JP2017010721A - Fuel cell stack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel cell stack capable of making a temperature in a stacking direction of the fuel cell stack uniform and maintaining the temperature at an appropriate temperature.SOLUTION: In a fuel cell stack 1, a heat exchange part 10 is disposed at a center in a stacking direction of power generation units 7, and first and second gas reservoir chambers 20 and 30 for storing air exhausted from the heat exchange part 10 are provided in both end portions in the stacking direction. Thus, air that is appropriately heated by the heat exchange part 10 can be stored in the first and second gas reservoir chambers 20 and 30. As a result, a temperature in the end portion of the fuel cell stack 1 in the stacking direction can be caused to rise by both the gas reservoir chambers 20 and 30. Further, both the gas reservoir chambers 20 and 30 are functioned as a heat insulation layer between the inside and the outside of the fuel cell stack 1. Therefore, the temperature of the fuel cell stack 1 in the stacking direction can be made uniform, and can be maintained at such an appropriate temperature that rupture or the like of a unit cell 17 does not occur.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a fuel cell stack in which a plurality of flat single cells each having an electrolyte layer, an air electrode, and a fuel electrode are stacked in the thickness direction.

Conventionally, a solid oxide fuel cell (hereinafter also referred to as SOFC) using a solid electrolyte (solid oxide) is known as a fuel cell.
In this SOFC, as a power generation unit, for example, a fuel electrode in contact with the fuel gas is provided on one side of the solid electrolyte layer, and an oxidant electrode (air electrode) in contact with the oxidant gas (air) is provided on the other side. The cell is in use.

  Further, in order to obtain a desired voltage, a fuel cell stack (cell stack) has been developed in which a plurality of single cells are stacked via an interconnector or the like and an end plate is disposed at an end in the stacking direction.

  For example, in Patent Document 1, as illustrated in FIG. 18A, chambers (P2) for storing gas (for example, air: O) introduced from outside the stack at both ends in the stacking direction of the fuel cell stack (P1). In this structure, a technique is disclosed in which pressure is applied to each unit cell (P3) from both sides in the stacking direction to ensure conductivity between the unit cells.

  Further, in the fuel cell stack in which the end plate described above is arranged at the end in the stacking direction, the heat radiation from the end plate is large, the temperature at the end of the fuel cell stack is lowered, and the output characteristics of the fuel cell stack are reduced. The countermeasures have also been proposed because of the decline. If the temperature is low, the internal resistance of the single cell increases, and the output decreases.

  Specifically, in Patent Document 2, as illustrated in FIG. 18B, the remaining oxidation not used in each single cell (P5) at the end in the stacking direction of the fuel cell stack (P4). A technique for disposing an exhaust gas combustor (P6) for burning the agent gas and the fuel gas and increasing the temperature at the end of the fuel cell stack is disclosed.

WO2010 / 038869 A1 publication JP 2009-99267 A

However, in the above-described conventional technology, it is not easy to make the temperature in the stacking direction of the fuel cell stack uniform and to keep the temperature moderate.
For example, in the case of the technique described in the cited document 1, since the structure is such that gas (air) that is colder from the outside is introduced into the end portion in the stacking direction of the fuel cell stack, the temperature in the stacking direction of the fuel cell stack is constant It was not easy to keep on. As a result, the output characteristics of the fuel cell stack may be degraded.

  On the other hand, in the technique described in the cited document 2, the exhaust gas combustor that is a heating source generates a very large amount of heat compared to the amount of heat generated by Joule heat during power generation in each unit cell. In some cases, the end side of the stack was locally heated too much, causing thermal distortion in the fuel cell stack.

When this thermal strain occurs, there is a problem that cracking (cell cracking) in a single cell is likely to occur and reliability is lowered.
As described above, in the prior art, it is not easy to equalize the temperature in the stacking direction of the fuel cell stack to a temperature suitable for power generation and to maintain an appropriate temperature so as not to damage the single cell. It was.

  The present invention has been made in view of these problems, and an object of the present invention is to provide a fuel cell stack in which the temperature in the stacking direction of the fuel cell stack can be made uniform and maintained at an appropriate temperature.

  (1) The present invention provides, as a first aspect, a flat plate that has an electrolyte layer and an air electrode and a fuel electrode arranged so as to sandwich the electrolyte layer, and generates power using an oxidant gas and a fuel gas. In the fuel cell stack in which a plurality of unit cells are stacked along the thickness direction of the unit cells, heat is exchanged inside the fuel cell stack at at least one end in the stacking direction of the fuel cell stack. And a gas reservoir chamber for storing at least one of the oxidant gas and the fuel gas.

  In the first aspect, a gas reservoir chamber is provided at at least one end in the stacking direction of the fuel cell stack, in which at least one of the oxidant gas and the fuel gas exchanged in the fuel cell stack is stored. Yes.

  As a result, in the gas reservoir chamber, the oxidant gas or fuel gas heat-exchanged inside the fuel cell stack, that is, the oxidant gas heated moderately by receiving heat from the surroundings inside the fuel cell stack, Fuel gas can be stored.

  As a result, the temperature of the end portion in the stacking direction of the fuel cell stack can be increased by the gas reservoir chamber, and the gas reservoir chamber serves as a heat insulating layer between the inside of the fuel cell stack and the outside in the stacking direction. Since it functions, the temperature in the stacking direction of the fuel cell stack can be made more uniform than before, and can be maintained at an appropriate temperature so that the single cell is not damaged. For example, the inside of the fuel cell stack can be maintained at a suitable temperature so that the single cell itself generates heat due to Joule heat.

  Thus, in the first aspect, since the temperature in the fuel cell stack can be maintained at an appropriate temperature, high power generation efficiency can be realized, and damage (cell cracking) due to thermal strain of a single cell can be suppressed. There is a remarkable effect.

  (2) As a second aspect of the present invention, the gas reservoir chamber is provided at both ends in the stacking direction of the fuel cell stack to store at least one of the oxidant gas and the fuel gas. It is characterized by.

  In the second aspect, since the gas reservoir chambers for storing the oxidant gas and the fuel gas are provided at both ends in the stacking direction of the fuel cell stack, the center and both end portions in the stacking direction of the fuel cell stack are provided. And the cell crack due to thermal strain can be suppressed.

(3) As a third aspect of the present invention, the oxidant gas is stored in one of the gas reservoir chambers at both ends in the stacking direction of the fuel cell stack, and the other gas reservoir chamber is provided. The fuel gas is stored in the fuel gas.
In the third aspect, since the oxidant gas is stored in one gas reservoir chamber in the stacking direction of the fuel cell stack and the fuel gas is stored in the other gas reservoir chamber, the oxidant gas and the fuel gas can be effectively used. Therefore, there is an advantage that the degree of freedom of design is increased.

