JP2022088029A - Separator for fuel cell - Google Patents

Abstract

To provide a separator for a fuel cell that can prevent retention of generated water.SOLUTION: A separator 30 as a separator for a fuel cell comprises: a first inlet manifold 50; a first outlet manifold 60; a power generation part 70; an inlet buffer part 75; and an outlet buffer part 80. The outlet buffer part 80 has a third inclined wall 82A that is provided inclined in a first direction and guides gas derived from a gas passage 40 to the first outlet manifold 60, and terminals 37 of a plurality of ribs 35 on the first outlet manifold 60 side are arranged in accordance with the inclination of the third inclined wall 82A.SELECTED DRAWING: Figure 2

Description

The present invention relates to a separator for a fuel cell.

Patent Document 1 discloses a fuel cell separator that constitutes a part of the fuel cell. The fuel cell separator is provided with an inlet manifold provided at one end in the longitudinal direction to allow gas to flow in, and an outlet manifold provided at the other end in the longitudinal direction to allow gas to flow out. .. Further, the fuel cell separator is provided with a power generation unit between the inlet manifold and the outlet manifold. The power generation unit has a plurality of ribs extending at intervals from each other, and each rib constitutes a plurality of gas flow paths. The gas flowing in from the inlet manifold flows to the inlet buffer section provided between the inlet manifold and the power generation section. In the inlet buffer section, the flowing gas is dispersed and gas is introduced into each gas flow path of the power generation section. Further, the gas introduced into each gas flow path is led out to the outlet buffer section provided between the power generation section and the outlet manifold. At the outlet buffer section, the gas derived from each gas flow path merges. The combined gas flows to the outlet manifold through the outlet buffer portion.

Japanese Unexamined Patent Publication No. 2015-76385

In a fuel cell, water is generated by power generation, and such generated water flows to the power generation section of the fuel cell separator. In the power generation section, the generated water is pushed toward the outlet buffer section by the gas flowing in each gas flow path. As a result, the generated water flows toward the end of each rib. By the way, since the volume of the outlet buffer portion is large compared to the flow path cross-sectional area of each gas flow path, the flow velocity of the gas greatly decreases when the gas is discharged from the gas flow path of the power generation section to the outlet buffer section. Sometimes. In this case, since the force to flow the generated water is weakened by the gas flow, the generated water in the power generation section is not drained from the end of each rib to the outlet buffer section, but adheres to the end of each rib and stays there. It becomes. In the fuel cell separator described in Patent Document 1, such a point is not taken into consideration and there is room for improvement.

An object of the present invention is to provide a separator for a fuel cell capable of suppressing the retention of generated water.

Fuel cell separators for solving the above problems are provided at one end in the first direction and an inlet manifold through which gas flows in, and at the other end in the first direction and an outlet through which gas flows out. A power generation unit having a manifold, a power generation unit having a plurality of gas flow paths composed of a plurality of ribs extending at intervals from each other, and an inlet in which gas flowing in from the inlet manifold is dispersed and introduced into each gas flow path of the power generation unit. A fuel cell separator including a buffer unit and an outlet buffer unit that merges gas drawn from each gas flow path of the power generation unit and flows out to the outlet manifold, wherein the outlet buffer unit is the first. It has an inclined wall that is inclined with respect to one direction and guides the gas led out from the gas flow path to the outlet manifold, and the end of the plurality of ribs on the outlet manifold side is the above. It is arranged according to the slope of the sloping wall.

In the above configuration, the end of each rib is arranged according to the inclination of the inclined wall of the outlet buffer portion. Therefore, even when the outlet buffer portion is provided with an inclined wall, it is possible to prevent the gap between the end of each rib and the inclined wall from becoming excessively large. As a result, a uniform flow can be generated in the gas led out from the gas flow path to the outlet buffer portion, and the gas can flow along the inclined wall between the end of each rib and the inclined wall. By flowing the gas along the end of each rib in this way, it becomes possible to flow the generated water collected at the end of each rib toward the outlet manifold. Therefore, according to the above configuration, the generated water adhering to the end portion of the rib can be easily drained to the outlet manifold, and it is possible to suppress the retention of the generated water.

