JP2009037991A - Mobile body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mobile body which efficiently feeds air being an oxidizer gas to a hollow cell, and is improved in energy conversion efficiency, in the mobile body such as a vehicle mounted with a fuel cell having the hollow cell. <P>SOLUTION: The mobile body is mounted with the fuel battery which comprises a cell stack 7 including two or more hollow cells 6 in which a fuel electrode is provided on the inner surface of a hollow electrolyte film while an air electrode is provided on the outer surface of it, with at least one end opened. The body comprises an air-intake hole 8 for taking air that is supplied to the air electrode of the hollow cell from the outside of the mobile body, an exhaust hole 9 for exhausting the air to the outside of the mobile body, an air-intake pipe 10, an exhaust pipe 11, and at least one blower 12 which is arranged at the air-intake pipe 10 and/or the exhaust pipe 11, to shape the stream of the air from the air-intake hole 8 to the exhaust hole 9. The air taken-in through the air-intake hole 8 is made to contact to with the air electrode provided on the outer surface of the hollow cell 6 in non-compressed state. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a moving body equipped with a fuel cell including a hollow cell.

  A fuel cell directly converts chemical energy into electrical energy by supplying fuel and an oxidant to two electrically connected electrodes and causing the fuel to be oxidized electrochemically. Unlike thermal power generation, fuel cells are not subject to the Carnot cycle, and thus exhibit high energy conversion efficiency. Solid polymer electrolyte fuel cells using a solid polymer electrolyte as an electrolyte have advantages such as easy miniaturization and operation at a low temperature. Has been.

In the solid polymer electrolyte fuel cell, when hydrogen is used as the fuel, the reaction of the formula (1) proceeds at the anode (fuel electrode).
H ₂ → 2H ⁺ + 2e ⁻ (1)
The electrons generated in the formula (1) reach the cathode (air electrode) after working with an external load via an external circuit. The proton generated in the formula (1) moves in the solid polymer electrolyte membrane from the hydrogen electrode side to the air electrode side by electroosmosis while being hydrated with water.

Further, when oxygen (air) is used as the oxidizing agent, the reaction of the formula (2) proceeds at the air electrode.
2H ⁺ + (1/2) O ₂ + 2e ⁻ → H ₂ O (2)
Water generated at the air electrode mainly passes through the gas diffusion layer and is discharged to the outside.
As described above, the fuel cell is a clean power generation device that has no emissions other than water.

Conventionally, as a solid polymer electrolyte fuel cell, a catalyst layer serving as a fuel electrode and an air electrode is provided on one surface of a planar solid polymer electrolyte membrane, and the obtained planar membrane / electrode Flat single cells have been developed in which gas diffusion layers are further provided on both sides of the joined body and sandwiched between planar separators. A plurality of such flat single cells are stacked and used as a fuel cell stack.
In order to improve the output density of the solid polymer electrolyte fuel cell, a proton conductive polymer membrane having a very thin film thickness is used as the solid polymer electrolyte membrane. This film thickness is already 100 μm or less, and even if a thinner electrolyte membrane is used to further improve the power density, the thickness of the single cell cannot be dramatically reduced from the present one. Similarly, the catalyst layer, the gas diffusion layer, the separator, and the like have been made thinner, but there is a limit to improving the output density per unit volume even by making all these members thinner. Therefore, it is expected that it will not be possible to meet the demand for miniaturization in the future.

Moreover, the sheet-like carbon material excellent in corrosivity is normally used for the said separator. In the separator, the carbon material itself is expensive, and a gas channel groove for uniformly distributing the fuel gas and the oxidant gas over the entire surface of the planar membrane / electrode assembly is formed by micromachining. Therefore, it has become very expensive. As a result, the manufacturing cost of the fuel cell was pushed up.
In addition to the above problems, for flat single cells, the periphery of single cells stacked in multiple layers should be reliably sealed so that fuel gas and oxidant gas do not leak from the gas flow path. However, there are a number of problems such as technical difficulties and a decrease in power generation efficiency due to deflection and deformation of the planar membrane / electrode assembly.

In recent years, solid polymer electrolyte fuel cells have been developed in which hollow cells each provided with electrodes on the inner surface side and outer surface side of a hollow electrolyte membrane are used as basic power generation units (for example, Patent Documents 1 to 5). Reference 4).
Since the fuel cell having such a hollow cell has a gas flow path in the hollow, a member corresponding to a separator used in a flat type is not necessary. Since different types of gas are supplied to the inner surface and the outer surface for power generation, it is not necessary to form a gas flow path. Therefore, cost reduction is expected in the manufacture. In addition, since the cell has a three-dimensional shape, the specific surface area with respect to the volume can be increased as compared with the flat single cell, and the power generation output density per volume can be expected to be improved.

JP-A-7-296840 JP 2000-299118 A JP 2004-319113 A JP 2004-158335 A

  Conventionally, many techniques other than the above-described Patent Documents 1 to 4 have been researched and developed for fuel cells including hollow cells. However, a specific mounting mode when a fuel cell is mounted on a moving body such as a vehicle and electricity obtained from the fuel cell is used as power is not sufficiently considered, and the advantages of the hollow cell are fully utilized. There is no moving body.

  The present invention has been accomplished in view of the above circumstances, and in a moving body such as a vehicle equipped with a fuel cell equipped with a hollow cell, air as an oxidant gas is efficiently supplied to the hollow cell. And it aims at providing the mobile body excellent in energy conversion efficiency.

The mobile body of the present invention is a mobile body equipped with a fuel cell, wherein the fuel cell is provided with a fuel electrode on the inner surface of the hollow electrolyte membrane and an air electrode on the outer surface of the hollow electrolyte membrane, and at least one end portion. Is provided with a cell stack including two or more hollow cells opened,
An air intake hole for taking in air to be supplied to the air electrode of the hollow cell from outside air of the moving body;
An exhaust hole for discharging air taken in from the intake hole and supplied to the air electrode of the hollow cell to the outside of the moving body;
An intake pipe for guiding the air taken in from the intake hole to the air electrode of the hollow cell;
An exhaust pipe for guiding the air supplied to the air electrode of the hollow cell to the exhaust hole;
And at least one blower disposed in the intake pipe and / or the exhaust pipe and capable of forming a flow of air from the intake hole to the exhaust hole,
The air taken in from the intake hole is brought into contact with an air electrode provided on the outer surface of the hollow cell in an uncompressed state.

