and the second communication hole are located at positions facing each other. In this case, when a compression load in the stacking direction is applied in the fuel cell stack, the portions of the protruding end surface of the communication hole sealing protrusion that are adjacent to the first communication hole and the second communication hole are less likely to generate a reaction force. Therefore, it can be difficult to seal the entire circumference of the communication hole sealing protrusion.

[0013] An object of the present application is to solve the above-described problems.

[0014] Means for Solving the Problems

[0015] An aspect of the present application is a separator for fuel cells, the separator for fuel cells having two metal separators joined to each other, each of the two metal separators having a first face formed with a reaction gas flow path for flowing a fuel gas or an oxidant gas, i.e., a reaction gas, and a second face formed with a refrigerant flow path for flowing a refrigerant, a reaction gas communication hole communicating with the reaction gas flow path being formed through in a separator thickness direction, a protruding portion being protrudingly formed on the first face, the protruding portion having a sealing protrusion for preventing a reaction gas from leaking, in the separator for fuel cells, at least one of an air removal communication hole and a refrigerant release communication hole being formed through in the separator thickness direction, the second face having a link flow path formed by a recess on a back side of a protruding shape constituting the protruding portion, at least one of the air removal communication hole and the refrigerant release communication hole communicating with the refrigerant flow path via the link flow path, the sealing protrusion having a communication hole sealing protrusion surrounding the air removal communication hole or the refrigerant release communication hole, the communication hole sealing protrusion having a pair of an outer peripheral wall and an inner peripheral wall, an inner passage being formed by being sandwiched by the outer peripheral wall and the inner peripheral wall and extending in a manner of surrounding the air removal communication hole or the refrigerant release communication hole, the outer peripheral wall having a first communication hole for communicating the inner passage of the communication hole sealing protrusion with the link flow path, the inner peripheral wall having a second communication hole for communicating the inner passage of the communication hole sealing protrusion with the air removal communication hole or the refrigerant release communication hole, the first communication hole and the second communication hole being located at positions deviated from each other in an extending direction of the inner passage.

[0016] Another aspect of the present application is a fuel cell stack in which the above-described separator for fuel cells and an electrolyte membrane-electrode structure are provided, and a plurality of the separators for fuel cells and a plurality of the electrolyte membrane-electrode structures are alternately stacked.

[0017] Effects of the Invention

[0018] According to the present application, at least one of the air removal communication hole and the refrigerant discharge communication hole communicates with the refrigerant flow path via a connecting flow path formed by a recess on the back side of the protruding shape of the protruding portion. Therefore, the recess on the back side of the protruding portion provided in the metal separator plate can be effectively used to achieve a simple refrigerant flow path configuration. In addition, the first communication hole and the second communication hole are located at positions offset from each other in the extension direction of the internal passage. Therefore, when a compression load in the stacking direction is applied to the fuel cell stack, the reaction force at the portion of the protruding end surface of the communication hole sealing protrusion adjacent to the first communication hole and the portion adjacent to the second communication hole can be prevented from excessively decreasing. Thus, the entire circumference of the communication hole sealing protrusion can be sealed well.

[0019] The above objects, features and advantages will be more apparent from the following description of the embodiments taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a perspective view of a fuel cell stack.

[0021] Figure 2 is an exploded perspective view of a power generating cell constituting a fuel cell stack.

[0022] Figure 3 is a schematic cross-sectional view of a power generating cell.

[0023] Figure 4 is a front view of a fuel cell separator as viewed from the first metal separator plate side.

[0024] Figure 5 is a front view of a fuel cell separator as viewed from the second metal separator plate side.

[0025] Figure 6 is a structural view of an air removal communication hole of a fuel cell separator and its periphery.

[0026] Figure 7 is a cross-sectional view along the line VII-VII in Figure 6 .

[0027] Figure 8 is a cross-sectional view along the line VIII-VIII in Figure 7 .

[0028] Figure 9 is a structural view of a refrigerant discharge communication hole of a fuel cell separator and its periphery.

[0029] Figure 10 is a partially omitted cross-sectional view of a fuel cell separator according to a comparative example. DETAILED DESCRIPTION

[0030] As shown in Figure 1 , the fuel cell stack 10 is provided with a stack 14. The stack 14 has a plurality of power generating unit cells 12 stacked in a horizontal direction (arrow symbol A direction). Each power generating unit cell 12 constitutes a fuel cell single body. The fuel cell stack 10 is mounted on a fuel cell vehicle such as a fuel cell electric automobile, not shown. In the present embodiment, the lower side means the lower side (gravity direction) in the set state of the fuel cell stack 10, and the upper side means the upper side (direction opposite to the gravity direction) in the set state of the fuel cell stack 10.

[0031] On one end in the stacking direction (arrow symbol A direction) of the stack 14, a wiring board 16a, an insulating member 18a, and an end panel 20a are provided in this order toward the outside. On the other end in the stacking direction of the stack 14, a wiring board 16b, an insulating member 18b, and an end panel 20b are provided in this order toward the outside. A link rod 24 is disposed between each edge of the end panel 20a and the end panel 20b. Each wiring board 16a, 16b is composed of a material having electrical conductivity. In the substantially center of the two wiring boards 16a, 16b, a terminal portion 68a, 68b extending toward the outside in the stacking direction is provided.

[0032] The end panels 20a, 20b have a horizontally long rectangular shape. Both ends of each link rod 24 are fixed to the inner surfaces of the end panels 20a, 20b by means of a bolt 26. Thereby, a compressive load in the stacking direction (arrow symbol A direction) is applied to the plurality of power generating unit cells 12. Also, the fuel cell stack 10 can be provided with a housing having the two end panels 20a, 20b as end plates. In this case, the stack 14 is housed in the housing.

[0033] As shown in Figure 2 , the power generating unit cell 12 has a horizontally long rectangular shape. The power generating unit cell 12 is provided with a resin film-equipped MEA 28, a first metal separator 30, and a second metal separator 32. The first metal separator 30 is disposed on one side of the resin film-equipped MEA 28. The second metal separator 32 is disposed on the other side of the resin film-equipped MEA 28.

[0034] The first metal separator 30 and the second metal separator 32 are each composed of a thin metal plate whose cross section is press-formed into a wave shape. The thin metal plate is, for example, a stainless steel plate on which surface treatment for corrosion prevention is performed on the surface or an aluminum plate on which surface treatment for corrosion prevention is performed on the surface. The fuel cell stack 10 is provided with a fuel cell separator 33. The fuel cell separator 33 is a joint separator composed of the first metal separator 30 and the second metal separator 32 being joined as one by being joined to each other.

