JPH0927334A - Solid polymer electrolyte film fuel cell and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To keep a solid polymer electrolyte film wet and make re-starting quick by arranging an inlet and outlet for supplying and exhausting a humidifying fluid for the solid polymer electrolyte film in a fuel gas path or an oxidizing gas path, and connecting the inlet and outlet to a humidifying fluid supply source. SOLUTION: When water is filled in each gas supply path of an anode plate 26 and a cathode plate 24 and that is detected with a detecting means, the energized state of a pump is stopped and stopped state is kept. A solid polymer electrolyte film 22 interposed between a first manifold plate 42 and a second manifold plate 50 keeps wet state together with the cathode plate 24 and the anode plate 26. When water is filled, a third opening/closing valve, a sixth opening/closing valve, a seventh opening/closing valve, and a ninth opening/ closing valve are closed. A fear that an operating gas remaining within a fuel cell cross leaks the electrolyte film and causes catalytic combustion is completely eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid polymer electrolyte membrane fuel cell and a control method thereof, and more specifically,
When a solid polymer electrolyte membrane fuel cell (hereinafter, also simply referred to as a fuel cell) is stopped, a humidifying fluid, for example, water is introduced into the fuel cell from a direction opposite to gravity to quickly and surely stop the fuel cell itself. The separator, the anode-side electrode plate, the electrolyte membrane, and the cathode-side electrode plate are maintained in a wet state during this stop period, and at the time of startup, the pressure and the inert fluid of the fuel gas and the oxidant gas when they are introduced into the fuel cell A solid polymer electrolyte membrane fuel that allows the inert fluid to be promptly discharged to the outside of the fuel cell through interaction by gravity, thereby enabling the fuel cell to be restarted as quickly as possible. The present invention relates to a battery and a control method thereof.

[0002]

2. Description of the Related Art A solid polymer electrolyte membrane fuel cell has a plurality of unit cells each composed of an electrolyte composed of a polymer ion-exchange membrane and catalyst electrodes and porous carbon electrodes arranged on both sides of the electrolyte. Configured. In this type of fuel cell, the hydrogen supplied to the anode side is hydrogen-ionized on the catalyst electrode and moves to the cathode side electrode plate via the appropriately humidified electrolyte. The electrons generated during that time are taken out to an external circuit and used as DC electric energy. Since the oxidant gas, for example, oxygen gas or air is supplied to the cathode side electrode plate, the hydrogen ions, the electrons and oxygen react with each other to generate water in the cathode side electrode plate. .

[0003]

At this time, the electrolyte composed of the polymer ion exchange membrane needs to be sufficiently humidified in order to maintain the ion permeability. In order to humidify the polymer ion exchange membrane, generally, a gas humidifier provided outside the fuel cell is used to humidify the oxidant gas and the fuel gas, and these are sent to the fuel cell as water vapor. The polymer ion exchange membrane is humidified. When the fuel cell of this type finishes the power generation action, the electrolyte composed of the polymer ion exchange membrane is not subjected to the humidification action, so that the polymer ion exchange membrane returns to the dry state. Therefore, when restarting this type of fuel cell, it is necessary to humidify the polymer ion exchange membrane again using an external gas humidifier. For this reason, it has been pointed out that inconvenience such as an extremely long time is required for starting the fuel cell.

On the other hand, the polymer ion exchange membrane used as an electrolyte is not a substance capable of completely separating a fuel gas and an oxidant gas, but has a slight gas permeability. Therefore,
There is a possibility that the fuel gas and the oxidant gas will leak the electrolyte to each other and cause catalytic combustion, for example, via the catalytic electrode. When the fuel cell is operating, a monitor etc. that monitors the power generation state of the fuel cell using this type of polymer ion exchange membrane is installed, and it is possible to detect the presence or absence of abnormality, but once the fuel cell is stopped However, if all the systems including this are kept in a stopped state, the monitor will not be monitored either. As a result, the fuel gas and the oxidant gas remain in the anode electrode plate and the cathode electrode plate, respectively. However, it is difficult to detect an abnormality during the suspension period of the system.

Further, in the solid polymer electrolyte membrane fuel cell, for example, when the fuel cell is operated in the range of room temperature to 100 ° C. and then temporarily stopped, a considerable time is required to cool the fuel cell itself. It In this case, the water content of the ionic conductive component of the fuel cell will decrease due to the high temperature condition for a long time as described above. After all, it has been pointed out that when the fuel cell is restarted, the ionic conductive resistance becomes high due to the low water content, and it takes a considerably long time to reach a predetermined output after the restart.

The present invention has been made to overcome the above-mentioned various problems, and a solid polymer electrolyte membrane fuel cell does not fall into an abnormal state even when it is stopped. Moreover, it is an object of the present invention to provide a solid polymer electrolyte membrane fuel cell and a control method thereof that can be started up very quickly when restarting.

