JP6007023B2 - Fuel cell system - Google Patents

Description

  The present invention relates to a fuel cell system, and more particularly to a fuel cell system including an atomizer that atomizes generated water generated in a fuel cell.

Vehicles equipped with a fuel cell system that generates electricity by reacting hydrogen with oxygen in the air have been put into practical use. In a fuel cell, an electromotive force is generated by an electrochemical reaction between hydrogen and oxygen, and water (product water) is generated. For this reason, in a vehicle equipped with a fuel cell system, the exhaust gas contains a large amount of water.
In the generated water discharge device for a fuel cell vehicle disclosed in Patent Document 1, an atomizing device that atomizes generated water generated in a fuel cell mounted on a motorcycle and discharges the atomized water to the outside of the vehicle body. I have. Further, the fuel cell vehicle is provided with a vehicle speed detecting means for detecting the traveling speed of the vehicle, and is controlled so as to release the atomized water when the traveling speed detected by the vehicle speed detecting means is equal to or higher than the set speed. For this reason, the atomized water is reliably diffused by a strong traveling wind when the traveling speed is equal to or higher than the set speed.

JP 2007-141475 A

By the way, when the fuel cell system as described above is applied to an industrial vehicle such as a forklift, there are the following problems. The forklift includes a travel motor and a cargo handling motor, and the travel motor and the cargo handling motor are driven by the electric power generated by the fuel cell to perform the travel operation and the cargo handling operation of the forklift.
The maximum speed of a forklift is limited to a low speed (20 km / h in Japan) compared to a motorcycle to which the fuel cell system disclosed in Patent Document 1 is applied, and a strong running wind like a motorcycle is generated. do not do. Therefore, in a forklift to which the fuel cell system is applied, it is not possible to diffuse the atomized water to the outside of the vehicle body due to strong traveling wind.
Further, in the case of a forklift to which a fuel cell system is applied, the vehicle body usually stays at the same position during cargo handling work. For this reason, there exists a problem that the atomized water which comes out of the atomizer provided in the vehicle body sprays a specific place locally during cargo handling work. The fuel cell system disclosed in Patent Document 1 cannot solve this type of problem.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a fuel cell system capable of preventing local spraying of atomized product water during cargo handling work. .

  In order to solve the above-mentioned problems, the invention described in claim 1 is directed to a fuel cell, a traveling motor and a cargo handling motor, and a gas / liquid that separates off-gas discharged with power generation of the fuel cell into product water and gas. A separator, an atomizer for atomizing the generated water supplied to an exhaust passage for transferring the gas after separation, the gas-liquid separator and the atomizer are connected, and the gas after separation is An exhaust pipe for guiding the atomizer; and a water conduit that connects the gas-liquid separator and the atomizer and supplies the generated water stored in the gas-liquid separator to the atomizer. A fuel cell system comprising: a water conduit tube valve provided on the water conduit and capable of being opened and closed; and a control device that controls the opening and closing of the water conduit tube valve, the control device including a load of the load handling motor. A threshold value is stored, and when the load on the cargo handling motor is greater than the threshold value, Control device is characterized by closing the water conduit valve.

  According to the first aspect of the present invention, when the load of the cargo handling motor is larger than the threshold value, the control device performs control to close the water conduit valve. Therefore, when the cargo handling work is performed with the load of the cargo handling motor being larger than the threshold value. Can be set to a state where the water conduit valve is closed and the atomization process is stopped (interrupted). In addition, when the load of the cargo handling motor is smaller than the threshold value and the cargo handling operation is not performed, it is possible to control the opening of the conduit pipe valve so that the atomization process can be performed. Therefore, at the time of cargo handling work, the atomization process can be stopped and local spraying of the atomized generated water can be prevented.

  The invention according to claim 2 is the fuel cell system according to claim 1, in which the generated water remaining in the exhaust passage is recovered and stored out of the generated water atomized by the atomizer. A tank, and a circulation pipe for connecting the recovery tank and the atomizer and supplying the recovered water stored in the recovery tank to the atomizer are provided.

  According to invention of Claim 2, the recovered water collect | recovered by the collection tank via the circulation pipe can be supplied to an atomizer, and atomization can be performed. Therefore, the recovered water can be efficiently atomized.

