JP2008041547A - Fuel cell vehicle and method of controlling fuel cell vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle which can exhaust out water generated in a fuel cell stack by switching a plurality of exhausting mouths while a vehicle is not in operation under a low temperature environment, and to provide a method of controlling the fuel cell vehicle. <P>SOLUTION: When an outer temperature is lower than a predetermined value and a vehicle is not in operation, the controlling means to control to exhaust out water generated in a fuel cell stack switches to exhaust out generated water for one or a plurality of the exhausting mouths out of a plurality of the exhausting mouths for a predetermined time and, after the predetermined time is over, switches a plurality of the exhausting mouths respectively to exhaust water for a predetermined time from the other one or a plurality of the exhausting mouths from which generated water have not been exhausted. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vehicle equipped with a fuel cell as a power source and a control method thereof.

  Conventionally, in a vehicle equipped with a fuel cell, it is known that water generated by power generation is drained to the outside through an exhaust pipe extending to the rear part of the vehicle body. There is also known a technique in which water generated by power generation is separated by a gas-liquid separator, and the separated water is temporarily stored in a recovery tank and then discharged from a plurality of water outlets (see, for example, Patent Document 1). ).

JP 2005-153853 A

  When the vehicle is stopped in a low-temperature environment and the water generated by power generation is drained to the outside through the exhaust pipe and multiple outlets, the longer the drainage time and the greater the amount of drainage, the more ice and snow is generated around the outlet. Become more.

  Therefore, when the vehicle is stopped in a low temperature environment and drainage is performed continuously through the exhaust pipe and the plurality of discharge ports, there is a problem that the amount of ice and snow generated around the discharge port increases.

  The present invention relates to a vehicle equipped with a fuel cell as a power source, a plurality of outlets for discharging water generated by the fuel cell to the outside, an outside air temperature detecting means for detecting the outside air temperature, Vehicle stop detection means for determining whether or not the vehicle is stopped, and control for discharging the generated water to the outside while switching the plurality of discharge ports when the outside air temperature is low and the vehicle is stopped And a control means for performing the above.

  In the present invention, it is preferable that the control means switches the discharge port every predetermined period and discharges the water generated by the fuel cell to the outside.

  In the present invention, the control means discharges water that is secondary generated by the fuel cell from any one or more of the plurality of discharge ports to the outside for a predetermined period, and after the predetermined period has elapsed, It is preferable to sequentially switch so that water is discharged to the outside only for a predetermined period from one or a plurality of other outlets from which the generated water has not yet been discharged.

  In the present invention, the predetermined period is preferably within 3 seconds.

  According to such a configuration, water generated secondary by the fuel cell is not continuously discharged from each outlet at the same time, so that a large amount of ice and snow is prevented from being generated around each outlet. can do.

  In the present invention, it is preferable that the control means switches the plurality of discharge ports on the basis of the water discharge amount for each of the plurality of discharge ports, and discharges the water generated by the fuel cell to the outside.

  In the present invention, the control means discharges water generated by the fuel cell from any one or more of the plurality of discharge ports to the outside by a predetermined reference amount, and when the discharge ends. It is preferable to sequentially switch so that water is discharged to the outside by a predetermined reference amount in the same manner from one or a plurality of other outlets from which water has not yet been discharged.

  According to such a configuration, it is possible to prevent a large amount of ice and snow from being generated around the discharge port by setting the amount of water discharged from each discharge port to an amount that does not affect the external environment.

  The present invention relates to a method for controlling a vehicle in which a fuel cell is mounted as a power source, and when the outside air temperature is low and the vehicle is stopped, the fuel cell performs a secondary operation while switching a plurality of discharge ports. It is characterized by discharging the water generated in the outside.

  In the control method of the present invention, it is preferable to switch a plurality of discharge ports every predetermined period and discharge the water generated by the fuel cell to the outside.

  In the control method of the present invention, it is preferable to switch a plurality of discharge means based on the discharge amount of water at each of the plurality of discharge ports, and discharge water generated secondary by the fuel cell to the outside.

  ADVANTAGE OF THE INVENTION According to this invention, when a vehicle is stopped in a low-temperature environment, it can prevent that a lot of ice and snow are produced | generated around a discharge port.

“Embodiment 1”
DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as embodiments) will be described with reference to the drawings.

  FIG. 1 is a layout diagram illustrating the layout of equipment mounted on a vehicle 70 in which the fuel cell of the present invention is mounted as a power source. The vehicle 70 according to the embodiment of the present invention includes a fuel cell stack 10, a control unit 30, a compressor 12, a hydrogen tank 14, an exhaust pipe 16, a plurality of control valves 18a to 18f, and discharge ports 20a to 20 provided downstream thereof. 20f, front wheels 32a and 32b, and rear wheels 34a and 34b.

