JP3519987B2 - Fuel cell stack - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to stacking a plurality of unit fuel battery cells each having an electrolyte sandwiched between an anode electrode and a cathode electrode via a separator, and end plates at both ends in the stacking direction. The present invention relates to a fuel cell stack that is arranged and fixed integrally.

[0002]

2. Description of the Related Art For example, a polymer electrolyte fuel cell is a unit fuel composed of an electrolyte composed of a polymer ion exchange membrane (cation exchange membrane), and an anode electrode and a cathode electrode are provided on opposite sides of the electrolyte. It is configured by sandwiching the battery cell with a separator. Usually, it is used as a fuel cell stack by stacking a predetermined number of unit fuel cells and separators.

In this type of fuel cell, the fuel gas supplied to the anode electrode, for example, hydrogen gas, is hydrogen-ionized on the catalyst electrode and moves to the cathode electrode side through the appropriately humidified electrolyte. To do. Electrons generated during that time are taken out to an external circuit and used as direct current electrical energy. Since an oxidant gas such as oxygen gas or air is supplied to the cathode side electrode, hydrogen ions, electrons and oxygen gas react with each other at the cathode side electrode to generate water.

Usually, the fuel gas and the oxidant gas supplied to the anode electrode and the cathode electrode are introduced into a gas passage provided in the fuel cell stack as a fluid containing steam for humidifying the electrolyte. . However,
The temperature of the fuel cell stack body may be lower than the temperature of the fluid containing water vapor when the fuel cell stack is started up or due to changes in operating conditions.

At this time, the temperature of the fuel gas (and / or oxidant gas) is lowered near the gas supply port of the fuel cell stack, and dew condensation is likely to occur in the fuel cell stack. Due to this, it has been pointed out that the fuel gas (and / or the oxidant gas) cannot be sufficiently supplied to the electrode reaction surface of each unit fuel cell, and the power generation performance deteriorates. For this reason, a so-called purging operation is performed in which the gas flow rate is increased to push out the dew condensation, but there is a problem in that the consumption amount of the fuel gas particularly increases.

Therefore, a structure has been proposed in which water vapor in a reaction gas containing a fuel gas and an oxidant gas is liquefied and discharged, and the technical idea thereof is disclosed in, for example, Japanese Patent Laid-Open No. 9-22717. . In this conventional technique, a water droplet removing device is provided inside the pressure plate that constitutes both ends of the fuel cell stack or outside the pressure plate. The water droplet removing device has a water storage chamber, and a gas inlet and a gas outlet communicate with the water storage chamber. Therefore, when the fuel gas (and the oxidant gas) is introduced from the gas inlet into the water storage chamber, the water vapor contained in the gas becomes water droplets and is stored in the water storage chamber, and the fuel droplets are removed. Gas (and oxidant gas) will be introduced into the fuel cell stack from the gas outlet.

[0007]

However, in the above-mentioned prior art, since the water droplet removing device is provided inside the pressure plate that constitutes the outer wall portion of the fuel cell stack or outside the pressure plate, the water droplets are removed. A temperature difference is likely to occur between the gas temperature passing through the removing device and the internal temperature of the fuel cell stack. As a result, especially at the time of starting the fuel cell stack, the temperature of the gas passing through the water droplet removing device becomes higher than the internal temperature of the fuel cell stack, and dew condensation occurs in the fuel cell stack. Has been pointed out.

The present invention solves this type of problem by effectively preventing the occurrence of dew condensation and ensuring that a fuel gas and / or an oxidant gas containing appropriate water vapor is supplied to each unit fuel cell unit. It is an object of the present invention to provide a fuel cell stack that can be supplied and that has a simple structure and is suitable for downsizing.

