JP5772001B2 - Fuel cell device - Google Patents

Description

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

  A plurality of single cells capable of obtaining power using fuel gas (hydrogen-containing gas) and air (oxygen-containing gas, oxidant gas) are accommodated in a storage container, and fuel gas and air are stored in the plurality of single cells. Various fuel cell devices that generate electricity by supplying the above are proposed. In such a fuel cell apparatus, when generating a fuel gas to be supplied to a plurality of single cells, for example, a steam reforming method is used in which hydrogen such as natural gas is reacted with steam to generate hydrogen. Various reformers for performing such steam reforming have been proposed.

  A reformer for steam reforming hydrocarbons contains a reforming catalyst inside and performs steam reforming by passing hydrocarbons and steam through the built-in reforming catalyst. . Thus, in steam reforming using a reformer, deterioration of a built-in reforming catalyst becomes a problem. Therefore, in the fuel cell device described in Patent Document 1 below, a fuel cell device including a reformer configured to extend the life of the reforming catalyst has been proposed.

  A fuel cell device disclosed in the following Patent Document 1 includes a cell stack in which a plurality of single cells are erected and electrically connected, and a manifold for supplying fuel gas to the single cells And a reformer disposed above the cell stack. The reformer has a vaporization section provided with a raw fuel supply port through which a raw fuel is supplied at the center of a cylindrical container. The reformer has reforming sections including reforming catalysts for reforming raw fuel flowing from the vaporization section into fuel gas on both sides of the container. Each reforming section and the manifold are connected by a fuel gas supply pipe, and the fuel gas supply pipe is provided with a fuel gas flow rate adjusting means for adjusting the flow rate of the fuel gas.

JP 2010-198896 A

  In the above-described conventional fuel cell device, when it is determined that the reforming catalyst contained in the reforming unit has deteriorated, the fuel gas flow rate adjusting means is operated, so that the fuel gas having a low purity is supplied to the manifold. Can be prevented from being supplied.

  Further, it is determined that the reforming catalyst stored in one reforming unit has deteriorated, and it is determined that the reforming catalyst stored in the other reforming unit can perform the reforming reaction normally. In some cases, the fuel gas delivered from one reforming part is suppressed from being supplied to the manifold, and the fuel gas delivered from the other reforming part is supplied to the single cell. Therefore, even when the reforming catalyst provided in one reforming section deteriorates, the life of the reformer is improved by continuously using the other reforming section as it is.

  However, in the conventional fuel cell device described above, when the power generation operation is initially performed using the reforming catalyst stored in the entire reformer, it is determined that some of the reforming catalyst has deteriorated. Then, the substantial capacity | capacitance of a reformer is reduced and it respond | corresponds. Therefore, it is considered that the fuel gas supply capability is remarkably lowered, and the power generation performance as the fuel cell device is lowered.

  Therefore, the present inventors have made an essential study on the deterioration of the reforming catalyst, and have repeatedly considered measures for extending the life of the reformer without greatly changing the reforming performance. When hydrocarbon is used as a raw material gas for fuel gas, steam reforming is performed in the reformer, and therefore it is required to supply hydrocarbon and steam at a predetermined ratio to the reformer. . The hydrocarbon and water vapor supplied in this way require a very small amount of water vapor relative to the amount of hydrocarbon supplied. The amount of hydrocarbons to be supplied fluctuates when the electric power drawn from the fuel cell device fluctuates or the flow of fuel gas in the fuel cell device pulsates. For this reason, it is virtually impossible to supply a minute amount of water vapor while fluctuating completely in synchronization with the amount of fluctuating hydrocarbons, and an imbalance between the amount of hydrocarbons supplied and the amount of water vapor supplied It is difficult to avoid the occurrence of carbon deposition due to.

  Thus, as long as the hydrocarbon is steam reformed, it is difficult to fundamentally solve the problem of carbon deposition. When the carbon deposition of the hydrocarbon, which is the raw material gas, occurs in the reformer, the deposited carbon adheres to the reforming catalyst housed in the reformer, thereby obstructing the flow of the hydrocarbon, which is the raw material gas. There is a risk that water vapor will be excessive in the reformer due to the loss of the raw material gas due to carbon deposition and the insufficient supply of the raw material gas due to flow inhibition. When the inside of the reformer containing the reforming catalyst becomes excessive in water vapor, ruthenium used as the reforming catalyst is detached and released out of the fuel cell device.

  Since it is difficult to fundamentally prevent the occurrence of carbon deposition, it is difficult to avoid deterioration of the reforming catalyst in the reformer, and the capacity in the reformer is limited due to the size of the fuel cell device. It can't be made unlimited. Therefore, it is required to use all the reforming catalysts well while making the progress of deterioration stepwise without wasting a limited amount of the reforming catalyst that can be accommodated in a limited capacity. Here, for example, the interior of the reformer is divided into a plurality of rooms, the reforming catalyst is distributed and stored in each room, and a driving means such as a solenoid is installed while detecting deterioration of the reforming catalyst in each room. It is also conceivable to use the reforming catalyst stepwise while driving the partition walls and switching the flow paths in order.

  However, the driving temperature of a fuel cell device using hydrocarbon as a raw material gas is extremely high, and a sensor for detecting the state in the reformer is disposed, or driving means such as a solenoid is disposed in the reformer. In practice, it is difficult to switch the flow path.

  The present invention has been made in view of such problems, and an object of the present invention is a fuel cell device that generates power using fuel gas and oxidant gas, and includes a sensor for detecting a state in the reformer and a reformer. An object of the present invention is to provide a fuel cell device that can use all the reforming catalysts contained in the reformer well without using a driving means for switching the flow path in the reactor.

  In order to solve the above-described problems, a fuel cell device according to the present invention is a fuel cell device that generates power using a fuel gas and an oxidant gas, and generates a fuel gas by steam reforming a raw material gas containing hydrocarbons. The reformer includes a plurality of electrically connected tubular single cells, and a cell assembly that generates power through the reaction of the fuel gas and the oxidant gas by the single cells. The reformer includes a main body portion and a reforming catalyst containing ruthenium accommodated in the main body portion. The main body includes an inlet for introducing a raw material gas, an outlet for flowing a fuel gas generated by steam reforming the raw material gas toward the cell assembly, and the inlet and the outlet. And a catalyst housing portion in which the reforming catalyst is housed. The catalyst housing portion has a first housing chamber and a second housing chamber. The pressure loss when the raw material gas flows into the second storage chamber and flows out as fuel gas is higher than the pressure loss when the raw material gas flows into the first storage chamber and flows out as fuel gas. Preliminarily configured so that carbon contained in the raw material gas is precipitated in the first storage chamber, and the flow resistance through which the raw material gas passes in the vicinity of the reforming catalyst stored in the first storage chamber is reduced. Is increased, the inflow of the raw material gas into the second storage chamber increases autonomously.

