Fuel cell unit structure

Abstract

To provide a cell unit structure of a fuel cell, in which the effect of suppressing a decrease in reaction gas concentration on a downstream side is further enhanced.SOLUTION: A cell unit structure of a fuel cell includes: an anode channel member for forming a channel supplying anode gas to an anode electrode; and a cathode channel member for forming a channel supplying cathode gas to a cathode electrode. In the cell unit structure of the fuel cell, at least one of the anode channel member and the cathode channel member is partitioned into a plurality of channels where gases flowing through adjacent channels are not mixed, by partitions. The plurality of channels each have an opening area where a bottom face in contact with a cell is open and a closed area where the bottom face is not open. The cell unit structure of the fuel cell has two opening patterns of a first pattern in which at least a part of the channels has the opening area on the upstream side and the closed area on the downstream side, and a second pattern in which a part of the remaining channels has the closed area on the upstream side and the opening are on the downstream side.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a cell unit structure of a fuel cell. [Background technology]

[0002] On the anode side of a fuel cell, there is a problem in that the concentration of reactant gas decreases as it flows downstream due to the generation of product gases such as water in the flow channels. Patent Document 1 discloses a gas flow channel structure in which a flow channel plate, interposed between a separator plate and an electrode and separating the separator-side flow channel from the electrode-side flow channel, is divided into at least two pieces, which are offset in a direction perpendicular to the gas flow direction, so that the upstream separator-side flow channel connects to the downstream electrode-side flow channel, and vice versa. With this structure, half of the gas supplied to the upstream flow channel plate flows through the electrode-side flow channel where the electrochemical reaction occurs, and the other half flows through the separator-side flow channel, which is not involved in the reaction. Then, upon entering the downstream flow channel plate, the gas that has flowed through the electrode-side flow channel flows through the separator-side flow channel, and the gas that has flowed through the separator-side flow channel flows through the electrode-side flow channel. In other words, a decrease in the reactant gas concentration in the reaction-side flow channel within the downstream flow channel plate can be suppressed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 1-140560 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the structure in which the same corrugated flow path plates are installed with a one-pitch offset as in the above document, gas whose reactant gas concentration has decreased by flowing along the electrode side on the upstream side flows into the electrode-side flow path at one end of the downstream flow path plate in the direction perpendicular to the gas flow direction. In other words, there is room for improvement in terms of suppressing the decrease in reactant gas concentration on the downstream side.

[0005] Therefore, an object of the present invention is to further enhance the effect of suppressing the decrease in the reactant gas concentration on the downstream side. [Means for solving the problem]

[0006] According to one aspect of the present invention, there is provided a cell unit structure for a fuel cell comprising an anode flow path member that forms a flow path for supplying anode gas to the anode electrode, and a cathode flow path member that forms a flow path for supplying cathode gas to the cathode electrode. At least one of the anode flow path member or the cathode flow path member is divided by a partition into multiple flow paths that prevent gases flowing through adjacent flow paths from mixing, and each of the multiple flow paths has an open region whose bottom surface that contacts the cell is open and a closed region that is not open. At least some of the multiple flow paths have two opening patterns: a first pattern in which the open region is on the upstream side and a closed region on the downstream side, and a second pattern in which the closed region is on the upstream side and an open region on the downstream side. The partitions are flow path member ribs formed on the anode flow path member or the cathode flow path member. [Effects of the Invention]

