JP2002050391A - Fuel cell system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel cell system in which multiple fuel cell stacks are arranged and which is made compact size and suitable for mounting on the automobiles. SOLUTION: The fuel cell system comprises a first and a second fuel cell stack 12, 14 that are arranged alternately and an outer manifold 16 that is incorporated in the first and the second fuel cell stack 12, 14. This outer manifold 16 is equipped with a common manifold portion 92 which is installed between the first and the second fuel cell stack 12, 14 and supplies or discharges a fluid such as fuel gas and oxidant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a fuel cell comprising a plurality of unit fuel cells, each comprising a solid polymer electrolyte membrane sandwiched between an anode electrode and a cathode electrode, which are horizontally stacked via a separator. The present invention relates to a fuel cell system including a battery stack.

[0002]

2. Description of the Related Art For example, a polymer electrolyte fuel cell is a unit in which an anode electrode and a cathode electrode are opposed to each other on both sides of an electrolyte membrane composed of a polymer ion exchange membrane (cation exchange membrane). The fuel cell is constituted by sandwiching the fuel cell between separators. This polymer electrolyte fuel cell is usually used as a fuel cell stack by stacking a predetermined number of unit fuel cells and separators.

In this type of fuel cell stack, a fuel gas, for example, a hydrogen-containing gas, supplied to an anode electrode is hydrogen-ionized on a catalyst electrode, and is humidified through a moderately humidified electrolyte membrane. Move to. The electrons generated during that time are taken out to an external circuit and used as DC electric energy. Since an oxidant gas, for example, an oxygen-containing gas or air is supplied to the cathode side electrode, the hydrogen ions, the electrons, and the oxygen gas react with each other to generate water at the cathode side electrode.

When the above-described fuel cell stack is mounted on a vehicle or the like and used, a considerably large number of unit fuel cells are required in order to obtain desired power. At this time, if an attempt is made to form a single fuel cell stack by stacking a considerable number of unit fuel cells, the length of the unit fuel cells in the stacking direction becomes considerably long, and fuel gas is transferred to each unit fuel. Problems such as the inability to evenly supply the battery cells occur.

[0005] Therefore, a fuel cell system in which a plurality of fuel cell stacks are prepared and each fuel cell stack is connected to each other via a manifold has been adopted.
For example, Japanese Patent Application Laid-Open No. 5-41239 discloses a high-temperature type in which a part or all of a manifold is constituted by at least two stacks each formed by stacking a plurality of cells each composed of a fuel electrode, a solid electrolyte, an air electrode, and a ceramic separator. A fuel cell module is disclosed.

Further, Japanese Patent Application Laid-Open No. Hei 5-21083 discloses that
A plurality of manifolds for circulating the reaction gas are arranged on the side surfaces of the plurality of unit cell stacks, and a gap between the opposing surfaces of the first unit cell stack and the second unit cell stack adjacent thereto is provided.
A fuel cell connected via a connecting member for passing a reaction gas is disclosed.

[0007]

However, in each of the above prior arts, the stacking direction of the stack is set to the direction of gravity. Therefore, when used in a vehicle, a considerably large number of unit fuel cells are stacked in the direction of gravity in order to obtain a desired electric power, and the height dimension of the entire stack is considerably long. Will be scaled.

However, when the fuel cell stack is mounted on a vehicle or the like, it is practically common to store the fuel cell stack below the seat or under the trunk, and a sufficient space is secured in the height direction of the fuel cell stack. Can not do it. As a result, the number of unit fuel cells to be stacked is limited, and it is pointed out that a desired power cannot be reliably obtained.

The present invention solves this kind of problem, and in particular, is suitable for a vehicle-mounted fuel cell that can effectively reduce the height of the entire system and reliably obtain desired power. The purpose is to provide a system.

[0010]

According to a first aspect of the present invention, there is provided a fuel cell system comprising: a plurality of fuel cell stacks arranged in parallel with each other along a stacking direction of unit fuel cells; The stack is provided with an external manifold for supplying and discharging a fuel gas and an oxidizing gas corresponding to at least the anode electrode and the cathode electrode. For this reason, the seal area around the communication hole is increased as in an internal manifold structure in which a communication hole for distributing a reaction gas (fuel gas or oxidant gas) to each unit fuel cell is provided in the separator surface. And the volume of the entire system can be reduced.

Further, the external manifold has a common manifold portion interposed between the adjacent fuel cell stacks for supplying or discharging at least a fuel gas and an oxidizing gas to the fuel cell stack. Therefore,
The structure of the entire external manifold is simplified,
The fuel cell system is effectively downsized, and the entire fuel cell system is downsized.

