JP5168623B2 - Fuel cell stack, fuel cell module including the same, and fuel cell including the same - Google Patents

Description

  The present invention relates to a fuel cell stack used for a solid oxide fuel cell (SOFC), a fuel cell module including the same, and a fuel cell including the same.

  Conventionally, in such a fuel cell, a plurality of fuel cells are accommodated in a storage container, and each of the plurality of fuel cells is supplied with fuel gas and air as an oxidant gas to operate. The reason why the plurality of fuel cells are used is that a sufficient electromotive force cannot be obtained with a single fuel cell. Therefore, a plurality of fuel cells are arranged in series or in parallel to increase the voltage and current.

A technique described in Patent Document 1 below proposes that a cylindrical fuel battery cell is used, which facilitates the serial arrangement and parallel arrangement of the fuel battery cells, and can reduce the size of the entire fuel cell. Has been. A fuel cell disclosed in the following Patent Document 1 includes a cylindrical single cell including a tubular cell and a connecting member in which a first electrode, an electrolyte, and a second electrode are sequentially laminated on the outer surface of a support. A current collector plate and a second current collector plate are connected via a connecting member.
JP 2002-289249 A

  The fuel cell described in Patent Document 1 holds a plurality of cylindrical single cells sandwiched between a first current collector plate and a second current collector plate. Accordingly, the first current collector plate and the second current collector plate serve to hold the cylindrical single cell and to collect electricity from the cylindrical single cell. Therefore, since it is necessary to collect electricity taken from the same pole of each cylindrical single cell on one current collector plate, the cylindrical single cells could only be arranged in parallel between the pair of current collector plates. . When the cylindrical unit cells are connected in series in the technique described in Patent Document 1, as shown in FIGS. 6 and 7 of Patent Document 1, the cylindrical unit cells are serially connected in the longitudinal direction. When the fuel cell is configured, there is a limitation on the form.

  Therefore, the present inventors have studied a fuel cell stack that can increase the degree of freedom of the arrangement of fuel cells. In the fuel cell stack that solves such a problem, it has been found that there is a problem that cannot be assumed in the past when securing the electrical connection between the fuel cells.

  Therefore, in the present invention, the degree of freedom of the arrangement mode of the fuel cells can be increased, and the fuel cell stack capable of reliably ensuring the electrical connection between the fuel cells, and the fuel including the fuel cell stack It aims at providing a battery module and a fuel cell provided with the same.

  In order to solve the above problems, a fuel cell stack according to the present invention is formed in an annular shape, and is arranged so as to overlap with the first electrode layer configured to allow gas to pass through the internal space. A plurality of fuel cells that are operated by a fuel gas and an oxidant gas, the solid electrolyte layer having an annular shape, and a second electrode layer that is disposed on the solid electrolyte layer and is annularly formed. A fuel cell stack comprising: a current collecting member for collecting current from one of the first electrode layer and the second electrode layer provided at an end of each of the plurality of fuel cells; and the fuel cell A plurality of fuel cell units, a holding plate for holding the plurality of fuel cell units upright with respect to the main surface, and a first fuel among the plurality of fuel cells Provided in the battery cell And a plurality of connecting members for electrically connecting a current collecting member provided in a second fuel cell among the plurality of fuel cells, and The member has a flat portion formed along the end surface of the fuel cell, and the connecting member is electrically connected to the current collecting member by at least a part of the connecting member being in contact with the flat portion of the current collecting member. Connected.

  ADVANTAGE OF THE INVENTION According to this invention, the fuel cell stack which can raise the freedom degree of the arrangement | positioning aspect of a fuel cell, and can ensure the electrical connection of fuel cells reliably is provided. A fuel cell module and a fuel cell including the same can be provided.

  Prior to describing the best mode for carrying out the present invention, the function and effect of the present invention will be described.

  A fuel cell stack according to the present invention includes a first electrode layer formed in an annular shape and configured to allow gas to pass through an internal space, and a solid formed in an annular shape so as to overlap the first electrode. The fuel cell stack includes an electrolyte layer and a second electrode layer formed in an annular shape so as to overlap with the solid electrolyte layer, and includes a plurality of fuel cells operated by a fuel gas and an oxidant gas. A plurality of fuel cells each having a current collecting member for collecting current from one of the first electrode layer and the second electrode layer provided at an end of each of the plurality of fuel cells, and the fuel cell. A cell unit; a holding plate for holding the plurality of fuel cell units upright with respect to a main surface thereof; and a first fuel cell among the plurality of fuel cells. A current collecting member; A plurality of connecting members for electrically connecting a current collecting member provided in a second fuel cell of the fuel cells, wherein the current collecting member comprises The connecting member has a flat portion formed along the end face, and the connecting member is electrically connected to the current collecting member by at least a part of the connecting member being in contact with the flat portion of the current collecting member.

  According to the present invention, the current collecting member having a flat portion formed along the end face of the fuel cell having the annularly formed portion, and the connecting member responsible for the electrical connection between the fuel cells, Since it is electrically connected by abutting on the flat surface portion of the current collecting member, a planar joined state having a predetermined area can be secured, and the reliability of electrical connection can be improved.

  In the fuel cell stack according to the present invention, it is also preferable that the connection member is sandwiched between a flat portion of the current collecting member and a main surface of the holding plate. According to this preferable aspect, since the connection member responsible for the electrical connection between the fuel cells is sandwiched between the planar portion of the current collector and the main surface of the holding plate, the plane of the connection member and the current collector is Can be brought into close contact with each other. Therefore, a planar joining state between the connecting member and the current collecting member can be ensured more reliably, and the reliability of electrical connection can be improved.

  Further, in the fuel cell stack according to the present invention, the current collecting member is attached to the fuel cell so as to surround an end portion including an end surface and a side surface of the fuel cell, and the connection member It is also preferable that the current collecting member is electrically connected to the current collecting member by abutting against a portion along the side surface of the fuel cell. According to this preferable aspect, the connecting member and the current collecting member are in contact with each other in a portion along the side surface of the fuel cell, together with the planar joined state. A planar joining state with the current collecting member can be ensured more reliably, and the reliability of electrical connection can be improved.

