JP4304972B2 - Air supply device for fuel cell - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an air supply device for a fuel cell, and more particularly to an air supply device for an in-vehicle fuel cell.
[0002]
[Prior art]
In a fuel cell, a fuel gas and an oxidant gas are electrochemically reacted through an electrolyte, and electric energy is directly taken out between electrodes provided on both surfaces of the electrolyte. In particular, a polymer electrolyte fuel cell using a polymer electrolyte has attracted attention as a power source for electric vehicles because of its low operating temperature and easy handling.
[0003]
That is, a fuel cell vehicle using a fuel cell as a power source is equipped with a hydrogen storage device such as a high-pressure hydrogen tank or a hydrogen storage alloy tank in the vehicle, and hydrogen and air supplied from the fuel cell are sent to the fuel cell to react with each other. It is an ultimate clean vehicle that drives the motor connected to the drive wheels with the electric energy taken out from the fuel cell, and the only exhaust material is water.
[0004]
As a conventional technique for supplying air to a fuel cell, there is a method of driving a fluid machine such as a compressor or a blower with an electric motor, which is disclosed in Patent Document 1, for example. According to this prior art, an air cleaner is installed on the upstream side of the compressor and a filter is also installed on the downstream side of the compressor.
[0005]
In these fluid machines such as compressors, grease and lubricating oil are used for lubricating bearings and drive gears. Therefore, if the filter is downstream of the compressor, even if the fluid machine is damaged, oil such as lubricating oil flowing out from the fluid machine can be prevented from being adsorbed by the filter and flowing into the fuel cell main body.
[0006]
[Patent Document 1]
JP 2002-110213 A (6th page, FIG. 4)
[0007]
[Problems to be solved by the invention]
When a fuel cell power plant is used as a drive source for a vehicle, there are many cases where an in-vehicle space is limited, and it is not easy to mount such a series of air supply parts in consideration of all vehicle conditions.
[0008]
For example, the filter and silencer placed on the intake side (upstream) of the compressor can be made of easily deformable resin parts, so that the crashable zone in the motor room in front of the vehicle to meet the collision safety standards It is also possible to arrange in.
[0009]
However, when supplying high-pressure air to the fuel cell, components such as a filter disposed on the high-pressure side downstream of the compressor must be designed as a pressurized container. For this reason, these parts are metal parts that are not easily deformed, and there are problems in layout such as difficulty in arranging them in the crushable zone, and problems in that the weight increases.
[0010]
From this point of view, it is desirable to place the filter upstream of the compressor. However, if the filter is placed upstream of the compressor, it will not be possible to prevent the oil that flows out if the compressor is damaged from flowing into the fuel cell. There is a problem in that the oil component that flows in may reduce the performance of the fuel cell body.
[0011]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides an air supply device that takes in air and supplies it to a fuel cell, an electric motor that drives the air supply device, a filter that is disposed on the intake side of the air supply device, and an air In the fuel cell air supply apparatus including a silencer disposed immediately after discharge from the feeder, the silencer is provided on an expansion chamber, an eddy current generator provided at the expansion chamber inlet, and an expansion chamber wall. The gist is that the silencer has a function of adsorbing oil in the air by including a sound absorbing material that can also adsorb oil .
In order to solve the above problems, the present invention provides an air supply device that takes in air and supplies it to the fuel cell, an electric motor that drives the air supply device, a filter that is disposed on the intake side of the air supply device, In a fuel cell air supply apparatus including a silencer disposed immediately after discharge of an air supply machine, the silencer is provided in an expansion chamber, an expansion chamber inlet and an outlet, and the air flow direction in the expansion chamber is determined. The gist is that the silencer has an oil adsorbing function in the air by including an insertion tube arranged so as to be substantially reversed at least once and a sound absorbing material provided on the expansion chamber wall and capable of adsorbing oil. To do.
