JP5276740B2 - Polymer electrolyte fuel cell - Google Patents

Description

  The present invention relates to a polymer electrolyte fuel cell.

  In recent years, a fuel cell stack comprising a plurality of stacked cells in which a anode-side electrode and a cathode-side electrode are opposed to each other with a solid polymer electrolyte membrane interposed therebetween is sandwiched between separators is used as a main part of the fuel cell. Molecular fuel cells have been developed and are being put to practical use in various applications.

  In the polymer electrolyte fuel cell, when hydrogen as a fuel gas is supplied to the anode of the fuel cell stack through a humidifier, and oxygen as an oxidant gas is supplied to the cathode of the fuel cell stack through the humidifier, in each catalyst layer, An electrochemical reaction takes place, producing water from hydrogen and oxygen and taking out electrical energy.

  In the polymer electrolyte fuel cell, there is a temperature at which the electrochemical reaction in the solid polymer electrolyte membrane is most efficiently performed. Therefore, by supplying cooling water into the fuel cell stack, the electric power of the solid polymer electrolyte membrane is It is configured to maintain the optimum temperature for chemical reaction. Further, the hydrogen gas and oxygen gas supplied into the fuel cell stack are also configured to be maintained at an optimum temperature for the electrochemical reaction of the solid polymer electrolyte membrane by the cooling water.

  Furthermore, the solid polymer fuel cell can function as an electrolyte by reducing the specific resistance of the membrane by setting the humidity of the solid polymer electrolyte membrane to approximately 100%. For this reason, in order to maintain the power generation efficiency of the polymer electrolyte fuel cell at a high level, it is necessary that the polymer electrolyte membrane contains sufficient water, and the gas is humidified by a humidifier through the supply pipe. By supplying the gas to the fuel cell stack, a gas having a humidity of approximately 100% is supplied to the solid polymer electrolyte membrane to maintain the optimum humidity for the electrochemical reaction of the solid polymer electrolyte membrane.

  Conventionally, the supply pipe from the humidifier to the fuel cell stack is provided with a heat medium layer made of a low thermal conductivity material on the outer periphery of the humidified gas supply pipe, and the heater is wound around the outer periphery of the heat medium layer. A configuration for keeping the gas temperature constant is known. An example of such a polymer electrolyte fuel cell is disclosed in Patent Document 1 below.

  In addition to the method of keeping the supply pipe warm and supplying the humidified gas to the fuel cell stack as described above, a pipe formed of a porous carbon sintered body is provided inside the water supply channel, and the porous carbon firing is provided. There is also known a configuration in which humidified gas is directly supplied to the fuel cell stack through a supply pipe that is sufficiently humidified by passing gas through the assembly and bubbling water. An example of such a polymer electrolyte fuel cell is disclosed in Patent Document 2 below.

JP 2000-67893 A Japanese Patent No. 3553200

  However, strictly speaking, in the polymer electrolyte fuel cell disclosed in Patent Document 1, heating and heat retention of the humidified gas supply pipe are not uniform, and actually there are a low-temperature part and a high-temperature part. Since the moisture of the humidified gas is condensed or the water condensed in the high temperature part is locally bumped, the temperature difference between the gas that reaches the fuel cell stack and the cooling water is not uniform. There is a problem that a gas having a humidity of about 100% cannot be obtained.

  Further, in the polymer electrolyte fuel cell disclosed in Patent Document 2, the water flowing through the water supply channel is humidified by bubbling water through the gas through the porous carbon sintered body. Since the substance moves from the high pressure side to the low pressure side, it is necessary to always pressurize the gas side to a high pressure state. For this reason, a separate pressurizing device must be provided, which causes a problem that the device configuration becomes complicated and the cost increases.

  Based on these facts, the present invention devised a system from the humidifier to the fuel cell stack, uniformizes the temperature of the gas and the cooling water at the gas inlet of the fuel cell stack, and further reduces the gas humidity to about 100 percent. An object of the present invention is to provide a polymer electrolyte fuel cell that can be brought close to.