[0009]

In the fuel cell stack according to claim 1 of the present invention, a dehumidifying mechanism is interposed between the end plates, and the dehumidifying mechanism has a first unit fuel cell from the fluid supply port. A chamber is provided in the middle of the flow path leading to the cell. Therefore, when the fluid containing at least one of the fuel gas and the oxidant gas is introduced into the chamber from the fluid supply port, the water content of the fluid is changed according to the temperature of the unit fuel cell unit adjacent to the chamber. The excess water is adjusted (heat exchange) and the excess water is smoothly discharged through the drainage means, while the fluid containing an appropriate amount of water is supplied to the unit fuel cells.

Therefore, no special temperature control is required and the amount of water in the fluid can be adjusted by using the heat of the unit fuel cell unit itself, and the occurrence of dew condensation is prevented as much as possible with a simple structure. It becomes possible to do. Moreover, since the dehumidifying mechanism is interposed between the end plates, the overall size of the fuel cell stack can be easily reduced.

Further, in the fuel cell stack according to the second aspect of the present invention, a plurality of flow channel grooves forming the chamber are formed in the surface of the dehumidifying plate forming the dehumidifying mechanism. Therefore, a sufficient flow path length can be ensured in the surface of the dehumidifying plate, heat exchange between the fluid supplied in the surface of the dehumidifying plate and the unit fuel cell is reliably performed, and the fluid It becomes possible to adjust the water content appropriately.

Furthermore, in the fuel cell stack according to a third aspect, the dehumidifying mechanism includes first and second dehumidifying plates, and a plurality of first flow path grooves provided in the surface of the first dehumidifying plate. The fluid that has circulated along the first dehumidification plate is supplied from the holes provided in the second dehumidification plate to the plurality of second flow path grooves formed in the surface of the second dehumidification plate,
It flows in the direction opposite to the flow channel. As a result, the fluid whose moisture content has been adjusted by flowing from the first dehumidifying plate through the first and second passage grooves of the second dehumidifying plate is returned to the predetermined gas passage and supplied to the unit fuel cell unit. . As a result, the number of gas flow paths can be reduced and the structure can be simplified.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic structural explanatory view of a fuel cell stack 10 according to a first embodiment of the present invention.
The fuel cell stack 10 includes a unit fuel cell 12 as a first unit.
A plurality of layers are stacked via the second separators 14 and 16 and are integrally fixed to both ends in the stacking direction via the first and second end plates 18a and 18b.

First and second end plates 18a, 1
The inner surface of 8b has a first insulating plate 2 and a second insulating plate 2b, respectively.
0a, 20b through the first and second electrode plates 22
A and 22b are laminated, and a dehumidifying mechanism 24 is laminated on the first electrode plate 22a. The dehumidifying mechanism 24 is connected to the first separator 14 via a seal plate 26.
Are stacked. The fuel cell stack 10 has a rectangular parallelepiped shape as a whole, and for example, the short side direction (arrow A direction) is directed in the gravity direction and the long side direction (arrow B direction).
Direction) is oriented in the horizontal direction.

As shown in FIGS. 2 and 3, the unit fuel cell unit 12 includes a solid polymer electrolyte membrane 28, and an anode electrode 30 and a cathode electrode 32 which are arranged so as to sandwich the electrolyte membrane 28. Further, the anode side electrode 30 and the cathode side electrode 32 are provided with first and second gas diffusion layers 34 and 36 made of, for example, porous carbon paper which is a porous layer.

First and second gaskets 38 and 40 are provided on both sides of the unit fuel cell unit 12, and the first gasket 38 has a large size for accommodating the anode electrode 30 and the first gas diffusion layer 34. While having an opening 42, the second gasket 40 has a large opening 44 for accommodating the cathode side electrode 32 and the second gas diffusion layer 36. Unit fuel cell 12 and first and second
The gaskets 38 and 40 are sandwiched between the first and second separators 14 and 16.

As shown in FIGS. 2 and 4, in the first separator 14, the surface 14a facing the anode 30 and the opposite surface 14b are set in a rectangular shape, for example, the long side 45a is horizontal. In addition to being oriented in the direction, the short side 45b is oriented in the direction of gravity.

