JP7732269B2 - Fuel cell unit structure - Google Patents

Description

The present invention relates to a cell unit structure for a fuel cell.

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, located between the separator plate and the 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, with the upstream separator-side flow channel connected 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 flowed through the electrode-side flow channel flows through the separator-side flow channel, and the gas that 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.

Japanese Patent Application Publication No. 1-140560

However, in a structure in which identically shaped corrugated flow path plates are installed offset by one pitch, as in the above document, gas whose reactant gas concentration has decreased due to 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.

The present invention therefore aims to further enhance the effect of suppressing a decrease in reactant gas concentration downstream.

According to one aspect of the present invention, there is provided a fuel cell unit structure including an anode flow channel member that forms a flow channel for supplying anode gas to the anode electrode, and a cathode flow channel member that forms a flow channel for supplying cathode gas to the cathode electrode. At least one of the anode flow channel member or the cathode flow channel member is divided by a partition into multiple flow channels that prevent gases flowing through adjacent flow channels from mixing, and each of the multiple flow channels has an open region where the bottom surface that contacts the cell is open and a closed region that is not open. At least some of the multiple flow channels 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 remaining portion has a closed region on the upstream side and an open region on the downstream side. The partition is a flow channel member rib molded on the anode flow channel member or the cathode flow channel member.

This aspect further enhances the effect of suppressing a decrease in the reactant gas concentration downstream.

FIG. 1 is a plan view of a typical fuel cell. FIG. 2 is a graph 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. 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. FIG. 4 is a plan view of the anode flow path member according to the first embodiment. FIG. 5 is an enlarged view of region IV in FIG. FIG. 6 is a cross-sectional view of the flow passages of the fuel cell stack according to the first embodiment, taken upstream of the position where the opening pattern is switched. FIG. 7 is a plan view of the anode flow path member near the transition portion between the closed region and the open region. FIG. 8 is a perspective view of a cross section taken along line VIII-VIII in FIG. FIG. 9 is a perspective view of the vicinity of a transition portion between a closed region and an open region of an anode flow path member according to the second embodiment. FIG. 10 is a cross-sectional view of the flow passage taken along line VIII-VIII in FIG. FIG. 11 is a plan view of the vicinity of a transition portion between a closed region and an open region of an anode flow path member according to the third embodiment. FIG. 12 is a cross-sectional view taken along line XII-XII in FIG. FIG. 13 is a cross-sectional view of an anode flow channel according to a modification of the third embodiment. FIG. 14 is an exploded perspective view of a cell unit according to the fourth embodiment. FIG. 15 is a cross-sectional view of a flow path of a cell unit according to the fourth embodiment. FIG. 16 is a cross-sectional view of a flow path of a cell unit according to the fifth embodiment. 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.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

[First embodiment]
First, the electromotive force of a typical solid oxide fuel cell (hereinafter simply referred to as a "fuel cell") will be described. 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 a 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.

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.

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).
E ^o is the standard electromotive force, ΔE _a and ΔE _c are concentration correction terms at the anode and cathode, respectively, and F, R, T and Pi are the Faraday constant, gas constant, temperature and partial pressure of each gas, respectively.

When a load current is extracted, _H2 is consumed at the anode and _O2 at the cathode due to the reactions, respectively. Therefore, as shown in FIG. 2, the greater the distance x from the inlet, the lower the _H2 partial pressure and _O2 partial pressure. On the other hand, because _H2O is produced at the anode due to the reactions, as shown in FIG. 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), the anode concentration correction term P _H2 decreases and P _H2O increases, resulting in a decrease in the concentration correction term ΔEa at the anode. The same is true for the concentration correction term _ΔEc at the cathode. However, in the case of a solid oxide fuel cell, due to its air-cooled structure, a larger amount of air than necessary for the reaction flows through the cathode, so the decrease in the concentration correction term ΔEc at the cathode is smaller than the concentration correction term ΔEa at the anode.

In other words, in a typical fuel cell, as shown in Figure 3, the greater the distance x from the inlet (i.e., the further downstream), the lower the electromotive force. In other words, in a typical fuel cell, the reaction is biased upstream, and the entire reaction area is not effectively utilized.

In this embodiment, therefore, in order to effectively utilize the reaction region, the reaction gas flow path is configured as described below.

Figure 4 is a plan view of the anode flow path member 1, which forms a flow path that supplies anode gas to the anode electrode. Figure 5 is an enlarged view of region IV in Figure 4.

The anode flow path member 1 has multiple flow paths 2 that are parallel to each other. These flow paths 2 are separated by partitions 3, so that gases flowing through adjacent flow paths 2 do not mix.

