The invention relates to a device (1) for determining the H2 concentration of a fluid in an exhaust gas line (12) of a fuel cell system (100), comprising a sensor (14) which is arranged in a pipe section (2), said pipe section having an inflow opening (4) and an outflow opening (6). An installation element (8) divides exhaust gas arriving through the inflow opening (4) into a first volumetric flow which flows through a first pipe volume (V1) and at least one additional volumetric flow which flows through at least one additional pipe volume (V2). A purge line (41) opens into the first pipe volume (V1) between the inflow opening (4) and the H2 sensor (14). The sensor (14) measures the H2 concentration of the exhaust gas in the first pipe volume (V1).

Some embodiments of the disclosures provide an anode recovery system of a fuel cell. The anode recovery system includes a gas supply unit connected to a power generation unit, a gas-liquid separator connected to the power generation unit and a first anode gas recovery control component; and a storage tank connected to the gas-liquid separator and a cathode recovery system. The gas supply unit is configured to provide anode gas to the power generation unit. A first part of unreacted anode gas from the power generation unit mixes with the anode gas and flows back to the power generation unit sequentially via the gas-liquid separator and the first anode gas recovery control component. A second part of the unreacted anode gas and generated water are discharged from the power generation unit to the storage tank and is further discharged to the cathode recovery system.

A control unit estimates a discharged fuel gas amount, i.e., an amount of fuel gas discharged from the outlet of a cathode flow field, of a fuel exhaust gas introduced from a communication flow path to the inlet of the cathode flow field and then flowing through a cathode. The control unit calculates an oxygen-containing gas amount necessary for dilution at the time of discharge into the atmosphere, from the estimated discharged fuel gas amount, and sets a discharge amount of the air pump, based on the calculated oxygen-containing gas amount.

To provide a fuel cell system configured to reduce false cross leak judgment. A fuel cell system wherein the controller preliminarily stores a first data group indicating a relationship between the flow rate of the oxidant gas, the opening degree of the bypass valve, and the hydrogen concentration of the oxidant off-gas; and wherein before the controller determines whether or not a cross leak has occurred, the controller varies the hydrogen concentration threshold used for determining whether or not a cross leak has occurred, by comparing the flow rate of the oxidant gas measured by the oxidant gas flow rate sensor and the opening degree of the bypass valve with the first data group.

A method for detecting leakage of a reducing fluid throughout an electrolyte membrane of an electrochemical cell is provided. The method includes the following consecutive steps: supplying the cell with anode and cathode streams; brisk and controlled variation of at least one of the following parameters: the pressure of the anode stream in the anode channel, the pressure of the cathode stream in the cathode channel, the flow rate of the anode stream into the anode channel, the flow rate of the cathode stream into the cathode channel, and the strength of the current exchanged between the two sides of the membrane; measurement of a first reducing fluid concentration in a first stream, including the cathode stream leaving the cathode channel; and deducing the presence or absence of leakage on the basis of the variation in the first measured concentration of reducing fluid over time. A corresponding fuel cell system is also provided.

Disclosed are a gas sampling system and a gas sampling method for a fuel cell, a current density distribution estimation method for the fuel cell, a calibration method and a calibration device for an internal state model for the fuel cell, and a computer equipment. The gas sampling method for a fuel cell includes arranging a plurality of sampling pipelines and a plurality of sampling points, the plurality of sampling points being arranged at a cathode inlet, an anode outlet, an anode inlet, a cathode outlet, and in an anode flow channel, and a cathode flow channel of the fuel cell, the sampling points arranged in the anode flow channel and the cathode flow channel being located in central regions of cross sections of the flow channels, and the sampling pipelines being connected to the plurality of sampling points, respectively, and configured to guide gas inside the fuel cell out.

A fuel cell system includes a controller which controls operations of an oxidizing gas supply/discharge system and a fuel gas supply/discharge system, and controls power generation of a fuel cell stack, and, when detecting a fuel gas concentration abnormality that a fuel gas concentration in an exhaust gas exceeds an allowable value during the power generation of the fuel cell stack, the controller increases a flow rate of air fed by an air compressor, and controls an opening of a bypass valve to execute exhaust gas dilution control for increasing a ratio of the flow rate of the air flowing out from the bypass piping to an exhaust gas piping with respect to the flow rate of the air to be supplied to the fuel cell stack.

An apparatus and method for reducing an exhaust hydrogen concentration in a fuel cell system includes a first air cut-off valve (ACV) blocking ambient air supplied to a cathode, a second ACV blocking exhaust hydrogen discharged from the cathode, and an air suction valve (ASV) operating in a first mode connecting the cathode and an intake port of an air compressor and in a second mode blocking connection between the cathode and the intake port of the air compressor. The apparatus also includes a controller for operating the ASV in the first mode to store air of the cathode while the first ACV is opened and the second ACV is closed when hydrogen is supplied to an anode, and for operating the ASV in the second mode to discharge ambient air through an exhaust line while the first ACV is opened and the second ACV is opened when ambient air is supplied to the cathode.

A method for treating hydrogen-containing and oxygen-containing residual gases of fuel cells, wherein the residual gases are fed to a gas circuit, and a residual gas mixture resulting therefrom is circulated in the gas circuit by a device for converting hydrogen and oxygen to water. In order to reduce the amount of hydrogen and oxygen in the residual gas mixture, at least part of the residual gas mixture is discharged from the gas circuit.

A system for capturing carbon dioxide in flue gas includes a fuel cell assembly including at least one fuel cell including a cathode portion configured to receive, as cathode inlet gas, the flue gas generated by the flue gas generating device or a derivative thereof, and to output cathode exhaust gas and an anode portion configure to receive an anode inlet gas and to output anode exhaust gas, a fuel cell assembly voltage monitor configured to measure a voltage across the fuel cell assembly, and a controller configured to receive the measured voltage across the fuel cell assembly from the fuel cell assembly voltage monitor, determine an estimated carbon dioxide utilization of the fuel cell assembly based on the measured voltage across the fuel cell assembly, and reduce the carbon dioxide utilization of the fuel cell assembly when the determined estimated carbon dioxide utilization is above a predetermined threshold utilization.