JP2002329505A - Method of manufacturing fuel cell tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simultaneously carry out a reduction of a fuel electrode or the like and an operation inspection of a fuel cell in manufacture of a cell tube for the fuel cell, reduce manufacturing processes, and finish operation confirmation of the fuel cell before installation in a fuel cell system. SOLUTION: The method of manufacturing the fuel cell tube is provided with a step (1) of forming a substrate tube 1 from slurry having raw material and an organic solvent, a step (2) of forming the fuel electrode, a lead film, an electrolyte and a interconnector on the substrate tube 1, a step (3) of closing one end part of the substrate tube 1, a step (4) of baking the closed substrate tube 1, a step of forming an air electrode on the baked substrate tube 1, a step of sending reducing gas inside the substrate tube 1 and baking the air electrode while deoxidizing the fuel electrode and the lead film, and a step of measuring a terminal voltage of the fuel cell on the substrate tube 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a fuel cell tube.

[0002]

2. Description of the Related Art FIG. 6 shows an example of a schematic configuration of a conventional fuel cell power generation system. However, in FIG. 6, a part related to gas preheating and heat exchange and a part related to current collection of generated power are omitted.

Referring to FIG. 6, a fuel cell includes a header 110 as a gas supply unit and a cell tube 11 as a power generation unit.
1 is provided. The header 110 has a partition plate 110a, a bottom plate 110b, a supply chamber 110c, and a discharge chamber 110d. The cell tube has a guide tube 112.

[0004] The inside of the header 110 is vertically divided by a partition plate 110a, and the upper part is configured as a supply chamber 110c and the lower part is configured as a discharge chamber 110d. Header 11
The upper end (one end) of the cell tube 111 is connected to and supported by the zero bottom plate 110b so that gas can enter and exit from the discharge chamber 110d. The lower end (the other end) of the cell tube 111 is closed. Cell tube 1
A guide tube 112 is coaxially inserted into the inside of the tube 11. The guide tube 112 has one end (upper end)
It is connected to and supported by the partition plate 110a so that gas can flow in and out of the supply chamber 110c. A plurality of such cell tubes 111 and guide tubes 112 exist, are connected to the header 110, and are supported. Here, the cell tube 111 is a cylindrical cell tube constituting a combustion battery in which fuel cells are formed on the outer peripheral surface of a porous base tube.

On the other hand, referring to FIG.
FIG. 2 is a schematic configuration diagram of a fuel cell 2 (fuel electrode 14-electrolyte 15-air electrode 16) formed on 1. On the outer peripheral surface of the base tube 1 of the cell tube 111, the base tube 1
The film of the fuel electrode 14 is formed at regular intervals in the longitudinal direction of the fuel cell. A film of the electrolyte 15 is formed so as to overlap therewith. However, there is a slight shift. Furthermore, a film of the air electrode 16 is formed thereon. This membrane is also slightly offset in the same direction as the electrolyte. The electrolyte and the air electrode of the adjacent fuel cell and the fuel electrode are joined by a film of the interconnector 17. When the interconnector 17 is made of metal, a protective film 18 for protecting the interconnector 17 is formed on the interconnector 17.

In the fuel cell having such a configuration, a fuel gas 101 such as hydrogen or methane is supplied into the supply chamber 110c, and an oxidizing gas such as oxygen or air is supplied along the outer peripheral surface of the cell tube 111. Supply 102. Then, the fuel gas 101 flows into each guide tube 112 at a uniform flow rate and reaches the tip of the guide tube 112. Thereafter, the fuel gas 101 is supplied to the cell tube 11.
The cell tube 111 is folded back by the closed end portion and flows from the other end of the cell tube 111 toward one end. Then, the side surface (wall surface) of the base tube 1 diffuses outward, and the fuel electrode 14
Reach On the other hand, the oxidizing gas 102 enters from the outside and reaches the air electrode 16 on the outer peripheral portion of the cell tube 111. Then, the fuel gas 101 and the oxidant gas 102 electrochemically react in the fuel cell 2 of the cell tube 111 to generate electric power.

In the above-described system, the production of the cell tube 111 having the fuel cell 2 is usually performed by the following process. First, an organic solvent is mixed with a raw material of ceramic powder to form a uniform slurry, and a tubular ceramic molded body is manufactured by extrusion molding. Subsequently, the fuel electrode / electrolyte / interconnector / air electrode (/ protective film) are applied and dried on the unsintered ceramic molded body by screen printing while slightly shifting. Then, the ceramic molded body on which application and drying of the electrodes and the like have been completed is fired in a firing furnace in an air atmosphere. Finally, a sealing member is attached and sintering is performed, and the cell tube 111 is completed.

In the cell tube 111 manufactured by the above process, all the electrodes and the like are baked in an oxidizing atmosphere, so that the electrodes and the like are all oxidized. For example, the fuel electrode 14
When nickel is used, nickel oxide is used. When used as a fuel cell, it is necessary to reduce the fuel electrode 14 and the like so as to function as an electrode and a catalyst (reduce nickel oxide to nickel).

