Abstract: As an activation time power generation mode of a fuel cell system, a control device executes: a first step of determining whether or not hydrogen is present in an anode gas flow path; a second step of bringing a contactor to a connected state if hydrogen is detected in the first step as being present in the anode gas flow path; a third step of supplying air to a cathode through a cathode gas flow path after the second step has been executed; and a fourth step of, if a voltage of the fuel cell stack detected by a voltage detection device reaches a predetermined voltage, connecting an electrical load to the fuel cell stack, and performing electric power generation of the fuel cell stack while maintaining the voltage at or below the predetermined voltage.

Abstract: A controller (control portion) of a fuel cell system is provided with a flow path switching control device that switches a thermostat valve (flow path switching valve) so that, after a fuel cell has stopped generating electric power, coolant is supplied to a radiator circulation path until the coolant temperature becomes a second temperature threshold value that is lower than a first temperature threshold value.

Abstract: Provided is a method of starting a fuel cell system including a hydrogen concentration acquisition process of acquiring a concentration of hydrogen in the anode, a threshold value determination process of determining whether or not the concentration of hydrogen which is acquired by the hydrogen concentration acquisition process is greater than or equal to a predetermined second threshold value, and a starting pressure setting process of setting a pressure of hydrogen supplied to an anode from a hydrogen tank when supplying hydrogen to the anode from the hydrogen tank in a state in which a contactor is shut off.

Abstract: Provided is a method of controlling a fuel cell system including a stop command sensing process of sensing a stop command output when the fuel cell system stops, an anode pressure increasing process of increasing pressure so that the pressure of the anode reaches a first predetermined pressure value, and a stop-time discharge process of performing discharge by consuming oxygen remaining within an oxidant off-gas while driving an oxidant off-gas circulation pump.

Abstract: In a method for stopping an operation of a fuel cell system, supply of a fuel gas to an anode side of a fuel cell provided in the fuel cell system is stopped. A fuel exhaust gas discharged from the fuel cell is recirculated to the anode side of the fuel cell. An oxidant-exhaust-gas discharge path through which an oxidant exhaust gas is to be discharged from the fuel cell is sealed at a downstream position of a connecting portion at which the oxidant-exhaust-gas discharge path is connected to an oxidant-exhaust-gas recirculation path. The oxidant exhaust gas is recirculated to a cathode side of the fuel cell through the oxidant-exhaust-gas recirculation path. Recirculation of the fuel exhaust gas is stopped. Recirculation of the oxidant exhaust gas is stopped. An oxidant-gas supply path through which an oxidant gas is to be supplied to the fuel cell is sealed.

Abstract: In a method for starting a fuel cell system, an oxidizer gas bypass passage is operated by an oxidizer gas bypass passage controller to supply oxidizer gas to a diluter from an oxidizer gas supply device under a condition where an oxidizer gas supply passage is sealed by an oxidizer gas supply passage sealing device and an oxidizer exhaust gas exhaust passage is sealed by an oxidizer exhaust gas exhaust passage sealing device. A fuel exhaust gas recirculation passage is operated by a fuel exhaust gas recirculation passage controller to supply fuel gas to the fuel cell from a fuel gas supply device.

Abstract: Provided is a fuel cell system capable of preventing a fuel cell from being polarized at a high potential for a long time during start-up. A fuel cell system 1 includes a first injector 23A and a second injector 23B in a fuel gas inlet passage. When an ECU 60 determines that a power generation down time is equal to or more than a predetermined period at start-up of a fuel cell stack 10, a target pressure of hydrogen supplied to an anode passage 12 is set to be higher for supply than when the power generation down time is less than the predetermined period. In addition, as the power generation down time of the fuel cell stack 10 becomes longer, the target pressure is set to be higher. Also, a pressure increase in the fuel cell stack is set to be lower than that during ordinary power generation.

Abstract: A fuel cell system includes a fuel cell, a fuel gas passage, and an oxidant gas passage. The fuel cell includes a solid polymer membrane, a fuel electrode, and an oxidant electrode. A coolant flows into the fuel cell via a coolant passage to adjust a temperature of the fuel cell. An oxidant gas outlet temperature detector is configured to detect an outlet temperature of an oxidant gas discharged from an outlet of the oxidant gas passage. A coolant temperature detector is configured to detect a temperature of the coolant passing through an inlet or an outlet of the coolant passage. A dry-up controller is configured to decide that the solid polymer membrane is in a dry-up state when a temperature difference between the temperature of the coolant and the outlet temperature of the oxidant gas exceeds a first threshold value.