[0035] The oxidant gas inlet communication holes 34a, the refrigerant inlet communication holes 36a, and the fuel gas outlet communication holes 38b are arranged in the vertical direction (arrow symbol C direction).

[0036] The plurality of oxidant gas inlet communication holes 34a communicate with each other in the arrow symbol A direction. The plurality of refrigerant inlet communication holes 36a communicate with each other in the arrow symbol A direction. The plurality of fuel gas outlet communication holes 38b communicate with each other in the arrow symbol A direction. The oxidant gas inlet communication holes 34a supply an oxidant gas (for example, an oxygen-containing gas) as one of the reaction gases. The refrigerant inlet communication holes 36a supply a refrigerant (for example, pure water, ethylene glycol, oil, or the like). The fuel gas outlet communication holes 38b discharge a fuel gas (for example, a hydrogen-containing gas) as the other of the reaction gases.

[0037] The fuel gas inlet communication holes 38a, the refrigerant outlet communication holes 36b, and the oxidant gas outlet communication holes 34b are arranged in the vertical direction (arrow symbol C direction).

[0038] The plurality of fuel gas inlet communication holes 38a communicate with each other in the arrow symbol A direction. The plurality of refrigerant outlet communication holes 36b communicate with each other in the arrow symbol A direction. The plurality of oxidant gas outlet communication holes 34b communicate with each other in the arrow symbol A direction. The fuel gas inlet communication holes 38a supply a fuel gas. The refrigerant outlet communication holes 36b discharge a refrigerant. The oxidant gas outlet communication holes 34b discharge an oxidant gas.

[0039] The oxidant gas inlet communication holes 34a, the oxidant gas outlet communication holes 34b, the fuel gas inlet communication holes 38a, and the fuel gas outlet communication holes 38b are reaction gas flow paths. The arrangement, shape, and size of the oxidant gas inlet communication holes 34a, the oxidant gas outlet communication holes 34b, the refrigerant inlet communication holes 36a, the refrigerant outlet communication holes 36b, the fuel gas inlet communication holes 38a, and the fuel gas outlet communication holes 38b are not limited to the present embodiment, and can be appropriately set according to the required specifications.

[0040] As Figure 3As shown, the MEA 28 with a resin membrane includes an electrolyte membrane-electrode structure 28a and a frame-shaped resin membrane 46 disposed on the outer periphery of the electrolyte membrane-electrode structure 28a. The electrolyte membrane-electrode structure 28a includes an electrolyte membrane 40, an anode electrode 42, and a cathode electrode 44. The anode electrode 42 and the cathode electrode 44 hold the electrolyte membrane 40.

[0041] Electrolyte membrane 40 is, for example, a solid polymer electrolyte membrane (cation exchange membrane). A solid polymer electrolyte membrane is, for example, a membrane containing water-containing perfluorosulfonic acid. Alternatively, electrolyte membrane 40 can be a fluorinated electrolyte membrane or an HC (hydrocarbon) electrolyte membrane.

[0042] The cathode electrode 44 has a first electrode catalyst layer 44a and a first gas diffusion layer 44b. The first electrode catalyst layer 44a is bonded to one side of the electrolyte membrane 40. The first gas diffusion layer 44b is stacked on the first electrode catalyst layer 44a. The anode electrode 42 has a second electrode catalyst layer 42a and a second gas diffusion layer 42b. The second electrode catalyst layer 42a is bonded to the other side of the electrolyte membrane 40. The second gas diffusion layer 42b is stacked on the second electrode catalyst layer 42a.

[0043] The inner peripheral end face of the resin membrane 46 is close to, overlaps with, or abuts against the outer peripheral end face of the electrolyte membrane 40. For example... Figure 2 As shown, an oxidant gas inlet communication hole 34a, a refrigerant inlet communication hole 36a, and a fuel gas outlet communication hole 38b are provided at the end edge of the resin membrane 46 in the direction of arrow B1. A fuel gas inlet communication hole 38a, a refrigerant outlet communication hole 36b, and an oxidant gas outlet communication hole 34b are provided at the end edge of the resin membrane 46 in the direction of arrow B2.

[0044] The resin membrane 46 may be made of, for example, PPS (polyphenylene sulfide), PPA (polyphthalamide), PEN (polyethylene naphthalate), PES (polyethersulfone), LCP (liquid crystal polymer), PVDF (polyvinylidene fluoride), silicone resin, fluororesin, or m-PPE (modified polyphenylene ether resin), PET (polyethylene terephthalate), PBT (polybutylene terephthalate), or modified polyolefin. Furthermore, the power-generating single cell 12 may be constructed with the electrolyte membrane 40 protruding outwards compared to the anode electrode 42 and cathode electrode 44, without using the resin membrane 46. In this case, a frame-shaped membrane may be provided on both sides of the portion of the electrolyte membrane 40 that protrudes outwards compared to the anode electrode 42 and cathode electrode 44.

[0045] like Figure 3As shown, the first metal partition 30 has a surface 30a as a first side and a back side 30b as a second side. Surface 30a faces the MEA 28 with the resin film. Back side 30b faces the second metal partition 32.

[0046] like Figure 4 As shown, an oxidant gas flow path 48 (reaction gas flow path) extending in the direction of arrow B is provided on the surface 30a of the first metal partition plate 30. The oxidant gas flow path 48 is connected to an oxidant gas inlet connection hole 34a and an oxidant gas outlet connection hole 34b. The oxidant gas flow path 48 supplies oxidant gas to the cathode electrode 44 (see reference). Figure 2 The oxidant gas flow path 48 has straight flow path grooves 48b between multiple protrusions 48a. Each protrusion 48a extends in the direction of arrow symbol B. Alternatively, the oxidant gas flow path 48 may have multiple wavy flow path grooves instead of multiple straight flow path grooves 48b.

[0047] An inlet buffer section 50A is provided between the oxidant gas inlet communication hole 34a in the surface 30a of the first metal partition plate 30 and the oxidant gas flow path 48. The inlet buffer section 50A has multiple protruding rows. The protruding rows include multiple protrusions 50a arranged in the direction of arrow symbol C. An outlet buffer section 50B is provided between the oxidant gas outlet communication hole 34b in the surface 30a of the first metal partition plate 30 and the oxidant gas flow path 48. The outlet buffer section 50B has multiple protruding rows. The protruding rows include multiple protrusions 50b arranged in the direction of arrow symbol C.

[0048] Furthermore, between the aforementioned protruding rows of the inlet buffer portion 50A in the back surface 30b of the first metal partition plate 30, a protruding row formed by a plurality of protrusions 67a arranged in the direction of arrow C is provided. Between the aforementioned protruding rows of the outlet buffer portion 50B in the back surface 30b of the first metal partition plate 30, a protruding row formed by a plurality of protrusions 67b arranged in the direction of arrow C is provided. The protrusions 67a and 67b constitute the buffer portion of the back surface 30b of the first metal partition plate 30.

