JPH03266370A - Fuel cell generator device - Google Patents

Abstract

PURPOSE:To prevent the output increase per unit volume and the cell breakage of thermal stress, by integrating a fuel manifold with an air manifold to form a box vessel, and mounting a fuel cell vertically thereto. CONSTITUTION:A fuel manifold 35 and an air manifold 36 are integrated and formed into a box vessel. For example, cylindrical cells 31 are mounted in such a manner that their axial directions are vertical to the box vessel. As the cylindrical cells 31 are supported by the box vessel, they can be formed without any support pipe, and thus a number of miniature ones can be closely disposed, resulting in an increase in output per unit volume of cell. The fuel and air are sent in the same direction through a box manifold. Thus, the temperature during operation is changed only in the axial direction of the cell, and the thermal expansion is released in the axial direction of the cell, so that the cell breakage of thermal stress can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a fuel cell power generation device that uses hydrogen, carbon oxide, hydrocarbons such as methane, and alcohols such as methanol.

[Conventional technology] (1) Conventional technology example 1 (Western Electric Corporation, USA, Exhibitor: FuelCe)
lls Handbook May, 1988) No. 5
The figure shows a cross-sectional view of a cylindrical shaped cell made of calcia stabilized zirconia. 1 in the figure is an electronically insulating elongated porous support tube. There is a thin (
A porous air electrode 2 with a thickness of 200 to 800 μm is attached. The air electrode 2 is made of a doped Berovskiite-type oxide such as LaMnO3, CaMn0.
, LaNiO3, LaCoO3, LaCrOi, etc., or a mixture of these oxides. An airtight solid electrolyte 3 made of yttria-stabilized zirconia is provided on the outer peripheral surface of the air electrode 2. This solid electrolyte 3 is surrounded by a fuel electrode 4 made of nickel-zirconia cermet. Note that 5 in the figure is an ink connector, and 6 is an ink connector contact. Both the solid electrolyte 3 and the ink connector 5 have discontinuities to allow for the incorporation of electrical connection material for serially connecting cells.

The cells having the above structure are assembled to generate power as shown in FIG. In the figure, 7 is a Ni felt, 8 is a Ni plate, 9 is a fuel unevenly concentrated body, and 10 is an air side current collector.

(2) Prior art example 2 (Argonne National Laboratory, U.S.A. Source: ATOMJCENEI?GY OF CANAD
A LJ) IITED June, 1987) Figure 7 shows a cross-sectional view of an assembly of flat cells.

11 in the figure is a fuel electrode (anode) made of nickel-zirconia cermet. An electrolyte 12 and an air electrode 13 are stacked on the fuel electrode 11 to form a cell 14. Here, the electrolyte 12 is made of ittria-stabilized zirconia. The air electrode is made of a doped Berovskiite-type oxide, e.g. LaMnO3, LaCoO
3, LaCry, etc. or a mixture of these oxides.

The fuel electrode 11 and the like are made by turning the material powder into a uniform slurry using a suitable dispersant and binder and forming it into a band-shaped film with a uniform thickness by tape casting. The fuel electrode 11. The electrolyte 12 and the air electrode 13 are
It is sintered at about 1300°C to form cells. A connecting material is interposed between the cells in order to electrically connect these cells and prevent the fuel and oxidizer from mixing. Also,
A fuel electrode material is provided between each cell 14 and the connecting material.

A corrugated plate 15 made of a cathode material is arranged, and through the gap created by this, fuel passes through the fuel electrode side and an oxidant passes through the air electrode side, causing a reaction. The fuel and oxidizer passages are orthogonal to each other, and the fuel and oxidizer are supplied and recovered from a supply manifold attached to the end of the rectangular cell.

Such a cell assembly generates electricity by attaching a ladder 17 to a fuel supply header 16 and an oxidizer supply, as shown in FIG.

[Problem to be solved by the invention] However, the conventional technology has the following problems.

(Prior art 1)... Output per unit volume is small. That is, since the porous support tube 1 made of calcia-stabilized zirconia is used to provide structural integrity to the cell, the cell diameter is limited, the weight is heavy, and the output per unit volume is limited. is small at approximately 1100k/m3. In addition, this output value is calculated based on the cell arrangement pitch of 1.5 D in FIG.
(D is cell diameter), fuel and air manifold thickness 1
cm, and the value calculated under the condition that the thickness of the fuel chamber is 1 cm+.