  (4) In the present invention, as a fourth aspect, the gas reservoir chamber is a space whose opening is partially closed, and the opening includes the oxidant gas and the fuel gas. It is characterized by being formed so as to open only to a gas supply path through which at least one gas is supplied.

  In the fourth aspect, the gas reservoir chamber has an opening that opens only to the gas supply path to which the oxidant gas and the fuel gas are supplied. Therefore, the oxidant gas and the fuel gas can be suitably stored. In addition, each gas can be efficiently introduced from each gas supply path.

  In the case where the oxidant gas is introduced into the gas reservoir chamber, the oxidant gas is introduced from the gas supply passage of the oxidant gas into the gas reservoir chamber through an opening opening in the gas supply passage. . On the other hand, when the fuel gas is introduced into the gas reservoir chamber, the fuel gas is introduced into the gas reservoir chamber from the fuel gas supply passage through an opening that opens to the gas supply passage.

  (5) As a fifth aspect of the present invention, as the fifth aspect, the gas reservoir chamber is a space having a partially closed opening, and the opening is provided in a gas supply path to which the gas is supplied. It is formed so as to open at one place.

  In the fifth aspect, in the gas reservoir chamber, the opening is formed so as to open at one place in the gas supply path to which the gas (that is, the oxidant gas or the fuel gas) is supplied, so that the gas flows out to the outside. Therefore, the gas can be suitably stored in the gas storage chamber.

  (6) As a sixth aspect, the present invention includes an end plate that is a plate-like member at at least one end in the stacking direction of the fuel cell stack, and the gas reservoir chamber includes the end plate, The fuel cell stack is provided between at least one of the single cells arranged in the stacking direction of the fuel cell stack.

  When an end plate is provided at the end in the stacking direction of the fuel cell stack, heat flows out through the end plate. In this sixth aspect, the end plate and the (outermost) single cell Since the gas reservoir chamber is disposed between the two, the temperature in the fuel cell stack can be kept more uniform.

(7) The present invention, as a seventh aspect, is characterized in that a heat exchanging portion that performs heat exchange inside the fuel cell stack is disposed between the single cells.
Since the heat exchange part is disposed between the single cells, the oxidant gas or the fuel gas introduced into the heat exchange part can receive heat from the single cells on both sides in the stacking direction. Therefore, heat exchange can be performed efficiently.

The configuration of the present invention will be described below.
The fuel gas indicates a gas containing a reducing agent (for example, hydrogen) serving as a fuel, and the oxidant gas indicates a gas (for example, air) containing an oxidant (for example, oxygen).

When power generation is performed using a single cell (and hence a fuel cell stack), fuel gas is introduced to the fuel electrode side, and oxidant gas is introduced to the air electrode side.
-As the fuel cell stack, for example, a solid oxide fuel cell (SOFC) using ZrO2 ceramic as an electrolyte, a molten carbonate fuel cell (MCFC) using Li-Na / K carbonate as an electrolyte, Examples thereof include a fuel cell stack such as a phosphoric acid fuel cell (PAFC) using phosphoric acid as an electrolyte.

  In addition, the electricity generated by the single cell can be taken out via, for example, a current collector and an interconnector. In this case, the interconnector and the current collector may be configured as separate members or as an integral member.

1 is a perspective view of a fuel cell stack of Example 1. FIG. FIG. 9 is a cross-sectional view (a cross-sectional view taken along line AA in FIG. 7) showing a part of the fuel cell stack of Example 1 broken along the air flow path in the stacking direction. FIG. 8 is a cross-sectional view (cross-sectional view taken along line AA in FIG. 7) showing the periphery of the heat exchange section by breaking the fuel cell stack of Example 1 in the stacking direction along the air flow path. 2 is an exploded perspective view showing a power generation unit and a first gas reservoir chamber at the upper end of the fuel cell stack of Example 1. FIG. FIG. 4 is an exploded perspective view showing a power generation unit and a second gas reservoir chamber at the lower end of the fuel cell stack according to the first embodiment. It is a perspective view which decomposes | disassembles and shows the structure of the heat exchange part in Example 1. FIG. 2 is a plan view showing air and fuel gas flow paths in the fuel cell stack of Example 1. FIG. (A) is a sectional view schematically showing an air flow path by breaking the fuel cell stack of Example 1 in the stacking direction (AA sectional view in FIG. 7), and (b) is the fuel cell stack in the stacking direction. FIG. 8 is a cross-sectional view (a cross-sectional view taken along the line BB in FIG. 7) schematically showing the flow path of the fuel gas fractured in FIG. 1 shows a modification of the fuel cell stack of Example 1, wherein (a) shows a part of a power generation unit and a first gas reservoir chamber on the upper end side of the fuel cell stack broken in the stacking direction along the air flow path. Explanatory drawing, (b) is explanatory drawing which fractures | ruptures the power generation unit and the 2nd gas reservoir chamber of the lower end side of a fuel cell stack in the lamination direction along the air flow path, and shows a part. FIG. 12 is a cross-sectional view (a cross-sectional view taken along the line CC in FIG. 11) showing a part of the fuel cell stack of Example 2 broken along the fuel gas flow path in the stacking direction. 6 is a plan view showing air and fuel gas flow paths in the fuel cell stack of Example 2. FIG. It is sectional drawing which fractures | ruptures the fuel cell stack of Example 3 in the lamination direction along the air flow path, and shows the one part. FIG. 10 is a cross-sectional view showing a part of the fuel cell stack of Example 4 broken along the air flow path in the stacking direction. The fuel cell stack of Example 5 is shown, (a) is sectional drawing (DD sectional drawing of Fig.15 (a)) which fractures | ruptures in the lamination direction along the air flow path, and shows the one part typically, (B) is sectional drawing (E-E sectional drawing of FIG.15 (b)) which is fractured | ruptured in the lamination direction along the flow path of a fuel gas, and shows the part typically. (A) is a top view which shows the flow path of the air in the fuel cell stack of Example 5, (b) is a top view which shows the flow path of the fuel gas in the fuel cell stack. The fuel cell stack of Example 6 is shown, (a) is sectional drawing (FF sectional drawing of FIG.16 (b)) which fractures | ruptures in the lamination direction along the flow path of air, and shows the one part typically, (B) is a top view which shows the flow path of the air. It is sectional drawing which fractures | ruptures the fuel cell stack of Example 7, and shows the one part. It is explanatory drawing of a prior art.

