JP2017183136A - Solid oxide fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To unify temperature distribution of a fuel battery cell assembly even in the case where gaps between fuel battery cells are different.SOLUTION: A solid oxide fuel cell comprises: a module case; a fuel gas manifold 66; a fuel battery cell stack which consists of fuel battery cell units 16 arranged with gaps; a combustion part which burns off-gas from the fuel battery cell; a reformer which reforms material gas to create fuel gas; a fuel gas supply pipe 64 which supplies fuel gas to the fuel gas manifold; and an air supply passage having an air blowout part which blowouts oxidant gas from a plurality of blowout ports 8f onto both side faces of a fuel battery cell assembly, in which at least a part of the plurality of the blowout ports 8f is arranged to position between adjacent fuel battery cell units 16, and the air blowout part includes a first region in which the wider the gap between fuel battery cell units 16 becomes, the larger an opening area of the blowout ports 8f becomes.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a solid oxide fuel cell device, and more particularly to a solid oxide fuel cell device that generates electric power by a reaction between a fuel gas obtained by reforming a raw material gas and air.

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

  In such a solid oxide fuel cell device, fuel gas is supplied to a fuel cell assembly in which fuel cells are arranged side by side at intervals, and the fuel cells are oxidized from the surroundings. Oxidant gas is supplied from the agent gas ejection hole. With regard to such a fuel cell device, for example, Patent Document 1 discloses a configuration in which the pitch of the oxidant gas ejection holes in the central portion of the fuel cell assembly is shortened in order to increase the power generation efficiency of the fuel cell assembly. It is disclosed.

Patent 5300172

  Although described in Patent Document 1, the center portion of the fuel cell assembly is heated to a high temperature. In contrast, the applicants have attempted to adjust the distance between adjacent fuel cells in the vicinity of the center of the fuel cell assembly. However, when the interval between the fuel cells is partially adjusted in this way, the flow rate of the oxidant gas flowing between the fuel cells is different, so that the temperature distribution of the fuel cell assembly becomes non-uniform. Such non-uniform temperature distribution leads to a decrease in power generation efficiency and early deterioration of fuel cells.

  The present invention has been made in view of the above problems, and is to make the temperature distribution of the fuel cell assembly uniform even when the intervals of the fuel cells are different.

  The present invention relates to a solid oxide fuel cell having three or more fuel cells that generate power by using a fuel gas and an oxidant gas, and is a module container having a rectangular shape in plan view and containing the fuel cells inside And a fuel cell manifold that is arranged in the module container and distributes and supplies the fuel gas to the fuel cells, and a fuel cell that is provided above the fuel gas manifold and arranged at intervals. A stack, a combustion part that burns off-gas from the fuel battery cell to generate exhaust gas above the fuel cell stack in the module container, and a combustion part that is provided above the combustion part in the module container and is heated by the exhaust gas A reformer that reforms the raw material gas to produce fuel gas, and is provided on one side of the module container to supply the fuel gas to the fuel gas manifold. A fuel gas supply pipe, and an air blowing section for blowing oxidant gas from a plurality of blow holes to at least one side surface of the fuel cell stack from the side of the fuel cell other than the side where the fuel gas supply pipe is provided And at least some of the plurality of outlet holes are disposed between adjacent fuel cells, and the air outlet portion has a larger opening area of the outlet holes as the distance between the fuel cells is larger. 1 region is included.

  In the region where the interval between the fuel cells is narrow, the flow rate of the oxidant gas is faster than in the region where the interval is wide. On the other hand, according to the present invention having the above configuration, in the first region, the larger the gap between the fuel cells, the larger the opening area of the air outlet, and thus the gap passes between the fuel cells regardless of the gap between the fuel cells. The flow rate of the oxidant gas becomes substantially constant. Thereby, the temperature distribution in the fuel cell stack becomes uniform, the power generation efficiency of the fuel cell stack can be improved, and early deterioration of the fuel cell can be prevented.

In this invention, Preferably, an air blowing part further contains the 2nd area | region where the opening area of a blowing hole is large, so that it approaches a fuel gas supply pipe | tube.
On the side of the module container where the fuel gas supply pipe is provided, there is a space for accommodating the fuel gas supply pipe, and the oxidant gas blown from the blowout holes is diffused into the space. As a result, the flow of the oxidant gas becomes asymmetric with respect to the side where the fuel gas supply pipe is not provided, and the temperature distribution of the fuel cell stack becomes uneven.
On the other hand, according to the present invention having the above-described configuration, the opening area of the blowout hole increases in the second region as it approaches the fuel gas supply pipe, and therefore the oxidant gas supplied on the fuel gas supply pipe side. The amount of oxidant gas on the fuel gas supply pipe side and the side where the fuel gas supply pipe is not provided is symmetrical, that is, the amount of oxidant gas contacting the fuel cells is uniform. Can be. Moreover, the temperature influence with respect to the fuel cell of a fuel gas supply pipe | tube can be reduced by increasing the flow volume of oxidant gas by the side of a fuel gas supply pipe | tube.

In this invention, Preferably, the blowing hole of an air blowing part is provided so that oxidant gas may be blown off to the two opposing side surfaces of a fuel cell stack.
In the conventional case where the interval between the fuel cells is adjusted in order to avoid a high temperature in the center of the fuel cell stack, the flow rate of the oxidant gas passing through the gap differs depending on the size of the interval. The collision of the oxidant gas supplied from the two sides facing each other creates turbulent flow.
According to the present invention configured as described above, since the opening area of the outlet is larger as the interval between the fuel cells is larger, the flow rate of the oxidant gas can be made substantially constant regardless of the interval between the fuel cells. The oxidant gas supplied from the side surface collides with substantially uniform energy at each interval and diffuses upward. Therefore, even when the oxidant gas is blown out from the two opposite side surfaces of the fuel cell stack, the oxidant gas is evenly supplied to the fuel cell by suppressing the generation of turbulent flow. The temperature distribution in the stack can be made more uniform.

  In the present invention, preferably, the blowout hole is also provided between the side wall of the module container and the fuel cell stack, and the opening area of the blowout hole provided between the module container and the fuel cell stack is: It is larger than the minimum opening area of the blowout holes in the first region.

  According to the present invention having the above configuration, the flow of the oxidant gas in the module container can be stabilized by providing the blowout hole between the module container and the fuel cell stack. Furthermore, by increasing the opening area of the outlet hole between the module container and the fuel cell stack, the flow rate of the oxidant gas flowing between the module container and the fuel cell stack increases, and the outside of the module container It is possible to reduce the temperature influence on the fuel battery cell due to the mechanical factor.

In the present invention, preferably, the plurality of blowout holes are formed at a height position near the lower end of the air electrode where the fuel cell is exposed.
The temperature inside the module container is low as it goes down, and the vicinity of the lower end of the fuel cell tends to be low. However, according to the present invention having the above configuration, the heated oxidant gas is blown near the lower end of the air electrode. The temperature distribution in the vertical direction of the battery cell can be made uniform.

  In the present invention, preferably, the fuel cell stack includes a current collector made of a metal material that electrically connects adjacent fuel cells at the lower end of the fuel cell, and the current collector is adjacent to the fuel cell stack. A pair of gripping portions that are respectively contacted and fixed to the fuel cells, and a connecting portion that connects between the pair of gripping portions, and the plurality of blowing holes are configured so that the blown oxidant gas directly hits the connecting portion. It is provided at a height in the vicinity of the grip portion so as not to be present.

