JP2007194074A - Fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell stack at least restraining lowering of power generation capacity caused by generated water locally stagnated on a surface of an anode or a cathode. <P>SOLUTION: A separator used for the fuel cell stack is constituted by superposing and jointing an anode facing plate 42, a middle plate 43, and a cathode facing plate 44, and a plurality of hydrogen supply ports 422i are formed on a plate face of the anode facing plate 42 by-two dimensionally scattering them. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fuel cell, and more specifically, a stack structure in which a plurality of laminated bodies each having an anode and a cathode disposed on both surfaces of a predetermined electrolyte membrane having proton conductivity are laminated with a separator interposed therebetween. The present invention relates to a fuel cell.

  A fuel cell that generates electricity by an electrochemical reaction between hydrogen and oxygen has attracted attention as an energy source. This fuel cell has a stack structure in which membrane electrode assemblies each having an anode (hydrogen electrode) and a cathode (oxygen electrode) and separators are alternately laminated on both surfaces of an electrolyte membrane having proton conductivity. (Hereinafter, a fuel cell having such a stack structure is also referred to as a fuel cell stack).

  Various techniques have been proposed for separators used in such fuel cell stacks. For example, Patent Document 1 below describes a technique related to a separator that includes a fuel gas plate facing an anode, an oxidant gas plate facing a cathode, and an intermediate plate sandwiched between these plates. In this technique, each plate is provided with a structure for supplying fuel gas or oxidant gas to the fuel cell, or for flowing a cooling medium for cooling the fuel cell. The fuel gas and the oxidant gas are supplied to the anode and the cathode from a part of the periphery of the anode and the cathode, respectively, and are supplied so as to spread over almost the entire surfaces of the anode and the cathode. .

JP 2004-6104 A

  By the way, in a fuel cell, water (product water) is generated by an electrochemical reaction between hydrogen and oxygen during power generation. This generated water is usually discharged to the outside together with the exhaust gas. However, when the generated water is locally accumulated on the surface of the anode or the cathode and a part of the flow path of the fuel gas (hydrogen) or the oxidant gas (oxygen) is blocked, the gas becomes the anode or In some cases, the cathode is not uniformly supplied, and the power generation capacity of the fuel cell is reduced. Such a defect is not limited to the local retention of generated water, but the above-described electrochemical reaction, that is, a gas that is not used for power generation (for example, nitrogen in air when oxygen-containing air is used as an oxidant gas) ) Could also occur when locally retained on the surface of the anode or cathode.

  The present invention has been made to solve the above-described problem, and suppresses a decrease in power generation capacity due to local accumulation of at least generated water on the surface of the anode or the cathode in the fuel cell stack. For the purpose.

In order to solve at least a part of the above-described problems, the present invention employs the following configuration.
The fuel cell of the present invention comprises
A fuel cell having a stack structure in which a plurality of laminated bodies each having an anode and a cathode are disposed on both surfaces of a predetermined electrolyte membrane having proton conductivity with a separator interposed therebetween,
The separator is
An anode facing plate facing the anode of the laminate;
A cathode facing plate facing the cathode of the laminate;
An intermediate plate sandwiched between the anode facing plate and the cathode facing plate;
At least one of the anode facing plate and the cathode facing plate penetrates in the thickness direction of the plate, and a predetermined reaction gas is introduced to the surface of the stacked body from a direction perpendicular to the surface of the stacked body. A plurality of reaction gas supply ports for supplying,
The intermediate plate is sandwiched between the anode facing plate and the cathode facing plate, thereby forming a reaction gas supply channel for supplying the reaction gas to each of the plurality of reaction gas supply ports. A gas supply flow path forming section;
The gist of the plurality of reaction gas supply ports is that they are two-dimensionally distributed with respect to the plate surface of the plate provided with the plurality of reaction gas supply ports.

  Here, the “predetermined reaction gas” is a fuel gas and an oxidant gas supplied to the laminate, that is, the anode and the cathode disposed in the membrane electrode assembly, respectively.

  According to the present invention, the corresponding reaction gas is two-dimensionally dispersed from the plurality of reaction gas supply ports on the surface of the stack of the fuel cell stack, that is, on the surface of the anode and the cathode of the membrane electrode assembly. Can be supplied. Therefore, it is possible to suppress the generated water generated by the power generation from locally staying on the surface of at least one of the anode and the cathode and blocking the reaction gas flow path. Further, it is possible to suppress the gas that is not used for power generation from locally staying on the surface of at least one of the anode and the cathode and blocking the reaction gas flow path. As a result, it is possible to suppress a decrease in the power generation capacity of the fuel cell stack described above.

In the fuel cell, the shape, opening area, and arrangement of the plurality of reaction gas supply ports can be arbitrarily set,
The plurality of reaction gas supply ports may be formed at, for example, substantially equidistant positions.

  By doing so, the in-plane distribution can be made uniform over the entire surface of at least one of the anode and the cathode of the laminate, and the corresponding reaction gas can be distributed and supplied two-dimensionally. As a result, power can be generated efficiently.

In the fuel cell,
It is preferable that the opening area of the plurality of reaction gas supply ports is increased as the reaction gas supply port to which the reaction gas is supplied from the downstream side of the reaction gas supply channel.

  A plurality of reaction gas supply ports having substantially the same opening area are arranged at approximately equal intervals from the upstream to the downstream of the reaction gas flowing through the reaction gas supply flow path, and at least one of the anode of the laminate and the cathode When supplying the reaction gas to the surface, the supply pressure becomes lower toward the downstream side of the reaction gas. In this case, the supply amount of the reaction gas supplied from each reaction gas supply port per unit time decreases toward the downstream side of the reaction gas.

  In the present invention, since the opening area of the reaction gas supply port is increased toward the downstream side of the reaction gas, the supply amount of the reaction gas supplied from each reaction gas supply port per unit time can be made uniform. As a result, power can be generated more efficiently.

In the fuel cell of the present invention,
The opening areas of the plurality of reaction gas supply ports are substantially the same,
The formation intervals of the plurality of reaction gas supply ports may be closer to the reaction gas supply port to which the reaction gas is supplied from the downstream side of the reaction gas supply channel.

  By doing this, even if the supply pressure of the reaction gas is low downstream of the reaction gas, the in-plane distribution of the supply amount of the reaction gas to at least one surface of the anode and the cathode can be made uniform. It can generate electricity well.

In any of the above fuel cells,
The intermediate plate is further sandwiched between the anode facing plate and the cathode facing plate, thereby forming a cooling medium flow path for forming a cooling medium flow path for flowing a cooling medium for cooling the fuel cell. It is preferable to provide a forming part.

  By doing so, the thickness of the separator can be made thinner than when the cooling medium flow path is formed using another member. As a result, the fuel cell stack can be reduced in size.

In the fuel cell, a plurality of intermediate plates may be prepared, and each of the intermediate plates may be provided with a reaction gas supply flow path forming part and a cooling medium flow path forming part separately.
It is preferable that the single intermediate plate includes both the reaction gas supply flow path forming portion and the cooling medium flow path forming portion.

  By doing so, the number of parts constituting the separator can be reduced as compared with the case where the reactive gas supply flow path forming part and the cooling medium flow path forming part are formed as separate members. Furthermore, the fuel cell can be reduced in size.

In any of the above fuel cells,
At least one of the anode facing plate and the cathode facing plate having the plurality of reaction gas supply ports is further penetrated in the thickness direction of the plate and supplied from the plurality of reaction gas supply ports. An exhaust gas exhaust port for exhausting exhaust gas, which is the remaining gas that has not been used for power generation among the reaction gas, in a direction perpendicular to the surface of the laminate,
The intermediate plate is further sandwiched between the anode facing plate and the cathode facing plate, thereby forming an exhaust gas exhaust passage for exhausting the exhaust gas from the exhaust gas exhaust port to the outside. You may make it provide a gas discharge flow path formation part.

  By doing so, it is possible to discharge reaction gas that is not consumed in power generation or gas that is not used in power generation to the outside.

In the fuel cell,
The plurality of reactive gas supply ports are provided in the anode facing plate,
At least during power generation, the exhaust gas may not be discharged to the outside from the gas discharge port in the anode facing plate.

  In this way, almost all of the fuel gas supplied to the anode can be consumed without being discharged to the outside at least during power generation, so that the fuel gas can be used efficiently.

In the fuel cell of the present invention,
The anode facing plate includes the plurality of reaction gas supply ports;
The reaction gas supplied from the plurality of reaction gas supply ports may be used for power generation without being discharged to the outside. The anode facing plate is provided with the above-described plurality of gas supply ports, but is not provided with a gas discharge port.

  By doing so, since all the fuel gas supplied to the anode can be used for power generation, the fuel gas can be used efficiently.

In any of the above fuel cells,
The anode facing plate, the cathode facing plate, and the intermediate plate are each preferably made of a flat plate member.

  By doing so, it is possible to easily process the anode facing plate, the cathode facing plate, and the intermediate plate.

In any of the above fuel cells,
The laminated body may include a gas diffusion layer made of a porous body for allowing the reaction gas to flow while diffusing in a direction along the surface on at least a cathode side surface of the laminated body.