  Hereinafter, a solid oxide fuel cell stack will be described as an example of a fuel cell stack to which the present invention is applied.

a) First, the schematic configuration of the fuel cell stack of the present embodiment will be described.
In the following drawings, the oxidant gas is indicated by “O”, and the fuel gas is indicated by “F”. “IN” indicates that gas is introduced, and “OUT” indicates that gas is discharged. Further, “upper” and “lower” indicating directions in the following description are the same as “upper” and “lower” in FIGS. 1 and 2.

  As shown in FIGS. 1 and 2, a solid oxide fuel cell stack (hereinafter simply referred to as a fuel cell stack) 1 of this embodiment includes a fuel gas (for example, hydrogen) and an oxidant gas (for example, air, specifically air). It is a device that generates power by being supplied with oxygen.

  This fuel cell stack 1 has a plurality of layered layers (for example, 24 stages: for example, the number of stages in each figure) between end plates 3 and 5 arranged at both ends in the vertical direction in FIGS. The power generation unit 7 of the fuel cell (which is simplified), the layered heat exchange unit 10, the layered first gas reservoir chamber 20, and the second gas reservoir chamber 30 are stacked. The power generation unit 7 is the smallest structural unit that generates power upon receiving supply of fuel gas and air.

  That is, the fuel cell stack 1 includes a plurality of power generation units 7 stacked above and below the heat exchanging unit 10, and includes a first gas reservoir chamber 20 above the power generation unit 7 at the upper end, and a power generation unit at the lower end. A second gas reservoir chamber 30 is provided at the lower part of 7.

  Here, a portion composed of a plurality (for example, 12 stages) of power generation units 7 disposed above the heat exchange unit 10 is referred to as an upper stack body 2a, and a plurality (for example, 12 stages) disposed below the heat exchange unit 10. The portion comprising the power generation unit 7 is referred to as the lower stack body 2b.

  As shown in FIG. 1, the members constituting the end plates 3 and 5, each power generation unit 7, the heat exchange unit 10, the first gas reservoir chamber 20, and the second gas reservoir chamber 30 are arranged in the stacking direction (FIG. 1). A plurality of (e.g., eight) through holes 9 penetrating in the vertical direction) are provided, and each bolt 11 (11a, 11b, 11c, 11d, 11e, 11f, 11g, 11h) and bolt disposed in the through hole 9 are provided. The end plates 3, 5, the power generation units 7, the heat exchange unit 10, and the first and second gas reservoir chambers 20, 30 are fixed integrally with each other by the nuts 13 that are screwed into the 11.

  Further, as shown in FIG. 3, air or fuel gas flows through specific (five) bolts 11 a, 11 b, 11 d, 11 f, and 11 h among the bolts 11 along the axial direction (that is, the stacking direction). An internal flow path 14 is formed, and the internal flow path 14 and the through holes 9 through which the bolts 11a, 11b, 11d, 11f, and 11h are inserted are formed by communication holes 15 through which each gas can pass. Communicate.

  Furthermore, each power generation unit 7 is provided with a plate-like single cell 17 at the center in the thickness direction. An air flow path 19 (air flow is indicated by arrows in FIG. 3) through which air flows is provided on one side (upper side in FIG. 3) of the single cell 17 and the other side ( A fuel flow path 21 through which the fuel gas flows is provided in the lower part of FIG. The fuel flow path 21 is a flow path in a direction perpendicular to the paper surface.

  Among these, the single cell 17 has a so-called fuel electrode support membrane type structure, and is a thin solid electrolyte layer 23 and a thin air electrode layer (on the upper side in FIG. 3) (on the upper side in FIG. 3). And a fuel electrode layer (anode) 27 formed on the other side (lower side in FIG. 3).

b) Next, the configuration of the power generation unit 7, the heat exchange unit 10, and the first and second gas reservoir chambers 20 and 30 will be described in detail.
As shown in FIGS. 4 and 5, the power generation unit 7 includes a metal interconnector 31, an air electrode insulating frame 33, a metal separator 35 (to which the single cell 17 is joined), and a metal fuel. A pole frame 37, a fuel electrode insulating frame 39, a metal interconnector 41, and the like are laminated.

  An air electrode side current collector 43 is disposed in the air flow path 19 in the frame of the air electrode insulation frame 33, and a fuel electrode side current collector is disposed in the fuel flow path 21 in the frame of the fuel electrode insulation frame 39. A body 45 is arranged.

  In particular, in the first embodiment, as shown in FIG. 4, the power generation unit 7 at the upper end of the upper stack body 2 a is configured with the first gas reservoir chamber 20 at the upper end (the outer end surface in the upper part of FIG. 4). For this purpose, a metal gas reservoir chamber frame 53 and the end plate 3 covering the upper side of the gas reservoir chamber frame 53 are arranged.

  Similarly, as shown in FIG. 5, the power generation unit 7 at the lower end of the lower stack body 2 b has the same configuration in order to configure the second gas reservoir chamber 30 at the lower end (the outer end surface below FIG. 5). A metal gas reservoir chamber frame 63 and the end plate 5 covering the lower side of the gas reservoir chamber frame 63 are disposed.

  Here, the end plates 3, 5 press and hold the power generation units 7 to be stacked and are plate members that serve as lids for the first and second gas reservoir chambers 20, 30. It is also an output terminal. The end plates 3 and 5 are made of a conductive plate material (for example, a metal plate such as stainless steel).

Hereinafter, each configuration will be described in more detail.
First, the air electrode layer 25, the solid electrolyte layer 23, and the fuel electrode layer 27 constituting the single cell 17 described above will be described.

The air electrode layer 25, La, Pr, Sm, Sr, Ba, Co, Fe, complex oxide containing _{Mn (La 1-x Sr x} CoO 3 composite _{oxide, La 1-x Sr x FeO} 3 system composite _{oxide, La 1-x Sr x Co} 1-y Fe y O 3 composite _{oxide, La 1-x Sr x MnO} 3 composite _{oxide, Pr 1-x Ba x CoO} 3 composite oxide, Sm _1-x Sr _x CoO ₃ composite oxide) or the like can be used.

  Examples of the solid electrolyte layer 23 include zirconia-based, ceria-based, and perovskite-based electrolyte materials. Examples of zirconia-based materials include yttria stabilized zirconia (YSZ), scandia stabilized zirconia (ScSZ), and calcia stabilized zirconia (CaSZ), and yttria stabilized zirconia (YSZ) is generally used. There are many examples. For ceria-based materials, so-called rare earth element-added ceria is used, and for perovskite-based materials, perovskite-type double oxides containing lanthanum elements are used.

