JP4848178B2 - Solid oxide fuel cell - Google Patents

Description

  The present invention relates to a solid oxide fuel cell (SOFC), a plurality of fuel cell tubes having fuel cells formed on a peripheral surface thereof, and a fuel gas for supplying fuel gas into the plurality of fuel cell tubes The first gas chamber and the second gas chamber for discharging the fuel gas that has been subjected to the power generation reaction in the fuel cell are separated from each other via a third gas chamber that supplies an oxidant gas to the fuel cell. The present invention relates to a solid oxide fuel cell.

Conventionally, a solid oxide fuel cell (hereinafter referred to as SOFC) in which a power generator is formed on the surface of a porous base tube is well known, and a power generation reaction occurs as follows. For example, the fuel gas is allowed to flow inside the cell tube provided with the fuel cells in which layers such as the fuel electrode, the solid electrolyte, and the air electrode are formed on the surface of the base tube maintained at a temperature of 1000 ° C. When air as an oxidant is flowed, O ²⁻ ions move in the battery cell, an electrochemical reaction occurs, and a potential difference between the air electrode and the fuel electrode is generated to generate power. In addition, you may comprise so that air may be flowed inside a cell tube and fuel gas may be flowed outside.

In recent years, such SOFCs are expected to be a third generation power generation system because of their high power generation efficiency because the operating temperature of the battery cells is as high as about 1000 ° C.
In general, the SOFC cell structure includes a flat plate type and a cylindrical type, and the cylindrical type includes a cylindrical vertical stripe type and a cylindrical horizontal stripe type. The flat plate type is characterized in that the output per unit volume is high. However, in practical use, there are problems of gas sealability on the side surface of the cell and nonuniformity of temperature distribution in the cell. On the other hand, the cylindrical type is inferior to the flat plate type in terms of power density, but is characterized by high mechanical strength due to its shape.
The base tube of the cylindrical solid oxide fuel cell is made of a porous ceramic such as CaO-stabilized ZrO ₂ having an open air porosity of about 30%, and a multi-porous property made of LaMnO ₃ based material on the outside thereof. air electrode, Y ₂ O ₃ consisting of stabilized ZrO ₂ or the like solid electrolyte, a multi-vent of Ni / ZrO ₂ such as a fuel electrode of are sequentially provided.

  As an example of a cylindrical horizontal stripe type fuel cell having such a configuration, a fuel cell having a disk-shaped base portion and a plurality of base tube (fuel cell support pipe) joined to the base portion is disclosed ( For example, see Patent Document 1.) Further, a fuel cell including a plurality of fuel cell tubes and a tube plate supported by the tube is disclosed (for example, see Patent Document 2).

JP 2003-308854 A JP 2004-22368 A

  However, the one disclosed in Patent Document 1 is characterized in that the joint portion of the base portion and the fuel cell support pipe is covered with an electrolyte that is a gas-impermeable membrane. There is no disclosure. Further, what is disclosed in Patent Document 2 is a structure in which a fuel cell support tube (cell tube) and a tube plate are joined by an interference fit, and the present application relates to an improvement of the fuel cell described in Patent Document 2. It is.

  FIG. 8 shows a schematic configuration in a state where the fuel cell module described in Patent Document 2 is covered with a heat insulating wall. A large-capacity fuel cell is formed by connecting a plurality of modules covered with such heat insulating walls. In the figure, 1 is a cell tube, 2 is an upper header, and the upper header 2 includes a tube plate 5 and frame members 3 and 4 for fixing and supporting the tube plate 5. Reference numeral 2 'denotes a lower header, and the lower header 2' includes a tube plate 5 'and a frame member 3', 4 'for fixing and supporting the tube plate 5', which are coupled by means not shown. The lower header 2 ′ is supported by the support base 8. Reference numeral 9 denotes a wall made of a heat insulating material, and reference numeral 10 denotes a cover that covers the upper header 2. A space between the heat insulating wall 9 and the frame members 3, 4, 3 ′, 4 ′ is sealed to form a plurality of fuel cell tubes 1. The fuel cell tube 1 penetrates through the tube plates 5 and 5 ′ and is interference-fitted at the penetration part, and a sealing effect and an adhesion effect are maintained by joining by the interference fit. A heat-resistant electric insulating layer such as aluminum oxide is formed on the interference fitting portion of the cell tube 1. FIG. 9 shows a perspective view of the internal module with the heat insulating wall 9 and the cover 10 removed, and the same components as those in FIG. 8 are given the same reference numerals. Reference numeral 21 denotes a heat insulating member omitted in FIG. Reference numeral 31 denotes a fuel battery cell. This fuel cell is a horizontal stripe cylindrical solid oxide fuel cell in which the cells 31 are connected in series.