In that case, as described above, the cell tube 11
1 is completed and incorporated in a fuel cell system to complete the fuel cell system. When the fuel cell system is started up, hydrogen is flown while increasing the temperature to reduce the electrodes and the like. Therefore, when there is an abnormality in the cell tube 111, it is confirmed after the fuel cell system is started up and the open circuit voltage (OCV) is measured after the reduction process is completed.

[0010]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method of manufacturing a fuel cell tube capable of terminating the reduction of a fuel electrode when manufacturing a cell tube for a fuel cell. is there.

Another object of the present invention is to provide a method of manufacturing a fuel cell tube capable of simultaneously performing a fuel cell operation test when manufacturing a fuel cell tube.

Still another object is to provide a method of manufacturing a fuel cell tube capable of reducing the number of steps of manufacturing a cell tube for a fuel cell.

Still another object of the present invention is to provide a method of manufacturing a fuel cell tube capable of confirming whether a fuel cell is normal or abnormal before installing it in a fuel cell system.

Still another object of the present invention is to provide a method of manufacturing a fuel cell tube capable of completing a fuel cell inspection before delivery of a fuel cell system.

[0015]

Means for Solving the Problems In the section of the means for solving the problems, the figure numbers and reference numerals are written to show the correspondence between the claims and the embodiments of the invention. It should not be used to interpret the claims.

In order to solve the above-mentioned problems, a method of manufacturing a fuel cell tube according to the present invention comprises a step of forming a base tube (FIG. 1, 1) from a slurry having a raw material and an organic solvent (FIG. 1, (1)). )) And a fuel electrode (FIG. 4, 14), a lead film (FIG. 3, 12/13), an electrolyte (FIG. 4, 15) and an interconnector (FIG. 4, 17). ), The step of forming each element (FIG. 1 (2)), the step of closing one end of the base tube (FIG. 1, 1) on which each element is formed (FIG. 1 (3)), Baking the closed base tube (FIG. 1, 1) (FIG. 1 (4));
A step (FIG. 2 (1)) of forming an air electrode (FIG. 4, 16) on the fired substrate tube (FIG. 2, 1) and the air electrode (FIG. 4, 16) were formed. A reducing gas is flowed inside the base tube (FIGS. 2 and 1) and the fuel electrode (FIGS.
14) and firing the air electrode (FIGS. 4, 16) while reducing the lead film (FIGS. 3, 12/13) (FIG. 2 (2)).

Further, in the method of manufacturing a fuel cell tube according to the present invention, the reducing gas is flowed inside the base tube (FIGS. 2 and 1) in which the air electrode (FIGS. 4 and 16) is formed. The pole (FIGS. 4, 14) and the lead film (FIG. 3, 12/13)
Baking the air electrode (FIGS. 4 and 16) while reducing the pressure further comprises measuring a terminal voltage of a fuel cell (FIG. 4, 2) on the base tube (FIG. 2, 1). I do.

Further, in the method for manufacturing a fuel cell tube according to the present invention, a step of forming a base tube (FIG. 1, 1) from a slurry having a raw material and an organic solvent (FIG. 1, (1)); Each element of a fuel electrode (FIG. 4, 14), a lead film (FIG. 3, 12/13), an electrolyte (FIG. 4, 15) and an interconnector (FIG. 4, 17) is formed in a tube (FIG. 1, 1). (FIG. 1 (2)) and a step of closing one end of the base tube (FIG. 1, 1) on which the respective elements are formed (FIG. 1).
(3)), a step of firing the closed base tube (FIG. 1, 1) (FIG. 1 (4)), and a reducing gas inside the fired base tube (FIG. 1, 1). While flowing
The fuel electrode (FIGS. 4 and 14) and the lead film (FIGS. 3 and 1)
2/13), and the fuel electrode (FIG. 4,
14) and the base tube (FIGS. 2 and 1) in which the lead film (FIGS. 3 and 12/13) is reduced is provided with an air electrode (FIGS. 4 and 16).
(1) of FIG. 2 and flowing the reducing gas inside the base tube (FIG. 2 and 1) where the air electrode (FIG. 4 and FIG. 16) is formed. , 14) and firing the air electrode (FIGS. 4, 16) while preventing oxidation of the lead film (FIGS. 3, 12/13).

Further, in the method of manufacturing a fuel cell tube according to the present invention, a reducing gas is flowed inside the base tube (FIGS. 2 and 1) in which the air electrode (FIGS. 4 and 16) is formed. Baking the air electrode (FIGS. 4 and 16) while preventing oxidation of the lead film (FIGS. 3 and 12/13) and the lead film (FIGS. 3 and 12/13). Measuring the terminal voltage of the battery cell (FIGS. 4 and 2).

