JP2009283378A - Solid oxide fuel cell tube body, molding method thereof, and manufacturing device therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly-reliable fuel cell tube body wherein a trunk section and a bottom section of the fuel cell tube body are integrally molded and malfunctions such as occurrence of cracks and strength deterioration do not occur in sections including the trunk section and the bottom section. <P>SOLUTION: In a molding method for a solid oxide fuel cell tube body formed with an anode having a fuel passage, a solid electrolyte and a cathode in sequence from an inner side of the tube body, or the cathode having an air passage, the solid electrolyte and the anode in sequence from the inner side of tube body, the forming method includes a process of molding ceramic slurry for forming a trunk section of the anode or the cathode formed inside the tube body by an extrusion molding method, a process of arranging a bottom surface sealing mold die at the front end portion of the extruded trunk section with a designated distance from the front end, and a process of molding the bottom section of the tube body by making the ceramic slurry flow between the front end and the bottom face sealing mold die. Thus, the trunk section and the bottom section are integrally molded. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a solid oxide fuel cell tube, a forming method thereof, and a manufacturing apparatus thereof, and relates to a fuel cell module and a fuel cell power generation system incorporating the solid oxide fuel cell tube.

  A fuel cell includes an anode (fuel electrode) and a cathode (air electrode) on both sides of a solid electrolyte, fuel gas is supplied to the anode side, and oxidant gas is supplied to the cathode side. The fuel cell oxidizes with the fuel via the solid electrolyte. It is the electric power generating apparatus which generates electric power by making an agent react electrochemically.

  A solid oxide fuel cell, which is a type of fuel cell, not only has high power generation efficiency, but also operates at a high temperature of 600 to 1000 ° C., so that a fuel reforming reaction can be performed in the cell, thereby diversifying the fuel. Can be planned. Further, since the structure of the battery system becomes simple, it has a potential for cost reduction as compared with other fuel cells. Furthermore, it is easy to use because the exhaust heat becomes high temperature, and it is easy to form not only a combined heat / electric system but also a hybrid system with other systems such as a gas turbine.

  Fuel cells are roughly classified into flat plate types, cylindrical types, flat cylindrical types, and the like depending on the shape of the solid electrolyte.

  A flat cylindrical fuel cell has a higher power density than a cylindrical fuel cell and exhibits a power density comparable to that of a flat plate fuel cell. Further, the flat cylindrical fuel cell has a simpler gas seal than the flat plate fuel cell. In particular, in a tubular shape in which one end of a flat cylindrical fuel cell tube is sealed (hereinafter referred to as a sealed fuel cell tube), the gas seal structure is the simplest, and a large number of tubes are stacked. Becomes easy. From the viewpoint of thermal stress, the flat cylindrical tube is more advantageous than the flat tube.

  The sealed fuel cell tubular body having the above-described characteristics also involves many difficulties from the viewpoint of manufacturing the tubular body. Up to now, as disclosed in Patent Document 1, a sealing portion (hereinafter referred to as a bottom portion) of one end of a tubular body and a tubular body portion that forms the main body of the tubular body are separately manufactured, A method of joining has been proposed.

Japanese translation of PCT publication No. 2002-512428

  As shown in FIG. 5, the fuel cell tube described in Patent Document 1 is manufactured by separately manufacturing a tube body 6 that forms the main body of the tube and a bottom 13 at one end of the tube. In this case, an adhesive member is applied to a predetermined portion, and the bonding surface 14 is brought into close contact to be bonded. In this method, there is a case where the bonding between the body portion 6 and the bottom portion 13 is incomplete, and in that case, there is a possibility that gas leakage occurs.

  It is an object of the present invention to provide a highly reliable sealed fuel cell body including a body part and a bottom part by integrally molding a body part and a bottom part of a solid oxide fuel cell body body seamlessly. Objective.

  A method for forming a solid oxide fuel cell tube according to the present invention includes an anode having a fuel flow path, a solid electrolyte and a cathode, or a cathode having an air flow path in order from the inside of the tube, A method of forming a solid oxide fuel cell tube formed by a solid electrolyte and an anode, wherein a ceramic slurry constituting the body of the anode or the cathode formed on the inside of the tube is extruded. A step of molding, a step of disposing a bottom surface sealing mold at a predetermined distance from the front end portion at the front end portion of the extruded body portion, and the front end portion and the bottom surface sealing mold. A step of forming the bottom portion of the tubular body by allowing the ceramic slurry to flow in between, and forming the body portion and the bottom portion integrally.

