JP2014225479A - Flat plate type fuel battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To equalize a fuel gas flow in a plane of a fuel electrode.SOLUTION: A flat plate type fuel battery comprises: a flat type fuel battery cell; and a flat plate type fuel electrode-side interconnector laminated on a plane on a fuel electrode side of the cell. The fuel electrode-side interconnector comprises: a fuel supply hole 9 formed in a central portion; a fuel recovery hole 10 formed in two outer circumferential places at positions 180° apart from each other; and a flow channel adjustment convex portion 14 shaped like a circular arc in a plan view and formed adjoining the fuel recovery hole 10 on a plane facing a fuel electrode of the cell at a position closer to the central portion than the fuel recovery hole 10. The length of the arc of the flow channel adjustment convex portion 14 is set in such a way that a flow channel length from the fuel supply hole 9 to the fuel recovery hole 10 for fuel gas flowing out in a direction toward the fuel recovery hole 10 and a flow channel length to the fuel recovery hole 10 for the fuel gas flowing out in a direction orthogonal to this flow-out direction of the fuel gas are substantially the same.

Description

  The present invention relates to a flat plate fuel cell, and more particularly to a structure of a fuel electrode side interconnector for supplying fuel gas to a fuel electrode of a fuel cell.

  In a circular flat plate type fuel cell, by supplying fuel to the center of the electrode, it is possible to reduce the electrical resistance of the transverse flow in the electrode and the mass transport loss, and to improve the power generation performance. In the past, the inventors have supplied a fuel to the center of the electrode and provided a fuel recovery hole at two locations on the outer edge of the fuel cell, thereby providing a stack configuration method that ensures high power generation performance of the cell. Have been devised (see Patent Document 1 and Non-Patent Document 1).

JP 2008-117736 A

M.Yokoo, K.Mizuki, K.Watanabe, K.Hayashi, “Development of a high power density 2.5kW class solid oxide fuel cell stack”, Journal of Power Sources 196, 2011, p.7937-7944

  In the conventional circular flat plate fuel cell, the fuel gas supplied from the gas supply hole flows into the gas recovery hole after being dispersed throughout the fuel electrode, but the fuel gas that has flowed out in the direction from the gas supply hole to the gas recovery hole And the fuel gas flowing out in the direction orthogonal to this direction, the fuel flow path length on the fuel electrode is greatly different, so the fuel gas is not sufficiently supplied in the direction where the fuel flow path length is long, There has been a problem that the flow of the fuel gas in the plane of the fuel electrode becomes uneven.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a flat plate fuel cell that can make the flow of fuel gas uniform in the plane of the fuel electrode.

  The flat plate type fuel cell of the present invention comprises a flat plate type fuel cell and a flat plate type fuel electrode side interconnector stacked on the fuel electrode side surface of the cell, and the fuel electrode side interconnector includes A fuel supply hole formed in the center so as to pass through the fuel electrode side interconnector, and two locations on the outer periphery so as to pass through the fuel electrode side interconnector formed in a position 180 ° apart from each other. Two arc-shaped fuel recovery holes and one per fuel recovery hole are provided adjacent to the fuel recovery hole on the surface facing the fuel electrode of the cell, and are more central than the adjacent fuel recovery holes Two first flow path adjustment convex portions having a circular arc shape in plan view formed at a position near the portion, and the centers of the two first flow path adjustment convex portions and the fuel electrode side interconnector Each of the two fan shapes The center angle of each of the four sectors after being bisected by a line segment passing through the center of the electrode side interconnector and the midpoint of the two fuel recovery holes is 35 to 45 °. The lengths of the arcs of the two first flow path adjustment projections are the length of the flow path from the fuel supply hole to the fuel recovery hole of the fuel gas flowing in the direction of the fuel recovery hole, and the fuel gas. The flow path length of the fuel gas that has flowed out in the direction orthogonal to the flow direction of the fuel to the fuel recovery hole is set to be substantially the same.