[0012]
【The invention's effect】
According to the present invention, since the silencer disposed on the discharge side of the air supply unit has a function of adsorbing oil in the air, the air supply is provided with a structure having no filter or oil separator downstream of the air supply unit. There is an effect that it is possible to prevent the oil from flowing into the fuel cell when the oil discharged normally due to breakage of the fine oil or air supply device normally discharged from the machine.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
[First Embodiment]
Next, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic diagram illustrating the configuration of an air system of a fuel cell vehicle to which a fuel cell air supply device according to the present invention is applied. In the figure, the air system of the fuel cell vehicle includes a dust filter 3 that physically removes solids and droplets such as dust and salt in the air, and nitrogen oxides and sulfides from the air that has passed through the dust filter 3. A chemical filter 4 that adsorbs harmful gases by chemical change, a first silencer 5 that reduces intake noise, an intake pipe 6, a compressor 1 that compresses air, and an electric motor 2 that drives the compressor 1, A high-pressure pipe 7, a second silencer 8 that reduces pulsation noise of high-pressure air discharged from the compressor 1 and adsorbs oil from the high-pressure air, an aftercooler 9 that cools the high-pressure air, and a humidifier 10; , A fuel cell body 11 having a cathode 12 and an anode 13, a pressure control valve 14 for adjusting the pressure of the cathode 12, air discharged from the pressure control valve 14, and an anode off gas (not shown) A combustor 15 that combusts hydrogen supplied from a pipe, a heat exchanger 16 that lowers the exhaust gas temperature of the combustor 15, a third silencer 17 that reduces noise of the exhaust gas after heat exchange, and an exhaust pipe 18. It has.
[0014]
In FIG. 1, a hydrogen supply and circulation system for supplying hydrogen to the anode 13 of the fuel cell main body 11, a pure water system for supplying pure water to the humidifier 10, and recovering pure water from the heat exchanger 16, The cooling system and the like are not shown. Similarly, a power source, an inverter and the like for driving the electric motor 2 are not shown.
[0015]
Although not particularly limited, the compressor 1, the electric motor 2, the dust filter 3, the chemical filter 4, the first silencer 5, the intake pipe 6, the high pressure pipe 7, and the second silencer 8 are provided in a motor room provided in front of the vehicle. It is preferable to arrange in. This motor room corresponds to the engine room of the internal combustion engine vehicle, and is called a motor room because a motor for driving the vehicle is arranged instead of the engine. Furthermore, the components below the after-cooler 9 are disposed, for example, under the floor of the vehicle.
[0016]
The dust filter 3 and the chemical filter 4 constitute a filter that purifies the air supplied to the compressor 1. The compressor 1 takes in purified air from the intake pipe 6 to which the first silencer 5 is connected, and sends the compressed air to the high-pressure pipe 7. The compressed and heated air is cooled by the aftercooler 9 through the second silencer 8 that also serves as an oil adsorber, and is supplied to the cathode 12 of the fuel cell body 11 via the humidifier 10.
[0017]
Hydrogen gas is stored in a high-pressure tank or the like and supplied to the anode 13 of the fuel cell main body 11, but details thereof are omitted here. In the fuel cell main body 11, electric power and water are generated by supplying air and hydrogen, which are omitted in the figure.
[0018]
Exhaust gas from the cathode 12 is exhausted from an exhaust pipe 18 via a pressure control valve 14, a combustor 15 (used only when starting the system and purging hydrogen gas), a heat exchanger 16, and a third silencer 17. The
[0019]
FIG. 2 is a cross-sectional view showing the structure of the second silencer 8 that also serves as an oil adsorber. The second silencer 8 includes an inlet pipe 21 and an outlet pipe 22 that are provided through the silencer case 20 in the front and rear directions, an extension chamber 23, a sound absorbing material 24 provided on the inner wall of the extension chamber 23, and an inlet pipe 22. And an installed eddy current generator 25.
[0020]
The sound absorbing material 24 also has an oil adsorbing function. As the sound absorbing material 24, a sound absorbing adsorbent using glass wool, stainless steel wool or the like may be used. However, vegetable fiber or chemical fiber mainly responsible for oil adsorbing function is mixed in glass wool, stainless steel wool or the like mainly responsible for sound absorbing properties, Or what laminated these can be utilized.
[0021]
FIG. 3 is a diagram for explaining the separation action of air and oil when the air and oil flow into the second silencer 8 in a mixed flow state for reasons such as outflow of lubricating oil due to compressor failure.