  According to the present invention, since the body portion and the sealing portion of the solid oxide fuel cell tube can be integrally formed, compared with the conventional method in which each is molded independently and then joined, the portion corresponding to the joined portion is formed. No defects such as cracking or strength reduction occur, and the manufacturing process and time can be shortened.

  As an embodiment according to the present invention, a body portion of a solid oxide fuel cell body is formed by an extrusion molding method, and the bottom surface of the extruded body portion is separated from the tip portion by a predetermined distance. A sealing mold is arranged, and a ceramic slurry is allowed to flow between the tip portion and the bottom surface sealing mold, thereby forming the bottom portion of the tube body and integrally forming the sealed fuel cell tube body. .

  FIG. 4 is a schematic view of a fuel cell tube formed by the forming method according to the present invention.

  This figure shows the entire fuel cell tube with the bottom 12 sealed, and three gas flow paths 10 are provided in the body 6 of the fuel cell tube. A gas flow path pocket 8 is formed at the bottom 12 of the fuel cell tube below the body 6. The gas supplied to the pipe body is supplied from the central gas flow path 10 into the pipe body, flows in the direction of the arrow of the gas inlet flow 11, reaches the gas flow path pocket 8, changes the flow direction, and The gas outlet flow 19 is directed through the gas flow path 10.

  FIG. 8 is a cross-sectional view of a solid oxide fuel cell tube manufactured according to the present invention.

  In this figure, a solid electrolyte 101 is formed on the outside of a cathode 103 having an air flow path 105, and an anode 102 is formed on the outside thereof in layers. A fuel flow path 106 is formed outside the anode 102. An interconnector 104 is provided on the cathode 103 so that a plurality of tubes can be electrically connected. In the figure, two interconnectors 104 are provided, but one or three or more may be used.

In this embodiment, the solid electrolyte 101 is made of yttria stabilized zirconia (hereinafter referred to as YSZ). The anode 102 is made of cermet containing nickel and YSZ. The cathode 103 is made of a substance (LaSrMnO ₂ ) containing lanthanum, strontium, manganese and oxygen. Of course, each material is not limited to the above materials.

  In this embodiment, first, the cathode 103 is formed, and the outer wall surface thereof is coated with the solid electrolyte 101. Then, the anode 102 is coated on the outside of the solid electrolyte 101. The coating method may be a dipping method, a thermal spray method, or a chemical vapor deposition method (CVD).

  In addition, the configuration of the tubular body may be the order of the anode 102, the solid electrolyte 101, and the cathode 103 from the inside.

  FIG. 9 is a cross-sectional view of a fuel cell module manufactured according to the present invention. Three solid oxide fuel cell tubes shown in FIG. 8 are connected in series via an interconnector 104 and enclosed in a housing 107. A fuel flow path 106 is formed between the anode 102 and the casing 107. A fuel inflow pipe 108, an air inflow pipe 109, a fuel outflow pipe 110, and an air outflow pipe 111 are connected to the casing 107 so that fuel and air can be supplied and discharged from the outside of the fuel cell module. It has become.

  Although not shown, the air inflow pipe 109 and the air outflow pipe 111 are branched and connected to the plurality of air flow paths 105 so that air can be distributed. Further, the anode 102 shown on the right side in the figure and the interconnector 104 shown on the left side in the figure are electrically connected to the outside so that the generated electrical energy can be taken out and used.

  A fuel cell power generation system incorporating one or more fuel cell modules as shown in this figure can also be constructed. In this case, it is possible to generate power and use surplus thermal energy.

  FIG. 1 is a schematic view of a method for integrally forming a body part and a bottom part of a fuel cell tube according to an embodiment of the present invention.

  Although the body die body of the fuel cell tube body is not shown, the body die inner wall 1 is shown. Three cores 2 (A, B, C) are installed inside the body mold inner wall 1, and an area sandwiched between the body mold inner wall 1 and the core metal 2 is initially a space. It has become. Ceramic slurry is extruded and supplied from above this space. In addition, as a ceramic slurry, an anode material, a cathode material, a base material, etc. can be considered. The flow 9 of the ceramic slurry is as shown in FIG.

