Fuel cell system and work machine

Abstract

To suppress dust in an air space from entering a fuel cell.SOLUTION: A fuel cell system mounted on a work machine includes an outside air introduction member including an outside air inlet, an air cleaner device that brings liquid into contact with the air outside the work machine introduced from the outside air inlet, and a fuel cell supplied with air and fuel gas after contact with the liquid.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a fuel cell system and a work machine. [Background technology]

[0002] Fuel cells generate electricity by chemically reacting hydrogen, which is a fuel gas, with oxygen, which is an oxidizing gas. Oxygen from the atmospheric space is often used as the oxidizing gas. When oxygen from the atmospheric space is used as the oxidizing gas, it is necessary to prevent dust from the atmospheric space from entering the fuel cell. Patent Document 1 discloses a technology in which a wet filter is placed in the oxidizing gas supply path of the fuel cell main body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-185193 Summary of the Invention [Problem to be solved by the invention]

[0004] At work sites such as mines, construction sites, and farmland, large amounts of dust are stirred up and suspended in the atmosphere during operations such as excavating, cutting, clearing, and transporting soil or rock. When a fuel cell is installed in a work machine operating at a work site, there is a demand for technology that can prevent dust from entering the fuel cell even when a large amount of dust is present in the atmosphere. [Means for solving the problem]

[0005] According to the present disclosure, there is provided a fuel cell system to be mounted on a work machine, the fuel cell system comprising: an outside air introduction member including an outside air introduction port; an air cleaner device that brings air outside the work machine introduced from the outside air introduction port into contact with a liquid; and a fuel cell to which the air that has come into contact with the liquid and fuel gas are supplied. [Effects of the Invention]

[0006] According to the present disclosure, dust in the atmospheric space is prevented from entering the fuel cell. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram schematically illustrating a work site according to an embodiment. [Figure 2] FIG. 2 is a perspective view showing a dump truck according to the embodiment. [Figure 3] FIG. 3 is a diagram schematically illustrating a dump truck according to the embodiment. [Figure 4] FIG. 4 is a cross-sectional view that schematically shows the air cleaner device according to the embodiment. [Figure 5] FIG. 5 is a cross-sectional view that schematically shows the air cleaner device according to the embodiment. [Figure 6] FIG. 6 is a cross-sectional view that schematically shows a part of the porous member according to the embodiment. [Figure 7] FIG. 7 is a perspective view showing a hydraulic excavator according to the embodiment. [Figure 8] FIG. 8 is a diagram schematically showing a hydraulic excavator according to an embodiment. [Figure 9] FIG. 9 is a diagram schematically showing an air cleaner device according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings, but the present disclosure is not limited to the embodiments. The components of the embodiments described below can be combined as appropriate. In addition, some components may not be used.

[0009] [First embodiment] A first embodiment will be described.

[0010] <Worksite> FIG. 1 is a diagram schematically illustrating a work site 1 according to an embodiment. A plurality of work machines 2 operate at the work site 1. In the embodiment, the work site 1 is a mine. A mine refers to a business site where minerals are extracted. Examples of the work machines 2 include a hydraulic excavator 2A and a dump truck 2B.

[0011] The work site 1 has a loading area 1A, an unloading area 1B, and a transport path 1C. The loading area 1A is an area where a hydraulic excavator 2A performs loading work to load a load onto a dump truck 2B. The unloading area 1B is an area where a dump truck 2B performs unloading work to unload a load. The transport path 1C is a passage for the dump truck 2B that connects the loading area 1A and the unloading area 1B.

[0012] <Dump truck> Fig. 2 is a perspective view showing a dump truck 2B according to the embodiment. Fig. 3 is a diagram schematically showing the dump truck 2B according to the embodiment. As shown in Figs. 2 and 3, the dump truck 2B includes a fuel cell system 3, an electric motor 104, a power take-off 106, a hydraulic pump 105, a valve device 107, front wheels 108A, rear wheels 108B, a left rear wheel drive motor 104A, a right rear wheel drive motor 104B, a steering cylinder 109, a vehicle body 110, a dump body 112, and a hoist cylinder 113.

[0013] The electric motor 104, the left rear wheel drive motor 104A, and the right rear wheel drive motor 104B are each driven by the electric power generated by the fuel cell system 3.

[0014] The hydraulic pump 105 is connected to the electric motor 104 via a power take-off 106. The hydraulic pump 105 is driven by the electric motor 104. The hydraulic oil discharged from the hydraulic pump 105 is supplied to each of the steering cylinder 109 and the hoist cylinder 113 via a valve device 107.

[0015] The front wheels 108A and the rear wheels 108B each support the vehicle body 110. A front tire 108C is mounted on the front wheel 108A. A rear tire 108D is mounted on the rear wheel 108B. The front wheels 108A include a left front wheel 108Al and a right front wheel 108Ar. The rear wheels 108B include a left rear wheel 108Bl and a right rear wheel 108Br.

