JP2013065416A - Solid oxide fuel battery device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solid oxide fuel battery (SOFC) device which has an excellent durability and allows the further reduction in its installation space, and which is configured so that a container can be effectively prevented from being damaged while the size in a direction of the thickness is reduced.SOLUTION: The SOFC device 1 comprises a fuel battery module 2. The fuel battery module has a casing 56 in which a fuel battery cell assemblage shaped in a substantially rectangular parallelepiped form is housed. The casing 56 has a barrel part 560 which includes: a pair of long-side walls 561, 561 opposed to long-side faces of the fuel battery cell assemblage; and a pair of short-side walls 562, 562 opposed to short-side faces of the fuel battery cell assemblage. Each long-side wall 561 has an end whose face 561s is opposed to a face 562s of the short-side wall 562, and in this condition, the end is bonded with the short-side wall at its tip 56T by means of welding or the like.

Description

  The present invention relates to a solid oxide fuel cell device that generates power using a fuel gas and an oxidant gas.

  A solid oxide fuel cell (hereinafter also referred to as “SOFC”) uses an oxide ion conductive solid electrolyte as an electrolyte, has electrodes attached to both sides thereof, and supplies fuel gas to one side. This is a fuel cell device that generates power by supplying an oxidant gas (air, oxygen, etc.) to the other side and generating a power generation reaction at a relatively high temperature.

  Specifically, the SOFC generally includes a plurality of tubular fuel cells each having a solid electrolyte layer sandwiched between a fuel electrode layer that is an inner electrode layer and an air electrode layer that is an outer electrode layer. An assembly (fuel cell stack) is provided, which operates when fuel gas and oxidant gas (air, oxygen, etc.) flow from one end side to the other end side of the fuel cell. From the outside of the SOFC, a gas to be reformed (city gas, etc.), which is a raw material gas, is supplied, and the gas to be reformed is introduced into a reformer containing a reforming catalyst, and reformed into a hydrogen-rich fuel gas. After being refined, it is configured to be supplied to the fuel cell assembly.

  In addition, the SOFC includes a plurality of processes for reforming the fuel gas in the reformer in the start-up process, that is, a partial oxidation reforming (POX) reaction process, an auto thermal reforming (ATR). The reaction process and the steam reforming (SR) reaction process are followed to shift to the power generation process. In the SOFC, the reformer, the fuel cell stack, and the like can be raised to the operating temperature by sequentially executing these steps.

  Such SOFCs are used for various purposes and are often placed outside the building (for example, in the vicinity of the outer wall of the building) when installed in a building such as a house or a store. At this time, in order to reduce the required installation space by minimizing the amount of protrusion from the outer wall surface, it is possible to install the SOFC in a narrow area between buildings. It is desirable to make the value as small as possible. Therefore, SOFCs used for such applications are usually formed so that the outer shape of the fuel cell assembly is a substantially rectangular parallelepiped shape, and the same substantially rectangular parallelepiped shape that can accommodate the fuel cell assembly as compactly as possible. In general, the long side wall tends to be disposed along the outer wall surface of the building. For example, Patent Document 1 describes an example of an SOFC having such a rectangular parallelepiped shape.

JP 2010-140734 A

  By the way, although the patent document 1 does not mention the detailed configuration of the SOFC container, for example, if it is a rectangular parallelepiped metal container, a flat plate-like long side member and a flat plate-like short side member are welded together. By joining together, a square tubular body can be formed.

  Here, as described above, when the fuel cell assembly is configured to be as compact as possible, the internal volume of the container is reduced, and as a result, the heat generated by the power generation reaction of the SOFC is generated from the fuel cell assembly. Difficult to be dissipated by radiation and conduction outside the container. In this case, a compact container having a small internal volume is more easily heated and deformed (expanded) than a container having a relatively large internal volume. Specifically, since the fuel cell of SOFC is usually heated to a high temperature of about 500 ° C. to 700 ° C. during power generation, in a container having a body having the above-described structure, a long side wall made of a long side member is used. Since the expansion amount of the short side member is significantly larger than the expansion amount of the short side wall made of the short side member, stress and load due to deformation caused by thermal expansion are excessively concentrated on the welded portion, and the part is damaged. It becomes easy to do. Such an event can be particularly noticeable in an SOFC in which the distance between the fuel cell assembly and the long side wall of the container is narrower and the dimension in the thickness direction is smaller.

