JPH08329960A - Fuel cell - Google Patents

Abstract

PURPOSE: To provide a fuel cell in which temperature inside a unit cell is made uniform and the cooling efficiency of a cooling plate is enhanced. CONSTITUTION: A heat transfer pipe 13 embedded in a cooling plate 4 is divided into a plurality of lines, and heat transfer pipes 13a, 13b connected to first and second cooling water supply manifolds 11a, 11b are extended to the central part of the cooling plate 4 and turn toward a fuel gas exhausting manifold 6 side so as to cross the cooling plate 4. The heat transfer pipes 13a, 13b are arranged so as to meander on the half surface of the cooling plate 4, and connected to first and second cooling water exhausting manifolds 12a, 12b. A control mechanism to control the flow rate and flow direction of the cooling water flowing through the cooling plate 4 is arranged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel cell improved to improve the cooling efficiency of a cooling plate of the fuel cell.

[0002]

2. Description of the Related Art A fuel cell is a device that directly oxidizes a fuel by an electrochemical process to directly convert energy released by an oxidation reaction into electrical energy. A fuel cell currently under development is formed by stacking a plurality of single cells in a rectangular column shape, in which a pair of porous electrodes composed of a fuel electrode and an air electrode are arranged with an electrolyte layer impregnated with an electrolyte sandwiched therebetween. To form a laminated body, and on the four side surfaces,
A reaction gas supply / exhaust manifold is installed. Further, it is preferable that the operating temperature of the laminate is higher in terms of reaction theory, but from the restriction of heat resistance of each of the constituent materials,
It is desirable to maintain around 200 ° C. Therefore, the cooling water is circulated through the heat transfer tubes embedded in the laminate to remove heat generated during operation.

FIG. 12 shows an example of a conventional fuel cell provided with a cooling plate. In the drawing, a cooling plate 4 in which a heat transfer tube 3 for circulating cooling water is embedded is provided inside the laminated body 1 for every several unit cells 2. Further, a fuel gas supply manifold 5, a fuel gas discharge manifold 6, and an air supply manifold 7 and an air discharge manifold 8 are arranged at opposite sides of the laminated body 1. . Further, a cooling water supply manifold 9 is disposed between the fuel gas supply manifold 5 and the air discharge manifold 8.
Further, a cooling water discharge manifold 10 is arranged between the fuel gas supply manifold 5 and the air supply manifold 7.

A heat transfer tube 3 embedded in the cooling plate 4
Is arranged so as to meander over the entire surface of the cooling plate 4, and
Both ends thereof are connected to the cooling water supply manifold 9 and the cooling water discharge manifold 10. And
The cooling water supplied to the cooling plate 4 enters the heat transfer tube 3 in the form of a single-phase flow from the cooling water supply manifold 9 and is heated by cooling the laminated body 1, and is boiled at a certain position to form two-phase. It becomes a flow and is discharged to the outside through the cooling water discharge manifold 10.

[0005]

Here, a problem in the conventional fuel cell as described above is uneven distribution of the high temperature portion due to a large temperature difference in the plane of the unit cell. That is, the calorific value in the cell plane is generally non-uniform,
The higher the amount of heat generation, the faster the catalyst contained in the unit cell may deteriorate, and the characteristics of the fuel cell may deteriorate. Therefore, it is necessary to lower the maximum temperature point. Therefore, in a conventional fuel cell cooling plate, when burying a heat transfer tube, a relatively low-temperature single-phase flow portion of cooling water is included in a portion requiring a particularly large cooling capacity within the same cell surface. It has been constructed so that a flow passage portion having a relatively large cooling capacity such as a portion reaching a boiling point or a boiling point can be arranged.

However, when increasing the area of the fuel cell unit cell and increasing the unevenness or uneven distribution of the high temperature portion in the unit cell surface, the conventional heat transfer tube arrangement has a relatively high cooling capacity. Since the range of the large portion is limited, the cooling capacity is limited, and there is a possibility that the battery characteristics may be deteriorated due to overheating of the unit cell.

The present invention has been proposed in order to solve the above-mentioned problems of the prior art. The purpose of the present invention is to make the temperature within the cell uniform and improve the cooling efficiency of the cooling plate. It is to provide a fuel cell capable of

[0008]

According to a first aspect of the present invention, a plurality of unit cells each having a pair of porous electrodes sandwiching an electrolyte layer impregnated with an electrolyte are stacked, and a side surface of the stacked body. A gas manifold for supplying / discharging reaction gas is arranged in the stack, a cooling plate is provided for each of the plurality of unit cells inside the laminate, and cooling water is supplied to the heat transfer pipe embedded in the cooling plate.
In a fuel cell that performs cooling by discharging, the heat transfer tube is composed of a plurality of systems, embedded in a cooling plate, and provided with a control mechanism for controlling the flow rate and flow direction of cooling water supplied to the heat transfer tube. It is characterized by that.

