JP2003109650A - Collector structure for fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the quantity of heat uselessly escaping to the outside through collector bars and to prevent rise of temperature of the collector bars. SOLUTION: Heat exchange coils 25, 35 are wound on outer peripheries of the collector bars 22, 32 mounted on both ends of a fuel cell stack 1, a fuel gas or an oxidant gas to be introduced to the fuel cell stack 1 is circulated to the heat exchange coils 25, 35, and the gas is preheated with the heat recovered from the collector bars 22, 32.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel cell current collector structure.

[0002]

2. Description of the Related Art In some fuel cells, a current collector rod (current extraction terminal) for taking out the electric power generated in the power generation unit is provided at both ends of the power generation unit. A large current of about 100 A flows through these collector rods when the current is taken out. Therefore, for the purpose of reducing IR loss, a metal rod having a relatively large diameter is used as the collector rod.

[0003]

By the way, the current collector is
Since it projects from the inside of the fuel cell module to the outside, the heat inside the fuel cell module travels through the collector rod and escapes to the outside. Conventionally, the heat transmitted from the power generation section to the current collector was left to escape to the outside as it is. However, if the diameter of the current collector is increased to reduce the IR loss, a large amount of heat in the power generation section goes out through the current collector. There is a problem that it escapes and is not preferable for improving power generation efficiency. As another problem, a connector for extracting current is connected to the collector rod, but if the collector rod becomes too hot, the heat resistance of the connector may be adversely affected.

In view of the above circumstances, the present invention provides a fuel cell current collector structure capable of reducing the amount of heat that is wastefully escaped to the outside through the current collector and preventing the temperature of the current collector from rising. The purpose is to do.

[0005]

According to a first aspect of the present invention, a current collecting rod provided at each end of a power generation section of a fuel cell is provided with a gas passage for passing a gas for recovering heat of the current collecting rod. It is characterized by that.

According to a second aspect of the present invention, in the first aspect, the gas flow path is formed by a heat exchange coil wound around the outer circumference of the current collector rod.

According to a third aspect of the present invention, in the first aspect, the gas flow path is provided inside the collector rod.

According to a fourth aspect of the present invention, in any one of the first to third aspects, the gas to be sent to the power generation section of the fuel cell is circulated in the gas flow path, and the gas is preheated by the heat recovered from the collector rod. It is characterized by doing so.

According to the first to fourth aspects of the invention, the heat transmitted from the power generation section of the fuel cell to the current collecting rod can be recovered by the gas flowing through the gas flow path, and the heat contributes to power generation (mainly As in the invention of claim 4, it can be effectively used for preheating the gas supplied to the power generation section. Therefore, the efficiency of the fuel cell is improved by reducing wasteful heat dissipation, and the temperature of the current collecting rod is cooled by that much, so that the adverse effect on the connector connected to the current collecting rod can be reduced.

When the gas is supplied by winding the heat exchange coil around the outer circumference of the collector rod as in the second aspect of the invention, the heat exchange coil itself can be easily attached later, which is easy to realize. When the gas flow path is formed inside the current collecting rod as in the third aspect of the invention, the heat recovery efficiency can be increased and the outer periphery of the current collecting rod does not have extra parts such as coils. There are various advantages such as not affecting.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of a solid oxide fuel cell including the current collector structure of the first embodiment. This fuel cell has a fuel cell stack (power generation unit) 1 in which a plurality of power generation cells 5 are stacked. At both ends of the fuel cell stack 1, end plates 21 and 31 centering on the current collecting rods 22 and 32 are arranged. From the end plates 21 and 31 to the current collecting rods 22 and 32, there is a current to be extracted to the outside. It's flowing. Connectors (not shown) are connected to the collector rods 22 and 32.

The current collecting rods 22 and 32 are formed as metal cylinders having a diameter of a certain degree in order to reduce IR loss, and heat exchange coils 25 and 35 are wound around their outer circumferences. . Then, by flowing a gas to the heat exchange coils 25 and 35, the heat transmitted from the fuel cell stack 1 to the current collecting rods 22 and 32 can be recovered.

