JP2022066744A - Electrochemical reaction cell stack - Google Patents

Abstract

To suppress variation of in-plane temperature distribution of a unit cell constituting an electrochemical reaction cell stack.SOLUTION: An electrochemical reaction cell stack comprises an electrochemical reaction block and a pair of end members. A first heat dissipation member having heat dissipation property is further provided on a specific front face side of a specific end member which is at least one of the pair of end members. The first heat dissipation member is positioned outside of an inner portion in the electrochemical reaction cell stack in a first direction view. The inner portion adjacent with the first heat dissipation member is a cavity.SELECTED DRAWING: Figure 2

Description

The techniques disclosed herein relate to electrochemical reaction cell stacks.

A solid oxide fuel cell (hereinafter referred to as "SOFC") is known as one of the types of fuel cells that generate power by utilizing an electrochemical reaction between hydrogen and oxygen. The fuel cell power generation unit (hereinafter, simply referred to as “power generation unit”), which is a constituent unit of SOFC, has an electrolyte layer containing a solid oxide and a predetermined direction (hereinafter, referred to as “first direction”) with the electrolyte layer interposed therebetween. It has a fuel cell single cell (hereinafter, simply referred to as “single cell”) including an air electrode and a fuel electrode facing each other.

SOFC generally includes a structure in which a plurality of power generation units are arranged side by side in the first direction (hereinafter referred to as "power generation block") and a pair of end members facing each other in the first direction with the power generation block interposed therebetween. It is used in the form of a fuel cell stack equipped with.

As a power generation block of such a fuel cell stack, a power generation block including a gas flow member having a frame portion surrounding a region where an electrolyte layer, an air electrode, and a fuel electrode overlap each other is further known. The frame portion is formed with a manifold hole forming a manifold through which gas supplied or discharged to the air chamber facing the air electrode and the fuel chamber facing the fuel electrode passes (for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2018-181466

During power generation of the fuel cell stack, the power generation reaction in the power generation unit is an exothermic reaction. Therefore, in the first direction, the central portion of the fuel cell stack is relatively close to the manifold in the fuel cell stack. It tends to be hot. As a result, the temperature distribution in the plane of the single cell may vary, and the single cell may deteriorate due to the thermal stress caused by the variation in the temperature distribution, or the power generation efficiency of the single cell may decrease.

It should be noted that such a problem is an electrolysis having a plurality of electrolytic single cells which are constituent units of a solid oxide type electrolytic cell (hereinafter referred to as “SOEC”) that generates hydrogen by utilizing an electrolysis reaction of water. This is a common issue for cell stacks. In the present specification, the fuel cell single cell and the electrolytic single cell are collectively referred to as an electrochemical reaction single cell, and the fuel cell stack and the electrolytic cell stack are collectively referred to as an electrochemical reaction cell stack. Further, such a problem is common not only to SOFC and SOEC but also to other types of electrochemical reaction cell stacks.

This specification discloses a technique capable of solving the above-mentioned problems.

The techniques disclosed herein can be realized, for example, in the following forms.

(1) The electrochemical reaction cell stack disclosed in the present specification is an electrochemical reaction block composed of a plurality of electrochemical reaction units arranged side by side in the first direction, and each of the electrochemical reaction units. Is an electrochemical reaction single cell containing an electrolyte layer, an air electrode and a fuel electrode facing each other in the first direction across the electrolyte layer, and in the first direction view, the electrolyte layer and the said. A gas flow member having a frame portion surrounding a region where an air electrode and a fuel electrode overlap each other, and is supplied to or supplied to a gas chamber facing a specific electrode at least one of the air electrode and the fuel electrode. The first direction sandwiching the electrochemical reaction block and the electrochemical reaction block having a gas flow member having a manifold hole formed in the frame portion for forming a manifold through which gas discharged from the chamber passes. In an electrochemical reaction cell stack comprising a pair of end members facing each other, the pair of end members arranged such that at least a portion overlaps the frame portion in the first directional view. A first surface that is arranged on a specific surface of the surface of a specific end member that is at least one of the pair of end members and is a surface opposite to the electrochemical reaction block, and has heat insulating properties. The first heat insulating member is located outside the inner portion of the electrochemical reaction cell stack, including the center of the electrochemical reaction cell stack, in the first directional view. The inner portion adjacent to the first heat insulating member is hollow. In the present electrochemical reaction cell stack, the first heat insulating member is arranged on the specific surface of the specific end member. In the first directional view, the first insulating member is located outside the inner portion of the electrochemical reaction cell stack. Further, the inner portion is hollow. In other words, the heat insulating performance of the first heat insulating member is higher than the heat insulating performance of the inner portion which is a cavity. Therefore, in the first direction view, the temperature tends to be relatively high while suppressing heat dissipation from the portion close to the manifold (the portion overlapping the first heat insulating member) in the electrochemical reaction cell stack, which tends to be relatively low temperature. It is possible to facilitate heat dissipation from the central portion (the portion overlapping the inner portion) of the electrochemical reaction cell stack. Therefore, according to the present electrochemical reaction cell stack, the variation in the temperature distribution in the plane of the electrochemical reaction single cell is suppressed, and as a result, the deterioration of the electrochemical reaction single cell and the decrease in the power generation efficiency of the electrochemical reaction single cell are suppressed. Can be suppressed.

(2) The electrochemical reaction cell stack disclosed in the present specification is an electrochemical reaction block composed of a plurality of electrochemical reaction units arranged side by side in the first direction, and each of the electrochemical reaction units. Is an electrochemical reaction single cell containing an electrolyte layer, an air electrode and a fuel electrode facing each other in the first direction with the electrolyte layer interposed therebetween, and in the first direction view, the electrolyte layer and the air. A gas flow member having a pole and a frame portion arranged so as to surround a region where the fuel poles overlap each other, in a gas chamber facing a specific electrode at least one of the air pole and the fuel pole. The electrochemical reaction block comprising the gas flow member having a manifold hole formed in the frame portion forming a manifold through which the gas supplied or discharged from the gas chamber passes, and the electrochemical reaction block sandwiched between the above. An electrochemical reaction cell stack comprising a pair of end members facing each other in a first direction, the pair of end members arranged so that at least a part thereof overlaps the frame portion in the first direction view. In the first direction, the surface of the specific end member, which is at least one of the pair of end members, is arranged on the specific surface side, which is the surface opposite to the electrochemical reaction block, and said. In the first directional view, it is a first heat insulating member located outside the inner portion including the center of the electrochemical reaction cell stack, and is arranged on the specific surface side with the first heat insulating member having heat insulating properties. The second heat insulating member, which is a second heat insulating member located in the inner portion and has a heat insulating property, is provided, and the thickness of the first heat insulating member is the thickness of the second heat insulating member. Large compared to the thickness. According to the present electrochemical reaction cell stack, the first heat insulating member and the second heat insulating member are arranged on the specific surface side of the specific end member. In the first directional view, the first heat insulating member is located outside the inner portion of the electrochemical reaction cell stack, and the second heat insulating member is located inside the inner portion. Further, the thickness of the first heat insulating member is larger than the thickness of the second heat insulating member. In other words, for example, the thermal conductivity in the material for forming the first heat insulating member is equal to the thermal conductivity in the material for forming the second heat insulating member, or the heat in the material for forming the first heat insulating member is equal. In a configuration in which the conductivity is smaller than the thermal conductivity of the material for forming the second heat insulating member, the heat insulating performance of the first heat insulating member is higher than the heat insulating performance of the second heat insulating member. Therefore, in the first direction view, the temperature tends to be relatively high while suppressing heat dissipation from the portion close to the manifold (the portion overlapping the first heat insulating member) in the electrochemical reaction cell stack, which tends to be relatively low temperature. It is possible to facilitate heat dissipation from the central portion (the portion overlapping the second heat insulating member) of the electrochemical reaction cell stack. Therefore, according to the present electrochemical reaction cell stack, the variation in the temperature distribution in the plane of the electrochemical reaction single cell is suppressed, and as a result, the deterioration of the electrochemical reaction single cell and the decrease in the power generation efficiency of the electrochemical reaction single cell are suppressed. Can be suppressed.

(3) The electrochemical reaction cell stack disclosed in the present specification is an electrochemical reaction block composed of a plurality of electrochemical reaction units arranged side by side in the first direction, and each of the electrochemical reaction units. Is an electrochemical reaction single cell containing an electrolyte layer, an air electrode and a fuel electrode facing each other in the first direction with the electrolyte layer interposed therebetween, and in the first direction view, the electrolyte layer and the air. A gas flow member having a pole and a frame portion arranged so as to surround a region where the fuel poles overlap each other, in a gas chamber facing a specific electrode at least one of the air pole and the fuel pole. The electrochemical reaction block comprising the gas flow member having a manifold hole formed in the frame portion forming a manifold through which the gas supplied or discharged from the gas chamber passes, and the electrochemical reaction block sandwiched between the above. An electrochemical reaction cell stack comprising a pair of end members facing each other in a first direction, the pair of end members arranged so that at least a part thereof overlaps the frame portion in the first direction view. In the first direction, the surface of the specific end member, which is at least one of the pair of end members, is arranged on the specific surface side, which is the surface opposite to the electrochemical reaction block, and said. In the first directional view, it is a first heat insulating member located outside the inner portion including the center of the electrochemical reaction cell stack, and is arranged on the specific surface side with the first heat insulating member having heat insulating properties. The second heat insulating member, which is a second heat insulating member located in the inner portion and has a heat insulating property, is provided, and the thermal conductivity of the first heat insulating member is the second heat insulating member. It is small compared to the thermal conductivity of the member. According to the present electrochemical reaction cell stack, the first heat insulating member and the second heat insulating member are arranged on the specific surface side of the specific end member. In the first directional view, the first heat insulating member is located outside the inner portion of the electrochemical reaction cell stack, and the second heat insulating member is located inside the inner portion. Further, the thermal conductivity of the first heat insulating member is smaller than that of the second heat insulating member. In other words, for example, the thickness of the first heat insulating member is equal to the thickness of the second heat insulating member, or the thickness of the first heat insulating member is larger than the thickness of the second heat insulating member. The heat insulating performance of the first heat insulating member is higher than that of the second heat insulating member. Therefore, in the first direction view, the temperature tends to be relatively high while suppressing heat dissipation from the portion close to the manifold (the portion overlapping the first heat insulating member) in the electrochemical reaction cell stack, which tends to be relatively low temperature. It is possible to facilitate heat dissipation from the central portion (the portion overlapping the second heat insulating member) of the electrochemical reaction cell stack. Therefore, according to the present electrochemical reaction cell stack, the variation in the temperature distribution in the plane of the electrochemical reaction single cell is suppressed, and as a result, the deterioration of the electrochemical reaction single cell and the decrease in the power generation efficiency of the electrochemical reaction single cell are suppressed. Can be suppressed.