  By doing so, the reaction gas can be efficiently diffused and supplied to at least the entire surface of the cathode.

  The present invention can be configured as an invention of a fuel cell system including the fuel cell, in addition to the configuration as the fuel cell described above.

Hereinafter, embodiments of the present invention will be described in the following order based on examples.
A. First embodiment:
A1. Configuration of fuel cell system:
A2. Fuel cell module configuration:
B. Second embodiment:
C. Third embodiment:
D. Fourth embodiment:
E. Variation:

A. First embodiment:
A1. Configuration of fuel cell system:
FIG. 1 is an explanatory diagram showing a schematic configuration of a fuel cell system 1000 including a fuel cell stack 100 as a first embodiment of the present invention.

  The fuel cell stack 100 has a stack structure in which a plurality of cells that generate electricity by an electrochemical reaction between hydrogen and oxygen are stacked with a separator interposed therebetween. As will be described later, each cell has a configuration in which an anode and a cathode are arranged with an electrolyte membrane having proton conductivity interposed therebetween. In this example, a solid polymer membrane was used as the electrolyte membrane. Further, in this embodiment, as described later, the separator is provided with a plurality of through holes in three metal flat plates, and these are overlapped and joined to form a fuel gas to be supplied to the anode. A hydrogen flow path, an air flow path as an oxidant gas to be supplied to the cathode, and a cooling water flow path are formed. Note that the number of stacked cells can be arbitrarily set according to the output required for the fuel cell stack 100.

  The fuel cell stack 100 is configured by stacking an end plate 10, an insulating plate 20, a current collecting plate 30, a plurality of fuel cell modules 40, a current collecting plate 30, an insulating plate 20, and an end plate 10 in this order from one end. Yes. These are provided with a supply port and a discharge port for flowing hydrogen, air, and cooling water in the fuel cell stack 100. The fuel cell module 40 includes a separator 41 and an MEA unit 45 including an electrolyte membrane and the like, as will be described later. The fuel cell module 40 and the MEA unit 45 will be described in detail later.

  The end plate 10 is made of metal such as steel in order to ensure rigidity. The insulating plate 20 is formed of an insulating member such as rubber or resin. The current collecting plate 30 is made of a gas impermeable conductive member such as dense carbon or a copper plate. Each of the current collector plates 30 is provided with an output terminal (not shown) so that the power generated by the fuel cell stack 100 can be output.

  Although not shown in the figure, the fuel cell stack 100 is provided with the purpose of suppressing a decrease in cell performance due to an increase in contact resistance at any part of the stack structure or a gas leak. A pressing force is applied in the stacking direction of the stack structure.

  Hydrogen as fuel gas is supplied to the anode of the fuel cell stack 100 from a hydrogen tank 50 that stores high-pressure hydrogen via a pipe 53. Instead of the hydrogen tank 50, hydrogen may be generated by a reforming reaction using alcohol, hydrocarbon, aldehyde or the like as a raw material and supplied to the anode.

  The high-pressure hydrogen stored in the hydrogen tank 50 is supplied to the anode after the pressure and supply amount are adjusted by a shut valve 51 and a regulator 52 provided at the outlet of the hydrogen tank 50. The fuel cell system 1000 is a type of system that consumes all of the hydrogen supplied to the anode of the fuel cell stack 100 in order to generate power. Exhaust gas from the anode (hereinafter referred to as anode off gas) is externally used. There are no pipes for discharging. By doing so, the fuel gas can be used efficiently.

  Compressed air compressed by the compressor 60 is supplied to the cathode of the fuel cell stack 100 as an oxidant gas containing oxygen via a pipe 61. Exhaust gas from the cathode (hereinafter referred to as cathode off gas) is discharged to the outside via the pipe 62. Along with the cathode off-gas, the pipe 62 also discharges the generated water produced by the electrochemical reaction between hydrogen and oxygen at the cathode of the fuel cell stack 100.

  Cooling water for cooling the fuel cell stack 100 is also supplied to the fuel cell stack 100. The cooling water flows through the pipe 72 by the pump 70, is cooled by the radiator 71, and is supplied to the fuel cell stack 100.

A2. Fuel cell module configuration:
FIG. 2 is a plan view of components of the fuel cell module 40. As described above, the fuel cell module 40 is configured by overlapping the separator 41 and the MEA unit 45. In the separator 41, three flat plates each provided with a plurality of through holes, that is, an anode facing plate 42, an intermediate plate 43, and a cathode facing plate 44 are superposed in this order and hot-press bonded. It is made by. In this embodiment, the anode facing plate 42, the intermediate plate 43, and the cathode facing plate 44 are made of stainless steel flat plates having the same rectangular shape. As the anode facing plate 42, the intermediate plate 43, and the cathode facing plate 44, other metals such as titanium and aluminum may be used instead of stainless steel. Since each of these plates is exposed to cooling water as will be described later, it is preferable to use a metal having high corrosion resistance.

  FIG. 2A is a plan view of the anode facing plate 42 that comes into contact with the anode side surface of the MEA unit 45. As illustrated, the anode facing plate 42 includes a hydrogen supply through hole 422a, a plurality of hydrogen supply ports 422i, an air supply through hole 424a, an air discharge through hole 424b, and a cooling water supply through hole 426a. And a cooling water discharge through hole 426b. In this embodiment, the hydrogen supply through hole 422a, the air supply through hole 424a, the air discharge through hole 424b, the cooling water supply through hole 426a, and the cooling water discharge through hole 426b are substantially rectangular. It was supposed to be. These shapes, sizes, and arrangement positions can be arbitrarily set. The plurality of hydrogen supply ports 422i have a circular shape with the same diameter. The plurality of hydrogen supply ports 422i are two-dimensionally provided in a region facing the MEA portion 451 of the MEA unit 45 so that hydrogen can be supplied to the entire surface of the anode of the MEA unit 45 with a uniform in-plane distribution. And are arranged at almost equal intervals.

  FIG. 2B is a plan view of the cathode facing plate 44 that comes into contact with the cathode side surface of the MEA unit 45. As illustrated, the cathode facing plate 44 includes a hydrogen supply through hole 442a, an air supply through hole 444a, a plurality of air supply ports 444i, a plurality of air discharge ports 444o, and an air discharge through hole 444b. The cooling water supply through hole 446a and the cooling water discharge through hole 446b are provided. The hydrogen supply through hole 442a, the air supply through hole 444a, the air discharge through hole 444b, the cooling water supply through hole 446a, and the cooling water discharge through hole 446b are similar to the anode facing plate 42. It was assumed to be almost rectangular. In addition, the plurality of air supply ports 444i and the plurality of air discharge ports 444o are circular with the same diameter. The plurality of air supply ports 444i and the plurality of air discharge ports 444o supply air from the peripheral edge of the cathode of the MEA unit 45 close to the air supply through hole 444a and the air discharge through hole 444b, respectively. And it arrange | positions so that discharge | release of cathode off gas can be performed.

  FIG. 2C is a plan view of the intermediate plate 43. As illustrated, the intermediate plate 43 includes a hydrogen supply through hole 432a, an air supply through hole 434a, an air discharge through hole 434b, a cooling water supply through hole 436a, and a cooling water discharge through hole 436b. And. The hydrogen supply through-hole 432a, the air supply through-hole 434a, the air discharge through-hole 434b, the cooling water supply through-hole 436a, and the cooling water discharge through-hole 436b include the anode facing plate 42 and the cathode. Similar to the counter plate 44, the plate is substantially rectangular. The hydrogen supply through hole 432a is provided with a plurality of hydrogen supply flow path forming portions 432p for flowing hydrogen from the hydrogen supply through hole 432a to the plurality of hydrogen supply ports 422i of the anode facing plate 42, respectively. ing. The air supply through hole 434a is provided with a plurality of air supply flow path forming portions 434pi for flowing air from the air supply through hole 434a to the plurality of air supply ports 444i of the cathode facing plate 44, respectively. ing. The air discharge through hole 434 b is provided with a plurality of air discharge flow path forming portions 434 po for flowing a cathode off gas from the plurality of air discharge ports 444 o of the cathode facing plate 44 to the air discharge through hole 434 b. Yes. Further, as shown in the drawing, the cooling water supply through-hole 436a is formed so that the cooling water meanders and flows between the plurality of hydrogen supply flow path forming portions 432p in order to cool the entire heat generating portion of the MEA unit 45. And a cooling water flow path forming portion 436p that connects the cooling water discharge through hole 436b.

  FIG. 2D is a plan view seen from the cathode side of the MEA unit 45. FIG. 3 is a cross-sectional view of the MEA portion 451 of the MEA unit 45.