  In the present invention, since the catalyst storage unit has the first storage chamber and the second storage chamber, the reforming catalyst can be stored separately in the first storage chamber and the second storage chamber. The contained reforming catalyst can be used stepwise. Furthermore, the pressure loss when the raw material gas flows into the second storage chamber and flows out as fuel gas is higher than the pressure loss when the raw material gas flows into the first storage chamber and flows out as fuel gas. Thus, the source gas can be preferentially flowed into the first storage chamber without using a separate control means. Therefore, the reforming catalyst accommodated in the first accommodating chamber is preferentially used, and the reformed fuel gas can be supplied to the cell assembly.

  When steam reforming is performed using a raw material gas containing hydrocarbons, carbon deposition is a phenomenon that is unavoidable. It is assumed that the flow path is successfully switched to steam reforming in the two storage chambers. As described above, since the source gas is preferentially flowed into the first storage chamber, the effect of carbon deposition appears first in the first storage chamber. Therefore, carbon contained in the raw material gas is precipitated in the first storage chamber, and the flow resistance increases by narrowing the flow path through which the raw material gas passes in the vicinity of the reforming catalyst stored in the first storage chamber. If the flow resistance increases in the first containment chamber, the source gas flows into the first containment chamber and the fuel loss rather than the pressure loss when the feedstock gas flows into the second containment chamber and flows out as fuel gas. Pressure loss when flowing out as gas increases.

  In the present invention, the change in pressure loss caused by such carbon deposition is utilized, and the reforming path passing through the second storage chamber from the reforming path passing through the first storage chamber in accordance with the operation continuation status of the fuel cell device. The flow path is switched to. By switching the reforming path in this way, the reforming catalyst stored in the first storage chamber and the second storage chamber can be used up well, and one of the reforming paths is excessively blocked. It can also be prevented that the reforming catalyst ruthenium is separated due to excessive steam. Therefore, the unavoidable phenomenon of carbon deposition is reversed, and the entire reforming catalyst accommodated in the reformer can be used up without using any special control means.

  In the fuel cell device according to the present invention, the inlet and the outlet are formed on a lower surface of the main body portion facing the cell assembly, and the first storage chamber and the second storage chamber are formed of the main body portion. It is also preferable that they are arranged so as to line up and down along the direction from the lower surface to the upper surface.

  In this preferred embodiment, since the inflow port and the outflow port are formed on the lower surface of the main body portion facing the cell assembly, the raw material gas flows into the main body portion from the lower surface of the main body portion, and the reformed fuel gas is the main body. It flows out from the lower surface of the part. By adopting a configuration in which the source gas flows in from the lower surface of the main body portion in this way, the first storage chamber and the second storage chamber are arranged so as to be lined up and down along the direction from the lower surface of the main body portion to the upper surface. The raw material gas flows preferentially into the reforming path arranged on the lower surface side. As a result of such arrangement, a difference in the inflow of the raw material gas is provided, so that the difference in pressure loss between the first storage chamber and the second storage chamber can be reduced, while The reforming path can be switched in a state where the reforming path is not excessively blocked.

  In the fuel cell device according to the present invention, it is also preferable that the first storage chamber is disposed on the lower surface side and the second storage chamber is disposed on the upper surface side.

  In this preferred embodiment, the first storage chamber is arranged on the lower surface side to improve the ease of inflow of the source gas, while the second storage chamber is arranged on the upper surface side so that the source gas is difficult to flow in. ing. Therefore, at the stage where the reforming path is not blocked in the first storage chamber, the inflow of the raw material gas into the second storage chamber is suppressed, and the second passage after the reforming path is blocked in the first storage chamber. The material gas is configured to flow into the storage chamber. By such a device in construction, the inflow transition of the raw material gas into the second storage chamber is made gradual, and the reforming by the reforming catalyst in the second storage chamber after the reforming catalyst in the first storage chamber deteriorates. The performance can be ensured, and the reforming performance of the entire reformer can be enhanced.

  In the fuel cell device according to the present invention, the catalyst housing portion further includes a third housing chamber connected to both the first housing chamber and the second housing chamber, and the first housing chamber and the second housing chamber. It is also preferable that the chamber is disposed on the inlet side, and the third accommodating chamber is disposed on the outlet side.

  In the reformer of the present invention, the raw material gas is introduced from the inlet, while the reformed fuel gas is allowed to flow out from the outlet, so that carbon deposition occurs on the inlet side, and water vapor is generated on the outlet side. There is a tendency for catalyst deterioration due to excess to proceed. Therefore, in this preferred embodiment, the first storage chamber and the second storage chamber are provided on the inlet side, while the third storage chamber is provided on the outlet side and downstream of the first storage chamber and the second storage chamber. Thus, the catalyst deterioration on the downstream side can be kept in the first storage chamber and the second storage chamber, and the catalyst stored in the third storage chamber can be maintained in a state where it does not deteriorate.

  Further, in the fuel cell device according to the present invention, a second communication port is formed on the inflow side from the first communication port where the first storage chamber is connected to the third storage chamber. A shunt passage connecting the three storage chambers, and the source gas flows into the shunt passage more than the pressure loss when the raw material gas flows into the first storage chamber and flows out as fuel gas. It is also a preferable aspect that the pressure loss when flowing out into the three storage chambers is increased in advance. In this preferred embodiment, carbon contained in the source gas is deposited in the first storage chamber, and the flow resistance increases by narrowing the flow path through which the source gas passes in the vicinity of the reforming catalyst stored in the first storage chamber. Thus, it is also preferable that the inflow of the raw material gas into the third storage chamber via the branch passage is autonomously increased.

