JP6228204B2 - Fuel cell device - Google Patents

Description

  The present invention relates to a fuel cell device provided with a heat insulating material outside a cell stack that generates power using fuel and an oxidant.

  As a fuel cell device, for example, there is a solid oxide fuel cell device (SOFC device) as shown in Patent Document 1. In this apparatus, a cell stack that generates electricity by reacting a hydrogen-containing fuel and an oxidant is surrounded by a casing. Then, surplus hydrogen-containing fuel (off gas) is combusted inside the apparatus, and the combustion exhaust gas is purified by a catalyst, and then released to the outside of the apparatus.

  Further, a heat insulating material is disposed outside the cell stack in order to suppress heat radiation from the housing to the outside. As a result, the cell stack heated by the combustion of off-gas and the oxidant supplied to the cell stack can be maintained at a high temperature to increase power generation efficiency. In addition, a configuration in which a reformer is disposed in a casing is known as a form in which hydrogen-enriched gas obtained by reforming raw fuel with a reformer is supplied to a cell stack. In this case, the reforming reaction can be efficiently maintained by maintaining the reformer at a high temperature.

Japanese Patent Publication: JP 2011-222136 A

  By the way, in the fuel cell apparatus provided with the heat insulating material as in Patent Document 1, a structure in which the lower part (pedestal) of the cell stack is supported on the lower heat insulating material is common. However, in such a structure, if the dimensional error of the lower heat insulating material is large, the height of the fuel supply pipe connected to the cell stack directly or via a reformer and the hole of the housing that penetrates the fuel supply pipe is high. Deviation occurs, making assembly difficult. In order to suppress such a situation, the heat insulating material is required to have high dimensional accuracy, and the processing cost increases. Even if the heat insulating material is processed with high accuracy, the heat insulating material may be damaged by vibration, friction, etc. during transportation, and it may be difficult to maintain the dimensional accuracy. As a result, the packaging and transportation costs at the time of shipment of the heat insulating material itself and the fuel cell system increase.

  In addition, high-temperature hydrogen-enriched gas, oxidant, exhaust gas, and the like circulate in a moisture-containing state inside the fuel cell device in which the heat insulating material is disposed. Therefore, when the fuel cell device is stopped, condensation may occur as the internal temperature of the device decreases. Depending on the type of the heat insulating material, moisture adheres to the heat insulating material, which may deteriorate the heat insulating material and make it difficult to maintain dimensional accuracy. Due to the decrease in dimensional accuracy, the difficulty of assembly becomes significant during maintenance. In addition, after assembly, stress is applied to the support portion of the fuel supply pipe, and durability becomes a problem. In order to solve the problems as described above, it is not easy to select a heat insulating material that satisfies heat insulation, workability, water resistance, and cost.

  The present invention has been made paying attention to such a conventional problem, and improves the mounting accuracy of the cell stack and the members connected to the cell stack, assembling property such as fuel supply piping, durability, ignition heater, An object of the present invention is to provide a fuel cell device that can ensure off-gas ignition performance and the like by an ignition device such as an igniter and that can obtain high heat insulation performance.

In order to achieve the above object, a fuel cell device according to the present invention comprises:
A cell stack in which a plurality of fuel cells are supported by a pedestal;
A channel-shaped stack holding metal fitting that encloses the cell stack and is open at the top;
A housing containing a reformer that houses the cell stack and the stack holding fitting, and reforms raw fuel to supply a hydrogen-enriched gas to the cell stack above the cell stack ;
A heat insulating material disposed between the outside of the stack holding metal fitting and the inside of the housing;
With
The stack holding bracket is
The reformer that is supported by the casing or a connected body with the casing and holds the pedestal on the inner bottom wall of the stack holding metal fitting and supports the reformer so as not to contact the fuel cell. Having a vessel support,
The engaging member attached to the reformer side and the engaging member attached to the stack holding bracket side are slidably engaged with each other to support the reformer. It is characterized by that.

According to the aspect of the present invention, the cell stack is supported by the stack holding metal fitting, and the stack holding metal fitting is supported by the casing or a connecting body with the casing. For this reason, the positional accuracy in the housing | casing of the member connected to a cell stack and a cell stack is maintainable. Thereby, the assembly property of members, such as fuel supply piping connected with a cell stack, improves. Further, the accuracy of the mounting position in the height direction of the cell stack is improved. For this reason, the off-gas ignition performance etc. by ignition devices, such as an ignition heater and an igniter, can be maintained.
In addition, since the stack holding metal fitting is disposed between the heat insulating material and the cell stack, the heat insulating material can be protected, and deterioration due to condensation or the like can be suppressed. For this reason, the freedom degree of selection of a heat insulating material can be raised.
Further, since the stack holding metal fitting is disposed at a distance from the fuel cell of the cell stack, an insulation treatment or the like on the surface is unnecessary.

It is a longitudinal cross-sectional view (ZZ sectional drawing of FIG. 2) which shows the basic structure of the principal part of the solid oxide fuel cell apparatus which concerns on 1st Embodiment of this invention. It is XX sectional drawing of FIG. It is YY sectional drawing of FIG. It is principal part sectional drawing which shows the application form of the basic structure of 1st Embodiment. The basic structure of the principal part of the solid oxide fuel cell apparatus which concerns on 2nd Embodiment of this invention is shown, (A) is a longitudinal cross-sectional view, (B) is EE sectional drawing of (A). It is a longitudinal cross-sectional view which shows the basic structure of the principal part of the solid oxide fuel cell apparatus which concerns on 2nd Embodiment of this invention. It is principal part sectional drawing which shows the application form of the basic structure of 2nd Embodiment. It is a longitudinal cross-sectional view which shows the basic structure of the principal part of the solid oxide fuel cell apparatus which concerns on 3rd Embodiment of this invention. It is a longitudinal cross-sectional view which shows the basic structure of the principal part of the solid oxide fuel cell apparatus which concerns on 4th Embodiment of this invention. It is a perspective view which shows the stack holding | maintenance metal fitting of 4th Embodiment. It is a top view which shows the housing | casing of 4th Embodiment. It is a perspective view which shows the stack | holding metal fitting which concerns on the application form of 4th Embodiment. It is a longitudinal cross-sectional view which shows the basic structure of the principal part of the solid oxide fuel cell apparatus which concerns on 5th Embodiment of this invention. It is a longitudinal cross-sectional view which shows the basic structure of the principal part of the solid oxide fuel cell apparatus which concerns on 6th Embodiment of this invention. It is a longitudinal cross-sectional view which shows the basic structure of the principal part of the solid oxide fuel cell apparatus which concerns on 7th Embodiment of this invention. It is a perspective view which shows the container-shaped stack holding | maintenance metal fitting of 7th Embodiment. It is a longitudinal cross-sectional view which shows the basic structure of the principal part of the solid oxide fuel cell apparatus which concerns on 8th Embodiment of this invention. It is a longitudinal cross-sectional view of the direction orthogonal to FIG. 1 which shows the basic structure of the principal part of the solid oxide fuel cell apparatus which concerns on 9th Embodiment of this invention.

