JP2002015749A - Fuel cell system - Google Patents

Abstract

(57) [Summary] (Modifications) [PROBLEMS] To combine fuel cells of different types to effectively utilize each other's advantages, and to improve the degree of freedom in operating conditions. A phosphoric acid fuel cell stack, a polymer electrolyte fuel cell stack, and a fuel gas individually and simultaneously supplied to the phosphoric acid fuel cell stack and the polymer electrolyte fuel cell stack. Possible fuel gas supply mechanism 16 and the phosphoric acid type fuel cell stack 12
And an oxidizing gas supply mechanism 18 for supplying an oxidizing gas to the polymer electrolyte fuel cell stack 14. Specifically, at the time of startup based on the outside air temperature, the polymer electrolyte fuel cell stack is started first, and the obtained electric power is used for heating energy of the phosphoric acid type fuel cell stack.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel comprising a joined body comprising an electrolyte sandwiched between an anode electrode and a cathode electrode, wherein a plurality of power generation cells having the joined body sandwiched by separators are laminated. The present invention relates to a fuel cell system including a battery stack.

[0002]

2. Description of the Related Art For example, a phosphoric acid fuel cell (PAFC)
Is a method in which a bonded body composed of an anode electrode and a cathode electrode mainly composed of carbon is provided on both sides of an electrolyte layer in which concentrated phosphoric acid is impregnated in porous silicon carbide (matrix), and a separator ( A power generation cell configured by being sandwiched by bipolar plates is provided. Usually, a predetermined number of the power generation cells are stacked and used as a fuel cell stack.

On the other hand, a solid polymer fuel cell (SPFC)
Employs an electrolyte membrane composed of a polymer ion exchange membrane (cation exchange membrane). Similarly, a predetermined number of power generation cells composed of a joined body composed of the electrolyte membrane and a separator are laminated. It is used as a fuel cell stack.

In this type of fuel cell stack, a fuel gas supplied to the anode side electrode, for example, a gas mainly containing hydrogen (hydrogen-containing gas), is ionized on the catalyst electrode and passes through the electrolyte. It moves to the cathode side electrode side. The electrons generated during that time are taken out to an external circuit,
Used as DC electrical energy. Since an oxidant gas, for example, a gas mainly containing oxygen or air (oxygen-containing gas) is supplied to the cathode side electrode, hydrogen ions, electrons and oxygen react at the cathode side electrode. Water is produced.

[0005]

Generally, in a phosphoric acid fuel cell, the operating temperature is relatively high (120 ° C. to 200 ° C.).
(Before and after), generated water generated during operation is vaporized and discharged to the outside. However, at a relatively low temperature of 100 ° C. or less, such as at the time of starting operation, generated water exists as liquid water,
Liquid water exceeding the amount that can be stored in the electrolyte layer and the electrode may be introduced into the reaction gas channel.

However, the phosphoric acid constituting the electrolyte layer has a very high hydrophilicity and flows out of the electrolyte layer and the electrode together with the liquid water introduced into the reaction gas flow path. As a result, it has been pointed out that the power generation performance of the power generation cell is reduced and the life of the fuel cell itself is shortened.

On the other hand, in a polymer electrolyte fuel cell, a polymer ion exchange membrane, for example, an electrolyte membrane impregnated with Nafion 112 (manufactured by DuPont) is used, and the hydrogen ion conductivity in the electrolyte membrane is increased. Since it largely depends on the water content of the electrolyte membrane, it is necessary to retain liquid water in the electrolyte membrane. Therefore, the power generation temperature (operating temperature) of the fuel cell
Cannot be set to a temperature higher than the boiling point of liquid water, and usually the power generation temperature must be controlled to 80 ° C. to 90 ° C. or lower, which causes a problem that the whole system becomes complicated and the control becomes complicated. is there.

The present invention solves this kind of problem, and provides a fuel cell system in which different types of fuel cells can be combined to effectively utilize each other's advantages and have a high degree of freedom in operating conditions. The purpose is to:

[0009]

According to a first aspect of the present invention, there is provided a fuel cell system comprising: a phosphoric acid type fuel cell stack;
An air-cooled polymer electrolyte fuel cell stack is provided, and fuel gas is individually and simultaneously supplied to the phosphoric acid fuel cell stack and the polymer electrolyte fuel cell stack via a fuel gas supply mechanism. While possible, the oxidizing gas is supplied via an oxidizing gas supply mechanism. Therefore, the advantages of each of the phosphoric acid type fuel cell stack and the polymer electrolyte fuel cell stack can be effectively utilized while complementing the respective drawbacks, and the degree of freedom of the operating condition is greatly improved.