The flow paths 2 each have an open region 2B, where the bottom surface that comes into contact with the reaction surface of the cell 5 (described below), is open, and a closed region 2A, where it is not open. The 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 a second pattern in which the closed region 2A is on the upstream side and the open region 2B is on the downstream side. While Figures 4 and 5 show a structure in which the first and second patterns are alternately arranged, this is not limiting. For example, two flow paths 2 of the first pattern may be a first pattern group, and two flow paths 2 of the second pattern may be a second pattern group, where the first pattern group and the second pattern group are alternately arranged. However, at least some of the multiple flow paths 2 must be of the first pattern, and the rest must be of the second pattern.

Figure 6 is a cross-sectional view of the flow path of a fuel cell stack using the above-mentioned anode flow path member 1, taken upstream of the position where the opening pattern changes. Note that the cathode flow path member 9 has the same structure as the anode flow path member 1.

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), which contacts the anode flow path member 1. The cathode 8 similarly has a support layer in contact with the cathode flow path member 9. A 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 multiple cell units are stacked with separators 4 interposed between them.

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.

As shown in Figure 5, a flow path 2 with an open region 2B on the upstream side has a closed region 2A on the downstream side, and a flow path 2 with a closed region 2A on the upstream side has an open region 2B on the downstream side. Therefore, the anode gas An and generated water, whose concentration has decreased due to being subjected to reaction in the upstream open region 2B, flow downstream where the opening pattern has changed without being subjected to reaction. On the other hand, the anode gas An that has flowed through the closed region 2A on the upstream side is subjected to reaction at a high concentration on the downstream side where the opening pattern has changed.

This eliminates the problem of hydrogen partial pressure decreasing downstream, resulting in underutilization of the entire surface of the cell 5. Furthermore, each flow path 2 is separated by a partition 3, preventing the gases flowing through adjacent flow paths 2 from mixing. This prevents the high-concentration anode gas An from being mixed with the low-concentration anode gas An and water at the transition between the open region 2B and the closed region 2A.

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

As shown in Figure 6, it is desirable to set the opening pattern of the anode flow path member 1 and cathode flow path member 9, which face each other across the cell 5, so that their opening areas do not face each other. This is because if the opening areas face each other, reactions will be promoted in the facing areas, consuming the anode gas An and cathode gas Ca, and making it difficult for the gases to diffuse within the support layer.

In addition, in Figure 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 begin upstream from approximately the center in the flow direction.

As described above, the cell unit structure of the fuel cell according to this embodiment comprises an anode flow path member 1 that forms a flow path 2 for supplying anode gas to the anode electrode 6, and a cathode flow path member 9 that forms a flow path 2 for supplying 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 divided 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 with an open 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 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 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.

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

In this embodiment, the anode electrode 6 and the cathode electrode 8 have a support layer (porous support layer) 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 cell 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.

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

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

The partition section 3 of the anode flow path member 1 in this embodiment is a rib (hereinafter also referred to as rib 3) formed along the gas flow path direction by press working or the like. The rib 3 is 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.

Gaps where the ribs 3 end 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 downstream ribs 3 in the flow path 2 of the second pattern (closed region 2A on the upstream side and open region 2B on the downstream side).

In the above configuration, the openings 3B allow the interior 3A of the upstream rib 3 to function as a flow path. The anode gas An that flows through the interior 3A and exits the openings 3B into the flow path 2 flows through the downstream closed region 2A along with the anode gas An that has flowed through the opening region 2B (see the arrows in Figure 7). This means that the anode gas An also flows through the interior 3A of the rib 3, further increasing the area to which fuel is supplied to the anode 6 (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 to 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.

As described above, in this embodiment, the partitions 3 are ribs 3 (flow path member ribs) molded into 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, expanding the area of the reaction surface of the cell 5 to which fuel is supplied directly without going through a support layer.

In this embodiment, the ribs 3 are interrupted at the transition between the open region 2B and the closed region 2A, with the downstream end of the upstream rib 3 being open and the upstream end of the downstream rib 3 being closed. This allows the reaction gas to be discharged from inside the upstream rib 3.

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, whose downstream side is the open region 2B.

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

Figure 11 is a plan view of the anode flow path member 1 according to this embodiment, near the transition between the closed region 2A and the open region 2B. Figure 12 is a cross-sectional view taken along line XII-XII in Figure 11.

The first difference between this embodiment and the second embodiment is the channel width of the channel 2. Here, "channel width" refers to the dimension along the surface 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.

The second difference is the position of the separator ribs 10. As mentioned 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 misaligned. For this reason, the separator ribs 10 are arranged so that they contact the upstream ribs 3 from the open region 2B side and the downstream ribs 3 from the closed region 2A side. This prevents gases from adjacent flow paths 2 from mixing.

