JPH11111317A - Water-supplying device for fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably and continuously generate power by maintaining a liquid level difference between a communicating tube and a water-circulating pipeline for connecting a fuel battery main body to a water tank, so as to correspond to the difference between the fuel gas pressure at an outlet of a fuel cell main body and the atmospheric pressure for preventing the intrusion of the fuel gas from the fuel cell main body into the water tank. SOLUTION: For operating a fuel cell and stably generating power, a water- circulating pipeline 74 for connecting a fuel cell main body 3 to a water tank 19 is sealed with water so as to prevent the intrusion of the fuel gas from the fuel cell main body into the water tank 19. The length of a communicating pipe 75 and the water-circulating pipeline 74 are set and quantity of water in the water tank 19, and the communicating pipe 75 is adjusted so as to maintain the difference between a liquid level 76 in the communicating pipe 75 and a liquid level 77 in the water-circulating pipeline at a liquid level difference, corresponding to a difference of the fuel gas pressure at an outlet 84 of the fuel cell main body and the atmospheric pressure and for maintaining the liquid level 77 to be higher than the lowest part 85.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a water supply device for a fuel cell.

[0002]

2. Description of the Related Art Conventionally, a fuel cell body, a storage battery, a fuel supply source, a controller and the like are provided, and surplus power after supplying power generated in the fuel cell body to an external load is stored in the storage battery. 2. Description of the Related Art There is known a fuel cell which supplements electric power from a storage battery and supplies it to an external load when generated electric power is insufficient. Among such fuel cells, a mobile fuel cell in which a fuel cell main body, a storage battery, a fuel supply source, various controllers, and the like are mounted inside a case is also known. Since such mobile fuel cells are excellent in portability, many expectations have been gathered as power supplies for civil engineering and construction work, home emergency power supplies, and the like.

[0003] There are two types of fuel cells: acidic fuel cells and alkaline fuel cells. The characteristics of a polymer electrolyte fuel cell, one of the acidic fuel cells, will be described below. As shown in FIG. 6, the polymer electrolyte fuel cell uses a polymer ion exchange membrane (for example, a fluororesin-based ion exchange membrane having a sulfonic acid group) for the electrolyte 01, and a catalyst electrode (for example, platinum) on both sides thereof. Etc.) and an electrode assembly 06 including current collectors 02 and 03 and current collectors 04 and 05.

[0004] Hydrogen in the humidified fuel supplied to the anode electrode is hydrogen-ionized on the catalyst electrode (anode electrode) 02, and the hydrogen ions pass through the electrolyte 01 with H ^+. _{As 2} O, it moves together with water to the cathode electrode side. The transferred hydrogen ions react with oxygen in the oxidant (for example, air) on the catalyst electrode (cathode electrode) 03 and the electrons flowing through the external circuit 07 to generate water. The generated water is transported from the cathodes 03 and 05 to the remaining oxidant and discharged out of the fuel cell. At this time, the flow of electrons flowing through the external circuit 07 can be used as DC electric energy.

In order to realize the above-mentioned hydrogen ion permeability in the polymer ion exchange membrane serving as the electrolyte 01, it is necessary to keep the polymer ion exchange membrane in a sufficiently water-retaining state at all times. Yes, for example, the fuel or oxidant is made to contain saturated water vapor corresponding to the vicinity of the operating temperature of the fuel cell (normal temperature to about 100 ° C.), that is, humidified to supply the fuel and the oxidant to the electrode assembly 06 to retain the water of the membrane. I try to keep my condition. In addition, the fuel cell generates heat during operation and needs to be cooled.

On the other hand, in the case of an alkaline fuel cell, hydroxyl ions move in the electrolyte and react with fuel gas (hydrogen gas) on the anode electrode to generate water. The generated water is transported from the anode to the remaining fuel gas and discharged out of the fuel cell.

