JP2019071303A - Fuel cell submodule, fuel cell submodule and hybrid power system and assembly method for submodule - Google Patents

Abstract

To provide a fuel cell submodule capable of restraining a reduction in generation efficiency, and to provide a fuel cell module and a hybrid power system and an assembly method for the submodule.SOLUTION: A SOFC submodule 202 to be housed in a pressure vessel 205 includes at least one cell stack 101 generating power when supplying fuel gas and oxidizable gas, a lateral outer casing 4 placed to surround the cell stack 101 and defining a side, and a lower outer casing 5 connected to a lower end of a lateral outer casing 4 and closing an opening formed at the lower end of the lateral outer casing 4. The lateral outer casing 4 has an opening, defined by the upper limb of the lateral outer casing 4, at an upper end. A through hole is formed in the lower outer casing 5, and the lower outer casing 5 includes a cylindrical member communicating with the through hole and extending vertically downward.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a fuel cell submodule, a fuel cell module, a combined power generation system, and a method of assembling the submodule.

  There is known a fuel cell that generates electric power by causing a chemical reaction of a fuel gas and an oxidizing gas. Among them, Solid Oxide Fuel Cell (SOFC) uses ceramics such as zirconia ceramics as an electrolyte, and is operated using city gas, natural gas, petroleum, methanol, coal gasification gas, etc. as fuel. Fuel cell. Such an SOFC has a high operating temperature of about 700 to 1000 ° C. to increase the ion conductivity, and is known as a versatile high-efficiency high-temperature fuel cell. Such an SOFC is, for example, a complex power generation system combined with an internal combustion engine such as a micro gas turbine (hereinafter referred to as "MGT"), and the compressed air discharged from the compressor is used as an oxidizing gas to generate SOFC. By supplying the air electrode and the high temperature exhaust fuel gas discharged from the SOFC to the combustor of the MGT for combustion, and rotating the turbine with the high temperature combustion gas generated in the combustor, High power generation is made possible.

At the time of power generation in SOFC, the power generation unit of SOFC generates heat. The power generation unit preferably generates power within a preset temperature range on the basis of power generation efficiency, durability of constituent materials, and the like.
Therefore, for example, in Patent Document 1, a flow path connecting the internal space of the cartridge provided with the SOFC power generation unit and the external space of the cartridge in a pressure vessel that accommodates the cartridge provided with the SOFC power generation unit, and this flow And a flow control device for controlling the flow rate of oxidizing gas (air) through the passage. According to this configuration, the flow rate of the oxidizing gas leaked from the inner space of the cartridge to the outer space (the space in the pressure vessel) is adjusted according to the temperature inside the cartridge, and the temperature inside the cartridge is made appropriate. It is maintained within the range.

JP, 2016-91968, A

By the way, part of the oxidizing gas supplied as a structure covering the outer periphery of the cartridge in order to reduce the influence on power generation even if there is fluctuation in the supply of the oxidizing gas is the internal space of the cartridge and the external space It is possible to flow a small flow rate between The oxidizing gas supplied into the cartridge for power generation is heated by the heat generation of the power generation unit and rises in the cartridge. At this time, a part of the oxidizing gas leaks from the gap at the top of the cartridge to the outside space. The oxidizing gas leaked to the external space is cooled by heat radiation through heat exchange with the outside of the pressure vessel through the pressure vessel, descends in the external space, and is drawn into the internal space of the cartridge from the gap in the lower part of the cartridge. Thereby, in the pressure vessel, natural convection of the oxidizing gas is generated by the upward flow in the inner space of the cartridge and the downward flow in the outer space of the cartridge. Such natural convection may release heat to the outside of the pressure vessel via the pressure vessel as the oxidizing gas passes through the external space of the cartridge.
In recent years, development of a larger-scale combined power generation system in which a gas turbine with higher output and SOFC are combined has been developed. Since the pressure of the air discharged from the compressor tends to increase as the power of the gas turbine increases, the operating pressure in the pressure vessel also increases in a large scale SOFC combined cycle power generation system. In addition, raising the operating pressure in the pressure vessel is effective to improve the power generation efficiency of the SOFC. On the other hand, when the operating pressure in the pressure vessel is increased, the amount of oxidizing gas leaking from the inner space of the cartridge to the outer space is increased. This is because the gas density is increased by the increase of the operating pressure, the buoyancy acting on the oxidizing gas in the cartridge heated in the power generation unit is increased, and the pressure of the oxidizing gas in the cartridge and the heat insulating material This is because the loss is reduced. Due to these factors, when the operating pressure is high, the oxidizing gas leaked from the cartridge internal space in the pressure vessel increases its natural flow rate from the upper side to the lower side, and the oxidizing gas passes through the external space of the cartridge The amount of heat released to the outside of the pressure vessel through the pressure vessel also increases. As a result, the temperature of the power generation unit in the internal space of the cartridge is lowered more than necessary, which causes a decrease in the power generation efficiency of the SOFC.

  In the configuration disclosed in Patent Document 1, the flow rate of the oxidizing gas flowed out from the inner space of the cartridge to the outer space is adjusted according to the temperature inside the cartridge, but the vertical direction of the oxidizing gas in the pressure vessel As long as natural convection from the top to the bottom occurs, the heat is dissipated from the pressure vessel to the outside, which causes a problem of reducing the power generation efficiency of the SOFC. In addition, in the configuration disclosed in Patent Document 1, when the pressurization operation is performed, natural convection may further increase, and the power generation efficiency of the SOFC may be further reduced.

  The present invention has been made in view of such circumstances, and provides a fuel cell submodule, a fuel cell module, a combined power generation system, and a method of assembling the submodule capable of suppressing a decrease in power generation efficiency. With the goal.

In order to solve the above problems, the fuel cell submodule, the fuel cell module, the combined power generation system, and the method of assembling the submodule of the present invention adopt the following means.
A fuel cell sub-module according to an aspect of the present invention is a fuel cell sub-module housed in a pressure vessel, at least one cell including a fuel cell generating electricity by supplying a fuel gas and an oxidizing gas. A stack and a side armor plate disposed to surround the cell stack and defining a side.

In the above configuration, the oxidizing gas which is going to flow into the power generation region from the side of the outer peripheral surface of the sealing member of the fuel cell submodule (hereinafter, also simply referred to as "submodule") first Hindered by the board. As described above, since the inflow of the oxidizing gas is prevented, the space in the pressure vessel can be more reliably introduced into the area (hereinafter referred to as "power generation area") in which the fuel cell module of the submodule generates power. Unintended inflow of oxidizing gas can be suppressed. Therefore, it is possible to more reliably suppress the natural convection circulation of the oxidizing gas which circulates downward from above in the vertical direction inside the power generation region and outside the power generation region in the pressure vessel, and the natural convection circulation of the oxidizing gas It is possible to suppress the heat radiation to the outside of the pressure vessel due to it.
Moreover, when assembling a submodule, it can assemble on the basis of a side exterior board about lateral positioning. Therefore, the positioning operation at the time of assembling can be facilitated.

  In the fuel cell submodule according to one aspect of the present invention, the side exterior plate may have an opening defined by the upper edge of the side exterior plate at the upper end.

  In the above configuration, an opening defined by the upper edge is formed at the upper end of the side exterior plate. As described above, since the lid member covering the vertical upper part of the sub module is not provided, even if the member constituting the sub module is thermally expanded due to high temperature, the thermal expansion can be allowed in the vertical upper part. , Restraining the submodules.

  The fuel cell submodule according to one aspect of the present invention may further include a lower exterior plate connected to the lower end of the side exterior plate and closing an opening formed in the lower end of the side exterior plate.

In the above configuration, since the entire lower part of the submodule is covered with the lower exterior plate, the oxidizing gas which is going to flow into the submodule from the lower side is surely blocked by the lower exterior plate. Therefore, it is possible to more reliably prevent the unintended oxidizing gas from flowing from the space in the pressure vessel into the power generation area of the submodule.
In addition, when assembling the submodules, the positioning in the vertical vertical direction can be performed with reference to the lower exterior plate. Therefore, the positioning operation at the time of assembling can be facilitated.

