JP4025640B2 - Fuel cell - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fuel cell, and more particularly to a fuel cell having an air supply side manifold that uniformly distributes and supplies gas to fuel cells.
[0002]
[Prior art]
In recent years, various fuel cells in which a stack of fuel cells is accommodated in a storage container have been proposed as next-generation energy.
[0003]
A fuel cell is configured by sandwiching a solid electrolyte between an air electrode and a fuel electrode, supplying an oxygen-containing gas to the air electrode, and supplying a gas containing hydrogen or a gas that can be changed to hydrogen to the fuel electrode, A potential difference is generated between the electrodes facing each other with the solid electrolyte interposed therebetween, and power is generated.
[0004]
These fuel cells can be used in various combinations depending on the electrolyte and form used, but in most cases, the fuel cell is supplied with a gas containing oxygen and a gas containing hydrogen or a gas that can be changed to hydrogen to generate power. Do.
[0005]
In addition, since the amount of power generated per fuel cell is small, the fuel cell is configured by electrically connecting a plurality of fuel cells.
[0006]
Therefore, it is necessary to supply oxygen-containing gas, hydrogen-containing gas, or gas that can be changed to hydrogen to a plurality of fuel cells. At the same time, in order to improve the power generation amount and the power generation efficiency, the amount of gas supplied to each fuel cell needs to be the same.
[0007]
FIG. 8 shows a conventional flat fuel cell. In this flat fuel cell, an air supply side gas pipe 3 for introducing gas into the plurality of fuel cells 1 from the outside is provided in the air supply side manifold 5. The supply side manifold 5 is formed with supply side gas chambers 9 for introducing gas to the gas introduction ports 7 at one end of the plurality of fuel cells 1.
[0008]
A gas discharge port 11 for discharging the gas from the fuel cell 1 is formed at the other end of the fuel cell 1, and an exhaust side manifold 13 and an exhaust side gas for discharging the exhausted gas to the outside of the fuel cell. A pipe 15 is arranged. An exhaust side gas chamber 17 for collecting exhaust gas is formed in the exhaust side manifold 13. A gas flow path 19 that communicates from the gas inlet 7 to the gas outlet 11 is formed between the fuel cells 1.
[0009]
In the flat fuel cell, the fuel cell 1 generally has a rectangular plate shape, and the supply side manifold 5 and the exhaust side manifold 13 shown in FIG. 8 supply fuel gas to the fuel cell 1. Although it is for exhausting, although not shown, it has an air supply side manifold 5 and an exhaust side manifold 13 for supplying and exhausting an oxygen-containing gas in a direction perpendicular to the fuel gas.
[0010]
FIG. 9 shows a module in which the fuel cells 1 of FIG. 8 are stacked.
[0011]
The fuel cell 1 includes a fuel electrode 1a, a solid electrolyte 1b, an air electrode 1c, and a separator 1d. Gas flow paths 19 are formed on both surfaces of the separator 1d, and a gas flow path on the side in contact with the fuel electrode 1a. A fuel gas is supplied to 19 and an oxygen-containing gas is supplied to the gas flow path 19 on the side in contact with the air electrode 1c.
[0012]
In such a flat plate fuel cell, a fuel gas is supplied to the supply side manifold 5 shown in FIG. 8 and the gas introduction port formed at one end of the fuel cell 1 through the supply side gas chamber 9. The gas is guided to 7 and passed through the gas flow path 19 formed between the fuel cells 1. The gas that has passed through the gas flow path 19 is led from the gas discharge port 11 formed at the other end of the fuel cell 1 to the exhaust side gas chamber 17 formed in the exhaust side manifold 13, and the exhaust side gas pipe 15. Is exhausted to the outside of the fuel cell.
[0013]
At the same time, oxygen-containing gas is supplied to the fuel cell 1 through the other air supply side manifold (not shown) to generate electric power (see, for example, Patent Document 1).
[0014]
In such a fuel cell, gas is distributed and supplied to the plurality of fuel cells 1 from the supply-side gas pipe 3 through the supply-side gas chamber 9 provided in the supply-side manifold 5.
