JP2005158525A - Fuel cell assembly - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell assembly capable of lowering temperature differences around a fuel cell stack. <P>SOLUTION: The fuel cell assembly made by housing a fuel cell stack 57 inside a housing 2, has gas supply channels 80a, 80c, 82a, 82b, 82c, 82d for supplying gas to the fuel cell stack 57. The plurality of gas supply channels 80a, 80c, 82a, 82b, 82c 82d are arranged in opposition to each other around the fuel cell stack 57. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a fuel cell assembly, and more particularly to a fuel cell assembly suitably used in the configuration of a fuel cell power generation system such as a solid oxide fuel cell power generation system.

  In recent years, various types of fuel cell power generation systems such as solid polymer type, phosphoric acid type, molten carbonate type, and solid electrolyte type have been proposed as next-generation energy. In particular, the solid oxide fuel cell power generation system has an operating temperature as high as about 1000 ° C., but has advantages such as high power generation efficiency and use of exhaust heat, and research and development are being promoted.

In a typical example of a fuel cell power generation system, a fuel cell assembly including a housing defining a power generation chamber and a cell stack disposed in the housing is provided (Patent Document 1). Such a fuel cell assembly is provided with fuel gas supply means for supplying fuel gas to the cell stack and oxygen-containing gas supply means for supplying oxygen-containing gas to the cell stack.
JP 2000-149976 A

  However, in the fuel cell assembly described above, the fuel gas supply means and the oxygen-containing gas supply means for the stack provided in the power generation chamber are provided on one side of the cell stack, and are therefore introduced into the cell stack. Since the low-temperature gas before being biased is biased toward one direction of the power generation chamber (around the cell stack), a phenomenon occurs in which the temperature on the gas introduction side in the power generation chamber decreases. When the temperature distribution in the power generation chamber, that is, around the cell stack, increases, the power generation performance of the fuel cell in the low temperature portion decreases, and the performance of the entire fuel cell also decreases. In order to avoid this, it is not preferable to raise the overall temperature because the temperature of the high temperature part exceeds the heat resistance temperature of the metal material used in the fuel cell. Therefore, a structure of a power generation chamber in which the temperature distribution of the power generation chamber is reduced has been awaited. In particular, the gas introduction side to the cell stack and the gas outlet side from the cell stack, that is, the side portion of the cell stack in the gas outlet direction, has little influence on the power generation performance due to the temperature distribution. Since the temperature distribution in the side portion of the orthogonal cell stack directly affects the power generation performance, it has been desired to reduce the temperature distribution in this portion.

  An object of the present invention is to provide a fuel cell assembly that can reduce a temperature difference around the fuel cell stack.

  The inventor arranges a plurality of gas supply paths such as a fuel gas, an oxygen-containing gas, a reformed gas, and a reformed gas so as to face the periphery of the fuel cell stack. The present inventors have found that the temperature difference between the two can be reduced, the temperature of the plurality of fuel cells of the fuel cell stack can be made substantially uniform, and the power generation performance can be made uniform, and the present invention has been achieved.

  That is, the fuel cell assembly of the present invention is a fuel cell assembly comprising a fuel cell stack housed in a housing and having a gas supply path for supplying gas to the fuel cell stack, wherein a plurality of the gas supply assemblies are provided. The path is arranged so as to face the periphery of the fuel cell stack.

  In such a fuel cell assembly, the gas supply path for supplying the oxygen-containing gas, the fuel gas, and the reformed gas is disposed so as to face the periphery of the fuel cell stack. The temperature range that is lowered by the road is distributed around the fuel cell stack and is not biased to one side, so that the temperature difference around the fuel cell stack can be reduced. For this reason, the dispersion | variation in the electric power generation performance of the fuel cell in a fuel cell stack can be made small.

  The fuel cell assembly according to the present invention is characterized in that a gas supply path is disposed on the side of the fuel cell stack in a direction orthogonal to the direction of gas discharge from the fuel cell stack. In such a fuel cell assembly, in the gas outlet direction, the fuel gas heated to a high temperature by the combustion part at the upper part of the cell is led out, so there is almost no temperature drop and it does not contribute much to power generation. The side of the fuel cell stack in the direction orthogonal to the lead-out direction is a portion where the temperature tends to decrease due to the existence of a low-temperature gas supply path and contributes greatly to power generation. By dispersively arranging the fuel cell stack to the side, the temperature range that is lowered by the low temperature gas supply path can be dispersed around the fuel cell stack, and the fuel cell stack is not biased to one side. The temperature difference in the surroundings can be reduced.

  Furthermore, the fuel cell assembly of the present invention is characterized in that the fuel cell stack has a manifold in which a plurality of fuel cells are provided at predetermined intervals, and a gas supply path is connected to the manifold. To do. In such a fuel cell assembly, low-temperature gas is not supplied directly to the fuel cell stack, but is performed via the gas manifold, so that the fuel cell end on the gas introduction side and the fuel cell on the gas outlet side The temperature difference at the end can be reduced.

