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 system and method for preventing low performing cells in a fuel cell stack. The method includes periodically providing a pulse of the cathode input airflow at low stack current densities, and comparing the current density output of each cell in response to the pulse. Those cells that do not have significant water accumulation will provide one voltage signature and those cells that do have a significant water accumulation will provide another voltage signature. If one or more of the cells exhibit the voltage signature for water accumulation, then the cathode inlet airflow pulses can be provided more often to prevent the cells from failing.

Abstract: The present invention provides a fuel cell system including a reformer that reforms a raw fuel using a reforming catalyst to generate reformed gas, a fuel cell that generates electric power using the reformed gas generated by the reformer, a heat exchanger that exchanges heat between heat of combustion exhaust gas discharged from the fuel cell and water introduced thereinto, a condenser that condenses steam contained in the combustion exhaust gas discharged from primary side downstream of the heat exchanger to recover water, a pump for supplying the water to secondary side upstream of the heat exchanger; a hot-water temperature measurement instrument that measures temperature of hot water at secondary side downstream of the heat exchanger, and a control unit that controls a supply amount by the pump.

Abstract: A cell of a fuel cell includes an MEA, an anode-side gas diffusion layer, a cathode-side gas diffusion layer, an anode-side gas flow passage, a cathode-side gas flow passage, and separators. The anode-side gas flow passage and the cathode-side gas flow passage are opposed flow passages and are both set such that the contact area or the contact ratio of a metal porous body such as an expanded metal body which forms the gas flow channels with respect to the gas diffusion layer is decreased from the upstream toward the downstream of the gas flow passages. With the difference in the contact area or the contact ratio, the generated water is moved between the anode-side gas flow passage and the cathode-side gas flow passage.

Abstract: The present invention provides a fuel cell system including a fuel cell configured to cause reactant gas to be electrochemically reacted to generate electrical power when the reactant gas is supplied to the fuel cell, power consuming equipment such as a reactant gas supply apparatus and a heating device operable to consume electrical power generated by the fuel cell, and a controller for controlling operation of the fuel cell system. During a warm-up operation, the controller causes the reactant gas supply apparatus to start a flow of the reactant gas and to increase the flow of the reactant gas over time, such that the reactant gas supply device starts to consume power and consumes increased power over time. After starting the flow of the reactant gas, the controller causes the heating device to start heating the coolant such that the heating device consumes power.

Abstract: A water control sheet having superior drainage and gas diffusion properties and superior handling characteristics, and a gas diffusion sheet, a membrane-electrode assembly and a polymer electrolyte fuel cell, which utilize the water control sheet, are provided. The water control sheet is independent and located for use adjacent to a catalyst layer of a polymer electrolyte fuel cell, and is formed of a nonwoven fabric containing conductive fibers containing conductive particles at least inside a hydrophobic organic resin. The gas diffusion sheet, the membrane-electrode assembly and the polymer electrolyte fuel cell according to the present invention have the above water control sheet.

Abstract: A closed loop energy storage system configured with a hydrogen tank, an oxygen tank, a fuel cell stack and an electrolyzer. A heat exchanger freeze-dries the hydrogen and oxygen prior to their storage in their respective tanks. The heat exchanger also uses excess fuel cell heat to preheat streams of hydrogen and oxygen coming from the tanks. Phase separators serve both to separate water from hydrogen and oxygen, and to store the water. A thermal management system encloses all the system components except the tanks. An airfoil-shaped shell covers the system, and the larger of the two tanks extends substantially across the shell at its point of greatest camber thickness. The tanks are composed of polymer liners integral with composite shells.

Abstract: There is provided herein a dryer polymer substance including a hetero-phase polymer composition including two or more polymers wherein at least one of the two or more polymers include sulfonic groups, wherein the substance is adapted to pervaporate a fluid. The fluid may include water, water vapor or both. There is also provided herein a process for the preparation of a dryer polymer substance adapted to pervaporate a fluid (such as water, water vapor or both) the process includes mixing two or more polymers, wherein at least one of the two or more polymers may include groups which are adapted to be sulfonated, to produce a hetero-phase polymer composition and processing the polymer blend into a desired form.

