JP3413913B2 - Fuel cell - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION This invention relates to fuel cells and, more particularly, relates to a cooling member to form a passage of the cell and the cooling medium constituting the unit battery fuel cells made by stacking a plurality.

[0002]

2. Description of the Related Art In a fuel cell, heat is usually generated due to an electrochemical reaction carried out in each cell and heat is generated due to internal resistance. Therefore, in order to operate each cell in the temperature range where the power generation efficiency is high, it is necessary to prevent the temperature rise of the cell due to these heat generations. As a cooling method for preventing this temperature rise, a cooling member is generally provided between the stacked cells. In addition, to further increase power generation efficiency,
A fuel cell has been proposed in which the arrangement of cooling members and the passage of a cooling medium are devised so that the temperature in the cell plane becomes uniform. For example, by stacking cooling members in which the positions of the inlet and the outlet of the cooling medium are changed, the temperature difference between the inlet and the outlet is eliminated to make the temperature uniform (Japanese Patent Laid-Open No. 3-216).
961), or a fuel cell in which a plurality of cooling members having different passages for a cooling medium are stacked to make the temperature uniform by heat exchange between cells having different temperature distributions (JP-A-3-9826).
No. 9) are proposed.

Further, two cooling medium supply flow paths are provided along the stacking direction, and the direction of the cooling medium flowing in the cooling member is opposed to each adjacent cooling member to make the temperature distribution in the cell plane uniform. Fuel cell intended to achieve
No. 72) is proposed.

[0004]

However, in the conventional fuel cell in which the temperature in the cells is made uniform, the temperature in the single cell can be made uniform, but the temperature difference generated between the cells in the stacking direction. There was a problem that it could not be reduced. The temperature difference between the cells causes a decrease in power generation efficiency of the entire fuel cell. The fuel cell is operated by setting the load current density, the flow rate and pressure of the fuel gas, the amount of water vapor in the fuel gas, etc., assuming a cell state with the highest power generation efficiency. When a temperature difference occurs between cells, some cells are not in the expected state, and in this cell, the electrochemical reaction that occurs at the electrodes in the cells cannot be smoothly performed. As a result, the power generation efficiency is reduced.

Further, in a fuel cell in which two cooling medium supply channels are provided along the stacking direction, if the cooling medium supply channels are sufficiently separated from the stack, the temperature difference between the cells in the stacking direction will be some extent. Although it can be reduced, there is a problem that the size of the entire fuel cell is increased.

The fuel cell and the cooling member for a fuel cell according to the present invention are intended to solve these problems, to make the temperature between cells along the stacking direction uniform, and to miniaturize the fuel cell. I took it.

[0007]

In the fuel cell of the present invention, a plurality of cells, each of which is a unit cell composed of an electrolyte and two electrodes, and a cooling member, which is disposed between the cells and forms a passage for a cooling medium, are laminated. in the fuel cell having a laminate formed by the at least two cooling medium flow passage for supplying the cooling medium is provided along the stacking direction of that inside the laminate, along the stacking direction in the passage in the cooling member Provided 2
The flow direction of the cooling medium in one cooling medium flow path is opposite.

Here, in the fuel cell, a through hole is provided at substantially the same location of the cell and the cooling member, and when the cell and the cooling member are laminated, the through hole forms the cooling medium flow path. It can also be configured as. Further, in the fuel cell, wherein the cooling medium flow path, said
The cooling medium flow passage and the passage inside the cooling member may be communicated with the passage so that the cooling medium passage and the passage inside the cooling member form a single passage from the inlet to the outlet of the cooling medium. Further, in the fuel cell, the stacked body includes a cooling member that receives the cooling medium supplied from one of the two cooling medium channels, and the cooling medium from the other of the two cooling medium channels. It is also possible to adopt a configuration in which cooling members that receive supply of are alternately arranged.

Further , in this fuel cell, the cooling member is
When stacked, it provided at least four holes of predetermined shape forming a flow path of the cooling medium along the stacking direction, at least two holes of the hole communicating with the passageway of the cooling medium structure
It can also be achieved .

Here, in the fuel cell, the four holes of the cooling member are provided at positions where they can be overlapped with each other by rotating or reversing the cooling member. You can also For example, the cooling member may have a structure in which the surfaces to be stacked are formed in a rectangular shape, and the four holes are provided in each of the four corners of the rectangular shape.