  The fuel cell assembly according to the present invention includes a cell stack in which a plurality of fuel cells are arranged in tandem at predetermined intervals, and a gas supply disposed in the cell arrangement direction of the cell stack. A plurality of power generation units having a road are arranged in parallel. In such a fuel cell assembly, since the fuel cell stack is composed of a plurality of power generation units and dispersed, the temperature difference due to the low temperature gas supply path can be reduced, and even if any trouble occurs in the power generation unit, Only the power generation unit can be replaced.

  Furthermore, in the fuel cell assembly of the present invention, each of the plurality of power generation units has a gas supply path, and the gas supply path of the first power generation unit is a second power generation unit adjacent to the first power generation unit. It is provided on the side opposite to the position where the gas supply path is arranged. Furthermore, it is desirable that adjacent cell stacks are electrically connected in series.

  In such a fuel cell assembly, by producing a plurality of power generation units of the same type and reversing the arrangement direction, the fuel cell assembly of the present invention can be easily produced, and the fuel cell stack Since it is composed of a plurality of power generation units, the temperature difference can be further reduced as described above. In addition, by electrically connecting the same side of the cell stacks of the adjacent power generation units whose arrangement direction is reversed, the fuel cells can be connected in series and a high voltage can be obtained.

  Furthermore, in the fuel cell assembly of the present invention, the power generation unit has a reformer above the cell stack, and the gas supply path of the gas to be reformed is connected to the reformer via the side of the cell stack. It is connected. Furthermore, it is desirable that a gas supply path for the reformed fuel gas from the reformer is introduced into the fuel cell via the side of the cell stack.

  In such a fuel cell assembly, the gas to be reformed is generally supplied from the outside to the reformer through the side of the cell stack, and is therefore lower in temperature than the ambient temperature. Can be used.

  Furthermore, the fuel cell assembly of the present invention is characterized in that a gas supply path is extended from a reformer provided outside the housing. Since the fuel gas reformed by the reformer provided outside the housing is cooled before being supplied to the fuel cell stack, the present invention can be suitably used.

  In the fuel cell assembly of the present invention, the gas supply path for supplying the oxygen-containing gas, fuel gas, reformed gas, etc. is disposed so as to face the periphery of the fuel cell stack. The temperature range that is lowered by is distributed around the fuel cell stack and is not biased to one side, and the temperature difference around the fuel cell stack can be reduced. For this reason, the dispersion | variation in the electric power generation performance of the fuel cell in a fuel cell stack can be made small.

  The fuel cell assembly of the present invention will now be described in more detail with reference to the accompanying drawings.

  Referring to FIGS. 1 and 2, the illustrated fuel cell assembly includes a housing 2 having a substantially rectangular parallelepiped shape. The six wall surfaces of the housing 2 are heat insulating walls formed of an appropriate heat insulating material, 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). ) And a rear heat insulating wall (not shown). A power generation / combustion chamber 12 is defined in the housing 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 housing 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 in the housing 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 housing 2, more specifically, inside the right heat insulating wall 8 and inside the left heat insulating 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. The combustion gas discharge passage 30 may have a form other than the zigzag flow passage if desired.

  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. Note that the inflow channel 32 may have a form other than the zigzag type if desired.

  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 of the fuel cell assembly shown in the drawing 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. Therefore, the details of the configuration described above are left to the specification and drawings of Japanese Patent Application No. 2003-295790, and the description thereof is 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, and are arranged in parallel at a predetermined interval. Is configured. 5 together with FIGS. 1 and 2, the power generation unit 56a includes a rectangular parallelepiped fuel gas case 58a extending in the front-rear direction (direction perpendicular to the paper surface in FIG. 1).

  A cell stack 60a is mounted on the upper surface of the fuel gas manifold 58a that defines the fuel gas chamber 59a. The cell stack 60a is formed by arranging a plurality of plate-like and column-like upright cells 62 extending vertically in the vertical direction in the longitudinal direction (that is, the front-rear direction) of the fuel gas manifold 58a. The arrangement direction of the fuel cells 62 and the arrangement direction of the power generation units 56 are orthogonal to each other. Each of the cells 62 includes an electrode support substrate 64, a fuel electrode layer 66 as an inner electrode layer, a solid electrolyte layer 68, an oxygen electrode layer 70 as an outer electrode layer, and an interconnector 72, as clearly shown in FIG. It is configured.

  The electrode support substrate 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. A plurality (four in the illustrated example) of fuel gas passages 74 penetrating through the electrode support substrate 64 in the vertical direction are formed. Each of the electrode support substrates 64 is joined to the upper wall of the fuel manifold 58a by, for example, a ceramic adhesive having excellent heat resistance.

