JP2006100101A - Fuel cell system and its control method as well as vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To appropriately exhaust generated water formed by a fuel cell to the outside of a system. <P>SOLUTION: One part of air of an air supply system 40 is supplied to an off-gas exhaust tube 52 of an air exhaust system 50 by a bypass supply tube 62 by bypassing a fuel cell stack 22, water in the off-gas exhaust tube 52 is recovered into a storing tank 54, the stored water is heated and vaporized in a heating amount corresponding to a water level in the storing tank 54 or an output Pfc of the fuel cell stack 22 by a heater 56, and the vaporized water is scavenged and exhausted outside the system by using the off-gas from the fuel cell stack 22 and the air from the bypass supply tube 62. In this way, it can be suppressed that the water remains in the off-gas exhaust tube 52 when the system is stopped, and the water in the storing tank 54 can be exhausted appropriately in accordance with the amount of the formed water. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fuel cell system, a control method thereof, and a moving body.

Conventionally, as this type of fuel cell system, a system in which generated water generated by the fuel cell is stored in a tank and the stored generated water is heated using a coolant of the fuel cell has been proposed (for example, a patent). Reference 1). In this system, the generated water can be vaporized and discharged to the outside by heating the stored generated water using a cooling liquid.
Japanese Patent Laying-Open No. 2003-7323 (FIG. 1)

  However, in the above-described fuel cell system, when the temperature of the coolant is low, such as during warm-up operation immediately after starting the system or when the outside air temperature is low, the stored generated water cannot be sufficiently vaporized and the external May not be discharged. Further, the generated water from the fuel cell flows through the off-gas exhaust passage from the fuel cell and is stored in the tank. However, when the system is stopped, the generated water may remain in the exhaust passage. If the system is left in such a state, the generated water remaining in the exhaust passage may freeze when the outside air temperature is low.

  It is an object of the fuel cell system, the control method thereof, and the moving body of the present invention to appropriately discharge generated water generated by the fuel cell to the outside. Another object of the fuel cell system, the control method thereof, and the moving body of the present invention is to facilitate the movement of generated water in a passage through which off-gas flows. And the fuel cell system of the present invention, its control method, and a mobile object make it one of the objects to control freezing of generated water in a passage through which off-gas flows.

  In order to achieve at least a part of the above object, the fuel cell system, the control method thereof, and the moving body of the present invention employ the following means.

The first fuel cell system of the present invention comprises:
A fuel cell system comprising a fuel cell that generates electricity with the generation of water,
Storage means capable of storing the generated water generated by the fuel cell;
Discharge means for vaporizing or atomizing the generated water stored by the storage means and discharging it to the outside;
Status detection means for detecting the status of the system;
Discharge control means for controlling the discharge means so as to vaporize or atomize and discharge the generated water based on the detected state of the system;
It is a summary to provide.

  In the first fuel cell system of the present invention, the generated water stored by the storage unit is vaporized or atomized based on the state of the system detected by the state detection unit and discharged to the outside. As a result, the generated water can be appropriately discharged to the outside according to the state of the system.

  In such a first fuel cell system of the present invention, the state detection means includes at least one of the water level of the generated water stored by the storage means, the water temperature of the stored generated water, the output of the fuel cell, and the outside air temperature. It may be a means for detecting one as the state of the system. In this case, the state detection unit is a unit that detects the level of the generated water stored by the storage unit as the state of the system, and the discharge control unit stores the water as the detected water level is higher. It may be a means for controlling the discharge means so that the amount of vaporization or atomization of the generated water tends to increase. If it carries out like this, according to the water level of the generated water stored by the storage means, generated water can be discharged | emitted appropriately outside. The state detecting means is means for detecting the output of the fuel cell as the state of the system, and the discharge control means is configured to vaporize the stored generated water as the detected output of the fuel cell is higher. Alternatively, it may be a means for controlling the discharge means so as to increase the amount of vaporized and atomized. If it carries out like this, according to the output of a fuel cell, generated water can be appropriately discharged | emitted outside.