[0049] On the surface 30a of the first metal partition plate 30, through stamping, it faces the MEA28 with resin film ( Figure 2 The bulge-shaped part has a first protrusion 72A including a sealing protrusion 51. For example... Figure 3 As shown, the resin component 56 is fixed to the front end face of the protrusion of the sealing protrusion 51 by printing or coating. The resin component 56 may be made of polyester fiber, for example. Alternatively, the resin component 56 may be disposed on the resin film 46. The resin component 56 is not essential and may be omitted.

[0050] likeFigure 4 As shown, the sealing protrusion 51 has an inner protrusion 51a, an outer protrusion 52, and multiple connecting hole protrusions 53. The inner protrusion 51a is a raised seal surrounding the oxidant gas flow path 48, the inlet buffer section 50A, and the outlet buffer section 50B. The outer protrusion 52 is located further outward than the inner protrusion 51a. The outer protrusion 52 is a raised seal extending along the outer periphery of the first metal partition plate 30. The multiple connecting hole protrusions 53 are multiple raised seals that individually surround the oxidant gas inlet connecting hole 34a, the oxidant gas outlet connecting hole 34b, the fuel gas inlet connecting hole 38a, the fuel gas outlet connecting hole 38b, the refrigerant inlet connecting hole 36a, and the refrigerant outlet connecting hole 36b. The inner protrusion 51a, the outer protrusion 52, and the multiple connecting hole protrusions 53 each protrude from the surface 30a of the first metal partition plate 30 toward the MEA28 with the resin film.

[0051] Hereinafter, the connecting hole protrusion surrounding the oxidant gas inlet connecting hole 34a among the multiple connecting hole protrusions 53 will be referred to as "connecting hole protrusion 53a", and the connecting hole protrusion surrounding the oxidant gas outlet connecting hole 34b will be referred to as "connecting hole protrusion 53b". The first metal partition plate 30 is provided with bridge portions 80 and 82 that connect the inner and outer sides of the connecting hole protrusions 53a and 53b.

[0052] A bridge portion 80 is provided in the protrusion 53a of the connecting hole, located between the oxidant gas inlet connecting hole 34a and the oxidant gas flow path 48. The bridge portion 80 includes a flow path for supplying oxidant gas guided from the oxidant gas inlet connecting hole 34a to the oxidant gas flow path 48. A bridge portion 82 is provided in the protrusion 53b of the connecting hole, located between the oxidant gas outlet connecting hole 34b and the oxidant gas flow path 48. The bridge portion 82 includes a flow path for discharging oxidant gas guided from the oxidant gas flow path 48 to the oxidant gas outlet connecting hole 34b.

[0053] like Figure 3 As shown, the second metal partition plate 32 has a surface 32a as a first surface and a back surface 32b as a second surface. Surface 32a faces the MEA 28 with the resin film. Back surface 32b faces the first metal partition plate 30.

[0054] like Figure 5 As shown, a fuel gas flow path 58 (reaction gas flow path) extending in the direction of arrow B is provided on the surface 32a of the second metal partition plate 32. The fuel gas flow path 58 is connected to the fuel gas inlet communication hole 38a and the fuel gas outlet communication hole 38b. The fuel gas flow path 58 supplies fuel gas to the anode electrode 42 (see reference). Figure 2). The fuel gas flow path 58 has linear flow path grooves 58b between the plurality of convex portions 58a. Each convex portion 58a extends in the direction of the arrow symbol B. Alternatively, the fuel gas flow path 58 can have a plurality of wavy flow path grooves instead of the plurality of linear flow path grooves 58b.

[0055] An inlet buffer portion 60A is provided between the fuel gas inlet communication hole 38a in the surface 32a of the second metal separator plate 32 and the fuel gas flow path 58. The inlet buffer portion 60A has a plurality of convex rows. The convex rows include a plurality of convex portions 60a arranged in the direction of the arrow symbol C. An outlet buffer portion 60B is provided between the fuel gas outlet communication hole 38b in the surface 32a of the second metal separator plate 32 and the fuel gas flow path 58. The outlet buffer portion 60B has a plurality of convex rows. The convex rows include a plurality of convex portions 60b arranged in the direction of the arrow symbol C.

[0056] Further, between the above-mentioned convex rows of the inlet buffer portion 60A in the back surface 32b of the second metal separator plate 32, a convex row formed of a plurality of convex portions 69a arranged in the direction of the arrow symbol C is provided. Between the above-mentioned convex rows of the outlet buffer portion 60B in the back surface 32b of the second metal separator plate 32, a convex row formed of a plurality of convex portions 69b arranged in the direction of the arrow symbol C is provided. The convex portions 69a, 69b constitute the buffer portion of the back surface 32b of the second metal separator plate 32.

[0057] On the surface 32a of the second metal separator plate 32, a second protruding portion 72B including a sealing protrusion 61 is protrusion-molded toward the MEA 28 with the resin film by press molding. As shown in FIG. 6, the resin member 56 is fixed to the convex portion front end surface of the sealing protrusion 61 by printing or coating, or the like. The resin member 56 uses, for example, polyester fiber. The resin member 56 can be provided on the resin film 46 side. The resin member 56 is not indispensable, and can be omitted. Figure 3

[0058] As shown in FIG. 6, the resin member 56 is fixed to the convex portion front end surface of the sealing protrusion 61 by printing or coating, or the like. The resin member 56 uses, for example, polyester fiber. The resin member 56 can be provided on the resin film 46 side. The resin member 56 is not indispensable, and can be omitted.

[0058] As shown in FIG. 6, the resin member 56 is fixed to the convex portion front end surface of the sealing protrusion 61 by printing or coating, or the like. The resin member 56 uses, for example, polyester fiber. The resin member 56 can be provided on the resin film 46 side. The resin member 56 is not indispensable, and can be omitted. Figure 5As shown, the sealing protrusion 61 has an inner protrusion 61a, an outer protrusion 62, and multiple connecting hole protrusions 63. The inner protrusion 61a is a raised seal surrounding the fuel gas flow path 58, the inlet buffer 60A, and the outlet buffer 60B. The outer protrusion 62 is located further outward than the inner protrusion 61a. The outer protrusion 62 is a raised seal extending along the outer periphery of the second metal partition 32. The multiple connecting hole protrusions 63 are multiple raised seals that individually surround the oxidant gas inlet connecting hole 34a, the oxidant gas outlet connecting hole 34b, the fuel gas inlet connecting hole 38a, the fuel gas outlet connecting hole 38b, the refrigerant inlet connecting hole 36a, and the refrigerant outlet connecting hole 36b. The inner protrusion 61a, the outer protrusion 62, and the multiple connecting hole protrusions 63 each protrude from the surface 32a of the second metal partition 32 toward the MEA 28 with the resin film.

