JP2016162567A - Solid electrolyte fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flat plate type solid electrolyte fuel cell having a low level of deterioration as a battery in operating conditions such as changing loads and frequently repeated start and stop in the fuel cell for a moving body.SOLUTION: Disclosed is a cell stack which is an assembly of cell units formed by oppositely arranging fuel electrode surfaces of two flat plate type cells on both end surfaces of a fuel electrode frame 02 made of a non-conducting, non-metal material so as to face inward to each other, and also arranging an air electrode frame 03 made of the non-conducting, non-metal material at the outer part of each air electrode surface of the cells.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a solid oxide fuel cell (hereinafter also referred to as “SOFC”), which is particularly compact, capable of rapid start-up from a cold state, fast thermal self-sustaining, high load fluctuation tracking capability, and long-term output stability. The present invention relates to the provision of a solid oxide fuel cell having high productivity and higher productivity and maintainability.

  Since the Industrial Revolution, the steam engine with solid fuel (coal), the internal combustion engine with liquid fuel (petroleum) and fossil fuel, and the mechanism for converting them into power have changed every century. It is in the process of changing to a fuel cell using fuel.

  Among fuel cells, SOFC has no fuel selectivity, does not use precious metals, has high power generation efficiency, has a high exhaust heat utilization rate due to high exhaust temperature, and exhaust gas accompanying power generation is only water and CO2. Compared to other power systems that use fossil fuels, global development competition has been in progress since the last century because of its many advantages such as high adaptability to carbon dioxide storage, which is estimated to be necessary in the near future.

The SOFC is a cell, which is the smallest power generation unit, consisting of a combination of three power generation elements consisting of an air electrode that takes oxygen as ions, a solid electrolyte that moves only oxygen ions without passing through a gas, and a fuel electrode that takes fuel and ionizes it. , Defined as a collection of the cells. Electricity is generated by the oxidation reaction of the fuel at the three-layer interface composed of the above three power generation elements. In generating power, the oxygen ion migration rate of the solid electrolyte is increased, and the reaction rate at each electrode is also kept high. The operating temperature of SOFC is generally about 650 ° C to 900 ° C.
In order to cope with this high temperature, ceramic materials are used for all the power generation elements. The biggest issue for realizing SOFC is that the critical stress coefficient of ceramic materials is as small as 1/100 compared to metal, and the response to this is the basic issue of SOFC.

  As described in Patent Document 1, all fuel cells are formed by two fuel electrode spaces and an air electrode space partitioned by an ion transfer membrane. In SOFC, the fuel cell is roughly divided into a cylindrical type and a certain space having its own closed space. However, an interconnector is required for electrical connection of each cell and gas sealing. In recent years, when the operating temperature of SOFC is 800 ° C. or lower, an example using a metal interconnector is increasing.

Like all heat engines, SOFC does not convert all the energy of fuel consumed for power generation into power, that is, electric power, and unused heat energy is released to the outside as high-temperature exhaust gas.
However, a part of the heat is transmitted to the outside via the cell and each element surrounding the cell, and the temperature difference caused by the heat flow and the resulting thermal expansion, as well as the partial cell by sealing to prevent leakage It is presumed that thermal stress is generated in the cell, including the adhesion restraint, and this is a factor that causes the cell to deteriorate due to the same phenomenon as stress corrosion in mechanical engineering.

Even if the load during steady operation is constant, the distribution of power generation reaction is not uniform depending on the location, and because of the non-uniformity of material, shape, heat capacity, heat transfer rate, etc. of the components around the cell, it is not uniform within the cell. Temperature distribution occurs, resulting in thermal stress.
Degradation phenomena include sintering (electrode microstructure change), redox (volume change associated with fuel electrode redox), chromium poisoning (increased resistance due to chromium vapor), or sulfur poisoning. Is an important factor for comprehensively judging not only temperature but also fuel utilization, cell overvoltage, or oxygen partial pressure, but the temperature environment changes from room temperature to 600 ° C to 900 ° C. Among them, non-uniform temperature distribution and the accompanying thermal stress are presumed to be one of the major causes of deterioration.
In steady operation, it can be said that the thermal stress associated with these non-uniformities in the location is constant and does not change with time. Since many examples of durability exceeding tens of thousands of hours are seen, even if the internal temperature distribution is not uniform and thermal stress works, it can be said that if the non-uniformity is less than a certain value, durability can be obtained.
On the other hand, unfortunately, there are no examples that can be used for moving objects under repeated operating conditions of load fluctuation and start / stop. This is because the amount of fuel and air supplied to the cell also changes greatly with time, and the internal thermal stress caused by the change with time in the amount of heat generated is larger than that under constant-condition operation. Furthermore, even when the start temperature starts from room temperature, the temperature difference in the warm-up process is large, which is also a factor that generates a large thermal stress.

In the classification comparison of the flat type and the cylindrical type of the fuel cell according to Patent Document 1, the flat plate type SOFC is composed of flat cells, and it is necessary to form a closed space on the fuel electrode surface and the air electrode surface on both sides. As a single cell, productivity is high and it is advantageous in terms of cost.
Further, in a general flat plate type SOFC, in order to connect a plurality of cells in series, all the poles of each cell are arranged in the same direction, and air and fuel supplied to adjacent cells are further arranged. Although interconnectors having electrical conductivity for electrically connecting the two are separated from each other, the interconnectors adjacent to each other need to be electrically insulated.
On the other hand, the cylindrical type has a space closed by itself, and the thermal ambient condition is almost constant as compared with the flat plate, and it is more advantageous than the flat plate type to cope with the low critical coefficient of the ceramic. However, because it is difficult to use inexpensive metal interconnectors and it is difficult to support both ends of multiple connected cells, the volume occupied by all fuel cells is larger than the power generation area, and there are few opportunities for handling variable loads. It is estimated that there are many examples used in large-scale high-temperature SOFCs.

FIG. 22 shows an example of SOFC005 with a flat metal interconnector. A fuel communication path 50-1 and an air communication path 50-2 are arranged on each surface of the interconnector 50 to which the cell 51 is mounted, and form a pair of exit and entry with a path that is symmetrical with respect to the center. Forming an internal manifold.
The fuel electrode and air electrode of two adjacent cells are electrically connected by one interconnector, but the adjacent interconnectors need to be electrically insulated. Is bonded with a glass-based sealing material.

The present invention is based on a flat-plate SOFC, which is estimated to be advantageous in terms of cost, and the target temperature range is the entire range from low temperature to high temperature, but from the low temperature where there are many development examples including Europe. A flat-plate SOFC with a metal interconnector having an internal manifold shown in 005 of the medium temperature type is used for comparison.
Hereinafter, this is referred to as “SOFC with internal manifold”, and the SOFC of the present invention may be referred to as “two-cell opposed arrangement type SOFC”.