  Conventionally, in a fuel cell, in order to supply a sufficient amount of oxygen to an air electrode, air as an oxidant has been supplied in a compressed state using a compressor or the like. In general, a fuel cell including a hollow cell in which an air electrode is provided outside a hollow electrolyte membrane is different from a fuel cell including a flat cell because of a difference in a gas flow path structure for supplying air and the like. The pressure loss during air supply is small, and the electrode area per unit volume can be increased due to the cell structure.

  The inventors of the present invention are able to improve the energy conversion efficiency in the moving body by taking advantage of the high air supply characteristics and the electrode area in the fuel cell including the hollow cell as described above. Obtained knowledge. And even if the air taken in from the outside air of the mobile body, typically the traveling wind, is brought into contact with the outer surface (air electrode) of the hollow cell mounted on the mobile body in an uncompressed state without using a compressor, It has been found that sufficient power can be obtained as a power source for the moving body, and if necessary, the moving body can be driven in accordance with the operating conditions of the moving body by forming an air flow with a blower such as a fan. It was.

Since the moving body of the present invention does not use a compressor or can reduce the frequency of use of the compressor, the moving body can be operated in comparison with a moving body equipped with a fuel cell that supplies compressed air of the compressor. The power generation efficiency is excellent because the required power can be reduced, the size of the compressor can be reduced, and the moving body can be reduced in size and weight. In addition, since low-pressure, low-flow air supply, which was difficult with a compressor, is possible, detailed operation control of the fuel cell and power generation in a low current region with high power generation efficiency can be achieved.
Further, the moving body of the present invention is provided with a blower in at least one position of the air flow path from the intake hole to the exhaust hole, and operates the blower as necessary to generate an air flow from the intake hole to the exhaust hole. By forming, it is possible to increase the efficiency of air intake from the air intake hole, so the amount of air taken in from the air intake hole can be controlled, and the amount of air supplied to the air electrode can be controlled. . In addition, there is an advantage that the degree of freedom in the opening direction of the intake holes is increased by installing the blower. The blower is preferably provided at least in the exhaust pipe from the viewpoint of low resistance of airflow flowing from the intake hole to the cell stack, and formation of a uniform airflow.

  Since air can be taken in more efficiently from the intake hole, the air flow path from the intake hole to the exhaust hole is in contrast to the movable body that is generated when the movable body moves forward. It is preferable that the traveling wind, which is a relative air flow, flows into the intake hole, contacts the air electrode of the hollow cell, and is discharged from the exhaust hole. By effectively using the traveling wind generated by the movement of the moving body, it is possible to efficiently take in outside air.

  When an air filter is provided in the intake pipe, it is possible to prevent dust and the like from entering from outside air taken in from the intake hole.

  It is preferable that a back pressure valve is provided in the exhaust pipe because it is possible to adjust the flow rate of the air flow on the outer surface of the hollow cell. In the case of a structure including a back pressure valve, the cross-sectional area of the intake hole increases the cross-sectional area of the exhaust hole, so that the flow rate of the air flow by the back pressure valve can be easily adjusted.

  From the viewpoint of efficiently supplying the air taken in from the intake holes to each of the plurality of hollow cells constituting the cell stack, the cell stack is in contact with the vertical surface in the air flow direction that contacts the outer surface of the hollow cell. It is preferable that the hollow cells are arranged so that a projected area is larger than a projected area with respect to a parallel plane in the air flow direction.

  Similarly, in order to efficiently supply the air taken in from the air intake holes to each of the plurality of hollow cells constituting the cell stack, the arrangement form of the hollow cells with respect to the air flow direction is important. From such a viewpoint, for example, in the cell stack, the hollow cells are preferably arranged such that the axial direction thereof is non-parallel to the flow direction of the air contacting the outer surface of the hollow cells. In particular, the hollow cell is preferably arranged so that its axial direction is substantially perpendicular to the flow direction of air contacting the outer surface of the hollow cell.

  Furthermore, from the same viewpoint, in the cell stack, it is preferable that two or more hollow cells are arranged in a staggered manner with respect to the air flow direction in contact with the outer surface of the hollow cell.

  Similarly, from the viewpoint of the efficiency of supplying air to the air electrode, the cell stack has a projected area with respect to a vertical plane in the air flow direction that contacts the outer surface of the hollow cell, from the cross-sectional area of the intake hole. Is preferably small.

The moving body of the present invention includes an accelerator opening detecting means for detecting an accelerator opening of the moving body, an air supply amount detecting means for detecting an air supply amount supplied to an air electrode of the hollow cell, A required amount of air supplied to the air electrode is determined based on information from the accelerator opening detecting means, and a shortage of the air supply amount with respect to the required air amount is calculated, and the air request is supplied to the air electrode. By supplying a blower control means for operating the blower according to a shortage of air so that the amount of air is supplied, the air requirement amount according to the output required for the fuel cell is supplied to the hollow cell. Is possible.
At this time, specifically, the air supply amount detection means is at least one of a gas flow meter provided in the intake pipe and / or the exhaust pipe or a speed detector for detecting the speed of the moving body. When one is provided, the air supply amount can be detected from the air flow rate and / or the moving body speed.

  Since the moving body of the present invention supplies the air taken in from the outside air to the fuel cell without being compressed, compared with the case where the air compressed using the compressor is supplied to the fuel cell, the amount of compressor operation and energy efficiency are improved. In addition, the weight and size of the compressor can be reduced. Furthermore, since low-pressure and low-flow air supply, which was difficult with a compressor, is possible, more complex and detailed operation control of the fuel cell and operation in a low current region with high power generation efficiency can be achieved.

