Abstract: A fuel cell constructed with single layer bipolar plates, water damming layers and membrane electrode assembly with gas diffusion layers locally impregnated with water transporting materials, which has reactant gas flow fields placed on both sides of the single layer plates, while cooling liquid flow fields are integrated at least on one side of the plates. Disclosed novel configuration of the fuel cell provides a united means for humidifying reactant gases, hydrating membrane, removing generated water and cooling cells.

Abstract: A fuel cell is provided that includes a water transport plate separating an air flow field and a water flow field. The driving force for moving water across the water transport plate into the water flow field is produced by a differential pressure across a restriction. The restriction is arranged between an air outlet of the cathode water transport plate and a head of a reservoir that is in fluid communication with the water flow field.

Abstract: A fuel cell system 10 removes water retaining in a cathode catalyst layer 217 in a fuel cell 20, after a start-up of the fuel cell 20 and before feed of coolant to the fuel cell 20.

Abstract: A membrane electrode assembly for use in a fuel cell includes an anode electrode, a proton exchange membrane, an anion exchange membrane and a cathode electrode. The anode electrode includes a first catalyst. The first catalyst separates a reducing agent into a plurality of positively charged ions and negative charges. The proton exchange membrane is configured to favor transport of positively charged ions therethrough and is also configured to inhibit transport of negatively charged particles therethrough. The anion exchange membrane is configured to favor transport of negatively charged ions therethrough and is also configured to inhibit transport of positively charged ions therethrough. The cathode electrode includes a second catalyst and is disposed adjacent to a second side of the anion exchange membrane. The second catalyst reacts electrons with the at least one oxidizing agent so as to generate+reduced species.

Abstract: A humidifier device for humidifying a fluid in a fuel cell system of a motor vehicle is provided. The humidifier device has a housing, in which is arranged at least one membrane, and a bypass channel for bypassing the at least one membrane. The bypass channel has a non-circular cross-section.

Abstract: A fuel cell system is provided, comprising a cell unit capable of gas exhausting. The cell unit comprises an anode current collector and a cathode current collector. A membrane electrode assembly (MEA) is interposed between the anode current collector and the cathode current collector. A frame is formed to surround the MEA, the anode current collector, and the cathode current collector. A hydrophilic gas-blocking layer is disposed adjacent to an anode side of the MEA, underlying the MEA and the frame. A hydrophobic gas-penetrating layer is disposed under the hydrophilic gas-blocking layer. At least one gas exhaust is disposed in the frame, exposing a part of the hydrophilic gas-blocking layer and contacting the area surrounding adjacent to the cell unit for exhausting a gas produced by the MEA from the cell unit.

Abstract: A hydrogen purging device for a fuel cell system includes a humidifier that humidifies dry air supplied from an air blower, using moist air discharged from a cathode of a stack and supplies the humidified air to the cathode. A water trap and a hydrogen recirculation blower are sequentially connected to an outlet of an anode, wherein a hydrogen outlet of the water trap and an inlet of the humidifier are connected by a cathode-hydrogen purging line for purging hydrogen to the cathode so that the hydrogen discharged from the anode of the fuel stack is purged to the cathode during idling or during normal driving.

Abstract: A fuel cell system of the present invention includes: a reformer (1) configured to generate a hydrogen-containing fuel gas from a material gas and steam; a fuel cell (101) configured to generate electric power by using a fuel gas supplied from the reformer (1); a water tank (3) configured to store water; a water utilizing device configured to utilize the water supplied from the water tank (3); a first water supply unit (5) disposed on a water passage (30) extending from the water tank (3) to the water utilizing device and configured to supply the water in the water tank (3) to the water utilizing device; and a purifier (4) disposed on the water passage (30) and configured to purify the water flowing through the water passage (30), and the purifier (4) is provided such that when a water level of the water tank (3) is a full water level, the purifier (4) is filled with the water by the weight of the water.