[0022]
First, a fluid in which air 26 and oil 27 are mixed flows into the inlet pipe 21. In FIG. 3, the air 26 is indicated by a solid line arrow, and the oil component (mist, droplet) 27 is indicated by a broken line arrow. A spiral fin is formed in the vortex generator 25 provided at the inlet, and a strong swirl flow is generated when the inflowing fluid passes through the vortex generator 25. The oil 27 contained in the fluid is scattered toward the inner wall of the expansion chamber 23 by the centrifugal force caused by the swirling flow, and is adsorbed by the sound absorbing material 24.
On the other hand, the air 26 is discharged from the outlet pipe 22 without being affected by the centrifugal force.
[0023]
As described above, according to the present embodiment, by providing the second silencer 8 with the oil adsorption function, even when the filter and the oil separator downstream of the compressor are omitted, the oil spill due to the compressor breakage or the like is caused to the fuel cell. The filter can be prevented from reaching, and since the filter is installed upstream of the air supply machine, no large pressure is applied, so that the filter can be reduced in size and weight. Therefore, there is an effect that it is possible to achieve both the reliability of the air supply device and the reduction in size and weight.
[0024]
Further, since the rigidity of the filter can be reduced, the dust filter and the chemical filter can be used as a shock absorber at the time of a collision by arranging the dust filter and the chemical filter in the motor room in front of the vehicle.
[0025]
Here, the oil absorption function of the silencer is capable of sufficiently adsorbing the components even if the air supply unit breaks for some reason and as a result the internal lubricating oil components scatter or flow out to the downstream side of the air supply unit. By having a capacity, it is possible to prevent oil that cannot be adsorbed from flowing out into the fuel cell, and to ensure reliability when the air supply machine is damaged.
[0026]
In addition, the second silencer is equipped with the expansion chamber, the eddy current generator provided at the expansion chamber inlet, and the sound absorbing material that can be adsorbed on the expansion chamber wall. The oil component can be adsorbed on the sound absorbing material on the expansion chamber wall by the centrifugal force, and the oil component can be adsorbed efficiently with a simple structure.
[0027]
Moreover, since the dust filter and the chemical filter are provided, the purity of the air supplied to the fuel cell can be maintained at a high level.
[0028]
During normal operation, the oil content of the air supply unit contained in the air supplied from the air supply unit is kept to a very small amount that does not affect the fuel cell. There is no need to provide a filter or an oil separator downstream of the air supply machine, and both a reduction in size and weight and reliability during normal operation can be ensured.
[0029]
[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIGS. The system configuration of the second embodiment is the same as that of the first embodiment shown in FIG.
FIG. 4 is a cross-sectional view showing the structure of the second embodiment of the second silencer 8 that also serves as an oil adsorber. The second silencer 8 includes a silencer case 30, an inlet insertion tube 31, an outlet insertion tube 32, an expansion chamber 33, and a sound absorbing material 34 provided on the expansion chamber wall. The inlet insertion tube 31 and the outlet insertion tube 32 are arranged such that their axial centers are shifted and the ends of the tubes are close to each other. The sound absorbing material 34 also has an oil adsorbing function, and the thickness t2 of the sound absorbing material 34 at the facing surface of the inlet insertion tube 31 and the facing surface of the outlet insertion tube 32 is thicker than the thickness t1 of the sound absorbing material 34 at other portions. (T2> t1). The material of the sound absorbing material 34 is the same as that of the sound absorbing material 24 of the first embodiment.
[0030]
FIG. 5 is a diagram for explaining the separation action of air and oil when air and oil flow into the second silencer 8 in a mixed flow state for reasons such as outflow of lubricating oil due to compressor breakage.
[0031]
First, a fluid in which air 36 and oil 37 are mixed flows into the inlet insertion tube 31. In FIG. 5, as in FIG. 3, the air 36 is indicated by a solid line arrow, and the oil component (mist, droplet) 37 is indicated by a broken line arrow. Since the inlet insertion pipe 31 and the outlet insertion pipe 32 are arranged alternately, the flow of the air 36 is exhausted with a large meandering as indicated by the solid arrow shown in the expansion chamber 33 with turbulent flow.