The cross-sectional view which shows the schematic structure of the fuel cell provided with the separator for a fuel cell of one Embodiment. Perspective view of the separator for a fuel cell. The plan view which shows the end part of the 5th rib enlarged from the 1st rib. The perspective view which shows the structure of the end part of a rib. The plan view which shows the gas flow in the separator for a fuel cell.

An embodiment of the fuel cell separator will be described with reference to FIGS. 1 to 5. Hereinafter, the configuration of the fuel cell provided with the fuel cell separator will be described first.
As shown in FIG. 1, the fuel cell has a cell stack 10 in which a plurality of power generation cells 11 are stacked. Each power generation cell 11 is provided with a sheet-shaped membrane electrode gas diffusion layer junction 20 and a pair of separators 30 as fuel cell separators that sandwich the membrane electrode gas diffusion layer junction 20 in the thickness direction. There is.

The membrane electrode gas diffusion layer junction 20 has, for example, an electrolyte layer 21 formed of a solid polymer membrane. In the electrolyte layer 21, the anode electrode layer 22 is bonded to one side in the thickness direction, and the cathode electrode layer 23 is bonded to the other side in the thickness direction. The surface of the anode electrode layer 22 opposite to the electrolyte layer 21 is covered with the first gas diffusion layer 24. The surface of the cathode electrode layer 23 opposite to the electrolyte layer 21 is covered with the second gas diffusion layer 25. The membrane electrode gas diffusion layer junction 20 is composed of the electrolyte layer 21, the anode electrode layer 22, the cathode electrode layer 23, the first gas diffusion layer 24, and the second gas diffusion layer 25.

Of the pair of separators 30, the separator 30 located on the anode electrode layer 22 side of the membrane electrode gas diffusion layer junction 20 is called the first separator 31, and is located on the cathode electrode layer 23 side of the membrane electrode gas diffusion layer junction 20. The separator 30 is referred to as a second separator 90. The configuration of the first separator 31 and the configuration of the second separator 90 are symmetrical with respect to the membrane electrode gas diffusion layer junction 20. Therefore, in the following, the configuration of the first separator 31 will be described, and the configuration of the second separator 90 will be designated by a common reference numeral and detailed description thereof will be omitted.

As shown in FIG. 2, the first separator 31 is formed in the shape of a rectangular thin plate. The first separator 31 is made of, for example, a metal such as titanium, and is formed in an uneven shape. Therefore, the first separator 31 connects the main body plate portion 32, the bottom plate portion 33 one step lower in the thickness direction with respect to the main body plate portion 32, and the main body plate portion 32 and the bottom plate portion 33 extending in the thickness direction. It has a peripheral wall 34. In the first separator 31, the longitudinal direction in which the long side extends is the first direction, and the lateral direction in which the short side extends is the second direction.

The first separator 31 is provided with a first inlet manifold 50 into which hydrogen gas flows into one end portion located on one side in the first direction. Further, at one end of the first separator 31, a second inlet manifold 51 into which air flows in and a third inlet manifold 52 in which cooling liquid flows in are provided. The first inlet manifold 50, the second inlet manifold 51, and the third inlet manifold 52 are arranged side by side in the second direction. The first inlet manifold 50 is arranged on one side in the second direction.

The first separator 31 is provided with a first outlet manifold 60 through which hydrogen gas flows out at the other end portion located on the other side in the first direction. Further, at the other end of the first separator 31, a second outlet manifold 61 through which air flows out and a third outlet manifold 62 through which cooling liquid flows out are provided. The first outlet manifold 60, the second outlet manifold 61, and the third outlet manifold 62 are arranged side by side in the second direction. The first outlet manifold 60 is arranged on the other side in the second direction.

The first separator 31 is provided with a power generation unit 70 provided between the first inlet manifold 50 and the first outlet manifold 60. The power generation unit 70 is composed of a bottom plate portion 33, a plurality of ribs 35 provided on the bottom plate portion 33, and a peripheral wall 34. The plurality of ribs 35 extend in parallel in the first direction at intervals from each other. The plurality of ribs 35 constitute a plurality of gas flow paths 40 extending in the first direction in the power generation unit 70.