Further, a plurality of unit fuel cells constituting the fuel cell stack are stacked in a horizontal direction with a separator interposed therebetween. As a result, it is possible to obtain a desired power by stacking a large number of unit fuel cells while effectively suppressing the height dimension of the entire fuel cell system, and to provide a fuel cell system particularly suitable for in-vehicle use. be able to.

Further, the fuel cell system according to the second aspect of the present invention includes a support manifold portion disposed below or above the plurality of fuel cell stacks and supporting the fuel cell stack. Therefore, it is possible to reliably support each unit fuel cell and the separator via the support manifold portion, and it is possible to reliably prevent the separator from being displaced due to vibration or the like. Moreover, the fuel cell stack is supported on the side surface via the common manifold portion, and the lower surface or the upper surface is supported via the support manifold portion, so that the entire fuel cell stack can be firmly held.

Further, in the fuel cell system according to claim 3 of the present invention, the support manifold is disposed on the other side opposite to the one on which the common manifold is disposed. For this reason, the height dimension of the entire fuel cell system is substantially the height of the fuel cell stack, and the height of the fuel cell system is shortened as much as possible.

Further, in the fuel cell system according to claim 4 of the present invention, the external manifold is formed of an insulating member. This effectively maintains the insulation between the fuel cell stacks, and simplifies the operation of forming the external manifold to be economical.

[0016]

FIG. 1 is a schematic perspective view of a fuel cell system 10 according to a first embodiment of the present invention, and FIG.
1 is a schematic front view of the fuel cell system 10. FIG.

The fuel cell system 10 includes a first fuel cell stack 12 and a second fuel cell stack 14 arranged in parallel with each other along a horizontal direction (the direction of arrow A), and the first and second fuel cell stacks 12. , 14 are provided with at least a fuel gas and an oxidizing gas, and, if necessary, an external manifold 16 for supplying and discharging a cooling medium.

As shown in FIGS. 3 and 4, the first fuel cell stack 12 includes a unit fuel cell 32, and first and second separators 34 and 36 sandwiching the unit fuel cell 32. A plurality of these are stacked in the horizontal direction (the direction of arrow A). First fuel cell stack 1
2 has a rectangular parallelepiped shape as a whole, and is arranged with the short side direction (arrow B direction) oriented in the direction of gravity and the long side direction (arrow C direction) oriented in the horizontal direction.

The unit fuel cell 32 has a solid polymer electrolyte membrane 38, and a cathode 40 and an anode 42 disposed with the electrolyte membrane 38 interposed therebetween. The anode-side electrode 42 has first and second gas diffusion layers 44 and 46 made of, for example, porous carbon paper as a porous layer.
Is arranged.

On both sides of the unit fuel cell 32, first and second gaskets 48, 50 are provided. The first gasket 48 is large for accommodating the cathode 40 and the first gas diffusion layer 44. While having the opening 52, the second gasket 50 has a large opening 54 for accommodating the anode-side electrode 42 and the second gas diffusion layer 46. Unit fuel cell 32 and first and second units
The gaskets 48, 50 are sandwiched by the first and second separators 34, 36.

A plurality of independent oxidant gas flow grooves 56 are formed from the upper end of one end of the surface 34a of the first separator 34.
The oxidizing gas passage groove 56 extends in the direction of gravity while meandering in the horizontal direction. The oxidizing gas channel groove 56 is open outward from a lower portion on one end side of the first separator 34.

As shown in FIG. 5, the second separator 36 is formed in a rectangular shape, and a plurality of independent fuel gas flow grooves 58 are formed on the surface 36a of the second separator 36. . The inlet side of the fuel gas passage groove 58 is provided at a lower portion of one end of the second separator 36. After the fuel gas passage groove 58 extends upward, it extends in the gravity direction while meandering horizontally. And the second separator 36
Is open outward from the lower end on the other end side.

As shown in FIG. 3, a coolant channel groove 60 is formed on a surface 36b of the second separator 36 opposite to the surface 36a. The inlet side of the cooling medium passage groove 60 is
The cooling medium passage groove 60 is provided substantially at the center on one end side of the separator 36, and extends in the gravity direction while meandering in a substantially horizontal direction after extending upward.
6 is opened outward from substantially the center of the lower side.

As shown in FIG. 6, the unit fuel cells 32
The first and second end plates 62 and 64 are disposed at both ends in the stacking direction (the direction of arrow A), and the first end plate 62 has a power extraction terminal 6 serving as a positive electrode.
6 and a power extraction terminal 68 which is a negative electrode.

