JPH06267560A - Solid high polymer type fuel cell - Google Patents

Abstract

PURPOSE:To prevent steam within reaction gas from being condensed, and thereby enhance generating efficiency by providing each steam partition plate while its one side surface is faced to each reaction gas feed flow path, providing each cooling water flow path for the other side surface, and thereby appropriately humidifying reaction gas. CONSTITUTION:Each steam partition plate 17 and 18 is provided while its one side surface is faced to each reaction gas feed flow path 15 and 16, and water cooling flow path 21 and 22 are provided for the other side surface, so that a part of each wall surface is thereby formed. Fuel gas and oxidant gas are led to electrolyte electrode joint bodies 10 through 12 through the respective flow paths 15 and 16 so as to be consumed in the course of generating reaction. Exothermic of each cell caused by generating reaction is removed outside by cooling water flowing in the flow paths 21 and 22. And since a part of cooling water is turned out to be steam so as to be led to the flow paths 15 and 16 out of the surfaces of the steam partition plates 17 and 18, so that reaction gas is thereby humidified. Furthermore, steam is dispersed in the insides of electrodes 11 and 12, and finally arrives at the electrolyte 10, steam within reaction gas is thereby prevented from being condensed, humidifying is thereby accurately carried out, and thereby generating efficiency is enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polymer electrolyte fuel cell having a fuel cell cooling function and a reaction gas humidifying function.

[0002]

2. Description of the Related Art FIG. 2 is a perspective view showing a cut-away structure of a conventional polymer electrolyte fuel cell. That is, 1 is a gas partition plate for introducing a reaction gas (fuel gas), 2 is an electrode, 3 is an electrolyte, 4 is an electrode, 5 is another gas partition plate for introducing a reaction gas (oxidant gas), 6 Is a cooling water supply flow path, 7 is a fuel gas flow path, 8 is an oxidant gas flow path, and 9 is a cooling water supply flow path. The electrode 2, the electrolyte 3 and the electrode 4 are integrally joined to each other to form an electrolyte electrode assembly.

In the conventional solid polymer electrolyte fuel cell thus constructed, the electrolyte 3, the fuel gas supplied from the fuel gas passage 7 to the electrolyte 3 through the electrode 2, and the oxidant gas passage 8 are provided. A power generation reaction is performed by the oxidant gas supplied to the electrolyte 3 from the electrode 4 through the electrode 4 to generate a potential difference between the electrode 2 and the electrode 4. Since the electrolyte electrode assemblies 2 to 4 generate heat in accordance with this power generation reaction, cooling is necessary to keep the temperature of the polymer electrolyte fuel cell constant. Therefore, the cooling water supply channels 6 and 9 are provided inside the gas partition plates 1 and 5.
The cooling water is circulated in the cooling water supply passages 6 and 9 to remove the exhaust heat of the battery generated during power generation and keep the temperature of the polymer electrolyte fuel cell constant. There is.

On the other hand, in order to keep the ionic conductivity of the electrolyte 3 high and raise the power generation efficiency, it is necessary to keep the water content of the electrolyte 3 high. For this reason, the reaction gas is humidified and the electrolyte is made to contain water by the humidified steam. The humidification of the reaction gas is separately performed outside the fuel cell.

[0005]

As described above, in the conventional polymer electrolyte fuel cell, the cooling water is circulated through the cooling water supply passages 6 and 9 provided inside the gas partition plates 1 and 5, respectively. The fuel cell is cooled by flowing it. On the other hand, the humidification of the reaction gas is separately performed outside the fuel cell. For this reason, the control of the cooling water temperature and the humidity of the reaction gas have been performed by completely different systems. Therefore, it is difficult to perform harmonious and accurate control, and water vapor in the reaction gas may condense and the electrolyte electrode assembly may be submerged. Also, in order to prevent such condensation of water vapor, if the control width of the temperature control of the fuel cell is set small,
There is a problem that a large amount of pump power for circulating the cooling water is required and the efficiency of the power generation system including the cooling mechanism is reduced.

Therefore, according to the present invention, it is possible to accurately cool the fuel cell and humidify the reaction gas under the temperature and pressure conditions of the fuel cell, and to prevent the condensation of water vapor in the reaction gas. Another object of the present invention is to provide a polymer electrolyte fuel cell with good power generation efficiency.

[0007]

In order to solve the above problems and to achieve the object, the present invention provides an electrolyte electrode assembly comprising an electrolyte and a pair of electrodes arranged so as to sandwich the electrolyte, and the electrolyte electrode assembly. A pair of gas partition plates arranged on both sides of the electrode assembly and formed of a gas impermeable member, and a pair of gas partition plates respectively formed in the pair of gas partition plates and provided so as to partially contact the electrolyte electrode assembly. A reaction gas supply channel, a water-permeable gas / water partition plate having one side facing the reaction gas supply channel so as to form a part of the wall surface of the reaction gas supply channel, and the gas / water partition. The other side surface of the partition plate is provided with a cooling water supply passage provided so as to form a part of the wall surface.

[0008]

As a result of taking the above-mentioned means, the following effects occur. Since the reaction gas supply flow path is in contact with the cooling water supply flow path through the water-permeable partition plate, the fuel cell is cooled by the cooling water in the cooling supply flow path and a part of the cooling water Permeates the water-permeable air / water partition plate under the temperature and pressure atmosphere and enters the reaction gas supply channel. The cooling water that has reached the surface of the reaction gas supply channel is evaporated and diffused and supplied as water vapor into the reaction gas. Therefore, the reaction gas is appropriately humidified, and the water vapor in the reaction gas is not condensed.

