JP2009026524A - Fuel cell module and fuel cell - Google Patents

Abstract

An object of the present invention is to suppress the localization of impurities in a fuel cell and increase the power generation efficiency of the fuel cell.
As a mode of operation performed by supplying fuel gas, a fuel cell module 100 that consumes almost all of the supplied fuel gas by a power generator, the power generator 510 and both surfaces of the power generator 510 are provided. A plurality of gas passages 540 and 545 disposed on the gas flow path, a separator disposed on the outside of the gas flow path, and one gas flow path 540 out of the gas flow paths. The gas supply parts 517a and 517b are provided.
[Selection] Figure 9

Description

  The present invention relates to a fuel cell in which almost all of the supplied fuel gas is consumed by a power generator as a mode of operation performed by supplying the fuel gas.

  A fuel cell that generates electricity by stopping anode exhaust gas inside is known (Patent Document 1).

JP 2005-243476 A

  However, in the prior art, impurities that do not contribute to the reaction such as nitrogen leaked from the cathode are pushed by the fuel gas and localized in the most downstream portion of the fuel gas supply flow path, and the power generation efficiency of the fuel cell decreases. was there.

  The present invention has been made to solve at least a part of the above-described problems, and an object thereof is to suppress the localization of impurities in the fuel cell and increase the power generation efficiency of the fuel cell.

  In order to solve at least a part of the above problems, the present invention has the following configuration.

[Application Example 1]
The invention according to Application Example 1 of the present invention is a fuel cell module that consumes almost all of the supplied fuel gas as a mode of operation performed by supplying fuel gas. A gas channel disposed on both sides of the power generation body, a separator disposed on the outside of the gas channel, and a plurality of gas supplies from different directions to one of the gas channels. A gas supply unit. According to this application example, since the gas is supplied to the gas flow path from different directions, localization of impurities such as nitrogen can be suppressed and the power generation efficiency of the fuel cell can be increased.

  In the fuel cell module according to Application Example 1, the gas supply unit is disposed adjacent to an outer edge portion of the power generator. According to this application example, the power generator can be used efficiently.

  In the fuel cell module according to Application Example 1, the gas supply unit supplies gas toward the center of the power generation body. According to this application example, since the gases from a plurality of directions collide and mix with each other, localization of impurities such as nitrogen in the gas collision portion can be suppressed.

  In the fuel cell module according to Application Example 1, an outer edge of the power generation body is defined by a plurality of sides intersecting each other, and a first gas supply unit among the plurality of gas supply units is the plurality of sides of the power generation unit. The other gas supply unit is arranged adjacent to a second side different from the first side. According to this application example, the gas supply direction can be varied.

  In the fuel cell module according to Application Example 1, the first side and the second side face each other. According to this application example, localization of impurities such as nitrogen can be suppressed.

  In the fuel cell module according to Application Example 1, the power generation body is rectangular, and the first side and the second side are long sides. According to this application example, since the flow length of the fuel gas can be shortened, localization of impurities such as nitrogen can be suppressed.

[Application Example 2]
The invention according to Application Example 2 of the present invention is a fuel cell in which the fuel cell modules according to Application Example 1 are stacked. The fuel cell module includes a fuel gas supply manifold hole, and a communication path connecting the fuel gas supply manifold hole and the gas supply unit. The fuel cell is formed by the fuel gas supply manifold hole, and penetrates in the stacking direction of the fuel cell module, a fuel tank, and a pipe connecting the fuel tank and the fuel gas supply manifold And a fuel gas supply amount adjusting unit that is arranged in the pipe and changes a supply amount of the fuel gas supplied from the fuel tank to the fuel gas supply manifold. According to this application example, localization of impurities such as nitrogen can be suppressed, and the power generation efficiency of the fuel cell can be increased.

  The fuel cell according to Application Example 2 includes a plurality of fuel gas supply manifolds. According to this application example, the structure of the fuel cell is simplified.

  In the fuel cell according to Application Example 2, the fuel gas supply amount adjusting unit is provided for each of the plurality of fuel gas supply manifolds. According to this application example, since the supply amount of the fuel gas can be changed for each fuel gas supply manifold, localization of impurities such as nitrogen can be suppressed, and the power generation efficiency of the fuel cell can be increased.

  In the fuel cell according to Application Example 2, each of the plurality of fuel gas supply manifolds includes a pipe, and a pressure loss of a first pipe connected to the first fuel gas supply manifold of the pipes, The pressure loss of the second piping connected to the fuel gas supply manifold is made different. According to this application example, the amount of fuel gas supplied to the first fuel gas supply manifold and the second fuel gas supply manifold can be changed depending on the difference in pressure loss. As a result, the localization of impurities such as nitrogen can be suppressed, and the power generation efficiency of the fuel cell can be increased.

  In the fuel cell according to Application Example 2, the flow path length of the first pipe and the flow path length of the second pipe are different. According to this application example, since the flow path lengths of the pipes are different, the pressure loss of the pipes can be made different.

  In the fuel cell according to Application Example 2, the length of the first piping is different from the length of the second piping. According to this application example, since the pipe diameters are different, the pressure loss of the pipes can be made different.

  The fuel cell according to Application Example 2 includes control means for controlling the fuel gas supply amount adjusting unit. According to this application example, by changing the supply amount of the fuel gas, the gas flow in the gas flow path can be changed, and localization of impurities such as nitrogen can be suppressed.

  In the fuel cell according to Application Example 2, the control unit performs control so as to vary the amount of fuel gas supplied to the plurality of fuel gas supply manifolds. According to this application example, by changing the supply amount of the fuel gas supplied to each fuel gas supply manifold, the gas flow in the gas flow path can be changed, and localization of impurities such as nitrogen can be suppressed. .

  In the fuel cell according to Application Example 2, the control unit changes the fuel gas supply amount when the fuel cell is started or when a load on the fuel cell is changed. According to this application example, it is possible to suppress the localization of impurities such as nitrogen when the fuel cell is started or when the load on the fuel cell is changed.

  This type of fuel cell includes a mode in which almost all of the supplied fuel gas is consumed in the fuel gas consumption layer as a mode of operation performed by supplying the fuel gas. When hydrogen or a gas containing hydrogen is used as the fuel gas, the fuel gas supply side is the side from which electrons flow, and thus becomes an “anode”. Here, consuming almost all of the fuel gas means that the fuel gas is not actively used by being taken out of the fuel gas consumption layer and circulated through the fuel gas supply path. Consumption includes not only the electrochemical reaction for power generation, but also permeation to the opposite side of the electrolyte membrane. In addition, leakage that occurs when a fuel cell is actually configured may be included in the consumption. In a fuel cell, generating electricity while using such fuel gas is called dead-end operation. At this time, almost all of the fuel gas can be regarded as a mode of operation that is used for power generation in a state where it is retained inside without being discharged to the outside. In this case, as a result, the fuel consumption layer to which the fuel gas is supplied generally has a closed structure that does not discharge or release the fuel gas to the outside.

  The operation of the fuel cell performed by supplying the fuel gas to the anode side of the power generation body is called anode dead end operation. In the anode dead-end operation, power generation is continued in a state where fuel gas is not discharged from the anode side while the supply of fuel gas to the anode side is continued. As a result, power generation is performed with at least almost the entire amount of the fuel gas supplied during steady power generation being kept on the anode side. When the power generator is equipped with a membrane electrode assembly in which the anode and the cathode are joined to both surfaces of the electrolyte membrane, and a fuel gas (mostly hydrogen or hydrogen-containing gas) is supplied to the anode side to generate power Thus, almost all of the fuel gas supplied to the anode is used for power generation in a state of being retained inside without being discharged to the outside. In this case, as a result, the anode side to which the fuel gas is supplied generally has a closed structure that does not discharge or release the fuel gas to the outside.

  In this specification, an operation mode in which almost all the fuel gas supplied to the fuel gas consumption layer is consumed in the fuel gas consumption layer is called dead-end operation. This configuration is included in the dead-end operation even if a mode in which the fuel gas is extracted from the fuel gas consumption layer and used for the purpose is added. For example, a configuration in which a flow path for extracting a small amount of fuel gas from the fuel consumption layer or upstream thereof is provided, and the extracted fuel gas is burned and used for preheating such as an auxiliary machine can be considered. Unless the fuel gas is taken out from the consumption layer of the fuel gas or upstream thereof, there is no particular meaning in the consumption of the nominal fuel gas. It is not a configuration that is excluded from “consuming in a layer”.

  The fuel cell of the present invention further generates power continuously in a state where the partial pressure of impurities (for example, nitrogen) at the anode electrode (hydrogen electrode) is balanced with the partial pressure of impurities (for example, nitrogen) at the cathode electrode (air electrode). It can also be grasped as realizing the driving state. Here, the “balanced state” means, for example, an equilibrium state, and is not necessarily limited to a state where the partial pressures of both are equal.