JP 2012-14858 A

{High thermal inertia}
In SOFC, there are many examples of power generation under steady load conditions that show durability of tens of thousands of hours or more, but it is currently said that satisfactory running results have been obtained under varying load conditions required for moving bodies. One of the reasons is presumed that the internal thermal inertia of the cell is large.
As shown in FIG. 22, the SOFC with an internal manifold has a metal interconnector disposed between the cells. In this figure, assuming that the heat capacity of the cell is 1, the number of peripheral interconnectors is about 20 times that estimated, and even if the thermal expansion coefficients of the cells and interconnectors are combined, the temperature due to the difference in thermal inertia between the two in the fast temperature change process It is considered that the thermal stress generated due to the difference is a major factor leading to the deterioration of the cell. In order to increase the ability to cope with variable loads, it is necessary to significantly reduce the thermal inertia of the interconnector.

{Uneven heat distribution due to passage arrangement}
As shown in FIG. 22, the SOFC interconnector with an internal manifold is provided with supply and discharge paths for fuel and air on each of the four sides. The heat accompanying the power generation reaction is generated at the fuel electrode, and the fuel exhaust passage has the highest temperature due to this heat. Due to the thermal deformation of the interconnector due to the imbalance of the heat distribution, the cell is also deformed, and the stress in the cell generated thereby can be a factor of deterioration. It is necessary to make the temperature distribution of the support portion around the cell uniform.

{Fixing of interconnectors with sealing material}
As shown in FIG. 22, in an SOFC with a hold on the internal manifold, adjacent interconnectors are electrically insulated and a sealing material having an adhesive function is used to prevent gas leakage around the four passages of the interconnector. There are many. However, as indicated by 0013, there is a concern about leakage near the exhaust outlet particularly due to power generation of fuel having a high temperature due to deformation due to thermal imbalance of each passage.

{Sealing and fastening of cells and interconnectors using sealing materials}
In the SOFC with an internal manifold shown in FIG. 23, the cells and interconnectors that are in contact with each other in order to provide a perfect seal without leakage between the fuel and air spaces on the front and back of the cell and the adjacent air and fuel spaces. The joint portion is sealed and fastened with a bonding agent.
This is shown in the cell adhesion part fuel 51-1 and the cell adhesion part air 51-2 in FIG.
The heat capacities of the cell and the interconnector are greatly different, and even if the thermal expansion coefficients can be matched, a temperature difference occurs in a transient state, and a large thermal stress is generated on the cell side. The seal fastening for this seal is considered to be a cause of deterioration in a transient state with a large temperature change.
In order to reduce the internal thermal stress of the cell, it is necessary to create a sealing method for the joint surface that can absorb deformation due to thermal expansion due to the fact that the support portion around the cell is not fixed and has a certain sliding function.

{Chromium poisoning}
Chromium poisoning is a cause of cell deterioration. The presence of an SOFC metal interconnector with an internal manifold that is the source of chromium vapor during operation causes chromium poisoning. It is necessary not to use a metal interconnect.

{Productivity, maintainability}
In the SOFC with internal manifold shown in FIG. 23, individual interconnectors and cells are bonded, and even if there is a problem with one of a plurality of cells connected in series on the production line or market, the electrical connection part Is in the high temperature region and is difficult to identify.
Even if it can be specified, since the interconnector and the cell are individually bonded together, it is difficult to replace them individually, and it is highly likely that the entire cell stack will be replaced at high cost.

As a result of earnest research, the present inventors have succeeded in solving all the above problems. That is, the present invention is a solid electrolyte fuel cell having the following configuration.
(1) A pair of flat-type solid oxide fuel cells (hereinafter referred to as “cells”) are arranged opposite each other with a certain space facing each fuel electrode surface inward, and the certain space is defined as a fuel layer space. And a solid electrolyte type fuel cell unit (hereinafter referred to as a “cell unit”) having a space provided outside the air electrode surface of each of the cells. Fuel cell.
(2) A plurality of the cell units according to (1) are arranged in series with the air electrode surfaces of the cell units facing each other with a fixed space therebetween, and the fixed space between the fuel electrode surfaces is fueled. A solid oxide fuel cell comprising a solid electrolyte fuel cell stack (hereinafter referred to as a “cell stack”) having a layer space and a constant space between the air electrode surfaces as an air layer space .
(3) A frame-shaped fuel electrode frame disposed on the peripheral edge of the fuel electrode and a frame-shaped air electrode frame disposed on the peripheral edge of the air electrode, each frame comprising a fuel layer space and The solid oxide fuel cell as described in (2) above, which constitutes a sealing body that forms an air space.
(4) The fuel electrode frame has a fuel introduction hole communicating with a fuel supply portion outside the frame and an exhaust outflow hole communicating with an exhaust passage outside the frame. (2) or (3), characterized by having an air introduction hole communicating with an air passage for supplying air outside the frame and an air outflow hole communicating with the exhaust passage. The solid oxide fuel cell according to any one of the above.
(5) The solid oxide fuel cell as described in (4) above, wherein the fuel introduction hole is connected to a fuel supply manifold.
(6) The solid oxide fuel cell as described in (4) above, wherein the fuel introduction hole communicates with a fuel common hole provided in the fuel electrode frame and the air electrode frame constituting the cell stack.
(7) A frame-shaped conductive fuel electrode current collector is disposed at the periphery of the fuel electrode of the cell unit, and a frame-shaped conductive fuel electrode current collector is disposed in contact with the peripheral edge of the air electrode. The solid oxide fuel cell as described in any one of (3) to (6) above,
(8) A frame-shaped conductive fuel electrode current collector is provided at the fuel electrode peripheral portion of the cell unit, and a frame-shaped conductive fuel electrode current collector is provided at the air electrode peripheral portion. The solid oxide fuel cell according to any one of (3) to (6), wherein the fuel cell is slidably pressed through an elastic body that provides a pressing force required for the seal. .
(9) The solid oxide fuel cell as described in any one of (1) to (8) above, wherein a baffle plate is inserted in the center of the fuel layer space and / or the air layer space. .
(10) The outer peripheral surface not facing the air passage and the exhaust passage of the cell stack and the entire outer peripheral surface of the air passage and the exhaust passage provided in the outer peripheral portion of the cell stack are covered with a heat insulating material. The solid oxide fuel cell according to any one of (4) to (9), which is characterized in that

