JP2009026521A - Fuel cell system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress deterioration of a fuel cell performance in a fuel cell which includes a mode to consume almost all fuel gas supplied in an anode side as a mode of operation to be supplied with the fuel gas. <P>SOLUTION: The fuel cell system 1000 is provided with a fuel cell 100 and a reservoir part 48, and a fuel gas passage forming part arranged on the anode side is provided with a non-reaction fluid guide passage which guides non-reaction fluid staying in the fuel gas passage forming part to the reservoir part, and the fuel cell includes a mode to consume almost all fuel gas supplied on the anode side as an operation mode to be supplied with the fuel gas. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a fuel cell system including a fuel cell.

  Some fuel cells that generate electricity by an electrochemical reaction between a fuel gas (such as hydrogen) and an oxidant gas (such as oxygen) use a solid polymer electrolyte membrane as the electrolyte membrane and air as the oxidant gas. Air contains nitrogen and the like in addition to oxygen. Therefore, in such a fuel cell, impurities such as nitrogen contained in the air may pass through the electrolyte membrane and move from the cathode side to the anode side.

  When impurities such as nitrogen are present on the anode side, the fuel gas concentration is lowered, and the output voltage may be lowered.

  In the fuel cell described above, a fuel cell that includes a mode in which almost all of the supplied fuel gas is consumed on the anode side (also referred to as anode dead-end operation) has been proposed as a mode of operation performed by supplying fuel gas. (For example, refer to Patent Document 1).

JP 2005-243476 A

  In such a fuel cell, during operation in which almost all of the supplied fuel gas is consumed on the anode side, anode exhaust gas is not discharged, so impurities such as nitrogen are collected downstream of the anode side fuel gas flow. Nitrogen etc. stay locally. If it does so, it will become difficult to supply fuel gas to the part where nitrogen etc. stay locally, and there exists a possibility that output voltage may fall remarkably.

  Accordingly, an object of the present invention is to suppress a decrease in fuel cell performance in a fuel cell including a mode in which almost all supplied fuel gas is consumed on the anode side as a mode of operation performed by supplying fuel gas. And

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

Application Example 1 A fuel cell system,
An anode-side catalyst layer and a cathode-side catalyst layer are arranged on both surfaces of the electrolyte membrane, respectively, and the anode-side catalyst layer side of the electricity-generating body is arranged for electrochemical reaction in the anode-side catalyst layer. A fuel cell comprising: a fuel gas flow path forming unit that circulates the fuel gas used and supplies the fuel gas to the anode side catalyst layer;
A reservoir for storing a non-reactive fluid that is not used in the electrochemical reaction in the anode catalyst layer;
With
The fuel gas flow path forming part is
A non-reacting fluid guide channel for guiding the non-reacting fluid staying in the fuel gas channel forming unit to the storing unit;
The fuel cell system includes a mode in which almost all of the supplied fuel gas is consumed by the anode catalyst layer as a mode of operation performed by supplying the fuel gas.

  This type of fuel cell includes a mode in which almost all of the supplied fuel gas is consumed in the anode side catalyst 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 out, and thus becomes an “anode”. Here, consuming almost all of the fuel gas means that, from the viewpoint of fuel gas consumption, it is not used such as actively taking out the fuel gas and circulating it to 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 surface 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 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 the present specification, an operation mode in which almost all fuel gas supplied to the fuel gas consumption surface is consumed on the fuel gas consumption surface side is called dead-end operation. However, the configuration is included in the dead-end operation even if a mode in which the fuel gas is extracted and used for the purpose of fuel gas consumption is added. For example, it is possible to consider a configuration in which a flow path for extracting a small amount of fuel gas from the fuel consumption surface or upstream thereof is provided, and the extracted fuel gas is burned and used for preheating such as an auxiliary machine. Unless the fuel gas is taken out from the upstream side or the upstream side of the fuel gas, the nominal consumption of the fuel gas is referred to as “fuel gas consumption of almost all fuel gas” in this specification. It is not a configuration that is excluded from “consuming in terms of aspect”.

  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. 32 and 33, for example. The configuration example of FIG. 32 has a first flow path and a second flow path. 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 body as in the examples described later. For example, sandwiching the sealing materials S1 and S2 (FIG. 32) or a honeycomb structure You may comprise as formation of the flow path which uses the material H2 (FIG. 33).

  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. 32 and 33 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).

  For example, when air is used as the oxidant gas, a gas such as nitrogen that is not used for the electrochemical reaction in the cathode side catalyst layer is included. Gas that is not used for the electrochemical reaction in the cathode side catalyst layer may pass through the electrolyte membrane and move to the anode side. Moreover, when using reformed gas etc. as fuel gas, the gas which is not used for the electrochemical reaction in an anode side catalyst layer, such as carbon monoxide, a carbon dioxide, and methane, is contained. As described above, a gas that moves from the cathode side, a gas contained in the fuel gas, and the like that is not used for an electrochemical reaction in the anode side catalyst layer is referred to as a non-reacting fluid in the present specification. Called.

  When the anode exhaust gas is stopped and operated inside the fuel cell, the anode exhaust gas is not discharged, and thus the non-reactive fluid as described above stays. In this case, the fuel gas is hardly supplied to the portion due to the staying non-reacting fluid, so that the fuel gas concentration becomes low, power generation cannot be performed in that portion, and the output voltage may be lowered.

  According to the fuel cell of this application example, the non-reacting fluid staying in the staying part is guided by the non-reacting fluid guide flow path and flows into the storing part, so that the non-reacting fluid can be swept out from the anode side. . Therefore, it is possible to suppress the deterioration of the fuel cell performance due to the non-reactive fluid locally staying.

[Application Example 2] In the fuel cell system according to Application Example 1,
The non-reacting fluid guide channel is
A fuel cell, wherein the fuel gas is disposed downstream of a main flow when the fuel gas flows through the fuel gas flow path forming portion.

  When starting the fuel cell, the non-reacting fluid is collected and stays downstream of the main flow of fuel gas by the flow of fuel gas. According to the fuel cell of Application Example 2, it is possible to efficiently guide the staying non-reacting fluid to the storage unit.

[Application Example 3] In the fuel cell system according to Application Example 1 or 2,
The fuel gas flow path forming part is
A porous body having a plurality of pores communicating with each other;
The non-reacting fluid guide channel is
A fuel cell system, wherein the fuel cell system is a part formed in a part of the porous body so as to have a high porosity.