Abstract: Water contained in exhaust gas discharged from a fuel cell stack is separated by a gas-liquid separator and is accumulated in a recovery tank. The procedure of the invention sets a release amount of water and selects one or multiple positions for water release, based on the driving conditions including the vehicle speed and the acceleration, the turning state, activation or non-activation of skid reduction control, the distance from any object detected by clearance sonars, a distance from a subsequent vehicle measured by an extremely high frequency radar, and the presence of raindrops detected by a raindrop detection sensor, and releases the water accumulated in the recovery tank from water outlets at the selected one or multiple positions among water outlets at multiple different locations. This arrangement ensures adequate release of the water produced by the fuel cell stack to the atmosphere.

Abstract: In at least one embodiment, a microporous layer configured to be disposed between a catalyst layer and a gas diffusion layer of a fuel cell electrode assembly is provided. The microporous layer may have defined therein a plurality of hydrophilic pores, a plurality of hydrophobic pores with a diameter of 0.02 to 0.5 ?m, and a plurality of bores with a diameter of 0.5 to 100 ?m. The microporous layer structures and gas diffusion layer assemblies disclosed herein may be defined by a number of various designs and arrangements for use in proton exchange membrane fuel cell systems.

Abstract: Fuel cell systems and related methods involving accumulators with multiple regions of differing water fill rates are provided. At least one accumulator region with a relatively more-rapid fill rate than another accumulator region is drained of water at shutdown under freezing conditions to allow at least that region to be free of water and ice. That region is then available to receive water from and supply water to, a fuel cell nominally upon start-up. The region having the relatively more-rapid fill rate may typically be of relatively lesser volume, and may be positioned either relatively below or relatively above the other region(s).

Abstract: Water contained in exhaust gas discharged from a fuel cell stack is separated by a gas-liquid separator and is accumulated in a recovery tank. The procedure of the invention sets a release amount of water and selects one or multiple positions for water release, based on the driving conditions including the vehicle speed and the acceleration, the turning state, activation or non-activation of skid reduction control, the distance from any object detected by clearance sonars, a distance from a subsequent vehicle measured by an extremely high frequency radar, and the presence of raindrops detected by a raindrop detection sensor, and releases the water accumulated in the recovery tank from water outlets at the selected one or multiple positions among water outlets at multiple different locations. This arrangement ensures adequate release of the water produced by the fuel cell stack to the atmosphere.

Abstract: A fuel cell system includes a fuel cell formed by stacking a plurality of power generation cells, and an oxygen-containing gas supply apparatus for supplying an oxygen-containing gas to the fuel cell. The oxygen-containing gas supply apparatus includes an oxygen-containing gas supply channel connected to an oxygen-containing gas inlet of the fuel cell for allowing the oxygen-containing gas to flow from an air pump into the oxygen-containing gas inlet, a branch supply channel branched from the oxygen-containing gas supply channel and which is opened to the inside of a fuel cell chamber, an oxygen-containing gas discharge channel for discharging an oxygen-containing off gas from the fuel cell, and an oxygen-containing off gas circulation channel one end of which is connected to the oxygen-containing gas discharge channel, and another end of which is connected to the oxygen-containing gas supply channel at a position upstream from the air pump.

Abstract: A fuel cell assembly structure mainly comprises a housing in which there is an accommodating space; a plurality of unit cell stacks that are stacked in the same direction in the accommodating space of the housing and made by stacking in sequence a cathode layer, a power generation electrode, an anode layer and a connection disk; a connection disk connecting is series each unit cell stack, a sealing disk and a cover in sequence to cover the opening of the accommodating space of the housing. On the outer side of the cover there is a connection base, at least one surface of which has a plurality of conduits and the other end connects to a plurality of cell stack bypass manifolds that further connect to a plurality of side bypass manifolds.