  According to the present invention having the above configuration, since the heated oxidant gas is sprayed near the holding portion of the current collector made of a metal material having high thermal conductivity, the heat of the oxidant gas is transmitted through the current collector. The lower end portion of the fuel cell can be heated, whereby the temperature distribution in the vertical direction of the fuel cell can be made uniform. Further, when the blown out oxidant gas directly hits the connecting portion, the flow of the oxidant gas is disturbed, but according to the present invention having the above configuration, the oxidant gas is blown near the grip portion of the current collector. Disturbance of the oxidant gas flow is prevented, and the temperature distribution in the fuel cell stack becomes uniform.

  In the present invention, preferably, the fuel gas manifold is fixed with an end portion opposite to the fuel gas supply pipe as a base point, and the plurality of blowout holes in the second region have substantially the same height at the lower ends, The larger the opening area, the wider the area.

  When the fuel gas manifold is fixed with the opposite end of the fuel gas supply pipe as a base point as in the present invention having the above-described configuration, the fuel gas supply pipe side becomes higher due to variations in member dimensions and assembly. Variation in the vertical direction is likely to occur. That is, due to such variations, the positions of the air electrode and the current collector may vary upward in the fuel gas supply pipe. On the other hand, according to the present invention having the above-described configuration, the plurality of blowout holes in the second region have substantially the same lower end, and the larger the opening area, the wider the upper area. Even if variations occur on the tube side, the oxidant gas can be reliably blown to the air electrode.

  According to the present invention, the temperature distribution of the fuel cell assembly becomes uniform even when the intervals of the fuel cells are different.

1 is an overall configuration diagram showing a solid oxide fuel cell apparatus (SOFC) according to an embodiment of the present invention. FIG. 2 is a side sectional view showing a fuel cell module of a solid oxide fuel cell device according to an embodiment of the present invention. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. It is a disassembled perspective view of a module case and an air passage cover. It is a perspective view which shows the inner surface of the closing side plate which comprises a module case. FIG. 2 is an enlarged vertical sectional view showing a manifold and a lower end portion of a fuel cell unit of the solid oxide fuel cell device shown in FIG. 1. (A) is a perspective view which shows the 1st member which comprises a scattering suppression cover, (B) is a perspective view which shows the 2nd member which comprises a scattering suppression cover, (C) is 1st and 1st It is a perspective view which shows a mode that 2 members are attached. It is a vertical expanded sectional view of the apparatus longitudinal direction of the pipe joint vicinity in the state which attached the scattering suppression cover. It is a perspective view which shows the periphery of the scattering suppression cover in an assembly state. It is a fragmentary sectional view showing a fuel cell unit of a solid oxide fuel cell device by one embodiment of the present invention. FIG. 3 is a side sectional view showing a fuel cell module of a solid oxide fuel cell device according to an embodiment of the present invention, similar to FIG. 2. FIG. 4 is a cross-sectional view along the line III-III in FIG. 2, similar to FIG. 3. It is a horizontal sectional view showing the flow of power generation air flowing between fuel cell assemblies, (A) shows this embodiment, (B) shows a comparative example.

Next, a solid oxide fuel cell device according to an embodiment of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is an overall configuration diagram showing a solid oxide fuel cell apparatus (SOFC) according to an embodiment of the present invention. As shown in FIG. 1, a solid oxide fuel cell apparatus (SOFC) 1 according to an 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 container 8 (hereinafter referred to as “module case” as appropriate) is incorporated 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 (fuel cell stack) 12 is accommodated. The fuel cell assembly 12 includes a plurality of fuel cell units 16 (see FIG. 10) connected in series. In this example, the fuel cell assembly 12 includes 104 fuel cell units 16. The housing 6 is not essential, and a frame that holds the heat insulating material 7 may be used.

  A combustion chamber 18 as a combustion section is formed above the power generation chamber 10 of the module case 8 of the fuel cell module 2. In this combustion chamber 18, the remainder that was not used for the power generation reaction (which did not contribute to power generation) The fuel gas and the remaining air 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 120 for reforming the fuel gas is disposed above the combustion chamber 18, and the reformer 120 is heated to a temperature at which a reforming reaction can be performed by the combustion heat of the residual gas. Yes.

  Further, an evaporator 140 is provided in the heat insulating material 7 above the module case 8 in the housing 6. The evaporator 140 performs heat exchange between the supplied water and the exhaust gas, thereby evaporating the water to generate water vapor, and a mixed gas (hereinafter referred to as “fuel gas”) of the water vapor and the raw fuel gas. Is supplied to the reformer 120 in the module case 8.

  Next, the auxiliary unit 4 adjusts the flow rate of the water supplied from the pure water tank 26 that stores the water in which the moisture contained in the exhaust gas from the fuel cell module 2 is condensed and uses the filter as pure water. A water flow rate adjusting unit 28 (such as a “water pump” driven by a motor) is provided. The auxiliary unit 4 includes a gas shutoff valve 32 that shuts off the fuel supplied from the fuel supply source 30 that is a reduction in the supply of raw material gas such as city gas, and a desulfurizer 36 that removes sulfur from the fuel gas. A fuel flow rate adjusting unit 38 (such as a “fuel pump” driven by a motor) for adjusting the flow rate of the fuel gas, and a valve 39 for shutting off the fuel gas flowing out from the fuel flow rate adjusting unit 38 when the power is lost. Yes. 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 120, 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.

  In this embodiment, the partial oxidation reforming reaction (POX) and the steam reforming reaction (SR) are performed from the POX process in which only the partial oxidation reforming reaction (POX) occurs in the reformer 120 when the apparatus is started. The SR process in which only the steam reforming reaction is performed may be performed through the ATR process in which the mixed autothermal reforming reaction (ATR) occurs, or the POX process may be omitted and the ATR process may be changed to the SR process. You may comprise so that it may transfer, and it may comprise so that a POX process and an ATR process may be abbreviate | omitted and only an SR process may be performed. In the configuration in which only the SR step is performed, the reforming air flow rate adjustment unit 44 is unnecessary.

  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 an embodiment of the present invention will be described with reference to FIGS. 2 is a side sectional view showing a fuel cell module of a solid oxide fuel cell device according to an embodiment of the present invention, and FIG. 3 is a sectional view taken along line III-III in FIG. 4 is an exploded perspective view of the module case and the air passage cover. 2 and 3, the housing is omitted.

  As shown in FIGS. 2 and 3, the fuel cell module 2 includes a fuel cell assembly 12 and a reformer 120 provided inside a module case 8 covered with a heat insulating material 7, and the module case 8. And an evaporator 140 provided in the heat insulating material 7.

  First, as shown in FIG. 4, the module case 8 includes a substantially rectangular top plate 8a, bottom plate 8c, and a pair of opposing side plates 8b that connect the sides extending in the longitudinal direction (left-right direction in FIG. 2). A cylindrical body and a closed side plate that closes two opposing openings at both ends in the longitudinal direction of the cylindrical body and connects the sides extending in the width direction of the top plate 8a and the bottom plate 8c (left and right direction in FIG. 3) 8d and 8e.

  The module case 8 has a top plate 8 a and side plates 8 b covered with an air passage cover 160. The air passage cover 160 includes a top plate 160a and a pair of opposing side plates 160b. An opening 167 for passing through the exhaust pipe 171 and an opening 160c for connecting the power generation air introduction pipe 74 are provided at a substantially central portion of the top plate 160a. The top plate 160a and the top plate 8a and the side plate 160b and the side plate 8b are separated by a predetermined distance. Thereby, between the outside of the module case 8 and the heat insulating material 7, specifically, between the top plate 8a and the side plate 8b of the module case 8, and between the top plate 160a and the side plate 160b of the air passage cover 160, Air passages 161a and 161b as oxidant gas supply passages are formed along the outer surfaces of the plate 160a and the side plates 160b (see FIG. 3).