[0010] Specifically, at the time of starting by the outside air temperature,
The fuel gas is supplied only from the fuel gas supply mechanism to the polymer electrolyte fuel cell stack, and the oxidant gas is supplied from the oxidant gas supply mechanism to the polymer electrolyte fuel cell stack. Thus, the electric power required outside the operating temperature of the phosphoric acid type fuel cell stack can be supplemented by the polymer electrolyte fuel cell stack, and the phosphoric acid type fuel cell stack can be supplied through the polymer electrolyte fuel cell stack. It becomes possible to supply heating energy until the fuel cell reaches the operating temperature.

Next, when the phosphoric acid type fuel cell stack reaches the operating temperature, fuel gas is supplied to the phosphoric acid type fuel cell stack via a fuel gas supply mechanism. Therefore, in the phosphoric acid type fuel cell stack, the fuel gas and the oxidizing gas are supplied, and power generation is started. At this time, since the phosphoric acid type fuel cell stack is heated to a predetermined operating temperature, the reaction product water can be prevented from flowing out as liquid water together with phosphoric acid, and the power generation performance can be effectively maintained. Become.

Further, the phosphoric acid type fuel cell stack can be used as a normal power source, and insufficient electric power can be supplied by the polymer electrolyte fuel cell stack at the time of high load.
That is, a fuel gas is simultaneously supplied from the fuel gas supply mechanism to the phosphoric acid type fuel cell stack and the polymer electrolyte fuel cell stack, and the phosphoric acid type fuel cell stack and the polymer electrolyte fuel cell are supplied from the oxidizing gas supply mechanism. An oxidizing gas may be supplied to the battery stack.

In the fuel cell system according to a second aspect of the present invention, a medium supply mechanism for supplying a temperature adjusting medium into the phosphoric acid type fuel cell stack includes a medium inlet and a medium of the phosphoric acid type fuel cell stack. A medium circulation path communicating with the outlet is provided, and the medium circulation path includes a medium circulation pump, a medium heating heater, a heat exchanger, and an inlet and an outlet of the heat exchanger. First and second opening / closing valves, a bypass path branched outside the first and second opening / closing valves, and a third path for opening / closing the bypass path.
An on-off valve is provided.

Therefore, when it is difficult to maintain the stack temperature due to self-heating of the phosphoric acid type fuel cell stack, for example, at the time of starting due to the outside air temperature or at the time of low load, first, the polymer electrolyte fuel cell stack Only power generation is performed.
The power generated by this polymer electrolyte fuel cell stack is
The electric power required outside the operating temperature of the phosphoric acid type fuel cell stack is supplemented and supplied to the heater for heating the medium constituting the medium supply mechanism.

For this reason, via a heater for heating the medium,
The medium is heated in the medium circulation path, and the heated medium circulates through the phosphoric acid type fuel cell stack,
The phosphoric acid type fuel cell stack can be efficiently heated to the operating temperature. At this time, the first and second on-off valves are closed, while the third on-off valve is open, and the heated medium circulates through the bypass without being radiated by the heat exchanger, It is possible to efficiently raise the temperature of the fuel cell stack.

When the phosphoric acid type fuel cell stack reaches the operating temperature, the power generation of the polymer electrolyte fuel cell stack is stopped, and the supply of electric power to the heater for heating the medium is also stopped. Next, while the third on-off valve is closed, the first and second on-off valves are opened, and the medium circulating in the medium circulation path is cooled by passing through the heat exchanger. This makes it possible to reliably maintain (cool) the phosphoric acid type fuel cell stack at a predetermined operating temperature.

Further, in the fuel cell system according to claim 3 of the present invention, the oxidizing gas supply mechanism includes a first external manifold provided between the blowing means and the polymer electrolyte fuel cell stack, A second external manifold is provided between the polymer fuel cell stack and the phosphoric acid fuel cell stack. Therefore, an oxidizing gas such as air is introduced into the polymer electrolyte fuel cell stack from the first external manifold under the action of the blowing means.

