JPH03219563A - Solid electrolyte type fuel cell - Google Patents

Abstract

PURPOSE:To form a solid electrolyte type fuel cell excellent in reliability and characteristic by radially introducing a reaction gas between the center part and peripheral part of a reaction gas distributing device to dispense with the necessity of the whole gas seal between respective fuel cell members. CONSTITUTION:A flat type single cell 13 in which electrodes of a cathode 3 and an anode 2 are arranged on both main surfaces of a solid electrolyte 1 and a reaction gas distributing device 11A for separately supplying both reaction gases of an oxidizing agent gas and a fuel gas to both the electrodes are laminated to form a solid electrolyte type fuel cell. The reaction gases are introduced between the center part and peripheral part of the cell, and the electric connection with the single cell 13 is performed by the guide blades 8A of the distributing devices 4A, 11A, 11b. The reaction gases are supplied to or exhausted from the anode 2 and cathode 3 of the single cell 3 in parallel through the center part of the laminated single cell 13 and distributing devices 4A, 11A, 11B by manifolds 5, 6. Hence, the whole gas seal between respective cell members is not required.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to a solid electrolyte fuel cell that uses a solid electrolyte and converts its free energy into electrical energy through an electrochemical reaction. This invention relates to a solid oxide fuel cell that has excellent properties.

[Conventional technology]

While the power generation efficiency of conventional power generation devices that use heat engines such as gas turbines and diesel engines is limited by the Carnot cycle, the power generation efficiency of fuel cells is determined by changes in the free energy of electrochemical reactions. Since it depends on the relationship with ental ruby, it is expected to be higher than that of a heat engine.

Therefore, using a fuel cell as a power generation device is an effective use of resources, which not only results in relatively low emissions of CO, but also extremely low emissions of NO, which worsens the environment due to air pollution. In the future, it is expected to be one of the effective means to put a brake on the situation.

A fuel cell uses an electrolyte plate as an oxygen electrode (cathode) and a fuel electrode (
The structure is such that oxygen or air is supplied to the oxygen electrode side, and hydrogen or reformed gas such as natural gas, methanol, or petroleum, or coal gas is supplied to the fuel electrode side. This system extracts electricity chemically and also generates water. Fuel cells are classified according to the type of electrolyte, and alkaline type, phosphoric acid type, molten carbonate type, and solid electrolyte type have mainly been developed. A solid oxide fuel cell uses a solid oxide as an electrolyte and is operated at 900 to 1000°C.

In a solid electrolyte fuel cell, for example, a zirconia solid electrolyte stabilized with ittria (ZrO2Yz03
) Oxygen ions (0"-) migrate through the oxygen electrode. The reaction at the oxygen electrode is 1/20g + 2e-= O"--1--...
(1) The reaction at the fuel electrode is 11t + O”−LO+ 2e−−−(21Go
+ 0t--CO, + 2e--・-(3) The reaction of the entire battery is 1/20t + L -HgOf4t1/20t +
Go -Co□ , (5), which has the advantage that CO can be used directly as a fuel along with the molten carbonate type. Therefore, C
In addition to being able to supply directly to the fuel cell without going through an O transformer,
Since the operating temperature is as high as 1000°C and Ni is used for the fuel electrode, fuel gas can be reformed within the cell, eliminating the need for a reformer and making the fuel supply system much more complicated than other fuel cells. There are characteristics that make it simple. Furthermore, since the exhaust gas from the fuel cell is at a high temperature, the exhaust heat can be utilized over a wide range of areas.

The cell structures of solid oxide fuel cells are broadly classified into two types. One is U.S. Patent No. 3,460,991, 1
983 National Thuuel Cell Seminar (Nati
onal Fuel Ce1l Sem1nar)No
v, 13-1619830rkland, Flori
da p78 and 1985 Fuel Cell Seminar (F
May, 19-
221985 Tucson, Arzona p9
One cylindrical shape is disclosed in U.S. Pat. No. 3,554,808, U.S. Pat.
No. 490.445, 1983 National Fuel Cel Seminar
lSem1nar) Nov, 13-161983 p
It is a flat plate type disclosed by '74. Because solid oxide fuel cells are made of ceramic as their main material, they are mechanically fragile and prone to damage due to thermal stress caused by differences in thermal expansion and uneven power generation within the cell, which has prevented them from being realized for a long time. However, as revealed in the above patent, electrode and separator materials with thermal expansion coefficients almost the same as the electrolyte material have been discovered, and it has become possible to actually make prototype batteries and conduct power generation tests. 1983 National Thuuel Cell Seminar
Fuel Ce1l Sem1nar) Nov, 13
-1619830rkland, Florida p7
8 has a structure that focuses on escaping thermal expansion, so the reliability of each single cell is high, but there is still a nickel felt band at the joint between cells.
(felt pad), which has the problem of not being able to absorb thermal expansion sufficiently, and because of the structure in which current flows along the plane of the thin electrode, there is a drawback that resistance loss is large and power generation density is low.