[0016] The front wheels 108A are steered wheels that are steered by a steering cylinder 109. The rear wheels 108B are drive wheels that rotate by power generated by the left rear wheel drive motor 104A and the right rear wheel drive motor 104B. The left rear wheel 108Bl is connected to the left rear wheel drive motor 104A. The right rear wheel 108Br is connected to the right rear wheel drive motor 104B. The dump truck 2B travels as rear tires 108D attached to the rear wheels 108B rotate.

[0017] The steering cylinder 109 is a hydraulic cylinder, which is a type of hydraulic actuator. The steering cylinder 109 is driven by hydraulic oil discharged from the hydraulic pump 105. The valve device 107 adjusts the direction and flow rate of the hydraulic oil supplied from the hydraulic pump 105 to the steering cylinder 109. The steering cylinder 109 generates power to steer the front wheels 108A.

[0018] The body 110 is supported by the front wheels 108A and the rear wheels 108B.

[0019] The dump body 112 is a member into which cargo is loaded. The dump body 112 is rotated by a hoist cylinder 113. The dump body 112 is of a rear dump type. When the dump body 112 is rotated rearward by the hoist cylinder 113, cargo is discharged from the dump body 112.

[0020] The hoist cylinder 113 is a hydraulic cylinder, which is a type of hydraulic actuator. The hoist cylinder 113 is driven by hydraulic oil discharged from the hydraulic pump 105. The valve device 107 adjusts the direction and flow rate of the hydraulic oil supplied from the hydraulic pump 105 to the hoist cylinder 113. The hoist cylinder 113 generates power to rotate the dump body 112.

[0021] <Fuel cell system> The fuel cell system 3 is mounted on a dump truck 2B. As shown in Fig. 3, the fuel cell system 3 includes a fuel cell 20, an oxidizing gas supply device 30, a fuel gas supply device 40, a power conditioning device 50, and a refrigerant supply device 60.

[0022] The fuel cell 20 generates electricity by chemically reacting hydrogen, which is a fuel gas, with oxygen, which is an oxidizing gas. The fuel cell 20 has a stack structure in which a plurality of unit cells 21 are stacked.

[0023] The oxidizing gas supply device 30 supplies air containing oxygen to the cathode of the fuel cell 20. The oxidizing gas supply device 30 has an outside air introduction member 31, an air intake pipe 32, an air cleaner device 33, an air compressor , and an exhaust pipe .

[0024] The outside air introduction member 31 takes in air outside the dump truck 2B. The air outside the dump truck 2B is air in the atmospheric space around the dump truck 2B. The outside air introduction member 31 includes an outside air introduction port 31A that introduces air from the atmospheric space.

[0025] The air supply pipe 32 connects the outside air inlet 31A of the outside air introduction member 31 and the cathode inlet of the fuel cell 20.

[0026] The air cleaner device 33 is disposed in the air intake pipe 32. The air cleaner device 33 removes dust from the air introduced through the outside air inlet 31A.

[0027] The air compressor 34 is disposed in the air intake pipe 32 between the air cleaner device 33 and the fuel cell 20. The air compressor 34 generates a suction force at the outside air inlet 31A. As a result of the suction force generated at the outside air inlet 31A, air outside the dump truck 2B is introduced into the outside air inlet 31A. The air introduced into the outside air inlet 31A passes through the air cleaner device 33 and the air compressor 34, and then is supplied to the fuel cell 20.

[0028] The exhaust pipe 36 connects the cathode outlet of the fuel cell 20 to the atmospheric space around the dump truck 2B.

[0029] The fuel gas supply device 40 supplies hydrogen to the anode of the fuel cell 20. The fuel gas supply device 40 includes a hydrogen tank 41, an air supply pipe 42, a pressure regulating valve 43, a drain pipe 45, a gas-liquid separator 46, a circulation pipe 47, and a hydrogen circulation pump 48.

[0030] The hydrogen tank 41 contains hydrogen and is filled with hydrogen.

[0031] An air supply pipe 42 connects the hydrogen tank 41 to the anode inlet of the fuel cell 20 .

[0032] The pressure adjusting valve 43 is disposed in the intake pipe 42. The pressure adjusting valve 43 reduces the pressure of the hydrogen delivered from the hydrogen tank 41 to a specified pressure.

[0033] The drain pipe 45 connects the anode outlet of the fuel cell 20 to the exhaust pipe 36 .

[0034] The gas-liquid separator 46 is disposed in the drain pipe 45. The gas-liquid separator 46 separates and stores water from hydrogen discharged from the anode outlet of the fuel cell 20. The water stored in the gas-liquid separator 46 is discharged to the atmosphere via the drain pipe 45 and the exhaust pipe 36.

[0035] The drain pipe 45 does not have to be connected to the exhaust pipe .

[0036] The circulation pipe 47 connects the gas-liquid separator 46 and the air supply pipe 42 .

[0037] The hydrogen circulation pump 48 is disposed in the circulation pipe 47. The hydrogen circulation pump 48 is driven to return the hydrogen, which is discharged from the anode outlet of the fuel cell 20 and from which moisture has been removed in the gas-liquid separator 46, to the fuel cell 20. The hydrogen circulation pump 48 reuses the unreacted hydrogen discharged from the fuel cell 20.