<First Embodiment>
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1 to 3 show the basic structure of the main part of the solid oxide fuel cell device according to the first embodiment of the present invention. Inside the housing 1 surrounding the main part of the apparatus, there are a cell stack 11 that generates power using a hydrogen-containing fuel and an oxidant, an off-gas combustion unit 12, a reformer 13, an oxidant supply passage 14, and an exhaust gas passage 15. With.

  The cell stack 11 is an assembly in which a plurality of solid oxide fuel cells (fuel cell 11a) are connected in series and / or in parallel and supported by a pedestal. The fuel battery cell 11a is configured by laminating an anode (fuel electrode) and a cathode (oxidant electrode) on both surfaces of an electrolyte made of a solid oxide. Since the shape and arrangement of the fuel battery cells 11a can be arbitrarily selected, the cell stack in the figure is schematically shown by omitting them. In this embodiment, the manifold part 11b which functions as a base which supports the fuel cell 11a is illustrated. Hydrogen-enriched gas fuel is supplied from the reformer 13 through the hydrogen-enriched gas supply pipe 19 into the manifold portion 11b. The hydrogen-enriched gas fuel is supplied to the anode of each fuel cell 11a through a hole formed in the manifold portion 11b.

  The reformer 13 reforms the hydrogen-containing fuel and supplies the hydrogen-enriched gas to the anode (fuel electrode) of the cell stack 11. The oxidant supply passage 14 supplies an oxidant to the cathode (oxidant electrode) of the cell stack 11. The off-gas combustion unit 12 burns off-gas (excess hydrogen-containing fuel and excess oxidant) that did not contribute to power generation in the cell stack 11 to bring the reformer 13 into a high temperature state. The exhaust gas passage 15 discharges off-gas combustion exhaust gas to the outside. A heat insulating material 16 that suppresses heat radiation from the housing 1 to the outside is disposed between the cell stack 11 and the exhaust gas passage 15.

  As the hydrogen-containing fuel (raw fuel) supplied from the outside of the housing 1 to the reformer 13 via the fuel supply pipe 18, for example, a hydrocarbon fuel is used. As the hydrocarbon fuel, a compound containing carbon and hydrogen in its molecule (which may contain other elements such as oxygen) or a mixture thereof is used. For example, hydrocarbons, alcohols, ethers And biofuels. Specific examples of hydrocarbons include methane, ethane, propane, butane, natural gas, LPG (liquefied petroleum gas), city gas, town gas, gasoline, naphtha, kerosene, and light oil. Examples of alcohols include methanol and ethanol. Examples of ethers include dimethyl ether. Examples of biofuels include biogas, bioethanol, biodiesel, and biojet.

  The reforming method in the reformer 13 is not particularly limited, and for example, steam reforming, partial oxidation reforming, autothermal reforming, and other reforming methods can be employed. When steam reforming is used, a water vaporization unit is provided in the reformer 13 (or separately from the reformer 13). The water vaporization unit generates water vapor by heating and vaporizing water supplied from the outside of the housing 1. The reformer 13 may not be provided inside the housing 1. For example, there is a form in which a reformer is provided outside the housing 1 and reformed fuel is supplied to the cell stack from a fuel supply pipe. Alternatively, there is a form in which hydrogen-rich gas that does not require reforming is supplied from the fuel supply pipe to the cell stack. Alternatively, instead of the reformer, there is a form in which a dehydrogenation discharge pipe for discharging the dehydrogenation product from the dehydrogenation reaction unit and the dehydrogenation reaction unit is provided between the fuel supply pipe and the cell stack. In this embodiment, organic hydride storing hydrogen is supplied from the fuel supply pipe to the dehydrogenation reaction section, and hydrogen-rich gas generated by the dehydrogenation reaction is supplied to the cell stack.

  The oxidant supply passage 14 extends downward from the top wall of the housing 1 into the gaps between the plurality of fuel cells 11a. The passage wall member 14a has an upper end opening connected to the top wall of the housing 1 (or a connecting body to the housing 1), and an outflow hole 14b is formed in the lower portion of the passage wall member 14a. Then, an oxidant is introduced from the outside of the housing 1 into the passage wall member 14a (oxidant supply passage 14), and the oxidant is caused to flow into the housing 1 from the outflow hole 14b. The oxidant that has flowed out is supplied to the cathode (oxidant electrode) of each cell stack 11. The shape of the oxidant supply passage 14 may be, for example, a cylindrical shape having one end communicating with the upper end opening of the passage wall member 14a and the other end having an outflow hole 14b through which the oxidant flows out. Alternatively, the oxidant supply passage 14 may have a flat rectangular parallelepiped shape having a hollow inside. The flat rectangular parallelepiped oxidant supply passage 14 is inserted into a gap between the plurality of cells 11a so as not to contact the fuel cell 11a, the upper end communicates with the upper end opening of the passage wall member 14a, and the lower end has an outflow hole. 14b. The outflow holes 14 b are provided in an arbitrary number at arbitrary positions according to the shape of the cell stack 11. Note that a plurality of oxidant supply passages 14 may be provided in one housing 1 according to the shape of the cell stack.

  The exhaust gas passage 15 is formed between the inner wall of the housing 1 and a partition wall 15a disposed on the inner wall with a gap. The partition wall 15 a is connected to the housing 1. The exhaust gas of the combustion gas burned in the off-gas combustion unit 12 is introduced into the exhaust gas passage 15 from the exhaust gas inlet at the upper end of the exhaust gas passage 15. Next, the exhaust gas is discharged from a discharge passage 17 connected to the central portion of the bottom wall of the casing 1, purified and heat-exchanged by a catalyst and heat exchange unit (not shown), and then discharged to the outside.

