JP2009123521A - Fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell having an annular fuel cell stack formed of each hemispherical fuel cell. <P>SOLUTION: Each fuel cell 10 is formed into a hemisphere shape as a whole, the hemispherical outer surface 12 is used as one electrode and the inner surface 14 is used as the other electrode. For example, the outer surface 12 is used as a cathode and the inner surface 14 is used as an anode. When a plurality of fuel cells 10 are laminated, one outer surface 12 and the other inner surface 14 of adjoining two fuel cells 10 are superposed on each other. An annular doughnut-shaped fuel cell stack 50 is formed as a whole by laminating fuel cells 10 in the lamination direction along the periphery. An fastening belt 30 is attached along an annular outer circumference of the fuel cell stack 50. The fuel cell stack 50 is fastened from the outer circumference by the fastening belt 30. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a fuel cell having a fuel cell stack in which a plurality of fuel cells are stacked.

  There is known a fuel cell that converts chemical energy obtained by reacting a fuel gas containing hydrogen with an oxidizing gas containing oxygen into electric energy. Generally, a fuel cell includes a fuel cell stack formed by stacking a number of fuel cells that perform the above-described chemical reaction. Various proposals have been made for the shape of each fuel cell and the shape of the fuel cell stack.

  For example, Patent Document 1 describes a technique in which a plate-like ion conductive element (fuel cell) having a rectangular surface is stacked to form an annular ion conductive module (fuel cell stack). Patent Document 2 describes a technique in which fuel cells (fuel cells) configured in a substantially conical surface shape are stacked to form a cylindrical fuel cell stack.

Japanese National Patent Publication No. 8-500692 JP 2004-47155 A

  As described above, a variety of technologies relating to the shape of each fuel cell and the shape of the fuel cell stack have been proposed, and the present inventor has repeatedly researched and developed the structure of the fuel cell stack formed in an annular shape. It was. In particular, attention was paid to the shape of each fuel cell constituting the annular fuel cell stack.

  The present invention has been made in the course of research and development, and an object thereof is to improve the shape of each fuel cell constituting the annular fuel cell stack.

  In order to achieve the above object, a fuel cell according to a preferred embodiment of the present invention is a fuel cell having a fuel cell stack in which a plurality of fuel cells are stacked, and each of the fuel cells is a hemisphere as a whole. The fuel cell stack is formed in a planar shape, with the hemispherical outer surface as one pole and the inner surface as the other pole, and the fuel cell stack has one outer surface and the other inner surface of two adjacent fuel cells. A plurality of fuel cells are stacked and stacked in the stacking direction along the circumference, thereby forming an annular shape as a whole.

  According to the above aspect, a fuel cell having an annular fuel cell stack formed by hemispherical fuel cells is provided. In the above aspect, each fuel cell only needs to have a hemispherical shape as a whole, and a portion different from the hemispherical shape may exist in a part of each fuel cell. The hemispherical shape includes an ideal hemispherical surface, but may be a distorted true hemispherical surface without departing from the essence of the present invention. In addition, the fuel cell stack may have an annular shape as a whole, and a portion different from the annular shape may exist in a part of the fuel cell stack. In addition, although an annular shape includes an ideal annular shape, a true annular shape may be distorted without departing from the essence of the present invention. For example, an elliptical ring shape close to a true circular shape is also included in the circular concept. In addition, a shape obtained by twisting a true annular shape or an elliptical shape a little is included in the concept of an annular shape.

  In a preferred aspect, the fuel cell stack is clamped from an annular outer periphery thereof, and a load along the stacking direction is applied to the plurality of stacked fuel cells. According to this aspect, it is possible to apply a load uniformly to each of the plurality of fuel cells as compared to the conventional annular fuel cell stack in which flat plate fuel cells having a rectangular surface are stacked. A load can be applied uniformly in the plane of each fuel cell.

  In a preferred embodiment, the fuel cell has a hemispherical dummy cell substantially the same shape as each of the fuel cells, and the dummy cell is inserted between two fuel cells in a fuel cell stack formed in an annular shape. It functions as a terminal for taking out electricity from the stack, and gas is supplied to and discharged from the fuel cell stack through the dummy cell.

  In a preferred embodiment, each fuel cell is formed with a flow path for gas that is supplied from the inner surface into the cell and discharged from the outer surface to the outside of the cell, and the fuel cell stack includes a plurality of fuel cells. A gas flow path from the inner surface to the outer surface of each fuel battery cell is formed along the stacking direction.