[0038] The power conditioning device 50 supplies the electric power generated by the fuel cell 20 to the electric motor 104, the left rear wheel drive motor 104A, and the right rear wheel drive motor 104B. The power conditioning device 50 has a DC-DC converter 51, a motor inverter 52, a DC-DC converter 53, and a storage battery 54.

[0039] The DC-DC converter 51 boosts the voltage generated by the fuel cell 20. The DC-DC converter 51 supplies the direct current generated by the fuel cell 20 to the motor inverter 52.

[0040] The motor inverter 52 converts the direct current from the DC-DC converter 51 into three-phase alternating current and supplies it to the electric motor 104, the left rear wheel drive motor 104A, and the right rear wheel drive motor 104B. The electric motor 104, the left rear wheel drive motor 104A, and the right rear wheel drive motor 104B are each driven based on the three-phase alternating current supplied from the motor inverter 52.

[0041] The storage battery 54 is charged with power generated by the fuel cell 20. Like the fuel cell 20, the storage battery 54 functions as a power source for the work machine 2. The DC-DC converter 53 controls the charging and discharging of the storage battery 54 so that the storage battery 54 can supply power to the motor inverter 52 in cooperation with the fuel cell 20.

[0042] The DC-DC converter 53 and the storage battery 54 may be omitted.

[0043] The coolant supply device 60 supplies a coolant to the fuel cell 20 to cool the fuel cell 20. An example of the coolant is water. The coolant supply device 60 has a supply pipe 61, a discharge pipe 62, a radiator 63, and a coolant pump 64.

[0044] The supply pipe 61 is connected to the coolant inlet of the fuel cell 20 .

[0045] The discharge pipe 62 is connected to the coolant outlet of the fuel cell 20 .

[0046] The radiator 63 is connected to the supply pipe 61 and the discharge pipe 62 .

[0047] The refrigerant pump 64 is disposed in the supply pipe 61. The refrigerant pump 64 is driven to circulate the refrigerant in a circulation path including the supply pipe 61, the fuel cell 20, the discharge pipe 62, and the radiator 63. The radiator 63 exchanges heat between the refrigerant discharged from the fuel cell 20 and the air outside the dump truck 2B to cool the refrigerant.

[0048] <Air cleaner device> Fig. 4 is a cross-sectional view schematically showing an air cleaner device 33 according to an embodiment. Fig. 5 is a cross-sectional view schematically showing an air cleaner device 33 according to an embodiment. Fig. 4 is a cross-sectional view of the air cleaner device 33 as seen from the side. Fig. 5 is a cross-sectional view of the air cleaner device 33 as seen from the side, which is 90 degrees different from the perspective of Fig. 4.

[0049] The air cleaner device 33 removes dust from the air outside the dump truck 2B introduced through the outside air inlet 31A. The air cleaner device 33 brings the air outside the dump truck 2B introduced through the outside air inlet 31A into contact with a liquid. By bringing the air into contact with the liquid, dust contained in the air is removed from the air.

[0050] In the embodiment, the liquid is water. Note that the liquid may contain water and an additive added to the water. In other words, the liquid may be a liquid whose main component is water. Note that the liquid does not have to be water.

[0051] At a work site 1 where a dump truck 2B is operating, a large amount of dust floats in the air space around the dump truck 2B. In particular, in mines where minerals are mined, dust whose main component is metal, called metal powder, floats in the air space. For example, in mines where iron is mined, fine iron particles float in the air space as metal powder. In mines where copper is mined, fine copper particles float in the air space as metal powder.

[0052] The air introduced through the outside air inlet 31A is likely to contain a large amount of dust such as metal powder. When the air introduced through the outside air inlet 31A comes into contact with liquid in the air cleaner device 33, the dust contained in the air is removed from the air. After coming into contact with the liquid in the air cleaner device 33, the air is supplied to the fuel cell 20 via the air intake pipe 32. Because the air after coming into contact with the liquid is supplied to the fuel cell 20, dust in the atmospheric space is prevented from entering the fuel cell 20. By supplying the air after coming into contact with the liquid in the air cleaner device 33 and hydrogen from the hydrogen tank 41 to the fuel cell 20, the fuel cell 20 can generate electricity appropriately.

[0053] As shown in Figures 4 and 5, the air cleaner device 33 has a housing 70, a dust filter 77, a chemical filter 78, a porous member 71, a connecting member 72, a cleaner motor 73, a plug 74, a liquid supply device 75, and a liquid recovery device 76.

[0054] The housing 70 has an air inlet portion 70A, a support portion 70B, a storage portion 70C, and an air outlet portion 70D. In this embodiment, the air inlet portion 70A, the support portion 70B, the storage portion 70C, and the air outlet portion 70D are a single member. However, the air inlet portion 70A, the support portion 70B, the storage portion 70C, and the air outlet portion 70D may be separate members.