  In the fuel cell stack according to the present invention, it is also preferable that some of the plurality of connection members function as terminals for taking out electricity from the fuel cell stack. According to this preferred aspect, a part of the connection member that is responsible for electrical connection between the fuel cells also serves to take out electricity from the fuel cell stack, so that the number of members can be reduced.

  Moreover, in a fuel cell module provided with the fuel cell stack according to the present invention, it is possible to provide a fuel cell module having the above-described effects. Moreover, in a fuel cell provided with the fuel cell stack according to the present invention, a fuel cell having the above-described effects can be provided.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the accompanying drawings. In order to facilitate the understanding of the description, the same constituent elements in the drawings will be denoted by the same reference numerals as much as possible, and redundant description will be omitted.

  The fuel cell module FC according to the present embodiment will be described with reference to FIGS. FIG. 1 is a schematic perspective view in which the fuel cell module FC is partially broken. FIG. 2 is a view of the fuel cell module FC as viewed from the direction A in FIG. FIG. 3 is a view of the fuel cell module FC as viewed from the direction B in FIG.

  In the fuel cell module FC, ten fuel cell stacks 400 are arranged side by side in a space sealed by the cover member 1 (second member) and the base member 2 (first member). In each fuel cell stack 400, 16 fuel cell units 30 including the fuel cells 4 are arranged in 2 rows × 8 rows. The fuel cell unit 30 and the fuel cell 4 are electrically arranged in series.

  The cover member 1 includes a rectangular flat plate-like upper wall 10 and side walls 11 connected to the respective sides of the upper wall 10 and extending in one direction. A flange 12 is formed at the end opposite to the side connected to the upper wall 10 of the side wall 11. A space sealed by the cover member 1 and the base member 2 is formed by bringing the flange portion 12 of the cover member 1 into contact with the base plate 21 of the base member 2. This sealed space is partitioned by partition plates 22 and 23, and a cell chamber 13 and an exhaust gas chamber 14 are formed. An exhaust gas pipe 36 is connected to the exhaust gas chamber 14, and the exhaust gas is discharged outside through the exhaust gas pipe 36.

  The upper wall 10 is composed of a rectangular flat plate member and forms a single wall structure. The side wall 11 is constituted by four side wall portions 111, 112, 113 and 114. Each of the side wall portions 111, 112, 113, and 114 has a triple wall structure using three rectangular flat plate members. An air flow path 116 is provided inside the side wall portion 112, and an air flow path 118 is provided inside the side wall portion 114.

  A gas tank 6 is placed on the partition plates 22 and 23. Ten fuel cell stacks 400 are arranged side by side in the gas tank 6, and fuel gas is supplied from the gas tank 6 to the fuel cells 4 constituting each fuel cell stack 400.

  More specifically, an opening 61 (see FIG. 2) having substantially the same shape as the lower support plate 400 b (holding plate) of the fuel cell stack 400 is provided on the upper surface of the gas tank 6. The gas tank 6 and each fuel cell stack 400 are connected with the lower support plate 400b being in close contact with each other. Therefore, the fuel cell 4 constituting the fuel cell stack 400 is erected on the gas tank 6 with its tip portion facing upward and the portion opposite to the tip portion connected to the gas tank 6. . The gas tank 6 is placed on the partition plate 22, and the partition plate 22 is fixed to the base member 2. Therefore, the fuel cells 4 constituting the fuel cell stack 400 are erected on the partition plate 22 corresponding to the flat plate portion provided on the base member 2 as the first member. The gas tank 6 is disposed in contact with the exhaust gas chamber 14 so as to receive heat from the exhaust gas chamber 14 by heat conduction.

  A perspective view of the gas tank 6 is shown in FIG. The gas tank 6 has a rectangular parallelepiped main body 6a and flange portions 6b provided at both ends of the main body 6a. An outer frame portion 611 and a crosspiece portion 612 are provided on the upper surface of the main body 6a. In the case of this embodiment, nine crosspieces 612 are provided, and ten openings 61 are formed. Each crosspiece 612 is provided with two support columns 613. The support column 613 is provided between the crosspiece 612 and the bottom plate 614 of the main body 6a, and supports the crosspiece 612. The outer frame portion 611 and the crosspiece portion 612 are provided with a step so as to surround the opening 61. The lower support plate 400b of the fuel cell stack 400 is supported by this step. The gas tank 6 is also provided with a connecting pipe 34 through which the reformed fuel gas is introduced into the main body 6a.

  1 to 3, the reformer 7 is provided above each fuel cell stack 400. In the reformer 7, a reforming catalyst is enclosed. As the reforming catalyst, a catalyst in which nickel is applied to the surface of the alumina sphere and a catalyst in which ruthenium is applied to the surface of the alumina sphere are appropriately used. These reforming catalysts are spheres. On the other hand, the reformer 7 is connected to a fuel gas supply pipe 32, a water vapor supply pipe 33, and a connection pipe 34, and a circular hole is formed as an opening in a connection portion where these are connected. If the reforming catalyst is smaller than the opening, the reforming catalyst flows out from the reformer 7, and therefore, in the present embodiment, a mesh member (not shown) is provided as an inflow prevention unit. Although not explicitly shown in FIGS. 1 to 3, in the present embodiment, a solenoid valve is attached to each of the fuel gas supply pipe 32 and the water vapor supply pipe 33, and each solenoid valve is output from a CPU as a control unit. It is configured so as to be able to change the ratio of fuel gas to water vapor supplied to the reformer 7 by opening and closing in accordance with the instruction signal.

