JP2005100818A - Fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell of stable power generation performance, of easy maintenance and of a simple structure, in which a start-up time can be shortened and which is easy to manufacture. <P>SOLUTION: This is the fuel cell in which the fuel cell 62 and a gas tank 58 on which one end of the stem length direction of the fuel cells 62 is mounted and a plurality of the fuel cells 62 are erected are housed in the same chamber of a container 2, and in the vicinity of the tip part of the fuel cell 62, the gas which has passed from the gas tank 58 through the inside of the fuel cell 62 and the gas which has passed between the fuel cells 62 react and burn, and the tip part of the fuel cell 62 is made to be a non-power generation part A. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a fuel cell in which a fuel cell formed by sequentially forming an inner electrode, a solid electrolyte, and an outer electrode on the surface of a support is housed in a housing container.

  In recent years, various types of fuel cells in which a plurality of solid electrolyte fuel cells are accommodated in a storage container have been proposed as next-generation energy. A solid electrolyte fuel cell is configured, for example, by sequentially forming a solid electrolyte and a fuel side electrode on the surface of an oxygen side electrode having a gas passage. A fuel (hydrogen) is allowed to flow to the fuel side electrode side, Electric power is generated at about 1000 ° C. by flowing air (oxygen) to the side electrode side.

Conventionally, a fuel cell is configured such that a storage container is partitioned into a plurality of chambers by partition plates, and the upper and lower ends of the solid oxide fuel cell unit are supported and fixed by the partition plates. Air is supplied to the gas passage of the electrode and fuel gas is supplied to the fuel side electrode, and the air passing through the gas passage of the oxygen side electrode reacts with the fuel gas passing between the fuel cells in the vicinity of the tip of the fuel cell. By using this combustion gas, for example, the air in the air introduction pipe is heated, and the fuel cell is heated to about 1000 ° C., which is the operating temperature of the fuel cell using the solid electrolyte, and started. It has been proposed to shorten the time (see, for example, Patent Document 1).
JP 2001-218061 A

  However, since the conventional fuel cell burns in the vicinity of the tip of the fuel cell, the tip of the fuel cell becomes hot, and the tip is further supported and fixed by the partition plate due to thermal stress at the time of starting and stopping. Since it was necessary, there was a problem that the tip portion was broken or damaged, and the power generation at the tip portion became unstable, and the power generation performance of the fuel cell was lowered or became unstable.

  Further, in the conventional fuel cell, the storage container is partitioned by the partition wall, the gas chamber is formed in the storage container, and one end portion of the fuel cell is inserted and fixed in the through hole of the partition wall. There is a problem in that it is necessary to arrange and set the fuel cells one by one in the through holes of the inner partition wall, and it takes time to manufacture the fuel cells.

  Furthermore, for example, when one fuel battery cell is damaged, it is almost impossible to replace only the fuel battery cell, and there is a problem that the fuel cell itself fails.

  Further, in the conventional fuel cell, the air in the air introduction pipe is heated by the combustion gas, and the fuel cell is only indirectly heated by the heated air, and there is a problem that the start-up time is still long. .

  Furthermore, in order to support and fix the fuel cell, the storage container is partitioned into a plurality of chambers by a partition plate, and a chamber that causes the fuel gas to react with the air that has passed through the gas passage of the oxygen side electrode, There is a problem in that the heat generated by the combustion gas is not effectively used because it is separated from the chamber in which most of the fuel cells exist.

  Furthermore, in the conventional fuel cell, since the inside of the storage container needs to be partitioned by a plurality of partition plates, there is a problem that the structure is complicated and there are many manufacturing processes.

  An object of the present invention is to provide a fuel cell that has stable power generation performance, is easy to maintain, can be shortened in start-up time, and is easy to manufacture with a simple structure.

  The fuel cell of the present invention accommodates a fuel cell and a gas tank in which one end of the fuel cell in the axial length direction is attached and a plurality of the fuel cells are erected in the same chamber of a storage container, In the vicinity of the tip of the fuel cell, the gas passing through the fuel cell from the gas tank and the gas passing between the fuel cells react and burn, and the tip of the fuel cell does not generate electricity. It is characterized by being part.

