JP2013222565A - Sofc module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a module structure in which plural laminate-type SOFC elements are continued to prevent an output.SOLUTION: In an SOFC module 20, each of plural laminate type SOFC elements 1 comprises: a cathode-side side electrode 14 electrically connected to a cathode-side external electrode 14 on a face adjacent to the cathode-side external electrode 12; and an anode-side side electrode 13 electrically connected to an anode-side external electrode 11 on a face adjacent to the anode-side external electrode 11 and opposed to the cathode-side side electrode 14. The plural laminate type SOFC elements are aligned so that non-electrode faces are opposed to each other and formation faces of the anode-side external electrode 11 and the cathode-side external electrode 12 are directed to the same direction. Each of the laminate type SOFC elements 1 is physically and electrically parallel connected by holding the anode-side side electrode 13 and the cathode-side side electrode 14 with conductive holding plates 21, 22.

Description

  The present invention relates to a SOFC module capable of obtaining high power by connecting a plurality of stacked SOFC elements in electrical parallel.

  A thermoelectric generator is placed near the heat source of the gas appliance to recover the heat energy (energy harvest). Using the obtained power, the electronic devices attached to the gas appliance such as fans, sensors, and electronic display devices can be used without batteries. There is a desire to drive. Aiming at the realization of this demand, the practical application of gas appliances with thermoelectric generators is being studied. For example, in Patent Document 1, a flat solid oxide fuel cell (hereinafter referred to as SOFC (Solid Oxide Fuel Cell) cell) in which a fuel electrode and an air electrode are arranged to face each other through a solid electrolyte layer is parallel to a gas burner flame. A technique for collecting and recovering power has been proposed.

  According to Patent Document 1, a flat SOFC cell is erected around the flame opening so that the fuel electrode of the flat SOFC cell hits the gas burner flame and the air electrode does not hit the flame. By doing so, the fuel cell is heated to its operating temperature by the combustion heat of the flame of the gas burner, and the oxygen potential between the fuel electrode side and the air electrode side of the solid electrolyte is supplied by supplying the combustion gas to the fuel electrode. A gradient is generated, and electric power corresponding to the oxygen potential gradient can be obtained. Further, it is suggested that a plurality of areas are arranged around the flame opening and the area is increased.

  However, the output of the flat SOFC cell does not have a sufficient output for driving electronic devices such as fans. In order to increase the output of the flat plate type SOFC cell, it is desirable to make the solid electrolyte layer thinner and to have a larger area. Then, since the flat plate type SOFC cell is made of ceramics, it is easily broken. Because of such contradictory relationships, in the conventional flat plate type SOFC cell, a mechanism for driving an electronic device by placing it in a gas burner flame or the like has not been put into practical use.

  In order to increase the output, it is conceivable to stack a plurality of flat plate type SOFC cells via an interconnector or a separator. However, such a stack configuration complicates and enlarges the fuel and air supply system. In addition, if a fuel cell having such a stack configuration is to be installed in a gas appliance or the like, not only the original combustion function of the gas appliance is inhibited, but also the cost of the gas appliance is increased. Therefore, a configuration in which a plurality of flat plate SOFC cells are stacked is not suitable for the purpose of recovering and using thermal energy without impairing the original combustion function of the gas appliance.

  On the other hand, a SOFC element having a hexahedral structure having an anode external electrode and a cathode external electrode on opposite end surfaces without using an interconnector or a separator is disclosed (Patent Document 2). However, Patent Document 2 does not disclose anything about a method of generating power by applying a laminated SOFC element to a gas burner flame such as a stove.

JP 2007-42354 A JP 2011-34688 A

  According to Patent Document 2, by making the SOFC element have a laminated structure as described in Patent Document 2, the element can be reduced in size while suppressing a decrease in power generation efficiency. In consideration of generating power by applying the stacked SOFC element described in Patent Document 2 to a flame of a gas burner such as a stove, the anode external electrode is disposed in the gas burner flame, and the cathode external electrode is disposed outside the gas burner flame. The temperature of the stacked SOFC element is raised to its operating temperature by the combustion heat of the flame of the gas burner, and an oxygen potential gradient is generated between the anode external electrode and the cathode external electrode of the stacked SOFC element. An arrangement that obtains electric power according to the above is conceivable. Furthermore, since the stacked SOFC element disclosed in Patent Document 2 has a structure in which a large number of anodes and cathodes are stacked inside each element, it has a high power density, excellent thermal shock resistance, and a fuel and air supply device. Since it is not necessary, it is possible to reduce the size by using a single layered SOFC element, and heat energy can be recovered as electric power without impairing the combustion function of the gas appliance. This is because the stacked SOFC element disclosed in Patent Document 2 is small in size, so that only the anode external electrode portion of the stacked SOFC element is exposed to a flame, and an arrangement configuration that does not hinder the combustion function of the gas appliance is possible. It is to become.