  When the porosity is high, the gas flow is improved as compared with the portion where the porosity is low. When a portion with a high porosity is formed so as to connect the retention portion and the storage portion, the non-reactive fluid that stays in the retention portion preferentially flows into the storage portion through the portion with a high porosity. Therefore, the non-reacting fluid staying on the anode side can be swept out from the anode side.

[Application Example 4] In the fuel cell system according to Application Example 1 or 2,
The fuel gas flow path forming part is
A porous body having a plurality of pores communicating with each other;
The non-reacting fluid guide channel is
A fuel cell system comprising a groove formed on a surface of the porous body.

  When the groove is formed on the surface of the porous body, the groove has a low resistance when the gas flows, and therefore the gas flow is improved as compared with other portions of the porous body. When a groove that connects the portion where the non-reactive fluid stays and the storage portion is formed, the non-reactive fluid that stays preferentially flows into the storage portion through the groove portion. Therefore, the non-reacting fluid staying on the anode side can be swept out from the anode side.

[Application Example 4] The fuel cell system according to any one of Application Examples 1 to 3,
The reservoir is
A fuel cell system provided inside the fuel cell.

  If it does in this way, parts, such as piping which connects a fuel cell and a storage part, can be reduced, for example, the size of the whole fuel cell system can be made small, and cost reduction can be carried out.

  The present invention can be realized in various forms, for example, in the form of a fuel cell, a fuel cell system including the fuel cell, a vehicle equipped with the fuel cell system, and the like. .

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 as a first embodiment of the present invention.

  The fuel cell system 1000 according to this embodiment includes a fuel cell 100, a storage unit 48 that stores nitrogen or the like in the fuel cell 100, a hydrogen supply system that supplies hydrogen as a fuel gas, and air as an oxidant gas. An air supply / discharge system for supplying and discharging and a cooling water circulation system for cooling the fuel cell 100 are mainly provided.

  The fuel cell 100 is a solid polymer fuel cell that generates power using hydrogen and air. In the fuel cell 100, a laminated body 40 formed by laminating a plurality of power generation units 400, which will be described later, with separators 300 interposed therebetween is collected from both sides by current collecting plates 31, 32, insulating plates 21, 22, and end plates 11, 12. It is configured to be stacked so as to be sandwiched. The number of power generation units 400 stacked can be arbitrarily set according to the output required for the fuel cell 100.

  The reservoir 48 is a portion that is formed inside the fuel cell 100 and stores nitrogen or the like in the fuel cell 100 (details will be described later). A pipe 56 including an exhaust valve 57 is connected to the storage unit 48, and the nitrogen or the like in the storage unit 48 is released out of the fuel cell 100 by opening the exhaust valve 57 at a predetermined timing.

  The hydrogen supply system includes a hydrogen tank 50 and a pipe 53. The high pressure hydrogen stored in the hydrogen tank 50 is adjusted in pressure and supply amount by a shut valve 51 provided at the outlet of the hydrogen tank 50 and a regulator 52 provided in the pipe 53, It is supplied to the anode of the fuel cell 100. The fuel cell 100 is operated by stopping exhaust gas from the anode (hereinafter referred to as anode exhaust gas) inside the fuel cell 100. That is, almost all of the hydrogen supplied to the anode is used for power generation, and no piping for discharging the anode exhaust gas to the outside is provided. By doing so, it is possible to efficiently use the fuel gas, to eliminate the compressor loss due to the circulation of the fuel gas, and to improve the efficiency of the entire fuel cell system.

  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 air supply / discharge system includes a compressor 60, a pipe 61, and a pipe 62. The compressed air compressed by the compressor 60 is supplied to the cathode of the fuel cell 100 through the pipe 61 as an oxidant gas containing oxygen. Exhaust gas from the cathode (hereinafter referred to as cathode exhaust gas) is discharged to the outside through the pipe 62. In addition to the cathode exhaust gas, the pipe 62 also discharges generated water generated by an electrochemical reaction between hydrogen and oxygen at the cathode of the fuel cell 100.

  The cooling water circulation system includes a pump 70, a radiator 71, and a pipe 72. The cooling water flows through the pipe 72 by the pump 70, circulates in the fuel cell 100 to cool the fuel cell 100, is cooled again by the radiator 71, and is supplied to the fuel cell 100.

A2. Configuration of power generation unit:
FIG. 2 is a plan view showing the power generation unit 400 as viewed from the anode side, and FIG. 3 is a cross-sectional view showing a CC cut surface in FIG. As shown in FIG. 3, the power generation unit 400 of the present embodiment includes a seal member integrated MEA 420, a hydrogen flow path forming part 440, and an air flow path forming part 460.

A2.1. Structure of seal member integrated MEA:
As shown in FIGS. 2 and 3, the seal member integrated MEA 420 has an MEA 426 whose outer shape is substantially rectangular (in FIG. 2, it is hidden under the hydrogen flow path forming portion 440 for convenience of illustration). , And a seal member 428 integrally formed around the MEA 426.

  As shown in FIG. 3, the MEA 426 has an anode side catalyst layer 422 and an anode side diffusion layer 423 stacked on one surface of an electrolyte membrane 421, and a cathode side catalyst layer 424 and a cathode side diffusion layer on the other surface. 425 is a laminated membrane electrode assembly. In the MEA 426, the catalyst layer and the diffusion layer function as gas diffusion electrodes. The MEA 426 in this embodiment corresponds to the power generator in the claims.

  As shown in FIG. 2, the seal member 428 has a first hydrogen supply through hole 402s and a second hydrogen supply through hole 404s. Also, three air supply through holes 406 s and three air discharge through holes 408 s are formed. Further, a cooling water supply through hole 410s and a cooling water discharge through hole 412s are formed one by one. A seal portion is formed around each through-hole to prevent leakage of reaction gas when the fuel cell 100 is configured (indicated by a broken line in FIG. 2). As described above, since the fuel cell 100 of this embodiment is operated by stopping the anode exhaust gas inside the fuel cell 100, the hydrogen discharge through hole is not formed.

  Further, the seal member 428 is formed with one reservoir through hole 480s. As shown in FIGS. 2 and 3, a groove 429 is formed to connect a non-reacting fluid guide channel 442 formed in a hydrogen channel forming unit 440 described later and the reservoir through-hole 480 s. . In this embodiment, the groove portion 429 is formed in the seal member 428. For example, a groove that connects the non-reacting fluid guide channel 442 and the reservoir through hole 480a to the anode facing plate 310 ( Alternatively, a through hole) may be formed.