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for manufacturing a fuel cell tube according to the present invention will be described below with reference to the accompanying drawings. In the present embodiment, an example will be described with respect to a method of manufacturing a cylindrical fuel cell tube among cylindrical types, but the present invention is also applicable to fuel cells having other cylindrical structures. In the embodiments, the same or corresponding parts are denoted by the same reference numerals and described.

The configuration of an embodiment of the method for manufacturing a fuel cell tube according to the present invention will be described with reference to the drawings.

FIG. 1 and FIG. 2 are diagrams showing each configuration of the fuel cell at each stage in one embodiment of the method for manufacturing a fuel cell tube according to the present invention. In the method of manufacturing a fuel cell tube, each step is advanced in this order from FIG. 1 (1) to FIG. 1 (4), and then is completed through the steps of FIG. 2 (1) to FIG. 2 (3). Is the process of doing

Referring to FIGS. 1 to 5, a method of manufacturing a fuel cell tube according to the present invention includes a base tube 1, a fuel cell unit 2, a seal ring 3, a seal cap 4, and a fuel cell region. 5, mesh 6, screen plate 7, firing furnace 8,
Heater 9, ceramic mounting part 10, cell tube 11 as fuel cell tube, lead film 12, end lead film 13, fuel electrode 14, electrolyte 15, air electrode 16, interconnector 17, protective film 18, supply of reducing gas By each structure of the pipe 19, the reducing gas discharge pipe 20, and the reducing gas discharge chamber 22,
Done.

In the present invention, FIGS.
In the process (3), hydrogen is flown into the cell tube 11 at the same time as the formation of the electrodes and the like by firing in the air, so that the reduction is performed at the same time. Thereby, the cell tube 11 is completed (the base tube 1, the fuel electrode 14, and the electrolyte 1).
5, the air electrode 16, the interconnector 17, and the protective film 18, the completion of the formation of the fuel cell unit 2, the lead film 12, the end lead film 13, the seal ring 3, and the seal cap 4). The fact that the reduction treatment of the lead film 12 and the end lead film 13 is also terminated is a point that is significantly different from the conventional method for manufacturing a fuel cell tube. Then, by measuring the open circuit voltage (OCV) after the reduction process, it is possible to perform the performance check even when the cell tube 11 is completed.

Next, each component will be described with reference to FIGS. The base tube 1 is a base tube on which the fuel cell unit 2, the lead film 12, the end lead film 13, and the like are formed. It is a cylindrical cylindrical tube made of ceramics. The fuel gas flowing inside the base tube 1 can diffuse radially outward on the porous side surface (wall surface) and reach the fuel cell unit 2 formed on the outer peripheral portion of the base tube 1. is there.

The seal ring 3 is a ring used as a seal member when the base tube 1 on which the fuel cell unit 2 and the like are formed is attached to a fuel cell system. The shape includes a cylindrical tubular portion and a ring-shaped holding portion formed coaxially with the tubular portion and formed at one end of the tubular portion. The inner diameter of the cylindrical portion is substantially equal to the outer diameter of the base tube 1, and its wall thickness is
Of the order of thickness. The inner diameter of the holding portion is equal to the cylindrical portion, and the outer diameter is slightly larger than the cylindrical portion. In the fuel cell system, a cell tube 11 (described later) is formed of a metal plate (hereinafter, referred to as a metal plate).
(Referred to as “tube sheet”). At this time, the cell tube 11 is supported by the hole at the holding portion (the outer diameter is slightly larger than the cylindrical portion of the seal ring 3). The upper side of the tube sheet is the fuel gas side, and the lower side is the oxidant gas side. The seal ring 3 seals through the hole so that the fuel gas and the oxidizing gas do not enter and exit from each other. At the same time, it is a member for firmly supporting the cell tube 11 on the tube sheet. Cell tube 1
It has the same coefficient of thermal expansion as 1. For example, it is made of ceramics such as zirconia and magnesia spinel.

The seal cap 4 is a cylindrical lid,
It comprises a cylindrical portion and a cylindrical portion extending from the outer periphery of the cylindrical portion toward the cell tube 11. The inner diameter of the cylindrical portion is substantially equal to the outer diameter of the cell tube 11. The lower end of the cell tube 11 is closed to prevent fuel gas and the like flowing inside from leaking to the outside. Or, conversely, external gas is prevented from leaking into the cell tube 11. It is made of ceramics such as zirconia and magnesia spinel, which has the same thermal expansion coefficient as the cell tube 11.

The fuel electrode 14 is a fuel electrode (anode) of the fuel cell unit 2 formed directly on the base tube 1. When the electrolyte is an oxygen ion conductor, the oxygen ions transported via the electrolyte and hydrogen or carbon monoxide in the supplied fuel gas are combined to generate water or carbon dioxide. And the electrodes of the fuel cell unit 2. When the electrolyte is a hydrogen ion conductor, the electrolyte is a catalyst for ionizing hydrogen in the supplied fuel gas and supplying it to the electrolyte, and is also an electrode. In this embodiment, nickel / zirconia is used.

