JP2005032587A - Fuel cell system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable to diagnose the moisture of a cell in a fuel cell system. <P>SOLUTION: A solid polymer fuel cell has a specific relation between the open circuit voltage (OCV) of the cell and the moisture inside the cell. When the open circuit voltage of the cell is in a first threshold value or less, the cell is diagnosed that the inside of the cell is in a dry state, and when the open circuit voltage of the cell is in a second threshold value or more, the cell is diagnosed that the inside of the cell is in an excess moisture state. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a fuel cell system including a fuel cell that generates electric energy by a chemical reaction between hydrogen and oxygen, and is effective when applied to a moving body such as a vehicle, a ship, and a portable generator.

  2. Description of the Related Art Conventionally, a fuel cell system including a fuel cell that generates power using an electrochemical reaction between hydrogen and oxygen (air) is known. For example, in a polymer electrolyte fuel cell that is considered as a driving source for vehicles and the like, due to insufficient catalytic activity due to insufficient fuel cell temperature at startup, increased resistance due to insufficient moisture in the cell, inhibition of diffusion of reaction gas due to excessive moisture, etc. There is a problem of insufficient output.

In addition, when the fuel cell is used for a vehicle, startability in any environment is important. For this reason, the generated water is stored in the hydrogen and oxygen supply manifold part of the fuel cell, and when the power generation is started, the generated water is heated electrically, and the polymer electrolyte membrane of the cell is humidified with high-temperature steam to prevent insufficient output The system which performs is proposed (for example, refer patent document 1).
JP-A-8-195212

  However, although the above-described conventional system can humidify the cell, it cannot remove excessive moisture, and thus cannot prevent a decrease in output due to excessive moisture. Moreover, even if the system can humidify the cell and remove excess moisture, output reduction cannot be prevented unless appropriate control is performed according to the moisture state of the cell.

  The present invention has been made in view of the above points, and an object of the present invention is to make it possible to diagnose the moisture state of a cell in a fuel cell system. Another object is to make it possible to control the moisture state of the cell based on the diagnosis result of the moisture state of the cell.

  In order to achieve the above object, according to the first aspect of the present invention, a solid polymer electrolyte fuel cell that generates electricity by electrochemically reacting hydrogen in fuel gas and oxygen in oxidizing gas in a number of cells. A fuel cell system comprising (10), comprising: voltage detection means (17) for detecting an open circuit voltage of a cell; and diagnostic means (50) for diagnosing a moisture state of the cell based on the open circuit voltage. It is characterized by.

  In the polymer electrolyte fuel cell, there is a specific relationship between the open circuit voltage of the cell and the moisture in the cell (see FIG. 2). According to the invention described in claim 1, the relationship is utilized. The moisture state of the cell can be diagnosed.

  In the invention described in claim 2, the first threshold voltage (V1) and the second threshold voltage (V2) having a voltage value higher than the first threshold voltage (V1) are set, and the diagnosis means (50) When the open circuit voltage of the cell is equal to or lower than the first threshold voltage (V1), the inside of the cell is diagnosed and when the open circuit voltage of the cell is equal to or higher than the second threshold voltage (V2) It is characterized by diagnosing an excessive water state.

  According to this, it is possible to accurately diagnose whether the inside of the cell is in the dry state or the excessive water state by utilizing a specific relationship between the open circuit voltage of the cell and the moisture in the cell.

  The invention according to claim 3 is characterized in that when detecting the open circuit voltage of the cell, the fuel gas and the oxidizing gas are supplied to the fuel cell (10) without applying a back pressure to the fuel gas and the oxidizing gas. And

  According to this, the open circuit voltage of the cell is higher when no back pressure is applied, and the moisture state of the cell can be diagnosed more accurately.

  According to a fourth aspect of the present invention, a power supply device (12) capable of supplying electric power and an electric device (11, 16) that operates by being supplied with electric power from the power supply device (12) and the fuel cell (10) are provided. When detecting the open circuit voltage of the cell, power is supplied to the electric devices (11, 16) only from the power supply device (12) of the power supply device (12) and the fuel cell (10).

  According to this, it is possible to detect the open circuit voltage of the cell while operating the electric device.