  In the fuel cell according to the present invention, the fuel cell stands upright in the gas tank and burns in the vicinity of the tip of the fuel cell, but since the tip of the fuel cell is a non-power generation part, Even if some trouble occurs at the tip, the power generation performance of the fuel cell is stabilized with little influence on the power generation performance.

  Further, since one end of the fuel cell is attached to the gas tank and is erected, the fuel cell is not fixed to the storage container but is held and fixed to the gas tank accommodated in the storage container. A fuel cell can be produced simply by placing a cell upright and storing it in a storage container. For example, when one fuel cell is damaged, a gas tank in which the fuel cell is set up is stored. It can be taken out of the container and replaced with other non-defective products, which facilitates maintenance.

  Furthermore, since the fuel cell is stored upright in the gas tank in the same chamber of the storage container, a conventional partition plate for partitioning the storage container becomes unnecessary, and the fuel cell and the partition plate Since no sealing is required, the structure is simple and the manufacturing is easy. In addition, the heat of the combustion gas that burns in the vicinity of the tip of the fuel cell heats the entire chamber of the storage container in which the fuel cell is stored, so that the fuel cell can be directly heated and the fuel cell generates power Start-up time can be shortened.

  In the fuel cell of the present invention, the fuel cell is formed by sequentially forming an inner electrode, a solid electrolyte, and an outer electrode on a support capable of passing gas in the axial direction. In such a fuel cell, since it has a support separately from the inner electrode, it can be controlled to a composition having optimum characteristics as the support and the inner electrode, respectively. It can be an inner electrode.

That is, when the inner electrode itself is used as a support, it is necessary to combine the characteristics as an electrode with the characteristics as a support, and the composition required for the electrode, for example, Ni + YSZ, occupies the largest volume in the fuel cell. When the support is configured, the difference in thermal expansion coefficient from the solid electrolyte made of, for example, YSZ is large, so there is a possibility that the solid electrolyte may be peeled off or cracked during production or operation. Since the substrate has a separate support, the composition of the support having the largest volume in the cell is adjusted to the characteristics required for the support, for example, it is composed of Ni + Y ₂ O ₃ , so that the thermal expansion coefficient is solid. It can be brought close to the electrolyte, and the solid electrolyte can be prevented from peeling off.

  In the fuel cell of the present invention, the fuel cell has a flat shape, and has a plurality of gas passages formed at predetermined intervals in the width direction and extending in the axial length direction. In such a fuel cell, the volume for generating a predetermined amount can be reduced by using a flat fuel cell, thereby reducing the volume of the fuel cell to be heated and increasing the heating rate of the fuel cell. This can further shorten the startup time until the fuel cell generates power.

  In addition, since the flat fuel cell has a plurality of gas passages formed at predetermined intervals in the width direction and extending in the axial length direction, the gas flowing in the fuel cell is solid even if it is flat. While being able to supply uniformly to electrolyte, the intensity | strength of a fuel cell can be improved compared with the case where one flat gas passage is formed.

  Furthermore, the fuel cell of the present invention is characterized in that the tip end portion of the fuel cell is chamfered. In such a fuel cell, stress concentration at the tip corner of the fuel cell can be suppressed, breakage and cracking can be suppressed, and stabilization of power generation performance can be further promoted.

  The fuel cell of the present invention is characterized in that the fuel cell is formed by sequentially forming a fuel side electrode, a solid electrolyte, and an oxygen side electrode on the surface of a conductive support. In such a fuel cell, the heat of the combustion gas combusted in the vicinity of the tip of the fuel cell is a support having good heat conduction mainly composed of a metal or an alloy, and the conductivity that occupies most of the fuel cell. The support can be conducted and the fuel cell can be heated from the inside, whereby the startup time until the fuel cell generates electricity can be further shortened.

  In the fuel cell according to the present invention, the fuel cell stands upright in the gas tank and burns in the vicinity of the tip of the fuel cell, but since the tip of the fuel cell is a non-power generation part, Even if some trouble occurs at the tip, the power generation performance of the fuel cell is stabilized with little influence on the power generation performance.

