JP2006173056A - Solid electrolyte fuel cell and stack structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solid electrolyte fuel cell and a stack structure excellent in thermal shock resistance and a starting property, capable of improving output density and preventing breakage due to local overheat. <P>SOLUTION: The solid electrolyte fuel cell is composed of a unit cell 6; a thin disc-shaped separator at one side 2 having a gas introducing hole 21 and a gas exhausting hole 22 at a central part, and a cell mounting part 25 fixing the unit cell 6; a separators at the other side 3 with a shape similar to the separator 2, of which peripheral edge part 3a is jointed to the peripheral edge part 2a of the separator 2; and a central flow passage part 5 provided with a gas introducing port 51 and a gas exhaustion port 52 communicated with the gas introducing holes 21, 31 and the gas exhausting holes 22, 32 of the separators 2, 3. A separation plate 4 forming a forward passage 41 guiding the gas supplied from the gas introducing port 51 to the peripheral edge parts 2a, 3a; and a return passage 42 arranged on a plane identical to that of the forward passage 41, guiding the gas supplied from the peripheral edge parts 2a, 3a to the gas exhaustion port 52; is arranged in a space S. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

    The present invention relates to a solid oxide fuel cell used in a stacked manner and a stack structure formed by stacking the solid oxide fuel cells.

Conventionally, as a solid oxide fuel cell as described above, for example, a cell mounting separator having a circular thin plate shape and having a single cell mounting portion, and a cell mounting separator having substantially the same shape and A separator with a peripheral edge joined to the peripheral edge of the cell mounting separator, and a central flow path component that supplies and discharges gas into the space formed between the two separators, and a ring plate separator is installed in the space. Then, there is a solid oxide fuel cell formed by dividing the forward path and the return path of the gas flow path vertically (in the fuel cell stacking direction), and the ring plate separator is a dimple formed on the separator or the cell mounting separator. The protrusions hold the flow path heights of the gas flow path and the return path.
JP 2002-151106 A

  However, in the above-described solid oxide fuel cell, since the ring plate separator is installed so as to cover the power generation part of the single cell, the pitch of one cycle in which the cell mounting separator and the separator are stacked is increased. That is, since the forward and return paths of the gas flow path are formed separately in the upper and lower directions, the thickness of the fuel cell is increased, and therefore the stacking density is decreased and the unit volume when stacked to form a stack structure There was a problem that the power generation output density per hit would decrease.

  Further, in the above solid oxide fuel cell, the flow height of the reciprocating path of the gas flow path is held by the dimple-like protrusions provided on the separator or the cell mounting separator, and the electric contact in the stacking direction is maintained. Therefore, in order to prevent the ring plate separator from being distorted with respect to the heating cycle, the thickness of the ring plate separator and the separator must be increased. Not only is the density reduced, but the heat capacity of the stack structure is increased.

  As described above, when the heat capacity of the stack structure increases, the heating energy required at the time of start-up increases, so the overall power generation efficiency from start-up to stop decreases, and frequent start-stop and load operation are performed. In the case of in-vehicle applications, how to reduce the heat capacity of the stack structure is an important matter, and solving these problems has been a conventional problem.

  The present invention has been made by paying attention to the above-described conventional problems, achieves an improvement in output density when laminated, can prevent damage due to local overheating, and has excellent thermal shock resistance and startability. An object of the present invention is to provide a solid oxide fuel cell and a stack structure.

  The solid oxide fuel cell of the present invention includes a single cell, one separator having a circular thin plate shape and having a gas introduction hole and a gas discharge hole in a central portion and a cell mounting portion for fixing the single cell; The other separator having the same shape as the one separator except for the cell attachment portion and having the peripheral edge joined to the peripheral edge of the one separator, and the gas introduction hole and the gas discharge hole of both separators communicate with each other. A central flow path component for supplying and discharging gas to and from the space formed between the separators and having a gas introduction port and a gas discharge port for the separator. A forward path through which the gas supplied through the gas introduction port of the introduction hole and the central flow path component reaches the peripheral edge of the separator of the space, and a space separator located on the same plane as the forward path The structure of the solid oxide fuel cell is characterized by having a partition plate that forms a return path that allows the gas reaching the peripheral edge to reach the gas discharge port of the central flow path component and the gas discharge hole of the separator. Is a means for solving the above-described conventional problems.

