JP2024034705A - Fuel cells, fuel cell systems, power generation equipment, and aircraft - Google Patents

Abstract

An object of the present invention is to provide a fuel cell, a fuel cell system, a power generation device, and an aircraft that have high durability against pressure changes. A fuel cell according to one aspect of the present invention includes at least one cell unit, a cell block, and a pressure difference effect suppressing section. The at least one cell unit includes a power generation cell in which an electrolyte layer is sandwiched between a fuel electrode and an oxidizer electrode, a first separator forming a flow path for fuel gas on the fuel electrode side, and a first separator on the oxidizer electrode side. and a second separator that forms a flow path for oxidant gas. The cell block consists of the at least one cell unit. The pressure difference effect suppressing unit suppresses deformation of the target separator, with at least one of the first separator and the second separator disposed at the outermost side in the cell block as the target separator. [Selection diagram] Figure 4

Description

The present invention relates to a fuel cell, a fuel cell system, a power generation device, and an aircraft.

A fuel cell is constructed using a power generation cell in which an electrolyte is sandwiched between electrodes. Flow paths through which gas serving as a fuel and gas serving as an oxidizing agent pass are formed on both sides of this power generation cell. For example, Patent Document 1 describes a quadrilateral fuel cell stack in which flat cell bodies are stacked. In this fuel cell stack, four gas manifolds for supplying and discharging fuel gas and oxidant gas are provided at each of the four corners of the quadrilateral. In addition, a manifold for supplying and discharging fuel gas is connected to the fuel gas passage formed on one side of the cell body, and an oxidant gas passage formed on the other side of the cell body is connected to a manifold for supplying and discharging fuel gas. A manifold for supplying and discharging oxidizing gas is connected (paragraphs [0026] [0031] FIGS. 1, 3, etc. of the specification of Patent Document 1).

Japanese Patent Application Publication No. 2019-117707

Fuel cells are expected to be applied in various fields such as aircraft, automobiles, and power generation. On the other hand, depending on the application and usage conditions of the fuel cell, the pressure of the gas flowing around the power generation cell may change, potentially damaging the fuel cell. Therefore, there is a need for a technology that can improve durability against pressure changes.

In view of the above circumstances, an object of the present invention is to provide a fuel cell, a fuel cell system, a power generation device, and an aircraft that have high durability against pressure changes.

In order to achieve the above object, a fuel cell according to one embodiment of the present invention includes at least one cell unit, a cell block, and a pressure difference effect suppressor.
The at least one cell unit includes a power generation cell in which an electrolyte layer is sandwiched between a fuel electrode and an oxidizer electrode, a first separator forming a flow path for fuel gas on the fuel electrode side, and a first separator on the oxidizer electrode side. and a second separator that forms a flow path for oxidant gas.
The cell block consists of the at least one cell unit.
The pressure difference effect suppressing unit suppresses the influence of the pressure difference on the target separator, with at least one of the first separator and the second separator disposed at the outermost side in the cell block as a target separator.

In this fuel cell, a cell block is composed of at least one cell unit. In each cell unit, a first separator that forms a flow path for fuel gas and a second separator that forms a flow path for oxidant gas are provided on the fuel electrode side and oxidizer electrode side of the electrolyte layer that constitutes the power generation cell. Each is placed. Further, the fuel cell is provided with a pressure difference effect suppressing section that suppresses the influence of deformation, leakage, etc. due to pressure difference, with at least one of the first and second separators disposed at the outermost side of the cell block as the target separator. . Thereby, for example, deformation due to pressure of the power generation cells adjacent to the target separator is suppressed, and durability against pressure changes can be increased.

The pressure difference effect suppressing unit may be a mechanism that suppresses at least one of deformation of the target separator due to the pressure difference and leakage around the target separator due to the pressure difference.

The at least one cell unit may be a plurality of cell units. In this case, the cell block may be a laminate in which the plurality of cell units are stacked so that the fuel gas flow path and the oxidant gas flow path are alternately formed.

The pressure difference effect suppressing section may be a pressure mechanism that applies pressure from outside the target separator.

The pressure mechanism may apply pressure from outside of the target separator that is equivalent to that of the target gas flowing on the opposite side of the target separator with the power generation cell in between, among the fuel gas and the oxidizing gas.

The pressure mechanism may form a working gas flow path outside the target separator that applies pressure from outside the target separator.

The working gas may be the target gas. In this case, the pressure mechanism may connect the flow path of the working gas to an inflow path and an outflow path common to the target gas.

The pressure mechanism may form a flow path for the working gas similar to a flow path for the target gas along the power generation cell.

The pressure difference influence suppressing section may be a reinforcing mechanism that is provided along the target separator and reinforces the rigidity of the target separator.

The reinforcing mechanism may include a groove or a rib provided along the target separator.

The electrolyte layer may be composed of a solid oxide electrolyte.

It may also be placed in a pressurized container.

A fuel cell system according to one embodiment of the present invention includes a pressurized container, a fuel cell, a first supply line, and a second supply line.
The fuel cell includes:
A power generation cell in which an electrolyte layer is sandwiched between a fuel electrode and an oxidizer electrode, a first separator that forms a flow path for fuel gas on the fuel electrode side, and a flow path for oxidant gas on the side of the oxidizer electrode. at least one cell unit having a second separator;
a cell block consisting of the at least one cell unit;
a pressure difference effect suppressing unit that suppresses the influence of a pressure difference on the target separator, with at least one of the first separator and the second separator disposed at the outermost side of the cell block as a target separator; stored in the pressurized container.
The first supply line supplies the fuel gas to the fuel cell.
The second supply line supplies the oxidant gas to the fuel cell.

A power generation device according to one embodiment of the present invention includes a pressurized container, a fuel cell, a generator, a gas turbine, a first supply line, and a second supply line.
The fuel cell includes:
A power generation cell in which an electrolyte layer is sandwiched between a fuel electrode and an oxidizer electrode, a first separator that forms a flow path for fuel gas on the fuel electrode side, and a flow path for oxidant gas on the side of the oxidizer electrode. at least one cell unit having a second separator;
a cell block consisting of the at least one cell unit;
a pressure difference effect suppressing unit that suppresses the influence of a pressure difference on the target separator, with at least one of the first separator and the second separator disposed at the outermost side of the cell block as a target separator; stored in the pressurized container.
The gas turbine includes a compressor that compresses air, a combustor that burns the air compressed by the compressor and the fuel gas, and a combustion gas from the combustor that is used as a driving source to drive the compressor and the power generator. It has a turbine that drives the machine.
The first supply line supplies the fuel gas to the fuel cell, and supplies the fuel gas discharged from the fuel cell to the combustor.
The second supply line supplies air compressed by the compressor as the oxidant gas to the fuel cell, and supplies air compressed by the compressor as pressurized gas to the pressurized container, Air exhausted from the fuel cell is supplied to the combustor.

An aircraft according to one embodiment of the present invention includes the power generation device.

As described above, according to the present invention, it is possible to provide a fuel cell, a fuel cell system, a power generation device, and an aircraft that have high durability against pressure changes. Note that the effects described here are not necessarily limited, and may be any of the effects described in this disclosure.

1 is a schematic diagram showing a configuration example of a power generation device including a fuel cell according to an embodiment of the present invention. FIG. 2 is a schematic diagram showing a configuration example of a cell unit of a fuel cell. FIG. 2 is a schematic diagram showing an example of the configuration of a cell unit of a fuel cell. FIG. 1 is a schematic diagram showing a configuration example of a fuel cell. FIG. 3 is a schematic diagram showing a configuration example of a pressure mechanism. FIG. 2 is a schematic diagram showing a configuration example of a fuel cell taken as a comparative example. It is a graph showing a pressure change at the time of starting a gas turbine. It is a graph showing current-voltage characteristics for each cell unit. 5 is a schematic diagram showing an example of a pressure state in the fuel cell shown in FIG. 4. FIG. 5 is a schematic diagram showing another example of the pressure state in the fuel cell shown in FIG. 4. FIG. It is a schematic diagram which shows the other structural example of a pressure mechanism. It is a schematic diagram which shows the other structural example of a pressure mechanism. It is a schematic diagram which shows the other structural example of a pressure mechanism. FIG. 1 is a schematic diagram showing an example of an aircraft equipped with a combined power generation jet engine. FIG. 1 is a schematic diagram showing a configuration example of a combined power generation jet engine. FIG. 7 is a schematic diagram showing an example of a pressure difference effect suppressing section according to another embodiment. It is a schematic diagram which shows an example of the pressure difference influence suppression part based on other embodiment. FIG. 7 is a schematic diagram showing an example of a pressure difference effect suppressing section according to another embodiment. FIG. 7 is a schematic diagram showing an example of a ground-mounted power generation device according to another embodiment.

Embodiments according to the present invention will be described below with reference to the drawings.

[Generation device]
FIG. 1 is a schematic diagram showing a configuration example of a power generation device including a fuel cell according to an embodiment of the present invention. The power generation device 100 is a device that performs combined power generation by combining a fuel cell 10 and a gas turbine 13. The fuel cell 10 and gas turbine 13 that constitute the power generation device 100 use a common oxidant gas and fuel gas.

In the power generation device 100 , the oxidant gas to be supplied to the fuel cell 10 is extracted by the compressor 51 of the gas turbine 13 . This oxidant gas is supplied to the fuel cell 10 together with the fuel gas. After the fuel cell 10 generates electricity, excess oxidant gas and fuel gas discharged from the fuel cell 10 are supplied to the combustor 52 of the gas turbine 13. The combustion gas ejected from the combustor 52 rotates a turbine 53 provided in the gas turbine 13, and the generator 12 connected to the turbine 53 is driven. In this way, the power generation device 100 is configured as a combined power generation system that generates power by the fuel cell 10 and the gas turbine 13.

The power generation device 100 shown in FIG. 1 is mounted on an aircraft. The electric power generated by the power generation device 100 is used, for example, to drive a motor that powers a propulsion fan of an aircraft.
As shown in FIG. 1, the power generation device 100 includes a fuel cell 10, a pressurized container 11, a generator 12, a gas turbine 13, a fuel tank 14, a fuel supply line 15, and an air supply line 16. and has.

For the fuel cell 10, a flat power generation cell 20 is used. The power generation cell 20 has a structure in which electrodes are provided on both sides of an electrolyte. Fuel gas is supplied to one electrode, and oxidant gas is supplied to the other electrode.
The fuel cell 10 is typically configured as a laminate (cell stack) in which a plurality of power generation cells 20 are stacked. The flat plate type fuel cell 10 can reduce the volume of the main body of the fuel cell 10 compared to the cylindrical type, and in this respect is preferable as a form to be applied to an aircraft.
Note that FIG. 1 schematically shows a cell unit 5 including one power generation cell 20 as the fuel cell 10. Cell unit 5 is the basic unit of fuel cell 10. The actual fuel cell 10 is constructed by stacking a plurality of cell units 5. The structure of a cell stack in which a plurality of cell units 5 are stacked will be described later with reference to FIG. 4.

