JPH06124722A - Heating and humidifying device and fuel cell - Google Patents

Abstract

PURPOSE:To enable a heating and humidifying device to be made compact, allow the arbitrary setting of an applied humidity amount within saturated vapor pressure, depending upon a change in the number of stacks, and further enable differential pressure to be enlarged between gas and cooling water sides via the application of a polymer film. CONSTITUTION:This device is characteristic in that gas and cooling water as turned into hot water state for applying heat and humidity, are respectively introduced to both sides of polymer films 44 and 45, and the films 44 and 45 or porous body is made to absorb the hot water. Also, the device is characteristic in that the absorbed water is vaporized into the gas for heat and humidity application on the other side of the body, or humidity is applied thereto concurrently via the heat of the hot water. Furthermore, the device is characteristic in that the device is integrally stacked on a fuel cell body having an electrode joint body with electrodes laid at both side of a solid electrolyte, and a fuel cell body with separators laid at both sides of the body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating / humidifying system device and a fuel cell in which the device is integrated with a fuel cell body.

[0002]

2. Description of the Related Art As is well known, the power generation principle of a solid polymer electrolyte fuel cell is as shown in FIG. The electrode assembly 1 is
As the electrolyte (ion exchange membrane) 2, a fluororesin polymer ion exchange membrane (for example, a fluororesin ion exchange membrane having a sulfonic acid group) is used, and a catalyst electrode (negative electrode) made of, for example, platinum on both sides with this as the center. ) 3, catalyst electrode (anode)
4 is attached, and both surfaces thereof are sandwiched between porous carbon electrodes (negative electrode) 5 and carbon electrode (anode) 6 and stacked.

Hydrogen supplied as fuel is used as a catalyst electrode 3
The hydrogen ions are ionized above, and the hydrogen ions are H ^{+ in the} electrolyte 2.
・ Move toward the anode as H ₂ O.

On the catalyst electrode 4, oxygen supplied as an oxidant or oxygen in the air and the electrons flowing through the external circuit 7 react with each other to generate and discharge water. At this time, the external circuit 7
The flow of electrons that has flowed through can be used as direct-current electrical energy.

In order to realize the above-mentioned hydrogen ion permeability in the ion exchange membrane serving as the electrolyte 2, it is necessary to always keep the ion exchange membrane in a sufficient water retention state. When the ion-exchange membrane is in a dry state, its hydrogen ion permeability is reduced, and the electric resistance of the fuel cell becomes large, which makes it impossible to generate electricity.

In order to maintain the water-retaining state of the ion exchange membrane serving as the electrolyte 2, hydrogen, which is usually supplied as a fuel, oxygen or air, which is supplied as an oxidant, or both are used up to around 80 ° C. which is the operating temperature of the fuel cell. Hydrogen that has been heated and moistened with steam equivalent to saturated steam partial pressure at that temperature,
Oxygen or air is supplied to the electrode assembly 1 so that the water exchange state of the ion exchange membrane, which is the electrolyte 2, is maintained. The chemical reaction formulas on the negative electrode side and the positive electrode side in the fuel cell of FIG. 1 are shown below.

Negative electrode side: H ₂ → 2H ⁺ + 2e ⁻ Anode side: (1/2) O ₂ + 2H ⁺ + 2e ⁻ → H ₂ O Total reaction: H ₂ + (1/2) O ₂ → H ₂ O Humidification / humidification system device for a conventional solid polymer electrolyte fuel cell, that is, a heating / humidification system for supplying hydrogen to a fuel cell by heating / humidifying hydrogen, which is a gaseous fuel, oxygen or air, which is a gaseous oxidizer. The device is as shown in FIG. In addition, although both are heated and humidified in FIG.
In some cases, only hydrogen, oxygen, or air is heated and humidified by this system device.

Hydrogen, oxygen or air is supplied to the electric heater 11 at a temperature substantially equal to the operating temperature of the fuel cell from about 40 ° C. to 100 ° C.
By passing through the pure water 12 heated before and after, hydrogen, oxygen, or air can be sufficiently humidified corresponding to the saturated vapor pressure. By supplying the sufficiently humidified hydrogen, oxygen or air to the fuel cell main body 13, water is constantly supplied to the ion exchange membrane which is the electrolyte 2, and it becomes possible to maintain the water retention state. The fuel cell body
It is also possible to guide 13 cooling water to the heating / humidifying devices 14 and 15 and use the hot water as a source of heating / humidifying water.

