JP6959040B2 - How to manufacture stack plates, electrochemical reaction cell stacks, and electrochemical reaction cell stacks - Google Patents

Description

The technique disclosed herein relates to a stacking plate provided in an electrochemical reaction cell stack.

A solid oxide fuel cell (hereinafter referred to as "SOFC") having an electrolyte layer containing a solid oxide is known as one of the types of fuel cells that generate power by utilizing an electrochemical reaction between hydrogen and oxygen. Has been done. SOFC generally refers to a plurality of fuel cell power generation units (hereinafter, simply referred to as “power generation units”) arranged side by side in a predetermined direction (hereinafter, also referred to as “arrangement direction”) and the plurality of fuel cell power generation units. It is used in the form of a fuel cell stack including a flat plate-shaped stacking plate (for example, an end plate) arranged on one side in the arrangement direction. The power generation unit is the smallest unit of SOFC power generation, and includes an electrolyte layer and an air electrode and a fuel electrode that face each other with the electrolyte layer in between.

In a conventional fuel cell, the outer peripheral line of the stack plate in the arrangement direction is substantially rectangular (see Patent Documents 1 to 4 below).

JP-A-2007-179935 Japanese Unexamined Patent Publication No. 2008-159291 Japanese Unexamined Patent Publication No. 2015-165488 Japanese Unexamined Patent Publication No. 2015-149265

In such a fuel cell stack, it is preferable to accurately arrange the stack plate at a predetermined position. This is because if the stack plate is displaced from the predetermined position, the stack plate and other components of the fuel cell stack may interfere with each other. Further, when the stack plate is formed with a through hole forming a bolt hole for inserting a bolt for fastening the fuel cell stack, if the stack plate is displaced from a predetermined position, it may be arranged. It may be difficult to insert the bolt into the bolt hole. Further, when the stack plate is formed with gas holes forming a gas path (manifold) formed in the fuel cell stack, when the stack plate is displaced from a predetermined position, the inside of the gas path is formed. There is a risk of loss of pressure in the gas flowing through.

By the way, in recent years, there has been a demand for weight reduction of fuel cells. For example, a method of reducing the weight of the fuel cell by removing a part of a substantially rectangular stacking plate can be considered. However, depending on the part to be removed, the part for positioning on the changed stack plate may not be in an appropriate position, and in the end, the stack plate may not be accurately placed in a predetermined position on the fuel cell stack. be.

It should be noted that such a problem is also a common problem for the fuel cell stack after production. It is also a common problem for electrolytic cell stacks, which are a form of solid oxide-type electrolytic cells (hereinafter referred to as "SOEC") that generate hydrogen by utilizing the electrolysis reaction of water. In the present specification, the fuel cell stack and the electrolytic cell stack are collectively referred to as an "electrochemical reaction cell stack".

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

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

(1) The stacking plate disclosed in the present specification includes an electrochemical reaction single cell having a solid electrolyte layer and an air electrode and a fuel electrode facing each other in a first direction across the solid electrolyte layer. A flat plate-shaped stacking plate arranged on at least one side in the first direction with respect to the plurality of electrochemical reaction single cells in a plurality of electrochemical reaction cell stacks arranged side by side in the first direction. In a stacking plate having through holes forming a gas flow path formed in the electrochemical reaction cell stack, the outer peripheral line of the stacking plate in the first direction is the minimum inscribed by the outer peripheral line. The virtual rectangle is parallel to the first virtual side of the virtual rectangle and is located between a plurality of first reference sides located on the first virtual side and the first reference sides. A recess recessed on the side of the second virtual side facing the first virtual side, and one or a plurality of second portions parallel to the second virtual side and located on the second virtual side. The through hole is formed in at least one of a plurality of edge portions facing each of the plurality of first reference sides at the peripheral edge of the stacking plate. The total length of the second reference side is shorter than the total length of the plurality of first reference sides. The outer peripheral line of the stacking plate has a plurality of first reference sides and a second reference side located on the opposite side thereof. Therefore, for example, when assembling an electrochemical reaction cell stack using a stack plate, a plurality of portions of the stack plate corresponding to the first reference side are brought into contact with a predetermined reference surface while being placed on the second reference side. By pressing the pressing member against the corresponding portion, the stacking plate can be accurately positioned at a predetermined position in the electrochemical reaction cell stack. Moreover, since the through hole forming the gas path is formed at the edge portion facing the first reference side, the through hole is accurately positioned at a predetermined position in the electrochemical reaction cell stack together with the stack plate. can do. Further, according to the stack plate, a recess is formed between the first reference sides, and the total length of at least one second reference side is the length of the plurality of first reference sides. By making it shorter than the total length, the weight is reduced by removing the meat. That is, according to the present stack plate, it is possible to improve the positioning accuracy of the stack plate in the electrochemical reaction cell stack and to reduce the weight of the stack plate at the same time.

(2) In the stacking plate, the total length of all the second reference sides may be a length of 50% or less of the length of the second virtual side. According to this stacking plate, the weight of the stacking plate can be reduced as compared with a configuration in which the total length of all the second reference sides is longer than 50% of the length of the second virtual side. can.

(3) In the stack plate, one end of the first reference side closest to one end of the first virtual side and the other first reference side closest to the other end of the first virtual side. The first distance between the ends is the one end of the second reference side closest to one end of the second virtual side and the second reference side closest to the other end of the second virtual side. It may be configured to be longer than the second distance from the other end of the. According to this stacking plate, the position of the first reference side with respect to the reference plane is stable as compared with the configuration in which the first distance is shorter than the second distance, so that the stacking plate is positioned in the electrochemical reaction cell stack. The accuracy can be further improved.

(4) In the stack plate, with one end of the second reference side closest to one end of the second virtual side in a directional view in which the first virtual side and the second virtual side face each other. The other end of the second reference side closest to the other end of the second virtual side is the one end of the first reference side closest to one end of the first virtual side and the said. It may be configured to be located between the other end of the first reference side closest to the other end of the first virtual side. According to this stack plate, one end of the second reference side closest to one end of the second virtual side and the second virtual side in the direction in which the first virtual side and the second virtual side face each other. At least one of the other ends of the second reference side closest to the other end of the side is the one end of the first reference side closest to one end of the first virtual side and the other end of the first virtual side. In the second direction, the outward force between one end of the first reference side and the other end of the first reference side is larger than that of a configuration that is not located between the other end of the first reference side that is close to the other. , It is possible to suppress a decrease in the accuracy of positioning the stack plate and the through hole with respect to the electrochemical reaction cell stack due to the fact that the second reference side is provided.

(5) In the stack plate, the total length of the plurality of first reference sides may be 10% or more of the length of the first virtual side. According to this stack plate, the first reference with respect to the reference plane is compared with the configuration in which the sum of the lengths of the plurality of first reference sides is less than 10% of the length of the first virtual side. Since the side positions are stable, the accuracy of positioning the stack plate and the through hole with respect to the electrochemical reaction cell stack can be further improved.

(6) In the stack plate, the outer peripheral line of the stack plate in the first directional view is further parallel to the third virtual side of the virtual rectangle and on the third virtual side. A plurality of third reference sides located in the above, and a recess located between the third reference sides and recessed on the side of the fourth virtual side facing the third virtual side in the virtual rectangle. It has one or more fourth reference sides parallel to the fourth virtual side and located on the fourth virtual side, and the plurality of third sides at the peripheral edge of the stacking plate. The through hole is formed in at least one of the plurality of edge portions facing the reference side, and the total length of all the fourth reference sides is the length of the plurality of third reference sides. The configuration may be shorter than the total of. According to this stack plate, it is possible to improve the positioning accuracy and reduce the weight of the electrochemical reaction cell stack in two directions orthogonal to each other.

(7) In the stacking plate, the total length of all the fourth reference sides may be a length of 50% or less of the length of the fourth virtual side. According to this stack plate, the weight of the stack plate is reduced as compared with the case where the total length of all the fourth reference sides is longer than 50% of the length of the fourth virtual side. Can be planned.

