JP2016051505A - Solid oxide fuel cell apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate temperature unevenness of a fuel cell module, secure an evaporating performance of an evaporator, and attain effective temperature rise at a time of startup by improving heat exchange performance of a heat exchanger.SOLUTION: A solid oxide fuel cell apparatus 1 comprises: a plurality of fuel cell units 16; a module case 8 for housing a plurality of fuel cell units; an adiabatic material 7 covering around the module case 8; a reformer 20 for generating fuel gas by reforming raw fuel gas by moisture vapor; a combustion chamber 18 for heating the reformer 20 by combusting the residual fuel gas; an exchanger 23 for exchanging heat between the oxidant gas and the exhaust gas; and an evaporator 25 provided in the adiabatic material 7 and outside the module case 8 and for generating moisture vapor by exchanging heat between water and the exhaust gas immediately after the heat exchanging in the exchanger 23.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a solid oxide fuel cell device, and more particularly to a solid oxide fuel cell device in which an evaporator is provided outside a module case that houses a plurality of fuel cells.

  A solid oxide fuel cell device (hereinafter also referred to as “SOFC”) uses an oxide ion conductive solid electrolyte as an electrolyte, attaches electrodes on both sides thereof, and supplies fuel gas on one side. The fuel cell operates at a relatively high temperature by supplying an oxidant gas (air, oxygen, etc.) to the other side.

  In JP 2012-221659 A (Patent Document 1), a plurality of fuel cells are arranged in a module case, and the fuel gas remaining without being used for power generation above the plurality of fuel cells ( A cell burner type solid oxide fuel cell device is described that burns off gas) and heats the reformer in the module case with combustion heat. In particular, in the solid oxide fuel cell device described in Patent Document 1, the module in the startup process is caused by the evaporator (vaporizer) that generates steam supplied to the reformer greatly deprives the surrounding heat. The evaporator is provided in the heat insulating material outside the module case from the viewpoint of suppressing deterioration in the temperature rise performance of the internal temperature and temperature unevenness (thermal unevenness) of the fuel cell module.

JP 2012-221659 A

  Here, conventionally, the temperature of the oxidant gas is raised using the exhaust gas obtained by combusting the off-gas, and specifically, the heat exchanger (air heat exchanger) is used to store the exhaust gas and the heat exchanger. The temperature of the oxidant gas is raised by exchanging heat with the oxidant gas, and this oxidant gas is supplied to the fuel cell, so that the operating temperature of the solid oxide fuel cell device at the time of start-up can be reduced. A rise is planned. In the solid oxide fuel cell device described in Patent Document 1 described above, a heat exchanger is provided on the downstream side of the evaporator in the flow direction of the exhaust gas, that is, after heat exchange is performed in the evaporator. The exhaust gas is supplied to a heat exchanger, and heat exchange is performed between the exhaust gas and the oxidant gas.

  However, in the configuration described in Patent Document 1 in which the heat exchanger is provided on the downstream side of the evaporator, the heat of the exhaust gas is greatly deprived by the upstream evaporator, so that the heat exchange performance in the downstream heat exchanger is (Heat recovery performance) decreases, and the oxidant gas cannot be heated appropriately in the heat exchanger. For this reason, the operating temperature of the solid oxide fuel cell device at the time of startup or the like cannot be quickly raised, and it takes time to raise the temperature at startup. In addition, when trying to accelerate the temperature rise at the time of startup, it is necessary to introduce a large amount of off-gas for heat self-sustainment, which tends to increase the running cost of the solid oxide fuel cell device.

  Therefore, the present invention can eliminate the temperature unevenness of the fuel cell module, and at the same time, effectively improves the heat exchange performance in the heat exchanger while ensuring the water evaporation performance in the evaporator, and effectively An object of the present invention is to provide a solid oxide fuel cell device capable of raising the temperature and lowering the running cost during power generation (increasing power generation efficiency).

In order to achieve the above object, the present invention provides a solid oxide fuel cell device that generates electric power by a reaction between a fuel gas and an oxidant gas, a plurality of fuel cells electrically connected to each other, and a plurality of fuel cells A module case that accommodates fuel cells, a heat insulating material provided to cover the periphery of the module case, an oxidant gas supply passage that supplies oxidant gas to a plurality of fuel cells, and a plurality of fuel gases A fuel gas supply passage to be supplied to the battery cell; a reformer which is disposed in the module case, reforms the raw fuel gas with water vapor to generate fuel gas, and supplies the fuel gas to the fuel gas supply passage; Combustion unit that burns fuel gas that is not used for power generation in multiple fuel cells and heats the reformer with combustion heat, and exhaust gas that should be discharged from the module case passes An exhaust passage, at least a part of which is covered with a heat insulating material, and an oxidant gas is supplied to exchange heat between the oxidant gas and the exhaust gas passing through the exhaust passage. The heat exchanger is provided for the exhaust passage and supplies the heat-exchanged oxidant gas to the oxidant gas supply passage, and is arranged so that at least a part of the periphery thereof is covered with a heat insulating material. The heat exchanger is supplied with water, and the water and the exhaust gas that passes through the exhaust passage and exchanges heat with the exhaust gas immediately after the heat exchange in the heat exchanger. The evaporator is provided for the exhaust passage, evaporates water by heat exchange to generate water vapor, and supplies the water vapor to the reformer, in the heat insulating material and outside the module case. Arranged, and having an evaporator And wherein the door.
In the present invention configured as described above, since the evaporator is provided in the heat insulating material outside the module case, the fuel cell can be generated when the evaporator is disposed inside the module case as described above. Cell temperature unevenness (heat unevenness) can be eliminated. In addition, when the evaporator is provided outside the module case in this way, the temperature of the exhaust gas in the module case can be maintained higher than when the evaporator is provided inside the module case. By supplying this high-temperature exhaust gas to the heat exchanger, the heat exchange property in the heat exchanger can be improved. Therefore, according to the present invention, the oxidant gas appropriately heated by the heat exchanger can be supplied to the fuel cell, and the temperature rise at the start of the solid oxide fuel cell device can be quickly performed. Further, it is possible to reduce the running cost during power generation (increase power generation efficiency).
In particular, in the present invention, the heat exchanger is provided upstream of the evaporator in the flow direction of the exhaust gas, and the exhaust gas before being heat-exchanged by the evaporator is supplied to the heat exchanger. Compared with a configuration (for example, a configuration described in Patent Document 1) provided on the downstream side of the heat exchanger, high-temperature exhaust gas can be supplied to the heat exchanger. Therefore, according to the present invention, it is possible to more effectively raise the temperature of the oxidant gas in the heat exchanger, and it is possible to raise the temperature of the solid oxide fuel cell device more greatly at the time of startup. Furthermore, in the present invention, the evaporator is disposed immediately below the heat exchanger in the flow direction of the exhaust gas, and the evaporator is provided in the heat insulating material, so that the exhaust gas is wasted between the heat exchanger and the evaporator. Since heat exchange is not performed, it is possible to appropriately secure the evaporation performance of water in the evaporator.
For this reason, according to the present invention, stable oxidant gas temperature rise performance (in other words, system temperature rise performance) and water evaporation performance are ensured even in the start-up process where the exhaust temperature is low. can do.

In the present invention, preferably, an exhaust passage portion that constitutes a part of the exhaust passage and through which exhaust gas passes is formed in a lower layer of the evaporator located on the module case side, and the evaporation located above the exhaust passage portion is formed. In the upper layer of the evaporator, there are formed an evaporation section for generating water vapor by evaporating water, and a mixing section for mixing the water vapor and the raw fuel gas. Steam from the mixing section of the evaporator to the reformer is formed. A mixed gas supply pipe that supplies a mixed gas with the raw fuel gas and further extends so as to pass through the exhaust passage portion of the evaporator.
As described above, when the evaporator is provided outside the module case, the temperature of the mixed gas decreases in the process of supplying the mixed gas from the evaporator to the reformer (in this case, the water vapor in the mixed gas). However, according to the present invention configured as described above, an evaporator outside the module case can be connected to the evaporator outside the module case. Since the mixed gas supply pipe communicating with the reformer inside the module case is passed through the exhaust passage portion of the evaporator, the exhaust gas passing through the exhaust passage portion flows around a part of the mixed gas supply pipe. Therefore, the temperature of the mixed gas in the mixed gas supply pipe can be raised by the exhaust gas. Therefore, according to the present invention, the heated mixed gas can be supplied to the reformer, and the problems in the case where the evaporator as described above is provided outside the module case can be solved. Specifically, the temperature drop of the mixed gas supplied to the reformer can be suppressed, and in particular, the water vapor in the mixed gas can be suppressed from liquefying, and the reforming performance in the reformer can be improved. Can be secured.

In the present invention, preferably, the mixed gas supply pipe is configured to pass through an upstream portion in the exhaust gas flow direction in the exhaust passage portion of the evaporator.
In the present invention configured as described above, the mixed gas supply pipe passes through the upstream portion of the exhaust passage portion of the evaporator, and the exhaust gas not used for heat exchange in the evaporation portion of the evaporator is supplied with the mixed gas. Since it is configured to flow around a part of the pipe, the temperature of the mixed gas in the mixed gas supply pipe can be effectively raised by the exhaust gas. Therefore, the temperature drop of the mixed gas supplied to the reformer can be more effectively suppressed, and in particular, the liquefaction of water vapor in the mixed gas can be reliably suppressed.

In the present invention, preferably, an exhaust passage portion that constitutes a part of the exhaust passage and through which the exhaust gas passes is formed in the lower layer of the heat exchanger located on the module case side, and is located above the exhaust passage portion. An oxidant gas passage portion through which the oxidant gas passes is formed in the upper layer of the heat exchanger, and the heat exchanger and the evaporator are arranged in a horizontal direction, and the exhaust passage portion of the heat exchanger and the evaporator Each of the exhaust passage portions is formed along the horizontal direction.
In the present invention configured as described above, the heat exchanger and the evaporator are arranged side by side in the horizontal direction, and the exhaust passage portion is formed along the horizontal direction in each lower layer of the heat exchanger and the evaporator. In addition, it is possible to optimize the arrangement structure of the heat insulating material and the handling of the exhaust gas and suppress wasteful heat exchange. Therefore, the solid oxide fuel cell device can be reduced in size, and heat exchange can be performed in the heat exchanger and the evaporator by effectively using the heat quantity of the exhaust gas.

In the present invention, preferably, a heat exchange module in which a heat exchanger and an evaporator are integrally formed is provided, and the heat exchange module has a substantially U-shaped cross-section with an open top, and is in a horizontal direction. The extending case constitutes both the exhaust passage portion of the heat exchanger and the exhaust passage portion of the evaporator, and covers the open portion of the case, and the oxidant gas passage portion of the heat exchanger and the evaporator portion of the evaporator. And the mixing section are fixed.
In the present invention configured as described above, the heat exchanger module in which the heat exchanger and the evaporator are integrally formed is used, and the exhaust passage portion of the heat exchanger and the exhaust passage portion of the evaporator are opened at the top. Since it is configured by a case having a substantially U-shaped cross-sectional shape, each exhaust passage portion of the heat exchanger and the evaporator can be formed by one case, and the solid oxide fuel cell device can be reduced in size and cost. I can plan. In addition, since the oxidant gas passage part of the heat exchanger and the evaporation part and mixing part of the evaporator are fixed so as to cover the open part of the case of this heat exchange module, the oxidant gas passage part of the heat exchanger and Support of the evaporator and the mixing section of the evaporator can be simplified, and further miniaturization and cost reduction can be achieved.

In the present invention, preferably, the heat exchange module is fixed to the top plate of the module case.
In the present invention configured as described above, since the heat exchange module is fixed to the top plate of the module case, the heat exchanger and the evaporator can be fixed and supported easily and reliably.

In the present invention, preferably, a part of the heat insulating material is arranged between the heat exchange module and the module case so as to fill the gap, and the part of the heat insulating material is fixed to the top plate of the module case. Yes.
In the present invention configured as described above, since the heat exchange module is supported with the heat insulating material sandwiched, the fixing of the heat insulating material can be facilitated, and the solid oxide fuel cell device can be reduced in size and cost. Can be planned.

  According to the solid oxide fuel cell device of the present invention, the temperature unevenness of the fuel cell module can be eliminated, and the heat exchange performance in the heat exchanger can be improved while ensuring the water evaporation performance in the evaporator. Thus, the temperature can be effectively increased at the time of startup, and the running cost during power generation can be reduced (power generation efficiency can be increased).

1 is an overall configuration diagram showing a solid oxide fuel cell device according to a first embodiment of the present invention. It is front sectional drawing which shows the fuel cell module of the solid oxide fuel cell apparatus by 1st Embodiment of this invention. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. 1 is a perspective view of a state in which a heat insulating material and a housing are removed from a fuel cell module of a solid oxide fuel cell device according to a first embodiment of the present invention. FIG. 5 (A) is a perspective view of the reformer according to the first embodiment of the present invention as viewed obliquely from above, and FIG. 5 (B) is a cross section taken along the line VB-VB in FIG. 5 (A). FIG. 5C is a cross-sectional view taken along the line VC-VC in FIG. 1 is a partial cross-sectional view showing a fuel cell unit of a solid oxide fuel cell according to a first embodiment of the present invention. 1 is a perspective view showing a fuel cell stack of a solid oxide fuel cell according to a first embodiment of the present invention. It is a schematic sectional drawing which shows the external shape of a part of top plate of the reformer and module case by 1st Embodiment of this invention. It is a schematic sectional drawing of the part of the mixed gas supply pipe | tube comprised so that thermal expansion could be absorbed by 1st Embodiment of this invention. It is a front sectional view showing a fuel cell module for explaining a gas flow in the fuel cell module of the solid oxide fuel cell device according to the first embodiment of the present invention. FIG. 3 is a cross-sectional view of the fuel cell module taken along line III-III in FIG. 2 for explaining a gas flow in the fuel cell module of the solid oxide fuel cell device according to the first embodiment of the present invention. It is a schematic sectional drawing of the evaporator by the modification of 1st Embodiment of this invention. 3 is a flowchart showing a method for manufacturing a solid oxide fuel cell device according to the first embodiment of the present invention. It is a whole block diagram which shows the solid oxide fuel cell apparatus by 2nd Embodiment of this invention. It is front sectional drawing which shows the fuel cell module of the solid oxide fuel cell apparatus by 2nd Embodiment of this invention. It is sectional drawing along the XVI-XVI line of FIG. It is a perspective view of the state which removed the heat insulating material and the housing from the fuel cell module of the solid oxide fuel cell apparatus by 2nd Embodiment of this invention. 18A is a perspective view of the reformer according to the second embodiment of the present invention as viewed obliquely from above, and FIG. 18B is a cross section taken along line XVIIIB-XVIIIB in FIG. FIG. 18C is a cross-sectional view taken along line XVIIIC-XVIIIC in FIG. It is a front sectional view showing a fuel cell module for explaining a gas flow in a fuel cell module of a solid oxide fuel cell device according to a second embodiment of the present invention. FIG. 16 is a cross-sectional view of the fuel cell module taken along the line XVI-XVI of FIG. 15 for explaining a gas flow in the fuel cell module of the solid oxide fuel cell device according to the second embodiment of the present invention. It is a schematic sectional drawing which shows a part of fuel cell module to which the shielding board by the modification of 2nd Embodiment of this invention is applied. It is a cross-sectional perspective view of the reformer by the modification of 2nd Embodiment of this invention.