  Further, since one end of the fuel cell is attached to the gas tank and is erected, the fuel cell is not fixed to the storage container but is held and fixed to the gas tank accommodated in the storage container. A fuel cell can be produced simply by placing a cell upright and storing it in a storage container. For example, when one fuel cell is damaged, a gas tank in which the fuel cell is set up is stored. It can be taken out of the container and replaced with other non-defective products, which facilitates maintenance.

  Furthermore, since the fuel cell is installed in a gas tank in the same chamber of the storage container, a conventional partition plate for partitioning the storage container becomes unnecessary, and the fuel cell and the partition plate Since sealing is not necessary, the structure is simple and manufacturing is easy. Moreover, since the heat of the combustion gas that burns in the vicinity of the tip of the fuel cell heats the entire chamber of the storage container in which the fuel cell is stored, the fuel cell can be quickly heated, and the fuel cell generates power. Can shorten the startup time.

  The fuel cell of the present invention will be described with reference to FIGS. 1 and 2. The fuel cell includes a storage container 2 having a substantially rectangular parallelepiped shape. On the six wall surfaces of the storage container 2, heat insulating walls formed of appropriate heat insulating materials, that is, an upper heat insulating wall 4, a lower heat insulating wall 6, a right heat insulating wall 8, a left heat insulating wall 10, and a front heat insulating wall (not shown) No) and a rear heat insulation wall (not shown). A power generation / combustion chamber 12 is defined in the storage container 2.

  The front heat insulation wall and / or the rear heat insulation wall are detachably or detachably mounted, and the power generation / combustion chamber 12 can be accessed by detaching or opening the front heat insulation wall and / or the rear heat insulation wall. If desired, an outer wall, which may be made of a metal plate, can be disposed on the outer surface of each heat insulating wall.

  A lower gas chamber 14 is disposed at the lower end in the storage container 2, and an upper gas chamber 16 is disposed at the upper end. The lower gas chamber 14 is defined in a rectangular parallelepiped case 15 having a relatively small vertical dimension, and the upper gas chamber 16 is similarly defined in a rectangular parallelepiped case 17 having a relatively small vertical dimension. A communication gas chamber 18 extending in the vertical direction is disposed on both the left and right sides of the storage container 2. The communication gas chamber 18 is defined in a rectangular parallelepiped case 19 having a relatively small size in the lateral direction (left-right direction in FIG. 1).

  Three communication cylinders 20 are attached to the upper surface of each communication gas chamber 18 at intervals in the front-rear direction, and each of the communication gas chambers 18 is provided on both sides of the lower surface of the upper gas chamber 16 via the communication cylinder 20. It communicates with the department. The inner sides of the lower ends of the communication gas chambers 18 are directly connected to both side surfaces of the lower gas chamber 14.

  Accordingly, both side portions of the upper gas chamber 16 are communicated with both side portions of the lower gas chamber 14 via the communication gas chamber 18. On the upper surface of the lower gas chamber 14, five hollow gas ejection plates 22 projecting upward at intervals in the lateral direction (left-right direction in FIG. 1) are arranged. The lower end of the gas ejection plate 22 communicates with the lower gas chamber 14, and a gas ejection hole (not shown) is formed in the upper part.

  A heat exchanger 24 having a flat plate shape as a whole is disposed on both sides of the storage container 2, more specifically, inside the right heat insulation wall 8 and inside the left heat insulation wall 10. Each of the heat exchangers 24 is constituted by a case 26 having a hollow flat plate shape extending substantially vertically.

  A partition plate 28 located in the middle in the lateral direction is disposed in the case 26, and the inside of the case 26 is partitioned into a discharge path 30 positioned on the inner side and an inflow path 32 positioned on the outer side. Five partition walls 34 and 36 are arranged in the discharge path 30 at intervals in the vertical direction. More specifically, in the discharge passage 30, the front edge is located rearwardly away from the front wall (not shown) of the case 26, but the rear edge is the rear wall (not shown) of the case 26. And a partition wall 36 whose front edge is connected to the front wall of the case 26 but whose rear edge is spaced forward from the rear wall of the case 26. Are alternately arranged, and thus the combustion gas discharge passage 30 is zigzag-shaped.