The fuel electrode layer 27 is preferably a metal, and Ni, Ni and ceramic cermets or Ni-based alloys can be used.
Further, as shown in FIGS. 4 and 5, the interconnectors 31 and 41 are made of a conductive plate material (for example, a metal plate such as stainless steel). The interconnectors 31 and 41 ensure conduction between the single cells 17 and prevent gas mixing between the single cells 17 (and thus between the power generation units 7).

The air electrode insulating frame 33 is a square frame member, and is an insulating plate made of soft mica, vermiculite, MgO, Al ₂ O ₃ or the like. The air electrode insulating frame 33 is formed with a space portion 33a penetrating in the thickness direction at the center (in plan view). The pair of through-holes 9 (9d, 9h) facing the air electrode insulating frame 33 are provided so that the long communication holes 33b communicate with each other, and each communication hole 33b and the space portion 33a are connected to each other. A plurality of grooves 33 c are provided as portions (communication portions) through which gas passes so as to communicate with each other.

  The air electrode side current collector 43 is a member made of, for example, stainless steel in which columnar members are arranged in parallel, and in the space portion 33a of the air electrode insulating frame 33, a pair of through holes 9 (9h, 9d). It is arranged along the arrangement direction.

  The separator 35 is made of a rectangular frame-like conductive plate material (for example, a metal plate such as stainless steel), and the inner periphery thereof is brazed and joined to the outer peripheral edge portion of the solid electrolyte layer 23 of the single cell 17. . By the separator 35 to which the single cell 17 is joined, the air flow path 19 and the fuel flow path 21 are separated in the power generation unit 7 so that the air and the fuel gas are not mixed.

The fuel electrode frame 37 is a square frame member made of stainless steel having heat resistance.
Like the air electrode insulating frame 33, the fuel electrode insulating frame 39 is a rectangular frame-like member, and is an insulating plate made of soft mica, vermiculite, MgO, Al ₂ O ₃ or the like. Similar to the air electrode insulation frame 33, the fuel electrode insulation frame 39 includes a central space 39a, communication holes 39b (long in communication with the through holes 9b and 9f), and communication holes 39b. Each groove 39c is provided to communicate with the space 39a.

The fuel electrode side current collector 45 is a known grid-like member (see, for example, the current collector member 19 described in JP2013-56042A), and a grid-like spacer (soft mica, vermiculite, An insulating spacer made of MgO, Al ₂ O ₃ or the like) 52 and a conductive member 54 of a metal plate attached to the spacer 52 (see FIG. 3).

Moreover, the gas reservoir chamber frame 53 shown in FIG. 4 is a rectangular frame-like member, and is made of, for example, stainless steel having conductivity.
The gas reservoir chamber frame 53 is provided with a square space 53a at the center (in plan view), and a through hole 9d and a space 53a through which air heated by the heat exchange unit 10 is discharged. Is provided with an opening 53b.

The end plate 3 is disposed so as to block the space 53a of the gas reservoir chamber frame 53 from the upper side of the figure.
As a result, the gas reservoir chamber frame 53 and the end plate 3 and the interconnector 31 arranged on both sides in the stacking direction form a sealed first gas reservoir chamber 20 that opens at only one through hole 9d. The

Similarly, the gas reservoir chamber frame 63 shown in FIG. 5 is a square frame-like member, and is made of, for example, stainless steel having conductivity.
The gas reservoir chamber frame 63 is provided with a square space 63a at the center (in plan view), and a through hole 9d and a space 63a through which air heated by the heat exchange unit 10 is discharged. An opening 63b is provided so as to communicate with each other.

Further, the end plate 5 is disposed so as to close the space 63a of the gas reservoir chamber frame 63 from the lower side in the figure.
As a result, the gas reservoir chamber frame 63 and the end plate 5 and the interconnector 41 arranged on both sides in the stacking direction form a sealed second gas reservoir chamber 30 that is opened only in the through hole 9d. The

  Further, as shown in FIG. 6, the heat exchanging portion 10 disposed between the upper stack body 2a and the lower stack body 2b has a rectangular frame shape, like the first and second gas reservoir chambers 20 and 30. The heat exchanger frame 12 is provided on both sides of the heat exchanger frame 12 in the thickness direction so as to cover the central space 12a of the heat exchanger frame 12, the interconnector 41 of the adjacent power generation unit 7, 31 is arranged. The heat exchange unit frame 12 is made of, for example, stainless steel having conductivity.

  As in the case of the interconnectors 41, 31, etc., eight through holes 9 into which the bolts 11 are inserted are formed in the heat exchange unit frame 12. Further, among the through holes 9, the through hole 9a into which the bolt 11a is inserted is provided with an opening 12b that communicates with the space 12a and introduces air into the space 12a, and the bolt 11d is inserted therethrough. The hole 9d is provided with an opening 12c that communicates with the space 12a and discharges air from the space 12a.

c) Next, a method for manufacturing the fuel cell stack 1 will be briefly described.
First, for example, a plate material made of SUS430 was punched out, and the interconnectors 31 and 41, the fuel electrode frame 37, the separator 35, the gas reservoir chamber frames 53 and 63, the heat exchange unit frame 12, and the end plates 3 and 5 were manufactured.

  Moreover, the single cell 17 was manufactured according to the usual method. Specifically, the green sheet laminate of the fuel electrode layer 27 and the solid electrolyte layer 23 was fired, and the material of the air electrode layer 25 was printed thereon. The single cell 17 was fixed to the separator 35 by brazing.

  Further, the frame-shaped air electrode insulating frame 33 and the fuel electrode insulating frame 39 shown in FIGS. 4 and 5 were produced by punching or grooving an insulating plate made of a known insulating material.

  Then, the above-described interconnectors 31, 41, the air electrode insulating frame 33, the separator 35 brazed to the single cell 17, the fuel electrode frame 37, the fuel electrode insulating frame 39, etc. are laminated, and each power generation unit 7 is assembled. In the center in the stacking direction (that is, between the upper stack body 2a and the lower stack body 2b), the heat exchanging unit frame 12 is disposed, and the gas reservoir chamber frames 53, 63, End plates 3 and 5 were laminated to form a laminate.

  Then, the bolts 11 are fitted into the through holes 9 of the laminated body, and nuts 13 are screwed and tightened to the respective bolts 11, and the laminated body is pressed and fixed integrally to complete the fuel cell stack 1. .

d) Next, the gas flow path in the first embodiment will be described with reference to FIG. 2, FIG. 7, FIG.
<Air flow path>
As shown in FIG. 7, air is introduced into the through hole 9a from the outside of the fuel cell stack 1 through the internal flow path 14 of the bolt 11a. And as shown in the said FIG. 2, it introduce | transduces in the heat exchange part 10 through the through-hole 9a through the opening part 12b (refer FIG. 6). In addition, in FIG. 2, the flow of the air so far is shown with a broken line.