  In the present embodiment, the fuel cell stack 10 is disposed on the front side of the vehicle 70, and a compressor 12 for supplying air as an oxidant to the fuel cell stack 10 is disposed further forward. A hydrogen tank 14 for supplying hydrogen gas, which is a fuel gas, to the fuel cell stack 10 is disposed behind the fuel cell stack 10. In the present embodiment, the arrangement of the mounted devices of the vehicle 70 is configured as illustrated in FIG. 1, but the arrangement of the mounted devices is not limited to this, and various changes can be made. For example, the fuel cell stack 10 may be disposed at the center of the vehicle 70 or the rear side of the vehicle 70, and the hydrogen tank 14 may be disposed at the center of the vehicle 70 or the front side of the vehicle. Here, the fuel cell stack 10 is configured by stacking a plurality of single cells. Each single cell has a structure in which an electrolyte membrane (for example, a polymer membrane) is sandwiched between an anode electrode and a cathode electrode, and both sides thereof are sandwiched between separators. The structure of the unit cell is the same as the unit cell structure of a fuel cell that has been widely known.

  The fuel cell stack 10 generates electric power by receiving supply of hydrogen gas as a fuel and air as an oxidant. The hydrogen gas and air supply system will be described later with reference to FIG.

  Along with the electrochemical reaction during the power generation, water is secondarily generated in the fuel cell stack 10, and the generated water is discharged from the plurality of discharge ports 20 a to 20 f through the exhaust pipe 16. Here, the control valves 18a to 18f connected to the control unit 30 are opened and closed by a signal from the control unit 30, and water is discharged from the plurality of discharge ports 20a to 20f. Will be described later.

  In the present embodiment, the exhaust pipe 16 is branched into a plurality of parts, and each of the branched exhaust pipes includes a plurality of outlets 20a to 20f. However, each of the outlets 20a to 20f prevents local generation of ice and snow. Therefore, it is preferable to provide a predetermined interval. In the present embodiment, six discharge ports 20a to 20f are provided. However, the number is not limited to six. For example, the number may be less than six, such as four. Of course, the number may be more than six, and various changes are possible.

FIG. 2 is a diagram showing an outline of the configuration of the fuel cell system mounted on the vehicle 70 of the present invention. The fuel cell system according to the present embodiment includes a fuel cell stack 10, a hydrogen supply system 50 that supplies hydrogen gas that is a fuel gas to the fuel cell stack 10, and an air supply that supplies air that is an oxidant to the fuel cell stack 10. Water generated by the reaction (2H ⁺ + 1 / 2O ₂ → H ₂ O) at the air electrode together with the exhaust gas (unreacted air) from the system 60 and the air electrode (cathode electrode) of the fuel cell stack 10 is externally supplied. And a release system 80 for releasing the product.

  The hydrogen supply system 50 includes a hydrogen supply path 52 that supplies hydrogen gas from the hydrogen tank 14 to the fuel electrode (anode) of each of the plurality of cells that constitute the fuel cell stack 10, and a hydrogen supply path 52 that supplies unreacted hydrogen gas. And a hydrogen recirculation pump 42 for sending the unreacted hydrogen gas to the hydrogen supply passage 52.

  The air supply system 60 humidifies the air pumped by the compressor 12 by the humidifier 40 and supplies the air to the air electrode (cathode) of each of the plurality of cells constituting the fuel cell stack 10. The exhaust gas discharge path 64 for discharging the exhaust gas together with water generated by the reaction at the air electrode. The exhaust gas is supplied to the humidifier 40 and humidifies the supply air pressure-fed from the compressor 12.

  The discharge system 80 includes an exhaust pipe 16 for discharging exhaust gas and water discharged from the fuel cell stack 10 to the outside, a plurality of control valves 18a to 18f, and discharge ports 20a to 20f. The control valves 18a to 18f are connected to the control unit 30, and the control unit 30 controls the opening and closing of the valves. Further, a vehicle speed sensor 101 for detecting the vehicle speed of the vehicle 70 and an outside air temperature sensor 102 for detecting the temperature of outside air are connected to the control unit 30.

  When the vehicle 70 is traveling normally, the control valves 18a to 18f are opened, and water generated in the fuel cell stack 10 is discharged together with the exhaust gas from the plurality of discharge ports 20a to 20f all at once. To do. Here, the opening degree of the control valves 18a to 18f may be fully open, or may be an opening degree that is adjusted according to the running state, and various modifications are possible.

