JP2017073346A - Fuel battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel battery capable of realizing stable brazing at an interconnector.SOLUTION: A fuel battery 1 includes interconnectors 11 which are arranged so as to sandwich a cell body 10 therebetween, the interconnector 11 is provided with fuel hollow flow passages 21, 22 for making fuel flow from a fuel introduction passage 17 to a fuel lead-out passage 18, and air hollow flow paths 23 and 24 for making air flow from the air introduction passage 19 to the air lead-out passage 20. The interconnector 11 includes a frame member 25 having concave portions 28 defining parts of the fuel hollow flow paths 21, 22, a frame member 26 having concave portions 31 defining parts of the air hollow flow paths 23 and 24, and an intermediate member 27 arranged between the frame members 25 and 26. The frame members 25 and 26 and the intermediate member 27 are joined by brazing, a protrusion 50 protrudes from the bottom surface of the concave portion 28, and a protrusion 51 protrudes from the bottom surface of the concave portion 31.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a fuel cell.

  As a conventional fuel cell, for example, a technique described in Patent Document 1 is known. The fuel cell described in Patent Document 1 is located between a pair of upper and lower interconnectors and each interconnector, and an air electrode is formed on one surface of the electrolyte and a fuel electrode is formed on the other surface of the electrolyte. The cell body includes a pair of upper and lower current collecting members that are disposed between the air electrode, the fuel electrode, and the interconnector and that electrically connect the air electrode, the fuel electrode, and the interconnector. In a fuel cell, a fuel chamber and an air chamber are formed by a lower interconnector, a fuel electrode insulating frame, a fuel electrode frame, a separator, an air electrode insulating frame, and an upper connector, and the fuel chamber and the air chamber are partitioned by an electrolyte. And have a structure independent of each other. The lower interconnector, fuel electrode insulation frame, fuel electrode frame, separator, air electrode insulation frame, and upper interconnector have air supply through holes for supplying air into the air chamber and air from the air chamber. An air exhaust through hole for exhausting to the outside, a fuel supply through hole for supplying fuel gas to the inside of the fuel chamber, and a fuel exhaust through hole for exhausting the fuel gas from the fuel chamber to the outside are provided. ing.

JP2013-55042A

  In the above prior art, it is conceivable to join the interconnector and the frame by brazing. When the interconnector and the frame are joined by brazing, a load is applied to the interconnector and the frame from both the upper and lower sides. At this time, depending on the structure of the interconnector or the frame, the interconnector or the frame may be bent, and stable brazing may be difficult.

  An object of the present invention is to provide a fuel cell capable of realizing stable brazing in an interconnector.

  A fuel cell according to an aspect of the present invention includes a cell main body that has a fuel electrode disposed on one side of an electrolyte and an air electrode disposed on the other side of the electrolyte, and that causes a power generation reaction between the fuel and air. The main body is disposed so as to be sandwiched between the fuel electrode side and the air electrode side, and includes an interconnector having a fuel flow path forming part facing the fuel electrode and an air flow path forming part facing the air electrode. A fuel introduction passage for introducing fuel, a fuel introduction passage for deriving fuel, an air introduction passage for introducing air, an air introduction passage for deriving air, and a flow of fuel from the fuel introduction passage to the fuel extraction passage A fuel flow path and an air flow path for flowing air from the air introduction path to the air discharge path are provided, and the interconnector has a first concave portion that defines a part of the fuel flow path. The frame-shaped member and part of the air flow path are defined. A second frame-shaped member having a second concave portion, and an intermediate member disposed between the first frame-shaped member and the second frame-shaped member and having a fuel flow path forming portion and an air flow path forming portion. The first frame-shaped member, the second frame-shaped member, and the intermediate member are joined by brazing, and a first protrusion is projected from the bottom surface of the first concave portion, and the bottom surface of the second concave portion is formed. Is characterized in that a second protrusion is provided.

  In the fuel cell as described above, when the first frame-shaped member, the second frame-shaped member, and the intermediate member are joined by brazing, the first frame-shaped member, the second frame-shaped member, and the intermediate member are joined to both the upper and lower sides. A load is applied. At this time, a first protrusion protrudes from the bottom surface of the first concave portion of the first frame member, and a second protrusion protrudes from the bottom surface of the second concave portion of the second frame member. Therefore, the first protrusion and the second protrusion receive a load. Therefore, the first concave portion that defines a part of the fuel flow path is provided in the first plate member, and the second concave portion that defines a part of the air flow path is provided in the second plate member. However, the first frame member and the second frame member are not easily bent. Thereby, stable brazing can be realized in the interconnector.

  The direction in which fuel flows from the fuel introduction passage to the fuel lead-out passage intersects the direction in which air flows from the air introduction passage to the air lead-out passage, and the total volume of the first protrusions arranged in the region on the air introduction passage side is The total volume of the first protrusions arranged in the region on the air outlet passage side may be larger.

