A fuel battery system includes a fuel battery, an electric storage, a voltage adjuster, a pump, an abnormity detector, and circuitry. The fuel battery generates electricity using fuel gas and oxidant gas. The voltage adjuster is connected to at least one of the fuel battery and the electric storage. The voltage adjuster is configured to adjust voltage output from the fuel battery or the electric storage to output the adjusted voltage to a load. The pump supplies the oxidant gas to the fuel battery using electric power output from at least one of the fuel battery and the electric storage. The voltage adjuster is connected between the fuel battery and the pump. The abnormity detector detects abnormity in the voltage adjuster. The circuitry is configured to restrict the electric power supplied to the pump in a case where the abnormity detector detects the abnormity in the voltage adjuster.

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 fuel cell system includes a first temperature sensor to detect a valve temperature of a sealing valve. A second temperature sensor is provided in a refrigerant circulation circuit to detect a fuel cell temperature of a fuel cell through a refrigerant. The circuitry is configured to calculate a sealing valve estimated temperature by subtracting a correction value from the fuel cell temperature detected by the second temperature sensor after the fuel cell stops generating electric power and after the sealing valve is closed. The circuitry is configured to determine whether at least one of the valve temperature and the sealing valve estimated temperature is lower than a predicted freezing temperature. The circuitry is configured to open the sealing valve when it is determined that the at least one of the valve temperature and the sealing valve estimated temperature is lower than the predicted freezing temperature.

A fuel cell system includes: a reaction gas supply unit configured to supply a reaction gas to a fuel cell stack; a humidifier configured to transfer moisture from an off-gas discharged from the fuel cell stack to the reaction gas; and a controller configured to control the reaction gas supply unit so as to regulate a supply amount of the reaction gas, wherein the controller is configured to acquire a temperature of the humidifier and set the supply amount of the reaction gas based on a target power generation amount of the fuel cell stack, and in a case where the temperature of the humidifier is equal to or lower than a prescribed warm-up determination value, the controller executes warm-up control to increase the supply amount of the reaction gas as compared with a case where the temperature of the humidifier is higher than the warm-up determination value.

A fuel cell system includes a fuel cell stack having a membrane electrode assembly and an internal reactant gas passage, a unit that detects or estimates an actual retained water quantity (R.W.Q.), and a power generation control unit having a normal-time mode, a normal-time drying mode and a stop-time drying mode. In the normal-time drying mode, the fuel cell stack is caused to generate electric power while being dried more than in the normal-time mode until the actual R.W.Q. is decreased to a target R.W.Q. In the stop-time drying mode, when the actual R.W.Q. is equal to or more than a flooding threshold at a time of detection of a system stop instruction, the fuel cell stack is caused to generate electric power while being dried more than in the normal-time drying mode until the actual R.W.Q. is decreased to a target R.W.Q.

A separator, subassembly for a separator, and method for heating a second outlet of a separator are disclosed. The separator has a housing with an inlet configured for introduction of a fluid stream into the housing, a first outlet configured for discharge of the fluid stream from the housing, and a second outlet configured for discharge from the housing of deposits which have been separated from the fluid stream. The separator also has, within the housing, a heat-conducting element within the housing and arranged in such a way that, an end of the heat-conducting element is arranged in or adjacent to the fluid stream and another end is arranged on the second outlet. The separator can also have a gas line in or on the housing that is connected fluidically to the second outlet so as to guide a heated gas to the second outlet.

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 method is provided for controlling an ion-exchange-membrane type fuel-cell stack installed in a system that includes a cooling circuit and a cooling pump for circulating coolant liquid in the cooling circuit. The method includes, in a start-up phase of starting up the fuel-cell stack, determining an internal temperature of the fuel-cell stack; measuring a temperature in the cooling circuit; applying a start-up current to the fuel-cell stack; and, in parallel: controlling the cooling pump to operate in a pulsed mode when the internal temperature of the fuel-cell stack is above a first predetermined threshold and the temperature of the cooling circuit is below a second predetermined threshold, and controlling the cooling pump to operate in a continuous mode when the temperature in the cooling circuit rises above the second predetermined threshold.

The fuel cell device includes an electrode assembly. A gas diffusion layer is on each side of the electrode assembly. A solid, non-porous plate is adjacent each of the gas diffusion layers. A hydrophilic soak up region is near an inlet portion of at least one of the gas diffusion layers. The hydrophilic soak up region is configured to absorb liquid water from the electrode assembly when the fuel cell device is shutdown.