JP2007180000A - Fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell capable of surely isolating gases inside and outside a gas manifold each other and having high reliability. <P>SOLUTION: In the fuel cell, a plurality of solid electrolyte type fuel cells 2 have one ends fixed respectively to a gas manifold 50, and gas in the gas manifold 50 passes through inside of the fuel cell 2. The gas manifold 50 includes a box-shaped manifold body 50a having an upper side opening part in which the fuel cells 2 are provided vertically by sealing their one ends with sealing material 55 and having an annular folded part 50c inside, and a lower side opening ; and a board-shaped bottom plate 50b. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a fuel cell in which one end of a plurality of fuel cells is fixed to a manifold, and gas in the manifold passes through the fuel cells.

  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, and fuel (hydrogen) is flowed to the fuel side electrode side, and air is supplied to the oxygen side electrode side. Electricity is generated at about 600 to 1000 ° C. by flowing (oxygen).

  2. Description of the Related Art Conventionally, a fuel cell is known in which one end of a solid oxide fuel cell is fixed to a top plate of a manifold by a fixing material, and the surface of the top plate and the surface of the fixing material are sealed tightly by a sealing material. (For example, patent document 1).

JP 2005-183376 A

By the way, from the viewpoint of mass productivity, the manifold of the fuel cell is preferably configured by joining a plate-like material to a box-shaped manifold body having an upper surface or a lower surface opened. Therefore, the fuel cell manifold is required to have bonding reliability in order to reliably shut off the gas inside and outside the manifold.
In addition, the fuel cell manifold is exposed to an oxidizing and reducing atmosphere in a high-temperature atmosphere and supports the fuel cell, so stress is generated at the joint between the manifold body and the fuel cell due to its weight and the like. It's easy to do. In addition, stress due to the difference in thermal expansion coefficient between the cell, the sealing material, and the manifold material is generated due to the temperature change, so that the joint is likely to crack and peel off, and further joining reliability is required. .
In view of the above problems, an object of the present invention is to provide a highly reliable fuel cell capable of reliably shutting off gas inside and outside a manifold.

In order to solve the above problems, the present invention has the following features.
The present invention according to claim 1 is a fuel cell in which one end of a plurality of solid oxide fuel cells is fixed to a manifold, and gas in the manifold passes through the fuel cells. The box is a box-like manifold that is erected in a state where one end of the fuel cell is sealed with a sealing material and has an upper surface side opening having an annular folded portion inside and a lower surface side opening. It consists of a main body and a plate-shaped bottom plate, It is characterized by the above-mentioned.
Since such a fuel cell has an annular folded portion inside the upper surface opening of the manifold body, the fuel cell and the sealing material, and stress generated due to the difference in thermal expansion coefficient between these and the manifold material are folded. In addition to relaxation, it is possible to increase the joint area between the manifold and the fuel cell, thereby improving the joint strength and enabling stable fixation.

According to a second aspect of the present invention, the manifold is formed by closing the opening portions at both ends of the tubular body, the fuel gas introduction member is connected to the closed portion, and the bottom plate is positioned on the side surface of the tubular body. Features.
In such a fuel cell, for example, by using a commercially available, for example, a rectangular or cylindrical tubular body, the manifold can be easily manufactured at low cost and in a short time, and the fuel cell can be easily fixed to the manifold.

According to a third aspect of the present invention, the bottom plate of the manifold includes an annular side wall portion having a shape corresponding to the lower surface side opening of the manifold body, and a plate-like bottom portion provided with the annular side wall portion. It is characterized by.
In such a fuel cell, the manifold main body can be placed on the annular side wall, facilitating assembly of the manifold, and an insulator and a fuel gas introduction member to be described later can be provided on the annular side wall. Become.

The present invention according to claim 4 is characterized in that the bottom plate and the manifold body are joined via an insulator.
In such a fuel cell, the insulation between the one end portion of the fuel cell and the annular folded portion is lowered due to aging of the fuel cell, variations during assembly, etc., and the current generated in the fuel cell Even if it leaks to the surface, since the manifold main body and the bottom plate are joined by the insulator, the insulation between the manifold main body and the bottom plate can be ensured.

The present invention according to claim 5 is characterized in that the insulator between the bottom plate and the manifold body is an insulating ceramic plate and a sealing material.
In such a fuel cell, since the ceramic plate is interposed in addition to the sealing material, it is possible to ensure the insulation more reliably and to easily perform the joining operation of the manifold body and the bottom plate.