  In the solid oxide fuel cell of the present invention, a gap is formed between the two separators, and one of the fuel gas and the air gas passes between the two separators forming the bag structure through the gas inlet of the central flow path component. Is introduced into the space, reaches the peripheral edge of the separator through the forward path formed by the partition plate, and is discharged from the gas outlet of the central flow path component through the return path also formed by the partition plate, This gas flows between the layers of the stacked solid oxide fuel cells.

  That is, the gas introduced into the space sufficiently flows to the single cell in the vicinity of the peripheral edge of the separator, and in addition, the forward path and the backward path formed by the partition plate are located on the same plane, so that one cycle is achieved. The pitch is reduced, and as a result, the output density is improved. Moreover, since the partition plate functions so as to prevent the space formed between both separators from being crushed, the thermal shock resistance and the startability are excellent without increasing the thickness of the separator.

  On the other hand, the stack structure of the present invention is formed by stacking the solid oxide fuel cells, and has the heat capacity of the partition plate of the solid oxide fuel cell located upstream of the gas flow introduced into the solid oxide fuel cell. It is characterized in that it is configured to be larger than the heat capacity of the partition plate of the solid oxide fuel cell located on the downstream side, and the configuration of this stack structure is a means for solving the above-described conventional problems .

  According to the solid oxide fuel cell of the present invention, since it has the above-described configuration, it is possible to sufficiently flow a gas to a single cell located in the vicinity of the separator peripheral portion, and to reduce the stacking pitch of one cycle. Therefore, it is possible to improve the power density when laminated, and to prevent damage due to local overheating, and in addition, maintain the space between both separators without increasing the thickness of the separators As a result, it is possible to obtain a very excellent effect that the thermal shock resistance and the startability can be improved.

  In the solid oxide fuel cell of the present invention, a porous sintered body having electrical conductivity, and a current collecting porous body such as a mesh or felt are installed at appropriate positions between both separators, and electrical connection in the stacking direction It is also possible to hold the current collecting function in the partition plate.

  At this time, it is also possible to employ a configuration in which the partition plate and the separator (or the partition plate and the current collecting porous body) are joined by a welding method, a paste baking method, or the like.

  Further, in the solid oxide fuel cell of the present invention, the central flow path component includes a gas introduction part having a gas introduction port and a gas discharge part having a gas discharge port. A structure in which a partition plate is integrally formed on a gasket that is sandwiched between parts and performs gas sealing can be used.

  In this case, the partition plate can be manufactured by cutting a part that is integral with the gasket and then bending the necessary part, or by forming the partition plate from a material different from the gasket and then by a method such as welding. It can also be integrated with the gasket.

  In addition, in order to improve the sealing performance of the gasket, a metal such as silver that can be softened and tightened can be plated on both sides of the gasket, and, for example, a brazing metal layer can be plated or vapor-deposited on both sides of the gasket. After forming the adhesive layer with a metal putty or pasty adhesive, etc., by applying a load and heating, the gas introduction part of the central channel part and A gas discharge part can also be joined.

  Further, in the solid oxide fuel cell of the present invention, the cell mounting portion of one separator is set to a region forming a donut shape between the central portion and the outer peripheral edge portion, and the cell mounting portion in the region forming the donut shape is set. It is possible to adopt a configuration in which one or more single cells are fixed to each other, and when the single cells have a small-diameter disk shape, they can be regularly arranged concentrically with the gas inlet located in the center of the separator. desirable. When the single cell has a donut shape, the inner ring and the outer ring that have been pressed are joined to the inner and outer peripheral edges, respectively. It may be connected to form a frame shape, and it is also possible to paste a fan-shaped single cell on this frame.

