JP5272883B2 - Generated water atomizer for fuel cell vehicles - Google Patents

Description

  The present invention relates to a generated water atomizing device for a fuel cell vehicle for forming generated water generated by a fuel cell into a mist and discharging it to the outside of a vehicle body.

  A fuel cell vehicle is, for example, a fuel cell that generates electric power, a tank that can store generated water generated by the fuel cell when generating electric power, and generated water atomization that discharges water in the tank to the outside of the vehicle body in a mist form It has a device (see Patent Documents 1 and 2). The generated water atomizer is used when the generated water is not preferably discharged in a liquid state. For example, it is used when it is not preferable that the generated water drops on the road surface and freezes in a cold region or in a freezer, or when it is desired to prevent the generated water from dripping on the floor surface and becoming a water pool indoors.

  Conventionally, a carburetor provided in an intake pipe of an engine is also known (see Patent Documents 3 and 4). The carburetor has, for example, an injection pipe for injecting fuel into an intake pipe, and a porous member having a plurality of holes is provided at the tip of the injection pipe. The fuel is injected from the porous member into the venturi formed in the intake pipe, and is vaporized by the air flowing through the venturi.

JP 2007-141475 A JP 2009-26498 A Japanese Utility Model Publication No. 53-18418 Japanese Utility Model Publication No. 56-8831

  By the way, the fuel cell vehicle has less noise than the engine vehicle. Therefore, in a fuel cell vehicle, noise generated from the generated water atomizer may be a problem. However, the generated water atomizers of Patent Documents 1 and 2 are not provided with a structure for noise countermeasures. Moreover, since the vaporization apparatus of patent documents 3 and 4 is provided in the engine vehicle, noise does not become a problem. SUMMARY OF THE INVENTION An object of the present invention is to provide a generated water atomizer that has low noise and is provided in a fuel cell vehicle.

  In order to solve the above-mentioned problems, the present invention is a generated water atomization device for a fuel cell vehicle having the configuration as described in each claim. According to the first aspect of the present invention, an exhaust pipe having a venturi portion in which a part of the inner peripheral diameter of the pipe is constricted, and introduction of supplying water in the tank in which generated water can be stored from the tank side to the exhaust pipe. Has a tube. A porous member having a plurality of holes through which water can be discharged into the exhaust pipe is provided at the leading end of the introduction pipe located at or near the venturi.

  Therefore, the water discharged to the surface of the porous member is cut out from the porous member by the gas in the exhaust pipe whose flow velocity is increased in the venturi portion and becomes a mist. Further, since the porous member has a plurality of holes, the surface is not smooth and a turbulent boundary layer can be formed around the porous member. For example, as shown in FIG. 5, a laminar boundary layer is formed around a pipe member 35 having a smooth outer peripheral surface, but a turbulent boundary layer is formed around a porous member.

  In the turbulent boundary layer, fluid molecules actively collide more frequently than in the laminar boundary layer, and the velocity is averaged. Therefore, in the turbulent boundary layer generated by the porous member, the velocity is averaged compared to the laminar boundary layer, and the backflow is less likely to occur and separation is unlikely to occur. The magnitude of the noise (sound power) is generally proportional to the eighth power of the flow velocity of the gas flowing in the pipe. Therefore, if the flow rate of the gas flowing in the exhaust pipe is the same, the noise becomes smaller as the non-uniformity in the flow velocity is smaller. Therefore, the speed is averaged by the turbulent boundary layer formed by the porous member, and the generation of noise can be suppressed by suppressing the occurrence of separation.

  According to invention of Claim 2, a porous member is a metal sintered compact. Accordingly, for example, a plurality of small holes can be easily formed as compared with a punching metal obtained by punching a metal pipe and a metal pipe formed with a plurality of slits. And the diameter of the water discharged | emitted to the surface of a porous member becomes small by making the diameter of a hole small, and this water is easy to make it mist-like. Moreover, by forming many holes, the irregularities on the surface of the porous member increase, and a turbulent boundary layer is easily formed. Thereby, generation | occurrence | production of noise can be suppressed strongly.

  According to the invention described in claim 3, the leading end portion of the introduction pipe is located in the vicinity of the inner peripheral surface of the exhaust pipe. A porous member projects into the exhaust pipe from the tip of the introduction pipe. Therefore, not the introduction pipe but the porous member protrudes from the exhaust pipe. For this reason, a turbulent boundary layer is formed in substantially the entire porous member protruding into the exhaust pipe, whereby the generation of noise can be strongly suppressed.