According to a third aspect of the present invention, in the fuel cell system according to the second aspect , a circulation pipe valve that can be opened and closed is provided in the circulation pipe.

According to the invention described in claim 3, since the circulation pipe valve is provided in the circulation pipe, it is possible to set the atomization process to be stopped by closing the circulation pipe valve at the time of cargo handling work.
Local spraying of atomized recovered water can be prevented.

  According to a fourth aspect of the present invention, in the fuel cell system according to the third aspect, the control device stores a first threshold value and a second threshold value that is greater than the first threshold value, and the control device includes: When the load of the cargo handling motor is larger than the first threshold, the conduit pipe valve is closed, and when the load of the cargo handling motor is larger than the second threshold, the circulation pipe valve is closed.

  According to the invention of claim 4, the control device can set the state in which the atomizing process is stopped by closing the conduit pipe valve when the load handling work is greater than the first threshold value as the threshold value. Local spraying due to the atomization of a large amount of generated water can be prevented. However, since only a small amount of generated water (recovered water) is atomized with respect to the recovered water, the recovered water is efficiently atomized by being atomized when the load of the cargo handling motor is smaller than the second threshold value. Can be processed.

  ADVANTAGE OF THE INVENTION According to this invention, it is possible to prevent local spraying of the atomized produced water at the time of cargo handling work.

1 is a front view showing an overall configuration of a forklift equipped with a fuel cell system according to a first embodiment. 1 is a block diagram showing an overall configuration of a fuel cell system according to a first embodiment. It is a schematic diagram which shows schematic structure of the atomizer in FIG. It is a graph which shows the relationship between the flow velocity of gas, and the particle diameter of mist. It is a flowchart which shows the control flow of the valve | bulb which concerns on 1st Embodiment. It is a flowchart which shows the control flow of the valve | bulb which concerns on 2nd Embodiment.

(First embodiment)
Hereinafter, a forklift equipped with the fuel cell system according to the first embodiment will be described with reference to FIGS.
As shown in FIG. 1, the forklift 10 is a forklift as an industrial vehicle 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 mast 12 </ b> A is provided with a hydraulic pump 16 and a lift cylinder 12 </ b> D that expands and contracts by the hydraulic pump 16. The hydraulic pump 16 is connected to the cargo handling motor 17 shown in FIG. 2, and the hydraulic pump 16 can be operated by driving the cargo handling motor 17. The fork 12C and the lift bracket 12B are raised and lowered by raising and lowering the mast 12A by the operation of the lift cylinder 12D.

  As shown in FIG. 1, the forklift 10 has drive wheels (front wheels) 13 at the front lower part of the vehicle body 11 and rear wheels 14 at the rear lower part of the vehicle body 11. A traveling motor 15 that applies power to the drive wheels 13 is provided inside the vehicle body 11. A fuel cell system 35 including a fuel cell 18 and a hydrogen tank 19 is provided inside the vehicle body 11. The traveling motor 15 and the cargo handling motor 17 are driven by the electric power generated by the fuel cell 18, and the traveling operation and the cargo handling operation of the forklift 10 are performed.

As shown in FIG. 2, the fuel cell system 35 includes a fuel cell unit 34 having the fuel cell 18. The fuel cell unit 34 includes a fuel cell 18, a hydrogen tank 19 that stores hydrogen, and a compressor 20 that supplies air to the fuel cell 18. A hydrogen tank 19 is connected to the anode side of the fuel cell 18 via a conduit 24. A humidifier 21 is connected to the cathode side of the fuel cell 18 via a conduit 26, and a compressor 20 is connected to the humidifier 21 via a conduit 25.
The fuel cell 18 is, for example, a polymer electrolyte fuel cell, which reacts hydrogen supplied from the hydrogen tank 19 with oxygen in the air supplied from the compressor 20 to generate direct current electric energy (DC power). Is generated.

  Hydrogen molecules supplied to the anode side of the fuel cell 18 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 side become oxygen ions and combine with hydrogen ions to produce water. The generated water is supplied to the humidifier 21 through the conduit 27 together with the exhaust of the air supplied to the cathode, and a part of the generated water is extracted by the humidifier 21 and reused. The remaining produced water is discharged to the gas-liquid separator 22 through the pipe line 28 together with the exhaust gas.