  Furthermore, in the solid oxide fuel cell of the present invention, the forward path formed by the partition plate in the space between both separators is a linear flow path extending from the gas inlet of the central flow path component toward the peripheral edge of the separator. The structure which consists of the annular flow path along a separator peripheral part is employable.

  When this configuration is adopted, when the gas introduced into the space is fuel gas, the annular flow path along the peripheral edge of the separator is the upstream side of the fuel gas, and the vicinity of the gas discharge port of the central flow path component is the downstream side. Therefore, a fuel gas with a higher fuel concentration can be supplied at the periphery of the separator having a wider flow path width, and the reaction speed is increased by the flow path width becoming narrower and increasing the flow velocity in the vicinity of the gas outlet where the fuel concentration becomes lower. Therefore, the power generation output can be averaged.

  That is, durability is improved by suppressing the temperature difference between the peripheral edge portion of the separator and the central portion.

  At this time, in the forward straight channel and the annular channel formed by the partition plate, the current collecting porous body installed on the upper surface of the single cell is not installed, or the collector installed on the upper surface of the single cell is used. It is desirable that the pressure loss be smaller than that of the electrical porous body. That is, in the space between both separators, the return path is formed by a partition plate on the current collecting porous body installed on the upper surface of the single cell, and the pressure loss in the forward path is set smaller than the pressure loss in the return path. Is desirable.

  When the above-described configuration is used, the gas introduced into the space through the gas inlet of the central flow path component is first guided to the peripheral edge of the separator via the forward straight flow path, and is uniform in the forward circular flow path. Pressure. Thereafter, the gas is discharged from the gas discharge port of the central flow path component through the current collecting porous body portion of the return path having a high pressure loss. Therefore, gas is evenly distributed from the peripheral edge portion of the separator to the current collecting porous body portion. Will be able to flow.

  In this way, by averaging the power generation output, it is possible to suppress a potential difference that occurs locally in one separator having the cell mounting portion, thereby suppressing power generation loss and suppressing damage due to local overheating. In this case, the durability can be improved.

  Furthermore, in the solid oxide fuel cell of the present invention, the forward straight flow path is disposed at a position connected to the gas introduction port of the central flow path component, the purpose of enhancing the gas flow rectification function, In order to prevent deformation such as distortion of the separator, it can be formed by adding a plate-like rectifying blade to the linear flow path.

  Furthermore, when the solid oxide fuel cells of the present invention are stacked, a gas introduction hole communicating with the gas introduction port passes through the center of the central flow path components laminated together. The purpose of improving the uniformity of gas distribution through the gas inlet of the central flow path component to each space of the solid oxide fuel cell and the gas from the gas inlet hole to the gas inlet of the central flow path component For the purpose of reducing the pressure loss when introducing the gas, the gasket can be provided with a guide portion located in the gas introduction hole. It is possible to adopt a configuration in which a guide portion that distributes to a plurality of gas inlets of the road part is provided.

  When this configuration is used, it is possible to improve the output density as a stack structure by uniformizing gas distribution to each of the stacked solid oxide fuel cells. It is possible to reduce pressure loss and improve distribution uniformity by generating a swirl flow in the gas introduction hole.

  That is, at the time of start-up, the stacked solid oxide fuel cells can be started up without a time difference, and damage due to the formation of local cells can be avoided.

  On the other hand, in a stack structure formed by stacking solid oxide fuel cells, when high temperature gas is introduced and heating at the time of startup is performed, the upstream portion of the stack structure receives a large thermal shock from the high temperature gas. . In particular, in the vicinity of the boundary between the central flow path component having a significantly different heat capacity and the thin plate portion of the separator, the thermal stress becomes large, causing warping and distortion, and the joint portion being easily broken.