According to the first aspect of the present invention, the porous member has an upstream region facing the gas flow in the exhaust pipe and a downstream region opposite to the upstream region. The porous member is provided with a cover that covers the downstream region. By the way, the amount of water discharged from the porous member is increased as the gas flow rate increases. The flow velocity of the gas flowing around the porous member is fast around the upstream region and slow around the downstream region. Therefore, there is a possibility that the water is not atomized in the downstream region of the porous member and is discharged into the exhaust pipe as a liquid. On the other hand, a cover is provided in the downstream region of the porous member. Therefore, it can be suppressed that water is discharged into the exhaust pipe as a liquid in the downstream region.

It is a side view of a forklift. It is a block diagram of a fuel cell system. It is sectional drawing of the component of a production | generation water atomizer. It is a schematic top view in an exhaust pipe which shows the mode of the gas which flows around a porous member. It is a schematic top view in the exhaust pipe which shows the mode of the gas which flows around the metal pipe of a comparative example. It is a top view of the porous member and cover concerning other embodiments. FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. 6. It is a top view of the porous member and cover concerning other embodiments. FIG. 9 is a cross-sectional view taken along the line IX-IX in FIG. 8. It is a top view of a porous member concerning other embodiments and an introduction tube. It is the XI-XI sectional view taken on the line of FIG. It is the schematic of the produced | generated water atomization apparatus concerning other embodiment.

  One embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, a vehicle 10 is a forklift that is used for indoor use, which is one of industrial vehicles, and includes a cargo handling device 12. The cargo handling device 12 includes a mast 12a erected on the front portion of the vehicle body 11, a lift bracket 12b attached to the mast 12a so as to be movable up and down, and a fork 12c attached to the lift bracket 12b. The fork 12c and the lift bracket 12b can be moved up and down by a lift cylinder 12d and a mast 12a attached to the mast 12a.

  As shown in FIG. 1, the vehicle 10 has drive wheels (front wheels) 13 at the front lower portion of the vehicle body 11 and rear wheels 14 at the rear lower portion of the vehicle body 11. A traveling motor 15 that applies power to the drive wheels 13 is provided inside the front side of the vehicle body 11. A fuel cell system 20 including a fuel cell 21 and a hydrogen tank 22 is provided inside the rear side of the vehicle body 11. The electric power generated by the fuel cell 21 is supplied to a hydraulic pump (not shown) serving as a hydraulic pressure source such as the lift cylinder 12d, the traveling motor 15, and the like.

  As shown in FIG. 2, the fuel cell system 20 includes a fuel cell 21, a tank 26 that can store generated water, and a generated water atomizer (vaporizer) 1 that atomizes the water in the tank 26. ing. The fuel cell 21 is, for example, a solid polymer type, and a hydrogen tank 22 is connected to the anode side via a conduit 27. Thereby, hydrogen is supplied from the hydrogen tank 22 to the anode side. A humidifier 24 is connected to the cathode side of the fuel cell 21 via a conduit 29, and a compressor 23 is connected to the humidifier 24 via a conduit 28. Therefore, the air containing oxygen which is the oxidant gas is pressurized by the compressor 23 and supplied to the humidifier 24. Then, moisture is supplied to oxygen in the humidifier 24, and air containing the oxygen is supplied to the cathode side of the fuel cell 21.

  Hydrogen molecules supplied to the anode of the fuel cell 21 become hydrogen ions and move to the cathode side along with moisture contained in the electrolyte membrane. Oxygen molecules in the air supplied to the cathode become oxygen ions and combine with hydrogen ions to form product water. The generated water is supplied to the humidifier 24 through the conduit 30 together with the exhaust of the air supplied to the cathode, and a part of the generated water is extracted by the humidifier 24 and reused. The remaining produced water is discharged to the diluter 25 through the pipe line 31 together with the exhaust (cathode side exhaust).

  A part of the water or nitrogen on the cathode side of the fuel cell 21 is reversely diffused and moves to the anode side. When these concentrations increase on the anode side, the power generation efficiency decreases. In order to suppress this, a purge gas pipe 32 is connected to the anode side as shown in FIG. The on-off valve 33 provided in the pipe line 32 is controlled and opened by a control device (not shown) when the fuel cell 21 continues to operate for a predetermined time. As a result, moisture and nitrogen accumulated on the anode side are discharged together with hydrogen gas to the diluter 25 side through the purge gas pipe 32 (exhaust on the anode side).