[0011]

The fuel cell of the present invention constructed as described above is
At least two cooling medium flow paths provided along the stacking direction of the stacked body supply the cooling medium to the passages of the cooling member. The cooling medium flows in opposite directions in the two cooling medium flow paths provided along the stacking direction. As a result, the temperature difference between the cells forming the stack is reduced. Here, if the fuel cell is provided with through holes at substantially the same locations of the cells and the cooling member, and when these cells and cooling members are stacked, the through holes form the cooling medium flow path, the fuel cell Can be downsized. In addition, each cooling medium flow path,
A cooling medium flow path and the cooling member internal passageway, such as a single channel from the inlet of the cooling medium to an outlet in the laminate, cold
The cooling medium flow path becomes simple if it communicates with the passage inside the cooling member . Further, if the stacked body is a fuel cell in which a cooling member supplied with the cooling medium from one of the two cooling medium channels and a cooling member supplied with the cooling medium from the other are alternately arranged , The temperature difference between cells becomes smaller.

In the fuel cell of the present invention, at least four holes having a predetermined shape are provided in the cooling member, and the cooling members are laminated to form a cooling medium flow path along the laminating direction. You can By connecting at least two of these holes with a cooling medium passage, one of at least four cooling medium flow passages serves as a cooling medium inflow passage, and the other one of them serves as a cooling medium outflow passage. And here,
A structure in which a cooling member for a fuel cell is provided at a position where the four holes can be overlapped by rotating or reversing the cooling member, for example, the stacking surface is formed into a rectangular shape and four holes are formed. Is provided at each of the four corners of the rectangular shape, and two sets of flow paths that connect two of the four flow paths of the cooling medium are formed only by rotating and reversing the cooling members and stacking them. be able to.

[0013]

Preferred embodiments of the present invention will be described below in order to further clarify the structure and operation of the present invention described above. FIG. 1 is an external perspective view illustrating the outline of the fuel cell 10.

The fuel cell 10 includes a laminated body 12 constituting the cell body, end plates 50a and 50b mounted on both ends of the laminated body 12, and a fuel gas supply device attached to the laminated body 12 for supplying fuel to the cell body. (Not shown). The laminated body 12 is a cell 2 that constitutes a unit battery.
0, a cooling member 30 arranged between the cells 20 to cool the cells 20, and a cooling member 40 arranged also between the cells 20 to cool the cells 20 are laminated in the thickness direction. In this embodiment, the laminated body 12 includes the cells 20,
The cooling member 30, the cell 20, the cell 20, the cooling member 40, and the cell 20 are regularly stacked in this order. In addition, in the embodiment, the laminated body 12 is provided with the cell 20, the cooling member 30, and the cell 2.
0, the cells 20, the cooling member 40, and the cells 20 are regularly stacked, but they may be stacked in any order.

The cell 20 is constructed as a general structure of a fuel cell. For example, when the cell 20 is composed of the polymer electrolyte fuel cell illustrated in FIG. 2, the cell 20 includes an electrolyte membrane 23, and a cathode 25 and an anode 26 that sandwich the electrolyte membrane 23 from both sides to form a sandwich structure.
If, cathode along with the sandwich this sandwich structure from both sides
Cathode fuel and A in the de 25 and anode 26
Collector electrodes 27 and 28 forming a flow path for the fuel on the node side
And a separator 29 disposed outside the collecting electrodes 27 and 28 and forming a partition wall when the cells 20 are stacked.

The electrolyte membrane 23 is an ion exchange membrane made of a polymer material such as a fluorine resin, and exhibits good electric conductivity in a wet state. Cathode 25 and ano
The cord 26 is formed of a carbon cloth woven with a yarn made of carbon fiber.
Carbon powder carrying platinum or an alloy of platinum and another metal as a catalyst is kneaded into the surface of the cloth on the side of the electrolyte membrane 23 and the gap. Here, in the example,
Although the cathode 25 and the anode 26 are formed of carbon cloth, a configuration in which they are formed of carbon paper or carbon felt made of carbon fiber is also suitable.

The collector electrodes 27 and 28 are made of porous carbon which is gas permeable and has a porosity of 40 to 80%. The collector electrode 27 is formed with a plurality of ribs 27a arranged in parallel, the water produced at the cathode 25 with forming a flow path of the oxygen-containing gas in the cathode fuel between the rib 27a and the cathode 25 of the surface An oxygen gas flow path 27b forming a water collection path is formed. Collector electrode 2
8 are formed a plurality of ribs 28a arranged in parallel to, anode between the rib 28a and the surface of the anode 26
A hydrogen gas flow passage 28b is formed which forms a flow passage for a mixed gas of hydrogen gas of the defuel and water vapor. The collecting electrode 27 and the collecting electrode 28 are arranged such that the ribs 27a and 28a are orthogonal to each other,
That is, the oxygen gas flow channel 27b and the hydrogen gas flow channel 28b are stacked in a perpendicular arrangement. Therefore, from the fuel gas supply device, the oxygen-containing gas is supplied to the oxygen gas flow path 27b along the arrow A direction in the drawing, and the hydrogen gas is supplied to the hydrogen gas flow path 28b along the arrow B direction in the drawing. The separator 29 is made of gas-impermeable carbon that is made gas-impermeable by compressing carbon.
Cathode 25 and anode 26, collecting electrodes 27 and 2
It forms a partition wall when the cells constituted by 8 are stacked in the thickness direction.