  However, when the stacked SOFC element described in Patent Document 2 is generated by burning with a flame, although the power density is high, the element size, that is, the volume of the stacked SOFC element is small, and the electronic device such as a fan is driven by one element. It is difficult to get enough power. On the other hand, when trying to apply the laminated SOFC element to the flame of a gas appliance or the like, it is preferable to expose the entire anode external electrode of the laminated SOFC element to the reducing flame in the flame from the point of fuel gas intake efficiency, Therefore, the stacked SOFC element needs to be small and have high output. When the number of stacked SOFC elements is greatly increased or lengthened, it becomes difficult to match the anode external electrode to the flame shape or the burner flame mouth shape. Furthermore, since an increase in temperature distribution and an increase in thermal stress in the element during use are expected, a large element cannot be manufactured.

  The present invention has been made in view of the above, and by using a plurality of stacked SOFC elements, connecting them in parallel electrically, and adopting an integral structure that can be applied to a flame shape, An object of the present invention is to provide an SOFC module that can be mounted on a gas appliance or the like and can obtain sufficient power for driving an electronic device such as a fan.

  In order to solve the above problems, an SOFC module according to the present invention is a module including a plurality of stacked SOFC elements and a pair of conductive sandwiching plates facing each other. Each of the stacked SOFC elements is a hexahedron. It has a shape, has a plurality of anodes and a plurality of cathodes inside, and has an anode side external electrode connected to the plurality of anodes and a cathode side external electrode connected to the plurality of cathodes on opposite end faces, A cathode side surface electrode electrically connected to the cathode side external electrode is provided on any one of four surfaces adjacent to the surface of the cathode side external electrode, and the anode is disposed on a surface facing the surface of the cathode side side electrode. An anode-side side electrode electrically connected to the side external electrode, and the plurality of stacked SOFC elements are arranged at least on the front side of the anode-side side electrode. The cathode side surface electrode faces in the same direction, and the anode side external electrode and the cathode side external electrode are arranged on the same side in the SOFC module, and the side surface between the pair of conductive sandwich plates The anode side surface electrodes are connected to one of the conductive clamping plates, and the cathode side side electrodes are connected to the other of the conductive clamping plates. ing. With such a configuration, a plurality of stacked SOFC elements can be used, and these can be mounted on gas appliances etc. by connecting them electrically in parallel and adopting an integrated structure that can be applied to a flame shape. In addition, an SOFC module capable of obtaining sufficient power for driving an electronic device such as a fan can be provided.

  Furthermore, in the SOFC module according to the present invention, the surface of the anode-side external electrode, the surface of the cathode-side external electrode, the surface of the cathode-side side electrode, and the surface of the anode-side side electrode are all directed in the same direction. Arranged between the pair of conductive sandwich plates, and sandwiched by the surface on which the side electrodes are formed, the anode side surface electrodes are connected to one of the conductive sandwich plates, and the cathode side side electrodes are It is good also as a structure connected with the other of the electroconductive clamping board. By setting it as such a structure, the SOFC module which concerns on this invention can be suitably arrange | positioned so that the edge part of a burner plate may be followed, for example.

  Furthermore, the SOFC module according to the present invention may be configured such that the plurality of stacked SOFC elements are arranged in a straight line, and the pair of conductive sandwich plates are in a straight line. By setting it as such a structure, the SOFC module which concerns on this invention can be suitably arrange | positioned, for example to the burner plate which has a linear flame mouth.

  Furthermore, the SOFC module according to the present invention may be configured such that the plurality of stacked SOFC elements are arranged in an L shape, and the pair of conductive sandwich plates are in an L shape. By setting it as such a structure, the SOFC module which concerns on this invention can be suitably arrange | positioned so that the edge part 2 side may be followed, for example to a rectangular burner plate.

  Furthermore, the SOFC module according to the present invention may be configured such that the plurality of stacked SOFC elements are arranged in an arc shape, and the pair of conductive sandwich plates are in an arc shape. By adopting such a configuration, the SOFC module according to the present invention can be suitably arranged on, for example, a burner plate having an arcuate flame opening.

  In the SOFC module according to the present invention, it is preferable that the pair of conductive sandwich plates be made of a noble metal material or a material obtained by coating a heat-resistant stainless steel base material with a noble metal.