  Therefore, in this figure, the extruded ceramic slurry forms the body shape of the fuel cell tube body having three gas flow paths 10.

  It is necessary to provide a gas flow path pocket 8 at the distal end of the tube. For this reason, at the time of extrusion molding at the tip of the core 2, the shape of the ceramic slurry is blocked to flow 9 between the core 2 A and the core 2 B and between the core 2 B and the core 2 C. A cutter 3 is provided. The cutter 3 constitutes a part of a mold. As a result, the ceramic slurry flows only in the outer peripheral portion of the tube body.

  Thereby, although the bottom of the tubular body has been removed, the outer peripheral portion of the gas flow path pocket 8 can be formed. The bottom surface sealing mold 4 is brought close to the lower end portion of the ceramic slurry in this state, and the bottom surface sealing die is arranged at a predetermined distance from the lower end portion of the ceramic slurry, and the lower end portion and the bottom surface sealing mold are disposed. The bottom of the tube is formed by flowing ceramic slurry between the mold 4 and the fuel cell tube is formed integrally. Thereafter, the formed ceramic slurry is dried and sintered to increase the strength.

  Since it is integrally molded, the body and bottom of the tube body are seamless, and defects such as cracking and strength reduction are unlikely to occur, and the manufacturing process and time can be shortened.

  In this figure, the body part mold, the mandrel 2, the cutter 3 and the bottom surface sealing mold 4 constitute a part of the fuel cell tube manufacturing apparatus.

  FIG. 2 is a production flow diagram of a method for integrally forming a fuel cell tube showing an embodiment according to the present invention.

  In this figure, it was set as the structure which changes the shape of a metal core 2 front-end | tip part as needed using the shape memory alloy for the cutter 3 of the metal core 2 front-end | tip part. In (a), with the cutter 3 opened, the ceramic slurry flow 9 flowing through the gap between the mandrel 2A and the mandrel 2B and the gap between the mandrel 2B and the mandrel 2C is stopped. As a result, the extruded ceramic slurry forms the outer peripheral portion of the gas flow path pocket 8 in a state where the bottom of the tube body is removed.

  Next, the bottom sealing die 4 is brought close to the lower end of the ceramic slurry. At this time, as shown in (b), the mandrel 2 and the cutter 3 are pushed downward by the depth of the gas flow path pocket 8 in the vertical direction, and the cutter 3 and the bottom surface sealing mold 4 are separated by ceramic slurry. A gap for forming the bottom surface of the tube body is provided between them.

  Then, when extrusion molding proceeds while supplying the ceramic slurry, the tubular body is surrounded by the inner wall 1 of the body part of the fuel cell tubular body, the cutter 3 attached to the tip of the core 2 and the bottom sealing mold 4. Form the bottom. At this time, the excess ceramic slurry is discharged as excess ceramic slurry 15 from the excess ceramic slurry discharge hole 5.

  (C) shows the operation procedure of the mold after the tube bottom is formed. The bottom surface sealing mold 4 is pulled down to separate from the bottom of the tube body. Then, after the mandrel 2 is returned to the vicinity of the upper end of the gas flow path pocket 8, the temperature of the opened cutter 3 is raised to restore the shape memory cutter 3 to its original shape. Thereby, the cutter 3 becomes small and becomes a dimension (width) that fits on the lower end surface of the mandrel 2.

  Here, only the temperature of the cutter 3 may be raised, or the temperature of the entire tubular body may be raised. As a means for heating, a heater different from the cutter 3 may be used, or the cutter 3 may be directly energized. Of course, the shape memory alloy can be deformed by lowering the temperature.

  Thereafter, as shown in (d), in a state where the reduced cutter 3 is at the lower end of the mandrel 2, the extrusion molding is further continued so that the three gas flow paths 10 have a predetermined length. You can also.

  Thereafter, the mandrel 2 is pulled out, and the formed ceramic slurry is dried and sintered to increase the strength. After sintering, the interconnector is bonded, and the solid electrolyte and the counter electrode are coated by dipping or the like.