  In the first fuel cell system of the present invention, the discharge means may be a means for vaporizing the stored generated water by heating and discharging it to the outside. May be a means for atomizing the stored produced water by vibration and discharging it to the outside.

  In the first fuel cell system of the present invention, the storage means communicates downstream of an offgas passage through which offgas from the fuel cell flows, and the fuel cell system further oxidizes the fuel cell. Air supply means for supplying air as gas, and bypass supply means for bypassing the fuel cell and supplying at least part of the air from the air supply means to the off-gas passage. it can. If it carries out like this, the generated water in an offgas channel can be moved by the air and offgas which a bypass supply means supplies to an offgas channel, and can be collected in a storage means. In this way, the generated water in the offgas passage can be collected in the storage means, so that it is possible to prevent the generated water from remaining in the offgas passage and freezing after the system is stopped. In this case, output detection means for detecting the output of the fuel cell, and the amount of air supplied from the air supply means to the off-gas passage by bypassing the fuel cell as the detected output of the fuel cell decreases. A bypass supply control means for controlling the bypass supply means in a tendency to increase can also be provided. In this way, the generated water in the offgas passage can be more easily moved when the output of the fuel cell is low. The air supply means may include bypass supply control means for controlling the bypass supply means so as to pulsate the amount of air supplied to the off gas passage by bypassing the fuel cell. Since the amount of air supplied from the air supply means to the offgas passage is pulsated, the generated water in the offgas passage can be easily moved.

The second fuel cell system of the present invention comprises:
A fuel cell system comprising a fuel cell that generates electricity with the generation of water,
Air supply means for supplying air as an oxidizing gas to the fuel cell;
Exhaust means for exhausting off-gas from the fuel cell through an exhaust passage;
Bypass supply means capable of bypassing the fuel cell and supplying the exhaust passage with at least part of air from the air supply means;
It is a summary to provide.

  In the second fuel cell system of the present invention, the generated water in the exhaust passage can be moved by the air and off gas supplied to the exhaust passage by the bypass supply means. Further, since the generated water in the exhaust passage can be moved, it is possible to suppress the generated water from remaining in the exhaust passage and freezing.

  The mobile body of the present invention is the fuel cell system of the present invention according to any one of the above-described aspects, that is, a fuel cell system basically including a fuel cell that generates electric power with generation of water. A storage means capable of storing the generated water generated in the step, a discharge means for vaporizing or atomizing the generated water stored in the storage means and discharging it to the outside, a state detection means for detecting the state of the system, and the detection A discharge control means for controlling the discharge means to vaporize or atomize and discharge the generated water based on the state of the generated system; A fuel cell system comprising a fuel cell for generating electricity, an air supply means for supplying air as oxidizing gas to the fuel cell, and an exhaust hand for exhausting off-gas from the fuel cell through an exhaust passage And a second fuel cell system according to the present invention, wherein at least part of the air from the air supply means bypasses the fuel cell and can be supplied to the exhaust passage. Is the gist.

  Since the mobile body of the present invention is equipped with the first or second fuel cell system of the present invention according to any one of the aspects described above, the effects exhibited by the first or second fuel cell system of the present invention, for example, The same effect as the effect that the generated water can be appropriately discharged to the outside according to the state of the system and the effect that the generated water remains in the exhaust passage and can be prevented from freezing can be obtained. it can.

The control method of the fuel cell system of the present invention includes:
A fuel cell that generates power with water generation, a storage unit that can store the generated water generated by the fuel cell, and a discharge unit that vaporizes or atomizes the generated water stored in the storage unit and discharges the generated water to the outside A control method of a fuel cell system comprising:
(A) detect the state of the system,
(B) The gist is to control the discharge means so as to vaporize or atomize and discharge the generated water based on the detected state of the system.

  In the fuel cell system control method of the present invention, the discharge means is controlled so that the generated water is discharged after being vaporized or atomized based on the detected state of the system. As a result, the generated water can be appropriately discharged to the outside according to the state of the system.

