JP2003317754A - Fuel cell system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive fuel cell system not contaminating the circulating water. <P>SOLUTION: The fuel cell system has a fuel cell body 10 for receiving hydrogen rich gas and air and generating power. The fuel cell system comprises an air supply system 40 having an air purifying means 42 for purifying air and for supplying the purified air to the fuel cell body 10, water circulating systems 50 and 60 having reserving means 52 and 63 for reserving water and for circulating the water to the fuel cell body 10, and ventilating means 58 and 67 for communicating the air supply system 40 with the reserving means 52 and 63 to ventilate the purified air to the reserving means 52 and 63. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel cell system which can be suitably used especially for moving bodies such as automobiles.

[0002]

2. Description of the Related Art In a fuel cell system, a tank provided in a water passage in the fuel cell system has conventionally opened the upper space of the tank to the atmosphere in order to increase or decrease the amount of water in the tank.

Further, Japanese Patent Laid-Open No. 11-273704 describes a technique relating to the prevention of freezing of pure water. When the system is stopped, the valve 122 is opened to introduce the external air into the water pipe, and the drain valve is used. The water is drained from the pipe by opening 50 to prevent freezing of the pure water in the pipe and to store the recovered pure water in the heat insulating tank to prevent the freezing.

[0004]

However, in the above-mentioned conventional fuel cell system, since the tank is open to the atmosphere, impurities such as microorganisms, dust and various ions existing in the air are introduced into the water system. Therefore, deterioration of water is promoted.

Further, in Japanese Patent Laid-Open No. 11-273704, external water is introduced into the water system in the system when draining water, and therefore, there are some types that contain various ions such as microorganisms and dust existing in the air. Since it is introduced into the water system, there is a problem that deterioration of water may be accelerated.

An object of the present invention is to provide a fuel cell system which does not pollute circulating water and is inexpensive.

[0007]

The present invention solves the above-mentioned problems by the following means for solving the problems. It should be noted that, for ease of understanding, reference numerals corresponding to the embodiments of the present invention will be given and described, but the present invention is not limited thereto.

A first aspect of the present invention is a fuel cell system having a fuel cell main body (10) which is supplied with hydrogen-rich gas and air to generate power, and which has an air purifying means (42) for purifying air. A water circulation system (50, 60) having an air supply system (40) for supplying purified air to the fuel cell body and a storage means (52, 63) for storing water, and circulating the water in the fuel cell body. And a ventilation means (58, 67) for communicating the air supply system with the storage means so that the purified air can be ventilated to the storage means.

A second invention is characterized in that, in the first invention, the water circulation system (60) circulates cooling water for cooling the fuel cell main body.

A third invention is characterized in that, in the first or second invention, the storing means (63) is a cooling water reservoir tank for storing cooling water.

A fourth invention is characterized in that, in the first invention, the water circulation system (50) circulates humidifying water for humidifying the purified air purified by the air purifying means.

A fifth invention is characterized in that, in the first or fourth invention, the storing means (52) is a humidifying water reservoir tank for storing the humidifying water.

In a sixth aspect based on the fourth aspect, the air supply system (40) is purified by the air purifying means,
A humidifying means (43) for humidifying the purified air supplied to the fuel cell main body with the circulating water from the storage means of the water circulation system is provided.

A seventh aspect of the invention is the fuel cell system according to the fourth or sixth aspect of the invention, which is provided in the ventilation means, makes the air supply system and the storage means inoperable and at the same time allows the storage means to communicate with the outside air, and The air supply system and the storage means are provided with a three-way switching valve means (55) that allows the storage means to ventilate at the same time as the storage means.

An eighth invention is characterized in that, in the seventh invention, a backflow preventing means (56) for preventing the inflow of outside air is provided, which is connected to the three-way switching valve means.

In a ninth aspect based on the seventh or eighth aspect, the three-way switching valve means is switched to be ventilated to the outside air, and residual water remaining in the water circulation system is discharged to the storage means. It is characterized by doing so.

In a tenth aspect based on the fourth or sixth aspect, the first ventilation switching means (55a) is provided in the ventilation means and enables or disables ventilation of the air supply system and the storage means. ) And a second means provided on the ventilation means for allowing or not allowing the storage means and the outside air to be aerated.
And a ventilation switching means (55b).

