Abstract: A method for no-purge starting up a fuel cell system is provided. The method includes calculating a nitrogen partial pressure from a target hydrogen concentration during driving that corresponds to a condition in which start-up without purging is possible and calculating a target hydrogen pressure satisfying the target hydrogen concentration from the calculated nitrogen partial pressure. Further, hydrogen is then supplied to the system based on the target hydrogen pressure.

Abstract: A system and method of controlling fuel cell system is provided that simultaneously drains condensation and purges hydrogen via single valve. In particular, condensate water is drained by opening a drain-purge valve at a point in time at which a production amount of the condensate water exceeds a capacity of a water trap. An opening time of the drain-purge valve is then determined depending on a hydrogen concentration of an anode side and a target hydrogen concentration after the draining the condensate water. Hydrogen is then purged by maintaining the drain-purge valve in a state in which it is opened for the determined opening time.

Abstract: A control method of an operation pressure of a fuel cell system maintains a differential pressure between a hydrogen side and an air side of a fuel cell stack to minimize a crossover amount of hydrogen while allowing hydrogen purge and reduces an exhausted hydrogen amount when a purge valve is opened at the time of purging hydrogen using a differential pressure of an anode outlet and a cathode outlet to improve a hydrogen utilization rate and system efficiency. According to the control method, pressures of a cathode inlet and a cathode outlet of the fuel cell stack and a pressure of an anode outlet are controlled such that the pressure of the anode outlet of the fuel cell stack is lower than the pressure of the cathode inlet and higher than the pressure of the cathode outlet.

Abstract: A control method and system of a fuel cell system is provided. The control method includes detecting, by a controller, a voltage of a fuel cell stack when power generation of a fuel cell is stopped while a fuel cell vehicle is being driven. In addition, hydrogen supply pressure at an anode side is adjusted based on a variation in the detected voltage.

Abstract: A method of operating a fuel cell system includes calculating voltages that are generated in each cell of a stack. It is determined whether the voltages satisfy a voltage stability condition. When it is determined that the voltages satisfy the voltage stability condition, it is determined whether a moisture balance condition and a hydrogen supply condition are satisfied. When it is determined that the moisture balance condition and the hydrogen supply condition are satisfied, the voltage stability condition is relieved and reset. It is determined whether the voltages that are generated in each cell of the stack satisfy the reset voltage stability condition. When it is determined that the voltages that are generated in each cell of the stack satisfy the reset voltage stability condition, the stack is normally operated.

Abstract: A hydrogen purging device and method for a fuel cell system are provided in which the opening/closing of a hydrogen purge valve is variably controlled based on a purge charge amount depending on an operating state of a fuel cell in the fuel cell system to improve the hydrogen utilization factor of the fuel cell, system efficiency, hydrogen circulation performance, and the like. The hydrogen purging device includes an operating state detector that detects an operating state of a fuel cell stack and a controller that determines an opening time of a hydrogen purge valve based on information regarding the stack operating state detected by the operating state detector. The controller then outputs a control signal to open the hydrogen purge valve. When the hydrogen purge valve is opened the hydrogen purging of the fuel cell stack is performed in response to the control signal output from the controller.

Abstract: A fuel cell system and a method of operating the same. The fuel cell system in particular includes an air discharge part provided on the anode of a fuel cell, and a controller that is configured to measure a purging period of recirculated hydrogen and an operating temperature of the fuel cell, and operate the air discharge part based on the measured values to prevent the anode from becoming poisoned due to the emission of CO gases.

Abstract: A system and method of controlling a performance of a fuel cell stack is provided. In particular, the output performance of the fuel cell stack is determined by comparing the difference between an initial voltage and a voltage after a predetermined time lapses with the difference between the initial voltage and a preset minimum voltage.

Abstract: A system and method of controlling fuel cell system is provided that simultaneously drains condensation and purges hydrogen via single valve. In particular, condensate water is drained by opening a drain-purge valve at a point in time at which a production amount of the condensate water exceeds a capacity of a water trap. An opening time of the drain-purge valve is then determined depending on a hydrogen concentration of an anode side and a target hydrogen concentration after the draining the condensate water. Hydrogen is then purged by maintaining the drain-purge valve in a state in which it is opened for the determined opening time.

Abstract: A fuel cell system and a method of operating the same. The fuel cell system in particular includes an air discharge part provided on the anode of a fuel cell, and a controller that is configured to measure a purging period of recirculated hydrogen and an operating temperature of the fuel cell, and operate the air discharge part based on the measured values to prevent the anode from becoming poisoned due to the emission of CO gases.

Abstract: A method of operating a fuel cell system includes calculating voltages that are generated in each cell of a stack. It is determined whether the voltages satisfy a voltage stability condition. When it is determined that the voltages satisfy the voltage stability condition, it is determined whether a moisture balance condition and a hydrogen supply condition are satisfied. When it is determined that the moisture balance condition and the hydrogen supply condition are satisfied, the voltage stability condition is relieved and reset. It is determined whether the voltages that are generated in each cell of the stack satisfy the reset voltage stability condition. When it is determined that the voltages that are generated in each cell of the stack satisfy the reset voltage stability condition, the stack is normally operated.