[0015]
[Patent Document 1]
JP-A-9-199150 [0016]
[Problems to be solved by the invention]
However, in the fuel cell having such a structure, a large amount of gas is supplied to the fuel cell 1 in the vicinity of the air supply side gas pipe 3 connected to the air supply side manifold 5, and a position away from the air supply side gas pipe 3. There is a problem in that the fuel battery cell 1 in FIG. Therefore, the fuel cell 1 located at a position away from the supply side gas pipe 3 is not effectively used, and there is a problem that the power generation amount of the fuel cell is reduced and the power generation efficiency is reduced.
[0017]
In a fuel cell, since the amount of gas supplied to each fuel cell 1 is excessive or insufficient greatly affects the power generation amount and power generation efficiency of the fuel cell, It is necessary to control the gas supply amount so as to be supplied uniformly.
[0018]
Therefore, a method of measuring the gas flow rate of each fuel cell 1 and controlling the gas flow rate using a valve or the like can be considered, but the structure becomes complicated and a control system is required. There are problems such as an increase in the size of the apparatus and an increase in cost.
[0019]
An object of the present invention is to provide a fuel cell that can supply gas uniformly to a plurality of fuel cells with a simple structure.
[0020]
[Means for Solving the Problems]
The fuel cell of the present invention, the storage container, a plurality housed a fuel cell having a gas flow path, the supply side manifold for supplying gas to each of the gas flow path having a fuel cell of the plurality of The air supply side manifold has a plurality of gas supply passages formed by branching from the air supply side gas piping, and the open ends of the gas supply passages are connected to the fuel cells. A gas supply port for supplying gas to the gas flow path of the battery cell is provided, and the lengths of the gas supply paths are the same .
[0021]
In such a fuel cell, the supply side manifold has a plurality of gas supply paths formed by branching from the supply side gas pipe, and the open end of each gas supply path is connected to the gas flow path of each fuel cell. Since each gas supply path has the same length, the pressure loss when passing through the gas supply path is the same even when looking at the fuel cell. A control device is not required, gas can be uniformly distributed and supplied to each fuel cell with a simple structure, and the fuel cell can be reduced in size and cost.
[0023]
The fuel cell of the present invention, the Kyukigawa manifold, the through holes are formed plate-like body with formed by stacking a plurality of said gas supply passage by successive said through hole is formed Features.
[0024]
Such an air supply side manifold is easy to manufacture and can be manufactured at low cost. Further, by making the through-hole formed in the plate-like body into a slit shape, in particular, gas can be uniformly distributed to each gas flow path of the fuel cell of the flat plate type fuel cell. In addition, by providing the through holes formed in the plate-like body at regular intervals, a three-dimensional gas supply path can be formed, and for example, it can be applied to a fuel cell using a cylindrical fuel cell. .
[0025]
The fuel cell of the present invention is characterized in that the Kyukigawa manifold is formed by a tube.
[0026]
Such an air supply side manifold can uniformly distribute gas to a large number of fuel cells, and is particularly preferably used in a fuel cell using a cylindrical fuel cell.
[0027]
The fuel cell of the present invention, the gas supply port, characterized in that it is connected to the gas inlet for introducing a gas into said plurality of fuel cells.
[0028]
In such a fuel cell, a plurality of gas supply ports formed in the supply side manifold are connected to the gas introduction ports of the fuel cells in a one-to-one relationship. Gas can be distributed evenly.
[0029]
The fuel cell of the present invention, the gas supply port, characterized in that respectively disposed opposite at a predetermined distance to the gas inlet.
[0030]
In such a fuel cell, a plurality of gas supply ports formed in the supply side manifold and the gas introduction ports of the fuel cell are provided in pairs, so that the gas is evenly distributed to all the fuel cells. it can. Further, since the gas supply port and the gas introduction port of the fuel cell are provided to face each other with a predetermined interval, a space is provided between the gas supply port and the gas introduction port, and the gas supply port In this structure, the gas inlets of the fuel cells and the gas inlets of the fuel cells are not directly connected to each other. Easy installation of the air side manifold.
[0031]
The fuel cell of the present invention, the edge of the gas outlet port side for discharging the gas from the fuel cell, the lid-like member having a suppressing gas emissions hole a gas flow amount of the gas channel It is provided.