In the polymer electrolyte fuel cell stack, a part of the oxidant gas introduced as described above is used for the reaction, and the remainder is separated from the polymer electrolyte fuel cell stack by the second.
Discharged to external manifold. At this time, the reaction product water generated in the polymer electrolyte fuel cell stack evaporates, and the polymer electrolyte fuel cell stack is cooled via heat of vaporization. On the other hand, from the polymer electrolyte fuel cell stack,
The oxidizing gas discharged to the external manifold is heated by the heat of vaporization, and can function as a heat source for heating the phosphoric acid type fuel cell stack.

Further, in the fuel cell system according to claim 4 of the present invention, a heating means for heating the oxidizing gas is provided in the second external manifold. Therefore,
The oxidizing gas discharged from the polymer electrolyte fuel cell stack is further heated through heating means and then supplied into the phosphoric acid fuel cell stack. Can be quickly heated to the operating temperature of

Further, in the fuel cell system according to claim 5 of the present invention, the oxidizing gas supply mechanism includes first and second supply passages selectively communicating with the second external manifold via switching means. And a blower is provided in the first supply flow path, and a supercharger and a cooler are provided in the second supply flow path.

For this reason, at the time of startup, the oxidizing gas is supplied to the polymer electrolyte fuel cell stack through the first supply channel. On the other hand, when operating the phosphoric acid type fuel cell stack, a large amount of oxidizing gas is supplied through the second supply passage in which the supercharger and the cooler are arranged, , High-load operation can be easily performed.

[0022]

FIG. 1 is a schematic structural explanatory view of a fuel cell system 10 according to a first embodiment of the present invention.

The fuel cell system 10 includes a phosphoric acid type fuel cell stack 12, an air-cooled solid polymer type fuel cell stack 14, the phosphoric acid type fuel cell stack 12, and the solid polymer type fuel cell stack 14. A fuel gas supply mechanism 16 capable of supplying fuel gas individually and simultaneously;
An oxidizing gas supply mechanism 18 that supplies an oxidizing gas to the phosphoric acid type fuel cell stack 12 and the polymer electrolyte fuel cell stack 14 is provided. The phosphoric acid type fuel cell stack 12 includes power generation cells 20, and a predetermined number of the power generation cells 20 are stacked in the direction of arrow A, and end plates 21 and 23 are arranged at both ends in the stacking direction.

The power generation cell 20 is provided with a cathode electrode 24 and an anode electrode 26 with an electrolyte layer 22 made of porous silicon carbide or a basic polymer, for example, polybenzimidazole impregnated with phosphoric acid interposed therebetween. The cathode electrode 24 and the anode electrode 26 are provided with a gas diffusion layer made of, for example, porous carbon paper, which is a porous layer. The power generation cell 20 is configured by disposing a pair of separators 30 as bipolar plates on both sides of the joined body 28.

An oxidizing gas passage 3 for supplying an oxidizing gas is provided on the surface of the separator 30 facing the cathode electrode 24.
2 and a fuel gas flow path 34 for supplying a fuel gas is formed on the surface of the separator 30 facing the anode 26.

The end plate 21 has a fuel gas inlet 3
6, the end plate 23 is provided with a fuel gas outlet 38, and the fuel gas inlet 36 and the fuel gas outlet 38 are provided in the phosphoric acid type fuel cell stack 12 in the drawing. It communicates with each fuel gas flow path 34 via an internal manifold that is not used.

The polymer electrolyte fuel cell stack 14 is constructed in substantially the same manner as the phosphoric acid fuel cell stack 12 described above. Detailed description is omitted. The power generation cell 20a constituting the polymer electrolyte fuel cell stack 14 includes an electrolyte membrane 22a made of a polymer ion exchange membrane (cation exchange membrane).
It has.

The fuel gas supply mechanism 16 includes a fuel gas path 40
And two branch paths 42a and 42b branching from the fuel gas path 40 in two directions.
2 and a fuel gas inlet 36 a of the polymer electrolyte fuel cell stack 14. On the way of the branch paths 42a and 42b, the inlet-side on-off valves 44 are respectively provided.
a, 44b are provided.

Branch paths 42a, 42b connected to the fuel gas outlet 38 of the phosphoric acid type fuel cell stack 12 and the fuel gas outlet 38a of the polymer electrolyte fuel cell stack 14.
On the way, the outlet-side on-off valves 46a and 46b are provided, and the branch paths 42a and 42b
Merge to 0.