Abstract: A water recovery assembly for use in a fuel cell system having an anode and a cathode, the anode being adapted to receive fuel and output anode exhaust, the water recovery assembly comprising a first cooling assembly adapted to receive and quench cool the anode exhaust and to recover a first portion of water including electrolyte from the anode exhaust, and to output quenched anode exhaust and the first portion of water, and a second cooling assembly adapted to receive the quenched anode exhaust and to recover a second portion of water from the quenched anode exhaust, the second portion of water being suitable for humidifying the fuel supplied to the anode.

Abstract: A fuel cell system includes a fuel cell module and a condenser apparatus. The condenser apparatus includes a first condenser using an oxygen-containing as a coolant, and a second condenser using hot water stored in a hot water tank as the coolant. Further, the fuel cell system includes a control device for controlling at least one of a flow rate of the exhaust gas supplied to the first condenser and a flow rate of the exhaust gas supplied to the second condenser based on at least any of a water level of the hot water in the hot water tank, a temperature of the hot water in the hot water tank, and a water level of the condensed water in the condenser apparatus.

Abstract: A ventilation system for a fuel cell power module is provided. The ventilation system includes a ventilation enclosure for evacuating fluids from the fuel cell power module, the ventilation enclosure having an air inlet for providing ingress of air to the enclosure. The ventilation system further concludes a ventilation shaft in fluid communication with the ventilation enclosure and an evacuation pump arranged to exhaust fluid from the ventilation enclosure to a desired location.

Abstract: A fuel cell system includes at least one fuel cell and a circulation system for anode exhaust gases of the fuel cell around an anode region. The fuel cell system also includes a drain line for feeding liquid and water from the region of the circulation system into a process air flow to a cathode region of the fuel cell. The drain line opens into a line element for the process air flow which runs from a lower position into an upper position arranged higher when used properly in the direction of gravity. The flow of the process air runs from the lower position to the upper position of the line element.

Abstract: A fuel cell system includes: a fuel cell unit 50; a first water tank 41 configured to store at least one of condensation water, cooling water, and stored hot water; a second water tank 43 configured to store at least one of the condensation water, the cooling water, and the stored hot water; a first water amount sensor 42 configured to detect the amount of water in the first water tank; a second water amount sensor 44 configured to detect the amount of water in the second water tank; a first water moving mechanism 60 configured to move water in the first water tank to the second water tank; and a controller 40 configured to perform control of the first water moving mechanism.

Abstract: A fuel cell system in which excess water vapor or nitrogen gas is prevented from remaining inside the fuel cell in intermittent operation. The fuel cell system includes an estimation unit that estimates a water vapor amount and a nitrogen gas amount at a plurality of predetermined positions inside the electrolyte membrane and the reaction gas flow channel of at least one unit cell of the fuel cell stack; and an operation control unit that compares, during an operation stop of intermittent operation, the water vapor amount and/or the nitrogen gas amount at each of the predetermined positions with a threshold for each of the predetermined positions, and supplies a gas to the reaction gas flow channel and discharges water vapor and nitrogen gas from inside the fuel cell when the water vapor amount and/or the nitrogen gas amount exceeds the threshold at at least one of the positions.

Abstract: A device to produce electricity by a chemical reaction without the addition of liquid electrolyte comprises an anode electrode, a polymer membrane electrolyte fabricated to conduct hydroxyl (OH—) ions, the membrane being in physical contact with the anode electrode on a first side of the membrane, and a cathode electrode in physical contact with a second side of the membrane. The anode electrode and cathode electrode contain catalysts, and the catalysts are constructed substantially entirely from non-precious metal catalysts. Water may be transferred to the cathode side of the membrane from an external source of water.

Abstract: Disclosed is a system with which fuel cell stacks can be tested automatically or manually so that production of pollutants and consumption of electricity are little. The system runs various analyses and tests on the fuel cell stacks and provides operative conditions such as temperatures and fluid flows needed in the tests.

Abstract: A fuel cell microporous layer including a plurality of porous particles wherein at least 90% of intruded volume by mercury porosimetry is introduced into pore size diameters ranging from about 0.43 ?m to about 0.03 ?m.

Abstract: A fuel cell system includes a water vapor transport device having a wet flow field layer having a coarse microtruss structure disposed between a pair of fine microtruss structures. The coarse and fine microtruss structures of the wet flow field layer are formed from a radiation-sensitive material. A dry flow field layer has a coarse microtruss structure disposed between a pair of fine microtruss structures. The coarse and fine microtruss structures of the dry flow field layer are also formed from a radiation-sensitive material. A membrane is disposed between the wet flow field layer and the dry flow field layer and adapted to permit a transfer of water vapor therethrough from the wet fluid to the dry fluid to form a humidified fluid.