  In the region corresponding to the region where the fuel introduction passage and the air introduction passage in the cell body are adjacent to each other, a power generation reaction occurs compared to the region corresponding to the region in which the fuel lead-out passage and the air introduction passage in the cell body are adjacent. Cheap. Therefore, by making the total volume of the first protrusions arranged in the region on the air introduction passage side larger than the total volume of the first projections arranged in the region on the air lead-out passage side, the fuel introduction passage and the air The pressure loss of fuel and air in the region adjacent to the introduction passage is larger than the pressure loss of fuel and air in the region adjacent to the fuel extraction passage and air extraction passage. Therefore, the uniformity of the power generation reaction in the cell body can be improved.

  The direction in which fuel flows from the fuel introduction passage to the fuel lead-out passage intersects the direction in which air flows from the air introduction passage to the air lead-out passage, and the total volume of the second protrusions arranged in the region on the fuel introduction passage side is The total volume of the second protrusions arranged in the region on the fuel outlet passage side may be larger.

  In the region corresponding to the region where the fuel introduction passage and the air introduction passage in the cell body are adjacent to each other, a power generation reaction occurs compared to the region corresponding to the region in which the fuel lead-out passage and the air introduction passage in the cell body are adjacent. Cheap. Therefore, by making the total volume of the second protrusions arranged in the region on the fuel introduction passage side larger than the total volume of the second projections arranged in the region on the fuel lead-out passage side, the fuel introduction passage and the air The pressure loss of fuel and air in the region adjacent to the introduction passage is larger than the pressure loss of fuel and air in the region adjacent to the fuel extraction passage and air extraction passage. Therefore, the uniformity of the power generation reaction in the cell body can be improved.

  The direction in which fuel flows from the fuel introduction passage to the fuel lead-out passage intersects the direction in which air flows from the air introduction passage to the air lead-out passage, and the total volume of the first protrusions arranged in the region on the air introduction passage side is The total volume of the second protrusions arranged in the region on the fuel introduction passage side is larger than the total volume of the first protrusions arranged in the region on the air lead-out passage side, and is arranged in the region on the fuel lead-out passage side. The total volume of the second protrusions may be larger.

  In the region corresponding to the region where the fuel introduction passage and the air introduction passage in the cell body are adjacent to each other, a power generation reaction occurs compared to the region corresponding to the region in which the fuel lead-out passage and the air introduction passage in the cell body are adjacent. Cheap. Therefore, the total volume of the first protrusions arranged in the region on the air introduction passage side is made larger than the total volume of the first projections arranged in the region on the air lead-out passage side, and the region on the fuel introduction passage side By making the total volume of the second protrusions disposed in the region larger than the total volume of the second protrusions disposed in the region on the fuel outlet passage side, the region on the side where the fuel introduction passage and the air introduction passage are adjacent to each other The pressure loss of the fuel and air in the fuel is larger than the pressure loss of the fuel and air in the region where the fuel outlet passage and the air outlet passage are adjacent to each other. Therefore, the uniformity of the power generation reaction in the cell body can be improved.

  At this time, the number of the first protrusions arranged in the region on the air introduction passage side is larger than the number of the first protrusions arranged in the region on the air lead-out passage side, and is arranged in the region on the fuel introduction passage side. The number of the second protrusions may be larger than the number of the second protrusions arranged in the region on the fuel outlet passage side. In this case, even if the volumes of the first protrusions are made equal, the total volume of the first protrusions arranged in the area on the air introduction passage side is the first protrusion arranged in the area on the air lead-out passage side. It becomes larger than the total volume of the part. Even if the volumes of the second protrusions are equal, the total volume of the second protrusions disposed in the region on the fuel introduction passage side is the total volume of the second protrusions disposed in the region on the fuel lead-out passage side. It becomes larger than the volume.

  The side surface of the first projection portion is a tapered surface such that the first projection portion tapers from the fuel introduction passage side toward the fuel lead-out passage side. The side surface of the second projection portion is the second projection portion. The tapered surface may be tapered from the air introduction passage side toward the air lead-out passage side. In this case, the fuel easily flows from the fuel introduction passage to the fuel outlet passage, and the air easily flows from the air introduction passage to the air outlet passage.

  ADVANTAGE OF THE INVENTION According to this invention, the fuel cell which can implement | achieve the stable brazing in an interconnector is provided.