  Therefore, the present invention has been made in view of such circumstances, and even if the dimension in the thickness direction is reduced, the container can be effectively prevented from being broken and broken, thereby providing excellent durability and installation. An object of the present invention is to provide a solid oxide fuel cell device capable of further reducing the space.

  In order to solve the above-described problems, a solid oxide fuel cell (SOFC) device according to the present invention performs power generation using a fuel gas and an oxidant gas, and includes a fuel electrode layer to which the fuel gas is supplied, an oxidation layer A plurality of fuel cells having an air electrode layer to which the agent gas is supplied and a solid electrolyte layer provided between the fuel electrode layer and the air electrode layer are connected in a substantially rectangular parallelepiped shape and electrically The fuel cell assembly connected to the fuel cell assembly and the fuel cell assembly configured in such a substantially rectangular parallelepiped shape are accommodated, and are opposed to the pair of long side surfaces defined in the fuel cell assembly. A container having a body including a pair of long side walls and a pair of short side walls facing a pair of short side surfaces defined in the fuel cell assembly; and ends of the pair of long side walls Planes on each other at the pair of short side walls. Is disposed opposite to the parts facing each other (surface part facing the inner side of the container in the pair of short side walls), and in at least a part of the part, the pair of long side walls and the pair of short side walls Are joined.

  In the SOFC configured as described above, a fuel cell assembly whose outer shape is a substantially rectangular parallelepiped shape is accommodated in a container including a trunk portion having a long side wall and a short side wall. The long side wall and the short side wall of the body portion of the container are respectively opposed to the long side surface and the short side surface of the fuel cell assembly, and the overall shape of the container is also a substantially rectangular parallelepiped shape. Therefore, by reducing the dimension of the short side wall of the container body as much as possible, the dimension of the SOFC in the thickness direction can be made as small as possible.

  At this time, the end surface of the long side wall is disposed so as to face a portion (opposing surface portion) facing each other in the pair of short side walls, and in that state, at least a part of the portion, the pair of long sides The side wall and the pair of short side walls are joined and fixed by, for example, welding. Therefore, even if the long side wall whose expansion amount is relatively large when heated to a high temperature as described above is thermally deformed, the end surface strongly contacts the short side wall in a plane shape, so that the long side wall While the expansion is restricted, it is possible to prevent the stress (for example, shearing force) that breaks or breaks the joint portion between the long side wall and the short side wall from acting on the portion.

  It is also preferable that the end surface of the long side wall is bent toward the outside of the container. In this case, the outer side surface of the portion bent outward in the long side wall becomes the end surface of the long side wall, and the remaining long portion can substantially function as the side wall. Specifically, when the long side wall is formed of, for example, a flat plate rectangular member, by bending the both end portions in an L shape, the outer surface (side facing outward) of the bent portion is the end portion. The body of the container is configured such that the long side wall having such a structure is sandwiched between the short side walls.

  If comprised in this way, since the part except an end surface in a long side wall will oppose the long side surface of a fuel cell assembly, when a long side wall is heated at high temperature, the part except the end surface Is deformed so as to substantially expand due to thermal expansion. At this time, since both side walls are joined to at least a part of the end side surface bent at the long side wall and the surface of the short side wall opposite to the end surface, the bent portion is used as a fixed fulcrum and bent. Deformation force acts on the long side wall with the portion as a free fulcrum. Then, since the reaction force (elastic moment) according to the deformation moment at that time acts on the long side wall as the center, the stress and load applied to the joint portion (for example, thrust load) (Shear stress due to the above) is reduced, and as a result, breakage and breakage of the joint portion and thus the container can be further prevented.

  Furthermore, it is also preferable that the long side wall is joined to the short side wall, for example, by welding or the like, preferably at the tip, more preferably at the tip of the end surface of the long side wall.