Abstract: A fuel cell system includes a fuel cell; a cathode inflow water amount determining portion that determines a cathode inflow water amount after activation of the fuel cell; an obtaining portion that obtains a pore total volume of the cathode side catalyst layer; an operating condition determining portion that determines, based on the determined cathode inflow water amount and the obtained pore total volume, an operating condition of the fuel cell that includes a current value of current that flows through the fuel cell and an upper limit value of a period of time for which the current flows, for bringing the cathode inflow water amount within a range that is equal to or less than the pore total volume; and an adjusting portion that adjusts the current value and the period of time for which current of the current value flows, such that the determined operating condition is realized.

Abstract: Disclosed is a hydrogen recirculation apparatus for a fuel cell vehicle. More specifically, the apparatus described herein includes a humidifier/heat exchanger humidifies and heat-exchanges dry hydrogen flowing through a low-pressure regulator and recirculated hydrogen flowing through a hydrogen recirculation blower. The humidifier/heat exchanger utilizes the condensed water flowing from a water separator as a source of humidity. The water heat-exchanged with hydrogen by the humidifier/heat exchanger is reused for cooling the hydrogen recirculation blower, and the water used in the hydrogen recirculation blower. The temperature increased by the operation of the hydrogen recirculation blower, is mixed with water flowing from the water separator before introduction into humidifier/heat exchanger.

Abstract: A fuel cell includes a direct liquid fuel cell and a humidifier. The direct liquid fuel cell includes an air intake channel for providing oxidant to the fuel cell and an exhaust channel for exhausting depleted oxidant. The humidifier forms a fluid connection between the air intake channel and the exhaust channel.

Abstract: A water vapor transfer assembly for a fuel cell system includes at least one water vapor transfer device. The water vapor transfer device permits a transfer of water from a wet stream to a dry stream. The water vapor transfer device is disposed between a pair of end plates. The end plates each have a plurality of outwardly extending ribs. The water vapor transfer device and the end plates are disposed within a housing having a pair of wet stream apertures and a pair of dry stream apertures formed therein. The housing further includes a plurality of channels formed adjacent the dry stream apertures. The channels are in fluid communication with the wet stream apertures. The outwardly extending ribs of the end plates cooperate with the channels to define a tortuous bypass flow path between the wet stream apertures of the housing.

Abstract: This invention provides a fuel cell system which can render the distribution of water in an electrolyte membrane even without lowing the pressure of a fuel system (1) comprises an electrolyte membrane (11), an oxidant electrode provided on one side of the electrolyte membrane (11), and a fuel electrode provided on the other side of the electrolyte membrane (11). An oxidant gas flow passage (14) for supplying an oxidant gas along the face of the oxidant electrode and a fuel gas flow passage (15) for supplying a fuel has along the face of the fuel electrode are provided so that the flow direction of the oxidant gas faces the flow direction of the fuel gas. A control unit (50) conducts control so that, when the electrolyte membrane (11) is dry, the flow rate of the fuel gas which flows through the fuel gas flow passage (15) is increased.

Abstract: A fuel cell system is provided that is capable of operating at high temperatures and near-ambient pressure with partial humidification of air supplied to the fuel cell stack. The fuel cells of the stack incorporate gas diffusion barrier layers at the cathode side thereof. The system includes a cooling loop for circulating a liquid coolant through the stack. In some embodiments, an incoming air stream is partially humidified with water vapor transferred from a cathode exhaust stream in a gas-exchange humidifier or enthalpy wheel. In other embodiments, a cathode recycle is employed to partially humidify the incoming air. The humidity of the air and cathode exhaust streams is maintained below a stack saturation point. Methods of operating the fuel cell system are also provided.