In this embodiment, the electrolyte layer 21 of the fuel cell 10 is composed of a solid oxide electrolyte. Therefore, the fuel cell 10 becomes a solid oxide fuel cell (SOFC). Further, the power generation device 100 functions as a part of a SOFC-GT combined power generation jet engine that combines a SOFC and a GT (gas turbine 13).
SOFC is a battery that operates at a relatively high temperature of, for example, about 700° C. to 1000° C., and can be expected to recover high-temperature waste heat. Furthermore, since all of the components that make up the SOFC are solid, the device configuration is simple, and stable performance and long life can be expected.
In aircraft, by using SOFC, it is possible to realize a propulsion engine that has significantly improved thermal efficiency and propulsion efficiency compared to conventional turbofan engines that use jet fuel or the like.

In this embodiment, hydrogen gas 1 is used as the fuel gas supplied to the fuel cell 10. Furthermore, air 2 is used as the oxidant gas. From the fuel cell 10, which generates electricity through a chemical reaction between hydrogen and air, only hydrogen and oxygen that remain without chemically reacting with water (H ₂ O) are discharged.
Note that the types of fuel gas and oxidant gas are not limited. For example, various hydrocarbons, alcohols, carbon monoxide, etc. may be used as the fuel gas. Moreover, air may be used as the oxidant gas.

The fuel cell 10 has a hydrogen inlet 24 that serves as an inlet for hydrogen gas 1, a hydrogen outlet 25 that serves as an outlet for hydrogen gas 1, an air inlet 26 that serves as an inlet for air 2, and an air outlet 27 that serves as an outlet for air 2. provided. The hydrogen inlet 24 and the hydrogen outlet 25 are connected to the fuel supply line 15, and the air inlet 26 and the air outlet 27 are connected to the air supply line 16. Hydrogen gas 1 and air 2 are supplied in conjunction with the operation of the engine (gas turbine 13), and the operating pressure, temperature, and flow rate change. The fuel cell 10 (stack body) is stored in a pressurized container 11. The specific configuration of the fuel cell 10 will be explained in detail later.

The pressurized container 11 is a container that stores the fuel cell 10. The pressurized container 11 is configured to maintain a state in which the air pressure inside the container is higher than the air pressure outside the container (pressurized atmosphere).
As shown in FIG. 1, an air supply line 16 and a container pressure relief valve 17 are connected to the pressurized container 11 so as to communicate with the inside of the container. Compressed air 2 is supplied into the container from the air supply line 16 . The container pressure relief valve 17 is a valve that releases high-pressure air 2 inside the container to the outside of the container. As the container pressure relief valve 17, for example, a pressure regulating valve (safety valve) that releases pressure when the pressure inside the container exceeds a predetermined pressure, a remote-controlled automatic valve, or the like is used.
In addition, various types of piping (such as piping for supplying and discharging hydrogen gas 1 and air 2) that penetrate the partition wall of the pressurized container 11 and connect to the fuel cell 10 are provided.

Generator 12 is connected to gas turbine 13 . Specifically, the generator 12 is connected to a rotating shaft 50 provided in the gas turbine 13, and is rotationally driven by the rotating shaft 50 to generate electric power. The type of generator 12 is not limited, and any type of generator can be used. The electric power generated by the generator 12 is supplied to the motor, battery, etc. together with the electric power generated by the fuel cell 10.

Gas turbine 13 includes a compressor 51, a combustor 52, and a turbine 53.
In this embodiment, a hydrogen gas turbine that uses hydrogen gas 1 as fuel is used as the gas turbine 13. Further, the gas turbine 13 is a power source for driving the generator 12. Therefore, the gas turbine 13 and the generator 12 constitute a hydrogen gas turbine generator.

Note that the gas turbine 13 may be configured as a jet engine that obtains propulsive force from a jet of combustion gas. For example, gas turbine 13 may be configured as a turbofan engine. In addition, the jet engine according to the present invention includes a case where a jet stream is generated, rotational force is generated using the turbine 53, and the generated rotational force is converted and used as propulsive force by a propeller or fan.

The compressor 51 compresses the air 2 taken into the gas turbine 13. The compressor 51 is connected to the turbine 53 via the rotating shaft 50 and is driven by the rotation of the turbine 53 (the rotating shaft 50). The specific configuration of the compressor 51 is not limited, and any type of compressor such as an axial compressor, a centrifugal compressor, a mixed flow compressor, etc. may be used.
The combustor 52 is a hydrogen combustor that combusts the hydrogen gas 1. The combustor 52 burns the air 2 (compressed air) compressed by the compressor 51 and the hydrogen gas 1 to generate high temperature and high pressure combustion gas. Combustion gas ejected from the combustor 52 is sent to a turbine 53 arranged downstream of the combustor 52.
The turbine 53 is connected to the rotating shaft 50 and drives the compressor 51 and the generator 12 using combustion gas from the combustor 52 as a driving source. The turbine 53 that has received the combustion gas rotates together with the rotating shaft 50, and the compressor 51 and the generator 12 are rotationally driven by the rotating shaft 50.

The fuel tank 14 is a tank that stores fuel for the fuel cell 10 and the gas turbine 13 (combustor 52). In this embodiment, the fuel tank 14 is a hydrogen tank that stores hydrogen. The fuel tank 14 is not limited to this, and for example, a tank configured to be able to store liquefied hydrogen and equipped with a pump for boosting fuel pressure inside a high-pressure insulated container or a low-pressure insulated container may be used as the fuel tank 14. .

The fuel supply line 15 supplies hydrogen gas 1 to the fuel cell 10 and supplies hydrogen gas 1 discharged from the fuel cell 10 to the combustor 52 of the gas turbine 13 . In this embodiment, the fuel supply line 15 corresponds to a first supply line.
The fuel supply line 15 includes a hydrogen pipe 55a, a flow rate regulating valve 56a, and a hydrogen pipe 55b. Further, the fuel supply line 15 has a confluence pipe 57 as a common pipe with the air supply line 16 described later. Note that in FIG. 1, the route through which the hydrogen gas 1 passes is schematically illustrated by a thick dotted line.

The hydrogen pipe 55a is a pipe that connects the fuel tank 14 that stores hydrogen and the hydrogen inlet 24 of the fuel cell 10. The hydrogen gas or liquefied hydrogen stored in the fuel tank 14 is, for example, fed under pressure through the hydrogen pipe 55a in a critical state. Further, the liquefied hydrogen is vaporized in the process of passing through the hydrogen pipe 55a, and hydrogen gas 1 is supplied to the hydrogen inlet 24.
The flow rate adjustment valve 56a is provided in the hydrogen pipe 55a, and adjusts the amount of hydrogen gas 1 supplied to the fuel cell 10 and the combustor 52. As the flow rate adjustment valve 56a, for example, an electromagnetic flow rate adjustment valve for extremely low temperatures is used.

The hydrogen pipe 55b is a pipe that connects the hydrogen outlet 25 of the fuel cell 10 and the merging pipe 57. High temperature hydrogen gas 1 discharged from the fuel cell 10 passes through the hydrogen pipe 55b and is supplied to the merging pipe 57.
The merging pipe 57 is a pipe in which hydrogen gas 1 that has passed through the hydrogen pipe 55b and air 2 that has passed through an air pipe 58b (described later) join together. Note that depending on the part inserted into the combustor 52, the hydrogen gas 1 and the air 2 may be connected as separate pipes without merging.

The air supply line 16 supplies air 2 (compressed air) compressed by the compressor 51 as an oxidant gas to the fuel cell 10, and supplies air 2 discharged from the fuel cell 10 to the combustor 52.
Further, the air supply line 16 supplies air 2 compressed by the compressor 51 to the pressurized container 11 as pressurized gas. In this embodiment, the air supply line 16 corresponds to a second supply line.
The air supply line 16 includes an air pipe 58a, a flow rate adjustment valve 56b, a flow path control valve 59, a flow meter 46, an air pipe 58b, a container pressurizing valve 47, an external air source 48, and a flow rate adjustment valve. 56c.

The air pipe 58a is a pipe that connects the compressor 51 of the gas turbine 13 and the air inlet 26 of the fuel cell 10. A flow rate adjustment valve 56b, a flow path control valve 59, and a flow meter 46 are connected in this order to the air pipe 58a from the outlet side of the compressor 51 to the air inlet 26.
The flow rate adjustment valve 56b adjusts the amount of air 2 (compressed air) supplied from the compressor 51 to the air pipe 58a. As the flow rate adjustment valve 56b, for example, an electromagnetic flow rate adjustment valve for high pressure gas is used.
The flow path control valve 59 opens and closes the flow path of the air 2 supplied from the compressor 51 to the air pipe 58a. As the flow rate adjustment valve 56b, for example, an electromagnetic cutoff valve or the like is used.
The flow meter 46 measures the flow rate of the air 2 supplied to the fuel cell 10 from the air pipe 58a.

The air pipe 58b is a pipe that connects the air outlet 27 of the fuel cell 10 and the merging pipe 57. The high temperature air 2 discharged from the fuel cell 10 passes through the air pipe 58b and is supplied to the merging pipe 57. Further, the merging pipe 57 is connected to the combustor 52 of the gas turbine 13. Therefore, the merging pipe 57 supplies the combustor 52 with a mixed gas in which the high temperature hydrogen gas 1 and air 2 discharged from the fuel cell 10 are mixed.

The container pressurizing valve 47 is a valve that is provided on a pipe that connects the air pipe 58a to the inside of the pressurized container 11, and pressurizes the pressurized container 11 with the compressed air in the air pipe 58a. As the container pressurizing valve 47, for example, a pressure regulating valve (pressure reducing valve) that adjusts the pressure on the air pipe 58a side and supplies it to the pressurized container 11 side is used.
In this way, the power generation device 100 is configured to adjust the pressure in the pressurized container 11 using the container pressure valve 47 and the container pressure release valve 17 to equalize the internal pressure and external pressure of the fuel cell 10.

The external air source 48 is a device that takes in air 2 independently of the gas turbine 13, and is connected to the air pipe 58a. As the external air source 48, for example, an air compressor that compresses and discharges air 2 taken in from the outside is used. The external air source 48 supplies air 2 to the air pipe 58a instead of the gas turbine 13 (compressor 51), for example, when the power generation device 100 is started up.
The flow rate adjustment valve 56c is provided between the external air source 48 and the air piping 58a, and adjusts the amount of air 2 supplied from the external air source 48 to the air piping 58a. As the flow rate adjustment valve 56c, for example, an electromagnetic flow rate adjustment valve for high pressure gas is used.