Abstract: Even in a fuel cell system which performs scavenging processing after the power generation of a fuel cell is stopped, the operation time for when a battery is being operated can be increased. When determining that the condition of running out of gas occurs based on a sensor value of a pressure sensor, a control unit stops the power generation of the fuel cell. The control unit, for example, shortens the time required for scavenging processing and then performs the scavenging processing. On the other hand, when determining that the condition of running out of gas does not occur and when the power generation of the fuel cell should be stopped, the control unit stops the power generation and then performs normal scavenging processing.

Abstract: A liquid electrolyte fuel cell system (10) comprises at least one fuel cell with a liquid electrolyte chamber between opposed electrodes, the electrodes being an anode and a cathode, and means (30, 32) for supplying a gas stream to a gas chamber adjacent to the cathode and withdrawing a spent gas stream (38) from the gas chamber adjacent to the cathode, the system also comprising a liquid electrolyte storage tank (40), and means (42, 44, 47, 48) to circulate liquid electrolyte between the liquid electrolyte storage tank (40) and the fuel cells. In addition the system comprises a water storage tank (60) adjacent to the storage tank (40), and means (50, 51) for condensing water vapour from the spent gas stream (38), and for feeding (56) the condensed water vapour into the water storage tank (60). The water storage tank (60) has an overflow outlet (64); and a communication duct (68) linking the liquid electrolyte storage tank (40) and the water storage tank (60) below the level of the overflow outlet (60).

Abstract: A fuel cell system includes a fuel cell stack in fluid communication with a separator. The separator has a first portion and a second portion forming a chamber. The first portion has a continuous inner wall and an end wall, with an inlet conduit connected to the inner wall and a liquid drain connected to the end wall. The second portion has an end wall and an outlet conduit extending into the chamber to form a channel with the inner wall of the first portion. A fuel cell separator includes a first end and a second end connected by a side wall to define a separation chamber. An inlet conduit is tangentially connected to the wall. An outlet conduit is connected to the first end and extending into the chamber to form a channel with the wall. A liquid drain is connected to the second end.

Abstract: A method and apparatus for improving the water balance in a power unit by providing the exhaust gas from the cathode side of the fuel cell as a feed gas to the combustion system condensing at least a portion of water present in the effluent from the combustion system in a condenser, and then transferring water vapor from the uncondensed portion of the effluent from the condenser to the gas fed to the cathode side of the fuel cell. Water from the exhaust gas from the cathode side of the fuel cell is either captured in the condenser, or is reused in the feed gas of the cathode side of the fuel cell. By humidifying the air fed into system with the water vapor present in the exhaust gas, water is not lost from the system. Instead, the air is being fed into the system is humidified with this water, which in turn allows the humidifier to operated at higher temperatures and/or use smaller radiators and fans and/or draw less parasitic power, thereby increasing overall system efficiency.

Abstract: A fuel cell system includes: a fuel cell including a cell laminate; an estimating unit for estimating a residual water content distribution in the reactant gas flow channel in a cell plane of each of the single cells and a moisture content distribution in the electrolyte membrane in consideration of water transfer through the electrolyte membrane between the anode electrode and the cathode electrode; and an operation control unit for limiting an electric current drawn from the fuel cell when a residual water content in the reactant gas flow channel estimated by the estimating unit is equal to or above a predetermined threshold.

Abstract: In preferred aspect, the present invention features a membrane humidifier for a fuel cell which can control the amount of air flow and the amount of humidification based on the amount of water produced in a fuel cell stack according to a power level of the fuel cell stack while humidifying dry air and supplying humidified air to the fuel cell stack.

Abstract: A fuel cell with a recovering unit and a method of driving the same are disclosed. In one embodiment, the fuel cell includes i) an electric generator to generate electricity based on electrochemical reaction, ii) a recovering unit to recover and mix the fuel, unreacted fuel, and gas and water produced by the electrochemical reaction, and supply the mixed fuel to the electric generator, wherein the recovering unit comprises a valve, configured to discharge gas, which is selectively opened and closed depending on the operation of the fuel cell. With this configuration, the gas or the fuel is not introduced into the electric generator, even though the recovering unit is inclined or turned over. Further, even though the fuel cell is not in use for a long time, the mixed fuel is prevented from evaporating through the discharging pipe.