  As shown in FIG. 2, the exhaust on the cathode side and the exhaust on the anode side of the fuel cell 21 are supplied to the diluter 25 via pipes 31 and 32. These exhaust gases are separated into gas and liquid (product water) in the diluter 25 due to the difference in specific gravity, and the product water that has become liquid falls into the tank 26 and is stored. In the diluter 25, the concentration of hydrogen contained in the exhaust on the anode side is diluted with the air contained in the exhaust on the cathode side. The gas in the diluter 25 is discharged to the exhaust pipe 4 connected to the exhaust port of the diluter 25.

  As shown in FIG. 3, the exhaust pipe 4 has an inlet side pipe portion 4a, a venturi portion 4b, and a spread pipe portion 4c. The inlet side pipe portion 4 a is cylindrical and has substantially the same inner and outer peripheral diameters in the entire length, and one end thereof is connected to the diluter 25. The venturi portion 4b is a portion in which a part of the inner peripheral diameter of the tube is constricted, and the inner peripheral diameter is smaller than that of the inlet side tube portion 4a. The expanding pipe portion 4c has an inner diameter that gradually increases from the venturi portion 4b toward the outlet portion 4c1. Therefore, the gas flowing in the exhaust pipe 4 becomes the fastest in the venturi portion 4b or in the vicinity of the venturi portion 4b.

  As shown in FIGS. 2 and 3, the generated water atomizer 1 includes an introduction pipe 2 and a porous member 3. The introduction pipe 2 has a first part 2 a extending from the tank 26 to the exhaust pipe 4 and a second part 2 b penetrating from the outer peripheral surface of the venturi part 4 b of the exhaust pipe 4 to the inner peripheral surface. The tip 2c of the second part 2b is located in the vicinity of the inner peripheral surface of the venturi 4b.

  As shown in FIG. 3, the porous member 3 is attached to the distal end portion 2 c of the second portion 2 b of the introduction pipe 2 and protrudes into the exhaust pipe 4. The porous member 3 is a porous metal sintered body. The metal sintered body is formed by press-molding metal powder and heat-treating it at a temperature below the melting point to combine the powder particles. Therefore, the porous member 3 has a plurality of holes formed between the powder particles, and water can be discharged from the inside of the porous member 3 to the outer surface through the holes. The diameter of the hole is small, for example, 50 to 200 μm.

  As shown in FIGS. 3 and 4, the porous member 3 has a substantially cylindrical shape, and includes a cylindrical side wall 3a and a lid 3b that covers a front end opening of the side wall 3a. The side wall portion 3a is erected substantially perpendicularly to the inner peripheral surface of the venturi portion 4b. The lid 3b has a disc shape and is located in the vicinity of the cross-sectional center line 4d of the venturi 4b.

  As shown in FIGS. 2 and 3, the atmospheric pressure in the tank 26 becomes higher due to exhaust from the fuel cell 21, and the pressure in the exhaust pipe 4 becomes lower than the pressure in the tank 26 due to pressure loss. Further, the pressure in the venturi portion 4 b is lower than the pressure in the inlet side pipe portion 4 a by the gas flowing through the exhaust pipe 4. Therefore, the water stored in the tank 26 is sucked into the introduction pipe 2 by using the pressure difference due to the pressure loss or the pressure drop in the venturi portion 4 b and supplied to the porous member 3.

  The water supplied to the porous member 3 is discharged from the inside of the porous member 3 to the outer surface through a plurality of holes (see FIGS. 3 and 4). The water discharged to the outer surface of the porous member 3 is cut out by the exhaust gas flowing through the exhaust pipe 4 and becomes a mist. Since the exhaust gas flowing in the exhaust pipe 4 has the highest flow velocity at or near the venturi portion 4b, the water discharged to the outer surface of the porous member 3 can be reliably atomized. The water in the form of mist is discharged from the exhaust pipe 4 into the atmosphere outside the vehicle body 11 (see FIG. 1) together with the exhaust gas.

  As described above, the generated water atomizer 1 includes the exhaust pipe 4 and the introduction pipe 2 as shown in FIG. A porous member 3 having a plurality of holes through which water can be discharged into the exhaust pipe 4 is provided at the distal end portion 2c of the introduction pipe 2 located in the venturi section 4b.