[0059] Hereinafter, the connecting hole protrusion surrounding the fuel gas inlet connecting hole 38a among the multiple connecting hole protrusions 63 will be referred to as "connecting hole protrusion 63a", and the connecting hole protrusion surrounding the fuel gas outlet connecting hole 38b will be referred to as "connecting hole protrusion 63b". The second metal partition plate 32 is provided with bridge portions 90 and 92 that connect the inner and outer sides of the connecting hole protrusions 63a and 63b.

[0060] A bridge portion 90 is provided in the protrusion 63a of the connecting hole, located between the fuel gas inlet connecting hole 38a and the fuel gas flow path 58. The bridge portion 90 includes a flow path for supplying fuel gas guided from the fuel gas inlet connecting hole 38a to the fuel gas flow path 58. A bridge portion 92 is provided in the protrusion 63b of the connecting hole, located between the fuel gas outlet connecting hole 38b and the fuel gas flow path 58. The bridge portion 92 includes a flow path for discharging fuel gas guided from the fuel gas flow path 58 to the fuel gas outlet connecting hole 38b.

[0061] like Figure 2 As shown, a refrigerant flow path 66 is formed between the back surface 30b of the first metal partition plate 30 and the back surface 32b of the second metal partition plate 32, which are joined together. The refrigerant flow path 66 communicates with the refrigerant inlet communication hole 36a and the refrigerant outlet communication hole 36b. The refrigerant flow path 66 is formed by overlapping the back surface shape of the oxidant gas flow path 48 of the first metal partition plate 30 with the back surface shape of the fuel gas flow path 58 of the second metal partition plate 32.

[0062] like Figure 4 as well as Figure 5As shown, the first metal separator plate 30 and the second metal separator plate 32 that constitute the separator 33 for fuel cell are joined to each other by laser welding lines 33a to 33e. The laser welding line 33a is formed so as to surround the oxidant gas inlet communication hole 34a and the bridge portion 80. The laser welding line 33b is formed so as to surround the fuel gas outlet communication hole 38b and the bridge portion 92.

[0063] The laser welding line 33c is formed so as to surround the fuel gas inlet communication hole 38a and the bridge portion 90. The laser welding line 33d is formed so as to surround the oxidant gas outlet communication hole 34b and the bridge portion 82. The laser welding line 33e is formed so as to surround the oxidant gas flow path 48, the fuel gas flow path 58, the refrigerant flow path 66, the oxidant gas inlet communication hole 34a, the oxidant gas outlet communication hole 34b, the fuel gas inlet communication hole 38a, the fuel gas outlet communication hole 38b, the refrigerant inlet communication hole 36a, the refrigerant outlet communication hole 36b, the air removal communication hole 94 and the refrigerant release communication hole 98 described later, and the outer peripheral portion of the separator 33 for fuel cell. The laser welding line 33e is located between the inner side protruding portion 51a, 61a and the outer side protruding portion 52, 62. Instead of laser welding, the first metal separator plate 30 and the second metal separator plate 32 can be joined by brazing.

[0064] As shown in FIG. 6, the air removal communication hole 94 and the refrigerant release communication hole 98 are formed through the first metal separator plate 30, the second metal separator plate 32 and the MEA 28 with resin film (resin film 46) in the separator thickness direction (stacking direction). Figure 2 As shown in FIG. 6, the air removal communication hole 94 and the refrigerant release communication hole 98 are formed through the first metal separator plate 30, the second metal separator plate 32 and the MEA 28 with resin film (resin film 46) in the separator thickness direction (stacking direction).

[0065] As shown in FIG. 6, the air removal communication hole 94 and the refrigerant release communication hole 98 are formed through the first metal separator plate 30, the second metal separator plate 32 and the MEA 28 with resin film (resin film 46) in the separator thickness direction (stacking direction). Figure 4 Figure 5 ​As shown, the air removal communication hole 94 is located above the uppermost part of the inner protrusions 51a and 61a. The air removal communication hole 94 is located above the uppermost communication hole 34a among the plurality of communication holes 34a, 36a, and 38b arranged in the vertical direction. In this embodiment, the air removal communication hole 94 is circular. Alternatively, the air removal communication hole 94 may be formed as an ellipse (not limited to a geometrically exact ellipse, but also including shapes similar to it), an oblong shape, or a polygon.

[0066] like Figure 4 As shown, on the surface 30a of the first metal partition plate 30, the resin film 46 is formed by stamping. Figure 2 The bulge-shaped structure includes a connecting hole 94 for air removal and a sealing protrusion 96a. (Example) Figure 5 As shown, the surface 32a of the second metal partition plate 32 is formed by stamping and faces the resin film 46. Figure 2 The bulge has a connecting hole 94 for air removal and a connecting hole sealing protrusion 96b.

[0067] like Figure 6 as well as Figure 7 As shown, the connecting hole sealing protrusions 96a and 96b have paired extending outer peripheral walls 96s1 and inner peripheral walls 96s2, and a first internal passage 97 formed by the outer peripheral walls 96s1 and 96s2, and extending in a manner surrounding the air removal connecting hole 94. The outer peripheral wall 96s1 faces the opposite direction to the air removal connecting hole 94. The inner peripheral wall 96s2 faces the air removal connecting hole 94. The planar shape of the connecting hole sealing protrusions 96a and 96b is circular (see reference). Figure 6 ).

[0068] like Figure 7 As shown, in this embodiment, the inner peripheral walls 96s2 and outer peripheral walls 96s1 of the connecting hole sealing protrusions 96a and 96b are inclined relative to the thickness direction of the separator (the same applies to the lower connecting protrusions 110a and 110b described later). Therefore, the cross-sectional shape of the connecting hole sealing protrusions 96a and 96b along the thickness direction of the separator is trapezoidal. Alternatively, the inner peripheral walls 96s2 and outer peripheral walls 96s1 of the connecting hole sealing protrusions 96a and 96b may be parallel to the thickness direction of the separator. That is, the cross-sectional shape of the connecting hole sealing protrusions 96a and 96b along the thickness direction of the separator may also be rectangular.

[0069] like Figure 6 as well as Figure 7As shown, the communication hole 94 for air removal communicates with the refrigerant flow path 66 via a first connecting flow path 100 (connecting flow path). The first connecting flow path 100 connects the first internal passage 97 (recess on the back side of the communication hole sealing protrusion 96a, 96b) and the internal space of the inner protrusion portion 51a, 61a (recess on the back side).