  Next, the best mode for carrying out the present invention will be described using examples.

  FIG. 1 is a configuration diagram showing an outline of a configuration of a fuel cell vehicle 10 equipped with a fuel cell system 20 as an embodiment of the present invention. As shown in the figure, the fuel cell vehicle 10 of the embodiment is driven by an inverter 12 that converts DC power from the fuel cell system 20 into three-phase AC power, and three-phase AC power that is converted by the inverter 12 and is not shown in the figure. A traveling motor 14 that outputs power to the shaft, a DC / DC converter 16 that converts DC power and adjusts the output voltage Vfc and output current Ifc of the fuel cell system 20, and fuel via the DC / DC converter 16 And a secondary battery 18 connected in parallel to the battery system 20.

  The fuel cell system 20 is connected to the inverter 12 and the DC / DC converter 16 via a circuit breaker 21. For example, an electrolyte membrane formed of a polymer is sandwiched between two electrodes (a fuel electrode and an air electrode). A fuel cell stack 22 formed by stacking a plurality of unit cell units, a hydrogen supply system 30 for supplying hydrogen from the high-pressure hydrogen tank 31 to the fuel electrode (negative electrode) of the fuel cell stack 22, and the fuel cell stack 22 An air supply system 40 that supplies air to the air electrode (positive electrode), an air discharge system 50 that discharges air (off-gas) from the air electrode of the fuel cell stack 22 to the outside, and a fuel cell stack 22 that is not illustrated. A cooling system and an electronic control unit 70 for controlling the whole including the fuel cell system 20 are provided.

  The hydrogen supply system 30 includes a hydrogen supply flow path 32 that supplies hydrogen from the high-pressure hydrogen tank 31 to the fuel cell stack 22, and a hydrogen circulation flow path that returns hydrogen discharged from the fuel cell stack 22 to the hydrogen supply flow path 32. 33. In the hydrogen supply flow path 32, a backflow prevention valve (check valve) for preventing hydrogen from flowing back from the high-pressure hydrogen tank 31 and a partition (not shown) for supplying and stopping supply of hydrogen to the fuel cell stack 22. Valves are provided. The hydrogen circulation channel 33 includes a hydrogen pump 34 for pumping hydrogen to the hydrogen supply channel 32, a gas-liquid separator 38 for separating gas and liquid by liquefying water vapor in the circulating hydrogen, and a hydrogen supply A non-illustrated backflow prevention valve (check valve) for preventing hydrogen from flowing back on the flow path 32 side, a gate valve for stopping discharge of hydrogen from the fuel cell stack 22, and the like are provided. The hydrogen supply flow path 32 and the hydrogen circulation flow path 33 are provided with various sensors (not shown) used for controlling the supply amount of hydrogen supplied to the fuel cell stack 22 and the operation state of the fuel cell stack 22. Yes. The water separated by the gas-liquid separator 38 is stored in the storage tank 54 via the air discharge system 50. A branch pipe 35 is attached to the hydrogen circulation flow path 33, and hydrogen in the hydrogen circulation flow path 33 is diluted with a part of the air from the air discharge system 50 in the diluter 39, and then The air is released to the atmosphere via the air discharge system 50.

  In the air supply system 40, the air measured by the mass flow meter 43 and pressurized by the air compressor 44 is guided to the humidifier 46 by the supply pipe 41, humidified, and supplied to the air electrode of the fuel cell stack 22 by the supply pipe 42.