The electrolyte 15 is an electrolyte of the fuel cell unit 2, and is an electrolyte membrane having ionic conductivity so that the fuel cell unit 2 generates power. The electrolyte includes an oxygen ion conductor that transports oxygen ions and a hydrogen ion conductor that transports hydrogen ions. In this embodiment, it is zirconia which is an oxygen ion conductor.

The air electrode 16 is an air electrode (cathode) of the fuel cell 11. When the electrolyte is an oxygen ion conductor, the electrolyte is a catalyst for ionizing oxygen in the supplied oxidizing gas and supplying the ionized oxygen to the electrolyte, and is also an electrode. When the electrolyte is a hydrogen ion conductor, the electrolyte is a catalyst for combining water ions transported via the electrolyte with oxygen in the supplied oxidant gas to generate water, and is also an electrode.
In this embodiment, it is lantern manga knight.

The interconnector 17 is an interconnector for connecting individual fuel cells. On one cell tube 11 (described later), a plurality of fuel cells are connected in series. The interconnector is a conductive film that makes the connection. The interconnector 17
The fuel electrode 14 of one fuel cell is connected to the air electrode 16 of the other adjacent fuel cell. The portions of the electrolyte may be combined. Ceramics and metals such as lanthanum chromite and titania (nickel, inconel,
Platinum etc.) film. In this embodiment, it is lanthanum chromite.

The protection film 18 is a film for protecting the interconnector 17. It is formed so as to cover the entire interconnector 17. The material is a metal oxide film or a ceramic film. When the interconnector 17 is made of ceramics, no protective film is required.

The fuel cell unit 2 includes a cell tube 11
FIG. 4 shows a fuel cell and an attached membrane formed on an outer peripheral surface (described later). It comprises a fuel electrode 14, an electrolyte 15, an air electrode 16, an interconnector 17, and a protective film 18. One battery forms one power-generating battery. Alternatively, in this embodiment, a region where the fuel cell is formed, a state where only the fuel electrode 14 is formed, and only the fuel electrode 14 and the electrolyte 15 are formed during the formation of the fuel cell. State, state formed up to fuel electrode 14, electrolyte 15, interconnector 17, state formed up to fuel electrode 14, electrolyte 15, interconnector 17, air electrode 16,
May be expressed in a total of five states. The fuel gas inside the cell tube 3 diffuses outward on the wall surface (side surface) of the cell tube and reaches the anode electrode of the battery on the surface, while the oxidizing gas outside the cell tube 11 is
Power reaches the cathode electrode on the battery surface, and power is generated.

The fuel cell region 5 is a region on the base tube 1 where the fuel cell unit 2 exists. The size of the fuel cell region 5 varies depending on the size and number of the fuel cell units 2.

The lead film 12 serves as a lead wire for drawing the DC power generated in the fuel cell region 5 to one electrode (not shown) at one end of a cell tube 11 (described later). It is. It is connected to the electrode (for example, the air electrode 16) of the cell at the one end (upper end) among the fuel cells on the outer peripheral portion of the base tube 1. Then, the lead film 12
Extends from the air electrode 16 to the outer peripheral portion of the base tube 1 to one end (upper end) thereof. The circumferential width is such that the resistance of the lead film 12 does not affect the extraction of power depending on the amount of electric power to be generated and the thickness of the lead film 12. May be the width.

The end lead film 13 serving as a lead film transfers the DC power generated in the fuel cell area 5 to one electrode (not shown) at the other end (lower end) of a cell tube 11 (described later). It is a film that plays the role of a lead wire for drawing out. It extends from the electrode (for example, fuel electrode 14) of the cell at the other end (lower end) of the fuel cells on the outer peripheral portion of the base tube 1, and extends to the other end (lower end). The lead film 12 and the end lead film 13 are connected to different types of electrodes in the fuel cell 5.

The cell tube 11 as the outer tube of the fuel cell tube is composed of the base tube 1, the fuel cell unit 2 (the fuel cell unit 2) having the fuel electrode 14, the electrolyte 15, the air electrode 16, the interconnector 17, and the protective film 18. Battery cell area 5), lead film 1
2. A cell tube including an end lead film 13, a seal ring 3, and a seal cap 4.

The screen plate 7 is a screen for performing screen printing. A mask pattern is formed. Then, when the printing paste is extruded from one side, the paste passes through the screen plate in the form of a mask pattern, and pastes on the printing object (substrate tube 1 in this case) on the opposite side according to the shape of the mask pattern. Is printed. Examples of the paste material include a nickel / zirconia paste for a fuel electrode, a zirconia paste for an electrolyte, and a lanthanum manganite paste for an air electrode.