[0007] According to the above aspect, the effect of suppressing a decrease in the reactant gas concentration on the downstream side can be further enhanced. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a plan view of a typical fuel cell. [Figure 2] FIG. 2 is a diagram showing the relationship between the gas partial pressure of hydrogen, oxygen, and water in the reaction gas flow channel and the distance x from the flow channel inlet. [Figure 3] FIG. 3 is a diagram showing the relationship between the electromotive force of the fuel cell and the distance x from the flow channel inlet. [Figure 4] FIG. 4 is a plan view of the anode flow path member according to the first embodiment. [Figure 5] FIG. 5 is an enlarged view of region IV in FIG. [Figure 6]FIG. 6 is a cross-sectional view of the flow passages of the fuel cell stack according to the first embodiment, on the upstream side of the position where the opening pattern switches. [Figure 7] FIG. 7 is a plan view of the anode flow path member near the transition area between the closed region and the open region. [Figure 8] FIG. 8 is a perspective view of a cross section taken along line VIII-VIII in FIG. [Figure 9] FIG. 9 is a perspective view of the vicinity of the transition portion between the closed region and the open region of the anode channel member according to the second embodiment. [Figure 10] FIG. 10 is a cross-sectional view of the flow channel taken along line VIII-VIII in FIG. [Figure 11] FIG. 11 is a plan view of the vicinity of the transition portion between the closed region and the open region of the anode channel member according to the third embodiment. [Figure 12] FIG. 12 is a cross-sectional view taken along line XII-XII in FIG. [Figure 13] FIG. 13 is a cross-sectional view of an anode flow channel according to a modification of the third embodiment. [Figure 14] FIG. 14 is an exploded perspective view of a cell unit according to the fourth embodiment. [Figure 15] FIG. 15 is a cross-sectional view of a flow path of a cell unit according to the fourth embodiment. [Figure 16] FIG. 16 is a cross-sectional view of a flow path of a cell unit according to the fifth embodiment. [Figure 17] FIG. 17 is a cross-sectional perspective view of an opening region near the inlet of a flow channel through which a reactant gas is supplied, in a cell unit according to the fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0010] [First embodiment] First, the electromotive force of a typical solid oxide fuel cell (hereinafter simply referred to as "fuel cell") will be explained. FIG. 1 is a plan view of a typical fuel cell. A reaction region ACTE is provided with multiple reactant gas flow paths. As shown in the figure, the upstream end (also referred to as the flow path inlet) of a reactant gas flow path is taken as the base point, and the distance from the flow path inlet is taken as x.

[0011] Fig. 2 shows the relationship between the gas partial pressure (molar fraction) of hydrogen (H2), oxygen (O2), and water (H2O) in the reactant gas flow channel and the distance x from the flow channel inlet. Fig. 3 shows the relationship between the electromotive force of the fuel cell and the distance x from the flow channel inlet.

[0012] The cell voltage of a fuel cell when no load current is being drawn (hereinafter also referred to as the theoretical electromotive force) corresponds to the maximum cell voltage. This theoretical electromotive force is expressed by the following equation (1):

number

[0013] When a load current is extracted, H2 is consumed at the anode and O2 at the cathode due to the reactions, and as shown in Figure 2, the greater the distance x from the inlet, the lower the H2 partial pressure and O2 partial pressure. On the other hand, as shown in Figure 2, H2O is produced at the anode due to the reaction, and as shown in Figure 2, the greater the distance x from the inlet, the higher the H2O partial pressure in the anode flow path. Applying this to equation (1) gives the anode concentration correction term P H2 decreases and P H2O As a result of the increase in concentration correction term ΔEa at the anode, the concentration correction term ΔE cHowever, in the case of a solid oxide fuel cell, since it has an air-cooled structure, a larger amount of air than is necessary for the reaction flows through the cathode, and therefore the decrease in the concentration correction term ΔEc at the cathode is smaller than the concentration correction term ΔEa at the anode.

[0014] That is, in a typical fuel cell, the electromotive force decreases as the distance x from the inlet increases (i.e., the further downstream), as shown in Figure 3. In other words, in a typical fuel cell, the reaction is biased toward the upstream, and the entire reaction area cannot be used effectively.

[0015] Therefore, in this embodiment, in order to effectively utilize the reaction region, the reaction gas flow path is configured as described below.

[0016] 4 is a plan view of the anode flow path member 1 that forms a flow path for supplying anode gas to the anode electrode, and FIG. 5 is an enlarged view of region IV in FIG.

[0017] A plurality of parallel flow paths 2 are provided in the anode flow path member 1. The flow paths 2 are separated by partitions 3, so that gases flowing through adjacent flow paths 2 do not mix.

[0018] Each flow channel 2 has an open region 2B, whose bottom surface is open and contacts the reaction surface of a cell 5 (described later), and a closed region 2A, which is not open. The flow channels 2 have two opening patterns: a first pattern in which the open region 2B is located upstream and the closed region 2A is located downstream, and a second pattern in which the closed region 2A is located upstream and the open region 2B is located downstream. While FIGS. 4 and 5 show a structure in which the first and second patterns are alternately arranged, this is not limiting. For example, two flow channels 2 of the first pattern may be defined as a first pattern group, and two flow channels 2 of the second pattern may be defined as a second pattern group, in which the first and second pattern groups are alternately arranged. However, at least some of the multiple flow channels 2 must be of the first pattern, and the remaining must be of the second pattern.

