JPH06176790A - Fuel cell module - Google Patents

Abstract

PURPOSE:To provide a fuel cell module which can operate safely at a high fuel utilization factor by electrically connecting cell tubes formed of plural cells in parallel and mutually connecting the cells between the cell tubes. CONSTITUTION:A number of cells 12 stuck to one cell tube 1 are connected together in series, several cell tubes are connected together in parallel at the uppermost and lowermost ends with bundle collectors 3 and the top and second cells 12 thereunder are connected together in parallel with element collectors 2. Fuel 5 is guided downward of the tube 1 through a fuel supply pipe 4, raised up while being served for generation and discharged as residual fuel 6. On the other hand, air 7 is entered from the lower side and discharged as residual air 8. As the cells are connected together with the collectors 2 to constitute a bundle, the electrical destruction of the cells 12 due to nonuniformity of the fuel 5 is prevented and the utilization factor and reliability of fuel are improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylindrical solid electrolyte fuel cell module as an example, and more particularly to a current collector of the module.

[0002]

2. Description of the Related Art In a conventional cylindrical solid electrolyte fuel cell module, a plurality of cell tubes are electrically connected in parallel and in series as appropriate, and a predetermined voltage and current are taken out to the outside. As shown in FIG. 3, the cell tubes 1 constituting a plurality of unit cells are connected in parallel by a bundle current collector 3, fuel 5 is injected into a fuel supply pipe 4 of the cell tube 1, and at the same time, from the cell tube 1. The residual fuel 6 is discharged, while the air 7 is supplied and the residual air 8 is discharged. In this case, the configuration of the bundle is to allow the entire module to operate even if an abnormality occurs in one cell tube 1.

[0003]

In the above-mentioned cylindrical solid oxide fuel cell, the fuel is distributed to the plurality of cell tubes 1 to generate electric power, but the fuel is evenly distributed to each cell tube 1. Can not do it. That is, in the module, when the fuel utilization rate is increased, that is, in other words, when the fuel supply amount is reduced, the fuel 5 is unevenly distributed, and the fuel utilization rate is increased to the limit of the cell tube 1. However, when the downstream side unit cell is in a fuel-deficient state, a voltage is applied by the electromotive force of another unit cell and a current forcibly flows to a negative potential, resulting in electrical breakdown. In addition, even in a module in which the fuel flows to the outside of the cell tube 1, when the fuel utilization rate is high, the fuel concentration becomes non-uniform depending on the position of the cell tube 1.
The problems mentioned above arise.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a fuel cell module which enables stable operation at a high fuel utilization rate.

[0005]

Means for Solving the Problems The present invention which achieves the above-mentioned object is to provide a fuel cell in which a plurality of unit cells are formed on one cell tube, by connecting the plurality of cell tubes electrically in parallel. , The cell tubes connected in parallel are electrically connected to each other.

[0006]

[Effect] Even if the fuel distribution is unbalanced in the module, the cell resistance of the unit cell with insufficient fuel supply increases and the current decreases, and the current flowing through other unit cells connected in parallel is reduced. To increase. In this way, the current is distributed according to the fuel supply state, so the cells are prevented from being electrically damaged, and the cells on the upstream side of the cell tube with insufficient fuel supply function normally. It becomes possible to do.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Now, an embodiment of the present invention will be described with reference to FIGS. The same parts as those in FIG. 3 are designated by the same reference numerals. In FIG. 1, the downstream side (outlet side) of the cell tube 1
The same battery is connected to the unit cell 12 by the element current collector 2. In this case, in this example, the element current collector 2 is applied to the uppermost cell and the second cell.

FIG. 2 is an electrical connection diagram. A large number of unit cells 12 attached to one cell tube 1 are connected in series, and several cell tubes are connected in parallel with the bundle current collector 3 at the uppermost end. The uppermost cell and the second cell of the unit cell 12 are connected in parallel by the element current collector 2, and the lower end is also connected in parallel by the bundle current collector 3. For this connection, five cell tubes 1 were set as one set, and the + electrode 9 and the-electrode 10 of the other set were connected.

In the module shown in FIG. 1, the fuel introduction pipe and the residual fuel discharge pipe are double pipes in the upper part, and the fuel 5 is introduced and supplied into the fuel supply pipe 4. Since the fuel supply pipe 4 is inserted below the cylindrical cell tube 1, the fuel 5 is discharged from the upper end of the cell tube 1 as the residual fuel 6 while being used for power generation while rising from below the inside of the cell tube 1. It A large number of the cell tubes 1 described above are housed in a module, and a large number of unit cells 12 are attached to the outer peripheral portion thereof. On the other hand, the lower part of this module has a supply part for the air 1 and an outlet for the residual air 8.
The unit cells 12 of one cell tube 1 are connected in series by an interconnector. The uppermost ends of the cell tubes 1 are first connected in parallel by the bundle current collector 3, and the bundles are connected in series to be taken out as an electric output to the outside.

By providing the element current collectors 2 at the uppermost and second steps of the unit cell 12, even if the outlet element is in a fuel-deficient state, forced energization is not performed and the elements are electrically protected by the same potential. To be done.

It is most effective to connect all the unit cells constituting the bundle with the element current collector 2, but an appropriate number may be connected if necessary. The present invention can also be applied to a module in which fuel flows to the outside of the tube. Further, it can be applied to a high temperature steam electrolysis cell.

[0012]

As described above in detail, according to the present invention, in a solid electrolyte fuel cell module in which a single cell tube constitutes a plurality of single cells, the element current collectors connect the single cells constituting the bundle. By doing so, it is possible to prevent the electric breakdown of the unit cell due to the non-uniformity of the fuel. As a result, the fuel utilization rate of the module can be set higher and at the same time the reliability can be improved.

[Brief description of drawings]

FIG. 1 is a block diagram of a module according to an embodiment.

FIG. 2 is an electrical connection diagram of the module.

FIG. 3 is a configuration diagram of a conventional example.

[Explanation of symbols]

 1 Cell tube 2 Element current collector 3 Bundle current collector 12 Single battery

Claims (1)

[Claims] 1. A fuel cell comprising a plurality of unit cells on one cell tube, wherein the plurality of cell tubes are electrically connected in parallel, and the unit cells of the cell tubes connected in parallel are mutually connected. A fuel cell module electrically connected to the fuel cell module.