JPH11204126A - Solid polymer electrolyte fuel cell - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To efficiently drain condensed water generated from a fuel cell from a lower part of a vehicle, and to easily mount the condensed water on the vehicle. SOLUTION: An exhaust port 21 is provided at the bottom of the fuel cell stack, and the exhaust port 21 has a first exhaust port 2.
A drain valve 6 is provided through the flow path 11 and the flow path 5, and a float 6 for opening and closing a second drain port 62 provided below the drain valve is provided in the drain valve.
1, the lower surface of the float is disposed below the opening position of the first discharge port 211 of the discharge port, and the drain valve is disposed near the wheel 4 of the vehicle. A solid polymer electrolyte fuel cell.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel cell, and more particularly to a solid polymer electrolyte fuel cell.

[0002]

2. Description of the Related Art Conventionally, solid polymer electrolyte fuel cells have
The application to automobiles and the like as a small and lightweight power source using hydrogen and oxygen as fuel is promising. Such a battery is composed of a solid polymer electrolyte membrane having ion exchange ability, and a positive electrode and a negative electrode arranged in contact with both sides thereof. Fuel hydrogen is electrochemically oxidized at the negative electrode to generate protons and electrons. This proton moves to the positive electrode to which oxygen is supplied in the polymer electrolyte membrane. On the other hand, the electrons generated at the negative electrode pass through the load connected to the battery and flow to the positive electrode, where protons, oxygen, and electrons react to generate water at the positive electrode.

As described above, a solid polymer electrolyte fuel cell has been studied as a power source for automobiles because of its low-temperature operability, small size and high power density. Perfluorocarbon polymer membrane having a sulfonic acid group (trade name;
(Nafion, DuPont).

In order for the polymer electrolyte membrane to function as an electrolyte, it is indispensable that the polymer electrolyte membrane is in a wet state containing water. Therefore, the supplied gas and air are supplied in a state containing a considerable amount of water vapor. .

[0005] Further, since the hydrogen in the fuel reacts with the oxygen in the air to produce water, the exhaust gas contains a large amount of moisture, which condenses under normal operating conditions and produces water. Is discharged as a liquid. This water accumulates in the flow path of the exhaust gas and reduces the flow path area. Further, when the amount of water increases and the cross-sectional area changes, the operation of the fuel cell is hindered. Therefore, it is necessary to remove the water before a serious hindrance occurs.

In order to solve this problem, Japanese Patent Laid-Open No.
Japanese Patent No. 95215 is one technique for eliminating this water. This technique humidifies at least one of an oxidizing gas and a fuel gas, supplies these gases to both sides of the solid electrolyte membrane, and causes an oxidation reaction to generate a reaction product containing water via the solid electrolyte membrane. In the fuel cell device, a first liquid reservoir is provided by branching downward from a flow path through which any one of the gases flows or another flow path communicating with the flow path, and the first liquid reservoir is provided. A second liquid reservoir is connected to a lower portion of the fuel cell device, and a valve that is alternately opened and closed is provided between each of the liquid reservoirs and on the outlet side of the second liquid reservoir. .

[0007]

However, according to this technique, the drainage mechanism is composed of three tanks stacked one above the other, so that the structure becomes high. The high height poses a space problem when the fuel cell is mounted as a power supply device for a vehicle.

[0008] In general, in a fuel cell in which condensed water may be generated, it is reasonable to supply air from above and exhaust from the bottom in order to ensure smooth operation characteristics. Further, even if the structure is such that the air is exhausted from above, at least only the drainage device needs to be disposed at the bottom.

The present invention solves the above-mentioned problems and the like, and provides a solid polymer electrolyte fuel cell which drains condensed water generated from a fuel cell efficiently from a lower part of a vehicle and is easy to mount on a vehicle. Is what you do.