According to a second aspect of the present invention, in the fuel cell according to the first aspect, the heat transfer tube is constituted by a single flow path.

According to a third aspect of the present invention, in the fuel cell according to the first aspect, the heat transfer tube is composed of a plurality of flow paths.

According to a fourth aspect of the present invention, in the fuel cell according to the first aspect, the second aspect, or the third aspect, the heat transfer tube composed of the plurality of systems has a part or all of the direction of the fuel passage. It is characterized in that it is arranged so as to intersect with the air flow of the battery.

According to a fifth aspect of the present invention, in the fuel cell according to the first aspect, the second aspect, or the third aspect, the heat transfer tube composed of the plurality of systems has a part or all of the heat transfer tubes in the fuel cell direction. It is characterized in that it is arranged so as to intersect with the fuel flow.

[0013]

According to the inventions of claims 1 to 3,
By arranging the heat transfer tubes of multiple systems according to the temperature distribution in the cell surface, and by controlling the flow rate of the cooling water and controlling the flow direction according to the temperature distribution in the cell surface by the control mechanism, The temperature control within the cooling plate surface can be performed with higher accuracy.

Further, according to the invention described in claims 4 and 5, the temperature in the cooling plate surface is set by setting the layout of the heat transfer tubes of a plurality of systems in accordance with the temperature distribution in the cell surface. The control can be performed with higher accuracy.

[0015]

EXAMPLES Examples of the fuel cell according to the present invention will be specifically described below with reference to FIGS. 1 to 11. FIG.
The same members as those of the conventional type shown in FIG.

[1. First Embodiment] In this embodiment,
As shown in FIG. 1, the first cooling water supply manifold 11a is disposed between the fuel gas supply manifold 5 and the air discharge manifold 8, and the second cooling water supply manifold 11b is provided. It is arranged between the fuel gas supply manifold 5 and the air supply manifold 7. On the other hand, the first cooling water discharge manifold 12a
A fuel gas discharge manifold 6 and an air discharge manifold 8 are arranged, and a second cooling water discharge manifold 12b is arranged between the fuel gas discharge manifold 6 and an air supply manifold 7. ing.

Further, the heat transfer tube 13 embedded in the cooling plate 4
Is divided into a plurality of systems, and the first heat transfer tube 13a is
It is arranged between the first cooling water supply manifold 11a and the first cooling water discharge manifold 12a, and
The second heat transfer pipe 13b includes a second cooling water supply manifold 11b and a second cooling water discharge manifold 12b.
It is arranged between.

Then, these heat transfer tubes 13a, 13b
Are respectively arranged so as to extend to the central portion of the cooling plate 4, turn toward the fuel gas discharge manifold 6 side so as to cross the cooling plate 4, and meander on the half surface of the cooling plate 4, respectively. Second cooling water discharge manifold 12
It is connected to a and 12b. In this embodiment, the heat transfer tubes 13a and 13b are arranged so as to intersect with the air flow in the fuel cell in order to reduce the temperature of the high temperature portion in the cell surface.

On the other hand, a pair of the first cooling water supply manifold 11a and the first cooling water discharge manifold 12 are paired.
a or the second cooling water supply manifold 11b
The second cooling water discharge manifold 12b are connected to each other by two pipes 14 and 15 that intersect with each other.
In addition, the first and second cooling water supply manifolds 11a,
A valve 16 is provided at 11b, and a valve 17 is provided at the first and second cooling water discharge manifolds 12a and 12b. Furthermore, the two pipes 14, which intersect with each other,
Valves 18 and 19 are provided at 15, respectively. A control mechanism (not shown) for controlling the opening and closing of these valves 16, 17, 18, and 19 is provided, and is configured to control the flow rate and direction of the cooling water flowing in the cooling plate 4. There is.

The present embodiment can also be constructed as shown in FIG. 2 or FIG. That is, in FIG. 2, the first heat transfer tube 13 a extends from the end of the cooling plate 4 toward the fuel gas discharge manifold 6 side so as to immediately cross the cooling plate 4, and meanders in the center of the cooling plate 4. The fuel gas discharge manifold 6 side, the air discharge manifold 8 is turned toward the first cooling water discharge manifold 12a. Also, the second
The heat transfer tube 13b is arranged in the same manner as in FIG.