[0009]

EXAMPLE FIG. 1 is a perspective view showing a cut-away structure of a polymer electrolyte fuel cell according to an example of the present invention. As shown in FIG. 1, an electrolyte electrode assembly is formed by a flat plate-shaped electrolyte 10 and a pair of electrodes 11 and 12 that are bonded to both sides of the electrolyte 10 so as to sandwich the electrolyte 10. Both side surfaces of this electrolyte electrode assembly are divided by a gas partition plate 13 made of a gas impermeable conductor such as a metal plate or a carbon plate,
It is sandwiched between 14. These gas partition plates 13 and 14 are provided with groove-shaped reaction gas supply channels 15 and 16, respectively.
The reaction gas supply passages 15 and 16 are provided so that one end face of the opening is in contact with the electrolyte electrode assembly. The other end faces of the reaction gas supply channels 15 and 16 are closed by gas-water partition plates 17 and 18 made of a water-permeable and gas-impermeable conductor (high water-permeable polymer material, etc.). There is. That is, one side surface of the water / water partition plates 17 and 18 is provided so as to form a part of the wall surface of the reaction gas supply flow paths 15 and 16. Both sides of the gas partition plates 13 and 14 are cooling plates 1
It is sandwiched between 9 and 20. These cooling plates 19,
A groove-shaped cooling water supply passage 2 is provided on the joint surface of the gas partition plate 20.
1, 22 are provided, and each cooling water supply flow path 21, 2 is provided.
The open end face of 2 is closed by the other side faces of the water / water partition plates 17 and 18 described above. That is, the air-water partition plates 17, 1
The other side surface 8 is provided so as to form a part of the wall surface of the cooling water supply channels 21 and 22.

With such a structure, the fuel gas and the oxidant gas are guided to the electrolyte electrode assemblies 10 to 12 through the reaction gas supply channels 15 and 16, respectively, and are consumed by the power generation reaction. Then, the exhaust heat of the battery during the power generation reaction is carried away to the outside by the cooling water flowing in the cooling water supply channels 21 and 22. In addition, a part of the cooling water is the air-water partition plate 17,
The surface of 18 becomes water vapor, and the reaction gas supply channel 1
The reaction gas is humidified because it is supplied into the gas chambers 5 and 16.
Furthermore, the water vapor diffuses inside the electrodes 11 and 12,
Reach the electrolyte 10. As a result, the electrolyte retains a high water content and exhibits high ionic conductivity.

In the above-described embodiment, the reaction gas supply passage 15, the cooling water supply passage 21, the reaction gas supply passage 16 and the cooling water supply passage 22 are water permeable and gas impermeable. The water and water partition plates 17 and 18 are configured as a common wall surface. Therefore, the fuel cell is cooled by the cooling water flowing through the cooling water supply channels 21 and 22, and
A part of the temperature-increased cooling water permeates the water-water partition plates 17 and 18 interposed between the cooling plates 19 and 20 and the gas partition plates 13 and 14 under the temperature and pressure atmosphere to supply the reaction gas. It enters the flow paths 15 and 16. Reaction gas supply channel 15,
The cooling water that has reached the surface 16 is evaporated and diffused and supplied as water vapor into the reaction gas. Therefore, the reaction gas is appropriately humidified, and the water vapor in the reaction gas is not condensed.
Thus, there is no need to separately humidify the reaction gas outside the fuel cell, and the water content of the electrolyte can be kept high and the ionic conductivity can be kept high without submerging the electrolyte electrode assembly by the condensed water of the humidified steam. further,
Since the humidity in the reaction gas is locally controlled by the temperature and pressure of the fuel cell, it is not necessary for the unit fuel cells to have the same temperature and pressure when forming the fuel cell stack. Therefore, since the temperature of the unit fuel cell may rise along the cooling water circulation passage, the temperature difference between the inlet and outlet of the cooling water introduced into the fuel cell stack can be made large, and The pump power is small, and the efficiency of the power generation system including the cooling mechanism is increased. It should be noted that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention.

[0012]

According to the present invention, the reaction gas supply passage provided in the gas partition plate and the cooling water supply passage provided in the cooling plate are partitioned by the water-permeable air / water partition plate. The cooling water circulating in the cooling water supply passage cools the fuel cell, and at the same time, a part of the cooling water permeates the water-water partition plate and is diffused and supplied into the reaction gas as vapor. Humidification is performed. Thus, the fuel cell can be cooled accurately and the reaction gas can be humidified in good condition under the temperature and pressure conditions of the fuel cell, the condensation of water vapor in the reaction gas can be prevented, and the solid high power generation with high power generation efficiency can be achieved. A molecular fuel cell can be provided.

[Brief description of drawings]

FIG. 1 is a perspective view showing a cut-away structure of a polymer electrolyte fuel cell according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a configuration of a conventional fuel cell by cutting it.

[Explanation of symbols]

10 ... Electrolyte 11, 12 ... Electrode 13, 14 ... Gas partition plate 15, 16 ... Reaction gas supply flow path 17, 18 ... Gas / water partition plate 19, 20 ... Cooling plate 21, 22 ... Cooling water supply flow path

Claims (1)

[Claims] 1. An electrolyte electrode assembly comprising an electrolyte and a pair of electrodes arranged so as to sandwich the electrolyte, and a pair of gases formed on both sides of the electrolyte electrode assembly and formed of gas impermeable members. A partition plate, a reaction gas supply channel formed in each of the pair of gas partition plates and provided so as to partially contact the electrolyte electrode assembly, and a part of a wall surface of the reaction gas supply channel. As described above, the water-permeable air / water partition plate is provided with one side facing the reaction gas supply flow path, and the cooling water supply flow is provided so that the other side surface of the air / water partition plate forms part of the wall surface. A polymer electrolyte fuel cell, characterized by comprising: a channel.