  In the air discharge system 50, the off gas from the air electrode of the fuel cell stack 22 is guided to the humidifier 46 by the off gas discharge pipe 51 to humidify the air from the air compressor 44 of the air supply system 40, and then the off gas discharge pipe 52 or It is released to the atmosphere via the storage tank 54. The storage tank 54 is provided in communication with the downstream end of the offgas discharge pipe 52 so as to store the generated water from the air electrode of the fuel cell stack 22 and the water separated by the gas-liquid separator 38. The storage tank 54 is operated by electric power from the secondary battery 18 and is heated by a heater 56 that stores water stored at two stages of normal output (Low output) and output higher than normal (Hi output), and a storage tank 54. A water level sensor 58 for detecting the water level Hw in the tank 54 is attached. Between the off-gas discharge pipe 52 and the supply pipe 41 of the air supply system 40, a part of the dry air flowing through the supply pipe 41 of the air supply system 40 bypasses the humidifier 46 and the fuel cell stack 22 to turn off the gas. A bypass supply pipe 62 is provided to supply to the discharge pipe 52. A damper 64 driven by an actuator (not shown) is attached to the bypass supply pipe 62 so that the amount of air supplied from the supply pipe 41 to the bypass supply pipe 62 can be adjusted. FIG. 2 is a configuration diagram showing an outline of the configuration of the damper 64. As shown in FIG. 2, the damper 64 adjusts the opening degree D to the bypass supply pipe 62 side, thereby adjusting the amount of air supplied from the air compressor 44 through the supply pipe 41 to the humidifier 46 and the fuel cell stack 22. The humidifier 46 and the fuel cell stack 22 are bypassed to adjust the amount of air supplied to the bypass supply pipe 62 side.

  The electronic control unit 70 is configured as a microcomputer centering on the CPU 72, and includes a ROM 74 for storing a processing program, a RAM 76 for temporarily storing data, and an input / output port (not shown) in addition to the CPU 72. The electronic control unit 70 includes an output voltage Vfc from the voltage sensor 28 attached to the power line connected to the output terminal of the fuel cell stack 22, an output current Ifc from the current sensor 29 attached to the power line, and storage. A sensor signal from a water level sensor 58 that is attached to the tank 54 and turns on when the water level in the storage tank 54 exceeds a predetermined water level, detection signals from various sensors that are attached to operate the fuel cell stack 22, and the like are input. Is entered through the port. Further, from the electronic control unit 70, a drive signal to the circuit breaker 23, a drive signal to the hydrogen pump 34, a drive signal to the air compressor 44, a drive signal to an actuator (not shown) of the damper 64, and a drive signal to the heater 56. Etc. are output via the output port. The electronic control unit 70 also serves as an electronic control unit that controls the entire fuel cell vehicle 10, and an input signal for driving the inverter 24 and the DC / DC converter 26 is input via an input port. A switching control signal to the DC / DC converter 26, a switching control signal to the inverter 24, and the like are output via the output port.

  In such a fuel cell system 20, the fuel cell stack 22 is driven by driving a hydrogen pump 34, an air compressor 44, a cooling water pump (not shown) based on signals from various sensors, and adjusting the opening of each gate valve and damper 64. To control.

  Next, the operation | movement at the time of collect | recovering the water produced | generated by the fuel cell stack 22 of the fuel cell system 20 of the Example comprised in this way to the storage tank 54, and discharging | emitting outside is demonstrated. The operation | movement which collect | recovers the water produced | generated by the fuel cell system 20 to the storage tank 54 first is demonstrated, and the operation | movement which discharges the water stored by the storage tank 54 outside after that is demonstrated. In the embodiment, it is assumed that the air compressor 44 is in constant operation with a preset supply air amount.

  FIG. 3 is a flowchart showing an example of a collection control routine executed by the electronic control unit 70. This routine is repeatedly executed every predetermined time (for example, every 8 msec). When this routine is executed, the CPU 72 of the electronic control unit 70 first executes processing for inputting signals and data necessary for control such as the output voltage Vfc from the voltage sensor 28 and the output current Ifc from the current sensor 29. (Step S100), the product of the input output voltage Vfc and the output current Ifc is set as the output Pfc of the fuel cell stack 22 (Step S110).

