JP6537015B2 - Solid oxide fuel cell device - Google Patents

Description

  The present invention relates to a solid oxide fuel cell device provided with a plurality of fuel cells that generate electric power by a reaction between a fuel gas obtained by reforming a raw fuel and an oxygen-containing gas.

  BACKGROUND ART In recent years, solid oxide fuel cells have been developed as fuel cell devices installed in apartment buildings, commercial facilities, and the like. Solid oxide fuel cell (SOFC) uses an oxide ion conductive solid electrolyte as an electrolyte, with electrodes attached on both sides, supplying fuel gas to one side, and air to the other side It is a fuel cell that generates an electric power by causing an electric power generation reaction under high temperature by supplying an oxygen-containing gas such as oxygen and the like.

□ Therefore, heat can be recovered from high temperature exhaust heat and used for hot water supply. That is, it is possible to increase the temperature of the hot water stored in the circulating water and the hot water storage tank which recovers heat from the exhaust heat using high temperature exhaust heat, and to reduce the capacity of the hot water storage tank for storing hot and cold water. Fuel cell devices are attracting attention as cogeneration systems combined with these hot water storage and hot water supply systems, as a method for realizing so-called miniaturization and cost reduction.

  Solid oxide fuel cell equipment installed in each residential department or office in a residential complex with multiple residential areas such as conventional condominiums, or in a retail facility such as a store or office, tenant building including tenants, office buildings, etc. In addition, it is considered to generate electric power by each solid oxide fuel cell device according to each demand power, and to utilize the electric power. However, when installing a solid oxide fuel cell device in an apartment house or a commercial facility, an installation space is required for each living unit and each office. In particular, since the installation space of the solid oxide fuel cell device is narrow and limited, the veranda, the balcony and the pipe shaft (also referred to as a pipe space) of an apartment complex can be effectively installed in a small shape The needs are extremely high.

  Here, a solid oxide fuel cell (hereinafter referred to as a fuel cell) used in a solid oxide fuel cell apparatus has an operating temperature of, for example, 600 ° C. to 1000 ° C., which is higher than that of fuel cells of other types. It is. For this reason, the fuel cell stack is configured by arranging a plurality of fuel cells so that the fuel cells can be heated using the heat generation of the fuel cells themselves generated by the power generation reaction.

  In JP-A-2014-167935 (Patent Document 1), a plurality of cylindrical fuel cells arranged upright on the upper surface of a fuel cell gas tank and a plurality of fuel cells disposed in a module container are disposed on top of the plurality of fuel cells. The reformer is described. The reformer is internally charged with a reforming catalyst, and the raw fuel gas is reformed into a hydrogen-rich fuel gas by catalytic reaction using the supplied raw fuel gas and water. The fuel gas generated by the fuel gas supply pipe connecting the reformer and the fuel manifold is supplied to the inside of the fuel manifold and then supplied to the internal passages provided in the plurality of cells, whereby the plurality of fuels are supplied. Electric power is generated by a power generation reaction with the oxygen-containing gas supplied to the outer surface of the battery cell. On the other hand, unreacted fuel gas (off gas) that does not contribute to power generation is discharged from the upper end of the fuel cell, and is ignited and burned in a combustion unit provided above the fuel cell. By heating the upper reformer, the combustion exhaust gas generated thereby makes the inside of the reformer high temperature to induce and sustain the reforming reaction required for the generation of the fuel gas.

  Here, in Patent Document 1, one of the fuel gas supply pipes for supplying the reformed fuel gas from the reformer to the fuel gas supply pipe is connected to the downstream side surface of the reformer, and is curved near the side surface. It is disclosed that it is pulled down vertically and the other is curved near the side of the fuel manifold and connected to the fuel gas tank.

JP, 2014-167935, A

  The fuel gas supply pipe disclosed in Patent Document 1 is configured to connect the downstream side of the reformer with the fuel reformer positioned in the module container and the fuel manifold positioned below in a simple configuration. A pipe extending vertically with the upstream of the manifold is used. On the other hand, since the fuel gas supply pipe is a side surface of the reformer and the fuel manifold, the upper end and the lower end of the fuel gas supply pipe are vertically connected to these side surfaces. It is necessary to make the

  However, although the fuel cell device, particularly the solid oxide fuel cell device, operates under high temperature conditions as described above, it is structurally difficult to make the temperature inside the module container uniform under all conditions. In particular, significant temperature distribution occurs when the fuel cell device is started and operated. For this reason, thermal stress due to thermal expansion or the like of the module container and the metal parts constituting the inside thereof is generated. For example, when the reformer inside the module container is thermally expanded compared to the fuel manifold due to the temperature difference in the module container, the thermal stress generated thereby may fix the fuel gas supply pipe in the fuel gas supply pipe, and Concentrate on the curved portion near the side of the fuel manifold. The concentration of the thermal stress partially or instantaneously degrades or breaks the fuel gas supply pipe due to the accumulation thereof, and reduces or eliminates the airtightness inside the fuel gas supply pipe. Therefore, configuring the fuel gas supply pipe with two pipes and arranging the joint portion in the curved portion in the vicinity of the side surface of the reformer and the fuel manifold is extremely effective in ensuring airtightness by concentration of thermal stress. difficult.

  Therefore, the fuel gas supply pipe disclosed in Patent Document 1 reduces the concentration of thermal stress that may occur under high temperature conditions by curving so as to draw a large arc in the vicinity of the side surfaces of the reformer and the fuel manifold. doing. However, in this case, the space in the module container in which the fuel gas supply pipe is installed is inevitably large, which has been a factor that hinders the miniaturization of the fuel cell device.

  From the above, in order to realize the miniaturization of the fuel cell device, it is strongly desired to make the space for holding the fuel gas supply pipe in the module container small or thin. On the other hand, in the module container which is in a high temperature state and has a temperature distribution, the occurrence of thermal stress due to thermal expansion of the constituent metal parts is inevitable. Therefore, the present invention relates to a fuel cell apparatus provided with a fuel gas supply pipe which can be installed in a narrow area while securing air tightness by preventing breakage and deterioration due to concentration of thermal stress. . Furthermore, it is an object to realize this at low cost along with downsizing.

Therefore, the present invention is a solid oxide fuel cell device provided with a plurality of fuel cells that generate electric power by a reaction between a fuel gas obtained by reforming raw fuel and an oxygen-containing gas, which accommodates a plurality of fuel cells. Module container, an oxygen-containing gas supply pipe for supplying an oxygen-containing gas to the surface of the fuel cell from the outside of the module container, an off gas discharged from the upper end of the fuel cell and an oxygen-containing gas in the module container And a reformer above the combustion unit, which is heated by the exhaust gas generated in the combustion unit and reforms the raw fuel into fuel gas, and supplies the raw fuel to the reformer from the outside of the module container Source fuel gas supply pipe, a fuel manifold for supplying the fuel gas reformed in the reformer to the internal flow channels of a plurality of fuel cells erected on the upper surface, and a lower end fixed to the fuel manifold A fuel gas supply pipe for supplying fuel gas in the reformer to the inside of the fuel manifold, the fuel gas supply pipe having a vertically-shaped portion extending vertically toward the reformer, and A stress relieving shape portion and a vertical shape portion that are curved so as to be inserted horizontally in the manifold and relieve local concentration of thermal stress, and are corrected by correcting the bending direction of the stress relieving shape portion The vertical shape portion, the stress relief shape portion and the direction correction shape portion are formed by one tubular member , and the module container has a main body including an upper surface, a bottom surface and two opposite side surfaces, and the other. The fuel gas supply pipe is in close proximity to one of the lids, and one of the lids in proximity to the fuel gas supply pipe is supplied with fuel gas. Close to the tube Oxygen-containing gas shield plate is provided in a portion.

  In the solid oxide fuel cell device, in order to realize the miniaturization of the module container, the space for containing the fuel gas supply pipe for supplying the reformed fuel gas from the reformer to the fuel manifold is also narrowed. It is required to do. Conventionally, since the fuel cell supply pipe hanging from the reformer needs to be inserted horizontally into the fuel manifold located below, it is necessary to curve horizontally from the vertical direction in the vicinity of the fuel manifold .

  By the way, the heat self-supporting SOFC module burns off gas at the upper end of the fuel cell stack and heats the reformer above, so that the upper part of the module container is hot and the lower part is relatively cold. It has a temperature distribution. For this reason, thermal stress is applied to various places from the difference in thermal expansion of each component metal part of the module between the upper side and the lower side of the module container, and this is no exception for the fuel supply piping. For example, when the reformer thermally expands in the horizontal direction due to the temperature distribution in the upper and lower parts in the module container, the fuel gas supply pipe fixed to the reformer concentrates stress at the junction with the fuel manifold which is the fixed part It will For this reason, stress concentrates on the fuel gas supply pipe in the vicinity of the fuel manifold which is curved in the vertical direction from the horizontal direction, and deterioration and damage are induced by its accumulation.

  In order to prevent this, the curved part of the fuel gas supply pipe near the fuel manifold is widely taken, that is, the radius of bending is increased to disperse the stress so as to relieve one point concentration of the thermal stress and improve the durability. It has been taken. However, this increases the space for accommodating the fuel gas supply pipe, which has been a factor that hinders the miniaturization of the module container. It is conceivable to separately insert and add a stress relieving member such as a bellows or the like to a part of the fuel gas supply pipe in order to relieve the thermal stress. However, when other members are connected to a part of the fuel gas supply pipe, the risk of damage due to thermal stress is increased at the joint, and the manufacturing cost of the fuel gas supply pipe is increased. Absent.

  Therefore, in the present invention, the fuel gas supply pipe has a vertical shape portion, a stress relief shape portion, and a direction correction shape portion, that is, a shape in which the fuel gas supply pipe consisting of one member is bent once and turned back Do. As a result, by using only one tubular member without adding other components such as the bellows member, it is possible to achieve both the alleviation of the applied thermal stress and the reduction of the storage space. As a result, it is possible to realize an inexpensive and compact fuel cell device that is highly durable.

  Although the fuel gas supply pipe according to the present invention is formed by one tubular member, the fuel gas supply pipe includes a vertical shape portion, a stress relief shape portion, and a direction correction shape portion in one tubular member. It is meant to have, and it is an object of the present invention to narrow the storage area of the fuel gas supply pipe while reducing the stress of the curved portion. Therefore, another fuel gas supply pipe fixed to the reformer is further provided above the vertically shaped portion of the fuel gas supply pipe, and the plurality of fuel cells, the fuel manifold and the fuel gas supply pipe are integrated. A configuration in which a fuel gas supply pipe and another fuel gas supply pipe are connected by a joining member such as a union joint after inserting a so-called fuel cell stack into a module container is also included in the present invention.

  In the present invention, preferably, the direction correction shape portion is disposed to be inclined toward the fuel cell in the module container in the vertical direction.

  By tilting the direction correction shape portion toward the fuel cell in the module container in the vertical direction, the shape of the fuel gas supply pipe is curved so that the lower end fixed to the fuel manifold has an acute angle. However, the upper side can be shaped to extend vertically toward the reformer. With such a shape, it is possible to widen the curved region at the lower end with respect to the shape of the fuel gas supply pipe that bends the lower end substantially at right angles, so 1 of the thermal stress on the fuel gas supply pipe It is possible to ease the concentration. At the same time, since the curved shape leads to the vertically extending vertical portion by the direction correction shape portion, the storage space of the fuel gas supply pipe can be reduced by returning the curved shape trajectory expanded by the stress relief shape portion to the vertical direction. It can be narrowed.

  Further, in the present invention, it is preferable that the stress relief shape portion has a bending radius of curvature larger than 2D with respect to the outer diameter D of the fuel gas supply pipe.