[0009]

However, the conventional heating / humidifying system device has the following problems.

(1) Heating / humidifying device (fuel side) 14, heating /
A compact container of pure water 12 is required as the humidifier (oxidizer side) 15, which lacks compactness.

(2) The amount of humidification can be controlled only by temperature adjustment using electric energy (for example, electric heater 11) from the outside.

(3) The number of control items such as the electric heater 11 increases, and the entire system becomes complicated.

(4) When heating and humidifying a gas having a pressure, the pressure resistance of the container must be taken into consideration, which complicates the design.

The present invention has been made in consideration of such circumstances, and the heating / humidifying device can be made compact by using a gas heating / humidifying system using a polymer membrane or a porous plate, and The amount of humidification can be set arbitrarily within the range of saturated vapor pressure by changing the number of stacks, and the adoption of a polymer membrane can increase the pressure difference between the gas side and the cooling water side. The purpose is to provide a battery.

[0015]

According to a first aspect of the present invention, a gas for heating / humidifying and cooling water that has become hot water are introduced to both sides of a polymer membrane or a porous body permeable to water, respectively. A heating method characterized in that hot water is absorbed by a polymer membrane or a porous body, and the absorbed water is evaporated into a gas on the other surface for heating and humidifying, or is simultaneously heated by the heat of the hot water. -It is a humidification system device.

According to a second aspect of the present invention, there is provided a fuel cell main body having an electrode assembly in which electrodes are arranged on both sides of a solid polymer electrolyte and a separator arranged in both sides of the electrode assembly. A fuel cell is characterized in that a temperature / humidification system device is integrally laminated.

FIG. 3 shows a principle diagram of a gas heating / humidification system device using a polymer membrane (for example, a fluororesin ion exchange membrane having a sulfonic acid group) according to the present invention. Reference numeral 21 in the figure denotes a polymer membrane arranged in the center, and guides the gas (for example, hydrogen, oxygen or air) and the cooling water of the fuel cell main body which has become hot water by collecting exhaust heat and the like on both sides. Has become.

FIGS. 4 (A) and 4 (B) are schematic configuration diagrams of a heating / humidifying system device using the polymer film 21, and FIG.
4A is a top view, and FIG. 4B is a side view of FIG. Reference numerals 22 and 23 in the figure denote a first separator (heated / humidified body side) and a second separator (cooling water side), which are arranged on both sides of the polymer film 21, respectively. The material of these separators 22 and 23 is carbon or metal. The first separator 22 on the polymer side 21 has a heating / humidifying body channel groove for guiding a gas (eg, hydrogen, oxygen or air) to be heated / humidified.
24 are provided. Second separator on the polymer side 21
The cooling water passage groove 25 that guides the cooling water that has become hot water is provided in the 23.

As a method of introducing gas and cooling water into both sides of the polymer film 21 instead of the heating / humidifying body flow path groove 24 and the cooling water flow path groove 25, a polymer film made of a porous carbon plate is used. It is also possible to heat and humidify by sandwiching 21 and passing gas and cooling water through the gap.

FIG. 5 shows a principle diagram of a gas heating / humidification system device using a porous body (for example, a ceramic plate or a carbon plate) which can permeate water according to the present invention. Reference numeral 31 in the figure denotes a porous body arranged in the center, and guides the gas (for example, hydrogen, oxygen or air) and the cooling water of the fuel cell body that has become hot water by collecting exhaust heat and the like on both sides. Has become.

FIGS. 6 (A) and 6 (B) are schematic configuration diagrams of a heating / humidifying system device using the porous body 31, and FIG.
6A is a top view, and FIG. 6B is a side view of FIG. Reference numerals 32 and 33 in the figure denote a first separator (heated / humidified body side) and a second separator (cooling water side) arranged on both sides of the porous body 31. The material of these separators 32, 33 is carbon or metal. First of the polymer side 31
The separator 32 includes a gas to be heated / humidified (for example,
A heating / humidifying body flow path groove 34 for guiding hydrogen, oxygen, or air) is provided. The second separator 32 on the polymer side 31 is provided with a cooling water flow channel groove 35 for guiding the cooling water that has become hot water.