Among the flat batteries, 1983 National Tsuyuel Cell
Seminar (National Fuel Ce1l 5e
nlnar) Nov.

13-1619830rkland, Florida
The one announced on page 74 has a monolithic structure in which the electrolyte, electrodes, and separator are sintered together, and has the feature of extremely high output density, but it not only requires advanced technology for manufacturing, but also has low thermal expansion. Since it has a structure that makes it almost impossible to escape, it has the disadvantage that it cannot be made large and its range of application is limited. Also, U.S. Patent No. 4,490.4
The fuel cell of Publication No. 45 uses a disk-shaped thin film (thickness 0.01 to 0.0
．． 0.02 inch) on the image side (thickness 0.003 to 0.02 inch).
005 inch) and sintered to form a single cell, which is sandwiched between ribbed separator plates. Since there is no tight gas seal, thermal expansion from each cell can escape.

[Problem to be solved by the invention]

However, in such a fuel cell, the reactant gas flows along the diameter on the main surface of the single cell, so the path of the reactant gas tends to be long, and the concentration gradient of the reactant gas becomes large, causing the cell to flow on the cell surface. There is a problem in that the non-uniformity of the output distribution increases.

This invention was made in view of the above-mentioned points, and its purpose is to allow each member of the battery to slide freely relative to each other, and to ensure that the path of the reactant gas is short (to prevent thermal damage to the battery members due to temperature changes in the fuel cell). It is an object of the present invention to provide a solid oxide fuel cell that is highly reliable and has excellent characteristics, and also to provide a solid oxide fuel cell that has excellent thermal efficiency by utilizing the combustion heat of exhaust gas.

[Means to solve the problem]

According to the present invention, the above-mentioned objects are as follows: 1) A flat plate type single cell having a cathode and an anode electrode arranged on both surfaces of a solid electrolyte body, and a double reaction of an oxidant gas and a fuel gas on both electrodes of this single cell. In a solid oxide fuel cell formed by stacking reactant gas distribution means for individually supplying gases, (1) guiding the reactant gas to the center and peripheral parts and electrically connecting it to the single cell; (2) reaction gas distribution means 4A, IIA, IIB having guide vanes 8A for performing
2) Manifolds 5 and 6 are provided that penetrate through the center of the stacked unit cell and the reactive gas distribution means and supply or exhaust reactive gas to the anode and cathode of the unit cell in parallel, respectively; 2) a solid electrolyte; A flat plate type single cell with cathode and anode electrodes arranged on both sides of the body, and a reactive gas distribution means for individually supplying both the oxidizing gas and fuel gas to both electrodes of this single cell are laminated. In a solid oxide fuel cell made up of: (1) a guide vane 8A that guides the reactive gas between the central part and the peripheral part and makes an electrical connection with the single cell, and a guide vane 8A that discharges the reactive gas to the peripheral part; Reactive gas distribution means 4A, IIA, 11B having a reaction gas exhaust slit 14, (2) passing through the center of the stacked single cells and the reaction gas distribution means, and discharging the anode and cathode of the single cell, respectively. a manifold 5.6 that supplies reactant gas in parallel; and (3) a flame shield that is provided around the cell stack in which the single cells and the reactant gas distribution means are stacked and blocks the combustion flame 23 generated around the cell stack. (4) a heat insulator 17 that accommodates the cell stack and the flame shield through a preheating chamber;
A. 3) A flat plate type single cell having a cathode and an anode disposed on both sides of a solid electrolyte body, and both reactant gases, oxidant gas and fuel gas, separately supplied to both electrodes of this single cell. (1) A guide for guiding the reactant gas to the connection between the central part and the peripheral part and for electrically connecting it to the single cell. Wings 8B13 and guide wings 8 for sealing the reaction gas provided in the periphery
and (2) a reactant gas distribution means 4C, IIC, 110 having B, and (2) penetrating the central part of the stacked unit cell and the reactant gas distribution means, and supplying the reactant gas to the anode and cathode of the single cell in parallel, respectively. Manifold for air or exhaust27.
28 and a manifold 5.6 penetrating the inner side of the guide vane for sealing the reaction gas at the periphery of the stacked single cell and the reactive gas distribution means; (3) a stacked cell of the stacked single cell and the reactive gas distribution means; This is achieved by providing a combustion chamber 30 adjacent to the stack chamber that accommodates the stack and partitioned from the stack chamber by a flameproof wall 32.