[0019] 6 is a cross-sectional view of the flow path upstream of the position where the opening pattern changes in a fuel cell stack using the above-mentioned anode flow path member 1. The cathode flow path member 9 has the same structure as the anode flow path member 1.

[0020] The cell 5 is formed by stacking an anode 6 and a cathode 8 with an electrolytic lipid layer 7 interposed between them. The anode 6 has a support layer (not shown) made of a porous material (e.g., porous metal), and this support layer is in contact with the anode flow path member 1. The cathode 8 similarly has a support layer in contact with the cathode flow path member 9. The fuel cell stack is formed by stacking an anode flow path member 1, a cell 5, and a cathode flow path member 9 in this order as a cell unit, and by stacking multiple cell units with separators 4 interposed between them.

[0021] As shown in FIG. 6, in the anode-side flow channel 2, the anode gas An (hydrogen) flows through the closed region 2A, and the anode gas An and water produced by reaction flow through the open region 2B. That is, the anode gas flowing through the closed region 2A flows through the flow path 2 without being subjected to a reaction. On the other hand, the anode gas An flowing through the open region 2B is consumed by being subjected to a reaction, and water is produced by this reaction, so that the anode gas An and water flow through the open region 2B. Note that the reaction in the anode electrode 6 does not occur only in the portion facing the open region 2B. The anode gas An flowing through the open region 2B diffuses within the support layer, so the reaction also occurs in the portion facing the closed region 2A.

[0022] 5, the flow path 2 with the open region 2B on the upstream side has the closed region 2A on the downstream side, and the flow path 2 with the closed region 2A on the upstream side has the open region 2B on the downstream side. Therefore, the anode gas An and the generated water, whose concentration has decreased by being subjected to the reaction in the open region 2B on the upstream side, flow downstream where the opening pattern has been switched without being subjected to the reaction. On the other hand, the anode gas An that has flowed through the closed region 2A on the upstream side is subjected to the reaction at a high concentration on the downstream side where the opening pattern has been switched.

[0023] This solves the problem that the hydrogen partial pressure decreases toward the downstream side, resulting in insufficient use of the entire surface of the cell 5. Furthermore, since each flow path 2 is separated by a partition 3 and gases flowing through adjacent flow paths 2 do not mix, low-concentration anode gas An and water do not mix with high-concentration anode gas An at the transition between the open region 2B and the closed region 2A.

[0024] The cathode gas Ca flowing through the cathode-side flow path 2 is similar to the anode-side flow path described above. However, since the effect of a decrease in the concentration (decrease in partial pressure) of the cathode gas is small even in the general configuration as described above, the cathode side may have the same configuration as the general one.

[0025] It is desirable to set the opening patterns of the anode flow path member 1 and the cathode flow path member 9, which face each other across the cell 5, so that their opening regions do not face each other, as shown in Fig. 6. This is because if the opening regions face each other, reactions are promoted in the facing regions, resulting in consumption of the anode gas An and the cathode gas Ca, making it difficult for the gases to diffuse within the support layer.

[0026] 4, the switching position between the closed region 2A and the open region 2B is approximately at the center of the flow direction of the flow channel 2 in both the first and second patterns, but this is not limited to this. For example, the open region 2B of the first pattern may extend downstream from approximately the center in the flow direction, and the open region 2B of the second pattern may start upstream from approximately the center in the flow direction.