[0070] Specifically, the first protrusion portion 72A and the second protrusion portion 72B have upper side connecting protrusions 102a, 102b, and the first connecting flow path 100 is provided inside the upper side connecting protrusions 102a, 102b. One end of the upper side connecting protrusions 102a, 102b is connected to the uppermost portion of the inner protrusion portion 51a, 61a. The other end of the upper side connecting protrusions 102a, 102b is connected to the outer peripheral wall 96s1 of the communication hole sealing protrusion 96a, 96b.

[0071] In Figure 6 , the upper side connecting protrusions 102a, 102b extend on the shortest path from the inner protrusion portion 51a, 61a to the communication hole sealing protrusion 96a, 96b. The upper side connecting protrusions 102a, 102b extend in a straight line shape over the entire length. The upper side connecting protrusions 102a, 102b extend downward from the lower end portion of the communication hole sealing protrusion 96a, 96b.

[0072] As Figure 7 and Figure 8 shown, the first connecting flow path 100 is formed by the back side shape of the upper side connecting protrusion 102a provided in the first metal partition plate 30 and the back side shape of the upper side connecting protrusion 102b provided in the second metal partition plate 32. The upper side connecting protrusions 102a, 102b, like the communication hole sealing protrusions 96a, 96b, have a trapezoidal cross-sectional shape in the partition thickness direction. Also, the upper side connecting protrusions 102a, 102b can have a rectangular cross-sectional shape in the partition thickness direction.

[0073] As Figure 6 and Figure 7As shown, the first metal separator 30 and the second metal separator 32 are respectively provided with passages 104a, 104b that protrude from inner peripheral walls 96s2 of the communication hole sealing protrusions 96a, 96b toward the air removal communication hole 94. The passages 104a, 104b extend from upper end portions of the communication hole sealing protrusions 96a, 96b toward the lower side. The refrigerant flow path 66 and the air removal communication hole 94 are communicated via an inner space of the inner protrusion portions 51a, 61a, an inner space of the upper side connecting protrusions 102a, 102b (first connecting flow path 100), the first internal passage 97 of the communication hole sealing protrusions 96a, 96b, and an inner space of the passages 104a, 104b. Also, it is possible that the fuel cell separator 33 has only either one of the upper side connecting protrusions 102a and 102b. It is also possible that the fuel cell separator 33 has only either one of the passages 104a and 104b.

[0074] It is also possible that, in order to prevent bypassing (bypassing in the direction of the arrow symbol B) of the reaction gas at the flow path width direction end portions of the reaction gas flow paths, the fuel cell separator 33 is provided with bypass preventing protrusions that are formed by protruding toward the resin film 46 by press molding and that protrude from the inner protrusion portions 51a, 61a toward the oxidant gas flow path 48 and the fuel gas flow path 58, respectively. It is also possible that a plurality of bypass preventing protrusions are provided at intervals in the flow path length direction (the direction of the arrow symbol B) of the reaction gas flow paths. In this case, the back side shape of the bypass preventing protrusions, i.e., the concave portions, constitute a part of the flow path that communicates the refrigerant flow path 66 and the air removal communication hole 94.

[0075] In Figure 6 and Figure 7 , a first communication hole 106a is provided in the outer peripheral wall 96s1 of the communication hole sealing protrusions 96a, 96b. The first communication hole 106a communicates the first connecting flow path 100 and the first internal passage 97 of the communication hole sealing protrusions 96a, 96b with each other. A second communication hole 106b is provided in the inner peripheral wall 96s2 of the communication hole sealing protrusions 96a, 96b. The second communication hole 106b communicates the first internal passage 97 of the communication hole sealing protrusions 96a, 96b and the inner space of the passages 104a, 104b with each other. That is, the second communication hole 106b communicates the air removal communication hole 94 via the inner space of the passages 104a, 104b.

[0076] The first connecting hole 106a and the second connecting hole 106b are located at positions offset from each other in the extending direction of the first internal passage 97 of the connecting hole sealing protrusions 96a and 96b. Specifically, the first connecting hole 106a is located below the air removal connecting hole 94. The first connecting hole 106a faces vertically. The second connecting hole 106b is located above the air removal connecting hole 94. The second connecting hole 106b faces vertically. The first connecting hole 106a and the second connecting hole 106b are located at positions offset from each other by 180° in the extending direction of the connecting hole sealing protrusions 96a and 96b. The first connecting hole 106a and the second connecting hole 106b do not face each other. The first connecting hole 106a is located at the lowermost part of the outer peripheral wall 96s1. The second connecting hole 106b is located at the uppermost part of the inner peripheral wall 96s2. The second connecting hole 106b is located above the first connecting hole 106a.

[0077] The positions of the first connecting hole 106a and the second connecting hole 106b can be appropriately set as long as they are not facing each other. That is, the first connecting hole 106a and the second connecting hole 106b can, for example, be located at a position offset from each other by 90° in the extending direction of the connecting hole sealing protrusions 96a and 96b.

[0078] The protruding ends of channels 104a and 104b open at the air removal communication hole 94. Furthermore, if a second communication hole 106b is provided in the inner peripheral wall 96s2, the fuel cell separator 33 may not have channels 104a and 104b.

[0079] The protrusion heights of the upper connecting protrusions 102a and 102b and the channels 104a and 104b are lower than the protrusion heights of the connecting hole sealing protrusions 96a and 96b, respectively (the same applies to the lower connecting protrusions 110a and 110b and the channels 112a and 112b, which will be described later).

[0080] like Figure 4 as well as Figure 5 As shown, the refrigerant venting connecting hole 98 is located below the lowest part of the inner protrusions 51a and 61a. The refrigerant venting connecting hole 98 is located below the lowest connecting hole 38b among the plurality of connecting holes 34a, 36a, and 38b arranged in the vertical direction. The refrigerant venting connecting hole 98 is circular. Alternatively, the refrigerant venting connecting hole 98 may be formed as an ellipse (not limited to a geometrically exact ellipse, but also including shapes similar to it), an oblong shape, or a polygon.

[0081] like Figure 4 As shown, on the surface 30a of the first metal partition plate 30, the resin film 46 is formed by stamping. Figure 2) is formed with a protrusion 99a for sealing a communication hole surrounding the communication hole 98 for refrigerant discharge. As shown in Figure 5 Figure 2 ) is formed with a protrusion 99b for sealing a communication hole surrounding the communication hole 98 for refrigerant discharge.