  A plurality of SOFC elements are sandwiched between a pair of conductive sandwich plates facing each other, thereby providing a module in which a plurality of SOFC elements are physically and electrically connected in parallel. It is possible to obtain sufficient power to drive an electronic device such as a fan without impairing the power.

  In addition, since the pair of conductive sandwich plates are made of a noble metal material or a material obtained by coating a stainless steel base material with a noble metal, it is possible to suppress deterioration with time of conductivity due to oxidation of the sandwich plate.

It is a perspective view which shows the structure of the SOFC module which concerns on Embodiment 1 of this invention. It is a figure which shows the example of a connection of the fuel cell power generation system using a SOFC module. It is a perspective view which shows the structure of the SOFC module which concerns on Embodiment 2 of this invention. It is a perspective view which shows the structure of the SOFC module which concerns on Embodiment 3 of this invention. It is a perspective view showing the burner plate with a SOFC module as an example of use of the SOFC module concerning Embodiment 1 of the present invention. It is a fragmentary top view which shows the arrangement | positioning relationship between a burner plate and a SOFC module. It is a fragmentary sectional view which shows the arrangement | positioning relationship between a burner plate and a SOFC module. It is sectional drawing which shows the internal structure of the laminated | stacked SOFC element used for a SOFC module. It is a perspective view which shows the electrode structure of the laminated | stacked SOFC element used for a SOFC module.

  Hereinafter, the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited by the form (henceforth embodiment) for implementing the following invention. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art, those that are substantially the same, and those in a so-called equivalent range. Furthermore, the constituent elements in the following embodiments can be appropriately combined.

  In the present embodiment, the fuel cell uses a stacked solid oxide fuel cell element (hereinafter referred to as “stacked SOFC element”). The stacked SOFC element is characterized by high power generation efficiency. A stacked SOFC element requires an increase in electrode effective area and a thin solid electrolyte layer in order to sufficiently extract current. The stacked SOFC element according to the present embodiment attempts to extract a large current by increasing the electrode effective area per unit volume as compared with the conventional flat plate type and cylindrical type SOFC. For this reason, the stacked SOFC element according to the present embodiment increases the effective electrode area per unit volume by forming an integrated stacked structure in which electrodes (anodes or cathodes) and solid electrolyte layers are alternately stacked. Thus, the power generation efficiency is improved and the size is reduced. In this specification, power generation efficiency refers to the amount of power generated with respect to consumed fuel gas (fuel gas used for power generation + fuel gas not used for power generation).

  Next, an outline of the stacked SOFC element 1 used in the above-described example will be described.

  FIG. 8 is a cross-sectional view showing the internal structure of the stacked SOFC element used in the SOFC module according to this embodiment. As shown in FIG. 8, the stacked SOFC element 1 includes a plurality of anodes 2, a plurality of cathodes 3, a solid electrolyte layer 4 disposed at least between the anode 2 and the cathode 3, and an adjacent solid electrolyte layer. It includes partition portions 5a and 5c arranged between each other, and is integrally formed into a hexahedral shape. Here, the stacked SOFC element 1 has anode-side external electrodes 11 connected to the plurality of anodes 2 and cathode-side external electrodes 12 connected to the plurality of cathode electrodes 3 on the opposing end surfaces. In the stacked SOFC element 1, a cathode-side side electrode 14 and a cathode-side side electrode 14 that are electrically connected to the cathode-side external electrode 12 are formed on any one of four surfaces adjacent to the cathode-side external electrode 12. An anode-side side electrode 13 that is electrically connected to the anode-side external electrode 11 is further provided on the surface facing the surface. As described above, the multilayer SOFC element 1 includes an electrode having an L-shaped cross section by connecting the anode-side external electrode 11 and the anode-side side electrode 13. Further, an electrode having an L-shaped cross section is provided by connecting the cathode side external electrode 12 and the cathode side surface electrode 14. The anode side electrode 13 and the cathode side electrode 14 may be formed on a part of each side. As described above, the plurality of anodes 2 are electrically connected to the anode side surface electrode 13 via the anode side external electrode 11, and the plurality of cathodes 3 are connected to the cathode side side electrode 14 via the cathode side external electrode 12. And are electrically connected.