Next, in FIG. 3, the first heat transfer tube 13
2a is arranged in the same manner as in FIG. 2, while the second heat transfer tube 13b is arranged so as to intersect with the fuel flow, and is configured to turn and meander at approximately the center of the cooling plate 4. Has been done. It should be noted that the first is arranged so as to intersect with the air flow.
It is also possible to replace the heat transfer tube 13a and the second heat transfer tube 13b arranged so as to intersect with the fuel flow.

The fuel cell of this embodiment having such a structure has the following actions and effects. That is, the heat transfer tubes embedded in the cooling plate 4 are divided into a plurality of systems, and the layout of the heat transfer tubes in the cooling plate 4 is determined in consideration of the distribution state of the high temperature part in the single cell plane. The cooling capacity of the cooling plate 4 can be locally increased. Further, since the flow rate and the flow direction of the cooling water flowing in the cooling plate 4 can be controlled by the control mechanism, the heat transfer tube embedded in the cooling plate 4 controls the temperature distribution with high accuracy. As a result, the temperature distribution within the cell surface can be made uniform, and the cell characteristics of the fuel cell can be improved.

[2. Second Embodiment] In this embodiment,
As shown in FIG. 4, the first cooling water supply manifold 11a is disposed between the fuel gas supply manifold 5 and the air discharge manifold 8, and the second cooling water supply manifold 11b is provided. It is arranged between the fuel gas discharge manifold 6 and the air supply manifold 7. On the other hand, the first cooling water discharge manifold 12a
The fuel gas supply manifold 5 and the air supply manifold 7 are arranged, and the second cooling water discharge manifold 12b is arranged between the fuel gas discharge manifold 6 and the air discharge manifold 8. ing.

The first heat transfer tube 13a and the second heat transfer tube 13b are both arranged so as to intersect with the air flow, and each of them makes a turn at approximately the center of the cooling plate 4 to meander the half surface of the cooling plate 4. And is connected to the first and second cooling water discharge manifolds 12a and 12b. Further, also in this embodiment, a control mechanism is provided as in the first embodiment.

The present embodiment can also be constructed as shown in FIG. That is, the installation positions of the first and second cooling water supply manifolds 11a and 11b are the same as those in FIG. 4, but the first cooling water discharge manifold 12a is used.
Is arranged between the fuel gas discharge manifold 6 and the air discharge manifold 8, and the second cooling water discharge manifold 12b is arranged between the fuel gas supply manifold 5 and the air supply manifold 7. It is set up.

The first heat transfer tube 13a and the second heat transfer tube 13b are both arranged so as to intersect with the fuel flow, and each of the first heat transfer tube 13a and the second heat transfer tube 13b is turned at substantially the central portion of the cooling plate 4 and the half surface of the cooling plate 4 is turned. It is arranged so as to meander and is connected to the first and second cooling water discharge manifolds 12a and 12b.

In the fuel cell of this embodiment having such a structure, the installation positions of the cooling water supply manifold 11 and the cooling water discharge manifold 12 and the layout of the heat transfer tubes 13 are changed as compared with the first embodiment. Since the basic configuration is the same as that of the first embodiment, the same operation and effect as those of the first embodiment can be obtained.

[3. Third Embodiment] In this embodiment,
As shown in FIG. 6, the first cooling water supply manifold 11a is disposed between the fuel gas supply manifold 5 and the air supply manifold 7, and the second cooling water supply manifold 11b is provided. It is arranged between the fuel gas discharge manifold 6 and the air supply manifold 7. On the other hand, the first cooling water discharge manifold 12a
The fuel gas supply manifold 5 and the air discharge manifold 8 are arranged, and the second cooling water discharge manifold 12b is arranged between the fuel gas discharge manifold 6 and the air discharge manifold 8. ing.

Further, the heat transfer tube 13 embedded in the cooling plate 4
Is divided into a plurality of systems, and the first heat transfer tube 13a is
It is arranged between the first cooling water supply manifold 11a and the first cooling water discharge manifold 12a, and
The second heat transfer pipe 13b includes a second cooling water supply manifold 11b and a second cooling water discharge manifold 12b.
It is arranged between.

And, these heat transfer tubes 13a, 13b
Are arranged so as to extend to the center of the cooling plate 4, turn toward the air discharge manifold 8 side across the cooling plate 4, and meander on the half surface of the cooling plate 4, respectively. 2 cooling water discharge manifolds 12a, 1
It is connected to 2b. In the present embodiment, in order to reduce the temperature of the high temperature portion in the cell surface, the heat transfer tube 13
a and 13b are arranged so as to intersect the fuel flow in the fuel cell. Further, also in this embodiment, a control mechanism is provided as in the first embodiment.