A polymer electrolyte fuel cell according to a first invention (corresponding to claim 1) for solving the above-described problem is
A fuel cell stack formed by stacking a plurality of the cells via a separator, forming a cell by sandwiching a solid polymer electrolyte membrane between an anode side electrode and a cathode side electrode;
Cooling water for cooling the fuel cell stack;
Fuel gas supplied to the anode side electrode;
An oxidant gas supplied to the cathode electrode;
A humidifier for humidifying the fuel gas and the oxidant gas with the cooling water;
A fuel gas supply pipe for supplying the humidified fuel gas from the humidifier to the fuel cell stack;
An oxidant gas supply pipe for supplying the humidified oxidant gas from the humidifier to the fuel cell stack;
In a polymer electrolyte fuel cell comprising a cooling water supply pipe for supplying the cooling water from the humidifier to the fuel cell stack,
The fuel gas and the oxidant gas are provided with a humidified gas supply means for supplying the fuel cell stack with a humidity of approximately 100%, and the fuel gas, the oxidant gas and the cooling water are in a uniform temperature state. Comprising a temperature-equalizing means for supplying the fuel cell stack with
The humidified gas supply means and the temperature equalizing means are:
The cooling water supply pipe is branched in the fuel cell stack to form a branch pipe, and the branch pipe is installed so as to flow through a side end portion of the separator, and the fuel gas and the oxidant gas are supplied to the branch pipe. A water ejection hole for spraying water immediately before flowing into the cell is formed.

According to the first invention, a fuel cell stack formed by forming a cell by sandwiching a solid polymer electrolyte membrane between an anode side electrode and a cathode side electrode, and stacking a plurality of cells via a separator; Cooling water for cooling the fuel cell stack, fuel gas supplied to the anode side electrode, oxidant gas supplied to the cathode side electrode, a humidifier for humidifying the fuel gas and oxidant gas with cooling water, and humidification A fuel gas supply pipe that supplies humidified fuel gas from the humidifier to the fuel cell stack, an oxidant gas supply pipe that supplies humidified oxidant gas from the humidifier to the fuel cell stack, and a humidifier to the fuel cell stack In a polymer electrolyte fuel cell having a cooling water supply pipe for supplying cooling water, the humidity of the fuel gas and the oxidant gas is supplied to the fuel cell stack in a state of approximately 100%. By providing the humidified gas supply means, the solid polymer electrolyte membrane can always be maintained at an optimum state of 100% humidity, so that the efficiency of the electrochemical reaction is maximized and the product life is extended. Can do.
By providing a temperature-equalizing means for supplying the fuel gas, oxidant gas and cooling water to the fuel cell stack in a uniform state, the solid polymer electrolyte membrane can always be maintained at an optimum temperature. The chemical reaction efficiency can be maximized and the product life can be extended.
The humidifying gas supply means and the temperature equalizing means branch the cooling water supply pipe into a branch pipe in the fuel cell stack, and install the branch pipe so as to flow at the side end of the separator. By forming a water ejection hole for spraying water immediately before the oxidant gas flows into the cell, the fuel gas and the oxidant gas can be more reliably humidified.

FIG. 3 is a main part configuration diagram of a fixed polymer fuel cell according to Reference Example 1. It is the figure which showed the change of the gas temperature between the humidifier which concerns on the reference example 1, and a fuel cell stack. 2 is a system configuration diagram of a fixed polymer fuel cell according to Reference Example 1. FIG. FIG. 6 is a configuration diagram of a main part of a fixed polymer fuel cell according to Reference Example 2. It is sectional drawing of the gas supply piping formed with the some hollow fiber which concerns on the reference example 2. FIG. FIG. 6 is a main part configuration diagram of a fixed polymer fuel cell according to Reference Example 3. 1 is a main part configuration diagram of a fixed polymer fuel cell according to Example 1. FIG. 1 is a perspective view of a fuel cell stack according to Example 1. FIG.

  A reference example and an example of a fixed polymer fuel cell according to the present invention will be described with reference to FIGS. FIG. 1 is a schematic diagram of a main part of a fixed polymer fuel cell according to Reference Example 1, FIG. 2 is a diagram showing a change in gas temperature between a humidifier and a fuel cell stack according to Reference Example 1, and FIG. 4 is a system configuration diagram of a fixed polymer fuel cell according to Reference Example 1, FIG. 4 is a configuration diagram of the main part of the fixed polymer fuel cell according to Reference Example 2, and FIG. 5 is formed of a plurality of hollow fibers according to Reference Example 2. FIG. 6 is a main part configuration diagram of a fixed polymer fuel cell according to Reference Example 3, FIG. 7 is a main part configuration diagram of a fixed polymer fuel cell according to Example 1, and FIG. 1 is a perspective view of a fuel cell stack according to Example 1. FIG.