  As described above, since the source gas is preferentially flowed into the first storage chamber, the effect of carbon deposition appears first in the first storage chamber. Therefore, carbon contained in the raw material gas is precipitated in the first storage chamber, and the flow resistance increases by narrowing the flow path through which the raw material gas passes in the vicinity of the reforming catalyst stored in the first storage chamber. If the flow resistance increases in the first storage chamber, then the source gas flows into the first storage chamber and the fuel flows more than the pressure loss when the source gas flows into the third storage chamber and flows out as fuel gas. Pressure loss when flowing out as gas increases.

  In this preferred embodiment, the variation in pressure loss due to such carbon deposition is utilized, and the third passage through the shunt passage from the reforming passage through the first storage chamber according to the operation continuation state of the fuel cell device. The flow path is switched to the reforming path via the storage chamber. By switching the reforming path in this manner, the reforming catalyst stored in the first storage chamber and the third storage chamber can be used up well, and one of the reforming paths is excessively blocked. It can also be prevented that the reforming catalyst ruthenium is separated due to excessive steam. Therefore, the unavoidable phenomenon of carbon deposition is reversed, and the entire reforming catalyst accommodated in the reformer can be used up without using any special control means.

  In the fuel cell device according to the present invention, the source gas supplied from the branch passage to the third storage chamber is more directly below the downstream side of the second storage chamber than directly below the first storage chamber. It is also preferable that the diversion passage is provided so as to be supplied.

  As described above, when the carbon contained in the raw material gas is precipitated in the first storage chamber and the flow resistance increases by narrowing the flow path through which the raw material gas passes in the vicinity of the reforming catalyst stored in the first storage chamber, It is assumed that the flow path leading to the third storage chamber without passing through the route is also affected by the carbon deposition. Therefore, in this preferred embodiment, the distribution gas is supplied so that the source gas supplied from the branch passage to the third storage chamber is supplied more directly downstream of the second storage chamber than directly downstream of the first storage chamber. By providing the path, it is possible to supply the raw material gas directly under the downstream side of the second storage chamber where the influence of carbon deposition is assumed to be smaller. Therefore, the reforming catalyst stored in the third storage chamber can be used up more effectively.

In the fuel cell device according to the present invention, the inflow port is formed closer to the first storage chamber than the second storage chamber, and closer to the second storage chamber than the first storage chamber. it is also preferred that the outflow port is formed.

  In this preferred embodiment, by forming the inlet close to the first storage chamber, the source gas can be reliably introduced into the first storage chamber at the beginning of operation. On the other hand, by forming the outlet close to the second storage chamber, the flow of the reformed fuel gas is discharged from the second storage chamber side, and the flow downstream of the first storage chamber is relatively It is reduced to. Therefore, the reformer catalyst is dispersed to the second storage chamber side while the reforming catalyst deterioration in the downstream of the first storage chamber is dispersed while intensively using the reforming catalyst stored in the first storage chamber at the beginning of operation. Overall reforming performance can be enhanced.

  In the fuel cell device according to the present invention, it is also preferable that the first storage chamber is disposed on the upper surface side and the second storage chamber is disposed on the lower surface side.

  In this preferable aspect, by disposing the second storage chamber on the lower surface side, the second storage chamber is brought close to the combustion portion where the remaining fuel gas and oxidant gas used in the power generation reaction in the cell assembly burn. be able to. Accordingly, when the reforming path in the first accommodating chamber is blocked, the second accommodating chamber into which the raw material gas flows is arranged on the lower surface side, so that the second accommodating which becomes a main component when the reforming performance is relatively deteriorated. The chamber temperature can be maintained high, and the reforming performance of the entire reformer can be enhanced.

  According to the present invention, a fuel cell device that generates power using fuel gas and oxidant gas, using a sensor for detecting a state in the reformer and a driving unit for switching a flow path in the reformer. Therefore, it is possible to provide a fuel cell device that can use all the reforming catalysts contained in the reformer well.

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 sectional drawing which shows typically the cross section along the horizontal surface of the reformer used for the fuel cell apparatus in one Embodiment of this invention. FIG. 10 is a diagram showing an initial state in which a reforming process is started by introducing a gas to be reformed in the reformer shown in FIG. 9. In the reformer shown in FIG. 9, it is a figure which shows the state which advanced the reforming process from FIG. It is a figure for demonstrating the formation aspect of the communicating hole in the modifier shown in FIG. It is a figure which shows the modification of the reformer shown in FIG. It is a figure which shows the modification of the reformer shown in FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In order to facilitate the understanding of the description, the same constituent elements in the drawings will be denoted by the same reference numerals as much as possible, and redundant description will be omitted.

  A solid oxide fuel cell which is a fuel cell device according to an embodiment of the present invention will be described. FIG. 1 is an overall configuration diagram showing a solid oxide fuel cell according to an embodiment of the present invention. As shown in FIG. 1, a solid oxide fuel cell 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. Inside the housing 6, a sealed space 8 is formed surrounded by 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.

  The fuel cell assembly 12 includes ten fuel cell stacks 14 (see FIG. 6). The fuel cell stack 14 is composed of 16 fuel cell units 16 (single cell, see FIG. 5). 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 in the sealed space 8 of the fuel cell module 2 above the power generation chamber 10 described above. In the combustion chamber 18, the remaining fuel gas that has not been used for the power generation reaction and the remaining oxidant gas (air) are combusted to generate combustion gas (exhaust gas).

  Above the combustion chamber 18 is disposed a reformer 20 that reforms the raw material gas to generate fuel gas. The reformer 20 is heated to a temperature at which the reforming reaction can be performed by the combustion heat of the combustion gas described above. Further, a heat exchanger 22 for heating an oxidant gas (power generation air) introduced from the outside by heat of the combustion gas is disposed above the reformer 20.

  The auxiliary unit 4 stores a pure water tank 26 that stores water from a water supply source 24 such as a tap water and makes it pure water with a filter, and a water flow rate adjusting unit 28 that adjusts the flow rate of water supplied from the water storage tank. (Such as a “water pump” driven by a motor). 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.

  The fuel cell module 2 is connected to a hot water production apparatus 50 to which exhaust gas is supplied. 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. 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.

  Subsequently, 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 in a state where the housing 6 of the fuel cell device according to the embodiment of the present invention is removed. In FIG. 2, in each fuel cell stack 14 constituting the fuel cell module 2, the direction in which eight fuel cell units 16 are arranged is the x-axis direction. The direction in which the fuel cell unit 16 is erected and extends is the y-axis direction, and the direction orthogonal to the x-axis and the y-axis is the z-axis direction. The x-axis, y-axis, and z-axis described in FIG. 3 and thereafter are based on the x-axis, y-axis, and z-axis in FIG.