The first separator 31 is provided with an inlet buffer unit 75 that connects the first inlet manifold 50 and the power generation unit 70. The inlet buffer portion 75 is composed of a bottom plate portion 33 and a peripheral wall 34. The inlet buffer portion 75 is connected to the first inlet manifold 50 and extends with the same width as the first inlet manifold 50, and the second introduction portion 76 is connected to the first introduction portion 76 and the power generation unit 70. It has a unit 77. The first introduction portion 76 is provided with a plurality of entrance convex portions 76A. Each inlet convex portion 76A is erected from the bottom plate portion 33 and extends in parallel with the first direction.

The second introduction unit 77 is formed in a shape in which the space gradually expands toward the power generation unit 70 side. Therefore, the peripheral wall 34 constituting the second introduction portion 77 has a first inclined wall 77A and a second inclined wall 77B provided so as to be inclined with respect to the first direction. The first inclined wall 77A and the second inclined wall 77B are connected to the peripheral wall 34 constituting the power generation unit 70. The first inclined wall 77A is inclined so that the other side in the first direction is located on one side in the second direction. Further, the second inclined wall 77B is inclined so that the other side in the first direction is located on the other side in the second direction. The second inclined wall 77B has a longer length in the second direction than the first inclined wall 77A. The inclination angle θ2 of the second inclined wall 77B with respect to the first direction is larger than the inclination angle θ1 of the first inclined wall 77A with respect to the first direction. The peripheral wall 34 also has an introduction wall 77C extending in the second direction from one end of the second inclined wall 77B. The inlet buffer unit 75 disperses the hydrogen gas flowing into the first inlet manifold 50 by passing through the first introduction unit 76 and the second introduction unit 77 in order, and introduces the hydrogen gas into each gas flow path 40 of the power generation unit 70.

Further, the first separator 31 is provided with an outlet buffer unit 80 that connects the power generation unit 70 and the first outlet manifold 60. The outlet buffer portion 80 is composed of a bottom plate portion 33 and a peripheral wall 34. The outlet buffer unit 80 is connected to the first outlet manifold 60 and extends with the same width as the first outlet manifold 60. The first outlet unit 81 and the second outlet unit 81 and the power generation unit 70 are connected to each other. It has a part 82. The first out-licensing unit 81 is provided with a plurality of outlet convex portions 81A. Each outlet convex portion 81A is erected from the bottom plate portion 33 and extends in parallel with the first direction.

The second out-licensing unit 82 is formed in a shape in which the space gradually expands toward the power generation unit 70 side. Therefore, the peripheral wall 34 constituting the second lead-out portion 82 has a third inclined wall 82A and a fourth inclined wall 82B provided so as to be inclined with respect to the first direction. The third inclined wall 82A and the fourth inclined wall 82B are connected to the peripheral wall 34 constituting the power generation unit 70. The third inclined wall 82A is inclined so that the other side in the first direction is located on the other side in the second direction. Further, the fourth inclined wall 82B is inclined so that the other side in the first direction is located on one side in the second direction. The third inclined wall 82A has a longer length in the second direction than the fourth inclined wall 82B. The inclination angle θ3 of the third inclined wall 82A with respect to the first direction is larger than the inclination angle θ4 of the fourth inclined wall 82B with respect to the first direction. The inclination angle θ3 of the third inclined wall 82A is the same as the inclination angle θ2 of the second inclined wall 77B, and the inclination angle θ4 of the fourth inclined wall 82B is the same as the inclination angle θ1 of the first inclined wall 77A ( θ2 = θ3> θ1 = θ4).

The peripheral wall 34 also has a lead-out wall 82C extending in the second direction from one end of the third inclined wall 82A. The outlet buffer unit 80 joins the hydrogen gas derived from each gas flow path 40 of the power generation unit 70 by passing the second outlet unit 82 and the first outlet unit 81 in this order to the first outlet manifold 60. Let it leak. Since the third inclined wall 82A and the fourth inclined wall 82B are provided so as to be inclined with respect to the first direction, they are also provided so as to be inclined with respect to the gas flow path 40 in the power generation unit 70. .. Therefore, the third inclined wall 82A and the fourth inclined wall 82B have a function of guiding the gas led out from the gas flow path 40 to the first outlet manifold 60.

