Abstract: A fuel cell system is provided that can establish, for a long time period, a stack to an idling stop state. The fuel cell system includes: an idling stop control means for setting the stack to an idling stop state by, decreasing both a supplied amount of air to the stack and generated electric current produced from the stack to less than during the idling power generation; and a discharge valve control means for determining whether there is a necessity to discharge nitrogen or generated water inside of the anode system, and for opening the purge valve or drain valve in a case of there being a necessity. The discharge valve control means shortens valve open times (PO2, DO2) of the purge valve and drain valve during idling stop to less than the valve open times (PO1, DO1) thereof during idling power generation.

Abstract: A fuel cell system includes an ECU that sets the fuel cell stack to a state of idling stop by lowering both a revolution speed of an air pump and a discharge current value of the fuel cell stack to less than during idling power generation within a range larger than 0, in response to a predetermined idling stop initiation condition having been satisfied during idling power generation. The ECU decreases the discharge current value further as the lowest cell voltage value CV_low of the fuel cell stack decreases so that the lowest cell voltage value CV_low does not fall below a cancellation threshold B, with an event of the lowest cell voltage CV_low of the fuel cell stack having fallen below the cancellation threshold B as a cancellation condition of idling stop.

Abstract: A fuel cell system that can quickly transition to idling stop and can suppress degradation of the electrolyte membrane and decline in cell voltage during idling stop, without requiring a discharge resistor to be provided, and a control method thereof are provided. A fuel cell system (1) includes a fuel cell (10) configured by layering a plurality of fuel cell cells that generate power by reactant gas being supplied thereto, and a supply device 20 that supplies reactant gas to the fuel cell (10), in which idling stop control is initiated to supply air of a lower flow rate than during idling power generation to the fuel cell (10), while producing lower current than during idling power generation from the fuel cell (10), in a case of a predetermined condition being established during idling power generation.

Abstract: A start-up method for a fuel cell system that includes a fuel cell that carries out power generation by the electrochemical reaction between a fuel gas and the oxygen gas in the air; a fuel gas discharge path and a fuel gas supply path that are connected to the fuel cell; a fuel gas circulation path in which the fuel gas discharge path merges with the fuel gas supply path; and a purge valve provided on the fuel gas circulation path in order to discharge the circulating fuel gas from the fuel gas circulation path. The method includes the steps of opening the purge valve at the same time that the fuel gas is supplied to the fuel cell and replacing the nitrogen gas that originates in the air and is present in the fuel gas circulation path by fuel gas; and closing the purge valve after the nitrogen gas in the fuel gas circulation path has been replaced by the fuel gas.

Abstract: A method includes an in-stop-mode power generating process and a first startup process. In the a first startup process, if an operation start instruction to start a fuel cell system is detected after the in-stop-mode power generating process, supply of a fuel gas from a fuel-gas supply apparatus is started, and supply of an oxide gas from an oxide-gas supply apparatus is started after a predetermined time has elapsed from the starting of supply of the fuel gas, when a pressure of an anode side is equal to or lower than a first threshold pressure.

Abstract: A fuel cell system comprising: an anode gas flow path supplied with an anode gas; a cathode gas flow path supplied with a cathode gas; a fuel cell generating electricity by the anode gas being supplied to the anode gas flow path and the cathode gas being supplied to the cathode gas flow path; an anode gas supplying unit supplying the anode gas to the anode gas flow path; a blowdown valve ejecting fluid from inside the anode gas flow path towards an exterior; and a control unit which controls the anode gas supplying unit and the blowdown valve, supplies the anode gas from the anode gas supplying unit to the anode gas flow path, and performs a periodic fluid substitution by opening the blowdown valve periodically, wherein the control unit comprises a low temperature condition determination unit.

Abstract: An object of the present invention is to provide a fuel cell system capable of starting below freezing point without increasing the size of the diluter. The fuel cell system 1 comprises an OCV purge execution unit 42 replacing gas retained in a fuel cell 10 by supplying additional anode gas from a supply device 20 to the fuel cell 10 when starting up the fuel cell. In addition, the fuel cell system 1 comprises a low temperature startup determination unit 41 determining whether to perform low temperature startup or normal startup on the fuel cell 10. The OCV purge execution unit 42 decreases the pressure of additional anode gas supplied from the supply device 20 and increases the total replacing amount of gas retained in the fuel cell 10 in a case of performing low temperature startup, as compared with a case of performing normal startup.