(8) In the stack plate, one end of the third reference side closest to one end of the third virtual side and the third reference side closest to the other end of the third virtual side. The third distance between the ends is the one end of the fourth reference side closest to one end of the fourth virtual side and the fourth reference side closest to the other end of the fourth virtual side. It may be configured to be longer than the fourth distance from the other end of the. According to this stacking plate, the position of the third reference side with respect to the reference plane is stable as compared with the configuration in which the third distance is shorter than the fourth distance, so that the stacking plate is positioned in the electrochemical reaction cell stack. The accuracy can be further improved.

(9) In the stack plate, one end of the first reference side closest to one end of the first virtual side and the other first reference side closest to the other end of the first virtual side. The first distance between the ends is 30% or more of the length of the first virtual side, and one end of the third reference side closest to one end of the third virtual side. The third distance between the third virtual side and the other end of the third reference side, which is the closest to the other end of the third virtual side, is 30% or more of the length of the third virtual side. A configuration that satisfies at least one of them may be used. According to the stack plate, the accuracy of positioning the stack plate and the through hole with respect to the electrochemical reaction cell stack can be further improved in at least one of the two directions orthogonal to each other.

(10) In the stacking plate, the through holes may be formed in each of the plurality of edge portions. According to this stack plate, each of the plurality of through holes can be accurately positioned at a predetermined position in the electrochemical reaction cell stack.

(11) In the stacking plate described above, in the directional view in which the first virtual side and the second virtual side face each other, the entire one through hole is the most of the one through hole. It may be configured to be located inside both ends of the specific reference side which is the first reference side located nearby. According to this stack plate, the accuracy of positioning the through hole with respect to the electrochemical reaction cell stack is further improved as compared with the configuration in which at least one of both ends of the through hole is located outside both ends of the first reference side. Can be made to.

(12) In the electrochemical reaction cell stack, the electrochemical reaction single cell having the solid electrolyte layer and the air electrode and the fuel electrode facing in the first direction across the solid electrolyte layer is in the first direction. A plurality of electrochemical reaction cell stacks arranged side by side may further have a stacking plate according to any one of claims 1 to 11. According to the present electrochemical reaction cell stack, since the above-mentioned stack plate is provided, it is possible to improve the positioning accuracy of the stack plate in the electrochemical reaction cell stack and to reduce the weight of the electrochemical reaction cell stack at the same time.

(13) The method for producing an electrochemical reaction cell stack disclosed in the present specification is an electrochemical reaction having a solid electrolyte layer and an air electrode and a fuel electrode facing each other in a first direction across the solid electrolyte layer. A plurality of single cells are arranged side by side in the first direction, and a flat plate-shaped stacking plate is arranged on at least one side of the plurality of electrochemical reaction single cells in the first direction. In the method for manufacturing a reaction cell stack, the outer peripheral line of the stack plate in the first directional view is parallel to the first virtual side of the smallest virtual rectangle inscribed by the outer peripheral line, and the first virtual side is parallel to the first virtual side. It is located between a plurality of first reference sides located on the virtual side and the first reference side, and is recessed on the side of the second virtual side facing the first virtual side in the virtual rectangle. The recess has one or a plurality of second reference sides parallel to the second virtual side and located on the second virtual side, and the plurality of the recesses are provided at the peripheral edge of the stacking plate. The through hole is formed in at least one of the plurality of edge portions facing each of the first reference sides of the first reference side, and the total length of all the second reference sides is the sum of the lengths of the plurality of first reference sides. An arrangement step of forming an array in which the plurality of electrochemical reaction single cells and the stack plate are arranged in the first direction, which is shorter than the total length of the reference sides, and the array Among them, while bringing the plurality of first reference side sides of the stack plate into contact with the reference wall, the first or more second reference side sides of the stack plate are viewed from the second reference side. It includes an application step of applying a force in a direction toward the reference wall.

The techniques disclosed in the present specification can be realized in various forms, for example, a stack plate, an electrochemical reaction cell stack, an electrochemical reaction module including an electrochemical reaction cell stack, and an electrochemical reaction. It can be realized in the form of an electrochemical reaction system including a reaction module, a method for producing them, and the like.

It is a perspective view which shows schematic structure of the fuel cell stack 100 in this embodiment. It is explanatory drawing which shows the XY plane structure of the upper side of the fuel cell stack 100 in this embodiment. It is explanatory drawing which shows the XY plane structure of the lower side of the fuel cell stack 100 in this embodiment. It is explanatory drawing which shows the XZ cross-sectional structure of the fuel cell stack 100 at the position IV-IV of FIGS. 1 to 3. FIG. It is explanatory drawing which shows the XZ cross-sectional structure of the fuel cell stack 100 at the position of VV of FIGS. 1 to 3. FIG. It is explanatory drawing which shows the YZ cross-sectional structure of the fuel cell stack 100 at the position of VI-VI of FIGS. 1 to 3. FIG. It is explanatory drawing which shows the YZ cross-sectional structure of the fuel cell stack 100 at the position of VII-VII of FIGS. 1 to 3. FIG. It is explanatory drawing which shows the XZ cross section composition of 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 YZ cross section configuration of two power generation units 102 which are adjacent to each other at the same position as the cross section shown in FIG. It is 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. 7. It is explanatory drawing which shows the XY plane structure of the upper side of an end plate 104. It is a flowchart of the manufacturing method of a fuel cell stack 100.

A. Embodiment:
A-1. composition:
(Structure of fuel cell stack 100)
1 to 7 are explanatory views schematically showing the configuration of the fuel cell stack 100 according to the present embodiment. FIG. 1 shows the external configuration of the fuel cell stack 100, FIG. 2 shows the plan configuration of the upper side of the fuel cell stack 100, and FIG. 3 shows the lower side of the fuel cell stack 100. 4 shows the cross-sectional structure of the fuel cell stack 100 at the positions IV-IV of FIGS. 1 to 3, and FIG. 5 shows the cross-sectional structure of the fuel cell stack 100 of FIGS. 1 to 3. The cross-sectional structure of the fuel cell stack 100 at the position of VV is shown, and FIG. 6 shows the cross-sectional structure of the fuel cell stack 100 at the position of VI-VI of FIGS. 1 to 3. FIG. 7 shows the cross-sectional configuration of the fuel cell stack 100 at the positions VII-VII of FIGS. 1 to 3. 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. 8 and later.

The fuel cell stack 100 includes a plurality of power generation units 102 (eight in this embodiment), a heat exchange unit 103, and a pair of end plates 104 and 106. The eight power generation units 102 are arranged side by side in a predetermined arrangement direction (vertical direction in this embodiment). However, of the eight power generation units 102, the four power generation units 102 from the first to the fourth from the bottom are arranged so as to be adjacent to each other, and the remaining four from the first to the fourth from the top. The power generation units 102 are also arranged so as to be adjacent to each other. A heat exchange unit 103 is arranged between the lower four power generation units 102 and the upper four power generation units 102. That is, the heat exchange unit 103 is arranged at the center position in the vertical direction in the aggregate composed of the eight power generation units 102 and the heat exchange unit 103. The pair of end plates 104 and 106 are arranged so as to sandwich an aggregate composed of eight power generation units 102 and a heat exchange unit 103 from above and below. Hereinafter, among the eight power generation units 102, the lower four power generation units 102 will be referred to as "upstream power generation unit 102U", and the remaining six power generation units 102 will be referred to as "downstream power generation unit 102D". The fuel cell stack 100 corresponds to the electrochemical reaction cell stack in the claims, and the arrangement direction (vertical direction) corresponds to the first direction in the claims.

The outer shape of each layer (power generation unit 102, heat exchange unit 103, end plates 104, 106) constituting the fuel cell stack 100 in the Z direction is substantially octagonal, as will be described later. The smallest rectangle among the rectangles inscribed by the outer peripheral line (outer shape) of each layer is called "virtual rectangle S". Hereinafter, a plurality of holes (eight in the present embodiment) penetrating in the vertical direction are formed on the peripheral edge of each layer in the Z direction, and the holes formed in each layer and corresponding to each other are formed in the vertical direction. A communication hole 108 extending in the vertical direction from one end plate 104 to the other end plate 106 is formed. In the following description, the holes formed in each layer of the fuel cell stack 100 to form the communication holes 108 may also be referred to as the communication holes 108. The communication holes 108 formed in the end plates 104 and 106 correspond to through holes in the claims.

