JP2012014922A - Fuel battery device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel battery device that is improved in power generation efficiency by uniformly supplying external gas to outside of fuel battery cells.SOLUTION: The fuel battery device 1 includes a reformer 20, a fuel battery cell aggregate 12 which is equipped with a plurality of tubular fuel battery cells 84 and has fuel gas flowing as internal gas from one-end part to the other-end part inside the fuel battery cells, a power generating air supply path 76 having a plurality of air outlets 78 for supplying power generating air as external gas and blowing out the power generating air to one-end part outside the tubular fuel battery cells, a combustion chamber 18 in which the remaining fuel gas not used for the power generation is burnt to generate fuel gas, and a combustion gas intake port 102 which is provided on the other-end part side of the fuel battery cells and exhausts the combustion gas generated at a combustion part to the outside. A bored plate 104 through which the combustion gas and the external gas are harder to pass at a part close to the combustion gas intake port 102 than at a part distant therefrom is arranged between the combustion chamber 18 and combustion gas intake port 102.

Description

  The present invention relates to a fuel cell device that generates power using a fuel gas and an oxidant gas (air).

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

  Specifically, this fuel cell apparatus (SOFC) is a fuel having a plurality of fuel cells that operate when fuel gas and oxidant gas (air, oxygen, etc.) flow from one end side to the other end side. Hydrogen-rich fuel that has a battery cell assembly, is supplied with a reformed gas (city gas, etc.), which is a raw material gas, and is introduced into a reformer containing a reforming catalyst. After reforming into gas, the fuel cell assembly is supplied.

  In the fuel cell device, the remaining fuel gas that has not been used for the power generation reaction in the fuel gas is burned and discharged to the outside as a combustion gas, while either one of the fuel gas and the oxidant gas is used as the external gas, The fuel cell assembly is supplied to the outside.

  For example, in Patent Document 1, a fuel gas is supplied to the inside of a fuel cell, an oxygen-containing gas (air) is supplied to the outside to generate power, and the remaining fuel gas that has not been used in the power generation reaction is supplied. A fuel cell apparatus has been proposed in which combustion gas is generated by combustion and a reformer is heated by the combustion gas.

JP 2005-19239 A

  An example of a conventional fuel cell device as disclosed in Patent Document 1 will be described with reference to FIG. The fuel cell device 120 includes a storage container 122, and a fuel cell stack 126 including a plurality of fuel cells 124, a reformer 128 to which a gas to be reformed is supplied, and a reformer 128 are reformed. A fuel gas tank 130 for storing the supplied fuel gas and supplying it to the inside of the fuel cell 124 is disposed. An oxygen-containing gas pipe 132 for supplying oxygen-containing gas (power generation air) to the outside of the fuel cell 124 is attached to the lower part of the storage container 122, and an exhaust gas pipe 134 is attached to the upper part. From the exhaust gas pipe 134, the combustion gas generated by the combustion of the fuel gas in the combustion section 134 preheats the reformer 128 and is then discharged to the outside.

  In the conventional fuel cell device 120 shown in FIG. 16, the combustion gas A generated in the combustion section 136 and the remaining oxygen-containing gas (power generation air) B that has not been used in the power generation reaction are at low pressure. Therefore, the fuel cell 124 positioned at the left center (C portion) and the lower right portion (D portion) in FIG. As a result, the efficiency of the power generation reaction by the fuel cell unit 126 decreases at these locations (C and D). As described above, in the fuel cell device having the conventional structure, the flow of the oxygen-containing gas (power generation air) B supplied to the outside of the fuel cell becomes uneven, and the power generation efficiency of the fuel cell device is reduced. there were. Further, in the fuel cell stack, the temperature of the fuel cell becomes non-uniform, which may lead to local deterioration, which is a problem.

  Therefore, the present invention has been made to solve the problems of the prior art, and it is possible to improve the power generation efficiency by uniformly supplying external gas such as power generation air to the outside of the fuel cell. An object of the present invention is to provide a fuel cell device.