  The fuel cell of the present invention further includes a configuration as shown in FIGS. 28 and 29, for example. The configuration example of FIG. 28 has a first channel and a second channel. The first channel is disposed upstream of the second channel. The first channel and the second channel communicate with each other via a high resistance communication portion 2100x having a higher flow resistance than the first channel or the second channel. These flow paths introduce fuel gas from outside the power generation area (outside of the fuel cell) via the fuel gas inlet (manifold). In other words, the supply of the fuel gas to the second flow path is introduced from the first flow path mainly through the high resistance communication portion 2100x (for example, only through the high resistance communication portion 2100x).

  The first flow path and the second flow path can also be formed by using a porous material as in the examples described later. For example, sandwiching the sealing materials S1 and S2 (FIG. 28) or a honeycomb structure You may comprise as formation (FIG. 29) of the flow path which uses the material H2.

  As the high resistance communication portion 2100x, for example, a plate-like member in which a plurality of introduction portions 2110x (through holes) as shown in FIGS. 28 and 29 are dispersed in the in-plane direction can be used. The high resistance communication part 2100x has at least one of the following roles. The first role is “a role of limiting fuel gas supply to a region in the second flow path close to the fuel gas inlet”. The second role is “a role of suppressing in-plane non-uniformity of the gas pressure acting in the direction perpendicular to the surface of the second flow path along the anode reaction portion”. The third role is “the role of changing the direction of the fuel gas flowing in the in-plane direction through the first flow path into the perpendicular direction (or the direction intersecting the plane)”.

The fuel cell of the present invention can be further understood as the following fuel cell system. That is, this fuel cell system
A fuel cell system including a mode in which almost all of the supplied fuel gas is consumed in the anode reaction section, the inlet for introducing the anode gas into the power generation cell;
A first gas flow path for guiding the anode gas supplied from the introduction port in the cell plane direction;
Extending along the anode reaction section,
The flow resistance is higher than that of the first gas flow path, and a plurality of communication portions distributed in the cell in-plane direction are provided while preventing the inflow of the anode gas from the first gas flow path to the second gas flow path. A high resistance portion for guiding the anode gas from the first gas flow path to the second gas flow path,
Is provided.

The fuel cell of the present invention can also be understood as a fuel cell system including the following configuration. That is, this fuel cell system
The high resistance portion has one communication portion corresponding to one region of the anode reaction portion, and another communication portion corresponding to another region,
In the anode gas consumed in the one region, the ratio of the gas that has passed through one communication portion of the high resistance portion is higher than the ratio of the gas that has passed through the other communication portion,
Or
The high resistance portion has one communication portion corresponding to one region of the anode reaction portion, and another communication portion corresponding to another region,
The anode gas that has passed through the one communicating portion may be configured such that the ratio consumed in one area of the anode reaction section is higher than the ratio consumed in the other area.

  On the other hand, it is preferable that the cathode channel does not have at least the high resistance communication portion. Further, it is preferable that the cathode channel is only the first gas channel that guides the cathode gas supplied from the cathode introduction port in the in-cell direction without providing the second channel. However, if the so-called gas diffusion layer is regarded as the second flow path, a combination of the first and second flow paths may be used. In any case, by omitting the high resistance communication portion only from the cathode electrode, it is possible to reduce the work of the cathode gas feeder and improve the drainage performance at the cathode electrode. It is suitable for a fuel cell system having low performance (no steady exhaust of fuel gas).

1. Configuration of Fuel Cell A fuel cell according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory diagram schematically showing the configuration of the fuel cell according to the present embodiment.

  The fuel cell 10 includes a module 100, an end plate 200, a current collector plate 210, an insulating plate 220, a tension plate 230, and a bolt 240. Each module 100 functions as a power generation unit. The configuration of the module 100 will be described later. A plurality of modules 100 are stacked on the fuel cell 10. The current collector plate 210 is a plate-like member having terminals (not shown) for taking out electric power from the stacked modules 100 to the outside, and is arranged so as to sandwich the stacked modules 100 from the stacking direction. The insulating plate 220 is a plate-like member made of, for example, rubber or insulating resin, and is disposed on the side of the current collecting plate 210 opposite to the module 100. The end plate 200 is a plate-like member formed of a metal such as steel, and is disposed on the side of the insulating plate 220 opposite to the current collector plate 210. The tension plate 230 is a plate-like member for connecting the two end plates 200 and fastening the fuel cell 10. The tension plate 230 is coupled to the end plates 200 at both ends in the stacking direction by bolts 240 in a state where a predetermined fastening force is applied to each module 100.

  The module 100, the end plate 200, the current collector plate 210, and the insulating plate 220 are formed with openings at predetermined positions, and the module 100, the end plate 200, the current collector plate 210, and the insulating plate 220 are laminated. Each of the openings is connected to form fuel gas supply manifolds 11a and 11b penetrating in the stacking direction. Although not illustrated, similarly, an oxidizing gas supply manifold, an oxidizing gas discharge manifold, a cooling medium supply manifold, and a cooling medium discharge manifold are also formed.

  A fuel gas supply system is connected to the fuel gas supply manifolds 11 a and 11 b of the fuel cell 10. An oxidizing gas supply / discharge system is connected to the oxidizing gas supply manifold (not shown) and the oxidizing gas discharge manifold (not shown) of the fuel cell 10. A cooling system is connected to a cooling medium supply manifold (not shown) and a cooling medium discharge manifold (not shown) of the fuel cell 10.

  The fuel gas supply system includes a hydrogen storage container 300, a pipe 305, a valve 310, and a fuel gas supply pressure control unit 315. The hydrogen storage container 300 is a container that stores high-purity hydrogen that is a fuel gas. As the hydrogen storage container 300, for example, a container for storing hydrogen gas at a high pressure or a container using a hydrogen storage alloy can be used. Further, instead of the hydrogen storage container 300, for example, a hydrogen generator that generates hydrogen by a reforming reaction using alcohol, hydrocarbon, or the like as a raw material or by a reaction between an alkali metal compound and water may be used. The pipe 305 connects the hydrogen storage container 300 and the fuel gas supply manifolds 11 a and 11 b of the fuel cell 10. The valve 310 is disposed on the pipe 305. A control signal from the fuel gas supply pressure control unit 315 is input to the valve 310. In the present embodiment, the opening degree of the valve 310 is controlled by the fuel gas supply pressure control unit 315, and the supply pressure of the fuel gas to the fuel cell 10 is controlled. The fuel gas is preferably a dry gas that is not humidified.

  In this embodiment, the fuel cell 10 does not include a fuel gas discharge manifold. The fuel gas is supplied to the fuel cell 10 at a predetermined pressure and is not discharged outside the fuel cell 10. That is, the fuel gas consumed by the fuel cell 10 is newly supplied to the fuel cell 10.

  The oxidizing gas supply / discharge system includes a pump 330, an oxidizing gas supply pipe 340, and an oxidizing gas discharge pipe 350. The pump 330 takes in air from the atmosphere, compresses it, and sends it to the fuel cell 10. The oxidizing gas supply pipe 340 connects the pump 330 and the oxidizing gas supply manifold (not shown) of the fuel cell. The oxidizing gas discharge pipe 350 discharges the exhaust gas discharged to the oxidizing gas discharge manifold (not shown) of the fuel cell to the atmosphere.

  The cooling system includes a radiator 360, a pump 370, and a pipe 380. The radiator 360 cools the cooling medium. The pump 370 circulates the cooling medium. The pipe 380 is a pipe through which the cooling medium flows, and connects the cooling medium supply manifold (not shown), the cooling medium discharge manifold (not shown), the radiator 360 and the pump 370 of the fuel cell 10.

2. Configuration of Module 100 The module 100 includes a separator and a membrane electrode gas diffusion layer assembly (hereinafter referred to as “MEGA”).
Hereinafter, the structure of a separator is demonstrated using drawing. The separator includes an anode facing plate, an intermediate plate, and a cathode facing plate. FIG. 2 is an explanatory view schematically showing the shape of the anode facing plate. FIG. 3 is an explanatory view schematically showing the shape of the intermediate plate. FIG. 4 is an explanatory view schematically showing the shape of the cathode facing plate.

  The anode facing plate 410 is a substantially rectangular plate-like member made of a conductive metal material such as titanium. Several holes are formed in the anode facing plate 410. That is, a fuel gas supply manifold hole 415a that forms the fuel gas supply manifold 11a is formed at the first corner of the anode facing plate 410, and a fuel gas supply manifold hole 415b is formed at the diagonal corner. Yes. In this embodiment, two fuel gas supply manifold holes are provided at diagonal positions. The fuel gas supply manifold hole 415a becomes a part of the fuel gas supply manifold 11a when the modules 100 are stacked. The fuel gas supply manifold hole 415b becomes a part of the fuel gas supply manifold 11b when the modules 100 are stacked.

  An oxidizing gas supply manifold hole 420 forming an oxidizing gas supply manifold is formed adjacent to the first long side of the anode facing plate 410, and an oxidizing gas discharge forming an oxidizing gas discharge manifold adjacent to the other long side. A manifold hole 425 is formed.