(4) The electrochemical reaction cell stack disclosed in the present specification is an electrochemical reaction block composed of a plurality of electrochemical reaction units arranged side by side in the first direction, and each of the electrochemical reaction units. Is an electrochemical reaction single cell containing an electrolyte layer, an air electrode and a fuel electrode facing each other in the first direction with the electrolyte layer interposed therebetween, and in the first direction view, the electrolyte layer and the air. A gas flow member having a pole and a frame portion arranged so as to surround a region where the fuel poles overlap each other, in a gas chamber facing a specific electrode at least one of the air pole and the fuel pole. The electrochemical reaction block comprising the gas flow member having a manifold hole formed in the frame portion forming a manifold through which the gas supplied or discharged from the gas chamber passes, and the electrochemical reaction block sandwiched between the above. An electrochemical reaction cell stack comprising a pair of end members facing each other in a first direction, the pair of end members arranged so that at least a part thereof overlaps the frame portion in the first direction view. In the first direction, the surface of the specific end member, which is at least one of the pair of end members, is arranged on the specific surface side, which is the surface opposite to the electrochemical reaction block, and said. In the first directional view, it is a first heat insulating member located outside the inner portion including the center of the electrochemical reaction cell stack, and is arranged on the specific surface side with the first heat insulating member having heat insulating properties. A second heat insulating member, which is a second heat insulating member located in the inner portion and has a heat insulating property, and the density of the first heat insulating member is the same as that of the second heat insulating member. Large compared to density. According to the present electrochemical reaction cell stack, the first heat insulating member and the second heat insulating member are arranged on the specific surface side of the specific end member. In the first directional view, the first heat insulating member is located outside the inner portion of the electrochemical reaction cell stack, and the second heat insulating member is located inside the inner portion. Further, the density of the first heat insulating member is higher than the density of the second heat insulating member. In other words, for example, in a configuration in which the thickness of the first heat insulating member is equal to the thickness of the second heat insulating member, the heat insulating performance of the first heat insulating member is compared with the heat insulating performance of the second heat insulating member. And expensive. Therefore, in the first direction view, the temperature tends to be relatively high while suppressing heat dissipation from the portion close to the manifold (the portion overlapping the first heat insulating member) in the electrochemical reaction cell stack, which tends to be relatively low temperature. It is possible to facilitate heat dissipation from the central portion (the portion overlapping the second heat insulating member) of the electrochemical reaction cell stack. Therefore, according to the present electrochemical reaction cell stack, the variation in the temperature distribution in the plane of the electrochemical reaction single cell is suppressed, and as a result, the deterioration of the electrochemical reaction single cell and the decrease in the power generation efficiency of the electrochemical reaction single cell are suppressed. Can be suppressed.

(5) The electrochemical reaction cell stack disclosed in the present specification is an electrochemical reaction block composed of a plurality of electrochemical reaction units arranged side by side in the first direction, and each of the electrochemical reaction units. Is an electrochemical reaction single cell containing an electrolyte layer, an air electrode and a fuel electrode facing each other in the first direction with the electrolyte layer interposed therebetween, and in the first direction view, the electrolyte layer and the air. A gas flow member having a pole and a frame portion arranged so as to surround a region where the fuel poles overlap each other, in a gas chamber facing a specific electrode at least one of the air pole and the fuel pole. The electrochemical reaction block comprising the gas flow member having a manifold hole formed in the frame portion forming a manifold through which the gas supplied or discharged from the gas chamber passes, and the electrochemical reaction block sandwiched between the above. An electrochemical reaction cell stack comprising a pair of end members facing each other in a first direction, the pair of end members arranged so that at least a part thereof overlaps the frame portion in the first direction view. In the first direction, the surface of the specific end member, which is at least one of the pair of end members, is arranged on the specific surface side, which is the surface opposite to the electrochemical reaction block, and said. In the first directional view, it is a first heat insulating member located outside the inner portion including the center of the electrochemical reaction cell stack, and is arranged on the specific surface side with the first heat insulating member having heat insulating properties. A second heat insulating member, which is a second heat insulating member located in the inner portion and has a heat insulating property, is provided, and the second heat insulating member includes the second heat insulating member in the second heat insulating member. At least one of a through hole and a bottomed hole opened in at least one of a first surface substantially orthogonal to the first direction and a second surface opposite to the first surface is formed. .. Since the inner heat insulating member has a through hole or a bottomed hole, the heat insulating material filling rate per unit volume in the inner heat insulating member is lower than the heat insulating material filling rate per unit volume in the outer heat insulating member. Therefore, in the first direction view, the temperature tends to be relatively high while suppressing heat dissipation from the portion close to the manifold (the portion overlapping the first heat insulating member) in the electrochemical reaction cell stack, which tends to be relatively low temperature. It is possible to facilitate heat dissipation from the central portion (the portion overlapping the second heat insulating member) of the electrochemical reaction cell stack. Therefore, according to the present electrochemical reaction cell stack, the variation in the temperature distribution in the plane of the electrochemical reaction single cell is suppressed, and as a result, the deterioration of the electrochemical reaction single cell and the decrease in the power generation efficiency of the electrochemical reaction single cell are suppressed. Can be suppressed.

(6) In the electrochemical reaction cell stack, the first heat insulating member may be arranged so as to surround the inner portion in the first directional view. In the electrochemical reaction cell stack in which this configuration is adopted, the first heat insulating member is arranged so as to surround the inner portion in the first directional view. Therefore, in the first direction view, the electrochemical reaction cell stack tends to have a relatively low temperature while facilitating heat dissipation from the central portion (the portion overlapping the inner portion) of the electrochemical reaction cell stack which tends to have a relatively high temperature. It is possible to more effectively suppress heat dissipation from the portion close to the manifold (the portion overlapping the first heat insulating member) in the above. Therefore, according to the present electrochemical reaction cell stack, the variation in the temperature distribution in the plane of the electrochemical reaction single cell can be suppressed more effectively, and as a result, the deterioration of the electrochemical reaction single cell and the deterioration of the electrochemical reaction single cell can be achieved. The decrease in power generation efficiency can be suppressed more effectively.

(7) In the electrochemical reaction cell stack, at least a part of the first heat insulating member may be configured to overlap the frame part in the first direction view. In the electrochemical reaction cell stack in which this configuration is adopted, at least a part of the first heat insulating member overlaps with the frame portion of the gas flow member in the first directional view. Therefore, in the first directional view, it is possible to more effectively suppress heat dissipation from the portion overlapping the frame portion in the electrochemical reaction cell stack, which tends to have a relatively low temperature. Therefore, according to the present electrochemical reaction cell stack, the variation in the temperature distribution in the plane of the electrochemical reaction single cell can be suppressed more effectively, and as a result, the deterioration of the electrochemical reaction single cell and the deterioration of the electrochemical reaction single cell can be achieved. The decrease in power generation efficiency can be suppressed more effectively.

(8) In the electrochemical reaction cell stack, the frame portion has a hole for the manifold, which is a second side facing the first side of the electrochemical reaction cell in the first direction. Two air chamber manifold holes located on the side and two air chamber manifold holes, respectively, through which gas supplied to or discharged from the air chamber facing the air electrode passes. , Two fuel chamber manifold holes located on the first side and the second side, respectively, in the first direction view, and are supplied or supplied to the fuel chamber facing the fuel electrode, respectively. It has two fuel chamber manifold holes through which the gas discharged from the fuel chamber passes, and in the first directional view, the first heat insulating member has a substantially rectangular outer edge having four sides. The specific air chamber manifold hole located on the first side of the two air chamber manifold holes among the four sides constituting the outer edge of the first heat insulating member. Of the two fuel chamber manifold holes, the side closest to both the specific fuel chamber manifold hole located on the first side is set as the first side, and the first heat insulating member. The side of the outer edge connected to the first side is defined as the second side, and the first partial outer edge constituting a part of the first side and the first portion facing the first partial outer edge. The shortest distance between the heat insulating member and the inner edge of the first portion is defined as the first width, and the outer edge of the second portion constituting a part of the second side and the outer edge of the second portion facing the outer edge of the second portion. When the shortest distance between the inner edge of the second portion of the first heat insulating member is the second width, the first width may be larger than the second width. In the electrochemical reaction cell stack in which this configuration is adopted, the first width of the first heat insulating member is larger than the second width. Therefore, in the first directional view, the heat insulating performance in the portion close to the manifold in the electrochemical reaction cell stack, which tends to be relatively low temperature, is more effectively enhanced, and the heat radiation from the portion close to the manifold is suppressed more effectively. be able to. Therefore, according to the present electrochemical reaction cell stack, the variation in the temperature distribution in the plane of the electrochemical reaction single cell can be suppressed more effectively, and as a result, the deterioration of the electrochemical reaction single cell and the deterioration of the electrochemical reaction single cell can be achieved. The decrease in power generation efficiency can be suppressed more effectively.

(9) A heat transfer member arranged on the specific surface of the electrochemical reaction cell stack and arranged in a region overlapping at least in the center of the electrochemical reaction cell stack in the first directional view. , A heat transfer member having a thermal conductivity higher than that of the specific end member may be provided. In the electrochemical reaction cell stack in which this configuration is adopted, the heat transfer member is arranged in a region overlapping at least in the center of the electrochemical reaction cell stack on the specific surface of the specific end member in the first directional view. Further, the thermal conductivity of the heat transfer member is higher than the thermal conductivity of the specific end member. Therefore, in the first direction view, the heat generated in the center of the electrochemical reaction cell stack, which tends to be relatively hot, is conducted to the heat transfer member via the specific end member, and the heat is further transferred. It can be diffused inside the member. Therefore, according to the present electrochemical reaction cell stack, the variation in the temperature distribution in the plane of the electrochemical reaction single cell can be suppressed more effectively, and as a result, the deterioration of the electrochemical reaction single cell and the deterioration of the electrochemical reaction single cell can be achieved. The decrease in power generation efficiency can be suppressed more effectively.

A perspective view showing an external configuration of the fuel cell stack 100 according to the first embodiment. Explanatory drawing which shows the XZ cross-sectional structure of the fuel cell stack 100 at the position of II-II of FIG. Explanatory drawing which shows the XZ cross-sectional structure of the fuel cell stack 100 at the position of III-III of FIG. Explanatory drawing which shows the XZ cross section configuration of two power generation units 102 adjacent to each other at the same position as the cross section shown in FIG. Explanatory drawing which shows the YZ cross section configuration of two power generation units 102 adjacent to each other at the same position as the cross section shown in FIG. Explanatory drawing which shows the XY cross-sectional structure of the heat insulating member 60 at the position of VI-VI of FIG. Explanatory drawing which shows the XZ cross-sectional structure of the fuel cell stack 100A in 2nd Embodiment Explanatory drawing which shows XY cross-sectional structure of the heat insulating member 60A in 2nd Embodiment Explanatory drawing which shows the XZ cross-sectional structure of the fuel cell stack 100B in 3rd Embodiment Explanatory drawing which shows XY cross-sectional structure of the heat insulating member 60B in 3rd Embodiment Explanatory drawing which shows XY cross-sectional structure of the heat insulating member 60C in the 1st modification. Explanatory drawing which shows XY cross-sectional structure of the heat insulating member 60D in the 2nd modification

A. First Embodiment:
A-1. Constitution:
(Structure of fuel cell stack 100)
FIG. 1 is a perspective view showing an external configuration of the fuel cell stack 100 according to the first embodiment, and FIG. 2 is an XZ cross section of the fuel cell stack 100 at the position II-II in FIG. 1 (and FIG. 6 described later). It is explanatory drawing which shows the structure, and FIG. 3 is an explanatory view which shows the XZ cross section structure of the fuel cell stack 100 at the position of III-III of FIG. 1 (and FIG. 6 which will be described later). Each figure shows XYZ axes that are orthogonal to each other to identify the direction. In the present specification, for convenience, the Z-axis positive direction is referred to as an upward direction, and the Z-axis negative direction is referred to as a downward direction, but the fuel cell stack 100 is actually in a direction different from such an orientation. It may be installed. The same applies to FIGS. 4 and later. Further, in the present specification, the direction orthogonal to the Z-axis direction is referred to as a plane direction.

The fuel cell stack 100 includes a plurality of (seven in this embodiment) fuel cell power generation unit (hereinafter, simply referred to as “power generation unit”) 102, a pair of terminal plates 410, 420, and a pair of insulating sheets 510, 520. , A pair of end plates 104, 106. The seven power generation units 102 are arranged side by side in a predetermined arrangement direction (vertical direction in this embodiment). The pair of terminal plates 410 and 420 are arranged so as to sandwich an aggregate (hereinafter referred to as "power generation block 103") composed of a plurality of power generation units 102 from above and below. The pair of insulating sheets 510 and 520 are arranged so as to sandwich the pair of terminal plates 410 and 420 from above and below. Further, the pair of end plates 104 and 106 are arranged so as to sandwich the pair of insulating sheets 510 and 520 from above and below. Further, the fuel cell stack 100 further includes a heat insulating member 60 and a heat transfer member 63 on the upper side of the upper end plate 104 in the upward direction. The heat insulating member 60 and the heat transfer member 63 will be described in detail later. The arrangement direction (vertical direction) corresponds to the first direction in the claims. The upper end plate 104 corresponds to the specific end member in the claims, and the heat insulating member 60 corresponds to the first heat insulating member in the claims.