The mobile body of the present invention is a mobile body equipped with a fuel cell, wherein the fuel cell is provided with a fuel electrode on the inner surface of the hollow electrolyte membrane and an air electrode on the outer surface of the hollow electrolyte membrane, and at least one end portion. Is provided with a cell stack including two or more hollow cells opened,
An air intake hole that takes in air to be supplied to the air electrode of the hollow cell from outside air, and an air that is taken in from the air intake hole and supplied to the air electrode of the hollow cell is outside the mobile body. An exhaust hole for discharging air to the air electrode of the hollow cell, and an exhaust gas for guiding the air supplied to the air electrode of the hollow cell to the exhaust hole A pipe, and at least one blower arranged in the intake pipe and / or the exhaust pipe and capable of forming a flow of air from the intake hole to the exhaust hole,
The air taken in from the intake hole is brought into contact with an air electrode provided on the outer surface of the hollow cell in an uncompressed state.

  Hereinafter, the moving body of the present invention will be described with reference to FIGS. In FIGS. 1 to 6, components and components are appropriately omitted in order to facilitate understanding of the structure of the moving body and the fuel cell.

In the following embodiment, the description will focus on a polymer electrolyte fuel cell using hydrogen gas as a fuel and air (oxygen) as an oxidant, but the present invention is not limited to the following embodiment. Absent.
Further, in the present invention, the moving body includes a power source such as an automobile, a train, a two-wheeled vehicle, a ship, and an aircraft, and is capable of self-propelled. In addition, even if the moving body moves using the mounted fuel cell as power, the moving body includes a power source other than the fuel cell and moves only with the power source or with the power source and the fuel cell as power. In addition, the fuel cell may not be used as a power source for movement.

FIG. 1 is a diagram showing an example of a mobile body (automobile) according to the present invention, and FIG. 2 is a conceptual diagram showing air supply and hydrogen supply to a cell stack.
1 and 2, the moving body 100 includes a fuel cell including a cell stack 7 having a plurality of hollow cells 6 (see FIGS. 3 to 4). The moving body 100 includes an intake hole 8 for taking in air supplied to the air electrode 3 of the hollow cell 6 constituting the cell stack 7 from outside air of the moving body 100, and a hollow type cell taken in from the intake hole 8. 6 and an exhaust hole 9 for discharging the air supplied to the air electrode 3 to the outside of the moving body 100. The air taken in from the intake hole 8 is guided to the outer surface (air electrode 3) of the hollow cell 6 by the intake pipe 10, and the air supplied to the air electrode 3 is guided to the exhaust hole 9 by the exhaust pipe 11. .

  An air flow path (air flow path) 13 that passes from the intake hole 8 through the cell stack 7 to the exhaust hole 9 is relative to the moving body 100 that is generated when the moving body 100 moves forward. A traveling wind, which is an airflow, flows into the intake hole 8, contacts the air electrode 3 of the hollow cell 6, and can be discharged from the exhaust hole 9. Therefore, when the moving body moves forward (moving direction in FIG. 1), the traveling wind efficiently flows into the air flow path 13 from the intake hole 8 and is supplied to the hollow cell 6.

  Further, a blower (fan) 12 is disposed in the exhaust pipe 11 and, if necessary, the blower 12 is driven by using a power other than an air flow (running wind) generated by the movement of the moving body 100 as power. The air in front of the air (upstream side of the air flow path) is sucked, sent to the rear of the blower 12, forcibly discharged from the discharge hole 9, and the airflow flowing from the intake hole 8 to the exhaust hole 9 in the air flow path 13 Can be formed.

  The inventors of the present invention provide a fuel cell having a hollow cell in which a fuel electrode is provided on the inner side of the hollow electrolyte membrane and an air electrode on the outer side (hereinafter also referred to as a hollow fuel cell), and a fuel having a flat cell. Compared with a battery (hereinafter sometimes referred to as a flat fuel cell), the pressure loss of air supplied to the air electrode is remarkably low, and the electrode area per unit volume can be increased. Focused on that. From these characteristics, a fuel cell having a hollow cell can obtain a sufficient amount of power generation without pumping air compressed using a compressor, unlike a fuel cell having a flat cell. I found it.

  That is, since the hollow fuel cell has a low pressure loss in the air supply, a sufficient amount of oxygen can be supplied to the air electrode even when non-compressed air is supplied. Since the area can be increased, sufficient performance can be obtained as the power generation amount per unit volume of the fuel cell even when the power generation amount per electrode unit area is low. In the present invention that makes full use of the characteristics of the hollow fuel cell as described above, the compressor is not used, the frequency of use of the compressor can be reduced, or the compression ratio of the compressor can be lowered. It is possible to reduce the size, reduce the size of the installed compressor, and reduce the size and weight of the moving body. As a result, the power generation efficiency of the fuel cell can be improved.

  In addition, according to the moving body of the present invention, it is possible to supply air at a low pressure and a low flow rate, which has been difficult with a fuel cell that supplies air by a compressor. Power generation in the basin can be realized.

  Furthermore, the moving body of the present invention is provided with a blower in at least one place of an air path (air flow path from the intake hole to the exhaust hole) that guides air to the cell stack and discharges it to the outside of the moving body. By operating the blower accordingly, it is possible to forcibly form an air flow flowing from the intake hole to the exhaust hole, so that the amount of air taken in from the intake hole can be controlled, and the air electrode The air supply amount can be controlled. In addition, since the forced air flow can be formed by installing the blower, there is an advantage that the degree of freedom in the opening direction of the intake holes is increased. Specifically, it is possible to take in the outside air of the moving body from the intake hole by the air flow forming action by the blower even from the intake hole that opens in a direction orthogonal to the moving direction of the moving body.