At the four corners of the stacking surface of the cell 20 thus constructed, the holes 22a of the same diameter are formed at even positions from the four corners.
22b, 22c and 22d are formed. This hole 22
A and the like form a flow path of the cooling medium along the stacking direction when the stack 12 is formed.

FIG. 3A is a perspective view illustrating the appearance of the cooling member 30. The cooling member 30 is made of gas-impermeable carbon, and is a plate-shaped member having a square surface to be stacked, as shown in the drawing, and is provided at the same position as the holes 22a of the cells 20 at four corners of the surface to be stacked. Holes 32a, 32 having the same diameter
b, 32c, 32d are formed. Similar to the holes 22a of the cell 20, the holes 32a and the like form a flow path of the cooling medium along the stacking direction when the stacked body 12 is formed. In addition, the cooling member 30 is provided with a groove 34 having a rectangular cross-sectional shape that connects the holes 32a and 32c in a zigzag shape.
The groove 34 forms a passage 38 for a cooling medium (for example, pure water, alternative CFCs, insulating oil, etc.) by stacking the cooling member 30 and the cell 20. In the embodiment, the holes 32a and 32c of the cooling member 30 are connected in a zigzag manner by the groove 34, but any shape may be used for the connection.

FIG. 3B is a perspective view illustrating the appearance of the cooling member 40. As shown, this cooling member 40
Has the same shape as the mirror image of the cooling member 30, and is made of gas-impermeable carbon that is the same material as the cooling member 30. Therefore, the cooling member 40 is a plate-shaped member having a square stacking surface, and the four corners of the stacking surface are
Holes 42a, 42b, 42c, 42d are formed.
Further, the cooling member 40 is formed with a groove 44 having a rectangular cross-section that connects the holes 42b and the holes 42d in a zigzag manner, and the cooling member 40 and the cells 20 are stacked to form a cooling medium. A passage 48 is formed.

FIG. 4A is a perspective view illustrating the appearance of the end plate 50a. The end plate 50a is
A square plate member that is slightly larger than the cell 20 and has holes 22a and 2 of the cell 20 when mounted on the laminated body 12.
Holes 52a and 52d having the same diameter as the hole 22a and the like are formed at positions matching with 2d. FIG. 4B is a perspective view illustrating the appearance of the end plate 50b. As shown, the end plate 50b is
It has the same shape as a, and when it is attached to the laminated body 12,
The end plate 50a is rotated 180 degrees and the upper and lower sides are interchanged so that the holes 52a and 52d become the holes 52b and 52c.

FIG. 5 is an explanatory view schematically illustrating the flow path of the cooling medium. As illustrated in FIG. 5A, the cell 2
0, the cooling members 30 and 40 are laminated in the thickness direction in the order described above to form the laminated body 12, and the end plates 50a and 50b are attached to both ends of the laminated body 12 to form the fuel cell 10. Holes 52a, 22a, 32a
And 42a, the flow path 62a of the cooling medium is
A channel 62c is formed by c, 22c, 32c and 42c. The inside of each flow path is coated with a coating material having electrical insulation.

One end of the flow passage 62a is closed by the end plate 50b, and the other end of the flow passage 62c is closed by the end plate 50a. The flow paths 62a and 62c are connected to each other by a cooling medium passage 38 formed by the groove 34 of the cooling member 30 and the cell 20. In addition, the flow path 62a is connected to the pipe 72.
Pump 70a and cooling medium tank via a (not shown)
And the flow path 62c is connected to a heat exchanger (not shown) and a cooling medium tank via a pipe 72c. Therefore, the pipe 72a, the pump 70a, the flow passage 62a, the passage 38, the flow passage 62c, the pipe 72c, the heat exchanger, and the cooling medium tank form a flow passage through which the cooling medium circulates.

The fuel cell 10 has holes 52b, 22b, 32b and 42b as shown in FIG. 5 (b).
The flow path 62b for the cooling medium is formed by the holes 52d, 22d,
A flow path 62d is formed by 32d and 42d.
The flow path 62b is formed by the end plate 50a so that the flow path 62d
Has one end closed by the end plate 50b. The channel 62b and the channel 62d are the grooves 4 of the cooling member 40.
4 communicates with the cell 20 via a cooling medium passage 48. Further, the flow path 62b is connected to the pump 70b and the cooling medium tank via the pipe 72b, and the flow path 6b.
2d is connected to the heat exchanger and the cooling medium tank via the pipe 72d. Therefore, the pipe 72b, the pump 70b, the flow passage 62b, the passage 48, the flow passage 62d, the pipe 72d, the heat exchanger and the cooling medium tank form a flow passage through which the cooling medium circulates.