  Subsequently, the opening degree D of the damper 64 toward the bypass supply pipe 62 is set based on the set output Pfc of the fuel cell stack 22 (step S120). In the embodiment, the opening degree D of the damper 64 is determined in advance by defining a relationship between the opening degree D of the damper 64 and the output Pfc of the fuel cell stack 22 when the air compressor 44 is operated at a predetermined supply air amount. The damper opening degree map is stored in the ROM 74, and when the output Pfc of the fuel cell stack 22 is given, the opening degree D of the corresponding damper 64 is derived and set from the stored map. FIG. 4 shows an example of the damper opening setting map. In FIG. 4, the opening degree D of the damper 64 is set to increase as the output Pfc of the fuel cell stack 22 decreases. The reason why the fuel cell stack 22 is necessary for operation when the output Pfc of the fuel cell stack 22 decreases. Therefore, when the amount of air supplied from the air compressor 44 is constant, the opening D of the damper 64 is increased to reduce the amount of air supplied to the fuel cell stack 22 and to supply to the bypass supply pipe 62. Based on increasing the amount of air to play.

  When the opening degree D of the damper 64 is set in this manner, the opening degree of the damper 64 is set to the set opening degree so that the amount of air supplied to the bypass supply pipe 62 pulsates at regular intervals. Is opened and closed to control the actuator (not shown) of the damper 64 so as to close the upstream end of the bypass supply pipe 62 (step S130), and this routine ends. In this way, by supplying dry air from the supply pipe 41 to the offgas discharge pipe 52 via the bypass supply pipe 62, the offgas discharge pipe is generated from the fuel cell stack 22 or separated from the gas-liquid separator 38. The water remaining in the gas 52 can be scavenged by the air from the bypass supply pipe 62 and the off gas from the fuel cell stack 22, moved to the downstream side of the off gas discharge pipe 52, and collected in the storage tank 54. Such water recovery can be performed regardless of the level of the output Pfc of the fuel cell stack 22. For example, when the output Pfc of the fuel cell stack 22 is low, the amount of air supplied to the fuel cell stack 22 is small and the amount of off-gas from the fuel cell stack 22 is small, but the amount of air supplied from the bypass supply pipe 62 is large. Therefore, the water in the offgas discharge pipe 52 can be sufficiently recovered in the storage tank 54. On the other hand, when the output Pfc of the fuel cell stack 22 is high, the amount of air supplied to the bypass supply pipe 62 decreases, but the amount of air supplied to the fuel cell stack 22 is large and the amount of off-gas from the fuel cell stack 22 is large. Therefore, the water in the offgas discharge pipe 52 can be sufficiently recovered in the storage tank 54. Thus, since the water in the offgas discharge pipe 52 is collected in the storage tank 54 during the operation of the fuel cell stack 22, it is possible to suppress the water from remaining in the offgas discharge pipe 52 after the system is stopped. The fuel cell stack 22 is supplied with an air amount necessary for operation by the damper 64. Therefore, even if a part of the air from the air compressor 44 is supplied to the bypass supply pipe 62, the fuel cell stack 22 can be operated. There will be no hindrance.

  Next, the operation | movement which discharges | emits the water collect | recovered by the storage tank 54 outside is demonstrated. FIG. 5 is a flowchart showing an example of the generated water discharge control routine executed by the electronic control unit 70. This routine is repeatedly executed every predetermined time (for example, every 8 msec). When this routine is executed, the CPU 72 of the electronic control unit 70 first needs to control the output voltage Vfc from the voltage sensor 28, the output current Ifc from the current sensor 29, the water level Hw of the storage tank 54 from the water level sensor 58, and the like. A process of inputting a simple signal and data is executed (step S200), and the product of the input output voltage Vfc and the output current Ifc is set as the output Pfc of the fuel cell stack 22 (step S210).

