A fuel supply control system and method for a fuel cell are disclosed. The system includes: a fuel cell configured to receive a fuel gas and an oxidation gas and generate electric power; a recirculation line configured to circulate gas containing the fuel gas and connected to a fuel electrode of the fuel cell; a discharge valve provided in the recirculation line and configured to allow the gas to be discharged to the outside when open; a discharge amount estimator configured to estimate a discharge amount of the discharged gas based on a supply amount of the fuel gas supplied to the recirculation line, a consumption amount of the fuel gas consumed in the fuel cell, and a change in the amount of the gas in the recirculation line; an offset calculator configured to calculate the discharge amount of the gas estimated by the discharge amount estimator with the discharge valve closed, as a discharge offset; and a controller configured to control opening/closing of the discharge valve.

In order to improve estimation accuracy of a purging amount, a fuel cell system comprises a supply valve that controls a supply of an anode gas into an anode system, a purge valve that discharges an off-gas from the anode system, a pressure detecting unit configured to estimate or measures a pressure inside the anode system, and a purging amount estimating unit configured to estimate a purging amount of the off-gas discharged from the anode system through the purge valve based on a pressure change inside the anode system during a purge valve close duration in a supply valve open state and a pressure change inside the anode system during a purge valve close duration in a supply valve close state.

A fuel cell system includes a fuel feeder that supplies fuel, a fuel cell stack that generates power through an electrochemical reaction using air and a hydrogen-containing gas generated from the fuel, a temperature sensor that senses the temperature of the fuel cell stack, and a controller. The fuel cell stack has a membrane electrode assembly including an electrolyte membrane through which protons can pass, a cathode on one side of the electrolyte membrane, and an anode on the other side of the electrolyte membrane. The controller defines an upper limit of current output from the fuel cell stack on the basis of the temperature of the fuel cell stack and the supply of the fuel and keeps the current output from the fuel cell stack at or below the upper limit.

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.

The invention provides an SOFC cooling system. For the feature that not all components work in the full operation process of an SOFC, a DC step-down transformer DCDC, a fan and a condenser are connected in parallel, and a solenoid valve is installed in each parallel pipeline for controlling on/off of each pipeline according to a corresponding signal. Compared with the traditional SOFC cooling system, the constant-flow serial cooling system will reduce pressure losses and the power of a water pump; a solenoid valve is installed in each parallel pipeline for controlling on/off of each branch according to a corresponding signal; considering the cooling requirements of SOFC during start-up, power generation and shutdown, all components are cooled in parallel through reasonable design of each parallel pipeline, consequently to improve the cooling effect and reduce the energy consumption; the invention also discloses a fuel cell and hybrid vehicle.

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.

System for recirculating hydrogen in a fuel cell including a tank having an inlet connectable to an outlet of the fuel cell and an outlet connectable to a line for feeding hydrogen to the fuel cell; the recirculation system includes a first check valve and a second check valve; the first check valve can be inserted between the outlet of the fuel cell and the inlet of the tank, for adjusting a flow from the fuel cell to the tank whilst the second check valve can be inserted between the outlet of the tank and the hydrogen feed line, for adjusting a flow of hydrogen from the tank to the feed line.

A method for controlling a carbon dioxide utilization in a fuel cell assembly includes: measuring a voltage across the fuel cell assembly; determining an estimated carbon dioxide utilization of the fuel cell assembly based on at least the measured voltage across the fuel cell assembly by determining an expected voltage of the fuel cell assembly based on at least a temperature of the fuel cell assembly, a current density across the fuel cell assembly, a fuel utilization of the fuel cell assembly, and a cathode oxygen utilization of the fuel cell assembly; determining the estimated carbon dioxide utilization based on a comparison between the measured voltage and the determined expected voltage; comparing the determined estimated carbon dioxide utilization to a predetermined threshold utilization; and upon determining that the determined estimated carbon dioxide utilization is higher than the predetermined threshold utilization, reducing the carbon utilization of the fuel cell assembly.

To provide a fuel cell system capable of discharging a fuel gas in an emergency while suppressing complication and an increase in cost of the system. The fuel cell system includes a fuel cell, a fuel gas tank, a fuel gas supply channel, a fuel gas supply unit, a main stop valve that controls opening and closing of the fuel gas tank, a fuel gas discharge channel, an exhaust drain valve that controls discharge of the fuel gas discharged from the fuel cell to an outside of the system, and a control unit. The control unit controls the exhaust drain valve, the fuel gas supply unit, and the main stop valve to open so as to discharge the fuel gas from the fuel gas tank when receiving an emission command of the fuel gas.