  In this way, the distance from the joint to any part of the long side wall is maximized, so that the deformation moment of the long side wall described above becomes the largest, and as a result, the deformation moment acting on the joint depends on the deformation moment. Since the reaction force (elastic moment) is also maximized, the stress applied to the joint is further reduced, and it becomes possible to further prevent breakage and breakage of the joint.

  According to the present invention, the end surfaces of the pair of long side walls in the container body portion of the SOFC are arranged to face the inward facing portions of the pair of short side walls, and at least of the portions In some cases, the long side wall and the short side wall are joined, so that even if the long side wall is heated and expanded by the heat generated by the power generation of the fuel cell, the end surface of the long side wall By strongly contacting the short side wall, it is possible to prevent the joint portion between the long side wall and the short side wall from being damaged or broken. As a result, the overall dimension of the SOFC in the thickness direction can be further reduced to reduce the installation space, and the durability of the container can be improved, so the versatility and product reliability of the SOFC device are markedly improved. Can be increased.

It is a perspective view which shows the external appearance of the fuel cell module in suitable one Embodiment of this invention. It is sectional drawing which looked at the fuel cell module shown in FIG. 1 from the A direction of FIG. 1 in the center vicinity. It is sectional drawing which looked at the fuel cell module shown in FIG. 1 from the B direction of FIG. 1 in the center vicinity. It is a perspective view which shows the state which removed a part (outer plate) of the casing from the fuel cell module shown in FIG. It is a schematic diagram corresponding to FIG. 2, Comprising: It is a figure which shows the flow of power generation air and combustion gas. It is a schematic diagram corresponding to FIG. 3, Comprising: It is a figure which shows the flow of power generation air and combustion gas. It is a fragmentary sectional view which shows the fuel cell unit of the fuel cell module shown in FIG. It is a perspective view which shows the structure of the fuel cell stack of the fuel cell module shown in FIG. It is a horizontal sectional view in the IX-IX line shown in Drawing 1-Drawing 4. It is a partially expanded sectional view which shows the site | part enclosed with the dashed-dotted line in FIG. 9, and its periphery, and shows the state by which the container is not heated. FIG. 10 is a partially enlarged cross-sectional view showing a portion D surrounded by an alternate long and short dash line in FIG. It is a partially expanded sectional view (sectional view corresponding to FIG. 9) which shows the structure of a comparative example.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In order to facilitate the understanding of the description, the same constituent elements in the drawings will be denoted by the same reference numerals as much as possible, and redundant description will be omitted. Further, the dimensional ratio is not limited to the illustrated ratio. Furthermore, the following embodiment is an illustration for explaining the present invention, and is not intended to limit the present invention only to the embodiment. Furthermore, the present invention can be variously modified without departing from the gist thereof.

  FIG. 1 is a perspective view schematically showing the external appearance of a SOFC apparatus in a preferred embodiment of the present invention. The fuel cell module 2 constitutes a part of the SOFC device 1 according to the present invention. The SOFC device 1 includes a fuel cell module 2 and an auxiliary unit (not shown).

  In FIG. 1, an x-axis, a y-axis, and a z-axis are defined as three-dimensional axis coordinates. That is, the height direction of the fuel cell module 2 is defined as the y-axis direction, the x-axis and the z-axis are defined along a plane orthogonal to the y-axis, and the direction along the short direction of the fuel cell module 2 is defined as the x-axis direction. The direction along the longitudinal direction of the fuel cell module 2 is defined as the z-axis direction. Further, the x-axis, y-axis, and z-axis described in FIG. 2 and subsequent figures are based on the x-axis, y-axis, and z-axis in FIG. Furthermore, the direction extending in the negative direction from the origin on the z axis is defined as the A direction, and the direction extending in the positive direction from the origin on the x axis is defined as the B direction.

  The fuel cell module 2 includes a casing 56 (container) that accommodates fuel cells (details will be described later), and a heat exchanger 22 provided on the upper portion of the casing 56. A reformed gas supply pipe 60 and a water supply pipe 62 are connected to the casing 56. On the other hand, a power generation air introduction pipe 74 and a combustion gas discharge pipe 82 are connected to the heat exchanger 22.