The oxidizing gas supply mechanism 18 is provided between the blower 50 serving as an air blowing means and the blower 50 and the polymer electrolyte fuel cell stack 14. A first external manifold 52 for supplying an oxidizing gas to the oxidizing gas passage 32a in the battery stack 14 is provided between the polymer electrolyte fuel cell stack 14 and the phosphoric acid fuel cell stack 12. A second oxidizing gas discharged from the oxidizing gas flow channel 32 a in the polymer electrolyte fuel cell stack 14 to the oxidizing gas flow channel 32 in the phosphoric acid fuel cell stack 12. An external manifold 54 is provided. In the second external manifold 54, a heating coil (heating means) 56 for heating the oxidizing gas is disposed.

The operation of the fuel cell system 10 according to the first embodiment configured as described above will be described below.

At the start of operation of the fuel cell system 10,
As shown in FIG. 2, the inlet-side on-off valve 44b and the outlet-side on-off valve 46b are arranged at the communicating position (open position), and the inlet-side on-off valve 44a and the outlet-side on-off valve 46a are arranged at the closed position. Therefore, the fuel gas inlet 3 of the end plate 21a constituting the polymer electrolyte fuel cell stack 14 from the fuel gas path 40 via the branch path 42b
A fuel gas such as a hydrogen-containing gas is supplied to 6a.

On the other hand, in the oxidizing gas supply mechanism 18, the blower 50 is driven and the oxidizing gas, which is air or an oxygen-containing gas, forms the polymer electrolyte fuel cell stack 14 through the first external manifold 52. Oxidant gas flow path 3
2a. For this reason, in the polymer electrolyte fuel cell stack 14, the oxidizing gas is supplied to the cathode 24a via the oxidizing gas flow path 32a of the separator 30a, and the fuel gas is supplied to the fuel gas flow of the separator 30a. It is supplied to the anode-side electrode 26a via the path 34a. As a result, power is generated in each power generation cell 20a, and power is supplied to a load such as a motor.

In each power generation cell 20a, a part of the oxidizing gas supplied from the first external manifold 52 is used for power generation, and an unused oxidizing gas is supplied from the oxidizing gas flow passage 32a to the second external gas passage 32a. It is discharged to the manifold 54. The temperature of the oxidizing gas discharged to the second external manifold 54 is increased by cooling the power generation cell 20a, and the oxidizing gas flow path forming the phosphoric acid type fuel cell stack 12 from the second external manifold 54. 32. Therefore, each power generation cell 20 is heated via the heated oxidizing gas.

Further, the polymer electrolyte fuel cell stack 1
4, the polymer electrolyte fuel cell stack 14 is cooled through heat of vaporization generated by the evaporation of the reaction water generated in the oxidant gas passage 32 a, and the discharged oxidant gas is The temperature is raised via heat of vaporization. Accordingly, the phosphoric acid type fuel cell stack 12 is heated to a desired operating temperature via the oxidizing gas which has been heated to a relatively high temperature.

When the phosphoric acid type fuel cell stack 12 reaches a desired operating temperature, the inlet opening / closing valve 44a and the outlet opening / closing valve 46a constituting the fuel gas supply mechanism 16 are opened, and the inlet opening / closing valves 44b and 44b are opened. Outlet valve 46
b is closed (see FIG. 1). Therefore, fuel gas is supplied from the fuel gas path 40 into the phosphoric acid type fuel cell stack 12 via the branch path 42a, and this fuel gas is supplied to the anode 26 via the fuel gas flow path 34 of the separator 30. Is done.

On the other hand, under the action of the blower 50 constituting the oxidizing gas supply mechanism 18, the second external manifold 52 passes from the first external manifold 52 through the oxidizing gas flow path 32a in the polymer electrolyte fuel cell stack 14. The oxidizing gas discharged to 54 is supplied to the cathode 24 via the oxidizing gas flow path 32 of the separator 30 constituting the phosphoric acid type fuel cell stack 12. Thereby, each power generation cell 2
0, power is generated, and desired electric power is supplied to a load such as a motor via the phosphoric acid type fuel cell stack 12.