A bolt 22 extending in the vertical direction is inserted into each communication hole 108, and the fuel cell stack 100 is fastened by the bolt 22 and the nuts 24 fitted on both sides of the bolt 22. As shown in FIGS. 4 to 7, between the nut 24 fitted on one side (upper side) of the bolt 22 and the upper surface of the end plate 104 forming the upper end of the fuel cell stack 100, and the bolt. An insulating sheet 26 is interposed between the nut 24 fitted on the other side (lower side) of the 22 and the lower surface of the end plate 106 forming the lower end of the fuel cell stack 100. However, in the place where the gas passage member 27 described later is provided, the insulating sheets arranged on the upper side and the lower side of the gas passage member 27 and the gas passage member 27 between the nut 24 and the surface of the end plate 106, respectively. 26 is intervening. 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 agent, or the like.

The outer diameter of the shaft portion of each bolt 22 is smaller than the inner diameter of each communication hole 108. Therefore, a space is secured between the outer peripheral surface of the shaft portion of each bolt 22 and the inner peripheral surface of each communication hole 108. As shown in FIGS. 2 to 5, the first virtual side S1 of the virtual rectangle S on the outer circumference of the fuel cell stack 100 around the Z direction (on the negative side of the X axis among the two sides parallel to the Y axis). The space formed by the bolt 22 (bolt 22A) located near the side) and the communication hole 108 into which the bolt 22A is inserted is a gas flow path into which the oxidant gas OG is introduced from the outside of the fuel cell stack 100. It functions as an oxidizing agent gas introduction manifold 161 and faces the first virtual side S1 on the outer circumference of the fuel cell stack 100 in the Z direction, and is the second virtual side S2 (of the two sides parallel to the Y axis). The space formed by the bolt 22 (bolt 22C) located near the midpoint (the side on the positive direction side of the X-axis) and the communication hole 108 into which the bolt 22C is inserted is an oxidation discharged from the heat exchange unit 103. It functions as an oxidizing agent gas supply manifold 163, which is a gas flow path that carries the agent gas OG toward each power generation unit 102. Further, as shown in FIGS. 2, 3 and 5, a bolt 22 (bolt 22B) located near the first virtual side S1 on the outer circumference of the fuel cell stack 100 in the Z direction and the bolt 22B are inserted. The space formed by the communication holes 108 functions as an oxidant gas discharge manifold 162 that discharges the oxidant off-gas OOG discharged from each power generation unit 102 to the outside of the fuel cell stack 100. In this embodiment, for example, air is used as the oxidant gas OG.

Further, as shown in FIGS. 2, 3 and 6, the third virtual side S3 of the virtual rectangle S on the outer circumference of the fuel cell stack 100 around the Z direction (the Y axis of the two sides parallel to the X axis). The fuel gas FG is introduced from the outside of the fuel cell stack 100 into the space formed by the bolt 22 (bolt 22F) located near the negative direction side) and the communication hole 108 into which the bolt 22F is inserted. The fourth virtual side S4 (which functions as a fuel gas introduction manifold 171 for supplying the fuel gas FG to each upstream power generation unit 102U and faces the third virtual side S3 on the outer circumference of the fuel cell stack 100 in the Z direction. A space formed by a bolt 22 (bolt 22D) located near the midpoint of two sides parallel to the X axis on the positive side of the Y axis) and a communication hole 108 into which the bolt 22D is inserted. Functions as a fuel gas relay manifold 172, which is a gas flow path that carries the fuel intermediate gas FMG, which is the gas discharged from the fuel chamber 176 of each upstream power generation unit 102U, toward each downstream power generation unit 102D. The fuel intermediate gas FMG contains hydrogen and the like that have not been used for the power generation reaction in the fuel chamber 176 of each power generation unit 102U upstream. As shown in FIGS. 2, 3 and 7, a bolt 22 (bolt 22E) located near the third virtual side S3 on the outer circumference of the fuel cell stack 100 in the Z direction and a communication in which the bolt 22E is inserted are inserted. The space formed by the holes 108 functions as a fuel gas discharge manifold 173 that discharges the fuel off-gas FOG, which is the gas discharged from the fuel chamber 176 of each power generation unit 102D downstream, to the outside of the fuel cell stack 100. In the present embodiment, for example, a hydrogen-rich gas obtained by reforming city gas is used as the fuel gas FG.

As shown in FIGS. 4 to 7, the fuel cell stack 100 is provided with four gas passage members 27. Each gas passage member 27 has a hollow cylindrical main body 28 and a hollow cylindrical branch 29 branched from the side surface of the main body 28. 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. Further, as shown in FIG. 4, the hole of the main body 28 of the gas passage member 27 arranged at the position of the bolt 22A forming the oxidant gas introduction manifold 161 communicates with the oxidant gas introduction manifold 161. As shown in FIG. 5, the hole of the main body 28 of the gas passage member 27 arranged at the position of the bolt 22B forming the oxidant gas discharge manifold 162 communicates with the oxidant gas discharge manifold 162. Further, as shown in FIG. 6, the hole of the main body 28 of the gas passage member 27 arranged at the position of the bolt 22F forming the fuel gas introduction manifold 171 communicates with the fuel gas introduction manifold 171. As shown in the above, the hole of the main body 28 of the gas passage member 27 arranged at the position of the bolt 22E forming the fuel gas discharge manifold 173 communicates with the fuel gas discharge manifold 173.

(Structure of end plates 104 and 106)
The pair of end plates 104 and 106 are substantially octagonal flat plate-shaped conductive members, and are made of, for example, stainless steel. One end plate 104 is located above the power generation unit 102 located at the top, and the other end plate 106 is located below the power generation unit 102 located at the bottom. A plurality of power generation units 102 are sandwiched by a pair of end plates 104 and 106 in a pressed state. The upper end plate 104 functions as a positive output terminal of the fuel cell stack 100, and the lower end plate 106 functions as a negative output terminal of the fuel cell stack 100. The end plates 104 and 106 correspond to stack plates within the scope of the claims.

(Structure of power generation unit 102)
8 to 10 are explanatory views showing a detailed configuration of the power generation unit 102. FIG. 8 shows an XZ cross-sectional configuration of one downstream power generation unit 102D and one upstream power generation unit 102U adjacent to each other at the same position as the cross section shown in FIG. 5, and FIG. 9 shows FIG. The YZ cross-sectional configuration of two power generation units 102U adjacent to each other at the same position as the cross section shown in FIG. 6 is shown, and FIG. 10 shows the downstream 2 adjacent to each other at the same position as the cross section shown in FIG. The YZ cross-sectional configuration of one power generation unit 102D is shown.

As shown in FIGS. 8 to 10, the power generation unit 102, which is the minimum unit of power generation, includes a single cell 110, a separator 120, an air pole side frame 130, an air pole side current collector 134, and a fuel pole side frame. It includes 140, a fuel electrode side current collector 144, and a pair of interconnectors 150 that form the uppermost layer and the lowermost layer of the power generation unit 102. Holes corresponding to the communication holes 108 into which the bolts 22 described above are inserted are formed in the peripheral edges of the separator 120, the air pole side frame 130, the fuel pole side frame 140, and the interconnector 150 in the Z direction.

The interconnector 150 is a substantially octagonal flat plate-shaped conductive member, and is made of, for example, ferritic stainless steel. The interconnector 150 ensures electrical continuity between the power generation units 102 and prevents mixing of reaction gases between the power generation units 102. 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 a certain 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 end plates 104 and 106, 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. 4-7).

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 fuel pole 116 supports the electrolyte layer 112 and the air pole 114. The single cell 110 corresponds to an electrochemical reaction single cell in the claims.

