JP2000223138A - Fuel cell system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-efficiency fuel cell system excellent in power generating performance, allowing control of temperature of a fuel gas and an oxidizer gas supplied to a fuel cell to necessary temperature so as to prevent condensation of water vapor. SOLUTION: This fuel cell system has a fuel cell 2 for generating power by use of a fuel gas and an oxidizer gas, and a combustion means 3 for burning a fuel gas off-gas from the fuel cell 2. In the fuel cell system, a heat exchanging means 51, 52 is provided between an exhaust gas exhausted from the combustion means 3 and at least one of the fuel gas and the oxidizer gas supplied to the fuel cell 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a fuel cell system.

[0002]

2. Description of the Related Art In order to reduce air pollution as much as possible, it is important to take measures against exhaust gas from automobiles. As one of the measures, electric vehicles are used. Has not been reached.

[0003] Fuel cells have attracted attention as clean power generation devices that generate no electricity other than water using hydrogen and oxygen by the reverse reaction of electrolysis, and automobiles that use the fuel cells are most likely to be used in the future. It is believed to be a clean car with potential. Among the above fuel cells, a solid polymer electrolyte fuel cell operates at a low temperature and is most promising for automobiles.

[0004] The solid polymer electrolyte fuel cell system generally has a fuel in which a large number of cells having a structure in which a solid polymer electrolyte is sandwiched between two electrodes (a fuel electrode and an oxidant electrode) are stacked. The fuel cell comprises a reformer for producing and supplying a fuel gas containing hydrogen as a main component to the fuel cell, an oxidizing gas supply means and a gas pipe for supplying an oxidizing gas, and a control device for controlling them. I have.

The fuel gas is sent to the fuel electrode side, and the oxidant gas is sent to the oxidant electrode side, and power is generated by an electrochemical reaction. There is an appropriate operating temperature range for operating the fuel cell, and power generation performance is degraded in a temperature range outside the temperature range. For this reason, the fuel cell is provided with a temperature control means using heat refrigerant oil or the like. In the case of a solid polymer electrolyte fuel cell, the temperature is controlled to about 70 ° C. in order to control the steam pressure.

[0006] The electrode catalyst of the fuel cell is poisoned by carbon monoxide, and its performance deteriorates. The electrode temperature of the fuel cell is 80
If the temperature is raised to at least ° C., the poisoning by carbon monoxide can be reduced, but it becomes difficult to properly maintain the power generation performance of the fuel cell, such as by controlling the steam pressure. When the temperature of the fuel gas and the oxidizing gas supplied to the fuel cell is set to 80 ° C. or higher, the poisoning of the electrode catalyst by carbon monoxide can be reduced. In the case of a solid polymer electrolyte fuel cell, since a solid polymer electrolyte membrane is used as an electrolyte, the temperature of the fuel gas and the oxidizing gas supplied to the fuel cell must be 100 ° C. or less.

In the case of a solid polymer electrolyte fuel cell, it is necessary to humidify the fuel cell in order to maintain its performance as an electrolyte, and the fuel gas and the oxidizing gas supplied to the fuel cell are supplied with water vapor. If the temperature of the fuel gas and the oxidizing gas is low, there is a problem that water vapor condenses. When water vapor is condensed into water, the amount of water vapor supplied to the fuel cell is insufficient, or the water is supplied in a water state to inhibit an electrode reaction, or a pipe of a fuel gas and an oxidizing gas supplied to the fuel cell. There is a problem that the road is blocked and supply of gas is obstructed, thereby lowering the power generation performance of the fuel cell.

As prior art 1, Japanese Patent Laid-Open No. 7-32637
No. 6 discloses a fuel cell system that heats a humidifying section provided in a pipeline of a fuel gas and an oxidizing gas supplied to the fuel cell by using a heat medium that controls the temperature of the fuel cell. . As prior art 2, Japanese Patent Application Laid-Open No. H8-64218 discloses a humidifier provided in a fuel gas / oxidant gas pipe line using fuel gas and oxidant gas off-gas. There is disclosed a fuel cell system for heating a fuel cell.