The present invention described in claim 6 is characterized in that a fuel gas introduction member is connected to the annular side wall portion of the bottom plate.
In such a fuel cell, even if the current generated in the fuel cell leaks into the manifold body, the insulation between the manifold body and the fuel gas introduction member can be ensured.

The present invention according to claim 7 is characterized in that the manifold has a folded support portion for supporting the fuel cell at the tip of the folded portion in the longitudinal direction of the annular folded portion.
In such a fuel cell, since the fuel cell can be supported by the folded support portion at the tip, even if the number of fuel cells increases, the stress generated by the weight of the fuel cell increases. Can be prevented.

The present invention according to claim 8 is characterized by having a sealing material for gas-sealing a joint portion between the fuel battery cell and the manifold and covering an upper portion of the manifold body.
In such a fuel cell, since the sealing material covers the upper part of the manifold body, the sealing material not only serves as a coating, but also because the joining interface is not on the surface, the stress concentration at the joining interface between the sealing material and the manifold body Can be reduced.

  With the fuel cell of the present invention, the temperature change occurred because one end of the plurality of fuel cells was gas-sealed by the sealing material in a state where the one end of the plurality of fuel cells was erected in the opening on the upper surface side of the manifold having the folded portion. In this case, the stress generated by the difference in the thermal expansion coefficient of the constituent materials is alleviated by the deformation of the folded portion of the manifold, thereby preventing the leakage of gas and improving the reliability without causing cracks or peeling at the joint. be able to.

  FIG. 1 is a diagram showing an embodiment of a fuel cell according to the present invention. Reference numeral 1 denotes a storage container having a heat insulating structure. Inside the storage container 1, a plurality of cell stacks 3 in which a plurality of fuel cells 2 are gathered in a tandem arrangement, and a combustion existing above the cell stack 3 An oxygen-containing gas supply pipe 5 inserted between the cell stacks 3 through the region 4, a reformer 6 provided above the combustion region 4, and heat provided above the reformer 6 It is comprised from the exchange part 7. FIG. The oxygen-containing gas supply pipe 5 is indicated by a broken line for easy understanding.

  The storage container 1 includes a frame 1a made of a heat-resistant metal and a heat insulating material 1b provided on the inner surface of the frame 1a.

  FIG. 2 is a cross-sectional view showing a cell stack of the fuel cell of the present invention. For example, as shown in FIG. 2, the cell stack 3 is configured by arranging a plurality of fuel cells 2, and the three cell stacks 3 are arranged in three rows, and the two outermost cell stacks 3 arranged adjacent to each other. The electrodes of the fuel cells 2 are connected by a conductive member 42, whereby a plurality of fuel cells 2 arranged in three rows are electrically connected in series. Each of the three cell stacks 3 has a gas manifold 50.

  If it demonstrates concretely, the fuel cell 2 is flat shape (elongated plate shape), The several fuel gas passage hole 8 is formed in the axial length direction in the inside. This fuel cell 2 is a hollow flat plate type, and comprises an outer surface of an elliptical columnar (flat) electrode support 2a, a fuel side electrode (inner electrode) 2b, a dense solid electrolyte 2c, and porous conductive ceramics. The oxygen side electrodes 2d are sequentially laminated, and the interconnector 2e is formed on the outer surface of the electrode support 2a opposite to the oxygen side electrode 2d.

  A current collecting member 9 is interposed between one fuel battery cell 2 and the other fuel battery cell 2, and an electrode support 2a of one fuel battery cell 2 is connected to the interconnector provided on the electrode support 2a. The cell stack 3 is configured by being electrically connected to the oxygen side electrode 2d of the other fuel cell 2 through the current collecting member 9e. The current collecting member 9 has a plate shape and / or a felt shape made of a metal and / or a conductive inorganic material.

  The fuel cell 2 will be described in more detail. The electrode support 2a is a plate-like piece that is elongated in the vertical direction, and has both flat and semicircular sides. The electrode support 2a is formed with a plurality of fuel gas passage holes 8 (6 in FIG. 2 and 4 in FIG. 3) penetrating in the vertical direction.

  The interconnector 2e is disposed on one surface of the electrode support 2a (upper surface in the cell stack 3 on the left side in FIG. 2). The fuel-side electrode 2b is disposed on the other surface of the electrode support 2a (the lower surface in the left cell stack 3 in FIG. 2) and on both side surfaces, and both ends thereof are joined to both ends of the interconnector 2e. The solid electrolyte 2c is disposed so as to cover the entire fuel side electrode 2b, and both ends thereof are joined to both ends of the interconnector 2e. The oxygen-side electrode 2d is disposed on the main part of the solid electrolyte 2c, that is, on the portion covering the other surface of the electrode support 2a, and is positioned to face the interconnector 2e with the electrode support 2a interposed therebetween.