As shown in FIG. 1, in each power generation cell 11, the first separator 31 has a top surface of each rib 35 provided in the power generation unit 70 with the first gas diffusion layer 24 of the membrane electrode gas diffusion layer junction 20. Arranged to touch. As a result, the hydrogen gas flowing through the gas flow path 40 of the first separator 31 is introduced into the anode electrode layer 22 through the first gas diffusion layer 24.

Further, the second separator 90 is arranged so that the top surface of each rib 35 provided in the power generation unit 70 is in contact with the second gas diffusion layer 25 of the membrane electrode gas diffusion layer junction 20. In the second separator 90, unlike the first separator 31, air flows in the gas flow path 40. That is, in the second separator 90, the second inlet manifold 51 and the second outlet manifold 61 communicate with each other through the inlet buffer section 75, the power generation section 70, and the outlet buffer section 80. The air flowing through each gas flow path 40 of the second separator 90 is introduced into the cathode electrode layer 23 through the second gas diffusion layer 25.

In each power generation cell 11, when hydrogen gas is supplied to the anode electrode layer 22 of the membrane electrode gas diffusion layer junction 20 and air is supplied to the cathode electrode layer 23 of the membrane electrode gas diffusion layer junction 20, they are supplied. Power is generated based on the reaction of the hydrogen gas and the air film electrode gas diffusion layer junction 20. In each power generation cell 11, heat is generated during power generation. Therefore, in a state where the power generation cells 11 are stacked, the first separator 31 in one power generation cell 11 and the second separator 90 in the other power generation cell 11 are overlapped to form a coolant passage 95 through which the coolant flows. .. The coolant passage 95 is composed of ribs 35 of a first separator 31 and a second separator 90. Each power generation cell 11 is cooled by the coolant flowing through the coolant passage 95.

Next, the configuration of each rib 35 provided in the first separator 31 will be described in detail.
As shown in FIG. 2, in the plurality of ribs 35, the tip 36 on the first inlet manifold 50 side is arranged at the same position in the first direction. On the other hand, the plurality of ribs 35 are arranged so that the position of the end 37 on the first outlet manifold 60 side is aligned with the inclination of the third inclined wall 82A and the inclination of the fourth inclined wall 82B.

That is, as shown in FIGS. 2 and 3, the plurality of ribs 35 are, in order from one side in the second direction, the first rib 35A, the second rib 35B, the third rib 35C, the fourth rib 35D, and the fifth rib 35E. , 6th rib 35F, 7th rib 35G, and 8th rib 35H. The end 37 of the first rib 35A to the fifth rib 35E faces the third inclined wall 82A in the first direction. In these first ribs 35A to fifth ribs 35E, the length of each rib 35 is located on the other side (right side in FIG. 3) in the first direction toward the fifth rib 35E side according to the inclination of the third inclined wall 82A. Is set.

More specifically, as shown in FIG. 3, the end 37 of the second rib 35B is located closer to the third inclined wall 82A than the end 37 of the first rib 35A, and from the end 37 of the second rib 35B. The distance d2 to the third inclined wall 82A is longer than the distance d1 from the end 37 to the third inclined wall 82A in the first rib 35A. Further, the end 37 of the third rib 35C is located closer to the third inclined wall 82A than the end 37 of the second rib 35B, and the distance d3 from the end 37 of the third rib 35C to the third inclined wall 82A is It is longer than the above distance d2 in the second rib 35B. Further, the end 37 of the fourth rib 35D is located closer to the third inclined wall 82A than the end 37 of the third rib 35C, and the distance d4 from the end 37 to the third inclined wall 82A in the fourth rib 35D is It is longer than the above distance d3 at the third rib 35C. Further, the end 37 of the fifth rib 35E is located closer to the third inclined wall 82A than the end 37 of the fourth rib 35D, and the distance d5 from the end 37 of the fifth rib 35E to the third inclined wall 82A is It is longer than the above distance d4.

In this way, the first ribs 35A to the fifth ribs 35E facing the third inclined wall 82A gradually become longer toward the fifth rib 35E so that their ends 37 match the inclination of the third inclined wall 82A. Is set to. As a result, from the first rib 35A to the fifth rib 35E arranged on the outermost side of the fifth rib 35E to the fifth rib 35E arranged on the innermost side, the end 37 of each rib 35 is in the first direction. Those located on the other side of the above are arranged so as to be located on the other side in the second direction. Further, in the present embodiment, the distance from the terminal 37 to the third inclined wall 82A becomes longer from the first rib 35A to the fifth rib 35E (d1 <d2 <d3 <d4 <d5).