  The to-be-reformed gas supply pipe 60 is a pipe line that supplies a to-be-reformed gas for reforming such as city gas into the casing 56. The water supply pipe 62 is a pipe for supplying water used when steam reforming the gas to be reformed. Furthermore, the power generation air introduction pipe 74 is a pipe that supplies air for causing a power generation reaction with the reformed fuel gas. The combustion gas discharge pipe 82 is a pipe line for discharging the combustion gas generated by burning the fuel gas after the power generation reaction.

  Next, the internal configuration of the fuel cell module 2 will be described with reference to FIGS. 2 is a cross-sectional view of the fuel cell module 2 as viewed from the direction A in FIG. 1 near its center, and FIG. 3 is a cross-sectional view of the fuel cell module 2 as viewed from the direction B in FIG. is there. 4 is a perspective view showing a state where a part (outer plate) of the casing 56 covering the fuel cell assembly is removed from the fuel cell module 2 shown in FIG. 5 is a schematic diagram corresponding to FIG. 2 and is a diagram showing the flow of power generation air and combustion gas. FIG. 5 is a schematic diagram corresponding to FIG. 6 and FIG. It is a figure which shows the flow of air and combustion gas.

  As shown in FIGS. 2 to 4, the fuel cell assembly 12 of the fuel cell module 2 is accommodated in the interior thereof so as to be entirely covered by the casing 56. Further, as shown in FIG. 5, the fuel cell assembly 12 as a whole has a substantially rectangular parallelepiped shape that is longer in the A direction than in the B direction, and the upper surface on the reformer 20 side and the lower surface on the fuel gas tank 68 side. A long side surface (described later) extending along the A direction in FIG. 2 and a short side surface (described later) extending along the B direction in FIG. 2 are defined.

  In the case of this embodiment, an evaporating mixer (not explicitly shown) for evaporating the water supplied from the water supply pipe 62 is provided inside the reformer 20. The evaporative mixer is heated by the combustion gas to convert water into water vapor, and to mix the water vapor, fuel gas (city gas) as the reformed gas, and air.

  The reformed gas supply pipe 60 and the water supply pipe 62 are both led to the inside of the casing 56 and then connected to the reformer 20, and more specifically, as shown in FIG. It is connected to the end on the right side of the figure, which is the upstream end of the vessel 20. Further, the reformer 20 is disposed further above the combustion chamber 18 defined above the fuel cell assembly 12. Thereby, the reformer 20 is heated by the combustion heat of the remaining fuel gas and air after the power generation reaction, and functions as an evaporative mixer and a reformer for causing the reforming reaction. Further, the upper end of the fuel supply pipe 66 is connected to the downstream end of the reformer 20 (the end on the left side in FIG. 3), and the lower end side 66 a of the fuel supply pipe 66 is in the fuel gas tank 68. It arrange | positions so that it may enter (refer FIG. 2).

  On the other hand, as shown in FIGS. 3 and 4, the fuel gas tank 68 is provided substantially directly below the fuel cell assembly 12. A plurality of small holes (not shown) are formed along the longitudinal direction (A direction) on the outer periphery of the lower end side 66 a of the fuel supply pipe 66 inserted into the fuel gas tank 68. The fuel gas reformed by the reformer 20 is supplied uniformly along the longitudinal direction into the fuel gas tank 68 through the plurality of small holes (not shown). The fuel gas supplied to the fuel gas tank 68 is supplied into a fuel gas flow path (details will be described later) inside each fuel cell unit 16 constituting the fuel cell assembly 12, and the fuel cell. The interior of the unit 16 is raised to reach the combustion chamber 18.

  Further, a mechanism for supplying power generation air to the inside of the fuel cell module 2 will be described with reference to FIGS. As shown in FIGS. 5 and 6, a heat exchanger 22 is provided above the reformer 20. The heat exchanger 22 is provided with a plurality of combustion gas pipes 70, and a power generation air flow path 72 is defined around the combustion gas pipes 70.