The present embodiment can also be constructed as shown in FIG. 7 or 8. That is, in FIG. 7, the first heat transfer tube 13 a is arranged so that the first heat transfer tube 13 a immediately crosses the cooling plate 4 from the end portion of the cooling plate 4.
Side toward the central portion of the cooling plate 4 while meandering, and is turned toward the fuel gas supply manifold 5 on the air discharge manifold 8 side and connected to the first cooling water discharge manifold 12a. There is. Further, the second heat transfer tube 13b is arranged similarly to FIG.

Next, referring to FIG. 8, the first heat transfer tube 13
a is arranged in the same manner as in FIG. 6, but the second heat transfer tube 13b is arranged so as to intersect with the air flow, and is configured to turn and meander at approximately the center of the cooling plate 4. Has been done. It should be noted that the second is arranged so as to intersect with the air flow.
It is also possible to replace the heat transfer tube 13b and the first heat transfer tube 13a arranged so as to intersect with the fuel flow.

The fuel cell of this embodiment having such a structure also has the same operation and effect as the first embodiment.

[4. Fourth Embodiment] In this embodiment,
As shown in FIG. 9, the heat transfer tubes divided into a plurality of systems are
The first and second branch heat transfer tubes 20a and 20b are formed by a plurality of flow paths in which a plurality of straight tube portions are connected in parallel with each other. In addition, the first cooling water supply manifold 11a
Is arranged between the fuel gas supply manifold 5 and the air discharge manifold 8, and the second cooling water supply manifold 11b is arranged between the fuel gas discharge manifold 6 and the air supply manifold 7. It is set up. On the other hand, the first cooling water discharge manifold 12a is disposed between the fuel gas supply manifold 5 and the air supply manifold 7, and the second cooling water discharge manifold 12b is the fuel gas discharge manifold. 6 and the air discharge manifold 8.

The first branch heat transfer tube 20a is
The straight pipe portions that are arranged between the first cooling water supply manifold 11a and the first cooling water discharge manifold 12a and are parallel to each other are arranged so as to intersect the fuel flow. In addition, the second branch heat transfer pipe 20b includes the second cooling water supply manifold 11b and the second cooling water discharge manifold 1
The straight pipe portions which are arranged between the two 2b and are parallel to each other are arranged so as to intersect the fuel flow. Further, also in this embodiment, a control mechanism is provided as in the first embodiment.

The present embodiment can also be constructed as shown in FIG. That is, in FIG.
First and second cooling water supply manifolds 11a and 11b
9 is the same as that shown in FIG. 9, but the first cooling water discharge manifold 12a is disposed between the fuel gas discharge manifold 6 and the air discharge manifold 8, and
The second cooling water discharge manifold 12b is arranged between the fuel gas supply manifold 5 and the air supply manifold 7.

The first branch heat transfer tube 20a is
It is arranged between the first cooling water supply manifold 11a and the first cooling water discharge manifold 12a, and the straight pipe portions parallel to each other are arranged so as to intersect the air flow. In addition, the second branch heat transfer pipe 20b includes the second cooling water supply manifold 11b and the second cooling water discharge manifold 1
The straight pipe portions which are arranged between the two 2b and are parallel to each other are arranged so as to intersect the fuel flow.

In the fuel cell of this embodiment having such a structure as well, the same operation and effect as those of the first embodiment are exhibited, and in addition, a branch heat transfer tube constituted by connecting a plurality of straight pipe portions in parallel with each other in advance. By using, the work of attaching the heat transfer tube to the cooling plate 4 is greatly simplified.

[5. Fifth Embodiment] In this embodiment,
As shown in FIG. 11, the first and second cooling water supply manifolds are composed of a cooling water supply manifold 21 having a branched structure. That is, the cooling water supply manifold 21 having the two branch lines 21a and 21b is arranged on one side surface of the laminated body 1, and one branch line 21a functions as the first cooling water supply manifold and the other one. The branch line 21b is configured to function as a second cooling water supply manifold.

The first and second cooling water discharging manifolds are composed of the cooling water discharging manifold 22 having a branched structure. That is, the cooling water discharge manifold 2 having the two branch lines 22a and 22b
2 is disposed on the side surface facing the cooling water supply manifold 21, one branch line 22a functions as a first cooling water discharge manifold, and the other branch line 2a.
2b is configured to function as a second cooling water discharge manifold.