A conventional fuel cell disclosed in Japanese Patent Application Laid-Open No. 6-310166 reforms a fuel cylinder 1 and an aqueous methanol solution jetted from the fuel cylinder 1 into a hydrogen component as shown in FIG. The fuel reformer 2 includes a fuel reformer 2, a fuel cell main body 3 for generating power using the hydrogen-based gas as fuel, and a case 5 for housing these components. The fuel cylinder 1 is detachably connected to the fuel reformer 2. . Reference numeral 4 denotes a control device.

On the other hand, a conventional fuel cell disclosed in Japanese Patent Application Laid-Open No. 9-171842, for example, as shown in FIG.
The inside of the case 5 is divided into spaces A, B, C, and D, and the hydrogen cylinder 1 housed in the space A on the left side of the case 5 and the case where power is generated using hydrogen supplied from the hydrogen cylinder 1 as fuel. 5, a storage battery 6 stored in a space C on the right side of the case 5, a storage battery 6 stored in a space C on the right side of the case 5, and a DC stored in a space D on the right side of the case 5.
The control unit 4 includes a power converter such as a / AC inverter and the like, and a closing lid 7 is provided at an upper part of the case 5.

[0009]

As described above, the fuel cell supplies water to the polymer ion exchange membrane and other electrolytes of the fuel cell in order to stably and continuously generate power.
It is necessary to cool the fuel cell body.
The conventional fuel cells disclosed in Japanese Patent Application Publication No. 0166 and Japanese Patent Application Laid-Open No. 9-171842 do not provide any means for supplying water to the electrolyte or cooling the fuel cell body, and have no suggestion. An object of the present invention is to provide a water supply device that is housed in a fuel cell and supplies water to an electrolyte of the fuel cell body or cools the fuel cell body in order to stably and continuously generate power. That is.

[0010]

In order to solve the above-mentioned problems, a first aspect of the present invention is to provide a fuel gas cylinder, a supply of a fuel gas and an oxidant in a case, and a supply of a fuel gas to a fuel gas flow path. A power supply unit having a fuel cell body for generating water by circulating water and a water tank for circulating and supplying water to the fuel cell body of a fuel cell containing a control device and the like are provided in the case. A water supply device, wherein the water tank is provided below the fuel cell main body and a communication pipe communicating with the atmosphere is provided,
When the operation of the fuel cell is stopped, the liquid level in the communication pipe is lower than the bottom surface of the fuel cell main body. During the operation of the fuel cell, the liquid level in the communication pipe and the water circulation connecting the fuel cell main body and the water tank are connected. The difference between the liquid level in the pipe and the liquid level in the water circulation pipe is maintained so that the difference between the fuel cell pressure at the outlet of the fuel cell main body and the atmospheric pressure corresponds to the liquid level difference. By setting the lengths of the communication pipe and the water circulation pipe so as to be able to be maintained above the lowermost part of the water circulation pipe, and adjusting the amount of water in the water tank and the communication pipe, the fuel cell The fuel gas from the main body is prevented from entering the water tank via the water circulation pipe.

In the present invention, power is supplied by receiving a fuel gas cylinder, a fuel gas such as hydrogen gas and methane gas, and an oxidizing agent such as air, and flowing water along with the fuel gas through a fuel gas distribution channel. A power supply unit including a fuel cell main body for producing high-temperature exhaust oxidizer and exhaust fuel gas, a power converter such as a DC / AC inverter for converting DC power generated by the fuel cell to AC, and a water supply unit for the fuel cell main body. A water supply device provided with a water tank and the like for circulating and supplying water, and a control device and the like for controlling these are compactly housed in a case.

The water tank is housed in, for example, a lower part of the rear of the fuel cell below a fuel cell body housed in the middle part of the rear part of the fuel cell, and is supplied to the fuel cell body by a pump or the like, and circulated. It is preferred to use.
The water tank is provided with a communication pipe communicating with the atmosphere, and when the operation of the fuel cell is stopped due to a power stop or the like, the liquid level in the communication pipe is always lower than the bottom of the fuel cell main body. The water in the tank does not flow back to the fuel cell main body, so that the fuel cell main body can be prevented from being submerged.