  Next, a solid oxide fuel cell device according to an embodiment of the present invention will be described with reference to the accompanying drawings.

<First Embodiment>
First, a solid oxide fuel cell apparatus (SOFC) according to a first embodiment of the present invention will be described.

  FIG. 1 is an overall configuration diagram showing a solid oxide fuel cell device according to a first embodiment of the present invention. As shown in FIG. 1, the solid oxide fuel cell apparatus 1 according to the first embodiment of the present invention includes a fuel cell module 2 and an auxiliary unit 4.

  The fuel cell module 2 includes a housing 6, and a metal module case 8 is built in the housing 6 via a heat insulating material 7. In the power generation chamber 10, which is the lower part of the module case 8, which is a sealed space, a fuel cell that performs a power generation reaction with fuel gas and oxidant gas (hereinafter referred to as “power generation air” or “air” as appropriate). A cell assembly 12 is arranged. The fuel cell assembly 12 includes nine fuel cell stacks 14 (see FIG. 7). The fuel cell stack 14 includes 16 fuel cell units 16 (each including a fuel cell). (See FIG. 6). In this example, the fuel cell assembly 12 has 144 fuel cell units 16. In the fuel cell assembly 12, all of the plurality of fuel cell units 16 are connected in series.

  A combustion chamber 18 as a combustion portion is formed above the power generation chamber 10 of the module case 8 of the fuel cell module 2. In this combustion chamber 18, residual fuel gas and residual air that have not been used for power generation reaction. Are combusted to generate exhaust gas (in other words, combustion gas). Further, the module case 8 is covered with the heat insulating material 7 to suppress the heat inside the fuel cell module 2 from being diffused to the outside air. Further, a reformer 20 for reforming the fuel gas is disposed above the combustion chamber 18, and the reformer 20 is heated to a temperature at which the reforming reaction can be performed by the combustion heat of the residual gas. doing.

  Furthermore, a heat exchange module 21 including a heat exchanger (air heat exchanger) 23 and an evaporator 25 (see FIG. 2 and the like), which will be described later, is provided in the heat insulating material 7 above the module case 8 in the housing 6. ing. The heat exchanger 23 is supplied with the exhaust gas generated by the combustion of the residual gas in the combustion chamber 18 and the power generation air, and performs heat exchange between the exhaust gas and the power generation air, thereby generating the power generation air. The air for power generation is supplied to the fuel cell assembly 12 in the module case 8 by heating. The evaporator 25 is supplied with the exhaust gas and water generated by the combustion of the residual gas in the combustion chamber 18, and performs heat exchange between these exhaust gas and water, thereby evaporating the water and generating water vapor. Then, this mixed gas of water vapor and raw fuel gas (hereinafter sometimes referred to as “fuel gas”) is supplied to the reformer 20 in the module case 8.

  Next, the auxiliary unit 4 stores pure water tank 26 that stores water condensed from moisture contained in the exhaust from the fuel cell module 2 and makes it pure water with a filter, and water supplied from the water storage tank. Is provided with a water flow rate adjusting unit 28 (such as a “water pump” driven by a motor). In addition, the auxiliary unit 4 adjusts the flow rate of the fuel gas, the gas shutoff valve 32 for shutting off the fuel supplied from the fuel supply source 30 such as city gas, the desulfurizer 36 for removing sulfur from the fuel gas, A fuel flow adjustment unit 38 (such as a “fuel pump” driven by a motor) and a valve 39 that shuts off fuel gas flowing out from the fuel flow adjustment unit 38 when power is lost. Further, the auxiliary unit 4 includes an electromagnetic valve 42 that shuts off the air supplied from the air supply source 40, a reforming air flow rate adjusting unit 44 that adjusts the air flow rate, and a power generation air flow rate adjusting unit 45 (with a motor). Driven "air blower", etc., a first heater 46 for heating the reforming air supplied to the reformer 20, and a second heater 48 for heating the power generating air supplied to the power generation chamber. I have. The first heater 46 and the second heater 48 are provided in order to efficiently raise the temperature at startup, but may be omitted.

  Next, a hot water production apparatus 50 to which exhaust gas is supplied is connected to the fuel cell module 2. The hot water production apparatus 50 is supplied with tap water from the water supply source 24, and the tap water is heated by the heat of the exhaust gas and supplied to a hot water storage tank of an external hot water heater (not shown). The fuel cell module 2 is provided with a control box 52 for controlling the amount of fuel gas supplied and the like. Furthermore, the fuel cell module 2 is connected to an inverter 54 that is a power extraction unit (power conversion unit) for supplying the power generated by the fuel cell module to the outside.

  Next, the structure of the fuel cell module of the solid oxide fuel cell device according to the first embodiment of the present invention will be described in detail with reference to FIGS. FIG. 2 is a side sectional view showing the fuel cell module of the solid oxide fuel cell device according to the first embodiment of the present invention, and FIG. 3 is a sectional view taken along line III-III in FIG. FIG. 4 is a perspective view showing the fuel cell module with the housing and the heat insulating material removed.

  As shown in FIGS. 2 and 3, the fuel cell module 2 mainly includes the heat exchange module 21 provided in the heat insulating material 7 and outside the module case 8 as described above, and the module case 8. The fuel cell assembly 12 and the reformer 20 are provided inside.

  The heat exchange module 21 includes a heat exchanger 23 and an evaporator 25 that are arranged side by side in the horizontal direction. In this heat exchange module 21, a heat exchanger 23 and an evaporator 25 are integrally formed, and are fixed on the top plate 8a of the module case 8 (see FIG. 4). Further, a portion 7 a of the heat insulating material 7 is disposed between the heat exchange module 21 and the module case 8 so as to fill these gaps, and the portion 7 a of the heat insulating material 7 is also disposed on the top plate 8 a of the module case 8. (See FIGS. 2 and 3).

  Next, the heat exchanger 23 of the heat exchange module 21 has a power generation air introduction pipe 74 connected to one side end side in the horizontal direction (see FIG. 4), and a module case on the other side end side in the horizontal direction. The 1st exhaust passage 71 connected with the exhaust port 11 formed on the top plate 8a of 8 is connected (refer FIG. 2). The exhaust port 11 is an opening through which the exhaust gas generated in the combustion chamber 18 in the module case 8 is discharged to the outside of the module case 8, and one side end of the reformer 20 in the module case 8 in the horizontal direction. The heat exchanger 23 is disposed in the heat insulating material 7 above the exhaust port 11 and is formed at a position on the top plate 8a of the module case 8 corresponding to the side.

  Further, as shown in FIG. 2, the heat exchanger 23 has a two-layer structure in the vertical direction, and the exhaust gas supplied from the first exhaust passage 71 is provided in the lower layer portion located on the module case 8 side. An exhaust passage portion 23c through which gas passes is formed, and a power generation air passage portion 23a (through which power generation air supplied from the power generation air introduction pipe 74 passes is formed in an upper layer portion located above the exhaust passage portion 23c. Corresponding to the oxidant gas passage portion). Plate-shaped offset fins 23b and 23d as heat exchange promoting members are respectively provided in the power generation air passage 23a and the exhaust passage 23c (see FIG. 2). The offset fins 23b and 23d extend in the horizontal direction along the traveling direction of the gas passing through the power generation air passage portion 23a and the exhaust passage portion 23c, respectively, and are provided at substantially the same place in the horizontal direction. .

  In such a heat exchanger 23, heat exchange is performed between the power generation air passing through the power generation air passage 23a and the exhaust gas passing through the exhaust passage 23c (particularly, offset fins 23b and 23d are provided). In addition, efficient heat exchange is performed in the power generation air passage portion 23a and the exhaust passage portion 23c), and the power generation air is heated by the heat of the exhaust gas.

Furthermore, the power generation air passage 23 a of the heat exchanger 23 is formed at the end of the heat exchanger 23 to which the first exhaust passage 71 is connected so as to pass through the inside of the first exhaust passage 71. A power generation air supply pipe 76 is connected (see FIG. 2). The power generation air supply pipe 76 is connected to a power generation air supply passage 77 provided along the side plate 8b of the module case 8 as an oxidant gas supply passage (see FIG. 3). The power generation air supply passage 77 is formed by a space between the side plate 8b of the module case 8 and a power generation air supply case 77a arranged so as to extend in the vertical direction along the side plate 8b (see FIG. 3 and FIG. 3). (See FIG. 4). The power generation air supply passage 77 injects power generation air into the power generation chamber 10 toward the fuel cell assembly 12 from a plurality of outlets 77 b provided in the lower part of the side plate 8 b of the module case 8.
More specifically, the power generation air supply passage 77 is provided for each of the one surface of the side plate 8b of the module case 8 and the surface opposite to the surface, that is, two power generation air supply passages 77. Is present.

  Next, as shown in FIG. 2, the evaporator 25 included in the heat exchange module 21 is arranged side by side with the above-described heat exchanger 23 in the horizontal direction, and more than the heat exchanger 23 in the exhaust gas flow direction. It is arranged downstream. More specifically, the evaporator 25 corresponds to the reformer 20 in the module case 8 corresponding to the other side end side opposite to the one side end side where the exhaust port 11 is provided in the top plate 8a of the module case 8. It is arranged in the upper heat insulating material 7 on the inlet side into which the mixed gas flows.

  Further, the evaporator 25 has a fuel supply pipe 63 for supplying water and raw fuel gas (which may include reforming air) to one side end in the horizontal direction, and an exhaust gas for discharging the exhaust gas. The exhaust pipe 82 is connected (see FIG. 4), and the exhaust passage 23c of the heat exchanger 23 is communicated with the other end in the horizontal direction (see FIG. 2). Specifically, as shown in FIG. 2, the evaporator 25 has a two-layer structure in the vertical direction, and communicates with the exhaust passage portion 23c of the heat exchanger 23 in the lower layer portion located on the module case 8 side. As shown, the exhaust gas passage 23c is arranged side by side in the horizontal direction, and the exhaust gas supplied from the exhaust passage portion 23c (that is, the exhaust gas after heat exchange is performed in the exhaust passage portion 23c of the heat exchanger 23). ) Through which the exhaust passage 25c passes. In addition, the evaporator 25 has an evaporation part 25a for generating water vapor by evaporating water supplied from the fuel supply pipe 63 in an upper layer portion located above the exhaust passage part 25c, and more than the evaporation part 25a. A mixing unit 25b that is provided on the upstream side in the exhaust gas flow direction and mixes the water vapor generated in the evaporation unit 25a and the raw fuel gas supplied from the fuel supply pipe 63 is formed. For example, the evaporator 25a and the mixer 25b of the evaporator 25 are formed in a space in which the evaporator 25 is partitioned by a partition plate provided with a plurality of communication holes.

  In such an evaporator 25, heat exchange is performed between the water in the evaporator 25a and the exhaust gas passing through the exhaust passage 25c, and the water in the evaporator 25a is evaporated by the heat of the exhaust gas, Water vapor will be generated. In addition, heat exchange is performed between the mixed gas in the mixing section 25b and the exhaust gas passing through the exhaust passage section 25c, and the temperature of the mixed gas is increased by the heat of the exhaust gas.

  The above-described exhaust passage portion 23c of the heat exchanger 23 and the exhaust passage portion 25c of the evaporator 25 have a substantially U-shaped cross-section with an open upper portion, as shown in FIG. The module 21 includes a case 21a, and a member fixed so as to cover the open portion of the case 21a, a power generation air passage portion 23a of the heat exchanger 23, an evaporation portion 25a and a mixing portion of the evaporator 25. 25b.

  Further, as shown in FIG. 2, a mixed gas supply pipe 62 for supplying a mixed gas from the mixing unit 25 b to the reformer 20 in the module case 8 is connected to the mixing unit 25 b of the evaporator 25. Yes. One end of the mixed gas supply pipe 62 is connected to a mixed gas supply port 20a provided in the reformer 20, and is bent by 90 ° at a point extending substantially horizontally from the mixed gas supply port 20a. The case 8, the heat insulating material 7 a, and the exhaust passage 25 c on the upstream side of the evaporator 25 extend in a substantially vertical direction so as to traverse in order, and the other end is connected to the mixing unit 25 b of the evaporator 25. In this case, the mixed gas supply pipe 62 is provided such that an end 62b connected to the mixing unit 25b of the evaporator 25 protrudes above the evaporation unit 25a of the evaporator 25 and the bottom surface of the mixing unit 25b. (See also FIG. 12).

  Next, the reformer 20 provided in the module case 8 will be described with reference to FIG. 5 in addition to FIGS. 2 and 3. FIG. 5 (A) is a perspective view of the reformer 20 according to the first embodiment of the present invention as viewed obliquely from above, and FIG. 5 (B) is along the line VB-VB in FIG. 5 (A). FIG. 5C is a cross-sectional view taken along the line VC-VC in FIG. 5A, and shows the reformer 20 with the top plate 20g removed. 5A to 5C also show the mixed gas supply pipe 62 and the fuel gas supply pipe 64 in addition to the reformer 20.