It is a perspective view showing the appearance of the fuel cell concerning one embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line A2-A2 and a cross-sectional view taken along line B2-B2 of FIG. FIG. 3 is an exploded perspective view of the interconnector shown in FIG. 2. FIG. 3 is an exploded cross-sectional view of the interconnector shown in FIG. 2. It is the bottom view and B5-B5 sectional view taken on the line of the 1st frame-shaped member shown by FIG.3 and FIG.4. It is the top view and B6-B6 sectional view taken on the line of the 2nd frame-shaped member shown by FIG.3 and FIG.4. As a comparative example, in the conventional interconnector, it is an expanded sectional view which shows the state when joining a 1st frame-shaped member, a 2nd frame-shaped member, and an intermediate member by brazing. FIG. 5 is an enlarged cross-sectional view illustrating a state when the first frame-shaped member, the second frame-shaped member, and the intermediate member illustrated in FIGS. 3 and 4 are joined by brazing. FIG. 6 is a bottom view showing a modification of the protrusion shown in FIG. 5A and a plan view showing a modification of the protrusion shown in FIG. It is sectional drawing which shows the other modification of the projection part shown by FIG. It is the bottom view of the 1st frame-shaped member of the interconnector in the fuel cell concerning other embodiments of the present invention, and the top view of the 2nd frame-shaped member.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or equivalent elements are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 is a perspective view showing the appearance of a fuel cell according to an embodiment of the present invention. In FIG. 1, a fuel cell 1 of this embodiment is a solid oxide fuel cell (SOFC), and generates electricity by chemically reacting hydrogen in fuel and oxygen in air.

  The fuel cell 1 includes a stack 2 and end plates 3A and 3B arranged so as to sandwich the stack 2 in the vertical direction. An insulating plate 4 is disposed between the stack 2 and the end plates 3A and 3B. The end plates 3A and 3B and the insulating plate 4 have a square shape in plan view. The stack 2 and the end plates 3A and 3B are fixed by four bolts 5.

  In the upper end plate 3A, a fuel introduction pipe 6 for introducing fuel into the stack 2, a fuel lead-out pipe 7 for extracting fuel from the stack 2, and air for introducing air into the stack 2 An air introduction pipe 8 and an air lead-out pipe 9 for leading air out of the stack 2 are attached. The fuel introduction pipe 6 and the fuel lead-out pipe 7 are attached to the central portion of the end plate 3A in the vicinity of two opposing edges. The air introduction pipe 8 and the air lead-out pipe 9 are attached to the central part of the end plate 3A near the other two opposite edges.

  2A is a cross-sectional view taken along line A2-A2 in FIG. 1, and FIG. 2B is a cross-sectional view taken along line B2-B2 in FIG. In FIGS. 2A and 2B, the end plates 3A and 3B and the insulating plate 4 are omitted.

  In FIG. 2, the stack 2 has a structure in which a plurality of cell bodies 10 and interconnectors 11 are alternately stacked. The uppermost layer and the lowermost layer of the stack 2 are interconnectors 11.

  The cell body 10 is disposed between two interconnectors 11 adjacent in the stacking direction. The cell body 10 includes an electrolyte 12, a fuel electrode (anode) 13 disposed on the lower surface side (one surface side) of the electrolyte 12, and an air electrode (cathode) disposed on the upper surface side (other surface side) of the electrolyte 12. 14. The cell main body 10 generates and reacts fuel and air.

  The interconnector 11 is disposed so as to sandwich the cell body 10 from the fuel electrode 13 side and the air electrode 14 side. The interconnector 11 has a fuel flow path forming portion 15 facing the fuel electrode 13 and an air flow path forming portion 16 facing the air electrode 14. The fuel flow path forming unit 15 forms a flow path for supplying fuel to the fuel electrode 13. The air flow path forming unit 16 forms a flow path for supplying air to the air electrode 14. The fuel flow path forming part 15 and the air flow path forming part 16 have a structure in which, for example, a plurality of columnar or wall-shaped protrusions are provided, and a space between the protrusions serves as a fuel and air flow path.

  The interconnector 11 includes a fuel introduction passage 17 that introduces fuel from the fuel introduction pipe 6, a fuel introduction passage 18 that introduces fuel to the fuel introduction pipe 7, an air introduction passage 19 that introduces air from the air introduction pipe 8, The air outlet pipe 9 has an air outlet passage 20 that guides air out. The fuel introduction passage 17, the fuel lead-out passage 18, the air introduction passage 19, and the air lead-out passage 20 all have a substantially oval cross section (see FIG. 3). The fuel introduction passage 17 and the fuel lead-out passage 18 are disposed to face each other with the fuel flow path forming portion 15 and the air flow path forming portion 16 interposed therebetween. The air introduction passage 19 and the air outlet passage 20 are opposed to each other in a direction perpendicular to the opposing direction of the fuel introduction passage 17 and the fuel outlet passage 18 with the fuel flow passage forming portion 15 and the air flow passage forming portion 16 interposed therebetween. Has been.

  Further, the interconnector 11 is disposed between the fuel introduction passage 17 and the fuel flow path forming portion 15 and is formed so as not to be exposed to the cell body 10 by the wall portion 11a. And a fuel hollow passage 22 that is disposed between the fuel outlet passage 18 and the fuel passage formation portion 15 and is not exposed to the cell body 10 by the wall portion 11b, and an air introduction passage. 19 and the air flow path forming portion 16 and the air hollow flow path 23 formed so as not to be exposed to the cell body 10 by the wall portion 11c, the air outlet path 20, and the air flow path The air hollow channel 24 is disposed between the forming portion 16 and the wall portion 11d so as not to be exposed to the cell body 10 by the wall portion 11d.