[0007]

In order to achieve the above-mentioned object, the present invention provides a solid polymer electrolyte membrane sandwiched between an anode-side electrode plate and a cathode-side electrode plate at least in a fuel cell. An inlet / outlet for supplying and discharging the humidifying fluid for the solid polymer electrolyte membrane is provided in the fuel gas passage or the oxidant gas passage, and the inlet / outlet is connected to the humidifying fluid supply source via a valve member.

Further, the present invention is a method for controlling a solid polymer electrolyte membrane fuel cell, which comprises a fuel gas supply passage provided at least on the anode side and a cathode side when the fuel cell is stopped, and an oxidizer. A humidifying fluid is supplied to the gas supply passage from below, and the humidifying fluid is held inside the fuel gas supply passage and the oxidant gas supply passage while the stopped state of the fuel cell is maintained. And

When the fuel cell is stopped, a humidifying fluid such as water is supplied to the fuel gas supply passage and the oxidant gas supply passage. As a result, the fuel gas, such as hydrogen gas and oxidant gas, such as air, remaining inside the respective gas supply passages and electrodes is led out from the respective passages, and the respective electrode and gas supply passages are discharged. Is fully filled with humidifying fluid.

When the fuel cell is maintained in a stopped state, as described above, the humidifying fluid remains inside the electrode and the respective gas supply passages, and the electrode and the solid polymer electrolyte membrane in contact with the electrode are kept in a wet state. To do.

Next, when the stopped state is terminated and the fuel cell is to be restarted, the humidifying fluid retained inside is discharged to the outside of the fuel cell due to its gravity. At that time, for example, the fuel gas is forcibly supplied to the anode side and at the same time, the oxidant gas is forcibly supplied to the cathode side. Due to the pressure of these fuel gas and oxidant gas that are originally used for power generation and the gravity of the humidifying fluid, the humidifying fluid is discharged to the outside as quickly as possible.

As a result, the time interval for restarting the fuel cell is particularly shortened, and the inconvenience of causing catalytic combustion when the fuel cell is stopped can be avoided.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION A solid polymer electrolyte membrane fuel cell and a method for controlling the same according to the present invention will be described in detail below with reference to the accompanying drawings.

As shown in FIGS. 1 and 2, the polymer electrolyte fuel cell according to this embodiment is basically constructed by stacking a large number of fuel cells 20 in the horizontal direction. The fuel cell unit 20 includes a cell body 28 composed of an anode-side electrode plate 26 and a cathode-side electrode plate 24 with a solid polymer electrolyte membrane 22 interposed therebetween. Regarding the configuration of the cell body 28, for example, International Publication WO094-1377.
The detailed description is given in No. 1, which is incorporated herein by reference.
In this case, as shown in FIG. 2, the solid polymer electrolyte membrane 22
Although the anode side electrode plate 26 and the cathode side electrode plate 24 are separately configured, it goes without saying that they may be integrally configured.

Therefore, as shown in FIG. 3, an elliptic hole 22a for passing a fuel gas such as hydrogen in one direction is provided on the upper side of the electrolyte membrane 22, and cooling water is passed therethrough. And a hole 22c for allowing an oxidant gas, for example, oxygen gas to pass therethrough, are provided on the upper side thereof, while a lower part of the electrolyte membrane 22 for allowing a fuel gas to pass therethrough. A hole 22d, a hole 22e for passing cooling water, and a hole 22f for further passing an oxidant gas are provided. The ellipse provided on the side of the electrolyte membrane 22 indicates a hole for reducing the weight of the electrolyte membrane 22, and the oval hole is a stud or the like for assembling and fixing the cell stack. Shows a hole through which

A first gasket 30 and a second gasket 32 are provided on both sides of the cell body 28 thus constructed. The first gasket 30 has a large opening 34 for accommodating the cathode side electrode plate 24, while the second gasket 32 has an opening 36 for accommodating the anode side electrode plate 26 defined therein. There is. It should be noted that the first gasket 30 and the second gasket 32 have holes 30a and 30 for allowing fuel gas to pass therethrough, similarly to the electrolyte membrane 22.
d, holes 30b and 30e for passing cooling water, and holes 30c and 30f for passing oxidant gas are provided on the upper side and the lower side, respectively, and the same applies to the second gasket 32. (See Figure 4). The ellipses provided on the sides of the first and second gaskets 30, 32 are holes for reducing the weight of the gaskets 30, 32, and the circular holes are the cell stacks. Shows a hole through which a stud, etc., penetrates when assembling and fixing.

Next, referring to FIG. 2, the first gasket 30 and the second gasket 32 are in contact with each other, and a hole for accommodating the anode side electrode plate 26 and the cathode side electrode plate 24 is formed in a part thereof. The formed separator 40 will be described.