  The fuel gas and water vapor introduced into the reformer 7 are reformed by the reforming catalyst stored in the reformer 7. The reformed fuel gas is supplied to the gas tank 6 through the connecting pipe 34. Inside the reformer 7, there is a space between a portion where the fuel gas supply pipe 32 and the water vapor supply pipe 33 are connected to the reformer 7 and a portion where the connection pipe 34 is connected to the reformer 7. A partition wall (not explicitly shown in FIGS. 1 to 3) is provided so as to partition. Therefore, the portion where the fuel gas supply pipe 32 and the water vapor supply pipe 33 are connected and the portion where the connection pipe 34 is connected are separated by a length approximately twice the longitudinal direction of the reformer 7. It becomes the same composition as there is. As a result, the fuel gas and air supplied to the reformer 7 can sufficiently touch the reforming catalyst.

  The fuel gas reformed by the reformer 7 is supplied to the gas tank 6 through the connecting pipe 34. The fuel gas rises from the gas tank 6 through an in-pipe flow path (not explicitly shown in FIGS. 1 to 3) of the fuel cell unit 30. Further, the air flowing outside the fuel cell 4 also rises. On the upper side of the fuel cell stack 400, an ignition device (not shown in the figure) for starting combustion of combustion gas and air is provided, and fuel gas and air are operated by the action of this ignition device and the combustion catalyst. And mix and burn. Therefore, the portion where the combustion gas and air are mixed and burned is the combustion portion, and the fuel cells 4 constituting the fuel cell stack 400 are heated from above by the combustion in the combustion portion.

  Each fuel battery cell 4 has a tubular shape, and is operated by the action of a gas flowing inside the pipe of the fuel battery cell 4 and a gas flowing outside the pipe. In the present embodiment, the gas flowing in the pipe of the fuel battery cell 4 is a fuel gas such as reformed gas obtained by reforming hydrogen or hydrocarbon fuel, and the gas flowing outside the pipe of the fuel battery cell 4 contains oxygen. Contains air.

  Here, the fuel cell unit 30 including the fuel cells 4 will be described with reference to FIG. As shown in FIG. 5, the fuel cell unit 30 is a tubular structure formed by the fuel cells 4 and extending in the vertical direction, and includes a cylindrical fuel cell 4 and one end of the fuel cell 4. It has an inner electrode terminal 40 (current collecting member) attached to 4a and an outer electrode terminal 42 (current collecting member) attached to the other end 4b.

  The fuel cell 4 is disposed between a cylindrical inner electrode layer 44 (first electrode layer), a cylindrical outer electrode layer 48 (second electrode layer), and the electrode layers 44, 48. The cylindrical electrolyte layer 46 (solid electrolyte layer) and the through flow path 50 formed inside the inner electrode layer 44 are provided. Further, an inner electrode exposed peripheral surface 44a in which the inner electrode layer 44 is exposed to the electrolyte layer 46 and the outer electrode layer 48 at one end 4a of the fuel cell 4, and the electrolyte layer 46 is an outer electrode layer. An electrolyte exposed peripheral surface 46 a exposed to 48 is provided. The other end 4b of the fuel cell 4 is configured by an outer electrode exposed peripheral surface 48a from which the outer electrode layer 48 is exposed.

  The inner electrode layer 44 includes, for example, a mixture of Ni and zirconia doped with at least one selected from rare earth elements such as Ca, Y, and Sc, ceria doped with at least one selected from Ni and rare earth elements, A mixture of Ni and a mixture of lanthanum gallate doped with at least one selected from Sr, Mg, Co, Fe, and Cu.

  The electrolyte layer 46 includes, for example, zirconia doped with at least one selected from rare earth elements such as Y and Sc, ceria doped with at least one selected from rare earth elements, lanthanum gallate doped with at least one selected from Sr and Mg, Formed from at least one of the following.

  The outer electrode layer 48 is made of, for example, lanthanum manganite doped with at least one selected from Sr and Ca, lanthanum ferrite doped with at least one selected from Sr, Co, Ni, and Cu, Sr, Fe, Ni, and Cu. It is formed from at least one selected from samarium cobalt and silver doped with at least one selected.

  In this case, the inner electrode layer 44 becomes a fuel electrode, and the outer electrode layer 48 becomes an air electrode. The thickness of the inner electrode layer 44 is, for example, 1 mm, the thickness of the electrolyte layer 46 is, for example, 30 μm, the thickness of the outer electrode layer 48 is, for example, 30 μm, and the outer diameter is For example, it is 1-10 mm.

  The inner electrode terminal 40 is disposed so as to cover the inner electrode outer peripheral surface 44a from the outside over the entire circumference and is electrically connected to the main body portion 40a (large diameter portion), and the longitudinal length of the fuel cell 4 from the main body portion 40a. It has a tubular portion 40b (small diameter portion) extending in the direction. The main body portion 40a and the tubular portion 40b are cylindrical and concentrically arranged, and the tube diameter of the tubular portion 40b is smaller than the tube diameter of the main body portion 40a. The tubular portion 40b has a connection channel 40c that communicates with the through channel 50 and communicates with the outside. A step portion 40 d between the main body portion 40 a and the tubular portion 40 b is in contact with the end surface 44 b of the inner electrode layer 44. The inner electrode terminal 40 is provided at an end portion of the fuel battery cell 4, and has a step portion 40 d as a flat portion formed along an end surface 44 b that is a part of the end face of the fuel battery cell 4. . The inner electrode terminal 40 is formed so as to surround an end including the side surface of the fuel battery cell 4 in addition to the end face 44 d which is an end face of the fuel battery cell 4.

