JP2016115628A - Fuel battery cartridge and manufacturing method thereof, and fuel battery module and fuel battery system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To promote a power generation reaction in a fuel battery cell, and to improve a power generation efficiency of a fuel battery cartridge.SOLUTION: In a manufacturing method of a fuel battery cartridge of the present invention, all of cell stacks 101 each of which includes a plurality of fuel battery cells 105 electrically connected on a base material in series, the base material comprising a porous substrate tube 103 having a porosity on one end side smaller than that on the other end side in an axial direction, are defined in electrical series connection for the one end side and the other end side of the substrate tube 103 in a predetermined direction of the plurality of fuel battery cells 105, and are arranged such that the one end side of the substrate tube 103 is directed toward the upstream side in a flow direction of fuel gas and the other end side of the substrate tube 103 is directed toward the downstream side in a flow direction of fuel gas.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a fuel cell cartridge and a method for manufacturing the same, and a fuel cell module and a fuel cell system. The present invention particularly relates to a fuel cell cartridge including a cell stack in which fuel cells are formed on a cylindrical porous substrate tube, a method for manufacturing the same, and a fuel cell module and a fuel cell system.

  A fuel cell is a power generator that supplies fuel gas to a fuel electrode and fluid (air) containing oxygen to an air electrode, and takes out electric power by an electrochemical reaction. As one of the fuel cells, there is a solid oxide fuel cell (SOFC) (refer to Patent Documents 1 to 4).

  The SOFC using a cylindrical cell stack has a cartridge structure in which a plurality of cell stacks are arranged substantially in parallel, and both ends of each cell stack are supported by a current collecting member or the like.

  The cell stack includes a porous base tube, and a fuel cell in which a fuel electrode, a solid electrolyte, and an air electrode are sequentially laminated on the outer peripheral surface of the base tube. A plurality of fuel cells are formed along the axial direction at an intermediate portion in the longitudinal direction (axial direction) of the base tube, and adjacent fuel cells are electrically connected in series via an interconnector.

  The fuel gas is introduced into the base tube from one end of the base tube and discharged from the other end of the base tube. On the other hand, an oxidant gas (for example, air) containing oxygen is supplied to the outside of the base tube.

JP 2008-71710 A (Claim 1, paragraph [0001]) JP 2014-116199 A (Claim 1, paragraphs [0019]-[0021]) Japanese Patent No. 5106884 (Claim 1, FIG. 2) Japanese Patent No. 5539417 (Claim 1)

  Since a plurality of fuel cells are connected in series in the cell stack, the amount of current flowing through each fuel cell (power generation reaction) is the same, and the voltage of each fuel cell is different. Since the amount of current flowing through each fuel cell is equal in the longitudinal direction (axial direction) of the base tube, the amount of current is controlled by the fuel cell on the fuel discharge side where the potential of the power generation reaction is low compared to the fuel cell on the fuel supply side. To do.

The fuel gas supplied from one end of the base tube passes through the base tube and is discharged from the other end. Since the reaction contribution components (H ₂ , CO) in the fuel gas are consumed in the power generation unit (fuel cell) of the cell stack, the concentration of the reaction contribution component decreases as the fuel gas is discharged. . For this reason, the performance (voltage) of the fuel cell from which the fuel gas is discharged is lower than that of the fuel cell to which the fuel gas is supplied. Further, pressure loss occurs on the side of the base tube where the fuel gas is discharged, because the fuel gas is circulated through the base tube than on the side where the fuel gas is supplied. Therefore, on the side where the fuel gas is discharged from the base tube, the partial pressure of the fuel gas is lower than on the side where the fuel gas is supplied, and the power generation reaction is less likely to occur. Therefore, the amount of current in the cell stack is limited by the amount of current in the fuel cell on the side from which the fuel gas is discharged.

  When the fuel cell from which the fuel gas is discharged has a low performance (voltage), or when the amount of current is limited by the fuel cell having a low potential for power generation reaction, the cell stack in which the fuel cells are connected in series The power generation efficiency of the fuel cell cartridge cannot be increased even if there is a fuel cell having a high potential for power generation reaction.

  This invention is made | formed in view of such a situation, Comprising: It aims at promoting the electric power generation reaction of a fuel cell, and improving the electric power generation efficiency of a fuel cell cartridge.

  In order to solve the above-described problems, the fuel cell cartridge and the manufacturing method thereof, the fuel cell module, and the fuel cell system of the present invention employ the following means.

  The present invention provides a plurality of fuel cells that are electrically connected in series on a base material of a porous base tube having a large porosity on the other end side with respect to the one end side in the axial direction. All the cell stacks provided are defined in electrical series connection in a predetermined direction of the plurality of fuel cells to the one end side and the other end side of the base tube, There is provided a method for manufacturing a fuel cell cartridge, wherein the one end side is directed to the upstream side in the fuel gas flow direction, and the other end side of the base tube is directed to the downstream side in the fuel gas flow direction.

  In the present invention, the porosity of the base tube is greater on the other end side than on the one end side. By arranging the larger porosity (the other end side) of the base tube on the fuel gas discharge side (downstream side), the power generation reaction on the downstream side can be promoted. As a result, the amount of power generation reaction on the downstream side that has limited the current in the cell stack increases, so that the power generation capacity of the entire cell stack can be increased. In the present invention, attention is paid to the base tube in which the porosity increases from the one end side toward the other end side, and all the cell stacks arranged in the fuel cell cartridge are fuel gas at the other end side of the base tube. It was decided to be arranged so as to face the downstream side in the flow direction. As a result, the power generation capacity of the entire fuel cell cartridge can be increased.

  In one aspect of the invention, the cell stack includes an A-type cell stack and a B-type cell stack, and forms the A-type cell stack in which the one end is a positive electrode and the other end is a negative electrode, and the one end The B type cell stack having the negative electrode on the side and the positive electrode on the other end may be formed, and the A type cell stack and the B type cell stack may be electrically connected in series.

  According to one aspect of the present invention, the A-type cell stack and the B-type cell stack have the same porosity distribution tendency and are cell stacks in which only the polarity is reversed. Since the cell stacks can be arranged with the polarity reversed, the cartridges can be easily connected in series. For example, when only the A type cell stack is formed and the B type cell stack having a different polarity is turned upside down, the porosity distribution tendency is also reversed. When such an A type cell stack and a B type cell stack are arranged, a portion with a low porosity is arranged on the downstream side of the fuel gas, and the electric power generation reaction is not promoted and the current in the downstream cell stack is reduced. Thereby, the power generation amount of the cell stack is reduced.

  In one aspect of the invention, the A type cell stack is formed by hanging and firing with the negative electrode side facing up, and the B type cell stack is formed by hanging and firing with the positive electrode side facing up. be able to.

  When suspended and fired, the base tube has a higher porosity on the upper side when suspended, and a lower porosity on the lower side.

  In one aspect of the invention described above, a lead portion that is electrically connected to an endmost portion of the plurality of fuel cells connected in series and guides the power generated by the fuel cells is the one end portion of the base tube. And forming the identification part on the lead part of at least one of the A-type cell stack and the B-type cell stack, and a step before firing. The lead portion material and the identification portion material may be formed on the substrate tube and then integrally fired to form the lead portion and the identification portion.

  Due to the structure of the cartridge, a long lead portion is required on the side to which the fuel gas is supplied (upstream side). According to the above invention, the one end portion side of the base tube having a low porosity has a long lead portion and is disposed on the fuel gas supply side.

  By forming an identification portion material before the porosity distribution occurs in the base tube and firing it integrally with the base tube, the A type cell stack and the B type cell stack can be discriminated. As a result, the A type cell stack and the B type cell stack can be appropriately arranged without making a mistake in the distribution of the porosity.

  In one aspect of the invention, the porosity is measured at an arbitrary position corresponding to the axial direction of the base tube, and a cell stack having a relatively small porosity is used as the fuel based on the measured porosity. It is preferable that a cell stack having a relatively large porosity value is arranged in an outer peripheral region that is an outer periphery of the central region in the fuel cell cartridge.

