JPH063739B2 - Fuel cell - Google Patents

Description

TECHNICAL FIELD The present invention relates to a fuel cell used in the energy sector for directly converting chemical energy of a fuel into electric energy.

[Prior Art] As a molten carbonate fuel cell proposed so far, for example, as shown in FIG. 5, an electrolyte plate a is sandwiched between both electrodes of an oxygen electrode b and a fuel electrode c, and While supplying air d containing CO as a working fluid to the oxygen electrode b side,
By supplying a fuel e such as H ₂ as a working fluid to the fuel electrode c side, a unit is provided so that power is generated by a potential difference generated between the oxygen electrode b and the fuel electrode c, and a separator f.
There is a structure in which a plurality of layers are laminated via a sheet and fixed with an appropriate tightening force.

The separator f used in the fuel cell is the sixth
As shown in the drawing, a supply flow path hole h for the air d is provided on one side of the peripheral portion,
Both the front and back surfaces are formed by providing a fuel supply flow passage hole i, an air discharge flow passage hole j and a fuel discharge flow passage hole k on the other side of the peripheral portion, and forming irregularities g inside the peripheral portion except the peripheral portion. It is usual that the gas passages are formed integrally with each other. or,
In order to allow the air d and the fuel e to flow along both sides of the separator f, as shown in FIG. 6, the supply flow passage holes h, i provided in the separator f on one side and the other side of the peripheral portion and The distance pieces 1 and m, which are provided so as to match the discharge flow passage holes j and k and are hollowed out, are used. The distance piece 1 on the oxygen electrode side is the air supply flow passage hole h.
And the discharge flow passage hole j are formed with fan-shaped notches n for opening the inside to the hollow portion, and the distance piece m on the fuel electrode side has the fuel supply flow passage hole i and the discharge flow passage hole k inside. Each of the distance pieces l, m is formed into a fan-shaped notch o to be opened in the cut-out portion, and the distance pieces l, m are separated by a separator f.
The peripheral portions of the separator f are overlapped and used so that the convex portions on the front and back surfaces of the separator f are brought into contact with the electrodes.

[Problems to be Solved by the Invention] However, a separator f used in a conventional fuel cell is used.
Since the unevenness g is formed by pressing or the like in a portion except the peripheral portion of the plate having a required thickness, the unevenness g portion merely forms a gas passage and is integrated with the peripheral portion. Due to a certain structure, the unevenness g portion lacks elasticity. Therefore, if the oxygen electrode b or the fuel electrode c is thick, the gap between the peripheral portion of the separator f and the electrolyte plate a may be opened to cause gas leakage, resulting in poor sealing.
Further, since the irregularity g forming portion is integral with the peripheral portion as described above, it is not compatible and the entire separator must be changed even when the design of the gas passage is changed.

Therefore, the present invention provides a fuel cell having a separator that enables elasticity and mass production, cost reduction, and compatibility by making the uneven portion that is in contact with the electrode and forms the gas passage separate from the separator body. Is to provide.

[Means for Solving the Problems] In the present invention, an air supply passage hole 9 and a fuel supply passage hole 10 are alternately formed on one side and a fuel discharge passage hole 12 is formed on the other side. The air discharge flow passage hole 11 is connected to the supply flow passage hole 9 and the discharge flow passage hole 12 is provided.
Are opposed to each other, and the separator main body 5 is alternately bored so that the discharge flow path holes 11 face the supply flow path holes 10, and the inner cutout portion 13 is provided inside the peripheral edge portion, and one side and the other side are provided. The supply flow path holes 9 and 10 and the discharge flow path holes 11 and 12 are provided so as to correspond to the supply flow path holes 9 and 10 and the discharge flow path holes 11 and 12 formed in the separator body 5. Notches that are formed by drilling and communicate with each of the supply flow passage holes 10 and each of the discharge flow passage holes 12 to the cutout portion 13.
Fuel electrode side distance piece 6a provided with 14 respectively,
An internal hollow portion 13, supply flow passage holes 9 and 10 and discharge flow passage holes 11 and 12 are provided at the same position as the fuel electrode side distance piece 6a. Oxygen electrode side distance pieces 6b each provided with a notch 15 communicating with the hollowed-out portion 13, and a pair of corrugated plates that form a corrugation with the convex surface as a flat surface and can be fitted into the internal hollowed-out portion 13 7a and 7b, and internal supply holes having an internal hollow portion 17 having an opening size smaller than that of the internal hollow portion 13 inwardly of the peripheral edge portion, and provided on one side and the other side of the separator main body 5 respectively. It is composed of a pair of masks 8a, 8b in which the supply flow path holes 9, 10 and the discharge flow path holes 11, 12 are provided so as to correspond to the holes 9, 10 and the respective discharge flow path holes 11, 12, and The fuel electrode side distance piece 6a in which one corrugated plate 7a is fitted in the hollow portion 13 and the one mask 8a are the separators described above. Oxygen electrode side distance piece fitted to the other of the corrugated plate 7b inside hollow portion 13 while sequentially stacked on one surface of the body 5
6b and the other mask 8b are sequentially laminated on the other surface of the separator body 5, and the adjacent separator body 5 and the overlapping portion of both distance pieces 6a and 6b and both distance pieces 6a and 6b and masks 8a and 8b are laminated. The overlapping portions are fixed to each other, and the fuel electrode 3 is fitted into the internal hollow portion 17 of one mask 8a to stack the electrolyte plate 1 on the mask 8a and the internal hollow portion 17 of the other mask 8b. The oxygen electrode 2 is fitted to the electrolyte plate 1 and the electrolyte plate 1 is laminated on the mask 8b.

