JP2007324006A - Fuel cell system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell system appropriately removing contaminants such as abrasion dust produced in a compressor while pressure loss is reduced. <P>SOLUTION: In the fuel cell system equipped with a fuel cell 6 generating electric power by electrochemical reaction of oxidative gas and fuel gas; the compressor 12 supplying oxidative gas to the fuel cell 6; an oxidative gas supply passage 5 connecting the compressor 12 and an oxidative gas supply port 9 of the fuel cell 6; and a filter 13 installed inside the oxidative gas supply passage 5, a magnetic material is contained in a coating material of a rotor 11 of the compressor 12, thereby removing abrasion dust of the coating material with the filter 13 made of a magnet. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fuel cell system, and in particular, a fuel cell that generates power by an electrochemical reaction between an oxidizing gas and a fuel gas, a compressor that supplies an oxidizing gas to the fuel cell through an oxidizing gas supply channel, and an oxidizing gas supply The present invention relates to a fuel cell system having a filter provided in a flow path.

  There are various types of fuel cells used in vehicles including a polymer electrolyte fuel cell (PEFC). A fuel cell system including these fuel cells is basically a power generation system that generates electric power by electrochemically reacting a fuel gas (hydrogen) and an oxidizing gas (oxygen or air).

  FIG. 6 shows a schematic configuration diagram of a system for supplying and discharging the oxidizing gas to the fuel cell. The oxidizing gas is taken from the atmosphere, pressurized by the compressor 2, passes through the oxidizing gas supply channel 5, and foreign matters are removed by the filter 3. After that, the humidification module 4 humidifies and supplies the fuel cell 6 from the oxidizing gas supply port 9 of the fuel cell 6. Further, the oxidizing gas discharged from the oxidizing gas discharge port 10 of the fuel cell 6 returns to the humidification module 4 via the pressure regulating valve 7 and is discharged from the oxidizing gas discharge channel 8. The oxidizing gas supply channel 5 is provided with a fuel cell inlet valve 19, and the oxidizing gas discharge channel 8 is provided with a fuel cell outlet valve 20.

  The compressor 2 supplies an oxidizing gas to the fuel cell 6 by rotating an internal rotor (not shown). This rotor is coated with a resinous coating material in order to ensure durability and the like. This coating material is scattered as minute wear powder by the rotation of the rotor. Similarly, the inner wall of the housing of the compressor 2 is coated in the same manner. However, when the rotor rotates, it is scattered as minute wear powder. Furthermore, although this rotor consists of aluminum resin, the fine powder of aluminum is scattered with the abrasion powder of a coating material.

  The abrasion powder and fine aluminum powder of these coating materials flow into the oxidizing gas supply flow path 5 together with the compressed air and mix into the humidification module 4 and the fuel cell 6. When foreign matter such as abrasion powder of coating material or fine powder of aluminum enters the humidifying module 4 or the fuel cell 6, the foreign matter may clog the filter in the humidifying module 4 or adversely affect the material of the humidifying module 4. Or the gas flow path inside the fuel cell 6 is closed to hinder power generation. Therefore, conventionally, a method has been adopted in which the filter 3 is provided in the oxidizing gas supply flow path 5 to capture foreign matter.

  On the other hand, Patent Document 1 discloses an air supply device for a fuel cell, particularly an air purification device for removing fine dust and organic matter in the air provided in an air supply path. FIG. 7 shows a schematic configuration of the air purification device 30. The air purification device 30 is provided in an air supply path 31 that is a cylindrical tube body 32, and includes a turbulent flow generation unit 33, an electrostatic collection device 36 including a friction body 34 and an electrostatic collection body 35, and filtration. And an expression filter 37. When the air flowing through the tubular body 32 passes through the turbulent flow generating portion 33, turbulent flow is generated by the protrusion 38, and the turbulent flow causes the electrostatic collector 35 to fly violently, contacting the friction body 34 and sliding. Move. The friction body 34 and the electrostatic collector 35 are charged in opposite polarities due to the friction at this time, so that fine dust having electric charge existing in the air is attracted to any one and collected. Large dust or dust having no electric charge is collected by the filter 37.

