JP4863600B2 - Fuel cell assembly - Google Patents

Description

The present invention relates to a fuel cell assembly, and more particularly relates to a fuel cell assembly suitable for use in construction of such a fuel cell power generation system of the solid electrolyte fuel cell power generation system.

As a next-generation energy, in recent years, a polymer electrolyte, phosphoric acid, and various types fuel cell power generation system, such as molten carbonate and solid oxide has been proposed. In particular, the solid electrolyte fuel cell power generation system is operating temperatures as high about 1000 ° C., the power generation efficiency is high, has the advantages such is possible waste heat utilization, research and development has been promoted.

In a typical example of a fuel cell power generation system, as described in Patent Document 1 below, a fuel cell assembly including a housing defining a power generation chamber and a cell stack disposed in the housing is provided. ing. Such a fuel cell assembly is provided with fuel gas supply means for supplying fuel gas to the cell stack and air supply means for supplying air to the cell stack.
JP 2000-182641 A

  However, in the fuel cell assembly as in Patent Document 1 described above, when power is generated by flowing current through the fuel cell, a phenomenon occurs in which the temperature in the power generation chamber that houses the cell stack rises above the desired power generation chamber temperature. There is a case. This is due to the fact that Joule heat and reaction heat are generated in the power generation part of the fuel cell by causing the current to flow through the fuel cell and the heat stays in the power generation chamber where the fuel cell is concentrated. It is.

  In order to prevent this temperature rise, it is conceivable to supply cooled (room temperature) air directly between the fuel cells in the power generation chamber. However, if low-temperature air is allowed to flow in the vicinity of the fuel cells, the hot fuel cells Due to the rapid cooling, there is a danger that a tensile stress is generated on the cell surface and a crack is generated. The occurrence of cracks in the fuel cell must be avoided because it immediately leads to functional deterioration of the entire fuel cell power generation system.

The present invention aims to provide a fuel cell assembly and a fuel cell power generation assembly temperature rise can be suppressed in the vicinity thereof.

  As a result of diligent research, the present inventor has supplied a low-temperature gas of the same type as the stored gas to the gas chamber in which the fuel gas or oxygen-containing gas heated by heat exchange is once stored. It was found that the temperature of the fuel cell assembly and the temperature in the vicinity thereof can be effectively reduced without causing cracks or the like in the cell by reducing the temperature of the fuel cell.

That is, the fuel cell assembly of the present invention, in a housing provided with a gas chamber to be supplied by the fuel gas or oxygen-containing gas is heated heating gas supply means, the fuel gas or oxygen is heated from the gas chamber A fuel cell assembly in which a plurality of cell stacks are arranged by arranging a plurality of fuel cells that are supplied with contained gas to generate power,
Low-temperature gas supply means comprising a low-temperature gas supply pipe that supplies a gas of the same type as the gas supplied to the gas chamber at a lower temperature than the heated fuel gas or oxygen-containing gas in the gas chamber Is provided separately from the heating gas supply means to the gas chamber, and the low temperature gas supply pipe is a central portion of the cell stack provided in the housing in the arrangement direction of the fuel cell. It is connected to the gas chamber so as to cool the central portion in the arrangement direction .

In such a fuel cell assembly, during normal operation, for example, fuel gas or oxygen-containing gas preheated by a heat exchanger is introduced into the gas chamber, and the fuel cell in the power generation chamber is used from the gas chamber using gas supply means. Gas is introduced into the cell assembly, but if the temperature of the fuel cell assembly and / or its vicinity rises more than expected, low temperature gas is supplied to the gas chamber by the low temperature gas supply means and heated (preheated). ) Is mixed with the fuel gas or oxygen-containing gas, the temperature of the gas chamber is lowered to some extent, and this low temperature gas can be supplied to the fuel cell, and the power generation chamber (fuel cell assembly and its vicinity) Therefore, the temperature rise in the power generation chamber can be appropriately controlled.
Further, in such a fuel cell assembly, the center portion of the cell stack in the arrangement direction and the center portion of the fuel cell in the arrangement direction are most easily heated, but the low temperature gas supply pipe is provided in the housing. Since it is connected to the gas chamber so as to cool the central portion of the cell stack in the arrangement direction and the central portion of the fuel cell in the arrangement direction , this portion can be cooled most, so that the temperature of the fuel cell is uniform. Can be achieved.

  Also, since the preheated fuel gas or oxygen-containing gas and the low temperature gas supplied by the low temperature gas supply means are mixed, the mixed gas is not so low in temperature. The cell does not generate much thermal stress, can suppress the occurrence of cracks due to thermal shock, etc., suppress the functional deterioration of the entire fuel cell power generation system, and extend the life.