As shown in FIG. 2, in the present embodiment, the seventh rib 35G having the shortest distance in the second direction to the center C of the first outlet manifold 60 is the rib located on the innermost side of each rib 35. It is set to 35. Therefore, with respect to the 7th rib 35G, the rib 35 located on the outermost side on one side in the second direction is the first rib 35A, and the rib 35 located on the outermost side on the other side in the second direction is the 8th rib 35H. Will be.

Further, among the ribs 35, the sixth rib 35F facing the lead-out wall 82C and the seventh rib 35G located on the innermost side have the same length as the length of the fifth rib 35E. Therefore, in the first direction, the positions of the ends 37 of the fifth rib 35E, the sixth rib 35F, and the seventh rib 35G are the same, and are arranged along the lead-out wall 82C.

Further, the end 37 of the eighth rib 35H located outside the seventh rib 35G faces the fourth inclined wall 82B. The end 37 of the eighth rib 35H is located on one side in the first direction with respect to the end 37 of the seventh rib 35G. That is, in the 7th rib 35G and the 8th rib 35H, the terminal 37 located on the other side in the first direction is arranged so as to be located on the one side in the second direction, and the fourth inclined wall 82B. It is arranged according to the inclination. The length of the 8th rib 35H is the same as the length of the 1st rib 35A. Therefore, in the first direction, the positions of the ends 37 of the first rib 35A and the eighth rib 35H are the same.

In this way, the position of the end 37 in the plurality of ribs 35 is arranged according to the inclination of the inclined wall, that the position of the end 37 of each rib 35 is arranged along the inclined wall from each end 37. It does not show only the arrangement mode in which the distances to the inclined walls are the same. That is, as in the present embodiment, the distance from the end 37 of each rib 35 to the inclined wall is different in each rib 35, but the arrangement of each end 37 includes an arrangement mode in which the arrangement of each end 37 shows the same inclined direction as the inclined direction of the inclined wall. .. In the present embodiment, in the first rib 35A to the fifth rib 35E facing the third inclined wall 82A, the other side in the first direction becomes the other side in the second direction as in the inclined direction of the third inclined wall 82A. The terminal 37 is arranged so as to be located, and the terminal 37 of the first rib 35A to the fifth rib 35E is arranged according to the inclination of the third inclined wall 82A.

Of the ribs 35, the terminal 37s of the first rib 35A and the eighth rib 35H are located at the power generation unit 70. Further, of the ribs 35, the second rib 35B to the seventh rib 35G extend from the power generation unit 70 across the outlet buffer unit 80, and each end 37 is located at the outlet buffer unit 80.

Further, as shown in FIG. 2, the distance between the ribs 35 is gradually widened from the first rib 35A to the seventh rib 35G, and gradually narrowed from the seventh rib 35G to the eighth rib 35H. That is, the distance g2 between the first rib 35A and the second rib 35B in the second direction is wider than the distance g1 between the peripheral wall 34 and the first rib 35A in the second direction. Further, the distance g3 between the second rib 35B and the third rib 35C in the second direction is wider than the above distance g2. Further, the distance g4 between the third rib 35C and the fourth rib 35D in the second direction is wider than the above distance g3. Further, the distance g5 between the fourth rib 35D and the fifth rib 35E in the second direction is wider than the above distance g4. Further, the distance g6 between the fifth rib 35E and the sixth rib 35F in the second direction is wider than the above distance g5. Further, the distance g7 between the 6th rib 35F and the 7th rib 35G in the second direction is wider than the above distance g6.