The separator 40 basically includes a first manifold plate 42, a first surface pressure generating plate 44 that contacts the first manifold plate 42, the first surface pressure generating plate 44 and the second surface pressure generating member. Separator body 4 sandwiched between the plates 46
8 and a second manifold plate 50 that comes into contact with the second surface pressure generating plate 46.

As shown in FIG. 5, the first manifold plate 42 is basically a rectangular flat plate. A fuel gas supply recess 42a for supplying fuel gas is provided in the upper right corner, and a cooling water discharge hole 42b for supplying cooling water is provided adjacent to the recess 42a. Furthermore, an oxidant gas supply hole 42c for supplying an oxidant gas is provided in the upper left corner of the first manifold plate 42. A fuel gas discharge recess 42d for discharging fuel gas is provided in the lower left corner of the first manifold plate 42, and a cooling water supply hole is provided adjacent to the fuel gas discharge recess 42d. A portion 42e is provided. Then, the oxidant gas discharge hole 42 is provided at the lower right corner.
f is provided. In this case, the fuel gas supply recess 42a and the fuel gas discharge recess 42d are in communication with each other through an opening 45 for accommodating a fuel gas rectifying plate 80 described later. On the other hand, the oval holes extending vertically in the both sides of the first manifold plate 42 are
This is for reducing the weight of the manifold plate 42, and the circular hole is used for inserting a stud or the like when the fuel cell 20 is stacked.

In this case, the first manifold plate 42 and the second manifold plate 42
The manifold plate 50 is basically constructed symmetrically, and this is shown in FIG. Therefore, the second manifold plate 5
Although detailed description of 0 is omitted, here, reference numeral 50a indicates a fuel gas supply hole, and reference numeral 5
Reference numeral 50b indicates a hole for discharging the cooling water, and reference numeral 50c indicates a recess for supplying the oxidant gas. Further, reference numeral 50d indicates a fuel gas discharge hole, reference numeral 50e indicates a cooling water supply hole, and reference numeral 50f indicates an oxidant gas discharge recess. The oxidizing gas supply concave portion 50c and the oxidizing gas discharging concave portion 50f are in communication with each other through an opening portion 52 that accommodates an oxidizing gas straightening plate 82 described later.

The first surface pressure generating plate 44 which comes into contact with the first manifold plate 42 constructed as described above will be described with reference to FIG. Since the second surface pressure generating plate 46 is substantially the same as the first surface pressure generating plate 44, detailed description thereof will be omitted.

As is easily understood from the drawing, the first surface pressure generating plate 44 is integrated with a flat plate made of an electronically conductive material or a fuel gas rectifying plate 80 described later, or is made of the same material. It is formed by processing, and a fuel gas supply communicating hole 44a that communicates with the fuel gas supplying recess 42a of the first manifold plate 42 is provided in the upper right corner, and the cooling water is adjacent to the communicating hole 44a. A cooling water discharge communication hole 44b that communicates with the discharge hole portion 42b is defined. Further, a communication hole 44c communicating with the oxidant gas supply hole 42c is provided at the upper left corner of the first surface pressure generating plate 44. Furthermore, a communication hole 44d communicating with the fuel gas discharge recess 42d of the first manifold plate 42 is formed at the lower left corner of the first surface pressure generating plate 44, and cooling water is provided in the vicinity of this communication hole 44d. A communication hole 44e that communicates with the supply hole 42e is provided, and further, a communication hole 44f that communicates with the oxidant gas discharge hole 42f is provided at the lower right corner. The remaining oval holes defined in the first surface pressure generating plate 44 are for reducing the weight thereof,
Further, the perfect circular hole is used for inserting a stud when the fuel cells 20 are stacked and tightened.

FIG. 8 shows a third manifold plate, that is, a separator body 48, which is sandwiched between the first manifold plate 42 and the second manifold plate 50 via a separator plate described later. This separator body 48 is
The cooling water is supplied to cool the cell body 28. The relatively thick separator body 48 is preferably made of a conductive dense material (solid body), and communicates with the fuel gas supply recess 42 a of the first manifold plate 42 and the communication hole 44 a of the first surface pressure generating plate 44. Has a hole 48a for supplying the fuel gas in the upper right corner. Cooling water discharge recess 48b communicating with the cooling water discharge hole 42b of the first manifold plate 42 and the communication hole 44b of the first surface pressure generating plate 44.
Is adjacent to the hole 48a, and the separator body 4
8 is provided substantially above the center, and the oxidant gas supply hole 42 of the first manifold plate 42 is provided at the upper left corner.
c, an oxidant gas supply hole 48c communicating with the communication hole 44c of the first surface pressure generating plate 44 is provided. Further, in the lower left corner, a recess 42d for discharging the fuel gas of the first manifold plate 42 and a hole 48d for communicating with the communication hole 44d of the first surface pressure generating plate 44 are provided. A recess 48e for supplying cooling water is provided immediately below 48b. Further, at the lower right corner, the oxidant gas discharge hole 4 is formed.
8f is provided. The recess 48b and the recess 48e are in communication with each other by the opening 62 that is largely defined.