  According to a fifth aspect of the present invention, there is provided a fuel cell comprising a solid polymer electrolyte type fuel cell (10) for generating electricity by electrochemical reaction of hydrogen in fuel gas and oxygen in oxidizing gas in a number of cells. When the fuel cell (10) is activated and the inside of the cell is in a dry state, the load of the fuel cell (10) is controlled to be high as long as the cell voltage does not fall below the predetermined voltage (V4). At the same time, the temperature of the fuel cell (10) is controlled to be lower than when the moisture in the cell is in the optimum state.

  According to this, by increasing the load, the amount of generated water can be increased to wet the cell. In addition, by lowering the temperature of the fuel cell, the temperature of the air exhausted from the fuel cell also becomes lower, and low-temperature air is less likely to contain moisture than hot air, thus suppressing the removal of moisture in the fuel cell. can do. Therefore, in combination, the moisture in the cell can be quickly brought to an optimum state at the start-up in the dry state.

  In carrying out the invention described in claim 5, as in the invention described in claim 6, a cooling system (40 to 44) for controlling the temperature of the fuel cell (10) by circulating cooling water is provided. The temperature of the fuel cell (10) can be controlled to be low by increasing the flow rate of water.

  In carrying out the invention according to claim 5, as in the invention according to claim 7, the load of the fuel cell (10) is increased stepwise within a range where the cell voltage does not fall below the predetermined voltage (V4). Can do.

  The invention according to claim 8 includes the electric devices (11, 16) that operate by being supplied with electric power from the fuel cell (10), and the electric power generation amount is equal to or greater than the electric energy consumed by the electric devices (11, 16). Thus, the load of the fuel cell (10) is controlled to be high.

  According to this, the amount of generated water can be further increased to wet the cell more quickly.

  In the invention according to claim 9, a fuel cell comprising a solid polymer electrolyte type fuel cell (10) for generating electricity by electrochemical reaction of hydrogen in fuel gas and oxygen in oxidizing gas in a number of cells. The system controls the temperature of the fuel cell (10) to be higher when the fuel cell (10) is activated and when the moisture content in the cell is excessive than when the moisture content in the cell is optimal. In addition, it is characterized in that the supply amount of the oxidizing gas is controlled to be large.

  According to this, by raising the temperature of the fuel cell, the temperature of the air discharged from the fuel cell is also raised, and the amount of moisture taken away from the fuel cell can be increased. Further, by increasing the supply amount of the oxidizing gas, it is possible to promote the vaporization of the water in the fuel cell and remove the water. Therefore, in combination, the moisture in the cell can be quickly brought to an optimum state at the time of start-up in an excessive moisture state.

  Furthermore, the fuel cell can be activated by increasing the temperature of the fuel cell.

  In carrying out the invention according to claim 9, as in the invention according to claim 10, a cooling system (40 to 44) for controlling the temperature of the fuel cell (10) by circulating cooling water is provided, and cooling is performed. By reducing the flow rate of water, the temperature of the fuel cell (10) can be controlled to be high.

  In addition, the code | symbol in the bracket | parenthesis of each said means shows the correspondence with the specific means as described in embodiment mentioned later.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. In this embodiment, the fuel cell system is applied to an electric vehicle (fuel cell vehicle) that runs using the fuel cell as a power source.

  FIG. 1 shows the overall configuration of the fuel cell system of the present embodiment. As shown in FIG. 1, the fuel cell system of the present embodiment includes a fuel cell (FC stack) 10 that generates electric power by utilizing an electrochemical reaction between hydrogen and oxygen. The fuel cell 10 is configured to supply electric power to electric devices such as a motor generator 11, a secondary battery 12, and an auxiliary machine 16 for running the vehicle. The secondary battery 12 corresponds to the power supply device of the present invention. The motor generator 11 and the auxiliary machine 16 correspond to the electric device of the present invention.

In the fuel cell 10, the following electrochemical reaction between hydrogen and oxygen occurs to generate electric energy.
(Hydrogen electrode side) H ₂ → 2H ⁺ + 2e ⁻
(Oxygen electrode side) 2H ⁺ + 1 / 2O ₂ + 2e ⁻ → H ₂ O
In this embodiment, a solid polymer electrolyte fuel cell is used as the fuel cell 10, and a plurality of cells serving as basic units are stacked. Each cell has a configuration in which an electrolyte membrane is sandwiched between a pair of electrodes.