  The fuel hollow flow path 21 is in communication with the fuel introduction path 17 and the fuel flow path forming portion 15. The fuel hollow flow path 22 communicates with the fuel outlet passage 18 and the fuel flow path forming portion 15. The hollow fuel flow paths 21 and 22 constitute a fuel flow path for flowing fuel from the fuel introduction path 17 to the fuel discharge path 18 in cooperation with the fuel flow path forming portion 15.

  The air hollow flow path 23 communicates with the air introduction passage 19 and the air flow path forming portion 16. The air hollow flow path 24 is in communication with the air outlet passage 20 and the air flow path forming portion 16. The air hollow flow paths 23, 24 constitute an air flow path for flowing air from the air introduction path 19 to the air outlet path 20 in cooperation with the air flow path forming unit 16.

  In such an interconnector 11, the direction in which fuel flows from the fuel introduction passage 17 to the fuel outlet passage 18 and the direction in which air flows from the air introduction passage 19 to the air outlet passage 20 intersect perpendicularly.

  The fuel introduced from the fuel introduction pipe 6 to the fuel introduction passage 17 is supplied to the fuel electrode 13 of the cell body 10 through the fuel hollow passage 21 and the fuel passage formation portion 15, and air is supplied from the air introduction pipe 8. The air introduced into the introduction passage 19 is supplied to the air electrode 14 of the cell body 10 through the air hollow flow path 23 and the air flow path forming portion 16, so that a power generation reaction occurs in the cell body 10. The fuel that has passed through the fuel flow path forming portion 15 is led out to the fuel outlet pipe 7 through the fuel hollow flow path 22 and the fuel outlet passage 18, and the air that has passed through the air flow path forming portion 16 is used for air. The air is led out to the air outlet pipe 9 through the hollow flow path 24 and the air outlet passage 20.

  As shown in FIGS. 3 and 4, the interconnector 11 includes a frame-shaped member (first frame-shaped member) 25, a frame-shaped member (second frame-shaped member) 26, and an intermediate member 27. . FIG. 3 is an exploded perspective view of the interconnector 11. FIG. 4 is an exploded cross-sectional view of the interconnector 11.

  The intermediate member 27 is disposed between the frame-shaped members 25 and 26. The frame-like members 25 and 26 and the intermediate member 27 are made of thin plates. The outer shape of the frame-shaped members 25 and 26 and the intermediate member 27 has a substantially square shape in plan view. A fuel flow path forming portion 15 is provided on one surface side of the intermediate member 27, and an air flow path forming portion 16 is provided on the other surface side of the intermediate member 27.

  The frame-shaped member 25 includes a pair of fuel through-holes (first fuel through-holes) 29 that are part of the fuel introduction passage 17 and the fuel lead-out passage 18 and each have a substantially oval shape in plan view, and an air introduction passage. 19 and a pair of air through-holes (first air through-holes) 30 having a substantially oval shape in plan view, each constituting a part of the air outlet passage 20 and the air outlet passage 20. The longitudinal direction of the air through hole 30 and the longitudinal direction of the fuel through hole 29 are orthogonal to each other. The fuel flow path forming portion 15 of the intermediate member 27 penetrates into the inner region F1 of the frame member 25.

  As shown in FIG. 5, the frame-like member 25 has a pair of concave portions (first concave portions) 28 that respectively define the fuel hollow channels 21 and 22. 5A is a bottom view of the frame-shaped member 25, and FIG. 5B is a cross-sectional view taken along line B5-B5 of FIG. 5A. The concave portion 28 opens to the intermediate member 27 side. A rectangular parallelepiped protrusion (first protrusion) 50 projects from the center of the bottom surface of the recessed portion 28 in the frame member 25. The front end surface of the protrusion 50 is flush with the lower surface of the frame member 25.

  The frame-shaped member 26 includes a pair of fuel through-holes (second fuel through-holes) 32 that are part of the fuel introduction passage 17 and the fuel lead-out passage 18 and each have a substantially oval shape in plan view, and an air introduction passage. 19 and a pair of air through-holes (second air through-holes) 33 each having a substantially oval shape in plan view and constituting a part of the air outlet passage 20. The longitudinal direction of the air through hole 33 and the longitudinal direction of the fuel through hole 32 are orthogonal to each other. The air flow path forming portion 16 of the intermediate member 27 penetrates into the inner region F2 of the frame member 26.

  As shown also in FIG. 6, the frame-shaped member 26 has a pair of concave portions (second concave portions) 31 that respectively define the air hollow channels 23 and 24. 6A is a plan view of the frame-like member 26, and FIG. 6B is a cross-sectional view taken along line B6-B6 of FIG. 6A. The concave portion 31 opens to the intermediate member 27 side. A rectangular parallelepiped protrusion (second protrusion) 51 projects from the center of the bottom surface of the recessed portion 31 of the frame member 26. The front end surface of the protrusion 51 is flush with the upper surface of the frame member 26.