  The housing 1 includes a stack holding fixture 21 having a substantially channel shape between the exhaust gas partition wall 15a and the cell stack 11. The stack holding metal 21 defines a heat insulating material chamber Hi for housing a heat insulating material 16 for maintaining the cell stack 11 at a high temperature between the partition wall 15a and holds the cell stack 11. The stack holding metal 21 is supported at its upper end by the upper end surface of the partition wall 15a. The support of the stack holding metal 21 to the partition wall 15a may be fixed by welding or the like. Alternatively, as shown in the drawing, the stack holding metal fitting 21 may be supported only by bending the upper edge of the stack holding metal 21 outward and downward from the partition wall 15a and engaging the upper end of the partition wall 15a. Alternatively, the stack holding bracket 21 may be supported by extending a part of the stack holding bracket 21 and fastening it with the partition wall 15a or the housing 1 with a screw or the like. In order to increase the power generation efficiency, it is necessary to circulate the oxidant supplied from the oxidant supply passage 14 into the casing 1 so as to efficiently contact the cathode of each cell. Therefore, it is preferable that the distance between the stack holding metal fitting 21 and the cell stack 11 is close enough not to contact each other.

  In a structure in which the reformer is connected to the cell stack via a hydrogen-enriched gas supply pipe, etc., and does not have the above stack holding bracket, but supports the cell stack directly on the lower insulating material, the lower insulating material When the dimensional error in the height direction is large, the following problems occur. There is a difference in height between the fuel supply pipe that supplies the raw fuel to the reformer and the through hole of the fuel supply pipe formed in the housing. As a result, it becomes difficult to assemble the cell stack, the fuel supply pipe, the reformer, and the like. Even when the height dimension of the lower heat insulating material is secured before use, if the height of the heat insulating material changes due to the weight of the cell stack or the deterioration of the heat insulating material, the height position of the manifold portion 11b changes. . For this reason, the interval between h1 and h2 changes in FIG. As a result, the support part of the fuel supply pipe (the connection part between the through part of the housing 1 and the reformer 13; indicated by the boxes A and B in FIG. 1) and the connection part of the hydrogen-enriched gas supply pipe 19 ( Stress is generated in (indicated by C and D in FIG. 1), and durability is lowered. Note that. The same applies to the case where there is no reformer and the fuel supply pipe is directly connected to the cell stack.

  In addition to the fuel supply pipe 18, the fuel cell device includes many through parts (not shown). Examples thereof include an ignition device 91 for burning off-gas, and various sensors (not shown) such as a temperature sensor. When the height of the lower heat insulating material is changed, the height position (interval h3 between the ignition device and the upper end surface of the cell stack from which off gas is ejected) in the off-gas combustion portion of the ignition device is shifted from an appropriate position. For this reason, it becomes difficult for the ignition device 91 to ensure good ignition performance. In addition, the cell stack 11 and the sensors are displaced from each other, and the detection accuracy of the sensors is reduced.

  In order to deal with such a problem, in the present embodiment, the cell stack 11 is held by the metal stack holding metal fitting 21 that is less likely to be damaged or deformed than the heat insulating material, whereby the cell 1 is connected to the casing 1 connected to the partition wall 15a. The stack 11 can be accurately positioned. Thereby, as shown in FIG. 2, stress applied to the fuel supply pipe 18, the through hole, and the hydrogen-enriched gas supply pipe 19 can be relieved. As a result, good assemblability of these parts can be ensured, and durability of the connecting portion of the fuel supply pipe 18 can be ensured. Moreover, the ignition performance of the ignition device 91 and the detection accuracy by various sensors can be maintained satisfactorily.

  Although the location where the stack holding metal fitting 21 is connected and supported is not limited, it is preferable that the stack holding metal 21 is connected to a relatively high temperature portion in the housing 1 from the viewpoint of maintaining the cell stack 11 at a high temperature. Specifically, it is preferable to connect in the upward direction in the housing 1 where hot gas collects. For example, if the stack protection metal fitting 21 is connected to the bottom of the partition wall 15 a that is relatively low in the housing 1 or the bottom of the housing 1, the temperature of the cell stack 11 may decrease through the stack holding metal 21. On the other hand, when the stack holding metal fitting 21 is connected in the upward direction of the housing 1, the heat in the upward direction in the housing 1 is transferred to the cell stack 11 through the stack holding metal fitting 21. For this reason, the temperature difference of the up-down direction of the cell stack 11 can be suppressed. Thereby, the heat utilization efficiency and power generation efficiency of the fuel cell device can be improved. The height of the stack holding metal 21 may be equal to or less than the height of the upper end of the cell stack 11 as shown in FIG. According to this, it is avoided that the combustion flame in the off-gas combustion part 12 directly hits the upper end part of the stack holding metal fitting 21. For this reason, the deformation | transformation and thermal stress by the thermal expansion of the stack holding | maintenance metal fitting 21 can be reduced.

  Moreover, as a molding material of the stack holding metal fitting 21, it is preferable to use a material having an alumina film formed on the surface or a material that can be formed (for example, an aluminum content of 2 to 3%). For example, if a material having a Cr oxide film is used, the cathode electrode of the cell stack 11 may be poisoned with Cr and affect the power generation performance. On the other hand, by using the stack holding metal fitting 21 coated with alumina, the poisoning of Cr can be suppressed, and the influence on the power generation performance can be avoided. The stack holding metal fitting 21 can be formed by processing a non-porous metal plate, a perforated metal plate, or a mesh-like metal plate.

The heat insulating material 16 accommodated in the heat insulating material chamber Hi can be arbitrarily selected according to conditions such as a board shape, a blanket shape, a fiber shape, a granular shape, or a powder shape. Further, for example, as shown in FIG. 3, a plurality of board-like heat insulating materials 16 having different sizes may be accommodated inside the heat insulating material chamber Hi. If the heat insulating material 16 is tilted or flows, the flow of the oxidant is hindered, or if it adheres to the surface of the fuel cell 11a, the power generation efficiency may be reduced. Therefore, in the case of using the stack holding metal fitting 21 formed by processing a perforated or mesh-shaped metal plate, an opening material is selected so that the heat insulating material 16 does not leak from the heat insulating material chamber Hi to the cell stack 11 side. Is preferred.
In the form in which the stack holding metal fitting 21 is not provided, the following problem occurs. The heat insulating material 16 is limited to a type that can hold the shape with the heat insulating material itself such as a board so that the heat insulating material 16 does not hinder the flow of the oxidant or adheres to the surface of the fuel cell 11a. On the other hand, by providing the stack holding metal fitting 21, the condition of the shape holding performance of the heat insulating material itself can be relaxed.