  An air blowing part including a plurality of through-holes 8f is provided at the lower part of the side plate 8b of the module case 8 (see FIG. 4). The power generation air is supplied into the air passage 161a from a power generation air introduction pipe 74 provided at a substantially central portion on the closed side plate 8e side of the module case 8 in the top plate 160a of the air passage cover 160 (FIG. 2). reference). Then, the power generation air is injected into the power generation chamber 10 through the air passages 161a and 161b from the outlet 8f of the air outlet toward the fuel cell assembly 12 (see FIGS. 3 and 4).

  FIG. 5 is a perspective view showing the inner surface of the closing side plate 8 d constituting the module case 8. As shown in the figure, a first protrusion 180A and a second protrusion 180B are formed on the inner surface of the closing side plate 8d so as to extend in the vertical direction along the edges on both sides in the width direction. The first protrusion 180A and the second protrusion 180B each have a rectangular horizontal cross-sectional shape. The inner surfaces of the first projecting portion 180A and the second projecting portion 180B constitute projecting surfaces that project to the fuel cell side. A groove 180C having a rectangular cross section is formed between the first protrusion 180A and the second protrusion 180B.

  In addition, the air passages 161a and 161b have heat exchange promoting members that promote heat exchange between the exhaust gas in the first and second exhaust passages 172a and 172b and the air in the air passages 161a and 161b. Plate fins 162 and 163 are provided (see FIG. 3). The plate fins 162 are provided in the horizontal direction so as to extend in the longitudinal direction and the width direction between the top plate 8 a of the module case 8 and the top plate 160 a of the air passage cover 160. That is, the plate fin 162 is provided in a portion corresponding to a later-described first exhaust passage 172a in the air passage 161a. Further, the plate fin 163 extends between the side plate 8b of the module case 8 and the side plate 160b of the air passage cover 160 and extends above the fuel cell unit 16 in the longitudinal direction and the vertical direction. Is provided. That is, the plate fins 163 are provided in portions corresponding to a second exhaust passage 172b and an exhaust concentration portion 176, which will be described later, in the air passage 161b.

  The power generation air flowing through the air passages 161a and 161b is inside the module case 8 inside the plate fins 162 and 163 (specifically along the top plate 8a and the side plate 8b), particularly when passing through the plate fins 162 and 163. Heat exchange is performed with the exhaust gas passing through the exhaust passage). For this reason, the portions where the plate fins 162 and 163 are provided in the air passages 161a and 161b function as a heat exchanger (heat exchange section). The portion provided with the plate fins 162 constitutes a main heat exchanger portion, and the portion provided with the plate fins 163 constitutes a subordinate heat exchanger portion.

  Next, the evaporator 140 is fixed on the top plate 8a of the module case 8 so as to extend in the horizontal direction. Further, a portion 7a of the heat insulating material 7 is disposed between the evaporator 140 and the module case 8 so as to fill these gaps (see FIGS. 2 and 3).

  Specifically, the evaporator 140 includes a fuel supply pipe 63 that supplies water and raw fuel gas (which may include reforming air) to one side end side in the longitudinal direction (left-right direction in FIG. 2). The exhaust gas exhaust pipe 82 (see FIG. 3) for exhaust gas exhaust is connected, and the upper end of the exhaust pipe 171 is connected to the other side end in the longitudinal direction. The exhaust pipe 171 extends downward through an opening 167 formed in the top plate 160 a of the air passage cover 160, and is connected to an exhaust port 111 formed on the top plate 8 a of the module case 8. The exhaust port 111 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 is substantially at the center of the top plate 8 a that is substantially rectangular in top view. Is formed.

  In addition, as shown in FIGS. 2 and 3, the evaporator 140 has an evaporator case 141 that is substantially rectangular in top view. The evaporator case 141 is formed by joining two low-profile bottomed rectangular cylindrical upper case 142 and lower case 143 with an intermediate plate 144 sandwiched therebetween.

  Accordingly, the evaporator case 141 has a two-layer structure in the vertical direction, and an exhaust passage portion 140A through which the exhaust gas supplied from the exhaust pipe 171 passes is formed in the lower layer portion, and a fuel layer is formed in the upper layer portion. An evaporation unit 140B that evaporates water supplied from the supply pipe 63 to generate water vapor, and a mixing unit 140C that mixes the water vapor generated in the evaporation unit 140B and the raw fuel gas supplied from the fuel supply pipe 63 are provided. It has been.

  The evaporator 140B and the mixer 140C are formed in a space where the evaporator 140 is partitioned by a partition plate provided with a plurality of communication holes (slits). The evaporation unit 140B is filled with alumina balls (not shown).

  Similarly, the exhaust passage portion 140A is partitioned into three spaces from the upstream side to the downstream side of the exhaust gas by two partition plates having a plurality of communication holes. The second space is filled with a combustion catalyst (not shown). That is, the evaporator 140 of the present embodiment includes a combustion catalyst device.

  In such an evaporator 140, heat exchange is performed between the water in the evaporation section 140B and the exhaust gas passing through the exhaust passage section 140A, and the water in the evaporation section 140B is evaporated by the heat of the exhaust gas, Water vapor will be generated. Further, heat exchange is performed between the mixed gas in the mixing section 140C and the exhaust gas passing through the exhaust passage section 140A, and the temperature of the mixed gas is raised by the heat of the exhaust gas.

  Further, as shown in FIG. 2, a mixed gas supply pipe 112 for supplying a mixed gas to the reformer 120 is connected to the mixing unit 140C. The mixed gas supply pipe 112 is disposed so as to pass through the inside of the exhaust pipe 171, one end is connected to an opening 144 a formed in the intermediate plate 144, and the other end is formed on the top surface of the reformer 120. Connected to the mixed gas supply port 120a. The mixed gas supply pipe 112 passes through the exhaust passage portion 140A and the exhaust pipe 171 and extends vertically downward into the module case 8, where it is bent approximately 90 ° and extends horizontally along the top plate 8a. , Bent downward by approximately 90 ° and connected to the reformer 120.

  Next, the reformer 120 is disposed so as to extend horizontally along the longitudinal direction of the module case 8 above the combustion chamber 18, and the exhaust gas guiding member 130 is disposed between the top plate 8 a of the module case 8. And fixed to the top plate 8a with a predetermined distance therebetween. The reformer 120 has a substantially rectangular outer shape in a top view, but is an annular structure in which a through hole 120b is formed in the center, and has a casing in which an upper case 121 and a lower case 122 are joined. ing. The through hole 120b is positioned so as to overlap the exhaust port 111 formed in the top plate 8a in a top view, and preferably, the exhaust port 111 is formed at the center position of the through hole 120b.

  On one end side in the longitudinal direction of the reformer 120 (closed side plate 8e side of the module case 8), the mixed gas supply pipe 112 is connected to the mixed gas supply port 120a provided in the upper case 121, and the other end side ( On the closed side plate 8 d side), the fuel gas supply pipe 64 is connected to the lower case 122, and the hydrogen desulfurizer hydrogen extraction pipe 65 extending to the desulfurizer 36 is connected to the upper case 121. Therefore, the reformer 120 receives the mixed gas (that is, raw fuel gas mixed with water vapor (may include reforming air)) from the mixed gas supply pipe 112, reforms the mixed gas therein, The reformed gas (that is, fuel gas) is discharged from the fuel gas supply pipe 64 and the hydrogen extraction pipe 65 for hydrodesulfurizer.