  According to the aspect of the invention described above, the outer peripheral region that is the outer periphery of the central region of the fuel cell cartridge rather than the central region of the fuel cell cartridge by disposing the cell stack having a relatively low porosity in the central region of the fuel cell cartridge. The power generation reaction in the cell stack is promoted. In a fuel cell cartridge that has a structure in which the temperature in the central region tends to rise due to heat generation due to a power generation reaction, the difference in power generation capacity between cell stacks offsets the difference in the amount of heat generation due to the power generation reaction, resulting in a difference in temperature distribution within the fuel cell cartridge. Is less likely to occur. Thereby, the power generation efficiency of the cartridge can be increased. “Central region” and “outer peripheral region” are names when the cross section of the fuel cell cartridge is divided into two regions, and “central region” is a region including the center of the cross section of the fuel cell cartridge. The “outer peripheral region” is a region around the outer side of the “central region” and is on the edge side of the cross section of the fuel cell cartridge.

  The present invention also includes a plurality of cell stacks each including a porous base tube and a plurality of fuel cells formed and electrically connected to the base tube, and one end of the plurality of cell stacks. A fuel gas supply unit for supplying fuel gas to the cell stack; and a fuel gas discharge unit for disposing the other end portions of the plurality of cell stacks and for discharging the fuel gas supplied to the cell stack, The plurality of fuel cells are electrically connected in series in a predetermined direction to the one end side and the other end side of the cell stack, and the porosity of the base tube in all the cell stacks However, the one end side provides a fuel cell cartridge that is larger than the other end side.

  In the present invention, the porosity of the base tube is greater on the other end side than on the one end side. By arranging the larger porosity (the other end side) of the base tube on the fuel gas discharge side (downstream side), the power generation reaction on the downstream side can be promoted. As a result, the amount of power generation reaction on the downstream side that has limited the current in the cell stack increases, so that the power generation capacity of the entire cell stack can be increased. In the present invention, attention is paid to the base tube in which the porosity on the other end side is larger than the one end side, and all cell stacks arranged in the fuel cell cartridge are connected to the fuel gas at the other end side of the base tube. It was decided to be arranged so as to face the downstream side in the flow direction. As a result, the power generation capacity of the entire fuel cell cartridge can be increased.

  In one aspect of the invention, the plurality of cell stacks include an A type cell stack in which the one end side is a positive electrode and the other end side is a negative electrode, and the one end side is a negative electrode and the other end side is a positive electrode. A B-type cell stack.

  In one aspect of the invention described above, the fuel is electrically connected to the outermost ends of the plurality of fuel cells that are formed on the base tube on the one end side and the other end side and are connected in series. It is preferable to include a lead portion that guides the electric power generated by the battery cell, and an identification portion formed on the lead portion of at least one of the A-type cell stack and the B-type cell stack. .

  The plurality of cell stacks include cell stacks having different porosity values at arbitrary corresponding positions in the axial direction of the respective base tube, and the cell stacks having relatively small porosity values are disposed in the fuel cell cartridge. It is preferable that a cell stack having a relatively large porosity value is disposed in an outer peripheral region that is an outer periphery of the central region in the fuel cell cartridge.

  According to the present invention, the cell stack is arranged in the fuel cell cartridge in consideration of the porosity distribution in the axial direction of the base tube, thereby increasing the power generation reaction amount of the fuel cell in the rate limiting portion. Can do. As a result, the power generation amount of the entire cell stack increases, and the power generation efficiency of the fuel cell cartridge can be improved. A fuel cell module including such a fuel cell cartridge and a fuel cell system including the fuel cell module are excellent in power generation.

It is a side view of the cell stack concerning a 1st embodiment. It is arrow sectional drawing of XX of FIG. FIG. 2 is a cross-sectional view taken along line YY in FIG. 1. It is a perspective view which shows the outline | summary of the fuel cell module which concerns on 1st Embodiment. 1 is a longitudinal sectional view of a fuel cell cartridge according to a first embodiment. It is a side view of the cell stack concerning a 2nd embodiment. FIG. 7 is a cross-sectional view taken along the line XX in FIG. FIG. 7 is a cross-sectional view taken along the line YY in FIG. FIG. 7 is a cross-sectional view taken along the line XX in FIG. FIG. 7 is a cross-sectional view taken along line YY in FIG. It is a schematic side view of the A type cell stack and B type cell stack at the time of baking. It is a schematic block diagram of the fuel cell cartridge which concerns on 2nd Embodiment. It is a schematic cross-sectional view of a fuel cell cartridge according to a third embodiment. It is a graph which shows the relationship between the distance from a suspension lower part, and the porosity of a base tube.

  Hereinafter, an embodiment of a fuel cell cartridge and a manufacturing method thereof, a fuel cell module, and a fuel cell system according to the present invention will be described with reference to the drawings.

  In the following, for convenience of explanation, the positional relationship of each component is specified using the expressions “upper” and “lower” on the basis of the paper surface, but this is not necessarily limited to the vertical direction. For example, the upward direction on the paper surface may correspond to the downward direction in the vertical direction. Moreover, you may respond | correspond to the horizontal direction where the up-down direction in a paper surface goes orthogonally to a perpendicular direction. In the following, the distance in the longitudinal direction (axial direction) of the base tube is referred to as “length”.

[First Embodiment]
The fuel cell system according to the present embodiment includes a fuel cell module configured by a plurality of fuel cell cartridges including a plurality of cell stacks that generate electric power upon receiving supply of fuel gas and oxidant gas.

  First, the cell stack according to the present embodiment will be described with reference to FIGS. Here, FIG. 1 is a side view of the cell stack according to the present embodiment. 2 is a cross-sectional view taken along the line XX of FIG. 3 is a cross-sectional view taken along the line YY in FIG.

  The cell stack 101 includes a cylindrical base tube 103, a plurality of fuel cells 105 formed on the outer peripheral surface of the base tube 103, and an interconnector 107 formed between adjacent fuel cells 105. The fuel cell 105 is formed by stacking a fuel electrode 109, a solid electrolyte 111, and an air electrode 113.

  The cell stack 101 is a lead electrically connected to the fuel cell 105 formed at the end in the axial direction of the base tube 103 among the plurality of fuel cells 105 formed on the outer peripheral surface of the base tube 103. Part 114. The lead portions 114 are at both ends of the plurality of electrically connected fuel cells 105. The length of the lead part 114a on the one end side of the base tube is longer than the lead part 114b on the other end side. The lead part 114 includes a lead film 115 (115 a, 115 b) electrically connected to the fuel cell 105 and a protective film 117 formed on the lead film 115. The lead film 115 is formed on the base tube, one end is electrically connected to the fuel cell 105, and the other end extends toward the end of the base tube 103. The upper surface of the lead film 115 is exposed on the end side of the base tube 103. A seal bonding film 119 may be appropriately stacked on the protective film 117 covering the lead film 115. In the lead film 115 (115a, 115b), the length (La) of the lead film 115a of the lead part 114a is longer than the length (Lb) of the lead film 115b of the lead part 114b.

The base tube 103 is made of a porous material, and is made of, for example, CaO stabilized ZrO ₂ (CSZ), Y ₂ O ₃ stabilized ZrO ₂ (YSZ), or MgAl ₂ O ₄ . The base tube 103 supports the fuel battery cell 105, the interconnector 107, and the lead film 115, and supplies the fuel gas supplied to the inner peripheral surface of the base tube 103 through the pores of the base tube 103. Is diffused to the fuel electrode 109 formed on the outer peripheral surface of the electrode.

  The base tube is a cylindrical long member. The base tube has a porosity distribution in the axial direction (longitudinal direction). The porosity of the base tube is larger on the other end side than on the one end side of the base tube.