[0027] As described above, the cell unit structure of the fuel cell according to this embodiment includes an anode flow path member 1 that forms the flow paths 2 that supply anode gas to the anode electrode 6, and a cathode flow path member 9 that forms the flow paths 2 that supply cathode gas to the cathode electrode 8. At least one of the anode flow path member 1 or the cathode flow path member 9 is partitioned by partitions 3 into multiple flow paths 2 that prevent gases flowing through adjacent flow paths 2 from mixing, and each of the multiple flow paths 2 has an open region 2B that is open on the bottom surface that contacts the cell 5, and a closed region 2A that is not open. At least some of the multiple flow paths 2 have two opening patterns: a first pattern in which the open region 2B is on the upstream side and the closed region 2A is on the downstream side, and the remaining portion has a second pattern in which the closed region 2A is on the upstream side and the open region 2B is on the downstream side. As a result, the flow path 2 of the first pattern supplies a high concentration of gas to the upstream side of the reaction surface of the cell 5, and the flow path 2 of the second pattern supplies a high concentration of gas to the downstream side of the reaction surface of the cell 5, thereby suppressing a decrease in the reaction gas concentration downstream of the cell 5.

[0028] In this embodiment, the flow channels 2 of the first pattern and the flow channels 2 of the second pattern are arranged alternately in a direction perpendicular to the gas flow direction, thereby enabling the entire reaction surface of the cell 5 to be used efficiently.

[0029] In this embodiment, the anode 6 and the cathode 8 have support layers (porous support layers) formed of a porous material between the anode flow path member 1 and the cathode flow path member 9, respectively. This allows the reaction gas supplied to the cells 5 from the open region 2B to diffuse within the support layer, and the reaction gas is also supplied to the reaction surface facing the closed region 2A, allowing the entire reaction surface to be used efficiently.

[0030] [Second embodiment] The second embodiment will be described with reference to FIGS.

[0031] FIG. 7 is a plan view of the anode channel member 1 according to this embodiment, near the transition portion between the closed region 2A and the open region 2B. FIG. 8 is a perspective view of a cross section taken along line VIII-VIII in FIG. 7. FIG. 9 is a perspective view of the anode channel member 1 according to this embodiment, near the transition portion between the closed region 2A and the open region 2B. Note that in FIG. 9, only separator ribs 10 (described later) of the separator 4 are shown, and other portions are omitted. FIG. 10 is a cross-sectional view of the channel taken along line VIII-VIII in FIG. 7. Also, the cathode channel member 9 is omitted in FIGS. 8 to 10. The cathode channel member 9 according to this embodiment may be the same as that of the first embodiment, or may be one in which the partitions 3 of the cathode channel member 9 according to the first embodiment are replaced with ribs.

[0032] The partition sections 3 of the anode flow path member 1 of this embodiment are ribs (hereinafter also referred to as ribs 3) formed along the gas flow path direction by press working or the like. The ribs 3 are terminated near the transition between the open region 2B and the closed region 2A, and an opening 3B is provided at the downstream end of the upstream rib 3.

[0033] The gaps where the ribs 3 are discontinued are filled by separator ribs 10 provided on the separator 4. The separator ribs 10 protrude from the separator 4 toward the anode flow path member 1, and contact the upstream ribs 3 and the downstream ribs 3 in the flow path 2 of the second pattern (the upstream side is a closed region 2A and the downstream side is an open region 2B).

[0034] In the above configuration, the openings 3B also form a flow path within the interior 3A of the upstream rib 3. The anode gas An that flows through the interior 3A and then flows into the flow path 2 through the openings 3B flows through the downstream closed region 2A together with the anode gas An that has flowed through the opening region 2B (see the arrows in FIG. 7 ). This means that the anode gas An also flows through the interior 3A of the rib 3, increasing the area of ​​the anode 6 to which fuel is supplied (hereinafter also referred to as the fuel supply area). Furthermore, the anode gas An that has become low in concentration after flowing through the interior 3A of the rib 3 is discharged into the flow path 2 through the openings 3B. However, because the separator rib 10 blocks communication between the openings 3B and the downstream opening region 2B, the low-concentration anode gas An does not flow into the downstream opening region 2B. This means that the anode gas An flowing through the downstream opening region 2B can be maintained at a high concentration.

[0035] As described above, in this embodiment, the partitions 3 are ribs 3 (flow path member ribs) formed on the anode flow path member 1 or the cathode flow path member 9. This allows the reactant gas to flow inside the ribs 3 as well, thereby expanding the area of ​​the reaction surface of the cells 5 to which fuel is supplied directly without going through a support layer.

[0036] In this embodiment, the ribs 3 are discontinued at the transition between the open region 2B and the closed region 2A, and the downstream end of the upstream rib 3 is open, while the upstream end of the downstream rib 3 is closed. This allows the reaction gas to be discharged from inside the upstream rib 3.

