Abstract: A fuel cell system has a fuel cell stack and a controller. The fuel cell stack is formed by stacking cells. The controller executes first cell voltage recovery processing when the cell voltage of a first cell group, placed at each end of the fuel cell stack, is below a first lower limit voltage threshold and executes second cell voltage recovery processing, which is different from the first cell voltage recovery processing, when the cell voltage of a second cell group, placed at substantially the center of the fuel cell stack, is below a second lower limit voltage threshold.

Abstract: The fuel cell system includes a storage portion, a fuel cell, a fuel supply portion, a hydrogen circulation system and a boil-off gas supply portion. The storage portion stores liquid hydrogen. The fuel cell uses hydrogen gas as fuel gas. The fuel supply portion provides hydrogen gas to an anode of the fuel cell. The hydrogen gas is generated caused by a vaporization of liquid hydrogen stored in the storage portion. The hydrogen circulation system includes the anode of the fuel cell. The boil-off gas supply portion provides boil-off gas generated in the storage portion to the hydrogen circulation system.

Abstract: In a fuel cell unit that generates electric power using fuel gas supplied via an anode gas passage and air supplied via a cathode gas passage, an anode-off gas passage is connected to the downstream side of the anode gas passage. An orifice is provided at the anode-off gas passage and anode-off gas is discharged to the downstream side via the orifice.

Abstract: A fuel cell system capable of inhibiting dew condensation in an area affected by freezing by providing an area for actively promoting dew condensation is provided. The fuel cell system includes a fuel cell and an off-gas passage for allowing an off-gas discharged from the fuel cell flow through, wherein a dew condensation promoting area for promoting dew condensation is placed around a freezing-affected area that will be adversely affected by freezing.

Abstract: Consumed hydrogen-off gas is discharged from a fuel cell via a hydrogen-off gas exhaust flow passage. Consumed oxygen-off gas is discharged from the fuel cell via an oxygen-off gas exhaust flow passage. The oxygen-off gas flowing through the oxygen-off gas exhaust flow passage and the hydrogen-off gas flowing through the hydrogen-off gas exhaust flow passage are mixed and diluted in a mixing portion. The gases mixed in the mixing portion flow into a combustor via a gas-liquid separator. The combustor, which includes a platinum catalyst, causes hydrogen contained in the mixed gases to react with oxygen by combustion and further reduces the concentration of hydrogen contained in the mixed gases. The mixed gases whose concentration of hydrogen has been reduced by the combustor is discharged to the atmosphere.

Abstract: An on-board fuel cell system adapted to be installed on a motor vehicle includes a main passage connecting a hydrogen-gas storage device with an inlet of a fuel cell, a circulation passage that connects an outlet of the fuel cell with a first point in the main passage, a pump disposed in the circulation passage, and a bypass passage that connects a second point between the outlet of the storage device and the first point, with a third point located in the circulation passage between the outlet of the fuel cell and the pump. During a normal operation condition of the system, the hydrogen gas flows from the storage device to the fuel cell through the main passage, and hydrogen gas discharged from the fuel cell returns to the main passage through the circulation passage.

Abstract: A fuel cell system has a fuel cell stack and a controller. The fuel cell stack is formed by stacking cells. The controller executes first cell voltage recovery processing when the cell voltage of a first cell group, placed at each end of the fuel cell stack, is below a first lower limit voltage threshold and executes second cell voltage recovery processing, which is different from the first cell voltage recovery processing, when the cell voltage of a second cell group, placed at substantially the center of the fuel cell stack, is below a second lower limit voltage threshold.

Abstract: A fuel cell system has a fuel cell stack generating electricity with a reactive gas supplied thereto and a controller supplying to the fuel cell stack the reactive gas whose pressure is higher than a normal operational pressure on condition that a temperature of the fuel cell stack is equal to or less than a predetermined threshold temperature and that a moisture content of the fuel cell stack is equal to or less than a predetermined threshold value. Where a supply pressure of the reactive gas is raised, an amount of moisture taken away by the reactive gas becomes less, and thus, water balance within the fuel cell stack shifts toward accumulation of moisture contained in the reactive gas into the film-electrode joined body. However, since the moisture content of the fuel cell stack is equal to or less than the predetermined threshold value, the system can improve the starting performance of the fuel cell stack at low temperature while suppressing flooding.