  Similarly, the five partition walls 38 and 40, that is, the front edges thereof are also spaced apart from the front wall (not shown) of the case 26 in the inflow path 32 with a space in the vertical direction. The rear wall is connected to the rear wall (not shown) of the case 26, and the front edge of the partition wall 38 is connected to the front wall of the case 26. The partition walls 40 spaced apart from the front are alternately arranged, and thus the inflow passage 32 is also zigzag-shaped.

  A discharge opening 42 is formed at the upper end of the inner wall of the case 26, and the discharge path 30 is communicated with the power generation / combustion chamber 12 through the discharge opening 42. In the illustrated embodiment, heat insulating members 44 and 46 are disposed between each of the heat exchangers 24 and the communication gas chamber 18 and on the inner surface of the communication gas chamber 18. The upper end of the exhaust gas is positioned substantially at the same level as or slightly below the lower edge of the discharge opening 42, and the discharge opening 42 is left above the heat insulating members 44 and 46 and the communication gas chamber 18. Is connected to the power generation / combustion chamber 12 through a space between the three communication cylinders 20 disposed at the upper end.

  An inflow opening 48 is formed on the outer side of the upper wall of the case 26, and the inflow path 32 is communicated with the upper gas chamber 16 through the inflow opening 48. A double cylinder 50 (only the upper end portion thereof is shown in FIG. 1) extending in the vertical direction is disposed behind each of the heat exchangers 24. The double cylinder 50 is an outer cylinder. The member 52 and the inner cylinder member 54 are configured. The lower end of the discharge path 30 is connected to the lower end of the discharge path defined between the outer cylinder member 52 and the inner cylinder member 54, and the lower end of the inflow path 32 is defined in the inner cylinder member 54. Connected to the inflow channel.

  Thus, the configuration as described above in the illustrated fuel cell is substantially the same as the fuel cell assembly disclosed in the specification and drawings of Japanese Patent Application No. 2003-295790 filed by the present applicant. The details of the configuration described above will be referred to the specification and drawings of the above Japanese Patent Application No. 2003-295790, and description thereof will be omitted in this specification.

  Four power generation units 56a, 56b, 56c and 56d are arranged on the upper surface of the lower gas chamber 14 described above. The power generation units 56a, 56b, 56c, and 56d are respectively positioned between the gas ejection plates 22 described above. 3 together with FIGS. 1 and 2, the power generation unit 56a includes a rectangular parallelepiped fuel gas case (gas tank) 58a extending in the front-rear direction (a direction perpendicular to the paper surface in FIG. 1). ing.

  A cell stack 60a is mounted on the upper surface of the fuel gas tank 58a defining the fuel gas chamber 59a. The cell stack 60a is configured by arranging a plurality of upright cells 62 extending in the vertical direction in the longitudinal direction of the fuel gas tank 58a (that is, in the front-rear direction).

  As clearly shown in FIG. 4, each of the cells 62 is flat and has a support 64, a fuel electrode side electrode 66 as an inner electrode, a solid electrolyte 68, an oxygen side electrode 70 as an outer electrode, and an interconnector 72. It is composed of

  The support 64 is a plate-like piece that is elongated in the vertical direction, and has both flat surfaces and both sides of a semicircular shape. The support body 64 is formed with a plurality (four in the illustrated case) of fuel gas passages 74 penetrating the support body 64 in the vertical direction. That is, the support body 64 is formed with a fuel gas passage 74 extending in the axial length direction at a predetermined interval in the width direction.

  Each of the fuel cells 62 has a lower end portion joined to the upper wall of the fuel gas tank 58a by, for example, a ceramic adhesive having excellent heat resistance, and is erected on the fuel gas tank 58a. As described above, the fuel cell 62 is erected without being supported by the fuel gas tank 58a, and a conventional partition plate or the like is not necessary. The structure can be simplified and the manufacture becomes easy.