Moreover, it is as follows if it expresses as another aspect.
(1) A pair of flat-plate solid electrolyte fuel cells (hereinafter referred to as “cells”) are disposed opposite each other with a fuel electrode surface facing inward and with a fixed space therebetween, and the fixed space is defined as a fuel layer space; Each cell has a flat plate type solid oxide fuel cell unit (hereinafter referred to as a “cell unit”) in which a constant space whose outermost end surface is opened is provided on the outer surface of each air electrode surface. A solid electrolyte fuel cell (2), characterized in that the two cell units according to (1) are provided on the outermost air electrode of each of the cell units. A fixed space between the closed air electrode surfaces formed by joining together is defined as an air layer space, and a plurality of cell units are connected to the outermost end surface, and the fuel layer space and the air layer are alternately arranged via the cells. Solid oxide fuel cell / cell with space (3) a frame-shaped fuel electrode frame disposed on the periphery of the fuel electrode and the periphery of the air electrode The air electrode frame includes a frame-shaped air electrode frame, the fuel electrode frame forms a seal body that forms a fuel layer space, and the air electrode frame is formed by joining two cell units. The solid electrolyte fuel cell as described in (1) or (2) above, wherein a seal body is formed.
(4) The fuel electrode frame has a fuel introduction hole communicating with a fuel supply portion outside the frame and an exhaust outflow hole communicating with an exhaust passage in an outer peripheral portion of the frame. (1) to (3), characterized in that it has an air introduction hole communicating with the air supply air passage in the outer peripheral portion of the frame and an air outflow hole communicating with the exhaust passage. The solid oxide fuel cell according to any one of the above.
(5) The solid electrolyte fuel cell as described in (4), wherein the fuel introduction hole is connected to a fuel manifold for fuel supply outside the cell stack. The solid oxide fuel cell according to (4), characterized in that it is communicated with a common hole for fuel supply built in a cell stack penetrating all fuel electrode frames and air electrode frames constituting the stack ( 7) A fuel electrode current collector having a frame-like conductivity is arranged on the periphery of the fuel electrode surface of the cell in (1), and an air electrode current collector having a frame-like conductivity is further arranged on the periphery of the air electrode surface. Further, the solid electrode type is characterized in that the fuel electrode surface of the cell and the fuel electrode current collector surface in contact with the cell are joined via an elastic spacer spring that gives a pressing force required for current collection and gas sealing. Fuel cell (8) (4) A solid body characterized by covering an outer peripheral surface not facing the air passage and the exhaust passage of the rack and an outer peripheral surface of the air passage and the exhaust passage provided on the outer peripheral portion of the cell stack with a continuous heat insulating material. A solid oxide fuel cell, wherein one or a plurality of oxidation catalysts are arranged at appropriate positions in the exhaust passage of the electrolyte fuel cells (9) and (4).
(10) A solid oxide fuel cell characterized in that baffle plate fuel or baffle plate air is disposed in the fuel layer space of (2) or in the center of the air layer space, respectively.
(11) In the cell stack of (4), by arranging an air or fuel passage in the exhaust passage through which the high temperature gas passes, or by arranging an exhaust passage through which the high temperature gas passes in the air or fuel passage. A solid oxide fuel cell characterized in that heat exchange is performed between each gas.
(12) A solid oxide fuel cell including applying the layout of the flat cell two-cell opposed solid electrolyte fuel cell of the present invention to a solid electrolyte fuel cell using all ceramics.

As another aspect, it is as follows.
As a result of diligent research in view of the above, the present inventor has solved a problem by means of design, and has created a new mechanism aimed at application to a mobile object in the future.
Corresponding to [0011] The interconnector with large heat capacity of SOFC with internal manifold is abolished, a new cell is arranged in the part where the interconnector exists, the fuel electrodes of the two cells face each other, and an appropriate interval is provided A space that can be formed by closing the periphery of the space between the two opposed cells with a frame-shaped fuel electrode frame made of a non-conductive, non-metallic (eg ceramic) material. Is a fuel layer space, and a non-conductive, non-metallic frame-shaped air electrode frame in contact with the air electrode surfaces of the cells on both sides is arranged, and a combination of these elements is used as a cell unit. A closed space formed by joining the two cell units at the end faces of the air electrode frame is defined as an air layer space.
An assembly formed by joining the air electrode frame surfaces of a plurality of cell units is referred to as a cell stack, and each fuel electrode space in each of these cell stacks and each of the air electrode spaces formed by connection are supplied with fuel and A solid oxide fuel cell characterized in that by supplying air, power is generated without the need for a conventional metal interconnector with a large heat capacity.

  Corresponding to 0012, in a cell stack in which a fuel supply system, further an air supply system and an exhaust system are added to an assembly of a plurality of cell units, from the fuel electrode space and air electrode space belonging to each cell unit. The exhaust gas is separated from the cell unit and exhausted to an exhaust passage arranged around the cell unit. Unlike the conventional SOFC having a metal interconnector with an internal manifold, the exhaust gas is exhausted to the atmosphere. A solid oxide fuel cell characterized by having no direct thermal effect on the cell.

In the cell stack, which is an assembly of a plurality of cell units corresponding to 0013, fuel is directly supplied from the fuel manifold to the fuel supply path in the fuel electrode frame of each cell unit. In this case, no fuel leakage occurs because there is no fuel passage opening at the joint surface of each element of the cell unit.
Further, in the case of using a fuel common hole communicating with each cell unit, a complete seal can be achieved by providing a gasket hole in the joint surface of each frame and storing the gasket therein.
A solid oxide fuel cell characterized in that it does not require a sealing mechanism with an adhesive at a joint surface between interconnectors having four inlet and outlet passages for fuel and air required for a conventional SOFC with an internal manifold.

The surface of the cell unit according to claim 1, which may correspond to the above-described 0013 and 0014, may have a leakage area around the cell. The anode frame and the anode current collector in the anode space, and It is a joint surface. These joint surfaces are joined by a spacer spring as shown in claim 7 with an appropriate pressure contact force that is required for collecting and sealing and does not hinder lateral movement due to thermal expansion of the cell. A solid oxide fuel cell that minimizes the generation of thermal stress due to temperature differences and realizes current collection and gas sealing.
Further, the fuel electrode space and the air electrode space are located close to each other and open to the same exhaust passage, and the leakage of fuel is further reliably suppressed by minimizing the pressure difference between the two spaces.
Note that the anode current collector and the anode frame include bonding to reduce a leak path.

  Corresponding to the above-mentioned 0015, a solid oxide fuel cell characterized in that the possibility of chromium poisoning is reduced by not using a metal interconnector containing chromium as described in the paragraph 0019.

The cell unit corresponding to 0016 can easily confirm the power generation function alone by supplying a fuel to the fuel electrode space in the cell unit with a high temperature atmosphere in the periphery.
Therefore, it is possible to ensure a high level of quality even in a product as an aggregate of these by confirming the function of the cell units constituting the cell stack in advance.
In addition, even if problems occur in the market, it is easy to check the performance of each cell unit and easily replace the cell unit as needed, making it possible to reduce the cost, speedy and reliable maintenance. Solid oxide fuel cell.

{Abolition of interconnector with metal manifold}
The cell unit as a basic element of the two-cell opposed SOFC according to the first, second, and third aspects of the present invention is a ceramic material frame that forms two cells for power generation, a fuel layer space, and an air layer space. Thus, it is possible to obtain a high internal uniformity with a significant weight reduction as compared with the conventional method.
On the other hand, it can be said that the internal uniformity of the combination of the conventional metal interconnector with internal manifold and the ceramic cell is very low.
Here, when a sudden increase in the amount of heat generated due to load fluctuation occurs, the cell temperature with a small heat capacity rises in a short time, but the temperature rise of the metal manifold connected to it is slow and there is a large temperature difference between the two. This creates a high thermal stress locally.
The two-cell facing SOFC of the present invention has high internal uniformity, and it is expected that deterioration due to thermal stress caused by the conventional non-uniform temperature distribution can be greatly reduced. This weight reduction and internal uniformity are a prerequisite for future mobile applications.