A2.2. Configuration of reaction gas flow path forming part:
As shown in FIG. 2, the hydrogen flow path forming portion 440 and the air flow path forming portion 460 are formed in a substantially rectangular flat plate shape, and as shown in FIG. Arranged to match the frame. The hydrogen flow path forming part 440 and the air flow path forming part 460 are metal porous bodies having a plurality of holes communicating with each other. The metal porous body is produced by, for example, a foam sintering method using a stainless steel powder having corrosion resistance. Instead of stainless steel, other metals such as titanium may be used, or a conductive material such as carbon may be used. Moreover, you may create a porous body by the slurry foaming method or the powder sintering method instead of the foam sintering method.

  As shown in FIG. 2, the hydrogen flow path forming portion 440 includes a non-reacting fluid guide flow path 442 formed in a groove shape extending from the vicinity of the center of the hydrogen flow path forming portion 440 to the short side in parallel with the long side. Provided (shown with cross-hatching in FIG. 2). By forming the non-reacting fluid guide channel 442 in the hydrogen channel forming unit 440, nitrogen or the like remaining in the hydrogen channel forming unit 440 can be guided to the storage unit 48. The air channel forming portion 460 is not formed with a similar groove.

  The hydrogen flow path forming part 440 in this embodiment corresponds to the fuel gas flow path forming part in the claims.

A3. Separator configuration:
The separator 300 is manufactured by laminating an anode facing plate 310, an intermediate plate 320, and a cathode facing plate 330 in this order and performing hot press bonding. In this embodiment, the anode facing plate 310, the intermediate plate 320, and the cathode facing plate 330 are made of stainless steel flat plates having the same substantially rectangular shape as the outer shape of the power generation unit 400 described above. As the anode facing plate 310, the intermediate plate 320, and the cathode facing plate 330, 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. 4 is a plan view showing the anode facing plate 310 in contact with the hydrogen flow path forming portion 440. As shown in the figure, the anode facing plate 310 has a first hydrogen supply through hole 402a and a second hydrogen supply through hole 404a similar to the through holes formed in the sealing member 428 described above. One by one, through-holes for air supply 406a and three through-holes for air discharge 408a, respectively, three through-holes for cooling water supply 410a, through-holes for cooling water discharge 412a, and through-holes for reservoir 480a, respectively. One by one.

  Furthermore, a plurality of first hydrogen supply ports 402h and second hydrogen supply ports 404h are formed. The first hydrogen supply port 402h and the second hydrogen supply port 404h are arranged along the two long sides of the hydrogen flow path forming part 440 when the fuel cell 100 is configured. As indicated by arrows in the figure, hydrogen is supplied from the first hydrogen supply port 402h and the second hydrogen supply port 404h to the hydrogen flow path forming part 440 of the power generation unit 400. That is, hydrogen is supplied from both sides of the hydrogen flow path forming unit 440 from the two long sides toward the center.

  FIG. 5 is a plan view showing the intermediate plate 320. As shown in the figure, each of the intermediate plate 320 has a first hydrogen supply through hole 402m and a second hydrogen supply through hole 404m, which are the same as the through holes formed in the seal member 428 described above. Three through-holes for air supply 406m and three through-holes for air discharge 408m, respectively, three through-holes for cooling water supply 410m, through-holes for cooling water discharge 412m, and through-holes for storage part 480m are each 1 It is formed one by one.

  Further, the first hydrogen supply through hole 402m and the plurality of first hydrogen supply ports 402h are connected so that hydrogen flows from the first hydrogen supply through hole 402m to the plurality of first hydrogen supply ports 402h. A hydrogen supply connecting portion 402j is formed. Similarly, a hydrogen supply connecting portion 404j that connects the second hydrogen supply through hole 404m and the plurality of second hydrogen supply ports 404h is formed.

  Also, an air supply connecting portion 406j that connects the air supply through holes 406m and the plurality of air supply ports 406h so that air flows from the three air supply through holes 406m to a plurality of air supply ports 406h described later. , Is formed. Similarly, an air discharge connection for connecting the plurality of air discharge ports 408h and the air discharge through holes 408m so that the cathode exhaust gas flows from the plurality of air discharge ports 408h described later to the three air discharge through holes 408m. A portion 408j is formed.

  Further, in order to suppress an increase in the temperature of the fuel cell 100 due to power generation, a cooling water flow path 410p that allows cooling water to flow in the separator 300 so as to cool the entire heat generating portion (MEA 426) of the power generation unit 400, Is formed.

  FIG. 6 is a plan view showing the cathode facing plate 330 that contacts the air flow path forming portion 460. As shown in the drawing, the cathode facing plate 330 has a first hydrogen supply through-hole 402c and a second hydrogen supply through-hole 404c similar to the through-hole formed in the sealing member 428 described above. One by one, through-holes for air supply 406c, three through-holes for air discharge 408c, respectively, three through-holes for cooling water supply 410c, through-holes for cooling water discharge 412c, and through-holes for reservoir 480c, One by one.

  Further, a plurality of air supply ports 406h and air discharge ports 408h are formed. The air supply port 406 h and the air discharge port 408 h are arranged along the two long sides of the air flow path forming part 460 when the fuel cell 100 is configured. As indicated by the arrows in the figure, air is supplied from the air supply port 406h to the air flow path forming part 460 of the power generation unit 400, and the cathode exhaust gas is discharged through the air discharge port 408h.

  FIG. 7 is a plan view of the separator 300. As described above, the separator 300 is formed by joining the anode facing plate 310, the intermediate plate 320, and the cathode facing plate 330. Here, a state seen from the anode facing plate 310 side is shown. As can be seen from the drawing, when the anode facing plate 310, the intermediate plate 320, and the cathode facing plate 330 are stacked, the through holes overlap to form the through holes that penetrate the separator 300. Therefore, as will be described later, when the fuel cell 100 is configured, each manifold that penetrates the stacked body 40 along the stacking direction of the power generation units 400 is formed.

  Further, by stacking the anode facing plate 310, the intermediate plate 320, and the cathode facing plate 330, as shown in the figure, a first hydrogen supply through hole 402, a hydrogen supply connecting portion 402j, and a first hydrogen supply port. 402h is connected to form a hydrogen supply path. Similarly, an air supply path and a discharge path are formed.