The first fuel cell stack 12 is integrally fastened and fixed in the stacking direction (direction of arrow A) via a fastening mechanism 70. The fastening mechanism 70 includes a liquid chamber 72 provided on the outer surface side of the first end plate 62, an incompressible liquid for applying a surface pressure sealed in the liquid chamber 72, for example, a silicon oil 74, Two or three disc springs 76 which are provided on the outer surface side of the plate 64 and are spaced apart by a predetermined distance in the horizontal direction to press the second end plate 64 toward the first end plate 62; Prepare.

A backup plate 78 is provided opposite the first end plate 62 with the liquid chamber 72 interposed therebetween, and the liquid chamber 72 is formed between the backup plate 78 and a thin plate 80 made of aluminum or stainless steel. The disc springs 76 are arranged at substantially equal intervals in the plane of the second end plate 64 and are supported by the mounting plate 82. Mounting plate 82
For example, six tie rods 84 are inserted into the backup plate 78 from the
Are arranged so as to penetrate (or are spaced apart outwardly) the unit fuel cell 32 and the outer peripheral edges of the first and second separators 34 and 36, and a nut 86 is screwed into the end of the tie rod 84. As a result, the first fuel cell stack 12 is integrally held.

The second fuel cell stack 14 is basically configured in the same manner as the first fuel cell stack 12, and the same components are denoted by the same reference characters and will not be described in detail. . However, the second fuel cell stack 14 is configured symmetrically with respect to the first fuel cell stack 12 described above, and also has the cathode electrode 40
And the anode-side electrode 42 are disposed on the opposite side.

As shown in FIGS. 1, 2 and 7, the external manifold 16 is disposed below the first and second fuel cell stacks 12, 14 so that the first and second fuel cell stacks 12, 14 are disposed. And a support manifold section 90 for supporting the first and second fuel cell stacks 12, 1
4 and a common manifold portion 92 interposed therebetween, and is formed of an insulating member.

The support manifold section 90 extends in the width direction of the first and second fuel cell stacks 12 and 14 (in the direction of arrow C).
And first and second mounting surfaces 94a and 94b corresponding to the dimensions of the first and second fuel cell stacks 12 and 14 in the stacking direction (the direction of arrow A). The first and second mounting surfaces 94a and 94b are provided with the first and second mounting surfaces 94a and 94b.
The unit fuel cells 32 and the first and second separators 34 and 36 constituting the fuel cell stacks 12 and 14 are directly supported. On both sides of the first and second mounting surfaces 94a and 94b, both sides of each unit fuel cell 32 and the first and second separators 34 and 36 constituting the first and second fuel cell stacks 12 and 14 in the width direction. Walls 9 directly supporting the part
6a and 96b are provided integrally in a vertically upward direction.

The support manifold section 90 includes oxidizing gas discharge passages 100a and 100b communicating with the outlets of the oxidizing gas passage grooves 56 in the first and second fuel cell stacks 12 and 14, respectively. Cooling medium discharge passages 102a, 102b communicating with the outlet sides of the respective cooling medium passage grooves 60 in the first and second fuel cell stacks 12, 14, and the inside of the first and second fuel cell stacks 12, 14, Fuel gas discharge passage 104 communicating with the outlet side of fuel gas passage groove 58
a and 104b are formed at symmetrical positions.

The common manifold portion 92 has partition plates 108, 110 and 112 extending above the flat surface 106 provided at the center of the support manifold portion 90 and extending in the direction of arrow A at predetermined intervals. Prepare. The fuel gas supply channel 11 is provided between the flat surface 106 and the partition plate 108.
4 is formed, a cooling medium supply passage 116 is formed between the partition plate 108 and the partition plate 110, and the partition plate 11
An oxidant gas supply channel 118 is formed between the partition plate 112 and the partition plate 112.

The fuel gas supply passage 114 is provided in each of the fuel gas passage grooves 5 in the first and second fuel cell stacks 12 and 14.
8, the cooling medium supply passage 116 communicates with the inlet side of the cooling medium passage groove 60 of the first and second fuel cell stacks 12, 14, and the oxidant gas supply passage 11
8 communicates with the inlet side of each oxidizing gas channel groove 56 of the first and second fuel cell stacks 12 and 14.

