JP5482488B2 - Fuel cell stack - Google Patents

Description

  The present invention relates to a fuel cell stack.

  2. Description of the Related Art Conventionally, a fuel cell stack in which a plurality of cells that generate power using an electrochemical reaction between a fuel gas (hydrogen) and an oxidizing gas (air) is stacked is known.

  In these fuel cell stacks, in the cell stacking direction, a reaction gas supply manifold for supplying the reaction gas of the fuel gas and the oxidizing gas to each cell, and a reaction for discharging the reaction gas from the fuel cell stack. A gas exhaust manifold is formed. In the fuel cell stack, a drain manifold is formed in the cell stacking direction to discharge water generated by the power generation of the cells.

  Usually, a seal member is provided around each manifold in order to prevent leakage of reaction gas, water, and the like (see, for example, Patent Documents 1 to 5).

JP 2007-213928 A JP 2005-251526 A JP 2008-277184 A JP 2006-100087 A JP 2009-21099 A JP 2008-159546 A

  By the way, conventionally, in order to ensure drainage of water in the drainage manifold, a communication path that connects the reaction gas discharge manifold and the drainage manifold is disposed at the end of the fuel cell stack in the cell stacking direction. It is formed on a fuel cell member such as a non-power generation component. However, in order to form the communication path while ensuring the sealing performance by the seal member, complicated processing is required for the fuel cell member.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a fuel cell stack that does not require complicated processing for forming a communication path in a fuel cell member while ensuring sealing performance by the seal member.

  The present invention is a fuel cell stack in which a plurality of cells are stacked, the reactive gas discharge manifold formed in the cell stacking direction, the drainage manifold formed in the cell stacking direction, and the reactive gas discharge A communication path that communicates one end of the manifold and one end of the drainage manifold, a first seal member that circulates in the communication path, and an inner side of the first seal member that circulates the drainage manifold. And a second seal member.

  In the fuel cell stack, a throttle portion formed at the other end of the reaction gas discharge manifold, and a merge portion formed at the other end of the drainage manifold and joined to the reaction gas discharge manifold. It is preferable that the merging portion is formed on a lamination surface of a non-power generation member disposed at an end portion of the cell in the lamination direction.

  In the fuel cell stack, the cell further includes a third seal member disposed between a pair of separators sandwiching a membrane-electrode assembly in which a pair of electrodes are disposed on both sides of the electrolyte membrane. It is preferable that a fourth seal member disposed around the drainage manifold is provided, and the third seal member and a part of the fourth seal member are exposed to the drainage manifold and become tubular. .

  Further, the present invention is a fuel cell stack in which a plurality of cells are stacked, and a reaction gas discharge manifold formed in the cell stacking direction, and a throttle portion formed at one end of the reaction gas discharge manifold And a drain manifold pipe, and at least a part of the drain manifold pipe is provided in the reaction gas discharge manifold.

  ADVANTAGE OF THE INVENTION According to this invention, the fuel cell stack which does not require the complicated process for forming a communicating path in a fuel cell member can be provided, ensuring the sealing performance by a sealing member.

It is a schematic cross section which shows an example of a structure of the fuel cell stack concerning this embodiment. (A) is a partial schematic cross-sectional view showing an example of the configuration of one end of the fuel cell stack of the present embodiment, and (B) shows the configuration of the manifold and the seal member as viewed from the X direction of (A). It is a schematic plan view to show, (C) is a schematic plan view showing the configuration of the manifold and the seal member viewed from the Y direction of (A). It is a partial schematic cross section which shows another example of a structure of the one end of the fuel cell stack of this embodiment. It is a partial schematic cross section which shows an example of the structure of the cell which formed the communicating path. It is a partial schematic cross section which shows an example of a structure of the other end of the fuel cell stack of this embodiment. It is a partial schematic cross section which shows an example of a structure of the cell which comprises a cell laminated body. It is a partial schematic cross section which shows another example of a structure of the fuel cell stack which concerns on this embodiment. It is a partial schematic cross section which shows another example of a structure of the fuel cell stack which concerns on this embodiment. (A) is a partial schematic cross-sectional view showing an example of the configuration of one end of a conventional fuel cell stack, and (B) is a schematic diagram showing the configuration of a manifold and a seal member as viewed from the X direction of (A). It is a top view, (C) is a schematic plan view which shows the structure of the manifold and seal member seen from the Y direction of (A). It is a partial schematic cross section which shows the structure of the other end of the conventional fuel cell stack.