As described above, in the first embodiment, the phosphoric acid type fuel cell stack 12 operated at a relatively high temperature (120 ° C. to 200 ° C.) and the solid fuel cell stack operated at a relatively low temperature of 100 ° C. or lower. The molecular fuel cell stack 14 is used in combination. Then, when the phosphoric acid type fuel cell stack 12 becomes difficult to operate satisfactorily due to the outside air temperature as in the start of operation of the fuel cell system 10, only the polymer electrolyte fuel cell stack 14 is operated. Therefore, it is possible to supplement the required electric power and supply the heating energy until the phosphoric acid type fuel cell stack 12 reaches the operating temperature.

Next, when the phosphoric acid type fuel cell stack 12 reaches the operating temperature, the polymer electrolyte fuel cell stack 14
Is stopped, and power is generated by the phosphoric acid type fuel cell stack 12. Therefore, the advantages of the phosphoric acid type fuel cell stack 12 and the polymer electrolyte fuel cell stack 14 can be effectively utilized while complementing the respective disadvantages, and the degree of freedom in operating conditions is greatly improved. The effect is obtained.

Further, in the first embodiment, the phosphoric acid type fuel cell stack 12 is used as a normal power source, and the polymer electrolyte fuel cell stack 14 is used in combination to sufficiently supply insufficient electric power at high load. It becomes possible.

That is, the inlet side opening / closing valves 44a and 44b constituting the fuel gas supply mechanism 16 and the outlet side opening / closing valve 46
a and 46b open to supply the fuel gas to the fuel gas flow paths 34 and 34a of the phosphoric acid type fuel cell stack 12 and the polymer electrolyte fuel cell stack 14, and via the oxidizing gas supply mechanism 18. Oxidant gas flow paths 32a, 3
An oxidant gas is supplied to 2. Thereby, the phosphoric acid type fuel cell stack 12 and the polymer electrolyte fuel cell stack 1
4 can be operated at the same time, and sufficient power can be supplied.

Further, in the second external manifold 54, for example, a heating coil 56 is disposed as a heating means for heating the oxidizing gas. Therefore, the oxidant gas discharged from the polymer electrolyte fuel cell stack 14 to the second external manifold 54 is further heated through the heating coil 56, and
This has the advantage that the temperature rise is reliably performed in a short time.

FIG. 3 is a schematic configuration diagram of a fuel cell system 60 according to a second embodiment of the present invention. The same components as those of the fuel cell system 10 according to the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

The fuel cell system 60 includes an oxidizing gas supply mechanism 62.
2 is a first supply passage 66 selectively connected to the first external manifold 52 via a rotary switching valve 64.
And a second supply channel 68. First supply channel 66
Has a blower 70 as a blowing means, for example, while the second supply flow path 68 has a supercharger (supercharger) 72 and a cooler (intercooler) 74.

In the fuel cell system 60 according to the second embodiment configured as described above, at the time of startup, as shown in FIG. 66 communicates, and the inlet-side on-off valve 44a and the outlet-side on-off valve 46a are closed, while the inlet-side on-off valve 44b and the outlet-side on-off valve 46b are opened. Therefore, the fuel gas is supplied only to the polymer electrolyte fuel cell stack 14 side and the blower 70
The oxidizing gas is supplied from the first supply passage 66 to the polymer electrolyte fuel cell stack 14 via the first external manifold 52 under the action of the above.

Next, when the phosphoric acid type fuel cell stack 12 reaches a predetermined operating temperature, as shown in FIG. 3, the inlet opening / closing valve 44a and the outlet opening / closing valve 46a are opened, while the inlet opening / closing valve 46a is opened. The valve 44b and the outlet opening / closing valve 46b are closed. Then, the switching valve 64 constituting the oxidizing gas supply mechanism 62 is operated, and the first external manifold 52 communicates with the second supply channel 68.

Therefore, the first external manifold 52 has:
The oxidizing gas is forcibly introduced through the supercharger 72 and the cooler 74, and a predetermined amount of the oxidizing gas is reliably supplied to the phosphoric acid type fuel cell stack 12 through the polymer electrolyte fuel cell stack 14. It becomes possible to do. This provides an advantage that the phosphoric acid type fuel cell stack 12 can be reliably operated with a relatively high load. At this time, if the polymer electrolyte fuel cell stack 14 is used in combination, the same effects as those of the above-described first embodiment can be obtained.

FIG. 5 is a schematic structural explanatory view of a fuel cell system 80 according to a third embodiment of the present invention. The same components as those of the fuel cell system 10 according to the first embodiment are denoted by the same reference numerals, and a detailed description thereof will be omitted.

