JPH07272741A - Module structure for cylindrical solid electrolytic fuel cell - Google Patents

Abstract

PURPOSE:To reduce an amount of air and to form an equipment in small size by setting up an inside reforming reaction pipe in a generating chamber, supplying fuel and reforming vapor by reforming reaction pipe, and supplying to a cell through a fuel injection pipe after reforming. CONSTITUTION:In a lower partitioning plate 15 of a reforming material gas supply chamber 16, a reforming reaction pipe 17 with the upper opened to the chamber 16 is provided so that the lower of the pipe 17 leads to inside a generating chamber 18. Fuel and reforming vapor A are first introduced to the chamber 16 and reformed, while flowing in a downward direction in a charge part (annular part) of a catalyst 20 in the pipe 17, by receiving heat from the outside. Next, reformed fuel gas, flowing in a reformed gas supply pipe 19 from the lower to the upper, is introduced to a reformed gas supply chamber 21 and further supplied to a point end part of each solid electrolytic fuel cell (SOFC) 23 by a fuel injection pipe 22 communicating with the chamber 21. That is, the fuel gas is supplied to a fuel electrode of the cell 23, to suppress carbonizing here, simultaneously with fixedly holding an internal temperature in the generating chamber 18 by cooling action. consequently, introducing an amount of air can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a module structure for a cylindrical solid oxide fuel cell.

[0002]

2. Description of the Related Art FIG. 3 schematically shows a conventional solid oxide fuel cell module having a cylindrical tubular structure and an internal reforming system. In the figure, reference numeral 1 is fuel and reforming steam, 2 is a pre-reformer, 3 is SOFC, 4 is an air injection pipe, 5 is a power generation chamber, 6 is a fuel chamber, 7 is a combustion gas recirculation line, Reference numeral 8 shows reaction air, and 9 shows combustion exhaust gas.

As shown in the figure, in the conventional module, a part of the fuel gas 1 is reformed in advance by a pre-reformer 2 provided outside the power generation chamber 5 in order to suppress carbonization at the fuel electrode. In addition, the method of supplying to SOFC3 is adopted.

[0004]

By the way, in the above-mentioned conventional internal reforming type SOFC module, the reformer 2 is reformed by the pre-reformer 2 provided outside the power generation chamber 5. Methane (C
When H ₄ ) is used, the reaction formula (1) shown in “Chemical Formula 1” below is used.
The reaction proceeds.

[0005]

Embedded image CH ₄ + H ₂ O → CO + 3H ₂ −2,410 Kcal / Nm ³ (1)

In the above reaction, a part of the heat amount required for the reforming reaction is supplied to the external preformer 2, so that the heat absorption amount inside the power generation chamber 5 is reduced and the temperature rise during power generation is suppressed. , More air needs to be flushed.
Moreover, since a high-temperature gas is supplied to the preformer 2 as a heat source for reforming, there is a problem that the equipment becomes large.

In view of the above problems, it is an object of the present invention to provide a module structure of a cylindrical solid oxide fuel cell in which the amount of air is reduced and the equipment is downsized.

[0008]

A module structure of a cylindrical solid oxide fuel cell according to the present invention which achieves the above object, is a module structure of a cylindrical solid oxide fuel cell, in which an internal reforming reaction tube is used to generate electricity. It is characterized in that it is installed in a room, and fuel and reforming vapor are supplied to the reforming reaction tube and then supplied through a fuel injection tube in the cell.

[0009]

[Action]

(1) The fuel reforming reaction tube provided inside the power generation chamber absorbs heat in the power generation chamber to reform the fuel and perform SOF.
Carbonization at the fuel electrode of C (Solid Oxide Fuel Cell) is suppressed, and at the same time, the amount of air required to keep the internal temperature inside the power generation chamber constant by the cooling action is reduced. (2) By incorporating the pre-reformer inside the power generation chamber, a pipe or the like for supplying high-temperature gas to the pre-reformer is not required, and the equipment can be downsized and simplified, and the cost can be reduced. You can

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a schematic diagram of a module structure of a cylindrical solid oxide fuel cell according to the present embodiment, and FIG. 2 is a gas flow diagram of a main part thereof.

As shown in these drawings, a fuel supply pipe 13 for supplying fuel and reforming steam A is provided through a closing plate 12 which closes an upper opening of a module body 11. The lower end portion thereof is provided so as to penetrate a reforming source gas supply chamber 16 surrounded by an upper partition plate 14 and a lower partition plate 15. This reforming source gas supply chamber 16
The lower partition plate 15 is provided with a reforming reaction tube 17 having an upper opening to the gas supply chamber 16 so that the lower part thereof reaches the power generation chamber 18.

Further, as shown in FIG. 2, the reforming reaction tube 17 is a double tube having a reformed gas supply tube 19 in the inner central portion thereof. A reforming catalyst 20 is filled in an annular portion between the reforming gas supply pipe 19 and the reforming gas supply pipe 19. Further, the upper end of the reformed gas supply pipe 19 is attached to the upper partition plate 14, and opens into the reformed gas supply chamber 21 surrounded by the closing plate 12 and the upper partition plate 14 of the module body 11. There is. A fuel injection pipe 22 for injecting fuel is attached to the upper partition plate 14.