  The intermediate member 27 includes a pair of fuel through-holes (third fuel through-holes) 34 that are part of the fuel introduction passage 17 and the fuel lead-out passage 18, each having a substantially oval shape in plan view, and the air introduction passage 19. And a pair of air through-holes (third air through-holes) 35 having a substantially oval shape in plan view, each constituting a part of the air outlet passage 20. The longitudinal direction of the air through hole 35 and the longitudinal direction of the fuel through hole 34 are orthogonal to each other.

  The frame-shaped members 25 and 26 and the intermediate member 27 that are components of the interconnector 11 are made of a metal material. As the metal material, for example, a heat-resistant stainless steel Fe—Cr ferrite alloy, a Cr-based alloy, a Ni-based alloy, or the like is used. Thereby, it is possible to obtain an interconnector 11 having high electric conductivity and low cost.

  By using three members such as the frame-shaped members 25 and 26 and the intermediate member 27, the interconnector 11 having the fuel hollow channels 21 and 22 and the air hollow channels 23 and 24 can be easily made. it can.

  As shown in FIG. 3, the frame members 25 and 26 and the intermediate member 27 are joined by brazing using sheet-like brazing materials 36 and 37. The brazing material 36 is disposed between the frame-shaped member 25 and the intermediate member 27, and the brazing material 37 is disposed between the frame-shaped member 26 and the intermediate member 27. As the brazing materials 36 and 37, silver brazing, nickel brazing or the like is used.

  The brazing materials 36 and 37 have a frame shape. The brazing material 36 is provided with an opening 38 corresponding to the air through hole 30 of the frame member 25, but the opening corresponding to the fuel through hole 29 adjacent to the concave portion 28 of the frame member 25. Is not provided. The brazing material 37 is provided with an opening 39 corresponding to the fuel through hole 32 of the frame member 26, but the opening corresponding to the air through hole 33 adjacent to the concave portion 31 of the frame member 26. Is not provided.

  Thus, since the frame-shaped members 25 and 26 and the intermediate member 27 are joined by the sheet-like brazing materials 36 and 37, the joint surfaces of the frame-shaped members 25 and 26 and the intermediate member 27 are not easily uneven. Accordingly, variations in the thickness of the entire interconnector 11 can be suppressed.

  Returning to FIG. 2, a pair of seal members 40 and a pair of seal members 41 are arranged around the cell body 10 between the two interconnectors 11 adjacent in the stacking direction so as to surround the cell body 10. . Each seal member 40 is disposed to face the cell body 10. Each seal member 41 is disposed to face in the direction perpendicular to the facing direction of each seal member 40 across the cell body 10.

  The seal members 40 and 41 both have an annular shape. The sealing members 40 and 41 are members that seal between the two adjacent interconnectors 11 so as not to mix the fuel and air and electrically insulate the two adjacent interconnectors 11 from each other. The seal members 40 and 41 are made of an electrically insulating material (for example, glass). The inner region S1 of the seal member 40 is a passage through which fuel passes. The inner region S2 of the seal member 41 is a passage through which air passes.

  FIG. 7 is an enlarged cross-sectional view showing a state when the frame-like members 25 and 26 and the intermediate member 27 are joined by brazing in the conventional interconnector 11 as a comparative example. In FIG. 7, the protruding portion 51 is not provided on the bottom surface of the recessed portion 31 in the frame-shaped member 26. Although not shown, the protrusion 50 is not provided on the bottom surface of the concave portion 28 of the frame-like member 25.

  When the frame-shaped members 25 and 26 and the intermediate member 27 are joined by brazing, the frame-shaped member with the brazing members 36 and 37 interposed between the frame-shaped members 25 and 26 and the intermediate member 27, respectively. A load is applied to 25 and 26 and the intermediate member 27 from both the upper and lower sides. However, the protrusion 50 is not provided on the bottom surface of the concave portion 28 in the frame-like member 25, and the protrusion 51 is not provided on the bottom surface of the concave portion 31 in the frame-like member 26. Accordingly, the distance between the bottom surface of the concave portion 28 in the frame-shaped member 25 and the intermediate member 27 is increased, and the distance between the bottom surface of the concave portion 31 in the frame-shaped member 26 and the intermediate member 27 is increased. The frame members 25 and 26 are easily bent, and it is difficult to perform stable brazing. As a result, it becomes difficult to achieve airtightness of the interconnector 11 by brazing.

  On the other hand, in the present embodiment, the protrusion 50 protrudes from the bottom surface of the concave portion 28 of the frame member 25 and the protrusion 51 protrudes from the bottom surface of the concave portion 31 of the frame member 26. As shown in FIG. 8, when the frame-like members 25 and 26 and the intermediate member 27 are joined by brazing, the protrusions 50 and 51 receive a load. Accordingly, the concave portion 28 that defines the fuel hollow channels 21 and 22 is provided in the frame-shaped member 25, and the concave portion 31 that defines the air hollow channels 23 and 24 is provided in the frame-shaped member 26. However, the frame-shaped members 25 and 26 are not easily bent. Thereby, stable brazing can be realized in the interconnector 11. As a result, it is possible to ensure airtightness of the interconnector 11 by brazing.