  The reformer 120 is divided into three spaces by the two partition plates 123a and 123b, so that the reformer 120 receives a mixed gas from the mixed gas supply pipe 112 in the reformer 120. And a reforming section 120B filled with a reforming catalyst (not shown) for reforming the mixed gas, and a gas discharge section 120C for discharging the gas that has passed through the reforming section 120B are formed. (See FIG. 2). The reforming unit 120B is a space sandwiched between the partition plates 123a and 123b, and the reforming catalyst is held in this space. The mixed gas and the reformed fuel gas are movable through a plurality of communication holes (slits) provided in the partition plates 123a and 123b. 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 mixed gas supplied from the evaporator 140 through the mixed gas supply pipe 112 is ejected to the mixed gas receiving unit 120A through the mixed gas supply port 120a. The mixed gas is expanded in the mixed gas receiving unit 120A, the jetting speed is reduced, and is supplied to the reforming unit 120B through the partition plate 123a.

In the reforming unit 120B, the mixed gas moving at a low speed is reformed into a fuel gas by the reforming catalyst, and the fuel gas passes through the partition plate 123b and is supplied to the gas discharge unit 120C.
In the gas discharge unit 120C, the fuel gas is discharged to the fuel gas supply pipe 64 and the hydrogen extraction pipe 65 for the hydrodesulfurizer.

  A fuel gas supply pipe 64 as a fuel gas supply passage extends downward in the module case 8 along the closed side plate 8d, is bent approximately 90 ° in the vicinity of the bottom plate 8c, and extends in the horizontal direction. It extends into the manifold 66 formed below the inner side, and further extends horizontally in the manifold 66 to the vicinity of the closed side plate 8e on the opposite side. The fuel gas supply pipe 64 is divided into an inflow side pipe 64A connected to the manifold 66 and an outflow side pipe 64B connected to the reformer 120, and these inflow side pipe 64A and outflow side pipe 64B. Are connected by a pipe joint 64C. The pipe joint 64 </ b> C is formed of a material having lower heat resistance than the material constituting the inflow side pipe 64 </ b> A, the outflow side pipe 64 </ b> B, and the module case 8. The pipe joint 64 </ b> C is located obliquely above the fuel cell assembly 12.

  6 is an enlarged vertical sectional view of the manifold and the lower end portion of the fuel cell unit of the solid oxide fuel cell device shown in FIG. First and second fixing jigs 200 </ b> A and 200 </ b> B are provided on the bottom plate 8 c of the module case 8. 200 A of 1st fixing jigs are provided in the edge part by the side of the closing side board 8e in the module case 8, and have L-shaped cross-sectional shape. The second fixing jig 200 </ b> B is provided at the edge of the module case 8 on the closed side plate 8 d side. The manifold 66 is arranged in the module case 8 from the closed side plate 8d side so that the end opposite to the fuel gas supply pipe 64 serving as the base point contacts the first fixing jig 200A with the closed side plate 8d removed. Inserted into. Accordingly, the rear end side comes into contact with the second fixing jig 200B, and the manifold 66 is fixed in the module case 8 by the first fixing jig 200A and the second fixing jig 200B.

  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 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 unit 16 is attached above the manifold 66, and the fuel gas in the manifold 66 is supplied into the fuel cell unit 16. The An ignition device 83 for starting combustion of fuel gas and air is provided in the combustion chamber 18.

  Further, the pipe joint 64C that connects the inflow side pipe 64A and the outflow side pipe 64B is surrounded by the scattering suppression cover 190. FIG. 7A is a perspective view showing a first member constituting the scattering suppression cover, FIG. 7B is a perspective view showing a second member constituting the scattering suppression cover, and FIG. It is a perspective view which shows a mode that a 2nd member is attached. FIG. 8 is a vertically enlarged cross-sectional view in the longitudinal direction of the apparatus in the vicinity of the pipe joint in a state in which the scattering prevention cover is attached.

  As shown in FIG. 7A, the first member 191 has a rectangular parallelepiped shape such that one surface is open. Specifically, the first member 191 includes a lateral surface 191C, a front and rear surface 191D extending from front and rear edges of the lateral surface 191C, an upper surface 191A extending from an upper edge of the lateral surface 191C, and a lower surface of the lateral surface 191C. And a lower surface 191B extending from the edge. The upper and lower surfaces 191A and 191B are respectively formed with recesses 191F extending from the opening side. Further, a rectangular through hole 191E extending in the vertical direction is formed in the front and rear surface 191D.

  As shown in FIG. 7B, the second member 192 has a rectangular parallelepiped shape with one surface opened. Specifically, the second member 192 includes a lateral surface 192C, a front and back surface 192D extending from the front and rear edges of the lateral surface 192C, an upper surface 192A extending from an upper edge of the lateral surface 192C, and a lower surface of the lateral surface 192C. And a lower surface 192B extending from the edge. The upper and lower surfaces 192A and 192B are respectively formed with recesses 192F extending from the opening side. Further, a rectangular protrusion 192E extending in the vertical direction is formed on the front and rear surface 191D. In the protrusion 192E, the side on the opening side of the second member 192 is connected to the front and back surface 192D, and a gap is formed between the other side and the front and back surface 192D. The protruding portion 192E normally protrudes outward from the front and rear surface 192D, but can be bent until it is positioned inside the front and rear surface 192D. Further, the corners between the front and rear surfaces 192D and the upper and lower surfaces 192A and 192B are not connected, and a slit 192G is formed.

  Here, the recesses 191F and 192F of the first member 191 and the second member 192 are preferably bent toward the inside of the case. Thereby, it can prevent that peeling powder falls from the clearance gap between the fuel gas supply pipe 64 and the recessed parts 191F and 192F.

  The first member 191 and the second member 192 are made of a material having higher heat resistance than the pipe joint 64C. More preferably, the module case 8 is made of the same material.

  As shown in FIG. 7C, when the scattering prevention cover 190 is attached, the opening side of the first member 191 and the second member 192 is disposed so as to face each other with the pipe joint 64C interposed therebetween. Then, the first member 191 and the second member 192 are brought close to each other so that the fuel gas supply pipe 64 enters the recesses 191F and 192F, respectively. At this time, the upper and lower surfaces 191 </ b> A and 191 </ b> B of the first member 191 enter the slit 192 </ b> G of the second member 192. When the first and second members 191 and 192 are brought close to each other until the edges of the upper and lower surfaces 191A and 191B of the first member 191 come into contact with the lateral surface 192C of the second member 192, the second member 192 The protruding portion 192E enters and fits into the through hole 191E of the first member 191. As described above, the scattering prevention cover 190 is configured by fitting the first and second members 191 and 192, and the upper surfaces 191A and 192A contact the upper surface of the pipe joint 64C as shown in FIG. It is supported by touching. Further, in the state where the scattering suppression cover 190 is attached in this manner, the upper surfaces 191A and 192A and the lower surfaces 191B and 192B of the first and second members 191 and 192 overlap each other. A recovery space 194 is formed below the pipe joint 64 </ b> C in the scattering suppression cover 190.

  In the present embodiment, the through hole 191E of the first member 191 and the protrusion 192E of the second member 192 that are fitted to each other are formed on the front and rear surfaces 191D and 192D of the first and second members 191 and 192, respectively. However, the present invention is not limited to this, and the upper surfaces 191A and 192A may be provided. Moreover, in this embodiment, although the scattering suppression cover 190 is comprised by two members, you may comprise by three or more members.

