Disclosed are a deterioration estimation system for the fuel cell, a hydrogen supply system for a fuel cell including the same, and a hydrogen supply method for a fuel cell, the deterioration estimation system including a fuel cell which receives hydrogen gas and oxidizing gas respectively supplied to an anode side and a cathode side thereof to generate electrical power, a hydrogen supply line which is connected to the anode side of the fuel cell and supplies gas containing hydrogen gas to the fuel cell, a hydrogen supply valve which is located between the hydrogen supply line and a hydrogen tank, supplies, when opened, hydrogen gas stored in the hydrogen tank to the hydrogen supply line, and blocks the supply of the hydrogen gas when closed, and a deterioration estimating unit which estimates the deterioration state of the fuel cell, based on the opening and closing control of the hydrogen supply valve or a change in the pressure in the hydrogen supply line.

The subject matter described herein generally relates to a sensor and method for monitoring gas quality of a fuel reformer in a fuel cell system or a power generation system.

The present invention relates to a sensor device (10) for a fuel cell system (100) for determining a purging parameter (SP) for controlling a purging process of the fuel cell system (100), comprising a first flow channel (20) for arranging in an anode feed section (122) of an anode section (120) of a fuel cell stack (110) and a second flow channel (130) for arranging in a recirculation section (126) of the anode section (120) of the fuel cell stack (110), which are separated from each other, at least in sections, by means of a gas-tight membrane (40), wherein the membrane (40) is designed to be permeable for protons and has an electrode section (42, 44) on both sides, as well as comprising a measuring device (50) for determining a fuel concentration difference between the first flow channel (20) and the second flow channel (30) as a purging parameter (SP) based on an electrical voltage between the two electrode sections (42, 44).

A method for determining an average oxidation state (AOS) of a redox flow battery system includes measuring a charge capacity for a low potential charging period starting from a discharged state of the redox flow battery system to a turning point of a charge voltage; and determining the AOS using the measured charge capacity and volumes of anolyte and catholyte of the redox flow battery system. Other methods can be used to determine the AOS for a redox flow battery system or use discharge voltage instead of charging voltage.

A method and system of controlling hydrogen purge are provided. The method includes estimating an air supply rate supplied to a fuel cell stack and then executing hydrogen purge based on the estimated air supply rate.

A disclosed fuel cell system includes a fuel inlet that receives a fuel gas from a fuel source, a gas analyzer that determines a composition of the fuel gas received by the fuel inlet, and a stack including fuel cells that generate electricity using the fuel gas received from the fuel source. The fuel cell system further includes a controller that controls at least one of a fuel utilization of the stack, a current generated by the stack, or a voltage generated by the stack, based on the composition of the primary fuel gas determined by the gas analyzer. The controller may control the fuel cell system by increasing or decreasing a fuel flow rate to thereby increase or decrease the voltage generated by the stack to maintain a predetermined target voltage or to maintain a predetermined rate at which usable fuel is supplied to the stack based on composition.

A fuel cell ship includes a fuel cell compartment in which a fuel cell is installed, a tank compartment in which a fuel tank is installed, a fuel supply pipe through which fuel is supplied from the fuel tank to the fuel cell, and a control unit. The fuel supply pipe includes at least two shutoff valves. Fuel gas detectors that detect a fuel gas being in a gaseous state of the fuel are each installed in the compartments. If at least one of the fuel gas detectors detects that a concentration of the fuel gas is equal to or greater than a predetermined standard value, the control unit controls to close a shutoff valve in a compartment out of the tank compartment and the fuel cell compartment, where the fuel gas detector having detected the concentration equal to or greater than the standard value is installed.

A method for operating a fuel cell system is provided. The method includes controlling a provision of fuel to the fuel cell system operating in a steady-state mode. The catalyst sensor is operated by providing a portion of the fuel and anode exhaust generated by the system to the catalyst sensor. Further, a change in an outlet temperature of the catalyst sensor is detected. Thereafter, it is determined whether a reformation catalyst of the catalyst sensor is poisoned by contaminants in the fuel based on the detected change in the outlet temperature.

Disclosed is a method and a device configured to control deterioration avoidance operation of a fuel cell system. In one aspect, the method may include starting the deterioration avoidance operation when an operation of a fuel cell is restarted in a state where an energy storage device is operating, and the fuel cell is stopped; controlling anode hydrogen pressure based on a predetermined condition, the condition indicating that the anode hydrogen pressure needs to be increased; determining hydrogen recirculation and supplying hydrogen including a process to determine whether to recirculate hydrogen based on a predetermined condition, the condition indicating that hydrogen needs to be recirculated, before supplying hydrogen; determining air recirculation and supplying air including a process to determine whether to recirculate air based on a predetermined condition, the condition indicating that air needs to be recirculated, before supplying air; and terminating the deterioration avoidance operation and starting operation of the fuel cell.

A method and a device for detecting internal carbon deposition of a solid oxide fuel cell system. The method comprises the following steps: adjusting a temperature in a reformer of the solid oxide fuel cell system so that a mixed gas discharged from the reformer is at a detection temperature; sampling the mixed gas; detecting a gas sample to obtain a mole fraction of each gas, and calculating an equilibrium constant K1 of a Boudouard reaction according to the obtained mole fraction; calculating an equilibrium constant K2 of the Boudouard reaction according to thermodynamics; comparing K1 and K2, if K1 is less than K2, determining that there will be no carbon deposition in the solid oxide fuel cell system; and if K1 is greater than K2, determining that there will be carbon deposition in the solid oxide fuel cell system. By using the method, a carbon deposition condition in the solid oxide fuel cell system can be detected to effect early warning regarding the solid oxide fuel cell system and take preventive measures