  On the upper wall of the fuel gas tank 58a, a plurality of slits (not shown) extending in the left-right direction are formed at intervals in the direction perpendicular to the paper surface in FIG. A fuel gas passage 74 is in communication with each of the slits and thus with the fuel gas chamber 59a.

  The interconnector 72 is disposed on one side of the support 64 (upper surface in the cell stack 60a in FIG. 4). The fuel side electrode 66 is disposed on the other surface (the lower surface in the cell stack 60a of FIG. 4) and both side surfaces of the support 64, and both ends thereof are joined to both ends of the interconnector 72. The solid electrolyte 68 is disposed so as to cover the entire fuel side electrode 66, and both ends thereof are joined to both ends of the interconnector 72. The oxygen-side electrode 70 is disposed on the main part of the solid electrolyte 68, that is, on the portion covering the other surface of the support 64, and is positioned to face the interconnector 72 with the support 64 interposed therebetween.

  A current collecting member 76 is disposed between adjacent cells 62 in the cell stack 60a, and connects the interconnector 72 of one cell 62 and the oxygen side electrode 70 of the other cell 62. Current collecting members 76 are disposed on both ends of the cell stack 60a, that is, on one side and the other side of the cell 62 positioned at the upper and lower ends in FIG. Electric power extraction means (not shown) is connected to the current collecting members 76 located at both ends of the cell stack 60a. The electric power extraction means is connected to the front wall (not shown) and / or the rear of the storage container 2. It extends outside the storage container 2 through a wall (not shown). If desired, the cell stacks 60a, 60b, 60c and 60d are connected in series with each other by appropriate connection means instead of disposing the power extraction means in each of the cell stacks 60a, 60b, 60c and 60d. Common power extraction means may be provided for the cell stacks 60a, 60b, 60c and 60d.

  More specifically about the cell 62, the support 64 is gas permeable to allow fuel gas to permeate to the fuel side electrode 66, and is also conductive to collect current through the interconnector 72. It can be formed from a porous conductive ceramic (or cermet) that is required and satisfies such requirements.

  In order to manufacture the support 64 by simultaneous firing with the fuel side electrode 66 and / or the solid electrolyte 70, it is preferable to form the support 64 from an iron group metal component and a specific rare earth oxide. In order to provide the required gas permeability, it is preferable that the open porosity is in the range of 30% or more, in particular 35 to 50%, and the conductivity is also 300 S / cm or more, in particular 440 C / cm or more. Is preferred.

The fuel side electrode 66 can be formed of a porous conductive ceramic, for example, ZrO ₂ (referred to as stabilized zirconia) in which a rare earth element is dissolved and Ni and / or NiO.

The solid electrolyte 68 has a function as an electrolyte for bridging electrons between electrodes, and at the same time needs to have a gas barrier property in order to prevent leakage between the fuel gas and the oxygen-containing gas. Usually, it is formed from ZrO ₂ in which ₃ to 15 mol% of a rare earth element is dissolved.

The oxygen side electrode 70 can be formed of a conductive ceramic made of a so-called ABO ₃ type perovskite oxide. The oxygen side electrode 70 is required to have gas permeability, and the open porosity is preferably 20% or more, particularly preferably in the range of 30 to 50%.

  As shown in FIG. 5 (a), the oxygen-side electrode 70 is not formed at the front end portion on the combustion side of the fuel cell 62, the solid electrolyte 68 is exposed, and the non-power generation portion A is formed. Yes. Since the dense solid electrolyte 68 is formed, leakage of the fuel gas from the tip of the fuel cell 62 can be prevented. The non-power generation unit may be formed not by forming not only the oxygen side electrode 70 but also the solid electrolyte 68 and / or the fuel side electrode 66. In addition, the tip of the fuel cell 62 can be further protected by forming some kind of protective layer in the non-power generation part.

  In addition, as shown in FIG. 5 (b), the chamfered portion Y is formed by chamfering the front end corner of the fuel cell 62 on the burning side, that is, the angle between the outer peripheral surface and the end surface of the fuel cell 62. ing. Thereby, stress concentration at the tip corner of the fuel cell 62 can be suppressed, damage and cracks can be suppressed, and stabilization of power generation performance can be further promoted.