[0009]

However, in the prior art 1, since sufficient heat energy cannot be supplied to the humidifying water supplied to the fuel gas and the oxidizing gas, necessary heat vapor is supplied only by this heat energy. There is a problem that the poisoning of the electrode catalyst by carbon monoxide cannot be reduced, and the power generation performance of the fuel cell cannot be improved.

In the prior art 2, since sufficient thermal energy cannot be supplied to the fuel gas and the oxidizing gas supplied to the fuel cell, the poisoning of the electrode catalyst by carbon monoxide cannot be reduced. There is a problem that the supplied water is condensed and the power generation performance of the fuel cell is reduced.

The present invention solves the above-mentioned problems, and controls a fuel gas and an oxidizing gas to be supplied to a fuel cell to a required temperature to prevent a water vapor from condensing. I will provide a.

[0012]

In order to solve the above-mentioned technical problems, the technical means (hereinafter referred to as first technical means) taken in claim 1 of the present invention comprises a fuel gas and an oxidation gas. In a fuel cell system including a fuel cell that generates electric power by using an agent gas and a combustion unit that burns a fuel gas off-gas of the fuel cell, an exhaust gas discharged from the combustion unit, a fuel gas supplied to the fuel cell, A fuel cell system characterized in that heat exchange means is provided between at least one of the agent gases.

The effects of the first technical means are as follows.

That is, since the hydrogen contained in the fuel gas off-gas not used in the fuel cell has sufficient thermal energy, sufficient heat can be given to the fuel gas and the oxidizing gas supplied to the fuel cell, Since the temperature can be adjusted to be suitable for the battery system, the poisoning of the electrode catalyst by carbon monoxide can be reduced, and the fuel gas,
Condensation of water vapor contained in the oxidizing gas can be prevented,
A highly efficient fuel cell system with excellent power generation performance can be provided.

In order to solve the above technical problem, the technical means (hereinafter referred to as the second technical means) taken in claim 2 of the present invention is provided between the combustion means and the heat exchange means. And an oxidizing gas supply unit including a turbine that rotates by using combustion energy of exhaust gas discharged from the combustion unit and a compressor that is connected to the turbine and compresses the oxidizing gas. A fuel cell system according to claim 1.

The effects of the second technical means are as follows.

That is, since the thermal energy of hydrogen contained in the fuel gas off-gas which has not been used in the fuel cell can be used as power for the oxidizing gas supply means, a highly efficient fuel cell system can be provided.

In order to solve the above technical problem, the technical means (hereinafter referred to as third technical means) taken in claim 3 of the present invention is that the heat exchange means is a multi-tube cylindrical heat exchanger. 3. The fuel cell system according to claim 1, wherein the fuel cell system is an exchanger.

The effects of the third technical means are as follows.

That is, since the pressure loss of the exhaust gas can be reduced, the operation of the combustion means and the oxidizing gas supply means is not hindered.

In order to solve the above-mentioned technical problem, the technical means (hereinafter referred to as fourth technical means) taken in claim 4 of the present invention is characterized in that the exhaust gas supplied to the heat exchange means is 3. The fuel cell system according to claim 1, further comprising a flow rate control means for controlling a flow rate.

The effects of the fourth technical means are as follows.

That is, since the flow rate of the exhaust gas can be controlled by the flow rate control means, the temperature of the fuel gas and the oxidizing gas supplied to the fuel cell can be set to the optimum temperature.

In order to solve the above technical problem, the technical means (hereinafter referred to as fifth technical means) taken in claim 5 of the present invention comprises a fuel gas supplied to the fuel cell, an oxidizing gas, A temperature detecting means is provided at at least one inlet of the fuel cell of the agent gas, and a control device is provided for controlling the flow rate of the exhaust gas supplied to the heat exchanging means based on the temperature of the temperature detecting means by the flow rate controlling means. 3. The fuel cell system according to claim 1, wherein the fuel cell system comprises:

The effects of the fifth technical means are as follows.