  A fuel gas supply hole 417a is formed on the central side of the anode facing plate 410 of the oxidizing gas supply manifold hole 420, and a fuel gas supply hole 417b is formed on the central side of the anode facing plate 410 of the oxidizing gas discharge manifold hole 425. The fuel gas supply hole 417a and the fuel gas supply hole 417b face each other across the central portion of the anode facing plate 410. The fuel gas is supplied from the respective fuel gas supply holes 417a and fuel gas supply holes 417b toward the center of the anode facing plate 410.

  A cooling medium supply manifold hole 430 forming a cooling medium supply manifold is formed adjacent to the first short side of the anode facing plate 410 and a cooling medium discharge forming a cooling medium discharge manifold adjacent to the other short side. A manifold hole 435 is formed.

  These fuel gas supply manifold holes 415a and 415b, fuel gas supply holes 417a and fuel gas supply holes 417b, oxidation gas supply manifold holes 420 and oxidation gas discharge manifold holes 425, and cooling medium supply manifold holes 430 and cooling medium discharge manifold holes. 435 is formed by, for example, a press using a mold.

  The intermediate plate 440 is, for example, a substantially rectangular plate member made of a conductive material. For example, a resin material or a metal material is used as the material. Several holes are formed in the intermediate plate 440. That is, a fuel gas supply manifold hole 445a that forms the fuel gas supply manifold 11a is formed in the first corner of the intermediate plate 440, and a fuel gas supply manifold hole 445b is formed in the diagonal corner. .

  An oxidizing gas supply manifold hole 450 that forms an oxidizing gas supply manifold is formed adjacent to the first long side of the intermediate plate 440, and an oxidizing gas discharge manifold that forms an oxidizing gas discharge manifold adjacent to the other long side. A hole 455 is formed.

  An oxidizing gas supply communication hole 450 a is formed in the middle side of the intermediate plate 440 of the oxidizing gas supply manifold hole 450. The oxidizing gas supply manifold hole 450 and the oxidizing gas supply communication hole 450a are connected to form one opening. Similarly, an oxidizing gas discharge communication hole 455a is formed at the center side of the intermediate plate 440 of the oxidizing gas discharge manifold hole 455. The oxidizing gas discharge manifold hole 455 and the oxidizing gas discharge communication hole 455a are connected to form one opening.

  A fuel gas supply communication hole 445c elongated in the longitudinal direction is formed in the middle of the intermediate plate 440 of the oxidation gas supply communication hole 450a. The end of the fuel gas supply communication hole 445c and the fuel gas supply manifold hole 445a are connected to each other, and the fuel gas supply manifold hole 445a and the fuel gas supply communication hole 445c form one opening. Similarly, a fuel gas supply communication hole 445d elongated in the longitudinal direction is formed at the center side of the intermediate plate 440 of the oxidizing gas supply communication hole 450b. The end of the fuel gas supply communication hole 445d is connected to the fuel gas supply manifold hole 445b, and the fuel gas supply manifold hole 445b and the fuel gas supply communication hole 445d form one opening. The fuel gas supply communication hole 445c and the fuel gas supply communication hole 445d are at opposite positions with the central portion of the intermediate plate 440 in between.

  A plurality of cooling medium holes 460 elongated in the longitudinal direction are formed between the fuel gas supply communication hole 445c and the fuel gas supply communication hole 445d. Both ends of the cooling medium hole 460 become part of the cooling medium supply manifold and the cooling medium discharge manifold. The cooling medium hole 460 serves as a flow path for the cooling medium.

  Fuel gas supply manifold holes 445a and 445b, fuel gas supply communication holes 445c and fuel gas supply communication holes 445d, oxidation gas supply manifold holes 450 and oxidation gas discharge manifold holes 455, oxidation gas supply communication holes 450a and oxidation gas discharge communication holes 455a In addition, for example, when the intermediate plate 440 is a resin material, the cooling medium hole 460 is formed simultaneously with the intermediate plate by injection molding. When the intermediate plate 440 is a metal material, it is formed by pressing using a mold.

  The cathode facing plate 470 is a substantially rectangular plate-like member made of a conductive metal material such as titanium. Several holes are formed in the cathode facing plate 470. That is, a fuel gas supply manifold hole 475a that forms the fuel gas supply manifold 11a is formed at the first corner of the cathode facing plate 470, and a fuel gas supply manifold hole 475b is formed at the diagonal corner. Yes.

  An oxidizing gas supply manifold hole 480 that forms an oxidizing gas supply manifold is formed adjacent to the first long side of the cathode facing plate 470, and an oxidizing gas discharge manifold that forms an oxidizing gas discharge manifold adjacent to the other long side. A hole 485 is formed.

  A cooling medium supply manifold hole 490 that forms a cooling medium supply manifold is formed adjacent to the first short side of the cathode facing plate 470 and a cooling medium discharge that forms a cooling medium discharge manifold adjacent to the other short side. A manifold hole 495 is formed. An oxidizing gas supply hole 482 is formed at the cathode facing plate 470 center side of the oxidizing gas supply manifold hole 480, and an oxidizing gas discharge hole 487 is formed at the cathode facing plate 470 center side of the oxidizing gas discharge manifold hole 485.

  The fuel gas supply manifold holes 475a and 475b, the oxidation gas supply manifold hole 480 and the oxidation gas discharge manifold hole 485, the oxidation gas supply hole 482 and the oxidation gas discharge hole 487, and the cooling medium supply manifold hole 490 and the cooling medium discharge manifold hole 495 are provided. For example, it is formed by pressing using a mold.

  Hereinafter, the cross-sectional structure of the fuel cell will be described with reference to the drawings. FIG. 5 is an explanatory view schematically showing a cross section when the fuel cell 10 is cut at the position of the AA cutting line shown in FIGS. 2 to 4. FIG. 6 is an explanatory view schematically showing a cross section when the fuel cell 10 is cut at the position of the BB cutting line shown in FIGS. 2 to 4.

  The module 100 of the fuel cell 10 includes a separator 400 and a power generation unit 500. The fuel cell 10 has a structure in which a large number of modules 100 are stacked, and separators 400 and power generation units 500 are alternately stacked. In this embodiment, the unit from the intermediate plate 440 to the anode facing plate 410 is one unit of the module 100 as shown in FIG. Note that the module 100 only needs to have a set of the anode facing plate 410, the intermediate plate 440, the cathode facing plate 470, and the power generation unit 500 as one unit. It's just a matter of separation.

  The power generation unit 500 includes a MEGA 510, porous bodies 540 and 545, and a frame 550. The MEGA 510 includes an electrolyte membrane 515, an anode side catalyst layer 520, a cathode side catalyst layer 525, an anode side gas diffusion layer 530, and a cathode side gas diffusion layer 535. The electrolyte membrane 515, the anode side catalyst layer 520, and the cathode side catalyst layer 525 may be collectively referred to as a membrane electrode assembly (MEA).

  As the electrolyte membrane 515, a proton conductive ion exchange membrane made of a solid polymer material, for example, a fluorine-based resin such as perfluorocarbon sulfonic acid polymer is used.

  The anode side catalyst layer 520 and the cathode side catalyst layer 525 are formed on both surfaces of the electrolyte membrane 515. As the anode side catalyst layer 520 and the cathode side catalyst layer 525, a catalyst layer in which a catalyst for promoting an electrochemical reaction, for example, a platinum catalyst or a platinum alloy catalyst made of platinum and another metal is supported on carbon is used. The anode side catalyst layer 520 and the cathode side catalyst layer 525 are preferably flat. This is because impurities such as nitrogen are less likely to accumulate if they are flat.

  The anode side gas diffusion layer 530 is a layer for diffusing the fuel gas, and is disposed on the anode side catalyst layer 520. As the anode-side gas diffusion layer 530, for example, carbon cloth or carbon paper having both gas diffusibility and electron conductivity is used. The cathode side gas diffusion layer 535 is a layer for diffusing the oxidizing gas, and is disposed on the cathode side catalyst layer 525. As the cathode-side gas diffusion layer 535, for example, carbon cloth or carbon paper having both gas diffusibility and electron conductivity is used.

  The porous body 540 is a member for forming a fuel gas flow path, and is disposed on the anode-side gas diffusion layer 530. For example, a porous body made of metal such as stainless steel or titanium can be used as the porous body 540. The porous body 545 is a member for forming a flow path for the oxidizing gas, and is disposed on the cathode side gas diffusion layer 535. For example, a porous body made of metal such as stainless steel or titanium can be used as the porous body 545.

  The frame 550 will be described with reference to FIG. FIG. 7 is an explanatory diagram schematically showing a planar configuration of the frame 550.

  The frame 550 is a substantially rectangular plate-like member formed of an insulating resin material such as silicon rubber, butyl rubber, or fluorine rubber, and has an opening 555 for fitting the MEGA 510 in the center. In addition to the opening 555, several holes are formed in the frame 550. That is, a fuel gas supply manifold hole 565a that forms the fuel gas supply manifold 11a is formed at the first corner of the frame 550, and a fuel gas supply manifold hole 565b is formed at the diagonal corner.