On the other hand, on the upper side of the power generation chamber 18, the SOFC
A tube plate 24 to which 23 is attached is provided, a fuel injection tube 22 is connected to the center thereof, and a reforming gas is supplied below the SOFC 23. In addition, the fuel discharge chamber 25 surrounded by the lower partition plate 15 and the tube plate 24 is the power generation chamber 2
A discharge pipe 26, which is formed on the upper part of 2, discharges unreacted fuel gas.

On the lower side of the module body 11,
A reaction air supply pipe 27 for injecting the reaction air B is provided, and is connected to the power generation chamber 22 and
An air discharge pipe 28 for discharging unreacted air is arranged inside the reaction air supply pipe 27.

In the above structure, the fuel and the reforming steam A
Is a fuel supply pipe 1 provided at the center of the module body 11.
3 is introduced into the reforming gas supply chamber 16 and then the power generation chamber 1
It is supplied into the reforming reaction tube 17 filled with the reforming catalyst 20 provided in the inside 8. Here, after being reformed by a necessary amount, it is introduced into the reformed gas supply chamber 21 through the reformed gas supply pipe 19. Further, this reformed gas is supplied to each SOFC 23 via the fuel injection pipe 22 and is used as a fuel for power generation. The unreacted fuel gas in the SOFC 23 and the exhaust gas a such as water vapor and oxygen dioxide generated by power generation are introduced into the fuel discharge chamber 25 and then discharged to the outside of the module main body 11 through the discharge pipe 26.

On the other hand, the reaction air B is supplied from the reaction air pipe 27 provided in the lower portion of the power generation chamber, and the unreacted air is discharged to the outside from the air discharge pipe 28.

The gas flow in this internal reforming type SOFC module will be further described with reference to FIG.

As shown in FIG. 2, fuel and reforming steam A
Is first introduced into the reforming raw material supply chamber 16. The reforming reaction pipe 17 is a double pipe having a reformed gas supply pipe 19 arranged in the center thereof, and the reforming catalyst 20 is provided in the annular portion thereof.
Is filled. Therefore, the raw material introduced into the reforming raw material supply chamber 16 receives heat from the outside and is reformed while flowing downward in the filling portion (annular portion) of the catalyst 20 of the reforming reaction tube 17.

At this time, the reforming rate of the reformed gas (pre-reform rate) is adjusted by the catalyst filling amount (s / v value) and the number of the reforming reaction tubes 17.

The reformed fuel gas flows through the reformed gas supply pipe 19 from the bottom to the top, is introduced into the reformed gas supply chamber 21, and is further connected to the reformed gas supply chamber 21. It is supplied by 22 to the tip of each SOFC 23.
Then, the reformed gas flows through each SOFC 23 from the bottom to the top to be used for power generation, and the exhaust gas a such as unreacted fuel gas is passed from the fuel discharge chamber 25 through the discharge pipe 26 to the module main body 1
It is discharged to the outside of 1.

According to the structure of this embodiment, the power generation chamber 18
The fuel reforming reaction tube 17 provided inside the
By absorbing the heat inside, the catalyst 20 is activated and the fuel is reformed, and then the SOFC is passed through the fuel injection pipe 22.
It is supplied to the fuel electrode of No. 23 and suppresses the carbonization here, and at the same time, by the cooling action, the introduction of the amount of air necessary for keeping the internal temperature in the power generation chamber 18 constant can be greatly reduced compared to the conventional case. To be

Conventionally, as shown in FIG. 3, the reforming pre-reformer 2 was installed outside the power generation chamber 5, but
As in this embodiment, the reforming reaction tube 17 is provided inside the power generation chamber 18.
Incorporation of the above eliminates the need for a pipe or the like for supplying a high-temperature gas to the conventional pre-reformer 2, thus achieving downsizing and simplification of equipment.

[0023]

As described above, according to the present invention,
By directly recovering the heat generation of the SOFC in the power generation chamber as the heat absorption of the internal reforming reaction tube, it is possible to reduce the amount of air for keeping the temperature of the power generation chamber constant, and as a result, the power generation of the SOFC module can be reduced. Efficiency is improved.

Further, since the pre-reformer is integrated with the module, a high-temperature gas exhaust pipe for the pre-reformer is not required, so that the equipment can be downsized and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an internal reforming type SOFC module according to the present invention.

FIG. 2 is an enlarged schematic view of a main part thereof.

FIG. 3 is a schematic configuration diagram of a conventional internal reforming SOFC module.

[Explanation of symbols]

 11 Module Main Body 12 Closure Plate 13 Fuel Supply Pipes 14 and 15 Partition Plate 16 Gas Supply Chamber 17 Reforming Reaction Pipe 18 Power Generation Chamber 19 Reformed Gas Supply Pipe 20 Reforming Catalyst 21 Reformed Gas Supply Chamber 22 Fuel Injection Pipe 23 SOFC (solid electrolyte fuel cell) 24 tube plate 25 fuel discharge chamber 26 discharge pipe 27 reaction air supply pipe 28 air discharge pipe

Claims (1)

[Claims] 1. A module structure of a cylindrical solid oxide fuel cell, comprising an internal reforming reaction tube installed in a power generation chamber, supplying fuel and reforming vapor to the reforming reaction tube, and then supplying the reforming reaction tube to the reforming reaction tube. A module structure of a cylindrical solid oxide fuel cell, characterized in that the fuel is supplied through a fuel injection pipe in the cell.