That is, fuel gas supplied to the fuel cell,
Since the temperature of the oxidizing gas is controlled by feedback, the temperature of the fuel gas and the temperature of the oxidizing gas can be optimized.

[0027] In order to solve the above technical problem, the technical means (hereinafter referred to as sixth technical means) taken in claim 6 of the present invention comprises the above exhaust gas and the fuel supplied to the fuel cell. A heat exchange means is provided between each of the gas, the exhaust gas, and the oxidizing gas supplied to the fuel cell, and a flow control means for controlling a flow rate of the exhaust gas supplied to each of the heat exchange means is provided. Claim 1
And 2. The fuel cell system according to 2.

The effects of the sixth technical means are as follows.

That is, since the flow rates of the exhaust gas supplied to the heat exchange means for heating the fuel gas and the heat exchange means for heating the oxidant gas are separately controlled, the temperatures of the fuel gas and the oxidant gas are further optimized. It can be in a state.

In order to solve the above-mentioned technical problems, the technical means (hereinafter referred to as seventh technical means) taken in claim 7 of the present invention is characterized in that the oxidizing gas supply means comprises:
3. An apparatus for supplying an oxidizing gas to a fuel cell using the turbine and a motor as power.
It is a fuel cell system of the description.

The effects of the seventh technical means are as follows.

That is, when starting the fuel cell system in which the combustion means has not started combustion, the oxidizing gas can be supplied by the power of the motor at the time of starting, and after starting, the combustion of the fuel gas off-gas discharged from the fuel cell can be performed. Since the oxidizing gas can be supplied using energy, there is no need to provide another oxidizing gas supplying means at the time of starting and thereafter, and the fuel cell system can be downsized.

[0033]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described.
This will be described with reference to the drawings.

FIG. 1 is a diagram of a solid polymer electrolyte fuel cell system for a vehicle such as an automobile according to an embodiment of the present invention. The configuration of the present embodiment will be described. In this embodiment, air is used as the oxidizing gas, and a gas obtained by reforming methanol is used as the fuel gas.

The solid polymer electrolyte fuel cell system comprises a reformer 1, a fuel cell 2, a burner 3 as a combustion means,
It comprises a turbo assist compressor 4 as oxidizing gas supply means and heat exchangers 51 and 52 as heat exchange means. The solid polymer electrolyte fuel cell system includes a water tank 5, a methanol tank 6, flow control valves V1 and V2 as flow control means, a humidifier 7, thermometers 71 and 72 as temperature detection means, and a control device. 100 and various pumps and pipes are provided.

The reformer 1 is a device for reforming water and methanol, which are fuels, into a fuel gas containing hydrogen as a main component. The reformer 1 has a combustion unit 101, an evaporation unit 102, a reforming unit 103, and carbon monoxide. It comprises a reduction unit 104. The combustion unit 101 of the reformer 1 is connected to a methanol tank 6 storing methanol via a methanol pump P3, and is connected to an air compressor C1 via an air line 13. The evaporator 102 of the reformer 1 is connected to a water tank 5 storing water via a water pump P1, and is connected to the methanol tank 6 via a methanol pump P2.

The reformer 1 is connected to the heat exchanger 52 via a fuel gas line 14a. The heat exchanger 5
Numeral 2 is connected to a fuel gas supply port 21 of the fuel cell 2 via a fuel gas pipe 14b. The fuel gas line 14
The thermometer 72 is provided near the fuel gas supply port 21 of b.

The turbo assist compressor 4 comprises a turbine 41, a motor 42, and a compressor 43. The compressor 43 is a device for compressing and supplying air, which is an oxidizing gas, and is connected to the humidifier 7 via an air line 16. The compressor 43 is also connected to the reforming section 103 through an air line 16a branching from the air line 16, and is connected to the first portion through an air line 16b branching from the air line 16a. It is connected to the carbon oxide reducing unit 104.

The humidifier 7 is connected to the heat exchanger 51 via an air line 17a. The heat exchanger 51 is connected to the air supply port 22 of the fuel cell 2 via the air line 17b. The thermometer 71 is provided near the air supply port 22 of the air line 17b.