In the fuel cell 10 thus constructed, the oxygen-containing gas and the hydrogen gas are supplied from the fuel gas supply device (not shown) to the oxygen gas passage 27b and the hydrogen gas passage 28b of the cell 20 to form the cathode. 25 and a
An electrochemical reaction represented by the following equation is performed at the node 26 to directly convert chemical energy into electrical energy.

Cathode reaction: 2H ⁺ + 2e ⁻ + (1/2) O ₂ → H ₂ O Anode reaction: H ₂ → 2H ⁺ + 2e ⁻

The reaction heat and cell 20 associated with this electrochemical reaction
Although the temperature of the fuel cell 10 rises due to heat generation due to the internal resistance of the fuel cell, heat generation due to the contact resistance between the cells 20, and the like, the fuel cell 10 is cooled by flowing a cooling medium as follows. As shown in FIG. 5A, the cooling medium pressurized by the pump 70a from the cooling medium tank is the pipe 72a.
Through the hole 52a of the end plate 50a through the flow path 62
The adjacent cell 20 is cooled by flowing into a and passing through a passage 38 formed by the cell 20 and the groove 34 of the cooling member 30 arranged in the stacked body 12. And the cooling medium is
After exchanging heat with the heat exchanger through the flow path 62c and the pipe 72c, it returns to the cooling medium tank. On the other hand, as shown in FIG. 5B, the cooling medium pressurized by the pump 70b from the cooling medium tank passes through the pipe 72b and the end plate 5
0b from the hole 52b into the flow path 62b, and the adjacent cell 20 is cooled by passing through the passage 48 formed by the cell 44 and the groove 44 of the cooling member 40 arranged in the stacked body 12. The cooling medium is the flow path 62d and the pipe 72d.
After exchanging heat through the heat exchanger through the heat exchanger, it returns to the cooling medium tank. Therefore, the flow channels 62a, 62b, and 62c of the cooling medium formed along the stacking direction of the stacked body 12 are formed.
The cooling medium flows in the reverse direction in the channel 62d to cool the fuel cell.

Next, the temperature difference between the cells 20 constituting the laminated body 12 will be described. FIG. 6 shows a cell 20 (cell 2 next to the end plate 50a located at the end of the stack 12).
It is a graph which illustrated the relationship between the temperature difference between 0) and another cell 20 and the distance between both cells. The cell numbers in the graph are numbers sequentially assigned to the plurality of cells 20 forming the stacked body 12 from the cells 20 located at the ends of the stacked body 12. Curve A in the graph is the temperature characteristic of the laminated body 12 when a predetermined flow rate of the cooling medium is passed through the laminated body 12 of the present embodiment by the above-described flowing method. The curve B is obtained when the same amount of cooling medium as the curve A is uniformly flowed from the cell number 1 side to the opposite end to the laminated body in which the cooling members constituting the laminated body are all configured as the cooling members 30. Is the temperature characteristic of the laminate. As is clear from the graph, in the laminated body showing the curve B, the temperature difference with respect to the cell having the cell number 1 becomes larger as the cell number becomes larger, whereas the laminated body 1 showing the curve A becomes larger.
In the case of 2, the cells of all cell numbers except the cell number 1 show almost the same temperature difference.

In the fuel cell 10 described above, the laminated body 1
The cooling medium channels 62a and 62 along the stacking direction of
b is provided, the flow directions of the cooling medium are opposite to each other, and the cooling members 30 and the cooling members 40 are alternately arranged.
This has an excellent effect that the temperature difference in the stacking direction between the cells 20 constituting the No. 2 can be reduced. As a result,
The number of cells with high power generation efficiency can be increased, and the power generation efficiency of the entire fuel cell can be increased. In addition, holes 22a provided at the four corners of the cell 20, the cooling members 30, 40,
Since the cooling medium flow path 62a and the like are formed by 32a and 42a, there is no new member for forming the cooling medium flow path, and the structure can be simplified and downsized. Further, when the cooling member 30 is stacked, even if the surfaces to be stacked are mistakenly rotated by 90 degrees and arranged, the cooling medium is supplied from the flow path 62b that supplies the cooling member to the cooling member 40. Although the cooling effect is lower than when the cooling medium is supplied from 62a, it functions as a cooling member.

In the embodiment, the holes 32a and the holes 32c located diagonally of the cooling member 30 are connected by the groove 34, but it is also preferable to connect two holes which are not located diagonally. An example thereof will be described below.