  FIG. 9 is a perspective view showing an electrode configuration of a stacked SOFC element used in the SOFC module. In the present embodiment, as shown in FIG. 9, the stacked SOFC element 1 includes anode-side external electrodes on both sides in the direction N in which the electrodes of the plurality of anodes 2 and the plurality of cathodes 3 of the hexahedral-shaped stacked SOFC element 1 extend. 11 and the cathode side side electrode 13 and the cathode side side electrode 14 are formed on both sides in the direction M crossing the cathode side external electrode 12. That is, the stacked SOFC element 1 has a cathode-side side electrode 14 that is electrically connected to the cathode-side external electrode 12 on any one of four surfaces adjacent to the cathode-side external electrode 12, and is opposed to the cathode-side side electrode 14. And an anode side side electrode 13 electrically connected to the anode side external electrode 11. As described above, the multilayer SOFC element 1 includes an electrode having an L-shaped cross section by connecting the anode-side external electrode 11 and the anode-side side electrode 13. Further, an electrode having an L-shaped cross section is provided by connecting the cathode side external electrode 12 and the cathode side surface electrode 14. As a result, the SOFC module described later can connect the anode side surface electrode 13 and the cathode side surface electrode 14 of a plurality of elements by a conductive sandwiching plate described later, and connect them in electrical parallel to output electric power to an external load. be able to. In FIG. 9, the anode-side side electrode 13 and the cathode-side side electrode 14 are formed on both sides of the direction M crossing the direction N in which the electrodes of the plurality of anodes 2 and the plurality of cathodes 3 extend. You may form in the both sides of the direction which cross | intersects M and the direction N.

  In the stacked SOFC element 1 used in the SOFC module according to this embodiment, each of the anode 2 and the cathode 3 is a porous body made of platinum (Pt). The anode-side external electrode 11 and the cathode-side external electrode 12 are porous bodies made of the same material as the anode 2 and the cathode 3, that is, platinum. The stacked SOFC element 1 operates when fuel F (for example, hydrogen) is supplied from the anode side external electrode 11 side and oxygen A (air in the present embodiment) is supplied from the cathode side external electrode 12 side. To do. Therefore, the fuel F may be supplied to the anode-side external electrode 11 and the oxygen A may be supplied to the cathode-side external electrode 12 disposed on the side opposite to the anode-side external electrode 11. In order to distribute the fuel F supplied from the anode side external electrode 11 side and the oxygen A supplied from the cathode side external electrode 12 side to the inside of the anode 2 and the cathode 3, the anode side external electrode 11 and the anode 2, the cathode side external The electrode 12 and the cathode 3 are composed of a porous body. With such a structure, the supply system of fuel F and the supply system of oxygen A can be easily formed, and the fuel F and oxygen A react across the entire anode 2 and cathode 3, so that more power is extracted. It is. The anode 2 only needs to have the function of spreading the fuel F and the cathode 3 has the function of spreading oxygen A inside thereof. If such a function is provided, the anode 2 and the cathode 3 are porous. It does not have to be. For example, the anode 2 or the cathode 3 can have a gas passage structure. In this case, a structure having a gas passage may be used for either the anode 2 or the cathode 3, and a porous material may be used for the other. When the anode 2 and the cathode 3 are porous, the gap absorbs thermal expansion during heating, and the stress acting between the anode 2, the cathode 3, and the solid electrolyte layer 4 is relieved. Therefore, when the anode 2 and the cathode 3 are made porous, even if the linear expansion coefficients of the materials of the anode 2, the cathode 3, and the solid electrolyte layer 4 vary to some extent, the anode 2, the cathode 3, and the solid electrolyte The crack of the layer 4 can be suppressed. The anode-side side electrode connected to the anode-side external electrode and the cathode-side side electrode connected to the cathode-side external electrode may be formed of the same material as the corresponding external electrode, but are not limited thereto. The side electrode need not be porous.

In the stacked SOFC element used in this embodiment, the anode 2 and the cathode 3 are made of the same material (porous platinum), but the anode 2 and the cathode 3 may be made of different materials. As the anode 2, in addition to platinum, one that exhibits electron conductivity in a high-temperature reducing atmosphere can be used. Examples of such a material include cermet of nickel (Ni), solid electrolyte such as SDC and YSZ, and nickel (Ni). Here, SDC is a material as shown in Ce _0.85 Sm _0.15 O _2-δ , and YSZ is a material as shown in Zr _0.81 Y _0.19 O _2-δ. . In addition to platinum, cathode 3 that exhibits electron conductivity in a high-temperature oxidizing atmosphere can be used. Examples of such a material include CoFe ₂ O ₄ , MnFe ₂ O ₄ , NiFe ₂ O ₄ , BSCF, and the like. Here, BSCF is an oxide of barium (Ba), strontium (Sr), cobalt (Co), and iron (Fe). The materials of the anode 2 and the cathode 3 are not limited to those described above, and all materials applicable as SOFC anodes and cathodes can be used.

