JPS58129788A - Fused carbonate fuel cell layer body - Google Patents

Abstract

PURPOSE:To constitute an interconnector with a piece of metal lamina as well as to offer a fused carbonate fuel cell layer body capable of feeding gas through an external manifold system. CONSTITUTION:A unit cell 30 is plurally layered in interposing each interconnector 31 in between. On a layer surface of this laminate, side plates 32 making up a manifold each are airtightly fitted. In this connection, the unit cell 30 is made up of an anode 33, a cathode 35 and an electrolytic tile 34. The interconnector 31 carries circular truncated cone type convex parts 36 and 37 at its top and bottom surfaces while it is so made up as to be made smaller successively in a direction where the diameter of the convex part bottom is orthogonalized at the top and bottom surfaces. Next, a bank 39 bearing an electrode mounting shoulder part 38 at one side of the unit cell is formed on two sides paralleled in a direction where the bottom diameter of the convex part 36 of the top surface becomes smaller and another bank 41 bearing an electrode mounting shoulder part 40 of the other side is formed on the bottom surfae of twoo sides different from said two sides having formed the bank 39 of the top surface as well. Using the interconnector 31 that is formed in this way, a fused carbonate fuel cell layer body comprising 20 pieces of layers is constituted.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a molten carbonate fuel cell stack 42 that uses interconnectors formed from a single embossed sheet metal sheet.

[Prior art and its problems]

In general, a fuel cell is used as a structure in which a plurality of unit cells are stacked (two stacked) as shown in Fig. 1. Anode gas and cathode gas are mixed at the anode 1 and cathode 2 of adjacent unit cells in the stack It is common to insert an interconnector made of a thin metal plate in order to supply two units of electricity and to electrically connect adjacent unit cells in rows. 3 is an electrolyte tile, 4 is a current collector, and 5 is an interconnector forming a gas manifold.

FIG. 2 is a perspective view showing a schematic configuration of an interconnector.

The interconnector is usually made of stainless steel, and is placed between two corrugated thin plates 11 and 12 (with a flat thin plate 15 in between).
Created by welding.

Place the flat thin plate 15 on top of the corrugated thin plate 12, and place the two-component thin plate 11 on top of the corrugated thin plate 12 so that the direction of the troughs 14 of the corrugated thin plate 12 is
The corrugated thin plates 11 and 12 are placed perpendicular to the direction of the valley 13, and the points where the corrugated thin plates 11 and 12 contact the flat thin plate 15 are welded at the same time.

This interconnector had to be constructed from three thin metal plates, which had the disadvantage that the thickness increased, spot welding was required, and as the cell size increased, the number of spot welding points increased rapidly (two). .

(Conventional Example 2) Another laminate is known, a part of which is shown in FIG. 3(a). That is, in a fuel cell, an electrolyte tile 21 forming an electrolyte layer shown in FIG.
A separator plate 5 with concave and convex portions arranged in a line on both sides of the middle part (page 23) is placed on the outside of the 23, and a separator plate 5 is placed on both sides of the intermediate part (page 23) to protect the surrounding surface. Each electrode 2
2.23 is smaller than the size of the electrolyte tile 21, and has a size that fits into the recess of the electrolyte tile 21 and accommodates the uneven portion of the separator 5.

In addition, through holes 27 for gas flow are arranged and opened along two opposite sides of the electrolyte tile 21. When stacked, the space between the electrolyte tile 2] and the separator 5 is spaced around the through hole d. A spacing ring 4 having a plurality of conical protrusions for forming a gas flow gap is attached to the contact surface to the air gap.

In this configuration (2), the fuel gas A and the oxidant gas B leaked through the through holes 27 are alternately fed into the respective flow gaps by the spacing ring 4.

The abrasive gas B flows in the same direction through the gas passages on the front side of the separator part in FIG. 3(a), and the fuel gas A flows on the back side in the same direction, and is supplied to each electrode 22, 23.

A fuel cell with the above configuration (2) has a relatively wide gap around the electrolyte tile for gas flow (2 gaps must be provided as an internal gas manifold, and around the through-hole the electrolyte tile λ- may be partially supported, leading to damage such as destruction of the electrolyte tile and generation of electrical equipment.
In particular, as the number of laminated layers increases, a large amount of gas must flow, and as the size increases, the likelihood of damage increases. In addition, there are problems such as the need to drill through holes in electrolyte tiles, which complicates the processing process, and clogging of the gas flow path in the spacer ring. If two cracks occur in the electrolyte tile in the gas manifold section of the tie tile, the balance of retention of molten carbonate will be disrupted due to the differential pressure between the fuel gas and oxidizer gas at operating temperatures, causing gas to bubble and cross-mixing to occur. Easy, temperature rise, below 11m
There is a problem in that this cross-mixing becomes even more significant. Furthermore, since the gas manifold is formed around the electrolyte tile, the ratio of the electrodes to the size of the electrolyte tile is small.

[Purpose of the invention]

The object of the present invention is to provide a molten carbonate fuel cell stack in which an interconnector is constructed from a single thin metal plate (2) and gas can be supplied using an external manifold method (=
be.