The fuel electrode 109 is made of an oxide of a composite material of Ni and a zirconia-based electrolyte material. For example, Ni / YSZ is used. In this case, in the fuel electrode 109, Ni that is a component of the fuel electrode 109 has a catalytic action on the fuel gas. This catalytic action reacts with a fuel gas supplied through the base tube 103, for example, a mixed gas of methane (CH ₄ ) and water vapor, and reforms it into hydrogen (H ₂ ) and carbon monoxide (CO). Is. Further, the fuel electrode 109 has an interface between the solid electrolyte 111 and hydrogen (H ₂ ) and carbon monoxide (CO) obtained by reforming and oxygen ions (O ²⁻ ) supplied via the solid electrolyte 111. It reacts electrochemically in the vicinity to produce water (H ₂ O) and carbon dioxide (CO ₂ ). At this time, the fuel cell 105 generates electric power by electrons emitted from oxygen ions. Further, the fuel electrode 109 may be divided into a plurality of parts in order to obtain a predetermined film thickness.

The solid electrolyte 111 is mainly made of YSZ having gas tightness that prevents gas from passing through and high oxygen ion conductivity at high temperatures. The solid electrolyte 111 moves oxygen ions (O ²⁻ ) generated at the air electrode to the fuel electrode. Further, the solid electrolyte 111 may be divided into a plurality of parts in order to obtain a predetermined function.

The air electrode 113 is made of, for example, a LaSrMnO ₃ oxide or a LaCoO ₃ oxide. The air electrode 113 generates oxygen ions (O ²⁻ ) by dissociating oxygen in an oxidizing gas such as air supplied near the interface with the solid electrolyte 111.

The interconnector 107 is composed of a conductive perovskite oxide represented by M _1-x L _x TiO ₃ (M is an alkaline earth metal element, L is a lanthanoid element) such as SrTiO ₃ system, and is composed of fuel gas and oxidation It is a dense film so that it does not mix with sex gases. Further, the interconnector 107 has stable electrical conductivity in both an oxidizing atmosphere and a reducing atmosphere. The interconnector 107 electrically connects the air electrode 113 of one fuel battery cell 105 and the fuel electrode 109 of the other fuel battery cell 105 in adjacent fuel battery cells 105 so that the adjacent fuel battery cells 105 are connected to each other. Are connected in series in a predetermined direction to define a positive electrode and a negative electrode as the cell stack 101. The interconnector 107 may be divided into a plurality of parts in order to obtain a predetermined function.

  Since the lead film 115 (115a, 115b) needs to have electronic conductivity and a thermal expansion coefficient close to that of other materials constituting the cell stack 101, Ni such as Ni / YSZ and zirconia It is composed of a composite material with a system electrolyte material. The material of the lead film may be the same as the material of the fuel electrode. The lead film 115 leads direct current power generated by the plurality of fuel cells 105 connected in series by the interconnector to the vicinity of the end of the cell stack 101.

  The protective film 117 is made of the same material as the solid electrolyte 111. The protective film 117 plays a role of preventing leakage of the fuel gas and the oxidizing gas and a role of preventing the lead film 115 from being exposed to the oxidizing gas.

The seal bonding film 119 is a film that plays a role of increasing the surface roughness in order to improve the adhesive strength between the cell stack 101 and the adhesive. The material of the seal bonding film 119 is, for example, a mixture of CaTiO ₃ and YSZ. The seal bonding film 119 may be formed by roller printing.

The cell stack 101 can be manufactured as follows.
First, a material such as calcium stabilized zirconia (CSZ) is formed into the shape of the base tube 103 by an extrusion method (hereinafter referred to as “formed base tube”). Next, an aqueous vehicle or the like is mixed with the fuel electrode material, the solid electrolyte material, the interconnector material, the lead film material, and the protective film material to prepare a slurry. Using a screen printing method, a slurry for a fuel electrode, a slurry for a lead film, a slurry for a solid electrolyte, a slurry for a protective film, and a slurry for an interconnector are sequentially formed on the molded substrate tube.

  In the present embodiment, the fuel electrode 109, the lead film 115 (115a, 115b), the solid electrolyte 111, and the protective film 117 are made of the same material. Therefore, the process of producing and printing the fuel electrode slurry and the lead film slurry is substantially the same process. In addition, the steps for preparing and printing the solid electrolyte slurry and the protective film slurry are substantially the same steps. The lead film slurry is printed on both ends of the fuel cell, but is printed so that the length of the lead film 115a on one end side of the molded base tube is longer than that of the lead film 115b on the other end side. The protective film slurry is printed on the lead film slurry so that the upper surface of the lead film 115 is exposed at the end of the base tube 103.

  The base tube formed so that the other end side (the one with the shorter lead film (lead film 115b)) is vertically upward is suspended and integrally fired in the atmosphere at 1350 ° C. to 1500 ° C. for 3 hours to 5 hours. Thus, the base tube 103, the fuel electrode 109, the lead film 115, the solid electrolyte 111, the interconnector 107, and the protective film 117 are formed.

  Next, a water-based vehicle is mixed with the air electrode material to prepare an air electrode slurry. A slurry for the air electrode is screen-printed on the interconnector 107 after firing. Further, a water-based vehicle or the like is mixed with the seal bonding film material to prepare a seal bonding film slurry. A slurry for seal bonding film is roller-printed on the protective film 117 after sintering. Thereafter, the base tube 103 is suspended so that the other end side (the one with the shorter lead film (lead film 115b)) is directed vertically, and fired in the atmosphere at 1100 ° C. to 1400 ° C. for 1 hour to 4 hours. Then, the air electrode 113 and the seal bonding film 119 are formed.

  When suspended and fired, the base tube is shrunk on the lower side (lower side) in the vertical direction, but the weight is applied on the upper side (upper side) in the vertical direction and the base tube is not shrunk as much as the lower side. Therefore, in the base tube after firing, the porosity on the upper side is increased, and the porosity on the lower side is decreased.

  In addition, when the molded base tube, fuel electrode material, solid electrolyte material, etc. are suspended and integrally fired, gravity is applied in the axial direction of the base tube, and the fuel cell by each element (fuel electrode 109, solid electrolyte 111, interconnector 107, etc.) ) Differs in length in the axial direction of the base tube. When suspended, each element arranged on the upper side in the vertical direction is longer than each element arranged on the lower side in the vertical direction. For example, an element arranged on the upper side in the vertical direction is about 8% longer than an element arranged on the lower side in the vertical direction.

  Next, the SOFC module 201 and the SOFC cartridge 203 according to this embodiment will be described with reference to FIGS. Here, FIG. 4 shows one mode of the SOFC module 201. FIG. 5 shows a cross-sectional view of one aspect of the SOFC cartridge 203.

  As illustrated in FIG. 4, the SOFC module 201 includes, for example, a plurality of SOFC cartridges 203 and a pressure vessel 205 that stores the plurality of SOFC cartridges 203. The SOFC module 201 has a fuel gas supply pipe 207 and a plurality of fuel gas supply branch pipes 207a. The SOFC module 201 includes a fuel gas discharge pipe 209 and a plurality of fuel gas discharge branch pipes 209a. The SOFC module 201 includes an oxidizing gas supply pipe (not shown) and an oxidizing gas supply branch pipe (not shown). The SOFC module 201 includes an oxidizing gas discharge pipe (not shown) and a plurality of oxidizing gas discharge branch pipes (not shown).

  The fuel gas supply pipe 207 is provided outside the pressure vessel 205 and is connected to a fuel gas supply unit (not shown) that supplies a predetermined gas composition and a predetermined flow rate of fuel gas corresponding to the power generation amount of the SOFC module 201. At the same time, it is connected to a plurality of fuel gas supply branch pipes 207a. The fuel gas supply pipe 207 is configured to branch and guide a predetermined flow rate of fuel gas supplied from the fuel gas supply unit described above to a plurality of fuel gas supply branch pipes 207a. The fuel gas supply branch pipe 207 a is connected to the fuel gas supply pipe 207 and is connected to a plurality of SOFC cartridges 203. The fuel gas supply branch pipe 207a guides the fuel gas supplied from the fuel gas supply pipe 207 to the plurality of SOFC cartridges 203 at a substantially equal flow rate, and makes the power generation performance of the plurality of SOFC cartridges 203 substantially uniform. .