A fuel gas inlet 46a for passing a fuel gas such as hydrogen gas, and an oxidant gas such as oxygen gas or air are passed through the upper ends of both ends on the short side 45b side of the first separator 14. An oxidant gas inlet 48a is provided. A cooling medium inlet 50a for passing a cooling medium such as pure water, ethylene glycol, oil, or the like is provided at substantially the center of both end edges on the short side 45b side of the first separator 14.
And a cooling medium outlet 50b is provided, and a fuel gas outlet 46b and an oxidant gas outlet 48b are provided at the lower end portions of both ends of the first separator 14 on the short side 45b side. 48a is provided at a diagonal position.

The surface 14a of the first separator 14 is formed with a fuel gas passage 52 which communicates with the fuel gas inlet 46a and the fuel gas outlet 46b. The fuel gas channel 52 includes a plurality of, for example, six first gas channel grooves 54,
One end side of the first gas flow channel 54 is a fuel gas inlet 46a.
Communicate with. The first gas flow path groove 54 is formed by the fuel gas inlet 46.
It moves in the direction of gravity while meandering along the horizontal direction (direction of arrow B) from the side a, merges with the first and second collecting portions 56, 58, and then communicates with the four second gas flow channels 60. The second gas passage groove 60 extends in the horizontal direction and communicates with the fuel gas outlet 46b.

As shown in FIG. 2, the surface 1 of the separator 14 is
The surface 14b on the opposite side of 4a communicates with the cooling medium inlet 50a and the cooling medium outlet 50b, and the cooling medium flow paths 62a to 62a.
62d is provided. The cooling medium channels 62a to 62d are
One main flow channel 64a, 64b, which communicates with the cooling medium inlet 50a and the cooling medium outlet 50b, respectively, and a plurality of, for example, four, provided between the main flow channels 64a, 64b.
And a branch channel groove 66 of a book.

The second separator 16 is formed in a rectangular shape, and the fuel gas inlet 68a and the oxidant gas inlet 7 are provided on the upper side of both ends on the short side of the second separator 16.
0a is formed through, and a cooling medium inlet 72a and a cooling medium outlet 72b are formed through substantially both ends of the central portion. The fuel gas outlet 68b and the oxidant gas outlet 70b are provided at the lower end portions of both ends of the second separator 16 on the short side, and the fuel gas inlet 68a and the oxidant gas inlet 7
It is formed so as to be diagonal to 0a.

The cathode side electrode 32 of the second separator 16
An oxidant gas flow channel 74 that connects the oxidant gas inlet 70a and the oxidant gas outlet 70b is formed on the surface 16a that faces the. In the oxidant gas flow channel 74, the fuel gas flow channel 52
Similarly, the first gas passage groove 76 and the second gas passage groove 78 are formed to communicate with each other through the first and second collecting portions 80 and 82.

As shown in FIG. 5, the first end plate 1
8a is provided with a fuel gas supply port 84a and an oxidant gas supply port 86a on the upper side, a cooling medium supply port 88a and a cooling medium discharge port 88b on the center side thereof, and a fuel on the lower side thereof. Gas outlet 84b and oxidant gas outlet 86
b is provided, and a drain port 90 is provided between the fuel gas outlet 84b and the oxidant gas outlet 86b.

As shown in FIGS. 1 and 6, the dehumidifying mechanism 2
4 is in the middle of the gas flow path from the fuel gas supply port 84a to which at least one of the fuel gas and the oxidant gas (fuel gas in the first embodiment) is supplied to the first unit fuel cell unit 12 A chamber 92 provided and a drainage means 94 for draining water generated in the chamber 92 from the drainage port 90 to the outside are provided.

The dehumidifying mechanism 24 is provided with first and second dehumidifying plates 96, 98 which are laminated on each other. The surface 96a of the first and second dehumidifying plates 96, 98 facing the unit fuel cell 12 side, 98a includes a chamber 92
Of the plurality of flow channels 100a, 100b and 10
2a and 102b are formed. As shown in FIGS. 6 and 7, the fuel gas inlet 104a and the oxidant gas inlet 106a are on the upper end sides of the first dehumidifying plate 96 in the longitudinal direction, and the cooling medium inlet 108a and the cooling medium outlet 1 are on the upper side.
08b is provided on the center side, and the fuel gas outlet 104b and the oxidant gas outlet 106b are provided on the lower side, respectively.