  The reformer 20 is disposed so as to extend horizontally above the combustion chamber 18, and is fixed to the top plate 8a at a predetermined distance from the top plate 8a of the module case 8 (FIGS. 2 and 2). 3). The reformer 20 is supplied with the mixed gas from the mixed gas supply pipe 62 through the mixed gas supply port 20a. The preheating unit 20b preheats the mixed gas and the preheating unit 20b in the flow direction of the mixed gas. A reformer provided on the downstream side and filled with a reforming catalyst (not shown) for reforming a mixed gas (that is, raw fuel gas mixed with water vapor (may include reforming air)) 20c (see FIG. 5B). As the reforming catalyst, a catalyst obtained by imparting nickel to the alumina sphere surface or a catalyst obtained by imparting ruthenium to the alumina sphere surface is appropriately used. The preheating unit 20b and the reforming unit 20c of the reformer 20 are formed in a space in which the reformer 20 is partitioned by a partition plate 20n provided with a plurality of communication holes (see FIG. 5C). Here, the reformer 20 is configured such that the mixed gas from the mixed gas supply pipe 62 is ejected from the mixed gas supply port 20a, and this mixed gas is expanded in the preheating unit 20b to reduce the ejection speed. At the same time, the jetted mixed gas collides with the wall surface 20k on the downstream end side of the preheating part 20b, turns back, passes through the partition plate 20n, and is supplied to the reforming part 20c (FIG. 5 ( B) and (C)).

  The reformer 20 extends through the reformer 20 (specifically, the portion where the reforming portion 20c is formed) vertically and passes exhaust gas generated in the lower combustion chamber 18. A through hole 20d is formed (see FIGS. 5A and 5B). The through-hole 20d has a portion 62a of the above-described mixed gas supply pipe 62, specifically, a portion extending in the horizontal direction in the mixed gas supply pipe 62, the end of which is the mixed gas supply of the reformer 20. A portion 62a connected to the mouth 20a is disposed. The portion 62a of the mixed gas supply pipe 62 also functions as a preheating unit that preheats the mixed gas passing through the inside by the exhaust gas passing through the through hole 20d of the reformer 20 (hereinafter, the mixed gas supply pipe 62 The portion 62a is referred to as a “preheating portion 62a”).

  Further, the wall surface of the through hole 20 d of the reformer 20 is inclined so as to direct the exhaust gas generated in the combustion chamber 18 toward the preheating unit 20 b of the reformer 20 and the preheating unit 62 a of the mixed gas supply pipe 62. The inclined surface 20e functions as an exhaust guide portion (see FIG. 5B). An exhaust guide plate 80 for directing the exhaust gas generated in the combustion chamber 18 to the preheating unit 20b of the reformer 20 and the preheating unit 62a of the mixed gas supply pipe 62 is also provided on the inner surface of the module case 8. (See FIG. 2). The inclined surface 20e of the through hole 20d and the exhaust guide plate 80 correspond to an example of the exhaust guide portion and the exhaust gas directing means.

  Furthermore, the space formed in the upper part in the reformer 20 constitutes a second exhaust passage 72 (see FIGS. 2 and 3). Specifically, the space between the top plate 20g, which is the top surface of the portion where the preheating unit 20b and the reforming unit 20c are formed in the reformer 20, and the bottom surface of the top plate 8a of the module case 8 is the second space. An exhaust passage 72 is formed. More specifically, in the reformer 20, a cylindrical portion 20h extending from the top plate 20g to the lower surface of the top plate 8a of the module case 8 is integrally formed at the edge of the top plate 20g of the reformer 20. The cylindrical portion 20h constitutes the outer wall of the second exhaust passage 72 (see FIG. 5A). That is, the space surrounded by the top plate 20 g and the cylindrical portion 20 h of the reformer 20 and the top plate 8 a of the module case 8 constitutes the second exhaust passage 72. Further, a flange portion 20j extending outward of the reformer 20 is provided at the upper end portion of the cylindrical portion 20h of the reformer 20. In addition, the cylindrical portion 20h of the reformer 20 has a plurality of cuts at locations corresponding to the other end side opposite to the one end side where the exhaust port 11 is provided in the top plate 8a of the module case 8. A notch 20 i is formed, and this notch 20 i constitutes an exhaust gas inlet for introducing exhaust gas into the second exhaust passage 72.

  Here, the exhaust gas flows into the second exhaust passage 72 from the through hole 20d formed in the reformer 20 and the notch 20i formed in the cylindrical portion 20h of the reformer 20. . As shown in FIG. 3, an exhaust guide plate 81 is provided on the inner surface of the module case 8, and does not flow into the through-hole 20 d of the reformer 20, but outside the preheating unit 20 b and the reforming unit 20 c. The exhaust gas that has passed between the side surface and the inner side surface of the module case 8 is made to easily flow into the notch 20 i of the reformer 20 as the exhaust gas inlet of the second exhaust passage 72. Thus, the exhaust gas flowing into the second exhaust passage 72 from the through hole 20d and the cutout portion 20i of the reformer 20 passes through the exhaust port 11 formed on the top plate 8a of the module case 8 and the above. The first exhaust passage 71 is discharged (see FIG. 2).

  Next, as shown in FIG. 2, on the downstream end side of the reformer 20, fuel gas as a fuel gas supply passage for supplying fuel gas generated by reforming by the reforming unit 20c of the reformer 20 A supply pipe 64 is connected, and a hydrogen extraction pipe 65 for hydrodesulfurizer is connected to the upper part of the fuel gas supply pipe 64. The fuel gas supply pipe 64 extends downward, and further extends horizontally in a manifold 66 formed below the fuel cell assembly 12. A plurality of fuel supply holes 64 b are formed in the lower surface of the horizontal portion 64 a of the fuel gas supply pipe 64, and the reformed fuel gas is supplied into the manifold 66 from the fuel supply holes 64 b. A lower support plate 68 having a through hole for supporting the fuel cell stack 14 described above is attached above the manifold 66, and the fuel gas in the manifold 66 flows into the fuel cell unit 16. Supplied. An ignition device 83 for starting combustion of fuel gas and air is provided in the combustion chamber 18.

Next, the fuel cell unit 16 will be described with reference to FIG. FIG. 6 is a partial cross-sectional view showing a fuel cell unit of a solid oxide fuel cell according to an embodiment of the present invention.
As shown in FIG. 6, the fuel cell unit 16 includes a fuel cell 84 and inner electrode terminals 86 that are caps respectively connected to both ends of the fuel cell 84.
The fuel cell 84 is a tubular structure extending in the vertical direction, and includes a cylindrical inner electrode layer 90 that forms a fuel gas flow path 88 therein, a cylindrical outer electrode layer 92, an inner electrode layer 90, and an outer side. An electrolyte layer 94 is provided between the electrode layer 92 and the electrode layer 92. The inner electrode layer 90 is a fuel electrode through which fuel gas passes and becomes a (−) electrode, while the outer electrode layer 92 is an air electrode in contact with air and becomes a (+) electrode.

  Since the inner electrode terminal 86 attached to the upper end side and the lower end side of the fuel cell 84 has the same structure, the inner electrode terminal 86 attached to the upper end side will be specifically described here. 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. At the center of the inner electrode terminal 86, a fuel gas channel capillary 98 that communicates with the fuel gas channel 88 of the inner electrode layer 90 is formed.

  The fuel gas passage narrow tube 98 is an elongated thin tube provided so as to extend in the axial direction of the fuel cell 84 from the center of the inner electrode terminal 86. Therefore, a predetermined pressure loss occurs in the flow of the fuel gas flowing from the manifold 66 (see FIG. 2) into the fuel gas passage 88 through the fuel gas passage narrow tube 98 of the lower inner electrode terminal 86. To do. Accordingly, the fuel gas flow passage narrow tube 98 of the lower inner electrode terminal 86 acts as an inflow side flow passage resistance portion, and the flow passage resistance is set to a predetermined value. Further, a predetermined pressure loss also occurs in the flow of the fuel gas flowing out from the fuel gas flow path 88 to the combustion chamber 18 (see FIG. 2) through the fuel gas flow path narrow tube 98 of the upper inner electrode terminal 86. Therefore, the fuel gas flow passage narrow tube 98 of the upper inner electrode terminal 86 acts as an outflow side flow passage resistance portion, and the flow passage resistance is set to a predetermined value.

  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, and Ni and ceria doped with at least one selected from rare earth elements. The mixture is formed of at least one of Ni and a mixture of lanthanum garade doped with at least one selected from Sr, Mg, Co, Fe, and Cu.

  The electrolyte layer 94 is, 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, lanthanum gallate doped with at least one selected from Sr and Mg, Formed from at least one of the following.

  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 silver.

Next, the fuel cell stack 14 will be described with reference to FIG. FIG. 7 is a perspective view showing a fuel cell stack of a solid oxide fuel cell according to an embodiment of the present invention.
As shown in FIG. 7, the fuel cell stack 14 includes 16 fuel cell units 16, and these fuel cell units 16 are arranged in two rows of 8 each.
Each fuel cell unit 16 is supported by a rectangular lower support plate 68 made of ceramic (see FIG. 2) on the lower end side, and on the upper end side, two fuel cell unit units 16 at both ends are provided, each having a substantially square shape. Is supported by the upper support plate 100. The lower support plate 68 and the upper support plate 100 are formed with through holes through which the inner electrode terminal 86 can pass.

  Furthermore, a current collector 102 and an external terminal 104 are attached to the fuel cell unit 16. The current collector 102 includes a fuel electrode connection portion 102a that is electrically connected to an inner electrode terminal 86 attached to the inner electrode layer 90 that is a fuel electrode, and an outer peripheral surface of the outer electrode layer 92 that is an air electrode. It is integrally formed so as to connect the air electrode connecting portion 102b that is electrically connected. In addition, a silver thin film is formed on the entire outer surface of the outer electrode layer 92 (air electrode) of each fuel cell unit 16 as an electrode on the air electrode side. When the air electrode connecting portion 102b contacts the surface of the thin film, the current collector 102 is electrically connected to the entire air electrode.

  Further, two external terminals 104 are connected to the air electrode 86 of the fuel cell unit 16 located at the end of the fuel cell stack 14 (the far left side in FIG. 7). These external terminals 104 are connected to the inner electrode terminal 86 of the fuel cell unit 16 at the end of the adjacent fuel cell stack 14, and as described above, all 160 fuel cell units 16 are connected in series. It has come to be.

Next, the support structure of the reformer 20 in the top plate 8a of the module case 8 will be described with reference to FIG. FIG. 8 is a schematic sectional view showing the outer shape of a part of the top plate 8a of the reformer 20 and the module case 8 according to the first embodiment of the present invention.
As shown in FIG. 8, the reformer 20 has a flange portion 20j formed on the upper end portion of the upper cylindrical portion 20h (see also FIG. 5) provided on the lower surface of the top plate 8a of the module case 8. By being engaged with the support portion 8 d, the module case 8 is supported by the top plate 8 a. The flange portion 20j of the reformer 20 corresponds to the engaging portion, and the support portion 8d of the top plate 8a of the module case 8 corresponds to the engaged portion. By engaging the flange portion 20j of the reformer 20 with the support portion 8d of the top plate 8a of the module case 8 and attaching the reformer 20 to the top plate 8a of the module case 8, the reformer 20 The reformer 20 is supported to be slidable in the horizontal direction with respect to the top plate 8a of the module case 8 while blocking the passage of exhaust gas between the top plate 8a of the module case 8 and the top plate 8a. . In this case, since the reformer 20 can slide in the horizontal direction with respect to the top plate 8a of the module case 8, the thermal expansion of the reformer 20 and the mixed gas supply pipe 62 can be absorbed in the horizontal direction. .

Thus, the support structure of the reformer 20 in the top plate 8a of the module case 8 is not limited to absorbing the thermal expansion of the reformer 20 and the mixed gas supply pipe 62. In addition to the support structure, Alternatively, instead of the support structure, the mixed gas supply pipe 62 may be configured to absorb thermal expansion. This will be specifically described with reference to FIG.
FIG. 9 is a schematic cross-sectional view of a portion of the mixed gas supply pipe 62 configured to absorb thermal expansion according to the first embodiment of the present invention. As shown in FIG. 9, a portion extending in the horizontal direction in the mixed gas supply pipe 62, that is, a portion of the mixed gas supply pipe 62 positioned in the through hole 20 d of the reformer 20 (see also FIG. 5B). A bellows tube 62c that can absorb the difference in thermal expansion in the horizontal direction is applied.

In the conventional solid oxide fuel cell device, the reformer is supported from below by a support member provided at the lower portion of the reformer. In such a conventional solid oxide fuel cell device, the support member that supports the reformer from below is used as a reflecting plate that reflects the heat of the fuel cell unit 16, and thus a plurality of fuel cell units 16 are used. The reflection of heat from the surroundings to each of these was made uniform. Specifically, an uneven surface is formed on the support member that supports the reformer so that the reflection of heat from the surroundings to each of the plurality of fuel cell units 16 is uniform.
In contrast, in the present embodiment, as described above, the reformer 20 is fixed to the top plate 8a of the module case 8, and the reformer 20 is supported from above, that is, the reformer 20 is suspended. It is lowered (see FIG. 8). In such a configuration according to the present embodiment, a member that supports the reformer 20 cannot be used as a reflector, unlike a conventional solid oxide fuel cell device. Therefore, in the present embodiment, the side plate 8b of the module case 8 may be formed so that the reflection of heat from the surroundings to each of the plurality of fuel cells 16 is uniform. Specifically, as shown in FIG. 4, a fuel gas supply pipe 64 connected below the hydrogen extraction pipe 65 for the hydrodesulfurizer (this fuel gas supply pipe 64 reflects heat toward the fuel cell unit 16. The thermal distance between the fuel cell unit 16 and the surrounding members is a fuel cell unit 16 in which the fuel cell unit 16 is located in the vicinity and the fuel cell unit 16 in which the fuel gas supply pipe 64 is not located in the vicinity. The side plate 8b of the module case 8 facing the fuel cell unit 16 where the fuel gas supply pipe 64 is not located in the vicinity of the side plate 8b facing the fuel cell unit 16 so that the (ie, the distance to the member that reflects heat) is equal. A protruding portion 8c that protrudes may be formed. That is, the side plate 8b facing the fuel cell unit 16 where the fuel gas supply pipe 64 is not located in the vicinity is located inward of the side plate 8b facing the fuel cell unit 16 where the fuel gas supply pipe 64 is located in the vicinity. Thus, the side plate 8b of the module case 8 may be configured.