  The fuel gas discharge branch pipe 209 a is connected to the plurality of SOFC cartridges 203 and also connected to the fuel gas discharge pipe 209. The fuel gas discharge branch pipe 209 a guides the exhaust fuel gas discharged from the SOFC cartridge 203 to the fuel gas discharge pipe 209. The fuel gas discharge pipe 209 is connected to a plurality of fuel gas discharge branch pipes 209 a and a part thereof is disposed outside the pressure vessel 205. The fuel gas discharge pipe 209 guides the exhaust fuel gas led out from the fuel gas discharge branch pipe 209a at a substantially equal flow rate to the outside of the pressure vessel 205.

  Since the pressure vessel 205 is operated at an internal pressure of 0.1 MPa to about 1 MPa and an internal temperature of the atmospheric temperature to about 550 ° C., the pressure vessel 205 has a resistance to corrosion and resistance to oxidizing agents such as oxygen contained in the oxidizing gas. The possessed material is used. For example, a stainless steel material such as SUS304 is suitable.

  Here, in the present embodiment, a mode has been described in which a plurality of SOFC cartridges 203 are assembled and stored in the pressure vessel 205. However, the present invention is not limited to this. It can also be set as the aspect accommodated in the container 205. FIG.

  As shown in FIG. 5, the SOFC cartridge 203 includes a plurality of cell stacks 101, a power generation chamber 215, a fuel gas supply chamber (fuel gas supply portion) 217, a fuel gas discharge chamber (fuel gas discharge portion) 219, an oxidation chamber It has an oxidizing gas supply chamber 221 and an oxidizing gas discharge chamber 223. The SOFC cartridge 203 includes an upper tube plate 225a, a lower tube plate 225b, an upper heat insulator 227a, and a lower heat insulator 227b. In the present embodiment, the SOFC cartridge 203 includes a fuel gas supply chamber 217, a fuel gas discharge chamber 219, an oxidizing gas supply chamber 221, and an oxidizing gas discharge chamber 223 as shown in FIG. The fuel gas and the oxidizing gas have a structure that flows between the inside and the outside of the cell stack 101, but this is not always necessary, for example, the inside and the outside of the cell stack flow in parallel. Alternatively, the oxidizing gas may flow in a direction orthogonal to the longitudinal direction of the cell stack.

  The power generation chamber 215 is an area formed between the upper heat insulator 227a and the lower heat insulator 227b. The power generation chamber 215 is an area in which the fuel cell 105 of the cell stack 101 is disposed, and electricity is generated by electrochemically reacting the fuel gas and the oxidizing gas. Further, the temperature in the vicinity of the central portion of the power generation chamber 215 in the longitudinal direction of the cell stack 101 is a high temperature atmosphere of about 700 ° C. to 1000 ° C. during steady operation of the fuel cell module 201.

  The fuel gas supply chamber 217 is an area surrounded by the upper casing 229a and the upper tube plate 225a of the SOFC cartridge 203. The fuel gas supply chamber 217 communicates with the fuel gas supply branch pipe 207a through a fuel gas supply hole 231a provided in the upper casing 229a. In the fuel gas supply chamber 217, one end of the cylindrical cell stack 101 is disposed so as to be open to the fuel gas supply chamber 217. One end portion of the cell stack 101 is an end portion having a smaller porosity of the substrate tube (one end portion side of the substrate tube, the one facing downward in the vertical direction during hanging firing), and all cell stacks. For 101, the one with the smaller porosity is arranged in the same direction. The fuel gas supply chamber 217 guides the fuel gas supplied from the fuel gas supply branch pipe 207a through the fuel gas supply hole 231a into the base tube 103 of the plurality of cell stacks 101 at a substantially uniform flow rate. The power generation performance of the cell stack 101 is made substantially uniform.

  The fuel gas discharge chamber 219 is an area surrounded by the lower casing 229b and the lower tube plate 225b of the SOFC cartridge 203. The fuel gas discharge chamber 219 communicates with the fuel gas discharge branch pipe 209a through a fuel gas discharge hole 231b provided in the lower casing 229b. Further, the other end of the cylindrical cell stack 101 is disposed in the fuel gas discharge chamber 219 so as to be open to the fuel gas discharge chamber 219. The other end portion of the cell stack 101 is an end portion of the one in which the porosity of the base tube is increased (the other end portion side of the base tube, which is directed upward in the hanging firing), The cell stack 101 having the larger porosity in the same direction is arranged. The fuel gas discharge chamber 219 collects exhaust fuel gas that passes through the inside of the base tube 103 of the plurality of cell stacks 101 and is supplied to the fuel gas discharge chamber 219, and passes through the fuel gas discharge hole 231b. It leads to the discharge branch pipe 209a.

  Corresponding to the power generation amount of the SOFC module 201, a predetermined gas composition and a predetermined flow rate of oxidizing gas are branched to the oxidizing gas supply branch pipe and supplied to a plurality of SOFC cartridges 203. The oxidizing gas supply chamber 221 is a region surrounded by the lower casing 229b, the lower tube sheet 225b, and the lower heat insulator 227b of the SOFC cartridge 203. The oxidizing gas supply chamber 221 communicates with an oxidizing gas supply branch pipe (not shown) through an oxidizing gas supply hole 233a provided in the lower casing 229b. The oxidizing gas supply chamber 221 generates a predetermined flow rate of oxidizing gas supplied from an oxidizing gas supply branch pipe (not shown) through an oxidizing gas supply hole 233a through an oxidizing gas supply gap 235a described later. It leads to the chamber 215.

  The oxidizing gas discharge chamber 223 is a region surrounded by the upper casing 229a, the upper tube plate 225a, and the upper heat insulator 227a of the SOFC cartridge 203. The oxidizing gas discharge chamber 223 communicates with an oxidizing gas discharge branch pipe (not shown) through an oxidizing gas discharge hole 233b provided in the upper casing 229a. The oxidizing gas discharge chamber 223 allows the exhaust oxidizing gas supplied from the power generation chamber 215 to the oxidizing gas discharge chamber 223 via an oxidizing gas discharge gap 235b described later via the oxidizing gas discharge hole 233b. It leads to an oxidizing gas discharge branch pipe (not shown).

  The upper tube plate 225a is arranged between the top plate of the upper casing 229a and the upper heat insulator 227a so that the upper tube plate 225a, the top plate of the upper casing 229a and the upper heat insulator 227a are substantially parallel to each other. It is fixed to the side plate. The upper tube sheet 225a has a plurality of holes corresponding to the number of cell stacks 101 provided in the SOFC cartridge 203, and the cell stacks 101 are inserted into the holes, respectively. The upper tube sheet 225a hermetically supports one end of the plurality of cell stacks 101 through one or both of a sealing member and an adhesive member, and also includes a fuel gas supply chamber 217 and an oxidizing gas discharge chamber 223. And is to be isolated.

  The lower tube plate 225b is disposed on the side plate of the lower casing 229b so that the lower tube plate 225b, the bottom plate of the lower casing 229b, and the lower heat insulator 227b are substantially parallel between the bottom plate of the lower casing 229b and the lower heat insulator 227b. It is fixed. The lower tube sheet 225b has a plurality of holes corresponding to the number of cell stacks 101 provided in the SOFC cartridge 203, and the cell stacks 101 are inserted into the holes, respectively. The lower tube sheet 225b hermetically supports the other end of the plurality of cell stacks 101 through one or both of a sealing member and an adhesive member, and also includes a fuel gas discharge chamber 219 and an oxidizing gas supply chamber 221. And is to be isolated.

  The cell stack 101 is provided with a seal bonding film 119 at the seal portion between the upper tube plate 225a and the lower tube plate 225b to increase the surface roughness, and the adhesive strength between the cell stack 101 and the seal member and the adhesive member. Has been improved.