A piping mechanism 120 is mounted on one end of the external manifold 16. The piping mechanism 120 includes a piping block 122 corresponding to the shape of the external manifold 16.
6 is fixed by screws or the like. The piping block 122 is provided with an oxidizing gas discharge pipe 124 communicating with the oxidizing gas discharge flow paths 100a and 100b, and the oxidizing gas discharge pipe 124 has an oxidizing gas discharge port 126 formed therein. The piping block 122 includes a cooling medium discharge passage 10.
A cooling medium discharge pipe 128 communicating with the fuel gas discharge passages 104a and 104b is provided, and a cooling medium discharge port 132 is formed in the cooling medium discharge pipe 128. A fuel gas outlet 134 is formed in the fuel gas discharge pipe 130.

A fuel gas supply pipe 136 communicating with the fuel gas supply flow path 114 and a cooling medium supply pipe 138 communicating with the cooling medium supply flow path 116 are provided above the piping block 122.
Then, an oxidizing gas supply pipe 140 communicating with the oxidizing gas supply flow path 118 is mounted. The fuel gas supply pipe 136, the cooling medium supply pipe 138, and the oxidizing gas supply pipe 140 are provided with a fuel gas supply port 142, a cooling medium supply port 144, and an oxidizing gas supply port 146.

The other end of the external manifold 16 has a closing block 1 for preventing fuel gas, oxidizing gas and cooling medium from being led out from the other end.
47 are attached. A plurality of seal members 148 are disposed at contact portions between the first and second fuel cell stacks 12 and 14 and the external manifold 16 to prevent leakage of the fuel gas, the oxidizing gas, and the cooling medium (see FIG. 1). (See FIG. 2).

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

A fuel gas (for example, a gas containing hydrogen obtained by reforming a hydrocarbon) is supplied from a fuel gas supply port 142 to a fuel gas supply pipe 136 to a piping mechanism 120 constituting the fuel cell system 10. Oxidant gas supply port 1
Air or an oxygen-containing gas (hereinafter, simply referred to as air) is supplied to the oxidizing gas supply pipe 140 from 46 as an oxidizing gas. Further, a cooling medium such as pure water, ethylene glycol, or oil is supplied from the cooling medium supply port 144 to the cooling medium supply pipe 138.

The fuel gas supplied to the fuel gas supply pipe 136 is sent to the fuel gas supply passage 114 of the common manifold portion 92 constituting the external manifold 16, and along the fuel gas supply passage 114 in the direction of arrow A. Go to At this time, in the first and second fuel cell stacks 12 and 14 arranged on both sides of the common manifold portion 92, the fuel gas flow channel groove 58 formed on the surface 36a of each second separator 36 has a fuel side. It communicates with the gas supply channel 114. Therefore, the fuel gas is supplied to the fuel gas supply passage 11.
4, while flowing through the first and second fuel cell stacks 12,
The fuel is branched and supplied to the fuel gas flow channel 58 of each second separator 36.

As shown in FIG. 5, the fuel gas supplied to the fuel gas passage groove 58 is applied to the surface 36 a of the second separator 36.
After moving once to the upper end side, it moves in the direction of gravity while meandering horizontally along this surface 36a. At that time, the hydrogen gas in the fuel gas is supplied to the anode 42 of the unit fuel cell 32 through the second gas diffusion layer 46.
Then, the unused fuel gas is discharged from the lower side of the second separator 36 to the fuel gas discharge passage 104a of the support manifold section 90 constituting the external manifold 16.
This unused fuel gas is introduced from the fuel gas discharge passage 104a to the fuel gas discharge pipe 130 attached to the pipe block 122 constituting the pipe mechanism 120, and is supplied from the fuel cell system 10 through the fuel gas discharge port 134. Is discharged.

On the other hand, the air supplied to the oxidizing gas supply port 146 is sent to the oxidizing gas supply passage 118 of the common manifold section 92 via the oxidizing gas supply pipe 140.
The air flowing through the oxidizing gas supply channel 118 is supplied to the first and second fuel cell stacks 12 and 14 by the first
It is introduced into the oxidizing gas passage groove 56 of the separator 34 and moves in the gravity direction while meandering horizontally along the oxidizing gas passage groove 56 (see FIG. 3).

At this time, oxygen gas in the air is supplied from the first gas diffusion layer 44 to the cathode electrode 40, while unused air is supplied to the support manifold 90 through the oxidant gas flow channel groove 56. Oxidant gas discharge channels 100a, 100b
Is discharged. The oxidant gas discharge channels 100a, 10a
The air discharged to Ob is discharged to the outside from an oxidizing gas discharge port 126 through an oxidizing gas discharge pipe 124 mounted on a piping block 122.

As a result, power is generated in the first and second fuel cell stacks 12 and 14, and the load is connected to the first and second power extraction terminals 66 and 68 having different characteristics, for example, a motor (not shown). Power will be supplied.