  Next, the operation of the control valves 18a to 18f when the vehicle 70 is stopped and the outside air temperature is a predetermined value or less, for example, the outside air temperature is 0 degrees or less will be described. In this case, one of the control valves 18a to 18f is opened for a predetermined period by a signal from the control unit 30, and the other control valves are closed. And the water produced | generated by the fuel cell stack 10 is discharged | emitted outside with exhaust gas from one discharge port arrange | positioned downstream of this one control valve. Here, the valve opening degree of one control valve in the open state may be fully open, or may be an opening degree adjusted in accordance with the outside air temperature, and various modifications are possible. It is.

  The above-mentioned predetermined period can be set, for example, within 3 seconds. With this setting, water is not continuously discharged from each discharge port at the same time, thus preventing a large amount of ice and snow from being generated around the discharge port. it can.

  When the predetermined period elapses, one control valve that has been in an open state is closed, and then one of the other control valves other than the one control valve is in an open state for a predetermined period. Water is discharged to the outside from one outlet provided on the downstream side of the control valve. Thereafter, similarly, the control valves 18a to 18f are sequentially switched to discharge water together with the exhaust gas from the discharge ports 20a to 20f for a predetermined period.

  Next, switching control of the control valves 18a to 18f executed by the control unit 30 will be described. FIG. 3 is a flowchart illustrating an example of the switching control of the control valves 18a to 18f executed by the control unit 30.

  In the switching control of the control valves 18a to 18f, first, in step S201, it is determined whether or not the outside air temperature is a predetermined value or less by a signal from the outside air temperature sensor 102, and it is determined that the outside air temperature is a predetermined value or less. If so, the process proceeds to the next step S202. When it is determined that it is not less than the predetermined value, the switching control of the control valves 18a to 18f is not executed. The predetermined value of the outside air temperature may be 0 degrees, for example, and can be changed variously.

  In step S202, it is determined whether or not the vehicle 70 is in a stopped state based on a signal from the vehicle speed sensor 101. If it is determined that the vehicle 70 is in a stopped state, the process proceeds to the next step S203. When it is determined that the vehicle 70 is not in a stopped state, the control valve switching control is not performed.

  In step S203, any one of the control valves 18a to 18f is opened, the other control valves are closed, and the process proceeds to step S204. At this time, water generated in the fuel cell stack 10 is discharged to the outside from one discharge port provided on the downstream side of the one control valve in the open state.

  In step S204, it is determined whether or not the open state of the one control valve has elapsed for a predetermined period. When the predetermined period has elapsed, the process proceeds to step S205.

  In step S205, the one control valve is closed, and the process proceeds to step S206.

  In step S206, one of the control valves other than the control valve that has been in the open state is opened, the other control valves are closed, and the process proceeds to step S207.

  In step S207, it is determined whether or not the open state of one control valve that has been open in step S206 has passed a predetermined period. When the predetermined period has passed, the process proceeds to step S208.

  In step S208, the one control valve is closed, and the process proceeds to step S209.

  In step S209, it is determined whether or not the drainage from each of the discharge ports 20a to 20f provided on the downstream side of all the control valves 18a to 18f is completed. Whether or not drainage has ended can be determined, for example, based on whether or not all the control valves 18a to 18f have been opened for a predetermined period. However, the present invention is not limited to this, and various changes can be made. It is. If it is determined that drainage has not ended, the process proceeds to step S206, and steps S206 to S208 are repeated until it is determined that drainage has ended. When it is determined that the drainage has ended, the control valve switching control is ended.

  According to the present embodiment, when the vehicle is stopped in a low temperature environment, water is not continuously discharged from the respective discharge ports 20a to 20f, and the external environment is affected from each of the discharge ports 20a to 20f. Therefore, it is possible to prevent a large amount of ice and snow from being generated around the discharge port.

  In the present embodiment, the description will focus on an example in which the switching of the control valves is terminated when the switching of the plurality of control valves 18a to 18f makes one round and all the control valves 18a to 18f are opened for a predetermined period. However, the predetermined period during which each control valve is open is set to 1 second, for example, and the switching is performed three times so that the total discharge time from each discharge port does not affect the external environment. Of course, it may be configured to be set within 3 seconds, and various changes are possible.

  In the present embodiment, the example of switching the control valves 18a to 18f one by one has been mainly described. However, for example, the configuration may be such that two or three valves are switched, and various modifications are possible. Of course.

  In the present embodiment, the example in which the vehicle speed sensor 101 determines whether or not the vehicle 70 is in a stopped state has been mainly described. However, for example, even if the vehicle is stopped by turning on and off the ignition key, Of course, various changes are possible.