[0082] As shown in Figure 9 The protrusions 99a, 99b for sealing a communication hole have outer and inner peripheral walls 99s1, 99s2 extending in pairs, a second internal passage 101 formed by the outer and inner peripheral walls 99s1, 99s2 being sandwiched, and extending in a manner of surrounding the communication hole 98 for refrigerant discharge. The outer peripheral wall 99s1 faces in a direction opposite to the communication hole 98 for refrigerant discharge. The inner peripheral wall 99s2 faces the communication hole 98 for refrigerant discharge. The protrusions 99a, 99b for sealing a communication hole are circular in plan view. The protrusions 99a, 99b for sealing a communication hole are similarly configured as the protrusions 96a, 96b for sealing a communication hole described above.

[0083] The communication hole 98 for refrigerant discharge communicates with the refrigerant flow path 66 via a second connecting flow path 108 (connecting flow path). The second connecting flow path 108 connects the second internal passage 101 (recess on the back side of the protrusions 99a, 99b for sealing a communication hole) and the internal space of the inner protrusion portions 51a, 61a (recess on the back side).

[0084] Specifically, the first and second protrusion portions 72A, 72B have lower connecting protrusions 110a, 110b having the second connecting flow path 108 inside. One end of the lower connecting protrusions 110a, 110b is connected to the lowermost part of the inner protrusion portions 51a, 61a. The lowermost part of the inner protrusion portions 51a, 61a is provided at a position directly below the lowermost communication hole 38b among the plurality of communication holes 34a, 36a, 38b arranged in the vertical direction. The other end of the lower connecting protrusions 110a, 110b is connected to the outer peripheral wall 99s1 of the protrusions 99a, 99b for sealing a communication hole.

[0085] The lower connecting protrusions 110a, 110b extend on the shortest path from the inner protrusion portions 51a, 61a to the protrusions 99a, 99b for sealing a communication hole. The lower connecting protrusions 110a, 110b extend linearly over the entire length. The lower connecting protrusions 110a, 110b extend in a manner of being inclined to the oblique side with respect to the vertical direction from the lowermost part of the inner protrusion portions 51a, 61a toward the upper end of the protrusions 99a, 99b for sealing a communication hole.

[0086] ​The second connection flow path 108 is formed by the back side shape of the lower connection protrusion 110a provided on the first metal separator 30 and the back side shape of the lower connection protrusion 110b provided on the second metal separator 32. The lower connection protrusions 110a and 110b are configured similarly to the upper connection protrusions 102a and 102b described above.

[0087] The passages 112a and 112b are provided on the first metal separator 30 and the second metal separator 32, respectively, and protrude from the inner peripheral wall 99s2 of the communication hole sealing protrusion 99a and 99b toward the refrigerant discharge communication hole 98. The refrigerant flow path 66 and the refrigerant discharge communication hole 98 are connected via the internal space of the inner protrusion portion 51a and 61a, the internal space of the lower connection protrusion 110a and 110b (second connection flow path 108), the second internal passage 101 of the communication hole sealing protrusion 99a and 99b, and the internal space of the passage 112a and 112b. Also, the fuel cell separator 33 can have only either of the lower connection protrusion 110a and 110b. Also, the fuel cell separator 33 can have only either of the passage 112a and 112b.

[0088] The first communication hole 114a is provided on the outer peripheral wall 99s1 of the communication hole sealing protrusion 99a and 99b. The first communication hole 114a connects the second connection flow path 108 and the second internal passage 101 of the communication hole sealing protrusion 99a and 99b. The second communication hole 114b is provided on the inner peripheral wall 99s2 of the communication hole sealing protrusion 99a and 99b. The second communication hole 114b connects the internal space of the communication hole sealing protrusion 99a and 99b and the internal space of the passage 112a and 112b. That is, the second communication hole 114b connects the refrigerant discharge communication hole 98 via the internal space of the passage 112a and 112b.

[0089] The first connecting hole 114a and the second connecting hole 114b are located at positions offset from each other in the extending direction of the connecting hole sealing protrusions 99a and 99b. Specifically, the first connecting hole 114a is located above the refrigerant venting connecting hole 98. The first connecting hole 114a faces upwards at an angle relative to the vertical direction. The second connecting hole 114b is located below the refrigerant venting connecting hole 98. The second connecting hole 114b faces vertically. The first connecting hole 114a and the second connecting hole 114b are located at positions offset from each other by more than 90° in the extending direction of the connecting hole sealing protrusions 99a and 99b. The first connecting hole 114a and the second connecting hole 114b do not face each other. The first connecting hole 114a is located above the center of the outer peripheral wall 99s1 in the vertical direction. The second connecting hole 114b is located at the lowest part of the inner peripheral wall 99s2. The second connecting hole 114b is located below the first connecting hole 114a. The positions of the first connecting hole 114a and the second connecting hole 114b can be appropriately set as long as they are not facing each other.

[0090] The protruding ends of channels 112a and 112b open into the refrigerant venting communication hole 98. Furthermore, if a second communication hole 114b is provided in the inner peripheral wall 99s2, the fuel cell separator 33 may not have channels 112a and 112b.

[0091] The fuel cell stack 10 constructed in this way operates as follows.

[0092] First, such as Figure 1 As shown, oxidant gas is supplied to the oxidant gas inlet connection hole 34a of the end panel 20a. Fuel gas is supplied to the fuel gas inlet connection hole 38a of the end panel 20a. Refrigerant is supplied to the refrigerant inlet connection hole 36a of the end panel 20a.

[0093] like Figure 2 As shown, from the oxidant gas inlet connecting hole 34a via the bridge portion 80 ( Figure 4 Oxidizing gas is introduced into the oxidizing gas flow path 48 of the first metal separator 30. Then, the oxidizing gas moves along the oxidizing gas flow path 48 in the direction of arrow B and is supplied to the cathode electrode 44 of the electrolyte membrane-electrode structure 28a.

[0094] On the other hand, fuel gas is introduced from the fuel gas inlet connection hole 38a through the bridge portion 90 into the fuel gas flow path 58 of the second metal partition plate 32. The fuel gas moves along the fuel gas flow path 58 in the direction of arrow B and is supplied to the anode electrode 42 of the electrolyte membrane-electrode structure 28a.

[0095] Thus, in each electrolyte membrane-electrode structure 28a, the oxidant gas supplied to the cathode electrode 44 and the fuel gas supplied to the anode electrode 42 are consumed in the first electrode catalyst layer 44a and the second electrode catalyst layer 42a by electrochemical reactions. As a result, power generation is performed.

[0096] Next, the oxidant gas supplied to the cathode electrode 44 and consumed flows from the oxidant gas flow path 48 to the oxidant gas outlet communication hole 34b via the bridge portion 82 Figure 4 ) toward the oxidant gas outlet communication hole 34b. The oxidant gas is discharged in the arrow symbol A direction along the oxidant gas outlet communication hole 34b after flowing toward the oxidant gas outlet communication hole 34b. Likewise, the fuel gas supplied to the anode electrode 42 and consumed flows from the fuel gas flow path 58 to the fuel gas outlet communication hole 38b via the bridge portion 92. The fuel gas is discharged in the arrow symbol A direction along the fuel gas outlet communication hole 38b after flowing toward the fuel gas outlet communication hole 38b.