An eleventh invention is the tenth invention, wherein
A backflow preventing means (56) for preventing the inflow of outside air is provided, which is connected to the second ventilation switching means.

In a twelfth aspect based on the tenth or eleventh aspect, the first ventilation switching means is switched to a non-venting mode, and the second ventilation switching means is switched to a ventilation mode so that the water circulation system is controlled. The remaining residual water is drained to the storage means.

[0020]

[Operation / Effect] In the first invention, it is possible to prevent microorganisms and the like in the air from entering the water circulation system.

Specifically, in the second and third inventions, it is possible to prevent the microorganisms and the like from mixing in the cooling water, and in the fourth and fifth inventions, the microorganisms and the like are prevented from mixing in the humidifying water. be able to.

In the sixth aspect of the invention, the purified air purified by the air purifying means and supplied to the fuel cell body can be humidified, whereby the power generation reaction in the fuel cell body can be enhanced.

In the seventh invention, it is possible to drain residual water remaining in the water circulation system by utilizing air pressure.

In the eighth invention, the inflow of outside air can be prevented,
Furthermore, it is possible to reliably prevent the entry of microorganisms and the like in the air into the water circulation system.

In the ninth invention, the residual water remaining in the water circulation system can be drained by utilizing the air pressure, and it is not necessary to use a special drainage device, and the cost can be kept low.

In the tenth invention, it is possible to drain residual water remaining in the water circulation system by utilizing air pressure.

In the eleventh aspect of the invention, it is possible to prevent the inflow of outside air, and it is possible to reliably prevent entry of microorganisms and the like in the air into the water circulation system.

In the twelfth invention, the residual water remaining in the water circulation system can be drained by utilizing the air pressure, and it is not necessary to use a special drainage device, and the cost can be kept low.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings. (First Embodiment) FIG. 1 is a system configuration diagram showing a first embodiment of a fuel cell system according to the present invention.

The fuel cell system 1 comprises an FC stack body 10, an anode system 20, a cathode system 30, a cooling system 60, and a control system 70.

The FC stack body 10 is a fuel cell body that generates electricity based on hydrogen supplied from the anode system 20 and air supplied from the cathode system 30. Also, F
Since the temperature of the C stack body 10 becomes high during power generation, the temperature is measured by the stack temperature sensor 72 and cooled by the cooling system 60.

The anode system 20 comprises a hydrogen tank 21, a pressure control valve 22, an ejector 23, and a purge valve 24, which are connected by a fuel supply pipe 25, an exhaust hydrogen pipe 26, and a circulation pipe 27. There is.

The hydrogen tank 21 stores hydrogen as fuel. A fuel supply pipe 25 is connected to the hydrogen tank 21.

The fuel supply pipe 25 is a pipe for supplying the hydrogen stored in the hydrogen tank 21 to the FC stack body 10. One end is connected to the hydrogen tank 21 and the other end is FC.
It is connected to the stack body 10.

The pressure control valve 22 is provided in the middle of the fuel supply pipe 25 and reduces the pressure of hydrogen in the hydrogen tank 21 to a desired pressure and supplies it to the FC stack body 10.

The ejector 23 is provided in the path of the fuel supply pipe 25 and between the pressure control valve 22 and the FC stack body 10. The ejector 23 is connected to a circulation pipe 27. The ejector 23 utilizes the phenomenon that when the fuel hydrogen flows through the fuel supply pipe 25, the inside of the ejector 23 becomes negative pressure, and the hydrogen (exhaust hydrogen) in the circulation pipe 27 is used.
Is inhaled and the exhaust hydrogen is mixed with fresh hydrogen.

The exhaust hydrogen pipe 26 is connected to the FC stack body 10.
It is a pipe for feeding surplus hydrogen (exhaust hydrogen) discharged from the fuel cell, one end of which is connected to the FC stack body 10 and the other end of which is connected to an exhaust hydrogen combustor 46 (described later).

The purge valve 24 is provided in the path of the exhaust hydrogen pipe 26 and between the FC stack body 10 and the exhaust hydrogen combustor 46. The purge valve 24 is normally closed and opens when the concentration of impurities such as nitrogen and CO increases in the anode system 20 to purge the circulating hydrogen and let it out to the exhaust hydrogen combustor 46.