Moreover, in one structural example of the flat plate type fuel cell of the present invention, the fuel electrode side interconnector further includes two first flow path adjusting convex portions on a surface facing the fuel electrode of the cell. One point is formed at a position near the center and in a direction from the center of the fuel electrode side interconnector toward both ends of the two arcs constituting the two first flow path adjustment convex portions. It has four second flow path adjustment convex portions having a circular arc shape in plan view.
Moreover, in one configuration example of the flat plate fuel cell of the present invention, the fuel electrode side interconnector is further the same as the two first flow path adjusting convex portions on the surface facing the fuel electrode of the cell. It is characterized by having a stress adjusting convex part formed at a position on the circumference with a space between the two first flow path adjusting convex parts.
Further, in one configuration example of the flat plate fuel cell of the present invention, each of the two fuel recovery holes is formed at a position outside the outer peripheral portion of the cell.
Further, in one configuration example of the flat plate fuel cell of the present invention, the heights of the two first flow path adjusting convex portions are set to a height that makes contact with the fuel electrode. Is.

  According to the present invention, by providing the first flow path adjustment convex portion having an arc shape in plan view adjacent to the fuel recovery hole on the surface of the fuel electrode side interconnector facing the fuel electrode of the fuel cell, The length of the flow path from the fuel supply hole to the fuel recovery hole of the fuel gas flowing out in the direction of the fuel recovery hole, and the length of the flow path from the fuel supply hole to the fuel recovery hole of the fuel gas flowing out in the direction perpendicular to the direction of the fuel gas outflow Can be made substantially the same, and the flow of the fuel gas in the plane of the fuel electrode can be made substantially uniform in all directions.

  In the present invention, the fuel electrode side interconnector is positioned closer to the center than the first flow path adjustment convex portion on the surface of the fuel electrode side interconnector facing the fuel electrode of the fuel cell, and the center of the fuel electrode side interconnector. By providing the second flow path adjustment convex portion having a circular arc shape in plan view at a position in the direction from the first to the end of the first flow path adjustment convex portion, the flow of the fuel gas in the plane of the fuel electrode is uniform. The property can be further improved.

  In the present invention, the stress adjustment convex portion is provided at the same circumferential position as the first flow path adjustment convex portion on the surface of the fuel electrode side interconnector facing the fuel electrode of the fuel cell. The stress concentration in the outer peripheral portion of the fuel cell can be alleviated and the fuel cell can be prevented from being damaged.

  Further, in the present invention, by providing the fuel recovery hole at a position outside the outer peripheral portion of the fuel cell, a gap can be provided between the fuel recovery hole and the first flow path adjustment convex portion. Further, not only etching processing but also stamp processing can be selected as a method for processing the unevenness of the fuel electrode side interconnector.

1 is an exploded perspective view showing a configuration of a flat plate fuel cell stack according to a first embodiment of the present invention. It is a top view which shows the structure of the anode current collection part of the interconnector which concerns on the 1st Embodiment of this invention. It is sectional drawing of the interconnector which concerns on the 1st Embodiment of this invention. It is a top view which shows the structure of the anode current collection part of the interconnector which concerns on the 2nd Embodiment of this invention. It is a top view which shows the structure of the anode current collection part of the interconnector which concerns on the 3rd Embodiment of this invention. It is a top view which shows the structure of the anode current collection part of the interconnector which concerns on the 4th Embodiment of this invention. It is sectional drawing of the interconnector which concerns on the 4th Embodiment of this invention.

[First Embodiment]
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an exploded perspective view showing the configuration of a flat plate fuel cell stack according to the first embodiment of the present invention. The flat plate type fuel cell stack 1 according to the present embodiment includes a flat plate type fuel cell 2 having a circular shape in plan view, and a housing member that houses the fuel cell 2, and a plurality of these are provided as a set. It has a structure. The fuel battery cell 2 has a structure in which an electrolyte layer is sandwiched between an air electrode and a fuel electrode.