  A current collecting member 9 is disposed between adjacent cells 2 in the cell stack 3 to connect the interconnector 2e of one cell 2 and the oxygen side electrode 2d of the other cell 2. Conductive members 42 are disposed on both ends of the cell stack 3, that is, on one side and the other side of the cell 2 positioned at the upper end and the lower end in FIG. Electric power extraction means (not shown) is connected to the conductive members 42 located at both ends of the cell stack 3.

More specifically about the cell 2, the electrode support 2a is gas permeable to allow the fuel gas to permeate to the fuel side electrode 2b, and is also conductive to collect current via the interconnector 2e. Can be formed from a porous conductive ceramic (or cermet) that satisfies such requirements.

  In order to produce the electrode support 2a by co-firing with the fuel side electrode 2b and / or the solid electrolyte 2c, it is preferable to form the electrode support 2a from an iron group metal component and a 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.

In particular, the electrode support 2a is composed mainly of a rare earth element oxide composed of one or more selected from Y, Lu, Yb, Tm, Er, Ho, Dy, Gd, Sm and Pr, and Ni and / or NiO. Is desirable. By setting it as such a composition, it can approximate the thermal expansion coefficient of a solid electrolyte.
The fuel side electrode 2b 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 2c 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 2d can be formed of a conductive ceramic made of a so-called ABO ₃ type perovskite oxide. The oxygen side electrode 2d 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 2e can be formed from a conductive ceramic, it needs to have reduction resistance and oxidation resistance because it comes in 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 2e must be dense in order to prevent leakage of fuel gas passing through the fuel gas passage hole 8 formed in the electrode support 2a and oxygen-containing gas flowing outside the electrode support 2a. As described above, it is particularly desirable to have a relative density of 95% or more.

  The current collecting member 9 can be composed of a member having an appropriate shape formed from an elastic metal, alloy, or conductive ceramic, or a member obtained by adding a required surface treatment to a felt composed of metal fiber or alloy fiber. .

  The lower ends of the plurality of fuel cells 2 are supported and fixed to the gas manifold 50 as shown in FIGS. That is, the manifold main body 50a of the gas manifold 50 is used as a cell support that holds and fixes the lower end portion of the fuel battery cell 2. The manifold main body 50a is joined to the manifold bottom plate 50b, and the lower end of the fuel battery cell 2 is connected to the manifold main body 50a. The part is supported and fixed.

FIG. 3 is a view showing a state in which fuel cells are erected on the gas manifold according to the present invention. 4 is a cross-sectional view of FIG. 3 viewed from the width direction.
The gas manifold 50 includes a rectangular box-shaped manifold main body 50a having an upper surface side opening and a lower surface side opening, and a plate-shaped bottom plate 50b, and a fuel gas for supplying combustion gas to the side surface in the width direction. An introduction member 17 (gas supply pipe) is connected. The upper surface side opening is provided with an annular folded portion 50c so as to surround the opening. The folded portion 50c is manufactured, for example, by making cuts at the four corners of the opening, and folding it into a mountain fold as viewed from the upper opening, with the line connecting the four farthest portions from the cut opening as the folding line can do. In this gas manifold 50, the fuel battery cell 2 is gas-sealed by a sealing material 55 and is erected in a fixed state.

When the fuel cell 2 is erected on the gas manifold 50, first, a base that is approximately the same height as the tip of the annular folded portion 50c inside the upper opening is inserted into the upper opening from the lower opening. And prepare. This base is for supporting the lower ends of the plurality of fuel cells 2 when gas sealing. Next, the fuel cells 2 and the manifold body 50a are gas-sealed so as to be joined by, for example, a glass material in a state where the fuel cells 2 are arranged on the table at a predetermined interval.
The gas sealing is performed, for example, by applying a paste containing a glass material so as to cover the upper portion of the manifold main body 50a and performing a heat treatment. Next, after the fuel cell 2 is fixed to the manifold body 50a, the base is removed from the lower surface opening, and the bottom plate 50b is joined to the lower surface side opening.