Here, the opening 62 of the separator main body 48
The cooling water flow straightening plates 70 and 72 are fitted and fixed to. When the cooling water straightening plates 70 and 72 are combined, the thickness becomes substantially the same as the thickness of the separator body 48. The cooling water straightening plate 70 has a plurality of parallel grooves 70a extending in the vertical direction in the figure, and similarly, the cooling water straightening plate 72 also has a plurality of parallel grooves 72a arranged in parallel. ing. Therefore, when these cooling water straightening plates 70 and 72 are combined, the grooves 70a and 72a respectively define large cooling water straightening passages, and the respective cooling water straightening passages are provided with the cooling water discharging recesses. A communication state is secured with the cooling water supply recess 48e and the cooling water supply recess 48e.

As can be seen from FIGS. 1, 2 and 9, the fuel gas flow straightening plate 80 is fitted into the opening 45 of the first manifold plate 42 as described above. One surface of the fuel gas rectifying plate 80 is formed flat, and a plurality of parallel grooves 80a extending in the vertical direction are defined on the other surface. Due to the parallel grooves 80a, the fuel gas supply recess 4 is formed.
2a communicates with the fuel gas discharge recess 42d. on the other hand,
The oxidant gas rectifying plate 82 is fitted into the opening 52 of the second manifold plate 50. One surface of the oxidizing gas gas flow regulating plate 82 is formed flat, and the other surface thereof defines a plurality of parallel grooves 82a extending in the vertical direction. The parallel groove 82a allows the oxidant gas supply recess 50c to communicate with the oxidant gas discharge recess 50f. The first manifold plate 42 and the flow straightening plate 80 and the second manifold plate 50 and the flow straightening plate 82 have substantially the same thickness.

The separator body 48 having the above-mentioned structure
Is sandwiched between the first surface pressure generating plate 44 and the second surface pressure generating plate 46,
Further, these are sandwiched between the first manifold plate 42 and the second manifold plate 50. The second gasket 32 contacts the first manifold plate 42, the first gasket 30 contacts the second manifold plate 50, and the cell body 28 is sandwiched between the gaskets 30 and 32 as described above. To be done.

Explaining in the direction of the arrow in FIG. 2, the first manifold plate 42 incorporating the rectifying plate 80, the second gasket 32, the anode side electrode plate 26, the electrolyte membrane 22, the cathode side electrode plate 24, the first gasket. 30, straightening plate 82
Separator body 4 incorporating the second manifold plate 50 incorporating the above, the second surface pressure generating plate 46, and the flow regulating plates 72, 70
8. Like the first surface pressure generating plate 44, a large number of these sets are laminated, one laminated end portion is brought into contact with the first end plate 84, and the other laminated end portion is brought into contact with the second end plate 86. Then, the first and second end plates 84 and 86 are tightened with stud bolts (not shown).

In this case, the first end plate 84 is formed with a through hole 84b for leading the cooling water so as to face the cooling water discharge hole portion 42b of the first manifold plate 42, and the through hole 84b is defined therein. A through hole 84c for introducing the oxidant gas is defined adjacently. Further, a through hole 84f is defined in the first end plate 84 so as to communicate with the oxidizing gas discharge hole 42f of the first manifold plate 42.

On the other hand, the second end plate 86 has a first
A through hole 86a for supplying the fuel gas is defined so as to communicate with the fuel gas supplying recess 42a of the manifold plate 42.

The second end plate 86 includes
For example, the cooling water supply hole 4 of the first manifold plate 42
A through hole 86e communicating with 2e is defined and a through hole 86d communicating with the fuel gas discharge hole 42d is defined. Thus, the fuel cell according to the present invention is constructed by stacking the communication holes, the holes and the recesses so as to communicate with each other. That is, the hole portion 22a of the solid polymer electrolyte membrane 22, the hole portion 30a of the first gasket 30, the hole portion 32a of the second gasket 32, which constitute the cell body 28,
The recesses 42a of the first manifold plate 42, the holes 48a of the separator body 48, and the holes 50a of the second manifold plate 50 ensure a communication state, respectively, and will be referred to as a cooling water supply hole and a cooling water discharge hole hereinafter. , Hole for supplying oxidant gas,
Similarly, the oxidant discharge holes are also kept in communication with each other.

Therefore, in the present invention, the through hole 8 of the second end plate 86 is formed in the recess 42a of the first manifold plate 42.
A supply pipe 100 for supplying a fuel gas, for example, a hydrogen gas, is connected via 6a, and the fuel gas is supplied to the recess 42d of the first manifold plate 42 through the through hole 86d of the second end plate 86. Discharge pipe line 10 for discharging
2 is connected. A first opening / closing valve 104 is provided in the fuel gas supply pipeline 100, and a second opening / closing valve 106 is provided in the fuel gas discharge pipeline 102. The fuel gas supply line 100
And the fuel gas discharge pipeline 102 are connected by a first bypass pipeline 108, and the first bypass pipeline 10 is connected.
8 is provided with a third on-off valve 110. The fuel gas discharge line 102 and the first bypass line 108 are the second opening / closing valve 1.
06, and is connected on the downstream side of the third on-off valve 110, and communicates with the reservoir 118 via the water condenser 112, the first steam separator 114, and the pipeline 116.