In order to operate the fuel cell and stably generate power, a water circulation pipe connecting the fuel cell main body and the water tank is sealed with a water seal, and the fuel gas from the fuel cell main body is used for water circulation. It is imperative to keep out of the water tank via the pipeline. In order to seal the water circulation pipe with water, the difference between the liquid level in the communication pipe and the liquid level in the water circulation pipe is
A liquid level difference corresponding to the difference between the fuel gas pressure and the atmospheric pressure at the outlet of the fuel cell body is maintained, and the liquid level in the water circulation pipe is higher than the lowermost part of the water circulation pipe. It is necessary to set the lengths of the communication pipe and the water circulation pipe so that they can be maintained, and to adjust the amount of water in the water tank and the communication pipe.

According to a second aspect of the present invention, in the water supply device for a fuel cell according to the first aspect, an auxiliary water tank connected to the water tank by a pipe leading to the water tank is located above the water tank. When the water in the water tank falls below a predetermined water level, water is supplied from the auxiliary water tank to the water tank via the pipe. The position where the auxiliary water tank is provided may be any position above the water tank, and may be provided in parallel with the fuel cell main body or may be provided further above the fuel cell main body. It can also be arranged in. By arranging an auxiliary water tank that replenishes water when the water in the water tank is consumed and falls below a predetermined water level, power generation can be performed more safely, stably and continuously.

According to a third aspect of the present invention, in the water supply device for a fuel cell according to the second aspect, an on-off valve is provided in the pipe leading to the water tank, and a liquid level in the water tank is detected. The opening and closing valve is opened and closed by a signal from the sensor. When the liquid level in the water tank drops and reaches the lower limit, the sensor detects it and sends a signal to a control device, and based on the signal, the control device sends a signal to the on-off valve such as a solenoid valve. Then, the on-off valve is opened to supply a predetermined amount of water from the auxiliary water tank to the water tank. And when the liquid level in the water tank rises and reaches the upper limit, the sensor detects it and sends a signal to the control device, based on which a signal is sent from the control device to the on-off valve, Close the on-off valve.

According to a fourth aspect of the present invention, in the water supply device for a fuel cell according to the second or third aspect, the auxiliary water tank is provided with a float switch, and the water in the auxiliary water tank is set to a predetermined value. When the water level falls below the water level, the fuel cell is stopped by a signal from the float switch, or a signal for lowering the water level is output. When the liquid level in the auxiliary water tank drops to the lower limit, a signal from the float switch is sent to a controller, and a signal is sent from the controller based on the signal to stop the fuel cell, or If a signal indicating a drop in the water level is output, safety is improved.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing the appearance of one embodiment of the fuel cell according to the present invention. FIG. 2 is an explanatory side view showing the inside of the fuel cell shown in FIG. FIG.
Indicates an electrical signal path (indicated by a dashed line in the figure) and a hydrogen gas path (3 in the figure)
It is an explanatory view showing an air path (displayed by a solid line in the figure), an electric power path (displayed by a thick solid line in the figure), and a water path (displayed by a broken line in the figure).

1 to 3, a fuel cell 10 according to the present invention has a structure in which a case 12 having an integral structure is partitioned into a front part A and a rear part B by a partition wall 11. Two fuel gas cylinders 1 are stored in the front part a in an upright state. The rear section B is divided into an upper section 13, a middle section 14, and a lower section 15, and houses a power supply section, a water tank 19, an auxiliary water tank 17, and the like. That is, the upper stage 13 has a secondary battery 44 or DC /
A control device 16 having a DC converter 46 and an auxiliary water tank 17 are housed therein, and the middle stage 14 houses a fuel cell main body 3 which is supplied with fuel and air as an oxidant and generates electricity by an electrochemical reaction. And the lower row 1
5 houses a DC / AC inverter 18 and a water tank 19 connected by a conduit 70 communicating with the auxiliary water tank 17.