  By making the degree of curvature of the stress relaxation shape portion larger than the minimum bending radius 2D (twice the outer diameter D), the concentration of thermal stress is alleviated without impairing the strength of the fuel gas supply pipe to supply the fuel gas The durability of the tube can be improved. Further, in the insertion portion of the fuel manifold, the roundness of the cross-sectional shape of the fuel gas supply pipe can be maintained, and airtightness can be secured.

  By uniformly guiding the oxygen-containing gas supplied to the cell stack housed in the module container to the combustion unit, it is possible to uniformly supply the oxygen-containing gas to the cell surface and stabilize the heat balance in the combustion unit. Become. However, since the fuel gas supply pipe is arranged, the flow distribution of the oxygen-containing gas is different between the side surface of the cell stack where the fuel gas supply pipe is arranged and the side surface opposite to this. In order to eliminate this, on the side surface of the cell stack where the fuel gas supply pipe is conventionally disposed, the oxygen-containing gas shielding plate is provided between the fuel gas supply pipe and the cell stack The flow condition was uniformed by approximating the gas flow state. However, in the case of miniaturizing the fuel cell module, in addition to securing a space for installing the oxygen-containing gas shielding plate, assembly work becomes difficult. On the other hand, the influence of the flow distribution of the oxygen-containing gas becomes more remarkable as the height of the module is reduced along with the reduction in size.

  Therefore, by directly installing the shielding plate on the lid, it is possible to maintain uniformity in the flow distribution of the oxygen-containing gas, and eliminate the decrease in workability associated with the downsizing.

  According to the present invention, it is possible to provide a fuel cell apparatus provided with a fuel gas supply pipe which can be installed in a narrow area while preventing breakage and deterioration due to concentration of thermal stress to ensure air tightness. Furthermore, this can be realized at low cost along with miniaturization.

1 is a side cross-sectional view of a solid oxide fuel cell device according to an embodiment of the present invention. It is sectional drawing in alignment with XX of FIG. It is side surface sectional drawing which shows the flow of the fuel gas in the solid oxide fuel cell apparatus by embodiment of this invention. FIG. 4A is a side cross-sectional view showing a case where the fuel gas supply pipe bends gently, and FIG. 4B is a side cross sectional view showing the case where the fuel gas supply pipe bends at a right angle. FIG. 1 is an entire configuration view showing a solid oxide fuel cell device according to an embodiment of the present invention. FIG. 1 is a side sectional view showing a fuel cell module of a solid oxide fuel cell device according to an embodiment of the present invention. It is sectional drawing along the III-III line of FIG. FIG. 1 is an exploded perspective view of a module container and an air passage cover of a solid oxide fuel cell device according to an embodiment of the present invention. FIG. 1 is a partial cross-sectional view showing a fuel cell unit of a solid oxide fuel cell device according to an embodiment of the present invention. FIG. 1 is a perspective view showing a fuel cell stack of a solid oxide fuel cell device according to one embodiment of the present invention. It is a side sectional view showing a fuel cell module for explaining a flow of gas in a fuel cell module of a solid oxide fuel cell device according to one embodiment of the present invention. FIG. 7 is a cross-sectional view of the fuel cell module along the line III-III of FIG. 6 for illustrating gas flow in the fuel cell module of the solid oxide fuel cell device according to one embodiment of the present invention. FIG. 1 is a partial cross-sectional view of the top of a fuel cell module of a solid oxide fuel cell device according to an embodiment of the present invention. It is explanatory drawing of the exhaust gas which flows around the reformer of the solid oxide fuel cell apparatus by one Example of this invention. FIG. 2 is a side cross-sectional perspective view of a reformer and an exhaust gas guiding member of a solid oxide fuel cell device according to one embodiment of the present invention. FIG. 2 is a front cross-sectional perspective view of the reformer and the exhaust gas guiding member of the solid oxide fuel cell device according to one embodiment of the present invention. It is explanatory drawing of the exhaust gas which flows through the through-hole of the reformer of the solid oxide fuel cell apparatus by one Example of this invention. It is front sectional drawing of the heat exchange part of the solid oxide fuel cell apparatus by one Example of this invention. It is explanatory drawing of the connection part of the top plate of the module container of a solid oxide fuel cell apparatus by one Example of this invention, and an exhaust pipe. It is explanatory drawing of the air supply path for electric power generation on the top plate of the module container of the solid oxide fuel cell apparatus by one Example of this invention. It is explanatory drawing of the exhaust passage under the top plate of the module container of the solid oxide fuel cell apparatus by one Example of this invention. FIG. 1 is a perspective view of a plate fin of a solid oxide fuel cell device according to an embodiment of the present invention. It is explanatory drawing of the plate fin arrange | positioned between the side plate of the air passage cover of the solid oxide fuel cell apparatus by one Example of this invention, and the side plate of a module container. It is explanatory drawing of the cover body of the module container of the solid oxide fuel cell apparatus by one Example of this invention.

  Next, a solid oxide fuel cell device according to an embodiment of the present invention will be described using FIGS. 1 to 4.

  FIG. 1 is a side cross-sectional view showing a solid oxide fuel cell device (hereinafter referred to as a fuel cell module 1000) according to an embodiment of the present invention, and FIG. 2 is a cross section along the X-X cross section in FIG. FIG. FIG. 3 is a side cross-sectional view showing the flow of the fuel gas (the gas after being reformed by the reformer 1002) of the fuel cell module 1000. As shown in FIG. 1 and FIG. 2, the fuel cell module 1000 includes a module container 1001, and a reformer 1002, a plurality of solid oxide fuel cells 1004, a fuel manifold 1005, a fuel in the module container 1001. A gas supply pipe 1010 is provided.

  The inside of the reformer 1002 is filled with a reforming catalyst, and the raw fuel gas is supplied by a catalytic reaction using the raw fuel gas and steam supplied from the raw fuel gas supply pipe (not shown) into the reformer. Reform to hydrogen rich fuel gas. The fuel gas supply pipe 1010 is connected to the bottom surface of the reformer 1002 and is connected to and fixed to a fuel manifold 1005 provided below the inside of the module container 1001. Thereby, the fuel gas reformed by the reformer 1002 passes through the fuel gas supply pipe 1010 and is supplied to the inside of the fuel manifold 1005 (see FIG. 3). A plurality of fuel cells 1004 are erected and fixed on the top surface of the fuel manifold 1005. As will be described in detail later, one or more internal passages are formed in the fuel cell 1004, and the fuel gas supplied from the fuel manifold 1005 passes through the internal passages. The fuel cell 1004 has a fuel electrode provided on the inner side via a solid electrolyte and an air electrode provided on the outer side, and a fuel gas supplied to the fuel electrode by an internal passage, and an outer side of the fuel cell 1004. Power is generated by the oxygen-containing gas supplied from the Further, the fuel gas (off gas) remaining after power generation is discharged from the upper end of the fuel cell 1004, mixed with the surrounding oxygen-containing gas and burned in the combustion unit 1003 above the fuel cell 1004, to generate combustion exhaust gas Be done. The generated combustion gas heats the reformer 1002 to raise the temperature of the reforming catalyst with the internal temperature of the reformer 1002 at a high temperature, and the raw fuel gas can be reformed to the fuel gas. Transition to the next state and hold it again.

  Here, the fuel cell 1004 is illustrated as a cylindrical shape, but is not limited to this and may be a flat plate shape or a flat cylindrical shape. By appropriately selecting the shape of the fuel cell 1004, the temperature distribution in the module container 1001, the size of the module container 1001, and the like can be freely adjusted.

  By the way, in order to realize the miniaturization of the fuel cell module 1000 described above, a space for accommodating the fuel gas supply pipe 1010 for supplying the reformed fuel gas from the reformer 1002 to the fuel manifold 1005 (fuel gas supply It is effective to narrow the tube housing portion 1014). Conventionally, since the fuel gas supply pipe hanging from the reformer 1002 needs to be inserted horizontally into the fuel manifold 1005 located below, it must be curved horizontally from the vertical direction at least in the vicinity of the fuel manifold 1005. is necessary.

  On the other hand, the fuel cell module 1000 of the thermal self-supporting type burns off gas at the upper end of the fuel cell 1004 to heat the reformer 1002 above it, so that the upper part of the module container 1001 is hot and the lower part is compared It has temperature distribution so that it becomes low temperature. For this reason, thermal stress is applied to various places due to the thermal expansion difference of each component metal part of the module above and below the module container 1001, and this is no exception for the fuel supply piping. For example, as shown in FIG. 4A, when the reformer 1002 thermally expands in the horizontal direction due to the temperature distribution in the upper and lower portions of the module container 1001, the fuel gas supply pipe fixed with the reformer 1002 is reformed Due to the thermal expansion displacement of the vessel 1002 in the direction of the arrow, stress is concentrated on the joint portion with the fuel manifold 1005 which is the fixed portion. For this reason, stress concentrates on the fuel gas supply pipe 2010 in the vicinity of the fuel manifold 1005 which curves in the horizontal direction from the vertical direction, and deterioration and damage are induced by the accumulation.

  In order to prevent this, as shown in FIG. 4B, the curved portion of the fuel gas supply pipe 3010 in the vicinity of the fuel manifold 1005 is widely taken, that is, the bending radius is increased to alleviate one point concentration of thermal stress. Measures to disperse the stress and improve the durability have been taken. However, the space for accommodating the fuel gas supply pipe 3010 (the fuel gas supply pipe accommodation portion 1014) is expanded by this, which has been a factor that hinders the miniaturization of the module container 1001. It is conceivable to separately insert and add a stress relieving member such as a bellows or the like to a part of the fuel gas supply pipe in order to relieve the thermal stress. However, when other members are connected to a part of the fuel gas supply pipe, the risk of damage due to thermal stress is increased at the joint, and the manufacturing cost of the fuel gas supply pipe is increased. Absent.

  Therefore, in the present invention, as shown in FIGS. 1 and 2, the lower end of the fuel gas supply pipe 1010 is fixed to the fuel manifold 1005, and the fuel gas in the reformer 1002 is supplied to the inside of the fuel manifold 1005. Have. In addition, the fuel gas supply pipe 1010 is curved so as to be inserted horizontally into the fuel manifold 1005 and a vertically-shaped portion 1011 extending vertically toward the reformer 1002 and relieves local concentration of thermal stress. Vertical shape portion 1013 having a stress relief shape portion 1013 and a direction correction shape portion 1012 connecting the stress relief shape portion 1013 and the vertical shape portion 1011 by correcting the bending direction of the stress relief shape portion; The stress relief shape portion 1013 and the direction correction shape portion 1012 are formed by one tubular member. In other words, the fuel gas supply pipe of the present invention is formed by one tubular member, and is once bent and turned back.

  That is, the fuel gas supply pipe 1010 in the present invention is connected to the conventional vertical portion extending vertically from the reformer 1002 and the side surface of the fuel manifold 1005 located below the reformer 1002. Instead of the configuration of the curved portion, a direction correction shape portion 1012 and a stress relaxation shape portion 1013 are formed at the lower end of the vertical shape portion 1011.

  The stress relaxation portion 1013 is similar to the conventional curved structure in that the fuel gas supply pipe 1010 is curved in order to connect to the side surface of the fuel manifold 1005 in the horizontal direction, but the thermal stress under high temperature conditions is localized to the curved portion. It is different in that the thermal stress is widely dispersed so as not to be concentrated. Specifically, the degree of curvature may be loosened, and for example, the radius of curvature of the curvature may be larger than 2D with respect to the outer diameter D of the fuel gas supply pipe. As described above, by providing the stress relaxation portion 1013 in the vicinity of the connection portion with the fuel manifold 1005 in the fuel gas supply pipe 1010, the thermal stress concentration due to the thermal expansion occurring at high temperature is alleviated, and the fuel manifold 1005 of the fuel gas supply pipe 1010 is It is possible to prevent local damage and deterioration in the fixed part.