[Operation] Each corrugated plate 7a, 7b is a separate body from the separator body 5 and has an elastic force.
b Since there is play in the inner peripheral portion with respect to the internal hollow 13 and the surface in contact with the fuel electrode 3 or the oxygen electrode 2 is flat, the thickness of the fuel electrode 3 and the oxygen electrode 2 is When the corrugated plates 7a and 7b are large, the corrugated plates 7a and 7b can be easily bent due to the elasticity of themselves and the play against the distance pieces 6a and 6b, and the fuel electrode 3 and the oxygen electrode 2 are evenly adhered to the electrolyte plate 1. It is possible to prevent the defective sealing.

Further, it is possible to convert only the corrugated plates 7a and 7b while leaving the separator body 5 and the distance pieces 6a and 6b as they are.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

FIGS. 1 to 4 show an embodiment of the present invention, in which a fuel cell unit sandwiching both sides of an electrolyte plate 1 with an oxygen electrode 2 and a fuel electrode 3 is laminated in each layer via a separator 4. In the laminated fuel cell, the separator 4 and the separator body 5 are stacked on both sides of the separator body 5 with distance spaces 6a and 6b, corrugated plates 7a and 7b, and a mask 8
It has a configuration in which a and 8b are integrally assembled. That is, the separator body 5 is provided with a plurality of air supply passage holes 9 and fuel supply passage holes 10 alternately on one side of the peripheral portion of the plate having the same size as the electrolyte plate 1, and on the other side of the periphery portion. A plurality of discharge flow passage holes 11 and a plurality of fuel discharge flow passage holes 12 are alternately provided. The distance pieces 6a, 6b have the respective flow passage holes 9, 10, 11, 12 on the one side and the other side of the peripheral portion in the same manner as described above, and have a hollowed-out structure. As shown in FIGS. 2 and 4, the stance piece 6a is provided with a fan-shaped notch 14 for opening the fuel supply passage hole 10 and the discharge passage hole 12 in the internal hollow portion 13, and the fan-shaped notch portion 14 on the oxygen electrode 2 side is provided. As shown in FIG. 3, the distance piece 6b is provided with a fan-shaped notch 15 for opening the air supply passage hole 9 and the exhaust passage hole 11 in the internal hollow portion 13.

The corrugated plates 7a, 7b are provided with a large number of strips having an uneven trapezoidal cross section and the unevenness 16 is discontinuous with respect to the gas flow direction, and the surface of each convex portion is a flat surface, The distance pieces 6a and 6b are sized so that they can be fitted in the internal cutout portion 13 and the cutout portions 14 and 15 with a margin.

The masks 8a and 8b are for holding the corrugated plates 7a and 7b fitted in the internal hollow portions 13 of the distance pieces 6a and 6b on the separator body 4, and have a size slightly smaller than the size of the corrugated plates 7a and 7b. It has an internal hollow portion 17 and each of the air and fuel supply passage holes 9,
10 and the discharge flow path holes 11 and 12 are provided.

The separator 4 in this embodiment has distance pieces 6a and 6b overlapped on both sides of the separator body 5, corrugated plates 7a and 7b are inserted in the internal hollow portion 13, and masks 8a and 8b are overlapped on the outside thereof to form a separator. Overlapping part of body 5 and distance pieces 6a, 6b, distance pieces 6a and 6
b and the overlapping portions of the masks 8a and 8b are brazed to form an integral structure as shown in FIG. 1, and air passes from the supply passage hole 9 through the notch 15 of the distance piece 6b to the corrugated plate 7b.
The surface of the corrugated plate 7a is made to flow irregularly from the supply flow path hole 11 through the notch 14 of the fuel electrode side distance piece 6a.