In the power generation device 100, air 2 is supplied from the compressor 51 or the external air source 48 to the air pipe 58a.
For example, when the power generator 100 is started up, the compressor 51 (rotating shaft 50) cannot generate compressed air at a sufficient pressure if the rotational speed of the compressor 51 (rotating shaft 50) is low. In this case, the flow path of the air 2 from the compressor 51 is cut off by the flow path control valve 59, and the air 2 is supplied from the external air source 48 to the air pipe 58a. For example, when air 2 of sufficient pressure can be supplied from the compressor 51, the flow path control valve 59 opens and the air 2 is supplied from the compressor 51 to the air pipe 58a. At this time, the flow rate adjustment valve 56c cuts off the supply of air 2 from the external air source 48 to the air pipe 58a. In this way, during normal operation, air 2 from the compressor 51 is supplied to the fuel cell 10.

Further, the flow rate (supply amount) of the air 2 supplied from the compressor 51 or the external air source 48 to the air piping 58a is measured by a flow meter 46 provided upstream of the air inlet 26, and based on the measurement result, The flow rate of the air 2 is adjusted by the flow rate adjustment valve 56b and the flow rate adjustment valve 56c.
The supply of air 2 from the compressor 51 or the external air source 48 to the air pipe 58a may be switched exclusively or may be temporarily used together.

[Configuration of fuel cell cell unit]
2 and 3 are schematic diagrams showing a configuration example of the cell unit 5 of the fuel cell 10. FIG. 2 schematically shows a cross-sectional view of the cell unit 5 stored in the pressurized container 11. Further, FIG. 3 schematically shows a perspective view in which a part of the cell unit 5 is enlarged.
The cell unit 5 is a basic unit of the fuel cell 10, and each cell unit 5 has a power generation function. The cell unit 5 includes the above-described power generation cell 20, a first interconnector 31, a second interconnector 32, a seal portion 33, a first current collector 34, and a second current collector 35. .

The power generation cell 20 has an electrolyte layer 21, a fuel electrode (anode) 22, and an air electrode (cathode) 23. The electrolyte layer 21, the fuel electrode 22, and the air electrode 23 are all configured in a flat plate shape. The power generation cell has a structure in which an electrolyte layer 21 is sandwiched between a fuel electrode 22 and an air electrode 23. In this embodiment, the fuel electrode 22 corresponds to a fuel electrode, and the air electrode 23 corresponds to an oxidizer electrode.

The electrolyte layer 21 is made of a material that has good oxygen ion conductivity at high temperatures, such as oxides of zirconia-based materials, ceria-based materials, and perovskite-based materials. Further, other forms such as proton conductive oxides may be used as long as they have high ionic conductivity at high temperatures. The fuel electrode 22 is an electrode that is in contact with the hydrogen gas 1. As the material of the fuel electrode 22, for example, metals such as Ni and Co, and porous cermets using these metals are used. The air electrode 23 is an electrode in contact with the air 2. Since the air electrode 23 is exposed to a high-temperature oxidizing atmosphere, it is made of a material that is chemically stable even in such an environment. As the material of the air electrode 23, for example, a perovskite-type oxide material with high electrical conductivity is used.

In the power generation cell 20 shown in FIG. 2, an electrolyte layer 21 is formed on one surface of the fuel electrode 22 (the upper surface of the fuel electrode 22 in the figure) so as to fit within that surface. Further, an air electrode 23 is formed on the surface of the electrolyte layer 21 opposite to the fuel electrode 22 (the upper surface of the electrolyte layer 21 in the figure) so as to fit within that surface. Therefore, the power generation cell 20 is a fuel electrode support type cell in which the electrolyte layer 21 and the air electrode 23 are supported by the fuel electrode 22. In this case, the fuel electrode 22 is fixed to a support member (cell holder) not shown.
Note that even if an air electrode support type power generation cell 20 in which the electrolyte layer 21 and the fuel electrode 22 are supported by the air electrode 23 or a metal support type power generation cell 20 in which a thin film of heat-resistant metal with high strength and toughness is sandwiched, the power generation cell 20 may be used. good.

The planar shapes of the electrolyte layer 21, the fuel electrode 22, and the air electrode 23 are, for example, circular, and the disk-shaped power generation cell 20 is configured by arranging them so that their centers overlap in a plan view. The diameter of the power generation cell 20 is appropriately set, for example, in the range of 5 cm to 30 cm. The thickness of the power generation cell 20 (total thickness of the fuel electrode 22, electrolyte layer 21, and air electrode 23 stacked) is, for example, about 0.5 mm. In FIG. 2, the thickness is emphasized with respect to the planar size of the power generation cell 20, but in reality, the power generation cell 20 is a very thin member.
Note that the planar shape, thickness, etc. of the power generation cell 20 (electrolyte layer 21, fuel electrode 22, and air electrode 23) are not limited, and may be appropriately set according to the required power generation performance, device weight, etc.

The first interconnector 31 is a plate-shaped member disposed facing the fuel electrode 22 of the power generation cell 20 . The first interconnector 31 forms a flow path for the hydrogen gas 1 on the fuel electrode 22 side.
The second interconnector 32 is a plate-shaped member disposed facing the air electrode 23 of the power generation cell 20 . The second interconnector 32 forms a flow path for the air 2 on the air electrode 23 side.
The first interconnector 31 and the second interconnector 32 function as separators that separate the flows of hydrogen gas 1 and air 2 in the cell unit 5. In this embodiment, the first interconnector 31 corresponds to a first separator, and the second interconnector 32 corresponds to a second separator.

A hydrogen flow path section 36 that serves as a flow path for the hydrogen gas 1 is formed on the surface of the first interconnector 31 facing the fuel electrode 22 . The hydrogen flow path section 36 includes, for example, gaps and grooves for allowing the hydrogen gas 1 to pass through. Furthermore, an air flow path section 37 that serves as a flow path for the air 2 is formed on the surface of the second interconnector 32 facing the air electrode 23 . The air flow path section 37 includes, for example, gaps and grooves for allowing the air 2 to pass through.
The flow path patterns provided in the hydrogen flow path section 36 and the air flow path section 37 may be the same pattern or different patterns.

In the example shown in FIG. 3, a plurality of convex portions 38 spaced apart from each other are provided on the surface of the first interconnector 31 (second interconnector 32) as the hydrogen flow path portion 36 (air flow path portion 37). The plurality of convex portions 38 are thin cylindrical protrusions, and are arranged in a grid pattern at regular intervals. By providing the hydrogen flow path section 36 (air flow path section 37), it becomes possible to secure a flow path for the hydrogen gas 1 (air 2) over the entire surface of the fuel electrode 22 (air electrode 23). The channel pattern using the convex portions 38 makes it possible to diffuse the hydrogen gas 1 and air 2 throughout the channel. Furthermore, it is possible to reduce the weight compared to the case where grooves are formed.

Note that the patterns of the hydrogen flow path section 36 and the air flow path section 37 are not limited. For example, the flow path may be constituted by a linear groove (see FIGS. 12 and 13, etc.) or a curved groove. Further, a flow path may be formed by combining convex portions and grooves arranged in a dispersed manner.

Furthermore, the surface of the first interconnector 31 opposite to the surface where the hydrogen flow path section 36 is formed, and the surface of the second interconnector 32 opposite to the surface where the air flow path section 37 is formed are , each function as a connection surface to be connected to another cell unit 5. The connecting surface is typically configured as a flat surface.

Further, the first interconnector 31 and the second interconnector 32 are made of a material with high electrical conductivity. The first interconnector 31 is electrically connected to the fuel electrode 22 via a first current collector 34, which will be described later. Further, the second interconnector 32 is electrically connected to the air electrode 23 via a second current collector 35, which will be described later. Therefore, in the cell unit 5, the first interconnector 31 functions as an electrode connected to the anode (fuel electrode), and the second interconnector 32 functions as an electrode connected to the cathode (air electrode).

The seal portion 33 is a sealing member provided between the first interconnector 31 and the second interconnector 32 so that hydrogen gas 1 and air 2 flowing across the power generation cell 20 do not leak. The seal portion 33 also functions as an insulating member that electrically isolates the first interconnector 31 and the second interconnector 32.
As the seal portion 33, an insulating sheet material (such as a mica sheet), a composite member made of a combination of an insulating material and a metal, or the like is used.

The first current collector 34 is provided between the fuel electrode 22 of the power generation cell 20 and the first interconnector 31, and electrically connects the fuel electrode 22 and the first interconnector 31. The second current collector 35 is provided between the air electrode 23 of the power generation cell 20 and the second interconnector 32, and electrically connects the air electrode 23 and the second interconnector 32.
By providing the first current collector 34 and the second current collector 35, it becomes possible to efficiently extract the power generated by the power generation cell 20.

The first current collector 34 and the second current collector 35 are constructed using a breathable member so as not to obstruct the flow of the hydrogen gas 1 and the air 2. For example, metal mesh, expanded metal, porous metal, etc. are used as the first current collector 34 and the second current collector 35. Note that it is not always necessary to provide the first current collector 34 and the second current collector 35. For example, the first interconnector 31 and the fuel electrode 22 may be directly connected, or the second interconnector 32 and the air electrode 23 may be directly connected. Further, a configuration in which either the first current collector 34 or the second current collector 35 is provided is also possible.

As shown in FIG. 2, a hydrogen inlet 24 and a hydrogen outlet 25 are connected to the space between the first interconnector 31 and the fuel electrode 22, and the hydrogen gas 1 passing through the first current collector 34 is connected to the space between the first interconnector 31 and the fuel electrode 22. A flow path is formed. Further, an air inlet 26 and an air outlet 27 are connected to the space between the second interconnector 32 and the air electrode 23, and a flow path for the air 2 passing through the second current collector 35 is formed.

The first interconnector 31 shown in FIG. 2 schematically has a through hole connected to the hydrogen inlet 24 and a through hole connected to the hydrogen outlet 25 at a position overlapping the power generation cell 20 when viewed from the thickness direction. Illustrated. Further, in the second interconnector 32, a through hole connected to the air inlet 26 and a through hole connected to the air outlet 27 are schematically illustrated at positions overlapping with the power generation cells 20 when viewed from the thickness direction. ing. The actual cell unit 5 is not provided with a through hole that overlaps with the power generation cell 20, and the cell unit 5 is connected to a hydrogen supply path, a hydrogen exhaust path, an air supply path, and an air exhaust path, which will be described later.

Moreover, as shown in FIG. 3, in this embodiment, the direction in which hydrogen gas 1 flows and the direction in which air 2 flows are set to be orthogonal to each other when viewed from the thickness direction. This makes it possible to arrange the inlet/outlet passage for hydrogen gas 1 and the inlet/outlet passage for air 2 at positions separated from each other. Note that the directions in which the hydrogen gas 1 and the air 2 flow can be set in the same direction (parallel flow) or opposite directions (counterflow) when viewed from the thickness direction.