  The upper heat insulator 227a is disposed at the lower end of the upper casing 229a so that the upper heat insulator 227a, the top plate of the upper casing 229a and the upper tube plate 225a are substantially parallel to each other, and is fixed to the side plate of the upper casing 229a. Yes. Further, the upper heat insulator 227a is provided with a plurality of holes corresponding to the number of cell stacks 101 provided in the SOFC cartridge 203. The diameter of the hole is set larger than the outer diameter of the cell stack 101. The upper heat insulator 227a has an oxidizing gas discharge gap 235b formed between the inner surface of this hole and the outer surface of the cell stack 101 inserted through the upper heat insulator 227a.

  The upper heat insulator 227a separates the power generation chamber 215 and the oxidizing gas discharge chamber 223, and the atmosphere around the upper tube sheet 225a is heated to reduce the strength and the corrosion caused by the oxidizing agent contained in the oxidizing gas. Suppresses the increase. The upper tube sheet 225a and the like are made of a metal material having high temperature durability such as Inconel, but the upper tube sheet 225a and the like are exposed to the high temperature in the power generation chamber 215, and the temperature difference in the upper tube sheet 225a and the like becomes large. This prevents thermal deformation. The upper heat insulator 227a guides the exhaust oxidizing gas exposed to a high temperature through the power generation chamber 215 to the oxidizing gas exhaust chamber 223 through the oxidizing gas discharge gap 235b.

  According to the present embodiment, the structure of the SOFC cartridge 203 described above allows the fuel gas and the oxidizing gas to flow oppositely on the inner side and the outer side of the cell stack 101. As a result, the exhaust oxidizing gas exchanges heat with the fuel gas supplied to the power generation chamber 215 through the inside of the base tube 103, and the upper tube plate 225a made of a metal material is buckled. It is cooled to a temperature that does not cause deformation and supplied to the oxidizing gas discharge chamber 223. In addition, the temperature of the fuel gas is raised by heat exchange with the exhaust oxidizing gas discharged from the power generation chamber 215 and supplied to the power generation chamber 215. As a result, the fuel gas preheated to a temperature suitable for power generation can be supplied to the power generation chamber 215 without using a heater or the like.

  The lower heat insulator 227b is disposed at the upper end of the lower casing 229b so that the lower heat insulator 227b, the bottom plate of the lower casing 229b, and the lower tube plate 225b are substantially parallel to each other, and is fixed to the side plate of the upper casing 229a. . Also, the lower heat insulator 227b is provided with a plurality of holes corresponding to the number of cell stacks 101 provided in the SOFC cartridge 203. The diameter of the hole is set larger than the outer diameter of the cell stack 101. The lower heat insulator 227b has an oxidizing gas supply gap 235a formed between the inner surface of this hole and the outer surface of the cell stack 101 inserted through the lower heat insulator 227b.

  The lower heat insulator 227b separates the power generation chamber 215 and the oxidizing gas supply chamber 221, and the atmosphere around the lower tube sheet 225b is heated to lower the strength and corrode by the oxidizing agent contained in the oxidizing gas. Suppresses the increase. The lower tube plate 225b and the like are made of a metal material having high temperature durability such as Inconel. However, the lower tube plate 225b and the like are exposed to a high temperature and the temperature difference in the lower tube plate 225b and the like is increased, so that the heat is deformed. It is something to prevent. The lower heat insulator 227b guides the oxidizing gas supplied to the oxidizing gas supply chamber 233 to the power generation chamber 215 through the oxidizing gas supply gap 235a.

  According to the present embodiment, the structure of the SOFC cartridge 203 described above allows the fuel gas and the oxidizing gas to flow oppositely on the inner side and the outer side of the cell stack 101. As a result, the exhaust fuel gas that has passed through the power generation chamber 215 through the interior of the base tube 103 is heat-exchanged with the oxidizing gas supplied to the power generation chamber 215, and the lower tube plate 225b made of a metal material. And the like are cooled to a temperature that does not cause deformation such as buckling, and supplied to the fuel gas discharge chamber 219. The oxidizing gas is heated by heat exchange with the exhaust fuel gas and supplied to the power generation chamber 215. As a result, the oxidizing gas heated to the temperature necessary for power generation can be supplied to the power generation chamber 215 without using a heater or the like.

  The direct-current power generated in the power generation chamber 215 is not covered by the protective film 117 after being led to the vicinity of the end of the cell stack 101 by the lead film 115 made of Ni / YSZ or the like provided in the plurality of fuel cells 105, The lead film 115 is electrically connected to a current collector plate (not shown) at the end of the base tube 103 where the upper surface of the lead film 115 is exposed. The current is collected on a current collecting rod (not shown) of the SOFC cartridge 203 via a current collecting plate (not shown) and taken out to the outside of each SOFC cartridge 203. The electric power derived to the outside of the SOFC cartridge 203 by the current collector rod is connected to the generated power of each SOFC cartridge 203 in a predetermined series number and parallel number, and is derived to the outside of the SOFC module 201. It is converted into predetermined AC power by an inverter that does not, and supplied to the power load.

  According to the present embodiment, in the SOFC cartridge 203, the plurality of cell stacks 101 are arranged such that the porosity of the base tube 103 (the one that faces the upper side in the vertical direction during the hanging firing) is the fuel gas discharge side ( It is arranged toward the downstream side in the fuel gas flow direction. When the porosity of the base tube 103 is large, the power generation reaction is promoted. Therefore, according to the present embodiment, it is possible to increase the amount of power generation reaction on the downstream side in the flow direction of the fuel gas, which has limited the current flowing through the cell stack 101, and increase the power generation capacity of the entire cell stack.

  Further, in the cell stack 101, the length of each element is larger in the case where the porosity of the base tube 103 is larger (the one facing the upper side in the vertical direction during hanging firing) than in the case where the porosity of the base tube 103 is small. It is getting longer. The amount of current flowing through each fuel cell is equal. If the fuel cell is long, the area through which current flows increases, and the amount of current per unit area decreases (current density decreases). Therefore, a long fuel cell has a substantially higher voltage than a short fuel cell, and as a result, the performance of the fuel cell is improved.

  In the SOFC cartridge 203, when the porosity of the base tube 103 is small, the region near the end of the base tube 103 where the porosity is particularly small requires a long lead portion 114a due to the cartridge structure upstream in the fuel gas flow direction. It is arranged in the area. For this reason, in the cell stack 101, the length (La) of the lead film 115a of the lead portion 114a upstream in the fuel gas flow direction is equal to the length (Lb) of the lead film 115b of the fuel gas flow direction downstream lead portion 114b. ) Longer than. Since the lead portions (114a, 114b) do not generate power, even if the lead portion 114a on the upstream side in the fuel gas flow direction is longer than the lead film 115b, power is generated due to the low porosity of the base tube 103. There is little impact on efficiency.

[Second Embodiment]
The second embodiment is characterized in that two types of cell stacks having different current flow directions are produced and arranged in the same cartridge. The configurations that are not particularly described are the same as those in the first embodiment.

  The present embodiment will be described with reference to the drawings. FIG. 6 is a side view of the cell stack according to the present embodiment. In the same figure, (A) is a side view of an A type cell stack, and (B) is a side view of a B type cell stack. FIG. 7 is a cross-sectional view taken along the line XX on the positive electrode side in FIG. FIG. 8 is a YY arrow cross-sectional view of the negative electrode side in FIG. FIG. 9 is a cross-sectional view taken along the line XX on the negative electrode side in FIG. FIG. 10 is a cross-sectional view taken along the line Y-Y on the positive electrode side in FIG.

  In the present embodiment, the cell stack includes an A type cell stack 101a and a B type cell stack 101b. Each of the A type cell stack 101a and the B type cell stack 101b is adjacent to a cylindrical base tube 103 and a plurality of fuel cells 105 formed on the outer peripheral surface of the base tube 103, as in the first embodiment. And an interconnector 107 formed between the fuel cells 105. In the cell stack (101a, 101b), the fuel cell 105 is formed by laminating a fuel electrode 109, a solid electrolyte 111, and an air electrode 113.