Abstract: A humidifier for humidifying a fuel cell composed of an anode side humidifier and a cathode side humidifier each possessing a plurality of hollow fiber membrane modules for migrating moisture between a supply gas, which is supplied to a fuel cell, and an exhaust gas, which is exhausted from the fuel cell to thereby humidify the supply gas, the humidifier comprising: a pair of heads which hold both ends of the hollow fiber membrane modules, a connecting member which connects each of heads, and a device for warming the supply gas composed of conduits through which a cooling medium exhausted from the fuel cell is passed. The device for warming the supply gas is configured so that first warms a humidifier at an outlet side of the supply gas, and then warms a humidifier at an inlet side of the supply gas.

Abstract: An anode reactant recycling system for a fuel cell is disclosed, the system including a hollow main body, a bleed conduit, an injector, a water separator, and a hydrophilic porous media. The anode reactant recycling system for a fuel cell is adapted to minimize a required number of components, eliminate the need for the anode heat exchanger, use a single valve for removal of condensate and reactant byproducts from the anode reactant recycling system, and provide an upstream volume for startup pressurization.

Abstract: A fuel cell system includes: a fuel cell stack configured to have a plurality of unit fuel cells arranged on an identical plane; a chassis configured to cover at least one side of said fuel cell stack via an air flow space; and a condensation water holding member configured to be provided in at least a part between said fuel cell stack and said chassis, have a mesh shape and have a function for keeping moisture.

Abstract: One embodiment of the invention comprises a fuel cell bipolar plate comprising a substrate comprising a first face, a reactant gas flow field defined in the first face, the reactant gas flow field comprising a plurality of lands and channels, and a plurality of microgrooves formed in the first face.

Abstract: A plate-type heat exchanger for use in a fuel cell system that has a fuel cell stack and a reformer is provided. The heat exchanger includes a substrate and a pair of cover plates. The substrate has a first face and a second face opposite to the first face. The substrate is disposed between the cover plates, and combined with the cover plates to form a first passageway and a second passageway. The first passageway is formed in the first face and circulates steam discharged from the fuel cell stack. The steam or water condensed from the steam is supplied to a water supply source. The second passageway is formed in the second face, and circulates water supplied from the water supply source. The water is supplied to the reformer after the circulation. The heat exchanger of the present invention improves performance and efficiency of a fuel cell system.

Abstract: An electric insulator for a fuel cell stack with a plurality of fuel cell plates is provided. The electric insulator includes an insulation layer having a water management feature adapted to militate against liquid water contacting the fuel cell plates. Fuel cell stacks having the water management feature are also described.

Abstract: Disclosed herein are a fluid tank used as a water controller system for fuel cells, wherein the fluid tank includes a housing defining an inner space for receiving a liquid-phase component and a gas-phase component, discharging carbon dioxide and air of the gas-phase component, and supplying the liquid-phase component into a fuel cell stack, and wherein the housing is constructed in a dual structure in which a hermetically-sealed type inner case is disposed inside a hermetically-sealed type outer case such that a space defined between the hermetically-sealed type cases is filled with water, the housing is provided on the outer case and the inner case at one side surface thereof with one or more gas and liquid separation membranes, respectively, and the housing is provided on the outer case and the inner case at the other side surface thereof with one or more gas and liquid separation membranes, respectively, whereby the gas-phase component passes through the water filled in the space defined between the inner

Abstract: A membrane humidifier is provided for a fuel cell. The membrane humidifier of the present invention includes a hollow housing, a joint member, a plurality of internal partition modules, and a plurality of hollow fiber membrane bundles. The hollow housing has a humid air inlet formed at one end thereof and a humid air outlet formed at the other end thereof. The joint member is formed integrally with an inner circumferential surface of the hollow housing. The plurality of internal partition modules are coupled to the joint member and arranged adjacent to each other in the hollow housing, and have a plurality of humid air guiding apertures passing therethrough. The plurality of hollow fiber membrane bundles are disposed in the plurality of internal partition modules, respectively.

Abstract: A direct oxidation fuel cell system includes a fuel cell and a cooling device. An anode-side separator of the fuel cell has a fuel flow channel in the face in contact with the anode. The direction of a flow of air supplied by the cooling device is set so that the upstream-side portion in the average flow direction of fuel in the fuel flow channel is selectively cooled. This allows the upstream-side portion of the polymer electrolyte membrane having large MCO to be cooled, thereby reducing the amount of MCO. Also, the downstream-side portion where the fuel concentration in the fuel flow channel is low has a relatively high temperature, thereby making it possible to improve the energy conversion efficiency.