Reference numeral 20 denotes a movable wheel. Reference numeral 21 denotes a handle to be used when moving, and reference numerals 22 and 22 denote rotatable auxiliary arm rods. The fuel cell 10 can be easily moved alone by using the movable wheel 20, the handle 21, and the like.

The case 12 has an L-shaped door 23 and an operation panel 24 on the front surface, and has two side surfaces 25 and 26, a rear surface 27 and a bottom surface 2
8, an upper surface 29, and a lid main body 30 that can be freely opened and closed to cover the front part A. Reference numeral 31 denotes an exhaust port provided at an upper portion of the door 23, and 32 denotes a side exhaust port for exhausting air or the like in the rear part B.

Here, the height of the case 12 is set slightly higher than the height of the fuel gas cylinder 1. The width of the front part a is set slightly larger than the sum of the two diameters of the fuel gas cylinder 1, the width of the exhaust duct 33, and the width of the operation panel 24, and the depth of the front part a is set slightly larger than the diameter of the fuel gas cylinder 1. ing.
The width and the depth of the rear part B are set slightly larger than the width and the depth of each member to be arranged. In this way, even if the case 12 is installed outdoors, water hardly penetrates, and the case 12 can be made compact.

As the fuel gas cylinder 1, for example, a commercially available one (10 L container, hydrogen amount 1.5 m ³ ) can be used. A hydrogen delivery valve 34 is provided at the upper end of each fuel gas cylinder 1, and the hydrogen delivery valve 34 and the fuel cell main body 3 are connected by a hydrogen supply pipe 35. Further, a pressure gauge 51 for displaying the pressure in the fuel gas cylinder 1, a regulator 47, and a solenoid valve 48 are inserted at predetermined positions of the hydrogen supply pipe 35.

The operation panel 24 has a digital display 3
6. A start / stop button 37, a display switching button 38, and the like are provided. By pressing the start / stop button 37, the operation of the fuel cell 10 can be started or stopped. By pressing the display switching button 38, the content displayed on the digital display unit 36 is changed to, for example,
The display can be switched to AC output, fuel pressure, or other display. Reference numeral 39 denotes a water-resistant outlet. The operation panel 24 may be provided with alarm lamps for warning of an overload state, replacement of the fuel gas cylinder 1, and the like, and a display unit for displaying an error or the like.

An exhaust duct 33 for discharging exhaust air from the fuel cell body 3 to the outside of the case 12 is provided in the front part A. One end of the exhaust duct 33 is fixed to the exhaust air outlet 60 side of the fuel cell main body 3, and is fixedly attached to the partition 11 in the vicinity of the exhaust air outlet 60, and the other end is, for example, at the tip thereof. It is in close contact with an exhaust port 31 provided on the door 23 via a packing provided. Therefore, the exhaust air does not leak into the front part a. Although the position of the exhaust duct 33 in the front part A is not particularly limited, it is preferable to provide the exhaust duct 33 as close to the fuel cell body 3 as possible.

A plurality of baffle plates 61 are provided inside the exhaust duct 33, and the high-temperature exhaust air flowing as shown by the white arrow contacts the baffle plate 61 and contains the contained moisture (water). The generated water and part of the circulating water are condensed on the inner surface of the exhaust duct 33 and the surface of the baffle plate 61, and the exhaust air from which the water has been separated is discharged to the outside of the case 12. The separated water collects in a drain pipe 62 provided at a lower portion by a gradient provided in the exhaust duct 33 as indicated by an arrow, and temporarily enters a drain tank 41 provided in connection with the drain pipe 62. It is stored. The lower part of the drain pipe 62 is used as a part of the drain tank 41. When the lower portions of the drainage tank 41 and the drainage pipe 62 are full of water, the drainage is drained out of the case 12 by manually opening an on-off valve 63 provided at the end of the drainage tank 41, for example.
Alternatively, the water can be discharged to the outside of the case 12 by detecting this with a sensor (not shown) and sending a signal to the control device 16 and opening the on-off valve 63 by a signal from the control device 16. The generated water can be recycled without draining.