  Fig.9 (a) is a bottom view which shows the modification of the frame-shaped member 25 shown by Fig.5 (a). In FIG. 9 (a), fuel is led out from the fuel through hole 29 side (upstream side) where the protrusion 50 forms a part of the fuel introduction passage 17 on both side surfaces of the protrusion 50 provided on the frame-like member 25. The tapered surface 50 a is tapered toward the fuel through hole 29 (downstream side) constituting a part of the passage 18. As a result, the fuel easily flows from the fuel introduction passage 17 to the fuel outlet passage 18.

  FIG.9 (b) is a top view which shows the modification of the frame-shaped member 26 shown by Fig.6 (a). In FIG. 9B, air is led out from the side of the air through hole 33 (upstream side) where the protrusion 51 forms part of the air introduction passage 19 on both side surfaces of the protrusion 51 provided on the frame-shaped member 26. The tapered surface 51a is tapered toward the air through hole 33 (downstream side) constituting a part of the passage 20. As a result, air easily flows from the air introduction passage 19 to the air outlet passage 20.

  Note that a taper surface 50a is provided only on one of the upstream protrusion 50 and the downstream protrusion 50, or only one of the upstream protrusion 51 and the downstream protrusion 51 is a taper surface 51a. May be provided. Further, only one side surface of the protruding portion 50 may be the tapered surface 50a, or only one side surface of the protruding portion 51 may be the tapered surface 51a. Further, the protrusions 50 and 51 may be provided with chamfering or R instead of the tapered surfaces 50a and 51a.

  FIG. 10 is a cross-sectional view showing another modification of the frame-shaped member 26 shown in FIG. In FIG. 10, both side surfaces of the protrusion 51 provided on the frame-shaped member 26 are tapered surfaces 51 b such that the protrusion 51 tapers from the proximal end side toward the distal end side. Thus, the air flow path volume can be increased by cutting both side surfaces of the protrusion 51 into a tapered shape.

  Note that the tapered surface 51b may be provided on only one of the upstream protrusion 51 and the downstream protrusion 51. Further, only one side surface of the protruding portion 51 may be a tapered surface 51b.

  Although not particularly illustrated, the side surface of the protrusion 50 provided on the frame-like member 25 may be a tapered surface such that the protrusion 50 is tapered from the base end side toward the tip end side. In this case, the flow volume of the fuel can be increased.

  FIG. 11A is a bottom view of a first frame member of an interconnector in a fuel cell according to another embodiment of the present invention. In FIG. 11A, a plurality (three in this case) of rectangular parallelepiped-shaped protrusions (first protrusions) 60 protrude from the bottom surface of the recessed portion 28 in the frame-shaped member 25. These projections 60 have the same volume. The number of the protrusions 60 arranged in the region on the air through hole 30 side (the left side in the figure) constituting a part of the air introduction passage 19 is the same as the number of the projections 60 on the air through hole 30 side constituting a part of the air outlet passage 20 ( More than the number of the protrusions 60 arranged in the region on the right side of the drawing. Accordingly, the total volume of the protrusions 60 arranged in the region on the air introduction passage 19 side is larger than the total volume of the protrusions 60 arranged in the region on the air lead-out passage 20 side.

  FIG. 11B is a plan view of the second frame-shaped member of the interconnector in the fuel cell according to another embodiment of the present invention. In FIG. 11B, a plurality of (three in this case) rectangular parallelepiped protrusions (second protrusions) 61 protrude from the bottom surface of the recessed portion 31 of the frame-shaped member 26. These projections 61 have the same volume. The number of protrusions 61 arranged in the region on the fuel through-hole 32 side (upper side in the drawing) constituting a part of the fuel introduction passage 17 is equal to the number of the fuel through-hole 32 side constituting a part of the fuel lead-out passage 18 ( The number is larger than the number of protrusions 61 arranged in the lower region in the drawing. Accordingly, the total volume of the protrusions 61 arranged in the region on the fuel introduction passage 17 side is larger than the total volume of the protrusions 61 arranged in the region on the fuel lead-out passage 18 side.

  By the way, in the region where the fuel introduction passage 17 and the air introduction passage 19 are adjacent, more fuel and air flow than in the region where the fuel lead-out passage 18 and the air lead-out passage 20 are adjacent. Therefore, in the region corresponding to the region on the side where the fuel introduction passage 17 and the air introduction passage 19 in the cell body 10 are adjacent to each other, the fuel lead-out passage 18 and the air lead-out passage 20 in the cell body 10 correspond to regions on the adjacent side. Power generation reaction is more likely to occur than in the area. Therefore, the total volume of the protrusions 60 arranged in the region on the air introduction passage 19 side is equal to the total volume of the protrusions 60 arranged in the region on the air lead-out passage 20 side, and is arranged in the region on the fuel introduction passage 17 side. When the total volume of the protrusions 61 is equal to the total volume of the protrusions 61 arranged in the region on the fuel outlet passage 18 side, the power generation reaction is not uniform in the cell body 10.