Abstract: The present application relates to a fuel cell system and a method for driving same, which can produce stable electricity, enhance load following capability, and simultaneously increasing fuel utilization rate and energy efficiency by separately managing a base load and a load following of a fuel cell, and the fuel cell system according to one embodiment of the present application comprises: a molten carbonate fuel cell for generating electricity by using fuel; a reaction gas for shifting discharge gas into water gas; a buffer tank for storing the water gas; and a driving device which is actuated by using the water gas that is stored and provided from the buffer tank.

Abstract: Provided is a fuel cell system using waste hydrogen generated from a sea water electrolyzing apparatus, the fuel cell system including: a sea water electrolyzing apparatus carrying out electrolysis of sea water used as cooling water in a nuclear power generation system to produce a chlorine-containing material; a hydrogen conveying line linked to one side of the sea water electrolyzing apparatus to convey waste hydrogen generated during the electrolysis; and a fuel cell linked to the hydrogen conveying line to generate electricity by using the waste hydrogen supplied from the hydrogen conveying line as fuel. The fuel cell system generates electricity by using waste hydrogen, which, otherwise, is totally discarded after being generated secondarily from the sea water electrolyzing apparatus, as fuel for the fuel cell.

Abstract: A fuel cell is disclosed comprising: a power generation layer including an electrolyte membrane, and an anode and a cathode provided on respective surfaces of the electrolyte membrane; a fuel gas flow path layer located on a side of the anode of the power generation layer to supply a fuel gas to the anode while flowing the fuel gas along a flow direction of the fuel gas approximately orthogonal to a stacking direction in which respective layers of the fuel cell are stacked; and an oxidizing gas flow path layer located on a side of the cathode of the power generation layer to supply an oxidizing gas to the cathode while flowing the oxidizing gas along a flow direction of the oxidizing gas opposed to the flow direction of the fuel gas.

Abstract: The fuel cell system includes a fuel cell stack, a fuel supply supplying a fuel to the fuel cell stack, and an oxidizing agent supply supplying an oxidizing agent to the fuel cell stack. The fuel cell stack includes a first end plate, a moisture exchanger, an electrical generator, and a second end plate. The moisture exchanger includes a first area where a dried supply oxidizing agent flows, a second area where a humid emission fuel flows, and a third area where a humid emission oxidizing agent flows, and the first area exchanges moisture with the second and third areas using a moisture exchange layer.

Abstract: A humidifier has a moisture exchanger with at least one water-permeable membrane as well as a humidifier device with a moisture reservoir which is positioned in the flow path of the moisture exchanger.

Abstract: A method for operating a fuel cell system involves operating the fuel cell with recirculation of anode exhaust gas below a predefined maximum load limit of the fuel cell and operating the fuel cell without recirculation of the anode exhaust gas between the load limit and the full load of the fuel cell.

Abstract: A fuel cell module includes a first area where an exhaust gas combustor and a start-up combustor are provided, an annular second area disposed around the first area where a heat exchanger is provided, an annular third area disposed around the second area where a reformer is provided, and an annular fourth area disposed around the third area where an evaporator is provided, and a condensed water collecting mechanism for collecting condensed water produced by condensation of water vapor in a combustion gas by allowing the condensed water to flow through the fourth area, then, the third area, then, the second area, and then, the first area.

Abstract: A fuel cell system includes a fuel cell stack and a humidifier. The humidifier includes an unreacted gas inlet port connected to an end of an unreacted hydrogen discharge pipeline, which is connected at the other end to a hydrogen outlet port of the fuel cell stack, such that the unreacted hydrogen discharged from the fuel cell stack via the hydrogen outlet port is led by the unreacted hydrogen discharge pipeline into the humidifier. The humidifier regulates the humidity and concentration of the unreacted hydrogen led thereinto, and the unreacted hydrogen is then discharged from the humidifier.