[0032]
In such a fuel cell, for example, even if the shape of the gas flow path between fuel cells or inside the fuel cells varies, the amount of gas flowing between the fuel cells or inside the fuel cells is made uniform. Therefore, by using it together with the supply side manifold that supplies gas uniformly between the fuel cells or inside the fuel cells, the amount of gas supplied can be made more uniform, The power generation performance can be improved.
[0033]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a cross-sectional view of one embodiment of the fuel cell of the present invention. In addition, the same code | symbol was attached | subjected to the same member as the prior art.
[0034]
The fuel cell shown here is a flat plate type fuel cell, in which a fuel cell 1 comprising a solid electrolyte 1b, a fuel electrode 1a, an air electrode 1c, and a separator 1d is laminated to form a module shown in FIG. A gas flow path 19 is formed between the fuel cells 1 of the module. A gas introduction port 7 is formed at one end of the fuel cell 1, and an air supply side manifold 22 having a gas supply path 21 formed on the side surface of the module in which the gas introduction port 7 is formed. Is arranged. A gas discharge port 11 is formed at the other end of the fuel cell 1, and an exhaust side manifold 13 having an exhaust side gas chamber 17 formed on the side surface of the module in which the gas discharge port 11 is formed. Is arranged. An air supply side gas pipe 3 is connected to the air supply side manifold 22, and an exhaust side gas pipe 15 is connected to the exhaust side manifold 13.
[0035]
The gas supply path 21 formed in the supply side manifold 22 has a fractal structure. The gas supply path 21 supplies fuel gas from the supply side gas pipe 3 to the gas inlet 7 of the fuel cell 1. Supply. A fractal is a pattern in which a certain regular branching pattern is repeatedly generated. In particular, a pattern in which a road coming from one direction branches at 90 degrees to the left and right is called an etch fractal. Here, the gas supply path 21 in the supply side manifold 22 of the present invention has a structure manufactured according to this fractal pattern. By making the gas supply path of the supply side manifold a fractal structure, the supply side The gas supply path distance from the gas pipe to the gas introduction part of the fuel battery cell, the cross-sectional area, the number of branches of the gas supply path, and the branch angle are equal regardless of which fuel battery cell is seen. All of the gas supply paths 21 have the same distance from the gas supply side gas pipe 3 to the gas introduction port 7 of the fuel cell 1, and the cross-sectional area, the number of branches, and the angle of the branch are equal. Without using a control device or the like, the fuel gas can be uniformly supplied to the gas inlets 7 of all the fuel cells 1, and the power generation capability of the fuel cells can be maximized . Miniaturization and cost reduction can be achieved .
[0036]
That is, conventionally, sufficient gas is not supplied to the fuel cell 1 separated from the supply side gas pipe 3, and for example, there is a problem that the fuel electrode 1a is oxidized due to a shortage of the fuel gas and the conductivity is lost. there were. In addition, due to the lack of the oxygen-containing gas, there is a problem that the air electrode 1c expands in volume and peels off from the solid electrolyte 1b.
[0037]
Further, the fuel cell 1 close to the supply-side gas pipe 3 has a problem that the fuel gas and the oxygen-containing gas are excessively supplied, and the power generation efficiency is lowered.
[0038]
On the other hand, in the fuel cell of the present invention, gas can be uniformly supplied to the gas inlets 7 of all the fuel cells 1, so that the above problem can be solved and the power generation capacity of the fuel cell can be maximized. it can.
[0039]
On the other hand, although not shown, the surface of the module in which the supply side manifold 22 for supplying the oxygen-containing gas to the other gas introduction port 7 of the fuel cell 1 is provided with the gas introduction port 7 for supplying the fuel gas. The oxygen-containing gas is also supplied to the other gas inlet 7 of the fuel cell 1 in the same manner as the fuel gas.
[0040]
FIG. 2 is a perspective view of the supply side manifold 22. A plurality of gas supply ports 21 a are formed on the surface of the supply side manifold 22 facing the fuel cell module, and fuel gas of the same gas amount is supplied to the gas introduction ports 7 of the fuel cells 1 from the plurality of gas supply ports 21 a. Supplied.