  To cope with this, as described above, the heat capacity of the partition plate of the solid oxide fuel cell located on the upstream side of the gas flow is made larger than the heat capacity of the partition plate of the solid oxide fuel cell located on the downstream side. Specifically, it is desirable to increase the heat capacity by increasing the number of partition plates or increasing the thickness. In this case, thermal stress can be relaxed and warping and distortion can be reinforced. Become.

  EXAMPLES Hereinafter, although an Example demonstrates this invention still in detail, this invention is not limited to a following example.

  1 to 4 show an embodiment of a solid oxide fuel cell according to the present invention. As shown in FIG. 1, this solid oxide fuel cell 1 has a circular thin plate shape and has a central portion. One separator 2 having a gas introduction hole 21 and a gas discharge hole 22 and also having a cell mounting portion 25 (shown only in FIG. 4) is formed into a circular thin plate like the one separator 2 and introduces gas into the central portion. The other separator 3 having the holes 31 and the gas discharge holes 32, the gas introduction holes 51 and 31 and the gas discharge holes 52 communicating with the gas discharge holes 22 and 32 of the separators 2 and 3 are provided. A central flow path component 5 that supplies and discharges gas to and from the space S formed between the separators 2 and 3 is provided. Join together Are to so that.

  The central flow path component 5 is located at each central portion of both separators 2 and 3 joined in a state of facing each other, and the gas introduction port 51 in which the gas introduction port 51 communicating with the gas introduction hole 31 of the separator 3 is formed. The gas discharge part 5O in which the gas discharge port 52 communicating with the part 5I and the gas discharge hole 22 of the separator 2 is formed is provided.

  In this case, in the space S formed between the separators 2 and 3, as shown in FIGS. 2 and 3, four forward paths 41 and four return paths 42 located on the same plane as the forward paths 41 are formed. Eight partition plates 4 are provided.

  The four forward passages 41 formed by these eight partition plates 4 allow the gas to be supplied through the gas introduction holes 31 of the separator 3 and the gas introduction ports 51 of the gas introduction part 5I of the central flow path component 5 to the space S. The separators 2a and 3a reach the separator peripheral edges 2a and 3a, while the four return paths 42 pass the gas that has reached the separator peripheral edges 2a and 3a in the space S to the gas discharge port 52 and the separator of the gas discharge part 5O of the central flow path component 5. The second gas exhaust hole 22 is reached.

  In this embodiment, a ring-shaped gasket 4A is provided between the gas introduction part 5I and the gas discharge part 5O of the central flow path component 5 so as to sandwich the gas between them. 4A is formed integrally with the eight partition plates 4, and the eight partition plates 4 extend radially from the gasket 4A at substantially equal intervals.

  In addition, as shown in FIG. 4A, the cell attachment portion 25 provided in the donut-shaped region between the central portion of one separator 2 and the peripheral edge portion 2a, that is, the center of one separator 2 A single cell 6 having a circular shape is fixed to the cell attachment portions 25 provided at the eight surrounding locations, and the partition plate 4 is positioned on the eight single cells 6.

  In this embodiment, the separators 2 and 3 were made of ferrite SUS having a thickness of 0.1 mm. Then, the rolled plate was set in a press device and subjected to press working, and the gas introduction part 5I and the gas discharge part 5O of the central flow path component 5 were fixed to the separators 2 and 3 by diffusion bonding.

  In addition, the partition plate 4 and the gasket 4A that are integrated with each other are formed by etching a SUS metal having a thickness of 0.1 mm, and a silver plating layer is formed on the surface of the gasket 4A. Two dotted lines were formed by bending each other up and down.

  At this time, for example, a brazing metal layer or an adhesive layer is formed on both surfaces of the gasket 4A and heated under a load, whereby the gas introduction part 5I and the gas discharge of the central flow path component 5 are passed through the gasket 4A. The part 5O can be joined, and the partition plate 4 can be made of a material different from that of the gasket 4A, and then joined to the gasket 4A by a method such as welding.