  Further, the anode-side external electrode 11 only needs to electrically connect the plurality of anodes 2, and the cathode-side external electrode 12 only needs to electrically connect the plurality of cathodes 3. Therefore, the anode side external electrode 11 and the anode 2 may be made of different materials, and the cathode side external electrode 12 and the cathode 3 may be made of different materials. Thereby, a more appropriate material can be used for the anode 2, the anode side external electrode 11, and the like.

  As described above, in the stacked SOFC element 1 used in the present embodiment, the partition portions 5a and 5c are provided between the solid electrolyte layers 4 adjacent to each other in the stacking direction, and the solid electrolyte layers 4 are connected to each other. Connecting. In this way, when the anode-side external electrode 11 and the cathode-side external electrode 12 are formed on the stacked SOFC element 1, the anode-side external electrode 11 and the anode-side external electrode 11 are connected between the cathode 3 and the anode-side external electrode 11, respectively. Partition portions 5a and 5c are arranged between the electrodes 12. Here, when leakage of electrons or gas (fuel F or oxygen A) occurs between the anode 2 and the cathode 3, the power generation efficiency per unit volume of the stacked SOFC element 1 decreases. For this reason, it is preferable that the solid electrolyte layer 4 and the partition parts 5a and 5c between the anode 2 and the cathode 3 are insulative to electrons and gas tight (not to allow gas to pass through). By using the same material for the solid electrolyte layer 4 and the partition portions 5a and 5c, there is an advantage that the stacked SOFC element 1 can be easily manufactured. In addition, you may comprise the solid electrolyte layer 4 and the partition parts 5a and 5c with a different material. Accordingly, it is possible to further effectively suppress the performance deterioration of the stacked SOFC element 1 by using a material that can easily secure electron insulation and gas tightness.

  The thickness of the solid electrolyte layer 4 is preferably as thin as possible, and can be about 1 μm to 50 μm. Moreover, since the thickness of the anode 2 and the thickness of the cathode 3 cannot be made very thin since the fuel F and the oxygen A are allowed to pass through, the thickness can be set to about 20 μm to 200 μm. Furthermore, the partition portions 5 a and 5 c may be made equal to the thickness of the anode 2 and the thickness of the cathode 2.

  Next, an SOFC module in which stacked SOFC elements according to this embodiment are combined and a fuel cell power generation system using the SOFC module will be described.

<Embodiment 1>
FIG. 1 is a perspective view showing the structure of the SOFC module according to Embodiment 1 of the present invention. As shown in FIG. 1, the SOFC module 20 includes a plurality of stacked SOFC elements 1 as described in FIGS. 8 and 9, and an I-shaped (linear) anode that sandwiches the stacked SOFC elements 1. A side clamping plate 21 and a cathode side clamping plate 22 are included. The stacked SOFC element 1 has the above-described structure, so that a plurality (six in the figure) of stacked SOFC elements 1 arranged in an I-shape (straight line) are electrically connected in parallel and fixed. Therefore, high power can be obtained while downsizing, which is suitable for power generation using a flame such as a gas burner as a fuel source. Each of the plurality of stacked SOFC elements 1 has a non-electrode surface, that is, a surface on which no side electrode is formed, facing each other to form an anode-side external electrode 11 formation surface, a cathode-side external electrode 12 formation surface, and a cathode-side side surface 14 All of the surface and the anode-side side surface 13 forming surface are arranged in the same direction.

  The anode side sandwiching plate 21 and the cathode side sandwiching plate 22 are made of plate-like conductive members, and are arranged so as to overlap the anode side side electrode 13 and the cathode side side electrode 14 of each stacked SOFC element 1. The In the first embodiment, the plurality of stacked SOFC elements 1 sandwiched between the anode side sandwiching plate 21 and the cathode side sandwiching plate 22 are fastened and fixed by bolts and nuts (not shown). The bolt and nut are configured to be electrically insulated from the anode side clamping plate 21 and the cathode side clamping plate 22. For example, bolts and nuts made of insulating ceramics may be used. With such a structure, the SOFC module 20 can connect a plurality of stacked SOFC elements 1 physically and electrically in parallel. By connecting lead wires (not shown) to the ends of the anode-side sandwich plate 21 and the cathode-side sandwich plate 22, power can be output to an external load.

  Note that the anode side sandwiching plate 21 and the cathode side sandwiching plate 22 are electrically conductive and need only be able to sandwich a plurality of stacked SOFC elements. The plate quality is not necessarily a plate-like dense body (hard), and is not limited to this. Alternatively, a metal foil, metal fiber, metal mesh or the like having elasticity or air permeability may be used.