A part of the water or nitrogen gas on the cathode side of the fuel cell 18 is reversely diffused and moves to the anode side. Then, when these concentrations increase on the anode side, the power generation efficiency decreases. In order to suppress this, a pipe 29 for purge gas is connected to the anode side. The on-off valve 30 provided in the pipe line 29 is controlled and opened by the control device 31 when the fuel cell 18 continues to operate for a predetermined time. As a result, moisture and nitrogen gas accumulated on the anode side are discharged together with hydrogen gas to the gas-liquid separator 22 side through the conduit 29.
The gas-liquid separator 22 is connected to the atomizer 23 via the exhaust pipe 36.

  As shown in FIG. 2, a capacitor 33 is connected to the fuel cell 18 via a power control unit 32. The electric power generated by the fuel cell 18 is adjusted in voltage by the power control unit 32 and then charged in the capacitor 33. The power control unit 32 is connected to the traveling motor 15 and the cargo handling motor 17. Further, the fuel cell system 35 is provided with a control device 31 that controls the entire system of the fuel cell system 35. The control device 31 is connected to the fuel cell unit 34, the power control unit 32, the atomizer 23, and the like. Yes.

  As shown in FIG. 3, the gas-liquid separator 22 is connected to the fuel cell 18 via pipe lines 28 and 29, and off gas generated in the fuel cell 18 is introduced. The off gas is a combination of the produced water and exhaust gas passing through the pipe line 28, and the water, nitrogen gas, and hydrogen gas accumulated on the anode side passing through the pipe line 29. The off-gas is separated into gas (gas) and liquid (product water) in the gas-liquid separator 22. The generated water falls and is stored in the water storage unit 37 in the gas-liquid separator 22. The gas (hydrogen, air, etc.) separated in the gas-liquid separator 22 is transferred to the atomizer 23 connected to the exhaust pipe 36. The exhaust path was supplied to an exhaust pipe 36 that connects the gas-liquid separator 22 and the atomizer 23, guides the separated gas to the atomizer 23, and an exhaust path that transfers the separated gas. It is formed by an atomizer 23 that atomizes the generated water.

  In the atomizer 23, a venturi part 38 for increasing the flow velocity of the gas transferred through the exhaust pipe 36 and an expansion chamber 39 connected to the downstream side of the venturi part 38 and communicating with the exhaust port 40 are formed. Has been. The flow passage cross-sectional diameter in the venturi portion 38 increases from the exhaust pipe 36 toward the expansion chamber 39, and the venturi portion 38 has a small-diameter portion 38A having the smallest flow passage cross-sectional diameter on the upstream side. The exhaust pipe 36 and the atomizer 23 (the venturi section 38 and the expansion chamber 39) form a gas exhaust path after separation.

  The gas-liquid separator 22 is connected to a water conduit 41 that guides the generated water stored in the water storage section 37 to the small diameter section 38A of the venturi section 38 that serves as a gas discharge path. At the tip of the water conduit 41, a water conduit nozzle 42 for introducing the generated water into the small diameter portion 38A is provided. In the middle of the water conduit 41, a water conduit valve 43 that can open and close the conduit is provided. The water conduit valve 43 is connected to the control device 31. The control device 31 performs opening / closing control of the water conduit valve 43.

  The expansion chamber 39 is connected to a recovery pipe 44 that recovers the generated water remaining in the expansion chamber 39 without being discharged from the exhaust port 40 to the outside. The generated water that has not been discharged to the outside from the exhaust port 40 is generated water that has not been atomized or generated water that has become droplets due to condensation even when atomized. The recovery pipe 44 is connected to a recovery tank 45 that stores the recovered generated water (recovered water). A circulation pipe 46 is connected to the recovery tank 45. The recovered water is generated water remaining in the expansion chamber 39 and is a small amount compared to the generated water separated by the gas-liquid separator 22. Therefore, the recovery tank 45 has a smaller volume for storing the generated water (recovered water) than the water storage unit 37. The circulation pipe 46 functions as a circulation path for circulating the collected water stored in the collection tank 45 to the small diameter part 38A of the venturi part 38 that becomes a gas discharge path. At the tip of the circulation pipe 46, a circulation pipe nozzle 47 for introducing recovered water into the small diameter portion 38A is provided. In the middle of the circulation pipe 46, a circulation pipe valve 48 capable of opening and closing the pipeline is provided. The circulation pipe valve 48 is connected to the control device 31. The control device 31 performs opening / closing control of the circulation pipe valve 48.