The fuel cell assembly of the present invention, the oxygen-containing gas heated in the gas chamber has a valve and Turkey supplied. The gas in the gas chamber is preferably supplied between the fuel cells. In such a fuel cell assembly, even if the airtight structure of the housing is not so perfect, since the outside of the fuel cell is an oxygen-containing gas, it is safe to escape from the housing, and is low-cost and safe. A fuel cell assembly can be supplied.

In the fuel cell assembly of the present invention, the heating gas supply means is a heat exchanger, and the heat exchanger is accommodated in the housing, and burns fuel gas that has not been used for power generation. and resulting combustion gas, and performs heat exchange with the fuel gas or oxygen-containing gas, wherein the fuel gas or oxygen-containing gas is heated by heat exchange is supplied to the gas chamber. In such a fuel cell assembly, heat exchange efficiency is improved because heat loss in the piping is reduced compared to a mode in which heat is exchanged by a heat exchanger separately installed outside the housing, and heat self-sustaining power generation is achieved. A suitable housing structure can be supplied.

In the fuel cell assembly of the present invention, during normal operation, for example, fuel gas or oxygen-containing gas preheated by a heat exchanger is introduced into the gas chamber, and the fuel in the power generation chamber is supplied from the gas chamber using gas supply means. Gas is introduced into the battery cell assembly, but when the temperature of the fuel cell assembly and / or its vicinity rises more than expected, a low temperature gas is supplied to the gas chamber by the low temperature gas supply means and heated ( It is mixed with preheated fuel gas or oxygen-containing gas, the temperature of the gas chamber is lowered to some extent, and this low temperature gas can be supplied to the fuel cell, and the power generation chamber (fuel cell assembly and its vicinity) ) Is suppressed, and the temperature in the power generation chamber can be appropriately controlled.
Further, since the low temperature gas supply pipe is connected to the gas chamber so as to cool the central portion in the arrangement direction of the cell stack provided in the housing and the central portion in the arrangement direction of the fuel cells. The battery cells can be made uniform in temperature.

  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, 2 and 3, 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 9, a front heat insulating wall 10, and a rear heat insulating wall. 11 is disposed. 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 removably mounted, and the power generation / combustion chamber 12 can be accessed by detaching or opening the front heat insulation wall 10 and / or the rear heat insulation wall 11. it can. 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.

  An air chamber (gas chamber) 16 is disposed at the upper end of the housing 2. The air chamber 16 is defined in a rectangular parallelepiped case 17 having a relatively small vertical dimension. The air chamber 16 communicates with an air introduction pipe (gas supply means) 22 for sending air (oxygen-containing gas) toward the power generation / combustion chamber. There are a plurality of air introduction pipes 22 and the shape thereof may be a cylinder or a hollow plate structure. The air introduction pipe 22 is disposed between the cell stacks described later, and has an opening at the lower end portion of the cell, and air is ejected from the opening portion. The air introduction tube 22 is preferably made of a material having high heat resistance such as ceramics.

  In the fuel cell assembly of the present invention, the air chamber 16 is provided with a low-temperature gas supply means including a low-temperature gas supply pipe 18. The low-temperature gas supply pipe 18 penetrates the upper heat insulating wall 4 and is externally provided. It is extended to.

  The low-temperature gas supply pipe 18 supplies the same type of gas as that supplied into the air chamber 16, that is, low-temperature air, into the air chamber 16. The air supplied through the low-temperature gas supply pipe 18 is It must be cooler than the temperature of the preheated air. In particular, about room temperature is desirable.

  As shown in FIG. 2, the low temperature gas supply pipe 18 is connected to a position of the air chamber 16 that cools the power generation units 56a, 56b, 56c, and 56d, that is, the central portion of the fuel cell assembly. In other words, the air introduction pipe 22 disposed between the power generation units 56a, 56b, 56c, and 56d has a low temperature so as to open at the position of the opposing case 17 side plate with respect to the center of the opening assembly to the case 17 side plate. A gas supply pipe 18 is provided.

  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 9. 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. Three 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. If desired, a form other than the zigzag flow path may be used.

  Similarly, the three 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. If desired, a form other than the zigzag flow path may be used.

  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, a heat insulating member 44 is disposed between each of the heat exchangers 24 and the power generation / combustion chamber 12, and the upper end of the heat insulating member 44 is substantially the same as the lower edge of the discharge opening 42. The discharge opening 42 is communicated with the power generation / combustion chamber 12 through a space remaining above the heat insulating member 44.