[0037] In this embodiment, a separator 4 is further provided to separate the anode gas flow path and the cathode gas flow path, and the interrupted portions of the rib 3 are blocked by separator ribs 10 formed on the separator 4. This prevents low-concentration reactant gas discharged from inside the rib 3 from flowing into the adjacent flow path 2, the downstream side of which is the open region 2B.

[0038] [Third embodiment] The third embodiment will be described with reference to FIGS.

[0039] 11 is a plan view of the anode channel member 1 according to this embodiment, near the transition portion between the closed region 2A and the open region 2B, and FIG. 12 is a cross-sectional view taken along line XII-XII in FIG.

[0040] The first difference between this embodiment and the second embodiment is the channel width of the channel 2. Here, the "channel width" refers to the dimension along the surface direction of the cell 5 and perpendicular to the gas flow direction. In this embodiment, the channel width of the closed region 2A is smaller than the channel width of the open region 2B.

[0041] The second difference is the position of the separator rib 10. As described above, the flow path widths of the closed region 2A and the open region 2B are different, so the positions of the ribs 3 on the upstream and downstream sides are shifted. For this reason, the separator rib 10 is arranged so that it contacts the upstream rib 3 from the open region 2B side and the downstream rib 3 from the closed region 2A side. This makes it possible to prevent gases in adjacent flow paths 2 from mixing.

[0042] The third difference is the position of the openings 3B of the ribs 3. In the second embodiment, the openings 3B are provided at the downstream end of the upstream rib 3. In contrast, in this embodiment, the openings 3B are provided on the side surface of the upstream rib 3 near the downstream end, on the side surface of the opening region 2B near the downstream end, and on the side surface of the downstream rib 3 near the upstream end, on the side surface of the opening region 2B near the upstream end.

[0043] With the above configuration, gas also flows into the interior 3A of the downstream rib 3, thereby increasing the fuel supply area of ​​the anode 6. Furthermore, even though the travel distance (hereinafter also referred to as the diffusion distance) of the fuel supplied to the anode 6 within the support layer is shorter than in the first and second embodiments, the anode gas An can be supplied to a wider area of ​​the anode 6 (see the arrows in FIG. 12). More specifically, the anode gas An is more easily supplied to the lower portion of the closed region 2A.

[0044] As described above, in this embodiment, the open region 2B has a narrower flow path width than the closed region 2A. This shortens the travel distance of the reaction gas supplied from the open region 2B when it diffuses through the support layer to the portion of the cell 5 facing the closed region 2A, allowing the entire reaction surface of the cell 5 to be used more efficiently.

[0045] In this embodiment, the rib 3 has openings 3B (through holes) on the side surface on the side of the opening region 2B, which allows the reactive gas to be supplied directly into the inside of the rib 3 from the flow channels 2 in the opening region 2B.

[0046] [Variations] Here, a modification of the third embodiment will be described. Like the third embodiment, this modification also falls within the scope of the present invention. FIG. 13 is a cross-sectional view of an anode flow channel according to the modification. The difference from FIG. 12 is that the flow channel height H1 of the open region 2B is lower than the flow channel height H2 of the closed region 2A. Here, the "flow channel height" refers to the dimension in the direction perpendicular to the gas flow direction and the surface direction of the cells 5. This difference in flow channel height is achieved by the shape of the separator 4.

[0047] The reason for making the flow channel heights different as described above is to make the flow channel height lower in the opening region 2B by the amount of the widened flow channel width, and to make the flow channel height higher in the closing region 2A by the amount of the narrowed flow channel width, thereby making the flow channel cross-sectional areas of the opening region 2B and the closing region 2A closer to each other. In other words, it is desirable to set the flow channel width and flow channel height of each so that the flow channel cross-sectional areas of the opening region 2B (including the inside of the rib 3) and the closing region 2A are equal.

[0048] By making the cross-sectional areas of both flow paths equal, the pressure loss becomes equal, and it is possible to equalize the gas flow rates of the first pattern flow paths 2 and the second pattern flow paths 2. This makes it possible to prevent an excess or deficiency of the anode gas An flowing through either the first pattern flow paths 2 or the second pattern flow paths 2.

