JPH11111311A - Solid polymer type fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To humidify and cool a solid polymer electrolyte film in a solid polymer type fuel cell, and to miniaturize the solid polymer type fuel cell. SOLUTION: This fuel cell is constituted by accumulating a plurality of unit cells 24, in each of which a fuel gas is circulated in a fuel chamber 20 and an oxidizing agent gas is circulated in oxidizing agent chamber 22 are respectively installed at an anode side and a cathode side of a cell 18 for every cell 18 having an anode on one side of a solid polymer electrolyte film and a cathode on the other side of it, and the solid polymer electrolyte film is humidified by using cooling water which is circulated to cool the cells 18. In this case, a cell unit 26 comprises a plurality of the accumulated unit cells 18, a humidifying chamber 28 to which fuel gas and the recycle cooling water are supplied for humidifying the fuel gas is disposed between the adjacent cell units 26 and 26, the humidifying chamber 28 and the cell units 26 are connected through a fuel passage 40, the fuel gas humidified in the humidifying chamber 28 is supplied from the humidifying chamber 28 to each fuel chambers 20 through the fuel passage 40.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polymer electrolyte fuel cell, and more particularly, to a polymer electrolyte fuel cell capable of efficiently wetting a polymer electrolyte membrane. is there.

[0002]

2. Description of the Related Art As shown in FIG. 9, a polymer electrolyte fuel cell (10) has an anode (14) on one surface of a polymer electrolyte membrane (12) which is ion-conductive and transfers protons. Constituting a cell (18) having a cathode (16) formed on the other surface,
The fuel cell (20) is provided on the anode side of the cell (18), and the unit cell (24) is provided with the oxidant chamber (22) on the cathode side. The unit cells (24) are usually stacked to form a polymer electrolyte fuel cell (10). A fuel gas containing hydrogen gas is supplied to the fuel chamber of the unit cell, and an oxidizing gas containing oxygen gas such as air is supplied to the oxidizing chamber. At the anode, protons and electrons are generated by the reaction of hydrogen gas in the fuel gas with H ₂ → 2H ⁺ + 2e ⁻ . Protons pass through the solid polymer electrolyte membrane to the cathode, and electrons flow to an external circuit (not shown). At the cathode, oxygen in the oxidant gas, protons that have moved through the solid electrolyte membrane, and electrons that have flowed in through the external circuit are １ ／ O ₂ + 2H ⁺
The reaction of + 2e ⁻ → H ₂ O generates water and generates an electromotive force.

The optimum operating temperature of a polymer electrolyte fuel cell is about 80 ° C. to 100 ° C. However, since the above reaction is a reaction involving heat generation, cooling water is generally introduced into the polymer electrolyte fuel cell. Is done.

On the other hand, the solid polymer electrolyte membrane is generally formed from an electrolyte material such as perfluorocarbon sulfonic acid and styrene-divinylbenzene sulfonic acid. The ionic conductivity of this kind of electrolyte material greatly depends on the moisture concentration in the atmosphere, and when the solid polymer electrolyte membrane is in a dry state, the resistance is large, which is not suitable for operating as a battery.

Accordingly, a part of the cooling water used for cooling the polymer electrolyte fuel cell is used for humidifying the fuel gas, and the humidified gas wets the polymer electrolyte membrane.
A method for improving conductivity has been adopted.

As a method of humidifying a gas, a method is known in which a humidifying device is provided outside a fuel cell, the gas is humidified in advance, and then the gas is supplied to each unit cell. , Reduced energy efficiency,
There is a problem that the polymer electrolyte fuel cell becomes complicated and large.

For this reason, in Japanese Patent Application Laid-Open No. Hei 7-240221, as shown in FIG. 10, each fuel chamber (20) and oxidant chamber (2
At the back of 2), a water channel (30) through which cooling water flows is provided, and the fuel chamber
(20) and the water channel (30), and the oxidizing agent chamber (22) and the water channel (30) are partitioned by a membrane (32) that allows water to permeate but does not allow gas to pass therethrough.
2) through the water channel (30) to the fuel chamber (20) and the oxidant chamber (2
A polymer electrolyte fuel cell (10) is disclosed in which the fuel gas in the fuel chamber and the oxidant gas in the oxidant chamber are humidified by the water reaching 2) to wet the solid polymer electrolyte membrane. .