In order to achieve the above-mentioned object, the present invention is electrically connected to a reformer that generates a fuel gas by reforming a raw material gas in a fuel cell device that generates power using a fuel gas and an oxidant gas. A fuel cell assembly in which a fuel gas and an oxidant gas react with each other to generate electric power, from one end inside the tubular fuel cell. A fuel cell assembly in which either one of the fuel gas or the oxidant gas flows as an internal gas to the other end, and the other end of the tubular fuel cell that supplies the other of the fuel gas or the oxidant gas as an external gas A gas supply path provided with a plurality of outlets for blowing out the external gas on the part side, a combustion part for burning the remaining fuel gas that has not been used for power generation out of the fuel gas, and generating a fuel gas; Tubular fuel cell An exhaust port for exhausting the combustion gas generated in the combustion unit to the outside, and between the combustion unit and the exhaust port, from the exhaust port at a portion near the exhaust port Compared with a distant part, the flow-path resistance provision member which made it difficult for a combustion gas and external gas to pass through is arrange | positioned.
In the present invention configured as described above, the combustion gas and the external gas are less likely to pass between the combustion portion and the discharge port in the portion near the discharge port than in the portion far from the discharge port. Since the flow path resistance imparting member is disposed, the directivity in which the flow of the combustion gas and the external gas is directed toward the discharge port, which occurs when there is no flow path resistance imparted member, is weakened. As a result, according to the present invention, it is possible to prevent the combustion gas and the external gas from flowing unevenly toward the exhaust port (the occurrence of uneven flow), and thereby to supply the external gas uniformly to the plurality of fuel cells. The power generation efficiency of the fuel cell device can be improved. Furthermore, local deterioration of the fuel cell caused by non-uniform flow of the external gas supplied to the outside of the fuel cell can be prevented.

In the present invention, preferably, the flow path resistance imparting member is a perforated plate provided with a plurality of through holes, and the opening area of the through hole near the discharge port is larger than the through hole of the portion far from the discharge port. Even smaller is set.
In the present invention configured as described above, the flow resistance by the flow resistance imparting member is adjusted by the opening area of the through-hole, and therefore a portion that is far from the discharge port in a portion close to the discharge port with a simple configuration. As a result, it is possible to make it difficult for the combustion gas and the external gas to pass through, and as a result, the combustion gas and the external gas are prevented from flowing unevenly toward the exhaust port (the occurrence of a drift), thereby The external gas can be uniformly supplied to the plurality of fuel cells, and the power generation efficiency of the fuel cell device can be improved.

In the present invention, preferably, the flow path resistance imparting member is a perforated plate provided with a plurality of through holes having the same opening area, and the number of through holes near the discharge port is a portion far from the discharge port. It is set to be smaller than the number of through holes.
In the present invention configured as described above, since the flow resistance by the flow resistance imparting member is adjusted by the number of through holes, the portion close to the discharge port is located far from the discharge port with a simple configuration. In comparison, it is possible to make it difficult for the combustion gas and the external gas to pass through. As a result, the combustion gas and the external gas are prevented from flowing unevenly toward the exhaust port (the occurrence of a drift), thereby It is possible to improve the power generation efficiency of the fuel cell device by uniformly supplying the external gas to the plurality of fuel cells.

In the present invention, preferably, the reformer is disposed in the combustion portion, and the through hole of the flow path resistance imparting member is disposed at a position facing the reformer.
In the present invention configured as described above, since the through hole of the flow path resistance imparting member is disposed at a position facing the reformer while being disposed in the combustion section, the combustion generated in the combustion section The gas flows around the reformer, passes through the through hole of the flow path resistance imparting member, and reaches the discharge port. As a result, according to the present invention, it is possible to prevent the combustion gas and the external gas from flowing unevenly toward the exhaust port (i.e., causing a drift), thereby supplying the external gas uniformly to the plurality of fuel cells. The contact area between the combustion gas and the reformer can be increased to sufficiently heat the reformer.

  According to the fuel cell device of the present invention, it is possible to uniformly supply external gas such as power generation air to the outside of the fuel cell, thereby improving the power generation efficiency.