A4. Reservoir configuration:
The storage part 48 in the present embodiment is formed inside the fuel cell 100. A through-hole penetrating the stacked body 40 is formed by the reservoir through-hole 480s formed in the seal member 428 of the power generation unit 400 and the reservoir through-holes 480a, 480m, and 480c formed in the separator 300. . As shown in FIG. 1, the laminate 40 is sandwiched from both sides by current collector plates 31 and 32, insulating plates 21 and 22, and end plates 11 and 12. Therefore, both ends of the through holes penetrating the stacked body 40 by the reservoir through holes 480a, 480m, and 480c are sealed by the current collector plates 31 and 32, and have a predetermined internal volume in the fuel cell 100. A reservoir 48 (FIG. 1) is formed.

  The end plate 12, the insulating plate 22, and the current collector plate 32 are provided with through holes having a size capable of connecting the pipe 56, and the pipe 56 is connected thereto. Therefore, by opening the exhaust valve 57 provided in the pipe 56, nitrogen or the like in the storage portion 48 can be released out of the fuel cell 100.

A5. Hydrogen and air flow:
FIG. 8 is an explanatory diagram schematically showing the cross-sectional configuration of the fuel cell 100 and the air flow. In FIG. 8, AA sectional drawing in FIGS. A part of the fuel cell 100 is extracted and displayed, and the other parts are omitted.

  When the fuel cell 100 is configured, the air supply through-holes 406 s, 406 a, 406 m, and 406 c, the air supply manifold that passes through the stacked body 40 along the stacking direction of the power generation unit 400, and the air discharge through-holes 408 s and 408 a. , 408m, and 408c form air discharge manifolds, respectively.

  As shown in FIG. 1, the air is compressed by a compressor 60 and supplied to the fuel cell 100 through a pipe 61. Then, as shown by arrows in FIG. 8, the supplied air passes through the air supply manifold formed by the air supply through holes 406s, 406a, 406m, and 406c formed in the power generation unit 400 and the separator 300, It is distributed to the air supply connection portion 406j of each separator 300 and supplied to the air flow path forming portion 460 via the air supply port 406h. The supplied oxygen in the air is used for the electrochemical reaction in the cathode side catalyst layer 424, and the remaining gas is circulated through the air discharge port 408h, the air discharge connection portion 408j, and the air discharge manifold as the anode exhaust gas, It is discharged into the atmosphere via the pipe 62.

  FIG. 9 is an explanatory diagram schematically showing the cross-sectional configuration of the fuel cell 100 and the flow of hydrogen. In FIG. 9, the BB sectional drawing in FIGS. 2-7 is shown. A part of the fuel cell 100 is extracted and displayed, and the other parts are omitted.

  When the fuel cell 100 is configured, a first hydrogen supply manifold that penetrates the stacked body 40 along the stacking direction of the power generation unit 400 is formed by the first hydrogen supply through holes 402a, 402m, and 402c. Similarly, a second hydrogen supply manifold is formed by the second hydrogen supply through holes 404a, 404m, and 404c.

  As shown in FIG. 1, hydrogen is supplied from the hydrogen tank 50 to the fuel cell 100 through a pipe 53. Then, as shown by the arrows in FIG. 9, the supplied hydrogen is supplied to a hydrogen supply manifold constituted by the second hydrogen supply through holes 404s, 404a, 404m, and 404c formed in the power generation unit 400 and the separator 300. Then, it is distributed to the hydrogen supply connecting portion 404j of each separator 300. Then, the hydrogen is supplied to the hydrogen flow path forming part 440 through the second hydrogen supply port 404h while flowing through the hydrogen supply connecting part 404j. Note that, as described above, in this embodiment, no discharge port or the like for discharging the anode exhaust gas is formed, and all of the supplied hydrogen is used for the electrochemical reaction in the anode side catalyst layer 422. .

  As shown in FIG. 8, oxygen is supplied to the cathode side of the power generation unit 400 through the air supply port 406h and is used for the electrochemical reaction in the cathode side catalyst layer 424 while flowing through the cathode side, It is discharged as cathode exhaust gas via 408h. On the other hand, hydrogen is supplied to the anode side of the power generation unit 400 through the first hydrogen supply port 402h and is supplied to the anode side of the power generation unit 400 through the second hydrogen supply port 404h. That is, as shown in FIG. 8, hydrogen circulates on the anode side of the power generation unit 400 so as to face each other.

A6. Effects of the first embodiment:
FIG. 10 is a plan view showing the power generation unit 400 as viewed from the anode side. In FIG. 10, the flow of hydrogen is indicated by arrows. As indicated by arrows in FIG. 10, hydrogen supplied to the hydrogen flow path forming unit 440 through the first hydrogen supply port 402h and the second hydrogen supply port 404h mainly flows so as to face each other.

  The fuel cell is operated by consuming almost all of the hydrogen supplied to the fuel cell in the anode side catalyst layer (so-called anode dead-end operation). When nitrogen or the like inside moves to the anode side through the electrolyte membrane 421, the nitrogen or the like is not discharged from the anode side, and thus stays on the anode side. In particular, when the operation of the fuel cell is stopped, the gas flow on the cathode side also disappears, so the concentration of nitrogen and the like in the fuel cell increases, and the amount of nitrogen and the like remaining on the anode side also increases. Therefore, when the fuel cell is started, a large amount of nitrogen and the like is collected near the center by the flow of hydrogen as shown in FIGS. As a result, the hydrogen concentration in the portion where a large amount of nitrogen stays is relatively low, which may reduce the power generation efficiency.

  FIG. 11 is an explanatory diagram schematically showing the cross-sectional configuration of the fuel cell 100 and the flow of nitrogen and the like. In FIG. 11, CC sectional drawing in FIGS. 2-7 is shown. A part of the fuel cell 100 is extracted and displayed, and the other parts are omitted.

  In the fuel cell 100 of the present embodiment, as described above, hydrogen is supplied to the hydrogen flow path forming unit 440 from the first hydrogen supply port 402h and the second hydrogen supply port 404h. As shown in FIG. 10, the downstream of the main flow of supplied hydrogen is near the center at a position parallel to the short side of the hydrogen flow path forming portion 440. As described above, the non-reacting fluid guide channel 442 having a groove shape parallel to the long side is formed in the hydrogen channel forming unit 440 from the vicinity of the center of the hydrogen channel forming unit 440. Therefore, as shown in FIG. 10, when the fuel cell 100 is started, nitrogen or the like collected in the vicinity of the center due to the flow of hydrogen is guided to the non-reacting fluid guide channel 442 as shown by a thick arrow in FIG. Then, it flows into the storage part 48 through the groove part 429 of the seal member 428. As shown in FIG. 11, the seal member 428 has a groove 429 that connects the non-reacting fluid guide channel 442 and the reservoir 48, and therefore stays in the hydrogen channel forming part 440. Nitrogen or the like is guided to the non-reacting fluid guide channel 442 and flows into the storage part 48 through the groove part 429 of the seal member 428.