FIG. 7A is a perspective view illustrating the appearance of the cooling member 130. As shown, the cooling member 130
Have holes 132a, 132b, 13 at the four corners of the stacking surface.
2c and 132d are formed, and the groove 13 connects the holes 132a and the holes 132b which are not diagonally arranged in a folded manner.
4 are formed. FIG. 7B is a perspective view illustrating the appearance of the cooling member 140. The cooling member 140 replaces the top and bottom of the cooling member 130 to form the holes 1 of the cooling member 130.
32a and hole 132b are replaced by hole 142c of cooling member 140.
And a hole 142d. That is, the same members are merely arranged differently.

The cooling members 130 and 140 and the cell 2
When 0 and 0 are stacked, holes 22a, 132a and 142a are formed.
And the like form a flow path 162a for the cooling medium. Therefore, the cooling medium can flow in the following two ways. One cooling medium flows into the flow path 162a having the holes 132a and 142a as constituent elements, passes through the groove 134 of the cooling member 130, and has the flow path 162b having the holes 132b and 142b as constituent elements.
Drained from. The other cooling medium is the holes 132c,
It flows into the flow path 162c having the component 142c, passes through the groove 144 of the cooling member 140, and flows out from the flow path 162d having the holes 132d and 142d as the component.

By using the cooling members 130 and 140 described above, since the cooling member 130 and the cooling member 140 have the same shape, it is possible to reduce the number of types of members constituting the fuel cell and reduce the cost. Further, since the flow paths (flow paths 162a and 162c) into which the cooling medium flows are located at diagonal positions, it is possible to reduce the local temperature difference within the same cell. Although the cooling members 130 and 140 are the same member, even if they are erroneously arranged, they function as cooling members only with different flow paths for receiving the supply of the cooling medium.

In the embodiment, the cooling member 30 and the cooling member 40 are configured to receive the supply of the cooling medium from one of the two cooling medium supply channels (the channels 162a and 162b). It is also preferable to provide two cooling medium passages and receive the cooling medium from both of them. An example thereof is shown in FIG.

FIG. 8 is a perspective view illustrating the appearance of the cooling member 230. Like the cooling member 30, the cooling member 230 has holes 232a, 232b, 232 at the four corners of the stacking surface.
c and 232d are formed. Of these four holes, the groove 234 communicates with the hole 232a and the hole 232b in a zigzag manner, and the groove 236 communicates with the hole 232c and the hole 232d in a zigzag manner. Therefore, if the cooling member 230 is laminated with the cell 20 to form a laminated body and the cooling medium is flown into the flow passage 262a having the hole 232a as a constituent element and the flow passage 262c having the hole 232c as a constituent element, The cooling medium of the system flows into the same cooling member 230. That is, the hole 232a
From the hole 232b through the groove 234 and from the hole 232c through the groove 236 and the hole 2
The cooling medium flowing out from 32d flows into the same cooling member 230. By using the cooling member 230 having such two cooling medium passages, the temperature difference between the cells can be further reduced. In addition, it is possible to reduce the types of members that make up the fuel cell.

In the embodiment, the holes 32a and the holes 32c located diagonally of the cooling member 30 and the cooling member 40 are connected by the groove 34, but a structure in which a plurality of grooves are connected is also suitable. An example thereof will be described below.

FIG. 9A is a perspective view illustrating the appearance of the cooling member 330. As shown, the cooling member 330
Have holes 332a, 332b, 33 at the four corners of the stacking surface.
2c and 332d are formed. Further, a plurality of ribs 333 are formed in parallel on the surface where the cooling member 330 is laminated, and a plurality of parallel grooves 334 are formed between the plurality of ribs 333. The plurality of grooves 334 connect the holes 332a and 332b. The groove 334 forms a passage 338 for the cooling medium when the cooling member 330 is laminated with the cell 20. FIG. 9b is a perspective view illustrating the appearance of the cooling member 340. As shown, the cooling member 340 has the same shape as the mirror image body of the cooling medium 330. That is, in the cooling member 340,
Holes 332a-d formed in the cooling member 330, holes 342a-corresponding to the plurality of ribs 333 and the plurality of grooves 334, respectively.
d, a plurality of ribs 343 and a plurality of grooves 344 are formed, and a cooling medium passage 348 is formed by stacking the cooling member 340 and the cell 20.