  An oxidizing gas supply manifold hole 570 that forms an oxidizing gas supply manifold is formed adjacent to the first long side of the frame 550, and an oxidizing gas discharge manifold hole 575 that forms an oxidizing gas discharge manifold adjacent to the other long side. Is formed.

  A cooling medium supply manifold hole 580 is formed adjacent to the first short side of the frame 550 to form a cooling medium supply manifold, and a cooling medium discharge manifold hole 585 is formed adjacent to the other short side to form a cooling medium discharge manifold. Is formed.

  Around the opening 555, the fuel gas supply manifold holes 565a and 565b, the oxidation gas supply manifold hole 570 and the oxidation gas discharge manifold hole 575, and the cooling medium supply manifold hole 580 and the cooling medium discharge manifold hole 585, a seal line 550a is provided. Is formed. The seal line 550a is pressure-bonded to the separator 400, whereby the opening 555, the fuel gas supply manifold holes 565a and 565b, the oxidizing gas supply manifold hole 570 and the oxidizing gas discharge manifold hole 575, and the cooling medium supply manifold hole 580 and the cooling are provided. The reaction gas is prevented from leaking from the medium discharge manifold hole 585 to the outside of the fuel cell 10.

  The frame 550 is formed integrally with the membrane electrode assembly by, for example, injection molding.

3. Operation of Fuel Cell Hereinafter, the flow of fuel gas will be described. The fuel gas is supplied from the hydrogen storage container 300 through the pipe 305 to the fuel gas supply manifolds 11a and 11b (FIG. 1). At this time, the supply pressure of the fuel gas is adjusted by the valve 310.

  The fuel gas is divided in the direction of the fuel gas supply communication hole 445c of each module 100 in the middle of flowing through the fuel gas supply manifold 11a, and is distributed to each module. The fuel gas moves in the longitudinal direction of the intermediate plate 440 through the fuel gas supply communication hole 445c, and is supplied into the anode-side porous body 540 through the fuel gas supply hole 417a of the anode facing plate 410 (FIG. 5). , FIG. 6).

  The fuel gas flows in the porous body 540 from the long side toward the center, that is, in the direction of the arrow 600a (from top to bottom in FIG. 7). On the other hand, the fuel gas distributed to the fuel gas supply manifold 11b also flows in the porous body 540 from the long side to the center, that is, in the direction of the arrow 600b (from bottom to top in FIG. 7). At this time, the fuel gas supplied to the porous body 540 through the fuel gas supply hole 417a and the fuel gas supplied to the porous body 540 through the fuel gas supply hole 417b collide with each other near the center of the module 100 and mixed with each other. To do.

  The power generation characteristics of the fuel cell 10 according to this embodiment will be described with reference to FIG. FIG. 8 is a graph showing the time dependence of the power generation voltage of the fuel cell. Line a is a graph showing the time dependence of the power generation voltage of the fuel cell according to this example. The line b is a graph showing the time dependency of the power generation voltage of the fuel cell according to the conventional fuel cell.

  In the graph shown by the line a, the generated voltage of the fuel cell 10 does not drop much even if time passes. On the other hand, in the graph shown by the line b, the power generation voltage of the fuel cell 10 rapidly decreases with time. In the conventional fuel cell, the flow of the fuel gas is one-way. As a result, in conventional fuel cells, impurities such as nitrogen leaking from the cathode side of the fuel cell through the membrane electrode assembly to the gas flow path on the anode side are pushed by the fuel gas and are localized downstream of the flow. As a result, the power generation efficiency of the fuel cell decreased. On the other hand, in the fuel cell 10 shown in this embodiment, as shown in FIG. 7, fuel gas is supplied from both above and below the porous body 540, and hits and diffuses near the center of the porous body. As a result, impurities such as nitrogen are diffused without being localized, thereby suppressing a decrease in power generation efficiency of the fuel cell.

  As described above, according to this embodiment, the fuel gas is supplied from the two locations of the fuel gas supply hole 417a and the fuel gas supply hole 417b to the porous body 540 in the two directions indicated by arrows 600a and 600b. Impurities are difficult to localize. Therefore, the power generation efficiency of the fuel cell can be improved.

  According to the present embodiment, since the fuel gas supply hole 417a and the fuel gas supply hole 417b are at the outer edge of the module 100, the membrane electrode assembly can be used efficiently.

  According to the present embodiment, since the fuel gas supplied from the fuel gas supply hole 417a and the fuel gas supply hole 417b collides and mixes at the center of the module 100, localization of impurities such as nitrogen gas can be suppressed.

  According to the present embodiment, since the fuel gas supply hole 417a and the fuel gas supply hole 417b are adjacent to different sides of the module, the flow direction of the fuel gas can be made different as indicated by arrows 600a and 600b.

  According to this embodiment, since the side of the module adjacent to the fuel gas supply hole 417a and the side of the module adjacent to the fuel gas supply hole 417b are opposed to each other, localization of impurities such as nitrogen gas is suppressed. it can.

  According to the present embodiment, since fuel gas is supplied from one fuel gas supply manifold to one fuel gas supply hole, there is no need to pipe from one fuel gas supply manifold to a plurality of fuel gas supply holes. The battery structure is simplified.

Modification 1:
Modification 1 will be described with reference to the drawings. FIG. 9 is an explanatory view schematically showing a fuel cell frame according to the first modification. Components having the same functions as those of the present embodiment are denoted by the same reference numerals, different points from the present embodiment will be described, and descriptions of common points will be omitted.

  The fuel cell according to Modification 1 is different from the fuel cell according to this embodiment in the arrangement of the fuel gas supply holes 417a and 417b. That is, in Modification 1, the fuel gas supply hole 417a is disposed adjacent to the first short side of the anode facing plate 410, and the fuel gas supply hole 417b is disposed adjacent to the other short side of the anode facing plate 410. (Not shown).

  In the first modification, the fuel gas supplied from the fuel gas supply hole 417a flows in the porous body 540 from the short side to the center, that is, in the direction of the arrow 600a (from left to right in FIG. 9). On the other hand, the fuel gas supplied from the fuel gas supply hole 417b similarly flows in the porous body 540 from the short side to the center, that is, in the direction of the arrow 600b (from right to left in FIG. 9). At this time, the fuel gas supplied to the porous body 540 through the fuel gas supply hole 417a and the fuel gas supplied to the porous body 540 through the fuel gas supply hole 417b collide with each other near the center of the module 100 and mixed with each other. To do.

  Also in the first modification, the fuel gas is supplied in the two directions indicated by the arrows 600a and 600b, so that impurities such as nitrogen gas are not easily localized. Therefore, the power generation efficiency of the fuel cell can be improved.

  In addition, when a present Example and the modification 1 are compared, the present Example is more preferable because the power generation voltage of the fuel cell is less likely to decrease. In the fuel cell according to the first modification, the side adjacent to the fuel gas supply hole 417a and the fuel gas supply hole 417b is the short side of the module 100. In the fuel cell, the side where the fuel gas supply hole 417a and the fuel gas supply hole 417b are adjacent is the long side of the module, so the flow path length through which the fuel gas flows is short. As a result, the present embodiment can more easily suppress the localization of impurities such as nitrogen gas and improve the power generation efficiency of the fuel cell.

Modification 2:
A fuel cell according to Modification 2 will be described with reference to FIG. FIG. 10 is an explanatory view schematically showing a fuel cell according to Modification 2. Since the modification 2 is different from the present embodiment only in the fuel gas supply system, only the differences will be described. In addition, the same code | symbol is attached | subjected about the thing of the same function as a present Example. In the present embodiment, the pipe 305 is branched between the valve 310 and the fuel cell 10, but the modification 2 is different in that the valves 310 a and 310 b are provided between the branch 305 a and the fuel cell 10. According to the modified example 2, since the amount of fuel gas supplied to the fuel gas supply manifolds 11a and 11b can be controlled, localization of impurities such as nitrogen gas can be suppressed.

  The operation of the fuel cell according to Modification 2 will be described with reference to FIG. FIG. 11 is an explanatory view schematically showing the operation of the fuel cell according to Modification 2.

(A) The fuel gas supply pressure control unit 315 opens the valve 310a and closes the valve 310b. The fuel gas is supplied to the fuel gas supply manifold 11a and is not supplied to the fuel gas supply manifold 11b. The flow of the fuel gas is in the direction of the arrow 600a as shown in FIG. At this time, impurities such as nitrogen are localized on the fuel gas supply manifold hole 565b side of the porous body 540.

(B) Next, the fuel gas supply pressure control unit 315 closes the valve 310a and opens the valve 310b. The fuel gas is consumed on the fuel gas supply manifold hole 565a side of the MEGA. On the other hand, the fuel gas is supplied to the porous body 540 from the fuel gas supply manifold hole 565b. As a result, as shown in FIG. 11B, impurities such as nitrogen are pushed by the fuel gas and move from the vicinity of the fuel gas supply manifold hole 565b of the porous body 540 toward the fuel gas supply manifold hole 565a and diffuse. .

(C) After a while, impurities such as nitrogen are localized on the fuel gas supply manifold hole 565a side of the porous body 540 as shown in FIG. 11 (c).