1 is an overall configuration diagram showing a fuel cell device according to an embodiment of the present invention. 1 is a perspective view showing a fuel cell module in a state where a housing of a fuel cell device according to an embodiment of the present invention is removed. It is sectional drawing which looked at the fuel cell module of the fuel cell apparatus by one Embodiment of this invention from the A direction of FIG. It is sectional drawing which looked at the fuel cell module of the fuel cell apparatus by one Embodiment of this invention from the B direction of FIG. It is a front view which shows the fuel cell unit of the fuel cell apparatus by one Embodiment of this invention. FIG. 3 is a perspective view of the fuel cell module showing a state where a casing covering the fuel cell assembly is removed from the fuel cell module shown in FIG. 2. It is a perspective view which shows the evaporative mixer in the fuel cell module shown in FIG. It is the schematic plan view which looked at the heat exchanger of the fuel cell module of the fuel cell apparatus by one Embodiment of this invention from upper direction. It is a schematic side view which shows the heat exchanger of the fuel cell module of the fuel cell apparatus by one Embodiment of this invention. It is the schematic which looked at the fuel cell module of the fuel cell apparatus by one Embodiment of this invention from the B direction of FIG. It is the schematic which looked at the fuel cell module of the fuel cell apparatus by one Embodiment of this invention from the A direction of FIG. It is a perspective view which shows a part of casing which covers the fuel cell assembly of the fuel cell module of the fuel cell apparatus by one Embodiment of this invention, and a heat exchanger. It is a top view which shows the 1st example of the flow-path resistance provision member (perforated board) provided in the heat exchanger of the fuel cell module of the fuel cell apparatus by one Embodiment of this invention. It is a top view which shows the 2nd example of the flow-path resistance provision member (perforated board) provided in the heat exchanger of the fuel cell module of the fuel cell apparatus by one Embodiment of this invention. It is the schematic which shows the flow of the air for electric power generation when the fuel cell assembly of the fuel cell module of the fuel cell apparatus by one Embodiment of this invention is seen from upper direction. It is a schematic sectional drawing which shows an example of the conventional fuel cell apparatus.

Next, a solid oxide fuel cell (hereinafter referred to as “fuel cell device” or “SOFC”) that is a 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 an SOFC according to an embodiment of the present invention. As shown in FIG. 1, the 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 sealed space 8 is formed in the housing 6 via a heat insulating material (not shown). A fuel cell assembly 12 that performs a power generation reaction with fuel gas and oxidant gas (air) is disposed in a power generation chamber 10 that is a lower portion of the sealed space 8.
As shown in FIG. 6, the fuel cell assembly 12 includes ten fuel cell stacks 14, and the fuel cell stack 14 includes 16 fuel cell units 16 (see FIG. 5). Has been. Thus, the fuel cell assembly 12 has 160 fuel cell units 16, and all of these fuel cell units 16 are connected in series.

A combustion chamber 18 is formed above the above-described power generation chamber 10 in the sealed space 8 of the fuel cell module 2. In this combustion chamber 18, residual fuel gas and residual oxidant gas (not used for power generation reaction) ( Air) is combusted to generate combustion gas (exhaust gas).
A reformer 20 for reforming the fuel gas (raw material gas) is disposed above the combustion chamber 18 and has a temperature at which the reformer 20 can perform a reforming reaction by the combustion heat of the combustion gas. It is heated to become. Further, a heat exchanger 22 for heating an oxidant gas (power generation air) introduced from the outside by heat of the combustion gas, which will be described in detail later, is disposed above the reformer 20.

  Next, the auxiliary unit 4 stores a pure water tank 26 that stores water from a water supply source 24 such as tap water and uses the filter to obtain pure water, and a water flow rate that adjusts the flow rate of the water supplied from the water storage tank. An adjustment unit 28 (such as a “water pump” driven by a motor) is provided. The auxiliary unit 4 also includes a gas shut-off valve 32 that shuts off the fuel gas supplied from a fuel supply source 30 such as city gas, a desulfurizer 36 for removing sulfur from the fuel gas, and a flow rate of the fuel gas. A fuel flow rate adjusting unit 38 (such as a “fuel pump” driven by a motor) is provided. Further, the auxiliary unit 4 includes an electromagnetic valve 42 that shuts off air that is an oxidant gas supplied from an air supply source 40, and a reforming air flow rate adjustment unit 44 that adjusts the flow rate of air (driven by a motor). “Air blower” and the like, a power generation air flow rate adjustment unit 45 (such as an “air blower” driven by a motor), a first heater 46 for heating the reforming air supplied to the reformer 20, and power generation And a second heater 48 for heating the power generation air supplied to the chamber. 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 internal structure of the SOFC fuel cell module 2 according to the embodiment of the present invention will be described with reference to FIGS. 2 to 4, 6, and 7. FIG. 2 is a perspective view showing the fuel cell module 2 with the housing 6 of the fuel cell device according to an embodiment of the present invention removed, and FIG. 3 is a fuel cell module of the fuel cell device according to an embodiment of the present invention. 2 is a cross-sectional view of the fuel cell device 2 of the fuel cell apparatus according to an embodiment of the present invention, as viewed from the B direction of FIG. 2, and FIG. FIG. 7 is a perspective view of the fuel cell module showing a state in which a casing covering the fuel cell assembly is removed from the fuel cell module shown in FIG. 2, and FIG. 7 is a perspective view showing an evaporative mixer in the fuel cell module shown in FIG. is there.