  As shown in FIG. 3, the MEA unit 451 disposed in the center of the MEA unit 45 includes a cathode catalyst layer 47c and a cathode diffusion layer 48c on one surface (cathode side) of the electrolyte membrane 46. In this membrane electrode laminate, the anode catalyst layer 47a and the anode diffusion layer 48a are laminated in this order on the other (anode side) surface. In this embodiment, porous carbon is used as the anode diffusion layer 48a and the cathode diffusion layer 48c. Furthermore, in this embodiment, metal porous body layers 49 functioning as gas flow path layers for flowing hydrogen and air when laminated with the separator 41 are disposed on both surfaces of the MEA portion 451, respectively. By using the cathode diffusion layer 48c, the anode diffusion layer 48a, and the metal porous body layer 49, gas can be efficiently diffused and supplied to the entire surfaces of the anode and the cathode. As the gas flow path layer, other members having conductivity and gas diffusibility such as carbon may be used instead of the metal porous body.

  The MEA unit 45 supports the MEA portion 451 with a silicone rubber frame. Instead of silicone rubber, other members having gas impermeability, elasticity, and heat resistance may be used. In addition, although illustration is abbreviate | omitted, the seal structure for preventing the leak of gas and a cooling water is integrally formed in the flame | frame at the time of lamination | stacking with the separator 41. FIG. This frame is formed by, for example, injection molding.

  As shown in FIG. 2D, the MEA unit 45 includes an MEA unit 451, a hydrogen supply through hole 452a provided in the frame, an air supply through hole 454a, an air discharge through hole 454b, A cooling water supply through-hole 456a and a cooling water discharge through-hole 456b are provided. The hydrogen supply through-hole 452a, the air supply through-hole 454a, the air discharge through-hole 454b, the cooling water supply through-hole 456a, and the cooling water discharge through-hole 456b include the anode facing plate 42 and the cathode. Like the counter plate 44 and the intermediate plate 43, it is assumed to be substantially rectangular.

  FIG. 4 is a plan view of the separator 41. As described above, the separator 41 is formed by joining the anode facing plate 42, the intermediate plate 43, and the cathode facing plate 44. Here, the state seen from the anode facing plate 42 side is shown.

  As can be seen from the figure, in the anode facing plate 42, the intermediate plate 43, and the cathode facing plate 44, the hydrogen supply through hole 422a, the hydrogen supply through hole 432a, and the hydrogen supply through hole 442a have the same shape. And are formed at the same position. The air supply through-hole 424a, the air supply through-hole 434a, and the air supply through-hole 444a have the same shape and are formed at the same positions. Also, the air discharge through hole 424b, the air discharge through hole 434b, and the air discharge through hole 444b have the same shape and are formed at the same positions. Also, the cooling water supply through hole 426a, the cooling water supply through hole 436a, and the cooling water supply through hole 446a have the same shape and are formed at the same positions. The cooling water discharge through hole 426b, the cooling water discharge through hole 436b, and the cooling water discharge through hole 446b have the same shape and are formed at the same positions.

  FIG. 5 is an explanatory view showing a cross-sectional structure of the fuel cell module 40. FIG. 5A shows a cross-sectional view taken along line AA in FIG. FIG. 5B is a cross-sectional view taken along the line BB in FIG.

  The metal porous body layer 49 on the anode diffusion layer 48a side of the MEA unit 451 in the MEA unit 45 is disposed so as to contact the anode facing plate 42 of the separator 41 when the MEA unit 45 and the separator 41 are laminated. Has been. Further, the metal porous body layer 49 on the cathode diffusion layer 48 c side is disposed so as to contact the cathode facing plate 44 of the separator 41 when the MEA unit 45 and the separator 41 are laminated.

  5A, in the fuel cell module 40, the hydrogen supply through hole 442a of the cathode facing plate 44, the hydrogen supply through hole 432a of the intermediate plate 43, and the anode facing plate 42 of The hydrogen flowing through the hydrogen supply through hole 422a branches from the hydrogen supply through hole 432a of the intermediate plate 43, passes through the hydrogen supply flow path forming portion 432p, and from the plurality of hydrogen supply ports 422i of the anode facing plate 42, It flows into the metal porous body layer 49 on the anode side and is distributed and supplied over the entire surface of the anode diffusion layer 48a.

  5B, in the fuel cell module 40, in the fuel cell module 40, the air supply through hole 424a of the anode facing plate 42, the air supply through hole 434a of the intermediate plate 43, and the cathode facing plate The air flowing through the air supply through-holes 444a of the intermediate plate 43 branches from the air supply through-holes 434a of the intermediate plate 43, passes through the air supply flow path forming portion 434pi, and from the air supply port 444i of the cathode facing plate 44, It is supplied in a direction perpendicular to the surface of the metal porous body layer 49 on the cathode side. The air flows while diffusing in the metal porous body layer 49 and the cathode diffusion layer 48 c, and the cathode off-gas is perpendicular to the surface of the metal porous body layer 49 from the air outlet 444 o of the cathode facing plate 44. And is discharged from the air discharge through hole 424b of the anode facing plate 42 through the air discharge flow path forming portion 434po of the MEA unit 45 and the air discharge through hole 434b.

  Although illustration is omitted, the cooling water flowing through the cooling water supply through hole 426a of the anode facing plate 42, the cooling water supply through hole 436a of the intermediate plate 43, and the cooling water supply through hole 446a of the cathode facing plate 44 are Then, it branches from the cooling water supply through hole 436a of the intermediate plate 43, passes through the cooling water flow path forming part 436p, and is discharged from the cooling water discharge through hole 436b.

  According to the fuel cell stack 100 of the first embodiment described above, it is perpendicular to the anode surface of the MEA unit 451 that generates power from a plurality of hydrogen supply ports 422i that are arranged on the anode facing plate 42 at approximately equal intervals. From the direction, hydrogen can be supplied by being two-dimensionally dispersed over almost the entire surface of the anode. Therefore, it is possible to prevent the generated water that has permeated the electrolyte membrane 46 from the cathode side to the anode side from staying locally on the surface of the anode and blocking the hydrogen flow path. Further, it is possible to suppress a gas such as nitrogen that is not used for power generation from permeating from the cathode side to the anode side and locally staying on the surface of the anode, thereby blocking the hydrogen flow path. As a result, a decrease in the power generation capacity of the fuel cell stack 100 can be suppressed.

  As described above, the fuel cell system 1000 according to the first embodiment is a system that consumes all of the hydrogen supplied to the anode of the fuel cell stack 100 in order to generate power, and discharges the anode off gas to the outside. There is no pipe to do this. Therefore, when the invention of the present application is not applied, as described above, a gas such as nitrogen that is not supplied to the power generation transmitted from the cathode side tends to locally stay on the surface of the anode. The decrease in power generation capacity of 100 was remarkable. By applying the fuel cell stack 100 of the first embodiment to the fuel cell system 1000, as described above, it is possible to effectively suppress local retention of a gas such as nitrogen that is not used for power generation on the surface of the anode. Therefore, the effect of suppressing a decrease in the power generation capacity of the fuel cell stack 100 is high.

  Further, in this embodiment, since the cooling water flow path forming portion 436p is provided in the intermediate plate 43, the thickness of the separator is made thinner than the case where the structure for flowing the cooling water is formed using other members. As a result, the fuel cell stack can be reduced in size.

  Further, by processing a single member of the hydrogen supply flow path forming portion 432p, the air supply flow path forming portion 434pi, the air discharge flow path forming portion 434po, and the cooling water flow path forming portion 436p, Since it forms, the number of parts which comprise a separator can be decreased rather than forming each with another member.

B. Second embodiment:
The fuel cell system of the second embodiment is the same as the fuel cell system 1000 of the first embodiment, except that the fuel cell stack is different from the fuel cell stack 100 of the first embodiment. Therefore, the fuel cell stack of the second embodiment will be described below.

  FIG. 6 is a plan view of components of the fuel cell module 40A in the fuel cell stack of the second embodiment. Similarly to the fuel cell module 40 in the first embodiment, the fuel cell module 40A in the second embodiment is configured by overlapping a separator 41A and an MEA unit 45A. The separator 41A is manufactured by superposing the anode facing plate 42A, the intermediate plate 43A, and the cathode facing plate 44A in this order and performing hot press bonding. Also in this embodiment, the anode facing plate 42A, the intermediate plate 43A, and the cathode facing plate 44A are made of stainless steel flat plates having the same rectangular shape.

  FIG. 6A is a plan view of the anode facing plate 42A that comes into contact with the anode side surface of the MEA unit 45A. As illustrated, the anode facing plate 42A includes a hydrogen supply through hole 422Aa, a plurality of hydrogen supply ports 422Ai, an air supply through hole 424Aa, an air discharge through hole 424Ab, and a cooling water supply through hole 426Aa. And a cooling water discharge through hole 426Ab. Also in the present embodiment, the hydrogen supply through hole 422Aa, the air supply through hole 424Aa, the air discharge through hole 424Ab, the cooling water supply through hole 426Aa, and the cooling water discharge through hole 426Ab are substantially the same. The plurality of hydrogen supply ports 422Ai are also circular with the same diameter. Similarly to the first embodiment, the plurality of hydrogen supply ports 422Ai are connected to the MEA unit 451 of the MEA unit 45A so that hydrogen can be supplied over the entire surface of the anode of the MEA unit 45A with a uniform in-plane distribution. They are two-dimensionally distributed and arranged at almost equal intervals in the opposing regions.