  Subsequently, it is determined whether or not the output Pfc of the fuel cell stack 22 exceeds the threshold value Plo and whether or not the water level Hw of the storage tank 54 exceeds the threshold value Hlo (step S220). Here, the threshold value Plo is set as the upper limit value of the output of the fuel cell stack 22 that is judged that it is not necessary to vaporize even if water is stored in the storage tank 54 because the amount of generated water from the fuel cell stack 22 is small. ing. The threshold value Hlo is set as the upper limit value of the water level at which it is determined that the amount of water in the storage tank 54 is small and it is not necessary to vaporize the stored water. If the output Pfc of the fuel cell stack 22 is less than or equal to the threshold value Plo or the water level Hw is less than or equal to the threshold value Hlo, it is determined that there is no need to vaporize the water in the storage tank 54 and the heater 56 is activated. 56 is stopped (step S230), and this routine is terminated.

  When the output Pfc of the fuel cell stack 22 exceeds the threshold value Plo or when the water level Hw of the storage tank 54 exceeds the threshold value Hlo, whether or not the output Pfc of the fuel cell stack 22 is lower than the threshold value Phi is stored. It is determined whether or not the water level Hw of the tank 54 is lower than the threshold value Hhi (step S240). Here, the threshold Phi is the upper limit of the output of the fuel cell stack 22 that is determined that the amount of water generated from the fuel cell stack 22 is not so much as the amount of water vaporized when the heater 56 is operated at low output. It is set as a value. Further, the threshold value Hhi is set as an upper limit value of the water level at which it is determined that the amount of water in the storage tank 54 is not so much as the amount of water vaporized when the heater 56 is operated at low output. When the output Pfc from the fuel cell stack 22 is lower than the threshold value Phi or the water level Hw is lower than the threshold value Hhi, it is determined that the heater 56 can be operated with the low output, and the heater 56 is operated with the low output. Control is performed (step S250), and this routine is terminated. On the other hand, when the output Pfc from the fuel cell stack 22 is higher than the threshold value Phi or the water level Hw is higher than the threshold value Hhi, it is necessary to increase the output of the heater 56 to increase the amount of water vaporized in the storage tank 54. Determination is made to control the heater 56 to operate with Hi output (step S260), and this routine is terminated. By operating the heater 56 in this manner, the water stored in the storage tank 54 is heated and vaporized, and the vaporized water is scavenged by using off-gas from the off-gas discharge pipe 52 and air from the bypass supply pipe 41. Drain out of the system. Since the output of the heater 56 is set based on the output Pfc of the fuel cell stack 22 and the water level Hw, the water in the storage tank 54 is appropriately supplied according to the amount of generated water and the amount of water stored in the storage tank 54. It can be vaporized and discharged. In addition, the power consumption of the secondary battery 18 after the system is stopped can be suppressed as compared with a system that operates the heater after the system is stopped.

  According to the fuel cell system 20 of the embodiment described above, part of the air in the air supply system 40 is discharged from the air discharge system 50 via the bypass supply pipe 62 when the fuel cell stack 22 is in operation. The water in the off-gas discharge pipe 52 can be collected in the storage tank 54 by being supplied to the pipe 52. Therefore, it is possible to suppress water from remaining in the offgas discharge pipe 52 when the system is stopped. Further, the water stored in the storage tank 54 is heated by the heater 56 with a heating amount corresponding to the output Pfc of the fuel cell stack 22 and the water level Hw in the storage tank 54 and is vaporized and discharged. The water in the storage tank 54 can be appropriately vaporized and discharged according to the amount of water. In addition, the power consumption of the secondary battery 18 after the system is stopped can be suppressed as compared with a system that operates the heater after the system is stopped.

  In the fuel cell system 20 of the embodiment, the opening degree D of the damper 64 is adjusted according to the output Pfc of the fuel cell stack 22 and the damper 64 is opened and closed at regular intervals. However, the fuel is not opened and closed. The damper 64 may be adjusted by the opening degree based on the output Pfc of the battery stack 22, or the damper 64 may be opened and closed at regular intervals without adjusting the opening degree D of the damper 64.