{Reduction of deterioration due to chromium poisoning}
In the cell unit according to claim 1, it is expected that the deterioration due to chromium poisoning is reduced by the non-use of the interconnector with a metal manifold, which is a source of chromium.

{Reduction of sealing points around cells and reduction of related stress}
In the cell unit according to claim 1 and 2, in the configuration of the fuel layer space and the air layer space, the gas seal is required at only one place around the fuel layer space which is the minimum closed per cell, and all the air layer space periphery is joined. A special seal beyond the contact seal at the joint surface is unnecessary because it contacts the large commercial space through the surface.
On the other hand, in the interconnector system in the conventional SOFC with an internal manifold, many joint surfaces require a bonding seal with an adhesive including electrical insulation. This bonding also includes cells, which contributes to the generation of thermal stress accompanying sticking.

{Easy multiple connection}
In the cell stack of claim 2, increasing the output by increasing the number of cell units can be easily realized.
Further, since the air passage and the exhaust passage of claim 4 are formed in the outer peripheral portion separated from the cell stack, the area of each passage can be easily increased as the number of cell units increases.
On the other hand, in the conventional power generation method using a combination of a cell and a metal interconnector in an SOFC with an internal manifold, the power generation part including the cell and the four passages for gas transfer are all arranged in the metal interconnector. Even when the number of interconnectors and cells is increased, it is necessary to readjust the thermal balance of the metal interconnector due to the expansion of the gas passage shape and the increase in total heat generation. There is a limit to the number that can be increased.
Therefore, in the cell stack of claim 2, the flexibility to change the output by changing the number of cell units can be said to be high in the two-node opposed SOFC of the present invention.

{Easy fuel supply without leaking into cell stack}
In the case of using an external fuel manifold directly connected to a fuel supply pipe fixed to the fuel electrode frame as a supply path to the individual fuel layer spaces of the fuel in the cell stack according to claims 4, 5, and 6, Since there is no fuel passage opening at the joint surface of each element of the unit, no fuel leakage occurs.
Furthermore, even when using a common hole that penetrates all cells and stacks as a fuel supply path, a gasket hole is provided in the common hole of each joint surface, and a fuel flow without any fuel leakage is possible by arranging a gasket fuel flow here. It becomes.
As an example of the gasket used here, a graphite-based gasket having a high sealing function even in a high temperature atmosphere as compared with being in a reducing atmosphere by fuel can be cited.
However, in the case of using a common hole, the maximum diameter of the common hole is almost determined by the peripheral shape, so that the response to output changes is low. In terms of cost, it is estimated that a common hole is advantageous, and it is necessary to use both appropriately.

{Thermal separation between gas passage and cell}
5. The cell stack according to claim 4, wherein an air passage and an exhaust passage are arranged in an outer peripheral portion of a space occupied by each cell unit in the cell stack, whereby the power generation portion and the gas passage portion have low thermal conductivity. Separated by a ceramic frame. As a result, in the two-cell opposed SOFC, the thermal influence from the gas passage around the cell due to the integration of the power generation section and gas passage section of the conventional SOFC with a metal internal manifold with high thermal conductivity is integrated. Therefore, it is possible to improve the uniformity of the internal temperature distribution of the cell.

{Gas passage with great design freedom}
The air supply to the individual air space in the cell stack according to claim 4 is performed from the air passage through the air introduction hole in the cathode frame. In addition, high-temperature gases are discharged from the fuel layer space and the air layer space to the exhaust passage through the exhaust outlet hole and the air outlet hole, respectively.
Both passages use the layout of the two-cell opposed SOFC according to the present invention effectively and are located on the outer periphery of the cell unit, which is the minimum unit of power generation, and therefore have a high degree of design freedom including its size.
Thus, the wide passage has a small ventilation resistance, the pressure distribution in the flow direction in the passage becomes substantially constant, and the same amount of gas can be supplied and exhausted regardless of the position of each cell unit in the cell stack. This uniformity is also an important factor for the cell in terms of durability.

{Overall insulation}
The outer peripheral surface of the air passage and the exhaust passage of claim 8, the both side surfaces of the cell stack, and the front and rear surfaces are covered with an integrated heat insulating structure to suppress heat transfer from the cell assembly surface, In addition to increasing the utilization, it is possible to reduce the uneven temperature distribution inside the cell assembly, which is the cause of cell deterioration, and this helps to improve the function of the cell and extend its life.

{Addition of oxidation catalyst}
The addition of the oxidation catalyst to the exhaust passage according to claim 9 helps to prevent generation of unused gas from the outside and uses heat generated by oxidation for fuel reforming and preheating of intake air to increase power generation efficiency.

{Current collection without current leakage by current collector}
The current collection from the cell according to claim 7 is performed by a fuel electrode current collector and an air electrode current collector which are arranged at the peripheral edge portions of both end faces of the cell and pressed by a spacer spring arranged on the air electrode side. .
The spacer spring and each current collector are housed in a recess formed between the fuel electrode frame and the air electrode frame, and the total depth of the recess is the thickness of the two current collectors on both sides of the cell, the thickness of the cell. And the total spring height after subtracting the required compression allowance of the spacer spring, and the pressing force of the spacer spring in the contact state where the fuel electrode frame and the air electrode frame are in complete contact is the peripheral edge of the cell due to the thermal expansion of the cell. Is set so that the pressing force between the current collector and the cell for collecting current and preventing fuel leakage becomes a required value.
As a result, current collection is performed while suppressing fuel leakage occurring in the cell, and minute movement between the joint surfaces is allowed, thereby reducing thermal stress.
The reduction of the force that restrains the deformation of the cell due to the thermal expansion has an internal stress reduction effect, and is an effective means for extending the cell life.
Furthermore, this current collection system keeps the current collection and sealing pressure applied to the cell constant regardless of the coupling force for the cell unit or cell stack configuration, which is also effective for extending the life of the cell. Act on.
In order to reduce the fuel leak path, the joint surface between the fuel electrode frame and the fuel electrode current collector includes a case where the fuel electrode is bonded.

{Conclusion of cell unit}
The connection for the cell unit configuration of the fuel electrode frame and the air electrode frame according to claim 3 can be either an adhesion method or a mechanical connection method. An example of the mechanical connection will be shown below.
The fastening part of the cell unit by the fastening band is outside the heat insulating structure of claim 8 and is isolated from the high temperature inside the cell stack, and the fastening rigidity of the fastening part is set to be relatively low. Absorption of deformation due to thermal expansion of each exposed frame provides stable fastening without affecting the life of the cell units and without loosening. This mechanical fastening is a means to cope with the case where the adhesive cannot be used thermally or chemically.

{Electric coupling between cells outside the insulation space}
The terminal part for connecting to the other current collector according to claim 7 is extended to the outside which reaches a room temperature through a minute space provided in the heat insulating structure around the cell, and the connection of each terminal part is subjected to high temperature corrosion. It is possible to use a metal having high conductivity such as copper which is not a concern, and an improvement in power generation efficiency can be expected by reducing the ohmic resistance of the conductive portion.
Furthermore, in a temperature environment similar to the room temperature of the output terminal of the cell, it is easy to equip control system parts that dislike high temperatures such as easy power distribution, cell function check, and addition of bypass circuit in case of malfunction. Yes.