  The fuel cell 2 is housed in the housing member so as to be sandwiched between the housing member on the air electrode side and the housing member on the fuel electrode side. At least a part of these housing members are electrically connected to each fuel cell 2 in a state where the fuel supplied to the fuel electrode side of each fuel cell 2 and the air supplied to the air electrode are not mixed. Functions as an interconnector.

  As shown in FIG. 1, the housing member on the fuel electrode side includes a flat plate-shaped cell housing plate 3 made of metal and having a rectangular shape in plan view, a fuel supply hole 9 for supplying fuel gas to the fuel electrode of the fuel cell 2, and a fuel A flat plate interconnector 4 having a rectangular shape in plan view, formed with a fuel recovery hole 10 for recovering gas, a fuel supply flow path for supplying fuel gas to the fuel electrode, and a fuel recovery flow for recovering fuel gas A flat plate-shaped fuel supply / recovery flow path plate 5 made of metal and having a rectangular shape in plan view is formed. These plates are laminated in the order of the fuel supply / recovery flow path plate 5, the interconnector 4, and the cell storage plate 3.

  At the four corners of each of the cell storage plate 3, the interconnector 4, and the fuel supply / recovery flow path plate 5, manifolds for supplying gas to the electrodes (fuel electrode and air electrode) and collecting the gas are configured. Through holes 6a, 6b, 6c, 6d are formed. The cell storage plate 3 is formed with a through-hole 7 having a circular shape in plan view, for example, for cell storage at the center thereof. The thickness of the cell storage plate 3 is set to be the same as the thickness of the fuel cell 2 or slightly thicker than the fuel cell 2. When the fuel cell 2 is directly mounted on the interconnector 4, the thickness of the cell storage plate 3 may be the same as that of the fuel cell 2. The diameter of the through hole 7 is set to be slightly larger than the outer diameter of the fuel battery cell 2, and the fuel battery cell 2 is disposed in the through hole 7.

  In the interconnector 4, a fuel supply hole 9 is formed at a central position, and a fuel recovery hole 10 is formed at a position communicating with the through hole 7 when the stack is stacked. The fuel supply / recovery flow path plate 5 passes through the fuel supply / recovery flow path plate 5 from a position communicating with the through hole 6b constituting the fuel supply manifold to a central position communicating with the fuel supply hole 9. The fuel supply flow path 11 is formed, and further penetrates the fuel supply / recovery flow path plate 5 from a position communicating with the through holes 6a and 6c constituting the fuel recovery manifold to a position communicating with the fuel recovery hole 10. A fuel recovery passage 12 is formed.

  In the flat type fuel cell, the portion of the interconnector 4 (anode current collector 8 in FIG. 1) that contacts the fuel electrode of the fuel cell 2 is uneven so that the fuel supply / recovery and current collection are optimized. It is common. In the present embodiment, the unevenness of the flow velocity distribution of the fuel is alleviated by devising the uneven shape of the anode current collector 8 of the interconnector 4.

  Hereinafter, the structure of the anode current collector 8 will be described in more detail. FIG. 2 is a plan view showing the structure of the anode current collector 8. As described above, the interconnector 4 is formed with the fuel supply hole 9 and the fuel recovery hole 10, and is formed with, for example, a columnar current collecting convex portion 13 on the surface facing the fuel electrode. As described above, a large number of current collecting convex portions 13 are formed in the anode current collecting portion 8 of the interconnector 4, and the current collecting convex portions 13 come into contact with the fuel electrode of the fuel cell 2 and are electrically connected. Get to get connected.

  Further, the anode current collector 8 is provided with two flow path adjusting convex portions 14 having a circular arc shape in plan view on the surface facing the fuel electrode. The fuel recovery hole 10 having a circular arc shape in plan view is formed at two positions at the end of the anode current collector 8 having a circular shape in plan view so as to be separated from each other by 180 °. The length of the arc of the fuel recovery hole 10 is about 8 to 14 mm. The flow path adjusting convex portion 14 is provided at one location for each fuel recovery hole 10 at a position closer to the center than the fuel recovery hole 10. The center of the arc formed by the fuel recovery hole 10 and the flow path adjusting projection 14 coincides with the center of the interconnector 4.