As described above, since the venturi portion 38 is formed in the atomizer 23, the pressure of the small diameter portion 38A becomes lower than the pressure of other portions. For this reason, the flow velocity of the separated gas introduced through the exhaust pipe 36 rapidly increases when passing through the small diameter portion 38A. And the pressure of the small diameter part 38A is lower than the pressure of the water storage part 37 which stores the produced water after the separation in the gas-liquid separator 22. For this reason, the generated water in the water storage part 37 is introduced into the small diameter part 38 </ b> A via the water conduit 41 and the water conduit nozzle 42 by the venturi effect. Then, the generated water introduced into the small-diameter portion 38A is atomized by the gas having an increased flow velocity, and flows into the expansion chamber 39 together with the gas. Most of the atomized generated water is discharged from the exhaust port 40 to the outside. Discharged.
When the water conduit valve 43 is open, the generated water is introduced into the small-diameter portion 38A, and thus the generated water is atomized in the atomizer 23, but the water conduit valve 43 is closed. In this case, since the generated water is not introduced into the small diameter portion 38A, the atomization process is not performed.

Further, the generated water remaining in the expansion chamber 39 without being discharged to the outside from the exhaust port 40 is recovered in the recovery tank 45 via the recovery pipe 44 connected to the expansion chamber 39. The pressure in the expansion chamber 39 is higher than the pressure in the small diameter portion 38A of the venturi portion 38. For this reason, the recovered water in the recovery tank 45 is again introduced into the small diameter portion 38A via the circulation pipe 46 and the circulation pipe nozzle 47 by the venturi effect. As a result, the recovered water in the recovery tank 45 is atomized again by the gas whose flow velocity has increased, and flows into the expansion chamber 39 together with the gas, and most of the atomized recovered water is discharged from the exhaust port 40 to the outside. Is done. Since the amount of the generated water (recovered water) in the recovery tank 45 is small compared to the amount of the generated water in the water storage unit 37, the recovered water to be atomized (stored in the recovery tank 45 and the circulation pipe nozzle 47). The amount of recovered water that is atomized through the water is smaller than the amount of product water that is atomized at the same flow rate (product water that is stored in the storage unit 37 and atomized through the water conduit nozzle 42). Thus, the diameters of the circulation pipe 46 and the circulation pipe nozzle 47 are set.
When the circulation pipe valve 48 is open, the recovered water is introduced into the small diameter portion 38A, so that the recovered water is atomized in the atomizer 23, but the circulation pipe valve 48 is closed. In this case, since the recovered water is not introduced into the small diameter portion 38A, the atomization process is not performed.

By the way, in order to atomize generated water or recovered water with the atomizer 23, a gas flow rate of a certain level or more is required. The graph shown in FIG. 4 is a graph showing the relationship between the gas flow rate and the particle diameter of the generated mist (mist). The particle diameter of the mist generated by the atomization process becomes smaller as the flow velocity of the gas flowing in through the exhaust pipe 36 increases. FIG. 4 shows experimental results conducted by the present applicant, and the gas flow rate represents the flow rate in the vicinity of the nozzle.
The gas flow rate is related to the power generation load of the fuel cell 18, and the gas flow rate increases as the power generation load of the fuel cell 18 increases. In the forklift 10, the traveling motor 15 and the cargo handling motor 17 are driven, and the power generation load of the fuel cell 18 increases while the forklift 10 is traveling and handling. Further, even in the handling operation with only the traveling operation or with the forklift stopped, the power generation load of the fuel cell increases when the traveling load and the cargo handling load are large. Accordingly, the atomization process can be performed by the atomizer 23 when at least one of the traveling motor 15 and the cargo handling motor 17 is driven and the power generation load of the fuel cell 18 is high.

Next, the control flow of the water conduit valve 43 and the circulation pipe valve 48 in the fuel cell system 35 will be described based on the flowchart shown in FIG.
First, when the control routine starts, the control device 31 obtains load information of the cargo handling motor 17 in step S101. The load information of the cargo handling motor 17 refers to information such as motor torque and motor rotation speed.
Next, in step S102, the control device 31 performs a process for determining whether or not the load of the cargo handling motor 17 is greater than a threshold value S that is preset and stored in the memory. The threshold S is set based on load information when the cargo handling motor 17 is driven and cargo handling work is started.