Abstract: A fuel cell system and method comprising a fuel cell stack formed by stacking fuel cells, a high voltage energy storage capable of being directly coupled to the fuel cell stack, a DC-DC converter connected to the fuel cell stack and the energy storage, a load operated by consuming at least electrical energy generated by the fuel cell stack or electrical energy discharged from the energy storage, a fuel cell warming up control unit for warming up the fuel cell stack, and a voltage adjustment unit for implementing voltage control to control the output voltage of the fuel cell stack to become equal to, or higher than the terminal voltage of the energy storage, at the time of warming up the fuel cell stack.

Abstract: Upon stop of electric power generation of a fuel cell a hydrogen shutoff valve is closed, and a cathode is purged. At the same time, an air introducing valve and the purge valve are opened. The air taken in by the compressor is introduced into the anode through the air introducing tube to exhaust the hydrogen remaining in the anode to replace the hydrogen with the air. When the replacement of the hydrogen with the air has been finished, the compressor is turned off and the air introducing valve and the purge valve are opened. After that, if a temperature of the fuel cell is determined to be equal to or lower than a threshold “a”, a cathode-prioritized purge and an anode-prioritized purging are performed.

Abstract: A fuel cell system includes: a fuel cell that generates an electric power and heat by a reaction of a reaction gas; a heat exchanger; a coolant circuit for a coolant between the fuel cell and the heat exchanger; a coolant circulating pump for circulating the coolant in the coolant circuit; and a drive motor for driving the coolant circulating pump, the coolant receiving and carrying the heat to the heat exchanger by the coolant circuit, the coolant circulating pump, and the drive motor. A rotational speed of the drive motor is controlled according to an upper limit of the rotational speed of the drive motor which may be determined on the basis of a cooling capacity of the heat exchanger, a speed of the vehicle mounting the fuel cell system, a generated electric power, and a flow rate of the reaction gas.

Abstract: A start-up method for a fuel cell system that includes a fuel cell that carries out power generation by the electrochemical reaction between a fuel gas and the oxygen gas in the air; a fuel gas discharge path and a fuel gas supply path that are connected to the fuel cell; a fuel gas circulation path in which the fuel gas discharge path merges with the fuel gas supply path; and a purge valve provided on the fuel gas circulation path in order to discharge the circulating fuel gas from the fuel gas circulation path. The method includes the steps of opening the purge valve at the same time that the fuel gas is supplied to the fuel cell and replacing the nitrogen gas that originates in the air and is present in the fuel gas circulation path by fuel gas; and closing the purge valve after the nitrogen gas in the fuel gas circulation path has been replaced by the fuel gas.

Abstract: A fuel cell system includes a fuel cell, a circulation path, a water reservoir, a water level detector, a water discharger and a controller. The fuel cell generates electric power using fuel gas supplied to an anode and oxidant gas supplied to a cathode. Off-gas discharged from the fuel cell is returned to the fuel cell again through the circulation path. The water reservoir is disposed in the circulation path and stores water separated from the off-gas. During monitoring after stop of the fuel cell system or at startup of the fuel cell system, the controller operates the water discharger to discharge the water stored in the water reservoir when the controller determines that a level of the water detected or estimated by the water level detector is equal to or higher than a predetermined reference water level.

Abstract: A fuel cell system which includes: a fuel cell having a fuel gas flow path and an oxidant gas flow path and generating electricity by being supplied a fuel gas to the fuel gas flow path and an oxidant gas to the oxidant gas flow path; fuel gas supplying means; a discharge valve; fuel gas exchange means for exchanging an atmosphere inside the fuel gas flow path for the fuel gas at a starting of the system; and cold start determination means for determining whether to conduct or not to conduct the cold start of the system, wherein when the cold start determination means determines to conduct the cold start, the cold start determination means increases a total discharge amount of a gas to be discharged for exchanging the atmosphere inside the fuel gas flow path for the fuel gas, and thereby increases a fuel gas concentration in the fuel gas flow path.