  FIG. 3 is a cross-sectional view of the fuel cell module 2 of the fuel cell apparatus according to the embodiment of the present invention as viewed from the direction A in FIG. 4 is a cross-sectional view of the fuel cell module 2 of the fuel cell apparatus according to the embodiment of the present invention as viewed from the direction B of FIG. FIG. 6 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. FIG. 7 is a perspective view showing an evaporating mixer in the fuel cell module shown in FIG.

  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. As shown in FIG. 6, the fuel cell assembly 12 has a substantially rectangular parallelepiped shape that is longer in the A direction than in the B direction, and includes an upper surface 12a, a lower surface 12b, and a long side surface 12c extending along the A direction in FIG. 2 is provided with a short side surface 12d extending along the direction B of FIG.

  As shown in FIG. 3, 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. The evaporative mixer 58 is heated by the combustion gas to turn water into water vapor, and to mix the water vapor with fuel gas (city gas) as reformed gas and air as oxidant gas. Is. 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 evaporation mixer 58. The to-be-reformed gas supply pipe 60 introduces the to-be-reformed gas (raw material gas) and the reforming air 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 evaporative mixer 58. 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 evaporation mixer 58 to the reformer 20 through the fuel supply pipe 64. The upper end of the fuel supply pipe 66 is connected to the downstream end of the reformer 20. The lower end side 66a of the fuel supply pipe 66 enters the fuel gas tank 68 and extends in the horizontal direction.

  As shown in FIGS. 3 and 4, the fuel gas tank 68 is provided directly below the fuel cell assembly 12. A plurality of small holes (not shown) are formed along the longitudinal direction (A direction) on the outer periphery of the lower end side 66 a of the fuel supply pipe 66 inserted into the fuel gas tank 68. The fuel gas reformed by the reformer 20 is uniformly supplied in the longitudinal direction into the fuel gas tank 68 through the plurality of small holes (not shown). The fuel gas supplied to the fuel gas tank 68 is supplied into a fuel gas flow path 88 (see FIG. 5) inside the fuel cell unit 16 and rises in the fuel cell unit 16 to enter the combustion chamber 18. It has come to.

  Next, a structure for supplying power generation air to the fuel cell module 2 will be described. As shown in FIG. 2-4, above the reformer 20, along the upper surface 12 a and the short side surface 12 d (the right short side surface in FIGS. 2 and 4) of the fuel cell assembly 12 of the fuel cell module 2. A heat exchanger 22 is provided. The heat exchanger 22 is provided with a plurality of combustion gas pipes 70 and a power generation air flow path 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 introduction port 74 a of a power generation air introduction pipe 74 is attached to one end side of the lower end of the portion provided along the short side surface 12 d of the heat exchanger 22. The power generation air is introduced into the heat exchanger 22 from the power generation air flow rate adjustment unit 45 by the power generation air introduction pipe 74.

  As shown in FIGS. 4 and 8, an outlet port 72 a of the power generation air flow path 72 is formed on the other end on the upper side of the heat exchanger 22. Further, as shown in FIG. 3, power generation air supply passages 76 are formed on the outer sides of both sides in the width direction (B direction: short side surface direction) of the casing 56 of the fuel cell module 2. Power generation air is supplied from an outlet port 72 a of the power generation air flow path 72. The power generation air supply path 76 is formed along the longitudinal direction of the fuel cell assembly 12 (in the direction of the long side surface 12c). Furthermore, in order to blow out the air for power generation toward each fuel cell unit 16 of the fuel cell assembly 12 in the power generation chamber 10 at a position corresponding to the lower side of the fuel cell assembly 12 below the fuel cell assembly 12. Are formed at equal intervals along the longitudinal direction. 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 terminals 86 attached to the upper end side and the lower end side of the fuel cell unit 16 have the same structure, the inner electrode terminal 86 attached to the upper end side will be specifically described here. 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 reformer 20 will be further described with reference to FIG. FIG. 9 is a schematic cross-sectional view showing the inside of the main body 20 when the cross section of the reformer 20 is viewed in a plane including the xz plane. As described above, the reformer 20 is disposed above the combustion chamber 18, and reforms the raw material gas to generate fuel gas. The reformer 20 is heated to a temperature at which the reforming reaction can be performed by the combustion heat of the combustion gas described above. In FIG. 9, the back side (the negative side in the y-axis direction) faces the combustion chamber 18 as viewed in the drawing.

  As shown in FIG. 9, the reformer 20 has a main body 20a. The inside of the main body 20a is filled with a spherical reforming catalyst (not shown). The main body 20 a includes a distribution chamber 201, a first storage chamber 202, a second storage chamber 203, a third storage chamber 204, and an aggregation chamber 205.

  The distribution chamber 201 is a space for receiving the raw material gas and water vapor from the evaporative mixer 58 via the fuel supply pipe 64 and distributing them to the first storage chamber 202 and the second storage chamber 203. An inlet 207 is formed on the bottom surface of the distribution chamber 201. A fuel supply pipe 64 is connected to the inflow port 207. The inflow port 207 is offset from the second storage chamber 203 toward the first storage chamber 204.

  The source gas and water vapor introduced into the inflow port 207 are distributed to the first storage chamber 202 and the second storage chamber 203. A communication hole 208 is formed in the wall that divides the distribution chamber 201 and the first storage chamber 202. A communication hole 209 is formed in the wall that divides the distribution chamber 202 and the second storage chamber 203.

  FIG. 9 shows a view seen from the direction through which the communication hole 208 and the communication hole 209 are viewed. As shown in FIG. 9, the communication hole 208 is formed as a round hole having a larger diameter than the communication hole 209. The communication holes 208 are formed at seven places, while the communication holes 209 are formed at six places. Therefore, the total opening area of the communication hole 208, which is the cross-sectional area of the flow path connecting the distribution chamber 201 and the first storage chamber 202, is the flow path breakage of the flow path connecting the distribution chamber 201 and the second storage chamber 203. It is comprised so that it may become larger than the total opening area of the communication hole 209 which is an area. Therefore, at least in the initial stage, the inflow resistance of the source gas from the distribution chamber 201 to the first storage chamber 202 is smaller than the inflow resistance of the source gas from the distribution chamber 201 to the second storage chamber 203. It is easier to flow into the first storage chamber 202 than the second storage chamber 203.