  However, as in the conventional example shown in FIG. 4B, the shape for the purpose of dispersion relaxation of the thermal stress as described above is to miniaturize the fuel cell module 1000 by expanding the fuel gas supply pipe housing portion 1014. To prevent Therefore, as shown in FIG. 1, the fuel gas supply pipe 1010 according to the present invention has a direction correction shape portion 1012 in addition to the stress relaxation shape portion 1013. The direction correction shape portion 1012 connects the trajectory of the piping axis directed outward of the fuel cell module 1000 by the stress relaxation shape portion 1013 to the lower end of the vertical system upper portion 1011 extending downward from the reformer 1002 in the vertical direction. To correct the direction. Therefore, as a result, the fuel gas supply pipe 1010 is bent once by the stress relief portion shape portion 1013 from the lower end to the upper end and is rewound back to be positioned at the lower end of the vertical shape portion 1011 by the direction correction shape portion 1012 It becomes a shape.

  The fuel gas supply pipe 1010 according to the present invention is formed by forming the vertical shape portion 1011, the stress relief shape portion 1013 and the direction correction shape portion 1012 into one tubular member. The configuration is achieved by twice bending the pipe for forming the curved portion of the stress relief shape portion 1013 and the pipe for forming the shape transitioning from the direction correction shape portion 1012 to the vertical shape portion 1011. It is possible to form using one piping.

  For this reason, compared with a fuel gas supply pipe having a curved structure formed by joining two or more pipes by joining means such as welding, it is significantly superior in airtightness. In particular, the cross-sectional shape of the fuel gas supply pipe 1010 at the connection point to the fuel manifold 1005 is set by appropriately setting the degree of bending such as making the bending radius of curvature larger than 2D with respect to the outer diameter D of the fuel gas supply pipe. Since it can be maintained in a true circle, airtightness can be secured. Furthermore, it is obvious that the manufacturing process is simple and the manufacturing cost is excellent because the pipe is only bent to a predetermined degree.

  Although the fuel gas supply pipe 1010 according to the present invention is formed by one tubular member, the fuel gas supply pipe is a vertical member 1011, a stress relief shape portion 1013, and a direction correction in one tubular member. It is meant to have the shape portion 1012 and aims to narrow the storage area of the fuel gas supply pipe 1010 while relaxing the stress of the curved portion. Therefore, another fuel gas supply pipe (not shown) fixed to the reformer 1002 is further provided above the vertical shaped portion of the fuel gas supply pipe 1010, and a plurality of fuel cells 1004 and a fuel manifold 1005 are provided. The present invention also relates to a configuration in which a fuel gas supply pipe 1010 and another fuel gas supply pipe are connected by a joining member such as a union joint after inserting a so-called fuel cell stack integrated with the fuel gas supply pipe 1010 into a module container 1001. It is included in

  Further, in FIG. 1, the fuel gas supply pipe 1010 is inserted into the inside of the fuel manifold 1005, and extends horizontally in the inside of the fuel manifold 1005. The fuel gas supply pipe 1010 extending into the fuel manifold 1005 has a plurality of fuel supply holes 1006 at the bottom, and the fuel gas supplied from the reformer 1002 is transferred to the fuel manifold 1005 through the fuel supply holes 1006. Supply toward the bottom. As a result, the fuel gas that has collided with the bottom surface of the fuel manifold 1005 is a hydrogen-rich gas, and is dispersed and ascends, thereby making it possible to each of the plurality of fuel cells provided on the top surface of the fuel manifold Thus, it is possible to supply a fuel gas of uniform concentration.

  However, the fuel gas supply pipe 1010 is not necessarily inserted into the fuel manifold 1005, and for example, the lower end of the fuel gas supply pipe 1010 may be positioned on the side surface of the fuel manifold 1005.

  As described above, by using only one tubular member, it is possible to achieve both the alleviation of the applied thermal stress and the reduction of the storage space. As a result, it is possible to realize an inexpensive and compact fuel cell device that is highly durable.

  Next, an embodiment of the present invention will be described with reference to the attached drawings.

  FIG. 5 is a whole block diagram showing a solid oxide fuel cell device (SOFC) according to an embodiment of the present invention. As shown in FIG. 5, a solid oxide fuel cell device (SOFC) 1 according to an embodiment of the present invention includes a fuel cell module 2 and an accessory unit 4.

  The fuel cell module 2 includes a housing 6, and a metal module container 8 is built in the housing 6 via a heat insulating material 7. In the power generation chamber 10 which is a lower portion of the module container 8 which is a sealed space, a fuel cell and an oxidant gas (hereinafter appropriately referred to as “power generation air” or “air”) perform a power generation reaction A cell assembly 12 is arranged. The fuel cell assembly 12 includes eight fuel cell stacks 14 (see FIG. 11), and the fuel cell stack 14 includes 16 fuel cell units 16 each including a fuel cell. See FIG. 10). In this example, the fuel cell assembly 12 has 128 fuel cell units 16. In the fuel cell assembly 12, all of the plurality of fuel cell units 16 are connected in series.

  Above the power generation chamber 10 of the module container 8 of the fuel cell module 2, a combustion chamber 18 is formed as a combustion unit, and in this combustion chamber 18, the remaining fuel gas and the remaining air not used for the power generation reaction The fuel burns and produces exhaust gas (in other words, combustion gas). Furthermore, the module container 8 is covered with the heat insulating material 7 to suppress the heat in the fuel cell module 2 from being dissipated to the outside air. Further, a reformer 120 for reforming the fuel gas is disposed above the combustion chamber 18, and the heat of combustion of the remaining gas heats the reformer 120 to a temperature at which the reforming reaction is possible. There is.

  Furthermore, an evaporator 140 is provided in the heat insulating material 7 above the module container 8 in the housing 6. The evaporator 140 evaporates water to generate steam by performing heat exchange between the supplied water and the exhaust gas, and a mixed gas of the steam and the raw fuel gas (hereinafter referred to as “fuel gas”) ) Is supplied to the reformer 120 in the module container 8.

  Next, the auxiliary unit 4 stores the water obtained by condensing the water contained in the exhaust from the fuel cell module 2 and uses the filter as pure water to obtain pure water, and the water supplied from the water storage tank The water flow rate adjustment unit 28 (motor-driven "water pump" etc.) which adjusts the flow rate of this is provided. In addition, the auxiliary unit 4 adjusts the flow rate of the fuel gas, the gas shut-off valve 32 for shutting off the fuel supplied from the fuel supply source 30 such as city gas, the desulfurizer 36 for removing sulfur from the fuel gas And a valve 39 for blocking the fuel gas flowing out of the fuel flow control unit 38 when the power is lost. Furthermore, the auxiliary unit 4 includes a solenoid valve 42 for blocking the air supplied from the air supply source 40, a reforming air flow rate adjustment unit 44 for adjusting the air flow rate, and a power generation air flow rate adjustment unit 45 A driven “air blower”, etc., a first heater 46 for heating the reforming air supplied to the reformer 120, and a second heater 48 for heating the power generation air supplied to the power generation chamber Have. The first heater 46 and the second heater 48 are provided to efficiently perform the temperature rise at the time of activation, but may be omitted.

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

  Next, the structure of a fuel cell module of a solid oxide fuel cell device according to an embodiment of the present invention will be described with reference to FIGS. 6 is a side sectional view showing a fuel cell module of a solid oxide fuel cell device according to one embodiment of the present invention, and FIG. 7 is a sectional view taken along the line III-III in FIG. 8 is an exploded perspective view of a module container and an air passage cover.

  As shown in FIGS. 6 and 7, the fuel cell module 2 has the fuel cell assembly 12 and the reformer 120 provided inside the module container 8 covered with the heat insulating material 7, and the module container 8. And an evaporator 140 provided in the heat insulating material 7.

  First, as shown in FIG. 8, the module container 8 comprises a substantially rectangular top plate 8a, a bottom plate 8c, and a pair of opposing side plates 8b connecting sides extending in the longitudinal direction (the horizontal direction in FIG. 6). A closed side plate which closes the cylindrical body and two opposing openings at both ends in the longitudinal direction of the cylindrical body, and connects the sides of the top plate 8a and the bottom plate 8c extending in the width direction (horizontal direction in FIG. 7) It consists of 8d and 8e.

  The module container 8 has a top plate 8 a and a side plate 8 b covered by an air passage cover 160. The air passage cover 160 has a top plate 160 a and a pair of side plates 160 b facing each other. An opening 167 for allowing the exhaust pipe 171 to penetrate is provided at a substantially central portion of the top plate 160 a. Between the top plate 160a and the top plate 8a, and between the side plate 160b and the side plate 8b, they are separated by a predetermined distance. Thereby, oxidation occurs between the outside of the module container 8 and the heat insulating material 7, specifically, between the top plate 8a and the side plate 8b of the module container 8 and the top plate 160a and the side plate 160b of the air passage cover 160. Air passages 161a and 161b are formed as agent gas supply passages (see FIG. 7).

  At the lower part of the side plate 8b of the module container 8, a plurality of through holes, ie, outlets 8f are provided (see FIG. 8). The power generation air is supplied from the power generation air introduction pipe 74 provided at a substantially central portion on the closing side plate 8 e side of the module container 8 in the top plate 160 a of the air flow path cover 160 through the flow path direction adjustment unit 164. It is supplied in 161a (refer FIG. 6, FIG. 8). Then, the power generation air is injected into the power generation chamber 10 from the outlet 8 f toward the fuel cell assembly 12 through the air passages 161 a and 161 b (see FIGS. 7 and 8).

  Further, plate fins 162 and 163, which are plate-like offset fins as heat exchange promoting members, are provided in the air passages 161a and 161b (see FIG. 7). The plate fins 162 are horizontally provided to extend in the longitudinal direction and the width direction between the top plate 8 a of the module container 8 and the top plate 160 a of the air passage cover 160, and the plate fins 163 are side plates 8 b of the module container 8. And a side plate 160 b of the air passage cover 160, and is provided at a position above the fuel cell unit 16 so as to extend in the longitudinal direction and the vertical direction.

  The power generation air flowing through the air passages 161a and 161b is in the inside of the module container 8 inside the plate fins 162 and 163 (specifically, along the top plate 8a and the side plate 8b) when passing through the plate fins 162 and 163. The heat exchange is performed with the exhaust gas passing through the exhaust passage (provided) to heat the exhaust gas. From such a thing, the part in which plate fin 162,163 was provided in air passage 161a, 161b functions as a heat exchanger (heat exchange part). In addition, the part in which the plate fin 162 was provided comprises the main heat exchanger part, and the part in which the plate fin 163 was provided comprises the heat exchanger part which follows.

  Next, the evaporator 140 is fixed so as to extend in the horizontal direction on the top plate 8 a of the module container 8. In addition, a portion 7a of the heat insulating material 7 is disposed between the evaporator 140 and the module container 8 so as to fill the gap (see FIGS. 6 and 7).

  Specifically, the evaporator 140 has a fuel supply pipe 63 for supplying water and raw fuel gas (which may include reforming air) on one side end side in the longitudinal direction (left and right direction in FIG. 6) An exhaust gas discharge pipe 82 (see FIG. 7) for discharging the exhaust gas is connected, and an upper end portion of the exhaust pipe 171 is connected to the other end side in the longitudinal direction. The exhaust pipe 171 extends downward through the opening 167 formed in the top plate 160 a of the air passage cover 160 and is connected to the exhaust port 111 formed on the top plate 8 a of the module container 8. The exhaust port 111 is an opening for discharging the exhaust gas generated in the combustion chamber 18 in the module container 8 to the outside of the module container 8, and substantially at the center of the top plate 8 a of the module container 8 in a substantially rectangular shape in top view. It is formed.