Returning to FIG. 8, the fuel gas is supplied into the upper header 2 through a passage (not shown), flows into the lower header through the cell tube, and is discharged from the lower header to an external device through a passage (not shown). Is done. On the other hand, air as an oxidant is supplied to a space surrounded by the tube plates 5, 5 ′ and the heat insulating wall 9 through a passage (not shown) and discharged to an external device through a passage (not shown). The cell tube 1 includes a fuel cell 31 in which a fuel electrode layer, an electrolyte layer, and an air electrode layer are sequentially formed on the outer periphery of the base tube. Oxygen in the supplied air receives electrons at the air electrode (cathode) on the outer surface of the tube and becomes O ²⁻ ions, and passes through the electrolyte layer. On the other hand, the fuel gas passing through the cavity of the cell tube 1 reacts with the O ²⁻ ions that have passed through the porous substrate tube and moved through the electrolyte at the fuel electrode (anode) to be changed into water and carbon dioxide. At this time, electrons are emitted and become current, which is taken out at the tip of the cell tube, but the current collector is not shown. The fuel cell 31 is maintained at a temperature of 900 ° C. to 1000 ° C. during power generation. Exhaust gas containing unreacted fuel gas is sent from the lower header to an external device (not shown). Oxygen is consumed and gas containing residual oxygen that has not been consumed is also sent to an external device (not shown). These gases are recombusted by an external device, used for preheating fuel or air, reforming fuel, and the like, and then discharged into the atmosphere.

  However, in the configuration of the fuel cell of Patent Document 2, the cell tube 1 is joined to the tube plates 5 and 5 ′ of the upper header 2 and the lower header 2 ′ by an interference fit, and the upper header is supported by the cell tube. The cell tube is supported by the tube plate of the lower header, and these are supported by the support base 8 via the lower header. The cell tube and the tube plate are deformed due to thermal deformation of the tube plate and deformation due to the weight of the header. A bending moment is applied to the joint portion and the cell tube may break, and a support structure that reduces the load on the cell tube is required. Even if the cell tube does not break, the fuel gas side and air side airtightness may be impaired by deformation of the fitting portion between the cell tube and the tube sheet.

  Accordingly, the present invention provides a cylindrical solid oxide fuel cell having a support structure that reduces the load on the cell tube to prevent the airtightness of the fuel gas side and the air side from being impaired, and further prevents the cell tube from being damaged. The purpose is to provide.

The present invention includes a plurality of fuel cell tubes each having a fuel cell formed on the peripheral surface;
A first gas chamber for supplying fuel gas into the plurality of fuel cell tubes and a second gas chamber for discharging fuel gas that has been subjected to a power generation reaction in the fuel cells are oxidized to the fuel cells. In the solid oxide fuel cell, which is separated from the third gas chamber for supplying the agent gas, the first and second gas chambers are pipes that divide the third gas chamber from these gas chambers. A plate and a side plate surrounding the tube plate, and both end portions of the plurality of fuel battery cell tubes penetrate the tube plate and are hermetically joined to the tube plate at the penetrating portion, and the tube plate between side plates, Ri Na is connected with a smooth curved surface without corners are formed, the first and second gas chambers, and the tube plate, side plates surrounding the tube plate, are surrounded in these A tube plate for closing the space, and the tube plate material Suggest solid oxide fuel cell characterized that you have been formed by material having a low coefficient of thermal expansion than the cover plate or the side plate.

  For example, if the first gas chamber is disposed at the top and the second gas chamber is disposed at the bottom, the second gas chamber is supported by a support base, and the first gas chamber is formed between its tube plate and the fuel cell tube. The joint of the first gas chamber and the cell tube will be supported by the tube plate at the joint between the tube plate of the second gas chamber and the cell tube. . During power generation, the fuel cell is maintained at a high temperature of 900 to 1000 ° C., so that the vertical load due to the weight of the first gas chamber or the total weight of the first gas chamber and the cell tube at the joint between the cell tube and the tube sheet. In addition to this, a load due to thermal expansion of the tube sheet or the like is applied. These loads act on the cell tube as a bending moment in addition to the force along the axial direction thereof, and are the most at the cell tube joint joined to the tube plate at a position adjacent to the side plates of the first and second gas chambers. growing.