  Returning to FIG. 9, the description will be continued. A third storage chamber 204 connected to both the first storage chamber 202 and the second storage chamber 203 is formed on the downstream side of the first storage chamber 202 and the second storage chamber 203. A communication hole 210 is formed in the wall that divides the first storage chamber 202 and the third storage chamber 204. A communication hole 211 is formed in the wall that divides the second storage chamber 203 and the third storage chamber 204.

  The communication hole 210 is formed as a round hole having a larger diameter than the communication hole 211. The communication holes 210 are formed at seven places, while the communication holes 211 are formed at six places. Therefore, the total opening area of the communication hole 210 which is the flow path cross-sectional area of the flow path connecting the first storage chamber 202 and the third storage chamber 204 is the flow path connecting the second storage chamber 203 and the third storage chamber 204. It is comprised so that it may become larger than the sum total opening area of the communication hole 211 which is the flow-path cross-sectional area. Therefore, at least in the initial stage, the inflow resistance of the source gas from the first storage chamber 202 to the third storage chamber 204 is smaller than the inflow resistance of the source gas from the second storage chamber 203 to the third storage chamber 204, More raw material gas flows into the third storage chamber 204 through the first storage chamber 202 than through the second storage chamber 203.

  The raw material gas flowing into the third storage chamber 204 from the first storage chamber 202 and the second storage chamber 203 is steam reformed in the flow process. Specifically, a reforming catalyst is sealed in each of the first storage chamber 202, the second storage chamber 203, and the third storage chamber 204. In the present embodiment, the reforming catalyst is formed by supporting ruthenium on a base material. The raw material gas flowing into the third storage chamber 204 from the first storage chamber 202 and the second storage chamber 203 is reformed as a hydrogen-rich fuel gas by the action of the reforming catalyst enclosed therein.

  The reformed fuel gas flows from the third storage chamber 204 into the aggregation chamber 205. A communication hole 212 and a communication hole 213 are formed in the wall that divides the third storage chamber 204 and the aggregation chamber 205. The communication hole 212 is formed at a position substantially corresponding to the downstream side of the communication hole 210 extending from the first storage chamber 202 along the outer wall of the main body 20a. The communication hole 213 is formed at a position corresponding to the downstream side where the communication hole 211 extends from the second storage chamber 203 along the outer wall of the main body portion 20a.

  The communication hole 213 is formed as a round hole having a larger diameter than the communication hole 212. The communication holes 213 are formed at seven places, while the communication holes 212 are formed at six places. Therefore, the total opening area of the communication hole 212, which is a flow path cross-sectional area of the flow path connecting the third storage chamber 204 and the aggregation chamber 205 located on the downstream side of the first storage chamber 202, is downstream of the second storage chamber 203. It is configured to be smaller than the total opening area of the communication hole 213 which is the flow path cross-sectional area of the flow path connecting the third storage chamber 204 and the aggregation chamber 205 located on the side. Therefore, at least in the initial stage, the inflow resistance of the fuel gas from the third storage chamber 204 located downstream of the first storage chamber 202 to the aggregation chamber 205 is the third resistance located downstream of the second storage chamber 203. The inflow resistance of the fuel gas from the storage chamber 204 to the aggregation chamber 205 is larger, and the fuel gas flows into the aggregation chamber 205 more through the communication hole 213 than through the communication hole 212.

  The aggregation chamber 205 is a space for sending fuel gas to the fuel gas tank 68 via the fuel supply pipe 66. An outlet 214 is formed on the bottom surface of the aggregation chamber 205. A fuel supply pipe 66 is connected to the outlet 214. The outflow port 214 is formed offset from the communication hole 212 toward the communication hole 213.

  In the case of this embodiment, a diversion passage 206 is provided in the space between the first storage chamber 202 and the second storage chamber 203 over the entire length of the first storage chamber 202 and the second storage chamber 203 in the z-axis direction. ing. A communication hole 215 is formed in the wall that divides the first storage chamber 202 and the diversion passage 206. A communication hole 216 is formed in the wall that divides the branch passage 206 and the third storage chamber 204. One communication hole 215 and one communication hole 216 are formed. The communication hole 215 and the communication hole 216 have the same diameter, and have substantially the same diameter as the communication hole 209. Therefore, at least in the initial state, the inflow resistance to the diversion passage 206 is high, and the raw material gas is configured to hardly flow into the diversion passage 206.

  Subsequently, the flow of the raw material gas and the fuel gas in the reformer 20 will be described with reference to FIGS. 10 and 11. FIG. 10 is a diagram showing the flow of the raw material gas and the fuel gas in the initial state where the raw material gas as the gas to be reformed is introduced and the reforming process is started. FIG. 11 shows the flow of the raw material gas and the fuel gas when the reforming process further proceeds from FIG.

  As shown in FIG. 10, the raw material gas introduced into the reformer 20 from the inlet 207 is introduced into the distribution chamber 201. A large amount of the source gas introduced into the distribution chamber 201 flows along the path that is most likely to flow. Accordingly, a large amount of source gas flows from the distribution chamber 201 into the first storage chamber 202, and the amount of source gas flowing from the distribution chamber 201 into the second storage chamber 203 is extremely small.

  The source gas that has flowed into the first storage chamber 202 flows into the third storage chamber 204 while being reformed by the reforming catalyst stored in the first storage chamber 202. A small amount of source gas that has flowed into the second storage chamber 203 also flows into the third storage chamber 204 while being reformed by the reforming catalyst stored in the second storage chamber 203.

  The source gas flowing into the third storage chamber 204 flows into the aggregation chamber 205 while being reformed by the reforming catalyst stored in the third storage chamber 204. In this case, the flow through the communication hole 213 is easier to flow in than the flow through the communication hole 212, so that the flow through the communication hole 213 is dominant.

  As described above, the flow of the raw material gas and the fuel gas in the reformer 20 is dominant in the initial state as follows. Most of the source gas flowing in from the inflow port 207 flows into the first storage chamber 202 via the communication hole 208. The source gas that has flowed into the first storage chamber 202 flows into the third storage chamber 204 via the communication hole 210. The raw material gas and the fuel gas that have flowed into the third storage chamber 204 flow into the collecting chamber 205 mainly through the communication hole 213 and through the communication hole 212. The fuel gas that has flowed into the collecting chamber 205 flows out from the outlet 214.