{Baffle plate fuel}
In the baffle plate fuel according to claim 10, the uneven flow pattern provided on the surface of the baffle plate creates turbulence in the fuel flow between the surfaces of the baffle plate fuel facing the respective fuel electrode layers, and the contact between the cell and the fuel. In addition to increasing opportunities, the separation of the reaction product from the cell surface is promoted, thereby increasing the power generation output and at the same time improving the fuel utilization rate.
Further, a fuel bypass connected to the fuel inlet in the fuel electrode frame is provided inside the baffle plate fuel, and a plurality of fuel branches communicating with the fuel bypass and having openings on the outer surface of the baffle plate fuel are used for the power generation surface. By supplying the fuel two-dimensionally in the vertical direction and to the cell, it is possible to obtain uniform heat generation and improve the fuel utilization rate due to power generation by forming strong turbulence and appropriate fuel distribution.

{Baffle plate air}
The baffle plate air according to claim 10 causes turbulence in the air flow between each air electrode layer and the baffle plate surface facing the air electrode layer due to the uneven pattern provided on the surface of the baffle plate, thereby supplying oxygen to the cell surface. The temperature distribution of the non-uniform cells can be reduced by the cooling effect by the air flow.
Furthermore, the air bypass provided inside the baffle plate and a plurality of air branches communicating with the air baffle plate and having openings on the outer surface of the baffle plate are arranged in a region where heat generation generated by the power generation reaction is gathered, and a relatively low temperature air bypass. For the purpose of reducing the unevenness of temperature distribution in the region, air supply having a two-dimensional spread can be performed.
Compared with the conventional one-dimensional air supply of SOFC with an internal manifold, it is possible to level the temperature distribution on the cell surface and suppress the generation of thermal stress on the cell surface.
Although the same applies to the fuel electrode space, the two-dimensional gas supply is effective for the effective use of the space due to the fact that the cells unique to the two-cell arrangement type SOFC of the present invention face each other and there is no interconnector. This is possible as a result.

{Use of current collector mesh}
If the energization function on the cell surface is insufficient due to temperature or other reasons, place a projecting part on the mesh when collecting electricity by placing a flexible mesh on the cell surface. A boss is disposed on the baffle plate according to claim 10 opposite to this, and the boss presses a protrusion on the mesh toward the power generation layer of the cell, thereby lowering the bonding force between the mesh and the power generation layer of the cell. Cell output can be maintained. It should be noted that an example is also included in which meshes are pressed against each other without using a baffle plate by taking advantage of the characteristics of the opposed cells inherent to the two-cell arrangement type SOFC of the present invention.

{Heat exchanger}
In general, the SOFC is intended to improve efficiency by increasing the intake air temperature on the air side, and for the purpose of fuel reforming on the fuel side, and preheats the air and fuel by the heat of the exhaust.
The heat exchanger according to claim 11 utilizes the fact that the design freedom of the gas passage unique to the two-cell opposed arrangement type SOFC of the present invention is large. The high temperature side is the exhaust passage, the low temperature side is the intake and fuel passage, It shows that heat is exchanged between the high temperature side and the low temperature side by disposing a low temperature side passage inside the high temperature side passage or a high temperature side passage inside the low temperature side passage.
The conventional SOFC with an internal manifold has a separate heat exchanger arranged outside the cell assembly. However, this plan uses a direct heat exchange for each gas passage, so there is no transfer loss in the middle and a high heat exchange rate. And a very compact solid oxide fuel cell in terms of space can be realized.
Furthermore, in this layout, a temperature difference between the exhaust passage side and the air passage side may occur in the cell stack. In response to this, the exhaust passage is bent and extended in the direction of the air passage at the rear end of the cell stack, and further bent and extended to the air passage entrance at the air passage portion, and the periphery of the air passage of the cell stack is provided here. Heating by the exhaust passage, which greatly reduces the temperature gradient inside the cell stack.
FIG. 21 shows an example in which an intake passage is arranged in the extended exhaust passage to perform intake residual heat and fuel is heated in the upper exhaust passage.

{All ceramics}
In the present invention, the metal parts inside the heat insulating structure of claim 4 are each current collector and spacer spring, but there is an upper limit that can be used in terms of temperature.
However, aiming at a high-efficiency cell in a high-temperature region, each current collector is applied to a ceramic having high-temperature conductivity, and the slide part is replaced with a simple adhesive fixing, so that the present invention is also applied to the all-ceramic SOFC in claim 8. It is possible to apply to the two-cell opposed arrangement type SOFC which is the basic layout of the above.
In this case, higher efficiency can be expected even at the expense of some quick response, and it is possible to take advantage of the simple structure, compactness, high maintainability and productivity of the two-cell facing SOFC. It is.
As an example, energization from the high temperature portion to the low temperature portion is performed through sealed graphite.

{Disassembly and assembly maintainability}
4. The fuel electrode frame and the air electrode frame of the cell unit according to claim 1 and claim 3, wherein the cell unit is connected to each other in a cell stack by a spring-loaded bolt outside the heat insulating structure. It is assumed that This makes it possible to confirm the function of the initial cell stack alone. In addition, operation is possible even in a cell-assembled state. In addition to checking the function of each cell unit, the problematic cell unit can be replaced independently, confirming the function compared to the conventional SOFC with internal manifold, Disassembly and assembly, cell unit maintenance and replacement can be easily performed.

{Cell material}
The materials used vary depending on the temperature, but are selected with reference to Table 1 below.

Cell unit conceptual diagram Cell stack conceptual diagram Entity configuration diagram of cell unit 002 Formation of fuel and air space by two cell units Disassembled perspective view of cell unit Cell unit current collector and gas seal details Cell unit electrical connection Configuration of cell unit band fastening 0011 Configuration of cell stack 002 Details of fixing method of cell unit in cell stack Cell assembling cross section of the fuel electrode space center Cross-sectional view of the cell cathode air space External view of cell assembly Structure of cell unit fuel supply hole 0012 Cell unit fuel supply hole built-in OO12 fuel electrode space sectional view Baffle plate fuel 30 cross-sectional perspective view Baffle plate air 31 cross-sectional perspective view Metal mesh details for current collector Example of prevention of metal mesh floating by flow control Fuel reforming by exhaust heat Intake preheating by exhaust heat SOFC exploded perspective view with flat metal interconnector SOFC 1/4 cut perspective view with flat metal interconnector Cylindrical SOFC partial cross section

{Cell unit conceptual diagram}
FIG. 1 is a conceptual diagram of the cell unit 001 shown in claim 1. The two left and right cells 01 are each formed by laminating a fuel electrode 01-2, an electrolyte 01-1, and an air electrode 01-3, and the fuel electrode surfaces of the two cells are arranged so as to face each other. A fuel layer space A is formed, and a constant space having its end face opened on the outer side of the air electrode surface shown in claim 1 is formed on the outer side of the air electrode surface side on both side surfaces.