  First, as shown in FIGS. 2 to 4, the fuel cell assembly 12 of the fuel cell module 2 is entirely covered with a casing 56. Here, as shown in FIG. 6, the fuel cell assembly 12 has a substantially rectangular parallelepiped shape in which the A direction is longer than the B direction (see FIG. 6), and the upper surface 12 a, the lower surface 12 b, and the A direction in FIG. 2. A long side surface 12c extending along the direction and a short side surface 12d extending along the direction B in FIG. 2 are provided.

  Next, an evaporative mixer 58 is provided along the long side surface 12 c of the fuel cell assembly 12 in the lowermost portion of the sealed space 8 in the fuel cell module 2. As will be described later, the evaporative mixer 58 is heated by combustion gas to turn water into steam, and this steam, fuel gas (city gas) as reformed gas, and air as oxidant gas, For mixing. As shown in FIGS. 2, 4, and 7, a reformed gas supply pipe 60 and a water supply pipe 62 are connected to one end side of the evaporative mixer 58. A reformed gas (fuel gas) and reforming air are introduced from the fuel flow rate adjusting unit 38 and the reforming air flow rate adjusting unit 44.

  As shown in FIG. 4, the lower end of the fuel supply pipe 64 is connected to the other end side of the evaporation mixer 58, and the upper end of the fuel supply pipe 64 is connected to the upstream end of the reformer 20. The fuel gas is supplied from the evaporative mixer 58 to the reformer 20 through the supply pipe 64. The upper end of the fuel supply pipe 66 is connected to the downstream end of the reformer 20, and the lower end side 66a of the fuel supply pipe 66 enters the fuel gas tank 68 and extends in the horizontal direction.

  The fuel gas tank 68 is provided directly below the fuel cell assembly 12 as shown in FIGS. 3 and 4. A plurality of small holes (not shown) are formed along the longitudinal direction (direction A) on the outer periphery of the lower end side 66a of the fuel supply pipe 66 inserted into the fuel gas tank 68. The reformed fuel gas is uniformly supplied into the fuel gas tank 68 in the longitudinal direction. As will be described later, the fuel gas supplied to the fuel gas tank 68 is supplied into a fuel gas flow path 88 (see FIG. 5) inside the fuel cell unit 16 and then rises in the fuel cell unit 16. The combustion chamber 18 is reached.

  Next, a structure for supplying power generation air to the fuel cell module 2 will be described. First, as shown in FIGS. 2 to 4, above the reformer 20, the upper surface 12a and the short side surface 12d of the fuel cell assembly 12 of the fuel cell module 2 (the right short side surface in FIGS. 2 and 4). The heat exchanger 22 described above is provided. The heat exchanger 22 is provided with a plurality of combustion gas pipes 70, which will be described in detail later, and a power generation air passage 72 formed around the combustion gas pipes 70.

  In the present embodiment, the heat exchanger 22 is provided along the upper surface 12a and the right short side surface 12d of the fuel cell assembly 12, but not limited thereto, the heat exchanger 22 is provided. Further, it may be provided along only the right short side surface 12d, may be provided only along both the right and left short side surfaces 12d, and further along the upper surface 12a and the short side surfaces 12d on both sides. It may be provided.

  As shown in FIG. 2, an inlet 74a of a power generation air introduction pipe 74 is attached to one end of the lower end of the portion provided along the short side surface 12d of the heat exchanger 22, and this power generation Power generation air is introduced into the heat exchanger 22 from the power generation air flow rate adjustment unit 45 by the air introduction pipe 74.