  Patent Document 2 discloses a gas supply system (apparatus) for a fuel cell. Here, an impurity removing device for removing foreign substances in the gas is provided on a passage wall or the like of a portion where the gas flow strikes. This impurity removing device may be a device containing magnet powder. When the foreign matter is a magnetic substance, the foreign matter in the gas is removed from the magnetic powder of the impurity removing device while the gas is flowing in contact with the magnet powder. It is disclosed that it is adsorbed and removed.

  Patent Document 3 shows an example of a roots type compressor (compressor) used for supplying an oxidizing gas of a fuel cell.

JP 2004-273244 A JP 2005-268003 A JP-A-2005-155408

  As described above, the wear powder generated by the rotation of the rotor of the compressor of the fuel cell and the fine aluminum powder as the rotor material must be appropriately removed. However, it is difficult to completely remove the foreign matters by the conventional foreign matter capturing method using a filter. Moreover, if the width of the filter mesh is reduced, the foreign substance removal performance can be improved, but the pressure loss increases and the power generation capacity is affected.

  On the other hand, the electrostatic collection device disclosed in Patent Document 1 has a problem in safety because it generates static electricity, and has a problem in that the collection capability is low because the electrostatic force is weak.

  An object of the present application is to solve this problem and to provide a fuel cell system that appropriately removes foreign matters such as wear powder generated by a compressor while reducing pressure loss.

  In order to achieve the above object, a fuel cell system according to the present invention includes a fuel cell that generates electricity by an electrochemical reaction between an oxidizing gas and a fuel gas, a compressor that supplies the oxidizing gas to the fuel cell, a compressor and a fuel cell. In a fuel cell system having an oxidant gas supply channel connecting the oxidant gas supply port and a filter provided in the oxidant gas supply channel, a magnetic material is included in the coating material of the rotor that rotates the compressor. Further, the present invention is characterized in that the abrasion powder of the coating material is removed by a filter made of a magnet. The compressor housing is preferably coated with a coating material containing a magnetic material.

  In order to achieve the above object, a fuel cell system according to the present invention includes a fuel cell that generates electric power by an electrochemical reaction between an oxidizing gas and a fuel gas, a compressor that supplies the fuel cell with an oxidizing gas, a compressor and a fuel In a fuel cell system having an oxidizing gas supply channel connecting an oxidizing gas supply port of a battery, and a filter provided in the oxidizing gas supply channel, the rotor of the compressor is a coating material containing magnet powder The filter is a mesh made of a magnetic material. Furthermore, the compressor housing is preferably coated with a coating material containing magnet powder.

  In addition, these fuel cell systems include a bypass channel that communicates the upstream and downstream oxidant gas supply channels of the filter, the bypass channel is opened, and within the oxidant gas supply channel downstream of the filter, It is preferable to replace the filter while supplying the oxidizing gas to the fuel cell by closing the on-off valve provided upstream from the junction of the flow path and the oxidizing gas supply flow path.

  In order to achieve the above object, a fuel cell system according to the present invention includes a fuel cell that generates electric power by an electrochemical reaction between an oxidizing gas and a fuel gas, a compressor that supplies the fuel cell with an oxidizing gas, a compressor and a fuel In a fuel cell system having an oxidant gas supply channel connecting the oxidant gas supply port of the battery and a filter provided in the oxidant gas supply channel, iron powder is included in the coating material of the rotor that rotates the compressor Thus, it is characterized in that the abrasion powder of the coating material is removed by the metal mesh which is made of a metal mesh and is magnetized by the current flowing in the coil wound with the filter. Further, the compressor housing is preferably coated with a coating material containing iron powder.

  The fuel cell system is connected to a bypass flow path that connects the upstream and downstream oxidizing gas supply passages of the filter and an oxidizing gas supply flow path that is downstream of the filter, and purge flow that discharges foreign matters attached to the filter. Open and close the bypass flow path and the purge flow path, and within the oxidizing gas supply flow path downstream of the filter and provided upstream from the junction of the bypass flow path and the oxidizing gas supply flow path It is preferable to scavenge the filter while supplying the oxidizing gas to the fuel cell by closing the valve and closing the current flowing through the coil. Furthermore, it is preferable that the purge flow path is electrically connected to the oxidizing gas discharge flow path of the fuel cell.