  Here, the internal atmosphere of the housing 1 will be described. In the fuel cell device, power generation is performed by an electrochemical reaction between hydrogen and oxygen in the fuel cell in a state where the inside of the housing 1 is maintained at a high temperature (for example, 600 to 1000 ° C.). And water is by-produced with this electric power generation. When the steam reforming reaction is performed in the reformer 13, a hydrogen-enriched gas containing moisture is supplied to the anode. Therefore, during operation of the fuel cell device, the housing 1 is filled with wet gas. When the fuel cell device is stopped, the temperature in the housing 1 decreases, and thus condensation may occur. For example, when the fuel cell device is urgently stopped and the wet gas in the housing 1 is not discharged by air blowing, condensation is particularly likely to occur. In the case where a material having low water resistance is selected as the heat insulating material 16, the adhesion of condensed water to the surface of the heat insulating material 16 causes deterioration of the heat insulating material 16.

  Such a problem can be solved by using the stack holding metal 21 formed from a non-porous metal plate. For example, the inner surface of the heat insulating material 16 is covered with the stack holding fixture 21, and the outer surface of the heat insulating material 16 is covered with the partition wall 15a. If it does in this way, the heat insulating material 16 will be isolated from the wet gas, and it can suppress that dew condensation water adheres to the surface of the heat insulating material 16. Thereby, when selecting the material of the heat insulating material 16, the water resistance condition can be relaxed, and the degree of freedom in selecting the heat insulating material 16 is increased. Here, the term “non-hole” means that no hole or slit is formed in a portion covering the heat insulating material. For example, you may provide the hole for connecting the stack | stuck holding | maintenance metal fitting 21 to the partition 15a.

  Moreover, the stack holding metal fitting 21 in the first embodiment fixes the position of the cell stack 11 by sandwiching the upper and lower surfaces of the flange portion of the manifold portion 11b projecting outward from the lower end portion of the fuel cell 11a. . Thereby, assembly property can be improved.

  In addition, as an application form of 1st Embodiment shown in FIG. 1, you may make it show in FIG. That is, the heat insulating material 22 may be disposed on the side of the upper part of the cell stack 11 (above the stack holding metal fitting 21). Moreover, you may make it show in FIG. 5 (A) and its EE sectional drawing (B). That is, the board-like heat insulating material 16 may be stored in the heat insulating material chamber Hi, and the heat insulating material 16 may be protruded from the opening 211b provided on the engagement surface 211a of the stack holding metal fitting 211. Thereby, the reformer 13 can be maintained at a high temperature, and the reforming reaction can be efficiently maintained. Further, the processing of a through hole or the like for inserting an ignition device 91, a flame detection sensor (not shown) or the like in the vicinity of the off-gas combustion unit 12 may be performed only on the heat insulating material. For this reason, the labor of processing can be reduced. In particular, in the form in which the heat insulating material 22 is disposed above the stack holding metal fitting 21, only the heat insulating material 22 may be selected from a kind of heat insulating material that can hold the shape with the heat insulating material itself. Thereby, the conditions of the shape maintenance performance to the heat insulating material 16 accommodated in the heat insulating material chamber Hi can be eased.

  In general, a technique is known in which an oxidant regulating member is interposed between a heat insulating material and a cell stack so as to block a gap between the heat insulating material and the cell stack and restrict the flow direction of the oxidant. The oxidant restricting member 23 returns the oxidant flowing upward between the cell stack 11 and the stack holding bracket 21 to the cell stack 11 side without moving straight. This serves to increase the chance of contact of the oxidant with the cathode electrode. As the oxidant regulating member 23, for example, a blanket-like heat insulating material can be used. In the present invention, an oxidant regulating member may be interposed between the stack holding fixture 21 and the cell stack 11. At this time, as shown in FIG. 4, a step 21 a that fixes the interposed position of the oxidant regulating member 23 may be formed in the stack holding metal 21. Thereby, the positioning of the oxidant regulating member 23 is facilitated, and the oxidant regulating member 23 can be prevented from falling off.

  When the step 21a for fixing the oxidant regulating member 23 is formed in a structure that does not include the stack holding metal fitting 21, the following is required. That is, since it is necessary to select a board-like heat insulating material and to shape the heat insulating material, workability and strength are required as a material for the heat insulating material 16. However, in this embodiment, the step 21a is processed on the stack holding metal fitting 21 made of metal that is easier to process than the heat insulating material. Thereby, the workability and strength conditions of the heat insulating material 16 can be relaxed.

Second Embodiment
FIG. 6 shows the basic structure of the main part of the solid oxide fuel cell device according to the second embodiment of the present invention. In the second embodiment, the same components as those in the first embodiment shown in FIG.

  The second embodiment has the following configuration. A heat insulating material 16 is disposed between the cell stack 11 and the partition wall 15 a, and an inner surface of the heat insulating material 16 is covered with a stack holding metal fitting 31. The stack holding metal fitting 31 is extended upward from the upper end surface of the cell stack 11, and the upper end portion is supported on the top wall of the casing 1 (or a connecting body to the casing 1). The upper end of the stack holding metal fitting 31 may be supported on the top wall of the housing 1 or the like by fixing by welding, fastening with screws, or the like. Alternatively, the stack holding metal fitting 31 may be provided with an engaging portion to be engaged. In addition, an outflow hole 31 b through which the combustion exhaust gas in the off-gas combustion unit 12 flows out to the outer exhaust gas passage 15 is opened at a portion above the reformer 13 of the stack holding metal fitting 31. Thereby, the cell stack 11 can be accurately positioned with respect to the housing 1 without blocking the flow of the combustion exhaust gas to the outer exhaust gas passage 15. Here, at least a portion of the inner surface of the stack holding metal 31 facing the off-gas combustion unit 12 (side of the space between the upper end surface of the cell stack 11 and the bottom surface of the reformer 13) may be coated with the heat-resistant material 31c. Good. If it does in this way, it can avoid that the combustion flame in the off-gas combustion part 12 hits the surface of the stack holding | maintenance metal fitting 31 directly. Thereby, the deformation | transformation and thermal stress by the thermal expansion of the stack holding metal fitting 31 can be reduced, and the durability of the stack holding metal fitting 31 can be ensured. Moreover, the conditions of the fireproof performance of the heat insulating material 16 can be eased.