  Moreover, the evaporator 140 has the substantially rectangular evaporator case 141 by top surface view, as shown in FIG.6 and FIG.7. The evaporator case 141 is formed by joining two low-profile bottomed rectangular cylindrical upper and lower cases 142 and 143 with the intermediate plate 144 interposed therebetween.

  Therefore, the evaporator case 141 has a two-layered structure in the vertical direction, and an exhaust passage portion 140A through which exhaust gas supplied from the exhaust pipe 171 passes is formed in the lower layer portion, and fuel is formed in the upper layer portion. An evaporator 140B for evaporating water supplied from the supply pipe 63 to generate steam, and a mixer 140C for mixing the water vapor generated by the evaporator 140B with the raw fuel gas supplied from the fuel supply pipe 63 are provided. It is done.

The evaporation part 140B and the mixing part 140C are formed in the space which divided the evaporator 140 by the partition plate in which the several communication hole (slit) was provided. In addition, alumina balls (not shown) are filled in the evaporation portion 140B.
Further, the exhaust passage portion 140A is divided into three spaces from the upstream side to the downstream side of the exhaust gas by two partition plates similarly having a plurality of communication holes. Then, a combustion catalyst (not shown) is filled in the second space. That is, the evaporator 140 of the present embodiment includes a combustion catalyst.

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

  Furthermore, as shown in FIG. 6, a mixed gas supply pipe 112 for supplying mixed gas to the reformer 120 is connected to the mixing section 140C. The mixed gas supply pipe 112 is disposed so as to pass through the inside of the exhaust pipe 171, one end thereof is connected to the opening 144 a formed in the intermediate plate 144, and the other end is formed on the top surface of the reformer 120. It is connected to the mixed gas supply port 120a. The mixed gas supply pipe 112 extends vertically downward to the module container 8 through the exhaust passage portion 140A and the exhaust pipe 171 and is bent approximately 90 ° there and extends horizontally along the top plate 8a. , And is bent downward approximately 90 degrees and connected to the reformer 120.

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

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

  The reformer 120 is configured such that the internal space thereof is divided into three spaces by two partition plates 123a and 123b, so that a mixed gas receiving unit 120A that receives mixed gas from the mixed gas supply pipe 112 in the reformer 120. , A reforming unit 120B filled with a reforming catalyst (not shown) for reforming the mixed gas, and a gas discharging unit 120C for discharging the gas that has passed through the reforming unit 120B. (See Figure 6). The reforming unit 120B is a space sandwiched by the partition plates 123a and 123b, and the reforming catalyst is held in this space. The mixed gas and the reformed fuel gas are movable through a plurality of communication holes (slits) provided in the partition plates 123a and 123b. Further, as the reforming catalyst, a catalyst provided with nickel on the surface of alumina spheres or a catalyst provided with ruthenium on the surface of alumina spheres may be suitably used.

The mixed gas supplied from the evaporator 140 through the mixed gas supply pipe 112 is ejected through the mixed gas supply port 120a to the mixed gas receiving unit 120A. The mixed gas is expanded in the mixed gas receiving unit 120A, the ejection speed is reduced, and the mixed gas passes through the partition plate 123a and is supplied to the reforming unit 120B.
In the reforming unit 120B, the mixed gas moving at a low speed is reformed into a fuel gas by the reforming catalyst, and the fuel gas passes through the partition plate 123b and is supplied to the gas discharge unit 120C.
In the gas discharge unit 120C, the fuel gas is discharged to the fuel gas supply pipe 64 and the hydrogen removal pipe 65 for a hydrodesulfurizer.

The fuel gas supply pipe 64 as the fuel gas supply passage has a vertical shape, a direction correction shape, and a stress relief shape. The vertical profile extends downwardly into the module container 8 and connects to the direction correction profile. The direction correction shape portion is disposed such that the upper side thereof is inclined at a predetermined angle toward the fuel cell in the module container 8 with respect to the vertical direction. Then, the fuel gas supply pipe 64 gently curves and extends in the horizontal direction in the stress relaxation shape portion near the bottom plate 8c,
It enters into a fuel manifold 66 formed below the fuel cell assembly 12 and extends horizontally in the fuel manifold 66 to the vicinity of the opposite closing side plate 8 e. The curvature of the fuel gas supply pipe 64 of the stress relaxation shape portion makes the bending radius of the curvature larger than 2D with respect to the outer diameter D. In general, the fuel gas supply pipe 64 is shaped to bend one member once and swing it back. As a result, by using only one tubular member without adding other components such as the bellows member, it is possible to achieve both the alleviation of the applied thermal stress and the reduction of the storage space. For this reason, it is possible to realize an inexpensive and compact fuel cell device that is highly durable.

  In the present embodiment, a plurality of fuel supply holes 64b are formed on the lower surface of the horizontal portion 64a of the fuel gas supply pipe 64, and the fuel gas is supplied into the fuel manifold 66 from the fuel supply holes 64b. Ru. A lower support plate 68 having a through hole for supporting the fuel cell stack 14 is attached above the fuel manifold 66, and the fuel gas in the fuel manifold 66 is contained in the fuel cell unit 16. Supplied. Further, an igniter 83 for starting the combustion of the fuel gas and the air is provided in the combustion chamber 18.

  The exhaust gas guiding member 130 is disposed so as to extend horizontally along the longitudinal direction of the module container 8 between the reformer 120 and the top plate 8 a. The exhaust gas guiding member 130 includes a lower guiding plate 131 and an upper guiding plate 132 which are separated by a predetermined distance in the vertical direction, and connection plates 133 and 134 to which both longitudinal sides thereof are attached (FIG. 6) , See FIG. 7). The upper guide plate 132 is bent downward at both ends in the width direction, and is connected to the lower guide plate 131. The connection plates 133 and 134 are connected at their upper ends to the top plate 8a and at their lower ends to the reformer 120, thereby fixing the exhaust gas guiding member 130 and the reformer 120 to the top plate 8a. ing.

  The lower guide plate 131 is formed with a convex stepped portion 131a in which a central portion in the width direction (left and right direction in FIG. 7) protrudes downward. On the other hand, in the upper guide plate 132, similarly to the lower guide plate 131, the recess 132a is formed such that the central portion in the width direction is concaved downward. The convex stepped portion 131a and the concave portion 132a extend in the longitudinal direction in parallel with each other in the vertical direction. The mixed gas supply pipe 112 extends horizontally in the recess 132 a in the module container 8, and then bends downward near the closing side plate 8 e to penetrate the upper induction plate 132 and the lower induction plate 131, It is connected to the reformer 120.

  In the exhaust gas guiding member 130, a gas reservoir 135, which is an internal space functioning as a heat insulating layer, is formed by the upper induction plate 132, the lower induction plate 131, and the connection plates 133 and 134. The gas reservoir 135 is in fluid communication with the combustion chamber 18. That is, the upper guide plate 132, the lower guide plate 131, and the connection plates 133 and 134 are connected to form a predetermined gap, and are not connected in an airtight manner. While it is possible for exhaust gas from the combustion chamber 18 to flow into the gas reservoir 135 during operation and air from the outside to flow during shutdown, the movement of gas between the inside and the outside of the gas reservoir 135 as a whole Is loose.

  Upper induction plate 132 is disposed at a predetermined vertical distance from top plate 8a, and exhaust air extending in the horizontal direction along the longitudinal direction and width direction between upper induction plate 132 and top plate 8a. A passage 172 is formed. The exhaust passage 172 is juxtaposed with the air passage 161a with the top plate 8a of the module container 8 interposed therebetween. In the exhaust passage 172, plate fins similar to the plate fins 162 and 163 in the air passages 161a and 161b are provided. 175 are arranged. The plate fins 175 are provided at substantially the same places as the plate fins 162 in top view, and are opposed in the vertical direction with the top plate 8 a interposed therebetween. In the portions of the air passage 161a and the exhaust passage 172 where the plate fins 162 and 175 are provided, efficient heat exchange is performed between the power generation air flowing through the air passage 161a and the exhaust gas flowing through the exhaust passage 172. Thus, the temperature of the power generation air is raised by the heat of the exhaust gas.

  Further, the reformer 120 is disposed at a predetermined horizontal distance from the side plate 8b of the module container 8, and the exhaust gas is allowed to pass upward from below between the reformer 120 and the side plate 8b. An exhaust passage 173 is formed. The exhaust gas guiding member 130 is also disposed at a predetermined horizontal distance from the side plate 8b, and the exhaust passage 173 extends to the top plate 8a including the passage between the exhaust gas guiding member 130 and the side plate 8b. ing. The exhaust passage 173 communicates with the exhaust passage 172 via an exhaust gas inlet 172a located at a corner between the top plate 8a and the side plate 8b. The exhaust gas inlet 172 a extends in the module container 8 in the longitudinal direction.

  Furthermore, the lower guide plate 131 is disposed at a predetermined vertical distance from the top surface of the upper case 121 of the reformer 120, and between the lower guide plate 131 and the upper case 121, and the reformer The through hole 120b of 120 forms an exhaust passage 174 for passing the exhaust gas that has passed through the through hole 120b from the lower side to the upper side. The exhaust passage 174 joins the exhaust passage 173 above the reformer 120.

Next, the fuel cell unit 16 will be described with reference to FIG. FIG. 9 is a partial cross-sectional view showing a fuel cell unit of a solid oxide fuel cell device according to one embodiment of the present invention.
As shown in FIG. 9, the fuel cell unit 16 includes a fuel cell 84 and an inner electrode terminal 86 which is a cap connected to both ends of the fuel cell 84.
The fuel cell 84 is a tubular structure extending in the vertical direction, and has a cylindrical inner electrode layer 90 forming a fuel gas channel 88 therein, a cylindrical outer electrode layer 92, an inner electrode layer 90, and an outer side. And an electrolyte layer 94 between the electrode layer 92 and the electrode layer 92. The inner electrode layer 90 is a fuel electrode through which the fuel gas passes and is a (-) electrode, while the outer electrode layer 92 is an air electrode in contact with air and is a (+) electrode.

  Since the inner electrode terminals 86 attached to the upper end side and the lower end side of the fuel cell 84 have the same structure, here, the inner electrode terminal 86 attached to the upper end side will be specifically described. An upper portion 90 a of the inner electrode layer 90 includes an outer circumferential surface 90 b exposed to the electrolyte layer 94, the outer electrode layer 92, and an upper end surface 90 c. The inner electrode terminal 86 is connected to the outer peripheral surface 90 b of the inner electrode layer 90 via the conductive seal material 96, and is in direct contact with the upper end surface 90 c of the inner electrode layer 90 to connect with the inner electrode layer 90. It is electrically connected. At a central portion of the inner electrode terminal 86, a fuel gas channel thin tube 98 communicating with the fuel gas channel 88 of the inner electrode layer 90 is formed.

  The fuel gas flow path narrow tube 98 is an elongated thin tube extending in the axial direction of the fuel cell 84 from the center of the inner electrode terminal 86. For this reason, there is a predetermined pressure loss in the flow of fuel gas flowing from the fuel manifold 66 (see FIG. 6) through the fuel gas flow passage narrow tube 98 of the lower inner electrode terminal 86 into the fuel gas flow passage 88. Occur. Therefore, the fuel gas flow passage thin tube 98 of the lower side inner electrode terminal 86 acts as an inflow side flow passage resistance portion, and the flow passage resistance thereof is set to a predetermined value. In addition, a predetermined pressure loss also occurs in the flow of the fuel gas flowing from the fuel gas flow passage 88 through the fuel gas flow passage narrow tube 98 of the upper inner electrode terminal 86 to the combustion chamber 18 (see FIG. 6). Therefore, the fuel gas flow passage thin tube 98 of the upper side inner electrode terminal 86 acts as an outflow side flow passage resistance portion, and the flow passage resistance thereof is set to a predetermined value.