As shown in FIG. 1, the Z-axis direction of each layer (upper end plate 104, each power generation unit 102, each terminal plate 410, 420, each insulating sheet 510, 520, and heat transfer member 63) constituting the fuel cell stack 100. Around the four corners of the outer circumference, holes that penetrate each layer in the vertical direction and are substantially circular in the Z-axis direction are formed. Further, a hole (screw hole) into which the lower end portion of the bolt 22, which will be described later, is screwed into the upper surface around the four corners of the outer periphery of the lower end plate 106 constituting the fuel cell stack 100 in the Z-axis direction. ) Is formed. The holes formed in each power generation unit 102, each terminal plate 410, 420, each insulating sheet 510, 520, each end plate 104, 106, and the heat transfer member 63 communicate with each other in the vertical direction, and the upper end It constitutes a bolt hole 109 extending vertically from the plate 104 to the lower end plate 106. In the following description, the holes formed in each layer for forming the bolt holes 109 may also be referred to as bolt holes 109.

Each bolt 22 is inserted into each bolt hole 109 extending in the vertical direction. At the lower end of each bolt 22, around the four corners of the outer perimeter of the lower end plate 106 around the Z axis so that each bolt 22 can engage the lower end plate 106. A screw portion that can be screwed is formed in the hole (screw hole) formed on the upper surface. As described above, in the fuel cell stack 100 of the present embodiment, each power generation unit 102 and each end plate 104, 106 are integrally fastened by the head 24 of each bolt 22 and the lower end plate 106. Here, "each bolt 22 is engaged with the lower end plate 106" means that each bolt 22 is directly or via another member (eg, a nut) the lower end plate 106. It means that it is attached to.

Further, as shown in FIGS. 1 to 3, the vicinity of the outer periphery around the Z-axis direction of each layer (each power generation unit 102, lower terminal plate 420, and lower insulating sheet 520) constituting the fuel cell stack 100. Is formed with holes that penetrate each power generation unit 102 and the lower terminal plate 420 in the vertical direction, and a plurality of holes formed in each power generation unit 102 and corresponding to each other communicate with each other in the vertical direction. It constitutes a communication hole 108 extending in the vertical direction over the power generation unit 102 of the above. In the following description, the holes formed in each layer to form the communication holes 108 may also be referred to as communication holes 108.

As shown in FIGS. 1 and 2, the fuel cell stack 100 is located near one side (the side on the positive side of the X-axis of the two sides parallel to the Y-axis) on the outer circumference of the fuel cell stack 100 around the Z-axis direction. The communication hole 108 is an oxidant gas introduction manifold 161 which is a gas flow path in which an oxidant gas OG is introduced from the outside of the fuel cell stack 100 and the oxidant gas OG is supplied to an air chamber 166 described later in each power generation unit 102. The communication hole 108 located near the opposite side of the side (the side on the negative side of the X-axis of the two sides parallel to the Y-axis) is from the air chamber 166 of each power generation unit 102. It functions as an oxidant gas discharge manifold 162, which is a gas flow path for discharging the oxidant off gas OOG, which is the discharged gas, to the outside of the fuel cell stack 100. As the oxidant gas OG, for example, air is used. The air chamber 166 corresponds to the gas chamber in the claims. The oxidant gas introduction manifold 161 and the oxidizer gas discharge manifold 162 each correspond to a manifold within the scope of the claims.

Further, as shown in FIGS. 1 and 3, among the sides constituting the outer periphery of the fuel cell stack 100 around the Z-axis direction, the vicinity of the side closest to the communication hole 108 functioning as the above-mentioned oxidant gas discharge manifold 162. In the other communication hole 108 located in, the fuel gas FG is introduced from the outside of the fuel cell stack 100, and the fuel gas FG is introduced into the fuel gas flow path which is a gas flow path for supplying the fuel gas FG to the fuel chamber 176 described later in each power generation unit 102. The other communication holes 108 located near the side closest to the communication holes 108, which function as the manifold 171 and function as the oxidant gas introduction manifold 161 described above, are the gas discharged from the fuel chamber 176 of each power generation unit 102. It functions as a fuel gas discharge manifold 172, which is a gas flow path for discharging a certain fuel off-gas FOG to the outside of the fuel cell stack 100. As the fuel gas FG, for example, a hydrogen-rich gas obtained by reforming a city gas is used. The fuel chamber 176 corresponds to the gas chamber in the claims. The fuel gas introduction manifold 171 and the fuel gas discharge manifold 172 each correspond to a manifold within the scope of the claims.

(Structure of terminal plates 410, 420, insulating sheets 510, 520 and end plates 104, 106)
The pair of terminal plates 410 and 420 are substantially rectangular flat plate-shaped conductive members, and are made of, for example, stainless steel. The thickness (plate thickness) of each terminal plate 410, 420 in the Z-axis direction is 0.2 mm or more and 3 mm or less. The upper terminal plate 410 is arranged on the upper side of the power generation block 103 composed of a plurality of power generation units 102, and the lower terminal plate 420 is arranged on the lower side of the power generation block 103. That is, the upper terminal plate 410 is arranged on the upward side of the power generation unit 102 including the single cell 110 located on the uppermost side in the Z-axis direction among the plurality of single cells 110. Further, the lower terminal plate 420 is arranged on the lower side of the power generation unit 102 including the single cell 110 located on the lowermost side in the Z-axis direction among the plurality of single cells 110. As shown in FIG. 1, four bolt holes 109 are formed in the upper terminal plate 410. Further, the lower terminal plate 420 is formed with four communication holes 108 and four bolt holes 109 (see FIGS. 2 and 3). The upper terminal plate 410 functions as a positive output terminal of the fuel cell stack 100, and the lower terminal plate 420 functions as a negative output terminal of the fuel cell stack 100.

The pair of insulating sheets 510 and 520 are substantially rectangular sheet-shaped insulating members. The insulating sheets 510 and 520 are made of, for example, mica, alumina, silicon nitride, zirconia, or the like. The thickness (sheet thickness) T1 of each of the insulating sheets 510 and 520 in the Z-axis direction is 0.1 mm or more and 5 mm or less, preferably 1 mm or more and 5 mm or less. The upper insulating sheet 510 is arranged on the upper side of the upper terminal plate 410, and the lower insulating sheet 520 is arranged on the lower side of the lower terminal plate 420. Similar to the upper terminal plate 410, the upper insulating sheet 510 is formed with four bolt holes 109. Further, similarly to the lower terminal plate 420, the lower insulating sheet 520 is formed with four communication holes 108 and four bolt holes 109. In the present specification, the "conductive member" means a member having an electrical resistivity of 100 μΩ · m or less, and the “insulating member” means a member having an electric resistivity of 10 MΩ · m or more. are doing.

The pair of end plates 104 and 106 are substantially rectangular flat plate-shaped conductive members, and are made of, for example, stainless steel. The thermal conductivity of the pair of end plates 104 and 106 is, for example, about 20 W / m · K. The thickness (plate thickness) of each of the end plates 104 and 106 in the Z-axis direction is 1 mm or more and 15 mm or less. The upper end plate 104 is arranged on the upper side of the upper insulating sheet 510, and the lower end plate 106 is arranged on the lower side of the lower insulating sheet 520. In other words, the pair of end plates 104 and 106 face each other in the Z-axis direction with the power generation block 103 interposed therebetween, and the frames in the air pole side frame 130 and the fuel pole side frame 140 described later are viewed in the Z-axis direction. It is arranged so as to overlap the parts. A pair of insulating sheets 510, 520, a pair of terminal plates 410, 420, and a plurality of power generation units 102 are sandwiched by a pair of end plates 104, 106 in a pressed state. As shown in FIG. 1, four bolt holes 109 are formed in the upper end plate 104. Further, the lower end plate 106 is formed with four flow path through holes 107 and four bolt holes 109 (see FIGS. 2 and 3). The four flow path through holes 107 communicate with the oxidant gas introduction manifold 161, the oxidant gas discharge manifold 162, the fuel gas introduction manifold 171 and the fuel gas discharge manifold 172, respectively.

(Structure of gas passage member 27, etc.)
As shown in FIGS. 2 and 3, the fuel cell stack 100 further has four gas passages located on the opposite side (ie, lower side) of the plurality of power generation units 102 with respect to the lower end plate 106. A member 27 is provided. The four gas passage members 27 are arranged at positions overlapping with the oxidant gas introduction manifold 161, the oxidant gas discharge manifold 162, the fuel gas introduction manifold 171 and the fuel gas discharge manifold 172, respectively. Each gas passage member 27 has a main body portion 28 in which a hole communicating with the flow path through hole 107 of the lower end plate 106 is formed, and a tubular branch portion 29 branched from the side surface of the main body portion 28. are doing. The hole of the branch portion 29 communicates with the hole of the main body portion 28. A gas pipe (not shown) is connected to the branch portion 29 of each gas passage member 27. An insulating sheet 26 is arranged between the main body 28 of each gas passage member 27 and the end plate 106. The insulating sheet 26 is made of, for example, a mica sheet, a ceramic fiber sheet, a ceramic dust sheet, a glass sheet, a glass-ceramic composite material, or the like.

(Structure of power generation unit 102)
FIG. 4 is an explanatory diagram showing an XZ cross-sectional configuration of two power generation units 102 adjacent to each other at the same position as the cross section shown in FIG. 2, and FIG. 5 is an explanatory view showing the XZ cross-sectional configuration of the two power generation units 102 adjacent to each other at the same position as the cross section shown in FIG. It is explanatory drawing which shows the XZ cross-sectional structure of two power generation units 102. As shown in FIGS. 4 and 5, the power generation unit 102, which is the minimum unit of power generation, includes a fuel cell single cell (hereinafter, simply referred to as “single cell”) 110, a separator 120, an air electrode side frame 130, and air. It includes a pole-side current collecting member 134, a fuel pole-side frame 140, a fuel pole-side current collecting member 144, and a pair of interconnectors 150 constituting the uppermost layer and the lowest layer of the power generation unit 102. On the outer periphery of the separator 120, the air pole side frame 130, the fuel pole side frame 140, and the interconnector 150 around the Z-axis direction, holes forming each communication hole 108 that functions as each of the above-mentioned manifolds 161, 162, 171 and 172 are formed. And the holes constituting each bolt hole 109 are formed. Since the power generation unit 102 includes a single cell 110, the above-mentioned power generation block 103 can also be expressed as a structure in which a plurality of single cells 110 are arranged side by side in the vertical direction. The air pole side frame 130 and the fuel pole side frame 140 correspond to gas flow members in the claims, respectively.

The pair of interconnectors 150 are substantially rectangular flat plate-shaped conductive members larger than the single cell 110 in the Z-axis direction, and are formed of, for example, ferritic stainless steel. The interconnector 150 ensures electrical conduction between the power generation units 102 and prevents mixing of the reaction gas between the power generation units 102. Further, in the present embodiment, when two power generation units 102 are arranged adjacent to each other, one interconnector 150 is shared by two adjacent power generation units 102. That is, the upper interconnector 150 in one power generation unit 102 is the same member as the lower interconnector 150 in another power generation unit 102 adjacent to the upper side of the power generation unit 102. Further, since the fuel cell stack 100 includes a pair of terminal plates 410 and 420, the power generation unit 102 located at the top of the fuel cell stack 100 does not have the upper interconnector 150 and is located at the bottom. The power generation unit 102 does not include the lower interconnector 150 (see FIGS. 2 and 3).