  In the fuel cell sub-module according to one aspect of the present invention, a through hole is formed in the lower exterior plate, and the lower exterior plate includes a cylindrical member communicating with the through hole and extending vertically downward. It may be

  In the above configuration, a through hole is formed in the lower exterior plate, and a cylindrical member communicating with the through hole is provided. Thereby, for example, even if there is a pipe extending vertically downward from the side of the fuel gas header, the pipe is inserted into the through hole and the inside of the cylindrical member to seal the pipe, It can communicate with the outside. Further, since the inside of the cylindrical member is inserted, the portion has a double pipe structure, and the pipe passes from the space in the pressure vessel to the portion of the sub-module even when the pipe penetrates the lower exterior plate. Inflow of oxidizing gas can be suppressed.

  Further, the fuel cell sub-module according to one aspect of the present invention includes a pipe through which the inside of the cylindrical member is inserted, and a part of the cylindrical member is formed of a flexible pipe having flexibility, the flexible The portion formed of a pipe may be located vertically above the portion for sealing and fixing the tubular member and the pipe.

  In the above-mentioned configuration, a part of the cylindrical member is formed of a flexible pipe having flexibility so as to allow expansion and contraction in the vertical vertical direction. Thereby, even if the tubular member or the pipe is thermally expanded under the influence of the high temperature of the power generation region of the sub module, the flexible pipe absorbs expansion and contraction in the vertical vertical direction, so the fixed portion between the tubular member and the pipe The generated load can be reduced. In addition, a part of piping may also be formed by the flexible pipe which has flexibility. With such a configuration, since expansion and contraction in the vertical vertical direction can be absorbed even on the piping side, the fixing portion between the tubular member and the piping is not restrained, thereby further reducing the stress generated in the piping. it can.

  In the fuel cell submodule according to one aspect of the present invention, a plurality of the cell stacks are connected, and the fuel gas is supplied to the plurality of cell stacks or the fuel gas is discharged from the plurality of cell stacks. The fuel cell system may further include a gas header, and a lower armor plate connected at one end to the lower end of the side armor plate and connected at the other end to the side end of the fuel gas header.

  In the above configuration, the bottom surface of the submodule with the fuel gas header is not covered by the lower exterior plate, so when connecting the piping, current collector, etc. to the bottom surface of the fuel gas header, the piping, current collection rod, etc. penetrates the lower exterior plate There is no need to make it a structure. In the case where the piping, the current collection rod, and the like penetrate the lower exterior plate, it is necessary to form a sealed structure while securing insulation in each piping and the current collection rod so that the oxidizing gas does not flow into the lower exterior plate. Although the structure is complicated, the above configuration allows easy connection.

  In the fuel cell submodule according to one aspect of the present invention, the upper surface of the lower exterior plate in the vertical direction and the bottom surface of the fuel gas header are vertically separated from each other, and the upper surface of the lower exterior plate in the vertical direction and the fuel The bottom surface of the gas header may be connected via a seal plate extending vertically in the vertical direction.

  In the above configuration, a seal plate is provided that connects the upper surface of the lower exterior plate and the bottom surface of the fuel gas header. Thus, it is possible to prevent the inflow of the oxidizing gas from the space while forming a space between the upper surface of the lower exterior plate and the bottom surface of the fuel gas header. Therefore, for example, even when there is a member extending vertically downward from the bottom surface of the fuel gas header, it is possible to suppress the inflow of the unintended oxidizing gas into the power generation unit. As a member extending vertically downward from the bottom surface of the fuel gas header, there is, for example, a leg portion for erecting the cartridge constituting the sub module in the sub module.

  Further, a fuel cell submodule according to an aspect of the present invention includes a sealing member that encloses at least a part of the cell stack, and a plurality of the cell stacks each have a central portion provided with the fuel cells. A part of the cell stack which includes the end part where the fuel cell is not provided, and the sealing member encloses is the central part where the fuel cell is provided, and the sealing member is the inside of the sealing member An oxidizing gas supply unit that supplies the oxidizing gas around the plurality of cell stacks, and an oxidizing gas discharge unit that discharges the oxidizing gas from the inside, and the oxidizing gas supply unit and the oxidation In the remaining part other than the sexual gas discharge part, the inflow of the oxidizing gas into the inside and the leakage of the oxidizing gas from the inside may be suppressed.

  In the above configuration, the sealing member in the submodule encloses the central portion in which the fuel cells of the plurality of cell stacks are provided. Thus, the periphery of the power generation area can be enclosed by the sealing member. Further, in the remaining portion other than the oxidizing gas supply unit and the oxidizing gas discharge portion, the sealing member flows in the oxidizing gas into the inside (that is, the power generation region) of the sealing member and the oxidizing gas from the inside of the sealing member. Since the discharge is prevented, it is possible to suppress the inflow and the leakage of the unintended oxidizing gas between the space in the pressure vessel and the power generation area of the submodule. Therefore, natural convection circulation of oxidizing gas which leaks from the inside of the power generation area and circulates from the upper side to the bottom of the power generation area in the pressure vessel, which may occur in the space inside the pressure vessel Can be suppressed. Therefore, the heat dissipation to the outside of the pressure vessel due to the natural convection circulation of the oxidizing gas can be suppressed, and the decrease in the power generation efficiency of the fuel cell module can be suppressed.

  Further, the fuel cell submodule according to one aspect of the present invention includes an oxidizing gas flow pipe communicating with the oxidizing gas supply unit or the oxidizing gas discharge unit, and the oxidizing gas flow pipe is connected to the side surface It may extend in the vertical up-down direction inside the exterior plate.

  In the above configuration, since the oxidizing gas flow pipe extends vertically in the side outer plate, the oxidizing gas flow pipe and the side outer plate do not interfere with each other. Therefore, since it is not necessary to form the structure for making an oxidizing gas distribution pipe penetrate in a side armoring board, it can be set as a simple structure. Also, for example, when a heat insulating material or the like is provided between the side exterior plate and the oxidizing gas flow pipe, the oxidizing gas flow pipe does not interfere with the heat insulating material. Therefore, since the submodule can be formed without providing a member for penetrating the heat insulating material, when the submodule is disassembled, the heat insulating material can be disassembled without breakage.

  A fuel cell module according to an aspect of the present invention includes a pressure vessel, and the fuel cell submodule according to any one of the above-described accommodated in the pressure vessel.

  According to one aspect of the present invention, there is provided a combined power generation system comprising: a fuel cell module as described above; and a gas turbine generating rotational power using exhaust fuel gas exhausted from the fuel cell module and exhaust oxidizing gas. The oxidizing gas compressed using the rotational power is supplied to the fuel cell module, and a plurality of the cell stacks generate electric power using the fuel gas and the oxidizing gas.

  According to one aspect of the present invention, there is provided a method of assembling a submodule, comprising: at least one cell stack including a fuel cell generating electricity by supplying a fuel gas and an oxidizing gas; Method of assembling a fuel cell sub-module comprising: a side exterior plate defining a side; and a lower exterior plate connected to the lower end of the side exterior plate and closing an opening formed at the lower end of the side exterior plate. A connecting step of connecting the side exterior plate and the lower exterior plate, and a cell stack inserting step of inserting the cell stack vertically from above with respect to the side exterior plate connected in the connecting step. Have.

  Further, the method of assembling a submodule according to one aspect of the present invention may further include a sealing member disposing step of arranging a sealing member so as to surround the cell stack.

  Moreover, the assembling method of the submodule which concerns on 1 aspect of this invention may further be equipped with the submodule heat insulating material fitting process which inserts a submodule heat insulating material in the inside of the said side exterior board and the said lower exterior board.

  According to the present invention, it is possible to suppress the decrease in the power generation efficiency of the fuel cell submodule.

Fig. 6 shows a cell stack according to an embodiment of the present invention. Fig. 2 shows a SOFC module according to an embodiment of the present invention. Fig. 2 shows a cross section of a SOFC cartridge according to an embodiment of the present invention. It is a longitudinal section showing a SOFC module concerning one embodiment of the present invention. It is an expanded sectional view of V part of FIG. FIG. 5 is a schematic view of the lower portion of the SOFC submodule of FIG. 4; It is the VII-VII arrow sectional drawing of FIG. It is a perspective view which shows the seal board of FIG. It is a figure which shows the assembling method of the SOFC submodule of FIG.