  Embodiments of the present invention will be described below.

  FIG. 1 is a schematic cross-sectional view showing an example of the configuration of the fuel cell stack according to the present embodiment. As shown in FIG. 1, a fuel cell stack 1 includes a cell stack 12 in which a plurality of cells 10 that generate power by an electrochemical reaction between a fuel gas and an oxidizing gas are stacked, and cell stacks at both ends in the cell stacking direction. And a non-power generating member 14 such as a terminal plate as a current collecting plate, an insulator as an insulating plate, and an end plate, which are sequentially arranged from the 12 side.

  In the fuel cell stack 1, a reaction gas discharge manifold 16 and a drainage manifold 18 are formed in the stacking direction of the cells 10. Although not shown, a reaction gas supply manifold, a cooling water supply / discharge manifold, and the like are also formed in the stacking direction of the cells 10. A communication path 20 that communicates one end of the reactive gas discharge manifold 16 and one end of the drainage manifold 18 is formed. Further, a throttle portion 22 (orifice) having a reduced manifold diameter is formed at the other end of the reactive gas discharge manifold 16 (on the side opposite to the communication path 20 side). Further, at the other end of the drainage manifold 18 (on the side opposite to the communication path 20 side), a merging portion 24 that merges with the reaction gas discharge manifold 16 is formed. Here, the reaction gas discharge manifold 16 shown in FIG. 1 is a fuel gas discharge manifold or an oxidizing gas discharge manifold, and the drainage manifold 18 is the fuel gas discharge manifold side of the reaction gas discharge manifold 16. It is sufficient that it is provided on at least one of the oxidizing gas manifold side.

  The flow of the reaction gas and generated water of the fuel cell stack 1 will be described below. First, fuel gas and oxidizing gas are distributed to each cell 10 through the reaction gas supply manifold and used for power generation of the cell 10. The fuel gas and the oxidizing gas (off gas) discharged from the cell 10 pass through the reaction gas discharge manifold 16 and are discharged from the fuel cell stack 1. Further, water generated during the power generation of the cell 10 mainly passes through the drainage manifold 18 and the junction 24 and is discharged from the fuel cell stack 1. Since the reactive gas passes through the throttle portion 22 of the reactive gas discharge manifold 16, the reactive gas discharge manifold 16 has a negative pressure. Therefore, the drainage manifold 18 communicating with the reactive gas discharge manifold 16 also has a negative pressure. Become. As a result, the drainage performance of the water in the drainage manifold 18 can be improved.

  FIG. 2A is a partial schematic cross-sectional view showing an example of the configuration of one end of the fuel cell stack according to the present embodiment, and FIG. 2B is a manifold viewed from the X direction of FIG. 2C is a schematic plan view showing the configuration of the seal member, and FIG. 2C is a schematic plan view showing the configuration of the manifold and the seal member as viewed from the Y direction in FIG. In the present embodiment, as shown in FIG. 2A, the communication path 20 is formed in a non-power generation member 14 (for example, a terminal plate) adjacent to the cell 10. The fuel cell stack 1 includes a first seal member 26 and a second seal member 28 that are disposed between the cell 10 and the non-power generation member 14. 2A to 2C, the first seal member 26 circulates in the communication path 20 from the reaction gas discharge manifold 16 to the drainage manifold 18, and the second seal member 28. Is inside the first seal member 26 and circulates around the drainage manifold 18. Between the cells 10, a fourth seal member 30 that circulates around the drainage manifold 18 and a fifth seal member 32 that is disposed from the reaction gas discharge manifold 16 to the drainage manifold 18 are disposed. . The fourth seal member 30 faces the second seal member 28, and the fifth seal member 32 faces the first seal member 26.

  FIG. 9A is a partial schematic cross-sectional view showing an example of the configuration of one end of a conventional fuel cell stack, and FIG. 9B shows a manifold and a seal when viewed from the X direction of FIG. 9A. FIG. 9C is a schematic plan view showing the configuration of the manifold and the seal member as viewed from the Y direction in FIG. 9A. As shown in FIGS. 9A to 9C, conventionally, the first seal member 26a disposed between the cell 10 and the non-power generation member 14 circulates around the reaction gas discharge manifold 16, Further, the second seal member 28 a disposed between the cell 10 and the non-power generation member 14 circulates around the drainage manifold 18. In the arrangement of the seal member, the reaction gas in the reaction gas discharge manifold 16 and the water in the drain manifold 18 are prevented from leaking (that is, the sealing performance of the seal member is ensured), and the communication passage 20 is formed. In order to form, the non-power generation member 14 requires a complicated process and a separate member for forming the receiving portion 34 that receives the seal member in the space serving as the communication path 20.

