JPH11273705A - Fuel cell system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent damage caused by freezing of water by recovering the whole water in a fuel cell system after finishing operation. SOLUTION: A solenoid valve 124 is closed, a solenoid valve 56 is opened, and a water supply pump 54 is driven to send water in a replenishing pipe 52 to a main tank 20. Water collected in water supply pipe 40, a fuel cell module 18, and a water exhaust pipe 44 is returned to a main tank 20 by driving a circulation pump 46. Water in the main tank 20 is recovered to a sub-tank 16 by driving a recovering pump 132 through a pump-up pipe 130. Then, the sub-tank 16 is demounted from a system and stored. Since the whole water in a water circulation line of in a fuel cell system is recovered into the sub-tank 16, frozen water may not exist in the system.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel cell device for generating electrical energy by electrically reacting hydrogen fuel with atmospheric oxygen.

[0002]

2. Description of the Related Art In a polymer electrolyte fuel cell, not all chemical energy of supplied fuel is converted into electric energy, and in many cases, more than half of chemical energy is converted into heat energy.

In order to discharge the generated heat to the outside of the polymer electrolyte fuel cell, a fuel cell device supplies water from a water storage tank to a fuel flow passage of the polymer electrolyte fuel cell through a water supply pipe. The polymer ion exchange membrane is moistened and the polymer electrolyte fuel cell is cooled, and unconsumed water is drained to a water storage tank through a drain pipe.

If the fuel cell device having such a configuration is installed outdoors in a cold region and is not operated for a certain period of time, water remaining in the polymer electrolyte fuel cell, the water storage tank, the water supply pipe, and the drain pipe is discharged. It may freeze and become inoperable, or the device may be damaged by the expansion pressure when the water freezes.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above-described circumstances, and has as its object to provide a fuel cell device that can avoid inconvenience caused by freezing of water.

[0006]

According to the first aspect of the present invention, a polymer electrolyte fuel cell electrochemically reacts hydrogen in a fuel gas with oxygen in the atmosphere by intervening water. Generates electrical energy. For polymer electrolyte fuel cells,
Water is supplied and cooled by the water supply means. Excess water is drained from the polymer electrolyte fuel cell through drainage means.

[0007] The fuel cell device is provided with a collecting means. When the collecting means is operated after the operation is completed, the water remaining in the polymer electrolyte fuel cell, the water supply means and the drainage means is collected.

For this reason, even if the fuel cell device is installed outdoors in a cold region and the operation is stopped for a certain period of time, since the frozen water does not exist in the device, the operation becomes impossible or the device may be damaged. Nothing. In addition, the collected water (usually pure water is used for the fuel cell device) can be managed indoors without being disposed of, and can be returned to the fuel cell device and used again. , Can be operated economically.

According to the second aspect of the present invention, the collecting means includes:
A main tank for supplying water to the water supply means and returning water through the drainage means, a sub-tank for replenishing water to the main tank through the replenishment means, a connecting means for detachably attaching the sub-tank to the replenishment means, and a main tank And a pumping means for pumping water into the sub-tank.

In this configuration, the replenishing means is stopped, and the replenishment of water from the sub tank to the main tank is stopped. Here, while returning the water remaining in the polymer electrolyte fuel cell, the water supply means, and the drainage means to the main tank, the pumping means is operated to pump the water in the main tank to the sub tank. After all the water in the main tank has been pumped to the sub-tank, the connecting means is operated to remove the sub-tank from the replenishing means.

As a result, all the water in the fuel cell device is collected in the sub-tank, and the sub-tank is stored in a room or the like, thereby completing the water collecting operation. Further, when the operation of the fuel cell device is started the next day, it is only necessary to set the sub-tank to the replenishing means via the connecting means, so that there is no complicated handling.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIGS.
The fuel cell device 10 according to the embodiment is stored in a box-shaped storage case 12 that has been subjected to a waterproof treatment. The storage case 12 is
The control device 14 and the sub tank 16 are housed in the upper stage. In addition, storage case 1
The fuel cell module 18 is housed in the middle part of the unit 2, and the main tank 20 and the inverter 22 are housed in the lower part.

The hydrogen cylinder 24 is provided in the storage case 12.
And can be easily replaced by opening the door 12A.

As shown in FIGS. 3 and 4, the fuel cell module 18 has an electrode / polymer membrane assembly in which a cathode 30 is joined to the front surface of a polymer ion exchange membrane (not shown) and an anode 26 is joined to the back surface. Have. The cell 32 is formed by sandwiching the electrode / polymer membrane assembly between the bipolar plates, and a plurality of (in this example, 50) cells 32 are stacked to form the fuel cell module 18.