Hereinafter, an embodiment of a fuel cell submodule, a fuel cell module, a combined power generation system, and a method of assembling the submodule according to the present invention will be described with reference to the drawings.
In the following, for convenience of explanation, the positional relationship between the respective components is indicated by the vertically upper side and the vertically lower side using the expressions “upper” and “lower” with reference to the paper surface. Further, in the present embodiment, those which can obtain the same effect in the vertical direction and in the horizontal direction with respect to the vertical direction may correspond to the horizontal direction in which the vertical direction in the drawing is perpendicular to the vertical direction. Further, in the following, a cylindrical shape is described as an example of a cell stack of a solid oxide fuel cell (SOFC), but this is not necessarily the case. For example, a flat cell stack may be used. Although the fuel cell is formed on the substrate, the substrate (fuel electrode or air electrode) may be thick without a substrate, and the substrate may also be used.

  First, a cylindrical cell stack using a base tube will be described as an example according to the present embodiment with reference to FIG. Here, FIG. 1 shows one aspect of the cell stack according to the present embodiment. The cell stack 101 has a cylindrical base tube 103, a plurality of fuel cells 105 formed on the outer peripheral surface of the base tube 103, and an interconnector 107 formed between adjacent fuel cells 105. The fuel cell 105 is formed by laminating a fuel electrode 109, a solid electrolyte 111 and an air electrode 113. Further, among the plurality of fuel cells 105 formed on the outer peripheral surface of the base tube 103, the cell stack 101 is attached to the air electrode 113 of the fuel cell 105 formed at one end of the end of the base tube 103 in the axial direction. A lead film 115 electrically connected via an interconnector 107 is provided, and a lead film 115 electrically connected to a fuel electrode 109 of the fuel cell 105 formed at the other end of the end is provided.

The base tube 103 is made of a porous material, for example, CaO stabilized ZrO ₂ (CSZ), a mixture of CSZ and nickel oxide (NiO) (CSZ + NiO), or Y ₂ O ₃ stabilized ZrO ₂ (YSZ), or It is mainly composed of MgAl ₂ O ₄ or the like. The base tube 103 supports the fuel cell 105, the interconnector 107, and the lead film 115, and the fuel gas supplied to the inner peripheral surface of the base tube 103 through the pores of the base tube 103. It diffuses to the fuel electrode 109 formed on the outer peripheral surface of the

The fuel electrode 109 is made of an oxide of a composite material of Ni and a zirconia-based electrolyte material, and for example, Ni / YSZ is used. The thickness of the fuel electrode 109 is 50 to 250 μm. In this case, in the fuel electrode 109, Ni, which is a component of the fuel electrode 109, has a catalytic effect on the fuel gas. This catalytic reaction reacts the mixed gas of fuel gas supplied via the base tube 103, for example, methane (CH ₄ ) and steam, and reforms it to hydrogen (H ₂ ) and carbon monoxide (CO). It is a thing. In addition, the fuel electrode 109 is an interface between the solid electrolyte 111 and hydrogen (H ₂ ) and carbon monoxide (CO) obtained by reforming, and oxygen ions (O ²⁻ ) supplied via the solid electrolyte 111. It is reacted electrochemically in the vicinity to generate water (H ₂ O) and carbon dioxide (CO ₂ ). At this time, the fuel cell 105 generates electric power by the electrons released from the oxygen ions.
Examples of fuel gas that can be supplied to the fuel electrode 109 of the SOFC 10 and used include hydrogen (H ₂ ) and carbon monoxide (CO), hydrocarbon gases such as methane (CH ₄ ), city gas, natural gas, oil, and the like The gas etc. which manufactured carbonaceous raw materials, such as methanol and coal, with gasification equipment are mentioned.

As the solid electrolyte 111, YSZ having gas tightness which is hard to pass gas and high oxygen ion conductivity at high temperature is mainly used. The solid electrolyte 111 is for transferring oxygen ions (O ²⁻ ) generated at the air electrode to the fuel electrode. The film thickness of the solid electrolyte 111 located on the surface of the fuel electrode 109 is 10 to 100 μm.

The air electrode 113 is made of, for example, a LaSrMnO ₃ -based oxide or a LaCoO ₃ -based oxide. The air electrode 113 dissociates oxygen in an oxidizing gas such as air supplied near the interface with the solid electrolyte 111 to generate oxygen ions (O ²⁻ ).
The air electrode 113 can also be configured in two layers. In this case, the air electrode layer (air electrode intermediate layer) on the solid electrolyte 111 side exhibits high ion conductivity and is made of a material having excellent catalytic activity. The air electrode layer (air electrode conductive layer) on the air electrode intermediate layer may be made of a perovskite type oxide represented by Sr and Ca-doped LaMnO ₃ . By doing this, the power generation performance can be further improved.
Oxidizing gas is a gas containing approximately 15% to 30% oxygen, and typically air is preferable, but besides air, mixed gas of combustion exhaust gas and air, mixed gas of oxygen and air, etc. Is available.

The interconnector 107 is composed of a conductive perovskite-type oxide represented by M _1-x L _x TiO ₃ (M is an alkaline earth metal element and L is a lanthanoid element) such as SrTiO ₃ . The interconnector 107 is a dense film so that the fuel gas and the oxidizing gas do not mix. Further, the interconnector 107 has stable durability and electrical conductivity under both the oxidizing atmosphere and the reducing atmosphere. The interconnector 107 electrically connects the air electrode 113 of one fuel cell 105 and the fuel electrode 109 of the other fuel cell 105 in the adjacent fuel cells 105, and the adjacent fuel cells 105 Are connected in series. The lead film 115 is required to have electron conductivity and to have close thermal expansion coefficients with other materials constituting the cell stack 101, so that Ni and a zirconia-based electrolyte material such as Ni / YSZ can be used. It is composed of a composite material. The lead film 115 leads the direct current power generated by the plurality of fuel cells 105 connected in series by the interconnect to the vicinity of the end of the cell stack 101.

  Next, the SOFC module and the SOFC cartridge according to the present embodiment will be described with reference to FIGS. 2 and 3. Here, FIG. 2 shows the SOFC module according to the present embodiment. FIG. 3 is a cross-sectional view of the SOFC cartridge according to the present embodiment.

  As shown in FIG. 2, the SOFC module (fuel cell module) 201 includes, for example, a plurality of SOFC cartridges 203 and a pressure vessel 205 for housing the plurality of SOFC cartridges 203. In addition, although the cell stack of cylindrical SOFC is illustrated in FIG. 2, it does not necessarily need to be this limitation, for example, may be a flat cell stack. The SOFC module 201 further includes a fuel gas supply pipe 207, a plurality of fuel gas supply branch pipes 207a, a fuel gas discharge pipe 209, and a plurality of fuel gas discharge branch pipes 209a. In addition, the SOFC module 201 includes an oxidizing gas supply pipe 211 (see FIG. 4), an oxidizing gas supply branch pipe (oxidizing gas flow pipe) 212 (see FIG. 4), and an oxidizing gas discharge pipe 213 (see FIG. 4). And a plurality of oxidizing gas discharge branch pipes 214 (see FIG. 4).

  The fuel gas supply pipe 207 is provided outside the pressure vessel 205 and connected to a fuel gas supply unit that supplies a fuel gas of a predetermined gas composition and a predetermined flow rate corresponding to the amount of power generation of the SOFC module 201. It is connected to the fuel gas supply branch pipe 207a. The fuel gas supply pipe 207 branches and guides the fuel gas having a predetermined flow rate supplied from the above-described fuel gas supply unit into a plurality of fuel gas supply branch pipes 207a. Further, the fuel gas supply branch pipe 207 a is connected to the fuel gas supply pipe 207 and to the plurality of SOFC cartridges 203. The fuel gas supply branch pipe 207a guides the fuel gas supplied from the fuel gas supply pipe 207 to the plurality of SOFC cartridges 203 at substantially equal flow rates, and makes the power generation performance of the plurality of SOFC cartridges 203 substantially uniform. .