  Next, a gas flow in the fuel cell module of the solid oxide fuel cell device according to the first embodiment of the present invention will be described with reference to FIGS. FIG. 10 is a side sectional view showing the fuel cell module of the solid oxide fuel cell device according to the first embodiment of the present invention, similar to FIG. 2, and FIG. 11 is similar to FIG. It is sectional drawing along the III-III line. FIGS. 10 and 11 are diagrams in which arrows indicating gas flows are newly added in FIGS. 2 and 3, respectively, and show the state in which the heat insulating material 7 is removed for convenience of explanation.

  As shown in FIG. 10, the power generation air flows into the heat exchanger 23 from the power generation air introduction pipe 74 (see FIG. 4) connected to one side end side in the horizontal direction of the heat exchanger 23 to generate heat. It flows in the power generation air passage 23a provided in the upper layer of the exchanger 23 toward the other end in the horizontal direction. At this time, the power generation air flowing in the power generation air passage portion 23a exchanges heat with the exhaust gas flowing in the exhaust passage portion 23c provided in the lower layer of the heat exchanger 23 (particularly the offset fins 23b). The heat generating air is heated by the heat of the exhaust gas. The power generation air heated by the exhaust gas in this way is connected to the other end in the horizontal direction of the heat exchanger 23 (the side opposite to the side where the power generation air introduction pipe 74 is connected). As shown in FIG. 11, the air flows through the power generation air supply passage 77 provided along the side plate 8 b of the module case 8, and a plurality of outlets 77 b provided in the lower portion of the side plate 8 b of the module case 8. From the fuel cell assembly 12 toward the fuel cell assembly 12.

  On the other hand, as shown in FIG. 10, water and raw fuel gas (fuel gas) are fed into the evaporator 25 from a fuel supply pipe 63 (see FIG. 4) connected to one end in the horizontal direction of the evaporator 25. Specifically, it is supplied into an evaporation section 25a provided in the upper layer of the evaporator 25. The water supplied to the evaporator 25a of the evaporator 25 is exhaust gas flowing in the exhaust passage 25c provided in the lower layer of the evaporator 25 (in the exhaust passage 23c provided in the heat exchanger 23 as described above). Heat exchange is performed with the exhaust gas after the heat exchange has already been performed, and it is heated by the heat of the exhaust gas to be vaporized into steam. The water vapor and the raw fuel gas supplied from the fuel supply pipe 63 flow in the horizontal direction in the evaporation portion 25a (specifically, toward the side opposite to the side where the fuel supply pipe 63 is connected). In the horizontal direction) and mixed in the mixing unit 25b at the end of the evaporation unit 25a.

  The mixed gas (fuel gas) obtained by mixing the water vapor and the raw fuel gas in the mixing unit 25b is connected to the side opposite to the side where the fuel supply pipe 63 is connected in the evaporator 25, and the exhaust passage of the evaporator 25 is connected. The gas flows through the part 25 c, the heat insulating material 7 a, and the mixed gas supply pipe 62 extending across the module case 8 and flows into the reformer 20 in the module case 8. In this case, the mixed gas includes the exhaust gas flowing through the exhaust passage portion 25c below the mixing portion 25b, the exhaust gas flowing around the portion of the mixed gas supply pipe 62 positioned in the exhaust passage portion 25c, and the inside of the module case 8. Heat is exchanged with the exhaust gas flowing around the portion of the mixed gas supply pipe 62 located at the position where the gas is heated. Particularly, in the module case 8, in the preheating part 62 a of the mixed gas supply pipe 62 located in the through hole 20 d of the reformer 20, the mixed gas flowing in the preheating part 62 a and the through hole 20 d of the reformer 20 are connected. Efficient heat exchange is performed with the passing exhaust gas.

  Thereafter, the mixed gas supplied from the mixed gas supply pipe 62 to the reformer 20 is provided on one side end side in the horizontal direction of the reformer 20 via the mixed gas supply port 20a of the reformer 20. The mixed gas that has flowed into the preheating portion 20b and has flowed into the preheating portion 20b is preheated by the exhaust gas flowing around the preheating portion 20b. In this case, since the preheating part 20b of the reformer 20 has a structure expanded from the mixed gas supply pipe 62, the mixed gas is jetted from the mixed gas supply pipe 62 to the preheating part 20b of the reformer 20, and thus The jetted mixed gas is expanded in the preheating unit 20b, and the jetting speed is reduced. Then, the mixed gas collides with the wall surface 20k (see FIG. 5B) on the downstream end side of the preheating portion 20b, turns back, and passes through the partition plate 20n in the reformer 20 (see FIG. 5C). Then, it flows into the reforming section 20c, which is located downstream of the preheating section 20b and filled with the reforming catalyst, and is reformed in the reforming section 20c to become fuel gas. The fuel gas thus generated is supplied to a fuel gas supply pipe 64 connected to the downstream end side of the reforming section 20 c of the reformer 20, and a hydrogen desulfurizer hydrogen extraction connected to the upper side of the fuel gas supply pipe 64. Flow through tube 65. The fuel gas is supplied into the manifold 66 from the fuel supply hole 64 b provided in the horizontal portion 64 a of the fuel gas supply pipe 64, and the fuel gas in the manifold 66 is supplied into each fuel cell unit 16. .

  On the other hand, the fuel gas remaining without being used for power generation in the fuel cell unit 16 is burned in the combustion chamber 18 in the module case 8 to become exhaust gas (combustion gas). As shown in FIG. Go up inside 8. Specifically, a part of the exhaust gas generated by the combustion passes through the through hole 20d of the reformer 20 and passes through the second exhaust passage 72 (in the reformer 20) formed in the upper part of the reformer 20. It flows into a space surrounded by the top plate 20g and the cylindrical portion 20h and the top plate 8a of the module case 8. In this case, the exhaust gas is directed to pass through the through hole 20d of the reformer 20 by the inclined surface 20e forming the through hole 20d of the reformer 20. More specifically, a part of the exhaust gas is located in the preheating part 20b of the reformer 20 and the preheating part 62a of the mixed gas supply pipe 62 (in the through hole 20d of the reformer 20) by the inclined surface 20e of the through hole 20d. Of the mixed gas supply pipe 62). In addition, the exhaust gas is directed so as to flow around the preheating unit 20 b of the reformer 20 and the preheating unit 62 a of the mixed gas supply pipe 62 by the exhaust guide plate 80 provided on the inner side surface of the module case 8. Is done. The exhaust gas flowing in this manner exchanges heat with the mixed gas in the preheating unit 20b of the reformer 20 and the preheating unit 62a of the mixed gas supply pipe 62, thereby heating the mixed gas.

  On the other hand, the remaining part of the exhaust gas that has not passed through the through-hole 20d of the reformer 20 is, as shown in FIG. A second portion is formed through a notch 20i (see FIG. 5A) as an exhaust gas inlet formed in the cylindrical portion 20h of the reformer 20 through the inner surface of the module case 8. It flows into the exhaust passage 72. In this case, the exhaust gas is directed to flow into the second exhaust passage 72 from the notch 20 i of the reformer 20 by the exhaust guide plate 81 provided on the inner surface of the module case 8.

  Thus, the exhaust gas flowing into the second exhaust passage 72 from the through hole 20d and the notch 20i of the reformer 20 is on the side where the through hole 20d and the notch 20i are provided as shown in FIG. It flows into the 1st exhaust passage 71 through the exhaust port 11 formed in the position on the top plate 8a of the module case 8 corresponding to the other side. The exhaust gas sequentially flows through the exhaust passage portion 23c of the heat exchanger 23 connected to the first exhaust passage 71 and the exhaust passage portion 25c of the evaporator 25 connected to the exhaust passage portion 23c. The exhaust gas is discharged from an exhaust gas discharge pipe 82 (see FIG. 4) connected to the downstream end side. At this time, as described above, the exhaust gas exchanges heat with the power generation air in the power generation air passage portion 23a of the heat exchanger 23, and the mixed gas and evaporator in the mixing portion 25b of the evaporator 25. Heat exchange is performed with water in the 25 evaporation sections 25a.

  Next, functions and effects of the solid oxide fuel cell device according to the first embodiment of the present invention will be described.

In one aspect of the present embodiment, the evaporator 25 is disposed in the heat insulating material 7 outside the module case 8 (see FIG. 2 and the like), and thus occurs when the evaporator 25 is disposed inside the module case 8. The obtained temperature unevenness (heat unevenness) of the fuel cell assembly 12 can be eliminated. Further, when the evaporator 25 is provided outside the module case 8, the temperature of the exhaust gas in the module case 8 can be made higher than when the evaporator 25 is provided inside the module case 8. By supplying this high temperature exhaust gas to the heat exchanger 23, the heat exchange property in the heat exchanger 23 can be improved. For this reason, it is possible to supply power generation air that has been appropriately heated by the heat exchanger 23, and to quickly raise the temperature at the start-up of the fuel cell module 2.
In particular, in the present embodiment, since the heat exchanger 23 is provided on the upstream side of the evaporator 25 in the exhaust gas flow direction, compared to the case where the heat exchanger 23 is provided on the downstream side of the evaporator 25, Since the high-temperature exhaust gas is supplied to the heat exchanger 23 (since the exhaust gas before being heat-exchanged by the evaporator 25 is supplied to the heat exchanger 23), the power generation air is more effective in the heat exchanger 23. Thus, the temperature of the fuel cell module 2 can be increased more greatly at startup. In this case, the evaporator 25 is disposed immediately after the heat exchanger 23 in the flow direction of the exhaust gas, and the evaporator 25 is provided in the heat insulating material 7, so that wasteful heat exchange of the exhaust gas is not performed, and thus the evaporation The water evaporation performance in the vessel 25 can be ensured appropriately.

  Further, when the evaporator 25 is provided outside the module case 8 as described above, the temperature of the mixed gas supplied to the reformer 20 is lowered (the water vapor in the mixed gas may be liquefied). However, according to the present embodiment, the evaporator 25 outside the module case 8 and the reformer 20 inside the module case 8 may be deteriorated. Since the mixed gas supply pipe 62 that communicates with the exhaust gas is passed through the exhaust passage 25c of the evaporator 25 (see FIG. 2 and the like), more specifically, the upstream portion of the exhaust passage 25c in the flow direction of the exhaust gas. Therefore, the temperature of the mixed gas can be raised by the exhaust gas flowing through the exhaust passage portion 25c. Therefore, the mixed gas whose temperature has been raised can be supplied to the reformer 20, and the above-described problems when the evaporator 25 is provided outside the module case 8 can be solved.

  Further, according to the present embodiment, the heat exchanger 23 and the evaporator 25 are arranged side by side in the horizontal direction, and the exhaust passage portions 23c and 25c are horizontally arranged in the lower layers of the heat exchanger 23 and the evaporator 25, respectively. Since it formed along (refer FIG. 2 etc.), the arrangement structure of the heat insulating material 7 and the handling of exhaust gas can be optimized, and useless heat exchange can be suppressed. Therefore, the fuel cell module 2 can be reduced in size, and heat exchange can be performed in the heat exchanger 23 and the evaporator 25 by effectively using the amount of heat of the exhaust gas.

  Further, according to the present embodiment, the heat exchange module 21 in which the heat exchanger 23 and the evaporator 25 are integrally formed is used, and the exhaust passage portion 23c of the heat exchanger 23 and the exhaust passage portion 25c of the evaporator 25 are provided. Since the upper portion is formed by the case 21a having a substantially U-shaped cross section (see FIG. 4), the exhaust passage portions 23c and 25c can be formed by the single case 21a, and the fuel cell module 2 can be reduced in size and size. Cost can be reduced. In addition, the power generation air passage portion 23a of the heat exchanger 23 and the evaporation portion 25a and the mixing portion 25b of the evaporator 25 are fixed so as to cover the open portion of the case 21a. Support of the air passage portion 23a and the evaporation portion 25a and the mixing portion 25b of the evaporator 25 can be simplified, and the fuel cell module 2 can be further reduced in size and cost.

  Moreover, according to this embodiment, since the heat exchange module 21 was fixed to the top plate 8a of the module case 8 (see FIG. 4), the heat exchanger 23 and the evaporator 25 can be fixed and supported easily and reliably. . In addition, since the heat exchange module 21 is supported with the heat insulating material 7a interposed therebetween (see FIG. 2 and the like), the heat insulating material 7a can be easily fixed, and the fuel cell module 2 can be reduced in size and cost. .

In another aspect of the present embodiment, the evaporator 25 is disposed in the heat insulating material 7 above the module case 8 so as to correspond to the inlet (mixed gas supply port 20a) side to which the mixed gas is supplied to the reformer 20. In addition, since the evaporator 25 and the inlet of the reformer 20 are connected by the mixed gas supply pipe 62 that vertically traverses the inside of the heat insulating material 7 and the module case 8 (see FIG. 2 and the like), the evaporator 25 With a simple configuration in which the positional relationship with the inlet of the reformer 20 is optimized, the mixed gas supply pipe 62 can be minimized, and the evaporator 25 as described above is provided outside the module case 8. The problem of the case can be solved. Specifically, the temperature drop of the mixed gas supplied to the reformer 20 can be suppressed (especially, the water vapor in the mixed gas can be suppressed from being liquefied). Quality performance can be secured.
In particular, in the present embodiment, the mixed gas supply pipe 62 that connects the evaporator 25 and the reformer 20 so as to cross the inside of the module case 8 is configured, that is, the mixed gas supply pipe 62 is connected to the reformer 20. Since it is configured to pass through the module case 8 in the process of connection, the mixed gas in the mixed gas supply pipe 62 can be heated by the exhaust gas in the module case 8, and the heated mixed gas is reformed. 20 can be supplied. Therefore, even with the configuration in which the evaporator 25 is provided outside the module case 8, high reforming performance in the reformer 20 can be realized with a simple configuration.

