The present disclosure relates to systems and methods of using a proportional control valve in a fuel cell stack system. The fuel cell stack system, may comprise a fuel cell stack including an anode with an anode inlet and an anode outlet, and a cathode with a cathode inlet and a cathode outlet, and a control valve, which controls the flow of a fuel into the anode. The flow of fuel may be based on a pressure differential measured across any two of the anode inlet, the anode outlet, the cathode inlet, and the cathode outlet.

A fuel cell system includes a fuel cell, a fuel gas supply channel, a regulator, an injector, and a controller. The controller drives the regulator in conjunction with the injector. The controller compares a fuel gas flow amount necessary for the fuel cell to generate electricity with a predetermined fuel gas flow amount, selects the fuel gas flow amount that is larger, and issues commands to the regulator and the injector. The predetermined fuel gas flow amount is set to be larger than the fuel gas flow amount necessary for the fuel cell to generate the electricity when a generated current or output of the fuel cell is smaller than a predetermined threshold value.

A pump for a fuel cell includes a pump portion, a motor, a controller, a housing, and a temperature detector. The controller executes an activation control and a sensorless vector control. In the activation control, the controller executes a cold activation mode process when the outside air temperature is less than or equal to a set temperature. In the cold activation mode process, the controller executes at least one of increasing a value of an activation current supplied to the motor relative to when a normal activation mode process is executed or setting a supply duration of the activation current to the motor to be longer than that of when the normal activation mode process is executed.

The invention relates to a gas-liquid separator (2) for separating at least one liquid component, in particular H.sub.2O, from a gaseous component, in particular H.sub.2, the separator comprising at least one container (6) which is supplied with a medium via an inlet (16), at least the liquid component of the medium being separated in at least one container (6) and the separated component of the medium being discharged from the at least one container (6) via a discharge valve (46) with the remaining gaseous component of the medium, in particular H.sub.2, being recirculated into an outflow line (5) via a first outlet (18). According to the invention, in addition to the liquid component, in particular H.sub.2O, a gaseous component N.sub.2 is separated from the medium by the gas-liquid separator (2).

The invention relates to a fuel cell system (10) comprising at least one fuel cell stack (11) having an anode section (12) and a cathode section (13), an ejector (14), a fuel mixture line (15) for conveying a fuel mixture—containing primary fuel and secondary fuel—from the ejector (14) to the anode section (12), a primary fuel line (16) for supplying the primary fuel to the ejector (14), and a recirculation line (17) for returning the secondary fuel from the anode section (16) to the ejector (14), wherein at least sections of the primary fuel line (16) extend through a heat exchange volume (18) within the recirculation line (17) for a heat-transmitting connection between the secondary fuel and the primary fuel.

The invention relates to a method for deactivating a fuel cell system (10) comprising a jet pump (28) for conveying an anode-side gas flow in a recirculation path (26), wherein the jet pump (28) comprises a metering valve (36) for metering H.sub.2. While the fuel cell system (10) is cooling, a flow passes through a drive nozzle (46) at least once in order to discharge condensed water. The t invention additionally relates to a jet pump (28) comprising a metering valve (36) and to the use of the method in order to deactivate a fuel cell system (10).

The invention relates to a method for operating a fuel cell system (1), in particular a PEM fuel cell system, in which at least one fuel cell (2) is supplied with a hydrogen-containing anode gas via an anode gas path (3) and anode gas exiting the fuel cell (2) is returned via a recirculation path (4), wherein, in order to reduce a nitrogen content in the anode gas, a flush valve (5) arranged in the recirculation path (4) is opened and the recirculation path (4) is flushed. According to the invention, the actual composition of the anode gas is determined using at least one sensor (6) and the ageing status of the at least one fuel cell (2) is determined by comparing the determined actual composition with a target composition and/or an actual composition determined earlier. The invention also relates to a control device (7) for carrying out the method according to the invention.

A fuel cell system includes a fuel cell, an anode gas supply system, an anode gas circulatory system, a cathode gas supply-discharge system, a gas-liquid discharge passage, a gas-liquid discharge valve configured to open and close the gas-liquid discharge passage, a flow-rate acquisition portion, and a controlling portion. After the controlling portion instructs the gas-liquid discharge valve to be opened, the controlling portion executes a normal-abnormality determination such that, when a discharge-gas flow rate of anode gas is a predetermined normal reference value or more, the controlling portion determines that the gas-liquid discharge valve is opened normally, and when the discharge-gas flow rate is lower than the normal reference value, the controlling portion determines that the gas-liquid discharge valve is not opened normally.

The present invention relates to an SOEC system (1), comprising a fuel cell stack (2) having a gas side (3) and an air side (4), and an ejector (5) for supplying a process fluid to a gas inlet (6) on the gas side (3), wherein the ejector (5) comprises a primary inlet (7), for introducing a water-containing primary process fluid through a primary line (8) of the SOEC system (1) into a primary portion (9) of the ejector (5), and a secondary inlet (10), for introducing recirculated secondary process fluid through a recirculation line (11) of the SOEC system (1) from a gas outlet (12) on the gas side (3) into a secondary portion (13) of the ejector (5), wherein the SOEC system (1) further comprises a control gas supply portion (14) for supplying control gas into the primary portion (9) and into the secondary portion (13) in order to control a pressure and/or mass flow in the primary portion (9) and in the secondary portion (13), and wherein the control gas supply portion (14) comprises a valve arrangement (19, 20) for controlling the pressure and/or the mass flow in the primary portion (9) and in the secondary portion (13).

The invention further relates to a method for operating an SOEC system (1) according to the invention.

The present disclosure generally relates to systems and methods for fuel cell regeneration after degradation.