  According to the first aspect of the present invention, since the tube plates of the first and second gas chambers are connected with smooth curved surfaces without forming corners on the side plates, the tube plates are likely to be extended by thermal expansion. In this case, the restraint is eased by the presence of the rounded portion, and the bending moment applied to the joint portion between the cell tube and the tube sheet, particularly, the bending moment applied to the cell tube disposed at a position adjacent to the side plate is reduced. However, if the thickness of the gas chamber member is made too thin, the deflection of the tube sheet due to the vertical load increases particularly. In this case, in order to prevent the occurrence of the deflection due to the drooping load, It is good to comprise so that the arrange | positioned gas chamber may be supported by a support | pillar.

  In this way, by connecting the tube plates and side plates of the first and second gas chambers with smooth curved surfaces without forming corners, the periphery of the tube plate is fixedly supported as in the conventional example shown in FIG. Since there is no need to provide a frame member to be performed, the weight of the first and second gas chambers can be reduced.

The first gas chamber and the second gas chamber of the tube plate is formed of a material the thermal expansion coefficient is smaller than the other portions of the gas chamber. The fuel cell provided on the surface of the cell tube is kept at a high temperature of 900 to 1000 ° C., and the connection portion of the tube plate with the cell tube becomes a high temperature around 600 ° C. As will be described later, when the cell tube and the tube plate are joined by an interference fitting in a barnacle (Fujitsumi) -shaped hole provided in the tube plate, due to the difference in thermal expansion between the cell tube and the tube plate made of a ceramic material. In order to avoid a reduction in the interference of the interference fitting portion as much as possible and to reduce the thermal deformation of the tube plate and reduce the load applied to the joint portion, the tube plate is preferably made of a material having a low coefficient of thermal expansion. However, such a material is generally expensive, and if the entire first and second gas chambers are made of such a material, the cost increases. By using only the tube plates of the first and second gas chambers as materials having a low coefficient of thermal expansion, it is possible to suppress an increase in cost. The tube sheet is joined to the side plate by welding or other methods.

  In the case where the first and second gas chambers are configured to fix and support the peripheral portion of the tube plate on the side plate of the gas chamber (header) as in the conventional example shown in FIG. In the first and second gas chambers, the tube plate will be relatively stretched due to the difference in thermal expansion due to the temperature difference between the tube plate and other parts, but this elongation is restrained by the fixed support part. The tube sheet bends in the vertical direction, and a load is applied to the joint. In the present invention, both end portions of the plurality of fuel battery cell tubes pass through the tube plates of the first and second gas chambers, respectively, and are hermetically joined to the tube plate at the penetrating portions. 2 The peripheral edge of the tube plate of the gas chamber is a deformation allowing portion between a fixed support end fixedly supported by the side plate of each gas chamber and a fuel cell tube joined to the tube plate at a position adjacent to the fixed support end. It is also possible to form. As the deformation allowing portion, the tube plates of the first and second gas chambers are formed in a wave shape from the fixed support end to a fuel cell tube joined to the tube plate at a position adjacent to the fixed support end. Thus, by providing flexibility against deformation, it is also an effective configuration of the deformation-permitting portion to weaken the constraint on the thermal expansion of the tube sheet and reduce the load at the joint.

  Further, as is clear from the conventional example shown in FIG. 8, the peripheral portion of the tube sheet is fixedly supported through the side wall of the gas chamber (header). That is, the constraint on the thermal expansion of the tube sheet depends on the rigidity of the side wall. Therefore, by reducing the thickness of the side wall, the constraint on the thermal expansion of the tube sheet can be weakened, and the load at the joint can be reduced. Specifically, the thickness of the side walls in the first and second gas chambers may be made thinner than the thickness of the lid body facing the tube sheet.