The circulation pipe 27 is a pipe for returning the exhaust hydrogen of the FC stack body 10 to the ejector 23 for circulation.
One end is connected to the exhaust hydrogen pipe 26 between the FC stack body 10 and the purge valve 24, and the other end is connected to the ejector 23.

With the configuration of the anode system 20 as described above, the hydrogen stored in the hydrogen tank 21 is supplied to the FC stack body 10 as follows.

That is, the hydrogen stored at a high pressure in the hydrogen tank 21 is depressurized to a desired pressure by the pressure control valve 22 and passes through the fuel supply pipe 25. Then, the exhaust hydrogen is mixed in the ejector 23 on the way, and the FC stack body 10 is mixed.
Is supplied to. Then, after passing through the FC stack body 10, the hydrogen is returned to the ejector 23 by the circulation pipe 27 and circulated. Then, when the concentration of impurities such as nitrogen and CO becomes high, the purge valve 24 is opened and discharged (purged) to the exhaust hydrogen combustor 46. Then, the purged exhaust hydrogen is mixed with stack exhaust air (described later) in the exhaust hydrogen combustor 46, burned and purified, and then discharged to the outside of the vehicle.

The cathode system 30 comprises an air supply system 40 and a humidifying water circulation system 50. The air supply system 40 includes a compressor 41, a filter 42, a humidifier 43, a moisture condensing device 44, a pressure control valve 45, and an exhaust hydrogen combustor 46, which are an air supply pipe 47 and an air exhaust. Piping 4
Connected by eight. In addition, the humidifying water circulation system 50
Includes a valve 51, a water tank 52, a pump 53, a valve 54, a three-way valve 55, and a check valve 56,
They are connected by a water passage 57 (57a, 57b) and an air pipe 58.

The compressor 41 sucks the outside air and sends it by pressure.

The air supply pipe 47 is an air supply means for supplying the air pressure-fed from the compressor 41 to the FC stack body 10, one end of which is connected to the compressor 41 and the other end of which is connected to the FC stack body 10.

The filter 42 is provided in the path of the air supply pipe 47 and traps (removes) microdust, sulfur and the like contained in the air pumped by the compressor 41 and oil and the like discharged from the compressor 41. It is an air purification means for cleaning.

The humidifier 43 is a humidifying means for humidifying the air (gas) cleaned by the filter 42 to enhance the power generation reaction in the FC stack body 10 and supplying the humidified gas to the FC stack body 10. . The humidifier 43 is
In the path of the air supply pipe 47, the filter 42 and the F
It is provided between the C stack body 10.

The air discharge pipe 48 is the FC stack body 10.
And sends the air discharged from the FC stack body 10 (stack exhaust air).

The moisture condensing device 44 is provided in the path of the air discharge pipe 48, and condenses the moisture in the air remaining without being consumed in the FC stack body 10 and the moisture produced in the FC stack body 10. This moisture condensing device 44 uses, for example, an air-cooling type heat exchanger in the present embodiment, but other means such as a device using a water separation membrane or cooling water may be used.

The pressure control valve 45 is provided in the path of the air discharge pipe 48 and downstream of the moisture condensing device 44.
It is a control means for controlling the pressure of the air supply system to a desired pressure.

The exhaust hydrogen combustor 46 is provided in the path of the air exhaust pipe 48 and downstream of the pressure control valve 45.
As described above, the exhaust hydrogen purged from the purge valve 24 is
It is mixed with the exhaust air whose pressure is adjusted by the pressure control valve 45, burned, purified, and then discharged to the outside of the vehicle.

One end of the water passage 57a is condensed water condensation device 4
4 and the other end is connected to the water tank 52, and the collected water condensed and collected by the condensed water condensing device 44 is collected in the water tank 52.
Lead to.

The valve 51 is provided in the path of the water passage 57a and switches the water passage 57a between communication and non-communication.

The water tank 52 is a storage means for storing the recovered water recovered by the condensed water condensing device 44 and having passed through the water passage 57a.

The water passage 57b has one end connected to the water tank 52 and the other end connected to the humidifier 43, and returns the water stored in the water tank 52 to the humidifier 43.

The pump 53 is provided in the path of the water passage 57b, and the amount of water required for humidifying the air from the water tank 52 to the humidifier is adjusted according to the operating state of the FC stack body 10. Send to 43. That is, as described above, the operation of the pump 53 is controlled based on the measurement value of the temperature / humidity sensor 73 (described later), and the required amount of water is supplied to the humidifier 43.
Send to.