The single cell can be formed in the form of a free-standing thin plate or supported on a substrate in the form of a membrane. Freestanding single cells do not use a supporting substrate. The same applies to the reaction gas distribution means, which includes a separate plate that is a self-supporting dense thin plate-like body or a porous substrate having guide wings, and a dense separator membrane supported on one main surface and supported on the other main surface. Any distribution means formed from a porous or dense substrate with guide vanes can be used. The manifold supplies fuel gas to the anode of the single cell or discharges the fuel gas after reaction. Further, an oxidizing gas is supplied to the cathode of the single cell, or the oxidizing gas is discharged after the reaction. The manifold can be formed by a reaction gas pipe or by polymerizing reaction gas flow holes formed in the thickness direction of the single cell and the reaction gas distribution means. Guide vanes of the reactant gas distribution means move the reactant gas between the center and the periphery of the single cell. The flow direction of the reaction gas can be linear, zigzag, spiral, etc.

Further, guide vanes for gas sealing can be provided at the outermost peripheral portion of the reactive gas distribution means. At this time, the reactive gas is not discharged around the cell stack in which the single cells and the reactive gas distribution means are stacked. Using a reaction gas exhaust slit, the reaction gas can be exhausted around the cell stack. Gas sealing does not need to be performed on the entire unit cell and reaction gas distribution means, but can be performed locally using a glass O-ring.

It is also possible to seal with a ceramic adhesive instead of the glass OIJ song. When the reaction gas is discharged around the cell stack, a combustion flame is generated in the flame chamber around the cell stack. At this time, the fuel gas reformer and the oxidizing gas external supply pipe or the reaction gas external supply pipe can be heated using the heat of the combustion flame. When reaction gases are not discharged into the flame chamber around the cell stack, each exhaust gas is collected by a manifold and reacted in a combustion chamber isolated from the stack chamber.

[Effect]

Since the reactant gas flows between the central manifold and the periphery of the reactant gas distribution means, the need for global gas seals between the fuel cell components is eliminated. Gas sealing can be performed locally, such as near the manifold. Furthermore, since the reactive gas flows between the central part and the peripheral part, the path of the reactive gas is shortened, and the concentration gradient of the reactive gas is reduced. Since the reaction gas discharged from the cell stack reacts and burns between the flame shield and the cell stack or in a combustion chamber partitioned from the cell stack, the heat of combustion can be effectively utilized.

〔Example〕

(Example 1) Next, embodiments of the present invention will be described based on the drawings.

FIG. 1 shows a porous substrate with a separator film of a cell stack according to an embodiment of the present invention.
FIG. 1(b) is a view taken along the line A--A in FIG. 1(a). The porous substrate 118 (reactive gas distribution means) is formed using lanthanum manganite (LaMnOs). Separator film 4A is made of dense lanthanum chromite (LaCrOs)
Formed in layers. The separator membrane 4A is also part of the reactive gas distribution means. An oxidant gas supply manifold 6 and a fuel gas supply manifold 5, which are reactive gas flow holes, are provided in the center of the porous substrate 11A with a separator film. The oxidant gas supply manifold 6 has a reaction gas supply slit 10.
＾ is formed. The porous substrate tia is provided with rib-shaped guide wings 8A for guiding the oxidant gas, slits 29 for radially guiding the oxidant gas, and reaction gas discharge slits 14 for discharging the oxidant gas. In addition, the lip that forms the fuel gas supply manifold has glass Q IJ song 2 for gas sealing.
is installed. FIG. 2 shows a porous substrate with a single cell of a cell stack according to an embodiment of the present invention, and FIG. The porous substrate 11B (reactive gas distribution means) is formed using nickel-zirconia (Nl-ZrOt) cermet.A single cell 13 is formed on the porous substrate 11B. Solid electrolyte body made of dense zirconia stabilized with mos) 1. Anode made of porous Ni-Zr0=cermet2. It consists of a cathode 3 made of porous lanthanum manganite. An oxidant gas supply manifold 6 and a fuel gas supply manifold 5 are provided in the center of the porous substrate 11B with the single cell 13. A reaction gas supply slit IOB is formed in the fuel gas supply manifold 5 . Porous substrate 11
B is provided with a lip-shaped guide vane 8A for guiding the fuel gas, a slit 29 for radially guiding the fuel gas, and a reaction gas exhaust slit 14 for discharging the fuel gas. A glass O-ring 12 is attached to the rib 18- of the substrate forming the oxidizing gas supply manifold 6 for gas sealing.