The single cell 110 includes an electrolyte layer 112, an air electrode (cathode) 114 and a fuel electrode (anode) 116 facing each other in the vertical direction (arrangement direction in which the power generation units 102 are arranged) with the electrolyte layer 112 interposed therebetween. The single cell 110 of the present embodiment is a fuel pole support type single cell in which the electrolyte layer 112 and the air pole 114 are supported by the fuel pole 116. The air electrode 114 and the fuel electrode 116 each correspond to specific electrodes within the scope of the claims.

The electrolyte layer 112 is a flat plate-shaped member having a substantially rectangular shape in the Z-axis direction, and is a dense layer. The electrolyte layer 112 is formed of, for example, a solid oxide such as YSZ (yttria-stabilized zirconia), ScSZ (scandia-stabilized zirconia), SDC (samarium-doped ceria), GDC (gadolinium-doped ceria), and perovskite-type oxide. There is. The air electrode 114 is a substantially rectangular flat plate-shaped member smaller than the electrolyte layer 112 in the Z-axis direction, and is a porous layer. The air electrode 114 is formed of, for example, a perovskite-type oxide (for example, LSCF (lanternstrontium cobalt iron oxide), LSM (lanternstrontium manganese oxide), LNF (lanthanum nickel iron oxide)). The fuel electrode 116 is a substantially rectangular flat plate-shaped member having substantially the same size as the electrolyte layer 112 in the Z-axis direction, and is a porous layer. The fuel electrode 116 is formed of, for example, Ni (nickel), a cermet composed of Ni and ceramic particles, a Ni-based alloy, or the like. As described above, the single cell 110 (power generation unit 102) of the present embodiment is a solid oxide fuel cell (SOFC) using a solid oxide as an electrolyte.

The separator 120 is a frame-shaped member in which a substantially rectangular hole 121 penetrating in the vertical direction is formed near the center, and is made of a metal material such as stainless steel, for example. The peripheral portion of the hole 121 in the separator 120 faces the peripheral edge of the surface of the electrolyte layer 112 on the side of the air electrode 114. The separator 120 is bonded to the electrolyte layer 112 (single cell 110) by a bonding portion 124 formed of a brazing material (for example, Ag wax) arranged at the facing portions thereof. The separator 120 partitions the air chamber 166 facing the air electrode 114 and the fuel chamber 176 facing the fuel electrode 116, and a gas leak from one electrode side to the other electrode side at the peripheral edge of the single cell 110. It is suppressed. A seal member (for example, a glass seal member) that seals between the air chamber 166 and the fuel chamber 176 may be further provided near the joint between the single cell 110 and the separator 120.

The air pole side frame 130 is a member having a frame portion in which a substantially rectangular air chamber hole 131 penetrating in the vertical direction is formed near the center, and is formed of, for example, an insulator such as mica. The frame portion is a portion surrounding the region where the electrolyte layer 112, the air pole 114, and the fuel pole 116 overlap each other in the Z-axis direction, and each communication function as each of the above-mentioned manifolds 161, 162, 171 and 172. The holes (manifold holes) constituting the holes 108 are formed in the frame portion. The air electrode side frame 130 is in contact with the peripheral edge of the surface of the separator 120 opposite to the side facing the electrolyte layer 112 and the peripheral edge of the surface of the interconnector 150 facing the air electrode 114. .. The air chamber hole 131 formed in the air electrode side frame 130 constitutes an air chamber 166 facing the air electrode 114. Further, the air electrode side frame 130 electrically insulates between the pair of interconnectors 150 included in the power generation unit 102. Further, in the air electrode side frame 130, the oxidant gas supply communication flow path 132 that communicates the oxidant gas introduction manifold 161 and the air chamber 166, and the oxidant that communicates the air chamber 166 and the oxidant gas discharge manifold 162. A gas discharge communication flow path 133 is formed.

The fuel pole side frame 140 is a member having a frame portion in which a substantially rectangular fuel chamber hole 141 penetrating in the vertical direction is formed near the center, and is formed of, for example, metal. The frame portion is a portion surrounding the region in the Z-axis direction, similarly to the frame portion in the air electrode side frame 130. Further, also in the fuel electrode side frame 140, the holes (manifold holes) constituting the above-mentioned communication holes 108 are formed in the frame portion. The fuel electrode side frame 140 is in contact with the peripheral edge of the surface of the separator 120 facing the electrolyte layer 112 and the peripheral edge of the surface of the interconnector 150 facing the fuel electrode 116. A fuel chamber hole 141 formed in the fuel pole side frame 140 constitutes a fuel chamber 176 facing the fuel pole 116. Further, in the fuel electrode side frame 140, a fuel gas supply communication flow path 142 that communicates the fuel gas introduction manifold 171 and the fuel chamber 176, and a fuel gas discharge communication flow that communicates the fuel chamber 176 and the fuel gas discharge manifold 172. A road 143 is formed.

The fuel electrode side current collector 144 is arranged in the fuel chamber 176. The fuel electrode side current collecting member 144 includes an interconnector facing portion 146, an electrode facing portion 145, and a connecting portion (not shown) connecting the electrode facing portion 145 and the interconnector facing portion 146, for example. It is made of nickel, nickel alloy, stainless steel, etc. The electrode facing portion 145 is in contact with the surface of the fuel electrode 116 opposite to the side facing the electrolyte layer 112, and the interconnector facing portion 146 is on the surface of the interconnector 150 on the side facing the fuel pole 116. Are in contact. Since the current collector member 144 on the fuel electrode side has such a configuration, the fuel electrode 116 and the interconnector 150 are electrically connected to each other. A spacer 149 formed of, for example, a mica is arranged between the electrode facing portion 145 and the interconnector facing portion 146. Therefore, the fuel electrode side current collector 144 follows the deformation of the power generation unit 102 due to the temperature cycle and the reaction gas pressure fluctuation, and the electrical connection between the fuel electrode 116 and the interconnector 150 via the fuel electrode side current collector 144 is established. Well maintained.

The air pole side current collecting member 134 is arranged in the air chamber 166. The air electrode side current collecting member 134 is composed of a plurality of substantially square columnar current collecting member elements 135, and is made of, for example, ferritic stainless steel. The air pole side current collecting member 134 is in contact with the surface of the air pole 114 on the side opposite to the side facing the electrolyte layer 112 and the surface of the interconnector 150 on the side facing the air pole 114. However, as described above, since the power generation unit 102 located at the top of the fuel cell stack 100 does not have the upper interconnector 150, the air electrode side current collector 134 in the power generation unit 102 is the upper terminal plate. It is in contact with 410. Since the current collector member 134 on the air electrode side has such a configuration, the air electrode 114 and the interconnector 150 are electrically connected to each other. In this embodiment, the air electrode side current collecting member 134 and the interconnector 150 are formed as an integral member. That is, the flat plate-shaped portion orthogonal to the vertical direction (Z-axis direction) in the integrated member functions as the interconnector 150, and is formed so as to project from the flat plate-shaped portion toward the air electrode 114. The current collector element 135, which is a plurality of convex portions, functions as the air pole side current collector member 134. Further, the integrated member of the air electrode side current collecting member 134 and the interconnector 150 may be covered with a conductive coat, and both are placed between the air electrode 114 and the air electrode side current collecting member 134. A conductive bonding layer to be bonded may be interposed. In each power generation unit 102, the air electrode side current collecting member 134 and the upper interconnector 150 may be different members.

A-2. Operation of fuel cell stack 100:
As shown in FIG. 2, when the oxidant gas OG is supplied via a gas pipe (not shown) connected to the branch portion 29 of the gas passage member 27 provided at the position of the oxidant gas introduction manifold 161. , Oxidizing agent gas OG includes a branch portion 29 of the gas passage member 27, a main body portion 28, a through hole 107 for a flow path of the lower end plate 106, a communication hole 108 of the lower insulating sheet 520, and a lower terminal plate. It is supplied to the oxidant gas introduction manifold 161 through the communication hole 108 of 420, and is supplied from the oxidant gas introduction manifold 161 to the air chamber 166 via the oxidizer gas supply communication flow path 132 of each power generation unit 102. Further, as shown in FIG. 3, when the fuel gas FG is supplied via a gas pipe (not shown) connected to the branch portion 29 of the gas passage member 27 provided at the position of the fuel gas introduction manifold 171. , The fuel gas FG includes a branch portion 29 of the gas passage member 27, a main body portion 28, a flow passage through hole 107 of the lower end plate 106, a communication hole 108 of the lower insulating sheet 520, and a lower terminal plate 420. It is supplied to the fuel gas introduction manifold 171 through the communication hole 108 of the above, and is supplied from the fuel gas introduction manifold 171 to the fuel chamber 176 via the fuel gas supply communication flow path 142 of each power generation unit 102.

When the oxidant gas OG is supplied to the air chamber 166 of each power generation unit 102 and the fuel gas FG is supplied to the fuel chamber 176, oxygen contained in the oxidant gas OG and hydrogen contained in the fuel gas FG in the single cell 110 are supplied. Power is generated by an electrochemical reaction with. This power generation reaction is an exothermic reaction. In each power generation unit 102, the air pole 114 of the single cell 110 is electrically connected to one of the interconnectors 150 (or the upper terminal plate 410) via the air pole side current collector 134, and the fuel pole 116 is the fuel pole. It is electrically connected to the other interconnector 150 (or the lower terminal plate 420) via the side current collector 144. Further, the plurality of power generation units 102 included in the fuel cell stack 100 are electrically connected in series. Therefore, the electric energy generated in each power generation unit 102 is taken out from the terminal plates 410 and 420 that function as the output terminals of the fuel cell stack 100. Since the SOFC generates electricity at a relatively high temperature (for example, 700 ° C. to 1000 ° C.), the fuel cell stack 100 is a heater (for example, until the high temperature can be maintained by the heat generated by the power generation after the start-up. It may be heated by (not shown).

As shown in FIG. 2, the oxidant off-gas OOG discharged from the air chamber 166 to the oxidant gas discharge manifold 162 via the oxidant gas discharge communication flow path 133 of each power generation unit 102 is the lower terminal plate 420. The communication hole 108, the communication hole 108 of the lower insulating sheet 520, the through hole 107 for the flow path of the lower end plate 106, the main body 28 of the gas passage member 27 provided at the position of the oxidant gas discharge manifold 162, and It is discharged to the outside of the fuel cell stack 100 via the branch portion 29 and a gas pipe (not shown) connected to the branch portion 29. Further, as shown in FIG. 3, the fuel off-gas FOG discharged from the fuel chamber 176 to the fuel gas discharge manifold 172 via the fuel gas discharge communication flow path 143 of each power generation unit 102 communicates with the lower terminal plate 420. The main body 28 and the branch portion of the gas passage member 27 provided at the positions of the hole 108, the communication hole 108 of the lower insulating sheet 520, the through hole 107 for the flow path of the lower end plate 106, and the fuel gas discharge manifold 172. After passing through 29, the fuel is discharged to the outside of the fuel cell stack 100 via a gas pipe (not shown) connected to the branch portion 29.

In each power generation unit 102 constituting the fuel cell stack 100 of the present embodiment, the main flow direction of the oxidant gas OG in the air chamber 166 and the main flow direction of the fuel gas FG in the fuel chamber 176 are substantially opposite directions ( (Directions facing each other). That is, the power generation unit 102 (fuel cell stack 100) of the present embodiment is a counterflow type SOFC.