  Next, the air introduced into the heat exchanging unit 10 (the air flow thereafter is indicated by a solid line) receives heat from the surrounding single cell 17 or the like (specifically, the power generation unit 7), and the heat exchanging unit 10 And supplied to the through hole 9d through the opening 12c (see FIG. 6).

The air after heat exchange supplied to the through hole 9d branches in the vertical direction in FIG. 2 and is distributed to the air flow path 19, the first gas reservoir chamber 20, and the second gas reservoir chamber 30 of each power generation unit 7. Supplied.
That is, a part of the air after heat exchange guided upward in FIG. 2 is supplied into the first gas reservoir chamber 20 at the upper part of the fuel cell stack 1 through the opening 53b. On the other hand, the air after heat exchange guided downward is supplied into the second gas reservoir chamber 30 below the fuel cell stack 1 through the opening 63b.

  Further, the air after heat exchange guided to the upper and lower sides of FIG. 2 and introduced into the air flow paths 19 is used for power generation in the air flow paths 19. The remaining air after power generation flows in the direction of the arrow in the figure, and is discharged from each air channel 19 to the outside through the through hole 9h.

  FIG. 8A schematically shows the flow of these air. The air introduced from the outside is heated by the heat exchanging unit 10 and then each power generation unit 7 and the first and second gas. The air introduced into the reservoir chambers 20 and 30 and discharged after power generation is discharged to the outside.

  2 and 8 (a), the air flow path introduced from the outside of the fuel cell stack 1 and the air flow path exhausted to the outside are displayed in an overlapping manner, but as described above. , They are separated as separate flow paths (through hole 9a and through hole 9h).

<Flow path of fuel gas>
The flow path of the fuel gas is the same as the conventional one, and as shown in FIGS. 7 and 8 (b), the fuel cell stack 1 has a through hole 9f through the internal flow path 14 of the bolt 11f. The introduced fuel gas is distributed and supplied to the fuel flow path 21 (not shown in FIG. 8B) of each power generation unit 7.

The remaining fuel gas used for power generation in each fuel channel 21 is introduced from each fuel channel 21 into the through hole 9b opposite to the through hole 9f.
The fuel gas after power generation introduced into the through hole 9b is discharged out of the fuel cell stack 1 through the internal flow path 14 of the bolt 11b.

e) The effect of the first embodiment will be described.
In the first embodiment, the heat exchange unit 10 is disposed in the center of the power generation unit 7 of the fuel cell stack 1 in the stacking direction, and the air discharged from the heat exchange unit 10 is supplied to both ends in the stacking direction. First and second gas reservoir chambers 20 and 30 are provided.

  Thus, the first and second gas reservoir chambers 20 and 30 are appropriately heated by the air discharged from the heat exchange unit 10, that is, the surrounding single cell 17 (and hence the power generation unit 7) in the heat exchange unit 10. You can collect fresh air. As a result, the temperature of the end portions in the stacking direction of the fuel cell stack 1 can be increased by the gas reservoir chambers 20 and 30, and the gas reservoir chambers 20 and 30 are disposed in the fuel cell stack 1 and the stack thereof. It functions as a heat insulation layer between the outside of the direction.

  Therefore, the temperature in the stacking direction of the fuel cell stack 1 can be made more uniform than before, and can be maintained at an appropriate temperature so that the single cell 17 is not damaged. For example, the inside of the fuel cell stack 1 can be maintained at an appropriate temperature such that the single cell 17 itself generates heat due to Joule heat.

  As described above, in the first embodiment, the temperature in the fuel cell stack 1 can be maintained at an appropriate temperature, so that high power generation efficiency can be realized and damage (cell cracking) due to thermal strain of the single cell 17 can be achieved. There is a remarkable effect that it can be suppressed.

  Further, in the first embodiment, the gas reservoir chambers 20 and 30 are opened at only one place in the through hole 9d to which air is supplied from the heat exchanging unit 10, so that it is difficult for the air to flow out to the outside. Air can be stored and air can be efficiently introduced from the through hole 9d.

  Further, in the first embodiment, since the gas reservoir chambers 20 and 30 are disposed between the end plates 3 and 5 and the (outermost) power generation unit 7, heat is released from the end plates 3 and 5. It is difficult to keep the temperature in the fuel cell stack 1 more uniform.

f) Others For example, the insides of the first and second gas reservoirs 20 and 30 may be hollow, but a current collector is disposed in order to increase conductivity in the stacking direction of the fuel cell stack 1. It's okay.

  For example, as shown in FIG. 9A, a current collector 91 having a structure similar to that of the fuel electrode side current collector 45 may be disposed in the first gas reservoir chamber 20. A similar current collector 91 may be disposed in the second gas reservoir chamber 30.

  Alternatively, as shown in FIG. 9B, the fuel cell stack 1 protrudes from the surface of the interconnector 41 at the lower end of the fuel cell stack 1 (the surface on the second gas reservoir chamber 20 side) toward the inside (downward in the figure) You may provide the convex part 93 which contacts the end plate 5 of the side. Conversely, the end plate 5 may be provided with a similar convex portion that projects toward the interconnector 41.

Further, a convex portion as formed on the second gas reservoir chamber 30 side may be provided on the first gas reservoir chamber 20 side.
The side for supplying air or fuel gas to the fuel cell stack 1 or the side for discharging air or fuel gas from the fuel cell stack 1 is on either side in the stacking direction of the fuel cell stack 1 (for example, FIG. 1 or above (downward or upward in FIG. 2).

Next, the second embodiment will be described, but the description of the same contents as the first embodiment will be omitted.
In addition, the same number is attached | subjected and demonstrated to the structure similar to Example 1. FIG.
As shown in FIG. 10, the fuel cell stack 101 according to the second embodiment includes a heat exchange unit 103 that exchanges heat of fuel gas instead of air between the upper and lower power generation units 7. The fuel gas heated in 103 is stored in first and second gas storage chambers 105 and 107 arranged at both ends in the stacking direction of the fuel cell stack 101. Details will be described below.

  In the fuel cell stack 101 of the second embodiment, as shown in FIGS. 10 and 11 (indicated by a broken line in FIG. 10), the fuel gas flows from the outside of the fuel cell stack 101 via the internal flow path 14 of the bolt 11c. Then, it is introduced into the through-hole 9 c and then introduced into the heat exchanging unit 103 arranged between the power generation units 7.