Abstract: A fuel cell system for a vehicle includes a fuel cell, a fuel supply device, an oxidizer supply device, an anode potential measuring device, and a discharge controller. The anode potential measuring device is configured to measure an anode potential of an anode. The discharge controller is configured to control discharge of electric current from the fuel cell as part of a process of stopping the fuel cell during idling of the vehicle. When receiving idle stop permission for the fuel cell, the discharge controller determines whether the fuel cell is permitted to discharge. When the anode potential is equal to or lower than a predetermined threshold value, the discharge controller permits the fuel cell to discharge. When the anode potential is higher than the predetermined threshold value, the discharge controller does not permit the fuel cell to discharge.

Abstract: Provided is a method of controlling a fuel cell system including a stop command sensing process of sensing a stop command output when the fuel cell system stops, an anode pressure increasing process of increasing pressure so that the pressure of the anode reaches a first predetermined pressure value, and a stop-time discharge process of performing discharge by consuming oxygen remaining within an oxidant off-gas while driving an oxidant off-gas circulation pump.

Abstract: Provided is a method of starting a fuel cell system including a hydrogen concentration acquisition process of acquiring a concentration of hydrogen in the anode, a threshold value determination process of determining whether or not the concentration of hydrogen which is acquired by the hydrogen concentration acquisition process is greater than or equal to a predetermined second threshold value, and a starting pressure setting process of setting a pressure of hydrogen supplied to an anode from a hydrogen tank when supplying hydrogen to the anode from the hydrogen tank in a state in which a contactor is shut off.

Abstract: As an activation time power generation mode of a fuel cell system, a control device executes: a first step of determining whether or not hydrogen is present in an anode gas flow path; a second step of bringing a contactor to a connected state if hydrogen is detected in the first step as being present in the anode gas flow path; a third step of supplying air to a cathode through a cathode gas flow path after the second step has been executed; and a fourth step of, if a voltage of the fuel cell stack detected by a voltage detection device reaches a predetermined voltage, connecting an electrical load to the fuel cell stack, and performing electric power generation of the fuel cell stack while maintaining the voltage at or below the predetermined voltage.

Abstract: A controller (control portion) of a fuel cell system is provided with a flow path switching control device that switches a thermostat valve (flow path switching valve) so that, after a fuel cell has stopped generating electric power, coolant is supplied to a radiator circulation path until the coolant temperature becomes a second temperature threshold value that is lower than a first temperature threshold value.

Abstract: Provided is a fuel cell system capable of preventing a fuel cell from being polarized at a high potential for a long time during start-up. A fuel cell system 1 includes a first injector 23A and a second injector 23B in a fuel gas inlet passage. When an ECU 60 determines that a power generation down time is equal to or more than a predetermined period at start-up of a fuel cell stack 10, a target pressure of hydrogen supplied to an anode passage 12 is set to be higher for supply than when the power generation down time is less than the predetermined period. In addition, as the power generation down time of the fuel cell stack 10 becomes longer, the target pressure is set to be higher. Also, a pressure increase in the fuel cell stack is set to be lower than that during ordinary power generation.

Abstract: A fuel cell system includes a fuel cell, a fuel gas passage, and an oxidant gas passage. The fuel cell includes a solid polymer membrane, a fuel electrode, and an oxidant electrode. A coolant flows into the fuel cell via a coolant passage to adjust a temperature of the fuel cell. An oxidant gas outlet temperature detector is configured to detect an outlet temperature of an oxidant gas discharged from an outlet of the oxidant gas passage. A coolant temperature detector is configured to detect a temperature of the coolant passing through an inlet or an outlet of the coolant passage. A dry-up controller is configured to decide that the solid polymer membrane is in a dry-up state when a temperature difference between the temperature of the coolant and the outlet temperature of the oxidant gas exceeds a first threshold value.

Abstract: A fuel cell system for a vehicle includes a fuel cell, a fuel supply device, an oxidizer supply device, an anode potential measuring device, and a discharge controller. The anode potential measuring device is configured to measure an anode potential of an anode. The discharge controller is configured to control discharge of electric current from the fuel cell as part of a process of stopping the fuel cell during idling of the vehicle. When receiving idle stop permission for the fuel cell, the discharge controller determines whether the fuel cell is permitted to discharge. When the anode potential is equal to or lower than a predetermined threshold value, the discharge controller permits the fuel cell to discharge. When the anode potential is higher than the predetermined threshold value, the discharge controller does not permit the fuel cell to discharge.

Abstract: A fuel cell stack includes a stack body formed by stacking a plurality of power generation units. A first end power generation unit and first dummy units are provided near an end plate where reactant gas pipes for the stack body are provided. A second end power generation unit and second dummy units are provided near an end plate of the stack body on the opposite side. The number of first dummy units is larger than the number of second dummy units.