  The outer electrode terminal 42 is disposed so as to cover the outer electrode outer circumferential surface 48 from the outside over the entire circumference and is electrically connected to the outer electrode terminal 42, and the longitudinal length of the fuel cell 4 from the main body portion 42 a. It has the tubular part 42b (small diameter part) extended in the direction. The main body portion 42a and the tubular portion 42b are cylindrical and concentric, and the tube diameter of the tubular portion 42b is smaller than the tube diameter of the main body portion 42a. The tubular portion 42b has a connection channel 42c that communicates with the through channel 50 and communicates with the outside. A step portion 42 d between the main body portion 42 a and the tubular portion 42 b is in contact with the outer electrode layer 48, the electrolyte layer 46, and the end surface 44 c of the inner electrode layer 44 via the annular insulating member 52. The outer electrode terminal 42 is provided at an end portion of the fuel battery cell 4, and has a step portion 42 d as a flat portion formed along the end face 44 c that is a part of the end face of the fuel battery cell 4. . The outer electrode terminal 42 is formed so as to surround an end including the side surface of the fuel battery cell 4 in addition to the end face 42 d which is an end face of the fuel battery cell 4.

  The overall shape of the inner electrode terminal 40 and the overall shape of the outer electrode terminal 42 are the same. Further, the inner electrode terminal 40 and the fuel battery cell 4, and the outer electrode terminal 42 and the fuel battery cell 4 are sealed and fixed by a conductive sealing material 54 over the entire circumference. The sealing material 54 is various brazing materials including, for example, silver, a mixture of silver and glass, gold, nickel, copper, and titanium. The connection flow path 40 c of the inner electrode terminal 40, the through flow path 50 of the fuel cell 4, and the connection flow path 42 c of the outer electrode terminal 42 constitute an in-pipe flow path 30 c of the fuel cell unit 30.

  Next, the fuel cell stack 400 will be described with reference to FIG. The fuel cell stack 400 includes 16 fuel cell units 30, an upper support plate 400a, a lower support plate 400b, a connection member 400c, and an external terminal 400d.

  The upper support plate 400a and the lower support plate 400b are substantially rectangular, and are respectively through holes that fit into the tubular portions 40b and 42b of the fuel cell unit 30 so as to support the fuel cell unit 30 in 2 rows × 8 rows. (Not explicitly shown in FIG. 5). The tubular portions 40b and 42b are inserted into the through holes. Between the tubular portions 40b and 42b and the lower support plate 400b, the gaps between the tubular portions 40b and 42b and the through holes are filled to prevent leakage of gas (fuel gas in this embodiment). A sealing member (not explicitly shown in FIG. 5) is arranged. More specifically, the tubular portions 40b and 42b protrude to the back surface 400bb side of the main surface 400ba on which the fuel cell unit 30 of the lower support plate 400b stands, and surround the protruding portions. The sealing member is arrange | positioned. The upper support plate 400a and the lower support plate 400b are formed of an electrically insulating material, for example, formed of heat resistant ceramics. Specifically, it is preferable to use alumina, zirconia, spinel, forsterite, magnesia, titania or the like.

  The 16 fuel cell units 30 are arranged so that they are electrically connected in series. Specifically, the fuel cell units 30 are arranged so that the inner electrode terminals 40 of the adjacent fuel cell units 30 are alternately arranged on the upper side and the lower side. Further, a connection member 400c for electrically connecting the 16 fuel cell units 30 in series is provided. The connection member 400c electrically connects one adjacent inner electrode terminal 40 and one outer electrode terminal 42. A mode in which the connecting member 400c electrically connects the adjacent inner electrode terminal 40 and the outer electrode terminal 42 is shown in FIG. As shown in FIG. 11, the connecting member 400c includes a first portion 400ca that abuts on one fuel cell unit 30 (including the fuel cell 4 as the first fuel cell), and the one fuel cell unit. And a second portion 400 cb that abuts on the fuel cell unit 30 adjacent to the fuel cell unit 30 (including the fuel cell 4 as the second fuel cell). The fourth portion 400ca is in contact with the third portion 400cc sandwiched between the step portion 40d of the inner electrode terminal 40 of the fuel cell unit 30 and the lower support plate 400b and the side surface of the main body portion 40a of the inner electrode terminal 40. Part 400cd. The second portion 400cb is in contact with the fifth portion 400ce sandwiched between the step portion 42d of the outer electrode terminal 42 of the fuel cell unit 30 and the lower support plate 400b, and the side surface of the main body portion 42a of the outer electrode terminal 42. A sixth portion 400cf in contact therewith. Accordingly, the connection member 400c is electrically connected to the inner electrode terminal 40 at the third portion 400cc and the fourth portion 400cd constituting the first portion 400ca, and the fifth portion 400ce and the fifth portion 400ce constituting the second portion 400cb. The six portions 400cf are electrically connected to the outer electrode terminal 42. Although only the relationship between the connection member 400c and the lower support plate 400b is illustrated in FIG. 11, the relationship between the connection member 400c and the upper support plate 400a is the same.

  Each of the inner electrode terminal 40 and the outer electrode terminal 42 at both ends of the 16 fuel cell units 30 connected in series is provided with an external terminal 400d for electrical connection with the outside. The connection member 400c and the external terminal 400d are made of, for example, a heat-resistant metal such as stainless steel, a nickel base alloy, or a chromium base alloy, or a ceramic material such as lanthanum chromite. In the present embodiment, the connection member 400c and the external terminal 400d are formed as separate and independent components. However, it is also preferable to integrally form the connection member 400c and the external terminal 400d disposed at the ends. is there.

  The external terminal 400d of each fuel cell stack 400 is electrically connected to the external terminal 400d of the adjacent fuel cell stack 400 by a connecting member 400e (see FIG. 1). The external terminals 400d of the fuel cell stack 400 at both ends are connected to the electrode rods 35a and 35b by connection members 400f, respectively (see FIG. 1).

  As described above, the lower support plate 400b as the holding plate holds the fuel cell unit 30 so as to stand on the main surface 400ba of the lower support plate 400b. The through holes formed in the lower support plate 400b are connecting members for electrically connecting the fuel cell units 30 when the tubular portions 40b and 42b of the fuel cell unit 30 are inserted into the through holes. It is formed at a position where the 400c does not contact each other. Further, the inner electrode terminal 40 and the outer electrode terminal 42 of each fuel cell unit 30 are arranged so as to stand on the main surface 400ba of the lower support plate 400b.

