A fuel cell system includes a control unit that detects an abnormality of a flow dividing valve provided in a bypass channel for an oxidation gas by using a detected opening degree detected by a valve opening degree detection sensor that detects the opening degree of the flow dividing valve. When the detected abnormality is an opening abnormality that is failure to open and the flow dividing valve can close, the control unit sends a closing command for making the opening degree smaller than a current opening degree to a valve driving motor. Either when the detected abnormality is a closing abnormality that is failure to close and the flow dividing valve can open or when the detected abnormality is an opening-closing abnormality that is failure both to close and to open, the control unit sends a maintaining command for maintaining the opening degree to the valve driving motor.

A fuel cell system includes a fuel cell that generates electricity by causing reaction of a fuel component contained in fuel gas, a supply path, a control valve, an ejector, a return path, and a controller. The control valve is provided on the supply path. The ejector is provided in a section on the supply path between the control valve and the fuel cell. The return path is connected between an exhaust port of the fuel cell and the ejector, and returns off-gas discharged from the exhaust port to the supply path by suction force generated by the ejector. The controller selectively executes a normal operation and a particular operation. In the particular operation, the control valve is continuously or intermittently opened to a second opening degree smaller than a first opening degree, when the fuel gas is supplied to the fuel cell at a first supply amount.

A fuel cell system includes a fuel cell stack, a fuel gas supply path, an injector, an ejector, a circulation path, a pressure difference detection unit that detects a pressure difference between an ejector inlet port pressure and an ejector outlet port pressure, and a control device. The control device calculates a required circulation flow rate that is required for a fuel off gas supplied from the fuel cell stack to the ejector, based on a required load for the fuel cell stack, calculates an estimated circulation flow rate that is an estimated flow rate of the fuel off gas supplied from the fuel cell stack to the ejector, based on the required load and the pressure difference, and increases the flow rate of a fuel gas supplied from the injector to the fuel cell stack when the estimated circulation flow rate is lower than the required circulation flow rate.

An illustrative example method of controlling operation of a fuel cell power plant includes opening a pneumatic valve using pneumatic pressure of pressurized fuel cell reactant, allowing the pressurized fuel cell reactant to flow through the pneumatic valve to a cell stack assembly, determining that shutdown of the cell stack assembly is desired, and control a rate that the pneumatic valve closes by controlling a rate of release of the pneumatic pressure.

A system for generating electricity by pyrolyzing organic materials and feeding the pyrolysis fluid to a battery of fuel-cells. The system includes a pyrolysis reactor receiving organic materials and producing pyrolysis fluid. The fluid pyrolysis is then separated into a plurality of sub-mixtures, each provided via a respective separator output. A plurality of fuel-cell devices for generating electricity using different technologies are each coupled to a respective separator output. A controller controls the pyrolysis reactor, the separator device, and the plurality of fuel-cell devices according to a signal representing a demand for electric power, a signal representing cost of operating at least one of the pyrolysis reactor and the fuel-cell generator, and a signal representing minimum price of electric power.

An apparatus for dilution of hydrogen concentration in a fuel cell exhaust system is provided. The apparatus includes a fuel cell exhaust line configured for receiving a flow of gas from a connected fuel cell and including a flow of hydrogen gas. The apparatus further includes a mixing chamber disposed to receive the flow of hydrogen gas and configured for mixing a flow of air with the flow of hydrogen gas. The mixing chamber includes a mixing mesh including at least one tab feature configured for altering a flow direction of at least a portion of one of the flow of hydrogen gas and for creating a turbulent flow region within the mixing chamber.

A fuel cell system and a method for controlling the same may adjust generation of condensate water in a fuel cell by setting relative humidities and temperature and pressure conditions of the fuel cell so as to maintain a constant current density, and may alleviate performance deterioration of the fuel cell during operation by removing an excessive amount of the generated condensate water by injecting a cathode pressure impulse into the fuel cell.

A method for operating a fuel cell system having a fuel cell stack includes detecting a failure of a first cooling fan that blows exterior air to a first radiator, opening a first valve such that first cooling water that passes via the fuel cell stack flows toward the fuel cell stack, controlling an RPM of a blower of an air conditioning system to a maximum level, controlling an opening degree of a second valve according to a cooling degree of the first radiator and a cooling degree of the air conditioning system, and controlling an RPM of a first pump that pumps the first cooling water to a maximum level.

A combined cooling and humidifying system for a fuel cell system includes a first line strand, second line strand, gas separator, and water feed device. The first line strand has a supply line for feeding water to a heat exchanger of the fuel cell system and a return line for receiving a water-steam mixture from the fuel cell system. The gas separator is in the return line to at least partially separate the steam from the water-steam mixture and provide it at a steam connection. The second line strand has a fluid inlet for feeding a gaseous fluid to the fuel cell system. The steam connection is coupled to the second line strand downstream of the fluid inlet to admix steam with the fluid. The water feed device is coupled to the supply line to compensate for a separating mass flow of steam in the first line strand.

A fuel cell system installed in a vehicle, the system comprising: a fuel cell, a secondary cell, a temperature acquirer for acquiring a temperature of the fuel cell, a state-of-charge value acquirer for acquiring a state-of-charge-value of the secondary cell, an outside temperature acquirer for acquiring an outside temperature, an outside pressure acquirer for acquiring an outside pressure, and a controller for controlling power of the secondary cell, wherein, when the temperature of the fuel cell exceeds a predetermined temperature, when the state-of-charge value of the secondary cell is a predetermined threshold value or more, when the outside temperature is a predetermined temperature or more, and when the outside pressure is a predetermined pressure or less, the controller increases the power of the secondary cell larger than power required of the secondary cell for normal running of the vehicle.