  A current collector (not shown) is arranged in eight regions partitioned by the partition plate 4, that is, in the four forward paths 41 and the four return paths 42, and the partition plate 4 between the separators 2 and 3 joined with the central flow path component 5. It was to be sandwiched with. At this time, the partition plate 4 was brought into contact with the other separator 3 and the surface of the single cell 6, and the peripheral portions 2a and 3a of the separators 2 and 3 were joined by laser welding.

  In the solid oxide fuel cell 1, the fuel gas is introduced into the space S between the separators 2 and 3 that form a bag structure through the gas introduction part 51 of the central flow path component 5 and the gas introduction port 51, and the arrow in FIG. As shown in FIG. 4, the gas reaches the separator peripheral portions 2a and 3a through the forward path 41 formed by the partition plate 4 and is discharged from the central flow path component 5 through the return path 42 also formed by the partition plate 4. The air gas is discharged from the gas discharge port 52 of the part 5O, and flows between the layers of the stacked solid oxide fuel cell 1.

  That is, the fuel gas introduced into the space S sufficiently flows to the single cells 6 in the vicinity of the separator peripheral portions 2a and 3a, and in addition, the forward path 41 and the return path 42 formed by the partition plate 4 are in the same plane. By being positioned, the pitch of one cycle is reduced, and as a result, the output density is improved. Further, since the partition plate 4 functions to prevent the space S formed between the separators 2 and 3 from being crushed, the thermal shock resistance and the startability can be improved without increasing the thickness of the separators 2 and 3. It will be excellent.

  In this embodiment, the case where the single cell 6 has a small-diameter disk shape is shown. However, the present invention is not limited to this. For example, as shown in FIG. 4B, the single cell 6A has a donut shape. In the case of forming, the inner ring 7 and the outer ring 8 that have been press-processed can be joined to the inner peripheral edge and the outer peripheral edge, respectively, and attached to the separator 2. 4 (c), the inner ring 7 and the outer ring 8 may be connected by vertical and horizontal bars 9 to form a frame 10, and a fan-shaped single cell 6B is attached to the frame 10. Is also possible.

  5 to 8 show other embodiments of the solid oxide fuel cell of the present invention. As shown in FIGS. 5 to 7, in this solid oxide fuel cell 101, the separators 2 and 3 are separated. A forward flow path 141 formed by the partition plate 104 in the space S of the straight flow path 141A extending from the small gas inlet 151 of the gas inlet 105I of the central flow path component 105 toward the separator peripheral edges 2a and 3a. And an annular channel 141B along the separator peripheral portions 2a and 3a.

  In this case, as shown in FIG. 8, the current collector 111 is interposed between the partition plate 104 forming the linear flow path 141A and the fan-shaped single cell 6B, and the fan-shaped return path formed by the partition plate 104 is used. The current collector 111 is arranged at 142, that is, the pressure loss of the forward path 141 is set smaller than the pressure loss of the return path 142, and the other configuration is the solid oxide fuel cell of the previous embodiment. Same as 1.

  In the solid oxide fuel cell 101, the gas introduced into the space S through the small gas inlet 151 of the gas inlet 105 </ b> I of the central flow path component 105 is firstly forwarded 141 as shown by the arrow in FIG. 7. Are guided to the separator peripheral portions 2a and 3a through the linear flow channel 141A, and become an equal pressure in the annular flow channel 141B along the separator peripheral portions 2a and 3a. Thereafter, the current is discharged from the gas discharge port 152 of the gas discharge portion 105O of the central flow path component 105 through the current collector 111 of the return path 142 having a high pressure loss. The gas can be made to flow evenly to these parts.

  In this way, by averaging the power generation output, it is possible to suppress a potential difference that occurs locally in one separator 2 having the cell mounting portion 25, thereby suppressing power generation loss and suppressing damage due to local overheating. Thus, durability can be improved.