  When the reforming process further proceeds from the state shown in FIG. 10, the state shown in FIG. 11 is obtained. When the raw material gas is introduced into the reformer 20 together with water vapor and taken out as a hydrogen-rich fuel gas, carbon deposition occurs in the reforming catalyst in the reformer 20. Therefore, carbon deposition occurs along the path in which the raw material gas and the fuel gas flow in the initial state, and the flow path near the reforming catalyst is substantially narrowed.

  Carbon deposition occurs throughout the reforming catalyst in the first storage chamber 202, and the flow rates of the raw material gas and the fuel gas from the communication hole 210 to the third storage chamber via the communication hole 208 are reduced. In addition, in the reforming catalyst in the third storage chamber 204, carbon deposition occurs in the region between the communication hole 210 and the communication hole 212, and the flow rate of the fuel gas passing through the communication hole 212 is reduced.

  Therefore, as shown in FIG. 11, the flow of the raw material gas and the fuel gas flowing into the third storage chamber via the second storage chamber 203 and flowing into the aggregation chamber 205 via the communication hole 213 is dominant. It will be a thing. Furthermore, the source gas that has flowed into the first storage chamber 202 increases the pressure loss in the first storage chamber 202, and therefore flows into the branch passage 206 via the communication hole 215. The raw material gas that has flowed into the diversion passage 206 flows into the portion of the third storage chamber 204 that is located directly downstream of the second storage chamber 202 via the communication hole 216.

  When the flow of the raw material gas and the fuel gas as shown in FIG. 11 is generated, the flow passes through the region where the carbon deposition has not yet occurred, and the reforming from the raw material gas to the fuel gas is performed using the reforming catalyst that has not deteriorated. The process proceeds.

  As described above, the solid oxide fuel cell 1 as the fuel cell device according to the present embodiment is a fuel cell device that generates power using fuel gas and oxidant gas, and steam-reforms a raw material gas containing hydrocarbons. A reformer 20 that generates fuel gas and a fuel cell unit 16 that is a plurality of electrically connected tubular single cells. The fuel cell unit 16 generates fuel gas and oxidant gas. And a fuel cell assembly 12 as a cell assembly that generates electricity by reacting. The reformer 20 includes a main body 20a and a reforming catalyst containing ruthenium accommodated inside the main body 20a. The main body 20a includes an inlet 207 for introducing a raw material gas, an outlet 214 for flowing a fuel gas generated by steam reforming the raw material gas toward the fuel cell assembly 12, an inlet 207, A first storage chamber 202, a second storage chamber 203, and a third storage chamber 204 are formed between the outlet 214 and a catalyst storage section that stores the reforming catalyst.

  As described above, in the initial state, the raw material gas flows into the second storage chamber 203 and becomes the fuel gas, rather than the pressure loss when the raw material gas flows into the first storage chamber 202 and flows out as fuel gas. Thus, the pressure loss when flowing out is increased in advance. As described with reference to FIG. 11, the carbon contained in the source gas is precipitated in the first storage chamber 202, and the flow path through which the source gas passes in the vicinity of the reforming catalyst stored in the first storage chamber 202. By narrowing the flow rate and increasing the flow resistance, the inflow of the source gas into the second storage chamber 203 increases autonomously.

  In this embodiment, since the first storage chamber 202 and the second storage chamber 203 are provided, the reforming catalyst can be stored separately in the first storage chamber 202 and the second storage chamber 203, respectively. It becomes possible to use the reforming catalyst accommodated in the stepwise. Furthermore, the pressure loss when the raw material gas flows into the second storage chamber 203 and flows out as the fuel gas is larger than the pressure loss when the raw material gas flows into the first storage chamber 202 and flows out as the fuel gas. Since it is configured in advance so as to be high, the source gas can be preferentially flowed into the first storage chamber 202 without using a separate control means (see FIG. 10). Therefore, the reforming catalyst stored in the first storage chamber 202 is preferentially used, and the reformed fuel gas can be supplied to the fuel cell assembly 12.

  When steam reforming is performed using a raw material gas containing hydrocarbon, carbon deposition is a phenomenon that is unavoidable, but in this embodiment, the carbon deposition phenomenon is effectively utilized in the opposite direction, and steam reforming in the first storage chamber 202 is performed. Then, the flow path is switched to the steam reforming in the second storage chamber 203. As described with reference to FIG. 10, since the source gas is preferentially flowed into the first storage chamber 202, the first storage chamber 202 is configured such that the influence of carbon deposition appears first. For this reason, carbon contained in the raw material gas is precipitated in the first storage chamber 202, and the flow resistance increases by narrowing the flow path through which the raw material gas passes in the vicinity of the reforming catalyst stored in the first storage chamber 202. If the flow resistance increases in the first storage chamber 202, the source gas is introduced into the first storage chamber 202 later than the pressure loss when the source gas flows into the second storage chamber 203 and flows out as fuel gas. The pressure loss when flowing in and flowing out as fuel gas increases (see FIG. 11).

  In the present embodiment, the pressure loss variation due to such carbon deposition (in other words, variation in inflow resistance) is utilized, and reforming is performed via the first storage chamber 202 in accordance with the operation continuation state of the fuel cell device. The flow path is switched from the path to the reforming path via the second storage chamber 203. By switching the reforming path in this way, the reforming catalyst stored in the first storage chamber 202 and the second storage chamber 203 can be used up well, and one of the reforming paths is excessively blocked. Accordingly, it is possible to prevent the ruthenium of the reforming catalyst from separating due to excessive steam. Therefore, the unavoidable phenomenon of carbon deposition is reversed, and the entire reforming catalyst accommodated in the reformer 20 can be used up without using any special control means.

  In the present embodiment, a third storage chamber 204 connected to both the first storage chamber 202 and the second storage chamber 203 is provided, and the first storage chamber 202 and the second storage chamber 203 are provided on the inlet 207 side. The chambers 204 are respectively arranged on the outlet 214 side.

  In the reformer 20 in the present embodiment, the raw material gas is introduced from the inlet 207, while the reformed fuel gas is caused to flow out of the outlet 214, so that carbon deposition occurs on the inlet 207 side, On the outlet 214 side, catalyst deterioration due to excessive steam tends to proceed. Therefore, in the present embodiment, while the first storage chamber 202 and the second storage chamber 203 are provided on the inlet 207 side, the first storage chamber 202 and the second storage chamber 203 are provided downstream of the first storage chamber 202 and the second storage chamber 203 and on the outlet 214 side. By providing the three storage chambers 204, the progress of catalyst deterioration on the downstream side is kept in the first storage chamber 202 and the second storage chamber 203, and the catalyst stored in the third storage chamber 204 is maintained in a state where it does not deteriorate. be able to.