In this way, the cell unit 5 has a structure in which fuel (hydrogen gas 1) and air 2 flow on both sides of the flat power generation cell 20 in which the electrolyte layer 21, the fuel electrode 22, and the air electrode 23 are laminated. A fuel cell 10 having a stack structure is constructed by stacking several tens to a hundred of such cell units 5.

[Overall configuration of fuel cell]
FIG. 4 is a schematic diagram showing a configuration example of the fuel cell 10.
The fuel cell 10 includes a cell stack 6 , a hydrogen supply path 40 , a hydrogen exhaust path 41 , an air supply path 42 , an air exhaust path 43 , a power extraction section 45 , and a pressure difference effect suppressing section 60 . Note that in FIG. 4, illustration of the pressurized container 11 is omitted. Further, in FIG. 4, the flows of hydrogen gas 1 and air 2 are schematically illustrated by dotted lines and solid lines, respectively.

The cell stack 6 is a cell block consisting of cell units 5, and is configured by a plurality of cell units 5 overlapping each other. Specifically, the cell stack 6 is a laminate in which a plurality of cell units 5 are stacked so that passages for hydrogen gas 1 and passages for air 2 are alternately formed. This is a configuration in which a plurality of cell units 5 are stacked such that the first interconnector 31 of one cell unit 5 and the second interconnector 32 of another cell unit 5 are in contact with each other. Therefore, in the cell stack 6, a flow path for hydrogen gas 1, a power generation cell 20, and a flow path for air 2 are repeatedly arranged in this order.

In the following, the upper and lower sides in the figure will be described as the upper and lower sides of the cell stack 6 (fuel cell 10). Note that the descriptions such as "upper side" and "lower side" do not limit the arrangement or posture of the cell stack 6.
Furthermore, in FIG. 4, each cell unit 5 is arranged such that the first interconnector 31 (flow path for hydrogen gas 1) is on the lower side and the second interconnector 32 (flow path for air 2) is on the upper side. Ru. The present invention is not limited to this, and an arrangement in which the first interconnector 31 is on the upper side and the second interconnector 32 is on the lower side is also possible. Further, the stacking direction of the cell stack 6 is not limited to the vertical direction, and the cell stack 6 may be arranged so that the stacking direction is the left-right direction (horizontal direction).

FIG. 4 schematically shows a cell stack 6 in which three cell units 5 are stacked. Among these, the cell unit 5 arranged on the uppermost side is described as the uppermost cell unit 5a, and the cell unit 5 arranged on the lowermost side is described as the lowermost cell unit 5b. Further, the cell unit 5 between the uppermost cell unit 5a and the lowermost cell unit 5b is referred to as an intermediate cell unit 5c.
In the cell stack 6, the first interconnector 31 of the uppermost cell unit 5a and the second interconnector 32 of the middle cell unit 5c are connected. Further, the first interconnector 31 of the intermediate cell unit 5c and the second interconnector 32 of the lowest cell unit 5b are connected.
Note that the number of stacked cell units 5 is not limited to this, and any number of cell units 5 may be stacked.

Furthermore, in the example shown in FIG. 4, among the adjacent cell units 5, the member that becomes the first interconnector 31 in one cell unit 5 and the member that becomes the second interconnector 32 in the other cell unit 5 are separate. It was a member of The present invention is not limited to this, and the member that becomes the first interconnector 31 in one cell unit 5 and the member that becomes the second interconnector 32 in the other cell unit 5 may be configured as one member.

For example, as a common member for adjacent cell units 5, a plate-shaped separator is used in which a hydrogen flow path portion 36 is formed on one surface and an air flow path portion 37 is formed on the other surface. In this case, the common member functions as the first interconnector 31 for one cell unit 5 and as the second interconnector 32 for the other cell unit 5. With such a configuration, it is possible to reduce the weight of the fuel cell 10.

The hydrogen supply path 40 is a flow path that is connected to the hydrogen inlet 24 and supplies hydrogen gas 1 to each cell unit 5. The hydrogen discharge path 41 is a flow path that is connected to the hydrogen outlet 25 and discharges the hydrogen gas 1 from each cell unit 5. The hydrogen supply path 40 and the hydrogen discharge path 41 are connected to the space between the first interconnector 31 of each cell unit 5 and the power generation cell 20, respectively.

The air supply path 42 is a flow path that is connected to the air inlet 26 and supplies air 2 to each cell unit 5. The air discharge path 43 is a flow path that is connected to the air outlet 27 and discharges the air 2 from each cell unit 5. The air supply path 42 and the air discharge path 43 are connected to the space between the second interconnector 32 of each cell unit 5 and the power generation cell 20, respectively.

The hydrogen supply path 40 and the air supply path 42 are gas manifolds that distribute and supply hydrogen gas 1 and air 2, and the hydrogen exhaust path 41 and air exhaust path 43 collect and discharge hydrogen gas 1 and air 2. This is a gas manifold.
The hydrogen supply path 40, the hydrogen discharge path 41, the air supply path 42, and the air discharge path 43 are provided, for example, in a peripheral portion that does not overlap with the power generation cells 20 when viewed from the stacking direction of the cell stack 6. Further, for example, it may be configured using external piping or the like.

The power extraction unit 45 is a terminal for extracting electric power from the fuel cell 10 configured as the cell stack 6. Here, the second interconnector 32 (the second interconnector 32 of the uppermost cell unit 5a) disposed at the outermost side of the cell stack 6 is provided with a power extraction portion 45a on the positive electrode side. Further, the first interconnector 31 disposed at the outermost side of the cell stack 6 (the first interconnector 31 of the lowest cell unit 5b) is provided with a power extraction portion 45b on the negative pole side.

One cell unit 5 can be regarded as a battery in which the second interconnector 32 serves as a positive electrode and the first interconnector 31 serves as a negative electrode. Therefore, as shown in FIG. 4, a cell stack 6 in which a plurality of cell units 5 are stacked functions as one battery in which a plurality of batteries (cell units 5) are connected in series. Further, the power extraction portion 45a on the positive electrode side and the power extraction portion 45b on the negative electrode side serve as terminals for extracting the power of the entire fuel cell 10. In this way, the fuel cell 10 is configured to extract current from the interconnector at the top end and the interconnector at the bottom end.

The pressure difference effect suppressing unit 60 suppresses the effect of the pressure difference on the target interconnector 30. Here, the target interconnector 30 is an interconnector to which the influence of pressure difference is to be suppressed. Specifically, at least one of the first interconnector 31 and the second interconnector 32 arranged at the outermost side in the cell stack 6 becomes the target interconnector 30. In this embodiment, the target interconnector 30 corresponds to the target separator.

In the example shown in FIG. 4, the first interconnector 31 (first interconnector 31 of the bottom cell unit 5b) disposed on the outermost side of the cell stack 6 and the first interconnector 31 disposed on the outermost side of the cell stack 6 The second interconnector 32 (the second interconnector 32 of the uppermost cell unit 5a) is the target interconnector 30. For these two target interconnectors 30, a pressure difference influence suppressing section 60 for suppressing deformation thereof is provided, respectively.
Below, the 1st interconnector 31 used as the target interconnector 30 is described as 1st interconnector 31t. Further, the second interconnector 32, which is the target interconnector 30, will be referred to as a second interconnector 32t.

Moreover, the pressure difference with respect to the target interconnector 30 is, for example, the difference in pressure between the inside and the outside of the target interconnector 30. The inside of the target interconnector 30 is the side of the target interconnector 30 facing the power generation cell 20, and the outside means the side opposite to the side facing the power generation cell 20.

The pressure difference applied to the target interconnector 30 may have an effect, for example, that the target interconnector 30 is deformed or that hydrogen gas, air, etc. leak around the target interconnector 30.
The pressure difference effect suppressing unit 60 is a mechanism that suppresses deformation of the target interconnector 30 due to such a pressure difference and leakage around the target interconnector 30 due to the pressure difference.

In this embodiment, the pressure difference effect suppressing unit 60 is a pressure mechanism 61 that applies pressure from the outside of the target interconnector 30. The fuel cell 10 shown in FIG. 4 includes a pressure mechanism 61a that applies pressure to the second interconnector 32t from the upper side in the figure, and a pressure mechanism 61a that applies pressure to the first interconnector 31t from the lower side in the figure. A pressure mechanism 61b that acts is provided.

The pressure mechanism 61 applies a pressure equivalent to that of the target gas from the outside of the target interconnector 30 . Here, the target gas is a gas among the hydrogen gas 1 and air 2 that flows to the opposite side of the target interconnector 30 with the power generation cell 20 in between. That is, the pressure mechanism 61 is a mechanism that applies pressure to the target interconnector 30 that is equivalent to the gas (target gas) flowing inside the power generation cell 20 disposed at the outermost side of the cell stack 6 .

For example, in the pressure mechanism 61a, the hydrogen gas 1 flowing to the opposite side of the second interconnector 32t across the power generation cell 20 of the uppermost cell unit 5a is the target gas. Therefore, the pressure mechanism 61a applies the same pressure as the hydrogen gas 1 to the second interconnector 32t from the outside. Furthermore, in the pressure mechanism 61b, the air 2 flowing toward the opposite side of the first interconnector 31t across the power generation cell 20 of the lowest cell unit 5b is the target gas. Therefore, the pressure mechanism 61b applies the same pressure as the air 2 to the second interconnector 32t from the outside.
By applying pressure to the target interconnector 30 in this manner, it becomes possible to cancel the pressure applied outward to the power generation cells 20 and the target interconnector 30.

Specifically, the pressure mechanism 61 forms a working gas flow path outside the target interconnector 30 that applies pressure from outside the target interconnector 30 . The working gas here is a gas for generating a pressure equivalent to that of the target gas in the pressure mechanism 61. The type of working gas is not limited, and any gas can be used.
As shown in FIG. 4, the pressure mechanism 61 has an outermost flow path 62 that serves as a flow path for working gas. The outermost channel 62 is a channel that spreads out in a plane. The planar shape and planar size of the outermost channel 62 are set to the same planar shape and planar size as, for example, the channels for hydrogen gas 1 and air 2 formed in the cell unit 5.

Further, the working gas is typically the target gas. In this case, the pressure mechanism 61 connects the outermost flow path 62, which is a flow path for the working gas, to an inflow path and an outflow path that are common to the target gas. The inflow path common to the target gas is the hydrogen supply path 40 or the air supply path 42. Further, the outflow path common to the target gas is the hydrogen exhaust path 41 or the air exhaust path 43.