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

With the above configuration, gas also flows inside the downstream rib 3 (3A), 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 Figure 12). More specifically, the anode gas An is more easily supplied to the lower portion of the closed region 2A.

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 as it diffuses through the support layer to the part of the cell 5 facing the closed region 2A, allowing for more efficient use of the entire reaction surface of the cell 5.

In this embodiment, the rib 3 has an opening 3B (through hole) on the side surface on the opening region 2B side. This allows the reactant gas to be supplied directly from the flow path 2 in the opening region 2B to the inside of the rib 3.

[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.

The reason for making the flow channel heights different as described above is to make the flow channel cross-sectional areas of the opening region 2B and the closed region 2A closer by lowering the flow channel height in proportion to the wider flow channel width in the opening region 2B and increasing the flow channel height in proportion to the narrower flow channel width in the closed region 2A. 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 closed region 2A are equal.

By making the cross-sectional area of both flow paths equal, the pressure loss is equalized, making it 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 excess or deficiency of the anode gas An flowing through either the first pattern flow paths 2 or the second pattern flow paths 2.

As described above, in this modified example, 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, thereby preventing 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.

[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.

In the above-described embodiments and modifications, the cell unit was 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 this embodiment is composed of a cell 5, an anode flow path member 1, and a cathode flow path member 9, as shown in Figure 14.

The anode flow path member 1 and the cathode flow path member 9 each have a flat plate shape with ribs 3An and 3Ca formed along the gas flow direction by pressing or other methods. The open area 2B is only provided on the anode flow path member 1. The side surface of the rib 3Ca of the cathode flow path member 9 has a communication hole that connects the inside and outside of the rib 3Ca.

As shown in Figure 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 Figure 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 Figure 15), thereby forming a cell unit. Welds 11 and 12 extend from the upstream end to the downstream end of the contact point between each member along the gas flow direction.

Adjacent cell units in the stacking direction are connected by joining the contact areas between the anode flow path member 1 and the cathode flow path member 9 by brazing or the like (joints 13 in Figure 15), with the ribs 3An of the anode flow path member 1 positioned to block the underside openings of the ribs 3Ca of the cathode flow path member 9. The joints 13 are provided over the entire contact area between the anode flow path member 1 and the cathode flow path member 9.

By stacking the cell units as described above, a flow path for anode gas An is formed between the anode flow path member 1 and the cathode flow path member 9, and a flow path for cathode gas Ca is formed between the cathode electrode 8 and the cathode flow path member 9. Since the ribs 3Ca of the cathode flow path member 9 have the aforementioned communication holes, the interior of the ribs 3Ca also serves as a flow path for cathode gas Ca. Furthermore, by opening the upstream ends of the ribs 3An of the anode flow path member 1, the interior of the ribs 3An also serves as a flow path for anode gas An.

With the above configuration, it is possible to form anode gas flow paths and cathode gas flow paths that are separated from each other without using a separator 4.

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.

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 the cell unit according to this embodiment.

Like the fourth embodiment, this embodiment also has a structure in which the anode flow path member 1 and the cathode flow path member 9 are joined together without using a separator 4. However, the anode flow path member 1 in this embodiment is a flat plate.

In addition, 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 rib 3Ca are provided on the portion (also referred to as the bottom) of rib 3Ca that forms the flow path for cathode gas Ca that contacts the anode flow path member 1. An opening 15 that connects the inside and outside of rib 3Ca is provided at the end of rib 3Ca on the flow path inlet side. Note that in Figure 17, member 14 attached to the surface of cathode electrode 8 facing the anode flow path member 1 is a cell support member that is arranged to surround the periphery of cell 5.

As a result, similar to the fourth embodiment, a flow path for cathode gas Ca is formed between the cathode 8 and cathode flow path member 9, and a flow path for anode gas An is formed between the anode flow path member 1 and cathode flow path member 9. Cathode gas Ca supplied to the cell unit flows through the opening 15 into the inside of rib 3Ca (i.e., the cathode flow path), and anode gas An flows through the gap between anode flow path member 1 and member 14 into the inside of rib 3An (i.e., the anode flow path). Note that while Figure 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 member 14 with the inside of rib 3An. As a result, anode gas An flows into the closed region 2A surrounded by the anode flow path member 1 and rib 3An.

As described above, in this embodiment, the anode flow path member 1 is a flat plate, and the cathode flow path member 9 is formed with ribs 3An that form the anode gas flow path and ribs 3Ca that form the cathode gas flow path. 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.

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

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 (10)

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