The fuel gas off-gas outlet 23 of the fuel cell 2 is connected to the fuel gas off-gas supply port 31 of the burner 3 via a fuel gas off-gas pipe 19. The air off-gas outlet 24 of the fuel cell 2 is connected to the air off-gas supply port 3 of the burner 3 through an air off-gas line 20.
It is connected to 3.

The burner 3 is a combustion means for burning the fuel gas off-gas by using the air off-gas as an auxiliary agent. An exhaust gas outlet 35 of the burner 3 is connected to a turbine 41 of the turbo assist compressor 4 via an exhaust gas line 27. The turbine 41 is connected to the atmosphere via an exhaust gas line 25.

The turbine 41 is connected to a flow control valve V 1 through an exhaust gas line 36 branched from the exhaust gas line 25, and the flow control valve V 1 is connected to the exhaust gas line 38.
And is connected to the heat exchanger 51 via the. The turbine 4
1 is also connected to a flow control valve V2 via an exhaust gas line 37 branching from the exhaust gas line 25,
The flow control valve V2 is connected to the heat exchanger 52 via the exhaust gas line 39.

The control device 100 is connected to a thermometer 71 via a signal line S1 and to a thermometer 72 via a signal line S2. The control device 100 is also connected to the flow control valve V1 via the signal line S3 and to the flow control valve V2 via the signal line S4.

The flow control valves V1 and V2 are motor-driven butterfly valves. FIG. 2 shows the flow control valve V
3 is a perspective view of the flow control valve V1. A butterfly valve section 9 is provided at the center of the pipe 32 through which the exhaust gas passes. The butterfly valve portion 9 is connected to a motor 10 via a shaft 8, and the motor controls the flow rate by opening and closing the butterfly valve portion 9.

Reference numerals 44 and 45 denote connecting portions of the pipe 32 with external pipes, which are connected to exhaust gas pipes 36 and 38, respectively. The flow control valve V2 is also the flow control valve V1.
It has the same structure as.

The heat exchangers 51 and 52 are multi-tubular cylindrical heat exchangers, so-called shell and tube type heat exchangers. FIG. 4 is a sectional view of the heat exchanger 51. A large number of air ducts 60 are provided in the heat exchanger body 51A. The pipe peripheral part 61 is a space around the air pipe 60, through which exhaust gas flows, and is sealed by a gas seal part 66. The air pipe 60 is a straight pipe and has a small pressure loss. The air pipe 60 may be a finned pipe to increase the heat exchange efficiency.

The air supply port 6 is provided in the heat exchanger body 51A.
2. The air outlet 63 is connected. The air supply port 6
2. The air outlet 63 is connected to the air line 17a, 17
b. An exhaust gas supply port 64 connected to the pipe peripheral portion 61 is provided on the heat exchanger body 51A.
An exhaust gas outlet 65 is provided, and the exhaust gas supply port 64 is connected to the exhaust gas pipe 38. Since the cross-sectional area of the pipe surrounding area 61 through which the exhaust gas flows is large, the pressure loss is small. The heat exchanger 52 has the same structure as the heat exchanger 51.

Hereinafter, the operation and operation of this embodiment will be described.

When the fuel cell system is started, methanol is supplied from the methanol tank 6 to the combustion section 101 of the reformer 1 by the methanol pump P3. The motor 42 of the turbo assist compressor 4 is also started, and the compressor 43 is started. At the same time air compressor C1
Is also started. The methanol supplied to the combustion unit 101 burns the air supplied from the air compressor C1 as a combustion aid, and heats the evaporator 102.

Water is supplied from the water tank 5 by the water pump P1.
Methanol is supplied from the methanol tank 6 to the evaporator 102 of the reformer 1 by the methanol pump P2.
The supplied water and methanol are supplied to the evaporator 1 of the reformer 1.
It is vaporized in 02 and sent to the reforming unit 103.