A-3. Detailed configuration of the heat insulating member 60 and the heat transfer member 63:
Next, the detailed configuration of the heat insulating member 60 and the heat transfer member 63 will be described. FIG. 6 is an XY cross-sectional view showing a detailed configuration of the heat insulating member 60. FIG. 6 shows the XY cross-sectional configuration of the fuel cell stack 100 at the VI-VI position of FIG. Note that, for convenience of explanation, FIG. 6 shows communication holes 108 (oxidizing agent gas introduction manifold 161, oxidant gas discharge manifold 162, fuel gas introduction manifold 171) formed in the air electrode side frame 130 and the fuel electrode side frame 140. , Fuel gas discharge manifold 172) and gas chamber holes (air chamber hole 131 and fuel chamber hole 141) are shown by dotted lines. In the actual configuration, the communication holes 108 are not formed in the heat insulating member 60 and the heat transfer member 63.

The heat transfer member 63 is a substantially rectangular flat plate-shaped conductive member, and is made of, for example, stainless steel. The thermal conductivity of the heat transfer member 63 is higher than the thermal conductivity of the upper end plate 104, for example, about 25 W / m · K or more. The thickness (plate thickness) of the heat transfer member 63 in the Z-axis direction is 1 mm or more and 25 mm or less. The heat transfer member 63 is arranged in contact with the surface of the upper end plate 104 on the opposite side of the power generation block 103 (hereinafter referred to as “surface S104”) in the Z-axis direction. More specifically, the heat transfer member 63 is arranged so as to overlap the inner portion IP and the outer portion OP in the Z-axis direction view. Here, the inner portion IP is a portion including the central PO of the fuel cell stack 100, and the outer portion OP is a portion located outside the inner portion IP. In the present embodiment, the inner edge of the outer portion OP overlaps the inner edge of the hole 121 of the separator 120 in the Z-axis direction, and the outer portion OP is each frame portion in the air pole side frame 130 and the fuel pole side frame 140. Includes. The surface S104 of the upper end plate 104 corresponds to a specific surface within the scope of the claims. The region of the upper end plate 104 that overlaps the inner portion IP of the surface S104 corresponds to the "region that overlaps at least the center of the electrochemical reaction cell stack" in the claims.

The heat insulating member 60 is located around a substantially rectangular hole 61 (in this embodiment, a substantially square in the Z-axis direction) penetrating in the vertical direction in the inner portion IP and around four corners of the outer circumference around the Z-axis direction. Moreover, it is a frame-shaped member having a substantially circular through hole formed in the Z-axis direction, and is formed of, for example, a silica-based material. The inner edges of the four through holes each surround the outer edge of the head 24 of the bolt 22 in the Z-axis direction. The thickness H (plate thickness) of the heat insulating member 60 in the Z-axis direction is, for example, 3 mm or more and 25 mm or less (see FIGS. 2 and 3). The thermal conductivity of the heat insulating member 60 is, for example, 0.01 W / m · K or more and 0.6 W / m · K or less at 600 ° C. The density of the heat insulating member 60 is, for example, 0.15 g / cm ³ or more and 2.5 g / cm ³ or less. The heat insulating member 60 is arranged in contact with the surface of the heat transfer member 63 opposite to the power generation block 103 (hereinafter referred to as “surface S63”) in the Z-axis direction. In other words, the heat insulating member 60 is arranged on the surface S104 side of the upper end plate 104 in the Z-axis direction. Further, the heat insulating member 60 is arranged so as to overlap the outer portion OP in the Z-axis direction view. More specifically, in the present embodiment, the heat insulating member 60 is arranged so as to overlap each frame portion in the air pole side frame 130 and the fuel pole side frame 140 in the Z-axis direction view. Further, the inner portion IP adjacent to the heat insulating member 60 is hollow. More specifically, in the present embodiment, the heat insulating member 60 is an inner portion where the electrolyte 112, the air electrode 114, and the fuel electrode 116 overlap with each other in the portion where the single cell 110 is located in the Z-axis direction. It is arranged so as to surround the IP. Therefore, the region of the surface S63 of the heat transfer member 63 that overlaps the inner portion IP is exposed to the outside of the fuel cell stack 100. The heat insulating member 60 is joined to the heat transfer member 63 with an adhesive or the like.

A-4. Effect of this embodiment:
As described above, the fuel cell stack 100 of the present embodiment includes a power generation block 103 and a pair of end plates 104 and 106. Further, a heat insulating member 60 is further provided on the surface S104 side of the upper end plate 104. The heat insulating member 60 is located at the outer portion OP of the fuel cell stack 100 in the Z-axis direction, and the inner portion IP adjacent to the heat insulating member 60 is hollow. In other words, the heat insulating performance of the heat insulating member 60 is higher than the heat insulating performance of the hollow inner portion IP. Therefore, when viewed in the Z-axis direction, the fuel cell stack 100 tends to have a relatively low temperature, and the heat is suppressed from the portion close to the manifolds 161, 162, 171 and 172 (the portion overlapping the heat insulating member 60), and the temperature is relatively high. It is possible to easily dissipate heat from the central portion (the portion overlapping the inner portion IP) of the fuel cell stack 100, which tends to become the fuel cell stack 100. Therefore, according to the fuel cell stack 100 of the present embodiment, it is possible to suppress the variation in the temperature distribution in the plane of the single cell 110, and eventually to suppress the deterioration of the single cell 110 and the deterioration of the power generation efficiency of the single cell 110. Can be done.

In the fuel cell stack 100 of the present embodiment, the heat insulating member 60 is arranged so as to surround the inner portion IP in the Z-axis direction view. Therefore, in the Z-axis direction view, the manifold in the fuel cell stack 100, which tends to have a relatively low temperature, while facilitating heat dissipation from the central portion (the portion overlapping the inner portion IP) of the fuel cell stack 100, which tends to have a relatively high temperature. It is possible to more effectively suppress heat dissipation from a portion close to 161, 162, 171 and 172 (a portion overlapping the heat insulating member 60). Therefore, according to the fuel cell stack 100 of the present embodiment, it is possible to more effectively suppress the variation in the temperature distribution in the plane of the single cell 110.

In the fuel cell stack 100 of the present embodiment, a part of the heat insulating member 60 overlaps the frame portions of the air pole side frame 130 and the fuel pole side frame 140 in the Z-axis direction view. Therefore, in the Z-axis direction view, it is possible to more effectively suppress heat dissipation from the portion of the fuel cell stack 100 that tends to have a relatively low temperature and that overlaps with the frame portion. Therefore, according to the fuel cell stack 100 of the present embodiment, it is possible to more effectively suppress the variation in the temperature distribution in the plane of the single cell 110.

The fuel cell stack 100 of the present embodiment includes a heat transfer member 63 arranged on the inner portion IP on the surface S104 of the upper end plate 104 in the Z-axis direction. Further, the thermal conductivity of the heat transfer member 63 is higher than the thermal conductivity of the upper end plate 104. Therefore, the heat generated in the center of the fuel cell stack 100, which tends to be relatively hot in the Z-axis direction, is conducted to the heat transfer member 63 via the upper end plate 104, and further, the heat is transferred. It can be diffused inside the heat member 63. Therefore, according to the fuel cell stack 100 of the present embodiment, it is possible to more effectively suppress the variation in the temperature distribution in the plane of the single cell 110.

B. Second embodiment:
FIG. 7 is an explanatory view showing an XZ cross-sectional configuration of the fuel cell stack 100A in the second embodiment, and FIG. 8 is an XY cross-sectional view showing a detailed configuration of the heat insulating member 60A in the second embodiment. FIG. 8 shows the XY cross-sectional configuration of the fuel cell stack 100A at the position VIII-VIII of FIG. Note that, as in FIG. 6, for convenience of explanation, each communication hole 108 and gas chamber hole (air chamber hole 131 and fuel chamber) formed in the air pole side frame 130 and the fuel pole side frame 140 are shown in FIG. The holes 141) are shown by dotted lines, but in the actual configuration, the communication holes 108 are not formed in the heat insulating member 60A and the heat transfer member 63.

As shown in FIG. 7, the fuel cell stack 100A of the second embodiment is different from the configuration of the fuel cell stack 100 of the first embodiment described above in that the heat insulating member 60A is provided in place of the heat insulating member 60. In the following, among the configurations of the fuel cell stack 100A of the second embodiment, the same configurations as the configurations of the fuel cell stack 100 of the first embodiment described above will be appropriately omitted by adding the same reference numerals. ..

The heat insulating member 60A of the present embodiment is arranged in contact with the surface S63 of the heat transfer member 63, similarly to the heat insulating member 60 of the first embodiment. The heat insulating member 60A of the present embodiment is composed of a separate member of the outer heat insulating member 601A and the inner heat insulating member 603A. In the present embodiment, the outer heat insulating member 601A has the same configuration as the heat insulating member 60 of the first embodiment. That is, the outer heat insulating member 601A is a frame-shaped member in which a hole 61A having a substantially rectangular shape (in this embodiment, a substantially square shape in the Z-axis direction) is formed, and is formed of, for example, a silica-based material. The thickness H (plate thickness) of the outer heat insulating member 601A is, for example, 5 mm or more and 25 mm or less (see FIG. 7). The outer heat insulating member 601A is arranged so as to overlap the outer portion OP in the Z-axis direction view. More specifically, in the present embodiment, the outer heat insulating member 601A is arranged so as to overlap each frame portion in the air pole side frame 130 and the fuel pole side frame 140 in the Z-axis direction view. The outer heat insulating member 601A corresponds to the first heat insulating member in the claims, and the inner heat insulating member 603A corresponds to the second heat insulating member in the claims.

The inner heat insulating member 603A is a flat plate-shaped member having a substantially rectangular shape (in this embodiment, a substantially square shape in the Z-axis direction), and is formed of, for example, a silica-based material. The thickness H3 (plate thickness) of the inner heat insulating member 603A in the Z-axis direction is, for example, 1 mm or more and 20 mm or less (see FIG. 7). The inner heat insulating member 603A is arranged so as to overlap the inner portion IP in the Z-axis direction view. More specifically, in the present embodiment, the inner heat insulating member 603A overlaps the portion where the electrolyte layer 112, the air electrode 114, and the fuel electrode 116 overlap in the portion where the single cell 110 is located in the Z-axis direction. It is arranged like this. In the present embodiment, the inner heat insulating member 603A is configured such that the outer edge 603e is in contact with the outer edge defining the hole 61A of the outer heat insulating member 601A.

As described above, in the fuel cell stack 100A of the present embodiment, the thickness H of the outer heat insulating member 601A is larger than the thickness H3 of the inner heat insulating member 603A. More specifically, the ratio of the thickness H of the outer heat insulating member 601A to the thickness H3 of the inner heat insulating member 603A ((H / H3) × 100) is 101% or more, preferably 200% or more.

The fuel cell stack 100A of the present embodiment includes a power generation block 103 and a pair of end plates 104 and 106. Further, the surface S104 of the upper end plate 104 is further provided with a heat insulating member 60A composed of an outer heat insulating member 601A and an inner heat insulating member 603A. In the Z-axis direction view, the outer heat insulating member 601A is arranged in the outer portion OP in the fuel cell stack 100A, and the inner heat insulating member 603A is arranged in the inner portion IP. The thickness H of the outer heat insulating member 601A is larger than the thickness H3 of the inner heat insulating member 603A. In other words, for example, the thermal conductivity in the forming material of the outer heat insulating member 601A is equivalent to the thermal conductivity in the forming material of the inner heat insulating member 603A, or the thermal conductivity in the forming material of the outer heat insulating member 601A is equal. In a configuration smaller than the thermal conductivity of the material for forming the inner heat insulating member 603A, the heat insulating performance of the outer heat insulating member 601A is higher than that of the inner heat insulating member 603A. Therefore, when viewed in the Z-axis direction, heat is relatively suppressed from the portion close to the manifolds 161, 162, 171 and 172 (the portion overlapping the outer heat insulating member 601A) in the fuel cell stack 100A, which tends to have a relatively low temperature. It is possible to easily dissipate heat from the central portion (the portion overlapping the inner heat insulating member 603A) of the fuel cell stack 100A, which tends to become hot. Therefore, according to the fuel cell stack 100A of the present embodiment, it is possible to suppress the variation in the temperature distribution in the plane of the single cell 110.