[0049] As described above, in this modification, the closed region 2A has a higher flow path height than the open region 2B. This reduces the difference in pressure loss between the open region 2B and the closed region 2A compared to when the flow path heights are the same, and therefore, it is possible to prevent an excess or deficiency of the anode gas An flowing in either the first pattern of flow paths 2 or the second pattern of flow paths 2.

[0050] [Fourth embodiment] The fourth embodiment will be described with reference to Figures 14 and 15. Figure 14 is an exploded perspective view of a cell unit according to this embodiment. Figure 15 is a cross-sectional view of the flow channels of the cell unit according to this embodiment.

[0051] In the above-described embodiments and modifications, the cell unit is composed of a cell 5, an anode flow path member 1, a cathode flow path member 9, and a separator 4. In contrast, the cell unit of the present embodiment is composed of a cell 5, an anode flow path member 1, and a cathode flow path member 9, as shown in FIG.

[0052] The anode flow path member 1 and the cathode flow path member 9 each have a shape in which ribs 3An and 3Ca are provided in the gas flow direction by pressing or the like on a flat plate. The opening region 2B is provided only on the anode flow path member 1. The side surface of the rib 3Ca of the cathode flow path member 9 is provided with a communication hole that connects the inside and outside of the rib 3Ca.

[0053] 15, the bottom surface of the closed region 2A of the anode flow path member 1 is welded to the support layer of the anode electrode 6 (weld 11 in FIG. 15), and the rib 3Ca of the cathode flow path member 9 is welded to the support layer of the cathode electrode 8 (weld 12 in FIG. 15), thereby forming a cell unit. The welds 11 and 12 extend along the gas flow direction from the upstream end to the downstream end of the contact point between the respective members.

[0054] Adjacent cell units in the stacking direction are connected by joining the contact portions of the anode flow path member 1 and the cathode flow path member 9 by brazing or the like (joint portion 13 in FIG. 15 ), with the rib 3An of the anode flow path member 1 positioned to cover the lower surface openings of the rib 3Ca of the cathode flow path member 9. The joint portion 13 is provided over the entire area of ​​the contact portion between the anode flow path member 1 and the cathode flow path member 9.

[0055] By stacking the cell units as described above, a flow path for the anode gas An is formed between the anode flow path member 1 and the cathode flow path member 9, and a flow path for the cathode gas Ca is formed between the cathode 8 and the cathode flow path member 9. Since the rib 3Ca of the cathode flow path member 9 has the above-mentioned communication holes, the interior of the rib 3Ca also serves as a flow path for the cathode gas Ca. Furthermore, by opening the upstream end of the rib 3An of the anode flow path member 1, the interior of the rib 3An also serves as a flow path for the anode gas An.

[0056] According to the above configuration, the anode gas flow channel and the cathode gas flow channel that are separated from each other can be formed without using a separator 4.

[0057] As described above, in this embodiment, the closed region 2A is provided only in the anode flow path member 1, and the anode flow path member 1 and the cathode flow path member 9 are joined together to form separate anode gas flow paths and cathode gas flow paths between adjacent cells 5. This reduces the number of parts that make up the cell unit, thereby reducing costs.

[0058] [Fifth embodiment] The fifth embodiment will be described with reference to Figures 16 and 17. Figure 16 is a cross-sectional view of the flow path of a cell unit according to this embodiment. Figure 17 is a cross-sectional perspective view of an opening region 2B near the flow path inlet through which reactant gas is supplied in a cell unit according to this embodiment.

[0059] Similar to the fourth embodiment, this embodiment also has a structure in which the anode channel member 1 and the cathode channel member 9 are joined together without using a separator 4. However, the anode channel member 1 of this embodiment is a flat plate.

[0060] Furthermore, ribs 3An that form a flow path for anode gas An are provided on the cathode flow path member 9. More specifically, ribs 3An that convex in the opposite direction to the convex direction of the ribs 3Ca are provided on the portions (also referred to as bottom portions) of the ribs 3Ca that form the flow path for cathode gas Ca that contact the anode flow path member 1. Openings 15 that communicate between the inside and outside of the ribs 3Ca are provided on the end portions on the flow path inlet side of the ribs 3Ca. In FIG. 17, a member 14 attached to the surface of the cathode 8 facing the anode flow path member 1 is a cell support member that is arranged to surround the periphery of the cells 5.