[0008]

However, in the polymer electrolyte fuel cell having the above structure, the water permeated through the membrane is directly supplied to the fuel chamber and the oxidant chamber to humidify the gas. It is necessary to provide a water channel for each fuel chamber and each oxidant chamber, and there is a problem that miniaturization cannot be sufficiently achieved.

According to the present invention, wetting and cooling of a polymer electrolyte membrane can be performed inside a polymer electrolyte fuel cell,
It is another object of the present invention to reduce the size of the polymer electrolyte fuel cell.

[0010]

In order to solve the above-mentioned problems, the present invention provides a cell having an anode (14) on one surface of a solid polymer electrolyte membrane (12) and a cathode (16) on the other surface. (18)
In contrast, a fuel chamber (20) through which fuel gas flows to the anode side,
A solid polymer is formed by stacking a plurality of unit cells (24) having an oxidant chamber (22) through which an oxidant gas flows on the cathode side, and using cooling water circulated to cool the cells (18). In a polymer electrolyte fuel cell that humidifies the electrolyte membrane (12), a cell unit (26) is formed by a plurality of unit cells (18) stacked, and an adjacent cell unit (26) and a cell unit (26) A humidification chamber (28) for supplying fuel gas and circulating cooling water to humidify the fuel gas,
(28) and the cell unit (26) are communicated by a fuel flow path (40), and the fuel gas humidified in the humidification chamber (28) passes through the fuel flow path (40) from the humidification chamber (28). The fuel is supplied to each fuel chamber (20). The number of unit cells (24) forming the cell unit (26) is desirably about 3 to 5.

A cooling water passage (46) through which circulating cooling water flows and a gas passage (48) through which gas flows are formed in the humidifying chamber (28), and the cooling water passage (46) and the gas passage (48) are formed. ), A membrane that allows water to pass through but not gas (hereinafter referred to as a `` water-permeable membrane (5
0) "), and the gas can be humidified by the water permeated through the water-permeable membrane (50). Note that it is desirable to use a conductive film as the water-permeable film (50). In addition, the cooling water passage (46) and the gas passage (4
8), a membrane that allows water to pass through but not gas
(Hereinafter referred to as “gas permeable membrane (52)”), the gas can be humidified by permeating through the membrane (52) and flowing into the cooling water. In addition, the gas permeable membrane (52)
It is preferable to use a conductive film.

In the above description, the fuel gas is circulated through the humidifying chamber (28) in order to humidify the fuel gas.
The oxidizing gas may be humidified by flowing the oxidizing gas in 8). In this case, cooling water and an oxidizing gas are supplied to the humidifying chamber (28), and the humidifying chamber (28) and each oxidizing chamber (22) are supplied.
May be connected to each other through the oxidizing agent flow path so that the oxidizing gas humidified in the humidifying chamber (28) reaches each oxidizing agent chamber (22).

[0013]

[Function and effect] The polymer electrolyte fuel cell of the present invention (10)
Since the fuel gas can be humidified using the cooling water while cooling the battery with the cooling water, there is no need to provide a space dedicated to humidification or cooling. Further, since the humidified fuel gas is supplied from the fuel flow path (40) to each fuel chamber (20) of the cell unit (26), it is not necessary to provide a humidifying chamber for each unit cell, and the solid polymer Type fuel cell
(10) The miniaturization can be achieved.

When a high-temperature hydrogen-rich gas obtained by reforming a hydrocarbon-based gas such as city gas is used as the fuel gas, the fuel gas and the circulating cooling water are mixed to adjust the temperature of the fuel gas to the operating temperature of the battery. Can be cooled to a degree. Since the fuel gas is cooled by the latent heat of evaporation of the circulating cooling water by mixing with the circulating cooling water, the fuel gas has an excellent cooling effect. Even when the fuel gas flowing into the humidification chamber (28) is at room temperature, the temperature of the fuel gas can be raised to about the operating temperature of the battery by mixing the fuel gas and the circulating cooling water. As described above, since the fuel gas is supplied to the fuel chamber (20) at a temperature close to the operating temperature of the battery, a temperature distribution hardly occurs inside the battery, and stable operation is possible.

[0015] Even when an oxidizing gas is introduced into the humidifying chamber instead of the fuel gas, substantially the same operation and effect as described above can be exhibited.