A joint pipe 38 is connected above the fuel cell module 18, and water is supplied from the main tank 20 to the fuel cell module 18 via a water supply pipe 40. This water serves to cool the fuel cell module 18 and wet the polymer ion exchange membrane.

On the other hand, below the fuel cell module 18, an L-shaped joint pipe 42 is attached. Fitting tube 4
2 is connected to a drain pipe 44 and the fuel cell module 1
8 discharges water.

As shown in FIG. 2, the drain pipe 44 penetrates through the top wall 20A of the closed main tank 20, and is connected to the gas phase portion A formed between the stored water W and the top wall 20A. Has reached. In this way, the water in the drain pipe 44 is completely recirculated into the main tank 20 by adopting a method of dropping water without entering the downstream port of the drain pipe 44 into the water W.

A water supply pipe 40 is connected below the side wall of the main tank 20. Then, water is supplied to the fuel cell module 18 by the circulation pump 46 through the cooling filter 48 (see FIG. 3). Further, on the bottom wall of the main tank 20, an electromagnetic valve 50 for draining which is opened and closed by the control device 14 is provided.

On the other hand, as shown in FIGS. 3 and 4, the sub-tank 1 stored in the upper stage of the storage case 12 (see FIG. 2)
6 is connected to the main tank 20 through a refill pipe 52. The refill pipe 52 is provided with a water pump 54 and an electromagnetic valve 56, and receives a signal from a water level sensor 58 provided at a fixed time or at the bottom of the main tank 20 to supply pure water from the sub tank 16 to the main tank 20. Refill the tank 20.

As shown in FIG. 5 and FIG.
A cap 112 having a piston 110 that reciprocates in the cylinder 109 is screwed into the opening 16A of the sixth. The piston 110 is urged by a spring 111 toward a spout 114 of a cylinder 109 whose diameter is reduced in a mortar shape. Then, on the inner peripheral surface of the spout 114,
The O-ring 116 attached to the tip of the piston 110 is fitted to the spout 114 even if the sub tank 16 is inverted.
It is configured not to leak water from.

The gantry 1 on which the sub tank 16 is mounted
A circular pool 120 is formed at 18. A pin 122 is erected from the bottom wall of the water reservoir 120. The pin 122 is attached to the puddle 120 by the cap 11.
When 2 is inserted, the piston 110 is pushed up against the urging force of the spring 116, and the water in the sub-tank 16 flows out into the pool 120.

Further, the replenishing pipe 5 is
Two terminals are connected. An electromagnetic valve 124 that is opened and closed by the control device 14 is disposed at the terminal. Further, a joint pipe 126 is provided on the upper side of the sub tank 16. A pumping pipe 130 is connected to the joint pipe 126 via a detachable rubber pipe 128.

The downstream part of the pumping pipe 130 is connected to the bottom wall of the main tank 20, and the water in the main tank 20 is pumped by the recovery pump 132 to the sub-tank 16 and recovered.

Next, the operation of the fuel cell device according to this embodiment will be described. When the start / stop button 84 of the operation panel 82 shown in FIG. 1 is pressed, the fuel cell device 10 is started, and the pressure is reduced from the hydrogen cylinder 24 through the regulator 60 and the solenoid valve 62 as shown in FIG. The hydrogen gas is supplied to the anode 26 of the fuel cell module 18.

When hydrogen is supplied to the anode 26, the hydrogen emits electrons to become hydrogen ions, and moves with the water in the polymer ion exchange membrane. The transferred hydrogen ions reach the cathode 30 and react with oxygen in the air supplied from the outside by the multiblade fan 64 to generate water. As a result, electrons flow from the anode 26 through an external circuit, and DC power is generated.

At this time, the main tank 20 is moved so that hydrogen ions can move through the polymer ion exchange membrane without resistance.
The water is supplied to the fuel cell module 18 through the water supply pipe 40 to keep the polymer ion exchange membrane wet and to cool the fuel cell module 18. Then, the water that has not been consumed reaches the joint pipe 42 by gravity.

[0027] Four drainage pipes 44 are connected to the joint pipe 42 to form an independent drainage system.
Make sure that water from the fuel cell module 18 is
It can be refluxed to zero.

On the other hand, a small amount of hydrogen gas supplied to the fuel cell module 18 and not reacted is sent to the gas phase portion A of the main tank 20 through the pipe 68. The main tank 20 is sealed, and a small amount of hydrogen gas guided to the main tank 20 passes through a hydrogen exhaust pipe 76, passes through a needle valve 72, and reaches a mixer 74. The fuel cell module 18
The unreacted air supplied to the mixer reaches the mixer 74 through the air exhaust pipe 77. In the mixer 74, a trace amount of hydrogen gas is sufficiently diluted with air and then released to the atmosphere.