The fuel cell system 80 has a medium supply mechanism 82 for supplying a temperature adjusting medium into the phosphoric acid type fuel cell stack 12. The medium supply mechanism 82 has a medium circulation path 84, and the medium circulation path 84
The medium outlet and the medium inlet (not shown) provided on the end plates 21 and 23 constituting the phosphoric acid type fuel cell stack 12 communicate with the medium outlet and the medium inlet. It communicates with a cooling path (not shown) in the inside.

In the medium circulation path 84, for example, a pump 86 for circulating a medium as a liquid cooling medium, a heater (heating coil) 88 for heating the medium, and a radiator (heat exchanger) 90 are provided. Is done. A cooling fan 92 is provided to face the radiator 90, and first and second on-off valves 94 and 96 for opening and closing the inlet side and the outlet side of the radiator 90 are provided in the medium circulation path 84. A bypass path 98 that branches off outside the first and second on-off valves 94 and 96 and a third on-off valve 100 that opens and closes the bypass path 98 are provided.

In the fuel cell system 80 according to the third embodiment configured as described above, at the time of starting due to the outside air temperature or at the time of low load, as shown in FIG.
And the outlet-side on-off valve 46a are closed, the inlet-side on-off valve 44b and the outlet-side opening valve 46b are opened, and the first and second on-off valves 94 and 96 constituting the medium supply mechanism 82 are closed. Meanwhile, the third on-off valve 100 is opened. Therefore, the fuel gas is supplied only to the polymer electrolyte fuel cell stack 14 side, and an oxidant gas is supplied to the polymer electrolyte fuel cell stack 14 under the action of the blower 50, and Fuel cell stack 1
4 is started.

The electric power generated by the polymer electrolyte fuel cell stack 14 supplements the electric power required within the operating temperature of the phosphoric acid fuel cell stack 12 and the medium supply mechanism 8
2 or the heater 88 alone.
And the heating coil 56. Accordingly, in the medium supply mechanism 82, the medium circulation path 84
The medium (liquid medium) in the fuel cell stack 12 is heated under the action of the pump 86.
And the temperature of the phosphoric acid type fuel cell stack 12 rises.

At this time, the first and second on-off valves 94 and 96 on the inlet side and the outlet side of the radiator 90 are closed, and the medium circulates through the phosphoric acid type fuel cell stack 12 through the bypass path 98. ing. Therefore, the medium is not radiated by the radiator 90, and the effect is obtained that the phosphoric acid type fuel cell stack 12 can be efficiently heated to a desired operating temperature.

On the other hand, when electric power is also supplied to the heating coil 56, the oxidant gas discharged from the polymer electrolyte fuel cell stack 14 is heated by the heating coil 56. Therefore, under the action of heated oxidant gas,
The temperature of the phosphoric acid type fuel cell stack 12 can be raised more efficiently.

Next, when the phosphoric acid type fuel cell stack 12 reaches the operating temperature, the operation of the polymer electrolyte fuel cell stack 14 is stopped, as shown in FIG. Power generation is started. At this time, the supply of power to the heater 88 and the heating coil 56 is stopped, and the first
And the second on-off valves 94 and 96 are opened, while the third on-off valve 100 is closed. Therefore, the medium circulation path 84
A radiator 90 communicates with the radiator 90,
The heat is released by passing through and cooled.
The phosphoric acid type fuel cell stack 12 is cooled (temperature controlled) so as to maintain the operating temperature.

As described above, in the third embodiment, the medium supply mechanism 82 for supplying the temperature adjusting medium into the phosphoric acid type fuel cell stack 12 is provided. As a result, at the time of starting at an outside air temperature or at a low load, only the polymer electrolyte fuel cell stack 14 is operated, and the heater 88 is energized via electric power generated by the polymer electrolyte fuel cell stack 14, The temperature inside the phosphoric acid type fuel cell stack 12 can be efficiently and quickly raised via the medium heated by the heater 88. Therefore, there is an effect that the operation of the phosphoric acid type fuel cell stack 12 is started in a short time, and efficient operation can be performed.

On the other hand, when the operation of the phosphoric acid type fuel cell stack 12 is started, in the medium supply mechanism 82, the radiator 90 radiates the medium, and the medium is discharged through the medium. Cooling is provided to maintain operating temperature. Therefore, there is an advantage that the phosphoric acid type fuel cell stack 12 can be reliably maintained at the operating temperature.