FIGS. 7A and 7B show a porous body 36 with grooves.
7A and 7B are schematic configuration diagrams of a heating / humidifying system device utilizing the above, FIG. 7A is a top view, and FIG. 7B is a side view of FIG. 37 and 38 in the figure are the porous bodies 36, respectively.
The first separator (on the heating / humidifying body side) and the second separator (on the cooling water side) arranged on both sides of the above are shown. The material of these separators 37, 38 is carbon or metal. The porous body 36 on the side of the first separator 37 has a gas (for example, hydrogen, oxygen or air) to be heated / humidified.
There is provided a heating / humidifying body flow path groove 39 for guiding the heat. Second
The porous body 36 on the separator 38 side is provided with a cooling water flow channel groove 40 that guides cooling water that has become hot water.

[0023]

The operation of the heating / humidifying system device according to the present invention is as described below.

In the case of the gas heating / humidifying system device using the polymer membrane shown in FIGS. 3 and 4, the polymer membrane 21 is sandwiched and the gas to be heated / humidified, exhaust heat, etc. are collected on both sides of the polymer membrane 21 to obtain hot water. The hot water is absorbed by the polymer film 21 by introducing the cooled water, and the absorbed water evaporates in the gas to be heated / humidified on the other surface or is simultaneously heated by the heat of the hot water. It is also possible to use this principle to simultaneously configure a heating / humidifying system. Also,
As shown in FIG. 4, the first separator 22, the polymer film 21, and the second
By configuring the separators 23 to be laminated and adjusting the flow rate passing through the heating / humidifying body flow path grooves 24, the humidification amount can be arbitrarily adjusted within the range of the saturated vapor pressure partial pressure.

In the case of the gas heating / humidifying system device using the porous body shown in FIGS. 5, 6 and 7, the porous body of water is arranged at the center and the gas to be heated / humidified on both sides thereof ( (For example, hydrogen, oxygen or air), by introducing hot water that has recovered exhaust heat, etc., the hot water is supplied to the porous body and contains water, which evaporates or warms water into the gas to be heated / humidified on multiple sides. It is also possible to simultaneously heat the same with the heat of the, and by using this principle, it is possible to configure a heating / humidifying system at the same time. 6 and 7 show an example of introducing hot water into the porous body by gas, the first separator, the polymer membrane and the second separator are laminated, and the flow velocity through the heating / humidifying body flow channel is By adjusting, the amount of humidification can be arbitrarily adjusted within the range of the saturated vapor pressure partial pressure.

[0026]

Embodiments of the present invention will be described below with reference to the drawings.

(Example 1) Referring to FIG. 41 in the figure
42 and 43 are a first separator (for hydrogen), a second separator (for cooling water / oxygen or air), and a third separator (for cooling water), respectively. Here, the material of each separator is carbon or metal. The first separator
A first polymer film 44 is arranged between 41 and the second separator 42, and a second polymer film 45 is arranged between the second separator 42 and the third separator 43. Here, the material of each polymer membrane is a fluororesin ion exchange membrane having a sulfonic acid group. In addition, the main surface of the first to third separators, for convenience,
The planes A, B, C, D, and E are referred to in this order from the left side of the drawing.

A first hydrogen flow path 46 for introducing hydrogen is provided on the surface B (on the side of the first polymer film 44) of the first separator 41. The C surface of the second separator 42 (the first polymer film 44
On the side), a first cooling water channel (for hydrogen) 47 for guiding the cooling water that has become hot water (from the fuel cell) is provided. A first oxygen or air flow path 48 for guiding oxygen or air is provided on the D surface (on the side of the second polymer film 45) of the second separator 42. E surface of the third separator 43 (the third polymer film 45 side)
A second cooling water channel (for oxygen or air) 49 is provided in the. The first hydrogen flow path 46 and the first cooling water flow path 47 are the first
The first oxygen or air passage 48 and the second cooling water passage 49 are arranged so as to be orthogonal to each other on the mating planes (B-C planes) sandwiching the polymer membrane 44, and the second polymer membrane 45 is sandwiched between them. Mating surface (D-E
They are arranged so that they are orthogonal to each other.

In the heating / humidifying system device having such a structure, for example, hydrogen supplied to the solid polymer electrolyte fuel cell is introduced from the A surface of the first separator 41 and supplied to the B surface of the first separator 41. On the other hand, oxygen or air is introduced from the A side of the first separator 41, and the second separator 42
It is supplied to the D side of. The hydrogen is branched and flows on the B surface of the first separator 41 along the first polymer film 44. Further, oxygen or air branches and flows on the D surface of the second separator 42 along the second polymer film 45.