  Next, regarding the joining of the tube plate and the cell tube, the cell tube is preferably fitted into a hole formed in the shape of a barnacle (Fujitsumi) of the tube plate and joined to the tube plate by an interference fit. Thus, it is taught in the drawing of Patent Document 2 that the cell tube is press-fitted into a hole formed in a barnacle shape of the tube plate and joined by an interference fit. In the present invention, the barnacle (Fuji 壷) -shaped hole is formed in a shape that narrows toward the distal end side of the cell tube. This facilitates the insertion of the cell tube. That is, the tip end side of the cell tube can be easily press-fitted from the rounded surface side of the barnacle (Fuji Aoi) -shaped hole.

  The cell tube is made of a porous ceramic material, and an electrical insulating layer is formed on the outermost surface of the portion to be inserted into the tube plate of the cell tube, but it is not always guaranteed that the roundness of the outer periphery is guaranteed. It's not easy. A ring member with a guaranteed roundness of the outer periphery is fixed to the cell tube, and the outer periphery of the ring member is fitted into a barnacle-like hole in the tube plate and joined to the tube plate, thereby preventing gas leakage at the joint. It can be completely prevented. This is also taught in Patent Document 2. The ring member is fixed to the cell tube by an inorganic adhesive having appropriate heat resistance and adhesive strength or other means and gas-sealed.

  A ring member may be fixed to the tip of the cell tube, and the ring member may be inserted into a hole formed in a barnacle shape (Fujitsumi) of the tube plate and joined to the tube plate by welding.

  A plurality of fuel battery cell tubes having fuel cells formed on the peripheral surface, a first gas chamber for supplying fuel gas into the plurality of fuel battery cell tubes, and a fuel that has undergone a power generation reaction in the fuel battery cells In a solid oxide fuel cell in which a second gas chamber for discharging gas is disposed separately from a third gas chamber for supplying an oxidant gas to the fuel cell, the first and second The load applied to the cell tube from the tube sheet by thermal deformation due to the gravity of the gas chamber and the fuel cell tube and the temperature difference of each part can be reduced, and the cell tube can be prevented from being broken and the gas leak occurring at the joint between the cell tube and the tube sheet. .

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, exemplary embodiments of the invention will be described with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, but are merely illustrative examples. Not too much.

  FIG. 1 is a diagram showing a schematic configuration of a module of a solid oxide fuel cell according to a first embodiment of the present invention. In the figure, 1 is a fuel cell tube, 2 is an upper header, and 2 'is a lower header. The lower header 2 ′ is supported by the support base 8. Since the operation of the fuel cell having such a configuration is the same as that of the conventional fuel cell module described with reference to FIG. 8, detailed description thereof is omitted, but the upper header 2 is replaced with the first gas chamber and the lower header 2 ′. Is the second gas chamber, the fuel gas flows from the first header 2 through the fuel cell tube to the lower header 2 ′. On the other hand, air as an oxidant gas flows into the third gas chamber which is a space between the upper header 2 and the lower header 2 '. As described above with reference to FIG. 8, the exhaust gas containing unreacted fuel gas is discharged from the lower header 2 ′ and sent to an external device (not shown), and oxygen is consumed to contain unconsumed residual oxygen. The gas is also discharged from the third gas chamber and sent to an external device (not shown). These gases are recombusted by an external device, used for preheating fuel or air, reforming fuel, and the like, and then discharged into the atmosphere.

  The upper header 2 includes a side plate 11, a tube plate 5 connected to the side plate with a smooth curved surface, and a lid plate 12, which are formed to have a substantially uniform thickness. The fuel cell tube 1 is joined to the tube plate 5 of the header 2. The tube plate 5 may be joined to the side plate 11 with a material different from that of the side plate 11. Also in this case, the tube plate 5 is connected to the side plate 11 through a rounded portion with a smooth curved surface so as not to form a corner portion. The same applies to the lower header 2 '. The lower header 2 ′ is supported by the support base 8.

  In such a configuration, the upper header 2 is supported by the cell tube 1, and a vertical load due to the weight of the header 2 is applied to the joint portion between the cell tube 1 and the tube sheet 5. Furthermore, although a load is applied to the joint portion due to restraint of thermal deformation of the tube plate 5, since the tube plate 5 is connected to the side plate 11 of the header 2 via the rounded portion, the tube plate 5 is thermally expanded. The resistance to deformation when doing so is small. That is, the deformation due to the thermal expansion of the tube plate 5, in practice, the constraint on the deformation difference due to the temperature difference between the temperature of the tube plate 5 and the temperature of the other part is weakened, and the load applied to the junction between the tube plate and the cell tube is reduced accordingly. Get smaller.