  FIG. 6B is a plan view of the cathode facing plate 44A that comes into contact with the cathode side surface of the MEA unit 45A. As illustrated, the cathode facing plate 44A includes a hydrogen supply through hole 442Aa, an air supply through hole 444Aa, a plurality of air supply ports 444Ai, a plurality of air discharge ports 444Ao, and an air discharge through hole 444Ab. The cooling water supply through hole 446Aa and the cooling water discharge through hole 446Ab are provided. The hydrogen supply through hole 442Aa, the air supply through hole 444Aa, the air discharge through hole 444Ab, the cooling water supply through hole 446Aa, and the cooling water discharge through hole 446Ab are similar to the anode facing plate 42A. The plurality of air supply ports 444Ai and the plurality of air discharge ports 444Ao are circular with the same diameter. The plurality of air supply ports 444Ai are two-dimensionally arranged in a region facing the MEA portion 451 of the MEA unit 45A so that air can be supplied with uniform in-plane distribution over the entire surface of the cathode of the MEA unit 45A. And are arranged at almost equal intervals. The plurality of air discharge ports 444Ao are arranged so that cathode off-gas can be discharged from the peripheral edge of the cathode of the MEA unit 45A close to the air discharge through hole 444Ab.

  FIG. 6C is a plan view of the intermediate plate 43A. As illustrated, the intermediate plate 43A includes a hydrogen supply through hole 432Aa, an air supply through hole 434Aa, an air discharge through hole 434Ab, a cooling water supply through hole 436Aa, and a cooling water discharge through hole 436Ab. And. The hydrogen supply through hole 432Aa, the air supply through hole 434Aa, the air discharge through hole 434Ab, the cooling water supply through hole 436Aa, and the cooling water discharge through hole 436Ab include the anode facing plate 42A and the cathode. Similar to the counter plate 44A, it is substantially rectangular. The hydrogen supply through hole 432Aa is provided with hydrogen supply flow path forming portions 432Ap for flowing hydrogen from the hydrogen supply through hole 432Aa to the plurality of hydrogen supply ports 422Ai of the anode facing plate 42A. . The air supply through hole 434Aa is provided with a plurality of air supply flow path forming portions 434Api for flowing air from the air supply through hole 434Aa to the plurality of air supply ports 444Ai of the cathode facing plate 44A. ing. The air discharge through hole 434Ab is provided with a plurality of air discharge flow path forming portions 434Apo for flowing cathode off gas from the plurality of air discharge ports 444Ao of the cathode facing plate 44A to the air discharge through hole 434Ab. Yes. Further, as shown in the figure, the cooling water meanders between the hydrogen supply flow path forming part 432Ap and the plurality of air supply flow path forming parts 434pi in order to cool the entire heat generation part of the MEA unit 45A. A cooling water flow path forming portion 436Ap that connects the cooling water supply through hole 436Aa and the cooling water discharge through hole 436Ab is formed so as to flow.

  FIG. 6D is a plan view seen from the cathode side of the MEA unit 45A. As illustrated, the MEA unit 45A includes an MEA portion 451, a hydrogen supply through hole 452Aa, an air supply through hole 454Aa, an air discharge through hole 454Ab, and a cooling water supply through hole provided in the frame. 456Aa and a cooling water discharge through hole 456Ab. The hydrogen supply through hole 452Aa, the air supply through hole 454Aa, the air discharge through hole 454Ab, the cooling water supply through hole 456Aa, and the cooling water discharge through hole 456Ab include the anode facing plate 42A and the cathode. Similar to the counter plate 44A and the intermediate plate 43A, the plate is substantially rectangular. The rest is the same as the MEA unit 45 in the first embodiment.

  FIG. 7 is a plan view of the separator 41A. The separator 41A is formed by joining the anode facing plate 42A, the intermediate plate 43A, and the cathode facing plate 44A in the same manner as the separator 41 in the first embodiment. Here, the state seen from the anode facing plate 42A side is shown.

  As can be seen, in the anode facing plate 42A, the intermediate plate 43A, and the cathode facing plate 44A, the hydrogen supply through hole 422Aa, the hydrogen supply through hole 432Aa, and the hydrogen supply through hole 442Aa have the same shape. And are formed at the same position. Also, the air supply through hole 424Aa, the air supply through hole 434Aa, and the air supply through hole 444Aa have the same shape, and are formed at the same positions. Also, the air discharge through hole 424Ab, the air discharge through hole 434Ab, and the air discharge through hole 444Ab have the same shape and are formed at the same positions. Also, the cooling water supply through-hole 426Aa, the cooling water supply through-hole 436Aa, and the cooling water supply through-hole 446Aa have the same shape and are formed at the same positions. Also, the cooling water discharge through hole 426Ab, the cooling water discharge through hole 436Ab, and the cooling water discharge through hole 446Ab have the same shape and are formed at the same positions.

  FIG. 8 is an explanatory view showing a cross-sectional structure of the fuel cell module 40A. FIG. 8A shows a cross-sectional view taken along the line AA in FIG. FIG. 8B shows a cross-sectional view taken along the line BB in FIG. Further, FIG. 8C shows a cross-sectional view taken along the line CC in FIG.

  7 and 8, in the fuel cell module 40A, the hydrogen supply through hole 442Aa of the cathode facing plate 44A, the hydrogen supply through hole 432Aa of the intermediate plate 43A, and the hydrogen supply through hole of the anode facing plate 42A. The hydrogen flowing through the hole 422Aa branches from the hydrogen supply through-hole 432Aa of the intermediate plate 43A, passes through the hydrogen supply flow path forming part 432Ap, and passes through the plurality of hydrogen supply ports 422Ai of the anode facing plate 42A to the metal on the anode side. It flows into the porous body layer 49 and is distributed and supplied over the entire surface of the anode diffusion layer 48a.

  In the fuel cell module 40A, the air flowing through the air supply through-hole 424Aa of the anode facing plate 42A, the air supply through-hole 434Aa of the intermediate plate 43A, and the air supply through-hole 444Aa of the cathode facing plate 44A flows through the intermediate plate 43A. Branching from the air supply through hole 434Aa, passing through the air supply flow path forming part 434Api, flowing from the plurality of air supply ports 444Ai of the cathode facing plate 44A to the metal porous body layer 49 on the cathode side, and diffusing for the cathode It is distributed and supplied over the entire surface of the layer 48c. The air flows while diffusing in the cathode diffusion layer 48c, and the cathode off gas is discharged from the air discharge port 444Ao of the cathode facing plate 44A in a direction perpendicular to the surface of the metal porous body layer 49, The air is discharged from the air discharge through hole 424Ab of the anode facing plate 42A through the air discharge flow path forming portion 434Apo of the MEA unit 45A and the air discharge through hole 434Ab.

  Further, the cooling water flowing through the cooling water supply through hole 426Aa of the anode facing plate 42A, the cooling water supply through hole 436Aa of the intermediate plate 43A, and the cooling water supply through hole 446Aa of the cathode facing plate 44A is cooled by the cooling of the intermediate plate 43A. The water is branched from the water supply through hole 436Aa, passes through the cooling water flow path forming part 436Ap, and is discharged from the cooling water discharge through hole 436Ab.

  According to the fuel cell stack of the second embodiment described above, the direction perpendicular to the surface of the anode of the MEA unit 451 that generates power from the plurality of hydrogen supply ports 422Ai that are arranged at substantially equal intervals on the anode facing plate 42A. Thus, hydrogen can be supplied two-dimensionally distributed over almost the entire surface of the anode. Further, two-dimensionally distributed from the plurality of air supply ports 444Ai arranged on the cathode facing plate 44A at almost equal intervals from the direction perpendicular to the surface of the cathode of the MEA unit 451 for generating power over almost the entire surface of the cathode. Air can be supplied. Therefore, in the anode of the fuel cell stack, the generated water that has permeated the electrolyte membrane 46 from the cathode side to the anode side and the gas such as nitrogen that is not used for power generation are locally retained on the surface of the anode, and the hydrogen flow path In the cathode, the generated water generated at the cathode can be locally retained on the surface of the cathode and the air flow path can be prevented from being blocked. . As a result, it is possible to suppress a decrease in the power generation capacity of the fuel cell stack.

C. Third embodiment:
FIG. 9 is an explanatory diagram showing a schematic configuration of a fuel cell system 1000B including a fuel cell stack 100B as a third embodiment. Unlike the fuel cell system 1000 of the first embodiment, the fuel cell system 1000B recirculates the anode off gas of the fuel cell stack 100B to the outside and the anode off gas to the hydrogen supply pipe 53. And a circulation pipe 54 for the purpose. Note that an exhaust valve 57 is disposed in the discharge pipe 56, and a pump 55 is disposed in the circulation pipe 54. Further, the fuel cell stack 100B has a structure for discharging the anode off gas, as will be described later. By controlling the driving of the pump 55 and the exhaust valve 57, it is possible to switch whether the anode off gas is discharged to the outside or circulated through the pipe 53. The rest is the same as the fuel cell system 1000 of the first embodiment.