On the other hand, the oxidant gas supply conduit 120 is connected to the recess 50c of the second manifold plate 50 through the through hole 84c of the first end plate 84, and the recess 50f of the second manifold plate 50 is The oxidant gas discharge conduit 122 is provided through the through hole 84f of the first end plate 84.
Is connected. The oxidant gas supply line 120 has a fourth
An opening / closing valve 124 is installed, and a fifth opening / closing valve 126 is installed in the oxidant gas discharge conduit 122. The oxidant gas supply conduit 120 and the oxidant gas discharge conduit 122 are connected by a second bypass conduit 128, and a sixth opening / closing valve 130 is interposed in the second bypass conduit 128. . Oxidant gas discharge line 122 and second bypass line 1
28 is connected to a pipe line 132 on the downstream side, and a second water condenser 134 and a second steam separator 136 are interposed in the pipe line 132 and communicated with the reservoir 118.
A pipe line 138 communicates with the reservoir 118, and a pump 140 is interposed in the pipe line 138. Branch lines 142, 144 and 146 communicate with the line 138,
A seventh opening / closing valve 148 is interposed in the pipe 142, and is connected to the fuel gas discharge pipe 102. Pipe line 1
An eighth opening / closing valve 150 is interposed in the valve 44, and the conduit 144 is formed in the through hole 86e of the second end plate 86.
Through the recess for supplying cooling water 48e. On the other hand, the pipe 146 is provided with a ninth opening / closing valve 152, and the pipe 146 is connected to the oxidizing gas discharge pipe 122.
It is connected to the. The recess 48b of the separator body 48 communicates with the reservoir 118 via the through hole 84b of the first end plate and the pipe 154, and the radiator 156 and the tenth on-off valve 158 are inserted in the pipe 154. . A fan 160 for forced cooling faces the radiator 156.

The fuel cell control system according to this embodiment is basically constructed as described above.
Next, the operation will be described with reference to FIGS.

FIG. 10 shows a state in which the fuel cell is in operation. In this case, the hydrogen gas H ₂ as the fuel gas humidified by the external humidifier is supplied to the fuel gas supply pipeline 100, so that the first on-off valve 104 is in the open state and the second on-off valve 106 is open. Is also open.

On the other hand, the third on-off valve 110 of the first bypass line 108 maintains the closed state. On the oxidant gas supply side, the fourth on-off valve 124 is in the open state, and the fifth on-off valve 12
6 is also open. Then, the sixth on-off valve 130 interposed in the second bypass conduit 128 maintains the closed state. The on-off valves 148 and 152 are closed, and the on-off valves 150 and 1 are
58 remains open. In this case, the pump 1 being driven
The water supplied from the reservoir 118 by the 40 passes through the separator body 48, removes the heat in the fuel cell, and cools (composed of the radiator 156 and the fan 160).
Then, it is cooled and returned to the reservoir 118. It is preferable that the water thus supplied contains almost no ionic conductive component and has a specific resistance of 14 mΩ · cm or more. As a result, the hydrogen gas H supplied from the fuel gas supply pipeline 100
Reference numeral ₂ denotes a fuel gas supply recess 42a of the first manifold plate 42, which is closed by a first end plate 84 on the most downstream side of the fuel gas flow path after being subjected to a power generation action through the fuel cell unit 20, It returns in the opposite direction through the groove 80a of the plate 80 and the fuel gas discharge recess 42d, and reaches the fuel gas discharge pipe line 102. Then, it passes through the second on-off valve 106, is cooled by the water condenser 112, and is separated into unreacted hydrogen and liquid, that is, water by the steam separator 114. The water thus separated passes through the conduit 116 and the reservoir 118.
Go back. Similarly, the oxidant gas O ₂ humidified by the external humidifier is supplied to the oxidant gas supply pipe 120, the fourth opening / closing valve 124,
Through the through hole 84c of the first end plate 84 to reach the oxidant gas supply recess 50c of the second manifold plate 50,
The recess 5 for discharging the oxidant gas passes through the groove 82a of the straightening plate 82.
Reach 0f.

As shown in FIGS. 1 and 2, the second end plate 86 is in contact with the second manifold plate 50 and the rectifying plate 82 fitted therein.
The groove 82a is closed by the flat second end plate 86. Therefore, when the oxidant gas (air) reaches the oxidant gas supply recess 50c of the second manifold plate 50 on the most downstream side, the oxidant gas is supplied to the recess 50c.
Through the groove 82a to reach the oxidant gas discharge recess 50f of the second manifold plate 50. Then, it passes through the hole 48f of the separator body 48, the hole 42f of the first manifold plate 42, and the like, and is led out from the through hole 84f of the first end plate 84 to the conduit 122 side.