C. Third embodiment:
FIG. 9 is an explanatory view showing an XZ cross-sectional configuration of the fuel cell stack 100B in the third embodiment, and FIG. 10 is an XY cross-sectional view showing a detailed configuration of the heat insulating member 60B in the third embodiment. FIG. 10 shows the XY cross-sectional configuration of the fuel cell stack 100B at the position XX of FIG. As in FIGS. 6 and 8, in FIG. 10, for convenience of explanation, each communication hole 108 and a gas chamber hole (air chamber hole 131) formed in the air electrode side frame 130 and the fuel electrode side frame 140 are shown. The holes for the fuel chamber 141) are shown by dotted lines, but in the actual configuration, the communication holes 108 are not formed in the heat insulating member 60B and the heat transfer member 63.

As shown in FIG. 9, the fuel cell stack 100B of the third embodiment is different from the configuration of the fuel cell stack 100A of the second embodiment described above in that the heat insulating member 60B is provided instead of the heat insulating member 60A. In the following, among the configurations of the fuel cell stack 100B of the third embodiment, the same configurations as the configurations of the fuel cell stacks 100 and 100A of the above-described embodiment will be appropriately described by adding the same reference numerals. ..

The heat insulating member 60B of the present embodiment is arranged in contact with the surface S63 of the heat transfer member 63, similarly to the heat insulating members 60 and 60A of the above-described embodiment. The heat insulating member 60B of the present embodiment is composed of a separate member of the outer heat insulating member 601B and the inner heat insulating member 603B. In the present embodiment, the outer heat insulating member 601B has the same configuration as the heat insulating member 60 of the first embodiment and the outer heat insulating member 601A of the second embodiment. That is, the outer heat insulating member 601B is a frame-shaped member in which a hole 61B having a substantially rectangular shape (in this embodiment, a substantially square shape in the Z-axis direction) is formed, and is formed of, for example, a silica-based material. The thickness H (plate thickness) of the outer heat insulating member 601B is, for example, 3 mm or more and 25 mm or less (see FIG. 9). The thermal conductivity of the outer heat insulating member 601B is, for example, 0.01 W / m · K or more and 0.6 W / m · K or less at 600 ° C. The outer heat insulating member 601B is arranged so as to overlap the outer portion OP in the Z-axis direction view. More specifically, in the present embodiment, the outer heat insulating member 601B is arranged so as to overlap each frame portion in the air pole side frame 130 and the fuel pole side frame 140 in the Z-axis direction view. The outer heat insulating member 601B corresponds to the first heat insulating member in the claims, and the inner heat insulating member 603B corresponds to the second heat insulating member in the claims.

The inner heat insulating member 603B is a flat plate-shaped member having a substantially rectangular shape (in this embodiment, a substantially square shape in the Z-axis direction), and is formed of, for example, a silica-based material. The thickness H (plate thickness) of the inner heat insulating member 603B in the Z-axis direction is equivalent to the thickness H of the outer heat insulating member 601B (see FIG. 7). The thermal conductivity of the inner heat insulating member 603B is, for example, 0.1 W / m · K or more and 1.5 W / m · K or less at 600 ° C. The inner heat insulating member 603B is arranged so as to overlap the inner portion IP in the Z-axis direction view. More specifically, in the present embodiment, the inner heat insulating member 603B overlaps the portion where the electrolyte layer 112, the air electrode 114, and the fuel electrode 116 overlap in the portion where the single cell 110 is located in the Z-axis direction. It is arranged like this. In the present embodiment, the inner heat insulating member 603B is configured such that the outer edge 603e is in contact with the outer edge defining the hole 61B of the outer heat insulating member 601B.

As described above, in the fuel cell stack 100B of the present embodiment, the thermal conductivity of the outer heat insulating member 601B is smaller than the thermal conductivity of the inner heat insulating member 603B. More specifically, the ratio of the value of the thermal conductivity of the inner heat insulating member 603B to the value of the thermal conductivity of the outer heat insulating member 601B ((the thermal conductivity value of the inner heat insulating member 603B / the thermal conductivity of the outer heat insulating member 601B). Value) × 100) is 101% or more, preferably 150% or more.

The fuel cell stack 100B of the present embodiment includes a power generation block 103 and a pair of end plates 104 and 106. Further, the surface S104 of the upper end plate 104 is further provided with a heat insulating member 60B composed of an outer heat insulating member 601B and an inner heat insulating member 603B. In the Z-axis direction view, the outer heat insulating member 601B is arranged in the outer portion OP in the fuel cell stack 100A, and the inner heat insulating member 603B is arranged in the inner portion IP. The thermal conductivity of the outer heat insulating member 601B is smaller than that of the inner heat insulating member 603B. In other words, for example, in a configuration in which the thickness H of the outer heat insulating member 601B and the thickness H of the inner heat insulating member 603B are equal to each other, or the thickness H of the outer heat insulating member 601B is larger than the thickness H of the inner heat insulating member 603B. The heat insulating performance of the outer heat insulating member 601B is higher than that of the inner heat insulating member 603B. Therefore, in the Z-axis direction, the fuel cell stack 100B, which tends to have a relatively low temperature, is relatively low in heat while suppressing heat dissipation from the portion close to the manifolds 161, 162, 171 and 172 (the portion overlapping the outer heat insulating member 601B). It is possible to easily dissipate heat from the central portion (the portion overlapping the inner heat insulating member 603B) of the fuel cell stack 100B, which tends to become hot. Therefore, according to the fuel cell stack 100B of the present embodiment, it is possible to suppress the variation in the temperature distribution in the plane of the single cell 110.

In the third embodiment, the thermal conductivity of the outer heat insulating member 601B and the thermal conductivity of the inner heat insulating member 603B are different from each other, or together with the density of the outer heat insulating member 601B and the inner heat insulating member 603B. A configuration with a different density can be adopted. More specifically, the density of the outer heat insulating member 601B can be larger than the density of the inner heat insulating member 603B. In such a configuration, the density of the outer heat insulating member 601B is, for example, 1 g / cm ³ or more and 3 g / cm ³ or less, and the density of the inner heat insulating member 603B is, for example, 0.15 g / cm ³ or more and 2 g / cm. It is cm ³ or less. More specifically, the ratio of the density value of the outer heat insulating member 601B to the density value of the inner heat insulating member 603B ((density value of the outer heat insulating member 601B / density value of the inner heat insulating member 603B) × 100) is 101. % Or more, preferably 150% or more.

In the above configuration, the density of the outer heat insulating member 601B is higher than the density of the inner heat insulating member 603B. In other words, for example, in a configuration in which the thickness H of the outer heat insulating member 601B and the thickness H of the inner heat insulating member 603B are equivalent, the heat insulating performance of the outer heat insulating member 601B is compared with the heat insulating performance of the inner heat insulating member 603B. expensive. Therefore, in the Z-axis direction, the fuel cell stack 100B, which tends to have a relatively low temperature, is relatively low in heat while suppressing heat dissipation from the portion close to the manifolds 161, 162, 171 and 172 (the portion overlapping the outer heat insulating member 601B). It is possible to easily dissipate heat from the central portion (the portion overlapping the inner heat insulating member 603B) of the fuel cell stack 100, which tends to become hot. Therefore, according to the fuel cell stack 100B of the present embodiment, it is possible to suppress the variation in the temperature distribution in the plane of the single cell 110.

D. Modification example:
The technique disclosed in the present specification is not limited to the above-described embodiment, and can be transformed into various forms without departing from the gist thereof, and for example, the following modifications are also possible.

D-1. First modification example:
FIG. 11 is an XY sectional view showing a detailed configuration of the heat insulating member 60C in the fuel cell stack 100C of the first modification. Note that, as in FIGS. 6, 8 and 10, in FIG. 11, for convenience of explanation, each communication hole 108 and a gas chamber hole (air chamber) formed in the air pole side frame 130 and the fuel pole side frame 140 are shown. The holes 131 and the holes 141) for the fuel chamber are shown by dotted lines, but in the actual configuration, the communication holes 108 are not formed in the heat insulating member 60C and the heat transfer member 63.

As shown in FIG. 11, the fuel cell stack 100C of the present modification is different from the configuration of the fuel cell stack 100A of the second embodiment described above in that the heat insulating member 60C is provided instead of the heat insulating member 60A. In the following, among the configurations of the fuel cell stack 100C of the present modification, the same configurations as the configurations of the fuel cell stack 100A of the second embodiment described above will be appropriately omitted by adding the same reference numerals.

The heat insulating member 60C of this modification is arranged in contact with the surface S63 of the heat transfer member 63, similarly to the heat insulating members 60, 60A, 60B of the above-described embodiment. The heat insulating member 60C of this modification is composed of a separate member of the outer heat insulating member 601C and the inner heat insulating member 603C. In this modification, the outer heat insulating member 601C has the same configuration as the outer heat insulating member 601A of the second embodiment except for the shape of the hole 61C. That is, the outer heat insulating member 601C is formed of, for example, a silica-based material. The thickness (plate thickness) of the outer heat insulating member 601C is, for example, 3 mm or more and 25 mm or less. The outer heat insulating member 601C is arranged so as to overlap the outer portion OP in the Z-axis direction view. More specifically, in the present modification, the outer heat insulating member 601C is arranged so as to overlap each frame portion in the air pole side frame 130 and the fuel pole side frame 140 in the Z-axis direction view. The outer heat insulating member 601C corresponds to the first heat insulating member in the claims, and the inner heat insulating member 603C corresponds to the second heat insulating member in the claims.

In this modification, the shape of the hole 61C of the outer heat insulating member 601C is substantially rectangular in the Z-axis direction. More specifically, the hole 61C has a width W1 of the outer heat insulating member 601C in the portion where each communication hole 108 (for example, the oxidant gas discharge manifold 162 and the fuel gas introduction manifold 171) is arranged in the Z-axis direction. , The width W2 of the outer heat insulating member 601C in the portion where the communication hole 108 is not arranged is formed to be larger than the width W2. The width W1 of the outer heat insulating member 601C is, for example, 10 mm or more and 50 mm or less, and the width W2 is, for example, 5 mm or more and 40 mm or less.

In the above, the width W1 is the shortest distance between the first partial outer edge Po1 constituting a part of the first side S1 and the first partial inner edge Pi1 facing the first partial outer edge Po1. Further, the width W2 is the shortest distance between the second partial outer edge Po2 forming a part of the second side S2 and the second partial inner edge Pi2 facing the second partial outer edge Po2. The first side S1 and the second side S2 (and the sides S3 and S4) are each side constituting the outer edge 601e of the outer heat insulating member 601C, respectively. The first side S1 is the side closest to both the oxidant gas discharge manifold 162 and the fuel gas introduction manifold 171 among the four sides constituting the outer edge 601e, and the second side S2 is This is the side connected to the first side S1. Further, the first partial inner edge Pi1 and the second partial inner edge Pi2 each form a part of the outer edge defining the hole 61C. The oxidant gas discharge manifold 162 corresponds to the hole for the manifold for the specific air chamber in the claims, and the fuel gas introduction manifold 171 corresponds to the hole for the manifold for the specific fuel chamber in the claims. The width W1 corresponds to the first width in the claims, and the width W2 corresponds to the second width in the claims.

The inner heat insulating member 603C has the same configuration as the inner heat insulating member 603A of the second embodiment except that the shape in the Z-axis direction is substantially rectangular. That is, the inner heat insulating member 603C is formed of, for example, a silica-based material. The thickness (plate thickness) of the inner heat insulating member 603C in the Z-axis direction is, for example, 1 mm or more and 25 mm or less. The inner heat insulating member 603C is arranged so as to overlap the inner portion IP in the Z-axis direction view. More specifically, in this modification, the inner heat insulating member 603C overlaps the portion where the electrolyte layer 112, the air electrode 114, and the fuel electrode 116 overlap in the portion where the single cell 110 is located in the Z-axis direction. It is arranged like this. In this modification, the inner heat insulating member 603C is configured such that the outer edge 603e is in contact with the outer edge defining the hole 61C of the outer heat insulating member 601C.