  A power generation air introduction pipe 74 is attached to one end side (the right end side in FIG. 3) of the upper surface of the heat exchanger 22. With this power generation air introduction pipe 74, power generation air is introduced into the heat exchanger 22 from a power generation air flow rate adjustment unit (not shown). Further, a pair of outlet ports 76 a of the power generation air flow path 72 is formed on the other end side (the left end side in FIG. 3) on the upper side of the heat exchanger 22. The outlet port 76a communicates with a pair of communication channels 76. Further, as shown in FIG. 2, power generation air is supplied along the longitudinal direction of the fuel cell assembly 12 on both outer sides in the width direction (B direction: short side surface direction) of the casing 56 of the fuel cell module 2. Roads 77 and 77 are defined.

  With this configuration, the power generation air supply path 77 is supplied with power generation air from the outlet port 72 a of the power generation air flow path 72 and the communication flow path 76. In addition, at a position corresponding to the lower side of the power generation air supply path 77 and the fuel cell assembly 12, the power generation air is directed toward each fuel cell unit 16 of the fuel cell assembly 12 in the power generation chamber 10. A plurality of air outlets 78a and 78b are formed for delivery. The power generation air blown out from these air outlets 78a, 78b flows along the outside of each fuel cell unit 16 (flows from below to above).

  Next, a mechanism for discharging combustion gas generated by combustion of fuel gas and power generation air (oxidant gas) in the combustion chamber 18 will be described. The combustion gas generated above the fuel cell unit 16 rises in the combustion chamber 18 and reaches the rectifying plate 21 provided with the opening 21a. The combustion gas is guided from the opening 21 a to the heat exchanger 22 side, and the combustion gas that has passed through the opening 21 a reaches the other end side of the heat exchanger 22. As described above, a plurality of combustion gas pipes 70 for discharging the combustion gas are provided in the heat exchanger 22, and a combustion gas discharge pipe 82 is provided at the downstream end side of these combustion gas pipes 70. Are connected, and thereby, the combustion gas is discharged to the outside.

  Next, the fuel cell unit 16 will be described with reference to FIG. FIG. 7 is a partial cross-sectional view showing the fuel cell unit 16 of the present embodiment. As shown in the figure, the fuel cell unit 16 includes a fuel cell 84 and inner electrode terminals 86 connected to the upper and lower ends of the fuel cell 84 in the figure.

  The fuel cell 84 is a tubular structure extending in the vertical direction, and includes a cylindrical inner electrode layer 90 (fuel electrode layer) and a cylindrical outer electrode layer 92 (air electrode) that define a fuel gas flow path 88 therein. Layer), and an electrolyte layer 94 disposed between the inner electrode layer 90 and the outer electrode layer 92. The inner electrode layer 90 is a fuel electrode through which fuel gas flows and functions as a (−) electrode, while the outer electrode layer 92 is an air electrode in contact with air and functions as a (+) electrode.

  Since the inner electrode terminals 86 and 86 attached to the upper end side and the lower end side of the fuel cell unit 16 have the same structure, the inner electrode terminal 86 attached to the upper end side will be specifically described here as an example. . The upper portion 90 a of the inner electrode layer 90 includes an outer peripheral surface 90 b and an upper end surface 90 c exposed to the electrolyte layer 94 and the outer electrode layer 92. The inner electrode terminal 86 is connected to the outer peripheral surface 90b of the inner electrode layer 90 through a conductive sealing material 96, and is further in direct contact with the upper end surface 90c of the inner electrode layer 90, thereby Electrically connected. In addition, a fuel gas passage 98 communicating with the fuel gas passage 88 of the inner electrode layer 90 is defined at the center of the inner electrode terminal 86.

  The inner electrode layer 90 includes, for example, a mixture of Ni and zirconia doped with at least one selected from rare earth elements such as Ca, Y, and Sc, ceria doped with Ni and at least one selected from rare earth elements, A mixture of Ni and lanthanum garade doped with at least one selected from Sr, Mg, Co, Fe, and Cu.

  The electrolyte layer 94 is made of, for example, zirconia doped with at least one selected from rare earth elements such as Y and Sc, ceria doped with at least one selected from rare earth elements, and lanthanum doped with at least one selected from Sr and Mg. It is formed from at least one kind of gallate.

  Further, the outer electrode layer 92 includes, for example, lanthanum manganite doped with at least one selected from Sr and Ca, lanthanum ferrite doped with at least one selected from Sr, Co, Ni and Cu, Sr, Fe, Ni and Cu. It is formed from at least one of lanthanum cobaltite doped with at least one selected from the group consisting of silver and the like.