The electrolyte layer 112 is a substantially rectangular flat plate-shaped member, and is formed of, for example, a solid oxide such as YSZ (yttria-stabilized zirconia), ScSZ (scandia-stabilized zirconia), and CaSZ (calcia-stabilized zirconia). The air electrode 114 is a substantially rectangular flat plate-shaped member, and is formed of, for example, a perovskite-type oxide (for example, LSCF (lanternstrontium cobalt iron oxide), LSM (lanternstrontium manganese oxide), LNF (lantern nickel iron)). Has been done. The fuel electrode 116 is a substantially rectangular flat plate-shaped member, and 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) that uses 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 formed of, for example, metal. 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 opposite portion 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. The single cell 110 to which the separator 120 is joined is also referred to as a single cell with a separator.

As shown in FIGS. 8 to 10, the air electrode side frame 130 is a frame-shaped member in which a substantially rectangular hole 131 penetrating in the vertical direction is formed near the center, and is formed of, for example, an insulator such as mica. Has been done. 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 hole 131 of 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 hole 132 that communicates the oxidant gas introduction manifold 161 and the air chamber 166, and the oxidant gas that communicates the air chamber 166 and the oxidant gas discharge manifold 162. A discharge communication hole 133 is formed.

As shown in FIGS. 8 to 10, the fuel electrode side frame 140 is a frame-shaped member in which a substantially rectangular hole 141 penetrating in the vertical direction is formed near the center, and is formed of, for example, metal. Hole 141 of the fuel electrode side frame 140 constitutes a fuel chamber 176 facing the fuel electrode 116. 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. As shown in FIG. 9, the fuel electrode side frame 140 of each upstream power generation unit 102U has a fuel gas supply communication hole 142U that connects the fuel gas introduction manifold 171 and the fuel chamber 176, and a fuel gas relay between the fuel chamber 176 and the fuel gas relay. A fuel gas discharge communication hole 143U that communicates with the manifold 172 is formed. As shown in FIG. 10, the fuel pole side frame 140 of each power generation unit 102D downstream has a fuel gas supply communication hole 142D that communicates the fuel gas relay manifold 172 and the fuel chamber 176, and the fuel chamber 176 and the fuel gas discharge. A fuel gas discharge communication hole 143D that communicates with the manifold 173 is formed.

The air electrode side current collector 134 is arranged in the air chamber 166 as shown in FIGS. 8 to 10. The air electrode side current collector 134 is composed of a plurality of substantially square columnar conductive members arranged at predetermined intervals, and is formed of, for example, ferritic stainless steel. The air electrode side current collector 134 is in contact with the surface of the air electrode 114 opposite to the side facing the electrolyte layer 112 and the surface of the interconnector 150 on the side facing the air electrode 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 has an upper end plate. It is in contact with 104. Since the air electrode side current collector 134 has such a configuration, the air electrode 114 and the interconnector 150 (or the end plate 104) are electrically connected to each other. The air electrode side current collector 134 and the interconnector 150 may be formed as an integral member.

The fuel electrode side current collector 144 is arranged in the fuel chamber 176 as shown in FIGS. 8 to 10. The fuel electrode side current collector 144 includes an interconnector facing portion 146, a plurality of electrode facing portions 145, and a connecting portion 147 connecting each electrode facing portion 145 and the interconnector facing portion 146, for example, nickel. It is made of nickel alloy, stainless steel, etc. Each electrode facing portion 145 is in contact with the surface of the fuel pole 116 opposite to the side facing the electrolyte layer 112, and the interconnector facing portion 146 is the surface of the interconnector 150 facing the fuel pole 116. Is in contact with. However, as described above, since the power generation unit 102 located at the bottom of the fuel cell stack 100 does not have the lower interconnector 150, the interconnector facing portion 146 in the power generation unit 102 is the lower end plate. It is in contact with 106. Since the fuel pole side current collector 144 has such a configuration, the fuel pole 116 and the interconnector 150 (or the end plate 106) are electrically connected to each other. A spacer 149 formed of, for example, mica is arranged between the electrode facing portion 145 and the interconnector facing portion 146. Therefore, the fuel pole 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 fuel pole 116 and the interconnector 150 (or the end plate 106) via the fuel pole side current collector 144 follow. Good electrical connection with is maintained.

(Structure of heat exchange unit 103)
As shown in FIGS. 4 to 7, the heat exchange portion 103 is an octagonal flat plate-shaped member, and is made of, for example, ferritic stainless steel. A hole 182 that penetrates in the vertical direction is formed near the center of the heat exchange portion 103. Further, in the heat exchange unit 103, a communication hole 184 that communicates the central hole 182 and the communication hole 108 that forms the oxidant gas introduction manifold 161 and a communication that forms the central hole 182 and the oxidant gas supply manifold 163 are formed. A communication hole 186 that communicates with the hole 108 is formed. The heat exchange unit 103 includes a lower interconnector 150 included in the power generation unit 102D adjacent to the upper side of the heat exchange unit 103 and an upper interconnector 150 included in the power generation unit 102U adjacent to the lower side of the heat exchange unit 103. It is sandwiched between and. Between these interconnectors 150, the space formed by the holes 182, the communication holes 184, and the communication holes 186 functions as a heat exchange flow path 188 through which the oxidant gas OG flows for heat exchange, which will be described later.

A-2. Operation of fuel cell stack 100:
As shown in FIG. 4, 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. , The oxidant gas OG is supplied to the oxidant gas introduction manifold 161 through the holes of the branch portion 29 and the main body portion 28 of the gas passage member 27. As shown in FIG. 4, the oxidant gas OG supplied to the oxidant gas introduction manifold 161 flows into the heat exchange flow path 188 formed in the heat exchange section 103, passes through the heat exchange flow path 188, and passes through the heat exchange flow path 188. It is discharged to the oxidant gas supply manifold 163. The heat exchange unit 103 is adjacent to the power generation unit 102 on the upper side and the lower side. Further, as will be described later, the power generation reaction in the power generation unit 102 is an exothermic reaction. Therefore, when the oxidant gas OG passes through the heat exchange flow path 188 in the heat exchange unit 103, heat exchange is performed between the oxidant gas OG and the power generation unit 102, and the temperature of the oxidant gas OG rises. do. Since the oxidant gas introduction manifold 161 does not communicate with the air chamber 166 of each power generation unit 102, the oxidant gas OG is supplied from the oxidant gas introduction manifold 161 to the air chamber 166 of each power generation unit 102. There is no such thing. As shown in FIGS. 4, 5 and 8, the oxidant gas OG discharged to the oxidant gas supply manifold 163 passes through the oxidant gas supply communication hole 132 of each power generation unit 102 from the oxidant gas supply manifold 163. It is supplied to the air chamber 166 via the air chamber 166.

Further, as shown in FIGS. 6 and 9, 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. Then, the fuel gas FG is supplied to the fuel gas introduction manifold 171 through the holes of the branch portion 29 and the main body portion 28 of the gas passage member 27, and the fuel gas of each power generation unit 102U upstream from the fuel gas introduction manifold 171. It is supplied to the fuel chamber 176 of each power generation unit 102U upstream through the supply communication hole 142U. Since the fuel gas introduction manifold 171 does not communicate with the fuel chamber 176 of each power generation unit 102D downstream, the fuel gas FG is supplied from the fuel gas introduction manifold 171 to the fuel chamber 176 of each power generation unit 102D downstream. There is nothing. The fuel intermediate gas FMG discharged from the fuel chamber 176 of each upstream power generation unit 102U is discharged to the fuel gas relay manifold 172 via the fuel gas discharge communication hole 143U. As shown in FIGS. 7 and 10, in the fuel chamber 176 of each downstream power generation unit 102D, the fuel intermediate gas FMG discharged from each upstream power generation unit 102U is transmitted to the fuel gas relay manifold 172 and downstream. It is supplied through the fuel gas supply communication hole 142D of each power generation unit 102D.

