Abstract: A fuel cell system includes: a fuel cell stack for generating electrical energy by reacting oxidant and mixed fuel, and for discharging non-reacted fuel, oxidant, moisture, and carbon dioxide; a mixer for preparing the mixed fuel by mixing at least a portion of the non-reacted fuel, oxidant and moisture with concentrated fuel and for supplying the mixed fuel to the fuel cell stack; a fuel supply unit for supplying the concentrated fuel to the mixer; an oxidant supply unit for supplying the oxidant to the fuel cell stack; a first heat exchanger between an outlet of the fuel cell stack and the mixer; and a second heat exchanger between the mixer and an inlet of the fuel cell stack.

Abstract: A fuel cell system includes: a fuel supply unit supplying a fuel; an air supply unit supplying air; a stack including a membrane electrode assembly (MEA) having an air path and a fuel path; a gas-liquid separator connected to an outlet of the fuel path and an outlet of the air path for separating gas-liquid into high-temperature liquid and moisture gas; a mixer mixing the high-temperature liquid separated by the gas-liquid separator and a fuel supplied from the fuel supply unit and connecting the gas-liquid separator and the MEA; a moisture absorbent connected to the gas-liquid separator to absorb condensed liquid in the high-temperature moisture gas; and a heat exchanger to vaporize the liquid absorbed by the moisture absorbent.

Abstract: A fuel cell system and a fuel cell power managing method in which the fuel cell system controls a current output of a fuel cell by adjusting a target voltage value of the fuel cell according to a difference between a current value of the fuel cell and a target constant current value. By doing so, the fuel cell system may allow the fuel cell to stably and constantly output a constant current.

Abstract: A fuel cell system includes a fuel cell stack for generating electricity by a electrochemical reaction of hydrogen and oxygen; a controller for controlling the operation of the system; a hydride storage tank for storing hydride powder as a source of hydrogen for the fuel cell stack; a hydrogen separating chamber for collecting hydrogen gas generated from a reaction of the hydride powder and liquid catalyst; a powder transferring device for transferring the hydride powder to the hydrogen separating chamber; and a residue collector for collecting residues that are generated from the reaction and settled at the bottom of the hydrogen separating chamber.

Abstract: A fuel cartridge for a fuel cell capable of accurately measuring the residual amount of fuel is disclosed. A fuel cartridge for a fuel cell may include a housing and a pouch contained within the housing and forming an inner space. The inner space of the pouch is formed by mechanically connecting a first plane portion and a second plane portion parallel to each other with a side portion intersecting both the first plane portion and the second plane portion. The pouch may be configured to contract or expand according to a residual amount of fuel in the inner space. The pouch may include a fuel path formed on the upper portion thereof. First and second electrodes may be positioned facing each other at opposite sides of the side portion with the pouch in the housing positioned therebetween when viewed in a plane. The first electrode and the second electrode may also have a plurality of opposite directions.

Abstract: A driving method of a fuel cell system, which includes a secondary battery and a fuel cell stack, is disclosed. The method includes detecting a state of charge (SOC) of the secondary battery, driving the fuel cell stack to an on-state whenever the SOC of the secondary battery is less than a predetermined first SOC, and driving the fuel cell stack to an off-state whenever the SOC of the secondary battery is greater than a predetermined second SOC. In this method, the fuel cell stack is driven at a fuel concentration having optimum efficiency, thereby increasing the fuel efficiency of the fuel cell system.

Abstract: A fuel cell system includes: a fuel supply unit supplying a fuel; an air supply unit supplying air; a stack including a membrane electrode assembly (MEA) having an air path and a fuel path; a gas-liquid separator connected to an outlet of the fuel path and an outlet of the air path for separating gas-liquid into high-temperature liquid and moisture gas; a mixer mixing the high-temperature liquid separated by the gas-liquid separator and a fuel supplied from the fuel supply unit and connecting the gas-liquid separator and the MEA; a moisture absorbent connected to the gas-liquid separator to absorb condensed liquid in the high-temperature moisture gas; and a heat exchanger to vaporize the liquid absorbed by the moisture absorbent.

Abstract: A fuel cell system for generating electrical energy by a chemical reaction between a fuel and an oxidizing agent. In exemplary embodiments of the present invention, by using a hydrophobic porous membrane, an alkaline material such as sodium that is generated together with hydrogen gas in a hydrolysis reaction of a metal hydride compound can be eliminated effectively.

Abstract: A fuel cell system, which can supply a stable flow rate of fuel to a fuel cell stack is disclosed. The fuel cell system may include a fuel cell stack for generating electricity by an electrochemical reaction of a fuel and an oxidizing agent, a fuel supply unit for supplying a fuel to the fuel cell stack, an oxidizing agent supply unit for supplying an oxidizing agent to the fuel cell stack, and a flow rate controller installed between the fuel cell stack and the fuel supply unit. The fuel cell system may include a feed pump for pressurizing the fuel, a first resistor connected to the front end of the feed pump to reduce flow rate and a second resistor connected to the rear end of the feed pump to reduce flow rate. A method of operating a fuel cell system is also disclosed. The method may include supplying fuel to a fuel cell stack from a fuel supply unit, reducing a flow rate by a first resistor, activating a feed pump, reducing a flow rate by a second resistor, and stopping the feed pump.

