Abstract: Disclosed is a core for a current transformer, which forms an upper core in a round shape, and is disposed at a position lower than the center of a power line having both ends of the upper core received, thereby minimizing the stress of a magnetic path, and increases the permeability, thereby enhancing the magnetic induction efficiency. The disclosed core for the current transformer includes an upper core curved in a semi-circular shape to have a receiving groove formed therein, and having both ends extended downwards to be disposed to be spaced apart from each other and a lower core disposed on the lower portion of the upper core, and having both ends extended upwards to be disposed to face both ends of the upper core.

Abstract: An ionic conductivity measurement device of an electrolytic membrane includes a humidification chamber configured to accommodate an ion-conductive electrolytic membrane and having concave grooves respectively formed at both sides thereof which face the electrolytic membrane to form a measurement space for measuring ionic conductivity of the electrolytic membrane; a plurality of channels formed at a bottom surface of each of the concave grooves; a gas distribution unit detachably coupled to each of the concave grooves with the electrolytic membrane being interposed therebetween; and a plurality of electrodes provided in contact with one side of the electrolytic membrane and supported by the gas distribution unit, the plurality of electrodes being disposed side by side to measure an impedance of the electrolytic membrane.

Abstract: An ionic conductivity measurement device of an electrolytic membrane includes a humidification chamber configured to accommodate an ion-conductive electrolytic membrane and having concave grooves respectively formed at both sides thereof which face the electrolytic membrane to form a measurement space for measuring ionic conductivity of the electrolytic membrane; a plurality of channels formed at a bottom surface of each of the concave grooves; a gas distribution unit detachably coupled to each of the concave grooves with the electrolytic membrane being interposed therebetween; and a plurality of electrodes provided in contact with one side of the electrolytic membrane and supported by the gas distribution unit, the plurality of electrodes being disposed side by side to measure an impedance of the electrolytic membrane.

Abstract: Disclosed herein is a fuel injection apparatus for injecting fuel into a fuel cartridge. The fuel injection apparatus may include, for example, a container for fuel storage, a fuel supply pipe in fluid communication with the container, a first valve installed on the fuel supply pipe, a pump installed on the fuel supply pipe, a pressure gauge installed on the fuel supply pipe, and a bypass pipe fluidly connecting the container with the fuel supply pipe. A second valve may be installed on the bypass pipe. Methods for injecting fuel into a fuel cartridge are also disclosed herein.

Abstract: A fuel cell stack includes a plurality of membrane electrode assemblies (MEAs) and a stamped metal separator. The metal separator is positioned between the membrane electrode assemblies. The separator includes at least one channel on both surfaces of the separator formed by a stamping process. The separator comprises a plurality of holes, each of which form a manifold communicating with each the channels.

Abstract: A direct methanol fuel cell (DMFC) system including: a separator receiving a gas-liquid mixture discharged from a stack and separating the mixture to gas and a liquid; a methanol cartridge storing high concentration methanol; and a fuel mixer for methanol dilution. The separator and the fuel mixer are separate structures, each including an agitator for stirring a liquid. The agitators can be on the same rotation axis.

Abstract: A fuel cell system is disclosed. The fuel cell system may include a fuel cell stack configured for generating electrical energy by a reaction of an oxidant and a fuel, a recovery unit including a first gas liquid separator configured for separating a by-product discharged by the fuel cell stack into a first gas and a first liquid, a first heat exchanger configured for cooling the first gas supplied by the first gas liquid separator, and a second gas liquid separator configured for separating a by-product supplied by the first heat exchanger into a second gas and a second liquid, and a remover unit fluidly connected to the second gas liquid separator and configured for removing the second gas from the recovery unit.

Abstract: A gas-liquid separator including a housing, a first absorbing member, a second absorbing member, and a liquid pump is disclosed. The housing may include an inflow port, a gas outlet port, and a liquid outlet port. The first absorbing member may be disposed contacting the liquid outlet port in an inner space of the housing. The first absorbing member may be configured to absorb liquid in a gas-liquid mixture received from the inlet port. The second absorbing member may be disposed apart from the first absorbing member in the inner space of the housing. The second absorbing member may have a smaller volume than the absorbing member.

Abstract: A fuel cell separator capable of improving stack performance by reducing the deviation in cell performance and diminishing dead space, and a fuel cell stack using the same are disclosed. The fuel cell separator may include a base member, a first channel group disposed on a surface of the base member and a second channel group disposed on the surface of the base member. The first channel group may include at least one channel and the second channel group may include at least one channel. The first channel group and the second channel group may extend parallel to each other in a first region of the surface and independent from each other in a second region of the surface.