[0055] The air inlet section 70A forms an inlet flow path 81 through which air outside the dump truck 2B introduced from the outside air inlet 31A flows. The air inlet section 70A is connected to the outside air introduction member 31 via at least a part of the air supply pipe 32. As shown in FIG. 5 , in the embodiment, a dust filter 77 and a chemical filter 78 are arranged in the inlet flow path 81. The dust filter 77 is a paper filter that collects dust contained in the air introduced from the outside air inlet 31A. The dust filter 77 collects dust with a large particle size. The chemical filter 78 is a paper filter that is kneaded with a material that collects chemical substances contained in the air introduced from the outside air inlet 31A. Examples of chemical substances that the chemical filter 78 can collect include sulfur, nitrogen, and chlorine compounds.

[0056] The support part 70B is connected to the lower part of the air inlet part 70A. The support part 70B forms a processing space 82 in which at least a portion of the porous member 71 is disposed. The support part 70B supports the porous member 71. The processing space 82 is connected to an inlet flow path 81. The inlet flow path 81 is connected to the upper end of the processing space 82. Air that flows through the inlet flow path 81 flows into the processing space 82.

[0057] The storage portion 70C is connected to the lower part of the support portion 70B. The storage portion 70C forms a storage space 83 in which a liquid is stored. The storage space 83 is connected to the processing space 82. The processing space 82 is disposed above the storage space 83. The processing space 82 and the storage space 83 are integrated. At least a portion of the porous member 71 is disposed in the storage space 83.

[0058] The air outlet portion 70D is connected to a side portion of the support portion 70B. The air outlet portion 70D forms an outlet passage 84 through which air flows from the processing space 82. The processing space 82 is connected to the outlet passage 84. The outlet passage 84 is connected to a side portion of the processing space 82. The air outlet portion 70D is connected to the fuel cell 20 via at least a portion of the air supply pipe 32. The air that has flowed through the processing space 82 flows into the outlet passage 84. The air that has flowed through the outlet passage 84 is supplied to the fuel cell 20 via the air compressor 34. As shown in FIG. 4 , in this embodiment, an eliminator 79 is disposed in the outlet passage 84. The eliminator 79 blocks liquid mist contained in the air from entering the fuel cell 20.

[0059] The porous member 71 has a plurality of holes. In an embodiment, the porous member 71 includes a mesh plate. Air can pass through the holes in the porous member 71. Liquid can also pass through the holes in the porous member 71. The porous member 71 can retain liquid.

[0060] In this embodiment, the porous member 71 is cylindrical and is formed by bending a mesh plate.

[0061] The porous member 71 may have a mesh structure in which a plurality of fibers or rod-shaped members are woven.

[0062] The connecting member 72 is fixed to the porous member 71. The connecting member 72 has a disk portion 72A connected to one axial end of the porous member 71, and a shaft portion 72B protruding from the disk portion 72A. The disk portion 72A is fixed to one axial end of the porous member 71 so as to close the opening of the porous member 71 provided on one axial side of the porous member 71. The shaft portion 72B protrudes from the center of the disk portion 72A to one axial side of the porous member 71.

[0063] The support portion 70B supports the porous member 71 via the connecting member 72. In the embodiment, the support portion 70B supports the shaft portion 72B of the connecting member 72. The support portion 70B supports the porous member 71 so that the central axis AX of the porous member 71 is perpendicular to the vertical axis. In other words, the support portion 70B supports the porous member 71 so that the central axis AX of the porous member 71 extends in the horizontal direction.

[0064] The support portion 70B rotatably supports the porous member 71. The support portion 70B supports the porous member 71 so that the porous member 71 rotates around the central axis AX. The support portion 70B has an opening in which the shaft portion 72B is disposed. The shaft portion 72B is supported by a bearing (not shown) disposed in the opening of the support portion 70B.

[0065] The cleaner motor 73 is an electric motor and is connected to the shaft portion 72B of the connecting member 72. The cleaner motor 73 generates power to rotate the porous member 71 about the central axis AX.

[0066] The plug 74 is placed in an opening 70E provided in the bottom of the storage section 70C. The plug 74 is attached to and detached from the opening 70E.

[0067] Liquid supply device 75 supplies liquid to storage space 83. Liquid supply device 75 is connected to storage space 83 via supply pipe 75A. Liquid supply device 75 supplies liquid to storage space 83 via supply pipe 75A.

[0068] Liquid recovery device 76 recovers liquid from storage space 83. Liquid recovery device 76 is connected to storage space 83 via recovery pipe 76A. Liquid recovery device 76 recovers liquid from storage space 83 by sucking the liquid in storage space 83 via recovery pipe 76A.

[0069] <Operation> Next, we will explain the operation of the fuel cell system 3. When the air compressor 34 is started, air outside the dump truck 2B is introduced into the outside air inlet 31A. The air introduced into the outside air inlet 31A flows into the treatment space 82 via the inflow passage 81. In addition, liquid is stored in the storage space 83.