  In the example shown in FIG. 1, the widths of the anode-side sandwich plate 21 and the cathode-side sandwich plate 22 are made shorter than the direction in which the electrodes of the plurality of anodes 2 and the plurality of cathodes 3 of the stacked SOFC element 1 extend. . With such a configuration, the cathode-side external electrode 11 and the cathode-side side electrode 14 by the cathode-side clamping plate 22, or the cathode-side external electrode 12 and the anode-side side electrode 13 by the anode-side clamping plate 21 are used. Can prevent a short circuit.

  When a plurality of stacked SOFC elements 1 are sandwiched between the anode side sandwiching plate 21 and the cathode side sandwiching plate 22, between the plurality of stacked SOFC elements 1 and the anode side sandwiching plate 21 or the cathode side sandwiching plate 22 sandwiching them. Buffer materials (not shown) such as conductive metal fibers, metal meshes, and conductive springs may be sandwiched. Thereby, these buffer materials can absorb the dimensional tolerance in the direction in which the anode side surface electrode 13 and the cathode side side electrode 14 of each stacked SOFC element 1 face each other, and the plurality of stacked SOFC elements 1 can be elastically sandwiched. The problem of physical and electrical connection can be solved.

  When sandwiching a plurality of stacked SOFC elements 1 between the anode-side sandwiching plate 21 and the cathode-side sandwiching plate 22, at least one of the conductive sandwiching plates is provided with a counterbore (not shown), and the stacked SOFC element 1 is sandwiched between them. It may be inserted. As a result, the movement of the stacked SOFC element 1 in the planar direction is limited, and the stacked SOFC element 1 can be prevented from being displaced or dropped due to physical shock or thermal shock.

  When a plurality of stacked SOFC elements 1 are sandwiched between the anode-side sandwiching plate 21 and the cathode-side sandwiching plate 22, a hard plate (not a ceramic plate or the like) is used as a reinforcing plate outside the anode-side sandwiching plate 21 and the cathode-side sandwiching plate 22. (Shown) may be stacked. Alternatively, rising portions (not shown) may be provided at the ends of the anode-side clamping plate 21 and the cathode-side clamping plate 22 so as to have an L-shaped cross section. By doing so, it is possible to suppress the deflection in the arrangement direction of the plurality of stacked SOFC elements 1 of the anode-side sandwiching plate 21 and the cathode-side sandwiching plate 22 and prevent the stacked SOFC element 1 from being displaced or dropped off.

  When the anode-side clamping plate 21 and the cathode-side clamping plate 22 sandwiching the plurality of stacked SOFC elements 1 are fastened and fixed with bolts and nuts (not shown), the tightening locations are the anode-side clamping plate 21 and the cathode-side clamping plate 22. It may be increased not only at both ends of the but also at multiple places in the middle. By doing so, the deflection of the anode side clamping plate 21 and the cathode side clamping plate 22 can be suppressed, and the stacked SOFC element 1 can be prevented from falling off. The bolts and nuts need to be electrically insulated from the anode side clamping plate 21 and the cathode side clamping plate 22.

  When sandwiching a plurality of stacked SOFC elements 1 between the anode-side sandwiching plate 21 and the cathode-side sandwiching plate 22, the stacked SOFC elements 1 are installed without any gaps, or between them, a spacing regulating plate (not fixed) It is also possible to install a structure such as the one shown in the figure and eliminate the gap between the stacked SOFC elements 1. By doing so, it can suppress that the oxygen potential gradient between an anode side external electrode and a cathode side external electrode falls by the surrounding of a flame, and an output falls.

  When a plurality of stacked SOFC elements 1 are sandwiched between the anode-side sandwiching plate 21 and the cathode-side sandwiching plate 22, between the anode-side external electrode 11 and the cathode-side side electrode 14 of the stacked SOFC element 1 and the cathode-side external electrode 12. An insulating plate (not shown) may be sandwiched in a range that covers the space between the anode side electrode 13 and the anode side surface electrode 13. By doing so, it is possible to suppress a short circuit between the anode-side external electrode 11 and the cathode-side side electrode 14 and a short-circuit between the cathode-side external electrode 12 and the anode-side side electrode 13 through the sandwiching plate, thereby reducing the output voltage. .

  When power generation is performed using a flame such as a gas burner as a fuel source, the conductive sandwich plate is exposed to an environment where high temperature oxidation is likely to occur, and a conduction failure is likely to occur. Therefore, the conductive sandwich plate is made of a noble metal material, or a heat-resistant stainless steel base material coated with a noble metal, so that the oxidation of the conductive sandwich plate can be suppressed and the occurrence of poor conduction can be prevented.