(D) The fuel gas supply pressure control unit 315 opens the valve 310a and closes the valve 310b. The fuel gas is consumed on the fuel gas supply manifold hole 565b side of the MEGA. On the other hand, the fuel gas is supplied to the porous body 540 from the fuel gas supply manifold hole 565a. As a result, as shown in FIG. 11D, impurities such as nitrogen are pushed by the fuel gas and move from the vicinity of the fuel gas supply manifold hole 565a of the porous body 540 toward the fuel gas supply manifold hole 565b and diffuse. .

Thereafter, (a) → (b) → (c) → (d) → (a) is repeated.
As described above, according to the second modification, the localization of impurities such as nitrogen can be further suppressed by changing the supply amount of the fuel gas supplied to the respective fuel gas supply manifolds 11a and 11b. As a result, the power generation efficiency of the fuel cell can be improved. When closing the valve 310a or 310b, a small amount of fuel gas may be allowed to flow without being completely closed. Since a large amount of fuel gas and a small amount of fuel gas are alternately supplied, localization of impurities such as nitrogen can be suppressed.

Modification 3:
Modification 3 will be described with reference to FIG. FIG. 12 is an explanatory view schematically showing a fuel cell according to Modification 3. Since the modification 3 is different from the present embodiment only in the fuel gas supply system, only different points will be described. In addition, while having the same code | symbol about the same function as a present Example, description to description and drawing is abbreviate | omitted. In Modification 3, the lengths of the pipes 305b and 305c from the branch of the pipe 305 to the fuel gas supply manifolds 11a and 11b are different. That is, in Modification 3, the pipe 305b is shorter than the pipe 305c. That is, the pressure loss in the pipe 305b is different from the pressure loss in the pipe 305c. As a result, since the delay with respect to the pressure wave generated by opening and closing the valve 310 is different, the fuel gas can be pulsated by opening and closing the single valve 310, and localization of impurities such as nitrogen can be suppressed.

Modification 4:
Modification 4 will be described with reference to FIG. FIG. 13 is an explanatory view schematically showing a fuel cell according to Modification 4. Since the modified example 4 is different from the present embodiment only in the fuel gas supply system, only different points will be described. In addition, about the thing of the same function as a present Example, the same code | symbol is attached | subjected and some drawings are abbreviate | omitted. In Modification 4, the pipes 305d and 305e have different thicknesses from the branching pipe 305 to the fuel gas supply manifolds 11a and 11b. That is, in the modified example 4, the pipe 305d is thicker than the pipe 305e. That is, the pressure loss in the pipe 305d is different from the pressure loss in the pipe 305e. As a result, since the delay with respect to the pressure wave generated by opening and closing the valve 310 is different, the fuel gas can be pulsated by opening and closing the single valve 310, and localization of impurities such as nitrogen can be suppressed.

Modification 5:
Modification 5 will be described with reference to FIG. FIG. 14 is an explanatory view schematically showing a fuel cell according to Modification 5. The modified example 5 is different from the example in the positions of the fuel gas supply hole 417a and the fuel gas supply hole 417b. That is, in this embodiment, the fuel gas supply hole 417a and the fuel gas supply hole 417b are in a line-symmetrical position with respect to the bisector running in the longitudinal direction. They are not in line symmetry with respect to a bisector running in the direction. As a result, since the fuel gas strikes away, localization of impurities such as nitrogen is difficult to occur.

Modification 6:
In the present embodiment, the fuel gas supply hole 417a and the fuel gas supply hole 417b are a plurality of holes arranged at a predetermined interval. For example, the plurality of holes may be integrated into one elongated hole. Ventilation resistance when passing through the fuel gas supply hole 417a and the fuel gas supply hole 417b can be reduced.

Modification 7:
In the present embodiment, a three-layer separator has been described as an example of the separator 400, but the configuration and shape of the separator 400 can be any other configuration and shape. For example, a carbon separator having a shape with grooves formed on the surface may be used.

Modification 8:
In this embodiment, the timing for changing the supply amount of the fuel gas has not been described. However, for example, the supply amount of the fuel gas may be changed when the fuel cell is started. At the start of the fuel cell, impurities such as nitrogen that have leaked from the cathode side through the membrane electrode assembly are diffused into the fuel gas supply manifolds 11a and 11b. When fuel gas is supplied in this state, impurities such as nitrogen are easily pushed and localized by the fuel gas, but by supplying the fuel gas while changing the supply amount, the flow of the fuel gas in the gas flow path is changed. And localization of impurities such as nitrogen can be suppressed. The supply amount of the fuel gas may be changed according to the nitrogen amount at the start, and the connection timing of the load to the fuel cell 10 may be changed according to the nitrogen amount at the start.

Modification 9:
In this embodiment, the anode-side gas diffusion layer 530 and the porous body 540 are divided, but they may have an integral structure. This is because the fuel gas flows in the same way. The same applies to the cathode side.

Modification 10:
In this embodiment, two fuel gas supply manifolds are provided. However, for example, one fuel gas supply manifold may be provided, and fuel gas may be supplied to a plurality of fuel gas supply holes by a common rail. Also by this, fuel gas can be supplied from two directions.

Modification 11:
In this embodiment, the fuel gas discharge manifold is not provided. However, for example, a fuel gas discharge manifold, an exhaust pipe connected to the fuel gas discharge manifold, and a valve disposed on the exhaust pipe may be provided. . As a result, a small amount of fuel gas can be exhausted during non-stationary conditions.

Modification 12:
In the above-described embodiment, a structure in which almost all of the fuel gas supplied to the anode is consumed by the anode is adopted. However, as a fuel supply flow path configuration to the anode that enables operation with such a structure. Various configurations can be adopted. In addition to the above-described configuration (hereinafter referred to as “shower channel type”), a typical channel configuration includes a comb-type configuration and a circulation-type configuration. First, a modified example of the shower channel type will be described.

First modification of fuel gas flow path:
FIG. 15 is an explanatory diagram showing a configuration of a first modification of the fuel gas flow path. The first modification of the fuel gas flow path has a configuration in which a dispersion plate 2100 corresponding to the shower plate of the above-described embodiment is formed integrally with the membrane electrode assembly 2000. The membrane electrode assembly 2000 has a hydrogen side electrode 2200 and an electrolyte membrane 2300. The dispersion plate 2100 is provided with a large number of pores (orifices) 2110 at predetermined intervals.

  FIG. 16 is an explanatory diagram for explaining the function of the dispersion plate 2100. The fuel gas is distributed in the upstream flow path isolated from the hydrogen side electrode 2200 that consumes the hydrogen gas by the dispersion plate 2100. The fuel gas distributed in the upstream flow path is locally supplied to the hydrogen side electrode 2200 that is the fuel gas consumption layer through the pores 2110 provided in the dispersion plate 2100. That is, in this modification, the fuel gas is directly supplied to the hydrogen-side electrode 2200 at a site corresponding to the position where the pores 2110 are present. As a configuration for realizing such local fuel gas supply, for example, a configuration in which the fuel gas is directly supplied to a portion that consumes the fuel gas without passing through the other region of the hydrogen side electrode 2200, Alternatively, a configuration in which fuel gas is mainly supplied in a direction perpendicular to the hydrogen side electrode 2200 from a direction away from the surface of the hydrogen side electrode 2200 (preferably a flow path isolated from the hydrogen side electrode 2200) may be employed. It is. On the other hand, the hydrogen side electrode 2200 may have a shape in which the retention of nitrogen hardly occurs. For example, it may be formed of a smooth surface (flat surface) and may have a shape that does not have a recess or the like on the electrolyte membrane 2300 side.

  The diameter and pitch of the pores 2110 of the dispersion plate 2100 can be determined experimentally. For example, in a predetermined operation state (for example, a rated operation state), the flow rate of the fuel gas passing through the pores 2110 is the diffusion of nitrogen gas. It may be possible to sufficiently suppress the backflow due to. In order to satisfy such a condition, the interval between the pores 2110 and the flow path cross-sectional area may be set so that a sufficient flow velocity or sufficient pressure loss occurs in the pores 2110. For example, in a polymer electrolyte fuel cell, it has been confirmed that a sufficient flow velocity or a sufficient pressure loss occurs when the aperture ratio of the dispersion plate 2100 is set to about 1% or less. The aperture ratio is a ratio obtained by dividing the opening area of the dispersion plate 2100 by the total area of the dispersion plate 2100. Such an opening ratio is about one to two digits less than that of the circulation type fuel gas flow path, and therefore the configuration in which the flow rate of the fuel gas is secured by using a compressor in the circulation type fuel gas flow path is essential. Is different. In this embodiment and the modified example, sufficient fuel gas can be obtained even in a structure with a low opening ratio by introducing high-pressure hydrogen from the fuel tank directly (or in a state in which the pressure is adjusted to a predetermined high-pressure by a pressure-regulating valve) to the fuel cell. Is secured.