In the reforming section 103, steam of water and methanol is supplied to the compressor 4 of the turbo assist compressor 4.
3 and mixed with the air sent from
d catalyst and a Cu—Zn catalyst) to reform the fuel gas containing hydrogen as a main component by the following reaction and reduce the carbon monoxide.
4

CH ₃ OH + 0.13O ₂ + 0.47N ₂ + 0.75H ₂ O → 2.75H ₂ + CO ₂ + 0.47N ₂ (1) The fuel gas contains 0.5 to 1% of carbon monoxide. Yes,
The carbon monoxide reduction unit 104 oxidizes carbon monoxide with air sent from the compressor 43 by a carbon monoxide reduction catalyst (for example, a Pt catalyst or the like) to change it into CO _2, and reduces the carbon monoxide concentration to 10 ppm or less. The heat is supplied to the fuel cell 2 via the heat exchanger 52.

On the other hand, air as the oxidizing gas is supplied from the compressor 43 to the fuel cell 2 via the humidifier 7 and the heat exchanger 51. The humidifier 7 uses a method of mixing water atomized by injection into air. As a humidifying method, there is a method of humidifying by ultrasonic waves or bubbling other than injection.

The fuel cell 2 has a number of stacked cells, each of which has a structure in which a solid polymer electrolyte membrane is sandwiched between two electrodes (a fuel electrode and an oxidant electrode). At the fuel electrode, the following reaction occurs when hydrogen gas in the fuel gas comes into contact with the catalyst.

2H ₂ → 4H ⁺ + 4e ⁻ (2) H ⁺ moves through the solid polymer electrolyte membrane, reaches the oxidant electrode catalyst, and reacts with oxygen in the air to form water. Electric power is generated by this electrochemical reaction.

4H ⁺ + 4e ⁻ + O ₂ → 2H ₂ O (3) Since water also moves with the movement of H ⁺ from the fuel electrode, it is necessary to supply the fuel gas supplied to the fuel electrode with moisture contained therein. . For this reason, more water than the water required for the reaction of the formula (1) is supplied from the water tank 5 to the evaporator 102. On the other hand, it is necessary to humidify the air in order to sufficiently bring out the performance of the polymer electrolyte membrane, and the humidifier 7 is provided.

In the fuel cell 2, the hydrogen in the fuel gas is 1
It is not used at 00%, but is about 80%. The fuel gas off-gas not used in the fuel cell 2 is sent to the fuel gas supply port 31 of the burner 3 via the fuel gas off-gas pipe 19.

On the other hand, since excess air is sent to the fuel cell 2, air off-gas is discharged from the air off-gas outlet 24.
Is discharged from The air off-gas is sent to the air supply port 33 of the burner 3 via the air off-gas line 20.

The burner 3 burns with the fuel gas off-gas and the air off-gas sent from the fuel cell 2. The exhaust gas from the burner 3 is sent to the turbine 41 of the turbo assist compressor 4 to rotate the turbine 41.

The exhaust gas from the burner 3 is sent to the turbine 41 of the turbo assist compressor 4.
To rotate. Since the compressor is rotated by the rotation of the turbine 41, the load on the motor 42 is reduced, and power can be saved. At the time of steady operation of the fuel cell system, there is sufficient combustion energy of the fuel gas off-gas, so that it is not necessary to operate the motor, and the motor is stopped. This effect is important in an in-vehicle fuel cell system such as an automobile where the auxiliary power is limited.

A part of the exhaust gas discharged from the turbine 41 is supplied to an exhaust gas supply port 64 of the heat exchanger 51 with its flow rate controlled by a flow control valve V1. The supplied exhaust gas is discharged from an exhaust gas outlet 65 through a pipe peripheral portion 61. When the exhaust gas passes through the pipe periphery 61, the exhaust gas flows through the air pipe 60 to heat the air supplied to the fuel cell 2.

This prevents condensation of water vapor in the air,
The air can be brought to a temperature required for the fuel cell 2. Since water supplied by the humidifier 7 evaporates and the air temperature decreases, the heating of the air by the heat exchanger 51 is important. Note that the humidifier 7 may be heated by the exhaust gas, or the humidifier 7 and the heat exchanger 51 may be combined.