“Embodiment 2”
FIG. 4 is a layout diagram illustrating the layout of equipment mounted on a vehicle 90 in which a fuel cell according to another embodiment of the present invention is mounted as a power source. FIG. 5 is a diagram showing an outline of a configuration of a fuel cell system mounted on a vehicle 90 according to another embodiment of the present invention. In this embodiment, a plurality of gas-liquid separators 22a to 22f are respectively provided in one non-branching exhaust pipe 16 extending rearward of the vehicle body, and the separated water is supplied to the gas-liquid separators 22a to 22f. It is stored and discharged to the outside from the discharge ports 26a to 26f by opening and closing operations of the control valves 24a to 24f. The gas-liquid separators 22 a to 22 f include a water level sensor (not shown), and the water level sensor is connected to the control unit 30. Further, an exhaust valve 28 for discharging the separated exhaust gas to the outside is provided at the downstream end of the exhaust valve 16, and the exhaust valve 28 is connected to a control unit. Since other configurations are the same as those of the above-described embodiment, description of overlapping portions will be omitted.

  In FIG. 5, the operation of the control valves 18a to 18f when the vehicle is stopped and the outside air temperature is a predetermined value or less, for example, the outside air temperature is 0 degrees or less will be described.

  In such a case, one of the control valves 24a to 24f is opened by a signal from the control unit 30, and the other control valves are closed. Then, based on the signals from the water level sensors of the gas-liquid separators 22a to 22f, when it is determined that a predetermined reference amount of water has been discharged from one discharge port provided on the downstream side of the one control valve, Close the one control valve.

  Next, one of the other control valves other than the one control valve is opened, and a predetermined reference amount of water is discharged from one discharge port as described above. Hereinafter, similarly, the control valves 24a to 24f are sequentially switched to discharge water by a predetermined reference amount from the discharge ports 26a to 26f. The predetermined reference amount is preferably an amount that does not affect the external environment so that a large amount of ice and snow is not generated around each outlet even when the outside air temperature is low.

  Here, the exhaust gas separated by the gas-liquid separators 22a to 22f is discharged to the outside from the exhaust valve 28. However, when the switching operation is completed, the exhaust valve 28 may be closed. Alternatively, it may be configured to be opened and vented to the outside. Further, the opening degree of the exhaust valve 28 may be fully opened or a predetermined adjustment opening degree, and it is needless to say that various changes can be made.

  Next, switching control of the control valves 24a to 24f executed by the control unit 30 will be described. FIG. 6 is a flowchart showing an example of switching control of the control valves 24a to 24f executed by the control unit 30.

  Steps S301 to S303 are the same as those in the first embodiment described above, and a description thereof will be omitted. In step S304, based on the signals from the water level sensors of the gas-liquid separators 22a to 22f, whether or not a predetermined reference amount of water has been discharged from one outlet provided on the downstream side of one open control valve. When it is determined that a predetermined reference amount of water has been discharged, the process proceeds to step S305, and in step S305, one open control valve is closed and the process proceeds to step S306.

  In step S306, any one of the control valves other than the control valve that has been opened is opened, the other control valves are closed, and the process proceeds to step S307.

  In step S307, similarly to step S304, based on the signals from the water level sensors of the gas-liquid separators 22a to 22f, a predetermined reference amount is output from one discharge port provided on the downstream side of one open control valve. When it is determined whether or not a predetermined amount of water has been discharged, the process proceeds to step S308, the one control valve is closed, and the process proceeds to step S309.

  In step S309, it is determined whether or not the drainage from each of the discharge ports 26a to 26f provided on the downstream side of all the control valves 24a to 24f is completed. Whether or not the drainage is completed is determined based on, for example, signals from the water level sensors of the gas-liquid separators 22a to 22f from the discharge ports 26a to 26f provided on the downstream side of all the control valves 24a to 24f. Although it can be determined by whether or not the amount of water has been discharged, it is needless to say that the present invention is not limited to this, and various modifications are possible. If it is determined that drainage has not ended, the process proceeds to step S306, and steps S306 to S308 are repeated until it is determined that drainage has ended. Then, when it is determined that the drainage is finished, the switching control of the control valves 24a to 24f is finished.

  According to the above configuration, when the vehicle is stopped in a low temperature environment, water is discharged from each of the discharge ports 26a to 26f by an amount that does not affect the external environment. It can be prevented from being generated.

  In the present embodiment, an example in which a plurality of gas-liquid separators 22a to 22g, control valves 24a to 24f, and discharge ports 26a to 26f are provided in one non-branching exhaust pipe 16 extending rearward of the vehicle, respectively. However, for example, the exhaust pipe 16 may be branched into a plurality of parts, and a gas-liquid separator or the like may be provided in each of the branched exhaust pipes.