  Next, as shown by a solid line in FIG. 10, the fuel gas heated by the heat exchange unit 103 is introduced into the through hole 9 f and then supplied to the fuel flow path 21 of each power generation unit 7. The gas is supplied to the first and second gas reservoir chambers 105 and 107 through the openings 109 and 110, respectively.

Then, the remaining fuel gas used for power generation in each fuel flow path 21 is introduced from each fuel flow path 21 into the through hole 9 b and then discharged out of the fuel cell stack 101.
As shown in FIG. 11, the air is introduced into the fuel cell stack 101 via the internal flow path 14 and the through hole 9d of the bolt 11d, and from the air flow path 19 of each power generation unit 7 to the through hole 9h. And it is discharged out of the fuel cell stack 101 via the internal flow path 14 of the bolt 11h.

Also in the second embodiment, the same effects as in the first embodiment are obtained.
In FIG. 10, similarly to FIG. 2, the air flow path (broken line portion) introduced from the outside of the fuel cell stack 1 and the air flow path discharged outside (solid line portion) are displayed in an overlapping manner. doing.

Next, the third embodiment will be described, but the description of the same contents as the first embodiment will be omitted.
In addition, the same number is attached | subjected and demonstrated to the structure similar to Example 1. FIG.
As shown in FIG. 12, the fuel cell stack 111 of the third embodiment includes the first gas reservoir chamber 20 on one side (upper side in the figure) in the stacking direction and the exhaust gas combustor 113 on the other side. It is. Details will be described below.

a) First, the configuration of the fuel cell stack 111 of the third embodiment will be described.
As shown in FIG. 12, in the fuel cell stack 111 of the third embodiment, a heat exchange unit 10 that heats air is disposed between the upper stack body 2a and the lower stack body 2b.

A first gas reservoir chamber 20 similar to that of the first embodiment is stacked on the upper end of the upper stack body 2a, and a plate-shaped exhaust gas combustor 113 is stacked on the lower end of the lower stack body 2b.
The exhaust gas combustor 113 is filled with a combustion catalyst 115 such as Ni, for example, and each flow path 117 (fuel gas) is introduced so that air and fuel gas after power generation are introduced into the exhaust gas combustor 113. Are not shown).

Further, unlike the first embodiment, the through-hole 9h through which the air discharging bolt 11h is inserted is closed by the head of the bolt 11h without opening downward.
Furthermore, in the third embodiment, another bolt 11 and its through hole 9 (not shown, for example, the bolt 11g and the through hole, which are different from the bolts 11a, 11b, 11d, 11f, and 11h used as air and fuel gas flow paths, are used. 9g) is used as a flow path (not shown) of the exhaust gas after combustion exhausted from the exhaust gas combustor 113, and exhaust gas is configured to be exhausted.

  In FIG. 12, similarly to FIG. 2, the flow path of air introduced from the outside of the fuel cell stack 1 (broken line portion) and the flow path of air discharged to the outside (solid line portion) are displayed in an overlapping manner. doing.

b) Next, the air flow path in the third embodiment will be described.
As shown in FIG. 12, in the fuel cell stack 111 of the third embodiment, air is introduced from the outside of the fuel cell stack 111 into the through hole 9a through the internal flow path 14 of the bolt 11a, and then the heat It is introduced into the exchange unit 10.

The air heated by the heat exchange unit 10 is introduced into the through-hole 9d and then distributed and supplied to the air flow path 19 of each power generation unit 7 and also supplied to the first gas reservoir chamber 20. The
The remaining air used for power generation in each air channel 19 is introduced into the through-hole 9 h from each air channel 19 and then introduced into the exhaust gas combustor 113.

  On the other hand, although not shown, the fuel gas is introduced from the outside of the fuel cell stack 111 into the through hole 9f of the fuel cell stack 111 through the internal flow path 14 of the bolt 11f. It is distributed and supplied to the flow path 21.

Next, the remaining fuel gas used for power generation in each fuel flow path 21 is introduced from each fuel flow path 21 into the through hole 9 b and then introduced into the exhaust gas combustor 113.
The fuel cell stack 111 is heated by the combustion of the air and the fuel gas introduced into the exhaust gas combustor 113. Then, the exhaust gas after combustion is discharged out of the fuel cell stack 111.

  Also in the third embodiment, the same effect as that of the first embodiment is obtained on the side where the first gas reservoir chamber 20 is disposed. Further, when the lower end side of the fuel cell stack 111 is easily cooled, the lower end side can be suitably heated by the exhaust gas combustor 113.

  In the third embodiment, as in the second embodiment, the fuel gas may be stored instead of storing the air in the first gas reservoir chamber 20.

Next, the fourth embodiment will be described, but the description of the same contents as the first embodiment will be omitted.
In addition, the same number is attached | subjected and demonstrated to the structure similar to Example 1. FIG.
As shown in FIG. 13, the fuel cell stack 121 of the fourth embodiment includes a first gas reservoir chamber 20 that stores air only in one of the stacking directions (upward in FIG. 13). Details will be described below.

  In the fuel cell stack 121 of the fourth embodiment, air is introduced from the outside of the fuel cell stack 121 into the through hole 9h via the internal flow path 14 of the bolt 11h, and then disposed between the power generation units 7. It is introduced into the heat exchange unit 10.

Next, the air heated in the heat exchange unit 10 is introduced into the through hole 9d, and then distributed and supplied to the air flow path 19 and the first gas reservoir chamber 20 of each power generation unit 7.
The remaining air used for power generation in each air channel 19 is introduced into the through hole 9h from each air channel 19 and then discharged out of the fuel cell stack 131.

Further, since the fuel gas is the same as that of the first embodiment, the description thereof is omitted.
In FIG. 13, similarly to FIG. 2, the air flow path (broken line portion) introduced from the outside of the fuel cell stack 1 and the air flow path discharged outside (solid line portion) are displayed in an overlapping manner. doing.

Also in the fourth embodiment, the same effects as those of the first embodiment are obtained on the side where the first gas reservoir chamber 20 is disposed.
In the fourth embodiment, the fuel gas may be stored in the first gas reservoir chamber 20 as in the second embodiment.

Next, although Example 5 is demonstrated, description of the content similar to the said Example 1 is abbreviate | omitted.
In addition, the same number is attached | subjected and demonstrated to the structure similar to Example 1. FIG.
As shown in FIG. 14, the fuel cell stack 131 of the fifth embodiment stores air in one of the first gas reservoir chambers 133 in the stacking direction and stores fuel gas in the other second gas reservoir chamber 135. It is. Details will be described below.

a) First, the configuration of the fuel cell stack 131 will be described.
In the fuel cell stack 131 of the fifth embodiment, the configuration of the air flow path in the first embodiment and the configuration of the fuel gas flow path in the second embodiment are combined.