Although the interconnector 72 can be formed from a conductive ceramic, it needs to have reduction resistance and oxidation resistance because of contact with a fuel gas that may be hydrogen gas and an oxygen-containing gas that may be air. In addition, a lanthanum chromite perovskite oxide (LaCrO ₃ oxide) is preferably used. The interconnect 72 must be dense in order to prevent leakage of the fuel gas passing through the fuel gas passage 74 formed in the support 64 and the oxygen-containing gas flowing outside the support 64, particularly 93% or more, It is desirable to have a relative density of 95% or higher.

  The current collecting member 76 can be composed of a member having an appropriate shape formed of a metal or alloy having elasticity, or a member obtained by adding a required surface treatment to a felt made of metal fiber or alloy fiber.

  Continuing the description with reference to FIGS. 1 to 3, the power generation unit 56a is advantageously a rectangular shape (or a cylindrical shape) that is elongated in the front-rear direction above the cell stack 60a. It also has. One end, that is, the upper end of the fuel gas supply pipe 80a is connected to the lower surface of the front end portion of the reforming case 78a.

  The fuel gas supply pipe 80a extends downward, then curves and extends rearward, and the other end of the fuel gas supply pipe 80a is connected to the front surface of the fuel gas case 58a. One end of a reformed gas supply pipe 82a is connected to the rear surface of the reforming case 78a. The to-be-reformed gas supply pipe 82a extends substantially horizontally and extends out of the storage container 2 through the rear wall (not shown) of the storage container 2.

  The to-be-reformed gas supply pipe 82a is connected to a to-be-reformed gas supply source (not shown) which may be a hydrocarbon gas such as city gas, and is connected to the reforming case 78a through the to-be-reformed gas supply pipe 82a. A gas to be reformed is supplied. An appropriate reforming catalyst for reforming the fuel gas into a hydrogen-rich fuel gas is accommodated in the reforming case 78a.

  In the illustrated embodiment, the reforming case 78a is connected to the fuel gas tank 58a via the fuel gas supply pipe 80a, and is thereby held at a required position. If necessary, the reforming case 78a is shown by a two-dot chain line in FIG. As shown in the figure, for example, an appropriate support member 84a may be provided between the lower surface of the reformed gas supply pipe 82a and the upper surface or rear surface of the rear end portion of the fuel gas tank 58a.

  The power generation unit 56c is substantially the same as the power generation unit 56a described above. The power generation units 56b and 56d are disposed opposite to the power generation units 56a and 56c in the front-rear direction, and accordingly, the fuel gas supply pipes connecting the reforming cases 78b and 78d and the fuel gas cases 58b and 58d ( (Not shown) is disposed on the rear side, and the reformed gas supply pipes 82b and 82d are extended from the front surfaces of the reforming cases 78b and 78d through the front wall (not shown) of the storage container 2. Except that the power generation units 56a and 56c are the same.

  Each of the power generation units 56a, 56b, 56c and 56d is on the upper surface of the case 15 which defines the lower gas chamber 14 between the gas injection plates 22, as will be clearly understood by referring to FIGS. It is placed and fixed in place by appropriate fixing means (not shown) such as a bolt.

  In the fuel cell as described above, the gas to be reformed is a gas to be reformed pipe (two reformed gas supply pipes 82b and 828d are shown in FIG. 2, and one gas to be reformed is shown in FIG. After being supplied to reforming cases 78a, 78b, 78c and 78d via reforming cases 78a, 78b, 78c and 78d via reforming cases 78a, 78b, 78c and 78d, Fuel gas chambers 59a, 59b, 59c defined in the fuel gas tanks 58a, 58b, 58c and 58d through the fuel gas feed pipes (two fuel gas feed pipes 80a and 80c are shown in FIG. 2). And 59d and then to the cell stacks 60a, 60b, 60c and 60d.