  In the present embodiment, when the switching of the plurality of control valves 24a to 24f makes one round and a predetermined reference amount of water is discharged from the discharge ports 26a to 26f provided on the downstream side of the control valves 24a to 24f. The example of ending the switching of the control valves 24a to 24f has been mainly described. However, for example, water discharged from one discharge port provided on the downstream side with one opening operation of one control valve. The amount of water is set to an amount lower than a predetermined reference amount, and the control valves 24a to 24f are switched a plurality of times so that the total discharge amount of water from each discharge port 24a to 24f does not affect the external environment. It may be configured to be set within.

  As mentioned above, although the form for implementing this invention was demonstrated, this invention is not limited to such embodiment at all, For example, it is good also as a form which combined Embodiment 1 and Embodiment 2, and of this invention Needless to say, the present invention can be implemented in various forms without departing from the scope of the invention.

1 is a layout diagram of a vehicle-mounted device in which a fuel cell according to Embodiment 1 of the present invention is mounted as a power source. 1 is a schematic configuration diagram of a fuel cell system mounted on a vehicle according to Embodiment 1 of the present invention. It is a flowchart explaining switching control of the control valve performed by the control part which concerns on Embodiment 1 of this invention. FIG. 6 is a layout diagram of a vehicle-mounted device on which a fuel cell according to Embodiment 2 of the present invention is mounted as a power source. It is the structure schematic of the fuel cell system which the vehicle concerning Embodiment 2 of this invention mounts. It is a flowchart explaining switching control of the control valve performed by the control part which concerns on Embodiment 2 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Fuel cell stack, 12 Compressor, 14 Hydrogen tank, 16 Exhaust pipe, 18a-18f, 24a-24f Control valve, 20a-20f, 26a-26f Exhaust port, 22a-22f Gas-liquid separator, 28 Exhaust valve, 30 control Part, 32a, 32b front wheel 34a, 34b rear wheel, 40 humidifier, 42 hydrogen recirculation pump, 50 hydrogen supply system, 52 hydrogen supply path, 54 hydrogen recirculation path, 60 air supply system, 62 air supply path, 64 exhaust Gas exhaust path, 70, 90 vehicle, 80 release system, 101 vehicle speed sensor, 102 outside air temperature sensor.

Claims (10)

In a vehicle equipped with a fuel cell as a power source,
A plurality of outlets for discharging water generated from the fuel cell to the outside;
An outside air temperature detecting means for detecting the outside air temperature;
Vehicle stop detection means for determining whether or not the vehicle is stopped;
Control means for performing control to discharge the generated water to the outside while switching the plurality of discharge ports when the outside air temperature is equal to or lower than a predetermined value and the vehicle is stopped. vehicle.   The vehicle according to claim 1, wherein the control unit switches the plurality of discharge ports every predetermined period and discharges the generated water to the outside. The control means discharges the generated water to the outside only for a predetermined period from any one or a plurality of discharge ports among the plurality of discharge ports.
2. After the predetermined period has elapsed, the generated water is sequentially switched to be discharged to the outside only for a predetermined period from one or a plurality of other outlets from which the generated water has not yet been discharged. Or the vehicle according to 2;   The vehicle according to claim 3, wherein the predetermined period is within 3 seconds.   2. The vehicle according to claim 1, wherein the control unit switches the plurality of discharge ports based on a discharge amount of the generated water for each of the plurality of discharge ports, and discharges the generated water to the outside. The control means discharges the generated water of a predetermined reference amount to the outside from any one or a plurality of discharge ports among the plurality of discharge ports,
2. When the discharge is completed, the product water is sequentially switched so that a predetermined reference amount of the generated water is discharged from one or more other outlets from which the generated water has not yet been discharged. Or the vehicle according to 5;   7. The vehicle according to claim 1, further comprising a plurality of storage means for storing water generated from the fuel cell, and discharging the stored water to the outside from the plurality of discharge ports. Vehicle. In a control method for a vehicle equipped with a fuel cell as a power source,
When the outside air temperature is equal to or lower than a predetermined value and the vehicle is stopped, the generated water is discharged outside while switching a plurality of outlets for discharging water generated from the fuel cell to the outside. A vehicle control method characterized by the above.   The vehicle control method according to claim 8, wherein the plurality of discharge ports are switched at predetermined intervals to discharge the generated water to the outside.   The vehicle control method according to claim 8, wherein the plurality of discharge ports are switched based on a discharge amount of the generated water for each of the plurality of discharge ports, and the generated water is discharged to the outside.

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