  The case where the load of the cargo handling motor 17 is larger than the threshold value S corresponds to when the cargo handling work is being performed. In this case, the process proceeds to step S103, and the control device 31 performs control to close the conduit pipe valve 43 and the circulation pipe valve 48. By controlling the conduit pipe valve 43 and the circulation pipe valve 48 to close, the conduits of the conduit pipe 41 and the circulation pipe 46 are blocked. Therefore, the generated water stored in the water storage part 37 of the gas-liquid separator 22 is not introduced into the small diameter part 38A via the water guide pipe 41 and the water pipe nozzle 42, and the atomization process is not performed. Further, the recovered water stored in the recovery tank 45 is not introduced into the small diameter portion 38A via the circulation pipe 46 and the circulation pipe nozzle 47, and the atomization process is not performed.

In step S102, when the load of the cargo handling motor 17 is smaller than the threshold value S, this corresponds to the case where the cargo handling operation is not performed at all or the motor load is small at the start of the cargo handling operation. In this case, the process proceeds to step S104, and the control device 31 performs control to open the water conduit valve 43 and the circulation pipe valve 48. By controlling the conduit pipe valve 43 and the circulation pipe valve 48 to open, the conduits of the conduit pipe 41 and the circulation pipe 46 are opened. Therefore, the generated water stored in the water storage part 37 of the gas-liquid separator 22 is introduced into the small diameter part 38A via the water conduit 41 and the water conduit nozzle 42, and can be atomized. Further, the recovered water stored in the recovery tank 45 is introduced into the small diameter portion 38A through the circulation pipe 46 and the circulation pipe nozzle 47, and can be atomized.
Therefore, when the traveling operation is performed in this state and the power generation load of the fuel cell 18 becomes large, the atomization process is performed.
Thus, the series of control routines ends. This control routine is repeatedly performed at predetermined intervals.

Next, the operation of the fuel cell system 35 of the present embodiment will be described.
The atomizer 23 can perform the atomization process when the traveling motor 15 and the cargo handling motor 17 are driven and the forklift 10 is traveling and handling, and the power generation load of the fuel cell 18 is reduced. It is in a high state. For example, when the power generation load of the fuel cell 18 is high and the load of the cargo handling motor 17 is smaller than the threshold value S, the load of the traveling motor 15 is large and the forklift 10 is traveling. At this time, since the control device 31 performs control to open the water conduit valve 43 and the circulation tube valve 48, the generated water and the recovered water are introduced into the small diameter portion 38A of the venturi portion 38 via the water conduit 41 and the circulation tube 46. Mist is generated by atomization by the gas having an increased flow velocity. And the produced | generated mist flows in into the expansion chamber 39 with gas, and is discharged | emitted from the exhaust port 40 outside. Therefore, since the atomization process can be performed during the traveling operation, the generated water and the recovered water can be atomized and reliably discharged to the outside.

  Further, when the power generation load of the fuel cell 18 is high and the load of the cargo handling motor 17 is larger than the threshold value S, the forklift 10 is in the cargo handling operation. At this time, since the control device 31 performs control to close the water conduit valve 43 and the circulation pipe valve 48, the generated water and the recovered water are not introduced into the small diameter portion 38 </ b> A of the venturi section 38 through the water conduit 41 and the circulation pipe 46. The atomization process is not performed. Further, during the cargo handling operation, the forklift 10 does not move and remains at a specific position. Therefore, even if the forklift 10 stays at a specific position, the atomization process is not performed, so that the atomized generated water and recovered water can be prevented from being sprayed locally.