  In the case of this embodiment described above, the fuel cell units 30 are arranged in 2 rows × 8 rows, but the arrangement of the fuel cell units 30 is not limited to this mode. FIG. 7 shows another example of the arrangement mode of the fuel cell unit 30. In the fuel cell stack 401 shown in FIG. 7, the fuel cell units 30 are arranged in 3 rows × 8 rows. In order to support the fuel cell unit 30 of 3 rows × 8 rows, the upper support plate 401a and the lower support plate 401b are provided with through holes (FIG. 7) that fit into the tubular portions 40b and 42b of the fuel cell unit 30. (Not explicitly shown) is formed in 3 rows × 8 rows.

  In the case of this example, it is preferable that the eight fuel cell units 30 arranged on the inner side are alternately arranged so as to be visible from between the eight fuel cell units 30 arranged on the outer side. . Thus, the quality check of the fuel cell stack 400 can be easily performed by arranging the fuel cell unit 30 arranged on the inside so as to be visible.

  Next, the side wall portions 111, 112, 113, and 114 constituting the side wall 11 will be described with reference to FIG. FIG. 8 is a view showing a cross section of the cover member 1 in the vicinity of the air flow paths 116 and 118. First, the configuration of the side wall portion 111 and the side wall portion 112 will be described, and the bonding state between the side wall portion 111 and the side wall portion 112 will be described.

  As shown in FIG. 8, the side wall part 111 is comprised by the side wall board 111a, the side wall board 111b, and the side wall board 111c which are three rectangular flat plate-shaped members. The side wall plates 111a, 111b, and 111c are arranged at predetermined intervals, and an air flow path space 111e (second space) is formed between the side wall plate 111a and the side wall plate 111b, and the side wall plate 111b and the side wall plate 111c. Between them, an exhaust gas passage space 111d (first space) is formed. An air pipe 31a is connected to the air flow path space 111e.

  The side wall portion 112 includes three side wall plates 112a, a side wall plate 112b, and a side wall plate 112c, which are members having a rectangular flat plate shape. The side wall plates 112a, 112b, and 112c are arranged at predetermined intervals, and an air flow path space 112e (second space) is formed between the side wall plate 112a and the side wall plate 112b, and the side wall plate 112b and the side wall plate 112c. Between them, an exhaust gas passage space 112d (first space) is formed.

  An air flow path 116 is provided on the lower side (base member 2 side) on the cell chamber 13 side, which is the inside of the side wall plate 112c. The air flow path 116 has a rectangular parallelepiped shape, and is formed along the direction from the side wall portion 111 to the side wall portion 113. The air flow path 116 includes an air chamber 116 a for temporarily storing air to be supplied into the cell chamber 13, and a plurality of airs for supplying air stored in the air chamber 116 a into the cell chamber 13. And an inflow hole 116b. The air flow path space 112e and the air chamber 116a are connected by a communication pipe 115. The communication pipe 115 passes through the exhaust gas passage space 112d and connects the air passage space 112e and the air chamber 116a. The plurality of air inflow holes 116b are formed along the longitudinal direction of the air chamber 116a, and are configured so that air can be supplied into the cell chamber 13 as evenly as possible.

  Next, the bonding state between the sidewall portion 111 and the sidewall portion 112 will be described. The side wall plate 111a constituting the side wall portion 111 and the side wall plate 112a constituting the side wall portion 112 are abutted and joined at each end. The side wall plate 112 b constituting the side wall portion 112 is configured such that an end thereof abuts on the side wall plate 111 a of the side wall portion 111. On the other hand, the side wall plate 111b constituting the side wall portion 111 is configured such that an end thereof abuts on the side wall plate 112b. Therefore, the air flow path space 111e of the side wall portion 111 and the air flow path space 112e of the side wall portion 112 are separated by a portion where the side wall plate 112b protrudes from the side wall plate 111b and abuts on the side wall plate 111a as a partition wall. ing. A portion of the side wall plate 112b protruding from the side wall plate 111b and in contact with the side wall plate 111a is partially cut away on the upper wall 10 side. Therefore, the air flow path space 111e of the side wall part 111 and the air flow path space 112e of the side wall part 112 are connected to each other on the upper side which is the remaining part while being separated by the partition wall.

  With such a configuration, the air that has flowed into the air flow path space 111e of the side wall portion 111 from the air pipe 31a flows obliquely upward in the air flow path space 111e and is connected to the air flow path space 112e of the side wall portion 112. It flows into the air flow path space 112e from the part (upper part) which is present. Thereafter, the air that has flowed into the air flow path space 112e flows obliquely downward in the air flow path space 112e and flows into the air flow path 116 from the connecting pipe 115. The air that has flowed into the air flow path 116 flows into the cell chamber 13 from the air inflow hole 116b.

  Further, the side wall plate 111c constituting the side wall portion 111 and the side wall plate 112c constituting the side wall portion 112 are abutted and joined at each end. On the other hand, the side wall plate 112b constituting the side wall portion 112 is configured such that the end thereof is in contact with the side wall plate 111a of the side wall portion 111. The side wall plate 111b constituting the side wall portion 111 is configured such that the end portion is the side wall. It is comprised so that it may contact | abut to the board 112b. Therefore, the exhaust gas passage space 111d of the side wall portion 111 and the exhaust gas passage space 112d of the side wall portion 112 are configured so as to be connected to each other without any partition walls. Further, the side wall plate 111c and the side wall plate 112c are configured not to contact the upper wall 10 so that the exhaust gas in the cell chamber 13 flows into the exhaust gas passage space 111d and the exhaust gas passage space 112d. It is configured. The side wall plate 111c and the side wall plate 112c are formed with slits (not shown in the figure) between the side wall plate 111c and the side wall plate 112c so that exhaust gas flows into the exhaust gas chamber 14. With such a configuration, the exhaust gas that has flowed into the exhaust gas passage space 111d and the exhaust gas passage space 112d from the upper side flows downward and flows into the exhaust gas chamber 14.