  4 and 8, an outlet port 72a of the power generation air flow path 72 is formed on the other end on the upper side of the heat exchanger 22, and further, as shown in FIG. A power generation air supply passage 76 is formed on the outer sides of both sides of the casing 56 of the module 2 in the width direction (B direction: short side surface direction). Air is supplied. The power generation air supply path 76 is formed along the longitudinal direction of the fuel cell assembly 12 (the direction of the long side surface 12c) and further corresponds to the lower side of the fuel cell assembly 12. A plurality of outlets 78 are formed at equal intervals along the longitudinal direction for blowing out the power generation air toward each fuel cell unit 16 of the fuel cell assembly 12 in the power generation chamber 10 Has been. The power generation air blown out from these air outlets 78 flows from below to above along the outside of each fuel cell unit 16.

  Next, a structure for discharging combustion gas generated by combustion of fuel gas and power generation air (oxidant gas) will be described. As described above, a plurality of combustion gas pipes 70 are provided in the heat exchanger 22 for discharging the combustion gas generated by burning the fuel gas and the power generation air (oxidant gas) in the combustion chamber 18. It has been. As shown in FIG. 4, a combustion gas discharge chamber 80 located below the fuel cell assembly 12 and extending in the longitudinal direction is formed on the downstream end side of these combustion gas pipes 70. The side and the combustion gas discharge chamber 80 are connected. The above-described evaporative mixer 58 is disposed in the combustion gas discharge chamber 80, and the fuel gas in the evaporative mixer 58 is heated along the longitudinal direction by the high-temperature combustion gas. ing. Further, a combustion gas discharge pipe 82 is connected to the lower surface of the combustion gas discharge chamber 80 so that the combustion gas is discharged to the outside.

Next, the fuel cell unit 16 will be described with reference to FIG. FIG. 5 is a partial cross-sectional view showing a SOFC fuel cell unit according to an embodiment of the present invention.
As shown in FIG. 5, the fuel cell unit 16 includes a fuel cell 84 and inner electrode terminals 86 respectively connected to the vertical 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 inside (inside), a cylindrical outer electrode layer 92, and an inner electrode layer. 90 and an electrolyte layer 94 between the outer electrode layer 92 and the outer 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 16 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. A fuel gas passage 98 communicating with the fuel gas passage 88 of the inner electrode layer 90 is formed at the center of the inner electrode terminal 86.

  The inner electrode layer 90 includes, for example, a mixture of Ni and zirconia doped with at least one selected from rare earth elements such as Ca, Y, and Sc, 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 detailed structure of the heat exchanger 22 will be described with reference to FIGS. 2 and 8 to 14. FIG. 8 is a schematic plan view of the fuel cell module heat exchanger of the fuel cell device according to the present embodiment as viewed from above, and FIG. 9 is a schematic diagram illustrating the fuel cell module heat exchanger of the fuel cell device according to the present embodiment. FIG. 10 is a schematic view of the fuel cell module of the fuel cell apparatus according to the present embodiment as viewed from the direction B in FIG. 2, and FIG. 11 shows the fuel cell module of the fuel cell apparatus according to the present embodiment in FIG. FIG. 12 is a perspective view showing a part of the casing covering the fuel cell assembly of the fuel cell module of the fuel cell device according to the present embodiment and the heat exchanger, and FIG. These are top views which show the 1st example of the flow-path resistance provision member (perforated plate) provided in the heat exchanger of the fuel cell module of the fuel cell apparatus by this embodiment, FIG. 14 is the fuel cell by this embodiment. apparatus Is a plan view showing a second example of a provided in the heat exchanger of the fuel cell module flow resistance imparting member (perforated plate).

  First, as shown in FIGS. 2, 8, and 9, a plurality of combustion gas pipes 70 are arranged in the heat exchanger 22 so as to extend substantially linearly in order to reduce the flow resistance. Yes. Further, a plurality of (specifically, seven) guide plates 100 extending in a direction perpendicular to the direction in which the combustion gas pipes 70 extend linearly are attached. These guide plates 100 are arranged in a staggered pattern at substantially equal intervals along the longitudinal direction of the combustion gas pipe 70. These guide plates 100 also function as a support member that supports the combustion gas pipe 70. By providing these guide plates 100, the power generation air flow path 72 becomes a meandering flow path, and the power generation air flows so as to cross the combustion gas pipe 70 a plurality of times.