  The tubular body manufactured by the above manufacturing flow can be integrally formed with the body portion and the bottom portion seamlessly.

  FIG. 3 is a production flow diagram of a method for integrally forming a tube according to another embodiment of the present invention. In this embodiment, the deformation direction of the tip shape of the mandrel 2 is changed, and the cutter 3 is completely accommodated in the mandrel 2. The material of the cutter 3 was a shape memory alloy as in the example shown in FIG.

  FIG. 6 is a schematic view of a method of integrally forming a tubular body showing a modification according to the present invention. A balloon 16 that is inflated by gas pressure is attached to the lower end of the mandrel 2. When the gas flow path pocket 8 is formed, the balloon 16 is inflated by injecting gas into the balloon 16 or increasing the temperature of the balloon 16 to expand the gas in the balloon 16. When pulling up the mandrel 2, the gas in the balloon 16 is removed or contracted so that it falls within the lower end of the mandrel 2.

  FIG. 7 is a schematic view of a method for integrally forming a tubular body according to another modification of the present invention. A drive mechanism 17 for changing the shape of the cutter 3 attached to the lower end of the mandrel 2 is provided, and a transmission unit 18 for transmitting drive power is connected between the cutter 3 and the drive mechanism 17. . Thereby, the position and dimension of the cutter 3 provided in the lower end part of the mandrel 2 can be changed, and the bottom part 12 and the gas flow path pocket 8 of a tubular body can be made into a desired shape.

  As described above, the embodiment of the present invention has been described by taking a flat cylindrical tube as an example. However, the same forming method can be adopted as long as it has a bottom even in an elliptical shape or a honeycomb structure, etc. There is no loss.

  In the fuel cell manufactured by the molding method according to the present invention, the tube body and the bottom can be integrated, so that defects and breakage due to the tube manufacturing process can be prevented, and the reliability of the tube can be dramatically improved. Can be increased.

  In the above molding method, the cutter 3, the balloon 16, and the like are molds for forming the gas flow path pocket 8, and are molds that can be deformed by using heat, gas, a driving mechanism, or the like. These molds can be collectively referred to as gas flow path pocket forming means.

It is the schematic of the integral formation method of the fuel cell tubular body which shows the Example by this invention. It is a manufacture flowchart of the integral formation method of the fuel cell tubular body which shows the Example by this invention. It is a manufacture flowchart of the integral formation method of the fuel cell tube which shows the other Example by this invention. 1 is a schematic view of a fuel cell tube molded by a molding method according to the present invention. It is the schematic which shows the shaping | molding method of the conventional fuel cell tubular body. It is the schematic of the integral molding method of the fuel cell tubular body which shows the modification by this invention. It is the schematic of the integral formation method of the fuel cell tubular body which shows the other modification by this invention. 1 is a cross-sectional view of a fuel cell tube manufactured according to the present invention. It is sectional drawing of the fuel cell module manufactured by this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Body part die of fuel cell tube, 2 ... Core metal, 3 ... Cutter, 4 ... Mold for bottom sealing, 5 ... Excess ceramic slurry discharge hole, 6 ... Body part of fuel cell tube, 7 ... Rib, 8 ... Gas channel pocket, 9 ... Ceramic slurry flow, 10 ... Gas channel, 11 ... Gas flow, 12 ... Bottom of fuel cell tube, 15 ... Excess ceramic slurry, 16 ... Balloon, 17 ... Drive mechanism .

Claims (14)