  The fuel cell system includes an air supply path 20 a for supplying air (oxidizing gas) to the oxygen electrode side of the fuel cell 10, an air discharge path 20 b for discharging air from the fuel cell 10, and the fuel cell 10. A hydrogen supply path 30a for supplying hydrogen (fuel gas) to the hydrogen electrode side and a hydrogen discharge path 30b for discharging unreacted hydrogen gas and the like from the fuel cell 10 are provided.

  The air supply path 20a is provided with a blower 21 for air pressure feeding. The blower 21 is driven by an electric motor 22. The air discharge path 20b is provided with an air discharge path opening / closing valve 23 for opening and closing the air discharge path 20b. When supplying air to the fuel cell 10, the air discharge path opening / closing valve 23 is opened and the blower 21 is driven by the electric motor 22.

  A humidifier 24 is provided in the air supply path 20a and the air discharge path 20b. The humidifier 24 humidifies the air discharged from the blower 21 using moisture contained in the humid exhaust air discharged from the fuel cell 10, and thereby the solid polymer electrolyte in the fuel cell 10. The membrane is in a wet state containing moisture so that the electrochemical reaction can be satisfactorily performed during power generation operation.

  The hydrogen supply path 30a includes a hydrogen cylinder 31 filled with hydrogen gas, a hydrogen pressure regulating valve 32 that adjusts the pressure of hydrogen supplied to the fuel cell 10, and a hydrogen supply path opening / closing valve 33 that opens and closes the hydrogen supply path 30a. Is provided. The hydrogen discharge path 30b is provided with a hydrogen discharge path on / off valve 34 that opens and closes the hydrogen discharge path 30b. When supplying hydrogen to the fuel cell 10, the hydrogen supply path opening / closing valve 33 is opened and adjusted to a desired hydrogen pressure by the hydrogen pressure regulating valve 32. The hydrogen discharge path 30b is opened and closed by a hydrogen discharge path opening / closing valve 34 in accordance with operating conditions. The hydrogen discharge path 30b discharges unreacted hydrogen gas, steam (or water), nitrogen, oxygen, and the like mixed through the solid polymer electrolyte membrane from the oxygen electrode.

  The fuel cell 10 generates heat with power generation. Therefore, the fuel cell system is provided with cooling systems 40 to 44 that cool the fuel cell 10 so that the operating temperature becomes a temperature suitable for an electrochemical reaction (about 80 ° C., hereinafter referred to as a control target temperature TH). It has been.

  The cooling system includes a cooling water path 40 that circulates cooling water (heat medium) in the fuel cell 10, a water pump 41 that circulates the cooling water, an electric motor 42 that drives the water pump 41, and a radiator 43 that includes a fan 44. Is provided. The heat generated in the fuel cell 10 is discharged out of the system by the radiator 43 through the cooling water. With such a cooling system, the cooling amount control of the fuel cell 10 can be performed by the flow rate control by the water pump 41 and the air volume control by the fan 44.

  The fuel cell 10 and the secondary battery 12 and the secondary battery 12 and the motor generator 11 are electrically connected via a DC-DC converter 13 capable of transmitting power in both directions. The DC-DC converter 13 controls the flow of electric power from the fuel cell 10 to the secondary battery 12 or from the secondary battery 12 to the fuel cell 10.

  An inverter 14 is arranged between the fuel cell 10 and the secondary battery 12 and the motor generator 11. The inverter 14 switches the function of the motor generator 11, that is, the function as an electric motor and the function as a generator.

  When the DC-DC converter 13 and the inverter 14 are operated, for example, when a large amount of electric power is suddenly required during sudden acceleration, the motor generator 11 is not only from the fuel cell 10 but also from the secondary battery 12. Can be powered. Further, the surplus power during the power generation of the fuel cell 10 and the power regenerated by the motor generator 11 can be stored in the secondary battery 12.

  The auxiliary machine 16 includes the electric motor 22 of the blower 21, the electric motor 42 of the water pump 41, and the like, and is connected to the secondary battery 12 via the inverter 15.

  The fuel cell system is provided with a cell monitor 17 that detects the voltage of each cell, a temperature sensor 18 that detects the temperature of the fuel cell 10, and a current detector 19 that detects the generated current of the fuel cell 10. The cell monitor 17 corresponds to the voltage detection means of the present invention.