When assembling a laminated fuel cell using the separator 4 having the above-mentioned configuration, as shown in FIG. 1, a fuel cell unit in which an electrolyte 1 is sandwiched between an oxygen electrode 2 and a fuel electrode 3,
The fuel cells integrated with each other are assembled by stacking them in multiple layers via the separator 4 and tightening the outer peripheral portion with a predetermined tightening force. In this case, the electrodes of the oxygen electrode 2 and the fuel electrode 3 are of such a size that they can fit into the internal hollow portions 17 of the masks 8a and 8b, and when assembled as a fuel cell, as shown in FIG. , 3 are located in the internal hollow portions 17 of the masks 8a, 8b, and the corrugated plate 7b connects the oxygen electrode 2 to the electrolyte plate 1
In addition, the corrugated plate 7a presses the fuel electrode 3 against the electrolyte plate 1, respectively.

When air and fuel are supplied in this state, the air is caused to flow along the corrugated plate 7b on the oxygen electrode 2 side by the oxygen electrode side distance piece 6b in each stage of the separator 4, and the discharge flow path hole 11 opening to the opposite side. More discharged. On the other hand, the fuel is caused to flow along the corrugated plate 7a on the fuel electrode 3 side by the fuel electrode side distance piece 6a in each stage separator 4, and is discharged from the discharge flow path hole 12 opening on the opposite side.
At this time, since the corrugated plates 7a, 7b are provided with the irregularities 16 in a discontinuous and irregular manner, the gas flowing out from each of the supply flow path holes 9, 10 flows while being diffused, which makes the flow distribution uniform. Can be done on a regular basis.

When thick ones are used as the oxygen electrode 2 and the fuel electrode 3, the increased thickness of the oxygen electrode 2 and the fuel electrode 3 is the separator.
It will protrude to the 4 side. In the conventional fuel cell, due to the rigidity of the separator itself, the gap between the separator and the electrolyte plate is opened by the increase in the thickness of the electrode. However, in the separator 4 of this embodiment, the corrugated plates 7a and 7b are made of thin plates. Since the unevenness 16 has a trapezoidal cross section and the periphery is fitted into the inner hollow portion 13 of the distance pieces 6a, 6b with play, it is elastic and can escape in the direction orthogonal to the gas flow direction. As a result, the increased thickness of the electrode can be absorbed by the bending of the corrugated plates 7a and 7b, and the electrode can be closely attached to the electrolyte plate 1, and at the same time, a gap is formed between the electrolyte plate 1 and the palletizer 4. It will not occur.

The fuel cell of the present invention is not limited to the above-mentioned embodiments, and for example, the edge portions of the corrugated plates 7a and 7b can be inserted into the notches 14 and 15 of the distance pieces 6a and 6b. However, this is the mask 8a, 8b on the outside of the notch 14, 15 of the distance piece 6a, 6b.
Is to prevent the masks 8a and 8b from drooping into the cutouts 14 and 15 as described above, while partially deforming to prevent the masks 8a and 8b from entering the cutouts 14 and 15. , 7b may be of a size that can fit inside the hollowed-out portion 13 of the distance pieces 6a, 6b, the corrugated plates 7a, 7b may be provided with protrusions and depressions 16 arranged differently from those shown in the drawing, and air and fuel supply passages may be provided. The case where the holes 9 and 10 are alternately provided on one side of each peripheral portion of the separator body 5, the distance pieces 6a and 6b, and the masks 8a and 8b is shown, but the air supply passage hole 9 and the fuel are provided on one side of the peripheral portion. Of the exhaust flow channel 12 of
It is needless to say that the air and the fuel may be opposed to each other by providing the fuel cell 11 and the fuel supply passage hole 10, and various changes may be made without departing from the scope of the present invention.

[Effects of the Invention] As described above, according to the fuel cell of the present invention, corrugated plates 7a and 7b having irregularities having irregular trapezoidal cross sections to provide elasticity are provided separately on both surfaces of the separator body 5. Arrange
Surrounding the corrugated plates 7a, 7b with the distance pieces 6a, 6b, and on the outside of the distance pieces 6a, 6b, masks 8a, 8b for pressing the corrugated plates 7a, 7b are overlaid, the separator body 5, the distance piece 6a, Of the air supply flow path hole 9, the fuel supply flow path hole 10, the air discharge flow path hole 11, and the fuel discharge flow path hole 12 provided at the peripheral portions of 6b, the masks 8a, 8b, the fuel electrode side In the distance piece 6a, the supply flow path hole 10
In addition, the discharge flow passage hole 12 is communicated with the cutout portion 13 by the cutout portion 14, and in the oxygen electrode side distance piece 6b, the supply flow passage hole 9 and the discharge flow passage hole 11 are communicated with the internal cutout portion 13 by the cutout portion 15. Therefore, various excellent effects as described below can be obtained.