Numeral 40 designates pumping water from the water tank 19 as shown in FIG. 3, supplying the water to a fuel gas distribution path, distributing the fuel gas together with the fuel gas, supplying the fuel gas to the polymer ion exchange membrane of the fuel cell body 3, and constantly retaining water. It is a circulation pump for keeping the state and cooling the fuel cell body 3, and water is circulated for use.

Reference numeral 42 denotes a fan which takes in the reaction air into the case 12 and sends it to the fuel cell main body 3. As shown in FIG. 3, hydrogen gas supplied from the fuel gas cylinder 1 to the anode electrode of the fuel cell body 3 via the regulator 47 and the solenoid valve 48 is supplied from the outside by the fan 42 to the reaction air inlet 4.
3 and the air which is taken into the case 12 through the case 12 and sent to the cathode electrode of the fuel cell main body 3 and the electrochemical reaction is performed in the fuel cell main body 3 to generate electric power. Case 1 as described above via mixer 50
2 to the outside. In the fuel cell 10, the fuel cell main body 3 is located near the reaction air intake 43 of the case 12, so that the intake from the outside can be smoothly performed.

The secondary battery 44 is, for example, a Ni-Cd secondary battery (12V-40Ah) using a nickel electrode for the positive electrode and a cadmium electrode for the negative electrode, and is installed in the control device 16 in this example. Normally, the secondary battery 44 is automatically charged by the surplus power of the fuel cell 10. However, the secondary battery 44 is connected to a charging input terminal 45 provided at a power extraction terminal unit (not shown) and an external AC power supply (not shown). AC100
V), the battery can be forcibly charged from the outside. The DC / DC converter 46 is a DC power voltage (24 to 50 V DC) from the fuel cell 10.
Is converted to a predetermined voltage (for example, DC 100 V), and the DC / AC inverter 18
V) to an alternating current (AC100V).

The control device 16 controls various controls, such as turning on / off an external output, processing a signal from a combustible gas sensor (not shown), transmitting an open / close signal to the solenoid valve 48 or the solenoid valve 49, and controlling the fuel cell body. 3 to transmit an ON / OFF signal to the DC / AC inverter 18 and the like. Alternatively, the primary pressure value measured by a pressure sensor (not shown) may be taken in, converted into a hydrogen gas remaining amount, transmitted to the digital display unit 36, and displayed. Further, data of the power output to the outside and data of the amount of charge of the secondary battery 44 are sent to the digital display unit 36,
This can also be displayed.

The hydrogen supply pipe 35 is connected to the fuel gas cylinder 1
It is arranged to connect with the fuel cell body 3. Further, the regulator 47 and the solenoid valve 48 are inserted between the fuel gas cylinder 1 and the fuel cell main body 3 as described above, and the opening / closing of the solenoid valve 48 turns on / off the delivery of hydrogen gas from the fuel gas cylinder 1. Is made.

The control unit 16 includes a fuel cell body 3, a secondary battery 44, a DC / DC converter 46, a DC / AC inverter 18, a solenoid valve 48, a fan 42, a circulation pump 40,
Not shown combustible gas sensor and main water tank water level meter, charging input terminal 45 and auxiliary water tank solenoid valve 4
9 for transmitting and receiving electrical signals to and from these devices. For example, when a flammable gas sensor (not shown) detects hydrogen gas having a concentration equal to or higher than a specified concentration, the signal is received, the electromagnetic valve 48 is closed to stop the supply of hydrogen gas, and the operation of the fuel cell body 3 is stopped. An alarm is issued by alarm lamps (not shown) or the operation of the entire fuel cell 10 is stopped.

The fuel cell main body 3 and the secondary battery 44 are electrically connected in parallel to each other. When the power from the fuel cell 3 is not sufficient, the control device supplies electric power from the secondary battery 44 when starting up. A constant electric power can be supplied to auxiliary equipment such as the water pump 16 and the water pump 40.