[0070] 4 and 5 , a lower portion of the porous member 71 below the central axis AX is disposed in the storage space 83. That is, the lower portion of the porous member 71 is immersed in the liquid in the storage space 83. An upper portion of the porous member 71 above the central axis AX is disposed in the processing space 82. That is, the upper portion of the porous member 71 is not immersed in the liquid in the storage space 83, but protrudes from the liquid in the storage space 83.

[0071] The support part 70B rotatably supports the porous member 71 so that the porous member 71 can change between a first state in which at least a portion of the porous member 71 is immersed in the liquid in the storage space 83 and a second state in which the porous member 71 is out of the liquid in the storage space 83. The cleaner motor 73 continues to rotate the porous member 71 at a specified rotation speed at least during the period in which air is flowing into the processing space 82 from the outside air inlet 31A.

[0072] The cleaner motor 73 rotates the porous member 71 so that at least a portion of the porous member 71 changes between a first state and a second state. When focusing on a portion of the porous member 71, as the porous member 71 rotates, the portion of the porous member 71 alternates between a first state in which it is immersed in the liquid in the storage space 83 and a second state in which it is out of the liquid in the storage space 83.

[0073] The portion of the porous member 71 immersed in the liquid in the storage space 83 is wet with the liquid. The portion of the porous member 71 that has changed from the first state to the second state is placed in the processing space 82 in a state wet with the liquid.

[0074] The air outside the dump truck 2B that flows through the inflow passage 81 of the air inlet section 70A changes from the first state to the second state and is supplied to at least a portion of the porous member 71 arranged in the processing space 82. That is, the air that is introduced from the outside air inlet 31A and flows through the inflow passage 81 is supplied in a wet state to a portion of the porous member 71 arranged in the processing space 82.

[0075] As described above, in this embodiment, the porous member 71 is cylindrical. Air from the inflow passage 81 is supplied from above to the outer surface of the porous member 71 in the second state.

[0076] The air that is supplied to the outer surface of the porous member 71 and passes through the holes of the porous member 71 flows into the inner space 71A of the porous member 71 and then flows out from the other axial end of the inner space 71A. The air that flows out from the other axial end of the inner space 71A flows through the outflow flow path 84 and is then supplied to the fuel cell 20.

[0077] 6 is a cross-sectional view schematically showing a portion of a porous member 71 according to an embodiment. As shown in FIG. 6, when the porous member 71 changes from the first state to the second state, a liquid film is formed on the surface of the porous member 71. A liquid film is also formed in the holes 71B of the porous member 71. Air supplied to the porous member 71 from the inflow channel 81 comes into contact with the liquid film formed on the porous member 71. When the air comes into contact with the liquid film formed on the porous member 71, dust contained in the air is captured by the liquid. The dust is held by the porous member 71 or the liquid wetting the porous member 71.

[0078] Furthermore, when air hits the liquid film formed in the holes 71B, liquid mist is generated. In the embodiment, the liquid mist is generated mainly in the inner space 71A of the porous member 71. Furthermore, when the porous member 71 wetted with liquid rotates, liquid mist is also generated in the inner space 71A of the porous member 71. The inner space 71A of the porous member 71 becomes a mist space where the generated mist exists.

[0079] At least a portion of the air that passes through the holes 71B passes through the inner space 71A, which is a mist space. As the air passes through the mist space, dust contained in the air is captured by the liquid. The dust falls into the storage space 83 together with the mist. The liquid in the storage space 83 captures the dust contained in the mist. The liquid in the storage space 83 collects the fallen dust.

[0080] When the porous member 71 changes from the second state to the first state due to rotation of the porous member 71, the portion of the porous member 71 that holds the dust in the processing space 82 becomes immersed in the liquid in the storage space 83. The dust that was held in the portion of the porous member 71 is captured by the liquid in the storage space 83. The portion of the porous member 71 immersed in the liquid in the storage space 83 is cleaned by the liquid in the storage space 83. The liquid in the storage space 83 collects the dust from the portion of the porous member 71 that has changed from the second state to the first state.

[0081] 4 and 5, the dust collected in the liquid in the storage space 83 settles at the bottom of the storage space 83. When the plug 74 is removed from the opening 70E, the dust that has settled at the bottom of the storage space 83 is discharged from the storage space 83 through the opening 70E.

[0082] In the embodiment, liquid recovery device 76 performs a liquid recovery operation in parallel with a liquid supply operation by liquid supply device 75. The liquid supply operation by liquid supply device 75 and the liquid recovery operation by liquid recovery device 76 are continued at least during the period when air is flowing into processing space 82 from outside air inlet 31A. This allows a constant amount of clean liquid to continue to be stored in storage space 83.

[0083] <Effects> As described above, according to the embodiment, the fuel cell system 3 includes the air cleaner device 33 that brings air from the atmospheric space introduced through the outside air inlet 31A into contact with a liquid. The air introduced through the outside air inlet 31A comes into contact with the liquid in the air cleaner device 33, thereby removing dust contained in the air. The air that has come into contact with the liquid is supplied to the fuel cell 20, thereby preventing dust in the atmospheric space from entering the fuel cell 20.