  The fuel gas discharge branch pipe 209 a is connected to the plurality of SOFC cartridges 203 and to the fuel gas discharge pipe 209. The fuel gas discharge branch pipe 209 a guides the exhaust fuel gas discharged from the SOFC cartridge 203 to the fuel gas discharge pipe 209. Further, the fuel gas discharge pipe 209 is connected to a plurality of fuel gas discharge branch pipes 209 a, and a part thereof is disposed outside the pressure vessel 205. The fuel gas discharge pipe 209 guides the exhaust fuel gas, which is derived at a substantially equal flow rate from the fuel gas discharge branch pipe 209a, to the outside of the pressure vessel 205.

  Since the pressure vessel 205 is operated at an internal pressure of 0.1 MPa to about 3 MPa and an internal temperature at ambient temperature to about 550 ° C., the pressure resistance and the corrosion resistance to oxidizing agents such as oxygen contained in the oxidizing gas are obtained. Used materials are used. For example, stainless steel such as SUS304 is suitable.

  Here, in the present embodiment, an aspect in which the plurality of SOFC cartridges 203 are collected and stored in the pressure vessel 205 is described, but the present invention is not limited thereto. For example, the pressure is not collected in the SOFC cartridges 203 It is also possible to adopt a mode in which it is housed in the container 205.

  As shown in FIG. 3, the SOFC cartridge 203 includes a plurality of cell stacks 101, a power generation chamber 215, a fuel gas supply chamber 217, a fuel gas discharge chamber (fuel gas header) 219, an oxidizing gas supply chamber 221, and oxidation. And an inert gas discharge chamber 223. The SOFC cartridge 203 further includes an upper tube plate 225a, a lower tube plate 225b, an upper heat insulator 227a, and a lower heat insulator 227b. In the present embodiment, in the SOFC cartridge 203, the fuel gas supply chamber 217, the fuel gas discharge chamber 219, the oxidizing gas supply chamber 221, and the oxidizing gas discharge chamber 223 are arranged as shown in FIG. Although the fuel gas and the oxidizing gas flow in such a manner that they flow opposite to each other inside and outside the cell stack 101, this is not necessarily the case, for example, flows in parallel between the inside and the outside of the cell stack Alternatively, the oxidizing gas may flow in a direction perpendicular to the longitudinal direction of the cell stack.

  The power generation chamber 215 is an area formed between the upper heat insulator 227a and the lower heat insulator 227b. The power generation chamber 215 is a region where the fuel cells 105 of the cell stack 101 are disposed, and is a region in which the fuel gas and the oxidizing gas are electrochemically reacted to generate power. Further, the temperature near the center of the cell stack 101 in the longitudinal direction of the power generation chamber 215 is monitored by a temperature sensor or the like, and becomes a high temperature atmosphere of approximately 700 ° C. to 1000 ° C. during steady operation of the SOFC module 201.

  The fuel gas supply chamber 217 is an area surrounded by the upper casing 229a and the upper tube plate 225a of the SOFC cartridge 203, and the fuel gas supply branch pipe 207a is formed by the fuel gas supply hole 231a provided in the upper portion of the upper casing 229a. It is in communication with The plurality of cell stacks 101 are joined to the upper tube plate 225a by a seal member 237a, and the fuel gas supply chamber 217 is a fuel supplied from the fuel gas supply branch pipe 207a through the fuel gas supply holes 231a. The gas is introduced into the base tubes 103 of the plurality of cell stacks 101 at a substantially uniform flow rate, and the power generation performance of the plurality of cell stacks 101 is substantially uniformed.

  The fuel gas discharge chamber 219 is a region surrounded by the lower casing 229b and the lower tube plate 225b of the SOFC cartridge 203, and the fuel gas discharge branch pipe 209a is formed by the fuel gas discharge hole 231b provided in the lower portion of the lower casing 229b. It is in communication with Further, the plurality of cell stacks 101 are joined to the lower tube plate 225b by the seal member 237b, and the fuel gas discharge chamber 219 passes through the inside of the base pipe 103 of the plurality of cell stacks 101 to discharge the fuel gas. The chamber 219 collects the exhaust fuel gas which passes through the inside of the base pipe 103 of the plurality of cell stacks 101 and is supplied to the fuel gas discharge chamber 219, and the fuel gas discharge branch pipe 209a passes through the fuel gas discharge holes 231b. Leading to

  An oxidizing gas having a predetermined gas composition and a predetermined flow rate is branched to the oxidizing gas supply branch pipe 212 corresponding to the amount of power generation of the SOFC module 201 and supplied to the plurality of SOFC cartridges 203. The oxidizing gas supply chamber 221 is an area surrounded by the lower casing 229b, the lower tube plate 225b, and the lower heat insulator 227b of the SOFC cartridge 203. Further, an oxidizing gas supply hole 233a provided on a side surface of the lower casing 229b communicates with an oxidizing gas supply branch (not shown). The oxidizing gas supply chamber 221 is provided with an oxidizing gas supply gap (an oxidizing gas described later, which is supplied with a predetermined flow rate from the oxidizing gas supply branch pipe (not shown) through the oxidizing gas supply hole 233a. Feeding portion) leads to the power generation chamber 215 via 235a.

  The oxidizing gas discharge chamber 223 is a region surrounded by the upper casing 229 a of the SOFC cartridge 203, the upper tube plate 225 a, and the upper heat insulator 227 a. Further, it is communicated with the oxidizing gas discharge branch pipe 214 by an oxidizing gas discharge hole 233b provided on the side surface of the upper casing 229a. The oxidizing gas discharge chamber 223 oxidizes the exhaust oxidizing gas supplied from the power generation chamber 215 to the oxidizing gas discharge chamber 223 via an oxidizing gas discharge gap (oxidizing gas discharge portion) 235b described later. It leads to the 3rd oxidizing gas discharge branch pipe which is not illustrated via gas exhaust hole 233b.

  The upper tube plate 225a is formed between the top plate of the upper casing 229a and the upper heat insulator 227a such that the upper tube plate 225a and the top plate of the upper casing 229a are substantially parallel to the upper heat insulator 227a. It is fixed to the side plate of. The upper tube plate 225a has a plurality of holes corresponding to the number of cell stacks 101 provided in the SOFC cartridge 203, and the cell stacks 101 are respectively inserted into the holes. The upper tube sheet 225a airtightly supports one end of the plurality of cell stacks 101 via one or both of the seal member 237a and the adhesive member, and at the same time, the fuel gas supply chamber 217 and the oxidizing gas discharge chamber 223 is to be isolated.

  The lower tube plate 225b is formed on the side plate of the lower casing 229b so that the lower tube plate 225b, the bottom plate of the lower casing 229b, and the lower insulator 227b are substantially parallel between the bottom plate of the lower casing 229b and the lower heat insulator 227b. It is fixed. The lower tube plate 225b has a plurality of holes corresponding to the number of cell stacks 101 provided in the SOFC cartridge 203, and the cell stacks 101 are respectively inserted into the holes. The lower tube sheet 225 b airtightly supports the other end of the plurality of cell stacks 101 via one or both of the seal member 237 b and the adhesive member, and at the same time, the fuel gas discharge chamber 219 and the oxidizing gas supply chamber 221 is to be isolated.

  The upper heat insulator 227a is disposed at the lower end of the upper casing 229a so that the upper heat insulator 227a, the top plate of the upper casing 229a, and the upper tube plate 225a are substantially parallel, and fixed to the side plate of the upper casing 229a There is. Further, the upper heat insulator 227a is provided with a plurality of holes corresponding to the number of the cell stacks 101 provided in the SOFC cartridge 203. The diameter of the hole is set to be larger than the outer diameter of the cell stack 101. The upper heat insulator 227a includes an oxidizing gas discharge gap 235b formed between the inner surface of the hole and the outer surface of the cell stack 101 inserted into the upper heat insulator 227a.

  The upper heat insulator 227a separates the power generation chamber 215 from the oxidizing gas discharge chamber 223, and the atmosphere around the upper tube plate 225a becomes high in temperature and the strength decreases and the corrosion by the oxidizing agent contained in the oxidizing gas occurs. Suppress the increase. Although the upper tube sheet 225a and the like are made of a high-temperature durable metal material such as Inconel, the upper tube sheet 225a and the like are exposed to the high temperature in the power generation chamber 215 and the temperature difference in the upper tube sheet 225a and the like becomes large. It prevents heat deformation. Further, the upper heat insulator 227 a is for guiding the exhaust oxidizing gas that has passed through the power generation chamber 215 and has been exposed to a high temperature to the oxidizing gas discharge chamber 223 through the oxidizing gas discharge gap 235 b.