The cooling members 330 and 340 and the cell 2
FIG. 10 shows a flow path of the cooling medium when 0 and 0 are stacked and the flow path 362a of the cooling medium is formed by the holes 22a, 332a and 342a and the like. FIG. 10A is an explanatory diagram schematically showing an example of the flow path of the cooling medium. As shown in the drawing, the end plate 50 a is provided at one end of the laminated body 12.
Are mounted so that their two holes are aligned with the flow passage 362a and the flow passage 362d, and the end plate 5 is attached to the other end.
0b indicates that the two holes are the flow channel 362b and the flow channel 362.
It is mounted so as to match with c. Therefore, the flow path of the cooling medium is the pipe 72a, the flow path 362a, and the passage 33.
8, a flow path formed by the flow path 362c and the pipe 72c (flow path indicated by a solid line in the figure), the pipe 72b, and the flow path 362.
b, a passage 348, a passage 362d, and a passage formed by the pipe 72d (a passage indicated by a broken line in the figure). As shown in the figure, the cooling medium is supplied to the pipes 72a and 72b by the pumps 70a and 70b.
Shed from. Therefore, the flow directions of the cooling medium flowing in the passages 338 and 348 are opposite to each other. That is, the cooling medium flowing in the passage 338 is the groove 33 of the cooling member 330.
4 from the top to the bottom in FIG. 9A, and the cooling medium flowing in the passage 348 flows through the groove 344 of the cooling member 340 in FIG.
(B) Flows from bottom to top in the middle.

The cooling members 330 and 340 described above
Is used, not only is the flow direction of the cooling medium flowing through the flow channels 362a and 362b reversed, but the flow direction of the cooling medium flowing through the cooling medium passages 338 and 348 is also reversed. The temperature difference within the 20 plane can be further reduced.

As shown in FIG. 10B, the cooling medium may flow in the same direction in the cooling medium passages 338 and 348. In this case, the laminated body 1
The end plate 50a is attached to one end of the end plate 2 so that its two holes are aligned with the flow channels 362a and 362b, and the other end is provided with the end plate 50b whose two holes are connected to the flow channels 362c and 362c. The cooling medium may be mounted so as to be aligned with the flow path 362d and flow from the pump 70a and the pump 70d to the pipe 72a and the pipe 72d.

Next, a fuel cell 410 which is a second embodiment of the present invention will be described. Fuel cell 41 of the second embodiment
0 has the same structure except the fuel cell 10 and the cell 20 of the first embodiment. Therefore, the same components as those of the fuel cell 10 of the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

The fuel cell 410 has four types of cells (cell 2
0a, 20b, 20c and 20d), one cell 20a of which is the cell 2 of the first embodiment shown in FIG.
The hole 22c and the hole 22d of 0 have the same structure. That is, the holes 22a and 22b are formed on the surface where the cells 20a are stacked.
2c and hole 22d are not formed. Cell 20b
Has the same structure as the cell 20 in which the holes 22a and 22d are not formed. The cell 20c has the same structure as the cell 20 in which the holes 22a and 22b are not formed, and the cell 20d is the hole 2 of the cell 20.
2b and the hole 22c are not formed. That is, the hole 22b and the hole 22 are provided in the cell 20b.
c, the cell 20c has holes 22c and 22d, and the cell 20d has holes 22a and 22d.

The cells 20a, 20b thus formed,
FIG. 11A shows an example of a fuel cell 410 configured by stacking 20c, 20d, cooling members 30, 40 and end plates 50a, 50b in the thickness direction. As shown in the figure, the fuel cell 410 includes a cell 20a, two cooling members 30, two cells 20b, a cooling member 40, two cells 20c, a cooling member 30, and a cell 20 from the end plate 50a.
Two d, a cooling member 40, and a cell 20a are laminated in this order. The end plate 50a is mounted so that the two holes formed on its stacking surface are aligned with the holes 22a and 22b of the cell 20a, and the end plate 50b has two holes of the cell 20c. It is mounted so as to be aligned with the holes 22c and 22d.

The flow path of the cooling medium in the fuel cell 410 thus formed is shown in FIG. 11 (b). As shown in the figure, in the fuel cell 410, the flow path 462a is formed in the cell 20a, the cell 20d, and the cooling members 30 and 40 along the stacking direction.
Is formed. Similarly, the fuel cell 410 includes a cell 20
a, the cell 20b, the cooling members 30 and 40, and the flow path 462.
b is formed, and the cells 20b, 20c, and the cooling member 30 are formed.
And 40 form a flow path 462c, and the cells 20c, 20d and the cooling members 30 and 40 form a flow path 462d.

The flow paths 462a and 462c are connected by a passage 38 formed by the cooling member 30 and the cell 20a and a passage 38 formed by the cooling member 30 and the cell 20c. Since the cells 20b and the cells 20c having no holes formed at positions matching the flow path 462a are arranged at both ends of the flow path 462a, the flow path 462a forms a passage formed by the cell 20a and the cooling member 30. It is formed as a single flow path having no branch from 38 to the passage 38 formed by the cell 20c and the cooling member 30. Similarly, since the cells 20a and the cells 20d having no holes formed therein are arranged at both ends of the flow path 462c at positions matching with the flow path 462c, the flow path 462c includes the cell 20a and the cooling member 30. A single passage having no branch is formed between the passage 38 formed and the passage 38 formed by the cell 20c and the cooling member 30.