The flow path groove 100a provided in the first dehumidifying plate 96 communicates with the fuel gas inlet 104a in the surface 96a and is inclined downward toward the center of the surface, while the flow path groove 100b is From this center side, the oxidant gas inlet 106
The oxidant gas inlet 10 is inclined upward toward the side a.
It communicates with the groove 110 in the vicinity of 6a. Channel groove 100a,
Through holes 112 for drainage are provided at both lower end confluence portions of the inclined wall surfaces 111a and 111b constituting 100b (see FIG. 7).

As shown in FIG. 8, the second dehumidifying plate 98
Has the same configuration as that of the first dehumidifying plate 96, and the same components are designated by the same reference numerals and detailed description thereof will be omitted. The second dehumidifying plate 98 has grooves 1 corresponding to the fuel gas inlet 104a of the first dehumidifying plate 96.
05 is formed and the first dehumidifying plate 96 is formed.
Through hole 114 communicating with the gas groove portion 110 is formed, and the through hole 114 communicates with the flow channel groove 102a. The flow passage groove 102a is inclined downward from the through hole 114 toward the center of the surface 98a, and the flow passage groove 102b is inclined vertically upward from the center toward the fuel gas inlet 104a side. It communicates with the gas inlet 104a.

Drainage through-holes 116 are provided at both lower end merging portions of the inclined wall surfaces 115a, 115b forming the flow path grooves 102a, 102b.
The dehumidifying plate 96 communicates with the drainage port 90 through the drainage through hole 112 (see FIG. 8). This drainage through hole 11
The drainage means 94 is configured by the reference numerals 2 and 116.

The operation of the fuel cell stack 10 according to the first embodiment having such a configuration will be described below.

A fuel gas (for example, a gas containing hydrogen obtained by reforming a hydrocarbon) is supplied into the fuel cell stack 10, and air (or oxygen gas) is supplied as an oxidant gas. Is introduced into the fuel gas passage 52 from the fuel gas inlet 46a of the first separator 14. As shown in FIG. 4, the fuel gas supplied to the fuel gas flow path 52 is introduced into the first gas flow path groove 54 and extends along the long side direction (arrow B direction) of the surface 14 a of the first separator 14. It moves in the direction of gravity while meandering.

At that time, the hydrogen gas in the fuel gas is supplied to the anode 30 of the unit fuel cell 12 through the first gas diffusion layer 34. Then, the unused fuel gas is once introduced into the first and second collecting portions 56 and 58 through the first gas passage groove 54, and then is distributed to the second gas passage groove 60 to be in the arrow B direction. While moving to the anode side electrode 3
0 while the remaining fuel gas is supplied to the fuel gas outlet 4
It is discharged from 6b.

On the other hand, in the second separator 16, as shown in FIG. 2, from the oxidizing gas inlet 70a to the oxidizing gas passage 7
The air supplied to 4 moves in the direction of gravity while meandering in the horizontal direction along the surface 16a. At that time, the oxygen gas in the air is supplied from the second gas diffusion layer 36 to the cathode side electrode 32 in the same manner as the fuel gas supplied to the fuel gas flow path 52, while the unused air is oxidant gas outlet. It is discharged from 70b.

A cooling medium is supplied to the fuel cell stack 10, and this cooling medium is supplied to the cooling medium inlets 50a and 72a of the first and second separators 14 and 16, respectively. As shown in FIG. 2, the cooling medium supplied to the cooling medium inlet 50a of the first separator 14 is introduced into the main channel groove 64a that constitutes the cooling medium channels 62a to 62d, and along the main channel groove 64a. Flows upwards, horizontally and downwards. The cooling medium is introduced into the plurality of branch flow channel grooves 66 branched from the respective main flow channel grooves 64a, flows in the horizontal direction along the branch flow channel groove 66 over substantially the entire surface 14b, and then is branched. It is discharged from the cooling medium outlet 50b through the main flow channel 64b where the flow channel 66 joins.