[Reference Example 1]
Hereinafter, a first reference example of the polymer electrolyte fuel cell according to the present invention will be described. First, the system configuration of the polymer electrolyte fuel cell according to this reference example will be described. FIG. 3 shows a system configuration diagram of a polymer electrolyte fuel cell according to this reference example. As shown in FIG. 3, the polymer electrolyte fuel cell includes a hydrogen gas supply source 10 that supplies hydrogen gas, an oxygen gas supply source 13 that supplies oxygen gas, and a cooling water supply source 11 that supplies cooling water. It has. In this reference example, hydrogen gas and oxygen gas are used, but it is also possible to use fuel gas other than hydrogen gas or oxidant gas other than oxygen gas.

  The hydrogen gas supplied from the hydrogen gas supply source 10 and the cooling water supplied from the cooling water supply source 11 are supplied to a hydrogen gas humidifier 12 that humidifies the hydrogen gas using the cooling water. The oxygen gas supplied from the oxygen gas supply source 13 and the cooling water supplied from the cooling water supply source 11 are supplied to an oxygen gas humidifier 14 that humidifies the oxygen gas using the cooling water.

  The hydrogen gas humidified by the hydrogen gas humidifier 12 and having a humidity of approximately 100% is supplied into the fuel cell stack 18 through the hydrogen gas supply pipe 15. The oxygen gas humidified by the oxygen gas humidifier is supplied to the inside of the fuel cell stack 18 through the oxygen gas supply pipe 16. Further, the cooling water used for humidification by the hydrogen gas humidifier 12 and the oxygen gas humidifier 14 is supplied into the fuel cell stack 18 through the cooling water supply pipe 17. The fuel cell stack 18 according to the present reference example has basically the same structure as that conventionally used, and therefore the detailed description of the fuel cell stack 18 here is omitted.

  Next, the structure of the main part of the polymer electrolyte fuel cell according to this reference example will be described. FIG. 1 shows a configuration diagram of a main part of a fixed polymer fuel cell according to this reference example. In addition, since the structure between the hydrogen gas humidifier 12 and the fuel cell stack 18 and between the oxygen gas humidifier 14 and the fuel cell stack 18 are common, in FIG. As the gas, the hydrogen gas humidifier 12 and the oxygen gas humidifier 14 are shown as the humidifier 19.

  As shown in FIG. 1, a gas supply pipe 20 is installed between the humidifier 19 and the fuel cell stack 18 to supply humidified gas having a humidity of approximately 100% humidified by the humidifier 19 to the inside of the fuel cell stack 18. To do. Further, between the humidifier 19 and the fuel cell stack 18, a cooling water supply pipe 17 that supplies the cooling water used for humidifying the gas in the humidifier 19 to the inside of the fuel cell stack 18 is installed.

  In the gas supply pipe 20, a heater 21 for heating the humidified gas immediately after coming out of the humidifier 19 is installed in a portion immediately adjacent to the humidifier 19. In this reference example, a tape heater is used as the heater 21, but other heating means may be used. In addition, a heater control device 22 is installed in the heater 21 so that the temperature can be arbitrarily adjusted.

  FIG. 2 is a diagram showing a change in gas temperature between the humidifier and the fuel cell stack according to this reference example. In addition, in FIG. 2, the state at the time of setting the temperature of a cooling water to 60 degreeC was shown as an example. As shown by A in FIG. 2, the humidified gas immediately after coming out of the humidified gas outlet of the humidifier 19 (see FIG. 1) is heated. This heating does not heat the entire gas supply pipe, but locally heats the immediate part of the humidifier 19. For this reason, the heated gas is in a state where the amount of saturated water vapor increases and the humidity decreases. That is, the moisture contained in the humidified gas is unlikely to condense.

  The heating of the gas is set so that the humidified gas reaches the same temperature as the cooling water indicated by B when the humidified gas reaches the humidified gas inlet of the fuel cell stack 18 (see FIG. 1). That is, when the gas reaches the fuel cell stack 18, the temperature of the gas and the temperature of the cooling water are the same, and the humidity of the gas is approximately 100%.

  Regarding the heating temperature of the heater 21, information on the temperature of the gas that has reached the fuel cell stack 18 is fed back to the heater control device 22, and the temperature of the gas that has reached the fuel cell stack 18 is the target temperature (here, 60 ° C.). It is also possible to automatically control the heater controller 22 so that

  As described above, the humidified gas heated by the heater 21 has an increased saturated water vapor amount. Therefore, the fuel cell stack 18 does not condense any moisture contained in the gas supply pipe 20 when it is humidified by the humidifier 19. Can reach the inside.