  According to the present embodiment, the fuel gas and the oxidizing gas flow to the inside and the outside of the cell stack 101 so as to face each other due to the above-described structure of the SOFC cartridge 203. As a result, the exhaust oxidizing gas undergoes heat exchange with the fuel gas supplied to the power generation chamber 215 through the inside of the base tube 103, and the upper tube sheet 225a and the like made of a metallic material is buckled or the like. It is cooled to a non-deformed temperature and supplied to the oxidizing gas discharge chamber 223. Further, the fuel gas is heated by heat exchange with the exhaust oxidizing gas discharged from the power generation chamber 215, and is supplied to the power generation chamber 215. As a result, the fuel gas preheated to a temperature suitable for power generation can be supplied to the power generation chamber 215 without using a heater or the like.

  The lower heat insulator 227b is disposed at the upper end of the lower casing 229b so that the lower heat insulator 227b, the bottom plate of the lower casing 229b, and the lower tube plate 225b are substantially parallel, and is fixed to the side plate of the lower casing 229b . The lower heat insulator 227 b is also provided with a plurality of holes corresponding to the number of cell stacks 101 provided in the SOFC cartridge 203. The diameter of the hole is set to be larger than the outer diameter of the cell stack 101. The lower heat insulator 227b includes an oxidizing gas supply gap 235a formed between the inner surface of the hole and the outer surface of the cell stack 101 inserted into the lower heat insulator 227b.

  The lower heat insulator 227b separates the power generation chamber 215 from the oxidizing gas supply chamber 221, and the atmosphere around the lower tube plate 225b becomes high in temperature and the strength decreases, and the corrosion by the oxidizing agent contained in the oxidizing gas occurs. Suppress the increase. The lower tube sheet 225b etc. is made of a high temperature durable metal material such as Inconel, but the lower tube sheet 225 b etc. is exposed to high temperature and thermally deformed due to the temperature difference inside the lower tube sheet 225 b etc. becoming large. It is something to prevent. The lower heat insulator 227 b is configured to guide the oxidizing gas supplied to the oxidizing gas supply chamber 221 through the oxidizing gas supply gap 235 a to the power generation chamber 215.

  According to the present embodiment, the fuel gas and the oxidizing gas flow to the inside and the outside of the cell stack 101 so as to face each other due to the above-described structure of the SOFC cartridge 203. As a result, the exhaust fuel gas passing through the interior of the base tube 103 and passing through the power generation chamber 215 is subjected to heat exchange with the oxidizing gas supplied to the power generation chamber 215, and the lower tube sheet 225b made of a metallic material. It is cooled to a temperature that does not cause deformation such as buckling, and is supplied to the fuel gas discharge chamber 219. Further, the oxidizing gas is heated by heat exchange with the exhaust fuel gas, and is supplied to the power generation chamber 215. As a result, the oxidizing gas heated to a temperature necessary for power generation can be supplied to the power generation chamber 215 without using a heater or the like.

  After the DC power generated in the power generation chamber 215 is drawn to the vicinity of the end of the cell stack 101 by lead films 115 formed of Ni / YSZ or the like provided in a plurality of fuel cells 105, the current collector of the SOFC cartridge 203 The current is collected via a current collector plate (not shown) and taken out to the outside of each SOFC cartridge 203. The DC power drawn to the outside of the SOFC cartridge 203 by the current collecting rod mutually connects the generated power of each SOFC cartridge 203 to a predetermined number of series and parallel numbers, and is drawn to the outside of the SOFC module 201, It is converted into predetermined AC power by a power conversion device (such as an inverter) such as a power conditioner (not shown), and is supplied to a power supply destination (for example, load equipment or a power system). The current collectors include one projecting above the SOFC cartridge 203 and one projecting below. An upwardly projecting current collector extends upward through the fuel gas supply chamber 217 and a submodule upper heat insulator 11 described later. The downwardly projecting current collector extends downward through the fuel gas discharge chamber 219 and a submodule lower thermal insulator 12 described later.

  The SOFC module 201 further includes the pressure vessel side heat insulating material 1. The pressure vessel side heat insulating material 1 is disposed so as to cover the inner circumferential wall of the pressure vessel 205.

  Next, details of the SOFC submodule (fuel cell submodule) 202 (see FIG. 2) in which a plurality of SOFC cartridges 203 are combined will be described using FIGS. 4 to 9. FIG. FIG. 4 schematically shows a longitudinal cross-sectional view of the SOFC module 201. For the sake of illustration, a plurality of SOFC cartridges 203 (see FIG. 2) are respectively divided and not shown, but are collectively shown in one. It is illustrated as a SOFC submodule 202.

  As shown in FIG. 4, the SOFC submodule 202 includes a plurality of SOFC cartridges 203 as well as a cartridge heat insulating material (sealing member) 2 surrounding the power generation chamber 215 and a plurality of SOFC cartridges 203 outside the cartridge heat insulating material 2. In the central axis direction of the SOFC submodule 202 from the entire area of the lower end of the submodule heat insulator 3 surrounding the whole, the frame-like side exterior plate 4 defining the side of the SOFC submodule 202, and the lower end of the side exterior plate 4 The lower exterior plate 5 extends a predetermined length substantially horizontally toward the lower side of the SOFC submodule 202 and is accommodated inside the pressure vessel 205.

  The cartridge heat insulating material 2 is formed by laminating and bonding a plurality of boards (or plates) formed of a heat insulating material. Further, in the cartridge heat insulating material 2, the cartridge upper heat insulating material 6 to which the upper heat insulator 227a (see FIG. 3) respectively provided to the plurality of SOFC cartridges 203 is joined and the lower heat insulator 227b respectively provided to the plurality of SOFC cartridges 203 are joined. The cartridge lower heat insulator 7 and the plate frame-shaped cartridge side heat insulator 8 connecting the entire side surface of the cartridge upper heat insulator 6 and the entire side surface of the cartridge lower heat insulator 7 are provided. The cartridge side heat insulating material 8 is composed of a plurality of heat insulating members 8a having upper and lower end surfaces having a key-like uneven shape, and the plurality of heat insulating members 8a are fitted with the unevenness of the heat insulating members 8a adjacent to each other vertically. As a structure in which a so-called inlay structure connected to the heat insulating member 8a is less likely to generate a continuous gap between the heat insulating members 8a, the passage of the oxidizing gas is suppressed (see FIG. 9). The cartridge upper heat insulator 6, the cartridge lower heat insulator 7, and the cartridge side heat insulator 8 are connected to form a box-like sealed space inside, and all the fuel cells provided in the SOFC submodule 202 inside 105 are arranged. That is, the cartridge upper heat insulator 6, the cartridge lower heat insulator 7, and the cartridge side heat insulator 8 pass through the remaining portions other than the oxidizing gas supply gap 235a and the oxidizing gas discharge gap 235b, An internally sealed power generation chamber 215 is formed so as to suppress the inflow or leakage of the oxidizing gas therebetween. Therefore, the cartridge heat insulating material 2 encloses only a part of the cell stack 101 in which the fuel cells 105 are provided. That is, since the fuel cell 105 is provided at a substantially central portion in the longitudinal direction of the cell stack 101 and is not provided at an end portion, the cartridge heat insulating material 2 surrounds only a substantially central portion of the cell stack 101 It will be.

  The submodule heat insulating material 3 is formed by laminating and joining a plurality of boards (or plates) formed of a heat insulating material, and is disposed inside the pressure vessel 205 so as to surround a plurality of SOFC cartridges 203. . The submodule heat insulating material 3 has a substantially rectangular parallelepiped shape in which a space is formed inside. The submodule heat insulator 3 includes a submodule upper heat insulator 11 corresponding to the upper surface of the rectangular parallelepiped, a submodule lower heat insulator 12 corresponding to the lower surface of the rectangular parallelepiped, and a submodule side heat insulator 13 corresponding to the side surface of the rectangular parallelepiped.