  As described above, air flows from the air pipe 31a into the air flow path space 111e from the lower side, and flows into the air flow path space 112e from the upper side after flowing to the upper side that is the opposite side of the flow, After flowing downward, it flows into the cell chamber 13. By adopting such a configuration, the time for heat exchange between the air to be heated and the exhaust gas compared to simply flowing the gas flowing in from the lower side or the upper side to the upper side or the lower side. As a result, the air or fuel gas can be sufficiently heated. Furthermore, since air or fuel gas flows in from the lower side of the cell chamber 13, it can be sufficiently brought into contact with the fuel cell 4 by moving up in the cell chamber 13 after flowing in, thereby performing efficient power generation. be able to.

  Next, the configuration of the side wall portion 113 and the side wall portion 114 will be described, and the bonding state between the side wall portion 113 and the side wall portion 114 will be described.

  The side wall portion 113 includes three side wall plates 113a, a side wall plate 113b, and a side wall plate 113c, which are members of a rectangular flat plate shape. The side wall plates 113a, 113b, and 113c are arranged at predetermined intervals, and an air flow path space 113e (second space) is formed between the side wall plate 113a and the side wall plate 113b, and the side wall plate 113b and the side wall plate 113c. Between them, an exhaust gas passage space 113d (first space) is formed. An air pipe 31b is connected to the air flow path space 113e.

  The side wall portion 114 includes three side wall plates 114a, a side wall plate 114b, and a side wall plate 114c, which are rectangular flat members. The side wall plates 114a, 114b, and 114c are arranged at predetermined intervals, respectively, and an air flow path space 114e (second space) is formed between the side wall plate 114a and the side wall plate 114b, and the side wall plate 114b and the side wall plate 114c. An exhaust gas passage space 114d (first space) is formed between the two.

  An air flow path 118 is provided on the lower side (base member 2 side) on the cell chamber 13 side, which is the inner side of the side wall plate 114c. The air flow path 118 has a rectangular parallelepiped shape, and is formed along a direction from the side wall portion 111 to the side wall portion 113. The air flow path 118 includes an air chamber 118 a for temporarily storing air to be supplied into the cell chamber 13, and a plurality of airs for supplying air stored in the air chamber 118 a into the cell chamber 13. And an inflow hole 118b. The air passage space 114e and the air chamber 118a are connected by a communication pipe 117. The communication pipe 117 penetrates the exhaust gas passage space 114d and connects the air passage space 114e and the air chamber 118a. The plurality of air inflow holes 118b are formed along the longitudinal direction of the air chamber 118a, and are configured so that air can be supplied into the cell chamber 13 as evenly as possible.

  Since the bonding state between the side wall portion 113 and the side wall portion 114 is the same as the bonding state between the side wall portion 111 and the side wall portion 112 described above, description thereof is omitted. Further, the air flow in the air flow path part 113e of the side wall part 113 and the air flow path part 114e of the side wall part 114, and the exhaust gas in the exhaust gas flow path part 113d of the side wall part 113 and the air flow path part 114d of the side wall part 114. Since the flow is the same as that already described, the description thereof is omitted.

  Next, the bonding state between the side wall portion 111 and the side wall portion 114 will be described. The side wall plate 111a constituting the side wall portion 111 and the side wall plate 114a constituting the side wall portion 114 are abutted and joined at each end. The side wall plate 114 b constituting the side wall portion 114 is configured such that an end thereof abuts on the side wall plate 111 a of the side wall portion 111. On the other hand, the side wall plate 111b constituting the side wall portion 111 is configured such that an end thereof abuts on the side wall plate 114b. Therefore, the air flow path space 111e of the side wall portion 111 and the air flow path space 114e of the side wall portion 114 are separated by a portion where the side wall plate 114b protrudes from the side wall plate 111b and contacts the side wall plate 111a as a partition wall. ing. Therefore, the air flow path space 111e of the side wall portion 111 and the air flow path space 114e of the side wall portion 114 are separated without being connected.

  With such a configuration, the flow of air from the air flow path space 111e to the air flow path space 112e and the flow of air from the air flow path space 113e to the air flow path space 114e are not hindered. .

  Further, the side wall plate 111c constituting the side wall portion 111 and the side wall plate 114c constituting the side wall portion 114 are abutted and joined at each end. On the other hand, the side wall plate 114b constituting the side wall portion 114 is configured such that the end thereof is in contact with the side wall plate 111a of the side wall portion 111, and the side wall plate 111b constituting the side wall portion 111 is configured such that the end portion is the side wall. It is comprised so that it may contact | abut to the board 112b. Therefore, the exhaust gas passage space 111d of the side wall portion 111 and the exhaust gas passage space 114d of the side wall portion 114 are configured so as to be connected without any partition walls. Further, the side wall plate 114c is configured not to contact the upper wall 10, and is configured such that the exhaust gas in the cell chamber 13 flows into the exhaust gas passage space 114d. A slit 114ca (see FIG. 3) is formed between the side wall plate 114c and the flange portion 12, and the exhaust gas flows into the exhaust gas chamber. By adopting such a configuration, the exhaust gas that has flowed into the exhaust gas passage space 114 d from the upper side flows downward and flows into the exhaust gas chamber 14. Such a slit is also formed as a slit 113ca in the side wall plate 113c (see FIG. 3).

  Since the joined state between the sidewall portion 112 and the sidewall portion 113 is the same as the joined state between the sidewall portion 111 and the sidewall portion 114 described above, description thereof is omitted.

  Returning to FIGS. 1 to 3, the fuel cell module FC will be further described. The partition plate 22 and the partition plate 23 that partition the cell chamber 13 and the exhaust gas chamber 14 will be described. In the case of this embodiment, both the partition plate 22 and the partition plate 23 are formed by substantially rectangular plate-like members. The partition plate 22 is formed of a relatively thick plate member, whereas the partition plate 23 is formed of a thin plate member having flexibility.