  In a preferred embodiment, the fuel cell stack is cooled between the outer surface of one of the two adjacent fuel cells and the inner surface of the other fuel cell, and flows through the surface of each fuel cell to cool the cell. A water flow path is formed.

  In a preferred aspect, the fuel cell stack includes a fastening belt that is attached along the annular outer periphery of the fuel cell stack and fastens the fuel cell stack from the outer periphery, and each of the fuel cells has a fastening belt at a portion that contacts the fastening belt. A support portion for supporting is formed.

  The present invention provides a fuel cell having an annular fuel cell stack formed by hemispherical fuel cells. For example, according to a preferred embodiment of the present invention, it is possible to apply a load uniformly to each of the plurality of fuel cells as compared with the conventional annular fuel cell stack, and to uniformly distribute the fuel cells in the plane. A load can be applied.

  Hereinafter, preferred embodiments of the present invention will be described. FIG. 1 is a diagram showing a preferred embodiment of the present invention. FIG. 1 is a perspective view of a fuel cell 100 and a fuel cell 10. The fuel cell 100 has a fuel cell stack 50 in which a plurality of fuel cells 10 are annularly stacked.

  As shown in FIG. 1B, each fuel cell 10 is formed in a hemispherical shape as a whole, with the hemispherical outer surface 12 as one pole and the inner surface 14 as the other pole. For example, the outer surface 12 is a cathode and the inner surface 14 is an anode. Of course, the outer surface 12 may be the anode and the inner surface 14 may be the cathode.

  Each fuel cell 10 is formed, for example, by superposing a hemispherical anode layer, a hemispherical electrolyte membrane, and a hemispherical cathode layer. For example, each fuel cell 10 is formed by laminating an anode separator, an anode diffusion layer, an anode catalyst layer, an electrolyte membrane, a cathode catalyst layer, a cathode diffusion layer, and a cathode separator in this order from the inner surface 14 side. A round hole may be provided in the zenith portion of each fuel cell 10.

  When a plurality of fuel cells 10 shown in FIG. 1B are stacked, one outer surface 12 and the other inner surface 14 of two adjacent fuel cells 10 are overlapped. Then, by laminating the plurality of fuel cells 10 in the laminating direction along the circumference, an annular donut-shaped fuel cell stack 50 is formed as a whole as shown in FIG.

  A fastening belt 30 is attached to the fuel cell stack 50 along its annular outer periphery, and the fuel cell stack 50 is fastened from the outer periphery by the fastening belt 30. By tightening the fastening belt 30, a load along the stacking direction is applied to the plurality of stacked fuel cells 10, and one outer surface 12 and the other inner surface of two adjacent fuel cells 10. The side surface 14 is in strong physical contact, and the electrical contact resistance (electric resistance) therebetween is reduced. Since each fuel battery cell 10 has a hemispherical shape, for example, compared to a flat plate shape, a load can be applied uniformly to each of the plurality of fuel battery cells 10. A load can be applied uniformly in the plane.

  In the fuel cell stack 50, a hemispherical dummy cell 20 having the same shape as each fuel cell 10 is provided. The dummy cells 20 are inserted between the two fuel cells 10 in the fuel cell stack 50 formed in an annular shape. The dummy cell 20 functions as a terminal for taking out electricity from the fuel cell stack 50, and gas is supplied to and discharged from the fuel cell stack 50 via the dummy cell 20. The cooling water may be supplied to or discharged from the fuel cell stack 50 via the dummy cell 20.

  The fuel cell stack 50 is enclosed in a thermostatic container 40 having a shape similar to the fuel cell stack 50. Then, the cooling water is circulated in the constant temperature container 40, and each fuel cell 10 of the fuel cell stack 50 is cooled by the cooling water.

  FIG. 2 is a diagram showing an example of a manufacturing method of the annular fuel cell stack shown in FIG. When forming an annular fuel cell stack, for example, as shown in FIG. 2, two semi-annular stacks corresponding to half of the annular ring are formed, and the two semi-annular stacks are combined. This makes it possible to form an annular fuel cell stack relatively easily.

  FIG. 3 is a diagram for explaining the flow of gas for each fuel cell 10. The fuel cell stack exchanges gas with the outside via the dummy cells 20. That is, the dummy cell 20 is provided with a gas inlet 22I and a gas outlet 22D. Gas is taken into the fuel cell stack from the gas inlet 22I, and gas in the fuel cell stack is discharged from the gas outlet 22D.