  Further, according to the present embodiment, the exhaust port 11 is formed at a position on the top plate 8a of the module case 8 corresponding to the side opposite to the side where the mixed gas supply port 20a is provided in the reformer 20, and this Since the heat exchanger 23 is disposed above the exhaust port 11 (see FIG. 2 and the like), high-temperature exhaust gas can be supplied to the heat exchanger 23 in the shortest distance, and the heat exchanger 23 can be provided only by arrangement. , The distance for heat exchange between the power generation air and the exhaust gas (that is, the horizontal length of the heat exchanger 23) can be increased. Therefore, with a simple configuration, even with exhaust gas with a small amount of heat in the startup process, the temperature of the power generation air can be appropriately raised, the temperature rise time in the fuel cell module 2 can be shortened, and stable startup is possible. Can be realized. In addition, since the evaporator 25 is arranged on the downstream side of the heat exchanger 23 and on the inlet side (mixed gas supply port 20a) side of the reformer 20, wasteful heat exchange is suppressed and stable evaporation of the evaporator 25 is performed. Performance can be ensured.

  Further, according to the present embodiment, the mixing unit 25c of the evaporator 25 is disposed upstream in the exhaust gas flow direction, and the mixed gas is supplied from the mixing unit 25c to the reformer 20 through the mixed gas supply pipe 62. Since it supplies (refer FIG. 2 etc.), between the comparatively high temperature exhaust gas which is not used for vaporization in the downstream evaporation part 20a, and the mixed gas in the gas state which is easy to raise temperature in the mixing part 25c Heat exchange can be performed, and the temperature of the mixed gas can be effectively increased in the mixing unit 25c. Therefore, the reforming performance of the reformer 20 can be stabilized. In such a configuration, the mixed gas supply pipe 62 can be the shortest path, and the temperature drop of the mixed gas is appropriately suppressed.

  Further, when the evaporator 25 is provided outside the module case 8 as described above, the vaporization performance is deteriorated, so that water falls through the mixed gas supply pipe 62 due to the vaporization delay and the reformer 20. However, according to the present embodiment, the upstream end 62b of the mixed gas supply pipe 62 is located above the bottom of the evaporator 25a and the mixer 25b of the evaporator 25. 2 (see FIG. 2), the fact that water drops into the reformer 20 by being dropped in the mixed gas supply pipe 62 is simplified by the arrangement of the mixed gas supply pipe 62. It can be suppressed by the configuration.

Further, as described above, if the evaporator 25 is provided outside the module case 8, the reformer 20 is provided in the module case 8, and these are connected by the mixed gas supply pipe 62 traversing the inside of the module case 8, Due to the temperature difference, the mixed gas supply pipe 62 may be deteriorated due to the stress due to the expansion difference. However, in this embodiment, the portion of the mixed gas supply pipe 62 located in the module case 8 is thermally expanded. Since the bellows tube 62c capable of absorbing the difference in the horizontal direction is applied (see FIG. 9), deterioration of the mixed gas supply tube 62 due to such a large temperature difference can be appropriately suppressed.
In addition, in this embodiment, the reformer 20 is also slidably attached to the top plate 8a of the module case 8 so as to be able to absorb the thermal expansion in the horizontal direction (see FIG. 8). Further, not only the stress relaxation of the reformer 20 but also the deformation stress of the reformer 20 acting on the mixed gas supply pipe 62 can be suppressed, and the above-described bellows pipe 62c of the mixed gas supply pipe 62 can be simplified. In addition, the connection strength of the mixed gas supply pipe 62 to the reformer 20 and the like can be increased.

  Further, according to the present embodiment, since the mixed gas supply pipe 62 is disposed so as to pass through the through hole 20b of the reformer 20 (see FIG. 2 and the like), the mixed gas supply pipe 62 is further shortened. In addition, the mixed gas in the mixed gas supply pipe 62 can be efficiently heated by the exhaust gas in the module case 8. In particular, in the present embodiment, the exhaust gas is mixed gas at a position where the inclined surface 20e of the through hole 20b of the reformer 20 is separated from the one side end side of the reformer 20 corresponding to the exhaust port 11 in the horizontal direction. Since it is formed so as to be directed to the supply pipe 62, the mixed gas in the mixed gas supply pipe 62 located in the through hole 20b of the reformer 20 can be effectively heated, and the high temperature mixed gas can be modified. The reforming performance of the reformer 20 can be enhanced by supplying it to the mass device 20.

  In still another aspect of the present embodiment, the preheating unit 20b is provided upstream of the reforming unit 20c in the flow direction of the mixed gas in the reformer 20 (see FIG. 2 and the like). The mixed gas can be appropriately heated by the exhaust gas flowing through. Therefore, the mixed gas heated to an appropriate temperature can be supplied to the reforming unit 20c, and the reforming performance in the reforming unit 20c can be stabilized.

Further, according to the present embodiment, the preheater 20b of the reformer 20 is disposed immediately above the upper end of the fuel cell assembly 12 and at a position exposed to the combustion heat and exhaust gas from the combustion chamber 18. Therefore (see FIG. 2 etc.), the temperature of the mixed gas can be appropriately raised in the preheating section 20b of the reformer 20, and the problem in the case where the evaporator 25 is provided outside the module case 8 is solved. be able to. Particularly, according to the present embodiment, the exhaust gas generated in the combustion chamber 18 is positively generated by the inclined surface 20e of the through hole 20b of the reformer 20 and the exhaust guide plate 80 provided on the inner side surface of the module case 8. Since it is directed to the preheating section 20b of the reformer 20 (see FIG. 2 and the like), the mixed gas supplied to the reforming section 20c of the reformer 20 is appropriately applied even with a small amount of exhaust gas in the starting process. It is possible to quickly stabilize the reforming performance in the reforming section 20c.
In addition, in the present embodiment, as described above, the exhaust gas directed to the preheating unit 20b of the reformer 20 is folded back after colliding with the preheating unit 20b and directed to the exhaust port 11. The mixed gas can be reliably heated without reducing the exhaust gas toward the preheating unit 20b. In this case, it is possible to secure a long heat exchange time between the exhaust gas and the mixed gas in the preheating unit 20b by utilizing the pressure loss improvement due to the return of the exhaust gas, and the mixed gas is more stably with a simple configuration. Can be heated.

  Moreover, according to this embodiment, since the preheating part 62a was also provided in the mixed gas supply pipe 62, the mixed gas supplied to the reformer 20 can be heated more reliably. In particular, in the present embodiment, the preheating portion 62a of the mixed gas supply pipe 62 is provided in a downstream portion in the flow direction of the mixed gas so that the exhaust gas from the combustion chamber 18 collides with the preheating portion 62a (that is, Since the preheating portion 62a is positively exposed to combustion heat and exhaust gas), it is arranged so as to be parallel to the virtual plane formed by the upper end portion of the fuel cell assembly 12 (see FIG. 2 and the like). The mixed gas can be heated with a simple configuration.

  Further, according to the present embodiment, the mixed gas ejected from the preheating part 62a of the mixed gas supply pipe 62 to the preheating part 20b of the reformer 20 is expanded in the preheating part 20b of the reformer 20, and the flow velocity is reduced. With this configuration, the heat exchange time between the mixed gas and the exhaust gas in the preheater 20b of the reformer 20 can be increased with a simple configuration, and the mixed gas can be effectively heated. Can do. In addition, in the present embodiment, since the mixed gas in the preheating unit 20b of the reformer 20 collides with the wall surface 20k on the downstream end side of the preheating unit 20b, is turned back and flows into the reforming unit 20c. In order to appropriately realize effective heat exchange and expansion of heat exchange time through the wall surface forming the preheating portion 20b without increasing the volume of the preheating portion 20b at the expense of the volume of the reforming portion 20c. Can do. In addition, according to the present embodiment, the mixed gas flows in the preheating portion 20b of the reformer 20 as described above, so that the mixing property of the mixed gas in the preheating portion 20b can be improved.

  Moreover, according to this embodiment, since the preheating part 62a of the mixed gas supply pipe 62 is disposed in the through hole 20d of the reformer 20 (see FIG. 2 and the like), the preheating part 62a of the mixed gas supply pipe 62 is effective. The temperature of the mixed gas can be increased. In particular, in the present embodiment, the exhaust gas is directed toward the preheating unit 20b of the reformer 20 and the preheating unit 62a of the mixed gas supply pipe 62 by the inclined surface 20e of the through hole 20d of the reformer 20, Without complicating the structure, efficient heat exchange between the mixed gas and the exhaust gas in the preheating units 20b and 62a of the reformer 20 and the mixed gas supply pipe 62 can be realized.

In still another aspect of the present embodiment, the reformer 20 is fixed to the top plate 8a so as to be slidable in the horizontal direction at a predetermined distance from the top plate 8a of the module case 8 in the vertical direction. That is, since the reformer 20 is suspended from the top plate 8a of the module case 8 (see FIG. 2 and FIG. 3), the fuel cell module 2 can be reduced in size and cost. This will be specifically described. In the configuration according to the comparative example in which the bottom plate of the reformer is supported from below using a support member such as a bracket, the support member is arranged at a distance from the fuel cell unit 16 that is at a high temperature. The use of a supporting member that is large in size and can withstand high temperatures increases the cost. On the other hand, when the reformer 20 is suspended from the top plate 8a of the module case 8 as in this embodiment, it is necessary to ensure the distance from the fuel cell unit 16 as in the comparative example. Therefore, the fuel cell module 2 can be reduced in size, and since it is not necessary to use a support member that can withstand high temperatures as in the comparative example, the cost of the support mechanism of the reformer 20 can be reduced. .
In addition, in this embodiment, the exhaust passage wall (specifically, the cylindrical portion 20h) integrally formed with the reformer 20 communicates with the exhaust port 11 formed in the top plate 8a of the module case 8. Since the second exhaust passage 72 is formed in the module case 8 (see FIGS. 2 and 5 and the like), the above-described exhaust passage wall is used as the top plate 8a of the module case 8 while ensuring the exhaust performance of exhaust gas exhaust. The fuel cell module 2 can be further reduced in size by using it as a supporting member for the reformer 20.

  Further, according to the present embodiment, the exhaust passage wall of the second exhaust passage 72 described above is formed by the cylindrical portion 20 h extending upward from the edge of the top plate 20 g of the reformer 20, and the module case 8. A notch 20i as an exhaust gas introduction port for introducing exhaust gas into the second exhaust passage 72 is provided at a location on the cylindrical portion 20h corresponding to the opposite side of the top plate 8a on which the exhaust port 11 is provided. Since it is formed (see FIG. 2 and FIG. 5 etc.), the exhaust flow is optimized, so the degree of freedom of arrangement of the exhaust port 11 on the top plate 8a can be increased, and the heat exchanger 23 and the like can be downsized. Is possible. In addition, while securing the support of the reformer 20 with respect to the top plate 8a by notching the cylindrical portion 20h that is a portion for supporting the reformer 20 with respect to the top plate 8a of the module case 8, The exhaust gas inlet can be easily formed.

Further, according to the present embodiment, the exhaust gas that directs the exhaust gas to the notch 20i at a position on the inner surface of the module case 8 corresponding to the notch 20i (exhaust gas introduction port) of the reformer 20. Since the guide plate 81 is provided (see FIG. 3), even if the distance between the top plate 20g of the reformer 20 and the top plate 8a of the module case 8 is reduced, that is, the vertical width of the second exhaust passage 72 is increased. Even if it is made smaller, the exhaust gas can be reliably introduced into the second exhaust passage 72 from the notch 20 i of the reformer 20. This will be specifically described.
In the configuration in which the reformer 20 is suspended from the top plate 8a of the module case 8 as described above, a member (specifically, the cylindrical portion 20h) that supports the reformer 20 with respect to the top plate 8a is reformed. If the vessel 20 is heavy and has a high temperature, the strength of the support member decreases, so that it cannot be made too long, that is, it is difficult to increase the distance between the top plate 20g of the reformer 20 and the top plate 8a of the module case 8. For this reason, the vertical width of the second exhaust passage 72 is reduced, making it difficult to introduce exhaust gas into the second exhaust passage 72, that is, from the notch 20i of the cylindrical portion 20h as the exhaust gas introduction port to the second. It becomes difficult to introduce the exhaust gas into the exhaust passage 72. Therefore, in this embodiment, the exhaust guide plate 81 for directing the exhaust gas is provided in the notch 20i as the exhaust gas introduction port. Thereby, even if the distance between the top plate 20g of the reformer 20 and the top plate 8a of the module case 8 is reduced, the exhaust gas is reliably supplied from the notch 20i of the reformer 20 into the second exhaust passage 72. Since it can be introduced, the fuel cell module 2 can be miniaturized.

  Further, if the vertical width of the second exhaust passage 72 is reduced as described above, the pressure loss increases and the exhaust performance decreases, but in the present embodiment, the reformer 20 is provided with a through hole 20d and this penetration is reduced. Since the exhaust gas is also introduced into the second exhaust passage 72 from the hole 20d (see FIG. 2 and the like), the exhaust gas can be reliably introduced into the second exhaust passage 72 even if the pressure loss is high. In this case, since the amount of high-temperature exhaust gas that goes around the upper surface of the reformer 20 (specifically, the top plate 20g of the reformer 20) increases, the temperature rise performance of the reformer 20 by the exhaust gas can be improved. it can.

  Moreover, according to this embodiment, since the through-hole 20d was formed in the location on the reformer 20 corresponding to the opposite side to the side in which the exhaust port 11 was provided in the top plate 8a of the module case 8, simple structure As a result, the exhaust flow can be optimized, and the temperature inside the module case 8 and the entire reformer 20 can be raised uniformly.