  Further, in this solid oxide fuel cell 101, the annular flow path 141B along the separator peripheral portions 2a and 3a is the upstream side of the fuel gas, and the vicinity of the gas discharge port 152 of the gas discharge portion 105O of the central flow path component 105 is the downstream side. Therefore, the separator peripheral portions 2a and 3a having a wide flow path width can supply fuel gas with a higher fuel concentration, and the flow path width becomes narrower near the gas discharge port 152 where the fuel concentration becomes lower. The reaction rate can be increased by the increase, and thus the power generation output can be averaged.

  That is, the durability is further improved by suppressing the temperature difference between the separator peripheral portions 2a and 3a and the central portion.

  In the solid oxide fuel cell 101 described above, the straight channel 141A of the forward channel 141 is disposed at a position where it is connected to the small gas inlet 151 of the gas inlet 105I of the central channel component 105. For the purpose of strengthening the rectification function and for preventing the deformation of the separators 2 and 3 such as distortion, a plate-like rectification blade may be added to the linear channel 141A.

  Here, when the solid oxide fuel cells 101 are laminated, a gas introduction hole 153 communicating with the small gas introduction port 151 passes through the centers of the central flow path components 105 laminated together. The purpose of improving the uniformity when gas is distributed from the introduction hole 153 to the respective spaces S of the solid oxide fuel cells 101 through the small gas introduction ports 151 of the central flow path component 105, and the gas introduction holes For the purpose of reducing the pressure loss when gas is introduced from 153 to the small gas inlet 151 of the central flow channel component 105, the gasket 104A can be provided with a guide portion 104B positioned in the gas inlet hole 153. That is, the gas flowing through the gas introduction holes 21 and 31 of the separators 2 and 3 is passed through the gasket 104A to the plurality of gas introduction ports 1 of the central flow path component 105. It is possible to provide a guide portion 104B which distribute to 1.

  When this configuration is used, it is possible to improve the output density as a stack structure by uniformizing gas distribution to each of the stacked solid oxide fuel cells 101. For example, the guide portion 104B is continuously formed as a screw shape. If a spiral flow is generated in the gas introduction hole 153, it is possible to reduce pressure loss and improve distribution uniformity.

  That is, at the time of start-up, the stacked solid oxide fuel cells 1 can be started up without a time difference, and damage due to the formation of local cells can be avoided.

  FIGS. 10 and 11 show an embodiment of a stack structure in which the solid oxide fuel cells of the present invention are stacked. As shown in FIG. 10, this stack structure 200 includes a solid oxide fuel. Each central flow path component 105 of the battery 101 is joined by applying an electrically insulating gas seal. For example, it is possible to use a method in which bonding is performed using a ceramic adhesive, a gasket made of glass and ceramic fibers is sandwiched and fusion-bonded, or an insulating plate is brazed and bonded.

  In the stack structure 200 formed by stacking such solid oxide fuel cells, when a high temperature gas is introduced and heating at the time of startup is performed, the upstream portion of the stack structure 200 receives a large thermal shock from the high temperature gas. It will be. In particular, in the vicinity of the boundary between the central flow path component 105 and the thin plate portion of the separator 2 having greatly different heat capacities, the thermal stress increases, which may cause warpage and distortion, or breakage of the joint.

  In order to cope with this, as described above, the heat capacity of the partition plate 104 of the solid oxide fuel cell 101 located on the upstream side of the gas flow is larger than the heat capacity of the partition plate 104 of the solid oxide fuel cell 101 located on the downstream side. More specifically, it is desirable to increase the heat capacity by increasing the number of partition plates 104 or increasing the thickness. In this case, thermal stress can be mitigated and reinforcement against warpage and distortion can be achieved. Will be made.