Abstract: Consumed hydrogen-off gas is discharged from a fuel cell via a hydrogen-off gas exhaust flow passage. Consumed oxygen-off gas is discharged from the fuel cell via an oxygen-off gas exhaust flow passage. The oxygen-off gas flowing through the oxygen-off gas exhaust flow passage and the hydrogen-off gas flowing through the hydrogen-off gas exhaust flow passage are mixed and diluted in a mixing portion. The gases mixed in the mixing portion flow into a combustor via a gas-liquid separator. The combustor, which includes a platinum catalyst, causes hydrogen contained in the mixed gases to react with oxygen by combustion and further reduces the concentration of hydrogen contained in the mixed gases. The mixed gases whose concentration of hydrogen has been reduced by the combustor is discharged to the atmosphere.

Abstract: There is provided a fuel cell system capable of notifying a user that control for low-temperature countermeasure is performed, without any strange feeling and false recognition. When control for low-temperature countermeasure such as scavenging at system termination or warm-up at system start-up is made, the user is reliably notified that the control is performed, by a text message or a speech message. Consequently, even in a situation where the system is operating after an ignition key is turned off, the user suffers neither strange feeling nor false recognition.

Abstract: The fuel cell system includes a storage portion, a fuel cell, a fuel supply portion, a hydrogen circulation system and a boil-off gas supply portion. The storage portion stores liquid hydrogen. The fuel cell uses hydrogen gas as fuel gas. The fuel supply portion provides hydrogen gas to an anode of the fuel cell. The hydrogen gas is generated caused by a vaporization of liquid hydrogen stored in the storage portion. The hydrogen circulation system includes the anode of the fuel cell. The boil-off gas supply portion provides boil-off gas generated in the storage portion to the hydrogen circulation system.

Abstract: In a fuel cell unit that generates electric power using fuel gas supplied via an anode gas passage and air supplied via a cathode gas passage, an anode-off gas passage is connected to the downstream side of the anode gas passage. An orifice is provided at the anode-off gas passage and anode-off gas is discharged to the downstream side via the orifice.

Abstract: Consumed hydrogen-off gas is discharged from a fuel cell via a hydrogen-off gas exhaust flow passage. Consumed oxygen-off gas is discharged from the fuel cell via an oxygen-off gas exhaust flow passage. The oxygen-off gas flowing through the oxygen-off gas exhaust flow passage and the hydrogen-off gas flowing through the hydrogen-off gas exhaust flow passage are mixed and diluted in a mixing portion. The gases mixed in the mixing portion flow into a combustor via a gas-liquid separator. The combustor, which includes a platinum catalyst, causes hydrogen contained in the mixed gases to react with oxygen by combustion and further reduces the concentration of hydrogen contained in the mixed gases. The mixed gases whose concentration of hydrogen has been reduced by the combustor is discharged to the atmosphere.

Abstract: An on-board fuel cell system adapted to be installed on a motor vehicle includes a main passage connecting a hydrogen-gas storage device with an inlet of a fuel cell, a circulation passage that connects an outlet of the fuel cell with a first point in the main passage, a pump disposed in the circulation passage, and a bypass passage that connects a second point between the outlet of the storage device and the first point, with a third point located in the circulation passage between the outlet of the fuel cell and the pump. During a normal operation condition of the system, the hydrogen gas flows from the storage device to the fuel cell through the main passage, and hydrogen gas discharged from the fuel cell returns to the main passage through the circulation passage.