When the oxidizer gas OG is supplied to the air chamber 166 of each upstream power generation unit 102U and the fuel gas FG is supplied to the fuel chamber 176 of each upstream power generation unit 102U, the single cell 110 of each upstream power generation unit 102U Power is generated by the electrochemical reaction of the oxidant gas OG and the fuel gas FG. Further, when the oxidant gas OG is supplied to the air chamber 166 of each downstream power generation unit 102D and the fuel intermediate gas FMG is supplied to the fuel chamber 176 of each downstream power generation unit 102D, a single unit of each downstream power generation unit 102D is supplied. In cell 110, power generation is performed by an electrochemical reaction between the oxidant gas OG and the fuel intermediate gas FMG. These power generation reactions are exothermic reactions. In each power generation unit 102, the air pole 114 of the single cell 110 is electrically connected to one of the interconnectors 150 via the air pole side current collector 134, and the fuel pole 116 is via the fuel pole side current collector 144. It is electrically connected to the other interconnector 150. Further, the plurality of power generation units 102 included in the fuel cell stack 100 are electrically connected in series, though they pass through the heat exchange unit 103. Therefore, the electric energy generated in each power generation unit 102 is taken out from the end plates 104 and 106 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 FIGS. 5 and 8, the oxidant off-gas OOG discharged from the air chambers 166 of the downstream and upstream power generation units 102U and 102D is the oxidant gas discharge manifold 162 via the oxidant gas discharge communication hole 133. A gas pipe (not shown) connected to the branch portion 29 through the holes of the main body portion 28 and the branch portion 29 of the gas passage member 27 provided at the position of the oxidant gas discharge manifold 162. It is discharged to the outside of the fuel cell stack 100 via the fuel cell stack 100. Further, as shown in FIGS. 7 and 10, the fuel off-gas FOG discharged from the fuel chamber 176 of each power generation unit 102D downstream is discharged to the fuel gas discharge manifold 173 through the fuel gas discharge communication hole 143D, and further. The fuel cell stack 100 is connected to the fuel cell stack 100 via a gas pipe (not shown) connected to the branch portion 29 through the holes of the main body portion 28 and the branch portion 29 of the gas passage member 27 provided at the position of the fuel gas discharge manifold 173. It is discharged to the outside. As described above, in the flow path configuration of the fuel gas FG of the fuel cell stack 100, the fuel gas FG introduced from the outside is supplied in parallel to the plurality of power generation units 102 upstream and discharged from each power generation unit 102U upstream. The fuel intermediate gas FMG is supplied in parallel to a plurality of power generation units 102D downstream via the fuel gas relay manifold 172, which is a so-called parallel series type.

A-3. Detailed configuration of end plates 104 and 106:
FIG. 11 is an explanatory view showing an XY plane configuration on the upper side of the end plate 104. Since the upper end plate 104 and the lower end plate 106 have the same structure, the detailed configuration of the end plates 104 and 106 will be described below by taking the upper end plate 104 as an example. As shown in FIG. 11, the outer shape of the end plate 104 in the Z direction is substantially octagonal as a whole. Hereinafter, regarding the outer peripheral line of the end plate 104 in the Z direction, the first virtual side S1 side and the second virtual side S2 side, the third virtual side S3 side, and the fourth virtual side S4 side in the virtual rectangle S It will be explained separately.

(First virtual side S1 side and second virtual side S2 side)
The outer peripheral line of the end plate 104 in the Z direction has two first reference sides 201, a first recess 203, and one second reference side 205. Each first reference side 201 is a straight line parallel to the first virtual side S1 and located on the first virtual side S1. The lengths of the two first reference sides 201 may be different from each other, but in the following, they are assumed to be the same (length A1). The total length (= A1 + A1) of all the first reference sides 201 located on the first virtual side S1 is 10% or more of the length of the first virtual side S1, and further, the first It is more preferable that the length of the virtual side S1 is 30% or more.

The first recess 203 is located between the two first reference sides 201 and is recessed on the second virtual side S2 side of the virtual rectangle S. The length of the first recess 203 in the direction parallel to the second virtual side S2 may be the same as the length A1 of each first reference side 201, or may be shorter than the length A1. However, the length may be longer than A1. The second reference side 205 is a straight line parallel to the second virtual side S2 and located on the second virtual side S2. The length (A2) of the second reference side 205 may be the same as the length A1 of the first reference side 201, may be shorter than the length A1, or may be longer than the length A1. May be. Further, the second reference side 205 is arranged at a position overlapping the first recess 203 in the facing direction (X direction) of the first virtual side S1 and the second virtual side S2. Further, the total length (= A2) of all the second reference sides 205 located on the second virtual side S2 is 50% or less of the length of the second virtual side S2.

Further, the total length (= A2) of all the second reference sides 205 is shorter than the total length (= A1 + A1) of all the first reference sides 201. Further, between one end P11 of the first reference side 201 closest to one end of the first virtual side S1 and the other end P12 of the first reference side 201 closest to the other end of the first virtual side S1. The first distance L1 is one end P21 of the second reference side 205 closest to one end of the second virtual side S2 and the other end of the second reference side 205 closest to the other end of the second virtual side S2. It is longer than the second distance from P22 (same as A2 in this embodiment). Further, in the direction (X direction) in which the first virtual side S1 and the second virtual side S2 face each other, one end P21 of the second reference side 205 closest to one end of the second virtual side S2 and the second The other end P22 of the second reference side 205 closest to the other end of the virtual side S2 of 2 is the one end P11 of the first reference side 201 closest to one end of the first virtual side S1 and the first It is located between the other end P12 of the first reference side 201 closest to the other end of the virtual side S1 of 1.

Further, a communication hole 108 that vertically penetrates the end plate 104 is formed at an edge portion of the peripheral edge of the end plate 104 that faces each of the two first reference sides 201. The communication hole 108 corresponds to a through hole in the claims. The edge portion facing the first reference side 201 is the peripheral portion along the outer peripheral line of the end plate 104 that is closest to the first reference side 201 and is the first first. It is a portion extending along the reference side 201. Further, the entire communication hole 108 formed in the end plate 104 is the entire communication hole 108 formed in the end plate 104 in the direction (X direction) in which the first virtual side S1 and the second virtual side S2 face each other. It is located inside both ends of the specific reference side, which is the first reference side 201 located closest to it.

(Third virtual side S3 side and fourth virtual side S4 side)
The outer peripheral line of the end plate 104 in the Z direction further has two third reference sides 211, a second recess 213, and one second reference side 215. Each third reference side 211 is a straight line parallel to the third virtual side S3 and located on the third virtual side S3. The lengths of the two third reference sides 211 may be different from each other, but in the following, they are assumed to be the same (length B1). The total length (= B1 + B1) of all the third reference sides 211 located on the third virtual side S3 is 10% or more of the length of the third virtual side S3, and the third virtual side More preferably, it is 30% or more of the length of S3.

The second recess 213 is located between the two third reference sides 211 and is recessed on the fourth virtual side S4 side of the virtual rectangle S. The length of the third recess 213 in the direction parallel to the third virtual side S3 may be the same as the length B1 of each third reference side 211, or may be shorter than the length B1. However, the length may be longer than B1. The fourth reference side 215 is a straight line parallel to the fourth virtual side S4 and located on the fourth virtual side S4. The length (B2) of the fourth reference side 215 may be the same as the length B1 of the third reference side 211, may be shorter than the length B1, or may be longer than the length B1. May be. Further, the fourth reference side 215 is arranged at a position overlapping the second recess 213 in the facing direction (Y direction) of the third virtual side S3 and the fourth virtual side S4. Further, the total length (= B2) of all the fourth reference sides 215 located on the fourth virtual side S4 is 50% or less of the length of the fourth virtual side 42.

Further, the total length (= B2) of all the fourth reference sides 215 is shorter than the total length (= B1 + B1) of all the third reference sides 211. Further, between one end P31 of the third reference side 211 closest to one end of the third virtual side S3 and the other end P32 of the third reference side 211 closest to the other end of the third virtual side S3. The third distance L2 includes one end P41 of the fourth reference side 215 closest to one end of the fourth virtual side S4 and the other end of the fourth reference side 215 closest to the other end of the fourth virtual side S4. It is longer than the fourth distance from P42 (same as A2 in this embodiment). Further, in the direction (Y direction) in which the third virtual side S3 and the fourth virtual side S4 face each other, one end P41 of the fourth reference side 215 closest to one end of the fourth virtual side S4 and the first The other end P42 of the fourth reference side 215 closest to the other end of the virtual side S4 of 4 is the one end P31 of the third reference side 211 closest to one end of the third virtual side S3 and the third. It is located between the other end P32 of the third reference side 211 closest to the other end of the virtual side S3 of 3.