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 air chamber 16 through the inflow opening 48. The heat exchanger 24 and the inflow opening 48 constitute heated gas supply means. 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 in the lower part of the above-described power generation / combustion chamber. The power generation units 56a, 56b, 56c, and 56d are respectively positioned between the air introduction pipes 22 described above. In other words, the air introduction pipe 22 is disposed between the power generation units 56a, 56b, 56c and 56d. 3 and 4 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 case 58a that defines the fuel gas chamber. 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 case 58a (that is, in the front-rear direction). As clearly shown in FIG. 5, each cell 62 includes an electrode support substrate 64, a fuel electrode layer 66 that is an inner electrode layer, a solid electrolyte layer 68, an oxygen electrode layer 70 that is an outer electrode layer, and an interconnector 72. Has been.

  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. The electrode support substrate 64 is formed with a plurality (six in the illustrated example) of fuel gas passages 74 penetrating the electrode support substrate 64 in the vertical direction. Each of the electrode support substrates 64 is bonded to the upper wall of the fuel gas case 58a by, for example, a ceramic adhesive having excellent heat resistance.

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

  The interconnector 72 is disposed on one side of the electrode support substrate 64 (upper surface in the cell stack 60a in FIG. 5). The fuel electrode layer 66 is disposed on the other surface (the lower surface in the cell stack 60a of FIG. 5) 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 end and the lower end 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 heat insulation wall 10 and / or the rear heat insulation wall 11 of the housing 2, or The outer heat insulating wall 6 extends outside the housing 2. 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 cell 62 by co-firing with the fuel electrode layer 66 and / or the solid electrolyte layer 68, it is preferable to form the electrode support substrate 64 from the iron group metal component and the specific rare earth oxide. In order to provide the required gas permeability, it is preferred 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 S / 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 for bridging electrons between electrodes, and at the same time needs to have a gas barrier property in order to prevent leakage between fuel gas and air. In general, it is 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 a reduction resistance and an oxidation resistance in order to come into contact with a fuel gas and air that may be hydrogen gas. A perovskite oxide (LaCrO ₃ oxide) is preferably used. The interconnector 72 must be dense in order to prevent leakage of fuel gas passing through the fuel gas passage 74 formed in the electrode support substrate 64 and air flowing outside the electrode support substrate 64, and is 93% or more. In particular, it is desired 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 FIG. 4, the power generation unit 56 a also includes a reforming case 78 a that is preferably a rectangular shape (or a cylindrical shape) that extends elongated in the front-rear direction above the cell stack 60 a. ing. One end, that is, the upper end of the fuel gas supply pipe 80a is connected to the front surface 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 82 a extends downward from the reforming case, and extends under the housing 2 and out of the housing 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 case 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 lower surface or rear surface of the rear end portion of the fuel gas case 58a.

  Referring to FIG. 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 disposed in the front-rear direction opposite to the power generation units 56a and 56c. Fuel gas supply pipes (not shown) connecting the quality cases 78b and 78d and the fuel gas cases 58b and 58d are arranged on the rear side, and the reformed gas supply pipes 82b and 82d are located downward from the reforming case. It extends under the housing 2 and extends out of the housing 2.

  In the fuel cell assembly as described above, the gas to be reformed is supplied to the reforming cases 78a, 78b, 78c and 78d via 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 cases 58a, 58b, 58c and 58d through the fuel gas supply pipes 80a, 80b, 80c and 80d after being reformed into hydrogen-rich fuel gas. It is supplied to the gas chamber and then supplied to the cell stacks 60a, 60b, 60c and 60d.

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.

  Fuel gas and air that have flown upward from the cell stacks 60a, 60b, 60c and 60d without being used for power generation are ignited by an ignition means (not shown) disposed in the power generation / combustion chamber 12 at the time of startup. It is ignited and burned. As is well known, the power generation / combustion chamber 12 has a high temperature of, 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 air. 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, air flows through the inflow path in the double cylinder 50, and heat exchange is performed between the combustion gas and air.

  Further, when the combustion gas is caused to flow in the exhaust passage 30 of the heat exchanger 24 in a zigzag manner, the air 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 air to preheat the air.

  When part or all of the cell stacks 60a, 60b, 60c and 60d deteriorates due to power generation over a long period of time, the front heat insulation wall 10 or the rear heat insulation wall 11 of the housing 2 is detached or opened. Part or all of the power generation units 56 a, 56 b, 56 c and 56 d are taken out 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.

  On the other hand, 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 is preheated (heated) through the heat exchanger 24. Is temporarily stored in the air chamber 16 and supplied between the cell stacks of the combustion / power generation chamber 12 through the air introduction pipe 22. At this time, the air introduction pipe 22 passes through the combustion gas atmosphere that burns in the vicinity of the fuel gas passage 74 at the upper end of the fuel cell 62 of the cell stack 60. Accordingly, the preheated air in the air chamber 16 is further heated in the combustion region above the cell stack 60, and the air heated to a high temperature is supplied to the cell.