The first and second fuel cell stacks 1
The inside of 2 and 14 is effectively cooled by the cooling medium. That is, the cooling medium supplied to the cooling medium supply port 144 is introduced from the cooling medium supply pipe 138 into the cooling medium supply passage 116 of the common manifold section 92. This cooling medium is introduced into a cooling medium flow channel 60 communicating with the approximate center of the side of the second separator 36 of the first and second fuel cell stacks 12 and 14 (see FIG. 3), and is once sent upward. After that, it moves in the direction of gravity while meandering in a substantially horizontal direction, and cools each unit fuel cell 32. The cooling medium used for cooling is
The cooling medium discharge pipe 12 is discharged to the cooling medium discharge channels 102a and 102b provided in the support manifold section 90 and communicates with the cooling medium discharge channels 102a and 102b.
8 and is discharged from the cooling medium discharge port 132.

In this case, in the first embodiment, the first and second fuel cell stacks 12 and 14 and the fuel gas, the oxidizing gas and the cooling medium are supplied to the first and second fuel cell stacks 12 and 14. And an external manifold 16 for discharging. For this reason, it is unnecessary to seal the outer periphery of the communication hole when providing the communication hole forming the internal manifold in the first and second fuel cell stacks 12 and 14, and the fuel cell system 1 has a reduced sealing area.
0 can be made compact. Moreover, the first and second separators 34, 3
6 does not require a communication hole portion, the area of the first and second separators 34, 36 is reduced, and the size of the first and second fuel cell stacks 12, 14 is easily reduced.

Further, the external manifold 16 has a common manifold portion 92 interposed between the first and second fuel cell stacks 12 and 14 adjacent to each other. The common manifold section 92 can distribute and supply the fuel gas, the oxidizing gas, and the cooling medium to the first and second fuel cell stacks 12 and 14, thereby reducing the number of manifolds. Accordingly, in the fuel cell system 10, the number of parts, the number of assembling steps, the mounting space, and the like can be effectively reduced, which is particularly suitable when the fuel cell system 10 is mounted on a vehicle or the like.

Further, in the first and second fuel cell stacks 12 and 14, unit fuel cells 32 are horizontally stacked via first and second separators 34 and 36. Therefore, even when a considerably large number of unit fuel cells 32 are stacked in order to obtain a desired electric power, the size in the height direction is not increased, and particularly in a vehicle in which the space in the height direction is narrow for use in a vehicle. When the fuel cell system 10 is arranged under the floor of the vehicle, it is possible to cope well.

Here, the unit fuel cell 32, the first and second separators 34 and 36, and the first and second fuel cell stacks 12 and 14 are arranged on the support manifold section 90 of the external manifold 16. Are directly supported by the first and second mounting surfaces 94a and 94b. Therefore, the first and second separators 34 and 36, which are particularly stacked in the horizontal direction, do not shift due to vibration or the like.
There is an advantage that the first and second fuel cell stacks 12 and 14 can be reliably supported.

FIG. 8 is a schematic perspective view of a fuel cell system 160 according to the second embodiment of the present invention. The first
The same components as those of the fuel cell system 10 according to the embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. The same applies to the third to sixth embodiments described below.

The fuel cell system 160 has an external manifold 162.
The oxidizing gas supply passages 164a and 164b and the cooling medium supply passage 166
a, 166b and fuel gas supply flow paths 168a, 168b
Are formed to extend in the laminating direction (the direction of arrow A). Common manifold section 9 constituting external manifold 162
2 includes a fuel gas discharge channel 1 extending upward from a lower side.
70, a cooling medium discharge channel 172, and an oxidizing gas discharge channel 174.

In the second embodiment configured as described above, the oxidizing gas supply passage 16 of the external manifold 162
When the oxidizing gas is supplied to the first and second fuel cell stacks 12 and 14, the oxidizing gas flows through the first separator 34 communicating with the oxidizing gas supply passages 164a and 164b. The oxidant gas is introduced into the passage groove 56. The oxidizing gas flows into the oxidizing gas flow channel groove 56.
Moving in the anti-gravity direction while meandering horizontally along
The oxidant gas is discharged to an oxidizing gas discharge channel 174 provided in the common manifold section 92.

Similarly, the fuel gas supply passages 168a, 168
The fuel gas supplied to the fuel gas flow channel 8b is introduced into the fuel gas flow channel groove 58 formed in each of the second separators 36 constituting the first and second fuel cell stacks 12, 14. After moving in the anti-gravity direction while meandering in the horizontal direction, the fuel gas is discharged to the fuel gas discharge passage 170 of the common manifold portion 92. Furthermore, the cooling medium supplied to the cooling medium supply channels 166a and 166b is the first cooling medium.
After moving in the antigravity direction along the coolant flow channel 60 in the second fuel cell stacks 12 and 14, the coolant is discharged to the coolant discharge flow channel 172 of the common manifold portion 92.