  FIG. 10 is a plan view of the components of the fuel cell module 40B in the fuel cell stack 100B of the third embodiment. Similarly to the fuel cell module 40 in the first embodiment, the fuel cell module 40B in the third embodiment is configured by superposing the separator 41B and the MEA unit 45B. The separator 41B is manufactured by superposing the anode facing plate 42B, the intermediate plate 43B, and the cathode facing plate 44B in this order and performing hot press bonding. Also in this embodiment, the anode facing plate 42B, the intermediate plate 43B, and the cathode facing plate 44B are made of stainless steel flat plates having the same rectangular shape.

  FIG. 10A is a plan view of the anode facing plate 42B that comes into contact with the anode side surface of the MEA unit 45B. As illustrated, the anode facing plate 42B includes a hydrogen supply through hole 422Ba, a plurality of hydrogen supply ports 422Bi, a plurality of hydrogen discharge ports 422Bo, a hydrogen discharge through hole 422Bb, and an air supply through hole 424Ba. The air discharge through hole 424Bb, the cooling water supply through hole 426Ba, and the cooling water discharge through hole 426Bb are provided. The hydrogen supply through hole 422Ba, the hydrogen discharge through hole 422Bb, the air supply through hole 424Ba, the air discharge through hole 424Bb, the cooling water supply through hole 426Ba, and the cooling water discharge through hole 426Bb It was assumed to be almost rectangular. In addition, the plurality of hydrogen supply ports 422Bi and the hydrogen discharge ports 422Bo have a circular shape with the same diameter. The plurality of hydrogen supply ports 422Bi are opposed to the MEA unit 451 of the MEA unit 45B so as to supply hydrogen with uniform in-plane distribution over the entire surface of the anode of the MEA unit 45B, as in the first embodiment. In the region to be distributed, they are two-dimensionally distributed and arranged at almost equal intervals. The plurality of hydrogen discharge ports 422Bo are arranged so that anode off-gas can be discharged from the peripheral edge of the anode of the MEA unit 45B close to the hydrogen discharge through hole 422Bb.

  FIG. 10B is a plan view of the cathode facing plate 44B that comes into contact with the cathode side surface of the MEA unit 45B. As illustrated, the cathode facing plate 44B includes a hydrogen supply through hole 442Ba, a hydrogen discharge through hole 442Bb, an air supply through hole 444Ba, a plurality of air supply ports 444Bi, and a plurality of air discharge ports 444Bo. The air discharge through hole 444Bb, the coolant supply through hole 446Ba, and the coolant discharge through hole 446Bb are provided. The hydrogen supply through hole 442Ba, the hydrogen discharge through hole 442Bb, the air supply through hole 444Ba, the air discharge through hole 444Bb, the cooling water supply through hole 446Ba, and the cooling water discharge through hole 446Bb Similarly to the anode facing plate 42B, the plurality of air supply ports 444Bi and the plurality of air discharge ports 444Bo have a circular shape with the same diameter. The plurality of air supply ports 444Bi and the plurality of air discharge ports 444Bo supply air from the peripheral edge of the cathode of the MEA unit 45B close to the air supply through hole 444Ba and the air discharge through hole 444Bb, respectively. And it arrange | positions so that discharge | release of cathode off gas can be performed.

  FIG. 10C is a plan view of the intermediate plate 43B. As illustrated, the intermediate plate 43B includes a hydrogen supply through hole 432Ba, a hydrogen discharge through hole 432Bb, an air supply through hole 434Ba, an air discharge through hole 434Bb, and a cooling water supply through hole 436Ba. And a through hole 436Bb for discharging the cooling water. The hydrogen supply through hole 432Ba, the hydrogen discharge through hole 432Bb, the air supply through hole 434Ba, the air discharge through hole 434Bb, the cooling water supply through hole 436Ba, and the cooling water discharge through hole 436Bb Similarly to the anode facing plate 42B and the cathode facing plate 44B, it is assumed to be substantially rectangular. The hydrogen supply through hole 432Ba is provided with a plurality of hydrogen supply flow path forming portions 432Bp for flowing hydrogen from the hydrogen supply through hole 432Ba to the plurality of hydrogen supply ports 422Bi of the anode facing plate 42B. ing. Further, the hydrogen discharge through holes 432Bb are provided with a plurality of hydrogen discharge flow path forming portions 432Bpo for flowing an anode off gas from the plurality of hydrogen discharge ports 422Bo of the anode facing plate 42B to the hydrogen discharge through holes 432Bb. Yes. The air supply through hole 434Ba is provided with a plurality of air supply flow path forming portions 434Bpi for flowing air from the air supply through hole 434Ba to the plurality of air supply ports 444Bi of the cathode facing plate 44B. ing. The air discharge through hole 434Bb is provided with a plurality of air discharge flow path forming portions 434Bpo for flowing cathode off gas from the plurality of air discharge ports 444Bo of the cathode facing plate 44B to the air discharge through hole 434Bb. Yes. Further, as shown in the drawing, in order to cool the entire heat generation part of the MEA unit 45B, the cooling water supply through-hole 436Ba so that the cooling water meanders and flows between the hydrogen supply flow path forming portions 432Bp, A cooling water flow path forming portion 436Bp that connects the cooling water discharge through hole 436Bb is formed.

  FIG. 10D is a plan view seen from the cathode side of the MEA unit 45B. As illustrated, the MEA unit 45B includes an MEA portion 451, a hydrogen supply through hole 452Ba provided in the frame, a hydrogen discharge through hole 452Bb, an air supply through hole 454Ba, and an air discharge through hole 454Bb. And a cooling water supply through hole 456Ba and a cooling water discharge through hole 456Bb. The hydrogen supply through hole 452Ba, the hydrogen discharge through hole 452Bb, the air supply through hole 454Ba, the air discharge through hole 454Bb, the cooling water supply through hole 456Ba, and the cooling water discharge through hole 456Bb Like the anode facing plate 42B, the cathode facing plate 44B, and the intermediate plate 43B, the plate is substantially rectangular. The rest is the same as the MEA unit 45 in the first embodiment.

  FIG. 11 is a plan view of the separator 41B. The separator 41B is formed by joining the anode facing plate 42B, the intermediate plate 43B, and the cathode facing plate 44B in the same manner as the separator 41 in the first embodiment. Here, the state seen from the anode facing plate 42B side is shown.

  As can be seen from the figure, in the anode facing plate 42B, the intermediate plate 43B, and the cathode facing plate 44B, the hydrogen supply through hole 422Ba, the hydrogen supply through hole 432Ba, and the hydrogen supply through hole 442Ba have the same shape. And are formed at the same position. The hydrogen discharge through hole 422Bb, the hydrogen discharge through hole 432Bb, and the hydrogen discharge through hole 442Bb have the same shape and are formed at the same positions. Also, the air supply through hole 424Ba, the air supply through hole 434Ba, and the air supply through hole 444Ba have the same shape and are formed at the same positions. Also, the air discharge through hole 424Bb, the air discharge through hole 434Bb, and the air discharge through hole 444Bb have the same shape and are formed at the same positions. The cooling water supply through-hole 426Ba, the cooling water supply through-hole 436Ba, and the cooling water supply through-hole 446Ba have the same shape and are formed at the same positions. The cooling water discharge through hole 426Bb, the cooling water discharge through hole 436Bb, and the cooling water discharge through hole 446Bb have the same shape and are formed at the same positions.

  FIG. 12 is an explanatory diagram showing a cross-sectional structure of the fuel cell module 40B. FIG. 12A shows a cross-sectional view taken along the line AA in FIG. FIG. 12B is a cross-sectional view taken along the line BB in FIG.

  As shown by the arrows in FIG. 12A, in the fuel cell module 40B, the hydrogen supply through-hole 442Ba of the cathode facing plate 44B, the hydrogen supply through-hole 432Ba of the intermediate plate 43B, and the anode facing plate 42B The hydrogen flowing through the hydrogen supply through hole 422Ba branches from the hydrogen supply through hole 432Ba of the intermediate plate 43B, passes through the hydrogen supply flow path forming portion 432Bp, and passes through the plurality of hydrogen supply ports 422Bi of the anode facing plate 42B. It flows into the metal porous body layer 49 on the anode side and is distributed and supplied over the entire surface of the anode diffusion layer 48a. Then, the anode off gas is discharged from the hydrogen discharge port 422Bo of the anode facing plate 42B in a direction perpendicular to the surface of the metal porous body layer 49, and the hydrogen discharge flow path forming portion 432Bpo of the MEA unit 45B and hydrogen The gas passes through the discharge through hole 432Bb and is discharged from the hydrogen discharge through hole 442Bb of the cathode facing plate 44B.