  FIG. 9 is a perspective view showing the periphery of the scattering prevention cover in the assembled state. The closed side plate 8d is closed after the scattering suppression cover 190 is attached to the pipe joint 64C. And in the state which closed the closed side board 8d, the scattering suppression cover 190 is accommodated in the groove part 180C of the closed side board 8d. The surface of the scattering suppression cover 190 on the side of the fuel cell unit 16 is located on the same plane as the protruding surface of the first protrusion 180A and the second protrusion 180B of the closing side plate 8d on the fuel cell unit 16 side. Yes.

  A fuel gas supply pipe 64 as a fuel gas supply passage extends downward in the module case 8 along the closed side plate 8d, is bent approximately 90 ° in the vicinity of the bottom plate 8c, and extends in the horizontal direction. It extends into the manifold 66 formed below the inner side, and further extends horizontally in the manifold 66 to the vicinity of the closed side plate 8e on the opposite side. 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 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 unit 16 is attached above the manifold 66, and the fuel gas in the manifold 66 is supplied into the fuel cell unit 16. The An ignition device 83 for starting combustion of fuel gas and air is provided in the combustion chamber 18.

  The exhaust gas guiding member 130 is disposed between the reformer 120 and the top plate 8 a so as to extend in the horizontal direction along the longitudinal direction of the module case 8. The exhaust gas guiding member 130 includes a lower guiding plate 131 and an upper guiding plate 132 that are separated by a predetermined distance in the vertical direction, and connecting plates 133 and 134 to which both ends of the longitudinal direction are attached (FIG. 2). FIG. 3). The upper guide plate 132 is bent at both ends in the width direction downward and is connected to the lower guide plate 131. The connecting plates 133 and 134 have upper ends connected to the top plate 8a and lower ends connected to the reformer 120, thereby fixing the exhaust gas guiding member 130 and the reformer 120 to the top plate 8a. ing.

  The lower guide plate 131 is formed with a convex step portion 131a in which the central portion in the width direction (left-right direction in FIG. 3) protrudes downward. On the other hand, as with the lower guide plate 131, the upper guide plate 132 is formed with a recess 132a so that the central portion in the width direction becomes concave downward. The convex step portion 131a and the concave portion 132a extend in the longitudinal direction in parallel in the vertical direction. The mixed gas supply pipe 112 extends horizontally in the recess 132a in the module case 8 and then bends downward in the vicinity of the closed side plate 8e, penetrates the upper guide plate 132 and the lower guide plate 131, It is connected to the reformer 120.

  In the exhaust gas guiding member 130, a gas reservoir (gas heat insulating layer) 135, which is an internal space that functions as a heat insulating layer, is formed by the upper guide plate 132, the lower guide plate 131, and the connecting plates 133 and 134. The gas reservoir 135 is in fluid communication with the combustion chamber 18. That is, the upper guide plate 132, the lower guide plate 131, and the connecting plates 133 and 134 are connected so as to form a predetermined gap, and are not airtightly connected. While it is possible for exhaust gas to flow into the gas reservoir 135 from the combustion chamber 18 during operation, or to allow air to flow in from the outside when stopped, the movement of gas between the inside and outside of the gas reservoir 135 is generally performed. Is moderate.

  The upper guide plate 132 is disposed at a predetermined vertical distance from the top plate 8a. Between the upper surface of the upper guide plate 132 and the top plate 8a, the upper guide plate 132 is horizontally aligned along the longitudinal direction and the width direction. An extended first exhaust passage 172a is formed. The first exhaust passage 172a is juxtaposed with the air passage 161a with the top plate 8a of the module case 8 interposed therebetween, and the plate fins 162, 163 in the air passages 161a, 161b are connected to the first exhaust passage 172a. Similar plate fins 175a are arranged. The plate fins 175a are provided at substantially the same location as the plate fins 162 when viewed from above, and face each other in the vertical direction across the top plate 8a.

  The upper guide plate 132 is disposed at a predetermined horizontal distance from the side surface of the upper guide plate 132 and the side plate 8b, and is arranged in the longitudinal direction and the vertical direction between the side surface of the upper guide plate 132 and the side plate 8b. An extended second exhaust passage 172b is formed. The second exhaust passage 172b communicates with the first exhaust passage 172a at the top. Also in the second exhaust passage 172b, plate fins 175b similar to the plate fins 162 and 163 in the air passages 161a and 161b are arranged. The lower end of the plate fin 175b extends to the height of the lower guide plate 131.

  Of the air passages 161a, 161b and the first and second exhaust passages 172a, 172b, in the portions where the plate fins 162, 163, 175a, 175b are provided, the power generation air flowing through the air passages 161a, 161b and the first and second Efficient heat exchange is performed with the exhaust gas flowing through the second exhaust passages 172a and 172b, and the power generation air is heated by the heat of the exhaust gas.

  The reformer 120 is disposed at a predetermined horizontal distance from the side plate 8b of the module case 8, and the exhaust gas passes between the reformer 120 and the side plate 8b from below to above. A third exhaust passage 173 is formed.

  Further, the lower guide plate 131 is disposed at a predetermined vertical distance from the top surface of the upper case 121 of the reformer 120, and between the lower guide plate 131 and the upper case 121 and the reformer. The 120 through-hole 120b forms a fourth exhaust passage 174 through which the exhaust gas that has passed through the through-hole 120b from the bottom to the top passes. The fourth exhaust passage 174 merges with the third exhaust passage 173 above the reformer 120 and in the vicinity of the side plate 8b to form an exhaust concentration portion 176 where exhaust gas concentrates.

Next, the fuel cell unit 16 will be described with reference to FIG. FIG. 10 is a partial cross-sectional view showing a fuel cell unit of a solid oxide fuel cell device according to an embodiment of the present invention.
As shown in FIG. 10, 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.

  As shown in FIG. 6, the fuel cell assembly 12 includes an inner electrode terminal 86 attached to an inner electrode layer 90 that is a fuel electrode of each fuel cell unit 16, and an air electrode of another fuel cell unit 16. All of the 104 fuel cell units 16 are connected in series to the outer peripheral surface of the outer electrode layer 92, which is electrically connected by the current collector 102. The current collector 102 includes a pair of grip portions 102a and 102b and a connecting portion 102c that connects between the pair of grip portions 102a and 102b. In the adjacent fuel cell unit 16, one grip portion 102 a of the current collector 102 is connected to the inner electrode terminal 86 of one fuel cell unit 16, and the other grip portion 102 b is connected to the other fuel cell unit 106. The outer electrode layer 92 is connected.

  The intervals between the fuel cell units 16 adjacent to each other in the longitudinal direction of the module case 8 are the intervals between the fifth and sixth from the closed side plate 8e, and the interval between the eighth and ninth (A portion in FIG. 6). However, it is larger than the interval between the other adjacent fuel cell units 16. In addition, the space | interval of the adjacent fuel cell unit 16 other than between the 5th and 6th from the closed side board 8e and between the 8th and 9th is constant.

  Next, as shown in FIG. 4, the air outlet 8 f that blows out the power generation air is formed at an opposing position of the opposing side plate 8 b of the module case 8, and the fuel cell assembly 12 is opposed to the air outlet 8 f. It is blown out by the power generation air toward the two sides. In the present embodiment, the air outlet 8f is provided on both of the opposing side plates 8b of the module case 8. However, the present invention is not limited to this, and the air outlet 8f may be formed only on one side plate 8b.