  FIG. 5 is a cross-sectional view in the longitudinal direction of a gas manifold having a folded back support portion at the tip of the annular folded portion in the longitudinal direction of the manifold body. A manifold main body 60a shown in FIG. 5 includes an annular folded portion inside the upper opening similarly to the manifold main body 50a shown in FIG. 4. Further, in the manifold main body 60a shown in FIG. A two-stage folding support part 60c having a folding part support part for supporting the fuel cell 2 at the tip is provided. The lower end portions of the plurality of fuel cells 2 are accommodated in the folded back support portion 60c, respectively, and are gas-sealed by the sealing material 55 while being supported by the folded back support portion 60c. Thereby, the base used when gas-sealing is unnecessary in this embodiment. Further, even when the number of fuel cells to be erected increases, the fuel cells 2 can be supported more stably. Further, when a metal such as SUS is used as the material of the manifold main body 50a and it is necessary to ensure insulation from the fuel battery cell 2, the fuel battery cell 2 and the folded back support portion 60c come into contact with each other. A thin insulating plate made of ceramic such as mica plate or forsterite can be sandwiched between the parts, for example, the second-stage folded support portion 60 c and the fuel cell 2.

The sealing material 55 used for fixing the fuel cell 2 and the manifold bodies 50a and 60a, which are supports, is made of ceramic, glass, cement or the like, and paste or slurry is used as the fuel cell. And a method of fixing a clay or a molded product matching the shape of the gap to the gap between the fuel cells, and firing the fuel cell 2 and the manifold bodies 50a and 60a. Fixed.
As the sealing material 55, since it is necessary to fix the fuel cell 2 to the manifold bodies 50a and 60a, it is desirable that the sealing material 55 be in a solid phase at the operating temperature of the fuel cell, for example, 600 ° C to 900 ° C. Due to being in the solid phase, the fuel cell 2 is held and fixed even during operation of the fuel cell, and at the same time, the inorganic thin film formed on the surface of the sealing material 55 is stably maintained without causing defects such as cracks and peeling. can do.

Further, it is necessary to prevent leakage of the fuel gas from the sealing material 55, and it is preferable that the sealing material 55 is dense. From the viewpoints of gastight sealing properties and stability, amorphous glass materials, crystals A glass material including a quality material is desirable.
Furthermore, it is desirable that the sealing material 55 be close to the thermal expansion of both the manifold main bodies 50a and 60a and the fuel battery cell 2, but there is a difference in the thermal expansion coefficient between the manifold main bodies 50a and 60a and the fuel battery cell 2. More preferably, it is preferable to use a material having a coefficient of thermal expansion between the manifold bodies 50a and 60a and the fuel battery cell 2.

A simulation result carried out to confirm the effect of the present invention will be described below.
FIG. 6 is a diagram showing a simulation result of the gas manifold. FIG. 7 is a cross-sectional perspective view of the conventional structure used in this simulation and the new structure gas manifold model of the present invention. FIG. 8 is a maximum principal stress distribution diagram in the model shown in FIG.

This simulation simulates the maximum principal stress caused by the difference in coefficient of thermal expansion due to the constituent material of the gas manifold in the state where the fuel cell is erected. Here, as shown in FIG. 7, the gas manifold of the prior art includes a gas manifold in which a metal support plate that supports fuel cells and whose joints are sealed with glass and a metal manifold body are joined. Simulation is in progress.
A gas manifold having a novel structure according to the present invention is a gas manifold made of an integral metal without the joint, having a folded portion at the upper opening, and glass at the joint between the fuel cell and the gas manifold. Simulates the structure with the seal. Both of these metals are made of SUS. In the conventional structure, the metal plate constituting the manifold body has a thickness of 1.5 mm and the support plate has a thickness of 3.0 mm. In the new structure of the present invention, the thickness of the metal plate of the manifold body is 1. Simulation is performed with only 5 mm. This is because the new structure has a folded portion in the upper opening, so that the folded portion can secure the same length as the thickness of the support plate of 3 mm.

  As shown in FIG. 6, in the present invention, it was confirmed by this simulation that the maximum principal stress generated in the fuel cell can be halved from 15.9 MPa of the conventional structure to 8.0 MPa. This is because stress generated between the folded portion and the fuel cell in the new structure is relaxed. Further, the maximum principal stress of 23.3 MPa, which is generated at the joint between the support plate having the conventional structure and the manifold body, is not generated in the novel structure of the present invention. It can also be confirmed from the maximum principal stress distribution diagram (gray scale) shown in FIG.

