A fuel cell system 10 includes a fuel cell 20, gas supply systems 30, 40, which supply gases to the fuel cell 20, and a controller 60, which controls the gas supply systems 30, 40. During a non-operation period of the fuel cell 20, the controller 60 controls the gas supply systems 30, 40 to carry out the scavenging treatment. If the scavenging treatment is interrupted by an operation performed by a user, then the controller 60 controls the gas supply systems 30, 40 and restarts the scavenging treatment after a predetermined time elapses from the interruption.

A fuel cell system 100 includes: a fuel cell 1 for generating a power by causing an electrochemical reaction between an oxidant gas supplied to an oxidant electrode 34 and a fuel gas supplied to a fuel electrode 67; a fuel gas supplier HS for supplying the fuel gas to the fuel electrode 67; and a controller 40 for controlling the fuel gas supplier HS to thereby supply the fuel gas to the fuel electrode 67, the controller 40 being configured to implement a pressure change when an outlet of the fuel electrode 67 side is closed, wherein based on a first pressure change pattern for implementing the pressure change at a first pressure width ΔP1, the controller 40 periodically changes a pressure of the fuel gas at the fuel electrode 67.

A fuel cell includes an electrode assembly having an electrolyte between an anode and a cathode for generating an electric current and byproduct water. A porous plate is located adjacent to the electrode and includes reactant gas channels for delivering a reactant gas to the electrode assembly. A separator plate is located adjacent the porous plate such that the porous plate is between the electrode assembly and the separator plate. The separator plate includes a reactant gas inlet manifold and a reactant gas outlet manifold in fluid connection with the reactant gas channels, and a purge manifold in fluid connection with the porous plate such that limiting flow of the reactant gas from the reactant gas outlet manifold and opening the purge manifold under a pressure of the reactant gas in the reactant gas channels drives the byproduct water toward the purge manifold for removal from the fuel cell.

A fuel cell control method includes detecting a state value indicating a state in a fuel cell during an operation of the fuel cell. The fuel cell includes a membrane electrode assembly and a separator stacked on the membrane electrode assembly. The membrane electrode assembly includes a solid polymer electrolyte membrane sandwiched between an anode electrode and a cathode electrode. It is determined whether a liquid connects the solid polymer electrolyte membrane and the separator based on the state value detected. The fuel cell is dried in a case where it is determined that the liquid connects the solid polymer electrolyte membrane and the separator.

A method of shutting down operation of a fuel cell system is disclosed, comprising a fuel cell stack, the method comprising the sequential steps of: i) ceasing a supply of fuel to the fuel cell stack; ii) closing a shut-off valve on an exhaust line in fluid communication with a cathode system of the fuel cell system, the cathode system comprising a cathode fluid flow path passing through the fuel cell stack; iii) pressurizing the cathode system with an air compressor in fluid communication with a cathode air inlet port in the fuel cell stack; and iv) ejecting water from the cathode flow path.

A shutdown control method of a fuel cell is provided. The method includes applying power to a controller in a shutdown state and determining, by the controller to which the power is applied, a possibility of moisture freezing based on an estimated outdoor temperature or the temperature of a fuel cell stack. A shutdown of the fuel cell is executed by performing moisture removal from the fuel cell stack in response to determining the possibility of moisture freezing after restart.

A method of operating a water electrolysis and electricity generating system includes, at a time of switching from the water electrolysis mode to the electricity generating mode, a water electrolysis stopping step, a purging step and an electricity generation starting step. In the purging step after the water electrolysis stopping step, an oxygen-containing gas is caused to flow from an oxygen-containing gas flow path to a first gas-liquid separator via an oxygen-containing gas introduction flow path, a first supply flow path, a first inlet port member, a first fluid flow path, a first outlet port member, and a first lead-out flow path. In the electricity generation starting step after the purging step, the cell member is caused to generate electricity based on a predetermined required load value.

A purging circuit for purging an anodic compartment of a cell of a fuel cell, this circuit including: a capacity, forming a related volume at least equal to 500 ml, for containing and homogenising a recovery gas, including an inlet and an outlet; a first nonreturn valve to prevent the recovery gas from returning through the outlet and allowing gas to flow from the first outlet to an inlet of the compartment; a second nonreturn valve to prevent gas from being discharged from the capacity through the inlet; a pressure sensor able to measure the pressure of a fluid present in the circuit; a valve controlling the flow of a supply gas to and from the compartment as a function of data of the sensor and allowing gas to flow from the first nonreturn valve to the inlet of the compartment.

The present invention provides a fuel cell system capable of suppressing the accumulation of impurities in a hydrogen system even when a hydrogen pump stops. A fuel cell system 100 includes a hydrogen pump 4, which is provided in a hydrogen gas circulation flow path 3 and which circulates a hydrogen off-gas discharged from the outlet side of a hydrogen electrode 1a of a fuel cell 1 to the inlet side of the hydrogen electrode 1a, a discharge valve 61, through which the hydrogen off-gas flowing in the hydrogen gas circulation flow path 3 is discharged out of the hydrogen gas circulation flow path 3, a determination section 81, which determines whether the hydrogen pump 4 is stopped, and a control unit 80, which controls the opening/closing of the discharge valve 61. If the determination section 81 determines that the hydrogen pump 4 has been stopped, then the control unit 80 controls the opening/closing of the discharge valve 61 to increase the discharge amount of the hydrogen off-gas discharged through the discharge valve 61 so as to be greater than the discharge amount of the hydrogen off-gas discharged on the assumption that the hydrogen pump 4 is in operation.

A fuel cell system comprises a fuel cell having an anode flow path extending through the fuel cell between an anode inlet and an anode outlet, and a cathode flow path extending through the fuel cell between a cathode inlet and a cathode outlet. An anode purge valve is coupled to the anode outlet and has an outlet coupled to the cathode inlet. A purge valve controller is configured to effect a purge cycle by opening and closing the anode purge valve and to monitor a fuel cell voltage profile during the purge cycle to determine an operational state of the anode purge valve. A fuel cell voltage drop during a period following a command signal instructing opening of the anode purge valve is used to indicate successful start of a purge cycle. A fuel cell voltage rise during a period following a command signal instructing closing of the anode purge valve is used to indicate a successful end to a purge cycle.