In the present invention, “the air is brought into contact with the outer surface of the hollow cell in an uncompressed state” means that the air flow flowing in from the intake hole is hollow in a state where the discharge pressure is increased and compressed through the compressor (compressor). Instead of contacting the outer surface of the mold cell, the air flow that flows from the intake hole to the exhaust hole does not go through the compressor, and the air pressure on the outer surface of the hollow cell is maintained at 110 kPa or less. It is to contact the outer surface of the cell. Compared with an air compression rate of 1.5 to 2 and a pressure of 150 kPa or more in a normal fuel cell, the compression rate and pressure are significantly smaller. Typically, the air flowing in from the intake hole is directly guided to the outer surface of the hollow cell, and is a wind that is an air flow or an air flow that is relative to the moving body caused by the movement of the moving body. Use airflow that naturally flows into the air intake holes, such as traveling wind. Even with an air flow that naturally flows into the air intake holes, even if the air supply is insufficient, it is sufficient to operate the blower or restrict the air flow rate by restricting the exhaust pipe diameter using the back pressure valve. Can be supplemented.
It should be noted that the present invention does not completely eliminate increasing or compressing the pressure of air supplied to the air electrode, and appropriately adding pressure as necessary, as long as the effects of the present invention are not impaired. Compression may be performed. A compressor may be installed and used temporarily when high output is desired for the fuel cell. Also, when a fan or other blower generates an airflow that flows from the intake hole and flows through the outer surface of the hollow cell, the pressure of the airflow increases depending on the structure of the air flow path from the intake hole to the exhaust hole. However, as compared with compressed air produced by a compressor, its pressure and compression ratio are small, and it requires less energy than compressor operation.

  The blower forms an air flow and does not compress gas (compression ratio of 2 or more) unlike a compressor. Specifically, a fan such as a sirocco fan or an axial fan (compression ratio 1). .1 or less).

The blower can be provided in the exhaust pipe as shown in FIG. 1, or in the intake pipe, and can be provided in both the exhaust pipe and the intake pipe. From the viewpoint of the uniformity of the airflow that flows around the hollow cells of the cell stack, the blower is preferably provided at least in the exhaust pipe. This is because the uniformity of the air flow that flows around the hollow cell increases, so that effects such as improved power generation efficiency of the cell stack and improved durability of the hollow cell can be obtained. In addition, by disposing the blower on the downstream side of the cell stack in the air flow path, it is possible to prevent the blower during non-operation from becoming a resistance to the air flow.
One or two or more blowers may be disposed in each of the intake pipe and the exhaust pipe.

  When the moving body is moving, the blower is idling due to the traveling wind flowing from the intake hole, but by operating it with a power source mounted on the moving body such as a fuel cell or battery, An airflow flowing to the discharge hole can be formed. When the air blower needs to control the air supply amount that achieves the amount of power generation required for the fuel cell, such as when the driver is accelerating, or when the moving body is stopped when the traveling wind cannot be used, May be operated as necessary to efficiently supply the gas to the outer surface (air electrode) of the hollow cell.

  It is preferable to control the operation of the blower (on / off) and the specific operation such as the rotational speed in accordance with the driving state of the moving body, the driver's intention to accelerate, and the like. Specific examples of the blower control system include the following. That is, an accelerator opening degree detecting means for detecting the accelerator opening degree of the moving body, an air supply amount detecting means for detecting an air supply amount supplied to the air electrode of the hollow cell, and the accelerator opening degree detecting means Based on the information, the required amount of air supplied to the air electrode of the hollow cell is determined, the shortage of the air supply amount with respect to the required air amount is calculated, and the required air amount is supplied to the air electrode. And a blower control means for operating the blower according to the air shortage.

The accelerator opening corresponds to the amount of depression of the accelerator pedal by the driver of the moving body, and represents the driver's intention to accelerate. Therefore, by detecting the accelerator opening, the driver's required driving force can be set. Based on the information of the accelerator opening detecting means, the fuel cell is obtained in order to obtain the power generation amount that achieves the required driving force. It is possible to determine the amount of air that needs to be supplied to the air electrode of the hollow cell to be formed (required air amount). On the other hand, the amount of air actually supplied to the air electrode of the hollow cell is detected by the air supply amount detection means, and a deficiency with respect to the air requirement amount (air requirement amount−air supply amount) is calculated. By operating the blower according to the shortage of air so that the required amount is supplied to the air electrode of the hollow cell, a power generation amount corresponding to the required driving force can be realized.
The means for detecting the amount of air actually supplied to the air electrode (air supply amount detecting means) is not particularly limited, and for example, a gas flow meter provided in the intake pipe and / or the exhaust pipe, or movement One example is a speed detector that detects the speed of the body. Each of the gas flow meter and the speed detector may be combined with other air supply amount detection means, or may be combined with the gas flow meter and the speed detector.
The specific configurations of the accelerator opening detection means and the blower control means are not limited, and can conform to general means.

  In the moving body of the present invention, the specific structure of the air flow path that allows the traveling wind to flow into the intake hole, contact the air electrode of the hollow cell, and be discharged from the discharge hole is as follows. There is no particular limitation as long as the traveling wind generated by the movement flows into the intake holes and can come into contact with the outer surface of the hollow cell disposed on the air flow path connected to the intake holes. From the viewpoint of efficient air intake from the intake holes, the intake holes are arranged in front of the moving body, the exhaust holes are arranged behind the moving body, and the air flow path from the intake holes to the exhaust holes is used to move the moving body. It is preferably formed along the direction, and typically, it is preferable that the flow path from the intake hole to the exhaust hole is a substantially linear flow path. Such an air flow path has a low air resistance, can efficiently take in the traveling wind from the intake holes, and can secure a flow rate of air supplied to the hollow cell.

  As shown in FIGS. 1 and 2, by providing the exhaust pipe 11 with the back pressure valve 15, it is possible to control the amount of air (flow rate) brought into contact with the hollow cell 6. For example, when the required current is low, the amount of oxygen required at the air electrode is small and the amount of moisture generated at the air electrode is small, so a small amount of air is supplied to the air electrode. If contact is made, moisture may be taken from the hollow cell, and on the contrary, the power generation performance of the hollow cell may be reduced. Therefore, by restricting the back pressure valve and reducing the diameter of the exhaust pipe, the amount of air flowing in from the intake hole is adjusted, and the flow rate of air contacting the hollow cell is lowered, while generating the required current, Drying of the hollow cell can be suppressed. Conversely, when the required current is high, it is possible to efficiently supply a large amount of oxygen to the air electrode by opening the back pressure valve and expanding the diameter of the exhaust pipe.