  Accordingly, local retention of nitrogen or the like in the hydrogen flow path forming unit 440 can be suppressed, and a decrease in power generation efficiency can be suppressed.

  In addition, when the operation of the fuel cell 100 is stopped, the amount of nitrogen or the like staying on the anode side is predicted in advance, and the storage unit 48 is formed in such a volume that the storage unit 48 is filled with the nitrogen or the like. Then, when the fuel cell 100 is started, nitrogen or the like staying on the anode side is swept from the anode side, flows into the storage unit 48, and when the storage unit 48 becomes full, it is then supplied to the hydrogen flow path forming unit 440. Since the hydrogen to be supplied is less likely to be guided to the non-reacting fluid guide channel 442 and to flow into the storage portion 48, hydrogen is not wasted. For example, during operation of the fuel cell 100, the exhaust valve 57 is kept closed, and after the operation is stopped, the exhaust valve 57 is opened for a predetermined time, so that nitrogen or the like in the reservoir 48 is removed from the fuel cell. You may make it discharge | release outside 100. If it does in this way, when starting the fuel cell 100 next, nitrogen etc. can be flowed in in the storage part 48. FIG.

B. Second embodiment:
FIG. 12 is an explanatory diagram showing a schematic configuration of a fuel cell system 1000A as the second embodiment. In the fuel cell system 1000 of the first embodiment, the storage section 48 for storing nitrogen or the like is formed in the fuel cell 100, but the fuel cell system 1000A of the second embodiment is similar to the fuel cell 100A. Separately, a storage part 48A is provided.

  The fuel cell system 1000A of the present embodiment is different from the first embodiment in the configuration of the storage section 48A, but the other configurations are the same as those in the first embodiment, so the detailed description of the configuration of the fuel cell system 1000A Are omitted.

  The reservoir 48A is connected to the fuel cell 100A via a pipe 58. Reservoir 48A has a predetermined internal volume, and can store nitrogen or the like remaining on the anode side of fuel cell 100A. A pipe 56 including an exhaust valve 57 is connected to the storage section 48, and the exhaust valve 57 is opened at a predetermined timing to release nitrogen or the like in the storage section 48A to the outside of the fuel cell 100.

B1. Configuration of power generation unit and separator:
As described above, the fuel cell system 1000A of the present embodiment includes the storage portion 48A outside the fuel cell 100A. Accordingly, some of the through holes formed in the power generation unit 400A and the separator 300A are This is different from the first embodiment.

  FIG. 13 is a plan view showing the anode facing plate 310A in contact with the hydrogen flow path forming portion 440, FIG. 14 is a plan view showing the intermediate plate 320A, and FIG. 15 is a cathode facing plate in contact with the air flow path forming portion 460. FIG. 16 is a plan view showing the power generation unit 400A as viewed from the anode side. The separator 300 </ b> A and the power generation unit 400 </ b> A according to the present embodiment are the same as the separator 300 and the power generation unit 400 according to the first embodiment, and form a first hydrogen supply path for supplying hydrogen to the hydrogen flow path forming unit 440. Cathode exhaust gas is supplied to the fuel cell, such as the hydrogen supply through-hole 402a, the second hydrogen supply through-hole 404a, and the like. A cooling water supply through hole 410a, a cooling water discharge through hole 412a, and the like for circulating cooling water into the fuel cell 100A, such as an air discharge through hole 408a that forms an air discharge path for discharging to the outside of 100A. The plate and the seal member 428A are respectively formed.

  The separator 300A of the present embodiment is different from the separator 300 of the first embodiment in that instead of the reservoir through holes 480a, 480m, and 480c, as shown in FIGS. , 482m, 482c. Further, the power generation unit 400A of the present embodiment is different from the power generation unit 400 of the first embodiment in that a nitrogen circulation through-hole 482s is formed as shown in FIG. 16 instead of the reservoir through-hole 480s. It is a point that has been. That is, the MEA 426, the hydrogen flow path forming part 440, and the air flow path forming part 460 in the power generation unit 400A are the same as those in the first embodiment.

  The nitrogen circulation through hole 482a and the like have a smaller opening area than the storage part through hole 480a and the like. As shown in FIG. 16, the size is formed so as to coincide with the width of the non-reacting fluid guide channel 442. In this way, when the fuel cell 100A is configured, the nitrogen that has been guided by the non-reacting fluid guide channel 442 and flowed into the nitrogen circulation through hole 482s has a predetermined flow velocity, such as the nitrogen circulation through hole 482a. And flows into the storage portion 48A through the pipe 58.

B2. Effects of the second embodiment:
FIG. 17 is an explanatory diagram schematically showing the cross-sectional configuration of the fuel cell 100A and the flow of nitrogen. In FIG. 17, AA sectional drawing in FIGS. A part of the fuel cell 100A is extracted and displayed, and the other parts are not shown.

  In the fuel cell 100A in the present embodiment, as in the first embodiment, the hydrogen supplied to the hydrogen flow path forming portion 440 via the first hydrogen supply port 402h and the second hydrogen supply port 404h is mainly And flow so as to face each other (similar to the arrows shown in FIG. 10). On the anode side of the fuel cell 100A, nitrogen or the like collected near the center of the hydrogen flow path forming unit 440 at the start of the fuel cell 100A is guided to the non-reacting fluid guide flow path 442 as shown in FIG. It flows into the nitrogen flow path 482 constituted by the nitrogen circulation through hole 482s and the like through the groove portion 429. And the nitrogen etc. distribute | circulate through the nitrogen flow path 482, and are stored by the storage part 48A (FIG. 12) via the piping 58. FIG.

  Therefore, similarly to the first embodiment, it is possible to suppress the local retention of nitrogen or the like in the hydrogen flow path forming portion 440, and it is possible to suppress a decrease in power generation efficiency.