  The midpoint of the flow path adjusting convex portion 14 is located on a line connecting the center of the interconnector 4 and the midpoint of the fuel recovery hole 10. That is, the sector formed by the flow path adjusting convex portion 14 and the center of the interconnector 4 is divided into two equal parts by a line segment L1 passing through the center of the interconnector 4 and the midpoints of the two fuel recovery holes 10. The central angle of the left half of the sector divided into two halves is 35 to 45 °, and the central angle of the right half of the sector is 35 to 45 °. In the example of FIG. 2, the central angle of the left half sector and the central angle of the right half sector are both 39 °. The width of the flow path adjusting convex portion 14 is, for example, 2 mm. The height of the flow path adjusting convex portion 14 is set to a height that contacts the fuel electrode of the fuel cell 2, as with the current collecting convex portion 13.

  The assembly procedure of the flat plate fuel cell using one cell will be briefly described. After the fuel supply / recovery flow path plate 5, the interconnector 4, and the cell storage plate 3 are stacked in this order, the through hole of the cell storage plate 3 is stacked. 7, the fuel cell 2 is accommodated with the fuel electrode facing downward, and the air electrode side accommodating member 15 is laminated on the fuel cell 2. At this time, the fuel cell 2 is mounted on the interconnector 4 so that the center thereof coincides with the center of the interconnector 4.

  Through holes 6a, 6b, 6c, and 6d formed in each plate are connected by stacking these plates, and manifolds are formed at the four corners of the housing member. Thus, the assembly of a single stack of flat plate fuel cells is completed. In order to obtain a high power generation output, a single stack may be stacked, for example, 10 to 40 units. In this case, the fuel supply channel 11 and the fuel recovery channel 12 are sandwiched between the interconnector 4 and the other single stack air electrode side accommodating member 15.

  The accommodation member 15 on the air electrode side is formed with through holes 6a, 6b, 6c, 6d at the four corners, and an air supply channel for supplying air to the air electrode of the fuel cell 2 and the like. The The air electrode side accommodating member 15 includes an air electrode side interconnector that is stacked on the air electrode side surface of the fuel cell 2. Since the structure of the housing member 15 on the air electrode side is out of the scope of the present invention, a detailed description of the structure of the housing member 15 is omitted.

  After assembling the flat plate fuel cell stack, the metal plates are diffusion-bonded at a high temperature of about 800 ° C. to ensure airtightness. In the present embodiment, the fuel cell 2 is directly mounted on the interconnector 4, but the present invention is not limited to this, and heat resistance is provided between the fuel electrode of the fuel cell 2 and the interconnector 4. You may insert the electroconductive board | plate which has unevenness | corrugations, such as a net | network, a porous metal, and a corrugated board.

  Next, the flow of the fuel gas will be briefly described. The fuel gas is supplied to the fuel supply hole 9 of the interconnector 4 through the fuel supply passage 11 of the fuel supply / recovery flow passage plate 5 from the through hole 6b constituting the fuel supply manifold, and from the fuel supply hole 9 It is supplied to the fuel electrode of the fuel cell 2. The used gas is discharged from the fuel recovery hole 10 of the interconnector 4 through the fuel recovery flow path 12 of the fuel supply / recovery flow path plate 5 to the through holes 6a and 6c constituting the fuel recovery manifold. , Discharged from these manifolds to the outside. As described above, the diameter of the through hole 7 is set to be slightly larger than the outer diameter of the fuel cell 2, and the position of the end of the through hole 7, specifically, from the outer periphery of the fuel cell 2. A fuel recovery hole 10 is provided at a slightly outer position. On the other hand, air is supplied to the air electrode of the fuel cell 2 from the through hole 6d constituting the air supply manifold through the air supply channel (not shown) in the housing member 15 on the air electrode side.