When the blower and the back pressure valve are provided in the exhaust pipe as shown in FIG. 1, the blower is provided with the back pressure valve upstream of the back pressure valve, that is, between the blower and the exhaust hole.
Further, in the form in which the back pressure valve is provided in the exhaust pipe, the controllability of the pipe diameter by the back pressure valve can be enhanced by making the cross-sectional area of the intake hole larger than the cross-sectional area of the exhaust hole. At this time, the ratio of the cross-sectional area of the intake hole and the cross-sectional area of the exhaust hole is not particularly limited, and may be set as appropriate.
In the case where at least one blower is arranged in each of the intake pipe and the exhaust pipe, the same effect as in the case where a back pressure valve is provided in the exhaust pipe is obtained by controlling the rotation speed of the blower in the intake pipe and the exhaust pipe. It is possible. Specifically, the flow rate of the air flowing around the cell stack can be reduced by increasing the rotational speed of the blower provided on the intake pipe than the rotational speed of the blower provided on the exhaust pipe.

The intake holes that serve as intake ports for the outside air and the exhaust holes that discharge the exhaust gas are not particularly limited in terms of arrangement position, number, cross-sectional shape, cross-sectional size, and the like. It is preferable that the hole is disposed behind the moving body, and an air flow path from the intake hole to the exhaust hole is formed along the moving direction of the moving body.
Since it is possible to efficiently take in the traveling wind generated when the moving body moves, the intake holes are preferably opened toward the front of the moving body. At this time, the opening toward the front of the moving body means that the air intake hole does not have to be parallel to the vertical plane with respect to the forward direction of the moving body, and the opening is opened with an inclination angle with respect to the vertical plane. It may be. From the same viewpoint, the intake hole is preferably provided in front of the moving body, but may be a side surface, a zenith portion, a bottom portion, or the like of the moving body. Even if it is on the side or rear of the moving body where it is difficult to capture the traveling wind, it is possible to take in air by the wind blowing on the side of the moving body or the operation of the blower when stopped, etc. An intake hole can be provided at the location. The installation of the intake holes at a plurality of locations makes it possible to efficiently use wind whose direction of flow is not determined as an oxidant for the fuel cell. The number of intake holes may be determined as appropriate depending on the size and arrangement position of the intake holes.

The size of the air intake hole is such that the projected area of the cell stack 7 with respect to the vertical surface in the flow direction of the air contacting the outer surface of the hollow cell 6 is smaller than the cross-sectional area of the air intake hole 8, thereby reducing the air to the hollow cell. Supply efficiency can be increased.
Here, the flow direction of air contacting the hollow cell outer surface of the cell stack is the direction of the flow of air flowing from the intake hole side to the exhaust hole side with respect to the cell stack arranged on the air flow path, Usually, it can be regarded as a direction connecting the front center portion on the intake hole side and the front center portion on the exhaust hole side of the cell stack in the air flow path. The projected area of the cell stack is the projected area of the space where the power generation region of the hollow cell is arranged. That is, in addition to the hollow cell, the cell stack includes a current collecting member, a cooling member, a protective member for the hollow cell, and the hollow cell includes a portion that does not contribute to power generation. It is not the projected area of the entire cell stack, but the projected area of the space where the power generation amount area of the hollow cell in which the contacted air can be used as an oxidant is arranged. The same applies to the projected area of the cell stack.

As shown in FIGS. 1 and 2, by providing the air filter 14 in the intake pipe 10, dust contained in the outside air can be removed, and deterioration of the hollow cell can be prevented. The air filter provided in the intake pipe is not particularly limited, and a general one can be used. Examples thereof include filter paper and sponge.
In addition to the above-described components, for example, a device such as a gas-liquid separator or a diluter 16 (see FIG. 2) can be disposed in the exhaust pipe. The gas-liquid separator separates and collects the moisture generated by the power generation of the fuel cell and the moisture in the air taken in from the intake holes from the exhaust gas, and sprays it on the air on the intake side of the air flow path, so that the hollow type The air supplied to the cell can be humidified. Also, when unreacted hydrogen gas supplied to the fuel electrode of the hollow cell is discharged from the exhaust hole, dilute the hydrogen gas concentration with a diluter before discharging to avoid problems in hydrogen discharge. Can do. Furthermore, a rainwater filter may be provided around the intake hole or in the intake pipe so that rainwater or the like does not enter from the intake hole. The structure of the gas-liquid separator, the diluter, and the rainwater filter is not particularly limited, and can conform to a conventional form.

  Next, the basic structure of the hollow cell provided in the fuel cell mounted on the moving body of the present invention will be described. 3 and 4 are schematic views showing one embodiment of a hollow cell used in the fuel cell of the present invention. 3 is a perspective view of the hollow cell, and FIG. 4 is a cross-sectional view of the hollow cell of FIG.

3 and 4, the hollow cell 6 includes a tubular solid polymer electrolyte membrane 1, a fuel electrode (anode) 2 provided on the inner surface side of the solid polymer electrolyte membrane 1, and air provided on the outer surface side. It has a pole (cathode) 3. Further, a columnar current collector is disposed on the surface of the fuel electrode 2 as an internal current collector (in this embodiment, a fuel electrode side (negative electrode side) current collector) 4, and an external current collector ( In the present embodiment, a spiral metal wire 5 a and a rod-shaped member 5 b are arranged as the air electrode side (positive electrode side current collector) 5. The external current collector 5 is arranged such that the rod-shaped members 5b are parallel to each other between adjacent hollow cells 6 and the plurality of hollow cells 6 and the plurality of rod-shaped members 5b are knitted by metal wires 5a. It is integrated so that it is embedded. Further, a groove 4 a that forms a flow path for the fuel gas is provided on the surface of the internal current collector 4.
Hydrogen gas, hollow cell on the hollow inner surface of the hollow cell having such a structure (substantially, the portion exposed to the inner surface side gas flow path formed by the groove 4a provided on the outer surface of the internal current collector 4) By allowing air to flow through the outer surface, fuel or air is supplied to the fuel electrode and the air electrode to generate electricity. In FIG. 3, the flow direction of the oxidant gas air is substantially perpendicular to the axial direction of the hollow cell. In the present specification, the term “substantially vertical” includes not only a completely vertical state but also a state that can be regarded as vertical (vertical state ± 3 °).