(1) Corrugated plate 7 in contact with fuel electrode 3 or oxygen electrode 2
Since the corrugated plates 7a and 7b are easily provided with elasticity by manufacturing a and 7b as separate members from the member forming the separator body 5, when the fuel electrode 3 and the oxygen electrode 2 are thick, The corrugated plates 7a, 7b easily bend due to the elasticity of the corrugated plates 7a, 7b, so that the fuel electrode 3 and the oxygen electrode 2 can be brought into close contact with the electrolyte plate 1 evenly, and no sealing failure occurs.

(2) Since the surface of the convex portions of the corrugated plates 7a, 7b is a flat surface, the fuel electrode 3 and the oxygen electrode 2 are not damaged.

(3) Since the corrugated plates 7a and 7b are manufactured separately, mass production is possible and cost can be reduced, and the design of the gas flow path can be changed compared to the conventional plate in which unevenness is processed. It can be easily handled by exchanging 7a and 7b.

[Brief description of drawings]

1 is a sectional view of an embodiment of the fuel cell of the present invention, FIG. 2 is a plan view showing a state in which a part of the surface of the separator shown in FIG. 1 is cut off, and FIG. 3 is shown in FIG. The bottom view which shows the state which cut off a part of the back surface of the separator, FIG. 4 is the perspective view which shows the state which separated the front surface side of the separator shown in FIG.
FIG. 5 is a cross-sectional view of a conventional fuel cell, and FIG. 6 is a perspective view showing a state in which an internal manifold type separator formed by overlapping distance pieces on both sides of a separator which has been recently considered is separated. 1 is an electrolyte plate, 2 is an oxygen electrode, 3 is a fuel electrode, 4 is a separator, 5 is a separator body, 6a and 6b are distance pieces, 7a and 7b are corrugated plates, 8a and 8b are masks, and 9 is an air supply passage. Hole, 10 is a fuel supply flow path hole, 11 is an air discharge flow path hole,
12 is a fuel discharge flow path hole, 13 is an internal hollow portion, 14 and 15 are notches, 16 is an unevenness, and 17 is an internal hollow portion.

Claims (1)

[Claims] 1. An air supply passage (9) and a fuel supply passage hole (10) are alternately formed on one side, and a fuel discharge passage hole (12) is formed on the other side.
And the air discharge flow path hole (11) face the supply flow path hole (9) with the discharge flow path hole (12) and the supply flow path hole (10) with the discharge flow path hole (10).
Separator body in which holes (11) are alternately bored so as to face each other.
(5) and each of the supply flow path holes (9), (10) having an internal hollow portion (13) inside the peripheral edge and formed in the separator body (5) on one side and the other side. ) And the respective discharge flow channel holes (11) and (12) so as to correspond to the supply flow channel holes (9) and (10) and the discharge flow channel holes (1
1) and (12) are drilled, and a cutout portion (14) communicating with each of the supply flow passage holes (10) and each of the discharge flow passage holes (12) to the cutout portion (13) is provided. Polar distance piece (6
a), the internal hollow portion (13), the supply flow passage holes (9) and (10), and the discharge flow passage hole at the same position as the fuel electrode side distance piece (6a).
Notches (15) having (11) and (12) communicating from the respective supply flow passage holes (9) and the respective discharge flow passage holes (11) to the hollow portion (13)
Oxygen electrode side distance piece (6b) provided respectively,
A pair of corrugated plates (7a) which form a corrugation with the surface of the convex portion as a flat surface and can be fitted into the internal hollow portion (13),
(7b) and an inner hollow portion (17) having an opening size smaller than that of the inner hollow portion (13) inward of the peripheral portion, and perforated in the separator body (5) on one side and the other side. The supply flow path holes (9), (10) and the discharge flow path holes (9), (10) and the discharge flow path holes (11), (10) and the exhaust flow path holes (11) 11), (12)
And a pair of masks (8a) and (8b) in which a corrugated plate (7a) is fitted in the internal hollow portion (13), and a mask (1a) on the fuel electrode side. 8a) and the oxygen electrode side distance piece (6b) in which the other corrugated plate (7b) is fitted to the inner hollow portion (13) and the other mask (8).
b) are sequentially laminated on the other surface of the separator body (5), and the overlapping body of the adjacent separator body (5) and both distance pieces (6a) and (6b) and both distance pieces (6)
a) and (6b) and masks (8a) and (8b) are fixed to each other, respectively, and the fuel electrode (3) is fitted to the inner hollow part (17) of one mask (8a). Mask the electrolyte plate (1) together (8a)
And the oxygen electrode (2) was fitted to the internal hollow part (17) of the other mask (8b) and the other mask (8b) was attached to the electrolyte plate.
A fuel cell characterized by being laminated on (1).