Abstract: A fuel cell having an oxygen-containing gas flow field and a fuel gas flow field, an oxygen-containing gas supply apparatus for supplying an oxygen-containing gas to the oxygen-containing gas flow field, a fuel gas supply apparatus for supplying a fuel gas to the fuel gas flow field, a scavenging gas supply apparatus for supplying air as a scavenging gas to the fuel gas flow field, and a controller are provided. The controller includes a voltage detection unit for detecting the voltage of the fuel cell after operation of the fuel cell is stopped and a scavenging control unit for starting scavenging in the fuel gas flow field by the scavenging gas supply apparatus after the detected voltage is decreased temporarily, increased, and decreased again to become a preset voltage or less.

Abstract: A start-up method for a fuel cell system that includes a fuel cell that carries out power generation by the electrochemical reaction between a fuel gas and the oxygen gas in the air; a fuel gas discharge path and a fuel gas supply path that are connected to the fuel cell; a fuel gas circulation path in which the fuel gas discharge path merges with the fuel gas supply path; and a purge valve provided on the fuel gas circulation path in order to discharge the circulating fuel gas from the fuel gas circulation path. The method includes the steps of opening the purge valve at the same time that the fuel gas is supplied to the fuel cell and replacing the nitrogen gas that originates in the air and is present in the fuel gas circulation path by fuel gas; and closing the purge valve after the nitrogen gas in the fuel gas circulation path has been replaced by the fuel gas.

Abstract: A fuel cell system including: a fuel cell including a fuel gas channel and an oxidant gas channel, which is configured to generate electricity using a fuel gas and an oxidant gas; a diluting unit configured to dilute gas discharged from the fuel gas channel by mixing the discharged gas with a dilution gas which is supplied from an oxidant gas supply unit and passed through and discharged from the fuel cell, and to exhaust the diluted gas to outside; a purge valve configured to purge gas in the fuel gas channel to the diluting unit; a scavenging unit configured to scavenge the fuel gas channel and the oxidant gas channel; and a dilution assist unit configured to supply a dilution assist gas to the diluting unit through an assist passage connected to the diluting unit to assist dilution in the diluting unit, during scavenging by the scavenging unit.

Abstract: A fuel cell having an oxygen-containing gas flow field and a fuel gas flow field, an oxygen-containing gas supply apparatus for supplying an oxygen-containing gas to the oxygen-containing gas flow field, a fuel gas supply apparatus for supplying a fuel gas to the fuel gas flow field, a scavenging gas supply apparatus for supplying air as a scavenging gas to the fuel gas flow field, and a controller are provided. The controller includes a voltage detection unit for detecting the voltage of the fuel cell after operation of the fuel cell is stopped and a scavenging control unit for starting scavenging in the fuel gas flow field by the scavenging gas supply apparatus after the detected voltage is decreased temporarily, increased, and decreased again to become a preset voltage or less.

Abstract: A fuel cell system includes a fuel cell, an operation controller, a checking unit, a scavenging unit, an instructing unit, a temperature sensor, a humidifier and a humidification controller. The operation controller selects one of a normal operation mode and a low-temperature operation mode. The checking unit determines whether the fuel cell has been started up in the low-temperature operation mode. The instructing unit provides an instruction for a shutoff of electricity generation. When the scavenging unit conducts scavenging based on the checking unit determining that the fuel cell has been started in the low-temperature operation mode in response to an instruction for a shutoff of electricity generation and an actual temperature of the fuel cell is higher than a predetermined temperature, the humidification controller controls an amount of humidification according to the actual temperature.

Abstract: A fuel-cell system 1 includes: a fuel cell 13 configured to generate electricity through reaction between hydrogen gas and air; a compressor 12 configured to supply air as a scavenging gas to a reactant gas path 13a of the fuel cell 13; a control part 18 configured to control an amount of air supplied from the compressor 12 to the fuel cell 13 to perform scavenging of the fuel cell 13; and pressure sensors P1 and P2 configured to monitor a pressure drop in the reactant gas path 13a of the fuel cell 13. The control part 18 controls an amount of supplied air so as to keep the pressure drop in the reactant gas path 13a substantially constant when the fuel cell 13 is scavenged. With this configuration, residual water can be suitably purged from the fuel cell while energy consumption is suppressed.

Abstract: In a fuel cell system including a fuel cell supplied with reaction gases for generating an electric power, and a combustion heater supplied with the reaction gases for heating the fuel cell during warming-up, an electric discharging circuit is provided to discharge an electric current from the fuel cell supplied with the reaction gases to decrease a voltage difference applied to the membrane sandwiched between the anode and cathode during the warming-up. The combustion heater is connected in series or in parallel with the fuel cell system.