For example, the outermost channel 62 of the pressure mechanism 61a on the upper side of the cell stack 6 is connected to the hydrogen supply channel 40 and the hydrogen discharge channel 41, and serves as a channel through which hydrogen gas 1, which is the target gas of the pressure mechanism 61a, flows as the working gas. . Further, the outermost flow path 62 of the pressure mechanism 61b on the lower side of the cell stack 6 is connected to the air supply path 42 and the air discharge path 43, and serves as a flow path through which the air 2, which is the target gas of the pressure mechanism 61b, flows.
By connecting the outermost channel 62 to the inflow and outflow channels of the target gas, it is possible to easily generate a pressure equivalent to that of the target gas. However, the flow of the target gas is not essential to the outermost flow path, and it is only necessary that pressure be applied thereto, so either the inflow path or the outflow path may be blocked.

FIG. 5 is a schematic diagram showing a configuration example of the pressure mechanism 61. Here, the pressure mechanism 61a provided in the second interconnector 32t of the uppermost cell unit 5a in FIG. 4 will be described. Note that the description of the pressure mechanism 61a described here can be read as appropriate as the description of the pressure mechanism 61b.
As shown in FIG. 5, the pressure mechanism 61 includes a flow path member 63 and a lid member 64.

The flow path member 63 is a plate-shaped member that forms the outermost flow path 62. A working gas flow path portion 65 is formed on one surface of the flow path member 63 . The working gas passage section 65 includes gaps and grooves for passing the working gas (hydrogen gas 1, which is the target gas of the pressure mechanism 61a in FIG. 5). The pattern of these gaps and grooves becomes the flow path pattern of the working gas.
The lid member 64 is a flat member disposed opposite the working gas passage section 65 of the passage member 63, and functions as a lid that closes the working gas passage section 65.

In this embodiment, a member similar to the first interconnector 31 is used as the flow path member 63. Therefore, a flow path pattern similar to that of the hydrogen flow path section 36 provided in the first interconnector 31 is formed in the working gas flow path section 65 . Here, a plurality of convex portions 38 spaced apart from each other are provided as the working gas flow path portion 65.

The flow path member 63 is connected to the second interconnector 32t, which is the target interconnector 30, with the working gas flow path portion 65 facing outside (upper side in the figure). Further, a lid member 64 is arranged opposite to the working gas flow path section 65. The space between the lid member 64 and the flow path member 63 (working gas flow path section 65) becomes the outermost flow path 62.
In this way, the pressure mechanism 61 forms a flow path similar to the flow path of the target gas (hydrogen gas 1 in FIG. 5) along the power generation cell 20 as the outermost flow path 62. As a result, in FIG. 5, it is possible to apply a load corresponding to the pressure of the hydrogen gas 1 to the power generation cell 20 (uppermost cell) of the uppermost cell unit 5a, similarly to the other power generation cells 20 of the cell stack 6. Become.

[Load applied to power generation cell]
Below, the load applied to the power generation cell 20 by the gas (hydrogen gas 1 and air 2) flowing through the fuel cell will be explained.
FIG. 6 is a schematic diagram showing a configuration example of a fuel cell as a comparative example. A fuel cell 105 shown in FIG. 6 is provided with a cell stack 6 configured similarly to that shown in FIG. Note that the fuel cell 105 is not provided with the pressure difference influence suppressing section 60 (pressure mechanism 61). Here, as an example, a load applied to the power generation cell 20 due to the pressure of the hydrogen gas 1 will be described.

In the cell unit 5, a flow path for hydrogen gas 1 is formed between the power generation cell 20 (fuel electrode 22) and the first interconnector 31 (hydrogen flow path portion 36). The pressure of the hydrogen gas 1 generates a force (load) that pushes the wall surface of the channel from the inside to the outside of the channel. Therefore, a load is applied to the power generation cell 20 upward in the figure, and a load is applied to the first interconnector 31 downward in the figure. In FIG. 6, the load generated by the pressure of the hydrogen gas 1 is schematically illustrated using white arrows.

In a cell stack 6 in which cell units 5 are stacked, it is conceivable that a load corresponding to the pressure of hydrogen gas 1 flowing through another adjacent cell unit 5 is applied to the power generation cell 20 in the cell unit 5. Note that the load caused by the hydrogen gas 1 flowing through the other cell units 5 is a load that is indirectly transmitted via the first interconnector 31 of the other cell unit 5.

For example, the power generation cell 20 (lowest cell) of the lowest cell unit 5b is loaded upward by the hydrogen gas 1 flowing inside the lowest cell unit 5b, and downwardly by the hydrogen gas 1 flowing inside the intermediate cell unit 5c. A load is applied to the
Similarly, an upward load is applied to the power generation cell 20 (intermediate cell) of the intermediate cell unit 5c by the hydrogen gas 1 flowing inside the intermediate cell unit 5c, and a downward load is applied to the power generation cell 20 (intermediate cell) by the hydrogen gas 1 flowing inside the uppermost cell unit 5a. is added.

In this way, both upward and downward loads depending on the pressure of the hydrogen gas 1 are applied to the lowest cell and the middle cell. Therefore, the load due to the pressure of hydrogen gas 1 applied to the bottom cell and the middle cell is substantially canceled.

On the other hand, an upward load is applied to the power generation cell 20 (top cell) of the top cell unit 5a by the hydrogen gas 1 flowing inside the top cell unit 5a, but there is a flow path for the hydrogen gas 1 above the top cell unit 5a. is not provided, so no downward load from the hydrogen gas 1 is applied to the uppermost cell.
In this way, only an upward load corresponding to the pressure of the hydrogen gas 1 is applied to the uppermost cell. Therefore, depending on the pressure of the hydrogen gas 1, the uppermost cell may be deformed or damaged. There is also a possibility that the hydrogen gas 1 supplied to the uppermost cell unit 5a may leak.

Furthermore, the load applied to each power generation cell 20 due to the pressure of the air 2 flowing through the cell unit 5 can be explained in the same manner as the case of the hydrogen gas 1. For example, upward and downward loads corresponding to the pressure of the air 2 are applied to the uppermost cell and the middle cell, and the load due to the pressure of the air 2 is canceled. On the other hand, only a downward load corresponding to the pressure of the air 2 is applied to the lowest cell. Therefore, depending on the pressure of the air 2, the lowermost cell may be deformed or damaged. There is also a possibility that the air 2 supplied to the lowermost cell unit 5b may leak.

As described with reference to FIG. 1, in a system that generates power by combining a fuel cell and a gas turbine, the flow paths for hydrogen gas 1 and air 2 used in the fuel cell are also connected to the gas turbine. Therefore, the pressures of hydrogen gas 1 and air 2 change in conjunction with the operation of the gas turbine. Below, we will explain the experimental results of a fuel cell combined with a gas turbine.

FIG. 7 is a graph showing pressure changes at the time of starting the gas turbine. This graph is data measured using an experimental fuel cell. Similar to the fuel cell 105 shown in FIG. 6, the experimental fuel cell is configured by combining two cell stacks 6 that are not provided with a pressure difference effect suppressing section 60 (pressure mechanism 61). Therefore, the experimental fuel cell includes two top cells and two bottom cells.
Further, data measurements were performed by connecting an experimental fuel cell to a system similar to the power generation device 100 described with reference to FIG.

FIG. 7 shows the pressure P1 of hydrogen gas 1 at the hydrogen inlet 24 (SOFC Hydrogen Inlet) of the experimental fuel cell when starting the gas turbine 13, the pressure P2 of the air 2 at the air inlet 26 (SOFC Air Inlet), A time change in the pressure P3 of the pressurized chamber 11 (Chamber) is plotted. Also, the temporal change in the rotational speed (HPC Rotational Speed) of the compressor 51 provided in the gas turbine 13 is plotted.
Further, the horizontal axis in FIG. 7 is time (sec), the left vertical axis is pressure (kPaA (absolute pressure)), and the right vertical axis is rotation speed (rpm).

Here, a starting operation was performed to bring the gas turbine 13 into an idling state (a state in which the rotational speed was about 4.5×10 ⁴ rpm) in 60 seconds from a state where the rotational speed of the compressor 51 was 0. When the gas turbine 13 is started, the compressor 51 is not operating sufficiently. Therefore, the flow path control valve 59 was closed, and the gas turbine 13 was started in a mode in which air 2 was supplied from the external air source 48.

Further, in the experimental fuel cell, the pressure difference among the pressure P1 of the hydrogen gas 1, the pressure P2 of the air 2, and the pressure P3 of the pressurized container 11 was suppressed to within 5 kPa. That is, each pressure was controlled so that the differential pressure between P1 and P2, the differential pressure between P2 and P3, and the differential pressure between P1 and P3 were all within 5 kPa. This can be achieved by appropriately adjusting the container pressure valve 47, the container pressure release valve 17, and the like. In this way, when the differential pressure was suppressed to within 5 kPa, it was possible to operate the experimental fuel cell without damaging it.

On the other hand, if the differential pressure is large, the fuel cell may be damaged.
In the system shown in FIG. 1, the pressure and flow rate of hydrogen gas 1 and air 2 change according to operating conditions such as startup and output changes of gas turbine 13, and the pressure inside pressurized container 11 changes accordingly. At this time, if a sudden change in output is made, the hydrogen flow path pressure (pressure P1 of hydrogen gas 1), air flow path pressure (pressure P2 of air 2), and pressure P3 of the pressurized container 11 will not be balanced, and each It is conceivable that the power generation cell 20 may be damaged or the current collector material may peel off due to the differential pressure.
As explained with reference to FIG. 6, an asymmetrical pressure load acts particularly on the uppermost cell and the lowermost cell. Therefore, there is a high possibility that the top cell or the bottom cell will be destroyed.

FIG. 8 is a graph showing current-voltage characteristics for each cell unit. The horizontal axis in FIG. 8 is the current (A) flowing through the power generation cell 20, and the vertical axis is the voltage (V) generated in the power generation cell 20. In FIG. 8, the current-voltage characteristics of the power generation cells 20 are plotted for each cell unit 5 included in the experimental fuel cell that has malfunctioned.

In the experiment, the experimental fuel cell malfunctioned when operated in such a way that the pressure difference between the pressure P1 of the hydrogen gas 1, the pressure P2 of the air 2, and the pressure P3 of the pressurized container 11 exceeded 10 kPa. Note that whether or not the fuel cell was malfunctioning was determined by monitoring the voltage of each cell unit 5 (power generation cell 20).

In FIG. 8, there is a group #0 of cell units 5 having mutually similar current-voltage characteristics. This group #0 is a group in which the power generation cells 20 are operating normally, and it is considered that no damage or the like has occurred.
On the other hand, in a malfunctioning power generation cell 20, the internal resistance increases, so a voltage drop occurs significantly when current is passed through the cell 20. In the cell unit 5 of chA and the cell unit 5 of chB shown in FIG. 8, when the current is increased with respect to group #0, the voltage decreases significantly, indicating that the power generation cell 20 is damaged.