  A support portion 24 is formed on the base plate 21 constituting the base portion 2 toward the cell chamber 13 side. The support portions 24 are plate-like protrusions, and four support portions 24 are arranged slightly inside the four corners of the cover portion 1. The partition plate 23 is placed on the four support portions 24, and the partition plate 22 is placed from above. Therefore, the partition plate 23 is sandwiched and fixed between the partition plate 22 and the support portion 24.

  The partition plate 23 is formed slightly larger than the partition plate 22. In the case of the arrangement described above, the outer periphery of the partition plate 23 protrudes from the outer periphery of the partition plate 22. The outer periphery of the partition plate 23 is formed slightly larger than the inner periphery of the cover member 1. In the case of the arrangement described above, when the cover member 2 is arranged, the outer periphery of the partition plate 23 bends and contacts the inner wall of the cover member 1.

  This state will be described with reference to FIG. FIG. 9 is an enlarged perspective view of a state in which the cover member 1 and the partition plate 23 are in contact with each other. When the partition plate 23 comes into contact with the side wall plate 111 c of the side wall portion 111, the partition plate 23 bends below the partition plate 22. Therefore, the exhaust gas flowing through the exhaust gas flow path 111d of the side wall portion 111 is sealed at the contact portion between the partition plate 23 and the side wall plate 111c and flows into the exhaust gas chamber 14 from the slit 111ca.

  In manufacturing the fuel cell module FC as described above, a manufacturing method including a preparation process, a first assembly process, a second assembly process, a third assembly process, and a fourth assembly process is employed.

  In the preparation step, a plurality of fuel cells 4 having the fuel cells 4, an inner electrode terminal 40 and an outer electrode terminal 42 corresponding to the number of the fuel cells 4, a connection member 400c, a plurality of upper support plates 401a, A plurality of lower support plates 401b and the gas tank 6 are prepared. Further, in this preparation step, other members constituting the fuel cell module FC are also prepared.

  In the first assembly step, the fuel cell unit 30 is formed by attaching the inner electrode terminal 40 and the outer electrode terminal 42 to each fuel cell 4.

  In the second assembling step, the plurality of fuel cell units 30 are arranged in two rows on each of the lower support plates 401b and are erected and held so as to be electrically connected to each other by the connection member 400c, and the upper support plate 401b is disposed. Thus, the fuel cell stack 400 is formed.

  In the third assembly step, the fuel cell stack 30 is disposed in each of the openings 61 of the gas tank 6, the openings 61 are closed by the lower support plate 401b, and a fuel gas chamber 6c for storing fuel gas is formed. As a result, the plurality of fuel cell units 30 are erected from the gas tank 6 on the side opposite to the fuel gas chamber 6c.

  In the fourth assembly step, the inner electrode terminal 40 or the outer electrode terminal 42 provided in the fuel cell 4 included in one fuel cell stack 400 and another fuel cell by the connection member 400e (inter-stack connection member). The inner electrode terminal 40 or the outer electrode terminal 42 provided in the fuel battery cell 4 included in the cell stack 400 is electrically connected. Thereafter, the fuel cell module FC described above is formed using the other members prepared in the preparation step.

  Next, the operation of the fuel cell including the fuel cell module FC according to the present embodiment and the operation method thereof will be described with reference to FIGS. In the following description, for the sake of convenience, the operation of the fuel cell module FC is described to describe the fuel cell including the fuel cell module FC.

  The operation method of the fuel cell module FC according to the present embodiment includes an ignition process, a reforming process, a cell operation process, and a combustion process. As will be described later, these steps are not necessarily executed sequentially, but are executed in parallel or executed in a different order.

  First, in order to warm the fuel cell module FC, fuel gas and air are supplied to the fuel cell module FC without applying a load to the circuit including the fuel cell module FC, that is, with the circuit including the fuel cell module FC open. Supply. At this stage, even if fuel gas and air are present, no current flows through the circuit, so the fuel cell module FC does not generate power.

  Specifically, fuel gas is supplied. Specifically, the fuel gas is supplied to the fuel gas supply pipe 32, reformed by the reformer 7, and then stored in the gas tank 6 (reforming process). Thereby, uniform and uniform supply of fuel gas to each fuel cell unit 30 is ensured. The fuel gas accumulated in the gas tank 6 flows through the in-pipe flow path 30c (see FIG. 4) of the fuel cell unit 30 and acts on the inner electrode layer 44 (see FIG. 4). The fuel gas that did not act reaches the upper space of each fuel cell unit 30.

  In addition, air in the atmosphere is supplied. Specifically, air in the atmosphere is supplied to the air supply pipes 31a and 31b by a blower or the like, and the air flow of the side wall portion 113 is transferred from the air flow path portion 111e of the side wall portion 111 to the air flow path portion 112e of the side wall portion 112. The air flows from the passage portion 113e to the air flow path portion 114e of the side wall portion 114. As described above, the air then flows into the air flow paths 116 and 118 and is guided into the cell chamber 13 through the air inflow holes 116b and 118b. The air guided into the cell chamber 13 which is a power generation chamber acts with the outer electrode layer 48 (see FIG. 4). The air that did not act reaches above each fuel cell unit 30.

  Next, the combustion gas and air are combusted using an ignition device (not shown) such as a spark plug or a heater (ignition process, combustion process). The resulting exhaust gas becomes hot. The exhaust gas is guided to the exhaust gas passage spaces 111 d, 112 d, 113 d, 114 d of the side wall portions 111, 112, 113, 114 and flows into the exhaust gas chamber 14. The exhaust gas that has flowed into the exhaust gas chamber 14 is discharged from the exhaust gas pipe 36.