  Here, in the present embodiment, the fuel gas flowing out from the fuel supply hole 9 toward the fuel recovery hole 10 is provided by providing the flow path adjusting convex portion 14 on the outer peripheral portion of the anode current collector 8 of the interconnector 4. The flow path length to the fuel recovery hole 10 and the flow path length to the fuel recovery hole 10 for the fuel gas that has flowed out in a direction orthogonal to the outflow direction can be made substantially the same. That is, as shown in FIG. 3, since the fuel electrode 20 of the fuel cell 2 and the flow path adjustment convex portion 14 are in contact, the fuel gas flowing out from the fuel supply hole 9 toward the fuel recovery hole 10 is It cannot flow directly into the fuel recovery hole 10. The fuel gas advances clockwise and counterclockwise along the inner wall of the arc-shaped flow path adjusting convex portion 14 in the plane of the anode current collector 8 of the interconnector 4 shown in FIG. It goes around the circumferential end of the path adjustment convex portion 14, proceeds along the outer wall of the flow path adjustment convex portion 14, and flows into the fuel supply hole 9. The fuel gas that flows out in the direction perpendicular to the direction from the fuel supply hole 9 to the fuel recovery hole 10 proceeds along the outer peripheral portion of the anode current collector 8 and the outer wall of the flow path adjustment convex portion 14 to supply fuel. It flows into the hole 9. Thus, the flow path length of the fuel gas flowing out from the fuel supply hole 9 in the direction of the fuel recovery hole 10 to the fuel recovery hole 10 and the flow of the fuel gas flowing out in the direction orthogonal to the outflow direction to the fuel recovery hole 10 The road length can be made substantially the same.

  By making the flow path lengths substantially the same, the pressure loss between the fuel supply hole 9 and the fuel recovery hole 10 becomes the same regardless of the outflow direction of the fuel gas. The flow of the fuel gas can be made substantially uniform in all directions, and the fuel gas can be more evenly supplied to the entire surface of the fuel electrode.

  When the width (radial dimension) of the flow path adjustment convex portion 14 is increased, the reaction area of the fuel electrode is reduced accordingly. Therefore, the flow path adjustment convex portion 14 should be as narrow as possible. preferable. Moreover, it is preferable that the height of the flow path adjusting convex portion 14 is the same as the height of the current collecting convex portion 13 in that the load is dispersed. The arc length of the flow path adjustment convex portion 14 is an optimum value from the viewpoint of making the flow path length uniform, but 1/4 of the circumferential length of the anode current collector 8 is an optimum value. However, the performance of the fuel cell is not drastically deteriorated even if it is mixed.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. Also in the present embodiment, the structure of the flat plate fuel cell stack is the same as that of the first embodiment, and the structure of the anode current collector 8 of the interconnector 4 is different from the first embodiment. This will be described using the reference numeral 1. FIG. 4 is a plan view showing the structure of the anode current collector 8 of the present embodiment. The anode current collector 8 of the present embodiment has the current collecting convex portion 13 and the flow path adjusting convex portion 14 described in the first embodiment on the surface facing the fuel electrode of the fuel cell 2. In addition, four flow path adjustment convex portions 16 having a circular arc shape in plan view are formed. The center of the arc formed by the flow path adjusting projection 16 coincides with the center of the interconnector 4.

  The central angle of the sector formed by the arc-shaped flow path adjusting convex portion 16 and the center of the interconnector 4 is 30 to 40 °. The midpoint of the flow path adjustment convex portion 16 is located on a line connecting the center of the interconnector 4 and the circumferential end of the flow path adjustment convex portion 14. That is, each flow path adjustment convex portion 16 is arranged so that the sector is divided into two equal parts by line segments L2 and L3 connecting the circumferential end of the flow path adjustment convex portion 14 and the center of the interconnector 4. Has been. The height of the flow path adjusting convex portion 16 is preferably the same as the height of the current collecting convex portion 13 and the flow path adjusting convex portion 14.