[0084] For example, it is difficult for the dust filter 77 to capture fine dust particles such as metal powder. Furthermore, if the mesh size of the dust filter 77 is made finer to capture fine dust particles, the intake resistance becomes too great and it becomes impossible to draw in as much air as desired, so the mesh size of the dust filter 77 cannot be made smaller than a certain size. If air were allowed to be drawn in, metal powder would end up entering the fuel cell 20. According to the embodiment, the air cleaner device 33 captures dust with a liquid, so that even if a large amount of dust is floating in the air space, such as at a mining work site 1, it can smoothly and efficiently remove dust from the air.

[0085] The air cleaner device 33 has a porous member 71 that is wet with liquid. When air passes through holes 71B of the porous member 71 that is wet with liquid, dust contained in the air is captured by the liquid held in the porous member 71.

[0086] A liquid film is formed in the holes 71B of the porous member 71. When air hits the liquid film, a liquid mist is generated in the inner space 71A. At least a portion of the air that passes through the holes 71B passes through the inner space 71A, which is a mist space where the generated mist exists. Dust contained in the air is captured by at least one of the liquid film and the liquid mist.

[0087] The air cleaner device 33 has a storage section 70C that forms a storage space 83 in which liquid is stored, a support section 70B that supports the porous member 71 so that the porous member 71 can change between a first state in which at least a portion of the porous member 71 is immersed in the liquid in the storage space 83 and a second state in which the porous member 71 is out of the liquid in the storage space 83, and an air inlet section 70A that forms an inlet flow path 81 through which air from the atmospheric space flows and is supplied to at least a portion of the porous member 71 that has changed from the first state to the second state. This allows air from the atmospheric space to be supplied to the porous member 71 wet with the liquid.

[0088] The porous member 71 is cylindrical. The support portion 70B rotatably supports the porous member 71 so that at least a portion of the porous member 71 can change between a first state and a second state. As a result, when focusing on a portion of the porous member 71, the portion of the porous member 71 can alternate between the first state and the second state. The portion of the porous member 71 in the first state can capture dust contained in the air. The portion of the porous member 71 in the second state is cleaned by the liquid in the storage space 83.

[0089] The air cleaner device 33 has a cleaner motor 73 that rotates the porous member 71 so that at least a portion of the porous member 71 changes between a first state and a second state. The power generated by the cleaner motor 73 allows the portion of the porous member 71 to alternate between the first state and the second state.

[0090] Air from the inflow passage 81 is supplied to the outer surface of the porous member 71 in the second state. After passing through the holes 71B of the porous member 71, the air flows into the inner space 71A of the porous member 71 and then flows out from the axial end of the inner space 71A. As a result, the air that has come into contact with the liquid is supplied to the fuel cell 20.

[0091] Liquid mist is generated by the rotation of porous member 71. Internal space 71A of porous member 71 includes a mist space in which the generated mist exists. As air passes through internal space 71A, dust contained in the air is captured by the liquid mist.

[0092] The portion of the porous member 71 that has changed from the second state to the first state is cleaned by the liquid in the storage space 83. The liquid in the storage space 83 can collect dust from at least the portion of the porous member 71 that has changed from the second state to the first state.

[0093] An opening 70E is provided at the bottom of the storage section 70C. The air cleaner device 33 has a plug 74 that is placed in the opening 70E. When the plug 74 is removed from the opening 70E, the dust that has settled at the bottom of the storage space 83 is discharged from the storage space 83 through the opening 70E.

[0094] The air cleaner device 33 has a liquid supply device 75 that supplies liquid to the storage space 83, and a liquid recovery device 76 that recovers liquid from the storage space 83. This allows clean liquid to be stored in the storage space 83.

[0095] <Modification> In the above-described embodiment, the cleaner motor 73 may be omitted. The porous member 71 rotatably supported by the support portion 70B may be rotated by the force of air supplied from the inflow passage 81. The porous member 71 rotatably supported by the support portion 70B may be rotated by the force of liquid supplied from the liquid supply device 75. Fins may be provided on the porous member 71. When air or liquid hits the fins, the porous member 71 can rotate smoothly.

[0096] In the above-described embodiment, water produced in the fuel cell 20 may be used as the liquid in the storage space 83. That is, water separated from hydrogen in the gas-liquid separator 46 may be supplied to the storage space 83. This allows the water produced in the fuel cell 20 to be used effectively.

[0097] In the above-described embodiment, the liquid supply device 75 and the liquid recovery device 76 may be omitted. The liquid in the storage space 83 may be replaced periodically.

[0098] In the above-described embodiment, a pre-cleaner may be disposed between the outside air inlet 31A and the dust filter 77.

[0099] In the above-described embodiment, a dust filter that captures dust by magnetic force or a dust filter that captures dust by electrostatic force may be disposed in the inflow passage 81.

[0100] [Second embodiment] A second embodiment will be described below. In the following description, the same or equivalent components as those in the above-described embodiment will be denoted by the same reference numerals, and the description of those components will be simplified or omitted.