{Conceptual diagram of cell stack}
FIG. 2 shows a basic configuration diagram of the cell stack 002 according to claim 2, which is formed by arranging a plurality of cell units 001 so that the outermost end surfaces of the constant space outside the air electrode surface of claim 1 are in contact with each other. Show. The adjacent constant space outside the air electrode surface adjacent to each other is joined together to form a closed space, an air layer space B, in which both side surfaces are air electrode surfaces.
As a result, a flat two-cell opposed arrangement solid electrolyte fuel cell, which is the subject of the present invention, is formed, in which a plurality of fuel layer spaces and air layer spaces are alternately coupled via the cells 01.

{One Example of Cell Unit 001}
FIG. 3 shows a fuel electrode frame 02 having a sealing function in the periphery shown in claim 3 in the fuel layer space shown in claim 1, and the air electrode frame 03 having a sealing function in claim 3 is arranged in two cells. An example in which the cell unit 001 is formed by disposing outwardly on each air electrode surface is shown. In addition, joining between the frames in the unit is basically performed by bonding except for mechanical joining.

{Formation of air space}
FIG. 4 shows an example of formation of the air space B by joining two cell units 001.
The contents are the same as those in FIG. The closed space formed by the two air electrode frames 03 of the two cell units 001 facing each other and having both ends thereof as the air electrode surface of each cell is defined as an air layer space B.

{Supply of fuel and air}
An embodiment relating to inflow and outflow of gas in claim 4 is shown in FIG. The fuel to the fuel layer space A in the fuel electrode frame 02 is adjusted to an appropriate pressure from an external fuel supply unit, and then the fuel introduction hole 02-1 having an appropriate orifice effect provided in the fuel electrode frame 02. Supplied. Further, the power generation reaction product and the residual fuel in the fuel layer space are discharged from the exhaust outlet hole 02-2 having an appropriate orifice effect to the exhaust passage in the outer periphery of the frame.
The air to the air layer space B is adjusted to an appropriate pressure from an external air supply unit, and then is connected to two connected airs that form the air layer space from the air passage in the outer peripheral portion of the air electrode frame 03. An air outlet hole formed by the pole frame 03 and supplied from an air introduction hole 03-1 having an appropriate orifice effect therein, and unreacted air is also formed by two connected air electrode frames 03 and having an appropriate orifice effect. It is discharged into the exhaust passage from 03-2.

{Cell unit exploded view}
FIG. 5 shows an exploded view of one embodiment of the cell unit 001. Here, in addition to the fuel electrode frame 02 and the air electrode frame 03 and the two cells 01 shown in FIG. 3, the fuel electrode current collector 04 in contact with the fuel electrode surface of each cell, and the air electrode current collector in contact with the air electrode surface 05, and a spacer spring 06 having a spring action, which is disposed in contact with the air electrode frame surface of the cell of the air electrode current collector. These including the cells are arranged in the space formed by the fuel electrode frame recess 02-3 and the air electrode frame recess 03-3 (when the recess provided in each frame is formed only in one frame) Also included).

{Cell unit current collector and gas seal details}
FIG. 6 shows an example of current collection and gas sealing of the cell unit 001 shown in claim 7. Here, in the space formed by the fuel electrode recess 02-3 and the air electrode recess 03-3 shown in the exploded view of FIG. 5, the fuel electrode current collector 04, the cell 01, the air electrode current collector 05, and the spacer spring. An example in which 06 is arranged is shown.
The total width in the thickness direction of each element arranged in the space is set to be larger than the width of the space, and the spacer spring 06 is compressed by the attachment of each element by the difference between both widths, and the elements are joined. A pressing force is generated on the surface.
Due to this pressing force, each current collector corresponding to each power generation layer of the cell is electrically connected, and the joining surface of the fuel electrode current collector 04 and the fuel electrode frame 01 serving as a fuel leak path and the cell 01 Leakage from the interface with the fuel electrode layer is prevented.

FIG. 7 shows an example of electrical connection of the cell unit 001. The fuel electrode current collector terminal 04-1 and the air electrode current collector terminal 05-1 in the cell unit 001 are connected by the unit internal connector 07, and the air electrode current collector terminals of each of the other unconnected cells 01 are connected. The anode current collector terminal is connected to the anode current collector terminal and the air cathode current collector terminal of each cell unit 001 adjacent to the left and right by a unit external connector 08. As a result, each cell unit is coupled in series.
The fuel supply pipe 09 at the lower end in the figure is fixedly bonded to the inlet of the fuel introduction hole 02-1 and is connected to the fuel manifold 16 arranged outside corresponding to claim 5 so as to enter the fuel electrode space. Supply fuel.

{Cell unit element coupling method}
The cell unit 001 is bonded to the fuel electrode frame 01 and the air electrode frames 03 on both sides by a heat-resistant adhesive when mechanical connection is not used.

{Mechanical coupling of cell unit elements}
FIG. 8 shows a cell; unit band fastening 0011 as an example of mechanically coupling two types of frames of a fuel electrode and an air electrode. The purpose of this is to mechanically fasten the cell unit when it is difficult to use a heat-resistant adhesive under temperature conditions in the production process.
As shown in FIG. 8, the cell unit band fastening 0011 includes a fuel electrode frame / band fastening 021 having a fuel electrode fastening boss 021-1 at the center of both sides and an air electrode fastening boss 031-1 at the center of both sides. The air electrode frame / band fastening 031 having the above is fastened by the fastening band 10. Thus, the present cell unit band fastening 0011 has the same function as the cell unit 001.

{Configuration of cell stack 002}
FIG. 9 shows a case where 10 cell units 001 are connected as an example of the cell stack 002 of claim 2. An end plate f11 is disposed at the front of the stacked cell unit 001, and an end plate r12 is disposed at the rear. The cell unit 001 is fastened at four places by bolts 13 with springs.
In the cell stack 002, the fuel layer spaces and the air layer spaces are alternately arranged, and the air layer spaces at both end surfaces of the cell stack are completely closed by the end plate f11 and the end plate r12, respectively.
The fuel supply in this figure is as shown in claim 5, and the fuel manifold 16 disposed outside the cell unit in the fuel supply pipe 09 of FIG. 7 fixed to the fuel electrode frame 02 of each cell unit 001. It is done by concatenating.
This fuel manifold has a flexible bellows in the middle of the piping to prevent bending stress from being applied to the piping due to subtle dimensional errors in the fuel supply pipe.

{Details of fixing method of cell unit in cell stack}
FIG. 10 shows an embodiment of a fixing method of the cell unit 001. In the drawing, as shown by one cell unit 001 arranged for reference, each cell unit is supported by two cell lower supports 14 arranged on the lower side thereof. The cell lower support 14 is supported by a spring-loaded bolt 13 penetrating the cell lower support 14.
All the cells and knits are fastened and fixed by four bolts 13 with springs, and the fastening force is always required by the springs of the bolts 13 with springs, including absorption of dimensional changes due to thermal deformation of the cell unit. Value is maintained.
It should be noted that the cell unit 001 in the cell stack 002 is joined only by the fastening force of the bolt 13 with the spring including the end plates at both ends, and no adhesive is used unless particularly required.
The total length of the cell lower support 14 is set to be shorter than the total length of all the cell units, and all the fastening force of the spring-loaded bolt 13 acts on the cell unit. The gap between the cell lower support 14 and the two end plates is filled with a flexible gasket cell support 15.