  The A type cell stack 101 a and the B type cell stack 101 b are fuel cell cells 105 formed at the end in the axial direction of the base tube 103 among the plurality of fuel cells 105 formed on the outer peripheral surface of the base tube 103. Have lead portions 114 (114a, 114b) electrically connected to each other. The lead part 114 includes a lead film 115 (115a, 115b) and a protective film 117 formed on the lead film. One end of the lead film 115 is electrically connected to the fuel cell 105, and the other end extends toward the end of the base tube 103. The upper surface of the lead film 115 is exposed on the end side of the base tube 103. A seal bonding film 119 may be appropriately stacked on the protective film 117 covering the lead film 115. In the A type cell stack 101a and the B type cell stack 101b, the lead film 115a provided on the positive electrode side is electrically connected to the air electrode 113 of the outermost fuel cell 105 via the interconnector 107. The lead film 115 b provided on the negative electrode side is electrically connected to the fuel electrode 109 of the outermost fuel cell 105.

  Each structure of the base tube 103 and the fuel cell 105, the material of the interconnector 107, the lead film 115, the seal bonding film 119, and the protective film 117 are the same as in the first embodiment.

  The A type cell stack 101a is a cell stack in which the porosity of the base tube 103 on the negative electrode side is larger than that on the positive electrode side. In the A type cell stack 101a, the lead part 114a and the lead film 115a (La) provided on the positive electrode side are longer than the lead part 114b and the lead film 115b (Lb) provided on the negative electrode side. In the A type cell stack 101a, the fuel cell 105b on the negative electrode side is longer than the fuel cell 105a on the positive electrode side.

  The B type cell stack 101b is a cell stack in which the porosity of the base tube 103 on the positive electrode side is larger than that on the negative electrode side. In the B type cell stack, the lead part 114a and the lead film 115a (La) provided on the negative electrode side are longer than the lead part 114b and the lead film 115b (Lb) provided on the positive electrode side. In the B type cell stack 101b, the fuel cell 105b on the positive electrode side is longer than the fuel cell 105a on the negative electrode side.

  In at least one of the A type cell stack 101a and the B type cell stack 101b, an identification unit 121 may be provided on the lead portion. The identification part 121 is installed using the same material as the formation film of each layer according to the location formed on the lead part. For example, as shown in FIG. 9, the identification portion 121 (l) formed so as to be in contact with the lead film 115a can be easily installed using the same material as the protective film 117 in conjunction with the formation of the protective film 117. . Further, the identification portion 121 (p) formed immediately above the protective film 117 in FIG. 9 is installed using the same material as the seal bonding film 119. Only one of the identification unit 121 (l) and the identification unit 121 (p) may be installed.

  The identification unit 121 is formed so that the A type cell stack 101a and the B type cell stack 101b can be identified by appearance. For example, an annular line identification unit 121 may be provided on the lead portion 114b on the positive electrode side of the B type cell stack 101b. When the identification unit 121 is provided in both the A type cell stack 101a and the B type cell stack 101b, the position, shape, and the like of the identification unit 121 are divided into patterns.

The identification unit 121 is not limited to the above-described annular line, and can be provided in the manufacturing process. If the external appearance can be identified, the shape can be appropriately changed.

  The A type cell stack 101a and the B type cell stack 101b can be manufactured as follows. FIG. 11 shows a schematic side view of the A type cell stack 101a and the B type cell stack 101b when suspended and fired. In the figure, (A) is an A type cell stack 101a when suspended and fired, (B) is a B type cell stack 101b when suspended and fired, and the upper side of the drawing is in the vertical direction. For simplification, FIG. 11 shows unfired fuel cells 105 ′, unfired lead portions 114 a ′ and 114 b ′, and unfired identification portions 121 (l) ′ and 121 (p).

  As in the first embodiment, a fuel electrode slurry, a lead film slurry, a solid electrolyte slurry, a protective film slurry, and an interconnector slurry are sequentially formed on the molded substrate tube. The lead film slurry is such that the lead film 115a on the positive electrode side of the A type cell stack 101a and the negative electrode side of the B type cell stack 101b is on the negative electrode side of the A type cell stack 101a and the positive electrode side of the B type cell stack 101b. Printing is performed so as to be longer than the lead film 115b. The slurry for the protective film is diverted to the slurry for the identification part (l) for forming the identification part 121 (l). The identification part (l) slurry is screen-printed on the lead film slurry formed so as to be spaced from the end of the formed protective film slurry. The identification portion slurry may be formed in a ring shape so as to make a round in the circumferential direction of the base tube 103.

  Thereafter, the base tube formed so that the shorter one of the lead films faces in the vertical direction is suspended. The A type cell stack 101a faces the negative electrode side, and the B type cell stack 101b faces the positive electrode side vertically. The A type cell stack 101a faces the positive side, and the B type cell stack 101b faces the negative side downward. The fuel electrode 109, the lead film 115, the solid electrolyte 111, the interconnector 107, the protective film 117, the seal bonding film 119, and the identification unit 121 are integrally fired at 1350 ° C. to 1500 ° C. for 3 hours to 5 hours in the atmosphere. Form.

  Next, a water-based vehicle is mixed with the air electrode material to prepare an air electrode slurry. A slurry for the air electrode is screen-printed on the interconnector after firing. In addition, a seal bonding membrane material is mixed with an aqueous vehicle to produce a seal bonding membrane slurry. A slurry for seal bonding film is roller-printed on the protective film 117 after sintering. The slurry for the seal bonding film is diverted to the slurry for the identification portion (p) for forming the identification portion 121 (p). The identification part (p) slurry is screen-printed on the protective film slurry formed so as to be spaced from the end of the formed seal bonding film slurry. Thereafter, the base tube is suspended so that the shorter one of the lead films (lead film 115b) faces vertically, and is fired in the atmosphere at 1100 ° C. to 1400 ° C. for 1 hour to 4 hours to form the air electrode 113. .

  The A type cell stack 101a and the B type cell stack 101b manufactured as described above are cell stacks in which only the polarity is inverted. As in the first embodiment, in the base tube after firing, the porosity on the upper side increases, and the porosity on the lower side decreases. In addition, each element disposed on the upper side in the vertical direction when suspended is longer than each element disposed on the lower side in the vertical direction.

  Since the identification portion (l) slurry and the identification portion (p) slurry are formed before firing the formed base tube, it is difficult to mistake the direction in which the cell stack is suspended in the integral firing. The direction of hanging by the length of the lead part 114a and the lead part 114b can be confirmed, and by providing the identification unit 121, the A type cell stack 101a and the B type cell stack 101b can be identified by appearance.

  FIG. 12 shows a schematic configuration diagram of the SOFC cartridge according to the present embodiment. FIG. 12 shows only the configuration necessary for the description, but the basic configuration is the same as that of the SOFC cartridge of the first embodiment.

  In FIG. 12, the SOFC cartridge 303 includes a casing 329, a plurality of cell stacks 101 (A type cell stack 101a and B type cell stack 101b), a power generation chamber 315, a fuel gas supply chamber 317, and a fuel gas discharge chamber 319. Have The SOFC cartridge has an upper tube plate 325a and a lower tube plate 325b. The oxidizing gas has a structure that flows in a direction perpendicular to the longitudinal direction of the cell stack, but this is not always necessary. For example, the oxidizing gas flows in parallel between the inside and outside of the cell stack, or the fuel gas and the oxidizing gas. May flow so that the inside and the outside of the cell stack 101 face each other.

  The power generation chamber 315 is an area formed between the casing 329, the upper tube plate 325a, and the lower tube plate 325b. The fuel cell 105 of the cell stack (101a, 101b) is arranged, and is an area where electric power is generated by electrochemically reacting the fuel gas and the oxidizing gas.