  On the upper wall of the fuel gas manifold 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 connected to each of the slits, and thus to the fuel gas chamber 59a.

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

  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 electrode layer 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, and the electric power extraction means is the front wall (not shown) and / or the rear wall of the housing 2. It extends outside the housing 2 (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 electrode support substrate 64 is gas permeable to allow fuel gas to permeate to the anode layer 66, and is also conductive to collect current through the interconnector 72. Can be formed from a porous conductive ceramic (or cermet) that satisfies such requirements.

  In order to manufacture the electrode support substrate 64 by simultaneous firing with the fuel electrode layer 66 and / or the solid electrolyte layer 70, it is preferable to form the electrode support substrate 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 electrode layer 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 layer 68 has a function as an electrolyte that bridges electrons between the electrodes, and at the same time has a gas barrier property to prevent leakage between the fuel gas and the oxygen-containing gas. It is necessary and is usually formed from ZrO ₂ in which ₃ to 15 mol% of a rare earth element is dissolved.

The oxygen electrode layer 70 can be formed of a conductive ceramic made of a so-called ABO ₃ type perovskite oxide. The oxygen electrode layer 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%.

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 interconnector 72 must be dense to prevent leakage of fuel gas passing through the fuel gas passage 74 formed in the electrode support substrate 64 and oxygen-containing gas flowing outside the electrode support substrate 64, and 93% As described above, it is particularly desirable to have a relative density of 95% or more.

  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 and 5, the power generation unit 56 a has a rectangular shape (or cylindrical shape) that is elongated in the front-rear direction above the cell stack 60 a. A case 78a is also provided. One end, that is, the upper end of the fuel gas supply pipe 80a for the reformed fuel gas is connected to the side 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 manifold 58a. One end of a reformed gas supply pipe 82a to be reformed is connected to the rear surface of the reforming case 78a. The to-be-reformed gas supply pipe 82 a extends downward from the reforming case, and extends under the housing 2 and out of the housing 2. The insides of the fuel gas supply pipe 80a and the reformed gas supply pipe 82a are gas supply paths.

  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 manifold 58a via the fuel gas supply pipe 80a and is held in a required position by this, but if necessary, the two-dot chain line in FIG. For example, an appropriate support member 84a can 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 manifold 58a.

  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 assembly as described above, the gas to be reformed is supplied to the reforming cases 78a, 78b, 78c and 78d through the gas to be reformed supply pipes 82a, 82b, 82c and 82d, and the reforming case 78a. , 78b, 78c and 78d, the fuel defined in the fuel gas manifolds 58a, 58b, 58c and 58d through the fuel gas feed pipes 80a, 80b, 80c and 80d after being reformed into hydrogen-rich fuel gas. The gas chambers 59a, 59b, 59c and 59d are supplied 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, at the oxygen 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 housing 2 is shown. The power generation units 56 a, 56 b, 56 c and 56 d are partially or entirely removed from the housing 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 housing 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 removed from the housing 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 reforming cases. Only the reforming catalyst in 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 assembly according to the present invention, as shown in FIG. 6, gas supply paths 80 a, 80 b, 80 c, and 80 d are disposed so as to face the periphery of the fuel cell stack 57. That is, the fuel gas supply paths 80a, 80b, 80c, and 80d are alternately arranged on the side surface side (side surface side in the arrangement direction of the fuel cell 60) of the fuel cell stack 57 facing each other. Further, the reformed gas supply pipes 82a, 82b, 82c, and 82d of the fuel gas to be reformed are alternately arranged on the side surfaces facing the fuel cell stack 57, and these reformed gas supply pipes are provided. The pipes 82a, 82b, 82c and 82d are alternately arranged with the fuel gas supply paths 80a, 80b, 80c and 80d on one and the other side surfaces.

  3, the power generation unit 56c is substantially the same as the power generation unit 56a described above, and the power generation units 56b and 56d are arranged in the front-rear direction opposite to the power generation units 56a and 56c. Accordingly, a fuel gas supply pipe (not shown) connecting the reforming cases 78b and 78d and the fuel gas manifolds 58b and 58d is disposed on the rear side, and the reformed gas supply pipes 82b and 82d are connected to the reforming case. It extends downward and extends under the housing 2 to the outside of the housing 2.

  In such a fuel cell assembly, the reformed gas introduced into the reforming cases 78a, 78b, 78c and 78d through the reformed gas supply pipes 82a, 82b, 82c and 82d is usually from the outside of the housing 2. Since the reformed gas supply pipes 82a, 82b, 82c and 82d are alternately arranged on the opposite side surfaces of the fuel cell stack 57, the temperature difference around the fuel cell stack 57 can be reduced. In particular, it is possible to reduce the temperature difference at the side of the fuel cell that contributes substantially to power generation, and to reduce the variation in power generation performance of the fuel cells in the fuel cell stack.