The fuel cell system 35 according to the first embodiment has the following effects.
(1) When the power generation load of the fuel cell 18 is high and the load of the cargo handling motor 17 is larger than the threshold value S (when cargo handling work is being performed), the control device 31 performs the water conduit valve 43 and the circulation. Since the pipe valve 48 is controlled to be closed, the atomization process is not performed. Further, during the cargo handling operation, the forklift 10 does not move and remains at a specific position. Therefore, even if the forklift 10 stays at a specific position, the atomization process is not performed, so that the atomized generated water and recovered water can be prevented from being sprayed locally.
(2) When the power generation load of the fuel cell 18 is high and the load of the cargo handling motor 17 is smaller than the threshold value S (the cargo handling operation is not performed at all or when the cargo handling operation is started), the vehicle travels. The load on the motor 15 is large, and the forklift 10 is running. At this time, since the control device 31 performs control to open the water conduit valve 43 and the circulation tube valve 48, the generated water and the recovered water are introduced into the small diameter portion 38A of the venturi portion 38 via the water conduit 41 and the circulation tube 46. The gas is atomized by the gas whose flow rate has increased, and is discharged from the exhaust port 40 to the outside. Therefore, since the atomization process can be performed during the traveling operation, the generated water and the recovered water can be atomized and reliably discharged to the outside even if the forklift 10 cannot obtain a strong traveling wind due to the low-speed traveling. is there.
(3) Since the recovered water stored in the recovery tank 45 is introduced into the atomizer 23 via the circulation pipe 46 and atomized, the recovered water can be efficiently atomized.

(Second Embodiment)
Next, the fuel cell system 35 according to the second embodiment will be described with reference to the drawings.
In this embodiment, the control flow of the conduit pipe valve 43 and the circulation pipe valve 48 in the first embodiment is changed, and other configurations are common.
Therefore, here, for convenience of explanation, some of the reference numerals used in the previous explanation are used in common, explanation of common configurations is omitted, and only the changed parts are explained.

As shown in FIG. 6, when the control routine starts, the control device 31 obtains load information of the cargo handling motor 17 in step S201.
Next, in step S202, the control device 31 determines whether or not the load of the cargo handling motor 17 is greater than a threshold value T1 as a first threshold value that is separately determined and stored in the memory.

  When the load of the cargo handling motor 17 is larger than the threshold value T1 (during the cargo handling operation), the process proceeds to step S203, and the control device 31 controls the water conduit valve 43 to be closed. By controlling the conduit pipe valve 43 to close, the conduit of the conduit pipe 41 is blocked. Therefore, the atomization process of the generated water stored in the water storage part 37 through the water conduit 41 and the water conduit nozzle 42 is not performed.

Next, in step S205, the control device 31 determines whether the load of the cargo handling motor 17 is greater than a threshold value T2 as a second threshold value that is separately defined and stored in the memory. Note that the threshold value T2 is larger than the threshold value T1.
When the cargo handling operation is performed in which the load of the cargo handling motor 17 is greater than the threshold value T2, the process proceeds to step S206, and the control device 31 performs control to close the circulation pipe valve 48. By controlling the circulation pipe valve 48 to be closed, the conduit of the circulation pipe 46 is blocked. Therefore, the atomization process of the recovered water stored in the recovery tank 45 via the circulation pipe 46 and the circulation pipe nozzle 47 is not performed.

  In step S205, when the load handling operation is performed with the load of the load handling motor 17 being smaller than the threshold value T2, the process proceeds to step S207, and the control device 31 performs control to open the circulation pipe valve 48. In this case, an atomization process of the recovered water stored in the recovery tank 45 through the circulation pipe 46 and the circulation pipe nozzle 47 is performed.

In step S202, when the load of the cargo handling motor 17 is smaller than the threshold value T1 (at the start of the cargo handling operation), the process proceeds to step S204, and the control device 31 performs control to open the water conduit pipe valve 43 and the circulation pipe valve 48. . By controlling the conduit pipe valve 43 and the circulation pipe valve 48 to open, the conduits of the conduit pipe 41 and the circulation pipe 46 are opened. Therefore, the generated water stored in the water storage part 37 of the gas-liquid separator 22 is introduced into the small diameter part 38A via the water conduit 41 and the water conduit nozzle 42, and can be atomized. Further, the recovered water stored in the recovery tank 45 is introduced into the small diameter portion 38A through the circulation pipe 46 and the circulation pipe nozzle 47, and can be atomized. Therefore, when the traveling operation is performed in this state and the power generation load of the fuel cell 18 becomes large, the atomization process is performed.
Thus, the series of control routines ends. This control routine is repeatedly performed at predetermined intervals.