[0101] In the above-described embodiment, the fuel cell system 3 is mounted on the dump truck 2B. The fuel cell system 3 may also be mounted on the hydraulic excavator 2A.

[0102] Fig. 7 is a perspective view showing a hydraulic excavator 2A according to an embodiment. Fig. 8 is a diagram schematically showing the hydraulic excavator 2A according to an embodiment. As shown in Figs. 7 and 8, the hydraulic excavator 2A includes a fuel cell system 3, an electric motor 4, a hydraulic pump 5, a valve device 7, a traveling body 8, a traveling motor 9, a rotating body 10, a swing motor 11, a work implement 12, and a work implement cylinder 13.

[0103] The fuel cell system 3 includes the air cleaner device 33 described in the above embodiment. The electric motor 4 is driven by the electric power generated by the fuel cell system 3.

[0104] The hydraulic pump 5 is driven by the electric motor 4. The hydraulic oil discharged from the hydraulic pump 5 is supplied to the travel motor 9, the swing motor 11, and the work implement cylinder 13 via a valve device 7.

[0105] The running body 8 runs while supporting the rotating body 10. The running body 8 has driving wheels 8A, driven wheels 8B, and crawler belts 8C supported by the driving wheels 8A and driven wheels 8B.

[0106] The travel motor 9 is a hydraulic motor, which is a type of hydraulic actuator. The travel motor 9 is driven by hydraulic oil discharged from the hydraulic pump 5. The travel motor 9 generates power to rotate the drive wheels 8A.

[0107] The revolving unit 10 is the body of the hydraulic excavator 2 A. The revolving unit 10 revolves while being supported by the traveling unit 8.

[0108] The swing motor 11 is a hydraulic motor, which is a type of hydraulic actuator. The swing motor 11 is driven by hydraulic oil discharged from the hydraulic pump 5. The swing motor 11 generates power to swing the swing body 10.

[0109] The work implement 12 is attached to the rotating body 10. The work implement 12 includes a boom 12A, an arm 12B, and a bucket 12C.

[0110] The work implement cylinder 13 is a hydraulic cylinder, which is a type of hydraulic actuator. The work implement cylinder 13 is driven by hydraulic oil discharged from the hydraulic pump 5. The work implement cylinder 13 generates power to operate the work implement 12. The work implement cylinder 13 includes a boom cylinder 13A, an arm cylinder 13B, and a bucket cylinder 13C.

[0111] As described above, the fuel cell system 3 may be mounted on the hydraulic excavator 2A. The fuel cell system 3 has the air cleaner device 33 described in the above embodiment. Therefore, dust in the atmospheric space is prevented from entering the fuel cell 20.

[0112] [Third embodiment] A third embodiment will be described below. In the following description, the same or equivalent components as those in the above-described embodiment will be denoted by the same reference numerals, and the description of those components will be simplified or omitted.

[0113] 9 is a diagram schematically showing an air cleaner device 133 according to an embodiment. As shown in FIG. 9, the air cleaner device 133 has a case 170, a porous member 171, and an air inlet pipe 172.

[0114] The case 170 contains a liquid. The liquid is stored in the case 170.

[0115] The porous member 171 is immersed in the liquid in the case 170. The porous member 171 is cylindrical. The porous member 171 has a plurality of holes. Air can pass through the holes in the porous member 171. Dust can also pass through the holes in the porous member 171. Liquid can also pass through the holes in the porous member 171.

[0116] The air inlet pipe 172 forms an inlet flow path 181 through which air outside the work machine 2 flows, which is introduced from an outside air inlet (not shown). The air that flows through the inlet flow path 181 is supplied to the inner space 171A of the porous member 171.

[0117] Air outside the work machine 2 is introduced through the outside air inlet, flows through the inlet flow path 181, and is then supplied to the inner space 171A of the porous member 171. The air supplied to the inner space 171A passes through the holes in the porous member 171. The air that has passed through the holes in the porous member 171 becomes bubbles and is ejected into the liquid surrounding the porous member 171. The air that has passed through the holes in the porous member 171 comes into contact with the liquid surrounding the porous member 171. If the air contains dust, the dust is captured by the liquid. The liquid contained in the case 170 collects the dust. The dust settles to the bottom of the case 170.