  On the other hand, oxygen-containing gas, which may be air, is supplied to the inflow path 32 of the heat exchanger 24 through the inflow path defined in the inner cylinder member 54 of the double cylinder 50, and then the upper gas chamber 16 and the communication gas chamber 18. The gas is supplied to the lower gas chamber 14 through the gas injection plate 22 and is injected toward the cell stacks 60a, 60b, 60c and 60d from the injection holes of the gas injection plate 22.

In each of the cell stacks 60a, 60b, 60c and 60d, in the oxygen side electrode,
1 / 2O ₂ + 2e ⁻ → O ²⁻ (solid electrolyte)
The electrode reaction of
O ²⁻ (solid electrolyte) + H ₂ → H ₂ O + 2e ⁻
The electrode reaction is generated and power is generated.

  The fuel gas and oxygen-containing gas that have flowed upward from the cell stacks 60a, 60b, 60c and 60d without being used for power generation are igniting means (not shown) disposed in the power generation / combustion chamber 12 at the time of startup. ) Is ignited and burned. As is well known, the temperature in the power generation / combustion chamber 12 becomes high, for example, about 1000 ° C. due to power generation in the cell stacks 60a, 60b, 60c and 60d, and also due to combustion of fuel gas and oxygen-containing gas. . The reforming cases 78a, 78b, 78c and 78d are disposed in the power generation / combustion chamber 12, and are positioned immediately above the cell stacks 60a, 60b, 60c and 60d, and are directly heated by the combustion flame. Thus, the high temperature generated in the power generation / combustion chamber 12 is effectively used for reforming the reformed gas.

  The combustion gas generated in the power generation / combustion chamber 12 flows into the discharge passage 30 from the discharge opening 42 formed in the heat exchanger 24, and flows through the discharge passage 30 extending in a zigzag shape. 50 is discharged through a discharge passage defined between the outer cylinder member 52 and the inner cylinder member 54. When the combustion gas flows through the discharge path in the double cylinder 50, the oxygen-containing gas flows through the inflow path in the double cylinder 50, and heat exchange is performed between the combustion gas and the oxygen-containing gas.

  In addition, when the combustion gas is caused to flow in the exhaust passage 30 of the heat exchanger 24 in a zigzag manner, the oxygen-containing gas is caused to flow in the inflow passage 32 of the heat exchanger 24 in a zigzag manner. Thus, heat is effectively exchanged between the combustion gas and the oxygen-containing gas, and the oxygen-containing gas is preheated. The oxygen-containing gas is heated by the high temperature in the power generation / combustion chamber 12 even when passing through the upper gas chamber 16, the communication gas chamber 18, and the lower gas chamber 14.

  When a part or all of the cell stacks 60a, 60b, 60c, and 60d deteriorate due to power generation over a long period of time, the front wall (not shown) or the rear wall (not shown) of the storage container 2 is shown. The power generation units 56a, 56b, 56c and 56d are partly or entirely removed from the storage container 2.

  Then, replace some or all of the power generation units 56a, 56b, 56c and 56d with new ones, or only the cell stacks 60a, 60b, 60c and 60d in some or all of the power generation units 56a, 56b, 56c and 56d. May be replaced with a new one and mounted again at a required position in the storage container 2. Even when it is necessary to replace the reforming catalyst accommodated in the reforming cases 78a, 78b, 78c and 78d in some or all of the power generation units 56a, 56b, 56c and 56d, the power generation units 56a, 56b , 56c and 56d are taken out from the storage container 2 and the reforming cases 78a, 78b, 78c and 78d themselves in the power generation units 56a, 56b, 56c and 56d are replaced with new ones or reformed. Only the reforming catalyst in the cases 78a, 78b, 78c and 78d may be replaced with a new one.

  In order to be able to perform the replacement of the reforming catalyst in the reforming cases 78a, 78b, 78c and 78d sufficiently easily, a part of the reforming cases 78a, 78b, 78c and 78d can be opened and closed if desired. It can be put on the door.