Next, as shown in FIG. 10, a combustion gas inlet port 102 is formed on the upstream side of the combustion gas pipe 70 of the heat exchanger 22, and the combustion gas generated in the combustion chamber 18 is lower in pressure than the combustion chamber 18. Toward the combustion gas inlet port 102. In the present embodiment, a perforated plate 104 as a flow path resistance imparting member is provided between the combustion gas inlet port 102 and the combustion chamber 18. The perforated plate 104 is formed as a part of the casing 56 and the heat exchanger 22 as shown in FIG.
Furthermore, in the present embodiment, the outer surface of the heat exchanger 22 also serves as at least a part of the wall surface of the casing 56 that covers the fuel cell assembly 12.

  A plurality of through holes 106 are formed in the perforated plate 104. As shown in FIG. 11, the through hole 106 is formed at a position above the reformer 20 and facing the reformer 20.

  Next, the perforated plate 104, which is a flow path resistance imparting member, will be described in detail with reference to FIGS. As shown in FIG. 13, a perforated plate 104, which is a first example, has a plurality of through holes 106 formed along the longitudinal direction, that is, four through holes 106a, 106b, 106c, and 106d. ing. These through-holes 106 are set such that the closer to the combustion gas inlet port 102 (106a), the smaller the opening area, and the farther (106d), the larger the opening area. Thereby, for example, in the through hole 106a having a small opening area, the flow resistance with respect to the passing combustion gas and the remaining power generation air that has not been used for the power generation reaction by the fuel cell unit 16 increases, and the flow rate decreases. On the other hand, in the through hole 106d having a large opening area, the flow resistance against the passing combustion gas and power generation air is reduced, and the flow rate is increased.

  Similarly, as shown in FIG. 14, the perforated plate 104, which is the second example, has a plurality of through holes 106 having the same opening area along the longitudinal direction. In this second example, the number of through-holes 106 is set to be smaller as it is closer to the combustion gas inlet port 102, and the number of through-holes 106 is set to be larger as it is farther away. As a result, as in the first example, in the through hole 106 close to the combustion gas inlet port 102, the total amount of the opening area is reduced, so that the flow resistance against the passing combustion gas and power generation air is increased, and the flow rate is increased. On the other hand, in the through hole 106 far from the combustion gas inlet port 102, the total amount of the opening area is increased, so that the flow resistance against the passing combustion gas and power generation air is reduced, and the flow rate is increased.

  Next, the operation (operation) of the fuel cell device according to the present embodiment described above will be described. First, in the fuel cell device according to the present embodiment, the plurality of air outlets 78 of the power generation air supply path 76 for supplying power generation air (oxidant gas) extend along the long side surface 12 c of the fuel cell assembly 12. Therefore, the power generation air (oxidant gas) is blown out in the direction (B direction) in which the thickness of the fuel cell assembly 12 having a substantially rectangular parallelepiped shape is thin. Power generation air (oxidant gas) can be distributed. On the other hand, even if the power generation air (oxidant gas) is blown out toward the short side surface of the fuel cell assembly 12, the power generation air (oxidant) is increased in the direction in which the fuel cell assembly 12 is thick (direction A). Gas) is blown out, and it is difficult to spread the power generation air (oxidant gas) to all of the fuel cells 12. Therefore, in the present embodiment, the heat exchanger 22 is arranged along the short side surface 12d of the fuel cell assembly 12. As a result, according to the fuel cell device according to the present embodiment, the arrangement of the heat exchanger 22 is devised while ensuring the power generation performance by spreading the power generation air (oxidant gas) to all of the fuel cells 84. As a result, the fuel cell device can be made compact.