  In the present embodiment, a communication hole 215 (second communication port) is formed on the inlet 207 side of the communication hole 210 (first communication port) connecting the first storage chamber 202 to the third storage chamber 204, and this communication is performed. A diversion passage 206 is provided to connect the hole 215 (second communication port) and the third storage chamber 204, and the pressure loss when the raw material gas flows into the first storage chamber 202 and flows out as fuel gas is more than the pressure loss. It is configured in advance so as to increase the pressure loss when the raw material gas flows into the flow passage 206 and flows out into the third storage chamber 204 as it is. With this configuration, carbon contained in the source gas is precipitated in the first storage chamber 202, and the flow resistance through which the source gas passes in the vicinity of the reforming catalyst stored in the first storage chamber 202 is reduced. As a result, the inflow of the raw material gas into the third storage chamber 204 via the diversion passage 206 increases autonomously.

  In the present embodiment, as described above, since the source gas is preferentially flowed into the first storage chamber 202, the first storage chamber 202 is configured such that the influence of carbon deposition appears first. For this reason, carbon contained in the raw material gas is precipitated in the first storage chamber 202, and the flow resistance increases by narrowing the flow path through which the raw material gas passes in the vicinity of the reforming catalyst stored in the first storage chamber 202. If the flow resistance increases in the first storage chamber 202, the source gas is introduced into the first storage chamber 202 later than the pressure loss when the raw material gas flows into the third storage chamber 204 and flows out as fuel gas. Pressure loss when flowing in and flowing out as fuel gas increases.

  By utilizing such fluctuations in pressure loss caused by carbon deposition, the third storage chamber 204 is routed from the reforming path passing through the first storage chamber 202 via the branch flow passage 206 in accordance with the operation continuation state of the fuel cell device. The flow path is switched to the reforming path via By switching the reforming path in this way, the reforming catalyst stored in the first storage chamber 202 and the third storage chamber 204 can be used up well, and one of the reforming paths is excessively blocked. Accordingly, it is possible to prevent the ruthenium of the reforming catalyst from separating due to excessive steam. Therefore, the unavoidable phenomenon of carbon deposition is reversed, and the entire reforming catalyst accommodated in the reformer 20 can be used up without using any special control means.

  In the present embodiment, the source gas supplied from the diversion passage 206 to the third storage chamber 204 is supplied more directly below the second storage chamber 203 than directly below the first storage chamber 202. In addition, a diversion passage 206 is provided.

  As described above, when the carbon contained in the raw material gas is precipitated in the first storage chamber 202, the flow resistance increases by narrowing the flow path through which the raw material gas passes in the vicinity of the reforming catalyst stored in the first storage chamber 202. Also, it is assumed that the flow path leading to the third storage chamber 204 without passing through the diversion path 206 is also affected by the carbon deposition. Accordingly, the source gas supplied from the diversion passage 206 to the third storage chamber 204 is distributed so that more source gas is supplied directly below the downstream side of the second storage chamber 203 than directly below the downstream side of the first storage chamber 202. By providing the path 206, the source gas can be supplied directly below the downstream side of the second storage chamber 203 where the influence of carbon deposition is assumed to be smaller. Therefore, the reforming catalyst stored in the third storage chamber 204 can be used up more effectively.

  In this embodiment, the inlet 207 is formed closer to the first storage chamber 202 than the second storage chamber 203, and the inlet 214 is formed closer to the second storage chamber 203 than the first storage chamber 202. Has been.

  By forming the inflow port 207 close to the first storage chamber 202, the source gas can be reliably introduced into the first storage chamber 202 at the beginning of operation. On the other hand, the flow of the reformed fuel gas is discharged from the second storage chamber 203 side by forming the outlet 214 close to the second storage chamber 203, and the downstream of the first storage chamber 202 The flow is relatively reduced. Therefore, by initially using the reforming catalyst stored in the first storage chamber 202 in an intensive manner, the deterioration of the reforming catalyst downstream of the first storage chamber 202 is distributed to the second storage chamber 203 side. The reforming performance of the entire reformer 20 can be improved.

  In the present embodiment, the inlet 207 and the outlet 214 are formed on the lower surface of the main body portion 20a facing the fuel cell assembly 12, and the first storage chamber 202 and the second storage chamber 203 are connected to the lower surface of the main body portion 20a. It is also a preferable aspect to arrange them so as to line up and down along the direction from the top to the top. FIG. 13 shows an example in which the reformer 20B is configured by arranging the first storage chamber 202 on the lower surface side and deforming the main body portion 20a into the main body portion 20b. FIG. 14 shows an example in which the second storage chamber 203 is disposed on the lower surface side, and the reformer 20C is configured by deforming the main body 20a to the main body 20c.

  In these modified examples, since the inlet 207 and the outlet 214 are formed on the lower surface of the main body portions 20b and 20c facing the fuel cell assembly 12, the source gas flows from the lower surface of the main body portions 20b and 20c to the main body portion. The reformed fuel gas flows into 20b and 20c and flows out from the lower surfaces of the main body portions 20b and 20c. The first storage chamber 202 and the second storage chamber 203 are moved up and down along the direction from the lower surface of the main body portions 20b and 20c to the upper surface while adopting the configuration in which the raw material gas flows in from the lower surface of the main body portions 20b and 20c. By arranging so as to line up with each other, the raw material gas flows preferentially into the reforming path arranged on the lower surface side. With such arrangement, a difference is provided in the ease of flow of the source gas, so that the difference in pressure loss between the first storage chamber 202 and the second storage chamber 203 can be reduced. Thus, switching in a state where one reforming path is not excessively blocked is possible.