A part of the exhaust gas discharged from the turbine 41 is supplied to the heat exchanger 52 with its flow rate controlled by a flow control valve V2. In the heat exchanger 52, the heat exchanger 5
As in 1, the fuel gas supplied to the fuel cell 2 is heated. This can prevent the condensation of water vapor in the fuel gas and at the same time keep the fuel gas at 80 to 100 ° C., so that the poisoning of the electrode catalyst of the fuel cell 2 by carbon monoxide can be reduced. it can.

The effect of the heat exchangers 51 and 52 is remarkable at the start. Since the inside of the pipe is not sufficiently warmed at the time of starting, the moisture in the gas tends to condense. When the condensation occurs, the gas flowing thereafter is cooled by the condensed water, so that the gas temperature decreases. These phenomena are reflected in the heat exchangers 51 and 52.
Can be avoided by using.

The opening of the flow control valves V1 and V2 is controlled by the control device 100 to control the temperatures of the air and the fuel gas. FIG. 5 shows the flow control valves V1 and V2.
FIG. 4 is a flowchart of the opening degree adjustment.

The temperature T1 measured by the thermometer 71 is transmitted to the control device 100 via the signal line S1. Thermometer 72
The temperature T2 measured by the control device 1 via the signal line S2
00 is transmitted. In step S101, the control device 100 compares the temperature T1 with a preset temperature value Ta. When the temperature T1 is lower than the temperature value Ta, the process proceeds to step S102.

In step S102, the opening of the flow control valve V1 is calculated according to a predetermined formula, and the flow advances to step S103. In step S103, a command is sent from the control device 100 via the signal line S3, and the opening degree of the flow control valve V1 is determined in step S102.
The value is adjusted to the value calculated in step S5, and the process proceeds to step S105.

If the temperature T1 is equal to or higher than the temperature value Ta in step S101, the process proceeds to step S104. In step S104, the flow control valve V1 is closed to stop the supply of the exhaust gas to the heat exchanger 51, and the process proceeds to step S105.

In step S105, the control device 10
At 0, the temperature T2 is compared with a preset temperature value Tb. When the temperature T2 is lower than the temperature value Tb, the process proceeds to step S106.

In step S106, the opening of the flow control valve V2 is calculated according to a predetermined calculation formula, and the flow advances to step S107. In step S107, a command is sent from the control device 100 via the signal line S4, and the opening of the flow control valve V2 is determined in step S106.
The value is adjusted to the value calculated in step, and the process returns to step S101.

When the temperature T2 is equal to or higher than the temperature value Tb in step S105, the process proceeds to step S108. In step S108, the flow control valve V2 is closed to stop the supply of the exhaust gas to the heat exchanger 52, and the process returns to step S101.

The processing of the above steps is repeated while the fuel cell system is in operation, and is stopped by stopping the operation of the fuel cell system.

One of effective means for increasing the power recovered on the turbine 41 side of the turbo assist compressor 4 is to increase the pressure of exhaust gas supplied to the turbine 41 (primary pressure) as much as possible. is necessary. In that case, if the pressure on the discharge side (secondary pressure) increases together with the primary pressure on the turbine, the effect of increasing the primary pressure cannot be obtained. That is, it is necessary to make the pressure difference between the primary pressure and the secondary pressure of the turbine 41 as large as possible.

To lower the secondary pressure, the turbine 4
It is necessary to reduce the pressure loss in the gas lines after the first. Since a butterfly valve having a small pressure loss is used as the flow control valves V1 and V2 and a multi-pipe cylindrical heat exchanger having a small pressure loss is used as the heat exchangers 51 and 52, the gas pipelines after the turbine 41 are used. Can be reduced, and the power recovery by the turbine 41 can be increased.

In this fuel cell system, the compressor 43 and the turbine 41 are connected to the air lines 16, 17a, 17
b, 20, the heat exchanger 51, and the fuel cell 2, so that the primary pressure of the turbine 41 is the discharge pressure of the compressor 43 and the pipeline connecting the compressor 43 and the turbine 41. And so on.