  Specifically, as shown in FIG. 14, the first heat exchange unit 137 that performs heat exchange of air and the second that performs heat exchange of fuel gas so as to be sandwiched between the plurality of power generation units 7 of the fuel cell stack 131. A heat exchanging part 139 is arranged.

  That is, the first heat exchange unit 137 is disposed between the plurality of power generation units 7 in the upper part and the plurality of power generation units 7 in the center of FIG. 14, and the plurality of power generation units 7 in the lower part and the plurality of power generation units 7 in the center The 2nd heat exchange part 139 is arrange | positioned between these.

A first gas reservoir chamber 133 that stores air is provided above the power generation unit 7 at the upper end, and a second gas reservoir chamber 135 that stores fuel gas is provided below the power generation unit 7 at the lower end.
b) Next, air and fuel gas flow paths in the fuel cell stack 131 will be described.

<Air flow path>
As shown in FIGS. 14 (a) and 15 (a), in the fuel cell stack 131 of the fifth embodiment, air passes from the outside of the fuel cell stack 131 through the internal flow path 14 of the bolt 11a. 9a, and then introduced into the first heat exchange unit 137.

Next, the air heated in the first heat exchange unit 137 is introduced into the through hole 9d and then distributed to the air flow path 19 (see FIG. 3) of each power generation unit 7 and the first gas reservoir chamber 133. Supplied.
The remaining air used for power generation in each air channel 19 is discharged from each air channel 19 to the outside through the through hole 9h.

<Flow path of fuel gas>
As shown in FIGS. 14B and 15B, in the fuel cell stack 131 of the fifth embodiment, the fuel gas penetrates from the outside of the fuel cell stack 131 through the internal flow path 14 of the bolt 11c. It introduce | transduces into the hole 9c, and is introduce | transduced into the 2nd heat exchange part 139 after that.

  Next, the fuel gas heated in the second heat exchange section 139 is introduced into the through hole 9f, and then distributed to the fuel flow path 21 (see FIG. 3) of each power generation unit 7 and the second gas reservoir chamber 135. Supplied.

And the remaining fuel gas used for electric power generation in each fuel flow path 21 is discharged | emitted outside from each fuel flow path 21 through the through-hole 9b.
The fifth embodiment also has the advantages of having the same effects as the first embodiment and having a high degree of design freedom.

Next, the sixth embodiment will be described, but the description of the same contents as the first embodiment will be omitted.
In addition, the same number is attached | subjected and demonstrated to the structure similar to Example 1. FIG.
As shown in FIG. 16, the fuel cell stack 141 of the sixth embodiment has a serial flow structure with respect to the air flow path, and the air after the first power generation is supplied to the first gas reservoir 20 and the second gas reservoir. It is introduced into the chamber 30.

a) First, the structure of the fuel cell stack 141 of the sixth embodiment will be described.
As shown in FIG. 16 (a), in the fuel cell stack 141 of the sixth embodiment, the upper stack body 2a composed of a plurality (for example, four stages) of power generation units 7 and the plurality (for example, four stages) of power generation units 7 are used. As in the first embodiment, the heat exchange unit 10 is provided between the lower stack body 2b.

Here, the upper stack body 2a is on the upstream side of the air serial flow, and the lower stack body 2b is on the downstream side of the air serial flow.
Similarly to the first embodiment, the first gas reservoir chamber 20 is provided in the upper part of the upper stack body 2a, and the second gas reservoir chamber 30 is provided in the lower part of the lower stack body 2b.

b) Next, air flow paths in the fuel cell stack 141 will be described.
As shown in FIG. 16, the air introduced from the outside of the fuel cell stack 141 into the through hole 9 a through the internal flow path 14 of the bolt 11 a is supplied to the heat exchange unit 10.

  And the air heated by the heat exchange part 10 is each through the through-hole 9d, each air flow path 19 (refer FIG. 3) of each power generation unit 7 of the upper stack main body 2a, the 1st gas reservoir chamber 20, and 2nd. It is supplied to the gas reservoir chamber 30.

Next, the remaining air used for the first power generation in each air flow path 19 is introduced into the through hole 9h and supplied to each power generation unit 7 of the lower stack body 2b from the through hole 9h.
The remaining air used for the second power generation in each air channel 19 is discharged to the outside through the through hole 9e.

In FIG. 16, the order of air flow is indicated by O 1 → O 2 → O 3.
In addition, since the flow path of the fuel gas is the same as that in the first embodiment, the description thereof is omitted.
In the sixth embodiment, the air flow path is a serial flow, and both gas reservoir chambers 20 and 30 for storing air after being heated by heat exchange in the heat exchange section 10 are provided on both sides in the stacking direction of the fuel cell stack 141. Since this is provided, the same effects as those of the first embodiment can be obtained.

  In the sixth embodiment, the air after power generation is stored in the gas storage chambers 20 and 30, but fuel gas may be stored as in the second embodiment. Alternatively, air may be stored in the first gas reservoir chamber 20 and fuel gas may be stored in the second gas reservoir chamber 30 (or the type of gas stored may be reversed upside down).

  In addition to using only the air flow path as a serial flow, the air and fuel gas flow paths may be set as a serial flow, or only the fuel gas flow path may be set as a serial flow.

Next, although Example 7 is demonstrated, description of the content similar to the said Example 1 is abbreviate | omitted.
In addition, the same number is attached | subjected and demonstrated to the structure similar to Example 1. FIG.
As shown in FIG. 17, in the fuel cell stack 161 of the seventh embodiment, the plurality of power generation units 7 are composed of the air electrode layer 25, the solid electrolyte layer 23, and the fuel electrode layer 27, as in the first embodiment. A single cell 17 and a square frame metal separator 35 bonded to the single cell 17 are provided.

Further, a plate-shaped metal interconnector 163 is disposed above the air electrode layer 25 (in the figure), and the convex portion 165 protruding from the lower side is in contact with the air electrode layer 25. .
The interconnector 163 is joined to a current collecting separator 167 having a metal square frame shape (thickness is smaller than that of the interconnector 163). The current collector separator 167 and the interconnector 163 are used to connect the interconnector 163 to the interconnector 163. The upper and lower flow paths (and therefore between the power generation units 7) are separated.

Further, below the fuel electrode layer 27 (in the figure), there is a fuel electrode side current collector 169 having a structure similar to that of the fuel electrode side current collector 45 of the first embodiment (consisting of an insulating plate and a metal plate). Has been placed.
In addition, a frame 171 made of a rectangular frame-like insulating plate is disposed between the current collector separator 167 (corresponding to the air flow path 19) and the separator 35, and the separator 35 (corresponding to the fuel flow path 21) Between the current collector separators 167, a frame 173 made of metal having a square frame shape is disposed.