  The inner electrode layer 90 is, for example, a mixture of Ni and zirconia doped with at least one selected from rare earth elements such as Ca, Y, and Sc, Ni, and ceria doped with at least one selected from rare earth elements. It is formed of at least one of a mixture, and a mixture of Ni and a lanthanum gallate 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 of at least one of the

  The outer electrode layer 92 is, for example, lanthanum manganite doped with at least one selected from Sr, Ca, lanthanum ferrite doped with at least one selected from Sr, Co, Ni, Cu, Sr, Fe, Ni, Cu It is formed of at least one of lanthanum cobaltite, silver, etc. doped with at least one selected from

Next, the fuel cell stack 14 will be described with reference to FIG. FIG. 10 is a perspective view showing a fuel cell stack of a solid oxide fuel cell device according to one embodiment of the present invention.
As shown in FIG. 10, the fuel cell stack 14 includes 16 fuel cell units 16, and these fuel cell units 16 are arranged in two rows of eight each.
Each of the fuel cell units 16 is supported by a rectangular lower support plate 68 (see FIG. 6) on the lower end side of the ceramic rectangular shape, and on the upper end side, two generally square two sheets of four fuel cell units 16 at both ends. Is supported by the upper support plate 100. The lower support plate 68 and the upper support plate 100 are each formed with a through hole through which the inner electrode terminal 86 can pass.

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

  Furthermore, two external terminals 104 are respectively connected to the air electrode of the fuel cell unit 16 located at the end of the fuel cell stack 14 (the far side in the left end in FIG. 10). These external terminals 104 are connected to the inner electrode terminals 86 of the fuel cell units 16 at the end of the adjacent fuel cell stacks 14, and all the 128 fuel cell units 16 are connected in series as described above. It is supposed to be

  Next, with reference to FIGS. 11 and 12, the flow of gas in the fuel cell module of the solid oxide fuel cell device according to one embodiment of the present invention will be described. 11 is a side sectional view showing a fuel cell module of a solid oxide fuel cell device according to an embodiment of the present invention, similar to FIG. 6, and FIG. 12 is a view similar to FIG. FIG. 7 is a cross-sectional view taken along line III. FIG. 11 and FIG. 12 are diagrams newly added with arrows indicating the flow of gas in FIG. 6 and FIG. 7, respectively. In the figure, solid arrows indicate the flow of fuel gas, broken arrows indicate the flow of power generation air, and dashed dotted arrows indicate the flow of exhaust gas.

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

  The mixed gas (fuel gas) formed in the mixing unit 140C is supplied to the reformer 120 in the module container 8 through the mixed gas supply pipe 112. The mixed gas supply pipe 112 sequentially passes through the exhaust passage portion 140A, the exhaust pipe 171, and the exhaust passage 172. Therefore, the mixed gas in the mixed gas supply pipe 112 is further heated by the exhaust gas flowing through these passages. Ru.

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

  Further, the fuel gas branches from the gas discharge unit 120C into the fuel gas supply pipe 64 and the hydrogen removal pipe 65 for the hydrodesulfurizer. Then, the fuel gas flowing into the fuel gas supply pipe 64 is supplied into the fuel manifold 66 from the fuel supply holes 64 b provided in the horizontal portion 64 a of the fuel gas supply pipe 64, and each fuel cell unit 16 from the fuel manifold 66. Supplied inside.

  Further, as shown in FIGS. 11 and 12, the power generation air is supplied from the power generation air introduction pipe 74 to the air passage 161a. When the power generation air passes through the plate fins 162, 163 in the air passages 161a, 161b, the exhaust air passes through the exhaust passages 172, 173 formed in the module container 8 below the plate fins 162, 163. The heat is efficiently exchanged with the gas and heated. In particular, since the plate fins 175 are provided in the exhaust passage 172 corresponding to the plate fins 162 of the air passage 161 a, the power generation air is connected to the exhaust gas through the plate fins 162 and the plate fins 175. Perform more efficient heat exchange. Thereafter, the power generation air is injected into the power generation chamber 10 toward the fuel cell assembly 12 from the plurality of outlets 8 f provided at the lower part of the side plate 8 b of the module container 8. In the present embodiment, since the exhaust passage is not formed at the side portion of the fuel cell assembly 12, heat exchange between the power generation air and the exhaust gas is not performed at this portion. Therefore, at the side portions of the fuel cell assembly 12, the temperature gradient in the vertical direction is less likely to occur in the power generation air in the air passage 161b.

  Further, as shown in FIG. 12, the fuel gas not used for power generation in the power generation chamber 10 is burned in the combustion chamber 18 to become exhaust gas (combustion gas), and ascends inside the module container 8. Specifically, the exhaust gas is branched into the exhaust passage 173 and the exhaust passage 174, and between the outer surface of the reformer 120 and the side plate 8 b of the module container 8 and the through hole 120 b of the reformer 120. And between the reformer 120 and the exhaust gas guiding member 130. At this time, the exhaust gas passing through the exhaust passage 174 is divided in two in the width direction by the convex step 131a disposed above the through hole 120b of the reformer 120, and does not stay in the lower portion of the exhaust gas guiding member 130. The exhaust gas is directed toward the exhaust passage 173 and quickly joins the exhaust gas flowing through the exhaust passage 173.

Thereafter, the exhaust gas flows into the exhaust passage 172 from the exhaust gas inlet 172a. In the exhaust passage 172, the exhaust gas flows in the horizontal direction in the exhaust passage 172, and flows out from the exhaust port 111 formed at the center of the top plate 8 a of the module container 8.
When the exhaust gas flows upward through the exhaust passage 173, heat exchange is performed between the power generation air and the exhaust gas through the plate fins 163 provided in the air passage 161b. Further, when the exhaust gas flows in the exhaust passage 172 in the horizontal direction, the plate fins 175 provided in the exhaust passage 172 and the plate fins 162 provided in the air passage 161 a corresponding to the plate fins 175. Efficient heat exchange is performed between the power generation air and the exhaust gas. Thus, the power generation air is heated by the heat of the exhaust gas.

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

  Next, the operation of the reformer of the present embodiment will be described with reference to FIGS. FIG. 13 is a partial cross-sectional view of the upper portion of a fuel cell module of a solid oxide fuel cell device according to an embodiment of the present invention, and FIG. 14 is an explanatory view of exhaust gas flowing around the reformer. FIGS. 15 and 16 are a side sectional perspective view and a front sectional perspective view of the reformer and the exhaust gas guiding member, respectively, and FIG. 17 is an explanatory view of the exhaust gas flowing through the through hole of the reformer.

  As shown in FIG. 13, the power generation air supplied into the power generation chamber 10 moves upward (see the broken arrow in FIG. 13) and burns off gas in the combustion chamber 18 to become exhaust gas. When the through hole 120b is not formed in the reformer 120, the exhaust gas passes only from the combustion chamber 18 through the exhaust passage 173 (extending along the inner surface of the side plate 8b of the module container 8) to the module container It will move to the upper part in the 8th. In this case, the flow distribution of the power generation air is biased to the vicinity of both end portions in the width direction of the top view with respect to the fuel cell assembly 12, and the air supply to the fuel cell unit 16 at the central portion is sufficient. There is a risk that the fuel cell unit 16 in this portion will be degraded.

  Therefore, in the present embodiment, by providing the through holes 120b in the reformer 120, the exhaust passage 174 (extending from the through holes 120b of the reformer 120 to between the reformer 120 and the exhaust gas guiding member 130) can be obtained. It is formed. Thereby, in the present embodiment, the exhaust gas can be branched from the combustion chamber 18 into the exhaust passage 174 and the exhaust passage 173, and can move toward the upper part in the module container 8 (see FIG. 14).

  Further, in the present embodiment, in particular, the flow rate of the exhaust gas flowing through the exhaust passage 174 rather than the exhaust passage 173 so that the flow ratio of the exhaust gas flowing through the exhaust passage 174 and the exhaust passage 173 becomes a predetermined value. The cross-sectional area of the exhaust passage 173, the cross-sectional area of the exhaust passage 174 on the upper side of the reformer 120, the opening area of the through hole 120b and the corner R shape of the through hole 120b It is done. Thus, even if the distance between the reformer 120 and the fuel cell assembly 12 is close, the exhaust gas can be reliably supplied to the exhaust passage 174. For this reason, in the present embodiment, the flow of power generation air is not biased to the vicinity of both end portions in the width direction of the fuel cell assembly 12 in top view as the exhaust gas flows. Since it flows, the nonuniformity of the air supply amount of the air for generation of electricity in power generation room 10 is controlled, and the flow of the air for generation of electricity becomes easy to be equalized.

  Further, in the present embodiment, the reformer 120 is heated by the exhaust gas colliding with the bottom surface thereof, and then heated from the side in the width direction by the exhaust gas passing through the exhaust passage 173, and It is also heated from the central part by the passing exhaust gas. As described above, in the present embodiment, the heating of the reformer 120 by the exhaust gas can be efficiently performed.

  Further, in the present embodiment, the through hole 120 b of the reformer 120 and the exhaust port 111 of the module container 8 are formed so as to at least partially overlap in top view. More preferably, the exhaust port 111 is disposed at a central portion in the longitudinal direction and the width direction of the through hole 120 b, which is a point symmetrical position of the through hole 120 b in top view. Further, the exhaust port 111 and the through hole 120 b are disposed in the central portion of the fuel cell assembly 12 in top view.

  If the exhaust port 111 is disposed in the width direction with respect to the through hole 120b in top view, the flow of exhaust gas from the through hole 120b to the exhaust port 111 is uneven at least in the width direction. Or become asymmetric. Then, along with the flow of such exhaust gas, the flow of power generation air also becomes uneven in the width direction. However, in the present embodiment, the exhaust port 111 and the through hole 120 b are disposed at the central portion of the module container 8 in top view and overlap each other, so the exhaust gas from the through hole 120 b to the exhaust port 111 Flow in at least the width direction, and the flow of power generation air also in the width direction. The reformer 120 is also disposed at the center position of the module container 8 in top view. Thereby, the deviation of the flow path distribution of the power generation air is suppressed, and the power generation air can be sufficiently supplied to the fuel cell unit 16 substantially uniformly including the central portion and the vicinity of both ends, so that the fuel cell It is possible to suppress the deterioration of the cell unit 16.

  Further, in the present embodiment, the flow rate of the exhaust gas is symmetrical (linearly symmetric) in the width direction of the reformer 120, that is, the flow rates of the exhaust passages 173 on both sides across the through hole 120b are uniform and flow The through holes 120 b are formed in line symmetry so as to divide the reformer 120 into at least approximately equal portions in the width direction in top view so as to eliminate the deviation of the path distribution. In the present embodiment, the through holes 120 b are formed in line symmetry so as to divide the reformer 120 substantially equally in the longitudinal direction in top view.

  Further, in the present embodiment, as shown in FIG. 15 and FIG. 16, the through hole 120 b of the reformer 120 is substantially oval in top view, and is formed to extend in the longitudinal direction. Further, the housing of the reformer 120 is composed of an upper case 121 and a lower case 122. In each of the upper case 121 and the lower case 122, connection concave portions 121a and 122a recessed inward so as to connect the through holes 120b from both end portions in the width direction are formed. In the present embodiment, the connecting recesses 121a and 122a are formed two by two in the longitudinal direction.