As described above, since the folded portion 50c and the folded support portion 60c are provided inside the upper surface openings of the manifold main bodies 50a and 60a, the stress generated by the difference in the thermal expansion coefficient between the fuel cell and the sealing material and the manifold material. Can be relaxed by the folded-back portion 50c and the folded-back support portion 60c, and by providing the folded-back portion 50c and the folded-back support portion 60c, the joint area between the manifold bodies 50a, 60a and the fuel cell 2 can be increased compared to the conventional structure. Therefore, the bonding strength can be improved and stable fixing can be performed.
Further, as shown in FIG. 5, since the fuel cell 2 can be supported by the folding support portion 60c at the tip, even if the number of fuel cells increases, the fuel cell is generated due to the weight of the fuel cell. An increase in stress can be prevented.
In addition, since the joint portion between the manifold main bodies 50a, 60a and the bottom plates 50b, 60b is located below the gas manifolds 50, 60, the seal portion is not easily deformed, and even if stress is generated, the joint portion is cracked or peeled off. Can be prevented, and gas leakage from the gas seal joints in the gas manifolds 50 and 60 can be prevented.

  Furthermore, in the fuel cell of the present invention, one end of the fuel cell 2 is a non-exposed region of the outer electrode, and the exposed solid electrolyte is fixed to the manifold main bodies 50a and 60a with a sealing material 55. In the fuel cell 2, the outer electrode is made porous because it is necessary to supply gas to the solid electrolyte, and the solid electrolyte is made dense because it is necessary to shut off the fuel gas and the oxygen-containing gas. Since the solid electrolyte portion is joined to the manifold main bodies 50a and 60a by the sealing material 55, leakage of gas from the fuel cell 2 can be prevented.

  A fuel gas introduction member 17 for supplying fuel gas to the inside of the fuel cell 2 is connected to the gas manifolds 50 and 60, and the fuel gas introduction member 17 is connected to the reformer 6. The to-be-reformed gas supply pipe 19 for supplying the to-be-reformed gas is connected to the to-be-reformed gas from the outside via the to-be-reformed gas supply pipe 19. The gas is reformed by the reformer 6 and the fuel gas is supplied to the gas manifolds 50 and 60 via the fuel gas introduction member 17.

  Further, as shown in FIG. 1, the oxygen-containing gas supply pipe 5 inserted through the combustion region 4 has a tip portion located below the power generation region and located between the cell stacks 3. Excess oxygen-containing gas that has not been used for power generation is configured to naturally flow into the combustion region 4.

  The heat exchanging unit 7 includes an exhaust gas passage 7a through which exhaust gas combusted above the fuel battery cell 2 is discharged, and an oxygen-containing gas storage chamber 7b provided to face the cell stack 3 through the combustion region 4. ing.

  The exhaust gas passage 7a is configured to discharge from above the fuel cell 2 to the outside, and air is introduced into the oxygen-containing gas storage chamber 7b from the outside, and oxygen-containing gas supply The tube 5 is in communication. The exhaust gas passage 7a is formed along the oxygen-containing gas storage chamber 7b, and heat is exchanged in this portion.

  In the fuel cell configured as described above, an oxygen-containing gas (for example, air) from the outside is introduced into the oxygen-containing gas storage chamber 7 b of the heat exchange unit 7, and the cell of the power generation chamber is connected via the oxygen-containing gas supply pipe 5. The gas is blown between the stacks 3 and supplied between the fuel cells 2, and the gas to be reformed is supplied into the reformer 6 through the gas to be reformed gas supply pipe 19. Then, fuel gas (for example, hydrogen) is supplied into the fuel gas passage hole 8 of the fuel cell 2 through the fuel gas introduction member 17 and the gas manifold 50, and power is generated in the fuel cell 2 in the power generation region.

  Excess fuel gas that has not been used for power generation is led out into the combustion region 4 from the upper end of the fuel gas passage hole 8, and surplus oxygen-containing gas that has not been used for power generation is led into the combustion region 4, The fuel gas and the surplus oxygen-containing gas are caused to react and burn to generate combustion gas. This combustion gas is led to the exhaust gas passage 7a of the heat exchanging section 7 through the combustion gas inlet and discharged from the upper end of 7. The

  In the fuel cell of the present invention, since one end of the fuel cell 2 is provided in the gas manifolds 50 and 60, the fuel cell 2 is not fixed to the storage container 1 but is stored in the storage container 1. Since it is held and fixed to the gas manifolds 50 and 60, for example, when one fuel battery cell 2 is damaged, the gas manifolds 50 and 60 to which the fuel battery cell 2 is held and fixed are taken out of the storage container 1, It can be replaced with a non-defective product, making maintenance easier.