Abstract: A hydrogen sensor assembly is disclosed. A sensor is disposed within a slotted sleeve and a spiral shaped sensor housing surrounds the sensor within the sleeve. The spiral shape applies a centrifugal force to the fluid stream. This results in separation of liquid water from the fluid stream. The sleeve forms an internal inner perimeter of the spiral housing. The sensor housing includes a first opening to facilitate a fluid communication between the sensing element and a fluid stream through the slotted sleeve.

Abstract: A separator for a fuel cell includes first and second ends connected by a side wall to define a separation chamber. The first end has a protrusion extending into the chamber to form a channel with the wall. An inlet conduit is tangentially connected to the wall. An outlet conduit connected to the wall between the inlet conduit and the first end. A liquid drain is connected to the second end. A fuel cell system includes a fuel cell stack and a separator. The separator has first and second portions forming a chamber and a divider. The first portion has a continuous inner wall, an end wall forming a central convex projection, an inlet conduit and an outlet conduit. The second portion has a continuous inner wall, an end wall, and a liquid drain.

Abstract: In various aspects, systems and methods are provided for integration of molten carbonate fuel cells with a Fischer-Tropsch synthesis process. The molten carbonate fuel cells can be integrated with a Fischer-Tropsch synthesis process in various manners, including providing synthesis gas for use in producing hydrocarbonaceous carbons. Additionally, integration of molten carbonate fuel cells with a Fischer-Tropsch synthesis process can facilitate further processing of vent streams or secondary product streams generated during the synthesis process.

Abstract: An evaporative humidifier for a polymer electrolyte membrane fuel cell system including a fuel cell stack, comprising: a condensation channel to which exhaust gas from the fuel cell stack is introduced; an evaporation channel to which supply gas for the fuel cell stack is introduced; a partition wall for separating the condensation channel and the evaporation channel from each other; and a water distribution unit for supplying water into the evaporation channel, wherein the water is condensed in the condensation channel by heat exchange between the exhaust gas and the supply gas.

Abstract: An enclosed separator unit for incorporation into a gas supply device of a fuel cell system, to separate liquid from the gas supply device, includes a separator for separating the liquid. A housing encloses the separator unit which is arranged in a gas space 21 in the housing and/or is in thermal contact with the gas space. A line system is provided for discharging the liquid from the separator, and at least one fluid dynamically active functional component is arranged in the line system, in the gas space 21.

Abstract: An electrode structure 15 is accommodated in a joint portion of frames 13 and 14. A first gas diffusion layer 19 and a first gas passage forming member 21 are laid on a first surface of the electrode structure 15, and a second gas diffusion layer 20 and a second gas passage forming member 22 are laid on a second surface of the electrode structure 15. A separator 23 is joined to surfaces of the frame 13 and the gas passage forming member 21, and a separator 24 is joined to surfaces of the frame 14 and the gas passage forming member 22. A porous layer 26 having continuous pores is located between the gas passage forming member 22 and the separator 24. A drainage promoting member 30 formed of a porous material having continuous pores is provided to communicate with a downstream end of a second gas passage T2 of the second gas passage forming member 22 and to communicate with a downstream end of the continuous pores of the porous layer 26.

Abstract: A device for separating a fluid having a water and gas portion in a fuel cell system includes a fluid inlet an a fluid outlet with an outlet valve. The separating device includes a first reservoir region for collecting the water portion of the fluid. The first reservoir region includes a first outlet to feed the water portion in the direction of the fluid outlet. The separating device also includes a second reservoir region having a second outlet that feeds the water portion in the direction of the fluid outlet so that the first reservoir region 19 is connected in series in terms of flow via the second reservoir region with the fluid outlet. In an installation position of the separating device the first outlet is arranged lower than the second outlet so that deposits of the water portion completely covering the first outlet are prevented from flowing away.