By the way, when the fuel cell stack 10 is started or the operating state changes, the fuel cell stack 1
There is a case where a temperature difference occurs between the temperature of 0 itself and the temperature of the fuel gas supplied to the fuel cell stack 10, and this fuel gas becomes higher in temperature than the fuel cell stack 10.

At that time, in the first embodiment, the dehumidifying mechanism 24 is built in the fuel cell stack 10, and the fuel gas introduced into the fuel gas supply port 84a formed in the first end plate 18a is It is supplied to the first unit fuel cell unit 12 through the chamber 92 that constitutes the dehumidification mechanism 24.

Here, as shown in FIG. 1, the first and second dehumidifying plates 96 and 98 are located inside the first and second end plates 18a and 18b, more specifically, the first electrode plate 22a. It is interposed between the first separator 14 and the first separator 14. The first and second dehumidifying plates 96, 98
Is formed by surface-treating, for example, a carbon plate or a metal plate such as aluminum so that an electric current can flow between the first electrode plate 22 a and the first separator 14, and the fuel cell stack 10 as a whole has the same structure. Maintained at temperature. The first electrode plate 22
a and the first separator 14 are adjacent to each other, and the first and second
If the dehumidifying plates 96 and 98 are adjacent to the first end plate 18a, it is not necessary to consider the conductivity of the first and second dehumidifying plates 96 and 98.

Then, the fuel gas is supplied from the fuel gas supply port 84a of the first end plate 18a through the fuel gas inlet 104a of the first dehumidifying plate 96 constituting the dehumidifying mechanism 24 into a plurality of flow passage grooves forming the chamber 92. 100a, 1
00b. As shown in FIG. 6, the flow channel 100
The fuel gas supplied to the a and 100b is cooled when flowing in the surface 96a, excess water is removed, and the plurality of flow path grooves are passed from the gas groove portion 110 through the through hole 114 of the second dehumidifying plate 98. It is introduced into 102a and 102b. The water condensed in the flow channels 100a and 100b is drained by the drainage means 94.
Is discharged to the outside of the fuel cell stack 10 through the drainage through-hole 112 that constitutes the At that time, the surface area of the first dehumidifying plate 96 is increased by the plurality of flow path grooves 100a, 100b, and the fuel gas and the first dehumidifying plate 96 are efficiently heat-exchanged.

The fuel gas supplied to the flow channel 102a is
A surface 98 is formed along the flow path groove 102b from the flow path groove 102a.
Heat is exchanged with the second dehumidifying plate 98 while flowing in a. As a result, the fuel gas is cooled to a temperature similar to that of the second dehumidifying plate 98, and excess water is removed by the drainage through holes 116.
Is discharged to the drainage port 90 through the drainage through-hole 112 from the unit fuel cell unit 12 while the fuel gas is adjusted to the same temperature as the unit fuel cell unit 12 and contains water vapor having an appropriate dew point. 12 are supplied.

Therefore, it is possible to reliably prevent the fuel gas having a temperature higher than that of the fuel cell stack 10 from being directly supplied to the unit fuel cell unit 12 to cause dew condensation in the fuel gas passage 52 of the first separator 14, for example. However, it is possible to effectively improve the power generation capacity of the entire fuel cell stack 10. Moreover, the dehumidifying mechanism 24 is the first
Further, since the fuel cell stack 10 is incorporated between the second end plates 18a and 18b, the fuel cell stack 10 as a whole can be easily downsized. Further, since the fuel cell stack 10 itself constitutes the heat exchange means for cooling the fuel gas,
There is an advantage that no special temperature control is required.