  During normal operation, air preheated by the heat exchanger 24 is introduced into the air chamber 16, and air is introduced from the air chamber 16 into the combustion / power generation chamber 12 using the air introduction pipe 22. When the temperature rises more than expected, the low-temperature air that has passed through the low-temperature gas supply pipe 18 without passing through the heat exchanger 24 is introduced into the air chamber 16 and preheated through the heat exchanger 24. And the air temperature of the air chamber 16 is reduced to some extent. By supplying this air between the power generation chambers 12, that is, between the cell stacks, air having a lower temperature than that during normal operation is introduced between the cell stacks. Therefore, a good fuel cell assembly that can appropriately control the temperature in the power generation chamber is provided.

  Moreover, since the air temperature in the air chamber 16 is mixed with the outside air supplied from the low temperature gas supply pipe 18 and the air preheated through the heat exchanger 24, the air temperature is not as low as room temperature. Even if the fuel cell 60 is supplied to the hot fuel cell 60, it is possible to avoid problems such as cracks and thermal shock destruction of the fuel cell 60, so that the deterioration of the function of the entire fuel cell power generation system can be suppressed and the life can be extended. .

Further, by supplying the supply of the low temperature gas from the low temperature gas supply pipe 18 toward the central portion of the opening of the air supply pipe 22, it is possible to provide the center portion in the arrangement direction of the cell stack that is most easily heated and the fuel cell . The air supplied from the air supply pipe 22 to the central portion in the arrangement direction can be at the lowest temperature, and the temperature can be increased as the distance from the central portion increases, so that an optimum cooling means can be obtained.

  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 relation to a fuel cell assembly having a specific reforming case above the cell stack. However, the present invention can be applied even when the reforming case is not located above the cell stack. I can do it.

  Further, in the above embodiment, a case has been described in which low temperature gas supply means is provided in the air chamber and air is supplied to the outer surface of the fuel cell by the air supply pipe. However, the present invention provides the inside of the fuel cell by the air supply pipe. Of course, air may be supplied to the air. In this case, it goes without saying that an air electrode is formed inside the fuel cell and a fuel electrode is formed outside.

  Further, in the above embodiment, an example in which the low temperature gas supply means is provided in the air chamber has been described. However, it is of course possible to provide the low temperature gas supply means in the fuel gas chamber and cool the fuel cell with the fuel gas. It is.

Sectional drawing which shows suitable embodiment of the fuel cell assembly of this invention. The top view of FIG. FIG. 2 is a perspective view showing a power generation unit assembly used in the fuel cell assembly of FIG. 1. The perspective view which shows the electric power generation unit of FIG. Sectional drawing which shows the cell stack of FIG.

Explanation of symbols

2: Housing 12: Power generation / combustion chamber 16: Air chamber (gas chamber)
18: Low temperature gas supply pipe 22: Air introduction pipe (gas supply pipe)
24: Heat exchangers 56a, 56b, 56c and 56d: Power generation units 58a, 58b, 58c and 58d: Fuel gas cases 60a, 60b, 60c and 60d: Cell stack 62: Fuel cell 78a, 78b, 78c and 78d: Modified Quality case

Claims (4)

In a housing provided with a gas chamber to be supplied by the fuel gas or oxygen-containing gas is heated heating gas supply means, fuel cell fuel gas or oxygen-containing gas is heated from the gas chamber to generate power is supplied A fuel cell assembly in which a plurality of cell stacks are arranged ,
Low-temperature gas supply means comprising a low-temperature gas supply pipe that supplies a gas of the same type as the gas supplied to the gas chamber at a lower temperature than the heated fuel gas or oxygen-containing gas in the gas chamber Is provided separately from the heating gas supply means to the gas chamber, and the low temperature gas supply pipe is a central portion of the cell stack provided in the housing in the arrangement direction of the fuel cell. A fuel cell assembly, wherein the fuel cell assembly is connected to the gas chamber so as to cool a central portion in the arrangement direction .   The fuel cell assembly according to claim 1, wherein a heated oxygen-containing gas is supplied to the gas chamber.   The fuel cell assembly according to claim 1, wherein the gas in the gas chamber is supplied between the fuel cells.   The heating gas supply means is a heat exchanger, and the heat exchanger is accommodated in the housing, and a combustion gas generated by burning a fuel gas not used for power generation, and a fuel gas or an oxygen-containing gas 4. The fuel cell assembly according to claim 1, wherein a fuel gas or an oxygen-containing gas heated by the heat exchange is supplied to the gas chamber. .

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