  The hollow cell 6 shown in FIG. 3 has hollow portions open at both ends, and the fuel gas flows from one end into the hollow and flows out from the other end. In the hollow cell 6, if the reaction gas can be sufficiently supplied to the inner surface side of the hollow electrolyte membrane, only one end of the hollow portion may be opened and the other end may be sealed. In particular, when a hydrogen electrode using hydrogen as a fuel is provided as the inner surface side electrode, hydrogen gas containing almost no non-reactive component can be supplied as a fuel gas into the hollow cell, and the diffusibility of hydrogen molecules can be reduced. Since it is high, it is possible to consume the reaction gas supplied into the hollow space, so that the reaction gas can be sufficiently supplied even within the hollow portion with one end sealed. Examples of the method of sealing one end of the hollow cell include a method of injecting resin or the like into the hollow one end, but is not particularly limited.

  3 and 4, the hollow cell 6 has a tubular electrolyte membrane. However, the hollow electrolyte membrane in the present invention is not limited to the tubular shape, and has a hollow portion, and the hollow portion has a fuel. As long as the reaction component necessary for the electrochemical reaction can be supplied to the electrode provided in the hollow space, it is sufficient.

  The inner diameter, outer diameter, length and the like of the tubular solid polymer electrolyte membrane 1 are not particularly limited, but the outer diameter of the tubular electrolyte membrane is preferably 0.01 to 10 mm, 0.1 More preferably, it is-1 mm, and it is especially preferable that it is 0.1-0.5 mm. At present, it is difficult to manufacture a tubular electrolyte membrane having an outer diameter of less than 0.01 mm due to technical problems. On the other hand, a tube electrolyte membrane having an outer diameter of more than 10 mm does not have a large surface area relative to the occupied volume. The output per unit volume of the obtained hollow cell may not be sufficiently obtained.

The electrolyte membrane is preferably thin from the viewpoint of improving proton conductivity. However, if the electrolyte membrane is too thin, the function of isolating gas is reduced, and the amount of aprotic hydrogen permeation is increased. However, compared to conventional fuel cells in which flat single cells for fuel cells are stacked, a fuel cell manufactured by collecting a large number of cells having a hollow shape can take a large electrode area, so a slightly thicker membrane is formed. Even when used, a sufficient output can be obtained. From this viewpoint, when a perfluorocarbon sulfonic acid resin film is used as the electrolyte membrane, the thickness of the electrolyte membrane is 10 to 100 μm, more preferably 50 to 60 μm, and still more preferably 50 to 55 μm.
Moreover, from the preferable range of said outer diameter and film thickness, the preferable range of an internal diameter is 0.01-10 mm, More preferably, it is 0.1-1 mm, More preferably, it is 0.1-0.5 mm. is there.

Since the fuel cell of the present invention has a hollow cell, the electrode area per unit volume can be made larger than that of a fuel cell having a flat cell. Therefore, as the solid polymer electrolyte membrane, perfluorocarbon sulfonic acid is used. Even when an electrolyte membrane that does not have a proton conductivity as high as that of a resin membrane is used, a fuel cell having a high output density per unit volume can be obtained. As the solid polymer electrolyte membrane, perfluorocarbon sulfonic acid resin and materials used for the electrolyte membrane of solid polymer fuel cells can be used. For example, fluorine other than perfluorocarbon sulfonic acid resin can be used. One kind of proton exchange groups such as at least sulfonic acid groups, phosphonic acid groups, and phosphoric acid groups, based on hydrocarbons such as polyolefins such as polystyrene ion exchange resins and polystyrene cation exchange membranes having sulfonic acid groups A complex of a basic polymer and a strong acid, which is disclosed in Japanese Patent Application Laid-Open No. 11-503262, etc., in which a basic polymer such as polybenzimidazole, polypyrimidine, and polybenzoxazole is doped with a strong acid And polymer electrolytes such as solid polymer electrolytes.
A solid polymer electrolyte membrane using such an electrolyte should be reinforced with a perfluorocarbon polymer in the form of a fibril, a fabric, a non-fabric, or a porous sheet, or the membrane surface can be coated with an inorganic oxide or metal. It can also be reinforced. Examples of the perfluorocarbon sulfonic acid resin membrane include commercially available products such as Nafion (trade name) manufactured by DuPont, USA and Flemion (trade name) manufactured by Asahi Glass.

In the present embodiment, a perfluorocarbon sulfonic acid resin membrane, which is a kind of proton conductive membrane and one of solid polymer electrolyte membranes, is described as an electrolyte membrane, but it is used in the fuel cell of the present invention. The electrolyte membrane to be used is not particularly limited, and may be proton-conductive or other ion-conductive such as hydroxide ion or oxide ion (O ²⁻ ). The proton conductive electrolyte membrane is not limited to the solid polymer electrolyte membrane as described above, but a porous electrolyte plate impregnated with an aqueous phosphoric acid solution, a proton conductor made of porous glass, or a hydrogel Phosphated phosphate glass, organic-inorganic hybrid proton conductive membrane having proton conductive functional groups introduced into the surface and pores of nanoporous glass, inorganic metal fiber reinforced electrolyte polymer, etc. can be used. .

Each of the electrodes 2 and 3 provided on the inner and outer surfaces of the electrolyte membrane 1 can be formed using an electrode material used in a polymer electrolyte fuel cell. Usually, only the catalyst layer or an electrode formed by laminating a catalyst layer and a gas diffusion layer in order from the electrolyte membrane side is used.
The catalyst layer includes catalyst particles, and may further include a proton conductive material for increasing the utilization efficiency of the catalyst particles. As the proton conductive material, those used as the material for the electrolyte membrane can be used. As the catalyst particles, catalyst particles in which a catalyst component is supported on a conductive material such as a carbon material such as carbonaceous particles or carbonaceous fibers are preferably used. Since the fuel cell of the present invention has a hollow cell, the electrode area per unit volume can be made larger than that of a fuel cell having a flat cell. Therefore, a catalyst component that is not as catalytic as platinum is used. However, a fuel cell having a high output density per unit volume can be obtained.