As described above, in the second embodiment, the flow directions of the oxidizing gas, the fuel gas, and the cooling medium are set to be opposite to those in the first embodiment, and the first and second manifolds 92 An oxidizing gas discharge channel 174, a fuel gas discharging channel 170, and a cooling medium discharging channel 172 for discharging the oxidizing gas, the fuel gas, and the cooling medium from the second fuel cell stacks 12, 14 are provided. For this reason, in the second embodiment, the same effects as in the first embodiment can be obtained, such as the number of manifolds can be reduced and the space in the height direction can be effectively reduced.

FIG. 9 is a schematic perspective view of a fuel cell system 180 according to the third embodiment of the present invention. The external manifold 182 constituting the fuel cell system 180
Includes a common manifold portion 92 interposed between the first and second fuel cell stacks 12 and 14, and a support manifold portion 184 disposed above the first and second fuel cell stacks 12 and 14. .

As described above, in the third embodiment, the external manifold 182 is disposed on the first and second fuel cell stacks 12 and 14, and the fuel cell system 180
It can be suitably used according to the installation status of the device.

FIG. 10 is a schematic perspective view of a fuel cell system 200 according to a fourth embodiment of the present invention.
2 is a schematic front view of the fuel cell system 200. FIG.

The fuel cell system 200 includes an external manifold 202, which is connected to the first and second fuel cell stacks 12, 1 adjacent to each other.
And a common manifold portion 204 interposed between the first and second fuel cell stacks 12 and 14 and the other side portion of the first and second fuel cell stacks 12 and 14 opposite to the one side where the common manifold portion 204 is arranged. Support manifold part 206,
208. The common manifold portion 204 and the support manifold portions 206 and 208 are integrally fixed to the first and second fuel cell stacks 12 and 14 by, for example, tie rods (not shown) inserted in the direction of arrow C.

The common manifold section 204 includes a fuel gas supply passage 114 for distributing and supplying the fuel gas to the first and second fuel cell stacks 12 and 14, and a fuel gas supply passage 114 for the first and second fuel cell stacks 12 and 14. A cooling medium supply passage for distributing and supplying a cooling medium;
Also, an oxidizing gas supply channel 118 for distributing and supplying an oxidizing gas to the second fuel cell stacks 12 and 14 is provided.

The supporting manifold sections 206 and 208 are provided with oxidizing gas discharge passages 210 a and 21 for discharging the oxidizing gas from the first and second fuel cell stacks 12 and 14.
0b and the first and second fuel cell stacks 12, 1
Cooling medium discharge passage 21 for discharging the cooling medium from the cooling medium 4
2a, 212b and fuel gas discharge passages 214a, 214b for discharging fuel gas from the first and second fuel cell stacks 12, 14 are provided.

As shown in FIG. 12, the first fuel cell stack 12 communicates with an oxidizing gas supply flow path 118 and an oxidizing gas discharge flow path 210a. A plurality of oxidizing gas flow grooves 216 for flowing the oxidizing gas, as shown in FIG. 13, communicate with the cooling medium supply flow path 116 and the cooling medium discharge flow path 212a, and extend in the horizontal direction. A cooling medium passage groove 218 for moving the cooling medium through the fuel gas supply passage 114 and the fuel gas discharge passage 214a as shown in FIG. And a plurality of fuel gas passage grooves 220 for moving the fuel gas.

In the fuel cell system 200 according to the fourth embodiment configured as described above, the common manifold section 204 is arranged between the first and second fuel cell stacks 12 and 14, and the first and second fuel cell stacks 12 and 14 are arranged. 2 A support manifold 20 is provided on the outer side of the fuel cell stacks 12 and 14.
6, 208 are arranged. For this reason, the height dimension of the entire fuel cell system 200 is substantially the same as the height dimension of the first and second fuel cell stacks 12 and 14, and the height of the fuel cell system 200 is made as small as possible. The effect that the length can be shortened is obtained. This, in particular,
There is an advantage that the fuel cell system 200 can be easily mounted under the floor of a vehicle having a small space in the height direction.

The common manifold section 204 has a flow path structure for discharging the fuel gas, the oxidizing gas and the cooling medium,
The support manifold sections 206 and 208 may have a supply channel structure for the fuel gas, the oxidizing gas, and the cooling medium. Hereinafter, the same applies to the fifth and sixth embodiments.