  On the other hand, in the present embodiment, the first seal member 26 is arranged so as to go around the communication path 20 from the reaction gas discharge manifold 16 to the drainage manifold 18, and the second seal member 28 is arranged in the first seal member 26. By arranging the drainage manifold 18 so as to circulate, it is possible to ensure the sealing performance of the sealing member without forming the receiving portion 34 that receives the sealing member in the space that becomes the communication path 20, The communication path 20 can be formed. As a result, the non-power generating member 14 does not require complicated processing or another member.

  FIG. 3 is a partial schematic cross-sectional view showing another example of the configuration of one end of the fuel cell stack of the present embodiment. In the present embodiment, the fuel cell stack 1 shown in FIG. 3 further includes a member 36 such as a cell or a separator in which a communication path 20 is formed between the cell 10 and the non-power generation member 14 such as a terminal plate. Yes. Similarly to the above, the fuel cell stack 1 includes the first seal member 26 and the second seal member 28 that are disposed between the cell 10 and the member 36 and between the member 36 and the non-power generation member 14. The first seal member 26 circulates in the communication path 20 from the reactive gas discharge manifold 16 to the drainage manifold 18, and the second seal member 28 is inside the first seal member 26 and is a drainage manifold. Orbiting 18 By arranging such a seal member, the communication path 20 can be formed simply by cutting off the space between the reaction gas discharge manifold 16 and the drainage manifold 18 formed in the member 36 such as a cell or a separator. . As a result, complicated processing is not required for the member 36 such as a cell or a separator that forms the communication path 20.

  FIG. 4 is a partial schematic cross-sectional view showing an example of the configuration of the cell in which the communication path is formed. The cell 10 shown in FIG. 4 includes a membrane-electrode assembly 38 and a pair of separators 40 that sandwich the membrane-electrode assembly 38. Although not shown, the membrane-electrode assembly 38 includes an electrolyte membrane and a pair of electrodes (an anode electrode and a cathode electrode) that sandwich the electrolyte membrane. When the communication path 20 is formed in such a cell 10, as described above, it is necessary to cut off the space between the reaction gas discharge manifold 16 and the drainage manifold 18. And in this process, there is a possibility that the separator 40 bends and the separators 40 come into contact with each other and short-circuit. Therefore, as shown in FIG. 4, a part of the second seal member 28 that circulates around the drainage manifold 18 inside the first seal member 26 is placed on the drainage manifold 18 side and the reactive gas discharge manifold 16 side. A part of the third sealing member 42 that is exposed and seals between the separators 40 is exposed to the drainage manifold 18 side and the reaction gas discharge manifold 16 side to prevent a short circuit due to bending of the separator 40 during processing. It is preferable to do.

  FIG. 5 is a partial schematic cross-sectional view showing an example of the configuration of the other end of the fuel cell stack according to the present embodiment. As shown in FIG. 5, a terminal plate 44, an insulator 46, and an end plate 48 are sequentially arranged on the other end (the side opposite to the communication path 20 side) in the stacking direction of the cells 10. Between the cells 10, between the cells 10 and the terminal plate 44, and between the terminal plate 44 and the insulator 46, a seal member 50 that circulates the reaction gas discharge manifold 16 and a seal member 52 that circulates the drainage manifold 18 are arranged. ing. A seal member 54 is also disposed between the insulator 46 and the end plate 48. In the present embodiment, the seal members 50, 52, and 54 may be arranged in any way as long as the reaction gas and water leak from the manifold can be prevented.

  In the present embodiment, the throttle portion 22 formed at the other end (the side opposite to the communication path 20 side) of the reaction gas discharge manifold 16 is formed in the insulator 46, but is not necessarily limited thereto. Further, a joining portion 24 that is formed at the other end of the drainage manifold 18 (on the side opposite to the communication passage 20 side) and joins the reaction gas discharge manifold 16 is formed on the laminated surface of the insulator 46. Here, the joining portion 24 is not limited to the insulator 46 as long as it is formed on the laminated surface of the non-power generating member 14.