On the other hand, the distance g8 between the 7th rib 35G and the 8th rib 35H in the second direction is narrower than the distance g7, and the distance g9 between the 8th rib 35H and the peripheral wall 34 in the second direction is larger than the distance g8. Is also narrow. In this way, among the plurality of gas flow paths 40 formed in the power generation unit 70 and extending in parallel, the flow path width (g7) of the gas flow path 40 composed of the sixth rib 35F and the seventh rib 35G is defined. As a reference, the gas flow path 40 located on the outer side has a smaller flow path width (g1 <g2 <g3 <g4 <g5 <g6 <g7, g9 <g8 <g7). Therefore, among the plurality of gas flow paths 40, the flow path width of the gas flow path 40 located on the outer side is narrower than the flow path width of the gas flow path 40 located on the inner side of the gas flow path 40. The width of each gas flow path 40 may be set so that the pressure loss of the hydrogen gas flowing through the power generation unit 70 is equal.

As shown in FIG. 4, the end portion 38 having the end 37 of each rib 35 is formed in a tapered shape. That is, the end portion 38 is formed in a quadrangular pyramid shape, and connects the triangular upper slope 38A connecting the top surface of the rib 35 and the bottom plate portion 33, and the side surface of the rib 35, the upper slope 38A, and the bottom plate portion 33. It consists of a pair of triangular side slopes 38B. The termination 37 corresponds to the apex of the quadrangular pyramid which is the connection point of the upper slope 38A, the pair of side slopes 38B, and the bottom plate portion 33.

Next, the operation and effect of this embodiment will be described.
(1) As shown by the solid arrow in FIG. 5, the hydrogen gas flowing into the first inlet manifold 50 is dispersed in the inlet buffer section 75 and introduced into each gas flow path 40 of the power generation section 70. In each gas flow path 40, the generated water generated by power generation is swept toward the outlet buffer portion 80 by hydrogen gas. As a result, the generated water flows toward the end 37 of each rib 35.

In the present embodiment, the end 37s of the plurality of ribs 35 are arranged according to the inclination of the third inclined wall 82A or the inclination of the fourth inclined wall 82B. Therefore, it is possible to prevent the gap between the third inclined wall 82A and the fourth inclined wall 82B and the end 37 of each rib 35 in the outlet buffer portion 80 from becoming excessively large. As a result, as shown by the alternate long and short dash line arrow in FIG. 5, the hydrogen gas led out from each gas flow path 40 to the outlet buffer portion 80 is caused to generate a uniform flow toward the first outlet manifold 60, and each rib is generated. Hydrogen gas can flow along the third inclined wall 82A and the fourth inclined wall 82B between the terminal 37 of 35 and the third inclined wall 82A and the fourth inclined wall 82B. As the hydrogen gas flows along the end 37 of each rib 35 in this way, the generated water collected at the end 37 of each rib 35 can flow toward the first outlet manifold 60. Therefore, the generated water adhering to the terminal portion 38 of the rib 35 can be easily drained to the first outlet manifold 60, so that the generated water can be suppressed from staying.

As in the present embodiment, the separator 30 is provided with an outlet buffer portion 80 for merging hydrogen gas derived from each gas flow path 40, so that each gas flow path 40 is directly connected to the first outlet manifold 60. Compared to the connected configuration, it is possible to improve drainage while reducing pressure loss.

(2) In the present embodiment, among the plurality of gas flow paths 40, the gas located outside with respect to the flow path width (g7) of the gas flow path 40 composed of the sixth rib 35F and the seventh rib 35G. The flow path width is gradually narrowed by the flow path 40. As a result, among the plurality of gas flow paths 40, the flow path width of the gas flow path 40 located on the outside is narrower than the flow path width of the gas flow path 40 located on the inner side. Therefore, the gas flow path 40 located on the outer side has a higher flow velocity of hydrogen gas. As a result, even in the first rib 35A and the eighth rib 35H, which are located far from the first outlet manifold 60 and the flow rate of the hydrogen gas flowing along the terminal 37 is small, the generated water adhering to the terminal 37 flows through the hydrogen gas. Allows flow toward the first outlet manifold 60. Therefore, it becomes possible to further suppress the retention of the generated water.