[0041]
FIG. 3 is an enlarged view of part A of FIG. 2, and shows a schematic diagram of the gas supply path 21 formed in the supply side manifold 22 and the gas passing through the gas supply path 21. A fractal-shaped gas supply path 21 is formed in the supply side manifold 22, and the gas that has passed through the gas supply path 21 is supplied from the gas supply port 21 a to the gas introduction port 7 of the fuel cell 1.
[0042]
FIG. 4 shows another embodiment of the fuel cell according to the present invention. This fuel cell is a flat plate fuel cell similar to that shown in FIG. 1, and includes a gas inlet 7 of the fuel cell 1 and an air supply side manifold 22. The gas supply port 21a of the gas supply path 21 formed at the front is provided to face the gas supply port 21a at a predetermined interval, and the air supply side gas chamber 9 is formed therebetween.
[0043]
In such a fuel cell, it is not necessary to connect the gas introduction port 7 of the fuel cell 1 and the gas supply port 21a of the gas supply path 21 formed in the supply side manifold 22 respectively. Positioning of the manifold 22 and the module is simplified. Further, the fuel gas or the oxygen-containing gas can be uniformly supplied to the gas introduction port 7 of each fuel battery cell 1 through the gas supply port 21 a formed in the supply side manifold 22. Can be maximized.
[0044]
FIG. 5 shows an example of a method for producing the air supply side manifold 22 of the present invention. The air supply side manifold 22 is formed, for example, in the plate-like body 22b shown in FIGS. And can be easily and accurately manufactured. The shape of the through hole 23 may be, for example, a slit shape, a hole shape, or a combination thereof. Further, for example, a brazing material is used for joining the plate-like bodies 22b. At this time, the through hole 23 provided in the plate-like body 22b shown in FIGS. 5A to 5K becomes the gas supply path 21 after being stacked.
[0045]
FIG. 6 shows still another embodiment of the fuel cell according to the present invention. This fuel cell is constituted by using a cylindrical fuel cell 25. The cylindrical fuel cell 25 is connected to the supply side manifold 22 at one end, and the supply side gas pipe 3 is connected to the supply side manifold 22. In this cylindrical fuel cell 25, a power generation part in which a solid electrolyte 25b is sandwiched between a fuel electrode 25a and an air electrode 25c is formed on a fuel electrode support 25e, and a gas inlet 7 of the cylindrical fuel cell 25 is formed. Further, the gas supply ports 21a of the supply side manifold 22 are connected to each other. A gas flow path 19 through which fuel gas flows is formed inside the cylindrical fuel cell 25. An oxygen-containing gas is supplied to the outside of the fuel battery cell 25.
[0046]
In such a fuel cell, the air supply side manifold 22 connected to the cylindrical fuel cell 25 is tubular and has an etch fractal structure, and the fuel gas or oxygen is uniformly distributed to all the cylindrical fuel cells 25. The contained gas can be distributed.
[0047]
Although the tubular air supply side manifold 22 has a complicated structure, it can be easily manufactured by welding a plurality of tubes or using screws or the like.
[0048]
FIG. 7 shows a cylindrical fuel cell 25 provided with a lid-like member 27, and a gas that suppresses the gas flow rate of the gas flow channel 19 at the end of the cylindrical fuel cell 25 on the gas exhaust port side. A lid-like member 27 having a discharge suppression hole 26 is provided.
[0049]
That is, as described above, the tubular air supply side manifold 22 having the fractal structure gas supply passage 21 is connected to the air supply side end of the cylindrical fuel cell 25, and the end on the exhaust port side is connected. A lid-like member 27 having a gas discharge suppression hole 26 is connected to the.
[0050]
The tubular fuel cell 25 is configured by sequentially laminating a porous fuel electrode 25a, a dense solid electrolyte 25b, and a porous air electrode 25c on the surface of a porous support 25e. The lid-like member 27 includes a shielding plate 27 a in which the gas discharge suppression hole 26 is formed, and an annular body 27 b that externally fits the lid-like member 27 to the tubular fuel cell 25.
[0051]
In such a fuel cell, the fuel gas is uniformly supplied to the gas inlet 7 of the cylindrical fuel cell 25 through the gas supply passage 21 having a fractal structure in the tubular supply side manifold 22, and the cylindrical fuel cell. It passes through the gas flow path 19 formed inside the cell 25, and further passes through the gas discharge suppression hole 26 formed in the lid-like member 27.