  FIG. 10 is a partial schematic cross-sectional view showing the configuration of the other end of the conventional fuel cell stack. As shown in FIG. 10, a terminal plate 44, an insulator 46, and an end plate 48 are sequentially arranged at the other end (the side opposite to the communication path 20 side) of the cell stack 12. Between the cells 10, between the cells 10 and the terminal plate 44, and between the terminal plate 44 and the insulator 46, a seal member 50 that circulates the reaction gas discharge manifold 16 and a seal member 52 that circulates the drainage manifold 18 are arranged. ing. A seal member 54 is also disposed between the insulator 46 and the end plate 48.

  Further, the throttle portion 22 formed at the other end of the reactive gas discharge manifold 16 (on the side opposite to the communication path 20 side) is formed in the insulator 46. A joining portion 24 a that is formed at the other end of the drainage manifold 18 (on the side opposite to the communication path 20 side) and joins the reaction gas discharge manifold 16 is formed inside the insulator 46. When the joining portion 24a is formed inside the non-power generation member 14, the non-power generation member 14 is formed with a receiving portion 56 that receives the seal members 50 and 52 in order to ensure the sealing performance of the seal members 50 and 52. Complicated processing is required.

  On the other hand, as in the present embodiment, the receiving portion 56 that receives the sealing members 50 and 52 on the non-power generating member 14 is formed by forming the joining portion 24 that joins the reactive gas discharge manifold 16 on the laminated surface of the insulator 46. The sealing performance of the sealing members 50 and 52 can be ensured without forming.

  FIG. 6 is a partial schematic cross-sectional view showing an example of the configuration of a cell constituting the cell stack. As shown in FIG. 6, a membrane-electrode assembly 38 and a pair of separators 40 that sandwich the membrane-electrode assembly 38 are provided. Although not shown, the membrane-electrode assembly 38 includes an electrolyte membrane and a pair of electrodes (an anode electrode and a cathode electrode) that sandwich the electrolyte membrane. The cell 10 includes a third seal member 42 that seals between the separators 40.

  Between the cells 10, a fourth seal member 30 that circulates around the drainage manifold 18 and a fifth seal member 32 that extends from the reaction gas discharge manifold 16 to the drainage manifold 18 are arranged. The fourth seal member 30 faces the second seal member 28 shown in FIG. 2, and the fifth seal member 32 faces the first seal member 26 shown in FIG.

  And as shown in FIG. 6, a part of 3rd seal member 42 and the 4th seal member 30 are exposed to the manifold 18 side for drainage, and are tubular. If the third seal member 42 and the fourth seal member 30 are not exposed to the drainage manifold 18 side and are arranged inside, a step is generated between the separator 40 and the seal member, and the drainage manifold 18 as a whole is formed. Becomes bellows. However, as in the present embodiment, a portion of the third seal member 42 and the fourth seal member 30 are exposed to the drainage manifold 18 side to form a tubular shape, thereby forming a smooth drainage manifold 18 without a step. . As a result, the drainage performance of the water in the drainage manifold 18 can be improved.

  FIG. 7 is a partial schematic cross-sectional view showing another example of the configuration of the fuel cell stack according to the present embodiment. As shown in FIG. 7, the fuel cell stack 2 is disposed at a cell stack 12 in which a plurality of cells 10 that generate power by an electrochemical reaction between a fuel gas and an oxidizing gas are stacked, and at an end in the cell stacking direction. And a non-power generation member 14 such as an insulator. Although not shown, a non-power generation member 14 such as an insulator is also disposed at the other end in the cell stacking direction.

  In the fuel cell stack 2, a reaction gas discharge manifold 16 is formed in the cell stacking direction. Although not shown, a reaction gas supply manifold, a cooling water supply / discharge manifold, and the like are also formed in the cell stacking direction. In the present embodiment, the throttle portion 22 formed at one end of the reaction gas discharge manifold 16 is formed in the non-power generation member 14 such as an insulator. Here, the reaction gas discharge manifold 16 shown in FIG. 7 is a fuel gas discharge manifold or an oxidizing gas discharge manifold.

  In addition, the fuel cell stack 2 includes a drainage manifold pipe 58 for draining water generated by the power generation of the cells 10. The drainage manifold pipe 58 is disposed in the reaction gas discharge manifold 16. The drain manifold pipe 58 may be provided in at least one of the reaction gas discharge manifold 16 in the fuel gas discharge manifold and the oxidizing gas manifold.

  Further, a seal member 50 that seals the reaction gas discharge manifold 16 is disposed between the cells 10 and between the non-power generation member 14 and the cell 10.