As described above, when the load of the cargo handling motor 17 is larger than the threshold value T1 with the start of the cargo handling operation, first, the water conduit valve 43 is closed, and then the load of the cargo handling motor 17 becomes larger than the threshold value T2. The circulation pipe valve 48 is closed.
That is, when the load of the cargo handling motor is larger than T2, both the generated water and the recovered water are not atomized. When the load of the cargo handling motor is larger than T1 and equal to or less than T2, only the recovered water is atomized. Done. And when the load of a cargo handling motor is T1 or less, atomization of both produced | generated water and collection | recovery water is performed. In this way, since the water guide pipe valve 43 and the circulation pipe valve 48 are controlled to be sequentially closed as the load of the load handling motor 17 increases during the load handling operation, the time for atomizing the recovered water can be increased. The recovered water can be efficiently atomized. When only the circulation pipe valve 48 is open, the recovered water stored in the recovery tank 45 can be atomized, but the amount of atomization is small. For this reason, even if the forklift 10 stays at a specific position during the cargo handling operation, a large amount of recovered water (generated water) will not be sprayed locally, so the influence of the discharged recovered water mist on the surroundings is not affected. small.
Further, at the start of a cargo handling operation in which the load of the cargo handling motor 17 is smaller than the threshold value T1, the water guide pipe valve 43 and the circulation pipe valve 48 can be opened to perform the atomization process.

The present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the spirit of the invention. For example, the following modifications may be made.
In the first and second embodiments, it has been described that the water guide pipe valve 43 is provided in the middle of the water guide pipe 41 and the circulation pipe valve 48 is provided in the middle of the circulation pipe 46, but the fuel cell system has only the water guide pipe valve 43. However, the circulation pipe valve 48 may be omitted. In this case, since the circulation pipe 46 side discharges only the recovered water in the recovery tank 45 even if the atomization process is performed, the fuel cell can be used in an environment where a small amount of mist is allowed. The atomization process is automatically performed according to the 18 power generation loads.
In the first and second embodiments, the example of the forklift 10 has been described. However, the present invention is not limited to the forklift, and may be applied to other industrial vehicles such as construction vehicles and towing vehicles, and general vehicles. The present invention can be applied to any vehicle as long as the fuel cell system can be mounted and a cargo handling device is provided.

DESCRIPTION OF SYMBOLS 10 Forklift 15 Traveling motor 17 Cargo handling motor 18 Fuel cell 22 Gas-liquid separator 23 Atomizer 31 Control device 35 Fuel cell system 36 Exhaust pipe 38 Venturi part 41 Water pipe 42 Water pipe nozzle 43 Water pipe valve 45 Recovery tank 46 Circulation pipe 47 Circulation pipe nozzle 48 Circulation pipe valve S Threshold value T1, T2 Threshold value

Claims (4)

Supplied to a fuel cell, a travel motor and a cargo handling motor, a gas-liquid separator that separates off-gas discharged as a result of power generation of the fuel cell into produced water and gas, and an exhaust path that transports the separated gas. An atomizer for atomizing the generated water, an exhaust pipe for connecting the gas-liquid separator and the atomizer, and guiding the separated gas to the atomizer, and the gas-liquid separator, A fuel cell system comprising: a water conduit that connects the atomizer and supplies the generated water stored in the gas-liquid separator to the atomizer;
A water conduit valve provided on the water conduit and capable of opening and closing;
A controller for controlling the opening and closing of the conduit pipe valve,
The control device stores a load threshold of the cargo handling motor, and when the load of the cargo handling motor is greater than the threshold, the control device closes the conduit pipe valve.   Of the generated water atomized by the atomizer, a recovery tank that recovers and stores the generated water remaining in the exhaust passage, and connects the recovery tank and the atomizer to the recovery tank. The fuel cell system according to claim 1, further comprising: a circulation pipe that supplies the collected recovered water to the atomizer. The fuel cell system according to claim 2 , wherein a circulation pipe valve that can be opened and closed is provided in the circulation pipe. The control device stores a first threshold value and a second threshold value greater than the first threshold value,
The controller closes the conduit pipe valve when the load of the cargo handling motor is greater than the first threshold value, and closes the circulation pipe valve when the load of the cargo handling motor is greater than the second threshold value. The fuel cell system according to claim 3, wherein

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