  Therefore, the water discharged to the surface of the porous member 3 is cut out from the porous member 3 by the gas in the exhaust pipe 4 whose flow velocity is increased in the venturi portion 4b and becomes a mist. Moreover, since the porous member 3 has a plurality of holes, the surface is not smooth, and a turbulent boundary layer can be formed around the porous member 3. For example, a laminar boundary layer is formed around a pipe member 35 having a smooth outer peripheral surface as shown in FIG. 5, but a turbulent boundary layer is formed around a porous member 3 as shown in FIG. .

  In the turbulent boundary layer, fluid molecules actively collide more frequently than in the laminar boundary layer, and the velocity is averaged. Therefore, in the turbulent boundary layer generated by the porous member 3, the velocity is averaged compared to the laminar boundary layer, and the backflow is less likely to occur and separation is unlikely to occur. The magnitude of the noise (sound power) is generally proportional to the eighth power of the flow velocity of the gas flowing in the pipe. Therefore, if the flow rate of the gas flowing in the exhaust pipe is the same, the noise becomes smaller as the non-uniformity in the flow velocity is smaller. Therefore, the speed is averaged by the turbulent boundary layer formed by the porous member 3, and the generation of noise can be suppressed by suppressing the occurrence of separation.

  The porous member 3 has a plurality of holes. For this reason, the possibility of clogging the holes and preventing water from being ejected is small compared to a conventional nozzle or the like having only one hole. Therefore, the durability of the generated water atomizer 1 is improved.

  The porous member 3 is a sintered metal as shown in FIG. Accordingly, for example, a plurality of small holes can be easily formed as compared with a punching metal obtained by punching a metal pipe and a metal pipe formed with a plurality of slits. And the diameter of the water discharged | emitted to the surface of the porous member 3 becomes small by making the diameter of a hole small, and this water is easy to make it mist-like. Further, by forming a large number of holes, the surface of the porous member 3 becomes uneven, and a turbulent boundary layer is easily formed. Thereby, generation | occurrence | production of noise can be suppressed strongly.

  As shown in FIG. 3, the leading end 2 c of the introduction pipe 2 is located in the vicinity of the inner peripheral surface of the exhaust pipe 4. A porous member 3 projects into the exhaust pipe 4 from the distal end portion 2 c of the introduction pipe 2. Therefore, not the introduction pipe 2 but the porous member 3 protrudes from the exhaust pipe 4. Therefore, a turbulent boundary layer is formed in substantially the entire porous member 3 protruding into the exhaust pipe 4, thereby making it possible to strongly suppress the generation of noise.

(Other embodiments)
The present invention is not limited to the above-described embodiment, and may be the following form. For example, you may have further the cover 5 shown in FIG. The cover 5 is made of, for example, metal, and prevents water from being discharged from the porous member 3 by covering a part of the side wall portion 3 a of the porous member 3.

  As shown in FIGS. 6 and 7, the side wall 3 a of the porous member 3 has an upstream region 3 a 1 facing the gas flowing through the exhaust pipe 4 and a downstream region 3 a 2 on the opposite side. The upstream region 3a1 and the downstream region 3a2 each have a semicircular arc shape. The cover 5 has a semicircular arc shape so as to cover the downstream region 3a2 of the porous member 3, and extends from the axially proximal end portion to the distal end portion of the downstream region 3a2.

  As described above, the porous member 3 is provided with the cover 5 that covers the downstream region 3a2 as shown in FIGS. By the way, the amount of water discharged from the porous member 3 is increased as the gas flow rate increases. The flow velocity of the gas flowing around the porous member 3 is fast around the upstream region 3a1 and slow around the downstream region 3a2. Therefore, in the downstream area 3a2 of the porous member 3, water may be discharged to the exhaust pipe 4 as a liquid without being atomized. On the other hand, a cover 5 is provided in the downstream region 3 a 2 of the porous member 3. Therefore, it can be suppressed that water is discharged to the exhaust pipe 4 in the downstream region 3a2 in the liquid state.

  The porous member 3 shown in FIGS. 6 and 7 is provided with a cover 5. However, the porous member 3 may be provided with a cover 6 shown in FIGS. As shown in FIGS. 8 and 9, the cover 6 is cylindrical, covers the entire circumference of the side wall 3a of the porous member 3, and extends from the axial base end of the side wall 3a to the tip. Therefore, the upstream region 3 a 1 and the downstream region 3 a 2 of the side wall 3 a are covered by the cover 6, and water can be discharged into the exhaust pipe 4 from the lid 3 b of the porous member 3.