  Further, a lid portion 31 a is connected to the outer surface of the stack holding metal fitting 31. The lid portion 31 a closes the upper portion of the heat insulating material chamber Hi between the lid portion 31 a and the partition wall 15 a of the exhaust gas passage 15. The lid portion 31a contacts the partition wall 15a, but is not supported by the partition wall 15a, and the stack holding bracket 31 including the lid portion 31a is supported only at the upper end portion. By doing in this way, the outflow and collapse of the heat insulating material 16 can be suppressed while supporting the upper end part of the stack holding metal fitting 31 with the top wall of the housing 1 or the like. Further, when the stack holding metal fitting 31 and the lid portion 31a formed from a non-porous plate are used, the heat insulating material 16 is isolated from the wet gas. Thereby, it can suppress that dew condensation water adheres to the surface of the heat insulating material 16. FIG. By these, when selecting the material of the heat insulating material 16, the form of the heat insulating material 16 and water resistance conditions can be relieved, and the freedom degree of selection of the heat insulating material 16 increases.

  As an application form of the second embodiment shown in FIG. 6, the features of the first embodiment shown in FIGS. 1, 3 and 4 can be applied, and the same effects as those of the embodiment can be obtained. Moreover, it is good also as a structure shown in FIG. For example, the partition wall 15a of the exhaust gas passage 15 extends upward to the vicinity of the upper end of the reformer 13, and the lid portion 31a of the stack holding metal fitting 31 is connected to the vicinity of the lower portion of the outflow hole 31b. And the capacity | capacitance of the heat insulating material 16 is increased by pulling up the upper end part of the heat insulating material 16 to the lower surface vicinity of this cover part 31a. Thereby, the heat | fever of waste gas can be efficiently supplied to the reformer 13, and a reforming reaction can be maintained efficiently. Further, since the reformer 13 and the cell stack 11 are fixed to the stack holding metal fitting 31, the off-gas combustion space distance, that is, the distance between the reformer 13 and the upper end portion of the cell stack 11 (portion indicated by h2 in FIG. 1). Is stably held. Thereby, the unevenness of the heat transfer of the offgas combustion heat transmitted to the reformer 13 can be reduced. In the application mode, the stack holding metal 31 is provided with a step 31d. The step 31d is provided to be close to the fuel cell 11a at a height facing the fuel cell 11a and to be separated from the flame in the vicinity of the off-gas combustion unit 12. Thereby, the deformation | transformation and thermal stress by the thermal expansion of the stack holding metal fitting 31 can be reduced, and the durability of the stack holding metal fitting 31 can be ensured. Moreover, the conditions of the fireproof performance of the heat insulating material 16 can be eased.

  In addition, a reformer support portion 31 e that supports the reformer 13 may be provided on the upper inner surface of the stack holding metal fitting 31. For example, the reformer support 31e may be fixed to the stack holding fitting 31 by welding. Alternatively, the reformer support 31e may be formed by bending a plate material in the stage of forming the stack holding metal fitting 31. Further, the reformer support portion 31e is not limited to a mode in which the reformer 13 is supported from the lower side, and may be a mode in which the reformer support unit 31e is supported from the upper side by a hook or the like. As described above, in the second embodiment, since the cell stack 11 and the reformer 13 are directly supported by the stack holding fitting 31, the mutual dimensions can be accurately maintained. For this reason, the dimensional accuracy of the space | interval of the off-gas combustion part 12 formed between the cell stack 11 upper end surface and the reformer 13 bottom face improves. Thereby, the off-gas combustion part 12 can heat the reformer 13 with good balance. Further, the upper part of the stack holding metal fitting 31 is heated to receive off-gas combustion heat. And the heat | fever of the upper part of this stack holding | maintenance metal fitting 31 can be efficiently supplied to the reformer 13 via the reformer support part 31e. As a result, the reforming reaction can be efficiently maintained. Here, in the structure for supporting the reformer 13 from the lower side as shown in FIG. 7, it is desirable to configure as follows. That is, the reformer support 31e is formed of a perforated or mesh-shaped metal plate so that the exhaust gas flows around the entire circumference of the reformer 13. Thereby, the exhaust gas can be circulated between the reformer 13 and the stack holding member 31. As a result, the heat of the exhaust gas can be efficiently supplied to the reformer 13.

<Third Embodiment>
FIG. 8 shows the basic structure of the main part of the solid oxide fuel cell device according to the third embodiment of the present invention. In the third embodiment, the same components as those in the first and second embodiments are denoted by the same reference numerals, and description thereof is omitted.

  In the third embodiment, a pair of oxidant supply passages 14 are disposed on both outer sides of the cell stack 11. An outflow hole 14 b is opened on the side of the cell stack 11 at the lower end of the passage wall member 14 a forming the pair of oxidant supply passages 14. Further, an exhaust gas outflow pipe 14c is connected to a portion above the reformer 13 through both side walls of the passage wall member 14a. Further, in order to discharge exhaust gas without delay, the stack holding metal fitting 41 is opened with an exhaust gas conduction hole 41b, and the oxidant supply passage 14 is opened with an exhaust gas conduction hole 14d in the exhaust gas outlet pipe 14c. In addition, the peripheral part of the exhaust gas outflow pipe 14c is sealed by welding. Thereby, it is possible to avoid leakage of the oxidant from the exhaust gas conduction hole 14d of the oxidant supply passage 14. The oxidant supplied from the pair of oxidant supply passages 14 flows out from the outflow hole 14 b and is supplied to the cathode electrode of each cell of the central cell stack 11. The off-gas combustion exhaust gas is discharged to the outer exhaust gas passage 15 through the exhaust gas outlet pipe 14 c and the outlet hole 41 b of the stack holding metal fitting 41. Thereby, the cell stack 11 can be accurately positioned with respect to the housing 1 without blocking the flow of the combustion exhaust gas to the outer exhaust gas passage 15. Thus, the stack holding metal fitting 41 can also be applied to a structure that is not directly opposed to the cell stack 11.

  Further, as an application form of the third embodiment shown in FIG. 8, the first and second embodiments shown in FIG. 1 and FIGS. 3 to 7 can be applied (however, the disposition of the oxidant regulating member 23). The effect similar to that of the embodiment can be obtained. In addition, in the third embodiment, the upper end portion of the stack holding metal fitting 41 may be replaced with a configuration in which the upper end portion of the partition wall forming the exhaust gas passage is supported as in the first embodiment shown in FIG. can get. In this case, the exhaust gas conduction hole 41b of the stack holding metal fitting 41 can be omitted.