  The lower surface of the submodule upper heat insulating material 11 is fixed to the upper surface of the upper casing 229a. The submodule side heat insulating material 13 is a plate-like member extending vertically downward from the side edges of the four sides of the submodule upper heat insulating material 11. The submodule side heat insulating material 13 is thermally expanded at, for example, the center or lower end of the inner peripheral surface. It is fixed to the outer peripheral surface of the cartridge side heat insulating material 8 so as to avoid relative positional displacement and mutual restraint. The top surface of the submodule lower heat insulating material 12 is fixed to the bottom surface of the lower casing 229b. The four side end portions of the submodule lower heat insulating material 12 extend to the vicinity of the lower end of the submodule side heat insulating material 13 and are fixed to a seal plate 15 described later. That is, the submodule lower heat insulator 12 and the submodule side heat insulator 13 are connected via the seal plate 15. Thus, the submodule lower thermal insulator 12 and the submodule lateral thermal insulator 13 are configured to form a box-like inner space 10 inside, and the submodule upper thermal insulator 11 is a submodule lateral thermal insulator The SOFC cartridge 203 is installed so as to allow vertical displacement due to thermal expansion.

  The submodule thermal insulator 3 separates the inside of the pressure vessel 205 into the outer space 9 and the inner space 10. The outer space 9 is a space formed between the pressure vessel 205 and the submodule thermal insulator 3. The inner space 10 is a space surrounded by the submodule heat insulating material 3 and accommodates a plurality of SOFC cartridges 203, the cartridge heat insulating material 2, and the like. That is, the inner space 10 is a space including the power generation chamber 215, and the inner space 10 and the power generation chamber 215 are separated by the cartridge heat insulating material 2.

  The side exterior plate 4 is a metal plate having a thickness of about 2 mm to 5 mm, and is a plate-like shape formed of a heat-resistant and corrosion-resistant plate (for example, SUS 304). It is fixed between the peripheral outer peripheral surface of the material 13. Further, the side exterior plate 4 has an opening at the lower end, and a lower exterior plate 5 described later covers a part of the lower end. Further, at the upper end of the side exterior plate 4, an opening defined by the upper edge of the side exterior plate 4 is formed. The lower end of the side exterior plate 4 is disposed below the bottom surface of the lower casing 229b.

  The lower exterior plate 5 is a plate-like member extending substantially horizontally toward the central axial direction of the SOFC submodule 202 from the lower end of the plate-like side exterior plate 4 to the lateral end of the lower casing 229b. It is formed of a metal plate (for example, SUS304) having a thickness of about 2 mm to 5 mm. The upper surface of the lower exterior plate 5 and the upper surface of the lower casing 229 b are separated to form a space, and a seal plate 15 described later is provided in this space. Further, as shown in FIGS. 5 and 6, a through hole 16 is formed in the lower exterior plate 5, and the lower exterior plate 5 is a cylindrical portion (tubular member) extending downward so as to communicate with the through hole 16. There are seventeen. As shown in FIG. 5, the oxidizing gas supply branch pipe 212 is inserted into the through hole 16 and the cylindrical portion 17. The cylindrical portion 17 and the oxidizing gas supply branch pipe 212 are sealed and fixed at the lower end portion of the cylindrical portion 17. Further, a part of the cylindrical portion 17 is formed by a flexible flexible pipe 18 which permits expansion and contraction in the vertical direction, and a part of the oxidizing gas supply branch pipe 212 similarly permits expansion and contraction in the vertical direction. A flexible flexible tube 19 is formed, and a thermal expansion difference due to a temperature difference between the tubular portion 17 and the oxidizing gas supply branch tube 212 is allowed.

As shown in FIG. 6, a seal plate 15 is provided between the upper surface of the lower exterior plate 5 and the lower surface of the lower casing 229b. As shown in FIGS. 7 and 8, the seal plate 15 is a frame-like member whose outer shape is substantially the same as the area of the bottom surface of the SOFC submodule 202, and an opening is formed in a substantially central portion. The seal plate 15 includes a rectangular annular horizontal portion 21 and a vertical portion 22 extending substantially vertically upward from substantially the entire inner peripheral end of the horizontal portion 21. The lower surface of the horizontal portion 21 is welded and fixed to the upper surface of the lower exterior plate 5, and the upper end of the vertical portion 22 is welded and fixed to the lower surface of the lower casing 229b. The submodule lower heat insulating material 12 is fitted over substantially the entire area of the opening formed in the substantially central portion of the seal plate 15. That is, the outer peripheral surface of the submodule lower heat insulating material 12 is fixed to the inner peripheral surface of the vertical portion 22.
A gap may be generated between the cartridge heat insulating material 2 and a peripheral structure such as the oxidizing gas supply chamber 221 made of metal due to the difference in the adiabatic expansion coefficient, and the oxidizing gas may leak. For this reason, a blanket material (elastic heat insulating material formed by pressing ceramic fiber) may be provided at a portion where a gap is likely to be generated to prevent the occurrence of the gap.

  Further, from the lower surface of the lower casing 229b, six legs 23 for making the SOFC cartridge 203 stand up in the pressure vessel 205 extend downward. In the example of the present embodiment, there are six legs 23, and the lower surface of each leg 23 is fixed to the upper surface of the horizontal portion 21 of the seal plate 15. That is, the six legs 23 are respectively mounted on a mount (not shown) provided in the pressure vessel 205 via the horizontal portion 21 and the lower exterior plate 5, and the SOFC cartridge 203 is It is set up in the SOFC submodule 202.

Next, the connection aspect of the above-mentioned fuel gas supply branch pipe 207a grade | etc., And the SOFC submodule 202 is demonstrated.
From the fuel gas supply holes 231a formed on the upper surface of the upper casing 229a, a plurality (two in the example of FIG. 4) of fuel gas supply branch pipes 207a extend upward through the submodule upper heat insulator 11 There is. The plurality of fuel gas supply branch pipes 207a extending upward respectively bend and merge. The merged fuel gas supply branch pipe 207 a is connected to the fuel gas supply pipe 207. Further, from the fuel gas discharge holes 231b formed on the lower surface of the lower casing 229b, a plurality of (two in the example of FIG. 4) fuel gas discharge branch pipes 209a penetrate the submodule lower thermal insulation material 12 and go downward. It extends. The plurality of fuel gas discharge branch pipes 209a extending downward respectively bend and merge. The merged fuel gas discharge branch pipe 209 a is connected to the fuel gas discharge pipe 209.

  An oxidizing gas discharge branch pipe 214 extends from an oxidizing gas discharge hole 233b formed on the side surface of the upper casing 229a. The oxidizing gas discharge branch pipe 214 extends from the oxidizing gas discharge hole 233 b in the horizontal direction to the inner peripheral surface of the submodule side heat insulating material 13 and extends upward along the inner peripheral surface of the submodule side heat insulating material 13. It is bent and extends upward so as to penetrate the submodule upper heat insulating material 11. The oxidizing gas discharge branch pipe 214 extending upward is bent outward near the upper end of the submodule side heat insulating material 13 and connected to the oxidizing gas discharge pipe 213. An oxidizing gas supply branch pipe 212 extends from an oxidizing gas supply hole 233a formed on the side surface of the lower casing 229b. The oxidizing gas supply branch pipe 212 extends from the oxidizing gas supply hole 233 a in the horizontal direction to the inner peripheral surface of the submodule side heat insulating material 13, and extends downward along the inner peripheral surface of the submodule side heat insulating material 13. It is bent. The oxidative gas supply branch pipe 212 which is bent and extends downward is connected to the oxidative gas supply pipe 211.

  The SOFC module 201 may be applied to a combined power generation system utilized in combination with GTCC (Gas Turbine Combined Cycle: gas turbine combined cycle power generation) or MGT (Micro Gas Turbine: micro gas turbine). In such a combined power generation system, the exhaust fuel gas and the exhaust oxidizing gas exhausted from the SOFC module 201 are supplied to the combustor (not shown) of the gas turbine to generate high-temperature combustion gas, and the combustion gas is The compressed gas that is compressed by driving the compressor is supplied as the oxidizing gas to the oxidizing gas supply pipe 211 of the SOFC module 201 by the rotational power generated by the adiabatic expansion by the gas turbine. The oxidizing gas is a gas containing approximately 15% to 30% of oxygen, and typically air is preferable, but in addition to air, a mixed gas of combustion exhaust gas and air, and a mixture of oxygen and air Gas can be used.