As shown in FIG. 6, the air outlet 8f is provided between the fuel cell assembly 12 and the fuel gas supply pipe 64, between adjacent fuel cell units 16, and between the fuel cell assembly 12 and the closing side plate 8e. Between. The lower end of the blower outlet 8f is located at the same height.
The air outlet 8 f is provided at a height position near the lower end of the outer electrode layer (air electrode) 92 of the fuel cell unit 16. Further, the air outlet 8f is higher than the connecting portion 102c of the current collector 102 and is located at a height position in the vicinity of the upper gripping portion 102b. Thus, the power generation air blown out from the outlet 8f does not directly hit the connecting portion 102c of the current collector 102, but between the adjacent fuel cell units 16, between the fuel cell assembly 12 and the closing side plate 8e. And between the fuel cell assembly 12 and the fuel gas supply pipe 64.

  As shown in FIG. 6, the plurality of air outlets 8 f are provided with a basic first region, a second region on the fuel gas supply pipe 64 side, and between the fuel cell assembly 12 and the closing side plate 8 e. In the third region, the opening area is set as described below. The opening area of the air outlet 8f is adjusted by changing the height in the vertical direction. That is, the air outlet 8f having a larger opening area extends upward.

  In the first region, the opening area of the outlet 8f is determined according to the interval between the adjacent fuel cell units 16, and in the first region, the wider the interval between the fuel cell units 16, the more The opening area of the outlet 8f is large. Specifically, in the present embodiment, the opening area of the air outlet 8f formed in the portion A where the distance between the adjacent fuel cell units 16 is large is the same as that between the other adjacent fuel cell units 16. It is larger than the opening area of the outlet 8f. In this embodiment, since the intervals between the fuel cell units 16 other than the portion A are constant, the opening area of the air outlet 8f between these fuel cell units 16 is constant. When there is a portion where the interval between the battery cell units 16 is narrow, the opening area of the outlet 8f may be reduced in this portion.

  Further, the opening area of the outlet 8f provided between the fuel cell assembly 12 in the third region and the closed side plate 8e is the minimum opening that is the minimum value of the opening area of the outlet 8f in the first region. It is set larger than the area.

  In the second region, the opening area of the air outlet 8f becomes larger as it is closer to the fuel gas supply pipe 64, and is set so as to approach the opening area of the air outlet 8f in the first area as the distance from the fuel gas supply pipe 64 increases. ing. In the present embodiment, in the second region, the opening area of the air outlet 8f between the fuel cell assembly 12 and the fuel gas supply pipe 64 is the largest, and gradually decreases as the distance from the fuel gas supply pipe 64 increases. ing.

  Next, a gas flow in the fuel cell module of the solid oxide fuel cell device according to the embodiment of the present invention will be described with reference to FIGS. 11 is a side cross-sectional view showing a fuel cell module of a solid oxide fuel cell device according to an embodiment of the present invention, similar to FIG. 2, and FIG. 12 is similar to FIG. It is sectional drawing along the -III line. FIGS. 11 and 12 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. In the figure, solid line arrows indicate the flow of fuel gas, broken line arrows indicate the flow of power generation air, and alternate long and short dashed arrows indicate the flow of exhaust gas.

  As shown in FIG. 11, water and raw fuel gas (fuel gas) are fed into an evaporator 140 </ b> B provided in the upper layer of the evaporator 140 from a fuel supply pipe 63 connected to one end in the longitudinal direction of the evaporator 140. Supplied. The water supplied to the evaporation section 140B is heated by the exhaust gas flowing through the exhaust passage section 140A provided in the lower layer of the evaporator 140 to become water vapor. The water vapor and the raw fuel gas supplied from the fuel supply pipe 63 flow downstream in the evaporation unit 140B and are mixed in the mixing unit 140C. The mixed gas in the mixing section 140C is heated by the exhaust gas flowing through the lower exhaust passage section 140A.

  The mixed gas (fuel gas) formed in the mixing unit 140C is supplied to the reformer 120 in the module case 8 through the mixed gas supply pipe 112. Since the mixed gas supply pipe 112 passes through the exhaust passage portion 140A, the exhaust pipe 171, and the first exhaust passage 172a in this order, the mixed gas in the mixed gas supply pipe 112 is further increased by the exhaust gas flowing through these passages. Heated.

  The mixed gas flows into the mixed gas receiving part 120A in the reformer 120, and from here passes through the partition plate 123a and flows into the reforming part 120B. The mixed gas is reformed in the reforming unit 120B to become fuel gas. The fuel gas thus generated passes through the partition plate 123b and flows into the gas discharge part 120C.

  Further, the fuel gas branches from the gas discharge part 120C into the fuel gas supply pipe 64 and the hydrogen extraction pipe 65 for hydrodesulfurizer. The fuel gas that has flowed into the fuel gas supply pipe 64 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 from the manifold 66 into each fuel cell unit 16. Supplied.

  Further, as shown in FIGS. 11 and 12, the power generation air is supplied from the power generation air introduction pipe 74 to the air passage 161a. When the power generation air passes through the plate fins 162 and 163 in the air passages 161 a and 161 b, the first and second exhaust passages 172 and 172 formed in the module case 8 below the plate fins 162 and 163. Efficient heat exchange is performed with the exhaust gas passing through 173, and the exhaust gas is heated.

  Thereafter, the power generation air is injected into the power generation chamber 10 from the plurality of air outlets 8 f provided at the lower portion of the side plate 8 b of the module case 8 toward the fuel cell assembly 12. In the present embodiment, since the exhaust passage is not formed in the side portion of the fuel cell assembly 12, heat exchange between the power generation air and the exhaust gas is suppressed in this portion. Therefore, in the side part of the fuel cell assembly 12, the temperature unevenness in the vertical direction is less likely to occur in the power generation air in the air passage 161b.

FIG. 13 is a horizontal sectional view showing the flow of power generation air flowing between the fuel cell assemblies, (A) shows this embodiment, and (B) shows a comparative example. In the figure, the arrow indicates the flow of power generation air, the length of the arrow indicates the flow velocity, and the width of the arrow indicates the flow rate.
As described above, in the present embodiment, the opening area of the air outlet 8f formed in the side plate 8b is adjusted according to the interval between the adjacent fuel cell units 16, and the portion A where the interval between the fuel cell units 16 is wide. Then, the opening area of the blower outlet 8f is larger than other parts. On the other hand, in the comparative example, the opening area of the air outlet 8f is constant regardless of the interval between the fuel battery cell units 16.

  As shown in FIG. 13B, in the comparative example, since the opening area of the air outlet 8f is constant, the flow rate of the power generation air blown from each air outlet 8f is constant. The power generation air blown out from each outlet 8f is blown between the fuel cell units 16. At this time, since the interval between the fuel cell units 16 in the A portion is wider than that in the other portions, the flow velocity of the power generation air flowing through the A portion is slower than in the other portions. As described above, when the flow rate of the power generation air is reduced, the fuel cell unit 16 on both sides of the portion A is reduced in power generation and the temperature is lowered accordingly. As described above, in the comparative example, the flow rate of the power generation air varies depending on the interval between the fuel cell units 16, and therefore the power generation amount for each fuel cell unit 16 in the fuel cell assembly 12 varies. The temperature non-uniformity occurs in the battery cell assembly 12.

  On the other hand, in this embodiment, the opening area of the outlet 8f is larger in the portion A where the interval between the fuel cell units 16 is wide than in the other portions. For this reason, as shown to FIG. 13 (A), the flow volume of the power generation air which blows off from the blower outlet 8f of A part becomes large compared with the flow volume of the power generation air which blows off from the blower outlet 8f of another site | part. For this reason, the difference in the flow rate of the power generation air passing between the fuel cell unit 16 in the part A and other parts is also very small. For this reason, the power generation amount for each fuel cell unit 16 in the fuel cell assembly 12 becomes uniform, and the temperature distribution in the fuel cell assembly 12 becomes uniform.