[0097] In addition, the refrigerant supplied to the refrigerant inlet communication hole 36a is introduced into the refrigerant flow path 66 formed between the first metal separator 30 and the second metal separator 32. The refrigerant flows in the arrow symbol B direction after being introduced into the refrigerant flow path 66. The refrigerant is discharged from the refrigerant outlet communication hole 36b after cooling the electrolyte membrane-electrode structure 28a.

[0098] The present embodiment achieves the following effects.

[0099] In the fuel cell separator 33 of the fuel cell stack 10, the air removal communication hole 94 communicates with the refrigerant flow path 66 via the first linking flow path 100 formed by the recessed portion on the back side of the protruding shape of the first protruding portion 72A and the second protruding portion 72B. In addition, the refrigerant bleed communication hole 98 communicates with the refrigerant flow path 66 via the second linking flow path 108 formed by the recessed portion on the back side of the protruding shape of the first protruding portion 72A and the second protruding portion 72B. Thus, the recessed portion on the back side of the protruding portion provided in the first metal separator 30 and the second metal separator 32 can be effectively utilized to achieve a simple refrigerant flow path configuration.

[0100] However, as Figure 10 shown in the case where the first communication hole 106a and the second communication hole 106b are located at positions facing each other, when a compression load in the stacking direction is applied to the fuel cell stack 10, the portion 103 of the protruding end surface of the communication hole seal protrusion 96a, 96b that abuts the first communication hole 106a and the second communication hole 106b is less likely to generate a reaction force.

[0101] In contrast, such as Figure 7 As shown, in the fuel cell separator 33 according to this embodiment, the first connecting hole 106a and the second connecting hole 106b are located at positions offset from each other in the extending direction of the first internal passage 97 surrounding the air removal connecting hole 94. Therefore, when a compressive load in the stacking direction is applied in the fuel cell stack 10, the reaction force at the portions adjacent to the first connecting hole 106a and the portions adjacent to the second connecting hole 106b on the protruding end faces of the connecting hole sealing protrusions 96a and 96b can be suppressed from being excessively reduced. As a result, the entire circumference of the connecting hole sealing protrusions 96a and 96b can be well sealed.

[0102] Furthermore, in the fuel cell separator 33, the first connecting hole 114a and the second connecting hole 114b are located at positions offset from each other in the extending direction of the second internal passage 101 surrounding the refrigerant venting connecting hole 98. Therefore, when a compressive load in the stacking direction is applied to the fuel cell stack 10, the excessive reaction force generated in the portions of the protruding end faces of the connecting hole sealing protrusions 99a and 99b adjacent to the first connecting hole 114a and the second connecting hole 114b can be suppressed. Thus, the entire circumference of the connecting hole sealing protrusions 99a and 99b can be effectively sealed.

[0103] The fuel cell separator 33 has channels 104a and 104b extending from the inner peripheral wall 96s2 toward the air removal communication hole 94. The internal space of the channels 104a and 104b is connected to the first internal passage 97 of the communication hole sealing protrusions 96a and 96b via the second communication hole 106b.

[0104] According to this structure, air that is guided from the refrigerant flow path 66 to the first internal passage 97 of the connecting hole sealing protrusions 96a, 96b can be efficiently discharged to the air removal connecting hole 94 through the internal space of the channels 104a, 104b.

[0105] The fuel cell separator 33 has channels 112a and 112b extending from the inner peripheral wall 99s2 toward the refrigerant venting communication hole 98. The internal space of the channels 112a and 112b is connected to the second internal passage 101 of the communication hole sealing protrusions 99a and 99b via the second communication hole 114b.

[0106] According to this structure, when the refrigerant is removed from the refrigerant flow path 66 during maintenance of the fuel cell stack 10, the refrigerant that was guided from the refrigerant flow path 66 to the second internal passage 101 of the connecting hole sealing protrusions 99a and 99b can be efficiently discharged to the refrigerant discharge connecting hole 98 through the internal space of the channels 112a and 112b.

[0107] In the configuration state where the fuel cell stack 10 with the fuel cell separator 33 is installed, the second connecting hole 106b is located above the center of the air removal connecting hole 94.

[0108] With this structure, air can be prevented from remaining in the upper portion of the first internal passage 97 of the connecting hole sealing protrusions 96a and 96b. This allows air in the refrigerant to be smoothly discharged through the air removal connecting hole 94.

[0109] In the configuration of the fuel cell stack 10, the second connecting hole 106b is located at the uppermost part of the inner peripheral wall 96s2 of the connecting hole sealing protrusions 96a and 96b.

[0110] With this structure, air retention above the first internal passage 97 of the connecting hole sealing protrusions 96a and 96b can be further suppressed. This allows air in the refrigerant to be discharged more smoothly through the air removal connecting hole 94.

[0111] With the fuel cell stack 10 in its current configuration, the second connecting hole 114b is located below the center of the refrigerant venting connecting hole 98.

[0112] With this structure, refrigerant can be efficiently discharged to the refrigerant venting port 98 when maintaining the fuel cell stack 10, etc.

[0113] With the fuel cell stack 10 in its current configuration, the second connecting hole 114b is located at the lowest part of the inner peripheral wall 99s2 of the connecting hole sealing protrusions 99a and 99b.

[0114] According to this structure, the refrigerant can be discharged more efficiently to the refrigerant venting port 98 when maintaining the fuel cell stack 10, etc.

[0115] Furthermore, the present invention is not limited to the embodiments described above, and various structures can be adopted without departing from the spirit of the present invention.

[0116] This embodiment discloses the following content.