[0016]

【Example】

<Embodiment 1> In this embodiment, a fuel gas and cooling water are supplied to a humidifying chamber.
This is an embodiment of the polymer electrolyte fuel cell (10) supplied to the humidification chamber (28) while preliminarily mixing inside the pipe (42) supplied to (28). Hereinafter, each part will be described with reference to FIGS. 1 to 3. The cell unit (26) is, as shown in FIG.
A plurality of unit cells (24) having a cell (18) sandwiched between a fuel plate (54) in which an oxidant chamber (22) is formed and a fuel plate (54) in which an oxidant chamber (22) is formed. Formed. A humidification plate (58) having a humidification chamber (28) is provided between the cell units (26). 2 and 3
As shown in (1), grooves (60) and (62) are formed on one surface of each of the fuel plate (54) and the humidification plate (58), and the grooves (60) of the fuel plate (54) are Fuel chamber (20), humidification plate
The concave groove (62) of (58) forms the humidification chamber (28). For example,
As shown in FIGS. 2 and 3, all plates have a common supply pipe (42) for fuel gas and cooling water, a fuel flow path (40), an oxidant flow path (64), a fuel outlet (66), The oxidizing agent outlet (68) and the cooling drain outlet (70) are penetrated and opened at the same position so as to communicate with each other in a state where the plates are stacked. Supply and discharge of the fuel gas, oxidant gas and cooling water to and from the polymer electrolyte fuel cell (10) are performed from a unit cell which is an end of the battery.
The flow direction of the fuel gas is indicated by a solid arrow, and the flow direction of the cooling water is indicated by a dotted arrow. The flow of the oxidizing gas is not shown.

The cell (18) includes a solid polymer electrolyte membrane (12),
An anode (14) on one surface of the solid polymer electrolyte membrane (12),
It is constituted by arranging a cathode (16) on the other surface (see FIG. 9),
As shown in FIG. 1, the outer periphery of the cell (18) is
Surrounded by

As shown in FIG. 2, the fuel plate (54) has a fuel chamber (20) formed with a number of grooves (60) at a position facing the cell. The fuel chamber (20) is connected to a fuel flow path (40) communicating with a humidification chamber (28) described later. Fuel chamber
The fuel exhaust gas consumed in (20) is discharged to a fuel outlet (66) provided at a position opposite to the fuel flow path (40).

The oxidizing agent plate (56) has an oxidizing agent chamber (22) formed of a gas-permeable and conductive oxidizing agent film at a position facing the cell. The oxidant chamber (22) communicates with the oxidant flow path (64), and the oxidant exhaust gas consumed in the oxidant chamber (22) is provided at a position opposite to the oxidant flow path (64). It is discharged from the oxidant outlet (68). The oxidant chamber
(22) may also be formed by a concave groove similarly to the fuel chamber.

The cell plate and fuel plate (5
4) and a unit cell (24) composed of an oxidizer plate (56)
Are laminated to form a cell unit (26). As shown in FIG. 1, a humidifying plate (58) having a humidifying chamber (28) is arranged between the cell units (26).

As shown in FIG. 3, the humidification chamber (28) is formed by opening a large number of concave grooves (62) serving as passages for fuel gas and cooling water substantially in the center of the humidification plate (58). Cell unit (2
It is arranged on the back of the fuel plate (54) which is the end of 6).
The humidification chamber (28) is a common pipe (42) for fuel gas and cooling water described later.
Is in communication with At the opposite end of the humidification chamber (28), steam-water separation as a steam-water separation means (44) communicating with the cooling water discharge port (70), which is a cooling water discharge port, and the fuel flow path (40) A groove is provided. The cooling drain outlet (70) is provided below the fuel flow path (40), and the humidified fuel gas and the cooling drain discharged from the humidifying chamber (28) through the water / water separation groove are provided in the water / water separation groove. The cooling water is discharged from the cooling drain outlet (70), and the fuel gas is discharged to the fuel flow path (40).

The common pipe (42) for the fuel gas and the cooling water communicating with the humidification chamber (28) is formed by disposing a cylindrical body (72) of a porous material in the pipe. Fuel gas is supplied into the inside of the porous cylinder (72), and cooling water is supplied between the common pipe (42) and the cylinder (72).

In the solid polymer fuel cell (10) having the above structure, the fuel gas is supplied into the cylinder of the common pipe (42) of the fuel gas and the cooling water, and the supply pipe (42) and the cylinder (72) are supplied. And supply cooling water between them. In addition, an oxidizing gas is supplied to the oxidizing channel (64). The fuel gas supplied to the inside of the cylinder (72) passes through the porous portion of the cylinder (72), is bubbled into the cooling water, and is mixed with the cooling water and the fuel gas.
(28) to cool the unit cell. Thereby, the temperature of each unit cell is adjusted to the optimal temperature for operation (about 80 ° C. to 10 ° C.).
(0 ° C.).