  The catalyst component is not particularly limited as long as it has a catalytic action with respect to the hydrogen oxidation reaction at the fuel electrode and the oxygen reduction reaction at the air electrode. For example, platinum (Pt), ruthenium (Ru), iridium ( Ir), rhodium (Rh), palladium (Pd), osmium (Os), tungsten (W), lead (Pb), iron (Fe), chromium (Cr), cobalt (Co), nickel (Ni), manganese ( Mn), vanadium (V), molybdenum (Mo), gallium (Ga), aluminum (Al) and other metals, or alloys thereof can be selected. Pt and an alloy made of Pt and another metal such as Ru are preferable.

As the gas diffusion layer, a porous conductive material mainly composed of a carbon material such as carbonaceous particles and / or carbonaceous fibers can be used. The sizes of the carbonaceous particles and the carbonaceous fibers may be appropriately selected in consideration of the dispersibility in the solution when the gas diffusion layer is produced, the drainage property of the obtained gas diffusion layer, and the like. The gas diffusion layer is, for example, polytetrafluoroethylene, polyvinylidene fluoride (PVDF), polytetrafluoroethylene, perfluorocarbon alkoxyalkane, ethylene-tetrafluoroethylene polymer, or these from the point of improving the drainage of moisture such as generated water It is preferable to perform water-repellent processing by impregnating a mixture of the above or the like or forming a water-repellent layer using these substances.
In addition, the structure of each electrode provided in the inner surface and outer surface of a hollow electrolyte membrane, the material used for an electrode, etc. may be the same, and may differ.

  The method of providing a pair of electrodes on the inner and outer surfaces of the tubular electrolyte membrane is not particularly limited. For example, the following methods (1) to (3) may be mentioned. That is, (1) First, a tubular electrolyte membrane is prepared. The method for preparing the tubular electrolyte membrane is not particularly limited, and a commercially available electrolyte membrane formed in a tubular shape can also be used. Then, a solution containing electrolyte and catalyst particles is applied and dried on the inner and outer surfaces of the tubular electrolyte membrane to form a catalyst layer, and carbonaceous particles and / or carbonaceous fibers are contained on the two catalyst layers. A method of forming a gas diffusion layer by applying and drying a solution is mentioned. At this time, the catalyst layer and the gas diffusion layer are formed so that a hollow portion exists on the inner surface of the gas diffusion layer formed on the inner surface side of the electrolyte membrane.

Or (2) First, a carbon material such as carbonaceous particles and / or carbonaceous fibers and formed into a tube shape (tubular carbonaceous material) is used as a gas diffusion layer of the inner surface side electrode (fuel electrode). Then, a solution containing an electrolyte and catalyst particles is applied to the outer surface of the gas diffusion layer and dried to form a fuel electrode side catalyst layer to produce a fuel electrode, and then a solution containing an electrolyte is applied to the outer surface of the catalyst layer. There is also a method in which an electrolyte membrane layer is applied and dried, and a catalyst layer and a gas diffusion layer of an air electrode (outer surface side electrode) are provided on the outer surface of the electrolyte membrane layer. The tubular carbonaceous material can be obtained, for example, by dispersing a carbon material such as carbonaceous particles and an epoxy and / or phenolic resin in a solvent to form a tubular shape, thermosetting, and firing.
Alternatively, (3) in the above method (2), there is a method in which a conductive porous sheet is wound around the rod-shaped internal current collector to form a gas diffusion layer of the inner surface side electrode.

In addition, the solvent used when forming the electrolyte membrane, the catalyst layer, and the gas diffusion layer may be appropriately selected according to the material to be dispersed and / or dissolved, and the coating method when forming each layer is also as follows. It can be appropriately selected from various methods such as spraying and screen printing.
The hollow cell having a hollow shape used in the fuel cell of the present invention is not limited to the configuration exemplified above, and a layer other than the catalyst layer and the gas diffusion layer is provided for the purpose of enhancing the function of the hollow cell. Also good.

3 and 4, the internal current collector 4 connected to the inner surface side electrode 2 of the hollow cell 6 is a columnar current collector having an outer diameter at least partially in contact with the inner peripheral surface of the inner surface side electrode. Grooves 4a extending in the axial direction (longitudinal direction) of the hollow cell are formed on the outer peripheral surface. Or what has a shape which forms the clearance gap through which reaction gas can circulate between the inner surfaces of the inner surface side electrodes can also be used as an internal current collector. A gap (groove) with the inner surface side electrode serves as a hollow gas passage for supplying fuel gas. As the groove, at least one groove extending in the axial direction (longitudinal direction) of the hollow cell is necessary, and grooves having various patterns or directions are formed on the outer peripheral surface of the internal current collector as necessary. .
In addition, the external current collector 5 connected to the outer surface side electrode 3 of the hollow cell includes a metal wire 5a that can secure a contact area with the electrode while securing an air supply amount to the outer surface side electrode, The current collection efficiency can be increased by combining the rod-shaped member 5b that further increases the current collection efficiency of the wire. Further, as shown in FIG. 3 and FIG. 4, the hollow cell may be cooled by making the rod-like member 5 b have a hollow shape and circulating a cooling medium in the hollow 5 c.

  As the metal used as the internal current collector or the external current collector, for example, at least one metal selected from Al, Cu, Fe, Ni, Cr, Ta, Ti, Zr, Sm, In, etc., Or their alloys such as stainless steel are preferred. Further, the surface thereof may be coated with Au, Pt, conductive resin or the like. Of these, stainless steel and titanium are preferred because of their excellent corrosion resistance. The thickness of the wire, the winding method, the thickness of the rod-shaped member, etc. are not particularly limited.

The internal current collector 4 and the external current collector 5 are not particularly limited, and the shape thereof is arbitrary as long as it is made of an electrically conductive material. Specifically, in addition to a columnar shape, a wire shape, a rod shape, a linear shape or a cylindrical shape may be used. For example, a spring-shaped metal wire, a metal foil, a sheet material such as a metal sheet or a carbon sheet, or the like can be applied. .
These current collectors are fixed on the electrodes with a conductive adhesive such as a carbon-based adhesive or an Ag paste as necessary.