FIG. 4A is an explanatory view showing the water supply device for the fuel cell of the present invention when the fuel cell is stopped.
FIG. 3 is an explanatory view showing the water supply device for a fuel cell of the present invention during fuel cell operation. In FIGS. 4A and 4B,
The water supply device 71 for a fuel cell according to the present invention includes a water tank 19 for supplying water to the fuel cell body 3 housed in the case 12, a circulation pump 40 for circulating water, and a water circulation pipeline. 72, 73, 74, etc., the water in the water tank 19 stored in the lower stage 15 of the fuel cell is supplied to the fuel cell main body 3 stored in the upper stage 13 of the fuel cell by the circulation pump 40, It is designed to be used cyclically as indicated by the arrow. The water tank 19 is provided with a communication pipe 75 communicating with the atmosphere. As shown in FIG. 4A, when the operation of the fuel cell is stopped, the liquid level 76 in the communication pipe 75 is changed to the bottom surface 83 of the fuel cell main body 3. In the following case, the water in the water tank 19 does not flow back to the fuel cell main body 3 and the fuel cell main body 3 can be prevented from being submerged. Reference numeral 78 denotes a fuel gas inlet, and 79 denotes an exhaust fuel gas outlet.

In order to operate the fuel cell and stably generate electric power, the water circulation pipe 74 connecting the fuel cell body 3 and the water tank 19 is sealed with a water seal.
From the tank 19 via the water circulation line 74
Not to enter. In order to seal the water circulation pipe 74 with water, the liquid level 76 in the communication pipe 75 and the water circulation pipe 7
4 is maintained at a liquid level difference (indicated by H in the figure) corresponding to the difference between the fuel gas pressure at the fuel cell main body outlet portion 84 and the atmospheric pressure, and the water circulation is maintained. Pipe 74
The lengths of the communication pipe 75 and the water circulation pipe 74 are set so that the liquid level 77 in the inside can be maintained above the lowermost part 85 of the water circulation pipe 74, and the water tank 19 and the communication pipe 7 can be maintained.
Adjust the amount of water in 5.

FIG. 5A is an explanatory view showing another fuel cell water supply device of the present invention when the fuel cell is stopped.
(B) is an explanatory view showing a water supply device for another fuel cell of the present invention during fuel cell operation. Figure 5 (a), (b)
In the water supply device 80 for another fuel cell of the present invention shown in FIG. 1, the auxiliary water tank 17 connected to the water tank 19 by the pipe 70 leading to the water tank 19 is disposed above the water tank 19, Specifically, it is installed in the upper stage 13 of the fuel cell, and when the water in the water tank 19 falls below a predetermined water level, water is supplied from the auxiliary water tank 17 to the water tank 19 via the pipe 70. Except that a solenoid valve 49 is provided in the middle of the pipe 70, a liquid level sensor 81 for detecting the liquid level in the water tank 19 is provided, and a float switch 81 is provided in the auxiliary water tank 17. Fig. 4 (a) and (b) above
This is the same as the water supply device 71 of the fuel cell of the present invention shown in FIG.

When the liquid level in the water tank 19 drops and reaches the lower limit, the liquid level sensor 81 detects this and sends a signal to the control device 16. And the solenoid valve 49 is opened to supply a predetermined amount of water from the auxiliary water tank 17 to the water tank 19. When the liquid level in the water tank 19 rises and reaches the upper limit, the liquid level sensor 81 detects this and sends a signal to the control device 16, based on which the control device 16 sends a signal to the solenoid valve 49. A signal is sent and the solenoid valve 49 is closed. When the water in the auxiliary water tank 17 falls below a predetermined water level, a signal from the float switch 18 is sent to the controller 16, and based on the signal, the controller 16 sends a signal to stop the fuel cell, or Outputs low water level warning.

Since the present invention is not limited to the above embodiment, various modifications can be made without departing from the spirit of the appended claims.