  As in the first embodiment, when the internal volume of the reservoir 48A is substantially the same as the volume of nitrogen or the like that stays on the anode side when the fuel cell 100 is stopped, it is described in the first embodiment. Thus, the amount of wasteful release of hydrogen can be reduced.

C. Non-reactive fluid guide channel variants:
In the first and second embodiments described above, the non-reacting fluid guide channel 442 formed in the groove shape is shown on the surface of the hydrogen channel forming portion 440 that contacts the separator. The shape of the guide channel 442 is not limited to the shape described above.

  (1) FIG. 18 is an explanatory view showing a non-reactive fluid guide channel 442V1 of a first modification of the non-reaction fluid guide channel 442, and FIG. 19 is a non-reaction fluid guide channel 442V2 of a second modification. FIG. 20 is an explanatory diagram showing a non-reacting fluid guide channel 442V3 of a third modified example, and FIG. 21 is an explanatory diagram showing a non-reacting fluid guiding channel 442V4 of a fourth modified example. . 18-21 shows the AA cut surface in Drawing 2 of power generation units 440V1-4 of a modification. The non-reacting fluid guide channels 442V1 to 442V4 are respectively used for the storage unit in the vicinity of the center of the hydrogen channel forming unit 440 in parallel with the long side, similarly to the first example and the second example. It extends to the through hole 480s (or the nitrogen circulation through hole 482s).

  As shown in FIG. 18, the non-reacting fluid guide channel 442V1 is formed in a groove shape on the surface of the hydrogen channel forming portion 440 that contacts the MEA 426. As shown in FIG. 19, the non-reacting fluid guide channel 442V2 is formed as a through-hole penetrating the hydrogen channel forming part 440 in the thickness direction. As shown in FIG. 20, the non-reacting fluid guide channel 442V3 is formed as a cavity in the hydrogen channel forming part 440. Even if the non-reactive fluid guide portion is as in the first to third modifications, the flow resistance of the non-reactive fluid guide portion is lower than that of other portions, so that nitrogen or the like stays in the hydrogen flow passage forming portion. The non-reacting fluid is guided to the non-reacting fluid guide channel and flows into the storage portion.

  (2) As shown in FIG. 21, the non-reacting fluid guide channel 442V3 may be formed so as to have a higher porosity than other portions of the hydrogen channel forming part 440. A portion with a high porosity has a lower flow path resistance than a portion with a low porosity, and therefore gas easily flows. Therefore, when the non-reactive fluid guide channel is formed so as to have a high porosity, the non-reactive fluid such as nitrogen staying in the hydrogen channel forming part is guided to the non-reactive fluid guide channel, and the storage unit Flow into.

  (3) The position where the non-reacting fluid guide channel 442 is formed is not limited to the above-described embodiment. For example, in the first embodiment, the second hydrogen supply through-hole 404s, the second hydrogen supply port 404h, and the like are not formed in the power generation unit 400 and the separator 300. When hydrogen is supplied only from the hydrogen supply port 402h, it is considered that nitrogen or the like is collected in a portion near the air discharge through hole 408s in the hydrogen flow path forming portion 440. Therefore, if the non-reacting fluid guide channel 442 is formed closer to the air discharge through hole 408s in the hydrogen channel forming unit 440, the collected nitrogen and the like can be efficiently guided to the storage unit 48.

D. Variations:
The present invention is not limited to the above-described embodiments, and can be implemented in various modes without departing from the gist thereof. For example, the following modifications are possible.

  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. As typical flow path configurations, here, in addition to the shower flow channel type, a comb-shaped configuration, a circulation-type configuration, and the like can be given. First, a modified example of the shower channel type will be described.

  (1-1) In the above-described embodiment, a configuration may be adopted in which a dispersion plate is further provided between the membrane electrode assembly and the hydrogen flow path forming portion.

  FIG. 22 is a schematic diagram showing a configuration example in which a shower channel type dispersion plate is arranged between the membrane electrode assembly and the hydrogen channel forming part. As shown in FIG. 22, the dispersion plate 2100 is formed in a sheet shape (thin film shape) and has a large number of through holes 2110 provided on the surface thereof in a dispersed manner. Each through-hole 2110 is circular and has the same diameter (that is, the same shape), penetrates in the thickness direction of the dispersion plate 2100, and is provided in a lattice shape on the surface of the dispersion plate 2100. In the dispersion plate 2100, the ratio of the opening portion of each through hole 2110 to the area of the sheet surface is referred to as an aperture ratio. The dispersion plate 2100 is set to have a relatively small aperture ratio. The aperture ratio of the dispersion plate 2100 is preferably less than 5%, more preferably less than 3%, and particularly preferably less than 1%. Therefore, in the dispersion plate 2100, the diameter of the through holes 2110 is relatively small, and the pitch between the through holes 2110 is relatively wide. Accordingly, the fuel gas passing through each through hole 2110 is accompanied by a large pressure loss. The dispersion plate 2100 is made of gold. In addition, you may join to one surface of the hydrogen flow path formation part 440 by thermocompression bonding, brazing, welding, etc. Further, the dispersion plate 2100 may be formed of a polymer type conductive paste. Examples of the polymer-type conductive paste include a silver paste, a carbon paste, and a silver / carbon paste. In this case, the polymer-type conductive paste may be formed into a sheet shape and then joined to one surface of the hydrogen flow path forming portion 440 by thermocompression bonding. The dispersion plate 2100 may be formed integrally with the membrane electrode assembly 2000.

  With this configuration, the pressure loss when the fuel gas passes through each through hole 2110 is increased, and the pressure distribution of the fuel gas in the hydrogen flow path forming portion 440 can be reduced, thereby dispersing the fuel gas. Variations in the amount of fuel gas supplied from each through hole 2110 in the plate 2100 to the anode-side diffusion layer 820B can be reduced. In addition, with the above configuration, a large pressure difference is generated between the hydrogen side electrode 2200 and the hydrogen flow path forming portion 440, and the hydrogen flow path forming portion 440 is compared with the hydrogen side electrode 2200. The pressure is quite high. Along with this, in each through hole 2110, the flow rate of the fuel gas becomes faster, and the flow rate of the fuel gas becomes faster than the diffusion rate of the leak gas. As a result, the dispersion plate 2100 suppresses the leak gas from entering the hydrogen flow path forming part 440 from the hydrogen side electrode 2200 through the through hole 2110, and suppresses the leakage gas from staying in the hydrogen flow path forming part 440. The

  Furthermore, it demonstrates in detail. FIG. 23 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 through hole 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 through hole 2110 is 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 through holes 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 through holes 2110 is the diffusion of nitrogen gas. It may be possible to sufficiently suppress the backflow due to. What is necessary is just to set the space | interval of a through-hole 2110 and a flow-path cross-sectional area so that sufficient flow velocity or sufficient pressure loss may generate | occur | produce in the through-hole 2110 so that the conditions concerned may be satisfied. 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.