  Further, since the fuel gas supply passages 80a, 80b, 80c, and 80d for supplying the fuel gas are disposed so as to face the periphery of the fuel cell stack 57, the temperature difference around the fuel cell stack 57 is further reduced. it can.

  The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to such embodiments, and various modifications and corrections can be made without departing from the scope of the present invention. It goes without saying that this is possible.

  For example, the present invention has been described in connection with a fuel cell assembly having a specific reforming case above the cell stack, but the gas supply to the reforming case is possible even when the reforming case is not above the cell stack. Of course, it is only necessary that the paths are provided at opposite positions around the fuel cell stack.

  Further, even when a reformed gas introduced from the outside is directly introduced into the fuel cell to generate electric power, it is needless to say that the gas supply path only needs to be provided at opposing positions around the fuel cell stack. It is.

  Furthermore, when the gas from the outside is other than the gas to be reformed, for example, when hydrogen gas is directly introduced into the cell stack, the gas supply passages are provided at opposing positions around the fuel cell stack. Of course it is good. Thus, the present invention can be suitably used when a gas supply path for gas supplied from the outside into the housing is disposed around the fuel cell stack. For example, the present invention can be used even when a reformer is provided outside the housing and the fuel gas reformed by the reformer is supplied into the housing.

  Although the present invention has been described in relation to a fuel cell assembly having a substantially rectangular parallelepiped housing with a specific heat exchanger, the specification and drawings of Japanese Patent Application No. 2000-292234 relating to the applicant's application have been described. The present invention can also be applied to a fuel cell assembly including a housing of another appropriate form such as a housing constituted of a disclosed multiple cylindrical body.

  Furthermore, although the gas supply pipe for supplying the fuel gas is disposed at the position facing the fuel cell stack, the gas supply pipe for supplying the oxygen-containing gas may be disposed at the position facing the fuel cell stack. Of course.

1 is a cross-sectional view illustrating a preferred embodiment of a fuel cell assembly configured in accordance with the present invention. The perspective view which abbreviate | omits one part and shows the fuel cell assembly of FIG. The perspective view which shows the fuel cell stack used for the fuel cell assembly of FIG. Sectional drawing which shows the cell stack in the fuel cell stack of FIG. The perspective view which shows the electric power generation unit of FIG. The plane conceptual diagram which shows the arrangement | positioning state of a gas supply path.

Explanation of symbols

2: Housing 56a, 56b, 56c and 56d: Power generation unit 57: Fuel cell stack 58a, 58b, 58c and 58d: Fuel gas manifold 60a, 60b, 60c and 60d: Cell stack 78a, 78b, 78c and 78d: Reforming case (Reformer)
80a and 80c: Fuel gas supply pipe (gas supply path)
82a, 82b, 82c, 82d: Reformed gas supply pipe (gas supply path)

Claims (9)

A fuel cell assembly comprising a fuel cell stack housed in a housing and having a plurality of gas supply paths for supplying gas to the fuel cell stack, wherein the plurality of gas supply paths are arranged around the fuel cell stack. A fuel cell assembly, wherein the fuel cell assembly is disposed so as to face the surface. 2. The fuel cell assembly according to claim 1, wherein a gas supply path is disposed on a side of the fuel cell stack in a direction orthogonal to a direction of gas discharge from the fuel cell stack. The fuel cell set according to claim 1 or 2, wherein the fuel cell stack has a manifold in which a plurality of fuel cells are provided at a predetermined interval, and a gas supply path is connected to the manifold. Solid. The fuel cell stack includes a plurality of power generation units arranged in parallel, each having a cell stack in which a plurality of fuel cells are arranged in tandem at predetermined intervals, and gas supply paths arranged in the cell arrangement direction of the cell stack. The fuel cell assembly according to any one of claims 1 to 3, wherein the fuel cell assembly is provided. Each of the plurality of power generation units has a gas supply path, and the gas supply path of the first power generation unit is on the opposite side of the gas supply path of the second power generation unit adjacent to the first power generation unit. The fuel cell assembly according to claim 4, wherein the fuel cell assembly is provided. 6. The fuel cell assembly according to claim 4, wherein adjacent cell stacks are electrically connected in series. The power generation unit includes a reformer above the cell stack, and a gas supply path for a gas to be reformed is connected to the reformer via a side of the cell stack. The fuel cell assembly according to any one of 4 to 6. 8. The fuel cell assembly according to claim 7, wherein a gas supply path for the reformed fuel gas from the reformer is introduced into the fuel cell via the side of the cell stack. 7. The fuel cell assembly according to claim 1, wherein the gas supply path extends from a reformer provided outside the housing.

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