The porous substrate 11A with a separator film is prepared as follows. The length and width are 300fi x 300fi and the thickness is 2n.
Lanthanum chromite is densely plasma sprayed onto the flat main surface of the porous substrate with rib-like guide wings to form a separator film 4A having a thickness of 40 μm. Porous substrate with single cell 1
1B is prepared as follows. Ni Zr0t cermet is porously plasma sprayed onto the flat main surface of a porous substrate having a length and width of 300 x 300 tx and a thickness of 2 fi to form an anode 2 with a thickness of 100 -. Zirconia stabilized with yttria is thermally sprayed onto the anode 2 to form a dense solid electrolyte body 1 with a thickness of 30 mm. Lanthanum manganite was then plasma sprayed.
A porous cathode 3 having a thickness of 800 mm is formed. Porous substrates using lanthanum manganite can also be made dense. However, even in this case, since lanthanum manganite is reduced in a reducing atmosphere, a separator film made of dense lanthanum chromite is necessary.

FIG. 3 is a sectional view showing a cell stack in which porous substrates with separator films 11A and porous substrates with single cells 11B are alternately laminated according to an embodiment of the present invention. Reaction gas supply slit) IOA.

An arrow indicates how the reaction gas is supplied through 10B. The arrows in the right column indicate the flow of oxidant gas, and the arrows in the left column indicate the flow of fuel gas. The lamination forms a manifold in which reaction gas flow holes are connected and each reaction gas is supplied to the reaction gas distribution means in parallel. FIG. 4 is a partially enlarged view showing part A in FIG. 3, FIG. 4 tal is a sectional view showing the state before heating, and FIG. 4 fbl is a sectional view showing the state after heating.

The glass O-ring 12 is melted by heating, creating a liquid seal. The inner wall of the rib of the substrate to which the glass O-ring 12 is attached is filled with ceramic cement or the like to form a clogging portion 3.
4 is formed. The reaction gas cannot pass through the clogging section 34.

Oxidizing gas is flowed through the porous substrate 11A made of lanthanum manganite. The oxidizing gas flows in a zigzag manner toward the periphery of the porous substrate 11A by the guide vanes 8A and the slits 29, so that the oxidizing gas is distributed to the cathode 3 of the single cell. On the other hand, the fuel gas is passed through the porous substrate 11B made of old -ZrO□ cermet. The fuel gas flows in the same manner as the oxidant gas, and the fuel gas is distributed to the anode 2 of the single cell. The separator film 4^ prevents the oxidizing gas and the fuel gas from coming into contact with each other. The electromotive force (0.5 to 0.9 V) generated in the single cell by the electrochemical reaction is added in series. Porous substrate 11A made of lanthanum manganite and separator film 4 made of lanthanum chromite
The porous substrate 11B made of A, Ni-ZrO, and cermet has electronic conductivity and can allow current to flow in series.

Since the separator film 4A is thermally sprayed onto the porous substrate 11A and is physically bonded to the porous substrate 11A, the separator film 4A can freely expand and contract thermally and slide against each other. Single cell 13 and porous substrate 11B
The relationship between the anode 2. and the anode constituting the single cell. Solid electrolyte body 1. The same applies to the relationship between the cathodes 3. Porous substrate 11A with separator film and porous substrate 1 with single cell
Even in a cell stack in which cells 1B are laminated, the spaces between the separator film 4A and the porous substrate 1-board 11B, and between the single cell 13 and the porous substrate 11A, freely expand and contract thermally and slide due to temperature changes in the cell stack. can do. This is because it is sufficient to laminate the porous substrate 11^ with a separator film and the porous substrate 11B with a single cell in order to guide the reactive gas radially between the central part and the peripheral part of the reactive gas distribution means. The gas seal is a porous substrate 11A.

11B is limited to local sealing by the glass O-ring 12 near the manifold. Since the gas seal by the glass O-ring becomes a liquid seal as described above, it does not interfere with thermal expansion and contraction of each component of the cell stack.

Furthermore, since the reactive gas flows radially, the path of the reactive gas can be shortened. This is extremely advantageous for the support film method in which the separator film 4^ and the single cells 13 are formed on the substrate.

This is because the supported membrane method requires a long path for the reactant gas in order to enable a large-area cell stack. The reaction gas that has completed the reaction is discharged from the vicinity of the cell stack and burned.

(Example 2) 2- FIG. 5 shows a cell stack according to a different example of the present invention, and FIG.
) is a CC arrow view. Hydrogen gas, which is a fuel gas, is passed through the fuel gas supply manifold 5 through a separate plate 4B (
reactant gas distribution means).