As described above, the higher the primary pressure of the turbine 41 is, the higher the power recovery amount in the turbine 41 is. Therefore, it is necessary to minimize the pressure loss. Since a multi-tubular cylindrical heat exchanger having a small pressure loss is used as the heat exchanger 51, the primary pressure of the turbine 41 can be increased, and the power recovery by the turbine 41 can be increased. it can.

As described above, in the present invention, since the multi-tube cylindrical heat exchanger having a small pressure loss is used, the turbine 4
1 to ensure power recovery, and also use the thermal energy of the exhaust gas from the burner 3. This results in a highly efficient fuel cell system. On the other hand, the exhaust gas from the burner 3 is directly transferred to the heat exchanger 5 without the turbo assist compressor 4.
1 and 52, the burner 3
The pressure loss of the heat exchangers 51 and 52 needs to be small in order to increase the combustion efficiency of the heat exchangers and complete combustion to obtain a highly efficient fuel cell system.

[0078]

As described above, the present invention relates to a fuel cell system including a fuel cell for generating power using a fuel gas and an oxidizing gas and a combustion means for burning off fuel gas off-gas of the fuel cell. A heat exchange means provided between exhaust gas discharged from the means and at least one of a fuel gas and an oxidant gas to be supplied to the fuel cell. A high-efficiency fuel cell system with excellent power generation performance that does not condense water vapor by controlling gas and oxidant gas to required temperatures can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram of a solid polymer electrolyte fuel cell system for mounting on a vehicle such as an automobile according to an embodiment of the present invention.

FIG. 2 is a sectional view of a flow control valve according to an embodiment of the present invention.

FIG. 3 is a perspective view of a flow control valve according to the embodiment of the present invention.

FIG. 4 is a cross-sectional view of the heat exchanger according to the embodiment of the present invention.

FIG. 5 is a flowchart for adjusting the opening of the flow control valve.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Reformer 2 ... Fuel cell 3 ... Burner (combustion means) 4 ... Turbo assist compressor (oxidant gas supply means) 7 ... Humidifier 41 ... Turbine 42 ... Motor 43 ... Compressor 51, 52 ... Heat exchanger (heat) Exchange means) 71, 72: thermometer (temperature detection means) 100: control device V1, V2: flow control valve (flow control means)

Claims (7)

[Claims] 1. A fuel cell system comprising: a fuel cell that generates power using a fuel gas and an oxidizing gas; and a combustion unit that burns a fuel gas off-gas of the fuel cell. A fuel cell system comprising a heat exchange means provided between at least one of a fuel gas and an oxidant gas supplied to the fuel cell. 2. Between the combustion means and the heat exchange means,
The oxidizing gas supply means, comprising: a turbine rotating by using combustion energy of exhaust gas discharged from the combustion means; and a compressor connected to the turbine and compressing the oxidizing gas. 2. The fuel cell system according to 1. 3. The fuel cell system according to claim 1, wherein said heat exchange means is a multi-tube cylindrical heat exchanger. 4. The fuel cell system according to claim 1, further comprising a flow rate control means for controlling a flow rate of the exhaust gas supplied to the heat exchange means. 5. A fuel cell, wherein at least one of a fuel gas and an oxidizing gas supplied to the fuel cell is provided with a temperature detecting means at an inlet of the fuel cell, and the temperature is supplied to the heat exchanging means based on a temperature of the temperature detecting means. 3. The fuel cell system according to claim 1, further comprising a control device for controlling a flow rate of the exhaust gas by the flow rate control means. 6. A heat exchange means is provided between the exhaust gas and the fuel gas supplied to the fuel cell, and between the exhaust gas and the oxidant gas supplied to the fuel cell, and the heat exchange means is provided to each of the heat exchange means. 3. The fuel cell system according to claim 1, further comprising flow control means for controlling a flow rate of the exhaust gas. 7. The fuel cell system according to claim 2, wherein the oxidizing gas supply means is a device that supplies the oxidizing gas to the fuel cell using the turbine and the motor as power.