The mesh 6 is a mask pattern formed on the screen plate 7. The thickness of the material to be printed is determined by the viscosity of the paste material, the thickness of the screen plate 7 at the mesh portion, and the like. In this embodiment, electrodes and the like are continuously printed on the entire circumference of the tubular base tube 1, and the electrodes and the like are formed at regular intervals in the longitudinal direction of the base tube 1. It is a mesh shape that can be printed in stripes. That is, a rectangular mesh whose vertical side length is slightly longer than the circumference of the unsintered base tube 1 and whose horizontal side length is equal to the electrode width of one fuel cell unit 2 is a fuel cell. The fuel cell units 2 are arranged at intervals corresponding to the number of the units 2.

The firing furnace 8 is an electric furnace for firing a formed body of ceramic such as a sheet or a tube. The control unit (not shown) controls the temperature (by a thermometer such as a thermocouple, not shown) and the atmosphere (gas flow meter,
A gas sensor or the like (not shown), electric power supplied to the heater 9 (not shown by an ammeter, a voltmeter, or the like) are grasped as needed, and appropriate control is performed. In addition, the firing temperature is constantly controlled based on a control program of the control unit.

The heater 9 is a heater for heating and raising the temperature of the compact in the firing furnace 8. It is installed around the room in the firing furnace 8 where the sample is placed. Various heating elements can be used depending on the temperature and atmosphere. However, firing of the ceramic molded body is performed in an oxidizing atmosphere at a high temperature (the maximum operating temperature is 1000 ° C. or higher).
A corresponding heating element is used. For example, Fe-C
r-Al alloy heating element, Pt-Rh alloy heating element, SiC
There are heating elements.

The ceramic mounting portion 10 is a jig for mounting one end of a ceramic molded body and fixing the position of the ceramic molded body at the upper portion of the firing furnace 1. In the case of a tube-shaped ceramic molded body, the ceramic molded body is fixed and fired in a state of being suspended therefrom.

In the case of FIG. 5, in addition to this, the base tube 1 (which is a ceramic molding) is formed so that the ceramic mounting portion 10, the seal ring 3, and the upper plate of the firing furnace 8 form a closed space. (Including electrodes, etc.). It has a cylindrical shape having a side surface and a bottom surface, and has a circular hole on the bottom surface so that the base tube 1 having the seal ring 3 can be attached thereto. The side opposite to the bottom of the side surface has a shape that can be attached to the upper plate of the firing furnace 8 with screws or the like. The firing furnace 8 normally performs firing in an air atmosphere, but in the case of FIG. 5, the reducing gas 21 is provided only inside the base tube 1 during firing.
Baking is performed while flowing (described later).

The reducing gas supply pipe 19 is provided at the upper part of the firing furnace 8, and when firing the base tube 1 (including its electrodes and the like) in the firing furnace 8 while reducing the inside to a reducing atmosphere, the lower end of the base tube 1 is provided. Is a thin tube for allowing the reducing gas 21 (described later) to reach deep inside. The diameter is smaller than the diameter of the base tube 1. It is made of metal or ceramics.

The reducing gas discharge pipe 20 is located above the combustion furnace 8. This is a tube through which the reducing gas 21 supplied from the reducing gas supply pipe 19 to the inside of the base tube 1 is discharged from the base tube 1 and then discharged from the firing furnace 8. It is made of metal or ceramics.

The reducing gas discharge chamber 22 includes a part of the upper plate of the firing furnace 1, the ceramic mounting portion 10, the reducing gas supply pipe 19, and the reducing gas discharge pipe 20. A chamber for fixing the base tube 1 having the seal ring 3 and for discharging the reducing gas 21 mainly discharged from the base tube 1.

The reducing gas 21 is a gas obtained by mixing an appropriate amount of hydrogen with hydrogen or an inert gas such as nitrogen or argon. Fuel electrode 14 produced by firing in an oxidizing atmosphere,
For example, in nickel / zirconia, nickel is oxidized to nickel oxide. Therefore, it is necessary to reduce nickel before operation of the fuel cell. The reducing gas 21 is
Used for that.

The operation of one embodiment of the method for manufacturing a fuel cell tube according to the present invention will be described with reference to the drawings. With reference to FIGS. 1 and 2, a process of a manufacturing method for manufacturing the cell tube 11 having the configuration as shown in FIG. 3 will be described.

First, in FIG. 1A, a uniform slurry is formed by mixing an organic solvent (including an additive) with a raw material (such as zirconia powder) of ceramic powder for the base tube 1. The base tube 1, which is a tubular ceramic molded body, is formed by extrusion. After the molding, it is dried at about 200 ° C. in a drying oven. The size (diameter × length) of the base tube 1 at this stage is a size in consideration of shrinkage by the subsequent firing process. This is taken into account when machining after firing.