  A combustion cycle test was performed on a burner plate to which the SOFC module 20 as shown in FIG. 1 was fixed. The results (number of conduction failures) are shown in Table 1. Ten SOFC modules 20 were prepared for each of the conductive sandwich plate materials shown in the examples and comparative examples. The burner plate to which the SOFC module 20 was fixed was ignited, and the initial power was measured after 10 minutes. Furthermore, the burner plate was extinguished, and after 1000 minutes of natural cooling for 20 minutes, power was generated again for 10 minutes, and the power after 1000 cycles was measured. When the rate of change between the initial power and the power after 1000 cycles was less than 10%, “◯” (no continuity failure), and when the rate of change was 10% or more, “X” (with continuity failure). While the cathode side clamping plate 22 was oxidized at a high temperature, Fe in Comparative Example 1 and a heat-resistant stainless steel base material in Comparative Example 2 had poor conduction, whereas Au in Example 1, Ag in Example 2, and Example The heat-resistant stainless steel substrate coated with Pt 3 and Pt of Example 4 was able to suppress the occurrence of poor conduction.

  FIG. 2 is a diagram illustrating a connection example of the fuel cell power generation system 80 using the SOFC module 20. As shown in FIG. 2, for example, the SOFC module 20 is formed as a module by connecting five stacked SOFC elements 1 in parallel. The fuel cell power generation system 80 has three SOFC modules 20 connected in series. The output and the terminal voltage of the fuel cell power generation system 80 can be arbitrarily changed by the connection of the stacked SOFC elements 1 and the combination of the SOFC modules 20. The fuel cell power generation system 80 stores power in the secondary battery 51 from the SOFC module 20 via the charging device 50.

<Embodiment 2>
FIG. 3 is a perspective view showing a SOFC module structure according to Embodiment 2 of the present invention. It is a modification of FIG. The anode side clamping plate 21 and the cathode side clamping plate 22 do not necessarily need to be I-shaped (straight). As shown in FIG. 3, it is sandwiched between an L-shaped anode-side sandwiching plate 21 and a cathode-side sandwiching plate 22. By doing so, a plurality (seven in the figure) of stacked SOFC elements 1 arranged in an L shape can be connected and fixed in electrical parallel. Alternatively, the L-shaped anode side clamping plate 21 and the cathode side clamping plate 22 may be arranged in a square shape by combining two sets of SOFC modules 20. In this way, for example, it is useful to arrange so as to surround the opening area of the burner plate.

<Embodiment 3>
FIG. 4 is a perspective view showing the SOFC module structure according to Embodiment 3 of the present invention. It is a modification of FIG. The anode side clamping plate 21 and the cathode side clamping plate 22 do not necessarily need to be I-shaped (straight). As shown in FIG. 4, it is clamped by an arcuate anode-side clamping plate 21 and a cathode-side clamping plate 22 that have a ring shape or a shape obtained by dividing the ring. By doing so, a plurality (seven in the figure) of stacked SOFC elements 1 arranged in an arc shape can be connected and fixed in parallel, so that, for example, a flame is injected in an arc shape such as a gas stove. This is useful for placing the SOFC module in a gas appliance or the like.

  Next, a usage example of the SOFC module 20 according to the first embodiment of the present invention will be described. The SOFC module attached to the burner plate will be described with reference to FIGS. FIG. 5 is a perspective view showing a burner plate with an SOFC module. The SOFC module 20 according to the first embodiment is installed at the peripheral portion of a burner plate 30 in which a plurality of flame openings 31 are arranged in a grid, for example, as shown in FIG. The SOFC module 20 is fixed at a position where the anode side external electrodes (not shown) of the plurality of stacked SOFC elements 1 hit a flame ejected from the flame port 31 of the burner plate 30. By doing so, a plurality of stacked SOFC elements 1 can be collectively installed on the burner plate 30 by a simple operation, and the anode side external electrodes of the plurality of stacked SOFC elements 1 connected in parallel are connected to the burner plate 30. It can be exposed to a flame (not shown) ejected from the flame outlet 31 in a lump. By connecting the lead wires 25 to the end portions of the anode side sandwiching plate 21 and the cathode side sandwiching plate 22, electric power can be output to an external load.