  Further, as shown in FIG. 12, the fuel gas that is not used for power generation in the power generation chamber 10 is burned in the combustion chamber 18 to become exhaust gas (combustion gas), and rises in the module case 8. Specifically, the exhaust gas is branched into a third exhaust passage 173 and a fourth exhaust passage 174, and between the outer surface of the reformer 120 and the side plate 8 b of the module case 8, and the reformer 120. The through-hole 120b passes between the reformer 120 and the exhaust gas guiding member 130. At this time, the exhaust gas passing through the fourth exhaust passage 174 is bisected in the width direction by the convex step portion 131a disposed above the through hole 120b of the reformer 120, and remains in the lower portion of the exhaust gas guiding member 130. Without being guided toward the third exhaust passage 173, the exhaust concentration portion 176 joins the exhaust gas flowing through the third exhaust passage 173. Here, since the plate fins 175b are provided in the second exhaust passage 172, the exhaust gas that has passed through the third exhaust passage 173 and the fourth exhaust passage 174 stays in the exhaust concentration portion 176 (see FIG. 12A). Part).

  Thereafter, the exhaust gas is introduced from the exhaust concentration portion 176 into the second exhaust passage 172b. Then, the exhaust gas that has passed through the second exhaust passage 172 b flows in the horizontal direction through the first exhaust passage 172 a and flows out from the exhaust port 111 formed at the center of the top plate 8 a of the module case 8.

  When the exhaust gas stays in the exhaust concentration portion 176, heat is generated between the power generation air and the exhaust gas via the plate fins 163 provided in the portion corresponding to the exhaust concentration portion 176 in the air passage 161b. Exchange is performed. Further, when the exhaust gas flows through the second exhaust passage 172b and the first exhaust passage 172a, the plate fins 175b and 175a provided in the second and first exhaust passages 172b and 172a, and the air passages 161a and 161b. Through the plate fins 162 and 163 provided at portions corresponding to the inner plate fins 175b and 175a, efficient heat exchange is performed between the power generation air and the exhaust gas. In this way, the temperature of the power generation air is raised by the heat of the exhaust gas.

  The exhaust gas flowing out from the exhaust port 111 passes through the exhaust pipe 171 provided outside the module case 8, flows into the exhaust passage part 140A of the evaporator 140, passes through the exhaust passage part 140A, and then evaporates. From the vessel 140 to the exhaust gas discharge pipe 82. As described above, the exhaust gas exchanges heat with the mixed gas in the mixing section 140C of the evaporator 140 and the water in the evaporation section 140B when flowing through the exhaust passage section 140A of the evaporator 140.

  In the combustion chamber 18, when the remaining fuel gas and the remaining air that have not been used for the power generation reaction are combusted in the combustion chamber 18, the pipe joint 64 </ b> C is exposed to a high temperature. As described above, when the pipe joint 64C is exposed to a high temperature, the surface of the pipe joint 64C deteriorates and peels into a powder form. However, the powder peeled from the pipe joint 64 </ b> C in this way is accommodated in the recovery space 194 in the scattering suppression cover 190 and does not scatter in the module case 8.

As described above, according to the embodiment, the following effects are produced.
In the above-described embodiment, a part of the plurality of air outlets 8f is arranged so as to be positioned between the adjacent fuel cell units 16, and in the first region, the air gaps between the fuel cell units 16 are wider. The opening area of 8f is large. In the region where the interval between the fuel cell units 16 is narrow, the flow rate of the oxidant gas becomes faster than in the region where the interval is wide. On the other hand, according to the above-described embodiment, the flow rate of the oxidant gas passing therethrough is substantially constant regardless of the interval between the fuel cell units 16. Thereby, the temperature distribution in the fuel cell assembly 12 becomes uniform, the power generation efficiency of the fuel cell assembly 12 can be improved, and the early deterioration of the fuel cell unit 16 can be prevented.

  Moreover, in the said embodiment, in the 2nd area | region, the opening area of the blower outlet 8f is large, so that the fuel gas supply pipe 64 is approached. A space for accommodating the fuel gas supply pipe 64 exists on the side of the module case 8 where the fuel gas supply pipe 64 is provided, and the oxidant gas blown out from the outlet 8f is also diffused into this space. End up. As a result, the flow of the oxidant gas becomes asymmetric with respect to the side where the fuel gas supply pipe 64 is not provided, and the temperature distribution of the fuel cell assembly 12 becomes uneven. On the other hand, according to the above-described embodiment, the opening area of the air outlet 8f increases as it approaches the fuel gas supply pipe 64 in the second region, and thus the oxidant supplied on the fuel gas supply pipe 64 side. The amount of gas can be increased, and the flow of oxidant gas between the fuel gas supply pipe 64 side and the side where the fuel gas supply pipe 64 is not provided is symmetrical, that is, the oxidant is in contact with the fuel cell unit 16. The amount of gas can be made uniform. Moreover, the temperature influence with respect to the fuel cell unit 16 of the fuel gas supply pipe 64 can be reduced by increasing the flow rate of the oxidant gas on the fuel gas supply pipe 64 side.

Moreover, in the said embodiment, the blower outlet 8f is provided so that oxidant gas may be blown off to the two opposing side surfaces of the fuel cell assembly 12. FIG.
In the conventional case where the interval between the fuel cells is adjusted in order to avoid a high temperature in the center of the fuel cell stack, the flow rate of the oxidant gas passing through the gap differs depending on the size of the interval. The collision of the oxidant gas supplied from the two sides facing each other creates turbulent flow.
On the other hand, as described above, the wider the interval between the fuel battery cell units 16, the larger the opening area of the air outlet 8f. Therefore, the flow rate of the oxidant gas is made substantially constant regardless of the interval between the fuel battery cell units 16. Therefore, the oxidant gas supplied from the two side surfaces collides with substantially uniform energy at each interval and diffuses upward. Thereby, even when the oxidant gas is blown out from the two opposite side surfaces of the fuel cell assembly 12 as in the above embodiment, the generation of the turbulent flow is suppressed and the fuel cell unit 16 is evenly distributed. Since the oxidant gas is supplied to the fuel cell assembly 12, the temperature distribution in the fuel cell assembly 12 can be made more uniform.

  In the above embodiment, the air outlet 8f is also provided in the third region between the closed side plate 8e of the module case 8 and the fuel cell assembly 12, and the module case 8 and the fuel cell assembly 12 are provided. The opening area of the air outlet 8f provided between the two is larger than the minimum opening area of the air outlet 8f in the first region. Thus, by providing the air outlet 8f between the closing side plate 8e of the module case 8 and the fuel cell assembly 12, the flow of the oxidant gas in the module case 8 can be stabilized. Furthermore, by increasing the opening area of the outlet 8f between the module case 8 and the fuel cell assembly 12, the flow rate of the oxidant gas flowing between the module case 8 and the fuel cell assembly 12 is increased. In addition, the influence of temperature on the fuel cell unit 16 due to external factors outside the module case 8 can be reduced.

  Further, in the above-described embodiment, the plurality of outlets 8 f are formed at a height position near the lower end of the outer electrode layer (air electrode) 92 where the fuel cell unit 16 is exposed. Although the temperature inside the module case 8 tends to become lower as it goes downward, according to the above-described embodiment, the heated oxidant gas is sprayed near the lower end of the outer electrode layer 92, and thus the temperature distribution in the vertical direction of the fuel cell unit 16. Can be made uniform.