Abstract: A fuel cell system includes a fuel cell module for generating electrical energy by electrochemical reactions of a fuel gas and an oxygen-containing gas, and a condenser for condensing water vapor in an exhaust gas discharged from the fuel cell module by heat exchange between the exhaust gas and a coolant to collect the condensed water and supplying the collected condensed water to the fuel cell module. The condenser includes an air cooling condenser using the oxygen-containing gas as the coolant and a water cooling condenser using hot water stored in a hot water tank as the coolant. A thermoelectric conversion mechanism for performing thermoelectric conversion by a temperature difference between the exhaust gas and the oxygen-containing gas is provided between the air cooling condenser and the water cooling condenser.

Abstract: A fuel cell power production system and method for supplying power to a load, comprising a high-temperature fuel cell including an anode compartment, adapted to receive fuel from a fuel supply path and to output anode exhaust, and a cathode compartment adapted to receive oxidant gas and to output cathode exhaust, a water transfer assembly for transferring water in the anode exhaust to the fuel supply path and for outputting water-separated anode exhaust; and a hydrogen utilization device adapted to receive oxidant gas and one of the water-separated anode exhaust and gas derived from the water-separated anode exhaust and to output hydrogen utilization device exhaust including oxidant gas, wherein the hydrogen utilization device exhaust is used to provide oxidant gas to said cathode compartment.

Abstract: A hydrogen generator includes: a water evaporation unit configured to mix water with a raw gas; a burner; a combustion exhaust gas flow channel provided on an inner side than the water evaporation unit and through which a combustion exhaust gas from the burner flows; a reforming catalyst layer configured to produce a reformed gas; and a carbon monoxide reduction unit configured to reduce an amount of carbon monoxide contained in the reformed gas. The water evaporation unit includes a flow channel member defining a flow channel through which the raw gas and the water flow. A pitch of the flow channel member is changed according to at least one of an amount of heat exchange between the combustion exhaust gas flow channel and the water evaporation unit and an amount of heat exchange between the water evaporation unit and the carbon monoxide reduction unit.

Abstract: A system includes a radiator side flow path for supplying a coolant which has cooled a fuel cell stack to a radiator, a bypass flow path for allowing the coolant which has cooled the fuel cell stack to bypass the radiator, a thermostat valve for increasing a flow rate of the coolant flowing through the radiator side flow path in a case where the temperature of the coolant is high as compared to a case where the temperature of the coolant is low, and an electric heater for warming up the coolant. The electric heater is controlled based on an outside atmospheric pressure and on the temperature of the coolant such that the temperature of the coolant flowing into the fuel cell stack is raised in a case where the outside atmospheric pressure is high as compared to a case where the outside atmospheric pressure is low.

Abstract: A fuel cell module includes a first area where an exhaust gas combustor and a start-up combustor are provided, an annular second area disposed around the first area where a heat exchanger is provided, an annular third area disposed around the second area where a reformer is provided, and an annular fourth area disposed around the third area where an evaporator is provided. A stress absorber for absorbing heat stress is provided in at least one of the first area, the second area, the third area, and the fourth area.

Abstract: A system and method for managing water produced by fuel cells where this waste water is captured and used for agricultural, industrial or community purposes along with electricity generated by the fuel cells. Water from a coastal (or lake coast) region can be converted by electricity into hydrogen and oxygen gas or hydrogen and chlorine gas with the hydrogen gas being piped to remote regions for conversion into fresh water and electricity by fuel cells. The oxygen or chlorine can be optionally recovered.

Abstract: A fuel cell system includes at least one fuel cell and a humidifying device for humidifying a supply air flow flowing to a cathode chamber of the fuel cell by an exhaust air flow discharged from the cathode chamber of the fuel cell. The supply air flow and the exhaust air flow are separated from one another by water vapor-permeable membranes. An anode water separator, through which exhaust gas from an anode chamber of the fuel cell flows, is integrated into the humidifying device.