Abstract: A fuel cell system includes: a fuel cell stack for generating electrical energy by reacting oxidant and mixed fuel, and for discharging non-reacted fuel, oxidant, moisture, and carbon dioxide; a mixer for preparing the mixed fuel by mixing at least a portion of the non-reacted fuel, oxidant and moisture with concentrated fuel and for supplying the mixed fuel to the fuel cell stack; a fuel supply unit for supplying the concentrated fuel to the mixer; an oxidant supply unit for supplying the oxidant to the fuel cell stack; a first heat exchanger between an outlet of the fuel cell stack and the mixer; and a second heat exchanger between the mixer and an inlet of the fuel cell stack.

Abstract: A fuel cell system and a fuel cell power managing method in which the fuel cell system controls a current output of a fuel cell by adjusting a target voltage value of the fuel cell according to a difference between a current value of the fuel cell and a target constant current value. By doing so, the fuel cell system may allow the fuel cell to stably and constantly output a constant current.

Abstract: An improved fluid recycling apparatus and a fuel cell system comprising the same effectively recycle moisture contained in fluid circulating in a fuel cell system and operate independent of orientation. The fluid recycling apparatus includes an electric penetration pump and a gas/liquid separation unit. The electric penetration pump has first and second electrodes and an electric penetration layer interposed between the first and second electrodes. The electric penetration pump directs a liquefied fluid through an electric fluid passage formed in the electric penetration layer by applying a voltage between the first electrode and the second electrode. The gas/liquid separation unit is disposed upstream of the electric fluid passage, contacting the electric penetration pump, and comprises a porous material that can absorb the liquefied fluid.

Abstract: A fuel cell system for generating electrical energy by a chemical reaction between a fuel and an oxidizing agent. In exemplary embodiments of the present invention, by using a hydrophobic porous membrane, an alkaline material such as sodium that is generated together with hydrogen gas in a hydrolysis reaction of a metal hydride compound can be eliminated effectively. Accordingly, the fuel cell system according to the exemplary embodiments of the present invention can stably generate electrical energy for a time longer than a conventional fuel cell system.

Abstract: A fuel cell system including a quartz crystal microbalance (QCM) concentration sensor, and in particular, comprising a bypass channel structure useful for installing a QCM concentration sensor to a fuel cell system. The fuel cell system includes a fuel cell stack generating electric energy by an electrochemical reaction of a hydrogen-containing fuel and an oxidant, a fuel cell including a fuel supplying unit supplying the hydrogen-containing fuel to the fuel cell stack, a QCM concentration sensing unit for measuring the concentration of a fluid in the fuel cell, and a drive controlling unit for controlling the operation of the fuel cell according to an output of the QCM concentration sensing unit.

Abstract: A fuel cell system includes a fuel cell stack for generating electric energy by an electrochemical reaction of hydrogen and oxygen; a hydride tank for storing a liquid hydride; a liquid catalyst tank for storing a liquid catalyst for promoting a hydrogen gas generation reaction from the liquid hydride; a reaction flow channel for promoting laminar flow of the liquid hydride and the liquid catalyst; and a hydrogen separator for storing the hydrogen gas generated from the reaction flow channel and transferring the hydrogen gas to the fuel cell stack.

Abstract: A fuel cell system including a correction means capable of accurately correcting a concentration sensing value according to temperature is discussed. The fuel cell system may include an electricity generating unit generating electric energy by means of the electrochemical reaction of fuel and an oxidizer, a fuel supplying unit supplying the fuel to the electricity generating unit, a main concentration sensor for measuring the concentration of the fuel, a reference cell filled with reference solution and including a reference concentration sensor for measuring the concentration of the reference solution, and/or a drive controlling unit controlling the operation of the electricity generating unit based on the concentration values measured in the main concentration sensor and the reference concentration sensor.

Abstract: A fuel cell system includes a fuel cell stack for generating electricity by a electrochemical reaction of hydrogen and oxygen; a controller for controlling the operation of the system; a hydride storage tank for storing hydride powder as a source of hydrogen for the fuel cell stack; a hydrogen separating chamber for collecting hydrogen gas generated from a reaction of the hydride powder and liquid catalyst; a powder transferring device for transferring the hydride powder to the hydrogen separating chamber; and a residue collector for collecting residues that are generated from the reaction and settled at the bottom of the hydrogen separating chamber.

Abstract: A method of electrolytic synthesis comprises applying a potential between a first electrode and a second electrode. The first electrode is in contact with a first fluid stream in a channel, the second electrode is in contact with a second fluid stream in the channel, and the first steam and the second stream are in parallel laminar flow in the channel.