  Further, according to the present embodiment, the flange portion 20j provided at the upper end portion of the cylindrical portion 20h of the reformer 20 is engaged with the support portion 8d of the top plate 8a of the module case 8, so that the reformer 20 is Since the module case 8 is supported so as to be slidable in the horizontal direction with respect to the top plate 8a (see FIG. 8), the thermal expansion of the reformer 20 can be appropriately absorbed. In this case, since the thermal expansion of the reformer 20 is absorbed by the support mechanism of the reformer 20 with respect to the top plate 8a of the module case 8, there is no need to separately apply a device that absorbs the thermal expansion, and the fuel cell module 2 is installed. It can be downsized. In addition, by engaging the flange portion 20j of the reformer 20 with the support portion 8d of the top plate 8a of the module case 8, the flow of exhaust gas between the flange portion 20j and the support portion 8d is suppressed. Therefore, the performance (specifically, airtightness) as the second exhaust passage 72 can be appropriately ensured.

  Further, according to the present embodiment, the protruding portion 8c that protrudes toward the fuel cell unit 16 is integrally formed on the side plate 8b of the module case 8 (see FIG. 4), and each of the plurality of fuel cell units 16 is formed. Since heat reflection from the surroundings is made uniform, there is no need to use a separate heat reflection plate, and the fuel cell module 2 can be downsized.

  Next, an evaporator according to a modification of the first embodiment of the present invention will be described with reference to FIG. FIG. 12 is a schematic cross-sectional view of an evaporator according to a modification of the first embodiment of the present invention. Here, only a configuration different from the evaporator 25 described above will be described.

  As shown in FIG. 12, the evaporator 25X according to the modification has an upper-layer evaporator 25a filled with ceramic balls 25e, and a lower-layer exhaust passage 25c has an exhaust gas purification function. A ceramic ball 25f carrying an exhaust purification catalyst (in other words, a combustion catalyst) is filled and disposed, and a boundary surface between the evaporation portion 25a and the exhaust passage portion 25c is formed by an uneven surface 25g. In addition, the evaporator 25X is provided with a heater 25d such as a ceramic heater on the upper part of the evaporator 25a. That is, in the evaporator 25X, the heater 25d, the evaporator 25a (including the mixing unit 25d), and the exhaust passage 25c are arranged in this order from top to bottom, and the upper portion of the heater 25d and the exhaust passage 25c. The above-described heat insulating material 7 (not shown in FIG. 12, see FIG. 2 and FIG. 3) is arranged at the lower part of FIG.

  In this way, in the evaporator 25X in which the exhaust gas passage portion 25c is filled with the exhaust gas purification catalyst, the exhaust gas purification catalyst in the exhaust gas passage portion 25c generates CO during cold start when exhaust gas containing a large amount of CO is generated. It generates heat when it is removed (since reforming to remove CO by the exhaust purification catalyst is an exothermic reaction), and the evaporation section 25a can be heated from below by the heat (oxidation reaction heat) generated by the exhaust purification catalyst. . That is, the evaporation section 25a can be heated not only by the heat of the exhaust gas passing through the exhaust passage section 25c but also by the oxidation reaction heat generated by the exhaust purification catalyst in the exhaust passage section 25c. Thus, with a relatively simple configuration of the evaporator 25X, stable vaporization of water in the evaporator 25a can be promoted, and the steam generated in the evaporator 25a can be reliably supplied to the reformer 20. By supplying, stable reforming of the reformer 20 can be realized.

  Further, since the heater 25d is provided at the upper portion of the evaporation section 25a, the use of the heater 25d at the time of cold start allows only the oxidation reaction heat generated by the exhaust purification catalyst in the exhaust passage section 25c as described above. In addition, the heat generated by the heater 25d can be transmitted to the evaporator 25a, that is, the evaporator 25a can be heated from both above and below, and stable vaporization and stabilization of the reformer 20 can be performed in the evaporator 25a. Effective reforming can be ensured. In this case, the single heater 25d is appropriately used for heating in order to activate the exhaust purification catalyst in the exhaust passage portion 25c at the time of cold start, and for using the evaporator 25a as described above. There is no need to apply two heaters for these two applications.

  In particular, the ceramic balls 25e and 25f are filled in both the evaporation section 25a and the exhaust passage section 25c, that is, the ceramic balls 25e and 25f are transferred so that the heat of the heater 25d is passed from the evaporation section 25a to the exhaust passage section 25c. 25f is filled and arranged in the evaporation section 25a and the entire exhaust passage section 25c, so that the ceramic balls 25e and 25f are used as heat conducting members, and the heat of the heater 25d is exhausted through the evaporation section 25a to the exhaust passage section 25c. (See arrow A1 in FIG. 12). With a simple configuration in which the ceramic balls 25e and 25f are filled and arranged, the exhaust purification catalyst in the exhaust passage 25c can be quickly activated by the single heater 25d, and the oxidation reaction of the exhaust purification catalyst The evaporation part 25a can be effectively heated from below by heat.

  Further, since the boundary surface between the evaporation portion 25a and the exhaust passage portion 25c is formed by the uneven surface 25g, the contact area between the ceramic ball 25e and the ceramic ball 25f sandwiching the boundary surface between the evaporation portion 25a and the exhaust passage portion 25c. Therefore, effective heat transfer from the heater 25d through the ceramic balls 25e and 25f can be realized.

Next, with reference to FIG. 13, the manufacturing method of the solid oxide fuel cell apparatus by 1st Embodiment of this invention is demonstrated. FIG. 13 is a flowchart showing a method of manufacturing the solid oxide fuel cell device according to the first embodiment of the present invention.
First, in step S1, heat exchange including the reformer 20, the heat exchanger 23, and the evaporator 25 is performed on the top plate 8a of the module case 8 that is configured separately from the side plate 8b of the module case 8. A subassembly process for fixing the module 21 is performed. Specifically, in the subassembly process, the reformer 20 is fixed to the lower surface of the top plate 8 a of the module case 8, and the heat exchange module 21 and the heat insulating material are attached to the upper surface of the top plate 8 a of the module case 8. 7 is fixed.
In step S2, a module case assembling process is performed in which the module case 8 is assembled by fixing the top plate 8a to which the reformer 20 and the heat exchange module 21 are fixed to the side plate 8b in the sub-assembly process.

  According to the method of manufacturing the solid oxide fuel cell device according to this embodiment, the top plate 8a is separated from the measuring plate 8b, and the reformer 20 and the heat exchange module 21 are sub-mounted on the top plate 8a in advance. Since the assembly is performed, the reformer 20 and the heat exchange module 21 can be easily assembled to the module case 8.

  In the above-described embodiment, the reformer 20 is fixed to the top plate 8a of the module case 8 so as to be slidable in the horizontal direction (see FIG. 8). In other embodiments, the reformer is You may fix 20 with respect to the top plate 8a of the module case 8 so that a movement in a horizontal direction is impossible.

  In the above-described embodiment, only one through-hole 20d is provided in the reformer 20 (see FIG. 5). In other embodiments, the reformer 20 has a through-hole similar to the through-hole 20d. Two or more may be provided. In that case, the mixed gas supply pipe 62 may be provided in any one of the two or more through holes.

Second Embodiment
Next, a solid oxide fuel cell apparatus (SOFC) according to a second embodiment of the present invention will be described.

  In the following description, the description of the same configurations and operational effects as those of the first embodiment described above will be omitted as appropriate, and only the configurations and operational effects different from those of the first embodiment will be described. That is, configurations and operational effects not specifically described here are the same as those in the first embodiment.

  FIG. 14 is an overall configuration diagram showing a solid oxide fuel cell device according to a second embodiment of the present invention. As shown in FIG. 1, a solid oxide fuel cell device 1X according to the second embodiment includes a fuel cell module 2X instead of the fuel cell module 2 shown in the first embodiment.

  In the fuel cell module 2 according to the first embodiment described above, the heat exchange module 21 including the heat exchanger 23 and the evaporator 25 is provided in the heat insulating material 7 outside the module case 8, but the fuel according to the second embodiment. The battery module 2 </ b> X does not include such a heat exchange module 21, and an evaporator 125 is provided in the heat insulating material 7 outside the module case 8. Further, the fuel cell module 2X according to the second embodiment has a reformer 120 having a configuration different from that of the reformer 20 shown in the first embodiment.

  Next, the structure of the fuel cell module of the solid oxide fuel cell device according to the second embodiment of the present invention will be described in detail with reference to FIGS. 15 is a side sectional view showing a fuel cell module of a solid oxide fuel cell device according to a second embodiment of the present invention, and FIG. 16 is a sectional view taken along line XVI-XVI in FIG. FIG. 17 is a perspective view showing the fuel cell module with the housing and the heat insulating material removed.

  As shown in FIGS. 15 and 16, the fuel cell module 2 </ b> X mainly includes the evaporator 125 provided inside the heat insulating material 7 and outside the module case 8 as described above. The fuel cell assembly 12 and the reformer 120 are provided inside.

  The evaporator 125 is fixed on the top plate 8a of the module case 8 (see FIG. 17). Further, a portion 7 a of the heat insulating material 7 is disposed between the heat exchange module 21 and the module case 8 so as to fill these gaps, and the portion 7 a of the heat insulating material 7 is also disposed on the top plate 8 a of the module case 8. (See FIGS. 15 and 16).

  Specifically, the evaporator 125 has a fuel supply pipe 63 for supplying water and raw fuel gas (which may include reforming air) to one end in the horizontal direction, and exhaust gas for exhaust. The first exhaust passage 171 connected to the exhaust port 111 formed on the top plate 8a of the module case 8 is connected to the other end in the horizontal direction (see FIG. 17). Are connected (see FIG. 15). The exhaust port 111 is an opening for exhausting the exhaust gas generated in the combustion chamber 18 in the module case 8 to the outside of the module case 8, and is formed at a substantially central portion of the top plate 8 a of the module case 8. The evaporator 125 is disposed in the heat insulating material 7 above the exhaust port 111.

  Further, as shown in FIG. 15, the evaporator 125 has a two-layer structure in the vertical direction, and an exhaust gas supplied from the first exhaust passage 171 is provided in a lower layer portion located on the module case 8 side. An exhaust passage portion 125c through which the gas passes is formed. In addition, the evaporator 125 has, in an upper layer portion located above the exhaust passage portion 125c, an evaporation portion 125a that generates water vapor by evaporating water supplied from the fuel supply pipe 63, and more than the evaporation portion 125a. A mixing unit 125b that is provided upstream in the flow direction of the exhaust gas and mixes the water vapor generated in the evaporation unit 125a and the raw fuel gas supplied from the fuel supply pipe 63 is formed. For example, the evaporator 125a and the mixer 125b of the evaporator 125 are formed in a space in which the evaporator 125 is partitioned by a partition plate provided with a plurality of communication holes.

  In such an evaporator 125, heat exchange is performed between the water in the evaporator 125a and the exhaust gas passing through the exhaust passage 125c, and the water in the evaporator 125a is evaporated by the heat of the exhaust gas, Water vapor will be generated. In addition, heat exchange is performed between the mixed gas in the mixing portion 125b and the exhaust gas passing through the exhaust passage portion 125c, and the temperature of the mixed gas is increased by the heat of the exhaust gas.

  Further, as shown in FIG. 15, the mixing portion 125b of the evaporator 125 is formed so as to pass through the inside of the first exhaust passage 171 at the end of the evaporator 125 to which the first exhaust passage 171 is connected. The mixed gas supply pipe 162 for supplying the mixed gas from the mixing unit 125 b to the reformer 120 in the module case 8 is connected. One end of the mixed gas supply pipe 162 is connected to the mixed gas supply port 120a provided in the reformer 120, and the module is bent by 90 ° at a point extending substantially horizontally from the mixed gas supply port 120a. The case 8, the heat insulating material 7 a, and the exhaust passage 125 c on the upstream side of the evaporator 125 extend in a substantially vertical direction so as to traverse in order, and the other end is connected to the mixing portion 125 b of the evaporator 125. In this case, the mixed gas supply pipe 162 is provided so that the end 162b connected to the mixing unit 125b of the evaporator 125 protrudes above the evaporation unit 125a of the evaporator 125 and the bottom surface of the mixing unit 125b. Yes.

  Next, a power generation air supply passage 177 as an oxidant gas supply passage is formed outside the module case 8, specifically, between the outer wall of the module case 8 and the heat insulating material 7 (see FIG. 16). ). The power generation air supply passage 177 is a space between the top plate 8a and the side plate 8b of the module case 8 and the power generation air supply case 177a arranged so as to extend along each of the top plate 8a and the side plate 8b. The power generation air is supplied from the power generation air introduction pipe 74 formed at the center position in front view on the top plate 8a of the module case 8 (see FIG. 17). The power generation air supply passage 177 injects power generation air into the power generation chamber 10 toward the fuel cell assembly 12 from a plurality of outlets 177b provided in the lower part of the side plate 8b of the module case 8 (FIG. 16). reference).

  In addition, plate-like offset fins 177c and 177d as heat exchange promoting members are provided inside the power generation air supply passage 177 (see FIG. 16). The offset fin 177c is provided in a portion of the power generation air supply passage 177 along the top plate 8a of the module case 8, and the offset fin 177d is a portion of the power generation air supply passage 177 along the side plate 8b of the module case 8. In addition, the fuel cell unit 16 is provided at a position above the fuel cell unit 16. The power generation air flowing in the power generation air supply passage 177 is provided in the module case 8 inside the offset fins 177c and 177d (specifically, in the module case 8), particularly when passing through the offset fins 177c and 177d. In addition, heat is exchanged with the exhaust gas passing through the second and third exhaust passages 173 and 173) and heated. For this reason, a part of the power generation air supply passage 177 functions as a heat exchanger (air heat exchanger).

  Next, the reformer 120 provided in the module case 8 will be described with reference to FIG. 18 in addition to FIGS. 15 and 16. FIG. 18A is a perspective view of the reformer 120 according to the second embodiment of the present invention as viewed obliquely from above, and FIG. 18B is along the line XVIIIB-XVIIIB in FIG. FIG. 18C is a cross-sectional view taken along line XVIIIC-XVIIIC in FIG. 18A to 18C, in addition to the reformer 120, a mixed gas supply pipe 162, a fuel gas supply pipe 64, and the like are also illustrated.