  In the seventh embodiment, as in the first embodiment, the heat exchange unit 10 is arranged between the power generation units 7 arranged at the top and bottom of the drawing. The heat exchanging unit 10 is composed of a pair of metal plates 181 and 183 arranged at the top and bottom of the figure, and a square frame-shaped metal spacer 185 arranged between the plates 181 and 183. Has been. Although not shown, the spacer 185 is provided with an opening for introducing or discharging air, as in the first embodiment.

  In addition, a rectangular frame-shaped metal spacer 191 (similar to the frame 173) is arranged between the uppermost power generation unit 7 and the end plate 3 in FIG. A first gas reservoir chamber 193 for storing air is provided. Although not shown, the spacer 174 is provided with an opening that communicates the first gas reservoir chamber 193 with the air discharge through hole 9 after heat exchange.

  In the first gas reservoir chamber 193, the fuel electrode side current collector 169 is arranged so that the end plate 3 and the interconnector 163 (to which the current collector separator 167 is joined) are in contact with each other and are conducted. Yes.

  Similarly, a spacer 195 made of a rectangular frame-like insulating plate (similar to the frame 171) is disposed between the lowermost power generation unit 7 and the end plate 5 in FIG. A second gas reservoir chamber 197 for storing the generated air is provided. Although not shown, the spacer 195 is provided with an opening that communicates the second gas reservoir chamber 177 and the air discharge through hole 9 after heat exchange.

  In the second gas reservoir chamber 197, the interconnector 163 (with the current collector separator 167 joined) is disposed so that the end plate 5 and the fuel electrode side current collector 169 are brought into contact with each other to be conducted. Yes.

  Also in the seventh embodiment, as in the first embodiment, since the air heated by the heat exchange unit 10 is introduced into the first and second gas reservoir chambers 193 and 197, the same as in the first embodiment. There is an effect.

  Furthermore, in the eighth embodiment, since the interconnector 163 is joined to the current collector separator 167 having a small plate thickness (thin), heat radiation in the side surface direction of the power generation unit 7 is reduced. That is, since heat is not easily released not only in the stacking direction but also in the side surface direction, the temperature in the power generation unit 7 can be kept more uniform.

As in the second embodiment, the fuel gas heated by the heat exchange unit 10 may be introduced into the first and second gas reservoir chambers 193 and 197.
Further, as in the fifth embodiment, air may be introduced into the first gas reservoir chamber 193 and fuel gas may be introduced into the second gas reservoir chamber 197. Alternatively, conversely, fuel gas may be introduced into the first gas reservoir chamber 193 and air may be introduced into the second gas reservoir chamber 197.

  In FIG. 17, a communication part that is a communication path that supplies gas to each air flow path 19 and each fuel flow path 21 from each through hole that is a supply path for each gas, each air flow path 19 and each fuel flow path 21. The communication part for discharging the gas from the gas to the through hole which is the discharge path of each gas, and the opening for supplying the gas from the discharge path of each gas to the first and second gas reservoir chambers 193 and 197 are omitted. Similarly to Examples 1 to 3 and the like, an opening may be provided as appropriate (opening to the through hole on the gas supply side) so that each gas can flow.

As mentioned above, although the Example of this invention was described, this invention is not limited to the said Example, A various aspect can be taken.
(1) For example, in the present invention, for example, a solid oxide fuel cell (SOFC) using a ZrO ₂ ceramic as an electrolyte, a molten carbonate fuel cell (MCFC) using a Li-Na / K carbonate as an electrolyte, for example. ) And a fuel cell stack of a fuel cell such as a phosphoric acid fuel cell (PAFC) using phosphoric acid as an electrolyte.

  (2) In addition, the electricity generated by the single cell can be taken out through, for example, a current collector and an interconnector. In this case, the interconnector and the current collector are configured as separate members. Alternatively, it may be configured as an integral member.

  (3) Further, although one opening portion (opening to the gas supply side) of the gas reservoir chamber is desirable for storing gas, a plurality of openings may be provided.

1, 101, 111, 121, 131, 141, 161 ... Fuel cell stack (solid oxide fuel cell stack)
3, 5 ... End plate 7 ... Power generation unit 9, 9a, 9b, 9c, 9d, 9e, 9f, 9g, 9h ... Through hole 10, 103 ... Heat exchange part 17 ... Single cell 19 ... Air flow path 20, 105, 133, 193 ... first gas reservoir chamber 21 ... fuel flow path 23 ... solid electrolyte layer 25 ... air electrode layer 27 ... fuel electrode layer 30, 107, 135, 197 ... second gas reservoir chamber 31, 41, 163 ... interconnector 53a, 63a, 109, 111 ... opening 137 ... first heat exchange part 139 ... second heat exchange part

Claims (7)

A flat single cell having an electrolyte layer and an air electrode and a fuel electrode arranged so as to sandwich the electrolyte layer and generating power using an oxidant gas and a fuel gas is formed in the thickness direction of the single cell. A plurality of fuel cell stacks stacked along
A gas reservoir chamber for storing at least one of the oxidant gas and the fuel gas heat-exchanged inside the fuel cell stack at at least one end in the stacking direction of the fuel cell stack; A fuel cell stack.   2. The fuel cell according to claim 1, further comprising: the gas reservoir chamber that stores at least one of the oxidant gas and the fuel gas at both ends in the stacking direction of the fuel cell stack. stack.   Of the gas reservoir chambers at both ends in the stacking direction of the fuel cell stack, the oxidant gas is stored in one gas reservoir chamber, and the fuel gas is stored in the other gas reservoir chamber. The fuel cell stack according to claim 2.   The gas reservoir chamber is a space that is partially closed and has an opening, and the opening is a gas supply path to which at least one of the oxidant gas and the fuel gas is supplied. The fuel cell stack according to claim 1, wherein the fuel cell stack is formed so as to open only.   The gas reservoir chamber is a space that is partially closed and has an opening, and the opening is formed so as to open at one place in a gas supply path to which the gas is supplied. The fuel cell stack according to any one of claims 1 to 4, wherein At least one end in the stacking direction of the fuel cell stack is provided with an end plate that is a plate-like member,
The gas reservoir chamber is provided between the end plate and at least one of the single cells arranged on the most end side in the stacking direction of the fuel cell stack. The fuel cell stack according to any one of 5.   The fuel cell stack according to any one of claims 1 to 6, wherein a heat exchanging portion that performs heat exchange inside the fuel cell stack is disposed between the single cells.