Second modification of fuel gas flow path:
Next, another configuration example of the above-described shower channel type will be described. FIG. 17 is an explanatory diagram showing a configuration of a second modification of the fuel gas flow path. In this modification, a dispersion plate 2101 disposed on a membrane electrode assembly 2201 including a hydrogen side electrode 2200 and an electrolyte membrane 2300 is realized using a dense porous body. The aperture ratio of the porous body of the dispersion plate 2101 is selected so that a sufficient flow rate or a sufficient pressure loss occurs. When the pores are used, the fuel gas is locally supplied for each pore, so to speak, while the fuel gas is locally supplied, whereas when the porous body is used, the fuel gas is continuously supplied. Has the advantage of being able to. Further, there is an advantage that the supply of the fuel gas to the hydrogen side electrode 2200 is made more uniform. The dense porous body may be manufactured by sintering carbon powder, or may be manufactured by hardening a carbon component or metal powder using a binding agent. The porosity may be a continuous porous body, and may have anisotropy that ensures continuity in the thickness direction and does not ensure continuity in the surface direction. What is necessary is just to determine similarly to the modification 1 about the aperture ratio of a porous body.

Third modification of fuel gas flow path:
Next, a third modification of the fuel gas channel will be described. FIG. 18 is an explanatory view showing a dispersion plate 2102 constituted by using press metal, and FIG. 19 is a schematic view showing a CC cross section thereof. The dispersion plate 2102 includes a protrusion 2102t for forming a flow path on the upstream side of the dispersion plate 2102, and a pore 2112 is formed on a side surface of the protrusion 2102t. This dispersion plate 2202 is disposed on the hydrogen side electrode 2200 side of the membrane electrode assembly 2202 provided with the hydrogen side electrode 2200 and the oxygen side electrode 2400 on both sides of the electrolyte membrane 2300. As shown in FIG. A flow path on the upstream side of the dispersion plate 2102 is integrally formed using the protrusion 2102t. The fuel gas is supplied to the hydrogen side electrode 2200 via the pores 2112 formed on the side surface of the protrusion 2102t.

  According to such a configuration, it is possible to easily form the dispersion plate 2102 by pressing, and to obtain an advantage that the flow path upstream of the dispersion plate 2102 can be easily formed. The fuel gas that has passed through the pores 2112 reaches the hydrogen-side electrode 2200 through the space inside the protrusion 2102t, so that sufficient dispersibility can be ensured. The pores 2112 may be formed by press working, or may be formed by other methods such as electric discharge machining in a pre-process or a post-process of forming the protrusion 2102t. What is necessary is just to determine the aperture ratio by the pore 2112 similarly to the modification 1.

Fourth modification of fuel gas flow path:
Next, a fourth modification example of the fuel gas flow channel will be described. FIG. 20 is an explanatory diagram illustrating a configuration example in which a flow path is formed inside the dispersion plate 2014hm. The dispersion plate 2014hm of this modification is provided in the thickness direction of the dispersion plate 2014hm from the plurality of flow channels 2142n formed in the short direction of the rectangular dispersion plate 2014hm, and is not shown in the drawing. A large number of pores 2143n opened on the hydrogen electrode side. The dispersion plate 2014hm is disposed on the hydrogen side electrode side of the membrane electrode assembly 2203 including the hydrogen side electrode (not shown) and the oxygen side electrode 2400 on both sides of the electrolyte membrane 2300, and the dispersion plate 2014hm passes through the dispersion plate 2014hm. Receive fuel gas supply. According to such a configuration, there is an advantage that a flow path to each pore 2143n can be individually prepared. In FIG. 20, the pores 2143n are arranged in a staggered pattern, but may be arranged in a lattice pattern or may be randomly arranged to some extent.

A fifth modification of the fuel gas flow path:
Next, a fifth modification of the fuel gas channel will be described. FIG. 21 is an explanatory diagram showing an example in which a dispersion plate 2014hp is formed using a pipe. As shown in FIG. 21, the dispersion plate 2014hp includes a rectangular frame 2140, and includes a large number of hollow pipes 2130 in the short direction. A plurality of pores 2141n are formed on the surface of the pipe 2130. The dispersion plate 2014hp is installed on the hydrogen side electrode 2200 of the membrane electrode assembly 2204 including the hydrogen side electrode 2200 and the electrolyte membrane 2300. When fuel gas is supplied from the gas inlet provided in the frame 2140 of the dispersion plate 2014hp, the fuel gas passes through the inside of each pipe 2130 of the dispersion plate 2014hp and is distributed from the pores 2141n to the hydrogen side electrode 2200. . According to such a configuration, in addition to being able to uniformly disperse the fuel gas, there is an advantage that it is not necessary to perform drilling except for the pores 2141n to configure the dispersion plate 2014hp. The pores 2141n may be disposed toward the hydrogen side electrode 2200 side, or may be disposed toward the opposite side. In the latter case, the dispersibility of the fuel gas is further improved.

  As described above, various configurations can be adopted as long as the fuel gas is guided to the hydrogen side electrode 2200 while being dispersed. The dispersion plate is not limited to a porous body or a press metal, and may be configured to guide the fuel gas to the hydrogen side electrode 2200 while distributing the fuel gas.

A sixth modification of the fuel gas flow path:
FIG. 22 is a schematic diagram showing a configuration example using a so-called branch channel type fuel gas channel. The illustrated fuel gas flow path is formed in a comb-like shape on a flow path forming member 5000 used in place of the anode-side porous body 540 of the above-described embodiment. Specifically, the gas flow path includes a main flow path 5010 for introducing fuel gas, a plurality of sub flow paths 5020 branched from the main flow path and formed in a direction intersecting with the main flow path 5010, and the sub flow paths. To a comb-tooth channel 5030 that further branches into a comb-tooth shape. Since the main flow path 5010 and the sub flow path 5020 have a sufficient flow path cross-sectional area as compared with the comb-shaped flow path 5030 at the tip, the pressure distribution in the surface of the flow path forming member 5000 is the same as that of the porous body 540. It is about the same or less.

  The flow path forming member 5000 can be formed using carbon, metal, or the like. In the case of using carbon, the flow path forming member 5000 having the flow path shown in FIG. 22 can be obtained by sintering the carbon powder at a high temperature or low temperature using a mold. In the case of using a metal, the flow path forming member 5000 having the same flow path may be formed by cutting a groove from the metal plate, or the flow having the flow path shown in the figure may be formed by pressing. A path forming member 5000 may be obtained. The flow path forming member 5000 does not have to be provided as a single product, and can be formed integrally with another member, for example, a separator.

  The flow path forming member 5000 may be used in place of the porous body 540, but may be replaced with the porous body 540 and the anode side gas diffusion layer 530. In this case, the comb-tooth channel 5030 may be a sufficiently narrow channel, and the sub-channel 5020 may be branched into a large number of so-called capillaries. In FIG. 22, the main flow path 5010 is provided along one edge of the flow path forming member 5000. However, in order to reduce the pressure difference of the fuel gas in the flow path forming member 5000, a plurality of main flow paths 5010 are provided. The sub-channel 5020 may be shortened, or the main channel 5010 may be provided at the center of the channel-forming member, and the sub-channel 5020 may be disposed on the left and right of the main channel 5010. . Similarly, the comb channel 5030 may be provided on both sides of the sub channel 5020. Furthermore, as shown in FIG. 23, a plurality of gas flow path systems including a main flow path 5010, sub flow paths 5020, and comb-tooth flow paths 5030 may be provided. FIG. 23 is a configuration diagram when a plurality of gas flow path systems are used. In this case, in any one of the gas flow path systems, at least one of the main flow path 5010, the sub flow path 5020, and the comb tooth flow path 5030, the main flow path 5010, the sub flow path 5020, and the comb tooth of the other flow path system. You may make it cross the flow path 5030.

Seventh modification of the fuel gas flow path:
Next, a serpentine type flow path configuration will be described with reference to FIG. FIG. 24 is a schematic diagram schematically illustrating a configuration example of a flow path forming member including a serpentine type flow path in which the flow path has a twisted shape. FIG. 24A illustrates a flow path forming member 5100 having a single fuel gas flow path, and FIG. 24B illustrates a flow path forming member in which a plurality of fuel gas flow paths are integrated. 5200 is illustrated.

  As shown in the figure, the flow path forming member 5100 illustrated in FIG. 24A has a plurality of flow channels alternately extended inward from the opposed outer walls 5110 and 5115 among the outer walls surrounding the fuel gas flow path. A road wall 5120 is provided. The part divided by the flow path wall 5120 is a continuous flow path. An inlet 5150 is formed at one end, and the fuel gas is supplied from here to the flow path. This flow path forming member 5100 is used in place of the porous body 840 of the above-described embodiment, similarly to the flow path forming member 5000 of FIG.

  FIG. 24B shows an example in which this serpentine channel is configured as a bundle of a plurality of channels. In this case, partition walls 5230 and 5240 that are not connected to the outer walls 5210 and 5215 are provided between the plurality of flow path walls 5220 alternately extended inward from the outer walls 5210 and 5215. An inflow port 5250 is formed at the entrance of the flow path. The fuel gas that has flowed in from the inflow port 5250 flows through the wide serpentine type flow path provided with the partition walls 5230 and 5240 and spreads all over the surface direction of the flow path forming member 5200. This flow path forming member 5200 is used in place of the porous body 540 of the above-described embodiment, similarly to the flow path forming member 5000 of FIG.