  The reformer 120 is disposed so as to extend in the horizontal direction above the combustion chamber 18, and is fixed to the top plate 8a at a predetermined distance from the top plate 8a of the module case 8 (see FIG. 15). . The reformer 120 is supplied with the mixed gas from the mixed gas supply pipe 162 through the mixed gas supply port 120a, and preheats the premixed gas 120 in the flow direction of the mixed gas. A reformer provided on the downstream side and filled with a reforming catalyst (not shown) for reforming a mixed gas (that is, raw fuel gas mixed with water vapor (may include reforming air)) 120c (see FIG. 18B). As the reforming catalyst, a catalyst obtained by imparting nickel to the alumina sphere surface or a catalyst obtained by imparting ruthenium to the alumina sphere surface is appropriately used. The preheating unit 120b and the reforming unit 120c of the reformer 120 are formed in a space in which the reformer 120 is partitioned by a partition plate 120e provided with a plurality of communication holes (see FIG. 18B). Here, the reformer 120 is configured such that the mixed gas from the mixed gas supply pipe 162 is ejected from the mixed gas supply port 120a, and this mixed gas is expanded in the preheating unit 120b to reduce the ejection speed. At the same time, the jetted mixed gas collides with the wall surface on the downstream end side of the preheating unit 120b and turns back, and is supplied to the reforming unit 120c through the partition plate 120e (FIG. 18B). )reference).

  Further, the reformer 120 has a recessed portion 120d that is recessed upward at a portion where the reforming portion 120c is formed (see FIG. 18B). The recess 120d is formed by closing the upper part of the through hole extending so as to penetrate in the vertical direction with a plate or the like. The recessed portion 120d has a portion 162a of the above-described mixed gas supply pipe 162, specifically, a portion extending in the horizontal direction in the mixed gas supply pipe 162, and an end portion of the recessed portion 120d is a mixed gas supply port of the reformer 120. A portion 162a connected to 120a is disposed. The portion 162a of the mixed gas supply pipe 162 also functions as a preheating portion that preheats the mixed gas passing through the inside by the exhaust gas in the recess 120d of the reformer 120 (hereinafter, the portion 162a of the mixed gas supply pipe 162). Is referred to as “preheating portion 162a”).

  The reformer 120 includes a top plate 120f that forms the top surfaces of the preheating unit 120b and the reforming unit 120c, and a shield that is provided above the top plate 120f and has a substantially U-shaped cross-section with the top open. It further includes a plate 120g and a flat plate 120h disposed on the upper portion of the shielding plate 120g (see FIGS. 18A to 18C). In the reformer 120, the space between the top plate 120f and the shielding plate 120g forms an exhaust induction chamber 201 for inducing and flowing exhaust gas above the preheating unit 120b and the reforming unit 120c. 120, a space between the shielding plate 120g and the flat plate 120h forms a gas reservoir 203 as a heat insulating layer through which almost no exhaust gas flows (in addition to FIGS. 18A to 18C, FIGS. 15 and 15). 16). Furthermore, a flange portion 120 i for fixing the reformer 120 to the top plate 8 a of the module case 8 is provided at the upper end portion of the reformer 120.

  Next, as shown in FIG. 15, on the downstream end side of the reformer 120, a fuel gas as a fuel gas supply passage for supplying fuel gas generated by reforming by the reforming unit 120c of the reformer 120 A supply pipe 64 is connected, and a hydrogen extraction pipe 65 for hydrodesulfurizer is connected to the upper part of the fuel gas supply pipe 64. The fuel gas supply pipe 64 extends downward, and further extends horizontally in a manifold 66 formed below the fuel cell assembly 12. A plurality of fuel supply holes 64 b are formed in the lower surface of the horizontal portion 64 a of the fuel gas supply pipe 64, and the reformed fuel gas is supplied into the manifold 66 from the fuel supply holes 64 b. A lower support plate 68 having a through hole for supporting the fuel cell stack 14 described above is attached above the manifold 66, and the fuel gas in the manifold 66 flows into the fuel cell unit 16. Supplied. An ignition device 83 for starting combustion of fuel gas and air is provided in the combustion chamber 18.

  Next, as shown in FIG. 16, in the module case 8, there is a horizontal gap between the upper surface of the reformer 120 (specifically, the flat plate 120 h of the reformer 120) and the lower surface of the top plate 8 a of the module case 8. A second exhaust passage 172 extending in the direction is formed. The second exhaust passage 172 is juxtaposed with a part of the power generation air supply passage 177 with the top plate 8 a of the module case 8 interposed therebetween. A plate-like offset fin 172a as a heat exchange promoting member is provided inside the second exhaust passage 172. The offset fins 172a are provided at substantially the same place in the horizontal direction as the offset fins 177c provided in the power generation air supply passage 177. In the portions of the power generation air supply passage 177 and the second exhaust passage 172 provided with such offset fins 177c and 172a, the power generation air flowing in the power generation air supply passage 177 and the exhaust gas flowing in the second exhaust passage 172 Thus, efficient heat exchange is performed, and the temperature of the power generation air is raised by the heat of the exhaust gas.

  Further, a third exhaust passage 173 extending in the vertical direction is formed between the outer surface of the reformer 120 and the inner surface of the module case 8. The third exhaust passage 173 communicates with the second exhaust passage 172, and the exhaust gas flows from the third exhaust passage 173 to the second exhaust passage 172. Specifically, exhaust gas flows into the second exhaust passage 172 from an exhaust gas introduction port 172b located at the upper end portion of the third exhaust passage 173 (in other words, the end portion in the horizontal direction of the second exhaust passage 172). . The exhaust gas that has flowed into the second exhaust passage 172 from the exhaust gas introduction port 172 b passes through the exhaust port 111 formed on the top plate 8 a of the module case 8 and is provided in the first exhaust passage provided outside the module case 8. To 171.

  Further, on the inner side surface of the module case 8 in the middle of the third exhaust passage 173, specifically, the exhaust of the second exhaust passage 172 is located above the preheating unit 120b and the reforming unit 120c of the reformer 120. On the inner surface of the module case 8 below the gas inlet 172b, an exhaust induction chamber 201 formed in the reformer 120 (a space between the top plate 120f and the shielding plate 120g of the reformer 120). An exhaust guide plate 205 (corresponding to the first exhaust guide portion) for directing exhaust gas so as to flow into the exhaust gas is provided.

  Next, the flow of gas in the fuel cell module of the solid oxide fuel cell device according to the second embodiment of the present invention will be described with reference to FIGS. 19 is a side sectional view showing a fuel cell module of a solid oxide fuel cell device according to the second embodiment of the present invention, similar to FIG. 15, and FIG. 20 is similar to FIG. It is sectional drawing along the XVI-XVI line. FIGS. 19 and 20 are diagrams in which arrows indicating gas flows are newly added in FIGS. 15 and 16, respectively, and show the state in which the heat insulating material 7 is removed for convenience of explanation. In FIG. 19, only the flow of fuel gas (including water, water vapor, and raw fuel gas) is shown.

  As shown in FIG. 19, water and raw fuel gas (fuel gas) are supplied into the evaporator 125 from a fuel supply pipe 63 (see FIG. 17) connected to one end in the horizontal direction of the evaporator 125. More specifically, the gas is supplied into an evaporation unit 125 a provided in the upper layer of the evaporator 125. The water supplied to the evaporator 125a of the evaporator 125 exchanges heat with the exhaust gas flowing through the exhaust passage 125c provided in the lower layer of the evaporator 125, and is heated by the heat of the exhaust gas. Into water vapor. The water vapor and the raw fuel gas supplied from the fuel supply pipe 63 flow in the horizontal direction in the evaporator 125a (specifically, toward the side opposite to the side where the fuel supply pipe 63 is connected). In the horizontal direction) and mixed in the mixing unit 125b at the end of the evaporation unit 125a.

  The mixed gas (fuel gas) obtained by mixing the water vapor and the raw fuel gas in the mixing unit 125b is connected to the side opposite to the side where the fuel supply pipe 63 is connected in the evaporator 125, and the exhaust passage of the evaporator 125 is connected. The gas flows through the part 125 c, the heat insulating material 7 a, and the mixed gas supply pipe 162 extending across the module case 8, and flows into the reformer 120 in the module case 8. In this case, the mixed gas is exhaust gas flowing through the exhaust passage portion 125c below the mixing portion 125b and exhaust gas flowing around the portion of the mixed gas supply pipe 162 located in the exhaust passage portion 125c and the first exhaust passage 171. Then, heat is exchanged between the exhaust gas flowing around the mixed gas supply pipe 162 located in the module case 8 and heated. Particularly, in the module case 8, in the preheating portion 162 a of the mixed gas supply pipe 162 located in the recess 120 d of the reformer 120, the mixed gas flowing in the preheating portion 162 a and the exhaust gas in the recess 120 d of the reformer 120. Efficient heat exchange is performed with the gas.

  Thereafter, the mixed gas supplied from the mixed gas supply pipe 162 to the reformer 120 is provided on one side end side in the horizontal direction of the reformer 120 via the mixed gas supply port 120a of the reformer 120. The mixed gas flowing into the preheating unit 120b and flowing into the preheating unit 120b is preheated by the exhaust gas flowing around the preheating unit 120b. In this case, since the preheating part 120b of the reformer 120 has a structure expanded from the mixed gas supply pipe 162, the mixed gas is ejected from the mixed gas supply pipe 162 to the preheating part 120b of the reformer 120. The jetted mixed gas is expanded in the preheating unit 120b, and the jetting speed is reduced. Then, the mixed gas collides with the wall surface on the downstream end side of the preheating unit 120b, turns back, passes through the partition plate 120e (see FIG. 18B) in the reformer 120, and is downstream of the preheating unit 120b. It flows into the reforming part 120c filled with the reforming catalyst, and is reformed in the reforming part 120c to become fuel gas. The fuel gas thus generated is supplied to the downstream side of the reforming section 120c of the reformer 120, and the hydrogen desulfurizer hydrogen extraction connected to the upper side of the fuel gas supply pipe 64. Flow through tube 65. The fuel gas is supplied into the manifold 66 from the fuel supply hole 64 b provided in the horizontal portion 64 a of the fuel gas supply pipe 64, and the fuel gas in the manifold 66 is supplied into each fuel cell unit 16. .

  On the other hand, as shown in FIG. 20, the power generation air supplied from the power generation air introduction pipe 74 (see FIGS. 17 and 19) is supplied from the top plate 8a and the side plate 8b of the module case 8, and the top plate 8a and the top plate 8a. It flows through a power generation air supply passage 177 formed by a space between the side plate 8b and a power generation air supply case 177a arranged so as to extend along each of the side plates 8b. At this time, when the power generation air flowing through the power generation air supply passage 177 passes through the offset fins 177c and 177d, the second and third air formed in the module case 8 inside the offset fins 177c and 177d. Efficient heat exchange is performed with the exhaust gas passing through the exhaust passages 172 and 173 to be heated. In particular, since the offset fin 172a is provided in the second exhaust passage 172 corresponding to the offset fin 177c of the power generation air supply passage 177, the power generation air is separated from the offset fin 177c in the power generation air supply passage 177. More efficient heat exchange with the exhaust gas is performed via the offset fins 172a in the second exhaust passage 172. Thereafter, the power generation air is injected into the power generation chamber 10 from the plurality of air outlets 77b provided at the lower portion of the side plate 8b of the module case 8 toward the fuel cell assembly 12.

  On the other hand, the remaining fuel gas that is not used for power generation in the fuel cell unit 16 is burned in the combustion chamber 18 in the module case 8 to become exhaust gas (combustion gas) as shown in FIG. Go up inside 8. Specifically, the exhaust gas generated by the combustion first passes through a third exhaust passage 173 formed between the outer surface of the reformer 120 and the inner surface of the module case 8. At this time, the exhaust gas is discharged from the exhaust guide chamber 201 (the top plate 120f and the shielding plate of the reformer 120) formed in the reformer 120 by the exhaust guide plate 205 provided on the inner surface of the module case 8. It is directed to flow into a space between 120 g. The exhaust gas that has passed through the exhaust induction chamber 201 (including the exhaust gas that has flowed into the exhaust induction chamber 201 and the exhaust gas that has not flown into the exhaust induction chamber 201) is stored in the gas reservoir 203 (reformation) above the exhaust induction chamber 201. Rises without flowing into the space between the shielding plate 120g and the flat plate 120h of the vessel 120 and flows into the second exhaust passage 172 from the exhaust gas inlet 172b.

  Thereafter, the exhaust gas flows in the second exhaust passage 172 in the horizontal direction, and flows out from the exhaust port 111 formed on the top plate 8 a of the module case 8. When the exhaust gas flows in the second exhaust passage 172 in the horizontal direction, the offset fin 172a provided in the second exhaust passage 172 and the power generation air supply passage 177 corresponding to the offset fin 172a are provided. Through the offset fin 177c formed, efficient heat exchange is performed between the power generation air flowing through the power generation air supply passage 177 and the exhaust gas flowing through the second exhaust passage 172, and the heat of the exhaust gas The power generation air is heated.

  The exhaust gas flowing out from the exhaust port 111 passes through the first exhaust passage 171 provided outside the module case 8 and then flows through the exhaust passage portion 125c of the evaporator 125 connected to the first exhaust passage 171. Then, the gas is discharged from an exhaust gas discharge pipe 82 (see FIG. 17) connected to the downstream end side of the evaporator 125. As described above, the exhaust gas exchanges heat with the mixed gas in the mixing section 125b of the evaporator 125 and the water in the evaporation section 125a of the evaporator 125 when flowing through the exhaust passage section 125c of the evaporator 125.

  Next, functions and effects of the solid oxide fuel cell device according to the second embodiment of the present invention will be described.