Abstract: An on-board fuel cell system adapted to be installed on a motor vehicle includes a main passage connecting a hydrogen-gas storage device with an inlet of a fuel cell, a circulation passage that connects an outlet of the fuel cell with a first point in the main passage, a pump disposed in the circulation passage, and a bypass passage that connects a second point between the outlet of the storage device and the first point, with a third point located in the circulation passage between the outlet of the fuel cell and the pump. During a normal operation condition of the system, the hydrogen gas flows from the storage device to the fuel cell through the main passage, and hydrogen gas discharged from the fuel cell returns to the main passage through the circulation passage.

Abstract: In a polymer electrolyte fuel cell system, a condition of humidification of electrolyte membranes is precisely determined, and adjustment is performed so that the condition of humidification of the electrolyte membranes substantially remains within a proper range. The system determines a condition of humidification of the electrolyte membranes of the fuel cell based on a differential value of the resistance of the fuel cell detected by a resistance detector when the electric current outputted by the fuel cell equals a predetermined value. The current from the cell is detected by an ammeter. The fuel cell is formed by stacking electrically conductive electrodes and separators, and proton-conductive electrolyte membranes. The electric conductivity of the electrodes and the separators is not affected by the humidification condition thereof, whereas the proton-conductivity of the electrolyte membranes greatly changes depending on the condition of humidification thereof.

Abstract: In a hydrogen supply system, a hydrogen-containing gas is circulated by a circulating pump if a requested hydrogen gas circulation amount VH is less than or equal to a first circulation amount V1. If the requested hydrogen gas circulation amount exceeds the first circulation amount V1, a first control valve is opened so that the circulation amount V1 of hydrogen-containing gas is circulated by a first ejector, and in addition, a circulation amount of hydrogen-containing gas equal to the difference between the circulation amount V1 and the requested hydrogen gas circulation amount VH is circulated by the circulating pump.

Abstract: In a polymer electrolyte fuel cell system, a condition of humidification of electrolyte membranes is precisely determined, and adjustment is performed so that the condition of humidification of the electrolyte membranes substantially remains within a proper range. The system determines a condition of humidification of the electrolyte membranes of the fuel cell based on a differential value of the resistance of the fuel cell detected by a resistance detector when the electric current outputted by the fuel cell equals a predetermined value. The current from the cell is detected by an ammeter. The fuel cell is formed by stacking electrically conductive electrodes and separators, and proton-conductive electrolyte membranes. The electric conductivity of the electrodes and the separators is not affected by the humidification condition thereof, whereas the proton-conductivity of the electrolyte membranes greatly changes depending on the condition of humidification thereof.

Abstract: In a polymer electrolyte fuel cell system, a condition of humidification of electrolyte membranes is precisely determined, and adjustment is performed so that the condition of humidification of the electrolyte membranes substantially remains within a proper range. The system determines a condition of humidification of the electrolyte membranes of the fuel cell based on a differential value of the resistance of the fuel cell detected by a resistance detector when the electric current outputted by the fuel cell equals a predetermined value. The current from the cell is detected by an ammeter. The fuel cell is formed by stacking electrically conductive electrodes and separators, and proton-conductive electrolyte membranes. The electric conductivity of the electrodes and the separators is not affected by the humidification condition thereof, whereas the proton-conductivity of the electrolyte membranes greatly changes depending on the condition of humidification thereof.

Abstract: Consumed hydrogen-off gas is discharged from a fuel cell via a hydrogen-off gas exhaust flow passage. Consumed oxygen-off gas is discharged from the fuel cell via an oxygen-off gas exhaust flow passage. The oxygen-off gas flowing through the oxygen-off gas exhaust flow passage and the hydrogen-off gas flowing through the hydrogen-off gas exhaust flow passage are mixed and diluted in a mixing portion. The gases mixed in the mixing portion flow into a combustor via a gas-liquid separator. The combustor, which includes a platinum catalyst, causes hydrogen contained in the mixed gases to react with oxygen by combustion and further reduces the concentration of hydrogen contained in the mixed gases. The mixed gases whose concentration of hydrogen has been reduced by the combustor is discharged to the atmosphere.