For example, the gas A at room temperature is used for the heat exchange coil 2
When introduced from one end of Nos. 5 and 35, the heated gas B can be taken out from the other end. Therefore, by passing the fuel gas and the oxidant gas supplied to the power generation cell 5 through the heat exchange coils 25 and 35, the fuel gas and the oxidant gas can be preheated. The preheated gas is introduced into a distributor for distributing and supplying the gas to each power generation cell. Further, since the temperature of the current collecting rods 22 and 32 is lowered by the amount of heat exchanged, it is possible to reduce adverse effects due to high temperature when connecting the connectors to the current collecting rods 22 and 32.

In the structure of the first embodiment, the heat exchange coils 25 and 35 are wound around the outer circumference of the current collecting rods 22 and 32 in order to flow the heat recovery gas. However, in the second embodiment of FIG. Like the structure, the gas flow path 26 is provided inside the collector rod 22.
May be formed directly to allow the gas to flow. In the case of the first embodiment, the attachment of the heat exchange coils 25 and 35 itself can be easily performed later, so that there is an advantage that it is easy to realize, and in the case of the second embodiment, the heat recovery efficiency becomes large. In addition, since no extra material such as a coil is attached to the outer circumference of the current collecting rod 22, it is possible to obtain the merit that the fitting of the outer circumference is not affected.

In the above description, the case where the gas B whose temperature has risen due to heat recovery is introduced into the distributor has been described, but as shown in FIGS. You may make it introduce | transduce into the electric power generation cell 5 directly through a hole 28 etc. which were provided in the board 21, without going through a distributor.

[0016]

As described above, according to the first to fourth aspects of the present invention, the heat transmitted to the current collecting rod is recovered by the gas flowing through the gas passage, so that wasteful heat dissipation is reduced. It is possible to improve the overall power generation efficiency by utilizing the recovered heat for the purpose of contributing to power generation, for example, for preheating gas introduced into the power generation unit. Further, since the current collector rod can be cooled, it is possible to prevent the current collector rod from being heated to a high temperature, and it is possible to reduce adverse effects on the connector connected to the current collector rod.

The gas flow path may be provided in the form of a heat exchange coil outside the collector rod as in the invention of claim 2 or directly inside the collector rod as in the invention of claim 3. However, in the case of the former, there is an advantage that it is easy to realize, and in the case of the latter,
In addition to increasing the heat recovery efficiency, there are no extra parts such as coils on the outer circumference of the current collector rod, so that there is an advantage in that there is no effect on the fitting of the outer circumference.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a fuel cell including a current collector structure according to a first embodiment of the present invention.

FIG. 2 is a main part configuration diagram of a current collector structure according to a second embodiment of the present invention.

FIG. 3 is a main part configuration diagram showing an application example of the first embodiment.

FIG. 4 is a main part configuration diagram showing an application example of the second embodiment.

[Explanation of symbols]

1 Fuel cell stack (power generation section) 22,32 Current collector 25,35 heat exchange coil 26 gas flow paths

Continued front page    (72) Inventor Koji Hoshino             1002-14 Mukoyama, Naka-machi, Naka-gun, Ibaraki Prefecture             Terari Co., Ltd.             Inside F term (reference) 5H026 AA02 CV01 CX06 CX09 EE02                       HH08

Claims (4)

[Claims] 1. A current collector for a fuel cell, characterized in that a current collector rod provided at each end of a power generation section of the fuel cell is provided with a gas flow path for passing a gas for recovering heat of the current collector rod. Part structure. 2. The gas flow path is formed by a heat exchange coil wound around the outer circumference of the current collector rod.
The fuel cell current collector structure described in 1. 3. The current collecting part structure of a fuel cell according to claim 1, wherein the gas flow path is provided inside a current collecting rod. 4. The gas to be sent to the power generation section of a fuel cell is circulated through the gas flow path to preheat the gas by the heat recovered from the collector rod. The fuel cell current collector structure as described above.