In the first embodiment, the dehumidifying mechanism 24 for removing the excess water contained in the fuel gas is used for explanation, but the dehumidifying mechanism (not shown) having the same structure is used for the oxidation. Excessive water contained in the agent gas may be removed. Further, in order to dehumidify the fuel gas and the oxidant gas, each dehumidifying mechanism may be incorporated in the fuel cell stack 10.

FIG. 9 is an exploded perspective view showing a dehumidifying mechanism 142 constituting the fuel cell stack 140 according to the second embodiment of the present invention. The same components as those of the fuel cell stack 10 according to the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

The dehumidifying mechanism 142 includes first and second dehumidifying plates 144 and 146, and the surfaces 144a and 146a of the first and second dehumidifying plates 144 and 146, respectively.
A plurality of flow channel grooves 148a, 148b and 150a, 150b are formed in the fuel gas inlet 104a and the groove portion 105 and are inclined downward toward the fuel gas outlet 104b. Channel grooves 148a, 148b and 15
0a and 150b are once continuous in the vertical direction at substantially the center of the respective surfaces 144a and 146a.
The drainage through holes 112 and 116 are communicated with the lower side of the a and 146a.

In the second embodiment thus constructed, when the fuel gas having a temperature higher than that of the fuel cell stack 140 is introduced into the dehumidifying mechanism 142, the fuel gas first
The plurality of flow channel grooves 148a, 14 of the first dehumidifying plate 144
8b is cooled when flowing along, and excess water is condensed as dew to be discharged from the drainage through hole 112.
Multiple channel grooves 150a, 150b of the dehumidifying plate 146
Is supplied to. The fuel gas supplied to the flow passage grooves 150a and 150b is inclined in the vertically upward direction.
Water is removed while moving to the groove portion 105 side along a and 150b, and then supplied to the unit fuel cell unit 12.

As a result, in the second embodiment, when the fuel gas passes through the chambers 92 of the first and second dehumidifying plates 144 and 146, it is heat-exchanged and cooled to a predetermined temperature, and excess moisture is contained. Are removed. Therefore, the fuel gas containing an appropriate amount of water vapor is supplied to the unit fuel cell unit 12, and the same effect as that of the first embodiment can be obtained.

FIG. 10 is an exploded perspective view showing a dehumidifying mechanism 162 constituting the fuel cell stack 160 according to the third embodiment of the present invention. The same components as those of the fuel cell stack 10 according to the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

The dehumidifying mechanism 162 is provided with first and second dehumidifying plates 164 and 166, and the respective surfaces 16
A plurality of flow channel grooves 168, 170 are formed in 4a, 166a in the vertical direction. In the dehumidifying mechanism 162, inclined portions 174a and 174b for surely supplying condensed water to the drainage through holes 172 are provided on the lower side of the flow channel grooves 168 and 170, respectively.

In the third embodiment constructed as described above, the pressure loss of the fuel gas is larger than that in the first and second embodiments, but the dehumidification efficiency is high. In addition, the fuel gas is used as the first and second dehumidifying plates 164, 1
Excess water is removed as it passes through the channel grooves 168 and 170 of 66, and this water is also absorbed by the inclined surfaces 174a and 174.
such as being surely discharged to the drainage through hole 172 along b.
The same effect as that of the first and second embodiments can be obtained.

In the first to third embodiments of the present invention, the first and second dehumidifying plates 9698,
144, 146, 164 and 166,
Each may be composed of a single dehumidifying plate. Also,
Individual drainage through holes 122, 116 as the drainage means 94.
Although 172 and 172 are provided, the moisture may be directly discharged to the fuel gas outlet 104b.

[0049]

In the fuel cell stack according to the present invention, the dehumidifying mechanism is interposed between the end plates, and the fuel gas and / or the oxidant gas is supplied to the chamber provided in the dehumidifying mechanism, so that the unit fuel The water content is adjusted according to the temperature of the battery cell, and the fuel gas and / or the oxidant gas containing the desired water vapor is supplied to each unit fuel cell. This reliably prevents dew condensation from occurring in the power generation unit, and simplifies the configuration.