[0032]
On the other hand, since the oil component 37 has an inertia larger than that of air, most of the oil component 37 travels straight and collides with the sound-absorbing material 34 facing the surface, and is absorbed there. Even in this configuration, substantially the same effect as the first embodiment can be obtained.
[0033]
As described above, in the present embodiment, the second silencer includes the extension chamber, the insertion tube provided at the entrance and the exit of the extension chamber, and arranged so as to substantially reverse the air flow direction once in the extension chamber, Since the sound absorbing material provided on the indoor wall and capable of adsorbing oil is provided, the oil can be adsorbed without impairing the performance as a silencer.
[0034]
In addition, since the thickness or amount of the sound absorbing material is increased relative to the other of the extended interior wall facing the insertion tube, the sound absorbing adsorbent is focused on the surface of the insertion tube where oil is most likely to scatter. It can arrange | position and can heighten the adsorption effect more.
[0035]
Although not shown in the present embodiment, by providing a resonance element such as a Helmholtz resonator in the silencer, it is possible to improve the silencing characteristics in a band including the resonance frequency. In addition, the installation of the resonance element makes the air flow more complicated, and has a slight advantage on the adsorption of oil.
[Brief description of the drawings]
FIG. 1 is a diagram showing an outline of a system according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view showing the structure of a silencer that also serves as an oil adsorber in the first embodiment of the present invention.
FIG. 3 is a diagram for explaining the oil-air separation action of the silencer shown in FIG. 2;
FIG. 4 is a cross-sectional view showing the structure of a silencer that also serves as an oil adsorber in a second embodiment of the present invention.
FIG. 5 is a diagram for explaining an oil-air separation action of the silencer shown in FIG. 4;
[Explanation of symbols]
8 ... second silencer 20 ... silencer case 21 ... inlet pipe 22 ... outlet pipe 23 ... expansion chamber 24 ... sound absorbing material 25 ... vortex generator 26 ... air 27 ... oil content

Claims (7)

An air supply machine that takes in air and supplies it to the fuel cell;
An electric motor that drives the air supply;
A filter disposed on the intake side of the air supply machine;
In an air supply device for a fuel cell composed of a silencer arranged immediately after discharge of an air supply machine,
The silencer includes an expansion chamber, a vortex generator provided at the entrance of the expansion chamber, and a sound absorbing material provided on the expansion chamber wall and capable of adsorbing oil.
An air supply device for a fuel cell, wherein the silencer has a function of adsorbing oil in air. An air supply machine that takes in air and supplies it to the fuel cell;
  An electric motor that drives the air supply;
  A filter disposed on the intake side of the air supply machine;
  In an air supply device for a fuel cell composed of a silencer arranged immediately after discharge of an air supply machine,
  The silencer includes an extension chamber, an insertion pipe provided at the entrance and exit of the extension chamber and disposed so as to substantially reverse the air flow direction at least once in the extension chamber, and an oil absorption on the extension chamber wall. By providing possible sound absorbing material,
  An air supply device for a fuel cell, wherein the silencer has a function of adsorbing oil in air. The said sound-absorbing material is characterized by mixing or stratifying vegetable fibers or chemical fibers mainly responsible for oil adsorption in glass wool or stainless steel wool mainly responsible for sound-absorbing properties. Item 3. The fuel cell air supply device according to Item 2.   3. The fuel cell air supply device according to claim 2, wherein the expansion chamber wall facing the insertion pipe is disposed with an increased thickness or amount of the sound absorbing material as compared with the other.   5. The fuel cell air supply device according to claim 1, wherein the silencer is provided with a resonance element in an expansion chamber. 6.   6. The filter according to claim 1, wherein the filter includes a dust filter that physically removes solid matter such as dust, and a chemical filter that adsorbs a harmful gas by a chemical reaction. An air supply device for a fuel cell as described in 1.   The fuel cell air according to any one of claims 1 to 6, wherein the fuel cell is used as a power source of a fuel cell vehicle, and the filter is disposed in a motor room in front of the vehicle. Feeding device.

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