The fuel gas and the cooling water, which have flowed into the humidifying chamber (28) and have been humidified, are discharged from the humidifying chamber (28) through the water / water separation groove, and the cooling water is located below by the action of gravity. The humidified fuel gas discharged from the cooling water drain outlet (70)
Discharged to 0). As described above, since the humidified fuel gas and the cooling water are separated into steam and water, excessive water is not supplied to the fuel chamber (20). The humidified fuel gas discharged from the humidification chamber (28) to the fuel flow path (40) is supplied to each fuel chamber (20) communicating with the fuel flow path (40) and wets the solid polymer electrolyte membrane (12). At the same time, it reacts with the oxidant gas supplied to each oxidant chamber (22) through the oxidant flow path (64) through the cell (18) to generate an electromotive force.

According to the solid polymer fuel cell having the above-described structure, both the cooling of the unit cells and the wetting of the solid polymer electrolyte membrane are performed by the cooling water and the fuel gas flowing through the humidifying chamber provided for each cell unit. Can be performed simultaneously.

In the above embodiment, the fuel plate and the oxidant plate are separately formed, but an integral plate (bipolar plate) having an oxidant plate provided on the back surface of the fuel plate may be used. Also, the humidification chamber may be provided integrally on the back surface of the fuel plate or the oxidant plate which is the end of the cell unit. Note that, instead of the fuel gas, an oxidizing gas may be supplied to the humidifying chamber, and the humidified oxidizing gas may be supplied to the oxidizing chamber.

<Embodiment 2> In this embodiment, as shown in FIG. 4, cooling water and fuel gas are stored in a humidifying chamber (28) provided between the cell units (26). Passage (46) (4
8) are separately provided, and a conductive film that allows gas to permeate but does not transmit water is provided between the cooling water passage (46) and the fuel passage (48).
Partitioned by (gas permeable membrane (52)), gas permeable membrane (52)
The humidification is performed by bubbling the fuel gas that has passed through the cooling water into the cooling water. In the drawing, arrows indicate the flow directions of the fuel gas and the cooling water (the flow directions of the oxidizing gas are not shown). The description of the configuration of the cell unit (26) will be omitted for the same portions as those in the first embodiment.

As shown in FIG. 4, the humidifying chamber (28) has a gas permeable membrane (52) between the first humidifying plate (82) and the second humidifying plate (84) each having a groove. It is configured to be sandwiched. The first humidifying plate (82) and the second humidifying plate, when the plate faces the left side in FIG.
(84) is shown in FIGS. 5 and 6, respectively. In this embodiment, the cell unit (2) is provided on the surface B of the first humidifying plate (82).
Since the fuel chamber (20) at the end of (6) is formed integrally,
A concave groove of the fuel chamber (20) is formed on the surface. As shown in FIG. 5, a cooling water passage (46) having a concave groove through which cooling water flows is formed on the A surface of the first humidifying plate (82) while communicating with a cooling water supply pipe (74). Provided. As shown in FIG. 6, the second humidifying plate (84) is provided with a gas passage (48) having a concave groove formed on the surface B in communication with the fuel gas supply pipe (76). No outlet for discharging the fuel gas is formed in the gas passage (48), and all the supplied fuel gas is bubbled from the gas permeable membrane (52) into the cooling water on the first humidifying plate side. . A part of the cooling water evaporates in the bubbled fuel gas, and the fuel gas becomes humidified. Second humidification plate (8
The groove A through which the oxidizing gas flows is formed on the side A of 4) to form an oxidizing chamber (22). The oxidizing agent chamber (22) communicates with the oxidizing agent channel (64) and the oxidizing agent outlet (68), respectively, and passes through the oxidizing agent channel (64) to the oxidizing agent chamber (22). Is supplied, and the oxidant exhaust gas is discharged from the oxidant outlet (68).
As in the first embodiment, the first humidifying plate (82) is preferably provided with a steam / water separating means (44) to separate the cooling water and the humidified fuel gas. The cooling water discharged from the humidifying chamber (28) is discharged from the cooling drain outlet (70) as in the first embodiment, and the humidified fuel gas discharged from the humidifying chamber (28) is supplied to the fuel passage (40). ) Is supplied to the fuel chamber (20) and used for the cell reaction.