  The flow path forming members 5100 and 5200 shown in FIG. 24 are made of carbon or metal in the same manner as the flow path forming member 5000 having the comb-shaped flow paths shown in FIG. The formation method is also the same. These flow path forming members 5100 and 5200 do not need to be provided as a single product, and can be formed integrally with other members, for example, a separator.

  In addition, as shown in FIG. 25, you may comprise so that gas may be supplied from the both ends of a serpentine type flow path. FIG. 25 is an explanatory diagram showing an example in which gas is supplied from both ends of the serpentine type channel.

Eighth modification of fuel gas flow path:
FIG. 26 is an explanatory view schematically showing an internal configuration of a circulation path type fuel cell 6000 as one of modifications of the fuel gas supply mode. As shown in the figure, in the fuel cell 6000 of this modification, the anode separator 6200 is provided with a recess 6220 serving as a fuel gas flow path, a fuel gas inlet port 6210, and a regulating plate 6230. The recess 6220 serving as the fuel gas flow path is formed over a region facing the anode 6100 of the membrane electrode assembly of the anode separator 6200. A nozzle 6300 is attached to the fuel gas inlet port 6210 of the anode separator 6200 so that the fuel gas can be ejected toward the recess 6220. By ejecting the fuel gas from the nozzle 6300, the fuel gas is supplied from the fuel gas inlet port 6210 into the recess 6220. The regulating plate 6230 is a member that regulates the flow direction of the fuel gas, and is erected from the bottom surface of the recess 6220 from the vicinity of the nozzle 6300 toward the center of the recess 6220. The end of the restriction plate 6230 on the side close to the nozzle 6300 is curved in accordance with the shape of the side surface of the nozzle 6300, and forms a passage A with the nozzle 6300.

  In such a fuel cell 6000, when the fuel gas supplied from the fuel gas inlet port 6210 is injected into the fuel gas flow path (recess 6220) from the injection hole 6320 of the nozzle 6300, the fuel gas is supplied to the anode side. The flow direction is regulated by the inner wall of the recess 6220 of the separator 6200 and the regulating plate 6230, and flows from the upstream side shown in the figure to the downstream side along the surface of the anode 6100 as shown by the white arrow in the figure. . At this time, due to the ejector effect generated by the high-speed fuel gas ejected from the nozzle 6300, the fluid containing the fuel gas and the impurity gas on the downstream side is separated from the gap (passage A) between one end of the restriction plate 6230 and the nozzle 6300. ) And circulates upstream. By doing so, the retention of the fluid on the fuel gas flow path and the anode 6120 surface can be suppressed.

  In the fuel cell 6000 of the eighth modification of the fuel gas flow path, the fluid is circulated in the direction along the surface of the anode 6100 using the ejector effect. Other configurations may be used as long as the fluid can be circulated in the direction along the surface of the anode. For example, in the fuel cell 6000, instead of the nozzle 6300 and the regulation plate 6230, a rectifying plate is provided in a portion that can be a fuel gas flow path such as in the surface of the anode separator 6200 or the anode 6100, and this rectifying plate, The fluid may be circulated in the direction along the surface of the anode 6100 by the flow of the fuel gas. Alternatively, a structure may be adopted in which a minute actuator (for example, a micromachine) is incorporated in a gas flow path such as the recess 6220 along the circulation path to cause circulation of the fuel gas. In addition, a configuration in which a temperature difference is provided in the recess 6220 to cause circulation using convection is also conceivable.

  Further, as shown in FIG. 27, a plurality of nozzles may be provided, and the restriction plate 6230 and the nozzles 6300a and 6300b may be arranged at point-symmetric positions. FIG. 27 is an explanatory view showing an example in which nozzles are arranged at point-symmetric positions. Due to the ejector effect generated by the high-speed fuel gas ejected from the nozzle 6300a, the fluid containing the fuel gas and the impurity gas on the downstream side of the gas ejected from the nozzle 6300b is allowed to flow between one end of the regulating plate 6230 and the nozzle 6300a. It is sucked from the gap (passage A) and flows upstream of the fuel gas ejected from the nozzle 6300a. Due to the ejector effect generated by the high-speed fuel gas ejected from the nozzle 6300b, the fluid containing the fuel gas and the impurity gas on the downstream side of the gas ejected from the nozzle 6300a is allowed to flow between one end of the regulating plate 6230 and the nozzle 6300b. It is sucked from the gap (passage B) and flows upstream of the fuel gas ejected from the nozzle 6300b. By doing so, the retention of the fluid on the fuel gas flow path and the anode 6120 surface can be suppressed.

Modification 13:
In the fuel cell of the above embodiment, the cathode-side oxidizing gas supply channel is formed by a single-layer cathode-side porous body 545, but the configuration of the oxidizing gas supply channel is not limited to this. For example, the oxidizing gas supply channel may be formed in a straight type or a serpentine type using a rib, or may be formed using a plurality of dimples. In this way, the oxidizing gas supply channel can be formed with a simple configuration. An appropriate configuration may be employed in accordance with the configuration of the entire fuel cell, usage conditions, and the like.

Modification 14:
Next, start-up control of the fuel cell of the above embodiment will be described. In the fuel cell of the modified example, at the time of start-up, supply of fuel gas is started to the anode-side fuel gas flow path, and after a predetermined time TA has elapsed, a load is connected for the first time and current is taken out from the fuel cell. In this way, the leaked gas (nitrogen gas or inert gas) leaking from the cathode side to the anode side after the end of power generation of the fuel cell is retained at the cathode pressure at the fuel gas pressure for a predetermined time TA. The load is connected after being pushed back to the side and the leakage gas retention amount is reduced. Therefore, in the anode side catalyst layer 520, the occurrence of a situation where the fuel cell is deficient when the fuel cell is started can be suppressed. Note that “starting” in this case refers to supplying reaction gas (fuel gas and oxidizing gas) to the fuel cell and connecting a load to the fuel cell. The reason why the leak gas stays on the anode side when the fuel cell is stopped is that the fuel gas pressure on the anode side decreases as a result of stopping the supply of the fuel gas. In particular, when an anode dead end configuration is adopted, it is not possible to expect leakage gas to be discharged into the discharge path by supplying fuel gas. Therefore, it is effective to secure a sufficient time TA from the start of the supply of the fuel gas until the load is connected.

Modification 15:
At the time of starting the fuel cell, at least one of the supply amount of the fuel gas and the predetermined time TA until the electrical load is connected is determined based on the leak gas retention amount at the start of operation of the fuel cell. It is also possible. For example, the leakage gas retention amount may be estimated from the fuel cell stop period and the temperature of the fuel cell from the end of the previous start to the current start in the fuel cell. The temperature of the fuel cell can be detected based on, for example, the temperature of the refrigerant that cools the fuel cell. In this way, it is possible to reduce the amount of leaked gas in the anode-side fuel gas flow path while reducing the start time of the fuel cell.

  Further, the timing for connecting the load when starting the fuel cell may be determined based on the hydrogen concentration on the anode side. In the fuel cell of the above embodiment, the hydrogen concentration sensor is attached to a predetermined portion in the anode-side fuel gas flow path, and at the time of start-up, the supply of fuel gas to the anode-side fuel gas flow path is started, and then the hydrogen concentration The hydrogen concentration value detected from the sensor is monitored. If an electrical load is connected when the hydrogen concentration value is higher than a predetermined threshold value, the anode-side catalyst layer 520 can be prevented from performing a hydrogen-deficient operation. In addition, a configuration in which the timing of electrical load connection is obtained from the pressure and temperature on the anode side is also possible.

  In the description of the above-described embodiments and modifications, a solid polymer fuel cell using a membrane electrode assembly as a power generator has been described as an example. However, the types of fuel cells to which the present invention can be used are not limited thereto. I can't. Needless to say, the present invention can also be used for fuel cells other than solid polymer types such as phosphoric acid type, solid oxide type, and molten carbonate type.

  The embodiments of the present invention have been described above based on some examples. However, the above-described embodiments of the present invention are for facilitating the understanding of the present invention and limit the present invention. It is not a thing. The present invention can be changed and improved without departing from the spirit and scope of the claims, and it is needless to say that the present invention includes equivalents thereof.