  On the other hand, in the present embodiment, the total volume of the projections 60 arranged in the region on the air introduction passage 19 side is larger than the total volume of the projections 60 arranged in the region on the air lead-out passage 20 side. The total volume of the protrusions 61 arranged in the region on the 17 side is larger than the total volume of the protrusions 61 arranged in the region on the fuel outlet passage 18 side. Therefore, the pressure loss of the fuel and air in the region where the fuel introduction passage 17 and the air introduction passage 19 are adjacent is more than the pressure loss of the fuel and air in the region where the fuel lead-out passage 18 and the air extraction passage 20 are adjacent. Also grows. Therefore, the difference in the amount of fuel and air flowing between the region adjacent to the fuel introduction passage 17 and the air introduction passage 19 and the region adjacent to the fuel lead-out passage 18 and the air lead-out passage 20 is reduced. Thereby, the uniformity of the power generation reaction in the cell body 10 can be improved.

  At this time, since the number of the protrusions 60 arranged in the area on the air introduction passage 19 side is larger than the number of the protrusions 60 arranged in the area on the air lead-out passage 20 side, the volume of each protrusion 60 is made equal. However, the total volume of the protrusions 60 arranged in the region on the air introduction passage 19 side is larger than the total volume of the protrusions 60 arranged in the region on the air lead-out passage 20 side. Further, since the number of the protrusions 61 disposed in the region on the fuel introduction passage 17 side is larger than the number of the protrusions 61 disposed in the region on the fuel lead-out passage 18 side, the volume of each protrusion 61 is made equal. In addition, the total volume of the protrusions 61 disposed in the region on the fuel introduction passage 17 side is larger than the total volume of the protrusions 61 disposed in the region on the fuel outlet passage 18 side.

  In the present embodiment, the number of projections 60 arranged in the region on the air introduction passage 19 side is larger than the number of projections 60 arranged in the region on the air lead-out passage 20 side. The number of the protrusions 61 disposed in the region is larger than the number of the protrusions 61 disposed in the region on the fuel outlet passage 18 side, but is not particularly limited thereto. For example, the number of projections 60 arranged in the region on the air introduction passage 19 side is equal to the number of projections 60 arranged in the region on the air lead-out passage 20 side, and the projection arranged in the region on the fuel introduction passage 17 side. Even if the number of the portions 61 is equal to the number of the protrusions 61 arranged in the region on the fuel outlet passage 18 side, the volume of the protrusions 60 arranged in the region on the air introduction passage 19 side is the region on the air outlet passage 20 side. If the volume of the projection 61 arranged in the region on the fuel introduction passage 17 is larger than the volume of the projection 61 arranged in the region on the fuel outlet passage 18 side. Good.

  Further, if the total volume of the projections 60 arranged in the region on the air introduction passage 19 side is larger than the total volume of the projections 60 arranged in the region on the air lead-out passage 20 side, the region on the fuel introduction passage 17 side is provided. The total volume of the protrusions 61 arranged may be equal to the total volume of the protrusions 61 arranged in the region on the fuel outlet passage 18 side. Also in this case, the pressure loss of the fuel and air in the region where the fuel introduction passage 17 and the air introduction passage 19 are adjacent is caused by the pressure loss of the fuel and air in the region where the fuel lead-out passage 18 and the air lead-out passage 20 are adjacent. Greater than the loss. Thereby, the uniformity of the power generation reaction in the cell body 10 can be improved.

  Similarly, if the total volume of the projections 61 arranged in the region on the fuel introduction passage 17 side is larger than the total volume of the projections 61 arranged in the region on the fuel lead-out passage 18 side, the region on the air introduction passage 19 side. The total volume of the protrusions 60 disposed in the air passage may be equal to the total volume of the protrusions 60 disposed in the region on the air outlet passage 20 side. Also in this case, the pressure loss of the fuel and air in the region where the fuel introduction passage 17 and the air introduction passage 19 are adjacent is caused by the pressure loss of the fuel and air in the region where the fuel lead-out passage 18 and the air lead-out passage 20 are adjacent. Greater than the loss. Thereby, the uniformity of the power generation reaction in the cell body 10 can be improved.

  As mentioned above, although embodiment of this invention has been described, this invention is not limited to the said embodiment. For example, in the above-described embodiment, the rectangular parallelepiped first protrusion protrudes from the bottom surface of the concave portion 28 of the frame-shaped member 25, and the rectangular parallelepiped second protrusion protrudes from the bottom surface of the concave portion 31 of the frame-shaped member 26. However, the shape of the first protrusion and the second protrusion is not particularly limited to a rectangular parallelepiped shape, and may be a columnar shape or the like.