[Summary of the invention]

In order to achieve the above object, the present invention has two protruding convex portions on the front and back sides of a single thin metal plate, a bank on two opposing sides of the top surface, and two opposing sides of the bottom surface. on the top surface (
= Banks are provided on two sides without banks, and the convex part on the top side is
The diameter of the circular bottom gradually decreases in the longitudinal direction of the banks on the two opposing sides of the top surface, and the convex BIS on the bottom side gradually decreases the diameter of the circular bottom in the longitudinal direction of the banks on the two opposing sides of the bottom surface. This is a molten carbonate fuel cell stack using an ink connector constructed by decreasing the amount of molten carbonate.

[Embodiments of the invention]

Next, one embodiment of the present invention will be explained from the drawings (see FIG. 2).

FIG. 4 is a perspective view of the main part of the present invention, in which a plurality of unit cells (9) are stacked with interconnectors 31 inserted between them. The side plates 32 forming the manifold are attached airtightly (2) on the laminated surfaces (-) of this laminated product.

Note that the unit cell 30 has an anode 33. Cathode 35. It is formed of electrolyte tiles 34. Figure 5 is a perspective view of the interconnector 31 used in Figure 4.
Sandwich a US 316 metal thin plate between male and female molds, and measure the upper and lower sides (the biconical truncated protrusion 36.37 with a maximum diameter of 2.3 mm at the bottom and a minimum diameter of Q, 5 m + height of the protrusion). The length is 15mm, and the distance between the centers of adjacent bottoms is 37117
11, the diameter of the bottom of the convex portion is formed in a direction perpendicular to each other on the upper surface side and the lower surface side (the diameter decreases in the second order).Next,
A metal plate of SUS 316 with a thickness of 2.1 mm is placed on two sides parallel to the direction in which the diameter of the bottom of the convex portion 36 on the upper surface becomes smaller by 8 mm, and has a shoulder gap for loading one electrode of the unit cell. A bank 39 is formed by beam welding, and a metal plate of SUS 316 with a thickness l and 8rnrn, which has a shoulder 40 for loading the electrode on the lower surface of two sides different from the two sides on which the bank 39 is provided on the upper surface, is electronically welded. The bank 41 is formed by beam welding.

Next, the surface 42.43f of the bank 39.41 that comes into contact with the electrolyte tile 34 is coated with nialumina.

Using the thus formed interconnector 31, a molten carbonate fuel cell stack according to the present invention having an effective area of 145 cy4 and an additional number of layers was constructed.

〔Effect of the invention〕

According to the present invention configured in this way, the following effects can be obtained.

■Weight is half of (Conventional Example 1) and almost the same as (Conventional Example 2).

(2) No need for a large number of spot welds compared to (Conventional Example 1).

(Conventional Example 2) (Compared to the two, gas can be supplied using an external manifold method, so it is necessary to drill holes around the electrolyte tiles.)

■ (Conventional Example 2) (- Compared to this, the proportion of the area where no electrode exists is small. When using a 30 cm square electrolyte tile (
In conventional example 2), the electrode was 24 cm x 28 cz, whereas in the present invention, it was 30 cTL x 2゛7 cm,
The ratio of electrodes increased from 74.7% to 90cm.

■ (Conventional example 2), E 0 between the fuel gas side and the oxidant gas
．． Applying a differential pressure of 3 kg/Crrt, room temperature to 650°C
When the thermal cycle was repeated three times, significant cross-mixing of gases occurred, but in the present invention, even when this was repeated five times, no significant cross-mixing occurred.

As mentioned above (2), although the interconnector of the present invention has a small number of parts and is composed of a single lightweight thin metal plate with a bank around it, the area occupied by the electrodes is large, and it is an external manifold type interconnector. Since fuel gas and oxidizer gas can be supplied, there is no need to make holes around the electrolyte tile, and the manufacturing process is simplified, so its industrial value is extremely high.

[Other embodiments of the invention]

1. The fuel electrode and the bank for loading the oxidizer may be formed with a bent structure.

2. Although the metal thin plate is made of SUS 316, the material is not limited to this. A steel plate may be coated with Ni.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing the basic configuration of a molten carbonate fuel cell;
FIG. 2 is a perspective view showing an interconnector used in one of the conventional examples, FIG. 3 is a perspective view showing the main parts of another conventional example, and FIG. 4 is the main part of an embodiment according to the present invention. A perspective view showing the fifth
The figure is a perspective view showing the interconnector of FIG. 4. Nod...unit cell, 31...interconnector 36, 3
7...Convex, 39.41... Bank agent Patent attorney Noriyuki Chika (and 1 other person) 1st
Figure (n) Figure 4 r

Claims (1)

[Claims] In a fuel cell that uses molten carbonized salt as an electrolyte, a truncated cone-shaped convex portion is provided on the front and back sides of one remaining thin plate, two opposing sides of the top surface (two banks are provided, and two opposing sides of the bottom surface are provided). A bank is provided on two sides without a bank on the top surface, and the convex part on the top surface side gradually decreases the diameter of the circular bottom in the longitudinal direction C2 of the bank on the two opposing sides of the top surface, and also on the bottom surface side. The convex part is an interconnector made of a single thin metal plate configured to gradually decrease the diameter of the two circular bottoms in the longitudinal direction of the banks on the two opposite sides of the bottom surface, and the top surface of this interconnector and A molten carbonate fuel cell stack, characterized in that a lower surface (2) is formed with a flow path through which a fuel gas and an oxidant gas flow in directions orthogonal to each other.