  The fuel cell system is provided with a control unit (ECU) 50 that performs various controls. The control unit 50 receives a required power signal from various loads, a voltage signal from the cell monitor 17, a temperature signal from the temperature sensor 18, and a current signal from the current detector 19. Further, the control unit 50 includes the secondary battery 12, the DC-DC converter 13, the inverters 14 and 15, the electric motor 22, the air discharge path opening / closing valve 23, the hydrogen pressure regulating valve 32, the hydrogen supply path opening / closing valve 33, and the hydrogen discharge path opening / closing. The control signal is output to the valve 34, the electric motor 42, the fan 44, and the like. The control unit 50 corresponds to the diagnostic means of the present invention.

  FIG. 2 is a characteristic diagram showing the relationship between the cell open circuit voltage (hereinafter referred to as OCV) in the solid polymer fuel cell 10 and the moisture in the cell. The OCV is a voltage of the cell when the air discharge path opening / closing valve 23 and the hydrogen discharge path opening / closing valve 34 are fully opened so that no back pressure is applied to the air and hydrogen supplied to the fuel cell 10. By the way, the open circuit voltage of the cell becomes higher when no back pressure is applied, and the moisture state of the cell can be diagnosed more accurately.

  As shown in FIG. 2, the polymer electrolyte fuel cell 10 has a characteristic that the OCV increases as the moisture in the cell increases, and the OCV becomes substantially constant when the moisture in the cell increases to a certain extent. Therefore, the moisture state of the cell can be determined by the OCV. Here, it is assumed that the minimum voltage when the moisture in the cell is within the optimum range is V1, the maximum voltage when the moisture within the cell is within the optimum range is V3, and the threshold voltage is V2. Note that V1 <V2 <V3, and the threshold voltage V2 is set to a value closer to the maximum voltage V3 than to the minimum voltage V1. The minimum voltage V1 corresponds to the first threshold voltage of the present invention, and the threshold voltage V2 corresponds to the second threshold voltage of the present invention.

  Next, diagnosis of the moisture state of the cell and control of the moisture in the cell based on the diagnosis result will be described. FIG. 3 is a flowchart showing the control at the start of the fuel cell system (at the start of power generation), and FIG. 4 is a diagram showing the concept of load control of the fuel cell 10.

  When the key switch of the vehicle is turned on, the control shown in FIG. 3 is started. First, in a state where no back pressure is applied to the air and hydrogen supplied to the fuel cell 10, a small amount of air and hydrogen are allowed to flow through the fuel cell 10 (step 101; hereinafter, step is abbreviated as S), and the OCV of the cell is measured by the cell monitor 17. To detect.

  Next, a cell moisture diagnosis is performed based on the OCV of the cell (S102). Specifically, if the OCV of the cell is equal to or lower than the minimum voltage V1 (S102 is NO), it is determined that the cell is in a dry state. And when it is judged that it is a dry state, control of S103-S108 is performed, and when it is judged that it is not a dry state, control of S109-S115 is performed.

  In S103 to S108, control to wet the fuel cell 10 is performed. First, the supply amount of air and hydrogen to the fuel cell 10 is increased, and power generation of the fuel cell 10 is started (S103). At this time, power generation is performed without depending on the electric power used by the motor generator 11 and the auxiliary machine 16, power is supplied from the secondary battery 12 when the power generation amount of the fuel cell 10 is insufficient, and power is supplied when the power generation amount of the fuel cell 10 is excessive. Store in secondary battery 12.

  Next, hydrogen is a stoichiometric value at the normal time (when the moisture in the cell is in the optimum range), and air is a stoichiometric value lower than the stoichiometric value at the normal time (when the moisture in the cell is in the optimum range). (S104). At this time, supply is performed while the air is humidified by the humidifier 24. Incidentally, the hydrogen stoichiometric value referred to in the present specification is a value obtained by dividing the hydrogen supply amount to the fuel cell 10 by the actual hydrogen consumption, and the air stoichiometric value is an actual air supply amount to the fuel cell 10. The value divided by the air consumption.

  Thus, by reducing the stoichiometric value of the air, the air discharged from the fuel cell 10 can be reduced, and the discharged air can be prevented from carrying away moisture in the fuel cell 10. Therefore, in combination with humidifying the air, the fuel cell 10 can be quickly moistened.

  Next, the rotational speed of the water pump 41 is increased to maximize the flow rate of the cooling water so that the temperature of the fuel cell 10 becomes lower than the low temperature side set temperature TL (S105). Incidentally, the low temperature side set temperature TL is set to a value (for example, 40 ° C.) lower than the control target temperature TH.