Further, since the gas in the gas manifolds 50 and 60 passes through the electrode support 2a from one end of the fuel cell 2 to the other end, the gas manifolds 50 and 60 can be used without using pipes or the like as in the prior art. Gas can be supplied to the fuel battery cell 2.
In addition, surplus fuel gas and oxygen-containing gas that did not contribute to power generation are introduced into the combustion region 4 and reacted and burned in the combustion region 4, and the combustion gas and the external oxygen-containing gas are transferred to the heat exchange section. The oxygen-containing gas is preheated by heat exchange between the combustion gas and the oxygen-containing gas in the heat exchange unit 7 and heating of the oxygen-containing gas in the oxygen-containing gas storage chamber 7b by combustion. Therefore, the starting time until the fuel cell 2 is heated to substantially generate power can be greatly shortened.
Furthermore, by providing the reformer 6 above the fuel battery cell 2, the reformer 6 can be directly heated by the combustion gas, heat necessary for reforming can be sufficiently supplied, and reforming performance can be improved.

  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-described embodiment, the example in which the cell stack 3 is configured using the fuel cell 2 having the elliptic cylinder shape and the plurality of fuel gas passage holes 8 as illustrated in FIG. 2 is described. However, the fuel cell is cylindrical. Thus, there may be one fuel gas passage hole, and the shape of the fuel cell is not particularly limited.

  The gas manifold can be made of a commercially available square or cylindrical pipe as it is, and can be manufactured at low cost. FIG. 9 is a view showing a state in which an upper opening and a lower opening are formed on the side surface of the tubular body. For example, as shown in FIG. 9, the gas manifold 70 is formed by closing both end openings of a rectangular pipe-like tubular body 70a with side plates 70b and 70c, and fuel gas on the side plate 70c closed on the axial end surface. The introduction member 75 is connected, an upper opening and a lower opening are formed on the side surface of the tubular body 70a, and one end of the fuel cell 2 is gas-sealed and fixed to the folded portion 71 of the upper opening. The lower opening is joined by a bottom plate 70d. In such a fuel cell, by using a commercially available, for example, rectangular tube or cylindrical tubular body, a gas manifold can be manufactured easily, inexpensively and in a short time, and the fuel cell can be easily fixed to the gas manifold. .

FIG. 10 is a cross-sectional view seen from the width direction of the gas manifold in which the upper end opening of the bottom plate and the manifold body are joined by an insulator. FIG. 11 is a cross-sectional view of FIG. 10 viewed from the longitudinal direction.
The gas manifold 80 shown in FIGS. 10 and 11 includes a rectangular box-shaped conductive manifold body 80a having an upper surface side opening and a lower surface side opening, and a plate-shaped conductive bottom plate 80b. Yes. The upper surface side opening is provided with an annular folded portion 80c so as to surround the opening. The folded portion 80c can be manufactured in the same manner as the folded portion (50c in FIG. 4), for example. In this gas manifold 80, the fuel cell 2 is gas-sealed with an insulating sealing material 55 and is erected in a fixed state.

The method of erecting the fuel cells 2 in the gas manifold 80 is also performed in the same manner as the gas manifold (50 in FIG. 4).
The bottom plate 80b of the gas manifold 80 includes an annular side wall portion 81 having a shape corresponding to the lower surface side opening of the manifold body 80a, and a plate-like bottom portion 82 provided with the annular side wall portion 81.

The upper end opening of the annular side wall 81 is widened through the step portion 81a, and the lower end of the manifold main body 80a is joined to the step portion 81a by an insulator 83.
That is, an insulating sealing material is loaded as the insulator 83 at the joint between the bottom plate 80b and the manifold body 80a. Alternatively, an insulating ceramic plate 84 such as a mica plate or forsterite is interposed and a sealing material is loaded. For example, the ceramic plate 84 may be disposed over the entire circumference on the step portion 81a, or may be partially disposed as necessary. The ceramic plate 84 serves as a spacer at the joint between the manifold body 80a and the bottom plate 80b, and reliably insulates them.
Furthermore, the fuel gas introduction member 17 is connected to the annular side wall portion 81 of the bottom plate 80b.