(Prior art 2) Cell destruction due to thermal stress. That is, since the flat cell 14 is used, it is necessary to fix at least two sides of the cell and create an airtight structure so that the fuel and oxidizer do not mix. However, in order to remove the heat generated in the cell 14 by the sensible heat of the fuel and oxidizer, the inlet of the fuel and oxidizer,
A temperature difference of 150-250°C occurs at the outlet. Therefore, compressive stress is generated within the flat plate, and there is a possibility that the cell 14 may be destroyed.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a fuel cell power generation device that can increase the output per unit volume and avoid cell destruction due to thermal stress.

[Means for Solving the Problems] In the present invention, the conventional method of assembling 5OFC cells as an assembly and then attaching fuel and air supply manifolds is now made into a manifold that is integrated with the cells. That is, in the present invention, the cell part where heat is generated by reaction is arranged perpendicularly to the manifold surface, and the fuel and
By flowing air, a temperature distribution is created only in the axial direction of the cell, and thermal expansion of the cell due to this temperature rise is released in the axial direction of the cell. More specifically, ``improvement of output per unit volume'' is achieved by using a cell that has no base tube and has structural integrity by itself, and by vertically and densely mounting it on a flat gas manifold. This was done by arranging. In addition, "prevention of cell destruction due to thermal stress" is achieved by placing the cell vertically on a flat gas manifold so that the fuel and oxidizer flow in parallel, and further limiting the supporting part of the cell to the end on the gas manifold side. It was done by doing.

[Function] According to the present invention, it is possible to improve the output per unit volume and prevent cell destruction due to thermal stress, which will be described in detail below.

(1) Improvement in output per unit volume Since the cell itself has structural integrity, the shape of the cell is arbitrary. Therefore, for a cylindrical cell, the diameter should be 5
It is possible to reduce the thickness to about n, and the thickness can be reduced to 1 to 2 mm in a flat cell. By densely arranging these on a flat gas manifold, the effective power generation area per unit volume of the cell is increased, and the output per unit volume is improved.

(2) Prevention of cell destruction due to thermal stress By making the fuel and oxidizer flow in parallel, the temperature distribution caused by heat generation due to internal resistance when current flows through the cell is prevented from occurring only in the gas flow direction of the cell. I can do it,
Temperature distribution within the gas manifold surface is less likely to occur.

In addition, since the support portion of the cell is limited to the end portion on the gas manifold side, distortion due to thermal expansion caused by heat generation of the cell is less likely to occur. These effects can prevent cell destruction due to thermal stress.

[Example] Hereinafter, an example of the present invention will be described with reference to FIGS. 1, 2, and 3. Here, FIG. 1 is a schematic perspective view of a fuel cell power generation device according to the present invention, FIG. 2 is a partial sectional view showing the state of connection between the fuel and air manifold and the cell, and FIG. 3 is an electrical It is a partial sectional view showing a connection.

Reference numeral 31 in the figure indicates a cylindrical solid electrolyte fuel cell (cell) in which the reaction takes place. This cell 31 has an air electrode 3
2, an electrolyte 33, and a fuel electrode 34, which are sequentially provided on the outer circumferential side. Air and fuel are supplied to the inside and outside of the cell 31, and the air electrode 32. electrolyte 33
A reaction occurs in the three-layer structure of the fuel electrode 34 and electricity is generated. The air electrode 32 is made of a doped Berovskiite-type oxide, for example, L a M n O3lCaM.
n0. , LaNi0. , LaCo0. .

It is formed using LaCrO3 or a mixture of these oxides. Electrolyte 33 is formed using yttria-stabilized zirconia. The fuel electrode 34 is formed using nickel-zirconia cermet.

The cells 31 are fuel manifolds 3 connected to each other.
5 and an air manifold 36 (hereinafter, both are collectively referred to as a box-shaped container) in large numbers. The fuel manifold 35 has a flat box shape with a fuel side porous current collector 37 made of calcia or yttria stabilized zirconia on one side and porous nickel zirconia cermet on the other side. The air manifold 36 is located on the side of the fuel manifold 35 made of calcia-stabilized zirconia, and has a box-like shape made of calcia or yttria-stabilized zirconia. On the fuel manifold side inside the air manifold 36, doped Berovsky stone oxide LaM is added.
There is an air side current collector 37 made of nO3°LaCrO3.