  In addition, these fuel cell systems are preferably provided with a combination of a plurality of filters, and each filter is preferably composed of a one-way mesh having mutually different mesh directions.

  With the above configuration, in the fuel cell system, the rotor is rotated by the compressor and the coating material on the inner wall of the housing includes the magnetic material. This magnetic substance is mixed with foreign matter such as wear powder of the coating material generated by the rotation of the compressor, and is scattered as a mixture. This magnetic material is magnetized by sliding due to the rotation of the compressor, and is attracted to and captured by a filter made of a magnet. That is, a foreign substance that is not a magnetic substance and has no electric charge can be appropriately removed by a filter made of a magnet by forming a mixture with the magnetic substance before the foreign substance is generated.

  In addition, the fuel cell system does not capture foreign matter such as wear powder itself, but captures a mixture having a larger size due to the mixture of magnetic substances. This makes it possible to make the width of the filter mesh larger than the conventional one. Furthermore, since the mixture is adsorbed by the magnetism of the magnet, it is possible to make the filter mesh larger than when it is simply captured by the filter mesh. Thus, by making the mesh of the filter large, it is possible to reduce the pressure loss while enhancing the dust collection capability of the filter.

  In the fuel cell system, the same effect can be obtained by including magnet powder in the rotor rotating the compressor and the coating material on the inner wall of the housing. That is, the magnet powder is mixed with foreign matter such as wear powder of the coating material generated by the rotation of the compressor, and is scattered as a mixture. Further, the magnet powder is magnetized by itself and is attracted to and captured by a filter made of a magnetic material. That is, by forming a mixture with a magnetic powder before a foreign substance is generated with respect to a foreign substance that is not a magnetic substance and has no electric charge, it can be appropriately removed by a filter made of a magnetic substance. Also in this case, since the filter mesh can be increased, the pressure loss can be reduced while increasing the dust collecting ability of the filter.

  Also, the fuel cell system includes iron powder in the rotor coating material that rotates the compressor, and is captured by a filter made of a metal mesh and magnetized by the current flowing in the coil wound around the filter. But the same effect occurs. Furthermore, in this case as well, the filter mesh can be increased, so that the pressure loss can be reduced while increasing the dust collecting ability of the filter.

  As described above, according to the fuel cell system of the present invention, it is possible to appropriately remove foreign matters such as wear powder generated by the compressor while reducing pressure loss.

  Hereinafter, an embodiment of a fuel cell system according to the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a schematic configuration of one embodiment of a fuel cell system according to the present invention. FIG. 1 shows an oxidant gas supply and discharge system of a fuel cell system 1. Oxidizing gas is taken from the atmosphere, pressurized by a compressor 12 having a built-in rotor 11, passes through the oxidizing gas supply channel 5, and foreign matter is removed by a filter 13 having a mesh 15. After that, the humidification module 4 humidifies and supplies the fuel cell 6 from the oxidizing gas supply port 9 of the fuel cell 6. Further, the oxidizing gas discharged from the oxidizing gas discharge port 10 of the fuel cell 6 returns to the humidification module 4 via the pressure regulating valve 7 and is discharged from the oxidizing gas discharge channel 8. A fuel cell inlet valve 19 is attached to the oxidizing gas supply flow path 5, and a fuel cell outlet valve 20 is attached to the oxidizing gas discharge flow path 8 to control the supply and discharge of the oxidizing gas.

  FIG. 2 is a sectional view showing a schematic configuration of a Roots type compressor 40 which is one embodiment of the compressor 12 used for supplying the oxidizing gas of the fuel cell 6. This Roots type compressor 40 is a mechanism in which a first rotor 42 and a second rotor 43, which are two rotors 11 having the same bowl-shaped cross-section, rotate opposite to each other in a housing 41. Have The air sucked from the suction port 44 is increased in pressure by the rotors 42 and 43 and discharged from the discharge port 45. The compressor 12 according to the present invention is not limited to the illustrated root type compressor 40 but includes all the compressors 12 having at least one rotor 11 inside the housing 41.