The valve 54 is provided between the pump 53 and the humidifier 43 in the water passage 57b, and switches between communication and non-communication between them.

The air pipe 58 is a ventilation means for communicating the air reservoir 52a in the upper part of the water tank 52 with the air supply pipe 47 to ventilate them.

The three-way valve 55 is a three-way switching valve means provided in the path of the air pipe 58 for switching the communication between the water tank 52 and the air supply pipe 47 and the communication between the water tank 52 and the outside air.

The check valve 56 communicates with the three-way valve 55,
This is a backflow prevention means that can exhaust only the direction of the outside air and prevents the inflow of outside air.

In this embodiment, no filter is provided in the process of water circulation, but it may be installed if necessary.

With the configuration of the cathode system 30 as described above, the air pressure-fed from the compressor 41 is supplied to the FC stack body 10 as follows.

That is, the air sent from the compressor 41 is supplied to the FC stack body 10 after the filter 42 removes micro dust and the like and is humidified by the humidifier 43. The air remaining without being consumed in the FC stack body 10 (stack exhaust air) and the generated water are sent to the moisture condensing device 44 downstream thereof, and the moisture is separated and removed. The stack exhaust air is sent to the exhaust hydrogen combustor 46 via the pressure control valve 45, the exhaust hydrogen purged from the purge valve 24 is mixed, burned and purified, and then exhausted to the outside of the vehicle. . On the other hand, the water condensed by the water condensing device 44 is sent to the water tank 52 via the valve 51 and further sent to the humidifier 43 by the pump 53. At this time, since the air reservoir portion 52a above the water tank 52 is communicated with the air supply pipe 47 via the air pipe 58, the water level of the water tank 52 moves smoothly.

The cooling system 60 uses water mixed with an antifreezing agent (for example, ethylene glycol) to remove the water from the FC stack body 1.
Cooling is carried out by flowing it into the cooling water passage inside 0. The cooling system 60 is
The three-way switching valve 61, the radiator 62, the reservoir tank 63, and the cooling water pump 64 are provided, and the cooling passage 6 is provided.
5, the bypass passage 66 and the air pipe 67 are connected to each other.

One end of the cooling passage 65 is connected to the FC stack body 10 and the three-way switching valve 61 provided in the middle thereof is provided.
After reaching the radiator 62 via the, and connecting the reservoir tank 63 in the middle, it is again connected to the FC stack body 10 via the cooling water pump 64.

The bypass passage 66 has one end connected to the three-way switching valve 61 and the other end connected to the cooling passage 65.
The cooling water passing through the bypass passage 66 bypasses the radiator 62.

The three-way switching valve 61 is provided in the cooling passage 65. The three-way switching valve 61 is a valve capable of switching the passage of the cooling water that has deprived the heat of the FC stack body 10 according to a command from the control unit 71, and allows the cooling water to pass through the cooling passage 65 or the bypass passage 66.

The radiator 62 is a radiator for radiating heat from the cooling water that has absorbed heat from the FC stack. The radiator outlet water temperature is controlled by operating a radiator fan (not shown) controlled by a signal from the control unit 71. Adjust to the temperature of.

The reservoir tank 63 is provided downstream of the radiator 62, and absorbs thermal expansion and thermal contraction of the temperature-controlled cooling water and replenishes the cooling water. Reservoir tank 6
The air reservoir 63a at the upper part of 3 is communicated with the air supply pipe 47 through the air pipe 67, so that the water level in the reservoir tank 63 can be moved smoothly.

The cooling water pump 64 is provided on the downstream side of the reservoir tank 63, and controls the feed amount of the cooling water so that the flow rate judged by the control unit 71 is obtained in accordance with the output of the stack temperature sensor 72 and the FC stack main body. Pump to 10.

The control system 70 includes a control unit 71.
Depending on the stack temperature sensor 72, temperature and humidity sensor 7
3, the measured values of the outside air temperature sensor 74 and the accelerator opening sensor 100 are input, calculation is performed based on the input values, and the pressure control valve 22, purge valve 24, compressor 41, pressure control valve 45, valve 51, pump Signals are output to 53, the valve 54, the three-way valve 55, the three-way switching valve 61, and the cooling water pump 64 to control the operation.