<Fourth embodiment>
FIG. 9 shows a basic structure of a main part of a solid oxide fuel cell device according to the fourth embodiment of the present invention. In the fourth embodiment, the same components as those in the first to third embodiments are denoted by the same reference numerals, and description thereof is omitted.
In the present embodiment, the cell stack 11 and the reformer 13 are included by the stack holding metal fitting 101 formed as shown in FIG. Further, the upper surface of the reformer 13 is supported by the stack holding metal fitting 101 and the upper end portion of the stack holding metal fitting 101 is supported by the upper end portion of the housing 1.

  The stack holding metal fitting 101 has a bottom wall 101A for supporting the cell stack 11, a side wall 101B whose outer surface is adjacent to the heat insulating material, and a top wall 101C positioned above the reformer 13, and has a square shape in cross section. It is formed of a cylinder. Outflow holes 101a through which the combustion exhaust gas in the off-gas combustion unit 12 flows into the outer exhaust gas passage 15 are opened at the upper portions of the both side walls 101B. A passage insertion port 101b for inserting the oxidant supply passage 14 is opened in the top wall 101C.

  101 C of top walls are the 1st bridge | bridging part which connects the longitudinal direction both ends piece part 101c which extends in the longitudinal direction at the outer periphery of the channel | path insertion port 101b, and extends in the longitudinal direction of these both side piece parts 101c. 101d and a second bridge portion 101e. A portion of the first bridge portion 101d extends a predetermined length in the direction toward the second bridge portion 101e, and the extended portion functions as a support portion 101f that supports the reformer 13 as will be described later. .

  For example, on the upper end of the reformer 13 in the longitudinal direction, for example, on the end of the hydrogen-enriched gas supply pipe 19 connection side in FIG. An extending arm member 13a is attached with both lower ends fixed. Then, by inserting the support portion 101f into an opening formed between the arm member 13a and the upper surface of the reformer 13, and placing the upper portion of the arm member 13a on the upper surface of the support portion 101f, the reformer 13 is Support hanging. The shape of the arm member 13a can be, for example, U-shaped or L-shaped.

  The stack holding metal fitting 101 is attached by being inserted into the housing 1 from the opening before connecting the lid of the housing 1 in a direction parallel to both side walls. As shown in FIG. 11, the housing 1 into which the stack holding metal fitting 101 is inserted has a support for suspending and supporting the stack holding metal fitting 101 at the edge on the opening side and the edge on the opposite side to the opening. One or more members 1a are provided.

  The stack holding metal fitting 101 is inserted into the inner space of the heat insulating material 16 from the opening of the housing 1. By the insertion, the first bridge portion 101d and the second bridge portion 101e of the stack holding metal fitting 101 are supported by being suspended by the support portions of the support members 1a at the corresponding portions of the housing 1, respectively.

  According to the fourth embodiment, since the reformer 13 and the cell stack 11 are fixed to the stack holding metal fitting 101, the off-gas combustion space distance, that is, the distance between the reformer 13 and the upper end portion of the cell stack 11 (FIG. 1). The portion indicated as h2 in FIG. Thereby, the unevenness of the heat transfer of the offgas combustion heat transmitted to the reformer 13 can be reduced. Further, since the stack holding metal fitting 101 is configured to support the upper surface of the reformer 13, the reformer 13 can be heated without obstructing the flow of off-gas or exhaust gas. Furthermore, it can be avoided that the combustion flame in the off-gas combustion unit 12 directly hits the surface of the reformer support (support unit 101f and arm member 13a). Thereby, the deformation | transformation by a thermal expansion of a reformer support part (support part 101f and arm member 13a) and a thermal stress can be reduced, and durability of a reformer support part (support part 101f and arm member 13a) is improved. It can be secured.

The stack holding metal fitting 101 may be configured to support a side surface other than the bottom surface of the reformer 13, and the same effect can be obtained.
Further, since the stack holding metal fitting 101 is supported on the upper part of the housing 1 at a high temperature, the temperature difference between the metal fitting support portions is small, and heat loss from the stack holding metal fitting 101 to the housing 1 can be suppressed.
In addition, since the cell stack 11 and the reformer 13 are integrally inserted into the housing 1 and attached to the stack holding metal fitting 101, the opportunity for the operator to contact the heat insulating material 16 during assembly is reduced, and the heat insulating material 16 Damage can be suppressed.

FIG. 12 shows a modification of the fourth embodiment. In this modification, a heat insulating material holding part 101D that holds the heat insulating material 16 is connected to the outside of the structure shown in FIG. The heat insulating material holding portion 101 </ b> D is formed of a member bent in a substantially U shape that holds the heat insulating material 16. Both end portions of the member are fixedly attached to upper portions of both end portions in the longitudinal direction of both side walls 101B of the stack holding metal fitting 101.
According to the modification, the cell stack 11 and the reformer 13 are supported by the stack holding metal fitting 101 and the heat insulating material 16 is held by the heat insulating material holding portion 101D, and the inside of the partition wall 15a is opened from the opening of the housing 1. It can be pushed into the space and housed and attached to the housing 1. The heat insulating material holding portion 101D may have any shape that can hold the heat insulating material 16 in contact with the bottom wall 101A and / or both side walls 101B. For example, the heat insulating material holding portion 101D may be provided on each surface of the bottom wall 101A and both side walls 101B. Further, the heat insulating material holding portion 101D may be a member bent in a substantially L shape.

<Fifth Embodiment>
FIG. 13 shows the basic structure of the main part of the solid oxide fuel cell device according to the fifth embodiment of the present invention. In the fourth embodiment, the same components as those in the first to fourth embodiments are denoted by the same reference numerals, and description thereof is omitted.

  In FIG. 13, the passage wall member 14 a in which the oxidant supply passage 14 is formed is connected to the top wall of the housing 1 (or a connecting body to the housing 1) at the upper end opening. The passage wall member 14a is arranged to extend downward in the gaps between the plurality of fuel cells 11a. A discharge passage 17 for discharging off-gas combustion exhaust gas is formed in the top wall of the housing 1. The heat insulating material chamber Hi is defined by the housing 1 and the stack holding metal fitting 51. The outer surface of the heat insulating material 16 is covered with the inner wall of the housing 1. The stack holding fitting 51 is formed in substantially the same shape as the stack holding fitting 21 of the first embodiment, but the upper end portion is supported by a support member 1 a fixed to the inner wall of the housing 1. The upper end portion of the stack holding metal 51 and the support member 1a isolate the internal heat insulating material from the exhaust gas, thereby suppressing the attachment of condensed water to the heat insulating material. The upper end of the stack holding metal 51 may be fixed to the support member 1a by welding or the like, or may be merely engaged with the support member 1a. Further, when a material having low water resistance is used as the internal heat insulating material 16, it is preferable to ensure sealing properties so that condensed water does not penetrate.