  The fuel gas supply chamber 317 is an area surrounded by the upper part of the casing 329 and the upper tube sheet 325a. The fuel gas supply chamber 317 communicates with a fuel gas supply branch pipe (not shown) through a fuel gas supply hole 331 a provided in the upper part of the casing 329. Further, one end of the cylindrical cell stack 101 is disposed in the fuel gas supply chamber 317 so as to be open to the fuel gas supply chamber 317. One end portion of the cell stack 101 is an end portion having a smaller porosity of the base tube (the one facing downward in the vertical direction during the suspension firing), and the pores in the same direction for all the cell stacks 101. The one with the smaller rate is placed.

  The fuel gas discharge chamber 319 is an area surrounded by the lower part of the casing 329 and the lower tube sheet 325b. The fuel gas discharge chamber 319 is communicated with a fuel gas discharge branch pipe (not shown) through a fuel gas discharge hole 331b provided in the lower portion of the casing 329. Further, the other end of the cylindrical cell stack 101 is disposed in the fuel gas discharge chamber 319 so as to be open to the fuel gas discharge chamber 319. The other end of the cell stack (101a, 101b) is the end of the substrate tube having a higher porosity (the one that faces upward in the hanging firing). The one with the larger porosity in the same direction is arranged.

  The upper tube sheet 325a supports one end (upper end) of the plurality of cell stacks 101. The lower tube sheet 325b supports the other end (lower end) of the plurality of cell stacks 101.

  The plurality of cell stacks 101 includes a plurality of A type cell stacks 101a and a plurality of B type cell stacks 101b.

  The plurality of A type cell stacks 101a are electrically connected in parallel by current collecting members to constitute an A type cell stack group 313a. In the A type cell stack group 313a, the plurality of A type cell stacks 101a are all laterally facing the fuel gas supply chamber side (vertical upper side) and the negative electrode facing the fuel gas discharge chamber side (vertical lower side). Are arranged side by side. The positive electrode side end portions of the plurality of A type cell stacks 101 a are assembled by the upper current collecting member 311. The negative electrode side end portions of the plurality of A type cell stacks 101 a are assembled by the lower current collecting member 312. Each of the upper current collecting member 311 and the lower current collecting member 312 has conductivity.

  A plurality of B type cell stacks 101b are electrically connected in parallel by current collecting members to constitute a B type cell stack group 313b. In the B type cell stack group 313b, the plurality of B type cell stacks 101b are all laterally facing the negative electrode toward the fuel gas supply chamber side (vertical upper side) and the positive electrode toward the fuel gas discharge chamber side (vertical lower side). Are arranged side by side. The negative electrode side end portions of the plurality of B type cell stacks 101 b are assembled by the upper current collecting member 311. The positive electrode side end portions of the plurality of B type cell stacks 101 b are assembled by the lower current collecting member 312.

  The A type cell stack group 313a and the B type cell stack group 313b are arranged side by side in the SOFC cartridge. In the adjacent A type cell stack group 313a and B type cell stack group 313b, either the upper current collecting member 311 or the lower current collecting member 312 is electrically connected. The current collecting member 311 on the unconnected side is connected to a current collecting rod 314 or the like, and the electric power can be led out of the SOFC cartridge via the current collecting rod 314.

  According to the present embodiment, by arranging the A type cell stack 101a and the B type cell stack 101b whose polarities are reversed in the SOFC cartridge, the wiring in the cartridge is connected to one end side and the other end of the cell stack. On the part side, they are collected in one direction. This eliminates the need for routing for connecting the current collector from one end side of the cell stack to the other end side, shortening the connection wiring member between the A type cell stack 101a and the B type cell stack 101b, Series wiring is easy.

  In series connection between cell stacks as in the past, it is possible to obtain efficient series wiring as described above in which cell stacks of the same polarity are inverted and arranged, but the porosity distribution in the axial direction of the base tube is also Since the generated currents of the inverted cell stacks are different by being inverted up and down, there is a problem in that the power generation performance of the entire cell stack is reduced if they are connected in series as they are. In this embodiment, when the A type cell stack 101a and the B type cell stack 101b are arranged with their polarities reversed, the porosity distribution in the axial direction of the base tube is manufactured so as to show the same tendency in all the cell stacks. ing. According to this embodiment, since the one with the larger porosity can be arranged in the same direction and arranged on the fuel gas discharge side, the power generation reaction on the downstream side in the fuel gas flow direction is promoted, and the entire cell stack is The power generation capacity can be increased.

  Further, in the cell stack 101 (A type cell stack 101a and B type cell stack 101b), in the case where the porosity of the substrate tube is large (the one facing upward in the vertical direction during hanging firing), the porosity of the substrate tube is Each element (fuel cell) is longer than the smaller one. The amount of current flowing on the upper and lower sides of the cell stack is the same. If the fuel cell is long, the area through which the current flows increases, and the current per unit area decreases (current density decreases). Therefore, a long fuel cell has a substantially higher voltage than a short fuel cell, and as a result, the performance of the fuel cell is improved.

  In the SOFC cartridge 303, the smaller the porosity of the base tube 103 is on the upstream side in the flow direction of the fuel gas. In particular, the region near the end of the base tube 103 where the porosity is small has a long lead film due to the cartridge structure. It is placed in the required area. Since no power is generated in the lead portion, there is little influence on the power generation efficiency.

[Third Embodiment]
3rd Embodiment demonstrates the aspect at the time of the individual difference having arisen in the porosity in the base tube 103 of the cell stack manufactured by hanging baking. The configurations that are not particularly described are the same as those in the first embodiment. The present embodiment will be described with reference to the drawings. FIG. 13 is a cross-sectional view of the SOFC cartridge according to the present embodiment. In FIG. 13, a plurality of cell stacks (101H, 101L) are supported by the upper tube sheet 225a.

  The plurality of cell stacks 101 manufactured by hanging firing may cause individual differences in porosity values at arbitrary positions due to the position in the furnace at the time of firing or the difference between lots. Even in such a case, since it is suspended and fired, the tendency of the porosity distribution in the axial direction of the base tube is common among the cell stacks. That is, in the plurality of cell stacks 101, the porosity of the base tube is one end side (side arranged downward in the vertical direction during hanging firing) and the other end side (vertical when hanging firing). The side arranged toward the upper side in the direction is larger.

  FIG. 14 shows the porosity of the base tube (before air electrode printing) integrally fired with the fuel electrode material and the like. In the figure, the abscissa represents the porosity of the substrate tube, the ordinate represents the position (mm) from the suspended lower end, ♦ represents the substrate tube 1, and Δ represents the substrate tube 2. The base tube 1 and the base tube 2 are suspended and fired in the same furnace. According to FIG. 14, the base tube 1 and the base tube 2 have the same tendency of the porosity distribution in the axial direction, but there is an individual difference of about 1% to 2% in the porosity value at an arbitrary position. Recognize. If the NiO is reduced to Ni by passing hydrogen through the base tube at a high temperature after the air electrode is formed and fired, the porosity of the base tube becomes higher than that in FIG. For example, the porosity of the base tube of FIG. 14 is about 23% to 26%, but increases to about 30% to 50% after the reduction treatment.

  In the SOFC cartridge 203, the cell stack 101H having a relatively large porosity value at an arbitrary position in the axial direction of the base tube has a relative porosity value at an arbitrary position in the axial direction of the base tube. It is arranged outside the smaller cell stack 101L. The “arbitrary position corresponding to the axial direction of the base tube” is a position where the distance from one end portion of the base tube is the same when the base tubes are aligned with the direction of the porosity distribution aligned, for example. The “outside” is the side closer to the edge of the SOFC cartridge in the SOFC cartridge. In FIG. 13, the side closer to the outer edge of the upper tube sheet 225a is the “outer side”.