  The generated water atomizer 1 shown in FIG. 3 has an introduction pipe 2 and a porous member 3. However, the generated water atomizer may have the introduction pipe 2 and the porous member 7 shown in FIGS. As shown in FIG. 11, the introduction pipe 2 has a second portion 2b that penetrates from the outer peripheral surface of the venturi portion 4b to the inner peripheral surface, and a third portion 2d that protrudes from the second portion 2b to the inside of the venturi portion 4b. ing. The third portion 2d extends from the inner peripheral surface of the venturi portion 4b to the vicinity of the cross-sectional center line of the venturi portion 4b. A disc-shaped porous member 7 that covers the opening of the tip 2e is provided at the tip 2e of the third portion 2d. Therefore, the water that has passed through the introduction pipe 2 is discharged from the porous member 7 into the exhaust pipe 4.

  The generated water atomizer 1 shown in FIG. 3 has an introduction pipe 2 and a porous member 3. However, the generated water atomizer may have the introduction pipe 8 and the porous member 9 shown in FIG. The introduction pipe 8 has a first part 8 a extending from the tank 26 to the exhaust pipe 4 and a second part 8 b extending inside the exhaust pipe 4. The lower end portion of the first part 8 a is located below the water surface of the water stored in the tank 26. The second part 8b extends from the end of the inlet side pipe part 4a of the exhaust pipe 4 toward the venturi part 4b. The distal end portion of the second portion 8b is located in the vicinity of the venturi portion 4b, and a porous member 9 formed in the same manner as the porous member 3 shown in FIG.

  The porous member 3 shown in FIG. 3 is a metal sintered body, but may be formed from a punching metal or an expanded metal. The punching metal is formed by punching a plurality of holes in a metal tube. The expanded metal forms a plurality of slits by forming a plurality of slits in a metal tube and stretching the metal tube to open the slits.

  The distal end portion 2c of the introduction pipe 2 shown in FIG. 3 is located in the vicinity of the inner peripheral surface of the exhaust pipe 4, and the porous member 3 is attached to the distal end portion 2c. However, the leading end of the introduction pipe may protrude into the exhaust pipe, an opening may be formed on a part of the tip, and a porous member may be provided at the opening. The exhaust pipe 4 shown in FIGS. 2 and 3 is connected to the exhaust side of the fuel cell 21. However, a compressor or the like may be connected to the exhaust pipe 4, and gas may be supplied to the exhaust pipe 4 by the compressor or the like. The vehicle 10 shown in FIG. 1 is an industrial vehicle, but may be a vehicle such as an automobile or a bus.

DESCRIPTION OF SYMBOLS 1 ... Generated water atomizer 2, 8 ... Introducing pipe 2c, 2e ... Tip part 3, 7, 9 ... Porous member 3a ... Side wall part 3a1 ... Upstream area | region 3a2 ... Downstream area | region 3b ... Cover part 4 ... Exhaust pipe 4b ... Venturi Parts 5, 6 ... cover 10 ... vehicle 12 ... cargo handling device 20 ... fuel cell system 21 ... fuel cell 22 ... hydrogen tank 23 ... compressor 24 ... humidifier 25 ... diluter 26 ... tank

Claims (4)

A generated water atomization device for a fuel cell vehicle for making the generated water generated by the fuel cell into a mist and discharging it to the outside of the vehicle body,
An exhaust pipe having a venturi portion in which a part of the inner peripheral diameter of the pipe is constricted, and an introduction pipe for supplying water in the tank in which the generated water can be stored from the tank side to the exhaust pipe,
A porous member having a plurality of holes through which water can be discharged into the exhaust pipe is provided at the leading end of the introduction pipe located at or near the venturi section ,
The porous member has an upstream region facing the gas flow in the exhaust pipe and a downstream region opposite to the upstream region,
The porous water member is provided with a cover that covers the downstream region, and a generated water atomizer for a fuel cell vehicle. It is the production | generation water atomization apparatus of the fuel cell vehicle of Claim 1, Comprising:
The porous water member is a sintered metal body, and is a generated water atomizer for a fuel cell vehicle. A generated water atomization device for a fuel cell vehicle according to claim 1 or 2,
The leading end of the introduction pipe is located near the inner peripheral surface of the exhaust pipe,
A generated water atomizing device for a fuel cell vehicle, characterized in that a porous member projects into the exhaust pipe from the tip of the introduction pipe. It is the production | generation water atomization apparatus of the fuel cell vehicle as described in any one of Claims 1-3,
The cover is configured to cover the downstream region of the porous member and not to cover the upstream region, the generated water atomizing device for a fuel cell vehicle.

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