In the above configuration, the width W1 in the outer heat insulating member 601C is larger than the width W2. Therefore, in the Z-axis direction view, the heat insulating performance in the portion close to the manifolds 161, 162, 171 and 172 in the fuel cell stack 100C, which tends to be relatively low temperature, is more effectively improved, and the manifolds 161, 162, 171 and 172 are used. It is possible to suppress heat dissipation from a close portion more effectively. Therefore, according to the fuel cell stack 100C of this modification, it is possible to more effectively suppress the variation in the temperature distribution in the plane of the single cell 110.

D-2. Second modification example:
FIG. 12 is an XY sectional view showing a detailed configuration of the heat insulating member 60D in the fuel cell stack 100D of the second modification. Note that, as in FIGS. 6, 8 and 10, in FIG. 12, for convenience of explanation, each communication hole 108 and a gas chamber hole (air chamber) formed in the air pole side frame 130 and the fuel pole side frame 140 are shown. The holes 131 and the holes 141) for the fuel chamber are shown by dotted lines, but in the actual configuration, the communication holes 108 are not formed in the heat insulating member 60D and the heat transfer member 63.

As shown in FIG. 12, the fuel cell stack 100D of the second modification is different from the configuration of the fuel cell stack 100A of the second embodiment described above in that the heat insulating member 60D is provided in place of the heat insulating member 60A. In the following, among the configurations of the fuel cell stack 100D of the present modification, the same configurations as the configurations of the fuel cell stack 100A of the second embodiment described above will be appropriately omitted by adding the same reference numerals.

The heat insulating member 60D of this modification is arranged in contact with the surface S63 of the heat transfer member 63, similarly to the heat insulating members 60, 60A, 60B, 60C of the above-described embodiment. The heat insulating member 60D of this modification is composed of a separate member of the outer heat insulating member 601D and the inner heat insulating member 603D. In this modification, the outer heat insulating member 601D has the same configuration as the outer heat insulating member 601A of the second embodiment. That is, the outer heat insulating member 601D is formed of, for example, a silica-based material. The thickness (plate thickness) of the outer heat insulating member 601D is, for example, 3 mm or more and 25 mm or less. The outer heat insulating member 601D is arranged so as to overlap the outer portion OP in the Z-axis direction view. More specifically, in the present modification, the outer heat insulating member 601D is arranged so as to overlap each frame portion in the air pole side frame 130 and the fuel pole side frame 140 in the Z-axis direction view. The outer heat insulating member 601D corresponds to the first heat insulating member in the claims, and the inner heat insulating member 603D corresponds to the second heat insulating member in the claims.

The inner heat insulating member 603D is a substantially rectangular (in this embodiment, a substantially square in the Z-axis direction view) flat plate-shaped member in which a plurality of through holes 603H penetrating in the Z-axis direction are formed, and is, for example, a silica-based member. It is made of material. The thickness (plate thickness) of the inner heat insulating member 603D in the Z-axis direction is equivalent to the thickness of the outer heat insulating member 601D. The inner heat insulating member 603B is arranged so as to overlap the inner portion IP in the Z-axis direction view. More specifically, in the present embodiment, the inner heat insulating member 603D overlaps the portion where the electrolyte layer 112, the air electrode 114, and the fuel electrode 116 overlap in the portion where the single cell 110 is located in the Z-axis direction. It is arranged like this. In this modification, the inner heat insulating member 603D is configured such that the outer edge 603e is in contact with the outer edge defining the hole 61D of the outer heat insulating member 601D.

As described above, in the fuel cell stack 100D of this modification, a plurality of through holes 603H are formed in the inner heat insulating member 603D. In other words, the through hole 603H is open to both the upper surface and the lower surface of the inner heat insulating member 603D which are substantially orthogonal to the Z-axis direction. The number of through holes 603H is, for example, 1 or more and 50 or less. The diameter of the through hole 603H is 2 mm or more and 80 mm or less. Since the through hole 603H is formed in the inner heat insulating member 603D of this modification, the heat insulating material filling rate per unit volume in the inner heat insulating member 603D is the same as the heat insulating material filling rate per unit volume in the outer heat insulating member 601D. Compared to low. For example, the heat insulating material filling rate of the inner heat insulating member 603D is, for example, 5% or more and 90% or less. Further, the ratio of the value of the heat insulating material filling rate of the inner heat insulating member 603D to the value of the heat insulating material filling rate of the outer heat insulating member 601D ((the heat insulating material filling rate value of the inner heat insulating member 603D / the heat insulating material of the outer heat insulating member 601D). The material filling rate value) × 100) is 5% or more, preferably 10% or more.

In the above configuration, as described above, since the inner heat insulating member 603D has the through hole 603H, the heat insulating material filling rate in the inner heat insulating member 603D is lower than the heat insulating material filling rate in the outer heat insulating member 601D. .. Therefore, in the Z-axis direction, the fuel cell stack 100D, which tends to have a relatively low temperature, is relatively low in heat while suppressing heat dissipation from the portion close to the manifolds 161, 162, 171 and 172 (the portion overlapping the outer heat insulating member 601D). It is possible to easily dissipate heat from the central portion (the portion overlapping the inner heat insulating member 603D) of the fuel cell stack 100D, which tends to be hot. Therefore, according to the fuel cell stack 100D of the present modification, it is possible to suppress the variation in the temperature distribution in the plane of the single cell 110, and eventually to suppress the deterioration of the single cell 110 and the deterioration of the power generation efficiency of the single cell 110. Can be done.

D-3. Other variants:
In the above embodiment and the first modification, the heat insulating member 60 and the outer heat insulating members 601A, 601B, 601C, and 601D are provided on the surface S104 of the upper end plate 104, but the present invention is not limited thereto. For example, instead of, or in combination with this, the heat insulating member 60 and the outer heat insulating members 601A, 601B, 601C, 601D may be provided on the lower surface of the lower end plate 106. In the first modification, the inner heat insulating member 603C may be omitted.

In the above-described embodiment and modification, the heat insulating member 60 and the outer heat insulating members 601A, 601B, 601C, and 601D do not have to be configured to completely surround the inner partial IP. For example, a slit may be formed in the width direction (for example, the direction of the width W1) of the outer heat insulating member 601C or the like. Further, the heat transfer member 63 in the outer portion OP may be exposed because a part of the outer heat insulating member 601C or the like is partially missing. Similarly to this, the heat transfer member 63 in the inner portion IP may be exposed by partially missing the outer heat insulating member 601C or the like.

In the above-described embodiment and modification, the size and shape of the heat insulating member 60 and the holes 61, 61A, 61B, 61C, 61D formed in the outer heat insulating members 601A, 601B, 601C, 601D are not particularly limited. For example, the shape of the hole 61 of the heat insulating member 60 may be substantially rectangular in the Z-axis direction. Further, the shape of the hole 61C of the outer heat insulating member 601C may be substantially square in the Z-axis direction. In such a configuration, the outer heat insulating member 601C (and thus the fuel cell stack 100C) has a substantially rectangular shape in which the length of the first side S1 is shorter than the length of the second side S2 in the Z-axis direction. .. Further, for example, in the Z-axis direction view, the inner edge of the hole 61 of the heat insulating member 60 may be located inside (center PO side) from the inner edge of the hole 121 of the separator 120, or may be located outside. May be good. As another example, in the Z-axis direction view, the inner edge of the hole 61 of the heat insulating member 60 overlaps the inner edge of the air chamber hole 131 or the fuel chamber hole 141 of the air pole side frame 130 or the fuel pole side frame 140. May be good. Further, the heat insulating member 60 does not have to overlap at least one of the air pole side frame 130 and the fuel pole side frame 140. The same applies to the outer heat insulating members 601A, 601B, 601C, and 601D.

In the above-described embodiment and modification, for example, the fuel cell stack 100 may be configured not to include the heat transfer member 63.

In the second modification, the number and diameter of the through holes 603H are not particularly limited. Further, a bottomed hole may be formed in place of the through hole 603H or together with the through hole 603H. The bottomed hole may be opened on either the upper surface or the lower surface of the inner heat insulating member 603D, but it is preferable that the bottomed hole is opened on the upper surface. In other words, from the viewpoint that heat can be easily dissipated from the heat transfer member 63 to the inner heat transfer member 603D, it is preferable that the contact area between the lower surface of the inner heat transfer member 603D and the surface S63 of the heat transfer member 63 is large.

In the second embodiment, the outer heat insulating member 601A and the inner heat insulating member 603A constituting the heat insulating member 60A may be integrally formed. Similarly, in the third embodiment and the modified example, the outer heat insulating member and the inner heat insulating member constituting the heat insulating member may be integrally formed.

In the second embodiment, the inner heat insulating member 603A does not have to have the outer edge 603e in contact with the outer edge defining the hole 61A of the outer heat insulating member 601A. Similarly, in the third embodiment and the modification, the outer edge of the inner heat insulating member may not be in contact with the outer edge defining the hole of the outer heat insulating member.

In the above embodiment and the modification, at least one of the air chamber hole 131, the oxidant gas supply communication flow path 132, and the oxidant gas discharge communication flow path 133 is not formed in the air electrode side frame 130. You may. Similarly, the fuel electrode side frame 140 may not have at least one of the fuel chamber hole 141, the fuel gas supply communication flow path 142, and the fuel gas discharge communication flow path 143.

The materials constituting each member in the above-described embodiment and modification are merely examples, and each member may be composed of another material. For example, the heat insulating members 60, 60A, 60B, 60C may be formed of a material other than the silica-based material. Further, the materials for forming the outer heat insulating members 601A, 601B and 601C are as long as the outer heat insulating members 601A, 601B and 601C have higher heat insulating properties than the inner heat insulating members 603A, 603B and 603C, respectively. , 603B, 603C may be the same as or different from the forming material.

Further, in the above-described embodiment and modification, the bolt hole 109 is provided independently of the communication hole 108 for each manifold, but the independent bolt hole 109 is not provided, and the communication hole 108 for each manifold is provided. It may also be used as a bolt hole. Further, in the above-described embodiment and modification, a counterflow type in which the main flow direction of the oxidant gas OG in the air chamber 166 and the main flow direction of the fuel gas FG in the fuel chamber 176 are substantially opposite to each other will be described as an example. However, the present invention is also applicable to other types (such as a coflow type in which the two flow directions are substantially the same, a cross flow type in which the two flow directions intersect, and the like).

In the above embodiment, the SOFC that generates power by utilizing the electrochemical reaction between hydrogen contained in the fuel gas and oxygen contained in the oxidizing agent gas is targeted, but the present invention utilizes the electrolysis reaction of water. It is also applicable to an electrolytic single cell, which is a constituent unit of a solid oxide type electrolytic cell (SOEC) that produces hydrogen, and an electrolytic cell stack including a plurality of electrolytic single cells. The configuration of the electrolytic cell stack is not described in detail here because it is known, for example, as described in Japanese Patent Application Laid-Open No. 2016-81813, but is schematically the same as the fuel cell stack 100 in the above-described embodiment. It is the composition of. That is, the fuel cell stack 100 in the above-described embodiment may be read as an electrolytic cell stack, the power generation unit 102 may be read as an electrolytic cell unit, and the single cell 110 may be read as an electrolytic cell. However, during the operation of the electrolytic cell stack, a voltage is applied between both electrodes so that the air electrode 114 is positive (anode) and the fuel electrode 116 is negative (cathode), and the voltage is applied through the communication hole 108. Steam as a raw material gas is supplied. As a result, an electrolysis reaction of water occurs in each electrolytic cell, hydrogen gas is generated in the fuel chamber 176, and hydrogen is taken out to the outside of the electrolytic cell stack through the communication hole 108. The above effect can be obtained by applying the present invention even in an electrolytic single cell having such a configuration.