Oxygen gas, which is a reactive gas, is supplied to the oxidant gas supply manifold 6.
By independence! It is introduced into the separate plate 4B, which is the i-plate. The oxidizing gas and the fuel gas are separately introduced into the two main surfaces of the separate plate 4B via the reactive gas supply holes 10B. The reaction gas supply manifold is a reaction gas tube made of zirconia stabilized with yttria (YzOa). Separate) 14B is lanthanum chromite (La
CrOs) and is densely fired to a thickness of 0.5 to 2 fi.

Lanthanum chromite has electronic conductivity and will not be oxidized even in an oxidizing atmosphere. Furthermore, lanthanum chromite exhibits a coefficient of thermal expansion similar to that of zirconia stabilized by I-nodoria. The single cells 13 are connected in series by this lanthanum chromite. A guide cylinder 8^ is provided on each of the two main surfaces of the separate plate 4B. This guide cylinder 8A guides the reaction gas from the center of the separate plate 4B toward the periphery. The oxidizing gas thus reaches the cathode 3 of the single cell. Meanwhile, the fuel gas reaches the anode 2 of the fuel cell.

The solid electrolyte body 1 is made of self-supporting thin plate-like zirconia stabilized with ittria and has a thickness of 50 to 500 mm. An anode 2 and a cathode 3 are baked onto the main surface of the solid electrolyte body 1 . NlZr0□ is used as anode 2.

The thickness is selected from 0.01 to 1 day.

Lanthanum manganite is used for the cathode 3.

Both are made porous.

In a fuel cell having such a configuration, a gas seal is not required between the unit cell 13 and the separate plate 4B. Therefore, it is sufficient to simply stack the single cells 13 and the separate plates 4B alternately. Therefore, in the process of thermal expansion, the single cell 13 and the separate plate 4B slide freely relative to each other, so no thermal stress is generated. The gap between the through hole and the through hole can be closed by providing a seal wall 9 on the separate plate 4B and forming a ceramic sealing part 7 between the seal wall 9 and the reaction gas supply manifolds 5 and 6. . Since the thermal stress generated by this sealing portion 7 is small, the overall thermal stress remains small. The reactant gas that has reached the periphery is combusted here, maintaining the temperature of the fuel cell at a predetermined high temperature.

Although the single cell has a disk shape in FIG. 5, it is not limited to this and may be square. Further, the guide cylinder 8A can be freely designed in consideration of equal gas distribution so as to maximize battery characteristics.

It is also possible to combine the reaction gas supply manifolds 5.6 into one instead of two. In this case, two reaction gases flow separately inside the reaction gas supply manifold. In this case, there is an advantage that the number of through holes is reduced.

FIG. 6 shows a cell stack according to a modification of the guide cylinder 8A, FIG. 6(a) is a plan view, and FIG. 6(b) is a
It is a DD arrow view of No.11. The guide cylinder 8A is formed in a spiral shape. The pitch of the guide cylinder 8A is selected to be an optimum value depending on the diameter of the cell stack. The reaction gas can flow uniformly through the single cell 13, and the exhaust gas can be collected in one place.

FIG. 7 is a sectional view showing a cell stack according to a modified example of the gas seal. A single cell 13 in which an anode 2 and a cathode 3 are laminated on a circular solid electrolyte body 1 and a circular separate plate 4B are alternately laminated, and a fuel gas supply manifold 5 serving as a reaction gas pipe and an oxidizing gas supply are provided. The manifold 6 penetrates therethrough. In addition, a fuel gas exhaust manifold and an oxidant gas exhaust manifold, which are reactive gas pipes, pass through the tube, but these are not shown. The anode 2 is provided with a glass reservoir 16A, and a glass O-ring 12B is mounted inside.

The cathode 3 is provided with a protrusion 15A. A glass reservoir 16B is formed on the upper surface of the separate plate 4B, and a protrusion 15B is formed on the lower surface. Such a solid oxide fuel cell is prepared as follows. A circular solid electrolyte body (100 ~
500μ thick) 1 is formed. The solid electrolyte body 1 includes a fuel gas supply manifold, an oxidant gas supply manifold, and a fuel gas discharge manifold.

26- It has a through hole for the oxidant gas exhaust manifold.