Abstract: A fuel cell case including a ventilating chamber disposed on an inside surface of the fuel cell case, a ventilator formed inside the ventilating chamber and an air inlet port formed on the outer surface of the ventilating chamber is disclosed. The ventilator may be formed protruding into the ventilating chamber. The fuel cell case may be formed such that ambient atmosphere is in fluid communication with the ventilating chamber, but water or other fluids outside the case do not enter the ventilator.

Abstract: The volume of liquid that remains in a liquid storage is calculated by measuring capacitances between several pairs of metal plates attached to each of several corresponding faces of the liquid storage and by combining liquid volumes corresponding to the capacitance based on the current position of the liquid storage. Such a method of measuring the volume of liquid can be used to measure the amount of fuel that remains in a fuel cell system.

Abstract: A fuel cell system including: a fuel cell stack configured to generate electrical energy by a reaction of a fuel and an oxidant; a fuel supply configured to supply the fuel to the fuel cell stack; and an oxidant supply configured to supply the oxidant to the fuel cell stack, wherein the fuel supply includes a mixer including an inflow port, the mixer alternately receiving the fuel and water through the inflow port and being configured to mix the fuel and the water to generate a diluted fuel and supply the diluted fuel to the fuel cell stack.

Abstract: A fuel cell stack including an electricity generating unit for generating electrical energy by electrochemically reacting a fuel and an oxidizing agent, the electricity generating unit including: a first separator; a second separator; a membrane electrode assembly (MEA) between the first separator and the second separator, each of the first and second separators including a channel on a surface facing the MEA and a manifold in the surface facing the MEA, the manifold communicating with the channel; and a gasket, positioned at an outer circumference portion of an area where the MEA is positioned, for sealing a space between the first and second separators and for covering an open area of a channel extension area of at least one of the first and second separators where the manifold communicates with the channel.

Abstract: Disclosed herein is a fuel injection apparatus for injecting fuel into a fuel cartridge. The fuel injection apparatus may include, for example, a container for fuel storage, a fuel supply pipe in fluid communication with the container, a first valve installed on the fuel supply pipe, a pump installed on the fuel supply pipe, a pressure gauge installed on the fuel supply pipe, and a bypass pipe fluidly connecting the container with the fuel supply pipe. A second valve may be installed on the bypass pipe. Methods for injecting fuel into a fuel cartridge are also disclosed herein.

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 method of operating a fuel cell includes: generating an electrical power in a fuel cell stack while no fuel is being supplied from a fuel tank; reducing an output voltage of the electrical power toward a target voltage to increase an output current of the electrical power; measuring a rate of increase of the output current; starting supply of fuel to the fuel cell stack when the rate of increase of the output current is below a threshold rate; and controlling a fuel concentration in the fuel cell stack to maintain the output current at a target current level.

Abstract: A fuel cell system includes a fuel cell system connector and a fuel cartridge connector. The fuel cell system connector includes an external structure configured to accommodate a connector of a fuel cartridge and an internal structure mounted in the external structure. A contacting surface between the external structure and the internal structure of the fuel cell system connector includes a first nano-processed surface on a fuel supply path. The fuel cartridge connector includes an external structure having a retention key and an internal structure mounted in the external structure. A contacting surface between the external structure and the internal structure of the fuel cartridge connector includes a second nano-processed surface on a fuel supply path.

Abstract: Disclosed is a separator for a fuel cell stack. The separator includes a plate having a first opening and a second opening on a surface thereof. A field or a channel is formed on the surface of the plate. The field has a first end and a second end. A field inlet is formed on the surface of the plate and connects the first end of the field to the first opening, and a field outlet is formed on the surface of the plate and connects the second end of the field to the second opening. An area of a cross-section of the field inlet, which is cut perpendicular to the surface of the plate, is smaller than an area of a cross-section of the field outlet, which is cut perpendicular to the surface of the plate.

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: An activation method and system to selectively activate defective cells in a laminated fuel cell stack. The system includes a tank to store a polar solvent used to activate the cells; a body including a transfer unit to transfer the polar solvent to the fuel cell stack and a control unit to control the transfer unit; and a nozzle coupled to the body, to be inserted into an inlet manifold of the fuel cell stack. The nozzle has an opening positioned opposite to a channel inlet of at least one non-activated cell of the plurality of cells, to jet the polar solvent into only a channel of the non-activated cell, through the opening.