A fuel cell system configured to enhance the life of a fuel cell is provided. The fuel cell system a fuel cell, an oxidant gas supplier configured to supply oxygen-containing oxidant gas to a cathode of the fuel cell, a fuel gas supplier configured to supply hydrogen-containing fuel gas to an anode of the fuel cell, an oxygen partial pressure estimator configured to estimate an oxygen partial pressure of the cathode of the fuel cell, a hydrogen partial pressure estimator configured to estimate a hydrogen partial pressure of the anode of the fuel cell, and a controller, wherein the controller calculates a target hydrogen partial pressure by a given equation (1), and wherein the controller controls the hydrogen partial pressure of the anode to the target hydrogen partial pressure.

A fuel cell system includes a fuel cell, a supply flow passage and a discharge flow passage for anode gas, a gas-liquid separator, a discharge valve, a differential pressure detection unit configured to detect a differential pressure between an upstream side and a downstream side of the discharge valve, and a control unit. The control unit is configured to estimate an effective cross-sectional area of the discharge valve for the anode off-gas, which is decreased by an amount of water flowing into the gas-liquid separator and flowing out from the discharge valve, based on the differential pressure, and to estimate a discharge amount of the anode off-gas based on the estimated effective cross-sectional area.

The present invention concerns a system and a fuel ejector for controlling the fuel flow in proton exchange membrane fuel cells. The ejector comprises a nozzle receiving pressurized fuel from a first inlet into said ejector and including a first tapered section narrowing towards the outlet end of said nozzle in order to provide a flow of fuel, a second inlet for receiving recirculated fuel from a proton exchange membrane fuel cell, a diffuser comprising at least a second tapered section receiving fuel from said nozzle and said second inlet, and an outlet for delivering fuel from said diffuser to the anode system of said proton exchange membrane fuel cell. A shaped elongate rod having a butt end and an opposite pointed is movable lengthwise along its axis to engage with said first tapered section in order to provide a fuel flow control means for the fuel at the outlet of said nozzle. The rod is extending to said at least one second tapered section in order to provide a restriction means for a fuel flow through said diffuser, and wherein said rod is provided at its butt end with a control mechanism arranged to move said rod lengthwise in order to vary the fuel flow path geometry at the outlet of said nozzle and at said diffuser.

According to the present embodiment, a fuel cell stack comprises a cell stack having a plurality of unit cells stacked therein, each of the unit cells including an electrolyte membrane, a fuel-electrode porous passage plate, and an oxidant-electrode porous passage plate, wherein in the cell stack, at least a part of one main surface of a conductive fuel-electrode porous passage plate is in contact with one main surface of a conductive oxidant-electrode porous passage plate, and a capillary force of water contained in a hydrophilic micropores of the conductive fuel-electrode porous passage plate and the conductive oxidant-electrode porous passage plate prevents an oxidant gas in an oxidant-electrode passage and a fuel gas in a fuel-electrode passage from directly mixing together.

Some embodiments of the disclosure provide a cathode circulation system of a fuel cell connected to a power generation unit of the fuel cell. The cathode circulation system includes a first gas supply tank for providing an inert gas, a second gas supply tank for providing a reaction gas, a mixing tank connected to the first gas supply tank and the second gas supply tank for mixing the inert gas and the reaction gas, a gas-liquid separator connected to the power generation unit, and at least one cathode gas pump provided between the mixing tank and the gas-liquid separator and between the mixing tank and the power generation unit.

A method for reducing cell degradation in a fuel cell system includes adding oxygen-containing gas to a fuel in the anode chamber to prevent an increase in a cell voltage above a predetermined maximum value.

The present disclosure generally relates to systems and methods for operating a fuel cell system including a three-port differential pressure switch in a recirculation loop of the fuel cell system comprising a blower and an ejector. A sensor in the three-port differential pressure switch is activated when a pressure ratio of a first pressure difference and second pressure difference exceeds a threshold ratio.

An ECU of a fuel cell system determines whether or not temperature information exceeds a temperature threshold for determination when receiving a signal related to power generation stop of a fuel cell stack during operation of a moving body. When the temperature information exceeds the determination temperature threshold, the ECU performs a stop control for stopping power generation of the fuel cell stack. On the other hand, when the temperature information is equal to or lower than the determination temperature threshold, the ECU performs an idle control for generating electric power smaller than electric power consumed by the air pump.

A fuel cell system includes a fuel cell. The fuel cell includes an anode having an anode inlet configured to receive anode feed gas, and an anode outlet configured to output anode exhaust. The fuel cell further includes a cathode having a cathode inlet and a cathode outlet. The fuel cell system further includes an anode blower configured to receive the anode exhaust and output a higher-pressure anode exhaust. The fuel cell system further includes an anode blower recycle line configured to receive a portion of the higher-pressure anode exhaust downstream from the anode blower and to output the portion of the higher-pressure anode exhaust upstream from the anode blower. The fuel cell system further includes a first valve disposed in the blower recycle line, the first valve configured to open when the anode of the fuel cell is under-pressurized.

A fuel cell system includes a fuel cell, a supply device configured to supply a cathode gas to the fuel cell; and a control unit configured to execute recovery processing of causing a catalyst of the fuel cell to recover from performance deterioration by lowering an output voltage of the fuel cell. The control unit is configured to, when the recovery processing that has been executed is completed, control the supply device to place the fuel cell in a power generation paused state while making a stoichiometric ratio of the cathode gas lower than a stoichiometric ratio of the cathode gas in a normal operation state that is a state before execution of the recovery processing.