  In the normal fuel cell stack, unlike the drain manifold pipe 58 of the present embodiment, a drain manifold penetrating in the cell stacking direction is provided, and a communication path that communicates the ends of the drain manifold and the reaction gas discharge manifold. Is formed. In the fuel cell stack having such a configuration, it is necessary to process the drainage manifold, and a seal member for sealing the drainage manifold and the communication path is required, which complicates the configuration of the fuel cell.

  On the other hand, by disposing the drainage manifold pipe 58 in the reaction gas manifold as in this embodiment, processing of the drainage manifold becomes unnecessary, and a seal member for sealing the drainage manifold and the communication path is provided. It becomes unnecessary.

  In the present embodiment, the method of fixing the drain manifold pipe 58 in the reaction gas manifold is not particularly limited. For example, a groove or the like is formed in the non-power generation member 14 or the like, and the drain manifold is formed in the groove. By installing the pipe 58, the drainage manifold pipe 58 is fixed in the reaction gas discharge manifold 16.

  FIG. 8 is a partial schematic cross-sectional view showing another example of the configuration of the fuel cell stack according to the present embodiment. In the present embodiment, as shown in FIG. 7, the entire drainage manifold pipe 58 may be disposed in the reaction gas discharge manifold 16, but as shown in FIG. It may be fixed by being inserted into the non-power generation member 14, and a part of the drainage manifold pipe 58 (other than the end part) may be disposed in the reaction gas discharge manifold 16. When a part of the drainage manifold pipe 58 is disposed in the reaction gas discharge manifold 16, it is necessary to form a junction 60 that connects the drainage manifold pipe 58 and the reaction gas manifold in the non-power generation member 14.

  The flow of the reaction gas and generated water of the fuel cell stack 2 is as follows. First, fuel gas and oxidizing gas are distributed to each cell 10 through the reaction gas supply manifold and used for power generation of the cell 10. Then, the fuel gas and the oxidizing gas (off gas) discharged from the cell 10 pass through the reaction gas discharge manifold 16 and are discharged from the fuel cell stack 2. Further, since the reactive gas passes through the throttle portion 22 of the reactive gas discharge manifold 16, the reactive gas discharge manifold 16 has a negative pressure. Therefore, the drainage manifold pipe 58 in the reactive gas discharge manifold 16 also has a negative pressure. Become. As a result, the water generated during the power generation of the cell 10 passes through the drainage manifold pipe 58 having a negative pressure and is discharged from the fuel cell stack 2.

  1, 2 Fuel cell stack, 10 cell, 12 cell stack, 14 Non-power generation member, 16 Reactant gas discharge manifold, 18 Drain manifold, 20 Communication path, 22 Throttle part, 24, 24a Merge part, 26, 26a, 28, 28a, 30, 32, 42, 50, 52, 54 Seal member, 34, 56 Receiving part, 36 member, 38 Membrane-electrode assembly, 40 Separator, 44 Terminal plate, 46 Insulator, 48 End plate, 58 Drainage Manifold pipe, 60 junction.

Claims (4)

A fuel cell stack in which a plurality of cells are stacked,
A reaction gas discharge manifold formed in the cell stacking direction;
A drainage manifold formed in the cell stacking direction;
A communication passage formed at the end of the cell in the stacking direction and communicating the reaction gas discharge manifold and the drainage manifold;
A first seal member that circulates in the communication path;
A fuel cell stack, comprising: a second seal member disposed inside the first seal member and circulating around the drainage manifold. The fuel cell stack according to claim 1, wherein
A constriction formed at the end of the reaction gas discharge manifold opposite to the communication path;
Formed at the end of the drainage manifold on the side opposite to the communication path, and a merging portion that merges with the reaction gas discharge manifold on the side opposite to the communication path,
The said junction part is formed along the lamination surface of the non-electric power generation member arrange | positioned at the lamination direction edge part of the said cell, The fuel cell stack characterized by the above-mentioned. The fuel cell stack according to claim 1 or 2,
The cell includes a third seal member disposed between a pair of separators sandwiching a membrane-electrode assembly in which a pair of electrodes are disposed on both sides of the electrolyte, and circulates the drainage manifold.
A fourth seal member disposed between the cells and circulating around the drainage manifold;
A part of the third seal member and the fourth seal member are exposed to the drainage manifold and have a tubular shape. A fuel cell stack in which a plurality of cells are stacked,
A reaction gas discharge manifold formed in the cell stacking direction;
A throttle formed at the end of the reaction gas discharge manifold on the reaction gas outlet side;
And a tubular drainage manifold provided in the reaction gas discharge manifold.

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