[0118] As described above, the air cleaner device 133 also prevents dust in the atmospheric space from entering the fuel cell 20. [Explanation of symbols]

[0119] 1...work site, 1A...loading area, 1B...soil removal area, 1C...transport path, 2...work machine, 2A...hydraulic excavator, 2B...dump truck, 3...fuel cell system, 4...electric motor, 5...hydraulic pump, 7...valve device, 8...traveling body, 8A...driving wheel, 8B...driven wheel, 8C...crawler, 9...traveling motor, 10...swivel body, 11...swivel motor, 12...working machine, 12A...boom, 12B...arm, 12C...bucket, 13...working machine cylinder, 13A...boom cylinder, 13B...arm cylinder, 13C...bucket cylinder, 20...fuel cell , 21...unit cell, 30...oxidizing gas supply device, 31...outside air introduction member, 31A...outside air introduction port, 32...air intake pipe, 33...air cleaner device, 34...air compressor, 36...exhaust pipe, 40...fuel gas supply device, 41...hydrogen tank, 42...air intake pipe, 43...pressure regulating valve, 45...drain pipe, 46...gas-liquid separator, 47...circulation pipe, 48...hydrogen circulation pump, 50...power conditioning device, 51...DC-DC converter, 52...motor inverter, 53...DC-DC converter, 54...storage battery, 60...refrigerant supply device, 61...supply pipe, 62...exhaust pipe , 63...radiator, 64...refrigerant pump, 70...housing, 70A...air inlet portion, 70B...support portion, 70C...storage portion, 70D...air outlet portion, 70E...opening, 71...porous member, 71A...inner space, 71B...hole, 72...connecting member, 72A...disk portion, 72B...shaft portion, 73...cleaner motor, 74...plug, 75...liquid supply device, 75A...supply pipe, 76...liquid recovery device, 76A...recovery pipe, 77...dust filter, 78...chemical filter, 79...eliminator, 81...inlet flow path, 82...treatment space, 83...storage space Between, 84...outlet flow path, 104...electric motor, 104A...left rear wheel drive motor, 104B...right rear wheel drive motor, 105...hydraulic pump, 106...power take-off, 107...valve device, 108A...front wheel, 108B...rear wheel, 108C...front tire, 108D...rear tire, 109...steering cylinder, 110...vehicle body, 112...dump body, 113...hoist cylinder, 133...air cleaner device, 170...case, 171...porous member, 171A...inner space, 172...air inlet pipe, 181...inlet flow path, AX...central axis.

Claims

1. A fuel cell system mounted on a work machine, an outside air introduction member including an outside air introduction port; an air cleaner device that brings air outside the work machine introduced through the outside air inlet into contact with liquid; a fuel cell to which the air and fuel gas that have come into contact with the liquid are supplied, The air cleaner device is a porous member formed by a mesh plate and wetted with a liquid; a film of the liquid is formed in the pores of the porous member; When the external air hits the film of the liquid, a mist of the liquid is generated, At least a part of the air that has passed through the hole passes through a mist space in which the generated mist exists, The air that has passed through the mist space is supplied to the fuel cell via an eliminator, The eliminator blocks liquid mist contained in the air from entering the fuel cell. Fuel cell system.

2. Air that has passed through the holes of the porous member is supplied to the fuel cell. The fuel cell system according to claim 1 .

3. The air cleaner device is a storage portion that forms a storage space in which the liquid is stored; a support portion that supports the porous member so that at least a portion of the porous member changes between a first state in which the porous member is immersed in the liquid in the storage space and a second state in which the porous member is exposed to the liquid in the storage space; an air inlet portion that forms an inlet flow path through which the outside air flows and is supplied to at least a portion of the porous member that has changed from the first state to the second state, The fuel cell system according to claim 2 .

4. the porous member is cylindrical; the support portion rotatably supports the porous member such that at least a portion of the porous member changes between the first state and the second state. The fuel cell system according to claim 3 .

5. The air cleaner device is a cleaner motor that rotates the porous member so that at least a portion of the porous member changes between the first state and the second state; The fuel cell system according to claim 4 .

6. The air from the inlet passage is supplied to the outer surface of the porous member in the second state, The air that has passed through the holes of the porous member flows into the inner space of the porous member and then flows out from the axial end of the inner space.

6. The fuel cell system according to claim 4 or 5.

7. The rotation of the porous member generates a mist of the liquid, The inner space includes a mist space in which the generated mist exists. The fuel cell system according to claim 6 .

8. The liquid in the storage space collects dust from at least a portion of the porous member that has changed from the second state to the first state. The fuel cell system according to any one of claims 3 to 7.

9. The dust includes metal powder. The fuel cell system according to claim 8 .

10. An opening is provided at the bottom of the storage section, The air cleaner device has a plug disposed in the opening.

10. The fuel cell system according to claim 8 or claim 9.

11. The air cleaner device is a liquid supply device that supplies liquid to the storage space; a liquid recovery device that recovers liquid from the storage space, The fuel cell system according to any one of claims 3 to 10.

12. the liquid in the storage space includes water produced in the fuel cell; 12. The fuel cell system according to claim 3.

13. A fuel cell system according to any one of claims 1 to 12; an electric motor driven by the electric power generated by the fuel cell; a hydraulic pump driven by the electric motor; a hydraulic actuator that is driven based on the hydraulic oil discharged from the hydraulic pump, Work machinery.

14. The car body and a work implement attached to the vehicle body, The hydraulic actuator includes a hydraulic cylinder that operates the work machine.

14. A work machine according to claim 13.

15. The car body and a dump body supported on the vehicle body, The hydraulic actuator includes a hydraulic cylinder that rotates the dump body.

14. A work machine according to claim 13.

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