  (1-2) Next, another configuration example of the above-described shower channel type will be described. FIG. 24 is an explanatory diagram showing another configuration example of the shower channel type. 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 through holes are used, the fuel gas is locally supplied to each through hole, so to speak, locally, 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 about the aperture ratio of a porous body similarly to having demonstrated to (1-1).

  (1-3) FIG. 25 is an explanatory view showing a dispersion plate 2102 configured using press metal, and FIG. 26 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 through hole 2112 is formed on a side surface of the protrusion 2102t. This dispersion plate 2102 is arranged 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 through a through hole 2112 formed in 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 through-hole 2112 reaches the hydrogen-side electrode 2200 through the space inside the protrusion 2102t, so that sufficient dispersibility can be ensured. The through-hole 2112 may be formed by press working, or may be formed by other methods such as electric discharge machining in the pre-process or post-process of forming the protrusion 2102t. What is necessary is just to determine the aperture ratio by the through-hole 2112 similarly to the modification 1. FIG.

  (1-4) FIG. 27 is an explanatory diagram showing 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 from the flow channel 2142n, not shown. A plurality of through holes 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 through hole 2143n can be individually prepared. In FIG. 19, the through holes 2143n are arranged in a zigzag pattern, but may be arranged in a lattice pattern or may be arranged randomly to some extent.

  (1-5) FIG. 28 is an explanatory view showing an example in which a dispersion plate 2014hp is formed using a pipe. As shown in FIG. 28, 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 through holes 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 through hole 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 through holes 2141n to configure the dispersion plate 2014hp. The through hole 2141n may be arranged toward the hydrogen side electrode 2200 side, or may be arranged 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.

  (2) In the above-described embodiment, the porous body voids are used as the hydrogen flow path (fuel gas flow path). However, the fuel gas flow path can take various configurations. .

  FIG. 29 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 in the flow path forming member 5000 disposed between the hydrogen flow path forming portion 440 of the above-described embodiment and the separator 300. 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-tooth flow path 5030 at the tip, the pressure distribution in the surface of the flow path forming member 5000 is the hydrogen flow path formation. It is about the same as or lower than that of the portion 440.

  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.

  In FIG. 29, 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 surface of 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.

  Next, a serpentine type flow path configuration will be described with reference to FIG. FIG. 30 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. 23A illustrates a flow path forming member 5100 having a single fuel gas flow path, and FIG. 23B 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. 30A has a plurality of flow streams alternately extended inward from the opposing 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 disposed between the hydrogen flow path forming portion 440 and the separator 300 in the above-described embodiment, similarly to the flow path forming member 5000 of FIG.

  FIG. 30B 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 disposed between the hydrogen flow path forming portion 440 and the separator 300 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. 30 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.

  Thus, when the flow path forming member 5000, 5100, or 5200 is further provided, in the hydrogen flow path forming portion 440, the non-reacting fluid guide flow path is located at a position corresponding to the downstream of hydrogen in the flow path forming member 5000 or the like. If 442 is formed, the same effect as the above-described embodiment can be obtained.

  (3) FIG. 31 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 this modification, the fluid is circulated in the direction along the surface of the anode 6100 using the ejector effect. However, the direction along the surface of the anode in the fuel cell is used. Other configurations may be used as long as the above-described fluid can be circulated. 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, 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.

  Even when this anode-side separator 6200 (and the corresponding cathode-side separator) is used in place of the separator 300 of this embodiment, a position corresponding to the downstream of hydrogen in the anode-side separator 6200 in the hydrogen flow path forming portion 440 (see FIG. If the non-reacting fluid guide channel 442 is formed in the vicinity of the position described as “downstream” in FIG. 31, the same effects as in the above-described embodiment can be obtained.

  (4) In the above-described embodiment, in the separator 300, the first hydrogen supply port 402h and the second hydrogen supply port 404h are arranged along the long side of the hydrogen flow path forming unit 440. The arrangement of the hydrogen supply ports is not limited to the arrangement of the above-described embodiment. For example, the first hydrogen supply port 402h and the second hydrogen supply port 404h may be arranged along the short side of the hydrogen flow path forming unit 440.

  Further, for example, hydrogen may be supplied only from one long side of the hydrogen flow path forming unit 440. That is, the second hydrogen supply port 404h may not be disposed. Even if it does in this way, if the non-reaction fluid guide flow path 442 is arrange | positioned in the position corresponded downstream of the flow of hydrogen, the effect similar to the above-mentioned Example can be acquired.

  (5) In the fuel cell of the above embodiment, the cathode side oxidant gas supply flow path is formed by a single porous body (air flow path forming portion 460). It 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 oxidant 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.

  (6-1) 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, the 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 to extract current 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 side at the pressure of the fuel gas for a predetermined time TA. The load is connected after the leakage gas retention amount is reduced. Therefore, occurrence of a situation where the anode 820 is operated in a state where the fuel gas is deficient when the fuel cell is started can be suppressed. In this case, “starting” means supplying a reaction gas (fuel gas and oxidant 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.

  (6-2) At the start of the fuel cell, at least one of the fuel gas supply amount and the predetermined time TA until the electrical load is connected is determined based on the leak gas retention amount at the start of the fuel cell operation. It is also possible to adopt a configuration. 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.

  (6-3) 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, the anode 820 can be prevented from being in 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.