Further, in the above embodiment, the solid oxide fuel cell (SOFC) has been described as an example, but the technique disclosed in the present specification is another type of fuel cell (MCFC) such as a molten carbonate fuel cell (MCFC). Alternatively, it can also be applied to electrolytic cells).

22: Bolt 24: Head 26: Insulation sheet 27: Gas passage member 28: Main body 29: Branch 60, 60A, 60B, 60C, 60D: Insulation member 61, 61A, 61B, 61C, 61D: Hole 63: Transmission Thermal members 100, 100A, 100B, 100C, 100D: Fuel cell stack 102: Power generation unit 103: Power generation block 104, 106: End plate 107: Through hole for flow path 108: Communication hole 109: Bolt hole 110: Single cell 112: Electrolyte layer 114: Air pole 116: Fuel pole 120: Separator 121: Hole 124: Joint 130: Air pole side frame 131: Air chamber hole 132: Oxidating agent gas supply communication flow path 133: Oxidating agent gas discharge communication flow path 134: Air pole side current collecting member 135: Current collecting member element 140: Fuel pole side frame 141: Fuel chamber hole 142: Fuel gas supply communication flow path 143: Fuel gas discharge communication flow path 144: Fuel pole side current collecting member 145: Electrode facing part 146: Interconnector facing part 149: Spacer 150: Interconnector 161: Oxidating agent gas introduction manifold 162: Oxidizing agent gas discharge manifold 166: Air chamber 171: Fuel gas introduction manifold 172: Fuel gas discharge manifold 176: Fuel chamber 410, 420: Terminal plate 510, 520: Insulation sheet 601A, 601B, 601C, 601D: Outer heat insulating member 601e: Outer edge 603A, 603B, 603C, 603D: Inner heat insulating member 603H: Through hole 603e: Outer edge FG: Fuel gas FOG: Fuel off gas IP: Inner part OG: Oxidating agent gas OOG: Oxidating agent off gas OP: Outer part S104: Surface S63: Surface

Claims (9)

It is an electrochemical reaction block composed of a plurality of electrochemical reaction units arranged side by side in the first direction, and each of the electrochemical reaction units sandwiches an electrolyte layer and the electrolyte layer in the first direction. An electrochemical reaction single cell including an air electrode and a fuel electrode facing each other, and a frame portion surrounding a region where the electrolyte layer, the air electrode, and the fuel electrode overlap each other in the first directional view. A manifold hole that constitutes a manifold that is a gas flow member and has a manifold that is supplied to or discharged from a gas chamber facing a specific electrode at least one of the air electrode and the fuel electrode. An electrochemical reaction block having a gas flow member formed in a frame portion,
A pair of end members facing each other in the first direction with the electrochemical reaction block interposed therebetween, and a pair of end members arranged so that at least a part thereof overlaps the frame portion in the first direction view. When,
In an electrochemical reaction cell stack equipped with
In the first direction, it is arranged on the specific surface side of the surface of the specific end member which is at least one of the pair of end members, which is the surface opposite to the electrochemical reaction block, and has heat insulating properties. With a first insulating member, which has
The first heat insulating member is located outside the inner portion of the electrochemical reaction cell stack including the center of the electrochemical reaction cell stack in the first directional view.
The inner portion adjacent to the first heat insulating member is hollow.
It is characterized by an electrochemical reaction cell stack. It is an electrochemical reaction block composed of a plurality of electrochemical reaction units arranged side by side in the first direction, and each of the electrochemical reaction units sandwiches an electrolyte layer and the electrolyte layer in the first direction. The electrochemical reaction single cell including the air electrode and the fuel electrode facing each other and the region in which the electrolyte layer, the air electrode, and the fuel electrode overlap each other in the first directional view are arranged so as to surround the region. A manifold that is a gas flow member having a frame portion and constitutes a manifold through which gas supplied to or discharged from the gas chamber is supplied to or discharged from the gas chamber facing a specific electrode at least one of the air electrode and the fuel electrode. An electrochemical reaction block comprising a gas flow member having a hole formed in the frame portion.
A pair of end members facing each other in the first direction with the electrochemical reaction block interposed therebetween, and a pair of end members arranged so that at least a part thereof overlaps the frame portion in the first direction view. When,
In an electrochemical reaction cell stack equipped with
In the first direction, it is arranged on the specific surface side of the surface of the specific end member which is at least one of the pair of end members, which is the surface opposite to the electrochemical reaction block, and is the first. The first heat insulating member, which is a first heat insulating member located outside the inner portion including the center of the electrochemical reaction cell stack and has heat insulating properties, and the first heat insulating member having heat insulating properties.
A second heat insulating member, which is arranged on the specific surface side and is located in the inner portion, and has a heat insulating property, is provided.
The thickness of the first heat insulating member is larger than the thickness of the second heat insulating member.
It is characterized by an electrochemical reaction cell stack. It is an electrochemical reaction block composed of a plurality of electrochemical reaction units arranged side by side in the first direction, and each of the electrochemical reaction units sandwiches an electrolyte layer and the electrolyte layer in the first direction. The electrochemical reaction single cell including the air electrode and the fuel electrode facing each other and the region in which the electrolyte layer, the air electrode, and the fuel electrode overlap each other in the first directional view are arranged so as to surround the region. A manifold that is a gas flow member having a frame portion and constitutes a manifold through which gas supplied to or discharged from the gas chamber is supplied to or discharged from the gas chamber facing a specific electrode at least one of the air electrode and the fuel electrode. An electrochemical reaction block comprising a gas flow member having a hole formed in the frame portion.
A pair of end members facing each other in the first direction with the electrochemical reaction block interposed therebetween, and a pair of end members arranged so that at least a part thereof overlaps the frame portion in the first direction view. When,
In an electrochemical reaction cell stack equipped with
In the first direction, it is arranged on the specific surface side of the surface of the specific end member which is at least one of the pair of end members, which is the surface opposite to the electrochemical reaction block, and is the first. The first heat insulating member, which is a first heat insulating member located outside the inner portion including the center of the electrochemical reaction cell stack and has heat insulating properties, and the first heat insulating member having heat insulating properties.
A second heat insulating member, which is arranged on the specific surface side and is located in the inner portion, and has a heat insulating property, is provided.
The thermal conductivity of the first heat insulating member is smaller than that of the second heat insulating member.
It is characterized by an electrochemical reaction cell stack. It is an electrochemical reaction block composed of a plurality of electrochemical reaction units arranged side by side in the first direction, and each of the electrochemical reaction units sandwiches an electrolyte layer and the electrolyte layer in the first direction. The electrochemical reaction single cell including the air electrode and the fuel electrode facing each other and the region in which the electrolyte layer, the air electrode, and the fuel electrode overlap each other in the first directional view are arranged so as to surround the region. A manifold that is a gas flow member having a frame portion and constitutes a manifold through which gas supplied to or discharged from the gas chamber is supplied to or discharged from the gas chamber facing a specific electrode at least one of the air electrode and the fuel electrode. An electrochemical reaction block comprising a gas flow member having a hole formed in the frame portion.
A pair of end members facing each other in the first direction with the electrochemical reaction block interposed therebetween, and a pair of end members arranged so that at least a part thereof overlaps the frame portion in the first direction view. When,
In an electrochemical reaction cell stack equipped with
In the first direction, it is arranged on the specific surface side of the surface of the specific end member which is at least one of the pair of end members, which is the surface opposite to the electrochemical reaction block, and is the first. The first heat insulating member, which is a first heat insulating member located outside the inner portion including the center of the electrochemical reaction cell stack and has heat insulating properties, and the first heat insulating member having heat insulating properties.
A second heat insulating member, which is arranged on the specific surface side and is located in the inner portion, and has a heat insulating property, is provided.
The density of the first heat insulating member is higher than the density of the second heat insulating member.
It is characterized by an electrochemical reaction cell stack. It is an electrochemical reaction block composed of a plurality of electrochemical reaction units arranged side by side in the first direction, and each of the electrochemical reaction units sandwiches an electrolyte layer and the electrolyte layer in the first direction. The electrochemical reaction single cell including the air electrode and the fuel electrode facing each other and the region in which the electrolyte layer, the air electrode, and the fuel electrode overlap each other in the first directional view are arranged so as to surround the region. A manifold that is a gas flow member having a frame portion and constitutes a manifold through which gas supplied to or discharged from the gas chamber is supplied to or discharged from the gas chamber facing a specific electrode at least one of the air electrode and the fuel electrode. An electrochemical reaction block comprising a gas flow member having a hole formed in the frame portion.
A pair of end members facing each other in the first direction with the electrochemical reaction block interposed therebetween, and a pair of end members arranged so that at least a part thereof overlaps the frame portion in the first direction view. When,
In an electrochemical reaction cell stack equipped with
In the first direction, it is arranged on the specific surface side of the surface of the specific end member which is at least one of the pair of end members, which is the surface opposite to the electrochemical reaction block, and is the first. The first heat insulating member, which is a first heat insulating member located outside the inner portion including the center of the electrochemical reaction cell stack and has heat insulating properties, and the first heat insulating member having heat insulating properties.
A second heat insulating member, which is arranged on the specific surface side and is located in the inner portion, and has a heat insulating property, is provided.
The second heat insulating member includes at least one of a first surface of the second heat insulating member that is substantially orthogonal to the first direction and a second surface opposite to the first surface. At least one of an opening through hole and a bottomed hole is formed,
It is characterized by an electrochemical reaction cell stack. In the electrochemical reaction cell stack according to any one of claims 1 to 5.
In the first directional view, the first heat insulating member is arranged so as to surround the inner portion.
It is characterized by an electrochemical reaction cell stack. In the electrochemical reaction cell stack according to any one of claims 1 to 6.
In the first directional view, at least a part of the first heat insulating member overlaps with the frame part.
It is characterized by an electrochemical reaction cell stack. In the electrochemical reaction cell stack according to any one of claims 1 to 7.
In the frame portion, as the manifold hole,
In the first directional view, two air chamber manifold holes located on the first side and the second side facing each other across the electrochemical reaction single cell, respectively, and the air electrode. Two air chamber manifold holes through which gas supplied to or discharged from the air chamber facing the air chamber passes.
In the first direction view, two fuel chamber manifold holes located on the first side and the second side, respectively, which are supplied to or said to the fuel chamber facing the fuel electrode. It has two fuel chamber manifold holes through which the gas discharged from the fuel chamber passes.
In the first directional view, the first heat insulating member has a substantially rectangular outer edge having four sides.
Of the four sides constituting the outer edge of the first heat insulating member, the hole for the manifold for the specific air chamber located on the first side of the holes for the manifold for the two air chambers, and the two fuels. The side closest to both the hole for the manifold for the specific fuel chamber located on the first side of the hole for the chamber manifold is set as the first side.
The side connected to the first side of the outer edge of the first heat insulating member is defined as the second side.
The first width is the shortest distance between the first partial outer edge constituting a part of the first side and the first partial inner edge of the first heat insulating member facing the first partial outer edge. year,
The shortest distance between the second partial outer edge constituting a part of the second side and the second partial inner edge of the first heat insulating member facing the second partial outer edge is the second width. When
The first width is larger than the second width.
It is characterized by an electrochemical reaction cell stack. The electrochemical reaction cell stack according to any one of claims 1 to 8.
A heat transfer member arranged on the specific surface and in a region overlapping at least in the center of the electrochemical reaction cell stack in the first directional view, which has a higher thermal conductivity than the specific end member. A heat transfer member having a thermal conductivity, provided
It is characterized by an electrochemical reaction cell stack.

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