  Next, in this embodiment, since the fuel cell assembly 12 blows out power generation air (oxidant gas) from the air outlet 78 disposed along the long side surface 12c, the vicinity of the long side surface 12c. The fuel cell 84 is easily cooled, but the fuel cell 84 near the short side surface 12d is difficult to cool because the power generation air (oxidant gas) is difficult to reach. As a result, the fuel cell assembly 12 There is a possibility that a temperature difference occurs along the longitudinal direction (long side surface direction), and the fuel cell assembly 12 cannot sufficiently exhibit the power generation performance. On the other hand, in the present embodiment, the outer surface of the heat exchanger 22 is also used as at least a part of the wall surface of the casing 56 that covers the fuel cell assembly 12, so that the fuel in the vicinity of the short side surface 12d. Heat from the battery cell 84 can be easily taken away by the heat exchanger 22, and as a result, a temperature difference that occurs along the longitudinal direction of the fuel cell assembly 12 can be reduced.

  Next, in the present embodiment, power generation air (oxidation) is directed from the air outlets 78 provided on both sides of the long side surface 12c of the fuel cell assembly 12 toward both sides of the long side surface 12c of the fuel cell assembly 12. As shown in FIG. 15, power generation air (oxidant gas) blown to the fuel cell assembly 12 from both sides of the long side surface 12c is supplied to the fuel cell assembly as shown in FIG. It is buffered inside the body 12 and flows out in the direction of the short side surface 12d and flows upward. As a result, according to the fuel cell device according to the present embodiment, the fuel cell 84 in the vicinity of the short side surface 12d of the fuel cell assembly 12 is cooled, and the temperature generated along the longitudinal direction of the fuel cell assembly 12 The difference can be reduced.

  Next, in the present embodiment, the inlet 74 a of the power generation air introduction pipe 74 that introduces the power generation air (oxidant gas) into the heat exchanger 22 is in the vicinity of the short side surface 12 d of the fuel cell assembly 12. Therefore, the fuel cell 84 in the vicinity of the short side surface 12d of the fuel cell assembly 12 is made efficient by the power generation air (oxidant gas) introduced into the heat exchanger 22 through the introduction port 74a. Cooled well, and according to this embodiment, the temperature difference produced along the longitudinal direction in the fuel cell assembly 12 can be reduced.

  Next, in the present embodiment, since the introduction port 74a of the power generation air introduction pipe 74 is provided on the side far from the combustion chamber 18 of the heat exchanger, the introduction at a relatively low temperature in the heat exchanger 22 is performed. The portion provided with the opening 74a is far away from the portion close to the combustion chamber 18 where the temperature is relatively high, thereby preventing local cooling and preventing the possibility of damage caused when the temperature difference is large. Can do.

  Next, in this embodiment, since the heat exchanger 22 is provided over the upper surface 12a and the short side surface 12d of the fuel cell assembly 12, the combustion gas, power generation air (oxidant gas), and Can take a long distance for heat exchange, and thus the power generation air (oxidant gas) can be easily heated to a high temperature.

  Next, in the present embodiment, since the combustion gas pipe 70 of the heat exchanger 22 extends substantially linearly, the flow path resistance is reduced, and the combustion gas is smoothly discharged from the combustion chamber 18 to promote combustion. In both cases, since the flow of power generation air (oxidant gas) is guided by the guide plate 100 so as to intersect the combustion gas pipe 70 a plurality of times, heat exchange can be performed efficiently.

  Next, in the present embodiment, the portion near the combustion gas inlet port 102 between the combustion chamber 18 and the combustion gas inlet port 102 which is an exhaust port is combusted as compared with the portion far from the combustion gas inlet port 102. Since the perforated plate (flow path resistance imparting member) 104 that makes it difficult for gas and power generation air (external gas) to pass therethrough is disposed, the combustion gas and power generation generated when there is no perforated plate 104 The directivity in which the air flow is directed toward the combustion gas inlet port 102 is weakened. As a result, according to the present embodiment, the combustion gas and the power generation air are prevented from flowing unevenly toward the combustion gas inlet port 102 (the occurrence of a drift), thereby generating power for the plurality of fuel cells 84. The power generation efficiency of the fuel cell device can be improved by supplying air (external gas) uniformly. Furthermore, local deterioration of the fuel cell 84 caused by non-uniform flow of power generation air supplied to the outside of the fuel cell 84 can also be prevented.

  Next, in this embodiment, since the flow resistance by the perforated plate 104 is adjusted by the opening area of the through hole 106 or the number of the through holes 106, the combustion gas inlet port 102 has a simple configuration. Compared with a portion far from the combustion gas inlet port 102, the combustion gas and the power generation air can be made less likely to pass through the portion closer to.