[0052]
Further, an oxygen-containing gas is supplied to the outside of the cylindrical fuel cell 25, and power is generated by a power generation unit in which a porous fuel electrode 25a, a dense solid electrolyte 25b, and a porous air electrode 25c are stacked.
[0053]
In such a fuel cell, the gas is uniformly supplied to the gas introduction port 7 of the cylindrical fuel cell 25 through the gas supply path 21 having a fractal structure, and the end of the cylindrical fuel cell 25 on the exhaust port side . Since the lid-like member 27 provided in the portion can exhaust the gas evenly on the exhaust side, the amount of gas passing through the plurality of cylindrical fuel cells 25 can be made more uniform with high accuracy.
[0054]
Therefore, in such a fuel cell, an optimal gas amount can be supplied to the gas flow path 19 of each cylindrical fuel cell 25, and the power generation amount can be maximized.
[0055]
In addition, this invention is not limited to the said form, A various change is possible in the range which does not change the summary of invention.
[0056]
For example, the angle of branching of the gas supply path 21 formed in the supply side manifold 22 is not necessarily 90 degrees, and may be branched symmetrically so that the gas flows uniformly. Further, the exhaust side manifold 13 may have the same shape as the supply side manifold 22 of the present invention. The lid member 27 may be used for a flat plate fuel cell.
[0057]
【The invention's effect】
In the present invention, in a fuel cell in which a plurality of fuel cells are stored in a storage container, a gas supply path is formed by branching from a supply-side gas pipe, and an open end of each gas supply path is formed in each fuel cell. The gas supply port is used to supply gas to the gas flow path. By using the same length for each gas supply path, the gas used for power generation can be distributed and supplied uniformly to each fuel cell. In addition, simplification of the structure, improvement of power generation efficiency, and cost reduction can be achieved simultaneously.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a flat plate fuel cell of the present invention.
2 is a perspective view showing an air supply side manifold of FIG. 1; FIG.
3 is a schematic diagram showing an air supply side manifold of FIG. 2; FIG.
FIG. 4 is a longitudinal sectional view showing another embodiment of the fuel cell of the present invention.
FIG. 5 is a longitudinal sectional view showing a manufacturing example of an air supply side manifold used in the fuel cell of the present invention.
FIG. 6 is a plan view showing another embodiment of the fuel cell of the present invention.
FIG. 7 is a longitudinal sectional view (a) showing an embodiment of the present invention in which a lid-like member is provided at an exhaust port side end, and a perspective view (b) of the lid-like member.
FIG. 8 is a longitudinal sectional view showing a conventional fuel cell.
FIG. 9 is a perspective view showing a conventional fuel cell.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Fuel cell 5 ... Supply side manifold 7 ... Gas introduction port 19 ... Gas flow path 21 ... Gas supply path 21a ... Gas supply port 22b ... Plate-shaped body 23... Through hole 26... Gas discharge suppression hole 27.

Claims (6)

A fuel cell comprising a fuel battery cell having a plurality of gas flow paths accommodated in a storage container, and an air supply side manifold for supplying gas to each of the gas flow paths of the plurality of fuel battery cells. The air supply side manifold has a plurality of gas supply paths formed by branching from the air supply side gas pipe, and the open ends of the gas supply paths are used as gas flow paths of the fuel cells. A fuel cell comprising a gas supply port for supplying gas, wherein each gas supply path has the same length . Wherein Kyukigawa manifold, the through holes are formed plate-like body with made by stacking a plurality of fuel of claim 1, wherein said gas supply passage by successive said through hole is formed battery. 2. The fuel cell according to claim 1, wherein the air supply side manifold is formed by a pipe. The gas supply port, the fuel cell according to any one of claims 1 to 3, characterized in that it is connected to the plurality of fuel gas inlets for introducing gas into the cell. The gas supply port, the fuel cell according to any one of claims 1 to 3, characterized in that provided opposite at the respective predetermined intervals in the gas inlet. The edge of the gas outlet port side for discharging the gas from the fuel cell, wherein the lid-like member having a suppressing gas emissions hole a gas flow amount of the gas flow path is provided The fuel cell according to any one of claims 1 to 5.

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