Abstract: A method for controlling humidity in a fuel cell, wherein hydrogen is fed at a nominal pressure to the inlet of the cell, characterized in that at predetermined periodicity the following steps are repeated: instruction is given to open a hydrogen purge valve arranged on the outlet of the anode circuit; the pressure of hydrogen is measured at the inlet to the anode circuit of the cell, and the measured value is compared with a threshold pressure value; the purge valve is closed when the measured pressure is equal to or lower than the predetermined threshold pressure value; the opening time of the purge valve is measured; and the humidity level prevailing at the cathode of the cell is inferred therefrom.

Abstract: This method for detecting a hydrogen leak applies to a fuel cell system (10) comprising a fuel cell (12); a hydrogen supply system (30) comprising a reservoir (32) and the supply circuit (34) connecting the reservoir to the anode compartment (16) of the fuel cell and comprising an ejector (36) of Venturi type; a recirculation circuit (60) for recirculating unconsumed hydrogen between the anode compartment of the cell and the Venturi-type ejector (36), the recirculation being driven by the Venturi-effect ejector. The method comprises steps involving calculating the total flow rate of hydrogen consumed; calculating the flow rate of hydrogen admitted to the ejector; determining the leak rate as the difference between the flowrate of hydrogen admitted and the total flow rate of hydrogen consumed; and detecting a potential leak of hydrogen by comparing the leak rate against at least a threshold value, such that the method detects all of the hydrogen leaks that occur in the system downstream of the ejector.

Abstract: A method for purging the hydrogen feed anode circuit of a fuel cell, whereby hydrogen is fed at a nominal pressure to the inlet of the cell, characterized in that at predetermined periodicity the following steps are repeated: instruction is given to open the hydrogen purge valve arranged on the outlet of the anode circuit; the pressure of hydrogen is measured at the inlet to the anode circuit of the cell, and the measured value is compared with a predetermined threshold pressure value; and the purge valve is closed when the measured pressure is equal to or lower than the predetermined threshold pressure value.

Abstract: A method for purging the hydrogen feed anode circuit of a fuel cell, whereby hydrogen is fed at a nominal pressure to the inlet of the cell, characterized in that at predetermined periodicity the following steps are repeated: instruction is given to open the hydrogen purge valve arranged on the outlet of the anode circuit; the pressure of hydrogen is measured at the inlet to the anode circuit of the cell, and the measured value is compared with a predetermined threshold pressure value; and the purge valve is closed when the measured pressure is equal to or lower than the predetermined threshold pressure value.

Abstract: A method for controlling humidity in a fuel cell, wherein hydrogen is fed at a nominal pressure to the inlet of the cell, characterized in that at predetermined periodicity the following steps are repeated: instruction is given to open a hydrogen purge valve arranged on the outlet of the anode circuit; the pressure of hydrogen is measured at the inlet to the anode circuit of the cell, and the measured value is compared with a threshold pressure value; the purge valve is closed when the measured pressure is equal to or lower than the predetermined threshold pressure value; the opening time of the purge valve is measured; and the humidity level prevailing at the cathode of the cell is inferred therefrom.

Abstract: A hydrogen leakage detector includes a sensor and a microcontroller. The sensor is sensitive to a concentration of hydrogen in air. A sensitive unit of the sensor is exposed directly to an in situ concentration of the hydrogen. The microcontroller is programmed to generate and output an analog signal corresponding to concentration information, based on a concentration measurement from the sensor, and to generate and output an analog signal indicating a correct operation of the detector.

Abstract: A fuel cell system includes a stack of electrochemical cells, a sensor, and a microcontroller. Each cell of the stack includes an electrode plate having a face in electrical contact with an electrolyte. At least one tube is connected to the face of each cell in a circuit for exchanging a gas with an area exterior to the stack. The sensor is sensitive to a concentration of the gas in air surrounding the stack. A sensitive unit of the sensor is exposed directly to an in situ quantity of a component of the gas. The microcontroller generates and outputs an analog signal corresponding to concentration information, based on a concentration measurement, and generates and outputs an analog signal indicating an operation status of the sensor.

Abstract: A cooling circuit for a fuel cell includes at least one channel, a mechanical support, a first sensor, and a second sensor. Each channel is formed in a bipolar plate of the fuel cell, and is adapted to permit a cooling fluid to flow. The first sensor senses a flow rate of the cooling fluid. The second sensor senses an electrical conductivity of the cooling fluid. Both the first sensor and the second sensor are installed on the mechanical support.

Abstract: A fuel cell system includes a stack of electrochemical cells, a sensor, and a microcontroller. Each cell of the stack includes an electrode plate having a face in electrical contact with an electrolyte. At least one tube is connected to the face of each cell in a circuit for exchanging a gas with an area exterior to the stack. The sensor is sensitive to a concentration of the gas in air surrounding the stack. A sensitive unit of the sensor is exposed directly to an in situ quantity of a component of the gas. The microcontroller is programmed to generate and output an analog signal corresponding to concentration information, based on a concentration measurement, and to generate and output an analog signal indicating an operation status of the sensor.

Abstract: A hydrogen leakage detector includes a sensor and a microcontroller. The sensor is sensitive to a concentration of hydrogen in air. A sensitive unit of the sensor is exposed directly to an in situ concentration of the hydrogen. The microcontroller is programmed to generate and output an analog signal corresponding to concentration information, based on a concentration measurement from the sensor, and to generate and output an analog signal indicating a correct operation of the detector.

Abstract: A cooling circuit for a fuel cell includes at least one channel, a mechanical support, a first sensor, and a second sensor. Each channel is formed in a bipolar plate of the fuel cell, and is adapted to permit a cooling fluid to flow. The first sensor senses a flow rate of the cooling fluid. The second sensor senses an electrical conductivity of the cooling fluid. Both the first sensor and the second sensor are installed on the mechanical support.