Abstract: A fuel cell vehicle is provided with a fuel cell which generates electric power by a reaction of a reaction gas and discharges water, a tank which accumulates water discharged from the fuel cell, a heater which vaporizes water accumulated in the tank, a discharge valve which switches between accumulating and discharging of the water with respect to the tank, an external air temperature sensor which detects an external air temperature, a vehicle speed sensor which detects a vehicle speed, a selector with which the driver selects an operation of the discharge valve between accumulating and discharging of the water with respect to the tank, and an ECU which controls these components and includes a control section and a control data storage section.

Abstract: A gas diffusion layer, a manufacturing apparatus and a manufacturing method thereof are provided. The gas diffusion layer having different hydrophilic/hydrophobic structure and channel therein can be manufactured quickly and easily by using a coating mask. The gas diffusion layer is used in various fuel cells to enhance the ability of water management and to solve the problem of flooding at the cathode, the problem of water deficit at the anode, and the problem of gas transfer. The gas diffusion layer includes a gas diffusion medium having a first property and a micro porous layer having a second property. The micro porous layer is formed on one surface of the gas diffusion medium. The micro porous layer has a plurality of channel layers penetrating the gas diffusion medium. One of the first property and the second property is hydrophilic, and the other is hydrophobic.

Abstract: A device to produce electricity by a chemical reaction without the addition of liquid electrolyte comprises an anode electrode, a polymer membrane electrolyte fabricated to conduct hydroxyl (OH—) ions, the membrane being in physical contact with the anode electrode on a first side of the membrane, and a cathode electrode in physical contact with a second side of the membrane. The anode electrode and cathode electrode contain catalysts, and the catalysts are constructed substantially entirely from non-precious metal catalysts. Water may be transferred to the cathode side of the membrane from an external source of water.

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: An object of the invention is to provide a fuel cell system capable of improving accuracy of water content estimation during a standstill. A fuel cell system includes a fuel cell having a plurality of single cells laminated together and an estimating unit for estimating residual water content distributions in a fuel gas flow channel and an oxidation gas flow channel and a moisture content distribution in an electrolyte membrane in a cell plane of each single cell while taking into consideration water transfer that occurs between an anode electrode and a cathode electrode via the electrolyte membrane. The estimating unit estimates a residual water content of the fuel gas flow channel during a standstill from a shutdown to a restart of the fuel cell system based on temperature information on each single cell acquired during the standstill.

Abstract: A vehicle equipped with a fuel cell recognizes an external characteristic of a following mobile unit. Corresponding to the recognized characteristic, the vehicle controls the permission, the amount and the prohibition of discharge of the water produced along with electricity generation of the fuel cell.

Abstract: A flow shifting fuel cell with water separator. The water separator is used to control the amount of moisture that passes through the anode flowpath of one or more fuel cells in one or more fuel cell stacks. The water separator is made up of a housing to direct the flow of a moisture-bearing fluid as well as act as a collection and container for separated moisture. Fluid that is cyclically passing through the fuel cell stack as part of its flow shifting mode of operation oscillates back and forth across a separation chamber formed within the water separator, thereby allowing bidirectional control of the moisture content within the fluid. A drain is formed in the separation chamber to allow removal of condensed water.

Abstract: A waste water management system for a fuel cell cabinet is provided. The waste water management system includes a sealed device that collects and manages the flow of the water from a fuel cell. The sealed device manages a flow of the water from the fuel cell to one of a container and an exterior of the fuel cell cabinet.

Abstract: A fuel cell system includes: an AC impedance measuring unit which measures an AC impedance of a fuel cell at a scavenging start and measures an AC impedance of the fuel cell when a predetermined time has elapsed from the scavenging start; a scavenging execution time estimation unit which estimates a scavenging execution time based on the AC impedance measured at the scavenging start, the AC impedance measured at the time when the predetermined time has elapsed from the scavenging start and the predetermined time; and a limit unit which limits the scavenging execution time to a predetermined maximum scavenging time if the scavenging execution time exceeds the maximum scavenging time.

Abstract: To mitigate bubble blockage in water passageways (78, 85), in or near reactant gas flow field plates (74, 81) of fuel cells (38), passageways are configured with (a) intersecting polygons, obtuse angles including triangles, trapezoids, or (b) hydrophobic surfaces (111), or (c) differing adjacent channels (127, 128), or (d) water permeable layers (93, 115, 116, 119) adjacent to water channels or hydrophobic/hydrophilic layers (114, 120).