According to the solid polymer fuel cell having the above-described structure, the effective area for bubbling can be increased, and the pressure loss due to passage through the gas permeable membrane can be reduced. Further, since the fuel gas and the cooling water can be supplied to the humidifying chamber from different flow paths, the amounts of the flowing fuel gas and the cooling water can be controlled substantially uniformly.

Examples of the gas permeable membrane having conductivity include a porous metal plate such as a porous carbon plate.

Third Embodiment In the second embodiment, the fuel gas is bubbled in the cooling water. In the third embodiment, a part of the cooling water is supplied into the fuel gas to humidify the fuel gas. It is. As shown in FIG. 7, the humidifying chambers (20) each have a groove (6).
2) Between the first humidifying plate (82) and the second humidifying plate (84) where (90) is opened, a conductive film that allows water to permeate but does not allow gas to permeate (water permeable membrane (50)) A cooling water is supplied to the cooling water passage (46) of the first humidifying plate (82), and a fuel gas is supplied to the gas passage (48) of the second humidifying plate (84). doing. In this embodiment, the cooling water passage (46) is not provided with a cooling drain outlet, and the first humidifying plate (8
The cooling water supplied to 2) cools the unit cells, passes through the water-permeable membrane (50), and is supplied to the second humidifying plate side. The cooling water that has passed through the water-permeable membrane (50) evaporates into the fuel gas to humidify the fuel gas. By this latent heat of evaporation, a further cooling effect can be obtained. The humidified fuel gas is supplied to each fuel chamber (20) through the fuel flow path (40), and is used for a cell reaction. In addition, the water-permeable membrane (5
If the water permeation amount of (0) is adjusted to an appropriate state, since the humidified fuel gas does not contain excessive cooling water, a structure without steam-water separation means can be provided. Examples of the water-permeable membrane having conductivity include a porous carbon plate impregnated with perfluorocarbon sulfonic acid or the like.

<Embodiment 4> This embodiment is an embodiment in which both the fuel gas and the oxidizing gas are humidified. As shown in FIG. 8, the humidifying chamber includes a fuel gas humidifying chamber (28) formed between the first humidifying plate (82) and the second humidifying plate (84).
An oxidizing gas humidifying chamber (29) is formed between the second humidifying plate (84) and the third humidifying plate (86). The humidification chamber (28) for the fuel gas has the same configuration as that of the third embodiment, and the description is omitted. In addition, the flow direction of the oxidizing agent is indicated by a dashed line arrow.

The humidifying chamber (29) for oxidizing gas is provided with a water gas permeable membrane (94) on the back surface of the second humidifying plate (84), which has conductivity and allows both gas and water to pass through. The water gas permeable membrane (9
4) and a third humidifying plate (86) having a cooling water passage (47) having a concave groove, with a conductive water-permeable membrane (51) interposed therebetween. The water gas permeable membrane (94) is connected to a pipe (75) for supplying an oxidizing gas, and the oxidizing gas flows inside the membrane (94). The third humidifying plate (86) is not provided with a cooling drain outlet, and the cooling water supplied to the cooling water passage (47) of the third humidifying plate (86) cools the unit cell (24). At the same time, it passes through the water permeable membrane (50) and is supplied to the water gas permeable membrane side. The cooling water that has passed through the water-permeable membrane (51) is evaporated into the oxidizing gas and humidifies the oxidizing gas. By this latent heat of evaporation, a further cooling effect can be obtained. The humidified oxidant gas flows into the oxidant flow path (64)
Is supplied to each of the oxidant chambers (22) and is used for the battery reaction. As described above, by humidifying not only the fuel gas but also the oxidant gas, the solid polymer electrolyte membrane can be more suitably wetted.

When the water permeation amount of the water permeable membrane is adjusted to an appropriate state, as in the third embodiment, since the humidified oxidizing gas does not contain excessive cooling water, gas-water separation A structure without means can be provided. Examples of the water-permeable membrane having conductivity include a porous carbon plate impregnated with perfluorocarbon sulfonic acid or the like.

The description of the above embodiments is for the purpose of illustrating the present invention and should not be construed as limiting the invention described in the claims or reducing the scope thereof. Further, the configuration of each part of the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made within the technical scope described in the claims.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a polymer electrolyte fuel cell according to Example 1 of the present invention.