Further, a communication hole 108 that vertically penetrates the end plate 104 is formed at an edge portion of the peripheral edge of the end plate 104 that faces each of the two third reference sides 211. Further, the entire communication hole 108 (width D1) formed in the end plate 104 is the one in the direction (Y direction) in which the third virtual side S3 and the fourth virtual side S4 face each other. It is located inside both ends of the specific reference side, which is the third reference side 211 located closest to the communication hole 108.

A-4. About the manufacturing method of the fuel cell stack 100:
FIG. 12 is a flowchart of a method for manufacturing the fuel cell stack 100 having the above-described configuration. First, each member (power generation unit 102, heat exchange unit 103, end plates 104, 106) constituting the fuel cell stack 100 is prepared (S110). Next, each member is formed into an array in which the members are laminated so as to be arranged in the vertical direction, for example (S120). S120 corresponds to the arrangement step in the claims. In this array, the end plates 104 and 106 may be arranged at positions deviated from the power generation unit 102 and the heat exchange unit 103 in the plane direction orthogonal to the vertical direction. When the end plates 104 and 106 are arranged at positions offset from the power generation unit 102 and the like, the communication holes 108 formed in the end plates 104 and 106 and the communication holes 108 formed in the power generation unit 102 and the like move up and down. Since they are displaced from each other in the directional view, the bolt 22 may not be smoothly inserted into the communication hole 108, or it may cause pressure loss in each manifold (161, 162, 171, 172) composed of the communication hole 108. be.

Therefore, in the array, the second reference of the end plates 104 and 106 while bringing the two first reference sides 201 sides of the end plates 104 and 106 into contact with the predetermined first reference wall (not shown). A force is applied to the side 205 in the direction from the second reference side 205 toward the first reference wall (S130). S130 corresponds to the granting step in the claims. The first reference wall is a wall having a plane parallel to the vertical direction and fixed at a predetermined position. Here, the shortest distances of the end plates 104 and 106 from the end faces on the first reference side 201 side to the communication holes 108 are substantially the same as each other. For example, with respect to the power generation unit 102 and the heat exchange unit 103, the direction toward the first reference wall with respect to the second reference side 205 of the end plates 104 and 106 while applying a force in the direction toward the first reference wall. Gives power to. As a result, in the opposite direction (X direction) between the first virtual side S1 and the second virtual side S2, the communication holes 108 formed in the end plates 104 and 106 together with the end plates 104 and 106 are stacked in the fuel cell stack. It can be accurately positioned at a predetermined position in 100.

Further, in the array, the fourth reference of the end plates 104 and 106 while contacting the plurality of third reference sides 211 sides of the end plates 104 and 106 with a predetermined second reference wall (not shown). A force is applied to the side 215 in the direction from the fourth reference side 215 toward the second reference wall (S140). S140 corresponds to the granting step in the claims. The second reference wall is a wall that is parallel in the vertical direction, has a plane orthogonal to the first reference wall, and is fixed at a predetermined position. Here, the shortest distances of the members from the end faces of the end plates 104 and 106 on the third reference side 211 side to the communication holes 108 coincide with each other. For example, with respect to the power generation unit 102 and the heat exchange unit 103, the direction toward the second reference wall with respect to the fourth reference side 215 of the end plates 104 and 106 while applying a force in the direction toward the second reference wall. Gives power to. As a result, in the opposite direction (Y direction) between the third virtual side S3 and the fourth virtual side S4, the communication holes 108 formed in the end plates 104 and 106 are stacked together with the end plates 104 and 106. It can be accurately positioned at a predetermined position in 100.

After that, the remaining assembly steps (for example, joining the air electrode 114 and the air electrode side current collector 134 and fastening the fuel cell stack 100 with bolts 22) are performed, and the assembly of the fuel cell stack 100 is completed (S150). ..

A-5. About the effect of this embodiment:
As described above, the outer peripheral lines of the end plates 104 and 106 of the present embodiment have a plurality of first reference sides 201 and a second reference side 205 located on the opposite side thereof. Therefore, for example, when assembling the fuel cell stack 100 using the end plates 104 and 106, the second portion of the end plates 104 and 106 corresponding to the first reference side 201 is brought into contact with the predetermined reference surface. By pressing the pressing member against the portion corresponding to the reference side 205 of the above, the end plates 104 and 106 can be accurately positioned at a predetermined position in 100. Moreover, since the communication holes 108 constituting the gas paths 161, 162 are formed at the edge portion facing the first reference side 201, the communication holes 108 are formed in the fuel cell stack 100 together with the end plates 104 and 106. It can be accurately positioned at a predetermined position. Further, in the end plates 104 and 106 of the present embodiment, the first recess 203 is formed between the first reference sides 201, and the total length of at least one second reference side 205 is calculated. By making it shorter than the total length of the plurality of first reference sides 201, weight reduction is achieved by lightening. That is, according to the end plates 104 and 106 of the present embodiment, it is possible to improve the positioning accuracy of the end plates 104 and 106 in the fuel cell stack 100 and to reduce the weight of the end plates 104 and 106 at the same time.

Further, in the present embodiment, the total length (= A2) of all the second reference sides 205 located on the second virtual side S2 is 50% or less of the length of the second virtual side S2. be. Therefore, the total length (= A2) of all the second reference sides 205 located on the second virtual side S2 is longer than 50% of the length of the second virtual side S2, as compared with the configuration. The weight of the end plates 104 and 106 can be reduced. Further, in the present embodiment, the first distance L1 between one end P11 and the other end P12 of the first reference side 201 is a second distance between one end P21 and the other end P22 of the second reference side 205. Longer than the distance. Therefore, the position of the first reference side 201 with respect to the reference plane is stable as compared with the configuration in which the first distance L1 is shorter than the second distance, so that the positioning accuracy of the end plates 104 and 106 in the fuel cell stack 100 can be improved. It can be improved further.

Further, in the above embodiment, one end P21 and the other end P22 of the second reference side 205 are both viewed in the direction (X direction) in which the first virtual side S1 and the second virtual side S2 face each other. , Is located between one end P11 and the other end P12 of the first reference side 201. Therefore, as compared with the configuration in which at least one of one end P21 and the other end P22 of the second reference side 205 is not located between one end P11 and the other end P12 of the first reference side 201, the first virtual In the direction parallel to the side S1 (Y direction), the fuel cell is caused by the outward force of one end P11 and the other end P12 of the first reference side 201 being applied to the second reference side 205. It is possible to prevent a decrease in the accuracy of positioning the end plates 104 and 106 and the communication hole 108 with respect to the stack 100.

Further, in the above embodiment, the total length (= A1 + A1) of all the first reference sides 201 located on the first virtual side S1 is 10% or more of the length of the first virtual side S1. be. Therefore, the first reference side with respect to the reference surface is compared with the configuration in which the total length (= A1 + A1) of the first reference side 201 is less than 10% of the length of the first virtual side S1. Since the position of 201 is stable, the accuracy of positioning the end plates 104, 106 and the communication hole 108 with respect to the fuel cell stack 100 can be further improved.

Further, in the above embodiment, a communication hole 108 that vertically penetrates the end plate 104 is formed at an edge portion of the peripheral edge of the end plate 104 that faces each of the two first reference sides 201. Therefore, each of the plurality of communication holes 108 can be accurately positioned at a predetermined position on the fuel cell stack 100.

Further, in the above embodiment, the entire one communication hole 108 formed in the end plate 104 is the same 1 in the direction (X direction) in which the first virtual side S1 and the second virtual side S2 face each other. It is located inside both ends of the specific reference side, which is the first reference side 201 located closest to the two communication holes 108. Therefore, the accuracy of positioning the communication hole 108 with respect to the fuel cell stack 100 can be further improved as compared with the configuration in which at least one of both ends of the communication hole 108 is located outside both ends of the first reference side 201. can.