Abstract: A fuel cell system in which excess water vapor or nitrogen gas is prevented from remaining inside the fuel cell in intermittent operation. The fuel cell system is provided with a fuel cell having a cell stack formed by stacking a plurality of unit cells each having an anode electrode, a cathode electrode, an electrode membrane located between the anode electrode and the cathode electrode, and a reaction gas flow channel.

Abstract: A fuel cell system includes an evaporating portion, a reforming portion forming an anode fluid, a fuel cell generating an electric power, a tank, a water supply passage connecting the tank and the evaporating portion and allowing water in the tank to be supplied to the evaporating portion, a water supply source provided at the water supply passage to transmit the water in the tank to the evaporating portion, a stepping motor driving the water supply source, and a control portion driving the stepping motor to transmit the water in the tank to the evaporating portion. The control portion performs a harmful vibration restraining process to change a resonance frequency of the stepping motor by changing the number of steps per rotation of the stepping motor based on a volume of the water transmitted to the evaporating portion per time unit.

Abstract: A fuel cell system provided with a fuel cell module, a water supply device for supplying water to the fuel cell module, a water container for supplying water to the water supply device, and a condenser for condensing water vapor in the exhaust gas which is discharged from the fuel cell module and supplying the condensed water to the water container. The water container contains therein an ion exchange device for removing impurities which are contained in the water supplied from the condenser. The water supply device is provided below and downstream of the water container. A pressure regulating device for absorbing a pulsation of the water supply device and absorbing the variation in the pressure in the fuel cell module is provided between the water supply device and the fuel cell module.

Abstract: A fuel cell includes a membrane-electrode assembly and a separator. The membrane-electrode assembly has an electrolyte and a pair of electrodes that are disposed on respective sides of the electrolyte. The membrane-electrode assembly and the separator are stacked in a stacking direction. A reaction surface of the membrane-electrode assembly is in a vertical direction along a direction of gravity and has a shape having a longer dimension in a horizontal direction. The fuel cell is provided with a reactant gas passage to allow a reactant gas to flow along a longitudinal direction of the reaction surface. The reactant gas is an oxidant gas or a fuel gas. A drain channel to allow product water from the reactant gas passage to be drained away is disposed between the membrane-electrode assembly and the separator and under the reaction surface in the direction of gravity.

Abstract: Disclosed is a small-sized low-cost fuel cell having high fuel efficiency, wherein a solid oxide electrolyte membrane is interposed between a fuel electrode and an oxidant electrode. The fuel cell comprises a fuel production member which produces a fuel by a chemical reaction with water that is generated at the fuel electrode. A discharge surface of the fuel production member, from which the fuel is discharged, and a supply surface of the fuel electrode, to which the fuel is supplied, are arranged in parallel so as to face each other. The discharge surface discharges the fuel in the form of a plane.

Abstract: A method of operating a fuel cell system in a vehicle that is switchable to a temporary stop mode and restarted from the stop mode. When, in certain driving situations, it is required to switch to the stop mode, it is then checked whether the operating conditions of the fuel cell system allow a switch to the stop mode. If the switch is allowed it takes place. When a restart of the fuel cell system is required on the basis of the vehicle the settings of the stop mode are cancelled again. The switch to the stop mode involves, with further existing electric contacting of the fuel cell, the air mass flow conveyed by the air conveying device being switched off or reduced to a predefined value and the pressure of the combustion gas supplied being reduced to a predefined value.

Abstract: A fuel cell system capable of reliably and rapidly discharging liquid in a fuel cell stack to the outside is provided. In a fuel cell system having a discharge path (76) that allows discharge of at least liquid in a fuel cell stack (20), at the time of actuation of the fuel cell stack (20), reaction gas is supplied to the fuel cell stack (20) at a higher speed or in a greater amount than during normal operation of the fuel cell stack (20). By supplying the reaction gas at a high speed or in a great amount before actuation, residual liquid in the fuel cell stack (20) can be blown off and thus reliably and rapidly discharged to the outside. The residual liquid can be discharged more easily when a volume (30) is provided in the discharge path (76) or the pressure inside the fuel cell stack (20) is set to a negative level at the time of actuation thereof.