It is explanatory drawing which shows typically the structure of the fuel cell which concerns on a present Example. It is explanatory drawing which shows the shape of an anode opposing plate typically. It is explanatory drawing which shows the shape of an intermediate | middle plate typically. It is explanatory drawing which shows the shape of a cathode opposing plate typically. It is explanatory drawing which shows typically a cross section when the fuel cell 10 is cut in the position of the AA cutting line shown in FIGS. It is explanatory drawing which shows typically a cross section when the fuel cell 10 is cut in the position of the BB cutting line shown in FIGS. 4 is an explanatory diagram schematically showing a planar configuration of a frame 550. FIG. It is a graph which shows the time dependence of the electric power generation voltage of a fuel cell. FIG. 10 is an explanatory diagram showing a configuration of a fuel cell frame 550 and a flow of fuel gas according to Modification 1; FIG. 10 is an explanatory diagram schematically showing a fuel cell according to Modification 2. 10 is an explanatory diagram schematically showing the operation of a fuel cell according to Modification 2. FIG. 10 is an explanatory view schematically showing a fuel cell according to Modification 3. FIG. It is explanatory drawing which shows typically the fuel cell which concerns on the modification 4. FIG. FIG. 10 is an explanatory diagram schematically showing a fuel cell according to Modification Example 5. It is explanatory drawing which shows the structure of the 1st modification of a fuel gas flow path. FIG. 11 is an explanatory diagram for explaining the function of a dispersion plate 2100. It is explanatory drawing which shows the structure of the 2nd modification of a fuel gas flow path. Explanatory drawing which shows the dispersion plate 2102 comprised using the press metal. It is a schematic diagram which shows CC cross section of the dispersion plate 2102 comprised using the press metal. It is explanatory drawing which shows the structural example which formed the flow path inside the dispersion | distribution board 2014hm. It is explanatory drawing which shows the example which formed the dispersion plate 2014hp using the pipe. It is a schematic diagram which shows the structural example using what is called a branched flow path type fuel gas flow path. It is a block diagram at the time of using a several gas flow path system. It is a schematic diagram which shows typically the example of a structure of the flow-path formation member provided with the serpentine type flow path in which the flow path has taken the shape of a cramp. It is explanatory drawing which shows the example in which gas was supplied from the both ends of the serpentine type flow path. 6 is an explanatory diagram schematically showing an internal configuration of a circulation path type fuel cell 6000. FIG. It is explanatory drawing which shows the example which has arrange | positioned the nozzle in the point symmetrical position. It is explanatory drawing which shows the other structural example (the 1). It is explanatory drawing which shows the other structural example (the 2).

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Fuel cell 11a ... Fuel gas supply manifold 11b ... Fuel gas supply manifold 100 ... Module 200 ... End plate 210 ... Current collecting plate 220 ... Insulation plate 230 ... Tension plate 240 ... Bolt 300 ... Hydrogen storage container 305 ... Piping 305a ... Branch 305b ... Pipe 305c ... Pipe 305d ... Pipe 305e ... Pipe 310 ... Valve 310a ... Valve 310b ... Valve 315 ... Fuel gas supply pressure control unit 330 ... Pump 340 ... Oxidant gas supply pipe 350 ... Oxidant gas discharge pipe 360 ... Radiator 370 ... Pump 380 ... Pipe 400 ... Separator 410 ... Anode facing plate 415a ... Fuel gas supply manifold hole 415b ... Fuel gas supply manifold hole 417a ... Fuel gas supply hole 417b ... Fuel gas supply hole 420 ... Converted gas supply manifold hole 425 ... Oxidizing gas discharge manifold hole 430 ... Cooling medium supply manifold hole 435 ... Cooling medium discharge manifold hole 440 ... Intermediate plate 445c direction ... Fuel gas supply communication hole 445a ... Fuel gas supply manifold hole 445b ... Fuel gas supply Manifold hole 445c ... Fuel gas supply communication hole 445d ... Fuel gas supply communication hole 450 ... Oxidation gas supply manifold hole 450a ... Oxidation gas supply communication hole 450b ... Oxidation gas supply communication hole 455 ... Oxidation gas discharge manifold hole 455a ... Oxidation gas discharge communication Hole 460 ... Cooling medium hole 470 ... Cathode facing plate 475a ... Fuel gas supply manifold hole 475b ... Fuel gas supply manifold hole 480 ... Oxidation gas supply manifold hole 482 ... Oxidation gas supply hole 485 ... Oxidation gas discharge Nihold hole 487 ... oxidizing gas discharge hole 490 ... cooling medium supply manifold hole 495 ... cooling medium discharge manifold hole 500 ... power generation section 515 ... electrolyte membrane 520 ... anode side catalyst layer 525 ... cathode side catalyst layer 530 ... anode side gas diffusion layer 535 ... cathode side gas diffusion layer 540 ... porous body 545 ... porous body 550 ... frame 550a ... seal line 555 ... opening 565a ... fuel gas supply manifold hole 565b ... fuel gas supply manifold hole 570 ... oxidizing gas supply manifold hole 575 ... oxidizing gas Discharge manifold hole 580 ... Cooling medium supply manifold hole 585 ... Cooling medium discharge manifold hole 600a ... Arrow 600b ... Arrow 840 ... Porous body 2000 ... Membrane electrode assembly 2014hm ... Dispersion plate 2014hp ... Dispersion plate 2100 ... Dispersion plate 2 DESCRIPTION OF SYMBOLS 01 ... Dispersion plate 2102 ... Dispersion plate 2110 ... Fine pore 2112 ... Fine pore 2130 ... Pipe 2140 ... Frame 2141n ... Fine pore 2142n ... Flow path 2143n ... Fine pore 2200 ... Hydrogen side electrode 2201 ... Membrane electrode assembly 2202 ... Membrane electrode junction Body 2203 ... Membrane electrode assembly 2204 ... Membrane electrode assembly 2300 ... Electrolyte membrane 2400 ... Oxygen side electrode 5000 ... Flow path forming member 5010 ... Main flow path 5020 ... Sub-flow path 5030 ... Comb tooth flow path 5100 ... Flow path forming member 5110 ... Outer wall 5120 ... Flow path wall 5150 ... Inlet 5200 ... Flow path forming member 5210 ... Outer wall 5220 ... Flow path wall 5230 ... Partition wall 5250 ... Inlet 6000 ... Fuel cell 6100 ... Anode 6200 ... Anode side separator 6210 ... Fuel gas inlet Port 6220 ... Recess 6230 ... Restriction plate 6300 ... Zur 6300a ... nozzle 6300b ... nozzle 6320 ... injection hole

Claims (15)

As a mode of operation performed by supplying fuel gas, a fuel cell module that consumes almost all of the supplied fuel gas by a power generator,
A power generator,
Gas flow paths disposed on both sides of the power generator;
A separator disposed outside the gas flow path;
A plurality of gas supply units for supplying gas from different directions to one of the gas flow paths;
A fuel cell module comprising: The fuel cell module according to claim 1, wherein
The fuel cell module, wherein the gas supply unit is disposed adjacent to an outer edge of the power generator. The fuel cell module according to claim 2, wherein
The gas supply unit supplies gas toward the central direction of the power generator,
Fuel cell module. In the fuel cell module according to claim 2 or 3,
The power generation body has an outer edge defined by a plurality of sides intersecting each other,
Of the plurality of gas supply units, the first gas supply unit is disposed adjacent to the first side of the plurality of sides of the power generation body, and the other gas supply unit is the first side. A fuel cell module disposed adjacent to a different second side. The fuel cell module according to claim 4, wherein
The fuel cell module, wherein the first side and the second side face each other. The fuel cell module according to claim 5, wherein
The power generator is rectangular,
The fuel cell module, wherein the first side and the second side are long sides. A fuel cell obtained by stacking the fuel cell modules according to any one of claims 1 to 6,
The fuel cell module is
A fuel gas supply manifold hole;
A communication passage connecting the fuel gas supply manifold hole and the gas supply unit;
The fuel cell
A fuel gas supply manifold formed by the fuel gas supply manifold hole and penetrating in the stacking direction of the fuel cell module;
A fuel tank,
A pipe connecting the fuel tank and the fuel gas supply manifold;
A fuel gas supply amount adjusting unit that is arranged in the pipe and changes a supply amount of fuel gas supplied from the fuel tank to the fuel gas supply manifold;
A fuel cell comprising: The fuel cell according to claim 7, wherein
A fuel cell comprising a plurality of fuel gas supply manifolds. The fuel cell according to claim 8, wherein
A fuel cell comprising the fuel gas supply amount adjusting unit for each of the plurality of fuel gas supply manifolds. The fuel cell according to claim 8, wherein
Each having piping to the plurality of fuel gas supply manifolds,
A fuel cell in which the pressure loss of the first pipe connected to the first fuel gas supply manifold is different from the pressure loss of the second pipe connected to the second fuel gas supply manifold. . The fuel cell according to claim 10, wherein
A fuel cell, wherein a flow path length of the first pipe is different from a flow path length of the second pipe; The fuel cell according to claim 10 or 11,
The fuel cell, wherein the first piping and the second piping are different. The fuel cell according to any one of claims 7 to 12,
A fuel cell comprising control means for controlling the fuel gas supply amount adjusting unit. The fuel cell according to claim 13, wherein
The said control means is a fuel cell which controls so that the fuel gas supply amount to these fuel gas supply manifolds may differ. The fuel cell according to any one of claims 7 to 14,
The said control means is a fuel cell which changes fuel gas supply amount at the time of the start of a fuel cell, or when the load with respect to a fuel cell changes.

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