  Note that one of the oxidizing gas (for example, air) and the fuel gas (for example, hydrogen) is taken in from the gas inlet 22I, and the other gas is taken in from the other gas inlet 22′I. Further, one of the oxidizing gas and the fuel gas is discharged from the gas outlet 22D, and the other gas is discharged from the other gas outlet 22′D.

  The gas taken in from the gas inlet 22I of the dummy cell 20 flows toward the fuel cell 10 (reference numeral 62) and is used for power generation of the fuel cell 10. The gas (reference numeral 62) taken from the dummy cell 20 and flowing toward the fuel battery cell 10 passes through the fuel battery cell 10 and is also sent to the next fuel battery cell 10 (not shown) (reference numeral 68).

  The gas (reference numeral 62) that has reached the fuel cell 10 enters the cell from the inner surface of the fuel cell 10 and diffuses in the cell (reference numeral 64). The gas diffused in the cell and used for power generation is discharged from the zenith portion on the outer surface of the fuel cell 10 (reference numeral 66). The gas is introduced from the inner surface of the hemispherical surface and discharged from the zenith portion of the outer surface, which is excellent in dispersibility. Also, for example, the cross flow may be realized by taking one gas into the cell from the position on the front side of the drawing and taking the other gas into the cell from the position on the back side of the drawing.

  The dummy cell 20 is provided with a cooling water inlet 24I and a cooling water outlet 24D, cooling water is taken into the fuel cell stack from the cooling water inlet 24I, and cooling water after circulation in the fuel cell stack is discharged from the cooling water outlet 24D. May be.

  FIG. 4 is a view for explaining the gas flow in the fuel cell stack 50. The gas taken in from the gas inlet 22I provided in the dummy cell flows in the fuel cell stack 50 in the direction from the inner surface to the outer surface of each fuel cell along the stacking direction of the plurality of fuel cells. For example, the flow is counterclockwise (reference numeral 72) as shown in FIG. And the gas utilized for electric power generation in each fuel battery cell flows through the discharge passage of the top part of each fuel battery cell, and is discharged | emitted from gas outlet 22D.

  As shown in FIG. 4, two dummy cells may be provided to take in the same gas from the two gas inlets 22I and to discharge the same gas from the two gas outlets 22D. For example, gas is supplied from one gas inlet 22I to half the stack of the fuel cell stack 50, and gas is discharged from one gas outlet 22D at the opposite position (position different by 180 °). Then, gas is supplied from the other gas inlet 22I to the remaining half of the fuel cell stack 50, and gas is discharged from the other gas outlet 22D at the opposite position. By providing a plurality of inlets and outlets for the same gas, pressure loss can be reduced.

  FIG. 5 is a view for explaining the flow of cooling water in the thermostatic container 40. In the thermostatic container 40, the cooling water flows in the direction of the arrow 80 along the stacking direction of the fuel cell stack 50, and cools each fuel cell in the fuel cell stack 50. For example, the cooling water flowing in the constant temperature container 40 may be cooled by cooling the constant temperature container 40 by a method such as air cooling.

  6 and 7 are diagrams for explaining the flow of cooling water on the surface of the fuel cell 10. The fuel cell stack enters between the outer surface of one of the two adjacent fuel cells 10 and the other inner surface, and flows through the surface of each fuel cell 10 to cool the cells. A path is formed.

  That is, as shown in FIG. 6, from the gap between the equator portions of two adjacent fuel cells 10, the outer surface of one fuel cell 10 (1) and the inner surface of the other fuel cell 10 (2) The cooling water enters between the two, and after the cooling water that has entered is used for cooling the fuel cell 10 (1) and the fuel cell 10 (2), it is discharged through the zenith portion of the fuel cell 10 (2). Is done.

  For example, as shown in FIG. 7, the cooling water flows along the outer surface of the fuel cell 10 (1) (reference numeral 72) while cooling the fuel cell 10 (1), while the fuel cell 10 (1) Toward the zenith portion of the fuel cell 10 and discharged from the zenith portion of the fuel cell 10 (1) (reference numeral 74). Incidentally, the waste water 76 from the cell in front of the fuel cell 10 (1) joins the flow of reference numeral 74 through the center of the fuel cell 10 (1). For example, the cooling water inlet provided in the dummy cell can be omitted by circulating the cooling water around the outer periphery of the annular fuel cell stack and draining it through the center of each fuel cell 10.