  When the exhaust gas rising from the combustion chamber 18 collides with the bottom surface of the lower case 122 of the reformer 120, the connecting recess 122a passes the exhaust gas on both sides in the width direction, that is, the through holes 120b (exhaust passage 174) and It is guided to the exhaust passage 173 along the side plate 8 b of the module container 8. Thus, in the present embodiment, the exhaust gas can be positively supplied to the through hole 120b without the flow of the exhaust gas being biased to the exhaust passage 173.

  The connection recesses 121 a and 122 a protrude toward the internal space of the reformer 120. Specifically, the connection recesses 121a and 122a protrude toward the inner space so as to narrow the flow path of the reforming unit 120B in the reformer 120. For this reason, the mixed gas flows through the reforming unit 120B while changing the flow path by the projecting portion of the connection concaves 121a and 122a, so the contact opportunity and the contact time between the mixed gas and the reforming catalyst increase. Thus, in the present embodiment, the reforming efficiency of the mixed gas can be improved. Furthermore, although the temperature of the reforming catalyst is raised to a predetermined temperature by the exhaust gas flowing around the reformer 120, the temperature of the reforming catalyst is raised due to the increase of the contact opportunity / contact time between the mixed gas and the reforming catalyst. Thus, the mixed gas can be efficiently heated.

  Further, in the present embodiment, the upper case 121 and the lower case 122 are formed of the same original case member. That is, the original case member is formed (for example, drawn) of a metal material using a predetermined mold. Then, the upper case 121 and the lower case 122 are formed by processing the same original case member. For this reason, cost reduction and improvement of the assemblability can be achieved at the same time. Moreover, if the case of the reformer 120 is made into one part configuration, a bulky case can not be formed by drawing, but in this embodiment, the case of the reformer 120 is made up of two parts by the upper case 121 and the lower case 122 Therefore, a bulky case can be formed. For this reason, when the volumes are the same, a small reformer with a smaller bottom area can be obtained.

  The upper case 121 and the lower case 122 respectively have flange portions 121b and 122b on the outer peripheral side and flange portions 121c and 122c on the inner peripheral side forming the through hole 120b, and the state where these flange portions are overlapped It is fixed by welding. The flange portions 121b and 122b on the outer peripheral side have the same width, and welding can be easily performed from the side of the case. On the other hand, when the flanges 121c and 122c on the inner peripheral side have the same width, it is difficult to weld these flanges from the side, and the assemblability is poor. For this reason, in the present embodiment, the flange portion 121c on the inner peripheral side is processed from the original case member so as to be narrower than the flange portion 122c (see FIG. 16). For this reason, it becomes possible for flange parts 121c and 122c to perform welding operation easily from the upper side using the level difference of these flange parts, and can improve assemblability.

  The upper case 121 and the lower case 122 have a curved shape so that the corner (including the corner of the through hole 120b) of the inner side surface thereof has an R shape having a predetermined curvature radius (see FIG. 15 and dashed line A in FIG. 14). The curvature radius is preferably 1.0 mm to 30 mm. For this reason, in the present embodiment, when the gas passes through the inside of the reformer 120, the gas is prevented from staying in the corner, so there is no dead space in the container and the catalyst is uniform relative to the reforming catalyst. It becomes easy to distribute gas to

  In addition, the connecting portion or corner portion between the peripheral surface of the through hole 120b and the lower surface of the lower case 122 has an R shape so as to have a predetermined radius of curvature over the peripheral edge of the through hole 120b (including the portion of the connecting recess 122a). (See dashed line A in FIG. 16). That is, as shown in FIG. 17, the case cross section of the reformer 120 has an R shape which is convex toward the outside from the bottom surface of the reformer 120 to the peripheral surface (side surface) of the through hole 120b. It has become.

  Since the corner between the circumferential surface of the through hole 120b and the bottom surface of the lower case 122 is formed in an arc shape having a predetermined curvature radius, the exhaust gas that collides with the lower case 122 is directed to the through hole 120b. It becomes easy to be induced. Then, by the flow of such exhaust gas, the power generation air is also guided toward the through holes 120 b. However, when the radius of curvature becomes too large, the amount of power generation air guided to the through hole 120 b becomes too large, and the amount of power generation air passing through the outer peripheral side of the reformer 120 becomes too small. The flow distribution of the power generation air will be uneven.

  For this reason, in the present embodiment, the curvature radius of the corner portion is set to 1.0 mm to 30 mm so that the flow ratio of power generation air in the exhaust passage 173 and the exhaust passage 174 becomes an appropriate value. Thus, sufficient power generation air can be distributed to the fuel cell units 16 disposed in the central portion and the peripheral portion.

Next, the operation of the exhaust gas guiding member of the present embodiment will be described with reference to FIG.
In this embodiment, the evaporator 140 is disposed outside the module container 8, and this arrangement prevents a local temperature drop (including a temperature drop of the exhaust gas) due to the heat of vaporization of water in the module container 8. The heat exchange between the exhaust gas and the power generation air is performed more efficiently. Therefore, in the present embodiment, substantial heat exchange is performed only at a limited portion in the vicinity of the top plate 8 a of the module container 8 while avoiding heat exchange at the side portion of the fuel cell unit 16. Is possible.

  For this reason, in the present embodiment, an air passage 161a and an exhaust passage 172 are formed above and below the top plate 8a, and substantial heat exchange is performed in this portion. However, in order to miniaturize the apparatus, the area of the top plate 8a is also reduced, which may make it impossible to secure an area for sufficient heat exchange. Therefore, in the present embodiment, high heat exchange efficiency is achieved by maintaining the temperature difference between the exhaust gas at the inlet and the outlet of the exhaust passage 172 as large as possible.

  For this reason, the exhaust gas guiding member 130 is employed in the present embodiment. The exhaust gas guiding member 130 causes the exhaust gas that has passed through the through hole 120 b and has risen to collide with the convex step portion 131 a protruding downward so as to face the through hole 120 b, and is directed in the width direction Promptly lead to the exhaust gas inlet 172a. Thus, the exhaust gas is quickly directed toward the exhaust gas inlet 172a without staying near the bottom surface of the exhaust gas guiding member 130.

  Since the exhaust passage 172 functioning as a heat exchange part is formed in the upper part of the exhaust gas guide member 130, the exhaust gas in the upper part of the exhaust gas guide member 130 is lower in temperature than the exhaust gas in the lower part. Therefore, when the exhaust gas stays in the vicinity of the bottom surface of the exhaust gas guiding member 130 in the exhaust passage 174, heat exchange occurs with the exhaust gas in the exhaust passage 172 via the exhaust gas guiding member 130, and the exhaust passage 174 The temperature of the exhaust gas inside may be reduced. Further, the exhaust gas in the exhaust passage 174 may be deprived of heat through the upper surface of the reformer 120 and the lower surface of the exhaust gas guide member 130. However, in the present embodiment, by providing the convex stepped portion 131a on the bottom surface of the exhaust gas guiding member 130, the high temperature exhaust gas that has risen through the through holes 120b of the reformer 120 can be exhausted. Since the light can be quickly guided laterally without staying near the bottom surface of the member 130, the exhaust gas introduction port 172a can be reached while maintaining a high temperature.

  In the exhaust passage 172, the exhaust gas flows from both end portions in the width direction (the exhaust gas inlet 172a which is the inlet of the exhaust passage 172) to the central portion (in particular, the exhaust 111 which is the outlet of the exhaust passage 172). At this time, since heat exchange with the power generation air is performed, the temperature of the exhaust gas in the vicinity of the concave portion 132a of the exhaust gas guide member 130 (see the broken line A in FIG. 13) is the lowest. In particular, the temperature in the vicinity of the exhaust port 111 disposed at the central portion in the longitudinal direction of the recess 132a is the lowest. On the other hand, in the exhaust passage 174, the temperature of the upper side of the through hole 120b of the reformer 120, that is, the vicinity of the convex step 131a (see the broken line B in FIG. 13) of the exhaust gas guiding member 130 becomes highest.

  Since the area of the broken line part A with the lowest temperature and the area of the broken line part B with the highest temperature (see FIG. 13) are located above and below the exhaust gas guiding member 130, the linear separation distance is small. Therefore, if heat exchange is performed between these regions, the inlet temperature of the exhaust gas may be lowered. Therefore, in the present embodiment, the gas reservoir 135 (gas chamber) is formed in the case member of the exhaust gas guiding member 130, and this gas reservoir 135 is made to function as a heat insulating material. Thus, in the present embodiment, heat exchange between the upper and lower spaces of the exhaust gas guiding member 130 (i.e., the exhaust passage 172 and the exhaust passage 174), in particular, between the regions A and B in FIG. Therefore, it is possible to prevent the temperature decrease of the high temperature exhaust gas which has risen through the through holes 120b of the reformer 120, and allow the exhaust gas inlet 172a to flow out while maintaining the high temperature state. Can be maintained at a high temperature.

In addition, since the exhaust gas guiding member 130 functions as a heat insulating material, it is suppressed that the heat of the exhaust gas in the exhaust passage 172 is taken away by the exhaust gas guiding member 130, and the exhaust gas in the exhaust passage 172 and the air passage 161 a The heat exchange with the power generation air can be promoted.
Furthermore, in the exhaust passage 172, the upper induction plate 132 of the exhaust gas guide member 130 functions as a heat reflecting plate, so that the radiant heat from the upper induction plate 132 can be given to the exhaust gas and air. Thereby, in the present embodiment, higher heat exchange efficiency in the heat exchange section can be achieved.

  Further, the exhaust gas guiding member 130 is formed of a member having heat conductivity (for example, a metal material or the like), and conducts heat by itself. Therefore, when the convex stepped portion 131a is heated by the collision of the high temperature exhaust gas with the convex stepped portion 131a of the exhaust gas guiding member 130, from the convex stepped portion 131a to another part of the exhaust gas guiding member 130. Heat conduction can not be completely shut off. Therefore, heat conduction to the upper surface of the exhaust gas guiding member 130 may also occur. As a result, the temperature difference between the upstream side and the downstream side of the exhaust passage 172 constituting the heat exchange portion is reduced on the upper surface of the exhaust gas guiding member 130, which is disadvantageous for the improvement of the heat exchange efficiency.

  Therefore, in the present embodiment, the recess 132a is formed in the downstream side portion of the exhaust passage 172 (that is, the central portion in the width direction) of the upper surface of the exhaust gas guiding member 130 where the temperature of exhaust gas is the lowest. A portion through which the main flow portion of the exhaust gas passes in the exhaust passage 172 (the passage height position other than the portion where the recess 132a is formed, and in FIG. 13, the height position where the plate fin 175 is located) and the exhaust gas guiding member 130 The distance between it and the bottom surface of the recess 132a is increased. As a result, heat exchange between the exhaust gas and the exhaust gas guiding member 130 is less likely to occur at the downstream side of the exhaust passage 172, and heat conduction from the convex step portion 131a to the concave portion 132a is suppressed. That is, since heat exchange with the exhaust gas hardly occurs in the vicinity of the recess 132a after the temperature of the recess 132a is once raised by heat conduction, the temperature of the recess 132a does not easily decrease. Thereby, in the present embodiment, higher heat exchange efficiency in the heat exchange section can be achieved.

  In addition, the mixed gas supply pipe 112 is piped from the exhaust port 111 to the reformer 120 through the inside of the module container 8. Therefore, although the mixed gas in the mixed gas supply pipe 112 can be preheated in the module container 8, the heat of the exhaust gas is taken away by this preheating, which is disadvantageous for improving the heat exchange efficiency. Therefore, in the present embodiment, the mixed gas supply pipe 112 is disposed in the recess 132a of the exhaust gas guiding member 130 at the downstream side of the exhaust passage 172 where the temperature of the exhaust gas is at the lowest temperature. The mixed gas supply pipe 112 is heated by the low temperature exhaust gas after heat exchange, not the high temperature exhaust gas before heat exchange. Thus, the heat of the exhaust gas is prevented from being excessively taken away by the mixed gas supply pipe 112, and the efficiency (heat exchange efficiency) of preheating the mixed gas can be reduced.