  The rotor 11 of the compressor 12 and the inner wall of the housing 41 are coated with a resinous coating material to ensure durability and the like. In the present embodiment, among resinous coating materials, a fluororesin coating material (ETFE) having high corrosion resistance, non-adhesiveness, low friction characteristics, and the like is used. This fluororesin coating material is coated on the inner walls of the rotor 11 and the housing 41 by powder coating or the like.

  FIG. 3A schematically shows how the mixture 16 generated from the rotor 11 of the compressor 12 is captured by the mesh 15 of the filter 13. FIG. 3B shows a mesh 15 of the filter 13 in the AA cross-sectional view of FIG. The rotor 11 rotates in the direction of “a” in FIG. 3 while being in contact with the inner wall 25 of the housing 41. The coating material 14 of the rotor 11 and the coating material 17 of the inner wall 25 of the housing 41 become minute wear powder due to mutual contact due to the rotation of the rotor 11 and scatter from the direction “b” in FIG. 3. Then, it flows to the oxidizing gas supply flow path 5 together with the compressed oxidizing gas (“c” in FIG. 3). The rotor 11 and the housing 41 are made of aluminum resin. The aluminum fine powder eluted from the rotor 11 and the housing 41 to the coating materials 14 and 17 is scattered together with the abrasion powder of the coating materials 14 and 17 and flows to the oxidizing gas supply channel 5 together with the compressed oxidizing gas (FIG. 3). "C").

  In the first embodiment according to the present invention, a magnetic material is sintered to the fluororesin coating materials 14 and 17. The filter 13 is provided with a mesh 15 made of a magnet. Here, the magnetic substance refers to a substance that can be magnetized, and examples thereof include iron oxide, chromium oxide, cobalt, and ferrite. A magnet refers to an object that is a source for generating a bipolar magnetic field. There are various types of magnets. In this embodiment, a samarium cobalt magnet or a neodymium magnet, which is a rare earth having a high attractive force and coercive force, is used. Sintering is a phenomenon in which an aggregate of solid powder is heated to a high temperature to be baked and solidified into a dense polycrystalline body. Specifically, a magnetic material is kneaded into the coating materials 14 and 17. It means that.

  In FIG. 3A, the fluororesin coating materials 14 and 17 obtained by sintering a magnetic material (represented by black dots in FIG. 3) become a mixture 16 that is wear powder mixed with the magnetic material. Since the mixture 16 is generated by contact due to the rotation of the rotor 11, the magnetic body in the mixture 16 has magnetism by sliding, and the mixture 16 itself has magnetism. This mixture 16 flows out into the oxidizing gas supply flow path 5 together with the compressed air, and is adsorbed and captured by the magnet in the mesh 15 made of the magnet of the filter 13. As shown in FIG. 3B, a mesh 15 is stretched over the entire surface of the oxidizing gas supply channel 5 in the oxidizing gas supply channel 5 in the filter 13. It is attracted and adsorbed to the mesh 15.

  In the second embodiment according to the present invention, magnet powder is sintered to the fluororesin coating materials 14 and 17. The filter 13 is provided with a mesh 15 made of a magnetic material. In this case, since the magnetic powder originally having magnetism is mixed in the mixture 16, the magnetic substance of the filter 13 is attracted and captured even if the magnetization due to sliding is insufficient. In this case, a mixture 16 with magnet powder is formed before a foreign substance is generated with respect to a foreign substance that is not a magnetic substance and has no charge, and can be removed by a filter 13 made of a magnetic substance. .

  In the third embodiment according to the present invention, iron powder is sintered to the fluororesin coating materials 14 and 17. Here, the iron powder only needs to be a substance having a property of being attracted to magnetism, and may be a magnet powder or a magnetic substance. The filter 13 is provided with a metal mesh 15 made of a magnetic material. Further, as shown in FIG. 4, in the filter 13, a coil 24 is wound around the oxidizing gas supply flow path 5, and a current is passed through the coil 24 to form a metal mesh 15 made of a magnetic material of the filter 13. Magnetized. The magnetized metal mesh 15 adsorbs and removes wear powder of the coating materials 14 and 17 in which iron powder is sintered.