The fuel cell mounted on the moving body of the present invention includes the hollow cell as described above, and usually two or more cell stacks in which two or more hollow cells are connected in parallel or in series are arranged in parallel. Or connect in series. A fuel supply method, a hollow cell current collection / connection method, and a cell stack current collection / connection method are not particularly limited.
In the cell stack including a plurality of hollow cells, the arrangement of the hollow cells is not particularly limited and may be set as appropriate. In order to efficiently supply air to the air electrode provided on the outer surface of the hollow cell, the projected area of the cell stack with respect to the vertical plane in the air flow direction that contacts the outer surface of the hollow cell is determined by the flow of the air. It is preferable that the hollow cells are arranged so as to be larger than a projected area with respect to a parallel plane in the direction.

Further, as shown in FIG. 5, by arranging the axial direction of the hollow cell so as to be non-parallel (see 5A in FIG. 5) with respect to the flow direction of the air contacting the outer surface of the hollow cell. The air supply efficiency for the air electrode can be improved. In particular, it is preferable that the axial direction of the hollow cell is substantially perpendicular to the air flow direction (see 5B in FIG. 5).
Further, in the cell stack, when a plurality of hollow cells are arranged in a staggered manner in the air flow direction as shown in 6A of FIG. 6, they are linearly arranged in the air flow direction as shown in 6B of FIG. Compared with, it is also possible to increase the air supply efficiency to the hollow cell. The specific form of the staggered arrangement is not particularly limited and may be set as appropriate.

It is a figure which shows one example of the moving body concerning this invention. It is a conceptual diagram which shows the air supply and hydrogen supply to the cell stack in the moving body of this invention. It is a perspective view of the hollow type cell (an example) which constitutes the cell stack of the fuel cell carried in the mobile object of the present invention. It is sectional drawing of the hollow type cell of FIG. It is a figure explaining the example of arrangement | positioning form of the hollow cell in the cell stack of the fuel cell mounted in the moving body of this invention. It is a figure explaining the example of arrangement | positioning form of the hollow cell in the cell stack of the fuel cell mounted in the moving body of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Hollow electrolyte membrane 2 ... Fuel electrode (inner surface side electrode)
3 ... Air electrode (outside electrode)
4 ... Fuel electrode side current collector (internal current collector)
4a ... Groove 5 ... Air electrode side current collector (external current collector)
5a ... wire 5b ... rod-like member 5c ... hollow 6 ... hollow cell 7 ... cell stack 8 ... intake hole 9 ... exhaust hole 10 ... intake pipe 11 ... exhaust pipe 12 ... blower 13 ... air flow path 14 ... air filter 15 ... back Pressure valve 16 ... Diluter

Claims (13)

A mobile body equipped with a fuel cell,
The fuel cell includes a cell stack including two or more hollow cells in which a fuel electrode is provided on an inner surface of a hollow electrolyte membrane and an air electrode is provided on an outer surface of the hollow electrolyte membrane, and at least one end portion is open. And
An air intake hole for taking in air to be supplied to the air electrode of the hollow cell from outside air of the moving body;
An exhaust hole for discharging air taken in from the intake hole and supplied to the air electrode of the hollow cell to the outside of the moving body;
An intake pipe for guiding the air taken in from the intake hole to the air electrode of the hollow cell;
An exhaust pipe for guiding the air supplied to the air electrode of the hollow cell to the exhaust hole;
At least one blower arranged in the intake pipe and / or the exhaust pipe and capable of forming an air flow from the intake hole to the exhaust hole;
With
The moving body, wherein the air taken in from the intake hole is brought into contact with an air electrode provided on an outer surface of the hollow cell in an uncompressed state.   In the air flow path from the intake hole to the exhaust hole, traveling wind, which is an airflow relative to the moving body generated when the moving body moves forward, flows into the intake hole and The moving body according to claim 1, wherein the moving body has a structure that contacts an air electrode of a hollow cell and can be discharged from the exhaust hole.   The moving body according to claim 1 or 2, wherein the blower is provided at least in the exhaust pipe.   The moving body according to claim 1, wherein an air filter is provided in the intake pipe.   The moving body according to claim 1, wherein a back pressure valve is provided in the exhaust pipe.   The moving body according to claim 5, wherein a cross-sectional area of the intake hole is larger than a cross-sectional area of the exhaust hole.   In the cell stack, the hollow cells are arranged so that a projected area with respect to a vertical plane in the air flow direction contacting the outer surface of the hollow cells is larger than a projected area with respect to a parallel plane in the air flow direction. The moving body according to any one of claims 1 to 6, wherein   The cell stack according to any one of claims 1 to 7, wherein the hollow cell is arranged so that an axial direction thereof is non-parallel to a flow direction of air contacting an outer surface of the hollow cell. The moving body described in 1.   The mobile body according to claim 8, wherein the hollow cell is arranged such that an axial direction thereof is substantially perpendicular to a flow direction of air contacting an outer surface of the hollow cell.   In the said cell stack, the said hollow cell is a mobile body in any one of Claims 1 thru | or 9 arrange | positioned with respect to the distribution direction of the air which contacts the outer surface of this hollow cell.   The mobile body according to any one of claims 1 to 10, wherein the cell stack has a projected area with respect to a vertical plane in a flow direction of air contacting an outer surface of the hollow cell that is smaller than a cross-sectional area of the intake hole. Accelerator opening detection means for detecting the accelerator opening of the moving body;
An air supply amount detecting means for detecting an air supply amount supplied to the air electrode of the hollow cell;
A required amount of air to be supplied to the air electrode is determined based on information from the accelerator opening detecting means, a shortage of the air supply amount with respect to the required air amount is calculated, and the air electrode is supplied to the air electrode. Blower control means for operating the blower according to the air shortage so that the required amount is supplied,
The mobile body according to claim 1, comprising:   The air supply amount detection means includes at least one of a gas flow meter provided in the intake pipe and / or the exhaust pipe, or a speed detector for detecting the speed of the moving body. The moving body described.

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