A method of assembling the SOFC submodule 202 according to the present embodiment will be described with reference to FIG.
First, the side exterior plate 4 and the lower exterior plate 5 are connected, and the one obtained by connecting the side exterior plate 4 and the lower exterior plate 5 (hereinafter simply referred to as "exterior plate" in this paragraph) is placed at a predetermined position. Deploy. Next, the submodule lower thermal insulator 12 and the submodule side thermal insulator 13 connected (hereinafter simply referred to as "submodule thermal insulator" in this paragraph) is fitted into the interior of the exterior plate from above, and the exterior plate Arranged inside the Next, the SOFC cartridge 203 is assembled. Specifically, arrangement of the cell stack 101, assembly of the plurality of heat insulating members 8a, arrangement of the cartridge side heat insulating material 8 in which the plurality of heat insulating members 8a are assembled, and the like are performed. Next, the assembled SOFC cartridge 203 is inserted from above into the interior of the submodule insulation, and disposed inside the submodule insulation. Finally, the submodule upper heat insulator 11 is inserted into the submodule heat insulator from above the SOFC cartridge 203. When disassembling the SOFC sub module 202, the reverse procedure is performed.

According to the present embodiment, the following effects are achieved.
In the present embodiment, the cartridge upper heat insulator 6, the cartridge lower heat insulator 7, and the cartridge side heat insulator 8 surround the power generation chamber 215. In the remaining part of the power generation chamber 215 other than the oxidizing gas supply gap 235a and the oxidizing gas discharge gap 235b, the inflow of the oxidizing gas by the cartridge upper heat insulator 6, the cartridge lower heat insulator 7, and the cartridge side heat insulator 8 Since the leakage is prevented, it is possible to suppress the inflow and leakage of the unintended oxidizing gas between the inside of the pressure vessel 205 and the power generation chamber 215. Therefore, the natural convection circulation of oxidizing gas which circulates from the top to the bottom of the inside of the power generation chamber 215 and the space outside the power generation chamber 215 in the space in the pressure container 205 may occur. It can be suppressed. Therefore, it is possible to suppress the heat radiation to the outside of the pressure vessel 205 due to the natural convection circulation of the oxidizing gas, and it is possible to suppress the decrease in the power generation efficiency of the SOFC module 201.

  Further, the cartridge side heat insulating material 8 is constituted by a plurality of heat insulating members 8 a whose upper and lower end surfaces have a key-like uneven shape. Therefore, the operation of positioning and intimately attaching the cartridge side heat insulating material 8 at the time of assembly can be simplified. Further, the plurality of heat insulating members 8a have a so-called inlay structure connected so that the concavities and convexities of the heat insulating members 8a adjacent to each other in the upper and lower sides are fitted together, and a continuous gap is less likely to occur between the heat insulating members 8a. As a structure, since the passage of the oxidizing gas is suppressed, the pressure loss becomes high in order to flow the oxidizing gas flowing through the gap between the heat insulating members 8a. Therefore, the inflow and leakage of the oxidizing gas from the gap between the heat insulating members 8a can be suppressed.

  In addition, since the side exterior plate 4 is provided, the oxidizing gas which is going to flow into the power generation chamber 215 from the side of the SOFC submodule 202 is first blocked by the side exterior plate 4, and the power generation chamber 215 The oxidizing gas which leaks from the pressure vessel 205 into the interior of the pressure vessel 205 is eventually blocked by the side cladding 4. Further, the oxidizing gas which is going to flow into the SOFC submodule 202 from below is first blocked by the bottom surface of the lower exterior plate 5 or the lower casing 229b. As described above, since the inflow of the oxidizing gas is prevented even outside the cartridge heat insulating material 2, the inflow of the unintended oxidizing gas between the inside of the power generation chamber 215 and the inside of the pressure vessel 205 is ensured more reliably. And leakage can be suppressed. Therefore, it is possible to suppress natural convection circulation of oxidizing gas which leaks from the inside of the power generation chamber 215 more reliably and circulates downward from the top of the power generation chamber 215 in the space in the pressure vessel 205 from above. Therefore, it is possible to suppress the heat radiation to the outside of the pressure vessel 205 due to the natural convection circulation of the oxidizing gas, and it is possible to suppress the decrease in the power generation efficiency of the SOFC module 201.

  Further, the bottom surface of the lower casing 229 b is not covered by the lower exterior plate 5. In the case where the fuel gas discharge branch pipe 209a or the current collection rod penetrates the lower exterior plate 5, the fuel gas discharge branch pipe 209a or the current collection rod penetrates so that the oxidizing gas does not flow into the lower exterior plate 5 The locations need to be individually sealed, which makes the structure complicated. In particular, the current collector needs to have a sealed structure while securing insulation, and the structure becomes complicated. In the present embodiment, the bottom surface of the lower casing 229 b is not covered with the lower exterior plate 5, and the bottom surface of the lower casing 229 b and the lower exterior plate 5 are connected using the seal plate 15. Since the formed opening is formed, the fuel gas discharge branch pipe 209a communicating with the fuel gas discharge chamber 219, the current collecting rod, and the like can have a simple structure that does not penetrate the lower exterior plate 5.

  Further, when the SOFC sub-module 202 is assembled, the lateral positioning can be assembled with the side exterior plate 4 as a reference, and the vertical positioning can be assembled with the lower exterior plate 5 as a reference Can. Therefore, the positioning operation at the time of assembling can be facilitated.

  In addition, a seal plate 15 is provided which connects the upper surface of the lower exterior plate 5 and the bottom surface of the lower casing 229b. As a result, as shown by the arrows in FIG. 7, even if the oxidizing gas flows in from the location where the fuel gas discharge branch pipe 209 a penetrates the submodule lower heat insulating material 12, the oxidizing gas that has flowed in is It is blocked by the seal plate 15 and does not reach the power generation chamber 215. Therefore, even if the space is formed between the upper surface of the lower exterior plate 5 and the bottom surface of the lower casing 229 b and the leg portion 23 is provided, the oxidizing gas is prevented from flowing into the SOFC submodule 202 can do.

  Further, since the lid of the upper side of the side exterior plate 4 covers the upper side of the SOFC sub-module 202 and is connected and fixed to the upper end of the side exterior plate 4 is not provided, the SOFC sub-module 202 is configured. Even when the member thermally expands due to high temperature, the thermal expansion can be allowed upward.

  Further, a through hole 16 is formed in the lower exterior plate 5, and a cylindrical portion 17 communicating with the through hole 16 is provided. As a result, the piping that needs to be disposed toward the lower side of the lower casing 229b, that is, the oxidizing gas supply branch pipe 212 extending downward from the side of the lower casing 229b, is inserted into the through hole 16 and the tubular portion 17 By being inserted, the oxidizing gas supply branch pipe 212 can be communicated with the oxidizing gas supply pipe 211 disposed outside the SOFC submodule 202. Further, since the inside of the cylindrical portion 17 is inserted, the oxidizing gas supply branch pipe 212 penetrates the lower exterior plate 5 by making the insertion part a double pipe structure and sealing one end thereof. Also, the oxidizing gas can be suppressed from flowing into the interior of the SOFC submodule 202 from the penetrating portion and leaking into the space in the pressure vessel 205.

  Further, a part of the cylindrical portion 17 is formed of a flexible pipe 18 which has flexibility and allows expansion and contraction in the vertical direction. Thereby, even if the cylindrical portion 17 or the oxidizing gas supply branch pipe 212 is exposed to a high temperature and a thermal expansion difference is generated due to the temperature difference between the cylindrical portion 17 and the oxidizing gas supply branch pipe 212, the flexible pipe 18 Since the expansion and contraction in the vertical direction is absorbed, the fixed part between the cylindrical portion 17 and the oxidizing gas supply branch pipe 212 is not restrained, so that the stress generated in the pipe can be reduced. Further, a part of the oxidizing gas supply branch pipe 212 is also formed of a flexible pipe 19 having flexibility. Therefore, since expansion and contraction in the vertical direction can be absorbed even on the side of the oxidizing gas supply branch pipe 212, stress generated in the piping is not restricted because the fixed portion between the cylindrical portion 17 and the oxidizing gas supply branch pipe 212 is not restricted. It can be further reduced.