  Next, the fuel cell stack 14 will be described with reference to FIG. FIG. 8 is a perspective view showing the fuel cell stack 14 of the present embodiment. As shown in the figure, one fuel cell stack 14 includes, for example, 16 fuel cell units 16, and the lower end side and the upper end side of the plurality of fuel cell units 16 are respectively made of ceramic fuel gas tanks. The upper plate 68a and the upper support plate 100 are integrally supported. The fuel gas tank upper plate 68a and the upper support plate 100 are formed with through holes through which the inner electrode terminals 86 of the fuel cell units 16 can pass.

  A current collector 102 and an external terminal 104 are attached to the fuel cell unit 16. The current collector 102 electrically connects the inner electrode terminal 86 attached to the inner electrode layer 90 that is a fuel electrode and the outer peripheral surface of the outer electrode layer 92 that is the air electrode of the adjacent fuel cell unit 16. Is to do. Further, the external terminal 104 is connected to the inner electrode terminal 86 at the upper end and the lower end of the two fuel cell units 16, 16 located at the end of each fuel cell stack 14, and further, adjacent fuel cells. It is also connected to the inner electrode terminal 86 of the upper end and lower end of the fuel cell unit 16 at the end of the battery cell stack 14 so that all of the fuel cell units 16 (for example, 160 lines described above) are connected in series. It has become. In this way, a plurality of fuel cell stacks 14 each having a plurality of fuel cell units 16 are connected and electrically connected to each other to form the fuel cell assembly 12 having a substantially rectangular parallelepiped shape as described above. ing.

  Furthermore, the structure of the casing 56 in which the fuel cell assembly 12 is accommodated will be described in more detail with reference to FIGS. FIG. 9 is a horizontal sectional view taken along line IX-IX shown in FIGS. 10 and 11 are both partially enlarged cross-sectional views showing the portion D surrounded by the alternate long and short dash line in FIG. 9 and its surroundings. FIG. 10 shows a state where the container 56 is not heated. 11 shows an example of a state in which the container 56 is heated. Further, FIG. 12 is a partially enlarged cross-sectional view (cross-sectional view corresponding to FIG. 9) showing a configuration of a comparative example that does not have the configuration of the present invention.

  As shown in FIG. 9, the casing 56 having a substantially rectangular parallelepiped shape includes a body portion 560 including a pair of long side walls 561 and 561 and a pair of short side walls 562 and 562. The long side walls 561 and 561 are provided to face a pair of long side surfaces 121 and 121 (shown by broken lines in the drawing) that are virtually defined in the fuel cell assembly 12 configured in a substantially rectangular parallelepiped shape. . Further, the short side walls 562 and 562 are formed of a flat plate-like member, and are formed on a pair of short side surfaces 122 and 122 (indicated by a two-dot chain line in the drawing) that are virtually defined in the fuel cell assembly 12. Opposite. In addition, in FIG. 9, the exterior housing | casing 30 provided so that the casing 56 may be covered is also illustrated.

  Further, the long side walls 561 and 561 have a shape in which both end portions of the flat plate-like rectangular member are bent in an L shape, and as shown in FIG. 10, the outer side of the bent portion (facing outward). Side surface, that is, the illustrated left surface in the region from the illustrated bending point L to the tip of the member is the end surface 561s. As described above, the end surfaces 561 s of the long side walls 561 and 561 are bent toward the outside of the casing 56 (outer region of the inside 50 of the casing 56).

  Furthermore, each end surface 561 s of the long side walls 561, 561 is opposed to the part facing each other in the short side walls 562, 562, that is, facing the inside 50 side of the casing 56 in the short side walls 562, 562. 156 s and 562 s are opposed to the entire surface, and at least a part of the part (part D in FIGS. 9 to 11), that is, the end face 561 s of the long side wall 561 at the four corners of the body 560. The long side walls 561 and 561 and the short side walls 562 and 562 are joined and fixed, for example, by welding or the like. In this manner, the long side wall 561, 561 having the end surface 561s is sandwiched by the short side wall 562, 562, whereby the body 560 of the casing 56 is configured.