Next, in FIG. 1B, the fuel electrode 14 is screen-printed on the unsintered and dried base tube 1.
(Ni / zirconia) paste is applied. When the paste is supplied from the lower part of the screen plate 7, the mesh 6
The paste permeates through the upper portion of the screen plate 7 only from the portion. By rotating the substrate tube 1 once on the screen plate 7, the fuel electrode 14 is printed on the substrate tube 1 continuously over the entire circumference along the circumference. In the longitudinal direction of the base tube 1, the fuel cell unit 2 is formed at regular intervals (in stripes), so that the electrodes and the like are also printed in stripes. At the same time, the lead film 1 was formed using the same Ni / zirconia paste.
2 and end lead films 13 are printed from both ends of the fuel cell region 5 to both ends of the base tube 1. After printing, it is dried at about 200 ° C. in a drying oven.

After the drying is completed, a paste for the electrolyte 15 (zirconia) having the same width as that of the fuel electrode 14 is printed in the same manner as the fuel electrode 14 with a slight shift from the fuel electrode 14. After printing, it is dried at about 200 ° C. in a drying oven. After drying, one end of the striped electrolyte, excluding both ends, is connected to an adjacent striped fuel electrode with an interconnector film in a striped manner for interconnector 17 (lanthanum chromite). The paste is printed in the same manner as the electrolyte 15. Then, it is dried at about 200 ° C. in a drying furnace.

Subsequently, in FIG. 1C, on the outer peripheral surface on one side of the base tube 1 on which the electrodes and the like are printed, the one end and the end of the fuel cell region 5 on the same side are connected. The seal ring 3 is fitted in the area between them. The seal ring 3
It is formed in advance by press molding (a mixture of a ceramic powder raw material and an organic solvent is put into a mold and molded by pressure). At the same time, the seal cap 4 is fitted into the other end of the base tube 1. The seal cap 4 is also press-formed in advance. The seal ring 3 and the seal cap 4 are in close contact with an appropriate strength.

Next, in FIG. 1 (4), the base tube 1 on which the seal ring 3 and the like made of (3) are attached and the electrodes and the like are printed is attached to the ceramics attaching portion 10 of the firing furnace 8 and the heater 9 Is performed while controlling the temperature. The firing temperature is 1200C to 1700C. At this time, although the base tube 1 shrinks by firing, the seal ring 3 and the seal cap 4 also shrink in the same manner. At that time, care should be taken to ensure that the base tube 1 and the seal ring 3 and the seal cap 4 are in good contact (seal). That is, the contraction rate of the base tube 1 is made equal to the contraction rate of the seal ring 3 and the seal cap 4.

By the above firing, the base tube 1 is
A fuel electrode 14, an electrolyte 15, and an interconnector 17 are formed. At the same time, a seal ring 3 is attached in close contact with the base tube 1 at one end. At the other end, the seal cap 4 is fitted tightly so that gas does not leak between the inside and the outside of the base tube 1.

Subsequently, in FIG. 2A, the paste for the air electrode 16 (lanthanum manganite) was slightly shifted from the electrolyte 15 by screen printing on the fired base tube 1 in the same manner as the electrolyte 15. Is applied. One end covers a part of the interconnector 17. In the longitudinal direction of the base tube 1, the fuel cell unit 2 is formed at regular intervals (in a stripe pattern).
Is formed, the electrodes and the like are also printed in a stripe pattern. After printing, it is dried at about 200 ° C. in a drying oven. At this time, the size of the screen plate 7 or the shape of the mesh 6 is changed so that the seal ring 3 and the seal cap 4 do not interfere with screen printing. For example, the size of the screen plate 7 is reduced to a size of only the fuel cell region 5. Alternatively, make a recess in the screen plate 7 shape,
The seal ring 3 and the seal cap 4 can be rotated.

After drying is completed, a protective film (alumina, alumina) is formed on the interconnector 17, the lead film 12, and the end lead film 13.
Printing is performed so as to cover with a paste for a dense insulating film such as zirconia or silica. Then, drying is performed at 200 ° C. in a drying furnace.

Next, in FIG. 2B, the base tube 1 on which the air electrode 16 and the like are printed is mounted on the ceramic mounting portion 10 of the firing furnace 8. The firing is performed while controlling the heater 9. The firing temperature is 400 to 1000 ° C. FIG. 5 shows an example of a mounting method at that time. The inner diameter of the hole on the bottom surface of the ceramic mounting portion 10 is the same as the outer diameter of the cylindrical portion of the seal ring 3, and the base tube 1 is fitted into the hole. Then, at the holding portion of the seal ring 3,
The base tube 1 is hung on a ceramic mounting part 10. Also,
The side opposite to the bottom surface of the side portion of the ceramic mounting portion 10 is
It is joined to the firing furnace 8 so that there is no gas leakage and the weight of the base tube 1 can be supported.

Since the base tube 1 is sintered by the sintering shown in FIG. 1 (4), it does not shrink in this process. That is, it is not necessary to consider shrinkage of the base tube 1, the seal ring 3, and the seal cap 4.