[0061] As a result, similar to the fourth embodiment, a flow path for cathode gas Ca is formed between the cathode 8 and the cathode flow path member 9, and a flow path for anode gas An is formed between the anode flow path member 1 and the cathode flow path member 9. Then, the cathode gas Ca supplied to the cell unit flows through the openings 15 into the inside of the rib 3Ca (i.e., the cathode flow path), and the anode gas An flows through the gap between the anode flow path member 1 and the member 14 into the inside of the rib 3An (i.e., the anode flow path). Note that while FIG. 17 shows the open region 2B, in the case of the closed region 2A, a communication hole is provided in the anode flow path member 1 that connects the gap between the anode flow path member 1 and the member 14 with the inside of the rib 3An. As a result, the anode gas An flows into the closed region 2A surrounded by the anode flow path member 1 and the rib 3An.

[0062] As described above, in this embodiment, the anode flow path member 1 is a flat plate, and the ribs 3An that form the anode gas flow path and the ribs 3Ca that form the cathode gas flow path are formed on the cathode flow path member 9. This not only reduces the number of parts that make up the cell unit, but also makes it easier to process the anode flow path member 1, further reducing costs.

[0063] It goes without saying that the present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the technical concept described in the claims. [Explanation of symbols]

[0064] 1 anode flow path member, 2 flow path, 2A closed region, 2B open region, 3 partition (rib), 4 separator, 5 cell, 6 anode electrode, 7 electrolyte layer, 8 cathode electrode, 9 cathode flow path member

Claims

1. an anode flow path member that forms a flow path for supplying an anode gas to the anode; a cathode flow path member that forms a flow path for supplying a cathode gas to the cathode; In a fuel cell unit structure comprising: at least one of the anode flow path member and the cathode flow path member is partitioned by a partition portion into a plurality of flow paths in which gases flowing through adjacent flow paths do not mix, and each of the plurality of flow paths has an open region whose bottom surface in contact with the cell is open and a closed region whose bottom surface is not open; At least some of the plurality of flow paths have two opening patterns: a first pattern in which the open region is located on an upstream side and the closed region is located on a downstream side; and the remaining part of the flow paths have a second pattern in which the closed region is located on an upstream side and the open region is located on a downstream side. The cell unit structure of a fuel cell, wherein the partition portion is a flow path member rib formed on the anode flow path member or the cathode flow path member.

2. 2. The fuel cell unit structure according to claim 1, A cell unit structure of a fuel cell, in which the flow channels of the first pattern and the flow channels of the second pattern are alternately arranged in a direction perpendicular to the gas flow direction.

3. In the cell unit structure of the fuel cell according to claim 2, the flow path member rib is interrupted at a transition portion between the open region and the closed region, A cell unit structure of a fuel cell, wherein the downstream end of the flow path member rib on the upstream side is open, and the upstream end of the flow path member rib on the downstream side is closed.

4. In the cell unit structure of the fuel cell according to claim 3, Further provided is a separator that separates the anode gas flow path and the cathode gas flow path, A cell unit structure of a fuel cell, wherein the interrupted portions of the flow path member ribs are closed by separator ribs formed on the separators.

5. 5. The fuel cell unit structure according to claim 1, The open region has a narrower flow path width than the closed region.

6. 5. The fuel cell unit structure according to claim 1, The flow path member rib has a through hole on the side surface on the opening region side.

7. 7. The fuel cell unit structure according to claim 1, The anode and cathode have a porous support layer between the anode flow path member and the cathode flow path member, respectively.

8. The fuel cell unit structure according to any one of claims 1 to 7, A cell unit structure of a fuel cell, wherein the closed region has a flow path height greater than that of the open region.

9. 3. The fuel cell unit structure according to claim 1, the closed region is provided only in the anode flow path member, A cell unit structure of a fuel cell, in which the anode flow path member and the cathode flow path member are joined together to form an anode gas flow path and a cathode gas flow path that are separated from each other between adjacent cells.

10. In the cell unit structure of the fuel cell according to claim 9, A cell unit structure of a fuel cell, wherein the anode flow path member is a flat plate, and the cathode flow path member is provided with ribs that form the anode gas flow path and ribs that form the cathode gas flow path.

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