{Cell assembly}
FIG. 11 is a vertical sectional view of an example including 5 or 6, 7 to 11 as cell assembly. The cross section displayed in FIG. 11 passes through the center of the fuel electrode frame 02 of the cell unit, and the power generation part of the cell in the drawing indicates the fuel layer space A.
The cell assembly includes a fuel cell current collector 04, an air electrode current collector 05, a polar air passage 17, and an exhaust passage 18 in the cell stack according to claim 4, and an outermost peripheral surface according to claim 8. Including air passage heat insulating material 19, exhaust passage heat insulating material 20, cell side heat insulating material 121, cell side heat insulating material r22, fuel manifold heat insulating material 23 is added as necessary.
The fuel is introduced into the fuel layer space via the fuel manifold 16, the fuel supply pipe 09, and the fuel introduction hole 02-1 provided in the fuel frame 02. Products and unreacted gas accompanying the power generation reaction are discharged to the exhaust passage 18 from the exhaust outlet hole 02-2.
Each heat insulating material of Claim 8 aims at the reduction of the thermal stress of the cell which suppressed the nonuniformity of the heat distribution by the heat radiation from the specific location to the exterior, the improvement of the electric power generation efficiency by the effective use of exhaust heat, etc.

  FIG. 12 is a cross-sectional view of the cell unit in the cell assembly of the previous item 0058 at the center of the air layer space. The air for power generation is introduced into the air layer space B through the air introduction hole 03-1 of the air electrode frame 03 from the lower air passage 17, and the residual air after the reaction is exhausted from the upper air outflow hole 03-2 to the 18 exhaust passages. To be discharged.

FIG. 13 shows an example of the appearance of the cell assembly of the previous item 0058. The fuel supply in this figure is a manifold system, and the supply is performed from the fuel supply port 24 and the air supply is performed from the air supply port 25, and the remaining fuel, air, and generated gas generated by power generation are collectively discharged from the discharge port 26.
In the figure, both the fuel electrode current collector terminal 04-1 and the air electrode current collector terminal 05-1 pass through the pores provided in the peripheral heat insulating material and extend to the outside of the heat insulating material, avoiding high temperatures. In a space close to room temperature, each terminal portion is connected by an internal connector 07 and an external connector 08.

FIG. 14 shows an example of a built-in cell unit fuel supply hole 0012 having a fuel supply hole according to claim 6. The fuel electrode / common hole 022-1 provided in the fuel electrode frame / built-in 022 and the air electrode frame / common hole 032-1 provided in the air electrode frame / built-in 032 on both sides are formed by connecting the cells / units to each other. By forming, a fuel supply path communicating with each other is formed.
Even if the frame is bonded or mechanically fixed in the cell unit, the gasket / fuel flow is formed in the gasket hole 28-1, as shown in FIG. 28 is arranged.

  FIG. 15 is a cross-sectional view of the cell unit 0012 at the center of the fuel layer space of the fuel electrode frame / built-in 022 with a built-in fuel supply hole in the cell unit 0012 of claim 6. The fuel enters the fuel electrode space A from the fuel electrode / common hole 022-1 through the fuel introduction hole 02-1, which extends in the horizontal direction in the drawing and communicates with the air space, and exhausts 02-2 after power generation. It is discharged from the outflow hole. The rear end of the fuel introduction hole 02-1 is closed by a plug / fuel 29.

FIG. 16 is a sectional perspective view of the baffle plate fuel 30. In this example, the baffle plate is disposed in the center of the fuel electrode space, and the fuel flow in the fuel passage formed by the fuel electrode surface of the cell and the baffle plate is disturbed by the fuel uneven surface 30-1 provided on both sides of the baffle plate. To promote power generation reaction.
Further, a fuel bypass 30-2 communicating with the fuel introduction port 02-1 in the fuel electrode frame 02 for supplying fuel to the fuel electrode space is provided inside the baffle plate, and a plurality of fuel bypasses 30-2 connected to this and opened to the previous fuel passage are provided. By the fuel path branch 30-3 having different passage areas, an appropriate amount of fuel corresponding to the location is supplied to the fuel electrode layer where power generation is performed.
Note that this method includes a case where the internal fuel bypass is not used and the flow is controlled only by the turbulence caused by the uneven surface of the flow divided by the baffle plate.
In the figure, the boss fuel 30-4 prevents separation of the metal mesh 32 from the cell surface when the metal mesh 32 is used for current collection.

FIG. 17 shows an example of the baffle plate air 31. Similarly to the baffle plate fuel 30, active oxygen supply to the air electrode layer is performed by the flow disturbance due to the air layer of the cell and the air uneven surface 31-1 on the baffle plate.
Further, an air bypass 31-2 having an opening at the upper portion of the air introduction hole 03-1 of the air electrode frame 03 is provided in the puff plate air 31 and a plurality of airs communicated with the air electrode space provided at the upper portion of the air bypass. Air supply having a two-dimensional spread on the cell surface is performed by the bypass circuit of the pass branch 31-3.
In the figure, the boss air 31-4 prevents separation of the metal mesh 32 from the cell surface when the metal mesh 32 is used for current collection.

FIG. 18 shows an example in which a metal current collector and a metal mesh 32 are used. When the conductive function of the cell surface cannot be expected sufficiently at a relatively low temperature, current collection is performed using a metal mesh. FIG. 18 is obtained by adding a metal mesh 32 to FIG. 3 without a mesh. The current collecting surface of the metal mesh 32 is disposed so as to be in contact with the fuel or air electrode surface of each cell, and the peripheral portion thereof is disposed so as to be in contact with the opposite side of the contact surface with the cell 01 of each current collector. The other surface not in contact with the current collector at the peripheral edge of the metal mesh 32 is arranged to contact the fuel electrode frame at the fuel electrode and to the spacer spring on the air electrode side.
In the case of using the metal mesh 32, in order to prevent fuel leakage, the anode current collector and the metal mesh are electrically connected in advance by welding or the like, and the anode electrode frame is bonded in such a manner that the mesh portion is embedded.

  FIG. 19 shows an example of preventing the metal mesh 32 from floating. The mesh protrusions 32-1 of each metal mesh 32 are controlled to move away from the cells by the baffle plate fuel or air boss fuel 30-4 or boss air 31-4, which are opposed to each other. Is preventing.

{Fuel reforming}
FIG. 20 shows an example in which reforming is performed by heating the fuel with exhaust heat in the exhaust passage 18. The fuel is led from the fuel supply port reforming 24-1 to the heat exchanger reforming 33, and is heated and reformed by the high-temperature gas in the exhaust passage reforming 18-1. The pipes constituting the reformer make a U-turn in the exhaust passage and are connected to the fuel manifold 16 from the fuel supply port side where the inlet is located.