  12B, in the fuel cell module 40B, in the fuel cell module 40B, the air supply through hole 424Ba of the anode facing plate 42B, the air supply through hole 434Ba of the intermediate plate 43B, and the cathode facing plate The air flowing through the air supply through-hole 444Ba of 44B branches off from the air supply through-hole 434Aa of the intermediate plate 43B, passes through the air supply flow path forming portion 434Bpi, and a plurality of air supply ports 444Bi of the cathode facing plate 44B. From the cathode in the direction perpendicular to the surface of the metal porous body layer 49 on the cathode side. The air flows while diffusing in the metal porous body layer 49 and the cathode diffusion layer 48c, and the cathode off-gas is perpendicular to the surface of the metal porous body layer 49 from the air discharge port 444Bo of the cathode facing plate 44B. And is discharged from the air discharge through hole 424Bb of the anode facing plate 42B through the air discharge flow path forming portion 434Bpo of the MEA unit 45B and the air discharge through hole 434Bb.

  The coolant flowing through the cooling water supply through hole 426Ba of the anode facing plate 42B, the cooling water supply through hole 436Ba of the intermediate plate 43B, and the cooling water supply through hole 446Ba of the cathode facing plate 44B is cooled by the intermediate plate 43B. The water supply through hole 436Ba branches off, passes through the cooling water flow path forming part 436Bp, and is discharged from the cooling water discharge through hole 436Bb.

  According to the fuel cell stack 100B of the third embodiment described above, as in the first embodiment, the MEA unit 451 that generates power from the plurality of hydrogen supply ports 422Bi arranged at substantially equal intervals on the anode facing plate 42B. From a direction perpendicular to the anode surface, hydrogen can be supplied two-dimensionally distributed over almost the entire surface of the anode. Therefore, it is possible to prevent the generated water that has permeated the electrolyte membrane 46 from the cathode side to the anode side from staying locally on the surface of the anode and blocking the hydrogen flow path. As a result, it is possible to suppress a decrease in the power generation capacity of the fuel cell stack. Further, anode off gas containing gas that is not used for power generation can be discharged to the outside of the fuel cell stack 100B.

D. Fourth embodiment:
The fuel cell system of the fourth embodiment is the same as the fuel cell system 1000B of the third embodiment, except that the fuel cell stack is different from the fuel cell stack 100B of the third embodiment. Therefore, the fuel cell stack of the fourth embodiment will be described below.

  FIG. 13 is a plan view of the components of the fuel cell module 40C in the fuel cell stack of the fourth embodiment. Similar to the fuel cell module 40 in the first embodiment, the fuel cell module 40C in the fourth embodiment is configured by overlapping a separator 41C and an MEA unit 45C. The separator 41C is manufactured by superposing the anode facing plate 42C, the intermediate plate 43C, and the cathode facing plate 44C in this order and performing hot press bonding. Also in this embodiment, the anode facing plate 42C, the intermediate plate 43C, and the cathode facing plate 44C use stainless steel flat plates having the same rectangular shape.

  FIG. 13A is a plan view of the anode facing plate 42C that comes into contact with the anode side surface of the MEA unit 45C. As illustrated, the anode facing plate 42C includes a hydrogen supply through hole 422Ca, a plurality of hydrogen supply ports 422Ci, a plurality of hydrogen discharge ports 422Co, a hydrogen discharge through hole 422Cb, and an air supply through hole 424Ca. In addition, an air discharge through hole 424Cb, a cooling water supply through hole 426Ca, and a cooling water discharge through hole 426Cb are provided. The hydrogen supply through hole 422Ca, the hydrogen discharge through hole 422Cb, the air supply through hole 424Ca, the air discharge through hole 424Cb, the cooling water supply through hole 426Ca, and the cooling water discharge through hole 426Cb It was assumed to be almost rectangular. In addition, the plurality of hydrogen supply ports 422Ci and the hydrogen discharge port 422Co have a circular shape with the same diameter. The plurality of hydrogen supply ports 422Ci are opposed to the MEA portion 451 of the MEA unit 45C so that hydrogen can be supplied with a uniform in-plane distribution over the entire anode surface of the MEA unit 45C, as in the third embodiment. In the region to be distributed, they are two-dimensionally distributed and arranged at almost equal intervals. The plurality of hydrogen discharge ports 422Co are arranged so that anode off-gas can be discharged from the peripheral edge of the anode of the MEA unit 45C close to the hydrogen discharge through-hole 422Cb.

  FIG. 13B is a plan view of the cathode facing plate 44C that comes into contact with the cathode side surface of the MEA unit 45C. As illustrated, the cathode facing plate 44C includes a hydrogen supply through hole 442Ca, a hydrogen discharge through hole 442Cb, an air supply through hole 444Ca, a plurality of air supply ports 444Ci, and a plurality of air discharge ports 444Co. , An air discharge through hole 444Cb, a cooling water supply through hole 446Ca, and a cooling water discharge through hole 446Cb are provided. The hydrogen supply through hole 442Ca, the hydrogen discharge through hole 442Cb, the air supply through hole 444Ca, the air discharge through hole 444Cb, the cooling water supply through hole 446Ca, and the cooling water discharge through hole 446Cb Similarly to the anode facing plate 42C, it is assumed that the plate is substantially rectangular, and the plurality of air supply ports 444Ci and the plurality of air discharge ports 444Co are circular with the same diameter. The plurality of air supply ports 444Ci face the MEA portion 451 of the MEA unit 45C so that air can be supplied with uniform in-plane distribution over the entire surface of the cathode of the MEA unit 45C, as in the third embodiment. In the region to be distributed, they are two-dimensionally distributed and arranged at almost equal intervals. The plurality of air discharge ports 444Co are arranged so that cathode off-gas can be discharged from the peripheral edge of the cathode of the MEA unit 45C close to the air discharge through hole 444Cb.

  FIG. 13C is a plan view of the intermediate plate 43C. As illustrated, the intermediate plate 43C includes a hydrogen supply through hole 432Ca, a hydrogen discharge through hole 432Cb, an air supply through hole 434Ca, an air discharge through hole 434Cb, and a cooling water supply through hole 436Ca. And a through hole 436Cb for discharging the cooling water. The hydrogen supply through hole 432Ca, the hydrogen discharge through hole 432Cb, the air supply through hole 434Ca, the air discharge through hole 434Cb, the cooling water supply through hole 436Ca, and the cooling water discharge through hole 436Cb As with the anode facing plate 42C and the cathode facing plate 44C, it is assumed to be substantially rectangular. The hydrogen supply through hole 432Ca is provided with a plurality of hydrogen supply flow path forming portions 432Cp for flowing hydrogen from the hydrogen supply through hole 432Ca to the plurality of hydrogen supply ports 422Ci of the anode facing plate 42C. ing. The hydrogen discharge through hole 432Cb is provided with a plurality of hydrogen discharge flow path forming portions 432Cpo for flowing an anode off gas from the plurality of hydrogen discharge ports 422Co of the anode facing plate 42C to the hydrogen discharge through hole 432Cb. Yes. The air supply through hole 434Ca is provided with a plurality of air supply flow path forming portions 434Cp for flowing air from the air supply through hole 434Ca to the plurality of air supply ports 444Ci of the cathode facing plate 44C. ing. The air discharge through hole 434Cb is provided with a plurality of air discharge flow path forming portions 434Cpo for flowing cathode off gas from the plurality of air discharge ports 444Co of the cathode facing plate 44C to the air discharge through hole 434Cb. Yes. Further, as shown in the figure, in order to cool the entire heat generation part of the MEA unit 45C, the cooling water meanders and flows between the hydrogen supply flow path forming portion 432Cp and the air supply flow path forming portion 434Cp. In addition, a cooling water flow path forming portion 436Cp that connects the cooling water supply through hole 436Ca and the cooling water discharge through hole 436Cb is formed.

  FIG. 13D is a plan view seen from the cathode side of the MEA unit 45C. As illustrated, the MEA unit 45C includes an MEA portion 451, a hydrogen supply through hole 452Ca provided in the frame, a hydrogen discharge through hole 452Cb, an air supply through hole 454Ca, and an air discharge through hole 454Cb. And a cooling water supply through hole 456Ca and a cooling water discharge through hole 456Cb. The hydrogen supply through hole 452Ca, the hydrogen discharge through hole 452Cb, the air supply through hole 454Ca, the air discharge through hole 454Cb, the cooling water supply through hole 456Ca, and the cooling water discharge through hole 456Cb Like the anode facing plate 42C, the cathode facing plate 44C, and the intermediate plate 43C, it is assumed to be substantially rectangular. The rest is the same as the MEA unit 45 in the first embodiment.

  FIG. 14 is a plan view of the separator 41C. The separator 41C is formed by joining the anode facing plate 42C, the intermediate plate 43C, and the cathode facing plate 44C in the same manner as the separator 41 in the first embodiment. Here, the state seen from the anode facing plate 42C side is shown.

  As can be seen, in the anode facing plate 42C, the intermediate plate 43C, and the cathode facing plate 44C, the hydrogen supply through hole 422Ca, the hydrogen supply through hole 432Ca, and the hydrogen supply through hole 442Ca have the same shape. And are formed at the same position. The hydrogen discharge through hole 422Cb, the hydrogen discharge through hole 432Cb, and the hydrogen discharge through hole 442Cb have the same shape and are formed at the same positions. The air supply through hole 424Ca, the air supply through hole 434Ca, and the air supply through hole 444Ca have the same shape and are formed at the same positions. Also, the air discharge through hole 424Cb, the air discharge through hole 434Cb, and the air discharge through hole 444Cb have the same shape and are formed at the same positions. The cooling water supply through-hole 426Ca, the cooling water supply through-hole 436Ca, and the cooling water supply through-hole 446Ca have the same shape and are formed at the same positions. Also, the cooling water discharge through hole 426Cb, the cooling water discharge through hole 436Cb, and the cooling water discharge through hole 446Cb have the same shape and are formed at the same positions.