Abstract: A fuel cell system having improved driving performance is disclosed. The fuel cell system includes a stack, which may include a membrane electrode assembly, a separator and end plates provided on the both sides of the stacked membrane electrode assembly and the separator. The membrane electrode assembly may include an anode electrode, a cathode electrode, and an electrolyte membrane. The separator may be positioned with respect to the anode electrode and the cathode electrode, respectively. The end plate may include an oxidant inlet configured to supply oxidant to the cathode electrode, an unreacted oxidant outlet configured to output the unreacted oxidant from the cathode electrode, and a absorption member in fluid communication between the oxidant inlet and the unreacted oxidant outlet.

Abstract: A fuel cell system includes a fuel cell stack for receiving a supplied reactant gas to generate a power; an air compressor for removing moisture remaining in the fuel cell stack during the stop of the power generation; a secondary cell for supplying an operative power to the air compressor; and a controller for controlling the balance of water flowing into and out of the fuel cell stack so that a time required to remove the moisture remaining in the fuel cell stack by the air compressor is substantially constant.

Abstract: A flow field plate for use in a fuel cell includes a porous, wettable plate body including a first reactant gas channel having an inlet portion, a second reactant gas channel having an outlet portion that is adjacent the inlet portion of the first reactant gas channel, and at least one moisture reservoir fluidly connected with pores of the porous, wettable plate body. The at least one moisture reservoir can selectively collect and release moisture received from a reactant gas in the outlet portion to thereby selectively move the moisture from the outlet portion toward the adjacent inlet portion.

Abstract: A fuel cell module includes a cell unit including an electrolyte membrane, a cathode disposed on one face of the electrolyte membrane, and an anode disposed on the other face of the electrolyte membrane, and a water reservoir which stores water produced at the cathode. The water reservoir includes an opening formed in a region other than the cathode of the cell unit, and a projection projecting from the opening to an anode side. The water covering a cathode surface of a fuel cell is reduced.

Abstract: A gas-supply passage (6) via which anode gas is supplied to a fuel cell unit (2) and a gas-discharge passage (12) via which anode gas is discharged from the fuel cell unit (2) are connected via a communication passage (30). Circulation pump (32) switches the communication state of the communication passage between a closed state and an opened state. Circulation pump (32) causes a gas flow from the gas-discharge passage to the gas-supply passage when the communication passage (30) is in the opened state. The communication passage (30) is normally closed, and it is opened when a predetermined condition related to the operation state of the fuel cell unit (2) is satisfied.

Abstract: The present invention relates to a fuel cell system for vehicles and a method for controlling the same which stably maintains an output of a fuel cell by precisely estimating a recirculated hydrogen amount to a stack. A fuel cell system according to the present invention may include: a stack comprising a plurality of unit cells for generating electrical energy by electrochemical reaction of a fuel and an oxidizing agent; a blower for recirculating a gas exhausted from the stack so as to supply the gas back to the stack; an ejector for recirculating the gas exhausted from the stack, receiving hydrogen so as to mix the hydrogen to the recirculated gas, and supplying the mixture to the stack; a sensor module for detecting a driving condition of the vehicle; and a control portion for controlling operations of the blower and the ejector by using the driving condition of the vehicle and performance maps of the blower and the ejector.

Abstract: A fuel cell stack includes: a plurality of membrane-electrode assemblies; first and second end plates respectively positioned outside outermost ones of the membrane-electrode assemblies; and a plurality of separators respectively positioned between the membrane-electrode assemblies and between the outermost ones of the membrane-electrode assemblies and the first and second end plates. The first end plate includes an oxidizing agent inlet, an oxidizing agent outlet, and a moisture supplying flow path connecting the oxidizing agent inlet and the oxidizing agent outlet. The moisture supplying flow path includes a first end portion adjacent to the oxidizing agent outlet and a second end portion adjacent to the oxidizing agent inlet, the first end portion being larger than the second end portion and being a different distance away from a surface of the first end plate facing away from the second end plate than the second end portion.