  Further, as an application form of the fifth embodiment shown in FIG. 13, the features of the first to third embodiments shown in FIG. 1 and FIGS. 3 to 8 can be applied, and effects similar to those of the embodiment can be obtained. Can be obtained. On the other hand, the partition wall 15a of the first embodiment shown in FIG. 1 may be provided, and the support member 1a shown in FIG. 8 may be provided on the inner wall surface of the partition wall 15a. In this case, the upper end portion of the stack holding metal fitting 21 is supported by the support member 1a, not the upper end portion of the partition wall 15a. Also by this, the cell stack 11 can be accurately positioned with respect to the housing 1.

<Sixth Embodiment>
FIG. 14 shows a basic structure of a main part of a solid oxide fuel cell device according to a sixth embodiment of the present invention. In the fifth embodiment, the same components as those in the first to fifth embodiments are denoted by the same reference numerals, and description thereof is omitted.

  In the present embodiment, the upper end portion of the stack holding metal fitting 61 is supported on the top wall of the housing 1 (or the connecting body to the housing 1). The stack holding fitting 61 is formed in substantially the same shape as the stack holding fitting 21 of the second embodiment, except that the outlet 31b is not provided. The heat insulating material chamber Hi is defined by the housing 1 and the stack holding metal fitting 61. The outer surface of the heat insulating material 16 is covered with the inner wall of the housing 1, and the inner surface of the heat insulating material 16 is covered with the outer wall of the stack holding metal fitting 61. An oxidant introduction passage 26 and an offgas combustion exhaust gas discharge passage 17 are provided on the top wall of the housing 1. A partition wall 25 surrounding the fuel cell 11 a and the reformer 13 is disposed inside the stack holding metal fitting 61. An oxidant supply passage 14 is defined between the top wall of the housing 1 and the top wall of the partition wall 25 and between the stack holding fitting 61 and the side wall of the partition wall 25. The oxidant introduced from the oxidant introduction passage 26 flows through the oxidant supply passage 14 from the upper side to the lower side of the housing 1. An outflow hole 14 b of the oxidant supply passage 14 is formed at the lower end of the partition wall 25. The oxidant that flows out from the outflow hole 14 b is supplied to the cathode electrode of each cell of the cell stack 11. An off-gas combustion exhaust gas discharge passage 17 is connected to the top wall of the partition wall 25. The off-gas combustion exhaust gas passes through the space around the reformer 13 (exhaust gas passage) and is discharged from the discharge passage 17 above the housing 1. Also in the present invention, the cell stack 11 can be accurately positioned with respect to the housing 1.

  In the sixth embodiment, the oxidant supply passage 14 is defined between the stack holding fitting 61 and the space through which the exhaust gas flows. For this reason, the deformation and thermal stress due to thermal expansion of the stack holding metal fitting 61 can be further reduced, and the durability of the stack holding metal fitting 61 can be ensured. Furthermore, a heat insulating material can be arrange | positioned in the outermost side inside a housing | casing, and an exhaust gas channel | path can be arrange | positioned inside a heat insulating material. Thereby, heat dissipation from the exhaust gas passage can also be suppressed, and higher heat insulation performance can be obtained. Further, since the exhaust gas passage is not disposed outside the heat insulating material, heat radiation from the exhaust gas passage can be suppressed. Thereby, higher heat insulation performance is obtained. Further, the lateral width of the short side surface of the housing 1 can be shortened, and the fuel device can be installed in an elongated space.

  Further, as an application form of the sixth embodiment shown in FIG. 14, the features of the fifth embodiment shown in FIG. 13 can be applied, and the same effects as those of the embodiment can be obtained.

<Seventh embodiment>
FIG. 15 shows a basic structure of a main part of a solid oxide fuel cell device according to a seventh embodiment of the present invention. In the sixth embodiment, the same components as those in the first to sixth embodiments are denoted by the same reference numerals, and description thereof is omitted.

In the present embodiment, the heat insulating material disposed outside the cell stack is included in a stack holding fitting 71 formed in a container shape as schematically shown in FIG. That is, the inside of the container shape corresponds to the heat insulating material chamber Hi. In the present embodiment, the structure including the cell stack 11, the oxidant supply passage 14, and the exhaust gas passage 15 similar to those in the first embodiment is configured as follows. The upper end portion of the container-shaped stack holding metal fitting 71 filled with the heat insulating material 16 is supported on the upper end portion of the partition wall 15a forming the exhaust gas passage 15 by fixing or engaging by welding or the like. In the present embodiment, the bottom of the stack holding metal fitting 71 can be supported on the bottom of the partition wall 15. For this reason, the upper end portion of the stack holding fitting 71 may not be supported by the upper end portion of the partition wall 15.
Thus, in this embodiment, by using the stack holding metal fitting 71 formed in a container shape, the heat insulating material 16 can be filled into the heat insulating material chamber Hi before assembling the fuel cell device. For this reason, the assemblability of the fuel cell device can be improved. Moreover, a granular or powdery heat insulating material can be densely filled as the heat insulating material. For this reason, generation | occurrence | production of the space | gap by powdering of a heat insulating material which can occur when a board-shaped heat insulating material etc. are used can be suppressed. Even when the bottom portion of the stack holding metal fitting 71 is supported on the bottom portion of the partition wall 15, the following effects can be obtained. That is, the stack holding metal 71 extends upward from the contact surface between the stack holding metal 71 and the bottom of the partition wall 15 to the manifold portion 11b. For this reason, it can suppress that the temperature of the fuel cell 11a falls through the manifold part 11b.

  As a modification of the seventh embodiment, the stack holding metal 71 may be extended upward and the upper end portion may be supported on the top wall of the housing 1 or the like. If it does in this way, it can also have a heat insulation function outside a reformer. In this case, an exhaust gas outlet pipe that penetrates the inner wall and the outer wall may be connected to both sides of the stack holding metal 71. If it does in this way, the combustion exhaust gas from an off-gas combustion part will flow out to an outside exhaust gas passage, without contacting heat insulation material 16 via an exhaust gas outflow pipe.