  Thus, by controlling the temperature of the fuel cell 10 to be low, the temperature of the air discharged from the fuel cell 10 is also reduced. And since low temperature air is hard to contain a water | moisture content than high temperature air, it can suppress taking away the water | moisture content in the fuel cell 10. FIG.

  Next, the power generation amount (load current) of the fuel cell 10 is increased to a load at which the cell voltage does not become the predetermined voltage V4 or less (S106), and when the cell voltage becomes the predetermined voltage V4 or less (S107 is N0), S104 to S106 are performed. Keep the load until the cell voltage recovers repeatedly. As a result, as shown in FIG. 4, the load current is increased step by step. Then, by increasing the load current, the amount of generated water is increased to wet the cell. Note that V4 <V1.

  Next, when the cell voltage exceeds the predetermined voltage V4 (YES in S107), the power supply to the motor generator 11 and the auxiliary machine 16 is switched to the secondary battery 12 only while the OCV of the cell is detected. Based on the OCV of the cell, the moisture diagnosis of the cell is performed (S108). If the OCV of the cell is equal to or lower than the minimum voltage V1 (S108 is NO), it is determined that the cell is still dry, and the process returns to S104 to continue the control to wet the fuel cell 10.

  On the other hand, if the OCV of the cell exceeds the minimum voltage V1 (YES in S108), it is determined that the cell is not in a dry state, and the process proceeds to S110. Also when S102 is YES, the process proceeds to S110 after starting the power generation of the fuel cell 10 in S109.

  In S110 to S115, control for raising the temperature of the fuel cell 10 and control for removing excess moisture are performed.

  First, hydrogen has a normal stoichiometric value, and air is supplied to the fuel cell 10 with a stoichiometric value higher than the normal stoichiometric value (S110). At this time, humidification by the humidifier 24 is stopped. Thus, by raising the stoichiometric value of air, it is possible to promote the vaporization of moisture in the fuel cell 10 and remove the moisture.

  Next, the number of rotations of the water pump 41 is decreased to minimize the flow rate of the cooling water, and the outflow of heat from the fuel cell 10 is suppressed to raise the temperature of the fuel cell 10 (S111). Thus, the fuel cell 10 can be activated by raising the temperature of the fuel cell 10. Further, by controlling the temperature of the fuel cell 10 to be high, the temperature of the air discharged from the fuel cell 10 is also increased, so that the amount of moisture taken away from the inside of the fuel cell 10 is increased so that the fuel cell 10 is dried. It is done.

  Next, a load equal to or greater than the amount of power used by the motor generator 11 and the auxiliary machine 16 is applied to the fuel cell 10, and surplus power is stored in the secondary battery 12 (S112). Thereby, heat generation of the fuel cell 10 is promoted.

  Next, it is determined whether or not the temperature of the fuel cell 10 measured by the temperature sensor 18 is equal to or higher than the control target temperature TH (S113). When the temperature of the fuel cell 10 is lower than the control target temperature TH (S113 is NO), the process returns to S110. On the other hand, when the temperature of the fuel cell 10 is equal to or higher than the control target temperature TH (S113 is YES), the flow rate of the cooling water is increased and the temperature of the fuel cell 10 is decreased (S114).

  Next, the power supply to the motor generator 11 and the auxiliary machine 16 is switched to the secondary battery 12 only while the OCV of the cell is detected, and the moisture diagnosis of the cell is performed based on the OCV of the cell detected at this time (S115). . If the OCV of the cell is equal to or lower than the minimum voltage V1, it is determined that the cell is in a dry state, and the process returns to S104. If the OCV of the cell is equal to or higher than the threshold voltage V2, it is determined that the cell is in an excessive moisture state. Return to. Further, if the OCV of the cell exceeds the minimum voltage V1 and less than the threshold voltage V2, it is estimated that the moisture in the cell is in the optimum range, the control at the time of starting is terminated, and the power usage of the motor generator 11 and the auxiliary machine 16 is used. The control shifts to normal control for controlling the power generation amount of the fuel cell 10 in accordance with the amount.