  Further, in the above embodiment, the plurality of outlets 8 f are provided in the vicinity of the upper gripping portion 102 a so that the blown oxidant gas does not hit the connecting portion 102 c of the current collector 102 connecting the fuel cell unit 16. Is provided at the height of As a result, the heated oxidant gas is sprayed near the grip portion 102a of the current collector 102 made of a metal material having high thermal conductivity, so that the heat of the oxidant gas is transmitted through the current collector 102, and the fuel cell. The lower end portion of the cell unit 16 can be heated, whereby the temperature distribution in the vertical direction of the fuel cell unit 16 can be made uniform. Furthermore, according to the embodiment, since the oxidant gas is sprayed near the grip portion 102a of the current collector 102, the oxidant gas flow is prevented from being disturbed, and the temperature distribution in the fuel cell assembly 12 is uniform. become.

  In the above embodiment, the manifold 66 is fixed with the end opposite to the fuel gas supply pipe 64 as a base point, and the plurality of outlet holes in the second region have substantially the same height at the lower ends. The larger the opening area, the wider the area. As in the above embodiment, when the manifold 66 is fixed with the opposite end of the fuel gas supply pipe 64 as a base point, the height direction of the fuel gas supply pipe 64 is increased due to variations in member dimensions and assembly. Variations are likely to occur. That is, due to such variations, the positions of the outer electrode layer 92 and the current collector 102 may vary upward in the fuel gas supply pipe 64. On the other hand, according to the above embodiment, the plurality of air outlets 8f in the second region have substantially the same lower end, and the larger the opening area, the wider the upper area. Even if variations occur on the 64 side, the oxidant gas can be reliably sprayed onto the outer electrode layer 92.

DESCRIPTION OF SYMBOLS 1 Solid oxide fuel cell apparatus 2 Fuel cell module 4 Auxiliary machine unit 6 Housing 7 Heat insulating material 8 Module case 8a Top plate 8b Side plate 8c Bottom plate 8d Closed side plate 8e Closed side plate 8f Outlet 10 Power generation chamber 12 Fuel cell assembly 16 Fuel cell unit 18 Combustion chamber 24 Water supply source 26 Pure water tank 28 Water flow rate adjustment unit 30 Fuel supply source 32 Gas shutoff valve 36 Desulfurizer 38 Fuel flow rate adjustment unit 39 Valve 40 Air supply source 42 Solenoid valve 44 Reforming air Flow rate adjusting unit 45 Power generation air flow rate adjusting unit 46 First heater 48 Second heater 50 Hot water production device 52 Control box 54 Inverter 63 Fuel supply pipe 64 Fuel gas supply pipe 64A Inlet side pipe 64B Outlet side pipe 64C Fitting 64a Horizontal portion 64b Fuel supply hole 65 Hydrogen extraction pipe 66 for hydrodesulfurizer Hold 68 Lower support plate 74 Power generation air introduction pipe 82 Exhaust gas discharge pipe 83 Ignition device 84 Fuel cell 86 Inner electrode terminal 88 Fuel gas flow path 90 Inner electrode layer 92 Outer electrode layer 94 Electrolyte layer 96 Sealing material 98 Fuel gas flow Road narrow tube 102 Current collector 102a Grasping part 102b Grasping part 102c Connecting part 111 Exhaust port 112 Mixed gas supply pipe 120 Reformer 120A Mixed gas receiving part 120B Reformed part 120C Gas exhaust part 120a Mixed gas supply port 120b Through hole 121 Upper side Case 122 Lower case 123a Partition plate 123b Partition plate 130 Exhaust gas guide member 131 Lower guide plate 131a Convex step portion 132 Upper guide plate 132a Recess 133 Connection plate 134 Connection plate 135 Gas insulation layer (gas reservoir)
140 Evaporator 140A Exhaust passage part 140B Evaporation part 140C Mixing part 141 Evaporator case 142 Upper case 143 Lower case 144 Intermediate plate 144a Opening 160 Air passage cover 160a Top plate 160b Side plate 161a Air passage 161b Air passage 162 Plate fin 163 Plate fin 164 Flow path direction adjusting portion 167 Opening portion 171 Exhaust pipe 172a First exhaust passage 172b Second exhaust passage 173 Third exhaust passage 174 Fourth exhaust passage 175a Plate fin 175b Plate fin 176 Exhaust concentration portion 180A First protrusion 180B First Two protrusions 180C Groove 190 Splashing suppression cover 191 First member 191A Upper surface 191B Lower surface 191C Horizontal surface 191D Front and rear surfaces 191E Through hole 191F Recess 192 Second member 192A Upper surface 192B Lower surface 192C Lateral surface 192D Front and rear surfaces 192E Protruding portion 192F Recessed portion 192G Slit 200A First fixing jig 200B Second fixing jig

Claims (7)

A solid oxide fuel cell comprising three or more fuel cells that generate power with fuel gas and oxidant gas,
A module container having a rectangular shape in plan view that houses the fuel cell therein;
A fuel gas manifold disposed in the module container and distributing and supplying the fuel gas to the fuel cells;
A fuel cell stack formed by the fuel cells arranged above the fuel gas manifold and spaced apart; and
Above the fuel cell stack in the module container, a combustion unit that burns off-gas from the fuel cell to generate exhaust gas;
A reformer that is provided above the combustion section in the module container and that reforms the raw material gas by heating with the exhaust gas to generate the fuel gas;
A fuel gas supply pipe that is provided on one side of the module container and supplies the fuel gas to the fuel gas manifold;
An air blowing portion for blowing the oxidant gas from a plurality of blowing holes on at least one side surface of the fuel cell stack from the side of the fuel cell other than the side where the fuel gas supply pipe is provided; Prepared,
At least some of the plurality of blowout holes are disposed so as to be positioned between the adjacent fuel cells,
The air blowing portion includes a first region in which an opening area of the blowing hole is larger as a distance between the fuel cells is larger.   2. The solid oxide fuel cell device according to claim 1, wherein the air blowing portion further includes a second region in which an opening area of the blowing hole is larger as the air blowing portion is closer to the fuel gas supply pipe.   3. The solid oxide fuel cell device according to claim 1, wherein the blowing hole of the air blowing portion is provided so as to blow the oxidant gas to two opposing side surfaces of the fuel cell stack. The outlet hole is also provided between the side wall of the module container and the fuel cell stack,
The opening area of the blowing hole provided between the module container and the fuel cell stack is larger than the minimum opening area of the blowing hole in the first region. 2. A solid oxide fuel cell device according to 1.   The solid oxide fuel cell device according to claim 4, wherein the plurality of blowout holes are formed at a height position in the vicinity of a lower end of an air electrode where the fuel cell is exposed. The fuel cell stack includes a current collector made of a metal material that electrically connects the adjacent fuel cells at the lower end of the fuel cell,
The current collector includes a pair of grip portions that are respectively contact-fixed to the adjacent fuel cells, and a connecting portion that connects between the pair of grip portions.
The solid oxide fuel cell device according to claim 5, wherein the plurality of blowout holes are provided at a height in the vicinity of the grip portion so that the blown out oxidant gas does not directly hit the connection portion. The fuel gas manifold is fixed with an end opposite to the fuel gas supply pipe as a base point,
7. The solid oxide fuel cell device according to claim 6, wherein the plurality of blowing holes in the second region have substantially the same bottom end and expand upward as the opening area increases.

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