(3) In the present embodiment, the distance from the end 37 of each rib 35 to the third inclined wall 82A or the fourth inclined wall 82B of the rib 35 arranged inside the rib 35 arranged outside is set. I tried to make it longer. As a result, in the hydrogen gas flow path formed between the end 37 of each rib 35 and the third inclined wall 82A or the fourth inclined wall 82B, the flow path width is narrowed toward the side farther from the first outlet manifold 60. be able to. According to such a configuration, in the hydrogen gas flow path formed between the end 37 of each rib 35 and the third inclined wall 82A or the fourth inclined wall 82B, the second outlet manifold 60 is located on the far side. It is possible to increase the flow velocity of the gas near the end 37 of the 1st rib 35A and the 8th rib 35H. Therefore, it is possible to promote the drainage of the generated water at the ribs 35 located on the outside such as the first rib 35A and the eighth rib 35H where the flow rate of the hydrogen gas flowing along the terminal 37 is small and the generated water tends to stay. Become.

(4) In each rib 35, the end portion 38 has a tapered shape. Therefore, when the generated water adhering to each rib 35 is made to flow toward the first outlet manifold 60 by the flow of hydrogen gas, the generated water tends to collect at the end 37 of the end portion 38. By collecting the generated water in this way, it is possible to increase the diameter of the droplets of the generated water and improve the drainage property when the hydrogen gas flows. Therefore, it is possible to promote the flow of generated water from the end 37 of the rib 35 to the first outlet manifold 60 side.

It should be noted that the same actions and effects as those of the above (1) to (4) can be obtained in the second separator 90.
This embodiment can be modified and implemented as follows. The present embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.

-The end portion 38 is formed into a quadrangular pyramid shape to form a tapered shape, but the tapered shape is not limited to such a shape. For example, it may be another pyramid shape such as a triangular pyramid or a pentagonal pyramid, or it may be a conical shape. Further, although the terminal 37 is connected to the bottom plate portion 33, the terminal 37 may be floated from the bottom plate portion 33. It should be noted that the end portion 38 does not necessarily have to have a tapered shape, and such a configuration may be omitted.

-In the above embodiment, in the 5th rib 35E, the 6th rib 35F, and the 7th rib 35G, the positions of the terminal 37s are the same in the first direction. Such a configuration can be changed as appropriate. For example, the end 37 may be arranged on the other side in the first direction from the 5th rib 35E to the 7th rib 35G by gradually increasing the length from the 5th rib 35E to the 7th rib 35G. ..

In the above embodiment, the distance from the end 37 of each rib 35 to the third inclined wall 82A is increased from the first rib 35A to the fifth rib 35E (d1 <d2 <d3 <d4 <d5). Such a configuration can be changed as appropriate. For example, the distance is constant from the second rib 35B to the fifth rib 35E, and only the distance d1 in the first rib 35A is shorter than the distance in the second rib 35B (d1 <d2 = d3 = d4 = d5). You may. Further, the distances from the first rib 35A to the third rib 35C are the same, and the distances between the fourth rib 35D and the fifth rib 35E are the same while being longer than the distances from the first rib 35A to the third rib 35C. (D1 = d2 = d3 <d4 = d5) and the like.

Further, instead of such a configuration, the distance from the end 37 of each rib 35 to the inclined wall may be constant (d1 = d2 = d3 = d4 = d5). In this case, the end 37 of each rib 35 will be arranged along the inclined wall. Further, the distance from the end 37 of each rib 35 to the inclined wall may be longer for the rib 35 arranged on the outside than for the rib 35 arranged on the inside. For example, the distance d1 in the first rib 35A may be longer than the distance in the second rib 35B (d1> d2). Even with such a configuration, the end 37 of each rib 35 may be arranged according to the inclination of the inclined wall.

-In the above embodiment, the width of each of the gas flow paths 40 is made constant in the first direction. Instead of such a configuration, the width of each flow path of each gas flow path 40 may be partially narrowed on the end portion 38 side. Even with such a configuration, as in the above embodiment, the width of the flow path on the end portion 38 side, which is partially narrowed in the gas flow path 40 located on the outside, is the gas flow path located on the inner side. It is desirable that the width of the flow path on the end portion 38 side, which is partially narrowed in 40, is narrower.

-In the above embodiment, the width of the gas flow path 40 located on the outer side of the plurality of gas flow paths 40 is gradually reduced. Such a configuration can be changed as appropriate. For example, the flow path width of the gas flow path 40 located on the outside and the gas flow path 40 located on the inside may be the same, or the flow path width of the gas flow path 40 located on the outside may be made inward. It may be made wider than the flow path width of the located gas flow path 40.