  Further, in the above embodiment, the brazing material is not provided on the tip surface of the protruding portion that protrudes from the bottom surface of the concave portion of the frame-shaped member. A brazing material may be provided.

  Furthermore, in the said embodiment, although the interconnector 11 is comprised from the metal material, as a material of the interconnector 11, it is not restricted to a metal in particular, If it is a material (conductive ceramic etc.) which can be brazed, Good.

  The fuel cell 1 of the above embodiment has the stack 2 in which a plurality of cell main bodies 10 and interconnectors 11 are alternately stacked. However, the present invention relates to one cell main body 10 and this cell. The present invention is also applicable to a fuel cell having a single cell structure that includes two interconnectors 11 arranged so as to sandwich the main body 10 from the fuel electrode 13 side and the air electrode 14 side.

  DESCRIPTION OF SYMBOLS 1 ... Fuel cell, 10 ... Cell main body, 11 ... Interconnector, 12 ... Electrolyte, 13 ... Fuel electrode, 14 ... Air electrode, 15 ... Fuel flow path formation part, 16 ... Air flow path formation part, 17 ... Fuel introduction passage , 18 ... Fuel outlet passage, 19 ... Air inlet passage, 20 ... Air outlet passage, 21, 22 ... Fuel hollow passage (fuel passage), 23, 24 ... Air hollow passage (air passage), 25 ... Frame-shaped member (first frame-shaped member), 26 ... Frame-shaped member (second frame-shaped member), 27 ... Intermediate member, 28 ... Concave portion (first concave portion), 31 ... Concave portion (second concave portion) ), 50 ... Projection (first projection), 50 a ... Tapered surface, 51 ... Projection (second projection), 51 a ... Tapered surface, 60 ... Projection (first projection), 61 ... Projection ( Second protrusion).

Claims (6)

A cell body having a fuel electrode disposed on one surface side of the electrolyte and an air electrode disposed on the other surface side of the electrolyte, and generating and reacting fuel and air;
An interconnector disposed so as to sandwich the cell body from the fuel electrode side and the air electrode side, and having a fuel flow path forming part facing the fuel electrode and an air flow path forming part facing the air electrode; Prepared,
The interconnector includes a fuel introduction passage for introducing fuel, a fuel extraction passage for extracting fuel, an air introduction passage for introducing air, an air extraction passage for extracting air, and the fuel extraction from the fuel introduction passage. A fuel flow path for flowing fuel to the passage, and an air flow path for flowing air from the air introduction path to the air outlet path,
The interconnector has a first frame-like member having a first concave part that defines a part of the fuel flow path, and a second frame shape having a second concave part that defines a part of the air flow path. A member, and an intermediate member disposed between the first frame-shaped member and the second frame-shaped member and having the fuel flow path forming portion and the air flow path forming portion,
The first frame-shaped member, the second frame-shaped member, and the intermediate member are joined by brazing,
A fuel cell, wherein a first protrusion protrudes from the bottom surface of the first concave portion, and a second protrusion protrudes from the bottom surface of the second concave portion. The direction in which fuel flows from the fuel introduction passage to the fuel lead-out passage intersects the direction in which air flows from the air introduction passage to the air lead-out passage,
The total volume of the first protrusions arranged in the region on the air introduction passage side is larger than the total volume of the first protrusions arranged in the region on the air lead-out passage side. The fuel cell according to 1. The direction in which fuel flows from the fuel introduction passage to the fuel lead-out passage intersects the direction in which air flows from the air introduction passage to the air lead-out passage,
The total volume of the second protrusions arranged in the region on the fuel introduction passage side is larger than the total volume of the second protrusions arranged in the region on the fuel lead-out passage side. The fuel cell according to 1. The direction in which fuel flows from the fuel introduction passage to the fuel lead-out passage intersects the direction in which air flows from the air introduction passage to the air lead-out passage,
The total volume of the first protrusions arranged in the region on the air introduction passage side is larger than the total volume of the first protrusions arranged in the region on the air lead-out passage side,
The total volume of the second protrusions arranged in the region on the fuel introduction passage side is larger than the total volume of the second protrusions arranged in the region on the fuel lead-out passage side. The fuel cell according to 1. The number of the first protrusions arranged in the region on the air introduction passage side is larger than the number of the first protrusions arranged in the region on the air lead-out passage side,
5. The number of the second protrusions arranged in the region on the fuel introduction passage side is larger than the number of the second protrusions arranged in the region on the fuel lead-out passage side. Fuel cell. The side surface of the first protrusion is a tapered surface such that the first protrusion is tapered from the fuel introduction passage side toward the fuel lead-out passage side,
The side surface of the second projecting portion has a tapered surface such that the second projecting portion tapers from the air introduction passage side toward the air lead-out passage side. The fuel cell according to any one of the above.

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