The stack temperature sensor 72 measures the temperature of the FC stack body 10.

The temperature / humidity sensor 73 is provided in the path of the air supply pipe 47 and between the humidifier 43 and the FC stack body 10. The temperature / humidity sensor 73 is a detector that measures the temperature and humidity of the air passing through the air supply pipe 47. The operation of the pump 53 is controlled based on the measurement result.

FIG. 2 is a flow chart for explaining the operation of the fuel cell system of this embodiment, focusing on the control by the control unit.

At S1, various sensors (outside air temperature sensor 74, stack temperature sensor 72, temperature / humidity sensor 73,
The value from the accelerator opening sensor 100) is read.

At S2, the ignition key is turned on.
Or not. At this time, if ON (that is,
If it is in operation, the process proceeds to S3, and if it is off (that is, the system is stopped), the process proceeds to S5.

In S3, the valve 51 and the valve 54
Open the valve. This is to open the valve that was closed when the system was stopped last time when the system was started. In addition, the three-way valve 55 is switched to the air supply pipe 47.
And the water tank 52 are connected.

In S4, normal operation is performed. Specifically, the following control is performed.

That is, on the anode side of the stack, the pressure control valve 22 is controlled to supply the fuel according to the amount of fuel and air corresponding to the output (electric power) according to the accelerator opening degree of the driver. On the cathode side of the stack, the compressor 41 is controlled to supply air, and the humidifier 43 further determines the desired humidity at the stack inlet from the stack temperature detected by the stack temperature sensor 72 and the temperature / humidity sensor 73. The humidification pump 53 is controlled so that the humidity is adjusted, and the humidification amount is adjusted.

Further, by controlling the cooling water pump 64, the FC
The flow rate of the cooling water is adjusted based on the amount of heat generated by the stack body 10 (the stack temperature measured by the stack temperature sensor 72). The temperature of the FC stack body 10 is low,
When it is not necessary to cool the cooling water, the three-way switching valve 61
Is switched to pass through the bypass passage 66, so that it does not pass through the radiator 62.

Further, the flow rate of a radiator fan (not shown) is controlled according to the temperature detected by the stack temperature sensor 72, and the radiator outlet temperature is controlled to be maintained at a substantially constant temperature.

During operation, the moisture in the air discharged from the FC stack body 10 is condensed by the moisture condenser 44 of the stack cathode system. This moisture is contained in the water passage 57.
It is led to the water tank 52 through a and is stored as humidifying water.

In the stack anode system, the exhaust gas from the FC stack body 10 is circulated by the circulation pipe 27 and the ejector 23. At this time, the concentration of impurities such as nitrogen in the air in the fuel gradually increases due to the permeation of the stack membrane. Therefore, the purge valve 24 is opened at predetermined intervals to purge the hydrogen in the circulation path, and the catalyst in the exhaust hydrogen combustor 46 downstream thereof is mixed with air to combust and purify the exhaust gas.

By the normal operation as described above, the output according to the accelerator operation by the driver is output as electric power from the fuel cell system, and the vehicle is driven by the motor (not shown).

Step S5 is a subroutine of the operation at the time of stop, which will be described later.

FIG. 3 is a flow chart for explaining the stop operation of the fuel cell system of this embodiment, focusing on the control by the control unit.

In S10, the timer T1 built in the control unit 71 is incremented based on the time after the ignition key is turned off.

In S11, the timer T1 is set to the predetermined time 1 (T
Th1) (Tthl <Tth2 <Tth3) is determined. If the predetermined time has passed, S1
4. If it is less than the predetermined time, go to S12.

The predetermined values Tth1 to Tth3 determine the time for which water or the like moves from each valve operation according to the pipe. In this embodiment, for example, Tth1 is 10 seconds, Tth1.
th2 is set to 20 seconds and Tth3 is set to 30 seconds.

In S12, the valve 54 is closed.

In S13, the three-way valve 55 is brought into communication with the outside air, and the water passage 5 from the water condenser 44 to the water tank 52 is connected.
Moisture in 7a is purged using the air pressure of the stack cathode system (first residual water drainage step).

At S14, the timer T1 is set to the predetermined time 2 (T
It is determined whether or not th2) has been exceeded. When the predetermined time has elapsed, the process proceeds to S17, and when it is less than the predetermined time, S
Proceed to 15.