[0058]

In the fuel cell system according to the present invention, the phosphoric acid type fuel cell stack and the polymer electrolyte fuel cell stack are operated selectively or simultaneously,
While compensating for each of the disadvantages, the respective advantages can be effectively utilized, and the degree of freedom in operating conditions is greatly improved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration explanatory view of a fuel cell system according to a first embodiment of the present invention.

FIG. 2 is an operation explanatory diagram at the time of starting operation of the fuel cell system.

FIG. 3 is a schematic configuration explanatory view of a fuel cell system according to a second embodiment of the present invention.

FIG. 4 is an operation explanatory diagram of the fuel cell system.

FIG. 5 is a schematic configuration explanatory view of a fuel cell system according to a third embodiment of the present invention.

FIG. 6 is a diagram illustrating the operation of the fuel cell system.

[Explanation of symbols]

10, 60, 80 ... fuel cell system 12 ... phosphoric acid type fuel cell stack 14 ... polymer electrolyte fuel cell stack 16 ... fuel gas supply mechanism 18, 62 ... oxidant gas supply mechanism 20, 20a ...
Power generation cell 22 ... Electrolyte layer 22a ... Electrolyte membrane 24, 24a ... Cathode side electrode 26, 26a ...
Anode-side electrode 28 ... joined body 30, 30a ...
Separator 32, 32a ... Oxidant gas flow path 34, 34a ...
Fuel gas passages 36, 36a ... fuel gas inlets 38, 38a ...
Fuel gas outlet 40 ... Fuel gas paths 42a, 42b
... Branch paths 44a, 44b, 46a, 46b, 94, 96, 100
... On-off valves 50,70 ... Blowers 52,54 ... External manifold 56 ... Heating coil 64 ... Switching valves 66,68 ... Supply flow path 72 ... Supercharger 74 ... Cooler 82 ... Medium supply mechanism 84 ... Medium circulation path 86 ... Pump 88: heater 90: radiator

Claims (5)

[Claims] 1. A phosphor comprising an electrolyte impregnated with phosphoric acid sandwiched between an anode electrode and a cathode electrode, wherein a plurality of power generation cells having the junction sandwiched by separators are stacked. An acid-type fuel cell stack, and a joined body composed of an electrolyte made of a polymer ion exchange membrane sandwiched between an anode electrode and a cathode electrode, and a plurality of power generation cells in which the joined body is sandwiched by separators are stacked. An air-cooled polymer electrolyte fuel cell stack, a fuel gas supply mechanism capable of individually and simultaneously supplying fuel gas to the phosphoric acid fuel cell stack and the polymer electrolyte fuel cell stack, Gas supply mechanism for supplying an oxidizing gas to the fuel cell stack and the polymer electrolyte fuel cell stack. Tem. 2. The fuel cell system according to claim 1, further comprising a medium supply mechanism for supplying a temperature adjusting medium into the phosphoric acid type fuel cell stack, wherein the medium supplying mechanism comprises the phosphoric acid type fuel cell stack. A medium circulation path communicating with a medium inlet and a medium outlet of the medium, the medium circulation path includes a medium circulation pump, a medium heating heater, a heat exchanger, and an inlet side of the heat exchanger. And a first on-off valve for opening and closing the outlet side, a bypass path branching outside the first and second on-off valves, and a third on-off valve opening and closing the bypass path. A fuel cell system characterized by the above-mentioned. 3. The fuel cell system according to claim 1, wherein the oxidizing gas supply mechanism is provided between a blowing unit, the blowing unit and the polymer electrolyte fuel cell stack, and A first external manifold for supplying the oxidizing gas to an oxidizing gas flow path in the polymer electrolyte fuel cell stack via a means, the polymer electrolyte fuel cell stack, and the phosphoric acid fuel cell And supplying the oxidizing gas discharged from the first oxidizing gas flow path in the polymer electrolyte fuel cell stack to the oxidizing gas flow path in the phosphoric acid fuel cell stack. And a second external manifold. 4. A fuel cell system according to claim 3, wherein said second external manifold is provided with a heating means for heating said oxidizing gas. 5. The fuel cell system according to claim 3, wherein the oxidizing gas supply mechanism selectively connects to the first external manifold via switching means and a second supply passage. A fuel cell system comprising: a flow path; a blower provided in the first supply flow path; and a supercharger and a cooler provided in the second supply flow path.