  In the first embodiment, by providing the flow path adjustment convex portion 14, the flow path length from the fuel supply hole 9 to the fuel recovery hole 10 of the fuel gas flowing in the direction of the fuel recovery hole 10, and this outflow The flow path length of the fuel gas flowing out in the direction orthogonal to the direction to the fuel recovery hole 10 is substantially the same, but the length of the flow path adjustment convex portion 14 from the fuel supply hole 9 is longer than these flow path lengths. The flow path length of the fuel gas that has flowed out in the direction of the end (the direction along the line segments L2 and L3 in FIG. 4) to the fuel recovery hole 10 is shorter.

  On the other hand, in the present embodiment, by providing the flow path adjustment convex portion 16, the fuel gas flowing out from the fuel supply hole 9 toward the end of the flow path adjustment convex portion 14 is retained on the fuel electrode. You can increase the time. That is, the fuel gas that has flowed out from the fuel supply hole 9 toward the end of the flow path adjusting projection 14 is an arc-shaped flow path adjusting pipe in the plane of the anode current collector 8 of the interconnector 4 shown in FIG. Proceeding clockwise and counterclockwise along the inner wall of the convex portion 16, flows around the circumferential end of the flow path adjusting convex portion 16 and then flows in the direction of the end of the flow path adjusting convex portion 14. Then, it proceeds along the outer wall of the flow path adjusting projection 14 and flows into the fuel supply hole 9. Thus, in the present embodiment, the uniformity of the flow of the fuel gas in the plane of the fuel electrode can be further improved. As described in the first embodiment, a conductive plate having irregularities such as a heat-resistant net, a porous metal, and a corrugated plate is inserted between the fuel electrode of the fuel cell 2 and the interconnector 4. May be.

[Third Embodiment]
Next, a third embodiment of the present invention will be described. Also in the present embodiment, the structure of the flat plate fuel cell stack is the same as that of the first embodiment, and the structure of the anode current collector 8 of the interconnector 4 is different from the first embodiment. This will be described using the reference numeral 1. FIG. 5 is a plan view showing the structure of the anode current collector 8 of the present embodiment. The anode current collector 8 of the present embodiment has the current collecting convex portion 13 and the flow path adjusting convex portion 14 described in the first embodiment on the surface facing the fuel electrode of the fuel cell 2. In addition, four stress adjusting convex portions 17 having a circular arc shape in plan view are formed. The center of the arc formed by the stress adjusting convex portion 17 coincides with the center of the interconnector 4.

  The flow path adjustment convex portion 14 is disposed on the circumference surrounding the center of the interconnector 4, but the stress adjustment convex portion 17 is arranged on the same circumference as the flow path adjustment convex portion 14. It arrange | positions at intervals of the convex part 14 for a road adjustment, and 10 degrees or more. The height of the stress adjusting convex portion 17 is preferably the same as the height of the current collecting convex portion 13 and the flow path adjusting convex portion 14.

  As described above, in the present embodiment, the stress adjusting convex portion 17 is provided to stack the fuel cell 2 having a slight warp, the fuel electrode side housing member, and the air electrode side housing member. When a load is applied, the stress concentration at the outer periphery of the fuel cell 2 can be relaxed, and the fuel cell 2 can be prevented from being damaged. As described in the first embodiment, a conductive plate having irregularities such as a heat-resistant net, a porous metal, and a corrugated plate is inserted between the fuel electrode of the fuel cell 2 and the interconnector 4. May be.

[Fourth Embodiment]
Next, a fourth embodiment of the present invention will be described. Also in the present embodiment, the structure of the flat plate fuel cell stack is the same as that of the first embodiment, and the structure of the anode current collector 8 of the interconnector 4 is different from the first embodiment. This will be described using the reference numeral 1. FIG. 6 is a plan view showing the structure of the anode current collector 8 of the present embodiment.