  Further, since the oxidizing gas supply branch pipe 212 and the oxidizing gas discharge branch pipe 214 extend in the vertical direction inside the side exterior plate 4 and the submodule side heat insulating material 13, the oxidizing gas supply branch The pipe 212 and the oxidizing gas discharge branch pipe 214 do not interfere with the side armor plate 4 and the submodule side heat insulating material 13. As a result, there is no need to form a structure for causing the oxidizing gas supply branch pipe 212 and the oxidizing gas discharge branch pipe 214 to pass through the side exterior plate 4, and thus the configuration can be simplified.

  In addition, since the oxidizing gas supply branch pipe 212 and the oxidizing gas discharge branch pipe 214 do not interfere with the side exterior plate 4 and the submodule side heat insulating material 13, the SOFC submodule 202 is assembled. In this case, the side exterior plate 4 and the submodule side thermal insulator 13 and the SOFC cartridge 203 can be assembled separately. After separately assembling the side exterior plate 4 and the submodule side heat insulating material 13 and the SOFC cartridge 203, the SOFC cartridge 203 is placed on the side exterior plate 4 and the submodule side heat insulating material 13 from above. By fitting, the SOFC submodule 202 can be easily assembled. Also in disassembling, the SOFC sub module 202 can be easily disassembled by pulling out the SOFC cartridge 203 from the upper side from the side exterior plate 4 and the sub module side heat insulating material 13. Further, since the oxidizing gas supply branch pipe 212 and the oxidizing gas discharge branch pipe 214 do not penetrate the submodule side heat insulating material 13, the submodule side heat insulating material 13 is broken when disassembling the SOFC submodule 202. It can be disassembled without

The present invention is not limited to the invention according to the above-described embodiments, and appropriate modifications can be made without departing from the scope of the invention. For example, although the lower exterior plate 5 covers only a part of the lower part of the SOFC submodule 202 in the above embodiment, the lower exterior plate may cover the entire lower part of the SOFC submodule 202. That is, the lower exterior plate may be provided so as to cover all the openings formed at the lower end of the side exterior plate 4 formed in a frame shape.
With such a configuration, the oxidizing gas that tends to flow into the SOFC submodule 202 from the side is blocked by the side exterior plate 4, and the entire lower part of the SOFC submodule 202 is covered with the lower exterior plate 5. The lower exterior plate 5 reliably prevents the oxidizing gas from flowing into the SOFC submodule 202 from below. Therefore, it is possible to more reliably suppress the inflow and leakage of unintended oxidizing gas between the inside of pressure vessel 205 and power generation chamber 215.

  In the above embodiment, the lower exterior plate 5 and the lower casing 229 b are fixed via the seal plate 15, but the lower exterior plate 5 and the lower casing 229 b are disposed so as not to be separated. And the lower casing 229b may be fixed directly.

2 Cartridge insulation (sealing member)
3 submodule heat insulator 4 side exterior plate 5 lower exterior plate 6 cartridge upper heat insulator 7 cartridge lower heat insulator 8 cartridge side heat insulator 11 submodule upper heat insulator 12 submodule lower heat insulator 13 submodule side heat insulator 15 Seal plate 16 through hole 17 cylindrical portion (cylindrical member)
23 leg part 101 cell stack 103 base tube 105 fuel cell 201 SOFC module (fuel cell module)
202 SOFC submodule (fuel cell submodule)
203 SOFC cartridge 205 pressure vessel 207 fuel gas supply pipe 207a fuel gas supply branch pipe 209 fuel gas discharge pipe 209a fuel gas discharge branch pipe 211 oxidizing gas supply pipe 212 oxidizing gas supply branch pipe (oxidizing gas flow pipe)
213 Oxidizing gas discharge pipe 214 Oxidizing gas discharge branch pipe 215 Power generation chamber 217 Fuel gas supply chamber 219 Fuel gas discharge chamber (fuel gas header)
221 Oxidizing gas supply chamber 223 Oxidizing gas discharge chamber 227a Upper heat insulator 227b Lower heat insulator 229a Upper casing 229b Lower casing 235a Oxidizing gas supply gap (oxidizing gas supply part)
235b Oxidizing gas discharge gap (oxidizing gas discharge part)

Claims (14)

A fuel cell submodule housed in a pressure vessel, comprising:
At least one cell stack comprising a fuel cell generating electricity by supplying a fuel gas and an oxidizing gas;
A fuel cell submodule including a side covering plate disposed so as to surround the cell stack and defining a side.   The fuel cell submodule according to claim 1, wherein the side armoring plate has an opening at an upper end thereof defined by an upper edge of the side armoring plate.   The fuel cell submodule according to claim 1, further comprising a lower exterior plate connected to the lower end of the side exterior plate and closing an opening formed in the lower end of the side exterior plate. A through hole is formed in the lower exterior plate,
The fuel cell submodule according to claim 3, wherein the lower exterior plate includes a cylindrical member which communicates with the through hole and extends vertically downward. It has piping which penetrates the inside of the above-mentioned cylindrical member,
A portion of the tubular member is formed of a flexible tube having flexibility,
5. The fuel cell submodule according to claim 4, wherein the portion formed of the flexible pipe is vertically above a portion for sealing and fixing the cylindrical member and the pipe. A fuel gas header connected to the plurality of cell stacks and supplying the fuel gas to the plurality of cell stacks or discharging the fuel gas from the plurality of cell stacks;
The fuel cell submodule according to claim 1, further comprising: a lower armor plate connected at one end to the lower end of the side armor plate and connected at the other end to the side end of the fuel gas header. The upper surface of the lower exterior plate in the vertical direction and the bottom surface of the fuel gas header are vertically separated from each other,
7. The fuel cell submodule according to claim 6, wherein the upper surface of the lower exterior plate in the vertical direction and the bottom surface of the fuel gas header are connected via a seal plate extending in the vertical direction. A sealing member surrounding at least a portion of the cell stack;
Each of the plurality of cell stacks includes a central portion in which the fuel cells are provided, and an end portion in which the fuel cells are not provided.
The part of the cell stack surrounded by the sealing member is the central portion where the fuel cell is provided,
The sealing member includes an oxidizing gas supply unit that supplies the oxidizing gas around the plurality of cell stacks inside the sealing member, and an oxidizing gas discharge unit that discharges the oxidizing gas from the inside. The fuel according to claim 1, wherein in the remaining portion other than the oxidizing gas supply unit and the oxidizing gas discharge unit, the inflow of the oxidizing gas into the inside and the leakage of the oxidizing gas from the inside are suppressed. Battery sub module. An oxidizing gas flow pipe communicating with the oxidizing gas supply unit or the oxidizing gas discharge unit;
The fuel cell submodule according to claim 8, wherein the oxidizing gas flow pipe extends vertically in the vertical direction inside the side armor plate. A pressure vessel,
A fuel cell module comprising: the fuel cell submodule according to any one of claims 1 to 9 housed in the pressure vessel. A fuel cell module according to claim 10,
A gas turbine generating rotational power using exhaust fuel gas exhausted from the fuel cell module and exhaust oxidizing gas;
The oxidizing gas compressed using the rotational power is supplied to the fuel cell module,
A combined power generation system, wherein a plurality of the cell stacks generate power using the fuel gas and the oxidizing gas. At least one cell stack comprising a fuel cell generating electricity by supplying a fuel gas and an oxidizing gas;
A side exterior plate disposed so as to surround the cell stack and defining a side, and a lower exterior plate connected to the lower end of the side exterior plate and closing an opening formed in the lower end of the side exterior plate A method of assembling a fuel cell sub-module comprising
A connecting step of connecting the side exterior plate and the lower exterior plate;
And a cell stack inserting step of inserting the cell stack vertically from above with respect to the side armoring plate connected in the connecting step.   The method of assembling a submodule according to claim 12, further comprising a sealing member disposing step of disposing a sealing member so as to surround the cell stack.   The method of assembling a submodule according to claim 12 or 13, further comprising a submodule heat insulator fitting step of fitting a submodule heat insulator into the inside of the side exterior plate and the lower exterior plate.

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