  According to the SOFC device 1 including the fuel cell module 2 configured as described above, the fuel cell assembly 12 is heated to a high temperature by power generation, and the long side wall 561 and the short side wall 562 are heated by the heat. It expands according to the (linear) coefficient of thermal expansion that depends on the physical properties of the material. At this time, since the long side wall 561 is longer than the short side wall 562, the amount of expansion is relatively large, and the direction indicated by the arrow 56v in FIG. 10 (± z axis direction in FIGS. 1 to 4). ).

  At this time, the end surface 561 s of the long side wall 561 of the casing 56 is disposed opposite to the surface 562 s of the short side wall 562 in the part D, and the distal end portions T of the long side wall 561 and the short side wall 562 are disposed. Therefore, when the long side wall 561 is extended by thermal expansion, the end surface 561s strongly contacts the short side wall 562 in a planar shape (both are pressed against each other). Thereby, the expansion of the long side wall 561 is restricted by the short side wall 562, and the long side wall 561 and the short side wall 562 are joined at the tip 56T. Stress that breaks or breaks the joint, that is, a load in the thrust direction (direction parallel to the end face 561 s of the long side wall 561 and the face 562 s of the short side wall 562) is applied. Can be deterred. That is, according to the SOFC device 1, a stress mode in which the tip 56T of the casing 56 is sheared does not occur.

  Therefore, it is possible to prevent the casing 56 from being damaged or broken at the distal end portion 56 </ b> T that is a joint portion between the long side wall 561 and the short side wall 562. As a result, the thickness 56w of the casing 56 (see FIG. 9), and consequently the dimension in the thickness direction of the entire fuel cell module 2 (substantially the outer casing 30) can be further reduced to reduce the installation space. In addition, since the durability of the casing 56 can be improved as described above, the versatility and product reliability as the SOFC device can be remarkably improved.

  Further, an end surface 561s of the long side wall 561 is bent in an L shape toward the outside of the casing 56, and a portion of the long side wall 561 excluding the end surface 561s is the fuel cell assembly 12. Therefore, when the long side wall 561 is exposed to a high temperature, the portion other than the end surface 561s can be deformed so as to substantially expand due to thermal expansion. At this time, as shown in FIG. 11, the long side wall 561 is changed from the state shown by the broken line (the state shown in FIG. 10), with the distal end portion 56 </ b> T being a joint as a fixed fulcrum and the bending point L as a free fulcrum. It deform | transforms so that it may swell to the outer side of the casing 56 (long side wall 561 ').

  Then, a reaction force (elastic moment) corresponding to the deformation moment caused by the deformation force acting on the long side wall 561 at that time reacts with these fulcrums. Specifically, the elastic moment N1 indicated by the illustrated arrow centering on the bending point L and the elastic moment N2 indicated by the illustrated arrow centering on the distal end portion 56T act on the long side wall 561. The stress applied to the portion 56T (shear stress due to the thrust load) is further reduced, and as a result, the casing 6 can be further prevented from being damaged or broken at the tip 56T.

  As a comparative example, as shown in FIG. 12, in the case of the body 4 of the casing, the flat long side wall 41 and the substantially flat short side wall 42 are combined as shown in the figure and joined at the tip 4T. Since the end face at the tip of the long side wall 41 does not face the surface 41s of the short side wall 41, when the long side wall 41 expands in the direction indicated by the arrow 56v due to thermal expansion, The thrust load acts directly, and the shearing force easily breaks or breaks the joining of the tip end portion 4T and the container.

  Furthermore, since the long side wall 561 and the short side wall 562 are joined by the end part 56T of the end part surface 561a of the long side wall 561 and the surface 562s of the short side wall 562, the front side part 56T that is the joint part is joined. The distance to the arbitrary part in the long side wall 561 is maximized. As a result, the deformation moment of the long side wall 561 described above becomes the largest, and as a result, the elastic moment N2 acting on the tip portion 56T is also maximized, thereby further reducing the stress applied to the tip portion 56T. Therefore, it is possible to further prevent the casing 56 from being damaged or broken at the distal end portion 56T.