FIG. 15 is a schematic front view of a fuel cell system 240 according to the fifth embodiment of the present invention.

The fuel cell system 240 includes the first fuel cell stack 1 arranged in parallel with each other along the stacking direction.
2, a second fuel cell stack 14 and a third fuel cell stack 242, and an external manifold 244. The external manifold 244 includes a first common manifold section 246 interposed between the first and second fuel cell stacks 12 and 14, and the second and third fuel cell stacks 1.
4 and 242 interposed between the second common manifold section 24
8, the first and third fuel cell stacks 12, 242
Support manifold portions 250, 2
52.

In the first common manifold section 246, an oxidizing gas discharge channel 174, a cooling medium discharge channel 172,
The fuel gas supply passage 114 is provided in the second common manifold portion 248 while the fuel gas discharge passage 170 is provided.
, Cooling medium supply passage 116, oxidant gas supply passage 1
18 are provided. The support manifold 250 includes
The fuel gas supply passage 114a and the cooling medium supply passage 116
a and an oxidizing gas supply passage 118a, while the support manifold 252 is provided with an oxidizing gas discharge passage 174a, a cooling medium discharge passage 172a, and a fuel gas discharge passage 170a. .

In the fuel cell system 240 according to the fifth embodiment configured as described above, the support manifold 2
The fuel gas, the oxidizing gas, and the cooling medium are supplied to the first fuel cell stack 12 via the fuel cell 50, and the fuel gas, the oxidizing gas, and the cooling medium are discharged from the first fuel cell stack 12 to the first common manifold section 246. Is done. Also,
Fuel gas supplied to the second common manifold section 248,
The oxidizing gas and the cooling medium are distributed and supplied to the second and third fuel cell stacks 14 and 242, and the fuel is supplied from the second and third fuel cell stacks 14 and 242 to the first common manifold section 246 and the support manifold section 252. Gas, oxidant gas and cooling medium are exhausted.

As described above, in the fifth embodiment, the first common manifold portion 246 is interposed between the first and second fuel cell stacks 12 and 14, and the second and third fuel cell stacks 14 and A second common manifold section 248 is interposed between 242. Thus, the number of manifolds is effectively reduced, so that the entire fuel cell system 240 can be made more compact, and the height of the fuel cell system 240 can be made as short as possible.

FIG. 16 is a schematic perspective view of a fuel cell system 260 according to the sixth embodiment of the present invention.
3 is a schematic front view of the fuel cell system 260. FIG.

The fuel cell system 260 includes a first fuel cell stack 12, a second fuel cell stack 14, a third fuel cell stack 242, and a fourth fuel cell stack 262.
And an external manifold 264. The external manifold 264 includes the first and second fuel cell stacks 12,
A first common manifold section 266 interposed between
A second common manifold section 268 interposed between the third and fourth fuel cell stacks 242 and 262, and a third common manifold section 270 interposed between the first and third fuel cell stacks 12 and 242; , The second and fourth
A fourth common manifold section 272 interposed between the fuel cell stacks 14 and 262;

First and second common manifold section 26
6, 268, the fuel gas supply channel 114, the cooling medium supply channel 116, and the oxidizing gas supply channel 118 are provided in reverse order, while the third and fourth common manifold portions 270, 272 has a fuel gas discharge channel 274
a, 274b and cooling medium discharge flow paths 276a, 276b
And oxidant gas discharge channels 278a and 278b are provided in reverse order.

The fuel cell system 2 configured as described above
At 60, the first common manifold section 266
The fuel gas, the oxidizing gas and the cooling medium are supplied to the second fuel cell stacks 12 and 14, and the fuel gas and the oxidizing gas are supplied to the third and fourth fuel cell stacks 242 and 262 via the second common manifold section 268. An agent gas and a cooling medium are supplied. Then, while the fuel gas, the oxidizing gas and the cooling medium are discharged from the first and third fuel cell stacks 12 and 242 to the third common manifold section 270, the second and fourth fuel cell stacks 14 and 26 are discharged.
The fuel gas, the oxidizing gas and the cooling medium are discharged to the second to fourth common manifold portions 272.

Thus, when the first to fourth fuel cell stacks 12, 14, 242, and 262 are assembled, the number of manifolds is reduced by half by using the external manifold 264, and the entire fuel cell system 260 can be easily made compact. Is obtained.