  Furthermore, in the present embodiment, since the through hole 106 of the perforated plate 104 is disposed at a position facing the reformer 20, the combustion generated in the combustion chamber 18 is disposed in the combustion chamber 18. The gas flows around the reformer 20, passes through the through hole 106 of the perforated plate 104, and reaches the combustion gas inlet port 102. As a result, according to the present embodiment, the combustion gas and power generation air are prevented from flowing unevenly toward the combustion gas inlet port 102 (i.e., the occurrence of drift), whereby the external gas is supplied to the plurality of fuel cells 84. Can be supplied uniformly, and the contact area between the combustion gas and the reformer can be increased to sufficiently heat the reformer 20.

  In the fuel cell device according to the present embodiment described above, the external gas supplied to the outside of the fuel cell 84 of the fuel cell assembly 12 is power generation air (oxidant gas). The internal gas flowing through the inside is fuel gas. However, the present embodiment is not limited to this, and fuel gas is used as the external gas, while power generation air (oxidant gas) is used as the internal gas flowing inside the fuel cell 84. May be.

  Furthermore, in the fuel cell device according to the present embodiment described above, the evaporative mixer 58 is disposed below the fuel cell assembly 12, but the present embodiment is not limited to this, and the evaporative mixer 58 is provided. The fuel cell assembly 12 may be disposed in the heat exchanger 22 disposed along the short side surface 12d. In this case, in the heat exchanger 22, both the external gas (fuel gas or power generation air) and the fuel gas in the evaporation mixer 58 are heated by the combustion gas.

1 Fuel cell equipment (SOFC)
2 Fuel cell module 6 Housing 8 Sealed space 10 Power generation chamber 12 Fuel cell assembly 14 Fuel cell stack 16 Fuel cell unit 18 Combustion chamber 20 Reformer 22 Heat exchanger 56 Casing 58 Evaporative mixer 60 Reformed gas Supply pipe 62 Water supply pipe 64, 66 Fuel supply pipe 68 Fuel gas tank 70 Fuel gas pipe 72 Power generation air flow path 72a Outlet port 74 Power generation air introduction pipe 74a Inlet port 76 Power generation air supply path 78 Air outlet 80 Combustion gas discharge Chamber 82 Combustion gas discharge pipe 84 Fuel cell 100 Guide plate 102 Combustion gas inlet port 104 Perforated plate (channel resistance imparting member)
106 Through hole

Claims (4)

In a fuel cell device that generates power using fuel gas and oxidant gas,
A reformer that reforms the raw material gas to produce fuel gas;
A fuel cell assembly having a plurality of electrically connected tubular fuel cells and generating power by reacting fuel gas and oxidant gas by these fuel cells, The fuel cell assembly, wherein either one of the fuel gas or the oxidant gas flows as an internal gas from one end to the other end on the inside;
A gas supply path having a plurality of outlets for supplying the other of the fuel gas or the oxidant gas as an external gas and blowing out the external gas to one end of the tubular fuel cell;
A combustion section that generates fuel gas by burning the remaining fuel gas that has not been used for power generation among the fuel gas;
A discharge port provided on the other end side of the tubular fuel cell, for discharging the combustion gas generated in the combustion section to the outside,
Between the combustion section and the discharge port, a flow path resistance imparting member is arranged so that the combustion gas and the external gas are less likely to pass through the portion near the discharge port than in the portion far from the discharge port. A fuel cell device characterized by comprising:   The flow path resistance imparting member is a perforated plate provided with a plurality of through holes, and an opening area of a through hole in a portion near the discharge port is set smaller than a through hole in a portion far from the discharge port. The fuel cell device according to claim 1.   The flow path resistance imparting member is a perforated plate provided with a plurality of through holes having the same opening area, and the number of through holes in a portion near the discharge port is the number of through holes in a portion far from the discharge port. 2. The fuel cell device according to claim 1, wherein the fuel cell device is set to be smaller than the first.   4. The fuel cell device according to claim 2, wherein the reformer is disposed in the combustion section, and a through hole of the flow path resistance imparting member is disposed at a position facing the reformer. 5. .

Images