  In the fuel cell of the present invention, the fuel cell 62 is erected on the fuel gas tank 58 and burns in the vicinity of the tip of the fuel cell 62, but the tip of the fuel cell 62 is the non-power generation part A. Therefore, even if any trouble occurs at the tip of the fuel cell 62, the power generation performance can be stabilized without substantially affecting the power generation performance.

  Further, since the heat of the combustion gas combusted in the vicinity of the upper end of the fuel cell 62 heats the entire chamber of the storage container 2 in which the fuel cell 62 is stored, the fuel cell 62 can be heated quickly, and the fuel cell The startup time until the cell 62 generates power can be shortened.

  In addition, this invention is not limited to the said form, A various change is possible in the range which does not change the summary of invention. For example, in the above embodiment, the example in which the fuel cells 62 are connected in series has been described, but it is needless to say that they may be connected in parallel. Further, although the fuel side electrode 66 is an inner electrode, the oxygen side electrode may be an inner electrode.

  Further, for example, the present invention has been described in relation to a fuel cell provided with a substantially rectangular parallelepiped storage container. However, the multiple cylindrical shape disclosed in the specification and drawings of Japanese Patent Application No. 2000-292234 relating to the application of the present applicant. Of course, the present invention can also be applied to a fuel cell having a storage container of another appropriate form such as a storage container composed of a body.

  Further, in the above example, the case where the oxygen-containing gas is supplied to each fuel cell 62 through the upper gas chamber 16, the communication gas chamber 18, the lower gas chamber 14, and the gas ejection plate 22 has been described. An oxygen-containing gas supply pipe connected to the gas chamber may be provided between the cell stacks through the combustion region. In the conventional case where the partition plate is disposed in the storage container, it is necessary to supply the oxygen-containing gas between the fuel cells by inserting the oxygen-containing gas supply pipe through the partition plate. Although the heating of the contained gas supply pipe was performed only partially, in the present invention, there is no partition plate, and the entire fuel cell and the oxygen containing gas supply pipe are disposed in the same chamber, so the combustion gas The entire oxygen-containing gas supply pipe can be heated by heating the oxygen-containing gas in the oxygen-containing gas supply pipe, whereby the fuel battery cell can be heated from the outside, and the startup time until the fuel battery cell generates power is further increased. Can be shortened.

1 is a cross-sectional view illustrating a preferred embodiment of a fuel cell configured according to the present invention. FIG. 2 is a perspective view showing the fuel cell of FIG. 1 with a part thereof omitted. The slope view which shows suitable embodiment of the electric power generation unit currently used for the fuel cell of FIG. Sectional drawing which shows the cell stack in the electric power generation unit of FIG. (A) is a side view showing a state of burning near the tip of a fuel cell, (b) is a side view showing an enlarged tip of the fuel cell.

Explanation of symbols

2: Storage container 12: Power generation / combustion chamber 58: Fuel gas tank 62: Fuel cell 64: Support body 66: Fuel side electrode (inner electrode)
68: Solid electrolyte 70: Oxygen side electrode (outer electrode)
74: Fuel gas passage A: Non-power generation part Y: Chamfering part

Claims (5)

A fuel battery cell and a gas tank in which one end portion in the axial length direction of the fuel battery cell is attached and a plurality of the fuel battery cells are erected are stored in the same chamber of the storage container, and in the vicinity of the tip of the fuel battery cell The gas passing through the fuel cell from the gas tank and the gas passing between the fuel cells react and burn, and the tip of the fuel cell is a non-power generation unit. A fuel cell. 2. The fuel cell according to claim 1, wherein the fuel cell is formed by sequentially forming an inner electrode, a solid electrolyte, and an outer electrode on a support capable of passing gas in the axial direction. 3. The fuel cell according to claim 1, wherein the fuel cell is flat and has a plurality of gas passages formed at predetermined intervals in the width direction and extending in the axial length direction. The fuel cell according to any one of claims 1 to 3, wherein the corner portion of the fuel cell is chamfered. The fuel cell according to any one of claims 1 to 4, wherein the fuel cell is formed by sequentially forming a fuel side electrode, a solid electrolyte, and an oxygen side electrode on a surface of a conductive support. .

Images