  In the fuel cell system 20 of the embodiment, the amount of air supplied to the fuel cell stack 22 and the amount of air supplied to the bypass supply pipe 62 are adjusted by operating the air compressor 44 at a constant operation and adjusting the opening D of the damper 64. The amount of air supplied to the fuel cell stack 22 and the amount of air supplied to the bypass supply pipe 62 are adjusted by controlling the operation of the air compressor 44 with the opening degree D of the damper 64 being constant. It is good.

  In the fuel cell system 20 of the embodiment, the water in the offgas discharge pipe 52 is moved to the storage tank 54 by the air supplied from the bypass supply pipe 62 and the offgas from the fuel cell stack 22. The off-gas discharge pipe 52 may be inclined or water-repellent treatment may be applied to the off-gas discharge pipe 52 so that water can easily move from the discharge pipe 52 to the storage tank 54. In this way, the water in the offgas discharge pipe 52 can be moved to the storage tank 54 more easily.

  In the fuel cell system 20 of the embodiment, the heater 56 heats and vaporizes the water in the storage tank 54 with a two-stage output. However, the higher the output Pfc of the fuel cell stack 22 is, or in the storage tank 54. Since the output of the heater 56 only needs to increase as the water level Hw increases, the number of switching stages of the heater 56 may be set to any number, may be more than two, or may be one. . Further, the output Pfc of the heater 56 may be variably controlled according to the output Pfc of the fuel cell stack 22 without providing the number of switching stages. In this case, the relationship between the heater 56 and the output Pfc of the fuel cell stack 22 is determined in advance and stored in the ROM 74 as a heater output setting map. When the output Pfc of the fuel cell stack 22 is given, the stored map is used. It is desirable to derive and set the output Ph of the heater 56. FIG. 6 shows an example of the heater output setting map. Alternatively, the heater 56 may be operated when the water level Hw in the storage tank 54 exceeds a predetermined value.

  In the fuel cell system 20 of the embodiment, the output of the heater 56 is set based on the detected value such as the output Pfc of the fuel cell stack 22 and the water level of the storage tank 54, but the output Pfc of the fuel cell stack 22 and the storage At least one of detection values indicating the state of the system other than the water level of the tank 54, for example, detection values indicating the state of other systems such as the outside air temperature from the outside air temperature sensor and the water temperature of the water stored in the storage tank 54. Based on this, the output of the heater 56 may be set.

  In the fuel cell system 20 of the embodiment, the water stored in the storage tank 54 is heated and vaporized by the heater 56, and an ultrasonic vibrator is attached to the storage tank 54. The water may be vibrated and atomized for discharge. In this case, it is desirable that the amount of atomization increases with the ultrasonic vibrator as the amount of water stored in the storage tank 54 increases.

  In the fuel cell system 20 of the embodiment, the amount of air supplied to the fuel cell stack 22 and the amount of air supplied to the bypass supply pipe 62 are adjusted using the damper 64, but the air supplied to the fuel cell stack 22 Any device that adjusts the amount and the amount of air supplied to the bypass supply pipe 62 may be used, and an electromagnetic valve such as a poppet valve, a rotary valve, or a spool valve may be used.

  In the embodiments described above, the present invention is applied to a fuel cell vehicle equipped with a fuel cell system as a power source. However, the present invention may be applied to various mobile objects including vehicles other than cars. However, the present invention may be applied to a system including a fuel cell system other than a moving body as a power source.