Ni ZrOx cermet is thermally sprayed to a thickness of 100 μm on one main surface of the solid electrolyte body 1 to form a porous anode 2 . Lanthanum manganite is sputtered on the other main surface of the solid electrolyte body 1 to form a porous cathode 3 having a thickness of 50 to 200 mm. In addition, a gasket-shaped glass reservoir 16A having a groove for storing glass is press-molded using Ni-ZrO2 cermet at a temperature of 1000°C.
It is fired in In addition, the gasket-like protrusion 15A is press-molded using lanthanum manganite at a temperature of 1000°C.
It is fired in The separate plate 4B is made of lanthanum chromite, is press-molded to have a through hole for a fuel gas supply manifold, etc., and has a glass reservoir 16B and a protrusion 15B, and is densely fired. Glass reservoir 16A, 1
Glass Q IJ song 2B and 12C are installed inside 6B. As a glass, the melting point is 900℃ and the working temperature is 10℃.
00°C soda lime glass is used. Single cell 13
and separate plates 4B are alternately stacked, and a fuel gas supply manifold and the like are set in the through holes. The operating temperature of the fuel cell is maintained at 1000°C. At this time, anode 2
The glass reservoir 16^ is burned. Further, a protrusion 15A is burned into the cathode 3. The glass O-rings 12B and 12C are melted to provide a liquid seal.

The fuel gas and oxidant gas that have completed the reaction are exhausted by a fuel gas exhaust manifold and a reaction gas exhaust manifold (not shown). Exhaust gases do not combust around the cell stack, but react in an isolated combustion chamber.

After the operation ends, the glass solidifies, but since the linear expansion coefficient of soda lime glass is larger than that of zirconia and other electrode materials, it occupies a small volume in the glass reservoirs 16A and 16B, causing cracking and damage to other battery constituent materials. do not have.

FIG. 8 is a sectional view showing a cell stack according to a different modification of the gas seal. Since a reaction gas exhaust manifold is not used, gas sealing around the cell stack is not performed.

Exhaust gases are combusted around the cell stack.

(Example 3) FIG. 9 is a sectional view of a solid oxide fuel cell having a combustion chamber according to an example of the present invention. A combustion chamber 34 is provided around the cell stack. Natural gas, which is a fuel gas, is introduced together with water vapor from the fuel gas external supply pipe 2OA, enters from the top of the reformer 22, makes a U-turn at the bottom, exits to the top, and passes through the fuel gas external supply pipe 20B to the cell stack 19. to go into. During this time, while the natural gas is being preheated in the preheating chamber 25,
It is reformed into hydrogen, COl and CO2 by a catalyst in the reformer. The temperature suitable for such modification is 700-850
℃, the exhaust gas or combustion gas from the operating temperature of the battery of 800 to 1000° C. can be used for sufficient reforming. In addition, the air that is the oxidizing gas enters from the oxidizing gas external supply pipe 21A and goes through the path 21B to spiral around the reformer and is preheated to near the operating temperature of the battery. Enter the battery from the inside.

After each reaction gas reacts within the cell stack, unreacted hydrogen and oxygen and generated water are discharged into the flame chamber 24 around the cell stack. There, they are mixed and combusted, forming a combustion flame 23. At this time, the flame shield 18 is arranged so that the flame does not directly heat the reformer 22, and the flame shield 18 is provided with small holes to minimize heat shielding. We take into consideration the following. The combusted gases, water vapor, carbon dioxide gas, and nitrogen are cooled in the preheating chamber 25 and taken out to the outside through the exhaust gas hole 26. However, since the exhaust gas is still at a sufficiently high temperature at this stage, it can also be used to generate hot water.

Reformer container material and oxidant gas external supply pipe 21A21B
A heat-resistant alloy such as Incoloy 800H is suitable for the flame shield 18, and a thin fireproof brick or alumina is suitable for the flame shield 18. Cell stack 19 flame chamber 24. Flame shield 18. The preheating chamber 25 is accommodated by a heat insulator 17A.

Fig. 10 shows a solid oxide fuel cell according to a modification of the combustion chamber, Fig. 10(a) is a sectional view, and Fig. 10Q)l is a view taken along the line E-E in Fig. 10(a). be. In the preheating chamber 25, the fuel gas external supply pipe 2OA and the oxidant gas external supply pipe 2
1A is preheated.

(Example 4) 30- Fig. 11 shows a porous substrate 11C with a separator film of a cell stack according to yet another embodiment of the present invention, Fig. 11+81 is a plan view, Fig. 11 (bl is the Figure +8
FIG. 1 is a FF arrow view of FIG. The porous substrate 11C has a peripheral fuel gas supply manifold 5. It also has a central fuel gas exhaust manifold 27 and an oxidant gas exhaust manifold 28. Furthermore, rib-shaped guide vanes 8A for guiding the oxidizing gas from the peripheral part to the central part and lip-shaped guide vanes 8B for gas sealing are provided. The materials and manufacturing method for the separator film 4C and the porous substrate 11C are the same as those for the porous substrate 11A with a separator film shown in FIG. FIG. 12 shows a porous substrate with a single cell of a cell stack according to still another embodiment of the present invention, FIG. 12 (al is a plan view, FIG. 12(b)
is a view taken along the line FF of FIG. 12 fal. The materials and manufacturing method for the single cell 13 and the porous substrate 110 are the same as those for the single cell-equipped porous substrate 11B shown in FIG. The porous substrate with a separator film 11C and the porous substrate with a single cell LID are stacked to form a cell stack 19 shown in FIG. 13.