  FIG. 2 shows the bending between the side plate of such a header and the cell tube joined to the tube plate adjacent to the side plate. (A) shows the bending due to the normal vertical load, (B) shows the bending. It is the calculation result of the bending by the temperature difference which arises normally, ie, the bending of the tube sheet by the thermal expansion difference by the temperature difference of the tube sheet of a header, and another site | part. In such a header, it can be seen that the vertical deflection is greater in the vertical direction than in the temperature difference. Since the side plate is the same thickness as the tube plate, and the restraint against thermal expansion of the tube plate is weak, the side plate spreads outward due to the temperature difference, and compared to the case where the side plate does not spread outward, the tube plate and cell tube The load generated at the joint portion is reduced.

  FIG. 3 shows a second embodiment of the present invention, and the same components as those in FIG. The difference from FIG. 1 is that the upper header 2 is supported by the support base 8 via the support column 9 and the support plate 10. If the upper header is supported with respect to the support base in this way, the deflection due to the vertical load as shown in FIG. 2A can be substantially eliminated, while the deflection due to the temperature difference can be suppressed to a small level. The load at the joint portion of the tube can be reduced. In the configuration of the fuel cell module, when the deflection due to the vertical load is larger than the allowable limit, the upper header is preferably supported on the support base in this way.

  In addition, in such a header configuration, a frame member for fixing and supporting the peripheral portion of the tube plate is not required as in the conventional configuration shown in FIG. 8, so that the configuration of the header is simplified and the weight can be reduced. .

  FIG. 4 shows a third embodiment of the present invention. In this embodiment, the tube plate is interposed between the fixed support ends of the frame members 3 and 4 for fixing and supporting the periphery of the tube plate 5 and the cell tube 1 joined to the tube plate 5 at a position adjacent to the fixed support ends. 8 is the same as the prior art example of FIG. 8 except that it is formed in a wavy shape 5a and the upper header 2 is supported on the support base 8 via the support column 9 and the support plate 10. It is. However, the shape of the tube sheet 5 is different from that of FIG. Thus, by providing the corrugated part 5a in the tube sheet 5, the tube sheet has flexibility with respect to thermal deformation, and the load caused by the thermal deformation can be reduced. However, since the deflection with respect to the vertical load naturally increases, the column 9 and the support plate 10 are provided so that the frame portion of the upper header is supported by the support base 8. In the figure, the lower part is configured symmetrically with the upper part, and the same configuration is indicated by a symbol 'and the description is omitted. With such a configuration, the vertical load applied to the joint between the tube sheet and the cell tube can be eliminated, and the load due to the temperature difference can be reduced.

FIG. 5 shows a fourth embodiment of the present invention. This embodiment is the same as the conventional example of FIG. 8 except that the thickness t of the side walls of the upper and lower headers 2 and 2 ′ is made thinner than the thickness T of the upper plate. It is. In FIG. 5, a gap is provided between the outer surface of the side wall of the lower header 2 ′ and the support base, although it is not clear in the figure.
As can be seen from FIG. 5, the thermal deformation of the tube plates 5 and 5 ′ is restrained by the side walls of the headers 2 and 2 ′ via the frame members 3, 4 and 3 ′ and 4 ′, respectively. By reducing the thickness t, the restraint can be weakened, and the load on the cell tube due to the thermal deformation of the tube sheet can be reduced. Specifically, the side wall of the header is made thinner than the thickness T of the lid body facing the tube plates 5 and 5 '.

  FIGS. 6 and 7 are diagrams for explaining the joint portion between the cell tube and the tube sheet. Such a joint method is disclosed in Patent Document 2 filed by the same applicant as the present invention, but is simple. Explained. In FIG. 6, the hole for press-fitting the cell tube of the tube sheet 5 is formed in a shape barnacle (Fuji 壷) shape that narrows toward the tip side of the cell tube. The cell tube 1 is joined to the tube plate 5 by fastening the cell tube 1 with the edge of the tube.