It should be noted that on the third virtual side S3 side and the fourth virtual side S4 side, the same effect as the first virtual side S1 side and the second virtual side S2 side can be obtained.

B. 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.

In the above embodiment, the end plates 104 and 106 are exemplified as the stack plate, but the present invention is not limited to this, and for example, a terminal plate provided with an external terminal may be used. Further, the plate is not limited to the plate located at the end in the first direction of the fuel cell stack 100, and may be a plate arranged between a plurality of single cells and other members. Further, in the above embodiment, the outer shape of the end plates 104, 106) in the Z direction is substantially octagonal, but the present invention is not limited to this, and other shapes inscribed in the virtual rectangle may be used.

In the above embodiment, the outer peripheral line of the end plate 104 in the Z direction may have three or more first reference sides 201, and the outer peripheral line has two or more second reference sides 205. There may be. Each of the reference sides 201 and 205 is not limited to a straight line along each virtual side, and may be a line substantially along each virtual side as a whole, and may be, for example, a slightly curved line. Further, the total length (= A1 + A1) of all the first reference sides 201 located on the first virtual side S1 may be less than 10% of the length of the first virtual side S1. , 40% or more, 50% or more, 60% or more of the length of the first virtual side S1 may be used. Further, in the above embodiment, the total length (= A2) of all the second reference sides 205 located on the second virtual side S2 is 50% or more of the length of the second virtual side S2. There may be.

Further, in the above embodiment, the first distance L1 between one end P11 and the other end P12 of the first reference side 201 is a second distance between one end P21 and the other end P22 of the second reference side 205. The length may be less than or equal to the distance of. Further, in the above embodiment, at least one of one end P21 and the other end P22 of the second reference side 205 is viewed in the direction (X direction) in which the first virtual side S1 and the second virtual side S2 face each other. , It may be located outside the both ends P11 and P22, not between one end P11 and the other end P12 of the first reference side 201.

Further, in the above embodiment, the communication hole 108 is formed only in a part of the edge portion (for example, one edge portion) facing each of the two first reference sides 201 at the peripheral edge portion of the end plate 104. It may be. Further, in the above embodiment, a part of one communication hole 108 formed in the end plate 104 is a part of the communication hole 108 formed in the end plate 104 in the direction (X direction) in which the first virtual side S1 and the second virtual side S2 face each other. It may be located outside both ends of the specific reference side, which is the first reference side 201 located closest to one communication hole 108.

Further, in the above embodiment, the third reference side 211 of the outer peripheral line of the end plate 104 in the Z direction may be zero, one, or three or more, and the outer peripheral line has a third reference side. The reference side 215 of 4 may be zero or two or more. Each reference side 211,215 is not limited to a straight line along each virtual side, and may be a line substantially along each virtual side as a whole, and may be, for example, a slightly curved line. Further, the total length (= B1 + B1) of all the third reference sides 211 located on the third virtual side S3 may be less than 10% of the length of the third virtual side S3. , 40% or more, 50% or more, 60% or more of the length of the third virtual side S3 may be used. Further, in the above embodiment, the total length (= B2) of all the fourth reference sides 215 located on the fourth virtual side S4 is 50% or more of the length of the fourth virtual side S4. There may be.

Further, in the above embodiment, the third distance L2 between one end P31 and the other end P32 of the third reference side 211 is a fourth distance between one end P41 and the other end P42 of the fourth reference side 215. The length may be less than or equal to the distance of. Further, in the above embodiment, at least one of one end P41 and the other end P42 of the fourth reference side 215 is viewed in the direction (Y direction) in which the third virtual side S3 and the fourth virtual side S4 face each other. , It may be located outside the both ends P31 and P32, not between one end P31 and the other end P32 of the third reference side 211.

Further, in the above embodiment, the communication hole 108 is formed only in a part of the edge portion (for example, one edge portion) facing each of the two third reference sides 211 at the peripheral edge portion of the end plate 104. The communication hole 108 may not be formed at any of the edge portions of the peripheral edge of the end plate 104 facing each of the two third reference sides 211. Further, in the above embodiment, a part of one communication hole 108 formed in the end plate 104 is a part of the communication hole 108 formed in the end plate 104 in the direction (Y direction) in which the third virtual side S3 and the fourth virtual side S4 face each other. It may be located outside both ends of the specific reference side, which is the third reference side 211 located closest to one communication hole 108.

In the above embodiment, the end plates 104 and 106 are the entire second reference side 205 between the two first reference sides 201 in the opposite direction view of the first virtual side and the second virtual side. (In other words, in the same opposite direction view, the entire second reference side 205 may overlap the first recess 203). With such a configuration, it is possible to more effectively improve the positioning accuracy of the stacking plate in the electrochemical reaction cell stack and reduce the weight of the stacking plate.

Further, in the above embodiment, the number of power generation units 102 included in the fuel cell stack 100 is only an example, and the number of power generation units 102 is appropriately determined according to the output voltage and the like required for the fuel cell stack 100. Further, the number of upstream power generation units 102U and the number of downstream power generation units 102D are just examples.

In the above embodiment, the number of bolts 22 used for fastening the fuel cell stack 100 is only an example, and the number of bolts 22 is appropriately determined according to the fastening force required for the fuel cell stack 100 and the like.

Further, in the above embodiment, it is assumed that the nuts 24 are fitted on both sides of the bolt 22, but it is assumed that the bolt 22 has a head and the nut 24 is fitted only on the opposite side of the head of the bolt 22. May be good.

Further, in the above embodiment, the end plates 104 and 106 function as output terminals, but instead of the end plates 104 and 106, another member connected to each of the end plates 104 and 106 (for example, the end plate 104). , 106, and the conductive plate arranged between the power generation unit 102) may function as an output terminal.

Further, in the above embodiment, the space between the outer peripheral surface of the shaft portion of each bolt 22 and the inner peripheral surface of each communication hole 108 is used as each manifold, but instead of this, the shaft of each bolt 22 is used. Axial holes may be formed in the portion, and the holes may be used as each manifold. Further, each manifold may be provided separately from each communication hole 108 into which each bolt 22 is inserted.

Further, in the above 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, but even in such a case. The two power generation units 102 may include their respective interconnectors 150. Further, in the above embodiment, the upper interconnector 150 of the power generation unit 102 located at the top of the fuel cell stack 100 and the lower interconnector 150 of the power generation unit 102 located at the bottom are omitted. These interconnectors 150 may be provided without omission.

Further, in the above embodiment, the fuel pole side current collector 144 may have the same configuration as the air pole side current collector 134, and the fuel pole side current collector 144 and the adjacent interconnector 150 are integrated members. It may be. Further, the fuel pole side frame 140 may be an insulator instead of the air pole side frame 130. Further, the air pole side frame 130 and the fuel pole side frame 140 may have a multi-layer structure.

Further, the material forming each member in the above embodiment is merely an example, and each member may be formed of another material.

Further, in the above embodiment, the city gas is reformed to obtain a hydrogen-rich fuel gas FG, but the fuel gas FG may be obtained from other raw materials such as LP gas, kerosene, methanol, and gasoline. Pure hydrogen may be used as the fuel gas FG.

In the present specification, the fact that the member B and the member C face each other with the member (or a portion having the member, the same applies hereinafter) A sandwiching the member A is not limited to the form in which the member A and the member B or the member C are adjacent to each other. It includes a form in which another component is interposed between the member A and the member B or the member C. For example, even in a configuration in which another layer is provided between the electrolyte layer 112 and the air electrode 114, it can be said that the air electrode 114 and the fuel electrode 116 face each other with the electrolyte layer 112 interposed therebetween.