<Eighth Embodiment>
FIG. 17 shows a basic structure of a main part of a solid oxide fuel cell device according to an eighth embodiment of the present invention. In the seventh embodiment, the same components as those in the first to seventh embodiments are denoted by the same reference numerals, and description thereof is omitted.

In the eighth embodiment, a configuration in which the stack holding metal fitting is formed in a container shape is applied to a type having a structure for discharging exhaust gas to the upper side of the casing. The stack holding metal 81 has a container shape similar to that of the seventh embodiment. Further, an engaging portion 81 b is formed above the lid portion 81 a that covers the upper end surface of the heat insulating material 16 of the stack holding metal member 81. The engaging portion 81 b is engaged with the support member 1 a fixed to the inner wall of the housing 1 to support the stack holding metal member 81. Thereby, the cell stack 11 can be accurately positioned with respect to the housing 1. The engaging portion 81b may be fixed to the support member 1a by welding or the like. Alternatively, the engaging portion 81b may support the stack holding metal member 81 only by engaging with the support member 1a. These are the same as in the other embodiments. In addition, it is preferable to support with a gap between the stack holding metal fitting 81 and the inner wall of the housing 1 and the low temperature bottom wall so as to suppress heat radiation.
As a modification of the eighth embodiment, the stack holding bracket 81 may be extended upward and the upper end portion may be supported on the top wall of the housing 1. In this way, the heat insulation function outside the reformer 13 can also be provided. For example, the stack holding bracket 81 may be supported by providing the support member 1 a on the top wall of the housing 1.

  In the above embodiment, the one in which the oxidant supply passage 14 is inserted into the gap between the fuel cells 11a is shown. For example, as shown in FIG. 1, an oxidant supply passage 14 is provided on both outer sides of the cell stack 11 in the direction connecting the raw fuel inlet and the hydrogen-enriched gas outlet of the reformer 13. On the other hand, as shown in FIG. 18, oxidant supply passages 14 are disposed on both outer sides of the cell stack 11 in a direction orthogonal to the direction connecting the raw fuel inlet and the hydrogen-enriched gas outlet of the reformer 13. It is good also as composition to do.

  Furthermore, it is good also as the following structures. A heat insulating material 16 is disposed perpendicular to the direction connecting the raw fuel inlet and the hydrogen-enriched gas outlet of the reformer 13. Then, a stack holding metal fitting is disposed so as to cover at least the inner surfaces of the heat insulating material and the lower heat insulating material on both outer sides of the cell stack. In this case, effects similar to those of the other embodiments can be obtained by supporting the upper portions of both sides of the cell stack of the stack holding bracket on the casing.

  The illustrated embodiments are merely illustrative of the invention. It goes without saying that the present invention includes various improvements and modifications made by those skilled in the art within the scope of the claims in addition to those directly shown by the described embodiments. For example, FIGS. 3, 5, 6 and 8 illustrate the structure in which the partition wall 15a is supported by the inner wall of the side surface of the housing 1. However, the present invention is not limited to this. For example, as shown in FIG. It may be supported by the bottom inner wall of the body 1.

  Further, although one end of the reformer has been described as the raw fuel inlet and the other end as the hydrogen-enriched gas outlet, a folded structure having a partition plate inside the reformer may be used. In that case, the raw fuel inlet and the hydrogen-enriched gas outlet may be formed at the same end. Moreover, in the 1st-9th embodiment, the rectangular parallelepiped reformer was illustrated. However, the present invention is not limited to this, and a cylindrical shape may be used. The number of reformers can be one or more depending on the scale of the fuel cell device.

DESCRIPTION OF SYMBOLS 1 ... Housing 1a ... Supporting member 11 ... Cell stack 11a ... Fuel cell 11b ... Manifold part (pedestal)
DESCRIPTION OF SYMBOLS 12 ... Off-gas combustion part 13 ... Reformer 13a ... Arm member 14 ... Oxidant supply passage 15 ... Exhaust gas passage 15a ... Partition 16 ... Heat insulating material 17 ... Exhaust passage 18 ... Fuel supply piping 21, 31, 41, 51, 61, 71, 81, 101 ... Stack holding bracket 31d ... Reformer support part 101f ... Support part

Claims (12)

A cell stack in which a plurality of fuel cells are supported by a pedestal;
A channel-shaped stack holding metal fitting that encloses the cell stack and is open at the top;
A housing containing a reformer that houses the cell stack and the stack holding fitting, and reforms raw fuel to supply a hydrogen-enriched gas to the cell stack above the cell stack ;
A heat insulating material disposed between the outside of the stack holding metal fitting and the inside of the housing;
With
The stack holding bracket is
The reformer that is supported by the casing or a connected body with the casing and holds the pedestal on the inner bottom wall of the stack holding metal fitting and supports the reformer so as not to contact the fuel cell. Having a vessel support,
The engaging member attached to the reformer side and the engaging member attached to the stack holding bracket side are slidably engaged with each other to support the reformer. A fuel cell device. Between the housing and the heat insulating material, comprising a partition wall that is a connecting body with the housing,
An exhaust gas passage is defined between the housing and the partition wall,
The fuel cell device according to claim 1, wherein the stack holding metal fitting is supported by the partition wall. 3. The fuel cell device according to claim 2, wherein an upper end of the stack holding bracket is supported by a side wall of the partition wall at a position above half of the vertical height of the cell stack. The fuel cell device according to claim 1, wherein an upper end of the stack holding metal fitting is supported by the housing. 5. The fuel cell device according to claim 4, wherein an upper end of the stack holding metal fitting is supported by the housing at a position above half of the vertical height of the cell stack. The fuel cell device according to claim 5, wherein an upper end of the stack holding metal fitting is supported by a top wall of the housing. The fuel cell device according to claim 5, wherein an upper end of the stack holding metal fitting is supported by a side wall of the housing. The fuel cell device according to claim 1, wherein the stack holding metal fitting includes an engaging portion that engages with the pedestal. The casing includes a reformer that reforms raw fuel and supplies a hydrogen-enriched gas to the cell stack above the cell stack,
2. The fuel cell device according to claim 1, wherein the heat insulating material is located between a side surface of the housing of the reformer. The fuel cell device according to claim 1 , wherein the stack holding metal fitting has a heat insulating material holding portion for holding the heat insulating material. The fuel cell device according to claim 1, wherein the stack holding metal fitting is formed in a container shape including the heat insulating material. 2. The fuel cell device according to claim 1, wherein the stack holding metal fitting is made of a non-porous metal plate and is disposed so as to block the flow of exhaust gas to the heat insulating material.