  FIG. 15 is an explanatory diagram showing a cross-sectional structure of the fuel cell module 40C. FIG. 15A shows a cross-sectional view taken along line AA in FIG. FIG. 15B is a cross-sectional view taken along the line BB in FIG. FIG. 15C is a cross-sectional view taken along the line CC in FIG. FIG. 15D is a cross-sectional view taken along the line DD in FIG.

  14 and 15, in the fuel cell module 40C, the hydrogen supply through hole 442Ca of the cathode facing plate 44C, the hydrogen supply through hole 432Ca of the intermediate plate 43C, and the hydrogen supply through hole of the anode facing plate 42C. The hydrogen flowing through the hole 422Ca branches from the hydrogen supply through-hole 432Ca of the intermediate plate 43C, passes through the hydrogen supply flow path forming portion 432Cp, and passes through the plurality of hydrogen supply ports 422Ci of the anode facing plate 42C to the metal on the anode side. It is distributed and supplied over the entire surface of the porous body layer 49. Then, the anode off gas is discharged from the hydrogen discharge port 422Co of the anode facing plate 42C in a direction perpendicular to the surface of the anode diffusion layer 48a, and the hydrogen discharge flow path forming portion 432Cpo of the MEA unit 45C and hydrogen The gas passes through the discharge through hole 432Cb and is discharged from the hydrogen discharge through hole 442Cb of the cathode facing plate 44B.

  In the fuel cell module 40C, the air flowing through the air supply through hole 424Ca of the anode facing plate 42C, the air supply through hole 434Ca of the intermediate plate 43C, and the air supply through hole 444Ca of the cathode facing plate 44C Branching from the air supply through-hole 434Ca, passing through the air supply flow path forming portion 434Cp, and dispersed from the plurality of air supply ports 444Ci of the cathode facing plate 44C over the entire surface of the cathode porous metal layer 49. Supplied. The air flows while diffusing in the metal porous body layer 49 and the cathode diffusion layer 48c, and the cathode off-gas is perpendicular to the surface of the metal porous body layer 49 from the air discharge port 444Co of the cathode facing plate 44C. And is discharged from the air discharge through hole 424Cb of the anode facing plate 42C through the air discharge flow path forming portion 434Cpo of the MEA unit 45C and the air discharge through hole 434Cb.

  Further, the cooling water flowing through the cooling water supply through hole 426Ca of the anode facing plate 42C, the cooling water supply through hole 436Ca of the intermediate plate 43C, and the cooling water supply through hole 446Ca of the cathode facing plate 44C is cooled by the intermediate plate 43C. It branches from the water supply through hole 436Ca, passes through the cooling water flow path forming part 436Cp, and is discharged from the cooling water discharge through hole 436Cb.

  Also in the fuel cell stack of the fourth embodiment described above, from a plurality of hydrogen supply ports 422Ci arranged at substantially equal intervals on the anode facing plate 42C, from a direction perpendicular to the anode surface of the MEA unit 451 that generates power. Then, hydrogen can be supplied two-dimensionally distributed over almost the entire surface of the anode. Further, two-dimensionally distributed over almost the entire surface of the cathode from a plurality of air supply ports 444Ci arranged at substantially equal intervals on the cathode facing plate 44C from a direction perpendicular to the surface of the cathode of the MEA unit 451 for generating power. Air can be supplied. Therefore, in the anode of the fuel cell stack, it is possible to prevent the generated water that has permeated the electrolyte membrane 46 from the cathode side to the anode side from staying locally on the surface of the anode and blocking the hydrogen flow path. In the cathode, the generated water generated at the cathode can be locally retained on the surface of the cathode and the air flow path can be prevented from being blocked. As a result, it is possible to suppress a decrease in the power generation capacity of the fuel cell stack. Also, anode off gas containing gas that is not used for power generation can be discharged to the outside of the fuel cell stack.

E. Variation:
As mentioned above, although several embodiment of this invention was described, this invention is not limited to such embodiment at all, and implementation in various aspects is possible within the range which does not deviate from the summary. It is. For example, the following modifications are possible.

E1. Modification 1:
FIG. 16 is an explanatory diagram showing a schematic configuration of a fuel cell system 1000D as a modified example. This fuel cell system 1000D is a system in which the circulation pipe 54 and the pump 55 are removed from the fuel cell systems of the third and fourth embodiments. The fuel cell stack 100D used in the fuel cell system 1000D is the fuel cell stack 100B of the third embodiment or the fuel cell stack of the fourth embodiment. In this fuel cell system 1000D, during power generation, the exhaust valve 57 is closed so that almost all of the hydrogen supplied to the anode of the fuel cell stack 100D is consumed, and the exhaust gas is not discharged outside. At the same time as the operation, the exhaust valve 57 is opened at a predetermined timing, and the gas stored in the interior and not used for power generation is released to the outside. By doing so, the fuel gas can be used efficiently.

E2. Modification 2:
In the first embodiment, in the anode facing plate 42, the plurality of hydrogen supply ports 422i are all circular with the same diameter and are arranged at substantially equal intervals. However, the present invention is not limited to this. The shape, size, and arrangement position of the plurality of hydrogen supply ports 422i can be arbitrarily set so that hydrogen can be supplied two-dimensionally distributed over the entire surface of the anode of the MEA unit 451.

  FIG. 17 is a plan view of anode facing plates 42E, 42F, and 42G as modifications of the anode facing plate 42 in the first embodiment.

  In the anode facing plate 42E shown in FIG. 17A, the plurality of hydrogen supply ports 422Ei are arranged at substantially equal intervals, and the diameter (opening area) becomes larger toward the downstream side of the gas. In the case where a plurality of hydrogen supply ports having the same opening area are arranged at equal intervals from the upstream to the downstream of the hydrogen flow and hydrogen is supplied to the surface of the anode of the MEA unit 451, the supply pressure is lower on the downstream side. Become. In this case, the supply amount of hydrogen supplied from each hydrogen supply port per unit time decreases toward the downstream side. In such a case, according to the anode facing plate 42E, the supply amount of hydrogen supplied from each hydrogen supply port 422Ei per unit time can be made uniform.

  Further, in the anode facing plate 42F shown in FIG. 17B, the plurality of hydrogen supply ports 422Fi have the same opening area, but the intervals between the arrangement positions are narrower toward the downstream side of the gas. By doing so, even if the hydrogen supply pressure is low downstream of the gas, the in-plane distribution of the hydrogen supply amount to the surface of the anode can be made uniform.

  In addition, as shown in FIG. 17C, in the anode facing plate 42G, the plurality of hydrogen supply ports 422Gi may have a slit shape. Further, other shapes may be used.

  These can also be applied to the hydrogen supply port in the anode facing plate of the other embodiments, and the air supply port in the cathode facing plate of the second and fourth embodiments.

E3. Modification 3:
FIG. 18 is an explanatory diagram showing a cross-sectional structure of a fuel cell module as a modification of the fuel cell module 40 of the first embodiment. A cross-sectional view of the MEA unit of the MEA unit is shown on the left side of FIG. 18A, and a diagram corresponding to the AA cross-sectional view in FIG. 4 is shown on the right side. Further, FIG. 18B shows a diagram corresponding to the BB cross-sectional view in FIG. Since the flow of hydrogen, air, and cooling water is the same as in the first embodiment, detailed description thereof is omitted. As shown in the drawing, the metal porous body layer may not be provided on the anode side of the MEA portion of the MEA unit. This is because even if the metal porous body layer is not provided on the anode side of the MEA portion, hydrogen can be supplied to almost the entire anode from the plurality of hydrogen supply ports 422 i provided in the anode facing plate 42.

E4. Modification 4:
In the above-described embodiments, the anode facing plate includes a plurality of hydrogen supply ports arranged two-dimensionally dispersed, and the anode facing plate and the plurality of cathode facing plates arranged two-dimensionally dispersed. However, at least one of the anode facing plate and the cathode facing plate includes a plurality of supply ports arranged in a two-dimensional manner. do it.

E5. Modification 5:
In the above embodiment, the cooling water flow path is formed inside the intermediate plate. However, the present invention is not limited to this, and the cooling water flow path may be formed using other members. However, according to the said Example, the thickness of a separator can be made thin rather than forming a cooling water flow path using another member. As a result, the fuel cell stack can be reduced in size. Moreover, according to the said Example, since the gas flow path and the cooling water flow path are formed by processing a single member, it is possible to reduce the number of parts compared to forming these using separate members. Can do.