-In the above embodiment, an example in which eight ribs 35 are provided is shown, but the number of ribs 35 can be changed as appropriate.
-In the above embodiment, an example in which a plurality of ribs 35 extend linearly in the first direction is shown, but the shape of the ribs 35 is not limited to these. For example, the ribs 35 may extend in a wavy shape at intervals from each other, or may form a plurality of folded flow paths.

-In the above embodiment, the tip 36 of each rib 35 is arranged at the same position in the first direction, but the tip 36 of each rib 35 may be arranged at a different position in the first direction. ..

-In the above embodiment, the shapes of the inlet buffer portion 75 and the outlet buffer portion 80 are appropriately changed. That is, either one of the first inclined wall 77A and the second inclined wall 77B may be omitted, or either one of the third inclined wall 82A and the fourth inclined wall 82B may be omitted. Further, each inclination angle of the first inclined wall 77A to the fourth inclined wall 82B may be appropriately changed. In short, the inlet buffer unit 75 and the outlet buffer unit 80 are capable of introducing gas into the power generation unit 70 and deriving gas from the power generation unit 70 according to the positions of the first inlet manifold 50 and the first outlet manifold 60. The shape of is set. Even in such a case, it is possible to obtain the same effect as in (1) above by arranging the end of each rib 35 according to the inclination of the inclined wall provided in the outlet buffer portion 80.

-In the above embodiment, the longitudinal direction of the separator 30 is set as the first direction, but the lateral direction may be set as the first direction.

10 ... Cell stack 11 ... Power generation cell 20 ... Membrane electrode gas diffusion layer Bonded body 21 ... Electrode layer 22 ... Anode electrode layer 23 ... Cathode electrode layer 24 ... First gas diffusion layer 25 ... Second gas diffusion layer 30 ... Separator 31 ... 1st separator 32 ... Main body plate 33 ... Bottom plate 34 ... Circumferential wall 35 ... Rib 35A ... 1st rib 35B ... 2nd rib 35C ... 3rd rib 35D ... 4th rib 35E ... 5th rib 35F ... 6th rib 35G ... 7th rib 35H ... 8th rib 36 ... Tip 37 ... Terminal 38 ... Terminal 38A ... Upper slope 38B ... Side slope 40 ... Gas flow path 50 ... 1st inlet manifold 51 ... 2nd inlet manifold 52 ... 3rd inlet manifold 60 ... 1st outlet manifold 61 ... 2nd outlet manifold 62 ... 3rd outlet manifold 70 ... Power generation unit 75 ... Inlet buffer part 76 ... 1st introduction part 76A ... Inlet convex part 77 ... 2nd introduction part 77A ... 1st inclined wall 77B ... 2nd sloping wall 77C ... Introductory wall 80 ... Exit buffer part 81 ... 1st sloping part 81A ... Exit convex part 82 ... 2nd sloping part 82A ... 3rd sloping wall 82B ... 4th sloping wall 82C ... Derived wall 90 ... 2 separator 95 ... Coolant passage

Claims (4)

An inlet manifold provided at one end in the first direction for gas to flow in, an outlet manifold provided at the other end in the first direction for gas outflow, and a plurality of ribs extending at intervals from each other. A power generation unit having a plurality of configured gas flow paths, an inlet buffer unit that disperses and introduces gas flowing from the inlet manifold into each gas flow path of the power generation unit, and each gas flow path of the power generation unit. A fuel cell separator provided with an outlet buffer portion for merging the gas derived from the fuel cell and discharging the gas to the outlet manifold.
The outlet buffer portion is provided so as to be inclined with respect to the first direction, and has an inclined wall for guiding the gas derived from the gas flow path to the outlet manifold.
The end of the plurality of ribs on the outlet manifold side is a fuel cell separator arranged according to the inclination of the inclined wall. The fuel cell separator according to claim 1, wherein the flow path width of the gas flow path located on the outer side of the plurality of gas flow paths is narrower than the flow path width of the gas flow path located on the inner side thereof. The fuel cell separator according to claim 1 or 2, wherein the distance from the end of the plurality of ribs to the inclined wall is longer in the ribs arranged inside than in the ribs arranged outside. The fuel cell separator according to any one of claims 1 to 3, wherein the rib has a tapered end portion having the end.

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