In S15, the valve 51 is closed.

In S16, the valve 54 is opened, and the water in the water path from the humidifier 43 to the water tank 52 is purged using the air pressure of the compressor 41 (second residual water drainage step).

At S17, the timer T1 is set to the predetermined time 3 (T
Th3) is exceeded. When the predetermined time has elapsed, the process proceeds to S21, and when it is less than the predetermined time, S
Proceed to 18.

At S18, the supply of air and hydrogen is stopped. Although hydrogen is also supplied here for the period up to this point, hydrogen in the anode may be stopped at the same time when the ignition key is turned off, depending on the differential pressure resistance performance between the cathode and the anode in the stack.

In S19, the three-way valve 55 is made to communicate with the air passage 58 to shut off the communication with the outside air.

In S20, the valve 51 is opened and the water pipe 5
7a communicates with the water tank 52.

At S21, all power supplies are turned off.

According to this embodiment, the air introduced into the water tank 52 and the reservoir tank 63 is supplied to the cathode system 30.
Since it is purified by the filter 42 provided in the air supply system 40, the microorganisms and the like contained in the outside air do not mix into the water tank 52 and the reservoir tank 63, and the water in the humidifying water circulation system 50 and the cooling system 60 is prevented. Is not contaminated. Therefore, it is not necessary to provide a device for purifying water, and even if it is provided, the operation frequency can be greatly reduced compared to the conventional product.

Further, the water tank 52 and the reservoir tank 6
Since the filter for cleaning the air introduced into the air cleaner 3 is provided in the air supply system 40 of the cathode system 30, the cost can be kept low.

Further, by providing valves 51, 54 and a three-way valve 55 and performing predetermined control, the cathode system 3
The water remaining in the humidification water circulation system 50 of 0 can be easily returned to the water tank 52 by the pressure difference from the outside air. Also,
With such a simple structure, it is possible to reduce the weight and, in turn, improve fuel efficiency. Further, it is hard to cause a failure.

Furthermore, since the pressure of the air system can be used to pressurize the cooling water during the system operation, the load on the cooling water pump 64 for adjusting the cooling water pressure to a predetermined pressure can be reduced. And a fuel cell system with high energy efficiency can be constructed.

Similarly, since a part of the energy for pressurizing the humidifying water for supplying the humidifying water can be shared by the pressure of the air system, the load on the pump for supplying the humidifying water should be reduced. And a fuel cell system with high energy efficiency can be obtained. (Second Embodiment) FIG. 4 is a system configuration diagram showing a second embodiment of the fuel cell system according to the present invention.

The same reference numerals are given to the parts that perform the same functions as those in the first embodiment, and the duplicated description will be omitted.

The fuel cell system 1 of this embodiment is different from that of the first embodiment in that the three-way valve 55 is replaced by a first ventilation valve 55a and a second ventilation valve 55b.

The first ventilation valve 55a is provided in the air pipe 58 and is a first ventilation switching means for switching the air reservoir 52a in the upper part of the water tank 52 and the air supply pipe 47 to be ventilable or non-ventilable.

The second ventilation valve 55b is provided between the first ventilation valve 55a and the air reservoir 52a of the water tank 52, and switches between the air reservoir 52a of the water tank 52 and the outside air so that it can be ventilated or not ventilated. It is a second ventilation switching means.

In the fuel cell system 1 of this embodiment, by combining the first ventilation valve 55a and the second ventilation valve 55b, the same function as that of the three-way valve 55 of the first embodiment is exerted. That is, by making the first ventilation valve 55a impermeable and the second ventilation valve 55b permeable, and by making the first ventilation valve 55a permeable and the second ventilation valve 55b impermeable, The same operation as the three-way valve 55 of the one embodiment is performed.

According to this embodiment, the same effect as that of the first embodiment can be obtained.

The present invention is not limited to the embodiment described above, and various modifications and changes can be made, which are also within the scope of the present invention.

For example, in the above-described embodiment, it is described that the water is not drained each time without performing the freezing determination to prevent the freezing. However, the water is drained only when there is a risk of freezing. You may do it. For example, when the value of the outside air temperature sensor such as the timing when the ignition is cut off is equal to or lower than a predetermined temperature (for example, 15 ° C.), water may be drained by controlling like this subroutine. In this way, the system can be stopped immediately after the ignition is turned off in the summer when the water is unlikely to freeze.