Further, the cooling water which has recovered the exhaust heat of the solid polymer electrolyte fuel cell into hot water (about 80 ° C.) is introduced from the A side of the first separator 41, and the C of the second separator 42.
Surface and the E surface of the third separator 43 are branched and supplied. C
The hot water branched and supplied to the surface E and the surface E are respectively the first polymer film.
44, via the second polymer film 45, hydrogen, oxygen or air is heated and humidified, and the warm water that has been heated and humidified is collected again and can be taken out from the first separator 41. The amount of humidification can be arbitrarily adjusted within the range of saturated water vapor partial pressure by stacking this structure.

In the heating / humidifying system device according to the first embodiment, the first polymer film 44 and the second polymer film 45 are arranged between the first separator 41, the second separator 42 and the third separator 43, respectively. Hydrogen on both sides of the first polymer film 44,
Since the cooling water that has become hot water is guided respectively, and oxygen or air and the cooling water that has become hot water are respectively guided to both surfaces of the second polymer film 45, the heating / humidifying device can be made compact, In addition, the amount of humidification can be arbitrarily set within the range of saturated vapor pressure by changing the number of laminated layers, and by adopting a polymer membrane, the pressure difference between the gas side and the cooling water side can be made large.

(Example 2) Compared to the case of FIG. 8, this Example 2 uses the first polymer film 44 as the first porous plate and the second polymer film 45 as the second porous plate. Except for the above, the configuration and operation are the same as in the case of the first embodiment.

According to the second embodiment, as in the above embodiment, the heating / humidifying device can be made compact, and the amount of humidification can be arbitrarily set within the range of saturated vapor pressure by changing the number of laminated layers. By adopting a quality plate, a large pressure difference between the gas side and the cooling water side can be secured.

(Embodiment 3) Referring to FIG. However, FIG.
The same members as and are denoted by the same reference numerals, and description thereof will be omitted. In addition, a laminated body in which the separators 41 to 43 and the polymer films 44 and 45 are laminated is referred to as a heating / humidifying section 51 for convenience.

Reference numeral 52 in the figure denotes a fuel cell main body which is integrated with the heating / humidifying section 51, and is composed of an electrode assembly 53, a third separator 54 and a fourth separator 55 on both sides. The material of these separators 54, 55 is carbon or metal. Fourth separator on the side of the electrode assembly 53
A second hydrogen flow path 56 is provided on the main surface (G surface) of 54. The main surface of the fifth separator 55 on the side of the electrode assembly 53 (H
The second oxygen or air flow path 57 is provided on the surface), and the third cooling water flow path 58 is provided on the main surface (I surface) of the fifth separator 55 opposite to the H surface. The hydrogen flow path 56 and the oxygen or air flow path 57 are formed on the mating surface (GH) sandwiching the electrode assembly 53.
They are arranged so that they are orthogonal to each other.

In the fuel cell having such a configuration, hydrogen (before heating / humidification) as a fuel and oxygen or air (before heating / humidification) as an oxidant are respectively generated in the F of the fourth separator 54 of the fuel cell main body 52. It is introduced from the holes at the two corners of the surface and directly introduced into the heating / humidifying section 51. Also, the cooling water is the fourth separator 54.
It is introduced from the hole at the other corner of the F surface of the fifth separator 55, absorbs the heat generated by the battery reaction occurring on the GH surface on the I surface of the fifth separator 55, and is introduced into the heating / humidifying section 51 after becoming hot water. It

Hydrogen, oxygen, or air introduced into the heating / humidifying section 51 is the cooling water that has become wet water and the first and second polymer films 4
It is flown so that it sandwiches 4, 45 and is orthogonal to each other. Here, part of the cooling water (warm water) is the first and second polymer films 44, 45.
It is absorbed by the water, and then vaporizes in the facing hydrogen, oxygen or air due to the partial pressure difference of water vapor. The amount of humidification can be set within the range of the saturated water vapor partial pressure at the fuel cell operating temperature by stacking the same structure with the first and second polymer membranes 44 and 45 sandwiched therebetween, if necessary.

The heated / humidified hydrogen, oxygen or air is
It is collected again at one end by the heating / humidifying section 51 and returned to the fuel cell main body section 52. Hydrogen returned to the fuel cell body 52,
Oxygen or air is flown in a direction orthogonal to each other with the electrode assembly 53 sandwiched therebetween, and a battery reaction occurs. After the reaction, the remaining hydrogen, oxygen, or air including the humidified and generated water is respectively separated by the fourth separator.
It is discharged from the vicinity of the hole introduced on the F side of 54.