This time, both the cell unit 5 of chA and the cell unit 5 of chB were the uppermost cell unit 5a (uppermost cell) arranged at the uppermost side of the cell stack 6. This is considered to be because the uppermost cell was damaged due to an asymmetrical pressure load acting on the uppermost cell during an operation in which a differential pressure exceeding 10 kPa was generated.

For example, when combining an industrial gas turbine with a fuel cell, starting, stopping, and adjusting the output take a long time, on the order of tens of minutes to several hours. Thereby, sudden changes in pressure can be eliminated and destruction of the power generation cell 20 can be avoided.
On the other hand, when applying a power generation device that combines a gas turbine and a fuel cell to an aircraft, output control that can handle rapid startup, acceleration, and deceleration is required. For this reason, unlike ground-based power generation, the operating environment may change rapidly. For example, in order to use a power generation device to power an aircraft, it is necessary to adjust the output within several tens of seconds during takeoff or ascent.

Such a sudden pressure change may cause damage to the power generation cell 20 as described above and impair the operation of the fuel cell. In particular, when a flat plate type fuel cell is used, an asymmetrical pressure load is applied to the cells at the upper or lower end (the uppermost cell or the lowermost cell), which often leads to destruction due to asymmetrical deformation. Therefore, it was necessary to ensure the durability of the fuel cell against sudden pressure changes.

[Operation of pressure mechanism]
FIG. 9 is a schematic diagram showing an example of the pressure state in the fuel cell shown in FIG. 4. In FIG. 9, a load applied to the power generation cell 20 due to the pressure of the hydrogen gas 1 in the fuel cell 10 provided with the pressure mechanism 61 will be explained.
When focusing on hydrogen gas 1, the power generation cell 20 (lowest cell) of the lowest cell unit 5b and the power generation cell (intermediate cell) of the intermediate cell unit 5c have a power generation cell according to the pressure of the hydrogen gas 1, as in FIG. An upward and downward load is applied. Thereby, the load due to the pressure of the hydrogen gas 1 applied to the bottom cell and the middle cell is substantially canceled.

On the other hand, a pressure mechanism 61a that forms an outermost channel 62 through which hydrogen gas 1 flows is provided above the uppermost cell unit 5a. The pressure of the hydrogen gas 1 flowing through the outermost channel 62 generates a force (load) that pushes the wall surface of the outermost channel 62 from the inside to the outside. Here, an upward load is applied to the lid member 64 forming the upper wall surface of the outermost channel 62, and a downward load is applied to the channel member 63 forming the lower wall surface. Of these, the downward load also acts on the power generation cell 20 (uppermost cell) of the uppermost cell unit 5a via the second interconnector 32 of the uppermost cell unit 5a.

That is, an upward load is applied to the uppermost cell from the hydrogen gas 1 passing directly below it, and a downward load is applied to the uppermost cell from the hydrogen gas 1 passing through the outermost channel 62 of the pressure mechanism 61a. As a result, the load due to the pressure of hydrogen gas 1 applied to the uppermost cell is substantially canceled as in the case of the lowermost cell and the intermediate cell.

In this way, the pressure mechanism 61a functions as a cell pressure equalization mechanism that equalizes the pressure (load) acting from above and below on the power generation cell 20 (top cell) provided at the upper end of the cell stack 6. Note that in the present disclosure, the pressure equalization mechanism is not a mechanism that equalizes the pressure of gas, but a mechanism that equalizes the pressure (load) applied to the power generation cell 20.
By providing the pressure mechanism 61a, even if the pressure difference between the pressure of the hydrogen gas 1 and the pressure of the air 2 or the pressure of the pressurized container 11 becomes large, for example, it is possible to prevent a situation in which an asymmetric pressure load is applied to the uppermost cell. It becomes possible.

Further, FIG. 10 schematically shows the load applied to the power generation cell 20 due to the pressure of the air 2. As shown in FIG. 10, when focusing on the air 2, a downward load is applied to the bottom cell from the air 2 passing directly above it, and an upward load is applied to the bottom cell from the air 2 passing through the outermost flow path 62 of the pressure mechanism 61b. A load will be added. As a result, the load due to the pressure of the air 2 applied to the bottom cell is substantially canceled as in the case of the top cell and the middle cell.

In this way, the pressure mechanism 61b functions as a cell pressure equalization mechanism that equalizes the pressure (load) acting from above and below on the power generation cell 20 (lowermost cell) provided at the lower end of the cell stack 6. .
By providing the pressure mechanism 61b, for example, even if the pressure difference between the pressure of the hydrogen gas 1 or the pressure of the pressurized container 11 and the pressure of the air 2 becomes large, a situation in which an asymmetrical pressure load is applied to the lowest cell can be prevented. becomes possible.

In this way, in the fuel cell 10 according to the present embodiment, the pressure mechanism 61a that forms a hydrogen flow path is provided above the air flow path above the power generation cell 20 (uppermost cell) of the uppermost cell unit 5a. . Furthermore, a pressure mechanism 61b that forms an air flow path is provided further below the hydrogen flow path below the power generation cell 20 (lowermost cell) of the lowermost cell unit 5b.
The pressure mechanisms 61a and 61b are cell pressure equalization mechanisms for the purpose of equalizing the pressures applied to the uppermost cell and the lowermost cell.

As a result, when pressurization or depressurization occurs only on the hydrogen side or the air side, all the power generation cells 20 including the top cell and the bottom cell are pressured in the same direction from both the top and bottom. It becomes possible to apply a load. This makes it possible to improve the durability of the uppermost cell and the lowermost cell against asymmetric pressure loads generated in the cell stack 6.

Specifically, it is possible to prevent asymmetrical deformation of the uppermost cell and the lowermost cell, and to avoid damage to each cell. In addition, for example, it is possible to prevent a situation where the degree of adhesion between the top cell and the bottom cell with the interconnector and current collector material decreases, and it is possible to avoid a situation where the current collection efficiency of each cell decreases. becomes.
Furthermore, the pressure mechanisms 61a and 61b suppress the pressure difference between the upper and lower target interconnectors 30 (the second interconnector 32t of the uppermost cell unit 5a and the first interconnector 31t of the lowermost cell unit 5b). Ru. This improves the sealing performance of the uppermost cell unit 5a and the lowermost cell unit 5b, making it possible to suppress leakage of hydrogen gas 1 and air 2.
By providing the pressure mechanisms 61a and 61b in this way, it is possible to realize a flat fuel cell 10 that is highly durable against pressure changes.

For example, as described with reference to FIGS. 7 and 8, in an experimental fuel cell without the pressure mechanism 61, the uppermost cell was damaged when a pressure difference of about 10 kPa was generated. In contrast, by providing the pressure mechanism 61 according to this embodiment, it is possible to realize a fuel cell 10 that is not damaged even if a pressure difference of about several tens of kPa occurs.
This makes it possible to provide a flat fuel cell 10 that has high durability against pressure changes and is fully applicable to aircrafts that require rapid start-up and output control.

[Other configuration examples of pressure mechanism]
11 to 13 are schematic diagrams showing other configuration examples of the pressure mechanism. 11 to 13, the pressure mechanisms 110, 111, and 112 provided in the second interconnector 32t of the uppermost cell unit 5a will be described. Note that the description of the pressure mechanisms 110, 111, and 112 described here can be read as appropriate as a description of the pressure mechanism provided in the first interconnector 31t of the lowest cell unit 5b.

The pressure mechanism 110 shown in FIG. 11 is configured using a flow path member 63. Note that the pressure mechanism 110 does not include the lid member 64 shown in FIG. 5 and the like.
The plate-shaped flow path member 63 is arranged with the surface on which the working gas flow path portion 65 formed of the plurality of convex portions 38 is formed facing the second interconnector 32t of the uppermost cell unit 5a. In this case, the space between the flow path member 63 (working gas flow path portion 65) and the second interconnector 32t becomes the outermost flow path 62. Moreover, as the flow path member 63, it is possible to use the same member as each interconnector.
The pressure mechanism 110 is lighter than the pressure mechanism 61 shown in FIG. 5 because it does not use a lid member.

In FIG. 12, a plate-shaped member in which a plurality of parallel grooves 39 are formed on one surface is used as the first interconnector 31 and the second interconnector 32. The groove 39 formed in the first interconnector 31 functions as a hydrogen flow path section 36, and the groove 39 formed in the second interconnector 32 functions as an air flow path section 37. In this way, parallel grooves 39 may be provided as flow paths for hydrogen gas 1 and air 2.
Further, the first interconnector 31 and the second interconnector 32 are arranged so that the direction of the groove 39 is the direction in which the hydrogen gas 1 and the air 2 flow. Therefore, the directions of the grooves 39 of the first interconnector 31 and the second interconnector 32 are perpendicular to each other when viewed from the thickness direction.
Since the flow path pattern using the parallel grooves 39 is less likely to hinder the flow, it is possible to smoothly supply the hydrogen gas 1 and air 2 to the entire flow path. Moreover, the structure of the groove 39 makes it possible to make the first interconnector 31 and the second interconnector 32 difficult to bend.

The pressure mechanism 111 shown in FIG. 12 is configured using a flow path member 63 in which a working gas flow path portion 65 consisting of a plurality of parallel grooves 39 is formed, and a lid member 64 on a flat plate. As the flow path member 63, it is possible to use the same member as each interconnector.
The flow path member 63 is connected to the second interconnector 32t with the working gas flow path portion 65 facing outside (upper side in the figure). Further, a lid member 64 is arranged opposite to the working gas flow path section 65. In this case, the space between the flow path member 63 (working gas flow path portion 65) and the lid member 64 becomes the outermost flow path 62. Note that the direction of the groove 39 of the flow path member 63 is arranged parallel to the direction of the groove 39 of the first interconnector 31.
The outermost channel 62 of the pressure mechanism 111 is similar to the channel for the hydrogen gas 1 formed between the first interconnector 31 and the power generation cell 20. Thereby, it becomes possible to sufficiently cancel the load applied to the power generation cell 20 by the hydrogen gas 1.

A pressure mechanism 112 shown in FIG. 13 is a modification of the pressure mechanism 111 shown in FIG. 12. The pressure mechanism 112 is configured using a flow path member 63 similar to that shown in FIG. Note that the pressure mechanism 112 does not include the lid member 64.
The plate-shaped flow path member 63 is arranged with the surface on which the working gas flow path portion 65 formed of the plurality of parallel grooves 39 is formed facing the second interconnector 32t of the uppermost cell unit 5a. In this case, the space between the flow path member 63 (working gas flow path portion 65) and the second interconnector 32t becomes the outermost flow path 62.
Further, although a plurality of parallel grooves 39 are provided inside the flow path member 63 to suppress deformation of the outermost flow path 62, grooves may be added to the outside of the flow path member 63.
Since the pressure mechanism 112 does not use a lid member, it is lighter than the pressure mechanism 61 shown in FIG. 12.