E6. Modification 6:
In the above embodiment, the anode facing plate, the intermediate plate, and the cathode facing plate are all flat plates, but the present invention is not limited thereto. It is good also as a separator using the anode opposing plate and the cathode opposing plate in which the groove-shaped gas flow path was formed like the technique described in patent document 1 shown previously. However, if the anode facing plate, the intermediate plate, and the cathode facing plate are flat plates, the processing can be easily performed.

It is explanatory drawing which shows schematic structure of the fuel cell system 1000 provided with the fuel cell stack 100 as 1st Example of this invention. 2 is a plan view of components of a fuel cell module 40. FIG. 3 is a cross-sectional view of an MEA portion 451 of the MEA unit 45. FIG. 4 is a plan view of a separator 41. FIG. 3 is an explanatory diagram showing a cross-sectional structure of a fuel cell module 40. FIG. It is a top view of the component of fuel cell module 40A in the fuel cell stack of 2nd Example. It is a top view of separator 41A. It is explanatory drawing which shows the cross-section of fuel cell module 40A. It is explanatory drawing which shows schematic structure of fuel cell system 1000B provided with the fuel cell stack 100B as 3rd Example. It is a top view of the component of the fuel cell module 40B in the fuel cell stack 100B of 3rd Example. It is a top view of separator 41B. It is explanatory drawing which shows the cross-section of the fuel cell module 40B. It is a top view of the component of the fuel cell module 40C in the fuel cell stack of 4th Example. It is a top view of separator 41C. It is explanatory drawing which shows the cross-section of the fuel cell module 40C. It is explanatory drawing which shows schematic structure of fuel cell system 1000D as a modification. It is a top view of anode facing plate 42E, 42F, 42G as a modification of the anode facing plate 42 in 1st Example. It is explanatory drawing which shows the cross-section of the fuel cell module as a modification of the fuel cell module 40 of 1st Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... End plate 20 ... Insulating plate 30 ... Current collecting plate 40, 40A, 40B, 40C ... Fuel cell module 41, 41A, 41B, 41C ... Separator 42, 42A, 42B, 42C, 42E, 42F, 42G ... Anode opposing plate 422a, 422Aa, 422Ba, 422Ca ... hydrogen supply through holes 422i, 422Ai, 422Bi, 422Ci, 422Ei, 422Fi, 422Gi ... hydrogen supply ports 422Bb, 422Cb ... hydrogen discharge through holes 422Bo, 422Co ... hydrogen discharge ports 424a, 4A 424Ba, 424Ca ... Air supply through holes 424b, 424Ab, 424Bb, 424Cb ... Air discharge through holes 426a, 426Aa, 426Ba, 426Ca ... Cooling water supply through holes 426b, 426Ab, 426Bb, 4 26Cb ... Cooling water discharge through-holes 43, 43A, 43B, 43C ... Intermediate plates 432a, 432Aa, 432Ba, 432Ca ... Hydrogen supply through-holes 432Bpo, 432Cpo ... Hydrogen discharge flow path forming portions 432p, 432Ap, 432Bp, 432Cp ... Hydrogen supply flow path forming portion 432Bb, 432Cb ... Hydrogen discharge through hole 434a, 434Aa, 434Ba, 434Ca ... Air supply through hole 434b, 434Ab, 434Bb, 434Cb ... Air discharge through hole 434pi, 434Api, 434Bpi, 434Cp ... Air supply flow path forming portions 434po, 434Apo, 434Bpo, 434Cpo ... Air discharge flow path forming portions 436a, 436Aa, 436Ba, 436Ca ... Cooling water supply through holes 436b, 436Ab, 436Bb, 43 Cb: Through hole for cooling water discharge 436p, 436Ap, 436Bp, 436Cp ... Cooling water flow path forming portion 44, 44A, 44B, 44C ... Cathode facing plate 442a, 442Aa, 442Ba, 442Ca ... Through hole for hydrogen supply 442Bb, 442Cb, hydrogen Discharge through hole 444a, 444Aa, 444Ba, 444Ca ... Air supply through hole 444b, 444Ab, 444Bb, 444Cb ... Air discharge through hole 444i, 444Ai, 444Bi, 444Ci ... Air supply port 444o, 444Ao, 444Bo, 444Co, ... Air Discharge port 446a, 446Aa, 446Ba, 446Ca ... Through hole for cooling water supply 446b, 446Ab, 446Bb, 446Cb ... Through hole for cooling water discharge 45, 45A, 45B, 45C ... MEA unit 451 ... ME Part A 452a, 452Aa, 452Ba, 452Ca ... Hydrogen supply through hole 452Bb, 452Cb ... Hydrogen discharge through hole 454a, 454Aa, 454Ba, 454Ca ... Air supply through hole 454b, 454Ab, 454Bb, 454Cb ... Air discharge through hole 456a, 456Aa, 456Ba, 456Ca ... Cooling water supply through hole 456b, 456Ab, 456Bb, 456Cb ... Cooling water discharge through hole 46 ... Electrolyte membrane 47a ... Anode catalyst layer 47c ... Cathode catalyst layer 48a ... Anode diffusion layer 48c ... Diffusion layer for cathode 49 ... Metal porous body layer 50 ... Hydrogen tank 51 ... Shut valve 52 ... Regulator 53 ... Pipe 54 ... Circulating pipe 55 ... Pump 56 ... Exhaust pipe 57 ... Exhaust valve 60 ... Compressors 61, 62 ... Pip 70 ... Pon 71 ... radiator 72 ... pipe 100 and 100B, 100D ... fuel cell stack 1000,1000B, 1000D ... fuel cell system

Claims (11)

A fuel cell having a stack structure in which a plurality of laminated bodies each having an anode and a cathode are disposed on both surfaces of a predetermined electrolyte membrane having proton conductivity with a separator interposed therebetween,
The separator is
An anode facing plate facing the anode of the laminate;
A cathode facing plate facing the cathode of the laminate;
An intermediate plate sandwiched between the anode facing plate and the cathode facing plate;
At least one of the anode facing plate and the cathode facing plate penetrates in the thickness direction of the plate, and a predetermined reaction gas is introduced to the surface of the stacked body from a direction perpendicular to the surface of the stacked body. A plurality of reaction gas supply ports for supplying,
The intermediate plate is sandwiched between the anode facing plate and the cathode facing plate, thereby forming a reaction gas supply channel for supplying the reaction gas to each of the plurality of reaction gas supply ports. A gas supply flow path forming section;
The plurality of reaction gas supply ports are two-dimensionally distributed with respect to the plate surface of the plate having the plurality of reaction gas supply ports.
Fuel cell. The fuel cell according to claim 1, wherein
The plurality of reactive gas supply ports are formed at substantially equal positions.
Fuel cell. The fuel cell according to claim 2, wherein
The reaction gas supply port to which the reaction gas is supplied from the downstream side of the reaction gas supply channel is wider as the opening area of the plurality of reaction gas supply ports.
Fuel cell. The fuel cell according to claim 1, wherein
The opening areas of the plurality of reaction gas supply ports are substantially the same,
The formation interval of the plurality of reaction gas supply ports is closer to the reaction gas supply port to which the reaction gas is supplied from the downstream side of the reaction gas supply channel.
Fuel cell. A fuel cell according to any one of claims 1 to 4,
The intermediate plate is further sandwiched between the anode facing plate and the cathode facing plate, thereby forming a cooling medium flow path for forming a cooling medium flow path for flowing a cooling medium for cooling the fuel cell. Comprising a forming part,
Fuel cell. The fuel cell according to claim 5, wherein
The single intermediate plate includes the reactive gas supply flow path forming portion and the cooling medium flow path forming portion.
Fuel cell. The fuel cell according to any one of claims 1 to 6,
At least one of the anode facing plate and the cathode facing plate having the plurality of reaction gas supply ports is further penetrated in the thickness direction of the plate and supplied from the plurality of reaction gas supply ports. An exhaust gas exhaust port for exhausting exhaust gas, which is the remaining gas that has not been used for power generation among the reaction gas, in a direction perpendicular to the surface of the laminate,
The intermediate plate is further sandwiched between the anode facing plate and the cathode facing plate, thereby forming an exhaust gas exhaust passage for exhausting the exhaust gas from the exhaust gas exhaust port to the outside. Comprising a gas discharge flow path forming section,
Fuel cell. The fuel cell according to claim 7, wherein
The plurality of reactive gas supply ports are provided in the anode facing plate,
At least during power generation, the exhaust gas is not discharged to the outside from the gas discharge port in the anode facing plate.
Fuel cell. The fuel cell according to any one of claims 1 to 6,
The cathode facing plate includes the plurality of reaction gas supply ports,
The reaction gas supplied from the plurality of reaction gas supply ports is used for power generation without being discharged to the outside.
Fuel cell. The fuel cell according to any one of claims 1 to 9,
The anode facing plate, the cathode facing plate, and the intermediate plate are each formed of a flat plate member.
Fuel cell. The fuel cell according to any one of claims 1 to 10,
The laminate includes a gas diffusion layer made of a porous body for allowing the reaction gas to flow while diffusing in a direction along the surface on at least a cathode side surface of the laminate.
Fuel cell.

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