  Also in the present embodiment, the through-holes 6a, 6b, 6c, 6d, the fuel supply hole 9, the fuel recovery hole 10, the current collecting convex portion 13, and the flow path adjusting convex portion 14 are formed in the interconnector 4. However, the difference from the first embodiment is that the fuel is recovered at a position sufficiently outside the outer peripheral portion of the fuel cell 2 as shown in FIG. The hole 10 is provided. In the first embodiment, since the distance between the fuel recovery hole 10 and the flow path adjusting convex portion 14 is short, it is necessary to use etching as a method for processing the unevenness of the anode current collector 8. On the other hand, in the present embodiment, as shown in FIG. 7, there is a gap 18 between the fuel recovery hole 10 and the flow path adjustment convex portion 14. Not only etching processing but also stamp processing can be selected.

  The present invention can be applied to a flat plate fuel cell.

  DESCRIPTION OF SYMBOLS 1 ... Flat type fuel cell stack, 2 ... Fuel cell, 3 ... Cell storage plate, 4 ... Interconnector, 5 ... Fuel supply / recovery flow path plate, 6a, 6b, 6c, 6d, 7 ... Through-hole, 8 ... Anode current collector, 9 ... fuel supply hole, 10 ... fuel recovery hole, 11 ... fuel supply flow path, 12 ... fuel recovery flow path, 13 ... current collection convex part, 14, 16 ... flow path adjustment convex part, 17 ... Stress adjusting convex portion, 20 ... Fuel electrode.

Claims (5)

A flat plate fuel cell;
And a flat plate fuel electrode side interconnector laminated on the fuel electrode side surface of this cell,
The fuel electrode side interconnector is
A fuel supply hole formed in the center so as to penetrate the fuel electrode side interconnector;
Two fuel recovery holes having a circular arc shape in plan view formed at two positions on the outer periphery so as to penetrate the fuel electrode side interconnector, and at positions spaced apart from each other by 180 °;
A plan view is provided on the surface of the cell facing the fuel electrode so as to be adjacent to the fuel recovery hole, one per fuel recovery hole, and closer to the center than the adjacent fuel recovery hole. Two arc-shaped first flow path adjustment convex portions,
Each of the two sectors formed by the two first flow path adjusting projections and the center of the fuel electrode side interconnector includes a center of the fuel electrode side interconnector and a midpoint of the two fuel recovery holes. The central angle of each of the four sectors after being divided into two equal parts by a line segment passing through
The lengths of the arcs of the two first flow path adjustment projections are the length of the flow path from the fuel supply hole to the fuel recovery hole of the fuel gas flowing out in the direction of the fuel recovery hole, A flat plate fuel cell, characterized in that the flow path length to the fuel recovery hole of fuel gas that has flowed out in a direction perpendicular to the outflow direction is set to be substantially the same. The flat plate fuel cell according to claim 1, wherein
The fuel electrode side interconnector is further located at a position closer to the center than the two first flow path adjustment convex portions on the surface facing the fuel electrode of the cell, and the fuel electrode side interconnector. Four second flow path adjustments having a circular arc shape in plan view, each formed at a position in a direction toward each of both ends of the two circular arcs constituting the two first flow path adjustment convex portions from the center A flat plate fuel cell having a convex portion. The flat plate fuel cell according to claim 1 or 2,
The fuel electrode-side interconnector further includes two first flow paths at positions on the same circumference as the two first flow path adjusting projections on the surface of the cell facing the fuel electrode. A flat plate type fuel cell having a stress adjusting convex portion formed with a gap between the adjusting convex portion. The flat plate fuel cell according to any one of claims 1 to 3,
Each of the two fuel recovery holes is formed at a position outside the outer peripheral portion of the cell. The flat plate fuel cell according to any one of claims 1 to 4,
The flat fuel cell according to claim 1, wherein the height of the two first flow path adjustment protrusions is set to a height that contacts the fuel electrode.

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