  The gas manifold 80 of the present invention shown in FIGS. 10 and 11 has a bottom plate 80b having a shape corresponding to the opening on the lower surface side of the manifold body 80a, and a plate-shaped bottom portion 82 provided with the annular side wall portion 81. Therefore, the manifold main body 80a can be placed on the annular side wall portion 81, the gas manifold 80 can be easily assembled, and the insulator 83 and the fuel gas introduction member 17 are provided on the annular side wall portion 81. It becomes possible.

  In addition, due to aging of the fuel cell, variation during assembly, etc., the insulation between the one end of the fuel cell 2 and the annular folded portion 80c is reduced, and the current generated in the fuel cell leaks to the manifold body 80a. Even so, the manifold body 80a and the bottom plate 80b are joined and insulated by the insulator 83 made of a sealing material with a sealing material or an insulating ceramic plate interposed therebetween, so that the insulation between the manifold body 80a and the bottom plate 80b is achieved. Sex can be secured.

  Further, since the fuel gas introduction member 17 is connected to the annular side wall portion 81 of the bottom plate 80b, the gas manifold 80 of the present invention can be connected to the manifold body 80a even if the current generated in the fuel cell 2 leaks. The insulation between the main body 80a and the fuel gas introduction member 17 can be ensured, and leakage to the outside via the fuel gas introduction member 17 can be prevented.

FIG. 12 is a cross-sectional view seen from the width direction of the gas manifold in which the bottom end opening of the bottom plate and the manifold body are joined by an insulator. FIG. 13 is a cross-sectional view of FIG. 12 viewed from the longitudinal direction.
The gas manifold 90 shown in FIGS. 12 and 13 is provided with another bottom plate 90a in place of the bottom plate (81b in FIG. 10) of the gas manifold (80 in FIG. 10). The bottom plate 90a is a manifold main body 80a. An annular side wall portion 91 having a shape corresponding to the lower surface side opening portion, and a plate-like bottom portion 92 provided with the annular side wall portion 91. The upper end opening portion of the annular side wall portion 91 is contracted via a step portion 91a. The lower end of the manifold body 80a is joined and placed on the step portion 91a by an insulator 83.
That is, an insulating sealing material is loaded as the insulator 83 at the joint between the bottom plate 90a and the manifold body 80a. Alternatively, the sealing material is loaded through an insulating ceramic plate such as a mica plate or forsterite.

  In the gas manifold 90 of the present invention shown in FIGS. 12 and 13, the bottom plate 90a includes an annular side wall portion 91 having a shape corresponding to the lower surface side opening of the manifold body 80a, and a plate-like bottom portion 92. The manifold body 80a can be placed on the step portion 91a of the portion 91, the gas manifold 90 can be easily assembled, and the insulator 83 and the fuel gas introduction member 17 can be provided on the annular side wall portion 91. become.

  In addition, due to aging of the fuel cell, variation during assembly, etc., the insulation between the one end of the fuel cell 2 and the annular folded portion 80c is reduced, and the current generated in the fuel cell leaks to the manifold body 80a. Even so, the manifold body 80a and the bottom plate 90a are joined and insulated by the insulator 83 made of a sealing material with a sealing material or an insulating ceramic plate interposed therebetween, so that the insulation between the manifold body 80a and the bottom plate 90a is achieved. Sex can be secured.

  Further, since the fuel gas introduction member 17 is connected to the annular side wall portion 91 of the bottom plate 90a in the gas manifold 90 of the present invention, even if the current generated in the fuel cell 2 leaks to the manifold body 80a, the manifold The insulation between the main body 80a and the fuel gas introduction member 17 can be ensured.

  It is also possible to load the insulator 83 between the manifold body 50a and the bottom plate 50b of the manifold 50 or between the manifold body 60a and the bottom plate 60b of the manifold 60. The insulation between the main body 50a and the bottom plate 50a or the insulation between the manifold main body 60a and the bottom plate 60a can be ensured.