FIG. 21 shows an example in which preheating is performed by exhaust heat of intake air simultaneously with fuel reform described in the above-mentioned 0061. This is a system in which high-temperature gas in the exhaust passage at the upper part of the cell is sent to the lower intake passage to heat the intake air.
Exhaust gas in the exhaust passage reformer 18-1 enters the exhaust passage preheat 18-3 below the exhaust passage lowering 18-2 and heats the air in the heat exchanger preheat 34 while ending the exhaust passage lateral movement 18- 4 is discharged to the outside through the exhaust port preheat 26-1.
The air enters the air passage heat exchanger 17-1 in the pipe forming the heat exchanger of the heat exchanger preheat 34 from the air supply port preheat 25-1, is heated here, and then enters the air passage preheat 17-2. Heated air is supplied to each air layer space from the air inlet hole 03-1 of the air electrode frame 03.
The air passage preheating 17-2 and the exhaust passage preheating 18-3 are completely divided by the separator plate 35. However, heat can be transmitted to the air side via this separate plate and the heat exchange rate can be further increased. It becomes. Further, by arranging a heat exchanger on the inflow side of gas including air and fuel having a lower temperature than the exhaust side and allowing the high temperature gas to pass therethrough, it is possible to make the entire temperature distribution uniform.

  When it is difficult to form the ceramic part used in the present invention by a simple stamp method, it is assumed that the part is formed by multiple division molding and bonding with an adhesive or a laser, or processing with a fine bull ceramic.

A Fuel layer space B Air layer space 001 Cell unit 0011 Cell unit band fastening 0012 Cell unit fuel supply hole built-in 002 Cell stack 003 Cell assembly 005 SOFC with flat metal interconnector
006 Cylindrical SOFC
01 Cell 01-1 Electrolyte 01-2 Fuel electrode 01-3 Air electrode 02 Fuel electrode frame 02-1 Fuel introduction hole 02-2 Exhaust outlet hole 02-3 Fuel electrode frame recess 021 Fuel electrode frame / band fastening 021-1 Fuel Electrode fastening boss 022 Fuel electrode frame / built-in 022-1 Fuel electrode / common hole 03 Air electrode frame 03-1 Air introduction hole 03-3 Air outflow hole 03-3 Air electrode frame recess 031 Air electrode frame / band fastening 031-1 Air electrode fastening boss 032 Air electrode frame / built-in 032-1 Air electrode / common hole 04 Fuel electrode current collector 04-1 Fuel electrode current collector terminal 05 Air electrode current collector 05-1 Air electrode current collector terminal 06 Spacer Spring 07 Unit internal connector 08 Unit external connector 09 Fuel supply pipe 10 Fastening band 11 End plate f
12 End plate r
13 Bolt with Spring 14 Cell Lower Support 15 Gasket Cell Support 16 Fuel Manifold 17 Air Passage 17-1 Air Passage Heat Exchange 17-2 Air Passage Preheating 18 Exhaust Passage 18-1 Exhaust Passage Reform 18-2 Exhaust Passage Down 18 -3 Exhaust passage preheating 18-4 Exhaust passage lateral movement 19 Air passage insulation 20 Exhaust passage insulation 20-1 Exhaust passage insulation reform 20-2 Exhaust passage insulation preheat 21 Cell side insulation 1
22 Cell side insulation
23 Fuel manifold insulating material 24 Fuel supply port 24-1 Fuel supply port reforming 25 Air supply port 25-1 Air supply port preheating 26 Exhaust port 26-1 Exhaust port preheating 27 Output terminal 28 Gasket / fuel flow 28-1 Gasket hole 29 Plug and fuel 30 Baffle plate fuel 30-1 Fuel uneven surface 30-2 Fuel bypass 30-3 Fuel path branch 30-4 Boss fuel 31 Baffle plate air 31-1 Air uneven surface 31-2 Air bypass 31-3 Air path Branch 31-4 Boss air 32 Metal mesh 32-1 Mesh protrusion 33 Heat exchanger reforming 34 Heat exchanger preheating 35 Separator plate 36 Front heat insulating material 37 Rear heat insulating material 50 Metal interconnector 50-1 Fuel passage 50-2 Air Passage 51 Metal Interconnector Cell 51-1 Cell Adhesive Portion Fuel 51 2 cell adhesion portion air 60 cylindrical electrolyte 61 cylindrical fuel electrode 62 cylindrical air electrode 63 cylindrical ceramic interconnector

Claims (10)

  A pair of flat-type solid oxide fuel cells (hereinafter referred to as “cells”) are disposed opposite each other with a fuel electrode surface facing inward and with a fixed space therebetween, and the fixed space is defined as a fuel layer space, and A solid oxide fuel cell comprising a flat solid electrolyte fuel cell unit (hereinafter referred to as a “cell unit”) having a space provided on the outside of the air electrode surface of each cell.   A plurality of the cell units according to claim 1, wherein the air electrode surfaces of the cell units are arranged to face each other with a constant space therebetween, and the constant space between the fuel electrode surfaces is defined as a fuel layer space, A solid oxide fuel cell comprising a solid oxide fuel cell stack (hereinafter referred to as “cell stack”) in which a constant space between the air electrode surfaces is an air layer space.   A frame-shaped fuel electrode frame disposed at the peripheral edge of the fuel electrode, and a frame-shaped air electrode frame disposed at the peripheral edge of the air electrode, each frame comprising a fuel layer space and an air layer space The solid oxide fuel cell according to claim 2, wherein a seal body is formed. The fuel electrode frame has a fuel introduction hole that communicates with a fuel supply portion outside the frame, and an exhaust outflow hole that communicates with an exhaust passage outside the frame,
The air electrode frame has an air introduction hole communicating with an air passage for supplying air outside the frame and an air outflow hole communicating with the exhaust passage. 4. The solid oxide fuel cell according to any one of 3 or 3.   5. The solid oxide fuel cell according to claim 4, wherein the fuel introduction hole is connected to a manifold for fuel supply. 5. The solid oxide fuel cell according to claim 4, wherein the fuel introduction hole communicates with a fuel common hole provided in the fuel electrode frame and the air electrode frame constituting the cell stack.   A frame-shaped conductive anode current collector is disposed in contact with the periphery of the fuel electrode of the cell unit, and a frame-shaped conductive anode current collector is disposed in contact with the peripheral edge of the air electrode. The solid oxide fuel cell according to any one of claims 3 to 6, wherein:   The gas seal requires a frame-shaped conductive anode current collector at the cell electrode periphery, and a frame-shaped conductive anode current collector at the air electrode periphery. 7. The solid oxide fuel cell according to claim 3, wherein the fuel cell is slidably pressed through an elastic body that gives a pressing force.   The solid oxide fuel cell according to any one of claims 1 to 8, wherein a baffle plate is inserted in a central portion of the fuel layer space and / or the air layer space. The outer peripheral surface not facing the air passage and the exhaust passage of the cell stack and the entire outer peripheral surface of the air passage and the exhaust passage provided on the outer peripheral portion of the cell stack are covered with a heat insulating material. The solid oxide fuel cell according to any one of claims 4 to 9.

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