Therefore, the flow paths 462a and 462c
And the passage 38 forms a folded flow path of the cooling medium in the stacked body 412. The flow passage 462a located at one end of the laminated body 412 is connected to the pump 70a and the cooling medium tank (not shown) by the pipe 72a, and the flow passage 462c located at the other end of the laminated body 412 is heat-exchanged by the pipe 72c. By connecting to a container (not shown) and a cooling medium tank, a flow path for circulating the cooling medium is formed.

Similarly, the pump 72d, the pipe 72d, the flow passage 462d, the passage 48, the flow passage 462b, the pipe 72b,
A heat exchanger (not shown) and a cooling medium tank form another circulation channel for the cooling medium.

In the fuel cell 410 thus constructed, the oxygen-containing gas and the hydrogen gas are supplied from the fuel gas supply device (not shown) to the oxygen gas passage 27b and the hydrogen gas passage 28b of the cell 20a or the like. An electrochemical reaction of the above formula takes place at the cathode 25 and the anode 26, converting chemical energy directly into electrical energy.

Further, the temperature rise of the fuel cell 410 due to the reaction heat and the like accompanying this electrochemical reaction is suppressed by the cooling medium flowing and being cooled as follows. Figure 11
As shown in (b), the cooling medium pressurized by the pump 70a from the cooling medium tank is the flow path 46 continuing to the pipe 72a.
The cells 20a and the like are cooled by passing through the folded flow path formed by 2a, the passage 38, and the flow path 462c, and after passing through the pipe 72c and undergoing heat exchange by the heat exchanger, return to the cooling medium tank. On the other hand, the cooling medium pressurized from the cooling medium tank by the pump 70d is the flow path 4 following the pipe 72d.
The cells 20c and the like are cooled by passing through a zigzag flow passage formed by 62d, the passage 48 and the flow passage 462b.
After exchanging heat with the heat exchanger through the pipe 72d,
Return to the cooling medium tank. Therefore, in the two channels of the cooling medium formed in the stacked body 412, the cooling media flow in directions opposite to each other along the stacking direction to cool the fuel cell 410.

In the fuel cell 410 described above, the cooling mediums are made to flow in the two channels of the cooling medium formed in the laminated body 412 so as to be opposite to each other in the laminating direction.
0 and the cooling member 40 are alternately arranged, the laminated body 412
It is possible to reduce the temperature difference in the stacking direction between the cells 20a and the like configuring the above. As a result, it is possible to increase the number of cells having a high power generation efficiency and increase the power generation efficiency of the entire fuel cell. In addition, the holes 2 provided in the cell 20a or the like
2a, 32a, 4 provided at the four corners of the cooling member 30, 40
Since the cooling medium flow path is formed by 2a or the like, there is no new member for forming the cooling medium flow path, and the structure can be simplified and downsized.

The embodiments of the present invention have been described above.
The present invention is not limited to such an embodiment. For example, a structure in which a passage for a cooling medium is formed inside a cooling member, or a plurality of convex portions provided on a surface on which the cooling member is laminated are provided as cells 20. A structure in which the space formed by is used as a passage for the cooling medium, a structure in which the cells 20 and the cooling member are integrally molded,
Needless to say, the present invention can be implemented in various modes without departing from the scope of the present invention.

[0052]

As described above, in the fuel cell of the present invention, at least two cooling medium passages are provided along the stacking direction of the laminated body, and the cooling medium flows in the two cooling medium passages in opposite directions. Therefore, the excellent effect that the temperature difference along the stacking direction of the stacked body can be reduced is achieved. As a result, the number of cells with high power generation efficiency can be increased, and the power generation efficiency of the fuel cell as a whole can be increased. Further, when a fuel cell is provided in which through holes are provided at substantially the same positions of the cells and the cooling member and the cell cooling members are stacked to form the cooling medium flow path, there is no cooling medium flow path outside the stacked body. Therefore, the fuel cell can be downsized.

In the fuel cell cooling member of the present invention, when laminated, at least four holes having a predetermined shape can be used as the flow path of the cooling medium. Since two of these holes are connected by the passage of the cooling medium, the channels of the cooling medium of two systems can be formed by the passages of the four cooling media.

In the fuel cell cooling member, the four holes are
A configuration in which the cooling member is provided at a position where it can be overlapped by replacement such as rotation and reversal, for example, by forming the stacking surface in a rectangular shape and providing four holes at predetermined positions from the four corners of the rectangular shape. By laminating the cooling members by rotating, reversing, etc., it is possible to form two sets of channels that connect two of the four channels of the cooling medium. As a result, since only one type of cooling member is required to form the two sets of flow paths, it is possible to reduce the number of members constituting the fuel cell.