  FIG. 8 is a view for explaining the fastening belt 30 attached to the fuel cell stack. The fastening belt 30 is attached along the annular outer periphery of the fuel cell stack, and tightens the plurality of fuel cells 10 from the outer periphery of the fuel cell stack as shown in FIG. Thereby, a load along the stacking direction is applied to the plurality of fuel cells 10 stacked in an annular shape, and one outer surface 12 and the other inner surface 14 of the two adjacent fuel cells 10. Are in strong physical contact with each other, and the electrical contact resistance (electric resistance) therebetween is reduced.

  Each fuel cell 10 is formed with a support portion that supports the fastening belt 30 at a portion where the fastening belt 30 contacts. For example, as shown in FIG. 8 (B), a recess 16 is provided in a portion that contacts the fastening belt 30 for each hemispherical fuel cell 10. Further, as shown in FIG. 8C, scratches 18 may be provided at the portions that contact the fastening belt 30 for each fuel cell 10. The fastening belt 30 is supported by the recess 16 and the scratch 18 so as not to deviate from the outer periphery of the fuel cell stack, and the fastening belt 30 can be strongly tightened.

  As mentioned above, although preferred embodiment of this invention was described, embodiment mentioned above is only a mere illustration in all the points, and does not limit the scope of the present invention. The present invention includes various modifications without departing from the essence thereof.

1 is a perspective view of a fuel cell 100 and a fuel cell 10 according to the present invention. It is a figure which shows an example of the manufacturing method of an annular | circular shaped fuel cell stack. 4 is a diagram for explaining a gas flow for each fuel cell 10. FIG. 4 is a diagram for explaining a gas flow in the fuel cell stack 50. FIG. It is a figure for demonstrating the flow of the cooling water in the constant temperature container. 3 is a diagram for explaining the flow of cooling water on the surface of the fuel cell 10. FIG. 3 is a diagram for explaining the flow of cooling water on the surface of the fuel cell 10. FIG. It is a figure for demonstrating the fastening belt attached to a fuel cell stack.

Explanation of symbols

  10 fuel cell, 20 dummy cell, 30 fastening belt, 50 fuel cell stack, 100 fuel cell.

Claims (6)

A fuel cell having a fuel cell stack in which a plurality of fuel cells are stacked,
Each fuel cell is formed in a semispherical shape as a whole, the hemispherical outer surface as one pole and the inner surface as the other pole,
The fuel cell stack is formed by stacking a plurality of fuel cells in a stacking direction along the circumference by overlapping one outer surface and the other inner surface of two adjacent fuel cells. Formed as a whole in an annular shape,
The fuel cell characterized by the above-mentioned. The fuel cell according to claim 1, wherein
The fuel cell stack is tightened from its annular outer periphery,
A load along the stacking direction is applied to the stacked fuel cells.
The fuel cell characterized by the above-mentioned. The fuel cell according to claim 2, wherein
A hemispherical dummy cell having substantially the same shape as each of the fuel cells,
The dummy cell is inserted between two fuel cells in a fuel cell stack formed in an annular shape, and functions as a terminal for taking out electricity from the fuel cell stack,
Gas is supplied to and discharged from the fuel cell stack through the dummy cell.
The fuel cell characterized by the above-mentioned. The fuel cell according to claim 3, wherein
Each fuel cell is provided with a gas flow path that is supplied from the inner surface into the cell and discharged from the outer surface to the outside of the cell,
In the fuel cell stack, a gas flow path from the inner surface to the outer surface of each fuel cell is formed along the stacking direction of the plurality of fuel cells.
The fuel cell characterized by the above-mentioned. The fuel cell according to claim 4, wherein
In the fuel cell stack, a cooling water flow path that enters between one outer surface and the other inner surface of two adjacent fuel cells and flows through the surface of each fuel cell to cool the cells. Is formed,
The fuel cell characterized by the above-mentioned. The fuel cell according to claim 5, wherein
A fastening belt that is attached along the annular outer periphery of the fuel cell stack and fastens the fuel cell stack from the outer periphery;
In each fuel cell, a support portion for supporting the fastening belt is formed at a portion where the fastening belt contacts.
The fuel cell characterized by the above-mentioned.

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