1 is an exploded perspective view showing an embodiment of a solid oxide fuel cell of the present invention. Example 1 FIG. 2 is an explanatory plan view showing a partition plate of the solid oxide fuel cell of FIG. 1 and a gasket integrated therewith. FIG. 2 is an explanatory diagram of gas flow paths showing a gas flow in the solid oxide fuel cell of FIG. 1. It is plane | planar explanatory drawing (a)-(c) of the separator which shows the arrangement pattern of the single cell of the solid oxide fuel cell in FIG. It is a disassembled perspective explanatory drawing which shows the other Example of the solid oxide fuel cell of this invention. (Example 2) FIG. 6 is an explanatory plan view showing a partition plate of the solid oxide fuel cell of FIG. 5 and a gasket integrated therewith. FIG. 6 is an explanatory diagram of a gas flow path showing a gas flow in the solid oxide fuel cell of FIG. 5. FIG. 6 is a cross-sectional explanatory view based on the position of the AA line in FIG. 5. FIG. 6 is an explanatory plan view showing another configuration example of the gasket in the solid oxide fuel cell of FIG. 5. Example 3 It is sectional explanatory drawing which shows one Example of the stack structure of this invention. Example 4 FIG. 12 is an overall perspective explanatory view of the stack structure of FIG. 11.

Explanation of symbols

1,101 Solid oxide fuel cell 2 One separator 2a, 3a Separator peripheral edge
3 Other separator 4, 104 Partition plate 4A, 104A Gasket 5, 105 Central flow path parts 5I, 105I Gas introduction part 5O, 105O Gas discharge part 6, 6A, 6B Single cell 21, 31 Gas introduction hole 22, 32 Gas discharge Hole 25 Cell mounting part 41, 141 Outward path 42, 142 Return path 51, 151 Gas inlet 52, 152 Gas outlet 104B Guide section 111 Current collector (collecting porous body)
141A Straight channel (outward)
141B Annular channel (outward)
200 Stack structure S space

Claims (6)

  A single cell, one separator having a circular thin plate shape and having a gas introduction hole and a gas discharge hole in the center portion and a cell attachment portion for fixing the single cell, and one except for the portion of the cell attachment portion The other separator having the same shape as that of the separator and having the peripheral edge joined to the peripheral edge of the one separator, and the gas inlet and the gas outlet that communicate with the gas inlet and the gas outlet of both separators. And a central flow path component that supplies and discharges gas to and from the space formed between the two separators, and the gas introduction hole of the separator and the gas flow of the central flow path component are introduced into the space formed between the two separators. A forward path for causing the gas supplied through the mouth to reach the peripheral edge of the separator in the space, and a gas that reaches the separator peripheral edge of the space in the same plane as the forward path. Solid oxide fuel cell characterized in that a partition plate that forms a return path to reach the gas outlet and the gas outlet of the separator goods.   The central flow path component includes a gas introduction part having a gas introduction port and a gas discharge part having a gas discharge port. The solid oxide fuel cell according to claim 1, wherein the partition plate is integrally formed.   The forward path formed by the partition plate in the space between both separators consists of a linear flow path extending from the gas inlet of the central flow path component toward the separator peripheral edge, and an annular flow path along the separator peripheral edge. The solid oxide fuel cell according to claim 1 or 2.   In the space between both separators, a return path is formed by a partition plate on the current collecting porous body installed on the upper surface of the single cell, and the pressure loss in the forward path is set smaller than the pressure loss in the return path. The solid oxide fuel cell according to any one of the items.   The solid oxide fuel according to any one of claims 2 to 4, wherein the gasket is provided with a guide portion that distributes the gas flowing in the gas introduction holes of both separators to the plurality of gas introduction ports of the central flow path component. battery.   6. The heat capacity of the partition plate of the solid oxide fuel cell, which is formed by stacking the solid oxide fuel cells according to claim 1 and located upstream of the gas flow introduced into the solid oxide fuel cell, The stack structure is characterized in that it is larger than the heat capacity of the partition plate of the solid oxide fuel cell located in the area.

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