The cooling water passes from the conduit 144 through the through hole 86e of the second end plate 86, the hole 50e of the second manifold plate 50, and the recess 4 of the separator body 48.
8e to groove 70a of the current plate 70, groove 72a of the current plate 72
Through the passage defined by
To reach the concave portion 48b. Then, finally, it passes through the through hole 84b of the first end plate 84, and the pipe line 154
Is returned to the reservoir 118. Therefore, from the fuel cell 20 to the published publication WO94 / 15377 during this period.
A direct current will be taken out through the process as shown in No.

Next, the operation when the fuel cell is stopped will be described below with reference to FIG.

First, on the fuel gas side, the first opening / closing valve 104,
The second on-off valve 106 is closed and the third on-off valve 1
Ten is opened. On the other hand, on the oxidant gas side, the fourth opening / closing valve 124 and the fifth opening / closing valve 126 are closed and the sixth opening / closing valve 124 is closed.
The on-off valve 130 is opened. As a result, the supply of fuel gas and oxidant gas is stopped. At that time, the fuel gas remaining in the pipeline 100 is discharged to the first steam separator 114 side through the first bypass pipeline 108. On the other hand, the oxidant gas remaining in the pipe 120 is led to the second steam separator 136 side through the second bypass pipe 128.

Next, the seventh on-off valve 148 and the ninth on-off valve 15
2 is opened and the on-off valves 150 and 158 are closed. The water supplied from the reservoir 118 by the driving pump 140 passes through the pipe lines 142 and 146 to the second end plate 86, the first manifold plate 42, the first end plate 84, and the second manifold plate 50 side. be introduced. At this time, the water is the first manifold plate 4 respectively.
2 and the second manifold plate 50 are gradually filled from the lower side to the upper side.

As a result, the fuel gas existing in the fuel gas supply pipe 100 passes through the second end plate 86, the first bypass pipe 108 and the third opening / closing valve 110, and passes through the water condenser 1
The first steam separator 114 is reached via 12. The water separated by the first steam separator 114 is introduced into the reservoir 118, and the fuel gas is discharged to the outside. On the other hand, on the oxidant gas supply side, it passes through the second bypass bus line 128 and the sixth on-off valve 130, and reaches the second steam separator 136 from the pipe line 132 through the second water condenser 134. The water separated by the second steam separator 136 is introduced into the reservoir 118,
The oxidant gas is discharged to the outside.

In this way, when the anode side electrode plate 26 and the cathode side electrode plate 24 and the respective gas supply passages are filled with water and detected by the detecting means, the pump 1
The urging of 40 is stopped, and the stopped state is maintained. In the meantime, the first manifold plate 42 and the second manifold plate 5
The solid polymer electrolyte membrane 22 sandwiched between 0s and the electrode plates 24 and 26 is kept in a wet state. When the water is filled, the third on-off valve 1
10, the sixth opening / closing valve 130, the seventh opening / closing valve 148, and the ninth opening / closing valve 152 are closed.

Next, the case of further restarting the fuel cell in which the stopped state is maintained as described above will be described.

In this state, the first opening / closing valve 104 to the tenth opening / closing valve 158 are in the closed state as described above. Therefore, referring to FIG. 12, the second opening / closing valve 106 and the fifth opening / closing valve 126 are opened. As a result, the water filled in the first manifold plate 42, the separator body 48, the second manifold plate 50, etc. is discharged through the pipe lines 116 and 132, and the reservoir 118 via the steam separators 114 and 136. Leading to.

Next, the first opening / closing valve 104 and the fourth opening / closing valve 1
24 is opened. As a result, the fuel gas is introduced through the conduit 100 and the oxidant gas is supplied to the conduit 120. Therefore, the second on-off valve 106 and the fifth on-off valve 12
The water discharged via 6 will be rapidly discharged to the reservoir 118 under the pressure of the fuel gas and the oxidant gas, respectively. Further, the opening / closing valves 150 and 158 are opened, the pump 140, the radiator, and the fan 160 are driven, and the fuel cell cooling system reaches a restart state.

As a result, the fuel cell is ready to generate electricity, a desired voltage is taken out from the fuel cell 20 and the restart of the fuel cell is completely achieved.

In the embodiment of the present invention, after the fuel cell is once stopped as described above, water is forcibly supplied to both the anode side and the cathode side, and water is kept in the fuel cell until restarting. Keep full

Therefore, there is no possibility that the working gas remaining in the fuel cell will cross-leak the electrolyte membrane and catalytically burn. As a result, it is possible to prevent damage to the fuel cell unit.