  Next, the operation of the heat exchanger of the present embodiment will be described with reference to FIGS. FIG. 18 is a cross-sectional view of a heat exchange part of a solid oxide fuel cell device according to one embodiment of the present invention, and FIG. 19 is an explanatory view of a connecting portion of a top plate of a module container and an exhaust pipe; FIG. 20 is an explanatory view of a power generation air supply passage on the top plate of the module container, FIG. 21 is an explanatory view of an exhaust passage under the top plate of the module container, and FIG. 22 is a perspective view of a plate fin FIG. 23 is an explanatory view of a plate fin disposed between the side plate of the air passage cover and the side plate of the module container.

  As shown in FIG. 18, the air passage cover 160 is attached to the module container 8 at a position slightly biased to one end side (right side in FIG. 18) in the longitudinal direction. Specifically, at the other end side of the module container 8 in the longitudinal direction, the hydrogen removal pipe 65 for hydrodesulfurization extends through the top plate 8 a and extends upward, but the air passage cover 160 is for hydrodesulfurization The hydrogen take-off pipe 65 is avoided, and the one end side of the module container 8 in the longitudinal direction is shifted. As a result, it is not necessary to provide the air passage cover 160 with a through hole for allowing the hydrodesulfurizer hydrogen extraction pipe 65 to penetrate. Further, when the through hole is provided in the air passage cover 160, it is necessary to airtightly fix the hydrogen removal pipe 65 for hydrodesulfurizer at the through hole by welding or the like, but such complicated processing steps are also unnecessary. It becomes.

  In addition, as shown in FIG. 18, an opening 165 is formed in an end central portion of one end side of the top plate 160 a of the air passage cover 160, and the flow direction adjusting portion is covered to cover the opening 165. 164 is fixed. The power generation air having flowed through the power generation air introduction pipe 74 is supplied to the air passage 161 a through the opening 165 through the flow direction adjusting unit 164. At least the supply-side end of the power generation air introduction pipe 74 extends horizontally along the longitudinal direction of the top plate 160 a of the air passage cover 160 (see FIG. 8). In the present embodiment, the supply side end of the power generation air introduction pipe 74 extends in parallel with the top plate 160a or the top plate 8a, but may be angled so that the tip side is lowered.

  The flow path direction adjustment portion 164 is a flow path member having a substantially semicircular attachment portion 164a for connecting the power generation air introduction pipe 74, and a convex flow path portion 164b formed to project upward. , And is attached so as to close the opening 165 of the top plate 160a. The convex flow path portion 164b is a cover member in which a substantially semicircular cross section gradually reduces along the traveling direction of the power generation air from the attachment portion 164a and forms an air flow path inside. . Therefore, the inner air flow path has a lower upper surface and a narrower width toward the tip end. The lower part of the convex flow path portion 164 b is in communication with the air passage 161 a through the opening 165.

  The air passage 161a formed under the top plate 160a is formed to have a large width dimension and longitudinal dimension but a low height of the passage. Therefore, the distance between the top plate 8a of the module container 8 and the top plate 160a of the air passage cover 160 (the height of the passage) is smaller than the diameter of the power generation air introduction pipe 74. It is difficult to connect the tube 74 to the air passage cover 160 at the height portion of the air passage 161a, and even if it can be connected, the pressure loss increases.

  In addition, when the power generation air introduction pipe 74 is disposed to extend in the vertical direction and the power generation air is supplied from above to the inside of the air passage 161a through the opening 165, the power generation air collides with the lower surface of the air passage 161a. And it becomes difficult to disperse toward the side passage space. For this reason, it becomes difficult to uniformly supply the power generation air to the entire area of the air passage 161a, and there is a region where the heat exchange efficiency is locally lowered, so that the heat exchange efficiency as a whole is lowered.

  Therefore, in the present embodiment, the supply side end of the power generation air introduction pipe 74 is connected to the top plate 160 a of the air passage cover 160 via the flow direction adjusting unit 164. With this configuration, the flow channel direction adjusting unit 164 can be assembled to the air passage cover 160 as a separate member, and the assembling property for connecting the power generation air introduction pipe 74 to the air passage cover 160 is improved. Ru. In addition, it is possible to assemble the flow passage direction adjusting unit 164 in advance to the air passage cover 160 and then assemble the air passage cover 160 to the module container 8.

  However, in this configuration, the power generation air introduction pipe 74 is offset above the air passage 161a, and the flow direction of the power generation air introduction pipe 74 and the flow path in the air passage 161a are substantially parallel in longitudinal components. However, they will be separated in the vertical direction. For this reason, the flow passage direction adjusting unit 164 is formed such that the height of the internal flow passage becomes lower as it is separated from the supply side end of the power generation air introduction pipe 74. Thus, the convex flow passage portion 164b gradually changes the flow passage direction of the power generation air supplied from the power generation air introduction pipe 74 downward, and the gentle flow direction of the air passage 161a is obtained. The power generation air can be delivered to the air passage 161a at an angle.

  Further, the convex flow passage portion 164b is formed so that the inner flow passage width becomes narrower in addition to the inner flow passage height becoming lower as the distance from the supply side end of the power generation air introduction pipe 74 increases. (See Figure 8). Therefore, in the convex flow passage portion 164b, the flow passage cross-sectional area gradually decreases in the traveling direction. For this reason, the power generation air is gradually accelerated without receiving a large resistance in the flow path direction adjustment unit 164. Thus, the power generation air supplied to the air passage 161a from one end side in the longitudinal direction of the air passage cover 160 can reach the other end side in the longitudinal direction of the air passage cover 160, and power generation is performed over the entire air passage 161a. It is possible to supply air uniformly.

  Further, when the flow channel direction adjusting unit 164 is not used, the inflow area from the power generation air introduction pipe 74 to the air passage 161a having a low flow path height is reduced, so that the pressure loss is increased as described above. However, by using the flow channel direction adjustment unit 164, a large inflow area can be secured. For this reason, in the present embodiment, the pressure loss can be reduced, and the power generation air can be smoothly supplied to the other end side in the longitudinal direction of the air passage cover 160 in the air passage 161a.

  Further, in the air passage 161a, two air distribution members 166 are disposed substantially in parallel along the longitudinal direction of the module container 8 on both sides of the exhaust pipe 171 (see FIGS. 19 and 20). The plate fins 162 are disposed outside the air passage 161 a with respect to the air distribution member 166 in the width direction, and therefore, when a gas such as the plate fins 162 moves between the two air distribution members 166. A space where no member (except for the exhaust pipe 171) which is the resistance of the above exists is formed.

  The air distribution member 166 is an elongated member extending to define the air passage 161a over substantially the entire length of the top plate 160a of the air passage cover 160 in the longitudinal direction. The air distribution member 166 has a large number of through holes spaced apart in the longitudinal direction and formed at predetermined intervals, and the air holes 161a are communicated in the width direction by the through holes (see FIG. 18). Further, the air distribution member 166 connects the top 8a and the top 160a (see FIG. 19).

  As shown in FIG. 20, the power generation air supplied via the flow direction adjusting unit 164 is directed from the one end side (right side in FIG. 20) of the air passage cover 160 toward the other end side from the two air distribution members 166. Flow between Since there is no physical resistance like a plate fin between the two air distribution members 166, the power generation air supplied to the inside of the air passage 161a with the flow velocity accelerated by the flow direction adjusting portion 164 is an air passage. The other end of the cover 160 can be reached. Then, the power generation air moves in the width direction through the through holes of the air distribution member 166.

  The power generation air that has passed through the through hole of the air distribution member 166 is subjected to heat exchange with the exhaust gas via the plate fins 162, the top plate 8a, and the plate fins 175 in the exhaust passage 172 to be heated. . Thereafter, the power generation air reaches both end portions in the width direction of the air passage 161a, and is injected into the power generation chamber 10 from the outlet 8f formed in the side plate 8b of the module container 8 via the air passage 161b. .

  The flow path direction adjustment unit 164 is an end side (a side extending in the width direction) different from an end side (a side extending in the longitudinal direction) of the four sides of the top plate 160 a of the air path cover 160 communicating with the air path 161 b. ) Is placed. For this reason, in the present embodiment, the power generation air is supplied in the width direction while being supplied along the longitudinal direction in the air passage 161a on the top plate 8a, and thereafter, for the air passage 161b on the side plate 8b. Power generation air can be evenly supplied in the longitudinal direction.

  In this embodiment, by assembling and fixing the air passage cover 160 from the outside of the module container 8, the air passages 161a and 161b can be easily formed outside the module container 8 (see FIG. 8). Also, after the plate fins 162 and 163 are previously disposed on the top plate 8a and the side plate 8b of the module container 8, the air passage cover 160 can be disposed, and the assemblability of the plate fins 162 and 163 is also good. .

In addition, since the air passage cover 160 can be fixed to the module container 8 by applying mechanical welding from the outside, mass production can be achieved. In particular, in the present embodiment, since the air passage cover 160 both includes the rectangular top plate 160a and the side plate 160b, the outer shell is formed in a straight line, and the application of welding by an automatic machine is easy.
As described above, in the present embodiment, the workability for forming the air passage is improved, and the manufacturing cost can be reduced.

  Further, in the present embodiment, only the exhaust passage needs to be formed in the module container 8, so that the manufacture becomes easy. Furthermore, since the exhaust passage is located in the module container 8, the exhaust gas can be prevented from leaking out of the module container 8. On the other hand, although the air passage is located outside the module container 8, even when the air passage can not be kept airtight, the power generation air can be retained only to leak out of the module container 8.

  Further, in the present embodiment, as shown in FIG. 19, an exhaust pipe 171 is fixed to the exhaust port 111 of the top plate 8 a of the module container 8. Therefore, by inserting the exhaust pipe 171 into the opening 167 of the air passage cover 160, the air passage cover 160 can be positioned with respect to the module container 8, so that good assembly performance can be ensured. .

Further, an annular portion 167a is formed at the opening 167 of the air passage cover 160 by curving the peripheral edge thereof so as to protrude upward. Therefore, the exhaust pipe 171 can be easily inserted into the opening 167 along the curved surface of the annular portion 167a.
Moreover, when fixing the annular part 167a and the exhaust pipe 171, the annular part 167a becomes a connection margin at the time of welding. For this reason, in the present embodiment, the opening 167 of the air passage cover 160 and the peripheral surface of the exhaust pipe 171 can be more reliably fixed by welding, as compared to the case where there is no connection margin such as the annular portion 167a. .
As described above, in the present embodiment, by providing the annular portion 167 a protruding upward in the opening 167, the workability at the time of assembling the air passage cover 160 to the module container 8 can be improved.

  In the present embodiment, as described above, substantial heat exchange is performed in the vicinity of the top plate 8 a of the module container 8 while avoiding heat exchange at the side portion of the fuel cell unit 16. . In this case, since the area of the top plate 8a is smaller than the area of the side plate 8b on the side of the fuel cell unit 16, there is a possibility that the area for performing sufficient heat exchange can not be secured. However, in the present embodiment, the heat exchange distance extending member 176 is provided in addition to the exhaust gas guiding member 130 described above so that sufficient heat exchange can be performed even in a small area.

  As shown in FIG. 21, plate fins 175 are disposed on the upper induction plate 132 of the exhaust gas guiding member 130 on both sides in the width direction across the mixed gas supply pipe 112 and the recess 132 a. In addition, a heat exchange distance extension member 176 is disposed inside the longitudinally extending central side of the plate fins 175. The two heat exchange distance extension members 176 are disposed substantially parallel along the longitudinal direction and symmetrically with respect to the exhaust port 111. The heat exchange distance extending member 176 is a long plate-like member whose length is approximately half of the longitudinal length of the top plate 8a, and the lower end portion thereof is fixed to the upper guide plate 132 and the upper end portion Is in contact with the top 8a (see FIG. 19).