In addition, the specific configuration of the pressure mechanism is not limited. For example, the flow path pattern provided in the flow path member 63 does not necessarily need to be the same as the flow path pattern provided in the interconnector. Therefore, a pressure mechanism may be configured using a flow path member 63 in which parallel grooves 39 are formed for a cell stack 6 using an interconnect in which a plurality of convex portions 38 are formed. Conversely, the pressure mechanism may be configured using a flow path member 63 in which a plurality of convex portions 38 are formed for a cell stack 6 using an interconnect in which parallel grooves 39 are formed.

[Aircraft equipped with power generation device 100]
In recent years, in line with the movement toward decarbonization, research is actively underway to develop aircraft that use hydrogen as fuel and to electrify aircraft. Along with the application of hydrogen and electrification to aircraft, electric aircraft using fuel cells are attracting attention.

In general, the advantage of applying fuel cells to aircraft is that in addition to being able to obtain electrical energy from fuel with high efficiency, it is also possible to use it as a new energy source by recovering the heat generated as a loss during power generation. One point can be mentioned. Therefore, when applying a fuel cell to an aircraft, it is promising to use it for combined power generation with an internal combustion engine such as a gas turbine. Below, an aircraft to which the fuel cell 10 according to the present embodiment is applied will be described.

FIG. 14 is a schematic diagram showing an example of an aircraft 70 equipped with a combined power generation jet engine. The aircraft 70 has a fuselage 71, main wings 72, a tail 73, and a plurality of electric fans 74. The aircraft 70 is also equipped with a combined power generation jet engine 75 that combines a fuel cell 10 (SOFC) and a gas turbine 13 to generate electricity using hydrogen fuel. The electric fan 74 described above serves as a propulsion mechanism for the combined power generation jet engine 75.

An aircraft 70 shown in FIG. 14 has a blended wing body shape in which a fuselage 71 and wings (main wings 72 and tail 73) are integrally designed, and left and right main wings 72 are provided on the sides of a flat fuselage 71. , left and right tail wings 73 are provided on the rear side of the fuselage 71. A plurality of electric fans 74 are arranged between the left and right tail wings 73. Although eight electric fans 74 are provided here, the number of electric fans 74 is not limited.

FIG. 15 is a schematic diagram showing a configuration example of a combined power generation jet engine.
Combined power generation jet engine 75 includes a power generation device 100, a power control section 76, and a plurality of electric fans 74. Among these, the power generation device 100 is a device that performs combined power generation by combining the fuel cell 10 and the gas turbine 13, as described with reference to FIG. 1, for example.
Note that hydrogen fuel (hydrogen gas 1) is supplied to the fuel cell 10 from a hydrogen fuel tank 77. Hydrogen fuel tank 77 corresponds to fuel tank 14 shown in FIG. Further, the gas turbine 13 is supplied with hydrogen fuel discharged from the fuel cell 10 and jet fuel supplied from the jet fuel tank 78.
Although the combination of fuels is a method that uses both hydrogen fuel and jet fuel, it is also possible to use a method in which all hydrogen fuel is used and only the hydrogen fuel discharged from the fuel cell 10 is supplied to the gas turbine 13. . Further, as an alternative to hydrogen fuel, a hydrocarbon fuel such as city gas or LP gas may be used.

The power control unit 76 performs power control such as conversion, synthesis, and distribution of power generated by the fuel cell 10 and gas turbine 13 of the power generation device 100. For example, the DC power generated by the fuel cell 10 is directly input to the combining/distributing unit 80 . Further, AC power generated by the generator 12 connected to the gas turbine 13 is converted into DC power by the converter 79 and input to the combination/distribution section 80 .

The combining/distributing section 80 is connected to a battery 81 . The battery 81 is charged with power from the power generation device 100, and supplies power to the combining/distributing unit 80 as needed.
Further, the synthesis/distribution unit 80 synthesizes the electric power from the fuel cell 10 , the gas turbine 13 (generator 12 ), and the battery 81 and distributes it to the plurality of inverters 82 provided corresponding to the plurality of electric fans 74 . . Each inverter 82 converts the DC power from the combining/distributing unit 80 into AC power and outputs the AC power to the motor 83 of the electric fan 74 .

Each of the plurality of electric fans 74 has a motor 83, a gear 84, and a fan 85. The motor 83 is rotated by power supplied from the inverter 82. Gear 84 transmits the rotation of motor 83 to fan 85 at a predetermined gear ratio. Propulsive force is generated by the motor 83 rotating the fan 85 via the gear 84.

When hydrogen gas 1 is used as fuel in combined power generation jet engine 75, carbon dioxide is not generated in fuel cell 10 and gas turbine 13. Therefore, the aircraft 70 equipped with the combined power generation jet engine 75 becomes an emission-free aircraft that suppresses the generation of greenhouse gases such as carbon dioxide.

This propulsion system is expected to have improved propulsive and thermal efficiency than existing jet engines. Specifically, by dispersing the electric fans 74 multiple times, the propulsion efficiency, which is the conversion efficiency from mechanical energy to propulsion energy, is improved. Furthermore, by combining the gas turbine 13 with the fuel cell 10, thermal efficiency, which is the efficiency of converting exothermic energy of fuel into mechanical energy, is improved.
This makes it possible to reduce the amount of hydrogen on board the aircraft 70 and downsize the hydrogen tank. As a result, emission-free aircraft will be able to achieve longer distance air transport than existing aircraft.

The present invention suppresses the application of asymmetrical loads to the uppermost cell and the lowermost cell in a flat plate type fuel cell 10 when the pressure of hydrogen gas 1 or air 2 changes rapidly. By applying such a fuel cell 10 to the combined power generation jet engine 75, it is possible to provide a power generation system that can stably operate within the pressure range required for the aircraft 70, and realize a highly reliable emission-free aircraft. It becomes possible to do so.

As described above, in the fuel cell 10 according to the present embodiment, the cell stack 6 is configured by the plurality of cell units 5. In each cell unit 5, a first interconnector 31 forming a flow path for hydrogen gas 1 and a flow path for air 2 are formed on the fuel electrode 22 side and the air electrode 23 side of the electrolyte layer 21 constituting the power generation cell 20. A second interconnector 32 is arranged, respectively. In addition, in the fuel cell 10, both the first interconnector 31 and the second interconnector 32 arranged at the outermost side of the cell stack 6 are used as target interconnectors 30 to suppress the effects of deformation, leakage, etc. due to pressure difference. A pressure difference influence suppressing section 60 is provided. Thereby, for example, deformation due to pressure of the power generation cells 20 (the uppermost cell and the lowermost cell) adjacent to the target interconnector 30 is suppressed, and durability against pressure changes can be increased.

<Other embodiments>
The present invention is not limited to the embodiments described above, and various other embodiments can be realized.

In the embodiment described above, a pressure mechanism functioning as a cell pressure equalization mechanism was provided as the pressure difference effect suppressing section 60. Further, in the pressure mechanism, hydrogen gas 1 and air 2 flowing through the cell unit 5 were used as the working gas to apply pressure.
The present invention is not limited to this, and a working gas other than the hydrogen gas 1 and air 2 flowing through the cell unit 5 may be used. In this case, a gas different from the gas consumed as fuel or oxidant in the fuel cell 10 is used as the working gas. The type of working gas may be hydrogen or air, or other inert gas such as nitrogen may be mixed.

The pressure of the working gas within the pressure mechanism 61 (outermost channel 62) is set according to the pressure of the hydrogen gas 1 and air 2. For example, the pressure of hydrogen gas 1 (air 2) is measured. The pressure of the working gas that should be brought to the same pressure as the hydrogen gas 1 (air 2) is adjusted to the same pressure as the measured hydrogen gas 1. In this way, the pressure of the working gas may be actively adjusted depending on the pressure of the hydrogen gas 1 and the air 2. This makes it possible to finely adjust the load applied to the power generation cell 20.

Further, in the above description, a case has been described in which a flow path member in which a flow path pattern of grooves and convex portions is formed is used as a member constituting the pressure mechanism. For example, the pressure mechanism may be configured using only a flat plate member on which no flow path pattern is formed. This is a configuration in which a flat plate member is used instead of the flow path member in each of the pressure mechanisms described above. Even when there is no flow path pattern as described above, it is possible to apply pressure to the target interconnector.

Further, in the pressure mechanism, the method of applying pressure to the target interconnector is not limited. For example, a mechanism that applies pressure using a liquid such as water or oil may be used. Alternatively, a mechanism that mechanically applies pressure using a piston, a motor, or the like may be used. These mechanisms are appropriately controlled according to the pressure of hydrogen gas 1 and air 2.

The pressure difference effect suppressing section 60 does not necessarily need to be a mechanism that applies pressure to the target interconnector. The pressure difference effect suppressing section 60 may be a reinforcing mechanism that is provided along the target interconnector and reinforces the rigidity of the target interconnector.

16 to 18 are schematic diagrams showing examples of pressure difference influence suppressing sections according to other embodiments. The pressure difference effect suppressing sections 60 shown in FIGS. 16 to 18 are all reinforcing mechanisms provided to increase the mechanical rigidity of the target interconnector 30. By providing the reinforcing mechanism, deformation of the target interconnector 30 itself is suppressed, and as a result, it becomes possible to suppress deformation of the power generation cells 20 adjacent to the target interconnector 30. Furthermore, since the target interconnector 30 is less likely to deform, the sealing performance around it is improved, and it is also possible to suppress leakage of hydrogen gas 1 and air 2.
Below, the case where the second interconnector 32t of the uppermost cell unit 5a is the target interconnector 30 will be described. Note that the description described here is also applicable to the case where the first interconnector 31t of the lowest cell unit 5b is the target interconnector 30.

The reinforcing mechanism 66a shown in FIG. 16 includes a groove 67 provided along the target interconnector 30. The groove portion 67 is a plurality of grooves formed on the outside of the target interconnector 30 (on the side opposite to the side facing the power generation cell 20). For example, linear grooves parallel to each other are formed as the groove portions 67 . For example, if the target interconnector 30 has an axial direction in which it is easy to bend, the groove is formed perpendicular to the axial direction.

For example, when the flow path pattern inside the target interconnector 30 is a parallel groove pattern (see FIGS. 12 and 13, etc.), the direction in which the groove pattern extends is the axial direction in which the target interconnector 30 tends to bend. In this case, a groove portion 67 is provided on the outside of the target interconnector 30 so as to be orthogonal to the extending direction of the groove pattern on the inside. This makes it possible to sufficiently suppress deformation of the target interconnector 30.

In addition, the specific configuration of the groove portion 67 is not limited, and a curved groove, a bent groove, or the like may be used as appropriate so that deformation of the target interconnector 30 can be suppressed.
The reinforcing mechanism 66a including the groove portion 67 can effectively increase the rigidity of the target interconnector 30 without significantly increasing its thickness. Further, it can be easily manufactured by using cutting or press working.