[Brief description of drawings]

FIG. 1 is a schematic configuration explanatory diagram of a fuel cell stack according to a first embodiment of the present invention.

FIG. 2 is an exploded perspective explanatory view of a unit fuel cell unit and first and second separators that form the fuel cell stack.

FIG. 3 shows a unit fuel cell shown in FIG. 2 and first and second fuel cells.
It is a schematic longitudinal cross-sectional explanatory drawing of a separator.

FIG. 4 is a front explanatory view of one surface of the first separator.

FIG. 5 is a perspective explanatory view of a first end plate that constitutes the fuel cell stack.

FIG. 6 is an exploded perspective view illustrating a dehumidifying mechanism that constitutes the fuel cell stack.

FIG. 7 is a front explanatory view of a first dehumidifying plate constituting the dehumidifying mechanism.

FIG. 8 is an explanatory front view of a second dehumidifying plate that constitutes the dehumidifying mechanism.

FIG. 9 is an exploded perspective view illustrating a dehumidifying mechanism that constitutes a fuel cell stack according to a second embodiment of the present invention.

FIG. 10 is an exploded perspective explanatory view of a dehumidifying mechanism forming a fuel cell stack according to a third embodiment of the present invention.

[Explanation of symbols]

10, 140, 160 ... Fuel cell stack 12 ... Unit fuel cell 14, 16 ... Separator 18a, 18b ... End plate 22a, 22b ...
Electrode plates 24, 142, 162 ... Dehumidifying mechanism 28 ... Electrolyte membrane 30 ... Anode side electrode 32 ... Cathode side electrode 52 ... Fuel gas flow channels 62a-62d ...
Cooling medium flow path 74 ... Oxidant gas flow path 84a ... Fuel gas supply port 84b ... Fuel gas discharge port 86a ... Oxidant gas supply port 86b ... Oxidant gas discharge port 88a ... Cooling medium supply port 88b ... Cooling medium discharge port 90 ... Drainage port 92 ... Chamber 94 ... Draining means 96, 98, 144, 146, 164, 166 ... Dehumidifying plates 100a, 100b, 102a, 102b, 148a,
148b, 150a, 150b, 168, 170 ... Flow path groove 104a ... Fuel gas inlet 104b ... Fuel gas outlet 105, 110 ... Groove portion 106a ... Oxidizing gas inlet 106b ... Oxidizing gas outlet 108a ... Cooling medium inlet 108b ... Cooling medium outlet 112, 114, 116, 172 ... Through holes

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Claims (3)

(57) [Claims] 1. A unit fuel cell comprising an electrolyte sandwiched between an electrode on the anode side and an electrode on the cathode side is laminated with a separator interposed therebetween, and end plates are arranged at both ends in the stacking direction to be integrated. A fixed fuel cell stack, wherein a space between the end plates is separate from the end plates.
And a fluid containing at least one of the fuel gas supplied to the anode electrode and the oxidant gas supplied to the cathode electrode is supplied to the dehumidification mechanism. and the first of the provided unit fuel reaches the cell on developing gas passage, chamber for adjusting according to the temperature of the unit fuel cells the water content of the fluid from the fluid supply port being, said chamber A fuel cell stack comprising: drainage means for discharging water generated in the chamber from the chamber. 2. The fuel cell stack according to claim 1, wherein the dehumidifying mechanism includes a dehumidifying plate, and a plurality of flow channel grooves forming the chamber are formed in a surface of the dehumidifying plate. And a fuel cell stack. 3. The fuel cell stack according to claim 1, wherein the dehumidifying mechanism includes first and second dehumidifying plates that are stacked on each other, and the chamber is provided in a plane of the first and second dehumidifying plates. A plurality of constituent first and second flow channel grooves are formed, and the second dehumidifying plate is configured to supply the fluid supplied to the first flow channel groove to the second flow channel groove. A fuel cell stack having a hole for flowing in a direction opposite to the first flow path groove.