  In the present embodiment, individual differences in the porosity of the base tube are managed at arbitrary positions in the axial direction of the cell stacks (cell stack 101H and cell stack 101L). Specifically, when manufacturing the cell stack 101, the base tube material is formed longer than the product standard so that an excess portion is formed at both ends of the base tube. After the base tube is suspended and integrally fired, excess portions are cut off and the porosity of the base tube is measured. The surplus part includes a surplus part (upper) that comes to the upper side when suspended and a surplus part (lower) that comes to the lower side. The porosity values of the surplus part (upper) and surplus part (lower) are managed separately. The arrangement of each cell stack (cell stack 101H and cell stack 101L) in the SOFC cartridge is determined based on the measured porosity value of the base tube. The porosity of the surplus portions (upper) of the plurality of cell stacks and the porosity of the surplus portions (lower) are compared, and the cell stack 101L having a relatively small porosity is disposed in the central region C of the SOFC cartridge. . The cell stack 101H having a relatively large porosity is arranged in an outer peripheral region (outer peripheral region D) that is a periphery outside the central region C.

  When each cell stack (the cell stack 101L and the cell stack 101H) is arranged in the cartridge, the end portion of the base tube having the larger porosity in the axial direction is directed to the downstream side in the fuel gas flow direction.

  In the SOFC cartridge, the temperature in the central region (C) tends to increase due to the effect of heat transfer with the surrounding structure. Since the power generation reaction is promoted when the ambient temperature of the cell stack is high, the power generation reaction in the outer peripheral region of the low temperature SOFC cartridge is limited even if the temperature of the central region of the SOFC cartridge is high. As a result, it becomes difficult for current to flow. According to the present embodiment, the base tube having a relatively low porosity is disposed in the central region of the SOFC cartridge, and the base tube having a relatively large porosity is disposed in the outer peripheral region of the SOFC cartridge. The temperature distribution of each cartridge and the heat generated by the power generation reaction of each cartridge can be offset. Further, the temperature can be raised in the outer peripheral region where the substrate tube having a large porosity is disposed. Thereby, a difference in temperature distribution in the power generation chamber is unlikely to occur, and the power generation efficiency of the fuel cell can be increased.

  Further, in the above, the porosity of the base tube is relatively compared and the arrangement of the base tube in the cartridge is determined. However, a threshold is set for the porosity of the porosity, and the base tube having a porosity larger than the threshold is set in the SOFC cartridge. The base tube having a porosity smaller than the threshold value may be arranged in the outer peripheral region of the SOFC cartridge. The threshold value is set by, for example, statistically processing data on a substrate tube to be input from inspection data measured in advance in the manufacturing process, and determining the arrangement of the substrate tube in the cartridge using an average value of variation as a threshold value.

  The third embodiment can be implemented in combination with the second embodiment.

  In addition, this invention is not limited to embodiment mentioned above, In the range which does not deviate from the summary, it can change suitably.

101 Cell stack 101a A type cell stack 101b B type cell stack 103 Base tube 105 Fuel cell 107 Interconnector 109 Fuel electrode 111 Solid electrolyte 113 Air electrode 114, 114a, 114b Lead part 114a ', 114b' Lead part (unfired)
115, 115a, 115b Lead film 117 Protective film 119 Seal bonding film 121 (l), 121 (p) Identification part 121 (l) ′, 121 (p) ′ Identification part (unfired)
201 Fuel cell module (SOFC module)
203, 303 SOFC cartridge 205 Pressure vessel 207 Fuel gas supply pipe 207a Fuel gas supply branch pipe 209 Fuel gas discharge pipe 209a Fuel gas discharge branch pipes 215, 315 Power generation chambers 217, 317 Fuel gas supply chamber (fuel gas supply section)
219, 319 Fuel gas discharge chamber (fuel gas discharge section)
221 Oxidizing gas supply chamber 223 Oxidizing gas discharge chamber 225a, 325a Upper tube plate 225b, 325b Lower tube plate 227a Upper heat insulator 227b Lower heat insulator 229a Upper casing 229b Lower casing 231a, 331a Fuel gas supply holes 231b, 331b Fuel gas Exhaust hole 233a Oxidizing gas supply hole 233b Oxidizing gas discharge hole 235a Oxidizing gas supply gap 235b Oxidizing gas discharge gap 311 Upper current collecting member 312 Lower current collecting member 313a A type cell stack group 313b B type cell stack group 314 Electric bar 329 casing

Claims (11)

All of the fuel cell units including a plurality of fuel cells that are electrically connected in series on a porous substrate tube having a large porosity on the other end side with respect to the one end side in the axial direction. Cell stack,
For the one end side and the other end side of the base tube, an electrical series connection is defined in a predetermined direction of the plurality of fuel cells,
A method of manufacturing a fuel cell cartridge, wherein the one end side of the base tube is oriented upstream in the fuel gas flow direction, and the other end side of the base tube is oriented downstream in the fuel gas flow direction. The cell stack includes an A type cell stack and a B type cell stack;
Forming the A type cell stack in which the one end side is a positive electrode and the other end side is a negative electrode;
Forming the B-type cell stack in which the one end side is a negative electrode and the other end side is a positive electrode;
The method for manufacturing a fuel cell cartridge according to claim 1, wherein the A type cell stack and the B type cell stack are electrically connected in series. The A type cell stack is formed by hanging and firing with the negative electrode side up,
The method of manufacturing a fuel cell cartridge according to claim 2, wherein the B type cell stack is formed by hanging and firing with the positive electrode side facing up. Lead portions that are electrically connected to the endmost portions of the plurality of fuel cells connected in series and guide the power generated by the fuel cells, on the one end side and the other end side of the base tube Forming the step,
Forming an identification portion on the lead portion of at least one of the A-type cell stack and the B-type cell stack;
Including
4. The method of manufacturing a fuel cell cartridge according to claim 2, wherein the lead portion material and the identification portion material are formed on the base tube before firing, and then integrally fired to form the lead portion and the identification portion. Measuring the porosity at any corresponding position in the axial direction of the substrate tube;
Based on the measured porosity, a cell stack having a relatively small porosity value is disposed in a central region in the fuel cell cartridge, and the cell stack having a relatively large porosity value is disposed in the fuel cell cartridge. The method for manufacturing a fuel cell cartridge according to any one of claims 1 to 4, wherein the fuel cell cartridge is disposed in an outer peripheral region that is an outer periphery of the central region. A plurality of cell stacks comprising a porous substrate tube and a plurality of fuel cells formed on and electrically connected to the substrate tube;
One end of a plurality of the cell stacks are disposed, and a fuel gas supply unit that supplies fuel gas to the cell stacks;
A plurality of the other end portions of the cell stack, a fuel gas discharge portion for discharging the fuel gas supplied to the cell stack;
With
The plurality of fuel cells are electrically connected in series in a predetermined direction to the one end side and the other end side of the cell stack,
The fuel cell cartridge in which the porosity of the base tube in all the cell stacks is larger on the one end side than on the other end side. A plurality of the cell stacks are
A type cell stack in which the one end side is a positive electrode and the other end side is a negative electrode;
A B type cell stack in which the one end side is a negative electrode and the other end side is a positive electrode;
The fuel cell cartridge according to claim 6, comprising: Electric power that is formed on the base tube on the one end side and the other end side, and is electrically connected to the outermost ends of the plurality of fuel cells connected in series and is generated by the fuel cells. Lead part to guide,
An identification portion formed on the lead portion of at least one of the A-type cell stack and the B-type cell stack;
The fuel cell cartridge according to claim 7, comprising:   The plurality of cell stacks include cell stacks having different porosity values at arbitrary corresponding positions in the axial direction of the respective base tube, and the cell stacks having relatively small porosity values are disposed in the fuel cell cartridge. The cell stack having a relatively large porosity value is disposed in an outer peripheral region that is an outer periphery of the central region in the fuel cell cartridge. The fuel cell cartridge according to any one of the above.   A fuel cell module comprising the fuel cell cartridge according to any one of claims 6 to 9. A fuel cell system comprising the fuel cell module according to claim 10.

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