The cell 31 includes a fuel side current collector 38 and an air side current collector 31.
are connected in parallel. The electrolyte 33 of the cell 31 is sintered and bonded to the stabilized zirconia plate of the fuel manifold 35 via zirconia slurry. The fuel electrode 34 and the air electrode 32 of the cell 31 each have a fuel electrode side current collector 38
It is in contact with the air side current collector 37 and has electrical conductivity.

In addition, in order to reduce contact resistance, NiO YSZ cermet slurry was applied to the fuel electrode side, and L a M n was applied to the air electrode side.
Sintering and joining may be performed via O3 slurry.

The ends of the air manifold 36 and fuel manifold 35 are connected to the next manifold, as shown in FIG. The air side current collector 37 is connected to the air manifold 3
6 is connected to the fuel side current collector 38 of the next manifold via a dense electrical connection material 39. In this way, the air electrode, which is a cathode, and the fuel electrode, which is an anode, are connected, and each manifold is electrically connected in series. The fuel gas is connected to the next manifold through the fuel manifold partition wall 40 and the fuel discharge hole 41 of the electrical connection member 39 of the next manifold. In addition, 42 in the figure is an air manifold partition,
Reference numeral 43 indicates an air supply hole, and 44 indicates a fuel supply hole.

In the fuel cell power generation device according to the above embodiment, a fuel manifold 35 and an air manifold 36 form a box-shaped container that supplies fuel and air, and an air electrode 32. A solid electrolyte fuel cell (SOFC), that is, a cell 31 consisting of an electrolyte 33 and a fuel electrode 34 is mounted vertically, and fuel and air are supplied to the cell 31 from the box-shaped container. Therefore, according to the present invention, the output per unit volume can be improved, and cell destruction due to thermal stress can be prevented.

In fact, when the relationship between the output per module unit volume and the cell length was investigated for the cell according to the present invention, the characteristic diagram shown in FIG. 4 was obtained. In the figure, the diameter of the cell 31 is 0.
5 cm, electrolyte thickness 100 μm.

The performance of the cell arranged as shown in FIG. 1 was calculated when the air electrode thickness was 300 μm and the fuel electrode thickness was 100 μm. From the figure, it is clear that when the element length is 1 cm, the output per module unit volume is as high as 0.36 MW/m' when the element voltage is 0.7 V and the current density is 0.75 A/cm2.

[Effects of the Invention] As detailed above, the present invention provides a fuel cell that can increase the output per unit volume, and can prevent cell destruction due to thermal stress without causing thermal distortion due to heat generated by reaction. We can provide power generation equipment.

[Brief explanation of drawings]

Fig. 1 is a schematic perspective view of a fuel cell power generation device according to an embodiment of the present invention, Fig. 2 is a partial cross-sectional view showing the state of connection between the fuel and air manifold and the cell, and Fig. 3 is an electric power generation device when the manifold is connected. Figure 4 is a characteristic diagram showing the relationship between the output per unit volume of the module and the cell length.
FIG. 5 is a cross-sectional view of a conventional cylindrical cell, FIG. 6 is an explanatory diagram of the assembled cell of FIG. 5, FIG. 7 is a cross-sectional view of a conventional plate-shaped cell assembly, and FIG. FIG. 7 is an explanatory diagram of the assembly shown in FIG. 7 in an assembled state. 31... Solid electrolyte fuel cell (cell), 32-3... Air electrode, 33... Electrolyte, 34... Fuel electrode, 35...
・Fuel manifold, 36... Air manifold, 3
7... Fuel side current collector, 38... Air side current collector, 39
... Electrical connection material, 40 ... Fuel manifold partition, 41 ... Fuel discharge hole.

Claims (1)

[Claims] A double-structured box-shaped container that supplies fuel and air, an air electrode,
A solid electrolyte fuel cell comprising an electrolyte and a fuel electrode, the fuel cell being mounted perpendicularly to the box-shaped container, and fuel and air being supplied from the box-shaped container to the fuel cell. A fuel cell power generation device.