  On the other hand, in the conventional method for keeping the gas supply pipe warm, for example, the temperature may partially decrease in the pipe as indicated by a curve C, and the temperature may rise again. In such a case, the gas temperature is kept at a substantially constant temperature as a whole, but when the temperature decreases, the saturated water vapor amount decreases and the water condenses, When the gas introduction part of the fuel cell stack is reached, water and gas are separated and the humidity of the gas is lowered.

  As described above, according to the polymer electrolyte fuel cell according to the present reference example, the hydrogen gas immediately after coming out of the humidifier 19 is provided in the portion near the humidifier 19 of the hydrogen gas supply pipe 15 and the oxygen gas supply pipe 16. And a heater 21 for heating the oxygen gas, and when the hydrogen gas and the oxygen gas reach the fuel cell stack 18, the heater 21 is controlled so that the temperature of the hydrogen gas, the oxygen gas and the cooling water becomes uniform. The humidity of hydrogen gas and oxygen gas is almost 100%, and the temperature of hydrogen gas, oxygen gas and cooling water is uniform, so that the efficiency of electrochemical reaction can be maximized and the product life can be extended. .

  Moreover, it is possible to prevent water from condensing in the fuel gas supply pipe and the oxidant gas supply pipe. Furthermore, the manufacturing cost can be reduced as compared with the conventional configuration in which the heater is installed over the entire fuel gas supply pipe and oxidant gas supply pipe.

[Reference Example 2]
Hereinafter, a second reference example of the polymer electrolyte fuel cell according to the present invention will be described. The system configuration of the polymer electrolyte fuel cell according to the present reference example is the same as the system configuration of the polymer electrolyte fuel cell according to the reference example 1, and the description thereof is omitted here.

  The configuration of the main part of the polymer electrolyte fuel cell according to this reference example will be described. FIG. 4 shows a configuration diagram of a main part of a polymer electrolyte fuel cell according to this reference example. Note that the structure between the hydrogen gas humidifier 12 (see FIG. 3) and the fuel cell stack 18 and the structure between the oxygen gas humidifier 14 (see FIG. 3) and the fuel cell stack 18 are the same. 4, hydrogen gas and oxygen gas are shown as gases, and the hydrogen gas humidifier 12 and oxygen gas humidifier 14 are shown as humidifiers 19.

  As shown in FIG. 4, a cooling water supply pipe 17 for supplying cooling water is installed between the humidifier 19 and the fuel cell stack 18, and a gas supply pipe for supplying gas into the cooling water supply pipe 17. 20 is installed. That is, the pipe between the humidifier 19 and the fuel cell stack 18 is a double pipe in which the cooling water supply pipe 17 forms an outer pipe and the gas supply pipe 20 forms an inner pipe. In this reference example, stainless steel was used as the material for the cooling water supply pipe 17 and a non-porous hollow fiber membrane was used as the material for the gas supply pipe 20. Here, the non-porous hollow fiber membrane is a membrane through which only substantially water vapor can permeate.

  Since the material of the gas supply pipe 20 according to this reference example is a non-porous hollow fiber membrane, without depending on the pressure of the gas in the gas supply pipe 20 and the pressure of the cooling water in the cooling water supply pipe 17, Since water vapor can pass from the inside of the cooling water supply pipe 17 to the inside of the gas supply pipe 20, the gas humidity and the temperature of the cooling water can be made uniform, and the humidity of the gas can be brought to a state of about 100%. it can.

  It is also possible to form the gas supply pipe 20 with a number of hollow fibers 23 whose surface is non-porous. FIG. 5 shows a cross-sectional view of a gas supply pipe formed by a number of hollow fibers 23 according to this reference example. As shown in FIG. 5, a large number of non-porous hollow fibers 23 are installed inside the cooling water supply pipe 17. In this way, by forming the gas supply pipe 20 with a large number of hollow fibers 23, the surface area of the gas supply pipe 20 can be increased, and the contact area with the cooling water indicated by hatching in FIG. 5 can be increased. The ability to humidify the gas can be further increased.