[0117] The above-described embodiment discloses a separator for fuel cell 33 provided with two metal separators 30, 32 engaged with each other, each of the two metal separators having a first face 30a, 32a formed with a reaction gas flow path 48, 58 for flowing a fuel gas or an oxidant gas, i.e., a reaction gas, and a second face 30b, 32b formed with a refrigerant flow path 66 for flowing a refrigerant, a reaction gas communication hole 34a, 34b, 38a, 38b communicating with the reaction gas flow path being formed through in a separator thickness direction, a protruding portion 72A, 72B being protrudingly formed at the first face, the protruding portion having a sealing protrusion 51, 61 for preventing reaction gas leakage, in the separator for fuel cell 33, at least one of an air removal communication hole 94 and a refrigerant discharge communication hole 98 being formed through in the separator thickness direction, the second face having a link flow path 100, 108 formed by a recess portion on a back side of a protruding shape constituting the protruding portion, at least one of the air removal communication hole and the refrigerant discharge communication hole communicating with the refrigerant flow path via the link flow path, the sealing protrusion having a communication hole sealing protrusion 96a, 96b, 99a, 99b surrounding the air removal communication hole or the refrigerant discharge communication hole, the communication hole sealing protrusion having a pair of outer peripheral walls 96s1, 99s1 and inner peripheral walls 96s2, 99s2, an inner passage 97, 101 being formed by the outer peripheral walls and the inner peripheral walls pinching the inner passage and extending in a manner of surrounding the air removal communication hole or the refrigerant discharge communication hole, the outer peripheral walls having a first communication hole 106a, 114a for mutually communicating the inner passage of the communication hole sealing protrusion with the link flow path, the inner peripheral walls having a second communication hole 106b, 114b for mutually communicating the inner passage of the communication hole sealing protrusion with the air removal communication hole or the refrigerant discharge communication hole, the first communication hole and the second communication hole being located at positions mutually deviated in an extending direction of the inner passage.

[0118] In the above-described separator for fuel cell, it can also be provided with a passage 104a, 104b, 112a, 112b extending from the inner peripheral wall toward the air removal communication hole or the refrigerant discharge communication hole, an inner space of the passage communicating with the inner passage via the second communication hole.

[0119] In the separator for fuel cell described above, it can also be that, in the set state in which the fuel cell stack 10 to which the separator for fuel cell is assembled is set, the second communication hole provided with the communication hole sealing protrusion that surrounds the refrigerant discharge communication hole is located at the uppermost portion of the inner peripheral wall of the communication hole sealing protrusion.

[0120] In the separator for fuel cell described above, it can also be that, in the set state, the second communication hole provided with the communication hole sealing protrusion that surrounds the refrigerant discharge communication hole is located at the lowermost portion of the inner peripheral wall of the communication hole sealing protrusion.

[0121] In the separator for fuel cell described above, it can also be that, in the set state in which the fuel cell stack 10 to which the separator for fuel cell is assembled is set, the second communication hole provided with the communication hole sealing protrusion that surrounds the refrigerant discharge communication hole is located at the uppermost portion of the inner peripheral wall of the communication hole sealing protrusion.

[0122] In the separator for fuel cell described above, it can also be that, in the set state, the second communication hole provided with the communication hole sealing protrusion that surrounds the refrigerant discharge communication hole is located at the lowermost portion of the inner peripheral wall of the communication hole sealing protrusion.

[0123] The above-described embodiment discloses a fuel cell stack in which the above-described separator for fuel cell and an electrolyte membrane-electrode structure 28a are provided, and a plurality of the separator for fuel cell and a plurality of the electrolyte membrane-electrode structure are alternately stacked.

[0124] Furthermore, the present application is not limited to the above-described disclosure, and various structures can be employed within the scope of the object of the present application.

Claims

1. A separator for a fuel cell, the separator (33) comprising two metal separator plates (30, 32) joined together, each metal separator plate having: a first surface (30a, 32a) having a reaction gas flow path (48, 58) for allowing fuel gas or oxidant gas, i.e., reaction gas, to flow; and a second surface (30b, 32b) having a refrigerant flow path (66) for allowing refrigerant to flow, wherein reaction gas communication holes (34a, 34b, 38a, 38b) communicating with the reaction gas flow path are formed through the separator in the thickness direction, and a protrusion (72A, 72B) is formed protruding on the first surface, the protrusion having a sealing protrusion (51, 61) for preventing reaction gas leakage, wherein in the separator (33), At least one of the air removal connecting hole (94) and the refrigerant venting connecting hole (98) is formed through the thickness direction of the separator. The second surface has connecting flow paths (100, 108), which are formed by recesses on the back side constituting the protruding shape of the protrusion. At least one of the air removal connecting hole and the refrigerant venting connecting hole is connected to the refrigerant flow path via the connecting flow path. The sealing protrusion has a connecting hole sealing protrusion (96a, 96b, 99a, 99b) surrounding the air removal connecting hole or the refrigerant venting connecting hole. The connecting hole sealing protrusion has paired extending outer peripheral walls (96s1, 99s1) and inner peripheral walls (96s2, 99s2), and internal passages (97, 101). The internal passages (97, 101) are formed by being sandwiched between the outer peripheral walls and the inner peripheral walls, and extend in a manner that surrounds the air removal connecting hole or the refrigerant venting connecting hole. The outer peripheral wall has a first connecting hole (106a, 114a) through which the internal passage of the connecting hole is connected to the connecting flow path, allowing the connecting hole to be sealed. The inner peripheral wall has a second connecting hole (106b, 114b) through which the internal passage for sealing the connecting hole communicates with the air removal connecting hole or the refrigerant venting connecting hole. The first connecting hole and the second connecting hole are located at positions that are offset from each other in the extension direction of the internal passage.

2. The separator for fuel cells according to claim 1, characterized in that, It includes channels (104a, 104b, 112a, 112b) that extend from the inner peripheral wall toward the air removal communication hole or the refrigerant venting communication hole. The internal space of the channel is connected to the internal passage via the second connecting hole.

3. The separator for fuel cells according to claim 1, characterized in that, Each of the two metal partition plates has a through hole for air removal. When the fuel cell stack (10) with the fuel cell separator is set in the set state, the second communication hole, which is provided with a communication hole sealing protrusion surrounding the communication hole for air removal, is located above the center of the communication hole for air removal.

4. The separator for a fuel cell according to claim 3, characterized in that, In the stated configuration, the second connecting hole, which is provided with a connecting hole sealing protrusion surrounding the air removal connecting hole, is located at the uppermost part of the inner peripheral wall of the connecting hole sealing protrusion.

5. The fuel cell separator according to any one of claims 1 to 4, characterized in that, Each of the two metal partition plates has a through hole for refrigerant venting. When the fuel cell stack with the fuel cell separator is set up, the second connecting hole, which is provided with a connecting hole sealing protrusion surrounding the connecting hole for refrigerant venting, is located below the center of the connecting hole for refrigerant venting.

6. The separator for a fuel cell according to claim 5, characterized in that, In the stated configuration, the second connecting hole, which is provided with a connecting hole sealing protrusion surrounding the refrigerant vent connecting hole, is located at the lowest part of the inner peripheral wall of the connecting hole sealing protrusion.

7. A fuel cell stack, wherein the fuel cell stack comprises: The fuel cell separator according to any one of claims 1 to 6; and Electrolyte membrane-electrode structure (28a), Multiple fuel cell separators and multiple electrolyte membrane-electrode structures are alternately stacked.

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