  Solid oxidation in which an anode having a plurality of fuel channels, a solid electrolyte and a cathode, or a cathode having a plurality of air channels, a solid electrolyte, and an anode are formed in this order from the inside of the tube. A solid oxide fuel cell body, which is a solid fuel cell body, wherein a body portion and a bottom portion of the tube body are integrally formed seamlessly.   2. The solid oxide according to claim 1, wherein the solid oxide fuel cell body has a substantially cylindrical shape, a flat cylindrical shape, an elliptical cylindrical shape, a honeycomb cylindrical shape, or a shape similar to these shapes. Fuel cell tube.   Gas flow channel pocket for communicating a plurality of fuel flow channels inside the anode or a plurality of air flow channels inside the cathode with the bottom of the anode or the cathode formed inside the tube body The solid oxide fuel cell body according to claim 1, wherein the solid oxide fuel cell body is provided.   A solid oxide fuel cell module comprising the solid oxide fuel cell tube according to any one of claims 1 to 3.   A solid oxide fuel cell power generation system comprising the solid oxide fuel cell module according to claim 4.   A solid oxide fuel cell tube formed by an anode having a fuel channel, a solid electrolyte and a cathode, or a cathode having an air channel, a solid electrolyte and an anode in this order from the inside of the tube Forming the ceramic slurry constituting the body of the anode or the cathode formed on the inside of the tube by an extrusion method, and at the tip of the extruded body, A step of disposing a bottom surface sealing mold at a predetermined distance from the front end portion; and a bottom portion of the tube body by allowing the ceramic slurry to flow between the front end portion and the bottom surface sealing mold. Forming a solid oxide fuel cell body, wherein the body portion and the bottom portion are integrally formed.   In order from the inside of the tubular body, an anode having a fuel flow path, a solid electrolyte and a cathode, or a cathode having an air flow path in order from the inside of the tubular body, a substantially cylindrical shape formed by the solid electrolyte and the anode, a flat cylindrical shape, A method of forming a solid oxide fuel cell tubular body having an elliptical cylindrical shape, a honeycomb tubular shape, or a shape similar to these shapes, wherein the body of the anode or the cathode formed inside the tubular body is formed. A step of forming a ceramic slurry to be formed by an extrusion molding method, a step of disposing a bottom sealing mold at a predetermined distance from the tip portion at the tip portion of the extruded barrel portion, and the tip portion And forming the bottom of the tubular body by allowing the ceramic slurry to flow between the bottom sealing mold and the bottom sealing mold, and the body and the bottom are integrally formed. Molding method of the solid oxide fuel cell tube.   The ceramic slurry is caused to flow between a gas flow path pocket forming means for forming a gas flow path pocket at the bottom of the anode or the cathode formed inside the tubular body and the bottom surface sealing mold. The method for forming a solid oxide fuel cell tube body according to claim 6 or 7, further comprising a step of forming the bottom portion of the tube body.   9. The molding of a solid oxide fuel cell tube body according to claim 8, further comprising a step of deforming the gas flow path pocket forming means formed of a deformable member using heat, gas, or a drive mechanism. Method.   The method for forming a solid oxide fuel cell tube according to claim 8 or 9, further comprising a step of deforming the gas flow path pocket forming means including a shape memory alloy or a balloon that changes in volume.   The solid oxide fuel cell tubular body according to claim 9 or 10, further comprising a step of deforming the member by changing the temperature of the member constituting the gas flow path pocket forming means. Method.   An anode having a fuel flow path, a solid electrolyte and a cathode, or a cathode having an air flow path, a solid electrolyte, and an anode forming the anode in order from the inside of the pipe. A manufacturing apparatus, comprising: a mold for extruding a body of the anode or the cathode formed inside the tube body; and a mold for sealing the bottom surface, and a tip of the extruded body A solid oxide fuel cell characterized in that the body portion and the bottom portion of the tubular body can be integrally formed by flowing a ceramic slurry between the portion and the bottom surface sealing mold. Tube manufacturing equipment.   In order from the inside of the tube, an anode having a fuel flow path, a solid electrolyte and a cathode, or from the inside of the tube, a cathode having an air flow path, a substantially cylindrical shape forming a solid electrolyte and an anode, a flat cylindrical shape, an ellipse An apparatus for manufacturing a solid oxide fuel cell tubular body having a tubular shape, a honeycomb tubular shape, or a shape similar to these shapes, and extruding the body of the anode or the cathode formed inside the tubular body And a bottom sealing mold, and a ceramic slurry is allowed to flow between the extruded tip of the barrel and the bottom sealing mold so that the tubular body An apparatus for producing a solid oxide fuel cell body, characterized in that a body portion and a bottom portion can be integrally formed.   The solid oxide form according to claim 12 or 13, further comprising a gas flow path pocket forming means for forming a gas flow path pocket at the bottom of the anode or the cathode formed inside the tube. Fuel cell tube manufacturing equipment.

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