  In FIG. 7, the ring member 31 is bonded to the cell tube 1 by an adhesive 32, and the ring member 31 is bonded to the cell tube 1 by an interference fit at the edge of a barnacle (Fujitsumi) -shaped hole of the tube plate 5. As the adhesive 32, an inorganic adhesive having appropriate heat resistance and adhesive strength is used. When shot peening is applied to the inner diameter of the ring, the adhesive strength of the adhesive is improved. As shown in FIGS. 6 and 7, the insertion of the cell tube is facilitated by forming the barnacle (Fuji 壷) -shaped hole so as to be narrowed toward the distal end side of the cell tube. That is, the tip end side of the cell tube can be easily press-fitted from the rounded surface side of the barnacle (Fuji Aoi) -shaped hole.

  In a fuel cell having a structure in which a cell tube of a cylindrical solid oxide fuel cell is used as a support member for the upper header and the lower header, a load caused by a vertical force applied to a joint portion between the cell tube and the tube sheet, and the header and the tube sheet Highly reliable cylindrical solid because it can reduce the load caused by the difference in expansion due to the temperature difference and prevent the cell tube from breaking and the gas leakage at the joint between the cell tube and the tube sheet. An oxide fuel cell can be provided.

It is a figure which shows schematic structure of the module of the solid oxide fuel cell which concerns on 1st Example of this invention. It is a figure which shows the deformation | transformation of the said continuous part by the vertical load and temperature difference in case a tube plate connects to a side plate with a smooth curved surface, (A) shows the deformation | transformation by a vertical load, (B) shows the deformation | transformation by a temperature difference. It is a figure which shows schematic structure of the module of the solid oxide fuel cell which concerns on 2nd Example of this invention. It is a figure which shows schematic structure of the module of the solid oxide fuel cell which concerns on 3rd Example of this invention. It is a figure which shows schematic structure of the module of the solid oxide fuel cell which concerns on 4th Example of this invention. It is local sectional drawing of one Example of the coupling | bonding form of the cell tube and tube sheet in a solid oxide fuel cell. It is local sectional drawing of the other Example of the coupling | bonding form of the cell tube and tube sheet in a solid oxide fuel cell. It is a figure which shows schematic structure of the state which covered the module of the conventional cylindrical solid oxide fuel cell to which this invention is applied with the heat insulation wall. 1 is a perspective view of a conventional cylindrical solid oxide fuel cell module to which the present invention is applied. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cell tube 2 Upper header 2 'Lower header 3, 4 Frame member 5 Tube plate 8 Support stand 9 Support column 10 Support plate 11 Side plate 12 Cover plate 21 Heat insulation member 31 Ring member 32 Adhesive 41 Heat insulation wall 42 Cover

Claims (4)

A plurality of fuel battery cell tubes having fuel cells formed on the peripheral surface;
A first gas chamber for supplying fuel gas into the plurality of fuel cell tubes and a second gas chamber for discharging fuel gas that has been subjected to a power generation reaction in the fuel cells are oxidized to the fuel cells. In the solid oxide fuel cell, which is disposed separately from the third gas chamber for supplying the agent gas,
The first and second gas chambers include a tube plate that divides the third gas chamber from these gas chambers, and a side plate surrounding the tube plate, and both ends of the plurality of fuel cell tubes are respectively connected to the tube. together are joined through the plate sealingly tubesheet at the through portion, between the tube plate the side plates, Ri Na is connected with a smooth curved surface without corners are formed,
The first and second gas chambers include a tube plate, a side plate surrounding the tube plate, and a lid plate for closing a space surrounded by the tube plate, and the tube plate material is formed from the lid plate or the side plate. solid oxide fuel cell according to claim Rukoto also be formed with material having a low coefficient of thermal expansion. A hole in the tube plate through which the fuel cell tube penetrates is formed in a barnacle (Fujitsumi) shape, and the fuel cell tube is fitted into the hole and is airtightly joined to the tube plate by an interference fit. The solid oxide fuel cell according to claim 1 . Ring members are respectively fixed to both ends of the fuel cell tube, and the ring members are inserted into holes formed in a barnacle (Fujitsumi) shape of the tube plate and are airtightly joined to the tube plate by an interference fit. The solid oxide fuel cell according to claim 1 , wherein Ring members are respectively fixed to both ends of the fuel cell tube, and the ring members are fitted into holes formed in a barnacle (Fujitsumi) shape of the tube plate and are hermetically joined to the tube plate by welding. The solid oxide fuel cell according to claim 1 , wherein:

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