[0010]

Means for Solving the Problems In order to solve the above technical problem, a technical measure taken in claim 1 of the present invention is to humidify at least one of an oxidizing gas and a fuel gas,
In a solid polymer electrolyte fuel cell in which these gases are supplied to both sides of the solid polymer electrolyte membrane and an oxidation reaction that produces a reaction product containing water is caused through the solid polymer electrolyte membrane, A discharge port is provided at the lowermost portion of the stack, and the discharge port is provided with a drain valve via a first discharge port and a flow path.
In the drain valve, a float that opens and closes a second drain port disposed below the drain valve is provided, and a float lower surface of the float is located below an opening position of the first discharge port of the discharge port. The solid polymer electrolyte fuel cell is provided, wherein the drain valve is provided near a wheel of a vehicle.

The effects of the first technical means are as follows.

That is, there is an effect that the condensed water generated from the fuel cell is efficiently drained from the lower part of the vehicle and is easily mounted on the vehicle.

[0013] In order to solve the above-mentioned technical problem, a technical measure taken in claim 2 of the present invention is characterized in that the drain valve is arranged within a width of a diameter of a wheel. Item 4. A solid polymer electrolyte fuel cell according to item 1.

The effects of the second technical means are as follows.

That is, if the diameter is greater than the diameter of the wheel, the drain valve 3 will protrude from the lower surface of the stack 2, and when the vehicle gets over a protrusion on the road surface or runs on a road surface having large undulations and undulations. Although it comes into contact with the road surface, the second technical means has an effect that it can be effectively solved.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described.
explain.

When the four fuel cell stacks 2 are mounted on a medium-sized vehicle 1, the layout in this case raises the position of the floor 11, which hinders the design of the interior space, and as a sedan-type passenger car, It is hard to hold. The minimum road clearance is necessary to avoid contact with the road surface when riding over a bumpy or wavy road when riding over a bump on the road surface, but the possibility of contact at that time is the same on the entire bottom of the vehicle Not a plane.

The position of the stack 2 of the present invention is arranged at the center position shown in FIG. 1 where the balance is the best, from the viewpoint of effective use and weight distribution in the interior space of the vehicle. in this case,
The load clearance is determined on the lower surface of the stack 2. When an effective drainage device is provided on the lower surface of the stack 2, it projects from the lower surface of the stack 2, and it is necessary to provide the stack at a higher position to secure the load clearance.

As shown in FIG. 1, the position with the four wheels 4 determines the height with respect to the road surface and the ease of contact. That is, the vicinity of the wheels 4 is less likely to contact the road surface than the center between the wheels 4.

Therefore, in the present invention, the drain valve 6, which needs to be provided at a low position, is disposed near the wheel 4, and the lower surface of the stack 2 is set at a position where a minimum load clearance is maintained.

Here, as shown in FIG. 2, the polymer electrolyte fuel cell is a fuel cell using a polymer electrolyte membrane (not shown) as an electrolyte. Electrodes are provided on both sides of the solid polymer electrolyte, and a fuel gas passage 7 or an oxidizing gas passage 8 is formed in the electrode. The unit cell thus configured is in the form of a thin film (or thin plate), and a large number of the unit cells are stacked to form the fuel cell stack 2.
It has been.

A fuel gas header and an oxidizing gas header are formed in the fuel cell stack 2, and the fuel cell gas and air of each unit cell are distributed and supplied from each header. A gas supply source is connected to each header via the fuel gas flow path 7 and the oxidizing gas flow path 8 formed of a pipe or a hose. This gas supply source is, for fuel gas, a hydrogen cylinder 9 and a humidifier (not shown) or a reformer (not shown) that generates hydrogen using methanol and water as raw materials. The oxidizing gas is, for example, an air compressor 10 that pressurizes and sends out air and a humidifier (not shown). Further, each header is connected to gas discharge channels 11 and 12 for discharging unreacted gas and reaction products.

In short, a solid polymer electrolyte fuel cell is
At least one of the oxidizing gas (air) and the fuel gas (hydrogen gas) is humidified through the air supply port 22, and these gases are supplied to both sides of the solid polymer electrolyte membrane, and a reaction containing water is generated. This is a structure in which an oxidation reaction that generates a substance is caused to occur via a solid polymer electrolyte membrane.