1 is a system configuration diagram showing an outline of a configuration of a fuel cell system 20 mounted as a power source in a fuel cell vehicle as one embodiment of the present invention. 3 is a configuration diagram showing an outline of a configuration of a damper 64. FIG. 3 is a flowchart showing an example of a generated water recovery control routine executed by an electronic control unit 70. It is explanatory drawing which shows an example of the map for damper opening degree setting. 3 is a flowchart showing an example of a generated water discharge control routine executed by an electronic control unit 70. It is explanatory drawing which shows an example of the map for heater output setting.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Fuel cell vehicle, 12 Inverter, 14 Motor, 16 DC / DC converter, 18 Secondary battery, 20 Fuel cell system, 22 Fuel cell stack, 21 Circuit breaker, 28 Voltage sensor, 29 Current sensor, 30 Hydrogen supply system, 31 High pressure hydrogen tank, 32 Hydrogen supply flow path, 33 Hydrogen circulation flow path, 34 Hydrogen pump, 35 Branch pipe, 38 Gas-liquid separator, 40 Air supply system, 41, 42 Supply pipe, 43 Mass flow meter, 44 Air compressor, 46 Humidifier, 50 Air exhaust system, 51, 52 Off gas exhaust pipe, 54 Storage tank, 56 Heater, 58 Water level sensor, 62 Bypass supply pipe, 64 Damper, 70 Electronic control unit, 72 CPU, 74 ROM, 76 RAM.

Claims (12)

A fuel cell system comprising a fuel cell that generates electricity with the generation of water,
Storage means capable of storing the generated water generated by the fuel cell;
Discharge means for vaporizing or atomizing the generated water stored by the storage means and discharging it to the outside;
Status detection means for detecting the status of the system;
Discharge control means for controlling the discharge means so as to vaporize or atomize and discharge the generated water based on the detected state of the system;
A fuel cell system comprising:   The state detection means is means for detecting at least one of a water level of the generated water stored by the storage means, a water temperature of the stored generated water, an output of the fuel cell, and an outside air temperature as a state of the system. The fuel cell system according to claim 1. The fuel cell system according to claim 2, wherein
The state detection means is means for detecting the water level of the generated water stored by the storage means as the state of the system,
The said discharge control means is a means which controls the said discharge means in the tendency for the vaporization atomization amount by which the stored generated water is vaporized or atomized so that the detected water level is high. The fuel cell system according to claim 2 or 3, wherein
The state detection means is means for detecting the output of the fuel cell as the state of the system,
The discharge control means is means for controlling the discharge means such that the higher the output of the detected fuel cell is, the more the amount of vaporized or atomized vaporized or atomized stored water is increased. system.   The fuel cell system according to any one of claims 1 to 4, wherein the discharge means is means for vaporizing the stored generated water by heating and discharging the generated water to the outside.   The fuel cell system according to any one of claims 1 to 4, wherein the discharging means is means for atomizing the stored generated water by shaking to discharge the generated water to the outside. The fuel cell system according to any one of claims 1 to 6,
The storage means communicates downstream of an offgas passage through which offgas from the fuel cell circulates,
The fuel cell system further includes:
Air supply means for supplying air as an oxidizing gas to the fuel cell;
Bypass supply means capable of supplying at least part of the air from the air supply means to the offgas passage by bypassing the fuel cell;
A fuel cell system comprising: The fuel cell system according to claim 7, wherein
Output detection means for detecting the output of the fuel cell;
Bypass supply control means for controlling the bypass supply means in such a manner that the amount of air supplied from the air supply means to the off-gas passage increases as the detected output of the fuel cell decreases. ,
A fuel cell system comprising:   The fuel cell system according to claim 7, further comprising a bypass supply control unit that controls the bypass supply unit so that the amount of air supplied to the off-gas passage bypasses the fuel cell from the air supply unit. A fuel cell system comprising a fuel cell that generates electricity with the generation of water,
Air supply means for supplying air as an oxidizing gas to the fuel cell;
Exhaust means for exhausting off-gas from the fuel cell through an exhaust passage;
Bypass supply means capable of bypassing the fuel cell and supplying the exhaust passage with at least part of air from the air supply means;
A fuel cell system comprising:   A mobile body using the fuel cell system according to claim 1 as a power source. A fuel cell that generates power with water generation, a storage unit that can store the generated water generated by the fuel cell, and a discharge unit that vaporizes or atomizes the generated water stored in the storage unit and discharges the generated water to the outside A control method of a fuel cell system comprising:
(A) detect the state of the system,
(B) A control method for a fuel cell system, wherein the discharge means is controlled to vaporize or atomize and discharge the generated water based on the detected state of the system.

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