After the heating / humidification is completed, the remaining cooling water (warm water) is collected at one end by the heating / humidification section 51, penetrates one corner of the fuel cell main body section 52, and from the vicinity of the cooling water introduction hole. Is discharged.

According to the third embodiment described above, the heating / humidifying section 51 in which the first and second polymer films 44 and 45 are arranged and laminated between the first to third separators 41, 42 and 43 is used as an electrode. Since the structure is integrated into the fuel cell main body 52 in which the fourth and fifth separators 54, 55 are arranged on both sides of the joined body 53, the fuel cell main body 52 is cooled to become hot water. Heating hydrogen, oxygen or air directly inside without extracting water to the outside
It becomes possible to humidify, and the fuel cell output, cooling water (warm water) temperature, and the amount of hydrogen or air humidified can be set arbitrarily by stacking the separator, electrode assembly, and polymer membrane. is there. Further, no piping for guiding the cooling water (warm water) to the heating / humidifying section 51 is required, and the entire system is very compact and easy. Furthermore, since the flow paths of hydrogen, oxygen or air and cooling water can be arranged orthogonal to each other, the separator structure is also very simple.

In the above embodiment, the case where the polymer film is arranged between the first to third separators has been described, but the present invention is not limited to this, and a porous body may be arranged.

[0042]

As described above in detail, according to the present invention,
By using a gas heating / humidifying system that uses a polymer membrane or porous plate, the heating / humidifying device can be made compact, and the amount of humidification can be set arbitrarily within the saturated vapor pressure range by changing the number of layers. Further, it is possible to provide a heating / humidifying system device and a fuel cell capable of increasing the differential pressure between the gas side and the cooling water side by adopting a polymer membrane.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a power generation principle of a solid polymer electrolyte fuel cell.

FIG. 2 is an explanatory diagram of a conventional heating / humidifying system device for a fuel cell.

FIG. 3 is an explanatory diagram showing the principle of a heating / humidifying system device for a fuel cell using a polymer membrane.

[Fig. 4] Heating of a fuel cell using a polymer membrane
It is an explanatory view of a humidification system device, Drawing 4 (A) is a top view and Drawing 4 (B) is a side view of Drawing 4 (A).

FIG. 5 is an explanatory diagram showing the principle of a heating / humidifying system device for a fuel cell using a porous plate.

[Fig. 6] Heating of a fuel cell using a porous plate
It is explanatory drawing of a humidification system apparatus, FIG.6 (A) is a top view, FIG.6 (B) is a side view of FIG.6 (A).

7A and 7B are explanatory views of a heating / humidifying system device for a fuel cell of a fuel cell using a grooved porous plate, FIG. 7A being a top view and FIG. 7B being FIG. 7A. Side view of.

FIG. 8 is an explanatory diagram of a heating / humidifying system device for a fuel cell according to the first embodiment of the present invention.

FIG. 9 is an explanatory diagram of a fuel cell according to a third embodiment of the present invention.

[Explanation of symbols]

41, 42, 43, 54, 55 ... Separator, 44, 45 ... Polymer membrane, 46, 56 ... Hydrogen flow channel, 47, 58 ... Cooling water flow channel, 48, 57 ... Oxygen or air flow channel.

Claims (3)

[Claims] 1. A polymer membrane or a porous body permeable to water is introduced into both sides of a gas to be heated / humidified and cooling water which has become warm water, and the warm water is absorbed by the polymer membrane or the porous body. A heating / humidifying system device characterized by allowing the absorbed water to evaporate into a gas for heating / humidifying on the other surface, or simultaneously humidifying by the heat of the hot water. 2. A polymer membrane or a porous body permeable to water, separators arranged on both sides of the polymer membrane or the porous body, and provided on one surface of the polymer membrane or the porous body. A cooling water channel, and a heating / humidifying body channel provided on the other surface of the polymer membrane or the porous body,
The gas to be heated / humidified is introduced into the humidifying body channel, and the cooling water that has become hot water is introduced into the cooling water channel, respectively, and the warm water is absorbed by the polymer membrane or the porous body, and the absorbed water is collected. Evaporate in the gas to be heated / humidified on the other side,
Alternatively, the heat of hot water is used to simultaneously humidify.
The heating / humidification system device described. 3. The heating / humidifying system device according to claim 2, wherein the fuel cell body has an electrode assembly having electrodes arranged on both sides of the solid polymer electrolyte and separators arranged on both sides of the electrode assembly. A fuel cell characterized by being integrally laminated.