FIG. 2 is a diagram showing a fuel chamber side of a humidifying plate.

FIG. 3 is a diagram showing a humidification chamber side of a humidification plate.

FIG. 4 is a schematic sectional view of a polymer electrolyte fuel cell according to Embodiment 2 of the present invention.

5 is a view of the front and back surfaces of the first humidification plate, wherein A is a view of the first humidification plate from the right side of FIG. 4;
FIG. 5 is a view of the first humidifying plate viewed from the left side of FIG. 4.

FIG. 6 is a view of the front and back surfaces of the second humidifying plate, where A is a view of the second humidifying plate from the right side of FIG. 4;
FIG. 5 is a view of the second humidifying plate viewed from the left side of FIG. 4.

FIG. 7 is a schematic sectional view of a polymer electrolyte fuel cell according to Example 3 of the present invention.

FIG. 8 is a schematic sectional view of a polymer electrolyte fuel cell according to Example 4 of the present invention.

FIG. 9 is a schematic cross-sectional view of a conventional polymer electrolyte fuel cell.

FIG. 10 is a schematic cross-sectional view of a conventional polymer electrolyte fuel cell having a humidification water channel.

[Explanation of symbols]

 (10) Solid polymer fuel cell (18) Cell (20) Fuel chamber (22) Oxidizer chamber (24) Unit cell (26) Cell unit (28) Humidifying chamber

Claims (5)

[Claims] 1. A cell (18) having an anode (14) on one side of a solid polymer electrolyte membrane (12) and a cathode (16) on the other side.
In contrast, a fuel chamber (20) through which fuel gas flows to the anode side,
A solid polymer is formed by stacking a plurality of unit cells (24) having an oxidant chamber (22) through which an oxidant gas flows on the cathode side, and using cooling water circulated to cool the cells (18). In a polymer electrolyte fuel cell that humidifies an electrolyte membrane (12), a cell unit (2) is formed by a plurality of stacked unit cells (18).
A humidifying chamber (28) for supplying fuel gas and circulating cooling water to humidify the fuel gas is provided between the adjacent cell units (26) and (26). A fuel flow path (40) is provided between the humidification chamber (28) and the cell unit (26).
The fuel gas humidified in the humidification chamber (28) is supplied from the humidification chamber (28) to each fuel chamber (20) through the fuel flow path (40). Characteristic polymer electrolyte fuel cell. 2. A cell (18) having an anode (14) on one side of a solid polymer electrolyte membrane (12) and a cathode (16) on the other side.
In contrast, a fuel chamber (20) through which fuel gas flows to the anode side,
A solid polymer is formed by stacking a plurality of unit cells (24) having an oxidant chamber (22) through which an oxidant gas flows on the cathode side, and using cooling water circulated to cool the cells (18). In a polymer electrolyte fuel cell that humidifies an electrolyte membrane (12), a cell unit (2) is formed by a plurality of stacked unit cells (18).
A humidifying chamber (28) is provided between adjacent cell units (26) to supply oxidizing gas and circulating cooling water to humidify the oxidizing gas. The humidifying chamber (28) and the cell unit (26) communicate with each other by an oxidizing agent flow path, and the oxidizing gas humidified in the humidifying chamber (28) flows from the humidifying chamber (28) to the oxidizing agent. A polymer electrolyte fuel cell characterized in that it is supplied to each oxidant chamber (22) through a flow path. 3. The gas is humidified by being mixed with cooling water, and the humidification chamber (28) has steam-water separation means (44) for separating humidified gas and water. Item 2
9. The polymer electrolyte fuel cell according to item 1. 4. The humidification chamber (28) includes a cooling water passage (46) through which cooling water flows, and a gas passage (48) through which gas flows, and the cooling water passage (46) and the gas passage (48) , Separated by a conductive membrane (50) that allows water to pass but not gas,
The polymer electrolyte fuel cell according to claim 1 or 2, wherein the gas is humidified by water permeating the membrane (50). 5. The humidification chamber (28) includes a cooling water passage (46) through which circulating cooling water flows, and a gas passage (48) through which gas flows.
The cooling water passage (46) and the gas passage (48) are separated by a conductive membrane (52) that allows gas to pass but does not allow water to pass, and the gas passes through the membrane (52) and passes through the circulating cooling water. The polymer electrolyte fuel cell according to claim 1, wherein the polymer electrolyte fuel cell is humidified.