[0038]

The water supply device for a fuel cell according to the present invention can reliably supply water to the electrolyte of the fuel cell main body and can cool the fuel cell main body. Can generate power stably and continuously.

[Brief description of the drawings]

FIG. 1 is a perspective view of one embodiment of a fuel cell according to the present invention.

FIG. 2 is an explanatory side view showing the inside of the fuel cell shown in FIG. 1;

FIG. 3 is a diagram showing components between components of the fuel cell shown in FIG.
FIG. 3 is an explanatory diagram showing an electric signal path, a hydrogen gas path, an air path, a power path, and a water path.

FIG. 4A is an explanatory view showing a water supply device of the fuel cell of the present invention when the fuel cell is stopped, and FIG. 4B is a view showing the water supply device of the fuel cell of the present invention during the fuel cell operation. FIG.

FIG. 5A is an explanatory view showing a water supply device of another fuel cell of the present invention when the fuel cell is stopped, and FIG. 5B is a diagram showing water supply of another fuel cell of the present invention during operation of the fuel cell. It is explanatory drawing which shows an apparatus.

FIG. 6 is an explanatory diagram showing characteristics of a polymer electrolyte fuel cell.

FIG. 7 is an explanatory diagram of a conventional fuel cell.

FIG. 8 is an explanatory diagram of another conventional fuel cell.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fuel gas cylinder 3 Fuel cell main body 10 Fuel cell 12 Case 16 Control device 17 Auxiliary water tank 19 Water tank 40 Circulation pump 70 Pipe line 71, 80 Water supply apparatus 72, 73, 74 Water circulation pipe 75 Communication pipe 76, 77 Liquid Surface 81 Liquid level sensor 82 Float switch 83 Bottom surface 84 Fuel cell main body outlet 85 Lowermost

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Ryuji Hatayama 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Inventor Koji Shindo 2-chome, Keihanhondori, Moriguchi-shi, Osaka No.5-5 Sanyo Electric Co., Ltd. (72) Inventor Akio Kawakami 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd.

Claims (4)

[Claims] 1. A power supply unit including a fuel gas cylinder in a case, a fuel cell main body for receiving a supply of fuel gas and an oxidizing agent, and generating electricity by flowing water together with the fuel gas through a fuel gas flow path, and a control device. A water supply device provided in the case with a water tank or the like for circulating and supplying water to the fuel cell body of the fuel cell containing the fuel cell, wherein the water tank is provided below the fuel cell body. The fuel cell system is provided with a communication pipe communicating with the atmosphere. When the fuel cell is stopped, the liquid level in the communication pipe is equal to or lower than the bottom of the fuel cell body, and during the fuel cell operation, the liquid level in the communication pipe is reduced. And the liquid level in the water circulation pipe connecting the fuel cell body and the water tank is maintained at a liquid level difference corresponding to the difference between the fuel gas pressure at the fuel cell body outlet and the atmospheric pressure. And for the water circulation The lengths of the communication pipe and the water circulation pipe are set so that the liquid level in the pipe can be maintained higher than the lowermost part of the water circulation pipe, and the amount of water in the water tank and the communication pipe is set. Wherein the fuel gas from the fuel cell body is prevented from entering the water tank via the water circulation pipe. 2. An auxiliary water tank connected to the water tank by a conduit leading to the water tank is disposed above the water tank, and when water in the water tank falls below a predetermined water level. 2. The water supply device for a fuel cell according to claim 1, wherein water is supplied from the auxiliary water tank to the water tank via the pipe. 3. An on-off valve is provided in the conduit leading to the water tank, and a sensor for detecting a liquid level in the water tank is provided, and the on-off valve is opened and closed by a signal from the sensor. The water supply device for a fuel cell according to claim 2. 4. A float switch is provided in the auxiliary water tank, and when the water in the auxiliary water tank falls below a predetermined water level, a signal from the float switch is used to stop the fuel cell or to reduce the water level. 4. The water supply device for a fuel cell according to claim 2, wherein the water supply device outputs a signal.