[Brief description of drawings]

FIG. 1 is an external perspective view schematically illustrating a fuel cell 10 that is an embodiment of the present invention.

FIG. 2 is an external perspective view illustrating the outline of a cell 20.

FIG. 3 is a perspective view illustrating the appearance of a cooling member 30 and a cooling member 40.

FIG. 4 is an end plate 50a and an end plate 5.
It is a perspective view which illustrates the external appearance of 0b.

FIG. 5 is an explanatory diagram schematically illustrating the flow of a cooling medium.

FIG. 6 is a graph exemplifying the relationship between the temperature difference between the cell 20 located at the end of the laminated body 12 and another cell 20 and the distance between both cells.

7 is a perspective view illustrating the appearance of cooling members 130 and 140. FIG.

FIG. 8 is a perspective view illustrating the appearance of a cooling member 230.

FIG. 9 is a perspective view illustrating the appearance of cooling members 330 and 340.

FIG. 10 is an explanatory view schematically illustrating the flow of a cooling medium of the fuel cell 410.

FIG. 11 is an explanatory view illustrating a laminated structure of a fuel cell 410 according to a second embodiment.

[Explanation of symbols]

10,410 ... Fuel cell 12, 412 ... laminated body 20, 20a, 20b, 20c, 20d ... Cell 22a, 22b, 22c, 22d ... holes 23 ... Electrolyte membrane 25 ... Anode 26 ... Cathode 27, 28 ... Collection electrode 27a, 28a ... Ribs 27b ... Oxygen gas flow path 28b ... Hydrogen gas flow path 29 ... Separator 30, 40 ... Cooling member 32a, 32b, 32c, 32d ... Hole 34, 44 ... Groove 38, 48 ... Passage 42a, 42b, 42c, 42d ... Hole 50a, 50b ... End plate 52a, 52b, 52c, 52d ... Hole 62a, 62b, 62c, 62d ... Flow path 70a, 70b ... Pump 72a, 72b, 72c, 72d ... Pipe 130, 140 ... Cooling member 132a, 132b, 132c, 132d ... hole 142a, 142b, 142c, 142d ... Holes 134, 144 ... Groove 162a, 162b, 162c, 162d ... Flow path 230 ... Cooling member 232a, 232b, 232c, 232d ... holes 234, 236 ... Groove 262a, 262c ... Channel 330, 340 ... Cooling member 332a, 332b, 332c, 332d ... Hole 333, 343 ... Ribs 334, 344 ... Groove 338, 348 ... Passage 342a, 342b, 342c, 342d ... holes 362a, 362b, 362c, 362d ... Channel 462a, 462b, 462c, 462d ... Channel

Claims (7)

(57) [Claims] 1. A fuel cell comprising a stack of a plurality of cells, each of which is a unit cell composed of an electrolyte and two electrodes, and a cooling member arranged between the cells to form a passage for a cooling medium. the passage provided along said at least two cooling medium flow passage for supplying the cooling medium to the stacking direction of its <br/> inside the laminate in member, the two cooling medium provided along the stacking direction you in the flow path
The fuel cell is characterized in that the flow direction of the cooling medium is reversed. Wherein a through hole is formed in a substantially same position of the cell and before Symbol cooling member, when stacking the cell and the cooling member, wherein the through hole is formed by forming the cooling medium channel The fuel cell according to item 1. 3. The cooling medium flow paths are each cooling medium flow path.
And the passage inside the cooling member form a single flow path from the inlet to the outlet of the cooling medium in the laminate .
The fuel cell according to claim 1 , wherein the fuel cell communicates with the passage . 4. The cooling member, wherein the laminated body receives the cooling medium supplied from one of the two cooling medium flow paths, and the cooling medium supplied from the other of the two cooling medium flow paths. The fuel cell according to any one of claims 1 to 3, wherein the cooling members for receiving the heat are alternately arranged. 5. The fuel according to any one of claims 1 to 4.
In the battery, the cooling member is provided with at least four holes each having a predetermined shape and forming a flow path of the cooling medium along the stacking direction when stacked, and at least two of the holes are provided in the cooling medium. fuel cells, characterized in that communicating with said passage. Wherein said four holes, rotating or <br/> fuel cell according to claim 5, wherein provided in a position that can not be superimposed by the replacement of the inversion of the cooling member. Wherein said cooling member, the surface of the laminate is formed in a rectangular shape, the four holes of the four corners of the rectangular shape
Fuel cells according to claim 5, wherein provided in each.