(Embodiment 5) FIG. 13 is a partial sectional view of a solid oxide fuel cell having a combustion chamber according to a different embodiment of the present invention. The fuel gas is supplied through a fuel gas external supply pipe 20B, a fuel gas supply manifold 5 shown in FIGS. 11 and 12, a fuel gas discharge manifold 27 shown in FIGS. 11 and 12, and a fuel gas external discharge pipe 31B. Pass. The oxidizing gas is supplied to the oxidizing gas external supply pipe 21B, the oxidizing gas supply manifold 6 shown in FIGS. 11 and 12, the oxidizing gas discharge manifold 28 shown in FIGS. 11 and 12, and the oxidizing gas external It passes through the discharge pipe 31A. The exhaust gas is burned in the combustion chamber 3o.

The combustion heat heats the fuel gas external supply pipe and the fuel gas external supply pipe, and preheats the reaction gas flowing inside. The combustion chamber 3o is separated from the stack chamber 33 by a flameproof wall 32. The combustion chamber 3° and the stack chamber 33 are formed by a heat insulator 17B.

Since the reactant gas is preheated and supplied to the stack 19, the ceramic material constituting the fuel cell will not be damaged by heat. Furthermore, since the temperature of the single cell of the fuel cell is maintained at a predetermined high temperature, the characteristics of the fuel cell are improved.

〔Effect of the invention〕

According to the present invention, since the reactive gas is introduced radially between the center and peripheral parts of the reactive gas distribution means, there is no need for an overall gas seal between each member of the fuel cell. Even if a gas seal is performed, a local seal is sufficient. Therefore, each member of the fuel cell can freely slide and undergo thermal expansion and contraction.

Also, due to the radial flow of the reactant gas, the reactant gas bath can be shortened, and the concentration gradient of the reactant gas is reduced.

In this way, a solid oxide fuel cell with excellent reliability and characteristics can be obtained. Further, the exhaust gas of the reaction gas can be combusted in a combustion chamber, and the combustion heat can be used to obtain a solid oxide fuel cell with excellent thermal efficiency.

[Brief explanation of drawings]

FIG. 1 shows a porous substrate with a separator film of a cell stack according to an embodiment of the present invention, and FIG. 1 Ta) is a plan view,
33-2 shows a porous substrate with a single cell of a cell stack according to an embodiment of the present invention. A plan view, FIG. 2(b) is a view taken along the line B-B in FIG. 2 Ta), FIG. FIG. 4(1)) is a sectional view showing the state before heating, FIG. 4(1)) is a sectional view showing the state after heating, and FIG. 5 is a partially enlarged view showing a different embodiment of this invention. Such a cell stack is shown, with FIG. 5(a) being a cross-sectional view and FIG.
bl is a view taken along the line C-C of FIG. 5 Ta), FIG. 6 shows a cell stack according to a modified example of the guide vane, FIG. 6 fa) is a plan view, and FIG. 6(b) is a diagram of FIG. (a) DD arrow view, 7th
The figure is a sectional view showing a cell stack according to a modified example of the gas seal, FIG. 8 is a sectional view showing a cell stack according to a different modified example of the gas seal, and FIG. 9 has a combustion chamber according to an embodiment of the present invention. A sectional view of a solid oxide fuel cell, FIG. 10 shows a solid oxide fuel cell according to a modification of the combustion chamber,
Figure 10 (al is a cross-sectional view, in Figure 10) is a
), FIG. 11 shows a porous substrate with a separator film of a cell stack according to yet another embodiment of the present invention, FIG. 11+al is a plan view, and FIG. 11
FIG. 12 shows a porous substrate with a single cell of a cell stack according to yet another embodiment of the present invention, FIG. 12 fa) is a plan view, and FIG. 12(a), and FIG. 13 are partial sectional views of a solid oxide fuel cell having a combustion chamber according to a different embodiment of the present invention. 4^, 4C: separator membrane; 5: Fuel gas supply manifold, 6: Oxidizing gas supply manifold, 8A: Guide vane, I
IA, IIB, IIC, IID: Porous substrate (reactive gas distribution means), 17^: Heat insulator, 18: Flame shield, 23
; Combustion flame, 27: Fuel gas discharge manifold, 28: Oxidizing gas discharge manifold, 30: Combustion chamber, 32: Flameproof wall,
5 sea seat uya

Claims (1)