Furthermore, since the ionic conductive component such as the electrolyte membrane is maintained in a high water content state even when the fuel cell is stopped, it is not dried, resulting in a low ionic conductive resistance. The result is that the restart can be achieved very easily and in a short time.

In the above-described embodiment, the detection means is used to detect that the fuel cell is full when the fuel cell is stopped. A concrete configuration example thereof is shown in FIG.

In the configuration example of FIG. 13, for example, the hole 50a of the second manifold plate 50 and the second surface pressure generating plate are centered on the fuel gas supply recess 48a of the separator body 48 and extend from the upstream side to the downstream side. The communication path 200 defined between the communication hole 46a of the first manifold plate 42 and the recess 42a of the first manifold plate 42 includes a first detection pair 300 and a second detection pair 4.
00 and are provided. Each detection pair 300 and 400
Is preferably composed of light emitting elements 300a and 400a and light receiving elements 300b and 400b. In this case, the respective detection pairs 300 and 400 may be tilted in the direction perpendicular to each other.

In the above-described structure, when the water rises from the lower side to the upper side as described above at the time of stop and finally reaches the communication passage 200, the light emitting element 300a or 400a.
The light emitted from does not reach the light receiving element 300b or 400b, and the full state is confirmed.

As described above, the first and second detection pairs 300 and 400 are tilted so that the optical paths intersect each other when the fuel cell is incorporated in a vehicle or the like and used as a power source. This is to ensure that full water can be detected even if the vehicle is stopped in a tilted state.

FIG. 14 shows another embodiment of the present invention.
In this embodiment, another mode of the second manifold plate 50 is shown, but it goes without saying that the second manifold plate 50 and the separator body 48 can also be used.

As can be seen from the figure, the manifold plate 500 connects the oxidizing gas supply hole portion 500c and the oxidizing gas discharge hole portion 500f by a labyrinth passage 502. In the figure, reference numeral 500a indicates a fuel gas supply hole, while reference numeral 500d indicates a fuel gas discharge hole. Then, reference numeral 500b
Indicates a hole for discharging cooling water, and reference numeral 500e.
Indicates a hole for supplying cooling water.

In this structure, since the oxidant gas passes through the single labyrinth-like passage 502, unlike the straightening plate 82 which defines parallel grooves, the oxidant gas is evenly distributed on the cathode side. Since it can be distributed to the electrode plate 24 and the rectifying plate 82 is not necessary, the number of parts can be reduced.

FIG. 15 is a view showing still another embodiment of the manifold plate shown in FIG. 2, which is a front view of the manifold plate having flow passages in which labyrinth-like passages are divided in parallel. 16 is a sectional view taken along line XVI-XVI of FIG. As a result of dividing the passages in parallel in this way, an effect that the gas pressure in the passages becomes uniform can be obtained.

[0058]

As described above, according to the present invention, in the solid polymer electrolyte membrane fuel cell, at least when the fuel cell is in the stopped state, the fuel gas supply passage and the oxidation are defined inside the separator. Humidifying fluid in the agent gas supply passage,
For example, it is filled with water, and as a result, the ion exchange component such as the electrolyte membrane is always kept in a wet state in the stopped state. Then, at the time of restart, the fuel gas and the oxidant gas are forcibly fed into the passage filled with the humidifying fluid, and as a result, the supply pressure of the fuel gas and the oxidant gas is further increased in the gravity direction of the humidifying fluid. Therefore, the humidifying fluid can be forcedly and quickly discharged to the outside.

Therefore, since the electrolyte membrane is always in a wet state without falling into a dry state, the fuel cell can be restarted quickly.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a connection relationship between a fuel cell of the present invention and a piping system.

2 is a partially omitted exploded perspective view of the fuel cell shown in FIG. 1. FIG.

FIG. 3 is a front view of a solid polymer electrolyte membrane and electrodes shown in FIG.

FIG. 4 is a front view of the gasket shown in FIG.

5 is a front view of the first manifold plate shown in FIG. 2. FIG.

6 is a front view of the second manifold plate shown in FIG. 2. FIG.

FIG. 7 is a front view of the surface pressure generating plate shown in FIG.

FIG. 8 is a front view of the separator body shown in FIG.

9 is a perspective view of the current plate shown in FIG. 2. FIG.

FIG. 10 is a diagram showing an open / closed state of a valve, which is interposed in a cooling passage of the fuel cell according to the present invention, during operation.

FIG. 11 is a diagram showing an open / closed state of a valve, which is interposed in a cooling passage of the fuel cell of the present invention and is stopped.

FIG. 12 is a diagram showing an opened / closed state of a valve, which is interposed in a cooling passage of the fuel cell of the present invention, at the time of restarting.

FIG. 13 is a schematic diagram showing an arrangement state of a full water state detecting means in the fuel cell of the present invention.

FIG. 14 is a front view showing another embodiment of the manifold plate shown in FIG.