The air pipe 58 is connected to the humidifier 43 and FC.
Although it is connected to the air supply pipe 47 between the stack body 10 and the stack main body 10, the air purified by the filter 42 may be ventilated to the air reservoir 52 a above the water tank 52. Therefore, the air pipe 58 may be connected to the air supply pipe 47 between the filter 42 and the humidifier 43.

Further, in the above first and second embodiments, the cooling water circulated in the cooling system 60 contains the antifreezing agent, but pure water may be used as in the humidifying water circulation system 50. In this case, in order to prevent freezing of pure water in the cooling system 60, the water removal structure and control as shown in the first and second embodiments may be applied.

[Brief description of drawings]

FIG. 1 is a system configuration diagram showing a first embodiment of a fuel cell system according to the present invention.

FIG. 2 is a flowchart for explaining the operation of the fuel cell system of the present embodiment, focusing on the control by the control unit.

FIG. 3 is a flowchart illustrating a stop operation of the fuel cell system according to the present embodiment, focusing on control by a control unit.

FIG. 4 is a system configuration diagram showing a second embodiment of the fuel cell system according to the present invention.

[Explanation of symbols]

1 Fuel cell system 10 FC stack body 20 Anode system 21 Hydrogen tank 22 Pressure control valve 23 Ejector 24 Purge valve 30 cathode system 40 Air supply system 42 filters 43 Humidifier 44 Moisture condensing device 47 Air supply piping 50 Humidification water circulation system 51 valve 52 water tank 52a Air trap 54 valves 55 three-way valve 56 check valve 57 (57a, 57b) Water passage 58 Air piping 60 cooling system 61 3-way switching valve 63 reservoir tank 63a Air trap 65 Cooling passage 66 Bypass passage 67 Air piping 70 Control system

Claims (12)

[Claims] 1. A fuel cell system having a fuel cell main body which is supplied with hydrogen-rich gas and air to generate electric power, and which has air purifying means for purifying air, and supplies the purified air to the fuel cell main body. An air supply system and a storage unit that stores water, and a water circulation system that circulates the water in the fuel cell main body, the air supply system and the storage unit are communicated with each other, and the purified air is stored in the storage unit. A fuel cell system, comprising: 2. The fuel cell system according to claim 1, wherein the water circulation system circulates cooling water for cooling the fuel cell body. 3. The fuel cell system according to claim 1, wherein the storage means is a cooling water reservoir tank for storing cooling water. 4. The fuel cell system according to claim 1, wherein the water circulation system circulates humidifying water for humidifying the purified air purified by the air purifying means. 5. The fuel cell system according to claim 1 or 4, wherein the storage means is a humidified water reservoir tank for storing humidified water. 6. The air supply system comprises a humidifying means for humidifying the purified air purified by the air purifying means and supplied to the fuel cell main body with circulating water from the storing means of the water circulating system. The fuel cell system according to claim 4, wherein: 7. The ventilation means is provided so that the air supply system and the storage means cannot be ventilated, and at the same time the storage means can be ventilated with the outside air, and the air supply system and the storage means can be ventilated. At the same time, the fuel cell system according to claim 4 or 6, further comprising a three-way switching valve means that prevents the storage means from being ventilated from the outside air. 8. The fuel cell system according to claim 7, further comprising a backflow preventing unit that is connected to the three-way switching valve unit and prevents the inflow of outside air. 9. The method according to claim 7, wherein the three-way switching valve means is switched to be ventilated to the outside air so that the residual water remaining in the water circulation system is discharged to the storage means. Item 8. The fuel cell system according to Item 8. 10. A first device, which is provided in the ventilation means and allows or does not allow ventilation between the air supply system and the storage means.
7. The ventilation switching means according to claim 4, and a second ventilation switching means which is provided in the ventilation means and which allows or does not vent the storage means and the outside air. Fuel cell system. 11. The fuel cell system according to claim 10, further comprising a backflow prevention unit that is connected to the second ventilation switching unit and that prevents the inflow of outside air. 12. The residual air remaining in the water circulation system is drained to the storage means by switching the first ventilation switching means to the non-venting mode and switching the second ventilation switching means to the ventilation mode. The fuel cell system according to claim 10 or 11, wherein the fuel cell system is configured as described above.