[Scope of Claims] 1) A flat plate type single cell having cathode and anode electrodes arranged on both main surfaces of a solid electrolyte body, and both reactant gases, oxidizing gas and fuel gas, being supplied to both electrodes of this single cell. In a solid oxide fuel cell formed by stacking reactant gas distribution means for individually supplying the reactant gas, (1) guiding the reactant gas between the central part and the peripheral part and electrically connecting it to the single cell; (2) A manifold that passes through the center of the stacked single cells and the reactive gas distribution means and supplies or exhausts reactive gas to the anode and cathode of the single cell in parallel, respectively. A solid oxide fuel cell characterized by comprising , and. 2) A flat plate type single cell with cathode and anode electrodes arranged on both main surfaces of a solid electrolyte body, and a reactive gas in which both the oxidizing gas and the fuel gas are individually supplied to both electrodes of this single cell. In a solid oxide fuel cell formed by laminating a distribution means, (1) a guide vane that guides the reactive gas between the central part and the peripheral part and makes an electrical connection with the single cell, and a peripheral part; (2) a reactive gas distribution means having a reactive gas discharge slit for discharging the reactive gas; a manifold that supplies air in parallel; (3) a flame shield that is provided around a cell stack in which a single cell and a reactive gas distribution means are stacked and blocks combustion flames generated around the cell stack; (4) A solid oxide fuel cell comprising: a heat insulating body that accommodates the cell stack and the flame shield through a preheating chamber. 3) A flat plate type single cell with a cathode and an anode arranged on both main surfaces of a solid electrolyte body, and reactive gas distribution that supplies both reactive gases, oxidizing gas and fuel gas, individually to both electrodes of this single cell. In a solid oxide fuel cell formed by stacking means, (1) guide vanes and peripheral parts that guide the reactive gas between the central part and the peripheral part and electrically connect with the single cell; (2) A reaction gas distribution means having a guide vane for sealing the reaction gas; (3) a manifold that passes through the inside of the guide vane for sealing the reaction gas at the periphery of the laminated unit cell and the reaction gas distribution means; A solid oxide fuel cell comprising a combustion chamber that is adjacent to a stack chamber that accommodates stacked cell stacks and is separated from the stack chamber by a flameproof wall. 4) The solid oxide fuel cell according to claim 1, 2 or 3, further comprising a manifold consisting of a reaction gas pipe. 5) The solid oxide fuel cell according to claim 1, 2 or 3, further comprising a manifold comprising reaction gas flow holes. 6) The solid oxide fuel cell according to claim 1, 2 or 3, further comprising guide vanes that guide the reactant gas in a straight line. 7) The solid oxide fuel cell according to claim 1, 2 or 3, further comprising guide vanes that guide the reaction gas in a zigzag manner. 8) The solid oxide fuel cell according to claim 1, 2 or 3, further comprising guide vanes for guiding the reaction gas in a spiral shape. 9) The solid oxide fuel cell according to claim 1, 2 or 3, comprising a self-supporting thin plate-like single cell. 10) The solid oxide fuel cell according to claim 1, 2 or 3, comprising a membrane-like single cell supported by a substrate. 11) The solid oxide fuel cell according to claim 1, 2 or 3, characterized in that the solid oxide fuel cell is provided with a self-supporting and dense thin plate-like reaction gas distribution means. 12) A porous substrate with guide wings, a substrate that supports a dense separator film on one main surface and has guide wings on the other main surface,
4. The solid oxide fuel cell according to claim 1, further comprising a reactive gas distribution means comprising: 13) The solid oxide fuel cell according to claim 1, 2 or 3, further comprising a glass O-ring for gas sealing. 14) The solid oxide fuel cell according to claim 1, 2 or 3, further comprising a ceramic sealing portion for gas sealing. 15) The solid oxide fuel cell according to claim 1, characterized in that a reaction gas discharge slit is provided at the periphery of the reaction gas distribution means. 16) A guide vane for a reactive gas gas seal provided at the periphery of the reactive gas distribution means, and a manifold penetrating inside the gas sealing guide vane at the periphery of the laminated unit cells and the reactive gas distribution means. 2. The solid oxide fuel cell according to claim 1, comprising: . 17) The solid oxide fuel cell according to claim 2, wherein the preheating chamber between the flame shield and the heat insulating container is provided with a fuel gas reformer and an oxidizing gas external supply pipe. 18) The solid oxide fuel cell according to claim 2, wherein a reaction gas external supply pipe is provided in the preheating chamber between the flame shield and the heat insulating container. 19) A reaction gas external supply pipe connected to the manifold and penetrating the inside of the combustion chamber, and a reaction gas external discharge pipe connected to the manifold and having a pipe end open to the inside of the combustion chamber. The solid oxide fuel cell according to claim 3.