15 is a view showing still another embodiment of the manifold plate shown in FIG. 2, and is a front view of the manifold plate having a flow path in which a labyrinth-shaped passage is divided in parallel.

FIG. 16 is a sectional view taken along line XVI-XVI in FIG. 15;

[Explanation of symbols]

20 ... Fuel cell 22 ... Solid polymer electrolyte membrane 24 ... Cathode side electrode plate 26 ... Anode side electrode plate 28 ... Cell body 30, 32 ... Gasket 40 ... Separator 42, 50 ... Manifold plate 44, 46 ... Surface pressure generating plate 48 ... Separator body 70, 72 ... Cooling water rectifying plate 80 ... Fuel gas rectifying plate 82 ... Oxidizing gas rectifying plate 84, 86 ... End plate

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Akio Yamamoto 1-4-1 Chuo, Wako-shi, Saitama Honda R & D Co., Ltd. (72) Inventor Ichiro Tanaka 1-4-1 Chuo, Wako-shi, Saitama Co., Ltd. Honda R & D Laboratory

Claims (12)

[Claims] 1. A fuel cell comprising a solid polymer electrolyte membrane sandwiched between an anode-side electrode plate and a cathode-side electrode plate, wherein at least a fuel gas passage or an oxidant gas passage is humidified for the solid polymer electrolyte membrane. A solid polymer electrolyte membrane fuel cell characterized in that inlets and outlets for supplying and discharging a fluid are respectively provided, and the inlets and outlets are connected to a humidifying fluid supply source via a valve member. 2. The solid polymer electrolyte according to claim 1, wherein at least the fuel gas passage on the anode side or the oxidant gas passage on the cathode side is provided with detection means for detecting the full state of the humidifying fluid. Membrane fuel cell. 3. The solid polymer electrolyte membrane fuel cell according to claim 2, wherein the detecting means is a light detecting means using a light emitting element and a light receiving element. 4. The fuel cell according to claim 2 or 3, wherein the detection means are provided in two pairs in the humidifying fluid passage, and the respective detection means are arranged to be inclined with respect to each other in the horizontal direction. Solid polymer electrolyte membrane fuel cell. 5. The fuel cell according to claim 1, wherein the anode side fuel gas passage has a first passage for supplying a fuel gas, and a first opening / closing provided in the first passage. A valve, a second passage for discharging the fuel gas from the anode side fuel gas passage, a second opening / closing valve interposed in the second passage, and the first and second passages are bypass-connected. A third passage, a third opening / closing valve provided in the third passage, a fourth passage for supplying an oxidizing gas to the cathode-side oxidizing gas passage, and a fourth passage provided in the fourth passage. A fourth on-off valve, a fifth passage for discharging the oxidant gas from the cathode-side oxidant gas passage, a fifth on-off valve interposed in the fifth passage, and the fourth and fifth A sixth passage for bypass-connecting the passage and a sixth opening / closing valve interposed in the sixth passage. Solid polymer electrolyte membrane fuel cell according to symptoms. 6. The fuel cell according to claim 1, wherein a labyrinth-shaped passage is defined in the separator for fuel gas supply, oxidant gas supply, or humidification fluid supply. A solid polymer electrolyte membrane fuel cell characterized by the above. 7. The solid polymer electrolyte membrane fuel cell according to claim 6, wherein the labyrinth-shaped passage is divided into a plurality of passages each having a smaller width. 8. The solid polymer electrolyte membrane fuel cell according to claim 1, wherein the humidifying fluid is deionized water. 9. A method for controlling a solid polymer electrolyte membrane fuel cell, wherein a fuel gas supply passage and an oxidant gas supply passage are provided at least on the anode side and the cathode side, respectively, when the fuel cell is stopped. A humidifying fluid is supplied to the inside of the fuel cell from below, and the humidifying fluid is held inside the fuel gas supply passage and inside the oxidant gas supply passage while the stopped state of the fuel cell is maintained. Control method of molecular electrolyte membrane fuel cell. 10. The method according to claim 9, wherein when the humidifying fluid is supplied to the fuel gas supply passage and the oxidant gas supply passage, the fuel gas remaining in the fuel gas supply passage and the oxidant gas supply passage. And a oxidant gas are forcibly discharged to the outside of the fuel cell by the humidifying fluid, a method for controlling a solid polymer electrolyte membrane fuel cell. 11. The method according to claim 9 or 10, wherein when the stopped state of the fuel cell is finished and the fuel cell is restarted, the fuel gas supply passage on the anode side and the oxidant gas supply passage on the cathode side are provided. A method for controlling a solid polymer electrolyte membrane fuel cell, comprising: forcibly discharging the humidified fluid retained by the fuel gas and the oxidant gas to the outside of the fuel cell. 12. The method for controlling a solid polymer electrolyte membrane fuel cell according to claim 9, wherein the humidifying fluid is deionized water.