  Here, FIG. 5 shows another embodiment of the filter 13. In the embodiment described above, the mesh 15 of the filter 13 is stretched in a lattice shape (two directions). In the present embodiment, the two meshes 15a and 15b are arranged with a space therebetween, and the meshes 15 are in one direction, and the directions of the two meshes 15a and 15b are orthogonal to each other. The mixture 16 passing through the oxidant gas flow path 5 is captured by one of the meshes 15a and 15b. Thus, the pressure loss of the oxidizing gas flow path 5 is further reduced by dividing and combining the mesh 15 of the filter 13 into meshes 15a and 15b.

  Hereinafter, a method for replacing the filter 13 and a method for discharging the mixture 16 attached to the filter 13 will be described with reference to FIG.

  First, a pressure sensor 17 that monitors the pressure of the filter 13 is installed at the inlet of the filter 13. Further, a purge flow is connected to the bypass gas flow path 22 that communicates the upstream and downstream oxidant gas supply flow path 5 of the filter 13 and the oxidant gas supply flow path 5 downstream of the filter 13 and discharges foreign matter adhering to the filter 13. A path 23 is provided. A filter bypass valve 18 is attached to the bypass flow path 22. A foreign substance exhaust valve 21 is also attached to the purge flow path.

  If the mixture 16 adheres to the mesh 15 of the filter 13 to cause clogging during the operation of the fuel cell system 1, the pressure of the oxidizing gas at the inlet of the filter 13 increases. The pressure sensor 17 detects the clogging of the filter 13 and transmits a signal. Based on the signal from the pressure sensor 17, the control unit (not shown) of the fuel cell system 1 closes the fuel cell inlet valve 19 and opens the filter bypass valve 18. Thus, the oxidizing gas is supplied to the fuel cell 6 through the bypass flow path 22 without temporarily passing through the filter 13.

  In the case of the first and second embodiments, the mesh 15 of the filter 13 is replaced while the oxidizing gas passes through the bypass flow path 22. That is, it is possible to replace the filter 13 including the mesh 15 to which the mixture 16 is attached while supplying the oxidizing gas to the fuel cell 6.

  In the case of the third embodiment, by closing the current flowing in the coil 24, the mixture 16 attached to the mesh 15 of the filter 13 loses magnetism and falls off. A control unit (not shown) of the fuel cell system 1 scavenges the dropped mixture 16. That is, the foreign substance exhaust valve 21 is opened and the oxidizing gas (air) is blown from the compressor 12, whereby the dropped mixture 16 is discharged through the purge flow path 23. According to this discharge method, the mixture 16 attached to the mesh 15 of the filter 13 can be discharged while the fuel cell 6 is operating. That is, in the case of the third embodiment, the mixture 16 attached to the filter 13 can be discharged without replacing the mesh 15 of the filter 13.

  The purge flow path 23 scavenges the dropped mixture 16 to the outside, but may be connected to the oxidizing gas discharge flow path 8 of the fuel cell 6. As a result, the purge flow path 23 unifies the flow path for discharging to the outside of the fuel cell system 1 and the oxidizing gas discharge flow path 8, thereby increasing the space efficiency.