  When the fuel gas and air are combusted, the temperature in the cell chamber 13 is raised. The air introduced from the outside is heated by exchanging heat with the exhaust gas as well as exchanging heat with the inside of the cell chamber 13 while flowing through the side wall portions 111, 112, 113 and 114.

  When the temperature in the cell chamber 16 and the fuel cell 4 reaches a predetermined power generation temperature lower than the rated temperature at which the fuel cell module FC is stably operated, the circuit including the fuel cell module FC is closed. Thereby, the fuel cell module FC starts power generation, and a current flows through the circuit (cell operation process). Due to the power generation of the fuel cell, the fuel cell 4 itself also generates heat, and the temperature of the fuel cell 4 rises. As a result, the temperature reaches a rated temperature at which the fuel cell module FC is operated, for example, 600 to 800 ° C.

Thereafter, in order to maintain the rated temperature, a larger amount of fuel gas and air than the amount of fuel gas and air consumed in the fuel cell 4 are supplied, and combustion in the cell chamber 13 is continued (combustion process). .

  Next, the configuration of the fuel cell FCS using the fuel cell module FC will be described with reference to FIG. FIG. 10 is a block diagram showing the configuration of the fuel cell FCS. The fuel cell FCS includes a fuel cell module FC, a fuel supply unit FP, an air supply unit AP, a water supply unit WP, a power extraction unit EP, and a control unit CS. The fuel supply unit FP, the air supply unit AP, the water supply unit WP, and the power extraction unit EP constitute an auxiliary device AD of the fuel cell FCS.

  The fuel supply unit FP is a part that supplies fuel gas from a city gas pipe as a fuel supply source to the fuel cell module FC, and includes a fuel pump and an electromagnetic valve. The fuel gas supplied from the fuel supply unit FP is sent out to the fuel gas supply pipe 32.

  The air supply unit AP is a part that supplies air from the atmosphere as an air supply source to the fuel cell module FC, and includes an air blower and an electromagnetic valve. Air supplied from the air supply unit AP is sent out to the air supply pipes 31a and 31b.

  The water supply unit WP is a part that supplies water from a water pipe as a water supply source to the fuel cell module FC, and includes a water pump and an electromagnetic valve. The water supplied from the water supply part WP becomes water vapor inside the fuel module FC and is sent out to the water vapor supply pipe 33.

  The power extraction unit EP is a part that extracts electric power from the fuel cell module FC, and includes a power conversion device such as an inverter. The power extraction unit EP is connected to the electrode rods 35a and 35b, and is configured to send the converted power to a power supply destination.

  The control unit CS is a part for controlling each of the fuel supply unit FP, the air supply unit AP, the driving auxiliary device AD, and the power extraction unit EP, and includes a CPU and a ROM. The operation of the fuel cell module FC as described above is executed based on an instruction signal from the control unit CS.

It is a figure which shows the fuel cell module which concerns on this embodiment. It is a figure which shows the fuel cell module which concerns on this embodiment. It is a figure which shows the fuel cell module which concerns on this embodiment. It is a figure which shows the gas tank of FIGS. 1-3 in detail. It is a figure which shows the fuel cell unit of FIGS. 1-3 in detail. It is a figure which shows the fuel cell stack of FIGS. 1-3 in detail. It is a figure which shows the modification of a fuel cell stack. It is a figure which shows the cover member of FIGS. 1-3 in detail. It is a figure which shows the partition plate of FIGS. 1-3 in detail. It is a block diagram which shows the structure of the fuel cell using the fuel cell module which concerns on this embodiment. It is a figure which shows the fuel cell stack of FIGS. 1-3 in detail.

Explanation of symbols

  FC ... fuel cell module, 1 ... cover member, 11 ... sidewall, 111, 112, 113, 114 ... sidewall portion, 12 ... flange portion, 13 ... cell chamber, 14 ... exhaust gas chamber, 2 ... base member, 21 ... base Plates 22, 23 ... Partition plates, 4 ... Fuel cell, 30 ... Fuel cell unit, 400 ... Fuel cell stack, 6 ... Gas tank, 7 ... Reformer, 31a, 31b ... Air supply pipe, 32 ... Fuel Gas supply pipe, 34 ... connecting pipe, 35a, 35b ... electrode rod, 36 ... exhaust gas pipe.

Claims (6)

A first electrode layer formed in an annular shape and configured to allow gas to pass through the internal space, a solid electrolyte layer formed in an annular shape so as to overlap with the first electrode, and an overlay on the solid electrolyte layer A fuel cell stack comprising a plurality of fuel cells that are operated by fuel gas and oxidant gas,
A plurality of fuel cell units each having a current collecting member provided at an end of each of the plurality of fuel cells to collect current from one of the first electrode layer and the second electrode layer, and the fuel cell When,
A holding plate for erecting and holding the plurality of fuel cell units with respect to the main surface;
A current collecting member provided in a first fuel cell of the plurality of fuel cells, and a current collecting member provided in a second fuel cell of the plurality of fuel cells. A plurality of connecting members for electrical connection,
The current collecting member has a flat portion formed along the end surface of the fuel cell,
The fuel cell stack, wherein the connecting member is electrically connected to the current collecting member by at least a part of the connecting member being in contact with a flat portion of the current collecting member.   2. The fuel cell stack according to claim 1, wherein the connecting member is sandwiched between a flat portion of the current collecting member and a main surface of the holding plate. The current collecting member is attached to the fuel cell so as to surround an end including the end surface and the side surface of the fuel cell.
The said connection member is electrically connected with the said current collection member, when the said current collection member contact | abuts to the part along the side surface of the said fuel cell, The said current collection member is characterized by the above-mentioned. The fuel cell stack described.   4. The fuel cell according to claim 1, wherein some of the plurality of connection members function as terminals for taking out electricity from the fuel cell stack. 5. Cell stack.   A fuel cell module comprising the fuel cell stack according to any one of claims 1 to 4.   A fuel cell comprising the fuel cell stack according to any one of claims 1 to 4.

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