  In addition, as above-mentioned, this invention is not limited to the specific example demonstrated in said embodiment, A various deformation | transformation is possible in the limit which does not change the summary. That is, those obtained by appropriately modifying the design of those specific examples by those skilled in the art are also included in the technical scope of the present invention as long as they have the features of the present invention. In other words, the elements included in the specific examples described above and their arrangement, materials, conditions, shapes, sizes, and the like are not limited to those illustrated, and can be changed as appropriate. Moreover, each element with which each embodiment mentioned above is provided can be combined as much as technically possible, and the combination of these is also included in the technical scope of the present invention as long as it includes the features of the present invention.

  For example, the end surface 561s of the long side wall 561 may not be bent in an L shape, and in this case, the peripheral edge (the end surface) of the long side wall 561 is opposed to the surface 561s of the short side wall 562 or The long side wall 561 and the short side wall 562 may be joined in contact with each other, and the end surface 561s of the long side wall 561 has another shape, for example, a U-shape (C shape). It may be bent. Moreover, a junction part is not restrict | limited to the front-end | tip part 56T, What is necessary is just the site | part which the edge part surface 561s of the long side wall 561 and the surface 562s of the short side wall 562 oppose.

  As described above, according to the SOFC device of the present invention, it is possible to reduce the installation space by reducing the dimension in the thickness direction, and to prevent the container containing the fuel cell module assembly from being damaged and broken. The durability can be improved. As a result, the versatility and product reliability of the SOFC device can be significantly improved, so that the SOFC device that can be used for various purposes, particularly those installed in a small area such as between buildings. In addition, the present invention can be widely and effectively used for devices, systems, facilities, and the like provided with the devices, and the manufacture and use thereof.

DESCRIPTION OF SYMBOLS 1 Solid oxide fuel cell (SOFC) apparatus 2 Fuel cell module 10 Power generation chamber 12 Fuel cell assembly 14 Fuel cell stack 16 Fuel cell unit 18 Combustion chamber 20 Reformer 21 Rectifier plate 21a Opening 22 Heat exchanger 30 Exterior casing 50 Casing interior 56 Casing 56T Front end portion 60 Reformed gas supply pipe 62 Water supply pipe 66 Fuel supply pipe 66a Lower end side 68 Fuel gas tank 68a Fuel gas tank upper plate 70 Combustion gas pipe 72 Power generation air flow path 72a Exit Port 74 Power generation air introduction pipe 76 Communication flow path 76a Outlet port 77 Power generation air supply paths 78a, 78b Outlet 82 Combustion gas discharge pipe 84 Fuel cell 86 Inner electrode terminal 88 Fuel gas flow path 90 Inner electrode layer 90a Upper part 90b Outer peripheral surface 90c Upper end surface 92 Outer electrode layer 94 Electrolyte layer 96 Sealing material 98 Fuel gas flow path 100 Upper support plate 102 Current collector 104 External terminal 121 Long side surface 122 Short side surface 560 Body 561, 561 'Long side wall 561s End surface 562 Short side wall 562s Surface N1, N2 Elastic moment

Claims (3)

A solid oxide fuel cell device that generates power with fuel gas and oxidant gas,
A plurality of fuel cells having a fuel electrode layer to which the fuel gas is supplied, an air electrode layer to which the oxidant gas is supplied, and a solid electrolyte layer provided between the fuel electrode layer and the air electrode layer A fuel cell assembly in which cells are connected in a substantially rectangular parallelepiped shape and electrically connected;
A pair of long side walls that house the fuel cell assembly and are opposed to a pair of long side surfaces defined in the fuel cell assembly, and a pair of pairs defined in the fuel cell assembly A container having a trunk including a pair of short side walls facing the short side surface;
With
The end surfaces of the pair of long side walls are disposed to face each other in the pair of short side walls, and the pair of long side walls and the pair of short sides in at least a part of the portions. The side walls are joined,
Solid oxide fuel cell device. The end surface of the long side wall is bent toward the outside of the container,
The solid oxide fuel cell device according to claim 1. The long side wall is joined to the short side wall at the tip of the end surface of the long side wall,
The solid oxide fuel cell device according to claim 2.

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