It is explanatory drawing which shows schematic structure of the fuel cell system 1000 as a 1st Example of this invention. It is a top view which shows the electric power generation unit 400 seeing from an anode side. FIG. 6 is a cross-sectional view showing a CC cut surface of the power generation unit 40. It is a top view which shows the anode opposing plate 310. FIG. 5 is a plan view showing an intermediate plate 320. FIG. It is a top view which shows the cathode opposing plate 330. FIG. 3 is a plan view of a separator 300. FIG. 2 is an explanatory diagram schematically showing a cross-sectional configuration of the fuel cell 100 and an air flow. FIG. 2 is an explanatory diagram schematically showing a cross-sectional configuration of a fuel cell 100 and a flow of hydrogen. FIG. It is the top view which looked at the electric power generation unit 400 seeing from the anode side. 2 is an explanatory diagram schematically showing a cross-sectional configuration of a fuel cell 100 and a flow of nitrogen or the like. FIG. It is explanatory drawing which shows schematic structure of the fuel cell system 1000A as a 2nd Example. It is a top view which shows the anode opposing plate 310A. It is a top view showing intermediate plate 320A. It is a top view which shows the cathode opposing plate 330A. It is a top view which shows 400 A of electric power generation units seeing from the anode side. It is explanatory drawing which shows roughly the cross-sectional structure of 100 A of fuel cells, and the flow of nitrogen. It is explanatory drawing which shows the non-reacting fluid guide channel 442V1 of the 1st modification of the non-reacting fluid guide channel 442. It is explanatory drawing which shows the non-reaction fluid guide flow path 442V2 of a 2nd modification. It is explanatory drawing which shows the non-reaction fluid guide flow path 442V3 of a 3rd modification. It is explanatory drawing which shows the non-reaction fluid guide flow path 442V4 of a 4th modification. It is a schematic diagram which shows the structural example which has arrange | positioned the shower flow-path type dispersion plate between a membrane electrode assembly and a hydrogen flow-path formation part. FIG. 11 is an explanatory diagram for explaining the function of a dispersion plate 2100. It is explanatory drawing which shows the other structural example of a shower flow path type. It is explanatory drawing which shows the dispersion plate 2102 comprised using the press metal. FIG. 6 is a schematic diagram showing a CC cross section of a dispersion plate 2102. 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 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 typically the internal structure of the circulation path type fuel cell 6000 as one of the modifications of the supply form of fuel gas. It is explanatory drawing which shows the other structural example (the 1) of the fuel cell of this invention. It is explanatory drawing which shows the other structural example (the 2) of the fuel cell of this invention.

Explanation of symbols

11, 12 ... End plate 21, 22 ... Insulating plate 31, 32 ... Current collector plate 40 ... Laminate 48, 48A ... Reservoir 50 ... Hydrogen tank 51 ... Shut Valve 52 ... Regulator 53, 56, 58, 61, 62, 72 ... Piping 57 ... Exhaust valve 60 ... Compressor 70 ... Pump 71 ... Radiator 100, 100A ... Fuel cell 300, 300A ... Separator 310, 310A ... Anode facing plate 320, 320A ... Intermediate plate 330, 330A ... Cathode facing plate 400, 400A ... Power generation unit 402a, 402c, 402m, 402s ... First hydrogen supply through hole 402h ... first hydrogen supply port 402j ... hydrogen supply connection 404a, 404c, 404m, 404s ... second hydrogen supply through hole 404h ... 2 hydrogen supply port 404j ... Element supply connection 406a, 406c, 406m, 406s ... Air supply through hole 406h ... Air supply port 406j ... Air supply connection 408a, 408c, 408m, 408s ... Air discharge through Hole 408h ... Air discharge port 408j ... Air discharge connection portion 410a, 410c, 410m, 410s ... Cooling water supply through hole 410p ... Cooling water flow path 412a, 412c, 412m, 412s ... Through hole for cooling water discharge 420 ... MEA with integrated seal member
421 ... Electrolyte membrane 422 ... Anode side catalyst layer 423 ... Anode side diffusion layer 424 ... Cathode side catalyst layer 425 ... Cathode side diffusion layer 428, 428A ... Sealing member 429 ... Groove part 440 ... Hydrogen flow path forming part 442 ... Non-reacting fluid guide flow path 460 ... Air flow path forming part 480a, 480c, 480m, 480s ... Through hole for reservoir 482 ... Nitrogen flow Channel 482a, 482s ... Nitrogen flow through hole 1000, 1000A ... Fuel cell system 2000 ... Membrane electrode assembly 2014hm, 2014hp, 2100, 2101, 2102 ... Dispersion plate 2102t ... Projection 2110 2112 ... Through hole 2130 ... Pipe 2140 ... Frame 2141n ... Through hole 2142n ... Flow path 2143n ... Through hole 2200 ... Hydrogen side electrode 2201, 2202, 2203, 2204. ..Membrane electrode bonding 2300 ... Electrolyte membrane 2400 ... Oxygen side electrode 5000, 5100, 5200 ... Flow path forming member 5010 ... Main flow path 5020 ... Sub-flow path 5030 ... Comb-shaped flow path 5110 ... Outer wall 5120, 5220 ... Flow path wall 5150, 5250 ... Inlet 5210 ... Outer wall 5230 ... Partition wall 6000 ... Fuel cell 6100 ... Anode 6200 ... Anode side separator 6210 .. Fuel gas inlet port 6220 ... recess 6230 ... regulating plate 6300 ... nozzle 6320 ... injection hole

Claims (5)

A fuel cell system,
An anode-side catalyst layer and a cathode-side catalyst layer are arranged on both surfaces of the electrolyte membrane, respectively, and the anode-side catalyst layer side of the electricity-generating body is arranged for electrochemical reaction in the anode-side catalyst layer. A fuel cell comprising: a fuel gas flow path forming unit that circulates the fuel gas used and supplies the fuel gas to the anode side catalyst layer;
A reservoir for storing a non-reactive fluid that is not used in the electrochemical reaction in the anode catalyst layer;
With
The fuel gas flow path forming part is
A non-reacting fluid guide channel for guiding the non-reacting fluid staying in the fuel gas channel forming unit to the storing unit;
The fuel cell system includes a mode in which almost all of the supplied fuel gas is consumed by the anode catalyst layer as a mode of operation performed by supplying the fuel gas. The fuel cell system according to claim 1,
The non-reacting fluid guide channel is
A fuel cell, wherein the fuel gas is disposed downstream of a main flow when the fuel gas flows through the fuel gas flow path forming portion. The fuel cell system according to claim 1 or 2,
The fuel gas flow path forming part is
A porous body having a plurality of pores communicating with each other;
The non-reacting fluid guide channel is
A fuel cell system, wherein the fuel cell system is a part formed in a part of the porous body so as to have a high porosity. The fuel cell system according to claim 1 or 2,
The fuel gas flow path forming part is
A porous body having a plurality of pores communicating with each other;
The non-reacting fluid guide channel is
A fuel cell system comprising a groove formed on a surface of the porous body. A fuel cell system according to any one of claims 1 to 4,
The reservoir is
A fuel cell system provided inside the fuel cell.

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