During firing, the reducing gas 21 is carried by the reducing gas supply pipe 19 to the lowermost portion of the base tube 1 in the firing furnace 8 (the position where the seal cap 4 is located). After that, it moves upward inside the base tube 1 on the outside of the reducing gas supply tube 19. At this time, the porous side (outer wall) surface of the base tube 1 is diffused toward the outer periphery of the base tube 1, and the fuel electrode 14 and the lead film 12 are diffused.
And reaches the end lead film 13. Then, they are reduced (nickel oxide is reduced to nickel) to lower the electric resistance and cause a favorable catalytic reaction. Since those films are covered with the dense electrolyte 15 or the protective film 18 on the upper part thereof, the reducing gas 21
However, it does not go out of the base tube 1. Further, since the seal ring 3 and the seal cap 4 (and the base tube 1) do not shrink and do not change in size, there is no fear that the reducing gas 21 leaks therefrom. The used reducing gas 21 exits from the uppermost portion (one end) of the base tube 1 to the reducing gas discharge chamber 22, and
It is discharged from the reducing gas discharge pipe 20 at the upper part of the firing furnace 8.

Then, in FIG. 2C, the cell tube 11 as the fuel cell tube is completed by the above process. Its cross section is as shown in FIG. 3, and
The fuel cell unit 2 is as shown in FIG.

In the present invention, the sealing member (seal ring 3 and seal cap 4) is attached during the manufacturing process of the cell tube 11 by the process of FIG.
Since firing is performed at the same time as the electrodes and the like, it has become possible to reduce the process of mounting and firing the sealing member that has been separately provided.

Further, in the present invention, by the process of FIG. 2B, the air electrode 16 and the protective film 18 can be baked on the outside of the base tube 1, and at the same time, the reduction treatment can be performed on the inside. That is, since the reduction process has been completed at the same time as the completion of the cell tube 11, it is possible to reduce the process of the reduction process that was conventionally performed by incorporating the cell tube 11 into the fuel cell system after the completion of the cell tube 11. became.

On the other hand, in the process of simultaneously performing the calcination and the reduction treatment of FIG. 2B, electrodes (such as platinum wires) are attached to the lead film 12 and the end lead film 13 and, at the stage where the calcination and reduction are sufficiently performed. The characteristics of the fuel cell unit 2 in the fuel cell region 5 can be grasped by checking the open-circuit voltage (OCV) or the voltage change by passing a weak current. That is, after the cell tube 11 is completed, the cell tube 11 can be incorporated into the fuel cell system, and the cell characteristic inspection of the fuel cell unit 2 which has been performed after the reduction process can be performed in the process of manufacturing the cell tube 11. Becomes Therefore, it is possible to sort cells before assembling them into a fuel cell system, thereby improving work efficiency, shortening the production time (reducing the construction period at the time of delivery), and reducing costs.

At the stage of FIG. 1 (4), it is also possible to carry out a reduction process. That is, first, at the stage of preparation of FIG.
0, the base tube 1 having the seal ring 3 and the seal cap 4 is attached using the reducing gas supply pipe 19 and the reducing gas discharge pipe 20. Next, not only outside the base tube 1,
With the reducing gas supply pipe 19, air is also flowed inside the pipe,
The seal ring 3 and the seal cap 4 such as the base tube 1 and the electrodes are fired. The firing temperature is 1200C to 1700C. At this time, the base tube 1, the seal ring 3, and the seal cap 4 contract. However, in advance, the size of the holding portion of the seal ring 3 is designed so that the holding portion of the seal ring 3 is contracted to such an extent that the holding state of the base tube 1 or the like at the holding portion of the seal ring 3 on the ceramic mounting portion 10 can be maintained. . When the baking is completed and the shrinkage stops, the reducing gas 21 can be supplied to the inside of the base tube 1 by the reducing gas supply pipe 19 to cause the reduction. The temperature at that time is 400 ~ 1
000 ° C. Also, air is allowed to flow outside.

Thereafter, the air electrode 16 and the protective film 18 shown in FIG. 2A are printed. When the air electrode 16 shown in FIG. 2B is fired, the reducing gas 21 is again supplied to the inside of the base tube 1 by the reducing gas supply pipe 19 so that the fuel electrode 14 is not oxidized. Is fired. Firing temperature is 4
00-1000 ° C.

At this time, the lead film 12 and the end lead film 1
An electrode (such as a platinum wire) is attached to the fuel cell 3, and at the stage when the air electrode 16 is fired, the open circuit voltage (OCV) or a change in voltage by passing a weak current is checked to determine the fuel in the fuel cell area 5. The characteristics of the battery cell unit 2 can be grasped. That is, after the cell tube 11 is completed, the cell tube 11 is incorporated into the fuel cell system, and the cell characteristic inspection of the fuel cell, which has been performed after the reduction process, can be performed in the process of manufacturing the cell tube 11. Therefore, it is possible to sort cells before assembling them into a fuel cell system, thereby improving work efficiency, shortening the production time (reducing the construction period at the time of delivery), and reducing costs.