According to this embodiment, by utilizing a specific relationship between the open circuit voltage of the cell and the moisture in the cell in the polymer electrolyte fuel cell, the open circuit voltage of the cell is detected and the moisture state of the cell is determined. Can be diagnosed. At that time, by comparing the open circuit voltage of the cell with the threshold voltage, it is possible to accurately diagnose whether the inside of the cell is in a dry state or in an excessive water state.
(Other embodiments)
In the above embodiment, the fuel cell system is applied to the fuel cell vehicle. However, the fuel cell system of the present invention can be applied to other than the fuel cell vehicle, for example, a home fuel cell system. Can be applied.

  Further, in the above embodiment, when performing S104, only the air out of the air and hydrogen supplied to the fuel cell 10 is humidified. However, only hydrogen may be humidified, or both the air and hydrogen are humidified. May be.

1 is a conceptual diagram showing an overall configuration of a fuel cell system according to an embodiment of the present invention. It is a characteristic view which shows the relationship between the open circuit voltage (OCV) of a cell and the moisture in a cell in a polymer electrolyte fuel cell. 2 is a flowchart showing control at the time of startup of the fuel cell system of FIG. 1. It is a figure which shows the concept of load control of the fuel cell of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Fuel cell, 17 ... Cell monitor (voltage detection means), 50 ... Control part (diagnosis means).

Claims (10)

A fuel cell system comprising a solid polymer electrolyte type fuel cell (10) for generating electricity by electrochemically reacting hydrogen in fuel gas and oxygen in oxidizing gas in a number of cells,
Voltage detection means (17) for detecting an open circuit voltage of the cell;
A fuel cell system comprising diagnostic means (50) for diagnosing the moisture state of the cell based on the open circuit voltage of the cell. A first threshold voltage (V1) and a second threshold voltage (V2) having a voltage value higher than the first threshold voltage (V1);
The diagnostic means (50) diagnoses that the inside of the cell is in a dry state when the open circuit voltage of the cell is not more than the first threshold voltage (V1), and the open circuit voltage of the cell is the second voltage. 2. The fuel cell system according to claim 1, wherein when the threshold voltage (V2) is equal to or higher than the threshold voltage, the inside of the cell is diagnosed as being in an excessive water state. The fuel gas and the oxidizing gas are supplied to the fuel cell (10) without applying back pressure to the fuel gas and the oxidizing gas when detecting an open circuit voltage of the cell. Item 3. The fuel cell system according to Item 1 or 2. A power supply device (12) capable of supplying power;
An electric device (11, 16) that operates by being supplied with electric power from the power supply device (12) and the fuel cell (10),
When detecting the open circuit voltage of the cell, power is supplied to the electric devices (11, 16) only from the power supply device (12) of the power supply device (12) and the fuel cell (10). The fuel cell system according to any one of claims 1 to 3. A fuel cell system comprising a solid polymer electrolyte type fuel cell (10) for generating electricity by electrochemically reacting hydrogen in fuel gas and oxygen in oxidizing gas in a number of cells,
When the fuel cell (10) is activated and the inside of the cell is in a dry state, the load of the fuel cell (10) is controlled to be high within a range where the voltage of the cell does not fall below a predetermined voltage (V4). The fuel cell system controls the temperature of the fuel cell (10) to be lower than when the moisture in the cell is in an optimum state. A cooling system (40 to 44) for controlling the temperature of the fuel cell (10) by circulating cooling water;
The fuel cell system according to claim 5, wherein the temperature of the fuel cell (10) is controlled to be low by increasing the flow rate of the cooling water. The fuel cell system according to claim 5 or 6, wherein the load of the fuel cell (10) is increased stepwise within a range where the voltage of the cell does not fall below a predetermined voltage (V4). Electric devices (11, 16) that are operated by being supplied with electric power from the fuel cell (10),
The load on the fuel cell (10) is controlled to be high so that the amount of power generation is greater than or equal to the amount of power consumed by the electric devices (11, 16). Fuel cell system. A fuel cell system comprising a solid polymer electrolyte type fuel cell (10) for generating electricity by electrochemically reacting hydrogen in fuel gas and oxygen in oxidizing gas in a number of cells,
When the fuel cell (10) is activated and the inside of the cell is in an excessive water state, the temperature of the fuel cell (10) is controlled to be higher than when the water in the cell is in an optimal state. A fuel cell system that controls a large supply amount of the oxidizing gas. A cooling system (40 to 44) for controlling the temperature of the fuel cell (10) by circulating cooling water;
The fuel cell system according to claim 9, wherein the temperature of the fuel cell (10) is controlled to be high by reducing the flow rate of the cooling water.

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