FIG. 14 shows an embodiment of the fuel cell stack apparatus 100 joined and fixed to the gas manifold 80 shown in FIG. FIG. 14A is a plan view of a fuel cell stack including two fuel cell stack bodies arranged in parallel and joined and fixed to a manifold according to the present invention. FIG. 14B is a partially cutaway front view of the fuel cell stack of FIG. FIG. 14C is a side view of the fuel cell stack of FIG. FIG.14 (d) is an A section expanded sectional view of (b). FIG. 14E is an enlarged cross-sectional view of the B part in FIG. FIG. 14F is an enlarged cross-sectional view of a C part in FIG. The fuel cell stack device 100 shown in the figure includes two fuel cell stacks 101 and 101 arranged in parallel, and the two fuel cell stacks 101 and 101 are joined and fixed to the gas manifold 80, respectively. . Therefore, the gas manifold 80 includes one bottom plate 80b and two manifold bodies 80a-1 and 80a-2. As shown in (f), two upper end openings of the bottom plate 80b are provided, and the manifold bodies 80a-1 and 80a-2 are provided with the insulator 83 and the ceramic on the step part 81a of each upper end opening. It is placed via a plate 84. Thereby, the bottom plate 80b and the manifold main body 80a are reliably insulated. The internal space of the gas manifold 80 is a single chamber, and gas is accommodated in this internal space. Gas is supplied from the internal space to the fuel gas passage hole of the fuel cell 2.
Note that the fuel cell stack can be similarly bonded and fixed to the gas manifolds 50, 60, 70, 80, or 90 instead of the gas manifold 80.

It is a figure which shows the fuel cell system of this invention. It is a cross-sectional view showing the cell stack of the fuel cell of the present invention. It is a figure which shows the state which stood the fuel cell in the gas manifold which concerns on this invention. It is sectional drawing which looked at FIG. 3 from the width direction. It is sectional drawing of the longitudinal direction of the gas manifold which comprised the folding | turning support part in the front-end | tip of the folding | turning part formed in the longitudinal direction. It is a figure which shows the simulation result of a gas manifold. It is a section perspective view of the conventional structure used for this simulation, and the new structure gas manifold model of the present invention. FIG. 8 is a maximum principal stress distribution diagram in the model shown in FIG. 7. It is a figure which shows the state which formed the upper side opening part and the lower side opening part in the side surface of the tubular body. It is sectional drawing seen from the width direction of the gas manifold in which the upper end opening part and the manifold main body which were expanded in the baseplate are joined by the insulator. It is sectional drawing which looked at FIG. 10 from the longitudinal direction. It is sectional drawing seen from the width direction of the gas manifold in which the upper end opening part and the manifold main body which the mouthpiece of the baseplate shrunk were joined by the insulator. It is sectional drawing which looked at FIG. 12 from the longitudinal direction. FIG. 2A is a plan view of a fuel cell stack including two fuel cell stack bodies that are arranged in parallel and bonded and fixed to a manifold according to the present invention. (B) is a partially cutaway front view of the fuel cell stack of (a). (C) is a side view of the fuel cell stack of (b). (D) is an A section expanded sectional view of (b). (E) is the B section expanded sectional view of (b). (F) is the C section expanded sectional view of (c).

Explanation of symbols

2 Fuel cell 17, 75 Fuel gas introduction member 50, 60, 70, 80, 90 Gas manifold 50a, 60a, 70a, 80a, 90a Manifold body 50b, 60b, 80b, 90a Bottom plate 50c, 60c, 70c, 80c Folding part 55, 65 Sealing material 81, 91 Annular side wall 82, 92 Plate-like bottom 83 Insulator

Claims (8)

A fuel cell in which one end of a plurality of solid oxide fuel cells is fixed to a manifold, and gas in the manifold passes through the fuel cells,
The manifold is
A box-shaped manifold body that is provided with an upper surface side opening portion having an annular folded portion on the inside, and a lower surface side opening portion that is erected in a state where one end portion of the fuel cell is sealed with a sealing material;
A fuel cell comprising a plate-like bottom plate.   2. The fuel according to claim 1, wherein the manifold closes both ends of the tubular body, a fuel gas introduction member is connected to the closed portion, and a bottom plate is located on a side surface of the tubular body. battery.   2. The fuel cell according to claim 1, wherein the bottom plate includes an annular side wall having a shape corresponding to an opening on the lower surface side of the manifold body, and a plate-like bottom provided with the annular side wall. .   The fuel cell according to any one of claims 1 to 3, wherein the bottom plate and the manifold body are joined via an insulator.   The fuel cell according to claim 4, wherein the insulator is an insulating ceramic plate and a sealing material.   6. The fuel cell according to claim 3, wherein a fuel gas introduction member is connected to the annular side wall portion of the bottom plate.   The fuel according to any one of claims 1 to 6, wherein the manifold has a folded support portion for supporting the fuel cell at a tip of a folded portion in a longitudinal direction of the annular folded portion. battery. The fuel cell according to any one of claims 1 to 7, further comprising a sealing material that gas seals a joint portion between the fuel cell and the manifold and covers an upper portion of the manifold body.

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