1 is a schematic configuration diagram of one embodiment showing an oxidizing gas supply and discharge system of a fuel cell system according to the present invention. FIG. It is sectional drawing which shows schematic structure of the roots type compressor which is one Example of a compressor. It is the schematic diagram and sectional drawing which show a mode that the mixture generated from the rotor of the compressor is capture | acquired with the mesh of a filter. It is explanatory drawing which shows a mode that a coil is wound around the oxidizing gas supply flow path of a filter, and a mesh is magnetized. It is explanatory drawing which shows the other Example of the mesh of a filter. It is a schematic block diagram which shows the supply and discharge | emission system of the oxidizing gas of the conventional fuel cell system. It is a schematic block diagram which shows the conventional air purification apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Fuel cell system, 2,12 Compressor, 3,13 filter, 4 humidification module, 5 Oxidation gas supply flow path, 6 Fuel cell, 7 Pressure regulation valve, 8 Oxidation gas discharge flow path, 9 Oxidation gas supply port, 10 Oxidation gas Discharge port, 11 rotor, 14, 17 coating material, 15, 15a, 15b mesh, 16 mixture, 17 pressure sensor, 18 filter bypass valve, 19 fuel cell inlet valve, 20 fuel cell outlet valve, 21 foreign matter exhaust valve, 22 Bypass channel, 23 Purge channel, 24 Coil, 25 Inner wall, 30 Air purifier, 31 Air supply channel, 32 Tube, 33 Turbulence generator, 34 Friction body, 35 Electrostatic collector, 36 Electrostatic trap Collector, 37 filter, 38 projection, 40 roots compressor, 41 housing, 42 first rotor, 43 second rotor, 44 suction port, 45 discharge port.

Claims (10)

A fuel cell that generates electricity by an electrochemical reaction between the oxidizing gas and the fuel gas; a compressor that supplies the fuel cell with oxidizing gas; an oxidizing gas supply channel that connects the compressor and the oxidizing gas supply port of the fuel cell; A fuel cell system having a filter provided in the gas supply flow path,
A fuel cell system comprising: a magnetic material included in a coating material of a rotor that rotates in a compressor; and a coating made of a magnet that removes abrasion powder from the coating material.   2. The fuel cell system according to claim 1, wherein the inner wall of the housing of the compressor is coated with a coating material containing a magnetic material. A fuel cell that generates electricity by an electrochemical reaction between the oxidizing gas and the fuel gas; a compressor that supplies the fuel cell with oxidizing gas; an oxidizing gas supply channel that connects the compressor and the oxidizing gas supply port of the fuel cell; A fuel cell system having a filter provided in the gas supply flow path,
A fuel cell system characterized in that a magnetic powder is included in a coating material of a rotor rotating in a compressor, thereby removing abrasion powder of the coating material by a filter made of a magnetic material.   4. The fuel cell system according to claim 3, wherein the inner wall of the housing of the compressor is coated with a coating material containing magnet powder.   5. The fuel cell system according to claim 1, further comprising: a bypass channel that communicates the upstream and downstream oxidizing gas supply channels of the filter, opens the bypass channel, and supplies the oxidizing gas downstream of the filter. It is characterized in that the filter is replaced while supplying the oxidizing gas to the fuel cell by closing the on-off valve provided in the channel and upstream from the junction of the bypass channel and the oxidizing gas supply channel. Fuel cell system. A fuel cell that generates electricity by an electrochemical reaction between the oxidizing gas and the fuel gas; a compressor that supplies the fuel cell with oxidizing gas; an oxidizing gas supply channel that connects the compressor and the oxidizing gas supply port of the fuel cell; A fuel cell system having a filter provided in the gas supply flow path,
Featuring iron powder in the rotor's rotating rotor coating material, it consists of a metal mesh, and the metal mesh magnetized by the current flowing in the coil around which the filter is wound is used to remove the abrasion powder of the coating material. Fuel cell system.   7. The fuel cell system according to claim 6, wherein an inner wall of the compressor housing is coated with a coating material containing iron powder.   8. The fuel cell system according to claim 6 or 7, wherein a foreign substance attached to the filter is connected to the bypass flow path that connects the upstream and downstream oxidizing gas supply flow paths of the filter and the oxidizing gas supply flow path downstream of the filter. A purge flow path for discharging the gas, and opening the bypass flow path and the purge flow path, and within the oxidizing gas supply flow path downstream of the filter, upstream from the junction of the bypass flow path and the oxidizing gas supply flow path The fuel cell system is characterized in that the filter is air scavenged while the oxidizing gas is supplied to the fuel cell by closing the on-off valve provided in the valve and closing the current flowing through the coil.   9. The fuel cell system according to claim 8, wherein the purge channel is electrically connected to the oxidizing gas discharge channel of the fuel cell. The fuel cell system according to any one of claims 1 to 9, wherein a plurality of filters are provided in combination, and each filter is formed of a one-way mesh having different mesh directions. system.

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