  FIG. 6 is a partial projection view showing an arrangement relationship between the burner plate 30 and the SOFC module 20 in the usage example of FIG. FIG. 7 is a partial cross-sectional view showing the positional relationship between the burner plate 30 and the SOFC module 20 in the usage example of FIG. As shown in FIGS. 6 and 7, the burner plate 30 has an opening region 33 in which a plurality of flame holes 32 penetrating from the air-fuel mixture supply surface 36 to the combustion surface 37 is formed, and is a peripheral region outside the opening region 33. The SOFC module 20 is arranged at 34. The SOFC module 20 includes a plurality of stacked SOFC elements 1 sandwiched between the anode-side sandwich plate 21 and the cathode-side sandwich plate 22 so that each anode-side external electrode 11 overlaps at least a part of the opening region 33, and The cathode-side external electrode 12 is arranged so as to face the outside of the opening region 33. Thus, the SOFC module 20 raises the temperature to the operating temperature by the combustion heat of the flame released from the flame holes 32 of the burner plate 30 and the radiant heat transmitted from the plate, and the combustion gas is supplied to the anode-side external electrode 11. Can be supplied. As a result, an oxygen potential gradient is generated between the anode-side external electrode 11 and the cathode-side external electrode 12, and electric power corresponding to the oxygen potential gradient can be obtained. The electric power obtained by the plurality of stacked SOFC elements 1 includes the anode-side external electrode 11-the anode-side side electrode 13-the anode-side clamping plate 21 and the cathode-side external electrode 12-the cathode-side side electrode 14-the cathode-side clamping plate. It can supply to external loads, such as a charging device and a secondary battery, through 22 paths.

  The SOFC module according to the present invention and a power generation apparatus (fuel cell power generation system) on which the SOFC module is mounted can be used for a gas appliance having a flame combustion section such as an infrared heater with a fan, a small water heater, or a built-in stove. By doing so, it is possible to realize a desire to drive electronic devices such as fans, sensors, and electronic display devices attached to gas appliances without using batteries.

DESCRIPTION OF SYMBOLS 1 Stack type SOFC element 2 Anode 3 Cathode 4 Solid electrolyte layer 5 Partition part 6 Blank part 11 Anode side external electrode 12 Cathode side external electrode 13 Anode side side electrode 14 Cathode side side electrode 20 SOFC module 21 Anode side clamping plate 22 Cathode side Clamping plate 23 Clamping bolt 24 Nut 25 Lead wire 30 Burner plate 31 Flame port 32 Flame hole 33 Opening region 34 Peripheral region 35 Flame 36 Mixture supply surface 37 Combustion surface 50 Charging device 51 Secondary battery 80 Fuel cell power generation system A Oxygen ( air)
F Fuel N Electrode extension direction M Cross direction

Claims (6)

In an SOFC module comprising a plurality of stacked SOFC elements and a pair of opposing conductive sandwich plates,
Each of the plurality of stacked SOFC elements has a hexahedron shape, includes a plurality of anodes and a plurality of cathodes therein, and has an anode-side external electrode connected to the plurality of anodes on opposite end surfaces, and the plurality of the plurality of stacked SOFC elements. A cathode-side external electrode connected to the cathode; a cathode-side side electrode electrically connected to the cathode-side external electrode on any one of the four surfaces adjacent to the surface of the cathode-side external electrode; Having an anode side electrode electrically connected to the anode side external electrode on the surface facing the surface of the cathode side electrode;
In the plurality of stacked SOFC elements, at least the surface of the anode side electrode and the surface of the cathode side electrode face the same direction, and the anode side external electrode and the cathode side external electrode are respectively in the SOFC module. Arranged to be on the same side, sandwiched between the pair of conductive sandwiching plates on the surface where the side electrode is formed, the anode side side electrodes are connected to one of the conductive sandwiching plates, and the cathode side The SOFC module, wherein side electrodes are connected to the other of the conductive sandwich plates.   The anode-side external electrode surface, the cathode-side external electrode surface, the cathode-side side electrode surface, and the anode-side side electrode surface are all aligned in the same direction, and the pair of conductive sandwiches The anode side surface electrodes are connected to one side of the conductive clamping plate, and the cathode side side electrodes are connected to the other side of the conductive clamping plate. The SOFC module according to claim 1, wherein:   The SOFC module according to claim 2, wherein the plurality of stacked SOFC elements are arranged in a straight line, and the pair of conductive sandwich plates are in a straight line.   The SOFC module according to claim 1, wherein the plurality of stacked SOFC elements are arranged in an L shape, and the pair of conductive sandwich plates are in an L shape.   The SOFC module according to claim 1, wherein the plurality of stacked SOFC elements are arranged in an arc shape, and the pair of conductive sandwich plates are in an arc shape.   The SOFC module according to any one of claims 1 to 5, wherein the conductive sandwich plate is made of a noble metal material or a material obtained by coating a heat-resistant stainless steel base material with a noble metal.

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