  In the modification shown in FIG. 13, the ease of inflow of the source gas is improved by arranging the first storage chamber 202 on the lower surface side, while the source gas flows in by arranging the second storage chamber 203 on the upper surface side. It is configured to be difficult. Accordingly, at the stage where the reforming path in the first storage chamber 202 is not blocked, the flow of the raw material gas into the second storage chamber 203 is suppressed, and the reforming path in the first storage chamber 202 is blocked. The material gas is configured to flow into the second storage chamber 203 later. By such a device in the configuration, the transition of the raw material gas into the second storage chamber 203 is made gradual, and the reforming in the second storage chamber 203 after the reforming catalyst in the first storage chamber 202 is deteriorated. The reforming performance by the quality catalyst can be ensured, and the reforming performance of the entire reformer can be enhanced.

  In the modification shown in FIG. 14, by disposing the second storage chamber 203 on the lower surface side, in the combustion section where the remaining fuel gas and oxidant gas used for the power generation reaction in the fuel cell assembly 12 burns, The 2nd storage chamber 203 can be made to adjoin. Therefore, when the reforming path in the first storage chamber 202 is blocked, the second storage chamber 203 into which the raw material gas flows is arranged on the lower surface side, so that the second main chamber 203 is mainly used when the reforming performance is relatively lowered. The temperature of the two storage chambers 203 can be maintained high, and the reforming performance of the entire reformer can be enhanced.

  The embodiments of the present invention have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. In other words, those specific examples that have been appropriately modified by those skilled in the art are also included in the scope of the present invention as long as they have the characteristics of the present invention. For example, the elements included in each of the specific examples described above and their arrangement, materials, conditions, shapes, sizes, and the like are not limited to those illustrated, but can be changed as appropriate. Moreover, each element with which each embodiment mentioned above is provided can be combined as long as technically possible, and the combination of these is also included in the scope of the present invention as long as it includes the features of the present invention.

1: Solid electrolyte fuel cell 2: Fuel cell module 4: Auxiliary unit 6: Housing 8: Sealed space 10: Power generation chamber 12: Fuel cell assembly 12a: Upper surface 12b: Lower surface 12c: Long side surface 12d: Short side Side 14: Fuel cell stack 16: Fuel cell unit 18: Combustion chamber 20: Reformer 22: Heat exchanger 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 40; air supply source 42: electromagnetic valve 44: reforming air flow rate adjustment unit 45: power generation air flow rate adjustment unit 46: first heater 48: second heater 50 : Hot water production device 52: Control box 54: Inverter 56: Casing 58: Evaporative mixer 60: Reformed gas supply pipe 62: Water supply pipe 64: Fuel supply pipe 66: Fuel supply Pipe 66a: Lower end side 68: Fuel gas tank 70: Combustion gas pipe 72: Power generation air flow path 72a: Outlet port 74: Power generation air introduction pipe 74a: Inlet 76: Power generation air supply path 78: Air outlet 80: Combustion Gas exhaust chamber 82: Combustion gas exhaust pipe 84: Fuel cell 86: Inner electrode terminal 88: Fuel gas flow path 90: Inner electrode layer 90a: Upper part 90b: Outer peripheral surface 90c: Upper end surface 92: Outer electrode layer 94: Electrolyte layer 96: Sealing material 98: Fuel gas flow path 20a: Main body 201: Distribution chamber 202: First storage chamber 203: Second storage chamber 204: Third storage chamber 205: Aggregation chamber 206: Dividing passage 207: Inlet 208 : Communication hole 209: Communication hole 210: Communication hole 211: Communication hole 212: Communication hole 213: Communication hole 214: Outlet 215: Communication hole 216: Communication hole

Claims (8)

A fuel cell device that generates power with fuel gas and oxidant gas,
A reformer that produces a fuel gas by steam reforming a raw material gas containing hydrocarbon;
A plurality of electrically connected tubular single cells, and a cell assembly in which fuel gas and oxidant gas react with each other to generate electric power.
The reformer has a main body part, and a reforming catalyst containing ruthenium accommodated in the main body part,
The main body includes an inlet for introducing a raw material gas, an outlet for flowing a fuel gas generated by steam reforming the raw material gas toward the cell assembly, and the inlet and the outlet. And a catalyst housing part in which the reforming catalyst is housed,
The catalyst housing portion has a first housing chamber and a second housing chamber,
The pressure loss when the raw material gas flows into the second storage chamber and flows out as fuel gas is higher than the pressure loss when the raw material gas flows into the first storage chamber and flows out as fuel gas. Pre-configured as
The carbon contained in the source gas is precipitated in the first storage chamber, and the flow resistance increases by narrowing the flow path through which the source gas passes in the vicinity of the reforming catalyst stored in the first storage chamber, thereby increasing the flow resistance. A fuel cell device configured to autonomously increase the inflow of the raw material gas into the storage chamber. The inflow port and the outflow port are formed on the lower surface of the main body portion facing the cell assembly,
2. The fuel cell device according to claim 1, wherein the first storage chamber and the second storage chamber are arranged so as to be aligned vertically along a direction from the lower surface to the upper surface of the main body portion.   The fuel cell device according to claim 2, wherein the first storage chamber is disposed on the lower surface side, and the second storage chamber is disposed on the upper surface side. The catalyst storage unit further includes a third storage chamber connected to both the first storage chamber and the second storage chamber,
2. The fuel cell device according to claim 1, wherein the first storage chamber and the second storage chamber are disposed on the inlet side, and the third storage chamber is disposed on the outlet side. A second communication port is formed on the inflow side from the first communication port connecting the first storage chamber to the third storage chamber, and a branch passage connecting the second communication port and the third storage chamber is provided. Provided,
The pressure loss when the raw material gas flows into the branch passage and flows out into the third storage chamber is higher than the pressure loss when the raw material gas flows into the first storage chamber and flows out as fuel gas. Pre-configured to be
In the first storage chamber, carbon contained in the raw material gas is precipitated, and the flow resistance is increased by narrowing the flow path through which the raw material gas passes in the vicinity of the reforming catalyst stored in the first storage chamber. The fuel cell device according to claim 4, wherein the inflow of the raw material gas into the third storage chamber via the path increases autonomously.   The source gas supplied from the branch passage to the third storage chamber is supplied more directly to the downstream side of the second storage chamber than to the downstream side of the first storage chamber. The fuel cell device according to claim 5, wherein the fuel cell device is provided. The inflow port is formed closer to the first storage chamber than the second storage chamber, and the outflow port is formed closer to the second storage chamber than the first storage chamber. The fuel cell device according to claim 1.   The fuel cell device according to claim 2, wherein the first storage chamber is disposed on the upper surface side, and the second storage chamber is disposed on the lower surface side.

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