When the water consumed in the fuel cell module 18 evaporates and the water level in the main tank 20 drops, a water level sensor 58 provided at the bottom sends a signal to the control device 14. The control device 14 opens the electromagnetic valve 56 and drives the water supply pump 54 to send the pure water stored in the sub tank 16 to the main tank 20 through the replenishment pipe 52, thereby enabling continuous operation.

On the other hand, the DC power generated by the fuel cell module 18 is converted into a predetermined voltage by a DC / DC converter 94 constituting the inverter 22, converted from DC to AC by an AC / DC inverter 96, and output from an AC output terminal. 98
To supply constant AC power. Further, the fuel cell device 10 of the present embodiment is a self-contained type, and is not supplied with electric power from the outside.

For this purpose, a secondary battery 78 as a power source used at the time of starting is provided. The secondary battery 78 is charged by the charging circuit 80 with surplus power at the time of power generation.

Next, referring to the flowchart of FIG.
The water recovery operation mode will be described. After pressing the run / stop button 84 (see FIG. 1) of the operation panel 82 again to end the operation of the fuel cell device 10, in step 200, pressing the collection button 136 switches to the collection operation mode.

Next, at step 202, the solenoid valve 1
24 is closed. Next, at step 204, the solenoid valve 5
6 is opened and the water supply pump 54 is driven so that the refill pipe 52
Drop the water in the main tank 20. Step 206
Then, the circulation pump 46 is driven to return the water retained in the water supply pipe 40, the fuel cell module 18, and the drain pipe 44 to the main tank 20, and in step 208, the collection pump 132 is driven for a predetermined time, and The water in the tank 20 is collected in the sub tank 16.

Here, when the rubber pipe 128 is removed from the joint pipe 126 of the sub-tank 16 and the sub-tank 16 is lifted, the piston 110 is moved downward by the urging force of the spring 111, and the O-ring 116 and the spout 114 are fitted. Combine. Therefore, water does not leak from the sub tank 16. Further, the limit switch 138 is operated, and the power supply of the fuel cell device is turned off.

As described above, since all the water in the water circulation system in the fuel cell device 10 is collected in the sub-tank 16, there is no freezing water in the device. For this reason, the operation is not disabled and the device is not damaged.

Further, by managing the sub-tank 16 indoors without discarding the collected water, the sub-tank 16 can be returned to the fuel cell device and used again, thereby enabling economical operation.

Further, the fuel cell device 10 can be operated only by setting the sub tank 16 on the gantry 118, so that there is no complicated handling.

[0038]

Since the present invention has the above-described structure, all the water in the fuel cell device can be recovered after the operation is completed. Therefore, damage due to freezing does not occur. Further, since the recovered water can be reused, economical operation can be performed.

[Brief description of the drawings]

FIG. 1 is an external view of a fuel cell device according to an embodiment.

FIG. 2 is a cross-sectional view of the inside of the fuel cell device according to the embodiment.

FIG. 3 is a schematic perspective view of a water circulation system of the fuel cell device according to the embodiment.

FIG. 4 is a block diagram of a fuel cell device according to the present embodiment.

FIG. 5 is a cross-sectional view showing a connection structure of a sub-tank of the fuel cell device according to the embodiment.

FIG. 6 is a cross-sectional view showing a connection structure of a sub-tank of the fuel cell device according to the present embodiment.

FIG. 7 is a flowchart showing the operation of the fuel cell device according to the embodiment.

[Explanation of symbols]

 14 Control device (control means) 16 Sub tank (recovery means) 18 Fuel cell module (polymer electrolyte fuel cell) 20 Main tank 40 Water supply pipe (water supply means) 42 Joint pipe (drain means) 44 Drain pipe (drain means) 46 Circulation pump (water supply means) 52 Refill pipe (refill means) 54 Water supply pump (refill means) 112 Cap (connection means) 120 Water reservoir (connection means) 122 Pin (connection means) 124 Solenoid valve (recovery means) 130 Pumping pipe (Pumping means, collecting means) 132 Collection pump (pumping means, collecting means)

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Koji Shindo 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd.

Claims (2)

[Claims] 1. A polymer electrolyte fuel cell that generates electric energy by electrochemically reacting hydrogen in a fuel gas with oxygen in the atmosphere based on the presence of water, and Water supply means for supplying water; drainage means for draining water of the polymer electrolyte fuel cell; collection means for collecting water remaining in the polymer electrolyte fuel cell, the water supply means, and the drainage means; A fuel cell device comprising: 2. The water supply means according to claim 2, wherein said recovery means supplies water to said water supply means and returns water through said drainage means, a sub-tank for replenishing water to said main tank through replenishment means, and said sub-tank comprises: 2. The fuel cell device according to claim 1, further comprising: a connecting means detachable from the replenishing means; and a pumping means for pumping water in the main tank to the sub tank.