According to the above process, the same effect as in the above-described case (the reduction process is performed at the stage (2) in FIG. 2) can be obtained.

[0068]

According to the present invention, the reduction of the fuel electrode and the like can be completed at the time of manufacturing the cell tube for the fuel cell, and the number of manufacturing steps can be reduced.

According to the present invention, when manufacturing a cell tube for a fuel cell, the operation inspection of the fuel cell can be performed at the same time, and it is possible to confirm whether the fuel cell is normal or abnormal before installing it in the fuel cell system.

[Brief description of the drawings]

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a diagram showing each production step of an embodiment of a method for producing a fuel cell tube according to the present invention.

FIG. 2 is a view showing each manufacturing step of an embodiment of the method for manufacturing a fuel cell tube according to the present invention.

FIG. 3 is a view showing a structure of a cell tube in an embodiment of a method for manufacturing a fuel cell tube according to the present invention.

FIG. 4 is a diagram showing a configuration of a fuel cell unit in an embodiment of a method for manufacturing a fuel cell tube according to the present invention.

FIG. 5 is a diagram showing a configuration of a ceramic mounting portion, a peripheral portion thereof, and a cell tube 11 in an embodiment of a method of manufacturing a fuel cell tube according to the present invention.

FIG. 6 is a diagram showing a configuration of an embodiment of a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base tube 2 Fuel cell cell part 2 3 Seal ring 4 Seal cap 5 Fuel cell area 6 Mesh 7 Screen plate 8 Firing furnace 9 Heater 10 Ceramic mounting part 11 Cell tube 12 Lead film 13 End lead film 14 Fuel electrode 15 Electrolyte Reference Signs List 16 air electrode 17 interconnector 18 protective film 19 reducing gas supply pipe 20 reducing gas discharge pipe 21 reducing gas 22 reducing gas discharge chamber 101 fuel gas 102 oxidizing gas 110 header 110a partition plate 110b bottom plate 110c supply chamber 110d discharge chamber 111 cell tube 112 guide tube

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Nagao Kurume, Inventor 1-1, Akunouracho, Nagasaki-shi, Nagasaki Mitsubishi Heavy Industries, Ltd. Nagasaki Shipyard (72) Katsumi Nagata 1-1-1, Akunoura-cho, Nagasaki-shi, Nagasaki Mitsubishi In Heavy Machinery Co., Ltd., Nagasaki Shipyard (72) Inventor Koji Ikeda 1-1, Akunoura-cho, Nagasaki City, Nagasaki Prefecture Mitsubishi Heavy Industries Co., Ltd. (72) Inventor Yoshiharu Watanabe 1-1, Akunouracho, Nagasaki City, Nagasaki Prefecture Mitsubishi Heavy Industries, Ltd.Nagasaki Shipyard (72) Inventor Hiroshi Tsukuda 5-7-17-1 Fukahoricho, Nagasaki City, Nagasaki Prefecture No. F-term (reference) in Nagasaki R & D Co., Ltd. 5H018 AA06 AS01 BB01 BB08 BB17 CC03 EE11 EE12 5H026 AA06 BB01 BB10 CV02 CX06 EE17

Claims (4)

[Claims] A step of forming a base tube from a slurry having a raw material and an organic solvent; forming each element of a fuel electrode, a lead film, an electrolyte, and an interconnector on the base tube; Closing one end of the base tube on which is formed; firing the closed base tube; forming an air electrode on the fired base tube; Baking the air electrode while reducing the fuel electrode and the lead film by flowing a reducing gas inside the base tube in which is formed the fuel cell cell tube. 2. The method according to claim 1, wherein the step of flowing the reducing gas into the inside of the base tube having the air electrode formed therein and firing the air electrode while reducing the fuel electrode and the lead film comprises: The method according to claim 1, further comprising: measuring a terminal voltage of the battery cell. 3. A step of forming a base tube from a slurry having a raw material and an organic solvent; a step of forming each element of a fuel electrode, a lead film, an electrolyte and an interconnector on the base tube; Closing one end of the base tube in which is formed; firing the closed base tube; flowing the reducing gas inside the fired base tube while the fuel electrode and the fuel electrode; Reducing the lead film; forming an air electrode on the base tube in which the fuel electrode and the lead film have been reduced; flowing a reducing gas inside the base tube on which the air electrode is formed. And baking the air electrode while preventing oxidation of the fuel electrode and the lead film. 4. A step of flowing a reducing gas inside the base tube in which the air electrode is formed and firing the air electrode while preventing oxidation of the fuel electrode and the lead film, The method according to claim 3, further comprising: measuring a terminal voltage of the battery cell.