[0072]

In the fuel cell system according to the present invention, a plurality of fuel cell stacks arranged via an external manifold are configured so that unit fuel cells and separators are stacked in a horizontal direction. The dimension in the height direction can be effectively shortened. As a result, in particular, it is possible to effectively arrange the device under the floor of a vehicle where the space in the height direction is narrow, and it is suitable for mounting on a vehicle.

Further, since the common manifold section is interposed between the fuel cell stacks, the number of manifolds can be reduced and the whole fuel cell system can be easily made compact. Furthermore, the seal portion on the outer periphery of the manifold used in the fuel cell stack of the internal manifold type is not required, and the fuel cell stack itself can be effectively reduced in size.

[Brief description of the drawings]

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

FIG. 2 is a schematic front view of the fuel cell system shown in FIG.

FIG. 3 is an exploded perspective view of a unit fuel cell and a separator constituting the fuel cell system.

FIG. 4 is an explanatory sectional view of the unit fuel cell and the separator.

FIG. 5 is an explanatory view of a fuel gas channel groove provided in the separator.

FIG. 6 is a partial cross-sectional side view of a fuel cell stack constituting the fuel cell system.

FIG. 7 is an exploded perspective view of an external manifold constituting the fuel cell system.

FIG. 8 is a schematic perspective view of a fuel cell system according to a second embodiment of the present invention.

FIG. 9 is a schematic perspective view of a fuel cell system according to a third embodiment of the present invention.

FIG. 10 is a schematic perspective view of a fuel cell system according to a fourth embodiment of the present invention.

11 is a schematic front view of the fuel cell system shown in FIG.

FIG. 12 is an explanatory view of an oxidizing gas flow channel groove of the fuel cell system.

FIG. 13 is an explanatory diagram of a cooling medium flow channel of the fuel cell system.

FIG. 14 is an explanatory view of a fuel gas channel groove of the fuel cell system.

FIG. 15 is a schematic front view of a fuel cell system according to a fifth embodiment of the present invention.

FIG. 16 is a schematic perspective view of a fuel cell system according to a sixth embodiment of the present invention.

FIG. 17 is a schematic front view of the fuel cell system.

[Explanation of symbols]

10, 160, 180, 200, 240, 260 ... fuel cell system 12, 14, 242, 262 ... fuel cell stack 16, 162, 182, 202, 244, 264 ... external manifold 32 ... unit fuel cell 34, 36 ... Separator 38 ... Electrolyte membrane 40 ... Cathode side electrode 42 ... Anode side electrode 56,216 ... Oxidant gas passage groove 58,220 ... Fuel gas passage groove 60,218 ... Cooling medium passage groove 70 ... Tightening mechanism 90,184 , 206, 208, 250, 252... Support manifold portions 92, 204, 246, 248, 266, 268, 27
0, 272: Common manifold portion 94a, 94b: Mounting surface 100a, 100b, 174, 174a, 210a, 2
10b, 278a, 278b ... oxidant gas discharge flow paths 102a, 102b, 172, 172a, 212a, 2
12b, 276a, 276b ... cooling medium discharge passages 104a, 104b, 170, 170a, 214a, 2
14b, 274a, 274b ... fuel gas discharge passages 114, 114a, 168a, 168b ... fuel gas supply passages 116, 116a, 166a, 166b ... cooling medium supply passages 118, 118a, 164a, 164b ... oxidant gas supply flows Road 120 ... Piping mechanism 122 ... Piping block

Claims (4)

[Claims] 1. A fuel cell comprising a fuel cell stack in which a plurality of unit fuel cells each comprising a solid polymer electrolyte membrane sandwiched between an anode-side electrode and a cathode-side electrode are horizontally stacked via a separator. A system, comprising: a plurality of fuel cell stacks arranged in parallel with each other along a stacking direction; a plurality of the fuel cell stacks; a fuel gas and an oxidant corresponding to at least the anode electrode and the cathode electrode. An external manifold for supplying and discharging gas, wherein the external manifold is interposed between the fuel cell stacks adjacent to each other, and at least the fuel gas and the oxidant gas are provided to the fuel cell stacks adjacent to each other. A fuel cell system comprising a common manifold section for supplying or discharging fuel. 2. The fuel cell system according to claim 1, wherein the external manifold includes a support manifold disposed below or above the plurality of fuel cell stacks and supporting the plurality of fuel cell stacks. A fuel cell system characterized by the above-mentioned. 3. The fuel cell system according to claim 1, wherein the external manifold is disposed on the other side of the fuel cell stack opposite to the side on which the common manifold is disposed. A fuel cell system comprising a manifold section. 4. The fuel cell system according to claim 1, wherein said external manifold is formed of an insulating member.