According to the present embodiment, the power generation air supply passage 177 and the second exhaust passage 172 are arranged side by side with the module case 8 interposed therebetween. Specifically, the power generation air supply passage 177 is formed outside the module case 8. In addition, since the second exhaust passage 172 is formed in the module case 8 (see FIG. 16), the fuel cell module 2X can be reduced in size and cost. This will be specifically described. In the conventional solid oxide fuel cell device, the exhaust gas is discharged from the exhaust port toward the upper reformer, and air heat exchange is performed in the process of flowing the upper exhaust gas downward. In such a case, the exhaust gas whose temperature is greatly lowered by the air flows below the fuel cell, so that the lower side of the fuel cell becomes low temperature (that is, a temperature gradient is generated in the vertical direction of the fuel cell). ), The fuel cell may be deteriorated. In the conventional solid oxide fuel cell apparatus, in order to prevent this, the passage through which the exhaust gas and power generation air flow and the fuel cell are separated from each other by a certain distance, or the exhaust gas and power generation air flow. A heat insulating material is partially provided between the passage and the fuel battery cell. For this reason, the module case has been enlarged. In addition, the heat reflection characteristics at the place where the heat insulating material is partially provided are changed, which adversely affects the fuel cell.
On the other hand, in the present embodiment, the second exhaust passage 172 is provided in the module case 8 above the fuel cell assembly 12, and air heat exchange is performed using the second exhaust passage 172. In other words, air heat exchange is performed at a position in the module case 8 above the fuel cell assembly 12, and the exhaust gas does not flow downward on the side of the fuel cell assembly 12. The thermal gradient in the vertical direction of the fuel cell assembly 12 can be suppressed. In this case, according to this embodiment, as in the prior art described above, the passage through which the exhaust gas and power generation air and the fuel cell assembly 12 are provided at a certain distance, or the exhaust gas and power generation Since it is not necessary to provide a heat insulating material between the passage through which the air flows and the fuel cell assembly 12, heat to the fuel cell assembly 12 can be obtained without increasing the size and cost of the fuel cell module 2X. The influence can be suppressed.
For this reason, according to the present embodiment, the fuel cell module 2X can be reduced in size and cost. Specifically, according to the present embodiment, it is not necessary to separate the fuel cell assembly 12 and the module case 8 in consideration of the thermal effect on the fuel cell assembly 12, and the fuel cell assembly 12 Since the module case 8 can be disposed close to the fuel cell module 2X, the fuel cell module 2X can be downsized.
Here, in the present embodiment, the air heat exchange is performed only by the power generation air supply passage 177 and the second exhaust passage 172 above the fuel cell assembly 12, and thus the heat exchange distance tends to be short (in other words, the heat exchange distance). The exchange area tends to be small), and it is difficult to raise the temperature of the power generation air. In order to cope with this, in the present embodiment, the evaporator 125 is provided outside the module case 8 in order to keep the temperature of the exhaust gas in the module case 8 that performs air heat exchange high (in this case, naturally, Air heat exchange is performed by the exhaust gas before heat exchange in the evaporator 125). By doing so, the temperature of the exhaust gas in the module case 8 that performs air heat exchange can be kept high, and even if the heat exchange distance is short, the power generation air can be sufficiently heated.
Further, according to the present embodiment, not only the indoor heat of the module case 8 and the air for power generation are naturally exchanged, but also the second exhaust passage 172 is formed above the fuel cell assembly 12 to form the fuel cell. Since air heat exchange is actively performed in an environment that does not affect the aggregate 12, stable air heat exchange can be reliably realized without being affected by the exhaust flow or the like. Furthermore, according to the present embodiment, with the configuration as described above, it is possible to raise the temperature of the power generation air with a small amount of heat of exhaust gas (that is, heat is likely to be self-sustaining), and to generate power for raising the temperature of the system The amount of working air is small.

  Further, according to the present embodiment, the offset fins 177c and 177d as heat exchange promoting members are provided at positions in the power generation air supply passage 177 above the fuel cell assembly 12 (see FIG. 16). The temperature raising performance of the power generation air by the exhaust gas can be enhanced. As a result, the power generation air supply passage 177 passes by the side of the fuel cell assembly 12 (see FIG. 16), but before the power generation air flows through the side of the fuel cell assembly 12, the power generation air is supplied. The temperature can be raised sufficiently, and the lower side of the fuel cell assembly 12 can be prevented from becoming low temperature with a simple configuration.

  Further, according to the present embodiment, since the third exhaust passage 173 is further formed between the outer side surface of the reformer 120 and the inner side surface of the module case 8, the exhaust gas is not limited to the power generation air but also the reformer. Heat can be exchanged with 120, and the temperature of both the reformer 120 and the power generation air can be increased with a simple configuration.

Further, according to the present embodiment, the shielding plate 120g provided between the reforming portion 120c of the reformer 120 and the top plate 8a of the module case 8 causes almost no exhaust gas to flow above the shielding plate 120g. Since the gas reservoir 203 is formed, it is possible to prevent the heat of the exhaust gas from being taken away by the top plate 8a of the module case 8 before the exhaust gas is introduced from the exhaust gas inlet 172b of the second exhaust passage 172. can do. As a result, the temperature of the exhaust gas introduced into the second exhaust passage 172 can be maintained high, that is, the high-temperature exhaust gas can be introduced into the second exhaust passage 172, and the power generation air can be supplied even with a short heat exchange distance. High temperature rise performance can be realized.
In addition, according to the present embodiment, since the exhaust induction chamber 201 is formed below the shielding plate 120g and above the reforming portion 120c, the reforming portion 120c is formed by the exhaust gas guided to the exhaust induction chamber 201. Can be heated from above. In this case, since the shielding plate 120g above the reforming unit 120c functions as a reflecting plate, radiant heat from the shielding plate 120g can be further applied to the reforming unit 120c, and the temperature of the reforming unit 120c can be effectively increased. Can do. In addition, since the gas reservoir 203 above the shielding plate 120g functions as a heat insulating layer, the temperature of the reforming unit 120c can be appropriately maintained.

  Further, according to the present embodiment, the exhaust guide plate 205 for directing the exhaust gas passing through the third exhaust passage 173 to the exhaust induction chamber 201 is provided, so that the exhaust gas passes from the third exhaust passage 173 to the second exhaust passage 172. The exhaust gas passing through the third exhaust passage 173 can be made to flow appropriately on the upper surface of the reforming portion 120c, and the exhaust gas can cause the reforming portion 120c to flow from above. It can be heated effectively. In this case, since the shielding plate 120g is provided in the upper part of the exhaust induction chamber 201, the exhaust gas does not flow to the top plate 8a side.

  Next, a modification of the second embodiment of the present invention will be described.

With reference to FIG. 21, the shielding board by the modification of 2nd Embodiment of this invention is demonstrated. FIG. 21 is a schematic cross-sectional view showing a part of a fuel cell module to which a shielding plate according to a modification of the second embodiment of the present invention is applied.
As shown in FIG. 21, the shielding plate 120j according to this modification is provided at the same position as the above-described shielding plate 120g (see FIGS. 16 and 18), but the inclined portion has an edge inclined upward. 120k. The inclined portion 120k of the shielding plate 120j corresponds to a second exhaust guide portion, and directs the exhaust gas to flow into the exhaust gas introduction port 172b of the second exhaust passage 172, as indicated by an arrow in FIG. In the present modification, the second exhaust passage 172 extends not only in the horizontal direction but also in the downward direction at the tip that extends in the horizontal direction, and the exhaust gas inlet 172b extends from the horizontal portion of the second exhaust passage 172. Is also located below. Also in this modification, the space below the shielding plate 120j and above the preheating portion 120b and the reforming portion 120c forms the exhaust induction chamber 201, and the space above the shielding plate 120j and below the second exhaust passage 172. Forms a gas reservoir 203.
According to such a modification, the exhaust gas can be effectively guided so that the exhaust gas flows from the exhaust gas inlet 172b into the second exhaust passage 172 by the inclined portion 120k provided in the shielding plate 120j. it can. Therefore, the exhaust gas maintained at a high temperature can be introduced into the second exhaust passage 172, and the heat exchange between the exhaust gas in the second exhaust passage 172 and the power generation air in the power generation air supply passage 177 is improved. Can be made. In addition, since a member for inducing exhaust gas is not separately used, the fuel cell module 2X can be downsized.

Next, a reformer according to a modification of the second embodiment of the present invention will be described with reference to FIG. FIG. 22 is a cross-sectional perspective view of a reformer according to a modification of the second embodiment of the present invention. FIG. 22 is a cross-sectional view along a cutting line similar to the XVIIIC-XVIIIC line in FIG.
As shown in FIG. 22, the reformer 120X according to the present modification has a portion corresponding to the recess 120d (see FIG. 18) of the reformer 120c, and the reformer 120X (specifically, the reformer 120c A through hole 120m is formed so as to extend vertically through the formed portion) and allow the exhaust gas generated in the lower combustion chamber 18 to pass therethrough. A preheating portion 162a of the mixed gas supply pipe 162 is disposed in the through hole 120m. In the reformer 120X having such a through-hole 120m, the exhaust gas is not only reformed between the preheater 120b and the outer surface of the reformer 120c and the inner surface of the module case 8 of the reformer 120, but also reformed. The through-hole 120m of the vessel 120X also passes through and flows from below to above.
Further, the reformer 120X according to the present modification is further provided with a shielding plate 120n having a central portion (a portion facing the through hole 120m) recessed downward between the top plate 120f and the shielding plate 120g. When such a shielding plate 120n is further provided, the space between the shielding plate 120n and the top plate 120f forms the exhaust induction chamber 201, and the space between the shielding plate 120n and the shielding plate 120g forms the gas reservoir 204. The space between the shielding plate 120g and the flat plate 120h forms a gas reservoir 203. That is, two gas reservoirs 203 and 204, in other words, two heat insulating layers are formed.

  In the modification shown in FIG. 22, only one through hole 120m is provided in the reformer 120X. However, in another embodiment, the reformer 120X has two through holes similar to the through hole 120m. Two or more may be provided. In that case, the mixed gas supply pipe 162 may be provided in any one of the two or more through holes. In still another embodiment, the upper portion of the through hole 120m of the reformer 120X may be closed with a plate or the like to form a recess.

1, 1X Solid oxide fuel cell system (SOFC)
2, 2X Fuel cell module 7 Heat insulating material 8 Module case 8a Top plate 8b Side plate 11 Exhaust port 12 Fuel cell assembly 16 Fuel cell unit 18 Combustion chamber 20, 120 Reformer 20a, 120a Mixed gas supply port 20b, 120b Preheating part 20c, 120c Reforming part 20d Through hole 21 Heat exchange module 23 Heat exchanger 23a Power generation air passage part 23b, 23d Offset fin 23c Exhaust passage part 25, 125 Evaporator 25a, 125a Evaporation part 25b, 125b Mixing part 25c , 125c Exhaust passage portion 62, 162 Mixed gas supply pipe 62a, 162a Preheating portion 71 First exhaust passage 72 Second exhaust passage 77 Power generation air supply passage 80, 81 Exhaust guide plate 171 First exhaust passage 172 Second exhaust passage 172a Offset fin 173 3rd exhaust Passage 177 generating air supply passage 177c, 177d offset fin 201 exhaust guide chamber 203 gas reservoir

Claims (7)

In a solid oxide fuel cell device that generates power by a reaction between a fuel gas and an oxidant gas,
A plurality of fuel cells electrically connected to each other;
A module case containing the plurality of fuel cells, and
A heat insulating material provided to cover the periphery of the module case;
An oxidant gas supply passage for supplying an oxidant gas to the plurality of fuel cells, and
A fuel gas supply passage for supplying fuel gas to the plurality of fuel cells, and
A reformer disposed in the module case, reforming the raw fuel gas with water vapor to generate fuel gas, and supplying the fuel gas to the fuel gas supply passage;
Combusting the fuel gas remaining without being used for power generation in the plurality of fuel cells, and heating the reformer with combustion heat; and
An exhaust passage through which exhaust gas to be discharged from the module case passes, wherein at least a part of the periphery of the exhaust passage is covered with the heat insulating material; and
An oxidant gas is supplied, and is provided for the exhaust passage so as to exchange heat between the oxidant gas and the exhaust gas passing through the exhaust passage. A heat exchanger for supplying the oxidant gas supply passage, wherein the heat exchanger is disposed so that at least a part of the heat exchanger is covered with the heat insulating material;
Water is supplied to the exhaust passage so that heat exchange is performed between the water and the exhaust gas passing through the exhaust passage and having just undergone heat exchange in the heat exchanger. An evaporator that evaporates water by heat exchange to generate water vapor and supplies the water vapor to the reformer, and is disposed inside the heat insulating material and outside the module case. The evaporator,
A solid oxide fuel cell device comprising: The lower layer of the evaporator located on the module case side forms a part of the exhaust passage, and an exhaust passage portion through which exhaust gas passes is formed. The upper layer of the evaporator located above the exhaust passage portion Is formed with an evaporating part for evaporating water to generate water vapor and a mixing part for mixing the water vapor and the raw fuel gas,
A mixed gas supply pipe for supplying a mixed gas of water vapor and raw fuel gas from the mixing section of the evaporator to the reformer, the mixed gas supply pipe extending so as to pass through an exhaust passage section of the evaporator The solid oxide fuel cell device according to claim 1, further comprising:   3. The solid oxide fuel cell device according to claim 2, wherein the mixed gas supply pipe is configured to pass through an upstream portion in an exhaust gas flow direction in an exhaust passage portion of the evaporator. A lower part of the heat exchanger located on the module case side forms a part of the exhaust passage, and an exhaust passage part through which exhaust gas passes is formed. The heat exchanger located above the exhaust passage part In the upper layer, an oxidant gas passage portion through which the oxidant gas passes is formed,
The heat exchanger and the evaporator are arranged side by side in the horizontal direction,
The solid oxide fuel cell device according to claim 3, wherein the exhaust passage portion of the heat exchanger and the exhaust passage portion of the evaporator are respectively formed along a horizontal direction. A heat exchange module in which the heat exchanger and the evaporator are integrally formed;
This heat exchange module has a substantially U-shaped cross-section with an open top, and constitutes both an exhaust passage portion of the heat exchanger and an exhaust passage portion of the evaporator by a case extending in the horizontal direction, and The solid oxide fuel cell device according to claim 4, wherein an oxidant gas passage portion of the heat exchanger and an evaporation portion and a mixing portion of the evaporator are fixed so as to cover an open portion of the case.   The solid oxide fuel cell device according to claim 5, wherein the heat exchange module is fixed to a top plate of the module case.   A part of the heat insulating material is disposed between the heat exchange module and the module case so as to fill the gap, and a part of the heat insulating material is fixed to a top plate of the module case. Item 7. The solid oxide fuel cell device according to Item 6.

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