Further, the cooling water supply manifold 2
1 and the cooling water discharge manifold 22 are connected by pipes 23 and 24 that intersect with each other. Further, the cooling water supply manifold 21 has valves 25, 2
6, 27 are provided, while the cooling water discharge manifold 22 is provided with valves 28, 29, 30. Further, valves 31 and 32 are provided in the pipes 23 and 24 that intersect each other. A control mechanism (not shown) for controlling the opening and closing of these valves 25 to 32 is provided, and is configured to control the flow rate and the flow direction of the cooling water flowing in the cooling plate 4.

In the fuel cell of this embodiment having such a structure as well, the same action and effect as in the first embodiment are obtained, and the cooling water supply manifold 21 and the cooling water discharge manifold 22 and the pipes intersecting each other are provided. By controlling the opening and closing of the valves 25 to 32 provided in 23 and 24,
Since the flow rate and flow direction of the cooling water flowing in the cooling plate 4 can be collectively controlled, the cooling capacity in the cooling plate surface can be locally increased or decreased according to various temperature distributions in the cell surface. Therefore, more accurate cooling can be performed.

[0043]

As described above, according to the present invention, a plurality of systems of heat transfer tubes are embedded and cooled so as to locally increase or decrease the cooling capacity in the cooling plate surface according to the temperature distribution in the cell surface. By providing the control mechanism for controlling the flow rate and the flow direction of water, it is possible to provide a fuel cell that can make the temperature within the unit cell uniform and improve the cooling efficiency of the cooling plate.

[Brief description of drawings]

FIG. 1 is a perspective view showing a configuration of a first embodiment of a fuel cell of the present invention.

FIG. 2 is a perspective view of a main part showing another configuration of the first embodiment shown in FIG.

FIG. 3 is a perspective view of a main part showing another configuration of the first embodiment shown in FIG.

FIG. 4 is a perspective view of an essential part showing the configuration of a second embodiment of the fuel cell of the present invention.

5 is a perspective view of an essential part showing another configuration of the second embodiment shown in FIG.

FIG. 6 is a perspective view of an essential part showing the configuration of a third embodiment of the fuel cell of the present invention.

FIG. 7 is a perspective view of an essential part showing another configuration of the third embodiment shown in FIG.

FIG. 8 is a perspective view of an essential part showing another configuration of the third embodiment shown in FIG.

FIG. 9 is a perspective view of an essential part showing the configuration of a fourth embodiment of the fuel cell of the present invention.

FIG. 10 is a perspective view of a main part showing another configuration of the fourth embodiment shown in FIG.

FIG. 11 is a perspective view showing the configuration of a fifth embodiment of the fuel cell of the present invention.

FIG. 12 is a perspective view showing an example of the configuration of a conventional fuel cell.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Laminated body 2 ... Single cell 3 ... Heat transfer tube 4 ... Cooling plate 5 ... Fuel gas supply manifold 6 ... Fuel gas discharge manifold 7 ... Air supply manifold 8 ... Air discharge manifold 9 ... Cooling water supply manifold 10 ... Cooling water discharge manifold 11 ... Cooling water supply manifold 12 ... Cooling water discharge manifold 13 ... Heat transfer tubes 14,15 ... Piping 16 to 19 ... Valve 20 ... Branch heat transfer tube 21 ... Cooling water supply manifold having a branch line 22 ... Manifold for discharging cooling water having a branch line 23, 24 ... Piping 25-32 ... Valve

Claims (5)

[Claims] 1. A plurality of unit cells each having a pair of porous electrodes arranged with an electrolyte layer impregnated with an electrolyte sandwiched therebetween, and a gas manifold for supplying / discharging a reaction gas is provided on a side surface of the stack. In the fuel cell, a cooling plate is provided for each of the plurality of unit cells inside the laminate, and cooling is performed by supplying / discharging cooling water to / from the heat transfer pipe embedded in the cooling plate. Is composed of multiple systems and embedded in the cooling plate,
Further, the fuel cell is provided with a control mechanism for controlling the flow rate and flow direction of the cooling water supplied to the heat transfer tube. 2. The heat transfer tube composed of a plurality of systems is configured with a single flow path, respectively.
The fuel cell described. 3. The heat transfer tube composed of a plurality of systems is configured with a plurality of flow paths, respectively.
The fuel cell described. 4. The heat transfer tube comprising a plurality of systems is arranged such that a part or all of the heat transfer tubes intersects with the air flow of the fuel cell. The fuel cell according to claim 2 or claim 3. 5. The heat transfer tube composed of a plurality of systems is arranged so that a part or all of the heat transfer tubes intersect the fuel flow of the fuel cell. The fuel cell according to claim 2 or claim 3.