Abstract: Disclosed is a system and method for operating a fuel cell system, which improves durability of a fuel cell stack by purging oxygen diffusing into an air electrode of the fuel cell stack while the fuel cell vehicle is parking. That is, the present invention provides a system and method for operating a fuel cell system, which prevents an interface between oxygen and hydrogen from forming at an anode by periodically supplying hydrogen to a cathode to purge oxygen when the oxygen concentration is greater than a predetermined level to prevent oxygen in the air from diffusing into the cathode while parking the fuel cell vehicle, thus preventing durability of a membrane electrode assembly of a fuel cell stack from deteriorating.

Abstract: The present invention provides a purge system for a fuel cell, which can reduce the time required to thaw a frozen valve during cold start-up and reduce the whole start-up time, thus improving the cold start performance. In preferred embodiments, the present invention provides a purge system for a fuel cell with improved cold start performance, the system preferably including a main pipe connected to a purge gas outlet of a fuel cell stack to discharge a purge gas purging the fuel cell stack and impurities; an auxiliary pipe branched from the main pipe; a purge valve installed in each of the main pipe and the auxiliary pipe to perform an purge operation; a cut-off valve installed at an upstream side of the purge valve in the auxiliary pipe; and a controller for controlling the operation of the purge valves and the cut-off valve.

Abstract: The present invention provides a startup control device and method for a fuel cell system. The startup control device includes a concentration meter, a hydrogen feed rate controller, and a controller. The concentration meter measures the concentration of oxygen located in the anode of a fuel cell stack. The hydrogen feed rate controller is disposed at an inlet of the anode. The controller receives an oxygen concentration signal value from the concentration meter while controlling the hydrogen feed rate controller to adjust a hydrogen feed rate to the anode.

Abstract: The present invention provides an apparatus and method for determining deterioration of a fuel cell, the method including measuring in real time fluoride ion concentration or pH value of outflow water from a fuel cell stack during operation in a fuel cell vehicle, calculating a fluoride emission rate from the measured value and, if the calculated fluoride emission rate is out of a predetermined normal range, determining deterioration of an electrolyte membrane of the fuel cell stack.

Abstract: Apparatuses and methods for accelerated activation of fuel cells are disclosed. The apparatuses include a fuel cell stack; an air supplying means coupled to a cathode catalyst side of the fuel cell stack through a mass flow controller and a humidifier; a hydrogen supplying means coupled to an anode catalyst side of the fuel cell stack through a mass flow controller and a humidifier; and a cable coupled to both ends of the fuel cell stack for short-circuiting the cathode and the anode.

Abstract: The present invention provides a purge system for a fuel cell, which can reduce the time required to thaw a frozen valve during cold start-up and reduce the whole start-up time, thus improving the cold start performance. In preferred embodiments, the present invention provides a purge system for a fuel cell with improved cold start performance, the system preferably including a main pipe connected to a purge gas outlet of a fuel cell stack to discharge a purge gas purging the fuel cell stack and impurities; an auxiliary pipe branched from the main pipe; a purge valve installed in each of the main pipe and the auxiliary pipe to perform an purge operation; a cut-off valve installed at an upstream side of the purge valve in the auxiliary pipe; and a controller for controlling the operation of the purge valves and the cut-off valve.

Abstract: The present invention provides a sealing structure of a sealing portion for maintaining the airtightness of a coolant passage in two stacked separators of a fuel cell, wherein a groove in which an adhesive is to be filled is formed on a surface of one of two separators, and dam portions are formed on both sides of the groove to prevent the adhesive applied in the groove from overflowing into a connection passage and a coolant passage. Accordingly, the adhesive overflowing from the groove when the two separators are bonded to each other by applying a pressure is collected in the dam portions to form three sealing lines, thus improving the airtightness of the sealing portion. Moreover, it is possible to solve the problem that the performance of the fuel cell stack is deteriorated when an antifreeze/coolant leaks from the coolant passage to an MEA, in which the fuel cell reaction takes place, or the leaking coolant contaminates a catalyst of the MEA.

Abstract: Apparatuses and methods for accelerated activation of fuel cells are disclosed. The apparatuses include a fuel cell stack; an air supplying means coupled to a cathode catalyst side of the fuel cell stack through a mass flow controller and a humidifier; a hydrogen supplying means coupled to an anode catalyst side of the fuel cell stack through a mass flow controller and a humidifier; and a cable coupled to both ends of the fuel cell stack for short-circuiting the cathode and the anode.

Abstract: A separating plate for a fuel cell includes first and second plates, each provided with a hydrogen channel, an oxygen channel, and a coolant channel. The first and second plates are attached to one another to form a main plate such that the first and second hydrogen, oxygen, and coolant channels compose main hydrogen, oxygen, and coolant channels, respectively. The main hydrogen and oxygen channels are fluidly isolated from each other. Distal ends of the main channels each communicate with a manifold through a communication passageway configured to supply hydrogen, oxygen, or coolant to a corresponding one of the main channels.