  Exhaust gas supplied from the exhaust passages 173 and 174 to the exhaust passage 172 via the exhaust gas inlet 172a is discharged from an exhaust port 111 provided substantially at the center of the top plate 8a. Therefore, when the heat exchange distance extension member 176 is not provided, the flow of exhaust gas is directed directly from the exhaust gas inlet 172a to the exhaust port 111, and the flow of exhaust gas is partially conducted in the exhaust passage 172. It is biased and can not transfer sufficient heat from the exhaust gas to the plate fins 175. As a result, sufficient heat exchange between the exhaust gas and the power generation air can not be performed.

  Therefore, in the present embodiment, by arranging the two heat exchange distance extending members 176 with the exhaust port 111 interposed therebetween, the exhaust gas is diverted and guided to the exhaust port 111. Specifically, the exhaust gas moves toward the central portion in the width direction of the exhaust passage 172 while passing through the plate fin 175 from the exhaust gas inlet 172a. However, since the heat exchange distance extension member 176 is disposed along the longitudinal direction on both sides of the exhaust port 111, the exhaust gas collides with the heat exchange distance extension member 176, and one end side or the other end in the longitudinal direction By the side, the space between the two heat exchange distance extension members 176 is reached, and the space is further passed to reach the exhaust port 111. As described above, in the present embodiment, by making the exhaust gas bypass the heat exchange distance extending member 176, the distance in which the exhaust gas flows in the exhaust passage 172 is extended, and heat exchange can be performed on the entire surface of the exhaust passage 172. Become. As a result, a sufficient amount of heat can be transferred from the exhaust gas to the power generation air in the air passage 161a, and as a result, the heat exchange efficiency between the exhaust gas and the power generation air can be improved.

Further, since the heat exchange distance extension member 176 is in contact with the top plate 8a at its upper end (see FIG. 19), the heat of the exhaust gas is directly conducted to the top plate 8a, and the inside of the air passage 161a is The power generation air can be heated.
Furthermore, since the power generation air supplied to the air passage 161a collides with the outer peripheral wall of the exhaust pipe 171, the air density is higher in the vicinity of the periphery of the exhaust pipe 171 than in the other regions (broken line A in FIG. 19). Reference), the exhaust pipe 171 is cooled. On the other hand, the upper end portion of the heat exchange distance extension member 176 is in contact with the top plate 8a in the vicinity of the exhaust pipe 171 (and the exhaust port 111) (see FIGS. 19 and 21). For this reason, heat conduction from the heat exchange distance extension member 176 to the exhaust pipe 171 whose temperature has been lowered is promoted, so that the temperature of the power generation air in the air passage 161a can be raised more efficiently.

  Next, as shown in FIG. 22, the plate fins 162, 163, and 175 are formed by pressing a thin rectangular metal plate, and are formed on the flat portion 200 and the flat portion 200 at predetermined intervals. And projections 202 respectively projecting toward both sides of the flat portion 200. The projecting portion 202 is formed by cutting out a part of the flat portion 200 and expanding it into a trapezoidal shape, and includes an inclined portion 202a and a top plate portion 202b. The inclined portion 202a and the top plate portion 202b of the projecting portion 202 are separated from the flat portion 200, and an opening 202c is formed in the separated portion. In the plate fin thus formed, when the gas flows along both side surfaces of the flat portion 200, the gas collides with the protrusion 202 in addition to the heat exchange between the gas and the flat portion 200 directly. The heat exchange between the gas and the protrusion 202 is thereby performed. Thereby, heat exchange can be efficiently performed between the gas and the plate fins.

  In addition, the collision of the gas with the protrusion 202 changes the flow direction of the gas. Specifically, the gas flow path is changed laterally by colliding with the outer surface (surface opposite to the opening 202c) or the inner surface (surface at the opening 202c side) of the inclined portion 202a of the protrusion 202. Ru. Thereby, the gas generally flows in the direction along the flow path, but locally flows in various directions and mixes with each other, thereby improving the dispersibility.

  Further, as shown in FIG. 23, the plate fins 163 are disposed so as to be sandwiched between the side plate 8 b of the module container 8 and the side plate 160 b of the air passage cover 160. The plate fins 163 are in contact with the side plate 8b at the top plate portion 202b of the projection 202, but are in contact with the side plate 160b via the protrusions 203 provided on the top plate portion 202b.

  The protruding portion 203 is formed to have a smaller contact area than the top plate portion 202b, and can be formed, for example, by projecting a part of the top plate portion 202b outward. Moreover, the projection part 203 can also be made into another member with a plate fin with favorable heat conductivity. In this case, it is preferable to form with a material whose thermal conductivity is lower than that of the plate fins.

  The protrusions 203 are not provided on the top plates 202 b of all the protrusions 202 on the side plate 160 b side, but are provided on at least one top plate 202 b. Therefore, among the protrusions 202 that project toward the side plate 160b, most of the protrusions 202 do not contact the side plate 160b, and only one or a few protrusions 202 contact the side plate 160b via the protrusions 203. ing.

  As described above, the plate fins 163 are in contact with the side plate 160 b through the protrusions 203 having a small contact area, preferably low thermal conductivity. Therefore, it is possible to suppress the heat dissipation (heat loss) from the plate fins 163 to the external heat insulating material 7 through the side plate 160b, and the exhaust gas of the exhaust passage 173 and the power generation air of the air passage 161b. The heat exchange efficiency during the heat treatment can be improved. The same applies to the plate fins 162.

  FIG. 24 is a view showing an example of a lid used for the module container 8. The lid 180 closes the side of the opened module container 8 and seals the inside of the module container 8. In the lid 180, the oxygen-containing gas shielding plate 181 is disposed on the inner side.

  By uniformly guiding the oxygen-containing gas supplied to the fuel cell unit 16 housed in the module container 8 to the combustion unit 18, the uniform supply of oxygen-containing gas to the cell surface and the heat balance in the combustion unit 18 Can be stabilized. However, since the fuel gas supply pipe 64 is disposed between the side surface of the fuel cell unit 16 where the fuel gas supply pipe 64 is disposed and the side surface opposite thereto, the flow distribution of the oxygen-containing gas is different. In order to solve this, a plate for shielding the oxygen-containing gas is provided between the fuel gas supply pipe 64 and the fuel cell unit 16 on the side surface of the fuel cell unit 16 where the fuel gas supply pipe 64 is disposed. This makes it possible to make the flow distribution uniform by approximating the oxygen-containing gas flow state on both sides, but in the case of miniaturizing the module container 8, in addition to securing the space for installing the shielding plate, the assembling operation is also possible. It will be difficult. On the other hand, the influence of the flow distribution of the oxygen-containing gas becomes more remarkable as the height of the module is reduced along with the reduction in size.

  Therefore, by directly installing the oxygen-containing gas shielding plate 181 on the lid 180, it is possible to maintain uniformity in the flow distribution of the oxygen-containing gas, and eliminate the deterioration in workability associated with the downsizing. As shown in FIG. 24, the oxygen-containing gas shielding plate 181 is formed by, for example, bending a single flat metal plate, and the portion where the fuel gas supply pipe 64 is installed is directed to the lid 180. By forming the concaved shape, the oxygen-containing gas shielding plate 181 and the fuel gas supply pipe 64 function as a wall that shields the flow path of the oxygen-containing gas, so that the oxygen-containing gas has the same oxygen content as the other side facing it. The flow distribution of the gas can be formed. The fuel gas supply pipe 64 and the oxygen-containing gas shielding plate 181 do not directly contact with each other because the fuel gas supply pipe 64 can be moved by application of thermal stress under high temperature conditions. Preferably, a predetermined distance is formed between the gas shielding plate 181 and the gas shielding plate 181.

  The solid oxide fuel cell device according to the present invention is widely useful in a solid oxide fuel cell device provided with a fuel gas supply pipe for supplying a fuel gas to a fuel manifold.

Reference Signs List 1 solid oxide fuel cell device 2 fuel cell module 7, 7 adiabatic material 8 module container 8 a top plate 8 b side plate 8 d, 8 e closing side plate 10 power generation chamber 16 fuel cell unit 18 combustion chamber (combustion unit)
63 Fuel supply pipe 64 Fuel gas supply pipe (fuel gas supply passage)
Reference Signs List 66 fuel manifold 74 air intake pipe for power generation 82 exhaust gas exhaust pipe 111 exhaust port 112 mixed gas supply pipe 120 reformer 120 b through hole 130 exhaust gas guiding member 131 a convex stepped portion 132 a concave portion 135 gas reservoir 140 evaporator 160 air passage Cover 160a Top plate 160b Side plate 161a, 161b Air passage 162, 163 Plate fin 164 Channel direction adjustment unit 171 Exhaust pipe 172a Exhaust gas inlet 172 Exhaust passage 173 Exhaust passage (second exhaust passage)
174 Exhaust passage (first exhaust passage)
175 plate fin 176 heat exchange distance extension member 180 lid 181 oxygen-containing gas shielding plate 1000 solid oxide fuel cell device (fuel cell module)
1001 module container 1002 reformer 1003 combustion unit 1004 fuel cell 1005 fuel manifold 1010 fuel gas supply pipe 1011 vertical shape portion 1012 direction correction shape portion 1013 stress relief shape portion 1014 fuel gas supply pipe housing portion

Claims (3)

What is claimed is: 1. A solid oxide fuel cell device comprising a plurality of fuel cells that generate electric power by a reaction between a fuel gas obtained by reforming raw fuel and an oxygen-containing gas.
A module container for accommodating the plurality of fuel cells;
An oxygen-containing gas supply pipe for supplying an oxygen-containing gas to the surface of the fuel cell from the outside of the module container;
A combustion unit which burns an off gas exhausted from the upper end of the fuel cell and an oxygen-containing gas in the module container;
A reformer above the combustion unit, which is heated by the exhaust gas generated in the combustion unit and reforms the raw fuel into a fuel gas;
A raw fuel gas supply pipe for supplying raw fuel to the reformer from the outside of the module container;
A fuel manifold for supplying fuel gas reformed in the reformer to the inner flow paths of the plurality of fuel cells erected on the upper surface;
A fuel gas supply pipe fixed at the lower end to the fuel manifold and supplying the fuel gas in the reformer to the inside of the fuel manifold;
The fuel gas supply pipe is curved so as to be inserted horizontally in the fuel manifold and a vertically-shaped portion extending in the vertical direction toward the reformer, and stress relaxation which relieves local concentration of thermal stress It has a shape portion and a direction correction shape portion connecting the stress relaxation shape portion and the vertical shape portion by correcting the bending direction in the stress relaxation shape portion, and the vertical shape portion, the stress relaxation shape portion And the direction correction profile is formed by one tubular member ,
The module container has a main body having a top surface, a bottom surface and two opposing side surfaces, and the other two opposing surfaces.
Composed of two side lids,
The fuel gas supply pipe is in close proximity to one of the lids, and in close proximity to the fuel gas supply pipe.
An oxygen-containing gas shielding plate is provided on one of the lids not in proximity to the fuel gas supply pipe.
What is claimed is: 1. A solid oxide fuel cell device characterized by: In claim 1,
The solid oxide fuel cell device according to claim 1, wherein the direction correction shape portion is disposed to be inclined toward the fuel cell in the module container with respect to a vertical direction. In claim 2,
The solid oxide fuel cell device according to claim 1, wherein the stress relief shape portion makes a bending radius of curvature larger than 2D with respect to an outer diameter D of the fuel gas supply pipe.

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