  As described above, according to the polymer electrolyte fuel cell according to the present reference example, the hydrogen gas supply pipe 15 is installed in the cooling water supply pipe 17 to form a double pipe, and the cooling water supply pipe 17 has the inside. By installing the oxygen gas supply pipe 16 as a double pipe, the hydrogen gas supply pipe 15 and the oxygen gas supply pipe 16 are formed of a non-porous hollow fiber membrane or a plurality of non-porous hollow fibers, thereby producing hydrogen. Since the humidity of the gas and oxygen gas is approximately 100% and the temperature of the hydrogen gas, oxygen gas and cooling water is uniform, the efficiency of the electrochemical reaction can be maximized and the product life can be extended. Moreover, compared with the case where a double tube is formed of a conventional porous material, it is not necessary to provide a pressurizing device or the like separately, so that the manufacturing cost can be reduced.

[Reference Example 3]
Hereinafter, a third reference example of the polymer electrolyte fuel cell according to the present invention will be described. The system configuration of the polymer electrolyte fuel cell according to the present reference example is the same as the system configuration of the polymer electrolyte fuel cell according to the reference example 1, and the description thereof is omitted here.

  The configuration of the main part of the polymer electrolyte fuel cell according to this reference example will be described. FIG. 6 shows a configuration diagram of a main part of a polymer electrolyte fuel cell according to this reference example. Since the structure between the hydrogen gas humidifier 12 (see FIG. 3) and the fuel cell stack 18 and the structure between the oxygen gas humidifier 14 (see FIG. 3) and the fuel cell stack are common, FIG. In FIG. 2, hydrogen gas and oxygen gas are shown as gases, and the hydrogen gas humidifier 12 and oxygen gas humidifier 14 are shown as humidifiers 19.

  As shown in FIG. 6, a gas supply pipe 20 that supplies gas and a cooling water supply pipe 17 that supplies cooling water are installed between the humidifier 19 and the fuel cell stack 18. In the gas supply pipe 20, a gas humidification chamber 24 is formed in a portion immediately adjacent to the fuel cell stack 18. The end of the cooling water supply pipe 17 on the fuel cell stack side penetrates the ceiling of the gas humidification chamber 24 and protrudes into the gas humidification chamber 24. A spray nozzle 25 is provided at the end of the cooling water supply pipe 17 to spray the cooling water into a fine mist. In the lower part of the gas humidification chamber 24, an air / water separator 26 is installed to liquefy the cooling water sprayed from the spray nozzle 25 again.

  The cooling water that has come out of the humidifier 19 is atomized by the spray nozzle 25. The gas coming out of the humidifier 19 passes through the gas humidification chamber 24 filled with the atomized cooling water and reaches the inside of the fuel cell stack 18. Further, the atomized cooling water is returned to the liquid state again by the steam separator 26 and then reaches the inside of the fuel cell stack 18. In this way, it is possible to make the humidity of the gas approximately 100 percent while making the temperature of the gas and the temperature of the cooling water uniform.

  As described above, according to the polymer electrolyte fuel cell according to the present reference example, the gas humidification for humidifying the hydrogen gas and the oxygen gas in the portion immediately adjacent to the fuel cell stack 18 of the hydrogen gas supply pipe 15 and the oxygen gas supply pipe 16. The chamber 24 is formed, the tip of the cooling water supply pipe 17 is protruded into the gas humidification chamber 24, and a spray nozzle 25 for spraying the coolant in the form of a mist is installed at this tip, By installing the steam separator 26 that returns the mist-like cooling water to a liquid state and supplies it to the fuel cell stack 18, the humidity of the hydrogen gas and oxygen gas becomes approximately 100%. Since the temperature of the cooling water becomes uniform, the efficiency of the electrochemical reaction can be maximized and the product life can be extended. In addition, since reliable humidification of hydrogen gas and oxygen gas can be realized with a simple structure, the manufacturing cost can be reduced.

  Hereinafter, a first embodiment of a polymer electrolyte fuel cell according to the present invention will be described. The system configuration of the polymer electrolyte fuel cell according to the present embodiment is the same as the system configuration of the polymer electrolyte fuel cell according to Reference Example 1, and thus the description thereof is omitted here.

  The structure of the main part of the polymer electrolyte fuel cell according to the present embodiment will be described. FIG. 7 is a block diagram of the main part of the fixed polymer fuel cell according to this example. Note that the structure between the hydrogen gas humidifier 12 (see FIG. 3) and the fuel cell stack 18 and the structure between the oxygen gas humidifier 14 (see FIG. 3) and the fuel cell stack 18 are the same. 7, hydrogen gas and oxygen gas are shown as gases, and the hydrogen gas humidifier 12 and oxygen gas humidifier 14 are shown as humidifiers 19.