The reinforcing mechanism 66b shown in FIG. 17 includes a rib portion 68 provided along the target interconnector 30. The reinforcing mechanism 66b shown in FIG. The rib portion 68 is a plurality of ribs formed on the outside of the target interconnector 30. For example, linear protrusions parallel to each other are formed as the rib portions 68 . Further, as in the case of the groove portion 67, if the target interconnector 30 has an axial direction in which it is easy to bend, a parallel protrusion is formed perpendicular to the axial direction.

The specific configuration of the rib portion 68 is not limited. For example, a curved protrusion, a bent protrusion, or the like may be used as appropriate. Further, the rib portion 68 is not limited to a linear protrusion, and for example, a lattice-like protrusion may be formed as the rib portion 68.
The reinforcing mechanism 66b including the rib portion 68 can effectively increase the rigidity even if the target interconnector 30 remains relatively thin. This makes it possible to realize a target interconnector 30 that is lightweight but difficult to deform.

The reinforcing mechanism 66c shown in FIG. 18 is a reinforcing member 69 having higher rigidity than the target interconnector 30. Here, a flat plate member having the same shape and size as the planar shape of the target interconnector 30 is used as the reinforcing member 69. The reinforcing member 69 is made of a material that is more rigid than the target interconnector 30, or is configured to have a more rigid structure.
In this way, by simply adding the reinforcing member 69, deformation of the target interconnector 30 can be easily suppressed.

In the embodiments so far, the pressure difference influence suppressing section 60 (the pressure mechanism 61 and the reinforcing mechanism 66) was mainly provided in both the uppermost cell unit 5a and the lowermost cell unit 5b. The present invention is not limited to this, and a configuration in which the pressure difference influence suppressing section 60 is provided in either the uppermost cell unit 5a or the lowermost cell unit 5b is also possible. That is, the pressure difference influence suppressing section 60 may be provided for either the first interconnector 31 or the second interconnector 32 disposed at the outermost side in the cell stack 6. For example, it is also possible to provide the pressure difference influence suppressing section 60 only on the side that is likely to be damaged by pressure changes.

Further, the fuel cell 10 does not need to be configured as a cell stack 6 in which a plurality of cell units 5 are stacked, and the fuel cell 10 may be configured by a single cell unit 5, for example. In this case, the pressure difference effect suppressing section 60 is provided for at least one of the first interconnector 31 and the second interconnector 32 that constitute the cell unit 5.

The fuel cell 10 may be mounted on a vehicle other than an aircraft. For example, the fuel cell 10 may be mounted on a car, train, ship, or the like. Further, the fuel cell 10 may be mounted on a flying object such as an aviation drone or a spacecraft. In addition, the present invention can be applied as a power source for any mobile body.
Further, the fuel cell 10 is not limited to being mounted on a moving body, and may be used in a stationary power generation device.

FIG. 19 is a schematic diagram showing an example of a ground-mounted power generation device according to another embodiment.
A power generation device 200 shown in FIG. 19 is a combined cycle system for stationary power generation, and is a hybrid system that combines a fuel cell 210 (SOFC) and a micro gas turbine 213. The power generation device 200 is a device that generates power using hydrogen gas 1 obtained by reforming city gas, LP gas, etc. as fuel. Here, the flows of hydrogen gas 1 and air 2 are schematically illustrated by thin dotted line arrows and thin solid line arrows.

Hydrogen gas 1 is supplied from a city gas line, part of which is supplied to the fuel cell 210, and the other part to the combustor 52 of the micro gas turbine 213. A portion of the hydrogen gas 1 that has passed through the fuel cell 210 and has reached a high temperature is supplied to the combustor 52, and the other portion is supplied to the fuel cell 210 again (recirculation blower). The recirculation blower can improve the power generation efficiency in the fuel cell 210.

Air 2 compressed by the compressor 51 of the micro gas turbine 213 is supplied to the fuel cell 210 via the regenerative heat exchanger 86. The air 2 that has passed through the fuel cell 210 and has become high temperature is supplied to the combustor 52 and is combusted together with the hydrogen gas 1. The combustion gas at this time rotates the turbine 53 of the micro gas turbine 213. Furthermore, the regenerative heat exchanger 86 exchanges heat between the combustion gas discharged from the turbine 53 and the air 2 discharged from the compressor 51, heats the air 2, and discharges the heated air 2. Further, the combustion gas discharged from the regenerative heat exchanger 86 is recovered as thermal energy by the waste heat recovery section 87. This thermal energy is used, for example, in hot water supply systems, heating systems, and the like.

For example, in conventional power generation systems, the fuel cell is operated to reach its rated output in about several hundred hours after starting the gas turbine. This is an operation to avoid damage to the fuel cell due to sudden pressure changes.

On the other hand, since the power generation device 200 to which the present invention is applied uses the fuel cell 210 provided with the pressure difference effect suppressing section 60, it has high durability against pressure changes.
This makes it possible to realize a highly efficient gas turbine generator or gas turbine engine that can be started or stopped rapidly in an emergency, for example.
In addition, in a power generation system used for home use, it is assumed that the system will be turned on and off frequently, but by applying the present invention, it is possible to realize a home fuel cell system that can be started and stopped suddenly. becomes.

The above description has mainly been about a combined power generation system that combines a fuel cell and a gas turbine. Fuel cells do not need to be used in conjunction with gas turbines. For example, even when a fuel cell is used alone, the durability of the fuel cell against pressure changes can be improved by applying the present invention.

In the above, the case where a solid oxide fuel cell (SOFC) is mainly used as the fuel cell has been described. The present invention is not limited to this, and it is also possible to apply the present invention to other types of fuel cells. For example, other types such as polymer electrolyte fuel cells (PEFC), phosphoric acid fuel cells (PAFC), and molten carbonate fuel cells (MCMF) The present invention may be applied to a fuel cell.

It is also possible to combine at least two of the characteristic parts according to the present invention described above. That is, the various characteristic portions described in each embodiment may be arbitrarily combined without distinction between each embodiment. Moreover, the various effects described above are merely examples and are not limited, and other effects may also be exhibited.

1... Hydrogen gas 2... Air 5... Cell unit 6... Cell stack 10, 210... Fuel cell 11... Pressurized container 12... Generator 13... Gas turbine 20... Power generation cell 30... Target interconnector 31... First interconnector 32...Second interconnector 51...Compressor 52...Combustor 53...Turbine 60...Pressure difference effect suppressor 61, 61a, 61b, 110, 111, 112...Pressure mechanism 66a, 66b, 66c...Reinforcement mechanism 70...Aircraft 100, 200...Power generation device

Claims (15)

A power generation cell in which an electrolyte layer is sandwiched between a fuel electrode and an oxidizer electrode, a first separator that forms a flow path for fuel gas on the fuel electrode side, and a flow path for oxidant gas on the side of the oxidizer electrode. at least one cell unit having a second separator;
a cell block consisting of the at least one cell unit;
a pressure difference effect suppressing unit that suppresses the influence of a pressure difference on the target separator, with at least one of the first separator and the second separator disposed at the outermost side of the cell block as a target separator; battery. The fuel cell according to claim 1, wherein the pressure difference effect suppressing section is a mechanism that suppresses at least one of deformation of the target separator due to the pressure difference and leakage around the target separator due to the pressure difference. . The fuel cell according to claim 1,
the at least one cell unit is a plurality of cell units,
The cell block is a laminate in which the plurality of cell units are stacked so that the fuel gas flow path and the oxidant gas flow path are alternately formed. The fuel cell. The fuel cell according to any one of claims 1 to 3,
The pressure difference effect suppressing section is a pressure mechanism that applies pressure from outside of the target separator. Fuel cell. The fuel cell according to claim 4,
The pressure mechanism applies a pressure from outside of the target separator that is equivalent to that of the target gas flowing on the opposite side of the target separator with the power generation cell in between, among the fuel gas and the oxidizing gas. The fuel cell according to claim 5,
The pressure mechanism forms a working gas flow path on the outside of the target separator that applies pressure from outside the target separator. The fuel cell according to claim 6,
The working gas is the target gas,
The pressure mechanism connects the flow path of the working gas to an inflow path and an outflow path common to the target gas. The fuel cell. The fuel cell according to claim 7,
The pressure mechanism forms a flow path for the working gas similar to the flow path for the target gas along the power generation cell. The fuel cell. The fuel cell according to any one of claims 1 to 3,
The pressure difference effect suppressing section is a reinforcing mechanism provided along the target separator and reinforcing the rigidity of the target separator. Fuel cell. The fuel cell according to claim 9,
The reinforcing mechanism includes a groove or a rib provided along the target separator. Fuel cell. The fuel cell according to any one of claims 1 to 3,
The electrolyte layer is composed of a solid oxide electrolyte. Fuel cell. The fuel cell according to any one of claims 1 to 3,
A fuel cell placed inside a pressurized container. a pressurized container;
A power generation cell in which an electrolyte layer is sandwiched between a fuel electrode and an oxidizer electrode, a first separator that forms a flow path for fuel gas on the fuel electrode side, and a flow path for oxidant gas on the side of the oxidizer electrode. at least one cell unit having a second separator;
a cell block consisting of the at least one cell unit;
a pressure difference effect suppressing unit that suppresses the influence of a pressure difference on the target separator, with at least one of the first separator and the second separator disposed at the outermost side of the cell block as a target separator; a fuel cell stored in the pressurized container;
a first supply line that supplies the fuel gas to the fuel cell;
a second supply line that supplies the oxidant gas to the fuel cell. a pressurized container;
A power generation cell in which an electrolyte layer is sandwiched between a fuel electrode and an oxidizer electrode, a first separator that forms a flow path for fuel gas on the fuel electrode side, and a flow path for oxidant gas on the side of the oxidizer electrode. at least one cell unit having a second separator;
a cell block consisting of the at least one cell unit;
a pressure difference effect suppressing unit that suppresses the influence of a pressure difference on the target separator, with at least one of the first separator and the second separator disposed at the outermost side of the cell block as a target separator; a fuel cell stored in the pressurized container;
generator and
A compressor that compresses air, a combustor that combusts the air compressed by the compressor and the fuel gas, and a turbine that uses the combustion gas from the combustor as a driving source to drive the compressor and the generator. a gas turbine having;
a first supply line that supplies the fuel gas to the fuel cell and supplies the fuel gas discharged from the fuel cell to the combustor;
Supplying air compressed by the compressor as the oxidant gas to the fuel cell, supplying air compressed by the compressor as pressurized gas to the pressurized container, and air exhausted from the fuel cell. and a second supply line for supplying the combustor to the combustor. An aircraft comprising the power generation device according to claim 14.

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