Further, 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 relates to the electrolysis reaction of water. It is also applicable to an electrolytic cell unit, which is the smallest unit of a solid oxide type electrolytic cell (SOEC) that uses it to generate hydrogen, and an electrolytic cell stack having a plurality of electrolytic cell units. The configuration of the electrolytic cell stack is not described in detail here because it is known as described in, for example, Japanese Patent Application Laid-Open No. 2016-81813, but is generally 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, and the power generation unit 102 may be read as an electrolytic cell unit. 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. Water vapor as a raw material gas is supplied. As a result, an electrolysis reaction of water occurs in each electrolytic cell unit, 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. Even in an electrolytic cell stack having such a configuration, the above-mentioned effect can be obtained by applying the present invention.

22: Bolt 24: Nut 26: Insulation sheet 27: Gas passage member 28: Main body 29: Branch 42: Virtual side 100: Fuel cell stack 102: Power generation unit 102D: Power generation unit 103: Heat exchange part 104, 106: End Plate 108: Communication 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: Hole 132: Oxidizing agent gas supply communication hole 133: Oxidizing agent gas discharge communication hole 134: Air pole side current collector 140: Fuel pole side frame 141: Hole 142D: Fuel gas supply communication hole 142U: Fuel gas supply communication hole 143D: Fuel gas discharge communication hole 143U: Fuel gas discharge communication hole Hole 144: Fuel electrode side current collector 145: Electrode facing part 146: Interconnector facing part 147: Connecting part 149: Spacer 150: Interconnector 161: Oxidizing agent gas introduction manifold 162: Oxidizing agent gas discharging manifold 163: Oxidating agent gas Supply manifold 166: Air chamber 171: Fuel gas introduction manifold 172: Fuel gas relay manifold 173: Fuel gas discharge manifold 176: Fuel chamber 182: Hole 184: Communication hole 186: Communication hole 188: Heat exchange flow path 201: First Reference side 203: First recess 205: Second reference side 211: Third reference side 213: Second recess 215: Fourth reference side A1: Length A: Member B1: Length D1: Width FG : Fuel gas FMG: Fuel intermediate gas FOG: Fuel off gas L1: Distance L2: Distance OG: Oxidizing agent gas OOG: Oxidizing agent off gas P11, P12, P21, P22, P31, P32, P41, P42: End S1: First Virtual side S2: Second virtual side S3: Third virtual side S4: Fourth virtual side S: Virtual rectangle

Claims (11)

An electrochemical reaction cell stack in which a plurality of electrochemical reaction single cells having a solid electrolyte layer and an air electrode and a fuel electrode facing each other in the first direction across the solid electrolyte layer are arranged side by side in the first direction. Is a flat plate-shaped stacking plate arranged on at least one side of the first direction with respect to the plurality of electrochemical reaction single cells, and constitutes a gas flow path formed in the electrochemical reaction cell stack. In the stacking plate in which the through hole is formed,
The outer peripheral line of the stacking plate in the first directional view is
A plurality of first reference sides parallel to the first virtual side of the smallest virtual rectangle inscribed by the outer peripheral line and located on the first virtual side.
A recess located between the first reference sides and recessed on the side of the second virtual side facing the first virtual side in the virtual rectangle.
It has one or more second reference sides that are parallel to the second virtual side and located on the second virtual side.
The through hole is formed in at least one of a plurality of edge portions facing each of the plurality of first reference sides at the peripheral edge of the stack plate.
Total length of all of the second reference edge is rather short than the sum of the lengths of the plurality of first reference edge,
The first distance between one end of the first reference side closest to one end of the first virtual side and the other end of the first reference side closest to the other end of the first virtual side. Is a second between one end of the second reference side closest to one end of the second virtual side and the other end of the second reference side closest to the other end of the second virtual side. Longer than the distance
In the direction in which the first virtual side and the second virtual side face each other, one end of the second reference side closest to one end of the second virtual side and the other of the second virtual side. The other ends of the second reference side closest to the ends are the one end of the first reference side closest to one end of the first virtual side and the other end of the first virtual side. Located between the nearest other end of the first reference side,
Moreover, in the directional view in which the first virtual side and the second virtual side face each other, the recess is the one end of the second reference side closest to one end of the second virtual side and the second. A stacking plate characterized in that it is located between the other end of the second reference side closest to the other end of the virtual side of 2. In the stack plate according to claim 1,
A stacking plate, wherein the total length of all the second reference sides is 50% or less of the length of the second virtual side. In the stack plate according to claim 1 or 2.
A stacking plate, wherein the total length of the plurality of first reference sides is 10% or more of the length of the first virtual side. In the stacking plate according to any one of claims 1 to 3.
The outer peripheral line of the stacking plate in the first directional view further
A plurality of third reference sides parallel to the third virtual side of the virtual rectangle and located on the third virtual side, and
A recess located between the third reference sides and recessed on the side of the fourth virtual side facing the third virtual side in the virtual rectangle.
It has one or more fourth reference sides parallel to the fourth virtual side and located on the fourth virtual side.
The through hole is formed in at least one of the plurality of edge portions facing the plurality of third reference sides at the peripheral edge of the stacking plate.
A stacking plate, characterized in that the sum of the lengths of all the fourth reference sides is shorter than the sum of the lengths of the plurality of third reference sides. In the stack plate according to claim 4,
A stacking plate, wherein the total length of all the fourth reference sides is 50% or less of the length of the fourth virtual side. In the stacking plate according to claim 4 or 5.
A third distance between one end of the third reference side closest to one end of the third virtual side and the other end of the third reference side closest to the other end of the third virtual side. Is a fourth between one end of the fourth reference side closest to one end of the fourth virtual side and the other end of the fourth reference side closest to the other end of the fourth virtual side. A stacking plate characterized by being longer than the distance of. In the stacking plate according to any one of claims 4 to 6.
The first distance between one end of the first reference side closest to one end of the first virtual side and the other end of the first reference side closest to the other end of the first virtual side. Is 30% or more of the length of the first virtual side, one end of the third reference side closest to one end of the third virtual side, and the other end of the third virtual side. The third distance from the other end of the third reference side closest to the third reference side is 30% or more of the length of the third virtual side, and at least one of them is satisfied. , Stack plate. In the stacking plate according to any one of claims 1 to 7.
A stacking plate, characterized in that the through holes are formed in each of the plurality of edge portions. In the stacking plate according to any one of claims 1 to 8.
In the directional view in which the first virtual side and the second virtual side face each other, the entire one through hole is specified as the first reference side located closest to the one through hole. A stacking plate characterized by being located inside both ends of the reference side. An electrochemical reaction cell stack in which a plurality of electrochemical reaction single cells having a solid electrolyte layer and an air electrode and a fuel electrode facing each other in the first direction across the solid electrolyte layer are arranged side by side in the first direction. In addition,
An electrochemical reaction cell stack comprising the stack plate according to any one of claims 1 to 9. A plurality of electrochemical reaction single cells having a solid electrolyte layer and an air electrode and a fuel electrode facing each other in the first direction across the solid electrolyte layer are arranged side by side in the first direction, and the plurality of cells are arranged side by side. In the method for manufacturing an electrochemical reaction cell stack in which a flat plate for stacking is arranged on at least one side of the first direction with respect to the electrochemical reaction single cell.
The outer peripheral line of the stacking plate in the first directional view is
A plurality of first reference sides parallel to the first virtual side of the smallest virtual rectangle inscribed by the outer peripheral line and located on the first virtual side.
A recess located between the first reference sides and recessed on the side of the second virtual side facing the first virtual side in the virtual rectangle.
It has one or more second reference sides that are parallel to the second virtual side and located on the second virtual side.
A through hole is formed in at least one of a plurality of edge portions facing each of the plurality of first reference sides at the peripheral edge of the stacking plate.
The sum of the lengths of all the second reference sides is shorter than the sum of the lengths of the plurality of first reference sides.
An arrangement step of forming an array in which the plurality of electrochemical reaction single cells and the stack plate are arranged in the first direction.
In the array, the second reference side of the stack plate is brought into contact with the reference wall, and the second reference side of the stack plate is in contact with the second reference side of the stack plate. A method for producing an electrochemical reaction cell stack, which comprises an application step of applying a force in a direction from a reference side to the reference wall.

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