  As shown in FIG. 7, a gas supply pipe 20 is installed between the humidifier 19 and the fuel cell stack 18 to supply the humidified gas humidified by the humidifier 19 to the inside of the fuel cell stack 18. To do. Further, between the humidifier 19 and the fuel cell stack 18, a cooling water supply pipe 17 that supplies the cooling water used for humidifying the gas in the humidifier 19 to the inside of the fuel cell stack 18 is installed. In this embodiment, the cooling water supply pipe 17 is branched into a plurality of pipes inside the fuel cell stack 18 to form a branch pipe 27.

  FIG. 8 is a perspective view of the fuel cell stack according to this example. As shown in FIG. 8, the fuel cell stack is formed by stacking a plurality of cells made of the solid polymer electrolyte membrane 28 in series via a separator 29. A groove portion 30 is formed in the separator 29, and hydrogen gas and oxygen gas are introduced into the groove portion 30 from different directions. In FIG. 8, the separators 29 are spaced apart from each other, but in actuality, the separators 29 are arranged so as to be in contact with each other without any gaps. Further, the supply direction of hydrogen gas and oxygen gas may be reversed.

  In the present embodiment, the cooling water supply pipe 17 is branched into a plurality of pipes in the fuel cell stack 18, and the branch pipes 27 are installed so as to flow through the side end portions of the separators 29. The branch pipe 27 is provided with a water ejection hole 31 so that water is ejected at a position corresponding to the groove portion 30 of the separator 29. The water ejected from the water ejection holes 31 is bathed in hydrogen gas and oxygen gas immediately before flowing into the groove portion 30. In this way, it is possible to make the humidity of the gas approximately 100 percent while making the temperature of the gas and the temperature of the cooling water uniform.

  As described above, in the polymer electrolyte fuel cell according to this embodiment, the cooling water supply pipe 17 is branched in the fuel cell stack 18 to form the branch pipe 27, and the branch pipe 27 is the side end of the separator 29. By forming the water outlet hole 31 through which water is sprayed immediately before the hydrogen gas and oxygen gas flow into the cell inside the branch pipe 27, the humidity of the hydrogen gas and oxygen gas becomes approximately 100%. Since the temperatures of hydrogen gas, oxygen gas and cooling water become uniform, the efficiency of the electrochemical reaction can be maximized and the product life can be extended. In addition, more reliable humidification can be performed on hydrogen gas and oxygen gas.

DESCRIPTION OF SYMBOLS 10 Hydrogen gas supply source 11 Cooling water supply source 12 Hydrogen gas humidifier 13 Oxygen gas supply source 14 Oxygen gas humidifier 15 Hydrogen gas supply pipe 16 Oxygen gas supply pipe 17 Cooling water supply pipe 18 Fuel cell stack 19 Humidifier 20 Gas supply Piping 21 Heater 22 Heater control device 23 Hollow fiber 24 Gas humidification chamber 25 Spray nozzle 26 Air / water separator 27 Branch piping 28 Solid polymer electrolyte membrane 29 Separator 30 Groove portion 31 Water ejection hole

Claims (1)

A fuel cell stack formed by stacking a plurality of the cells via a separator, forming a cell by sandwiching a solid polymer electrolyte membrane between an anode side electrode and a cathode side electrode;
Cooling water for cooling the fuel cell stack;
Fuel gas supplied to the anode side electrode;
An oxidant gas supplied to the cathode electrode;
A humidifier for humidifying the fuel gas and the oxidant gas with the cooling water;
A fuel gas supply pipe for supplying the humidified fuel gas from the humidifier to the fuel cell stack;
An oxidant gas supply pipe for supplying the humidified oxidant gas from the humidifier to the fuel cell stack;
In a polymer electrolyte fuel cell comprising a cooling water supply pipe for supplying the cooling water from the humidifier to the fuel cell stack,
The fuel gas and the oxidant gas are provided with a humidified gas supply means for supplying the fuel cell stack with a humidity of approximately 100%, and the fuel gas, the oxidant gas and the cooling water are in a uniform temperature state. Comprising a temperature-equalizing means for supplying the fuel cell stack with
The humidified gas supply means and the temperature equalizing means are:
The cooling water supply pipe is branched in the fuel cell stack to form a branch pipe, and the branch pipe is installed so as to flow through a side end portion of the separator, and the fuel gas and the oxidant gas are supplied to the branch pipe. A polymer electrolyte fuel cell, wherein a water ejection hole for spraying water immediately before flowing into a cell is formed.

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