As shown in FIG. 2, an exhaust / exhaust port 21 is provided at the lowermost portion of the fuel cell stack 2, and a first drain port 211 for drainage is formed in the exhaust port 21. . Further, a first drain passage 5 is provided at the first outlet 211, and a drain valve 6 is provided at an end thereof.

At the bottom of the drain valve 6, a float 61 for opening and closing a second drain port 62 is provided. When water enters the space 63, the float 61 moves up and down to open and close the second discharge port 62. At this time, the float lower surface 611 of the float 61 that opens and closes the second discharge port 62 is connected to the first discharge port 21 of the discharge port 21.
1 is disposed below the opening position.

The float 61 has a disk shape as shown in the plan sectional view in the upper part of FIG. 4, and the space 63 has a drainage reservoir 631 formed at a connection portion of the first drainage channel 5. I have. The second discharge port 62 is provided substantially at the center of the disk-shaped float 61. A discharge port 65 is provided at the lower end of the second drain port 62. This discharge port 6
A check valve 64 is provided between the second discharge port 62 and the second discharge port 62.
Prevents drainage backflow.

Further, as shown in FIG. 1, the drain valve 6 is disposed near the wheel 4 of the vehicle, and is preferably disposed within a width L of the diameter of the wheel 4. If the width of the wheel is equal to or larger than the diameter L of the wheel, the drain valve 3 will protrude from the lower surface of the stack 2, and when the vehicle gets over a protrusion on the road surface or travels on a road surface with large undulations and undulations, Contact with

The second drain port 65 is provided with a second discharge channel 7, and the second drain channel 7 is connected to a drain tank 8.

[0029]

The present invention has the following effects.

That is, at least one of the oxidizing gas and the fuel gas is humidified, these gases are supplied to both sides of the solid polymer electrolyte membrane, and the oxidation reaction that produces a reaction product containing water is performed by the solid polymer electrolyte. In a solid polymer electrolyte fuel cell produced through an electrolyte membrane, an exhaust port is provided at the bottom of a fuel cell stack, and the exhaust port has a drain valve through a first exhaust port and a flow path. Is provided, and a float for opening and closing a second drain port provided below the drain valve is provided in the drain valve, and a float lower surface of the float is provided with an opening of the first discharge port of the discharge port. The drain valve is disposed below the position, and the drain valve is disposed near the wheel of the vehicle. The has been condensed water efficiently drains from the bottom of the vehicle, has the effect that easily mounted on a vehicle.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a fuel cell mounted on a vehicle of the present invention.

FIG. 2 is a schematic view showing the relationship between the fuel cell of the present invention and a sectional side view of a drain valve and the like.

FIG. 3 is a front view (left) and a side view (right) of the fuel cell stack of the present invention.

FIG. 4 is a plan sectional view (top) and a side sectional view (bottom) of the drain valve of the present invention.

[Explanation of symbols]

 Reference Signs List 21 discharge port 211 first discharge port 5 flow path 6 drain valve 62 second discharge port 61 float 211 first discharge port 4 wheels

Claims (2)

[Claims] At least one of an oxidizing gas and a fuel gas is humidified, and these gases are supplied to both sides of the solid polymer electrolyte membrane, and an oxidation reaction that produces a reaction product containing water is performed by the solid polymer. In a solid polymer electrolyte fuel cell produced through an electrolyte membrane, an exhaust port is provided at the bottom of the fuel cell stack,
The discharge port is provided with a drain valve through a first discharge port and a flow path, and a float that opens and closes a second drain port disposed below the drain valve is provided in the drain valve. Wherein the float lower surface of the float is disposed below an opening position of the first discharge port of the discharge port, and the drain valve is disposed near a wheel of a vehicle. Electrolyte fuel cell. 2. The solid polymer electrolyte fuel cell according to claim 1, wherein the drain valve is disposed within a width of a diameter of a wheel.