The invention relates to a fuel cell stack having a variety of individual cells stacked up to form a stack, having at least one humidifier section integrated into the stack and arranged at one end of the individual cells as an electrochemical section. The invention is characterized in that a heat exchanger section is arranged on the side of the at least one humidifier section facing away from the electrochemical section, wherein flow plates for distributing fluids in at least three sections of the stack have the same external geometry.

A humidifier for humidifying a dry cathode supply air via a humid cathode exhaust air in a fuel cell system, may include a housing, a membrane stack, and/or a sealing arrangement. The membrane stack may include a plurality of membranes, two first side surfaces, two second side surfaces, and/or two third side surfaces. The plurality of membranes may be stacked on one another transversely to a longitudinal direction of the membrane stack. The first side surfaces may be arranged opposite one another. The second side surfaces may be arranged opposite one another. The third side surfaces may be arranged opposite one another. The sealing arrangement may include two sealing frames, each of the sealing frames is assigned to one of the respective first side surfaces. Each of the sealing frames may have a frame-shaped contact area and a retaining edge protruding from the contact area.

A membrane humidifier for a fuel cell, of the present invention, comprises: a middle case in which a plurality of hollow fiber membranes are accommodated; a cap case coupled to the middle case; potting parts formed at the ends of the plurality of hollow fiber membranes; an assembly member disposed between the cap case and the end of the middle case so as to provide air tight coupling therebetween; and a protrusion part extending toward the edges of the potting parts from the inside of the cap case so as to provide air tight coupling between the cap case and the potting parts.

A method for humidifying a reactant in a fuel cell system is provided having a fuel cell stack, which is fluidically connected to a humidifier, wherein the humidifier comprises a membrane, on whose surface channels are formed. At least one of the channels is associated with a storage element for temporary storing of liquid water, the method involving the following steps: extracting the liquid water from the fuel cell stack and feeding the liquid water to the humidifier, admitting at least part of the liquid water into the storage element and temporarily storing the part therein, at least partially emptying the storage element by evaporating of the liquid water and humidifying of the reactant being supplied to the fuel cell stack by means of the evaporated liquid water, wherein the liquid water is extracted from the fuel cell stack both at the anode side and at the cathode side. A fuel cell system for carrying out the method is also provided.

Methods and apparatus for reducing the tendency for mold formation and accumulation in membrane-based humidifiers used in PEM fuel cell systems can include reducing the oxygen concentration and/or generating hydrogen peroxide within the humidifier upon shutdown of a fuel cell system. In some embodiments, a fuel cell system comprises valves and lines located and operable to facilitate introduction of hydrogen into the humidifier upon shutdown of the system. In some embodiments, a fuel cell humidifier comprises a catalyst for promoting the generation of hydrogen peroxide from hydrogen and oxygen, and/or comprises acidic gas transport layers.

A membrane humidifier for a fuel cell is disclosed. The membrane includes a middle case in which a plurality of hollow fiber membranes are accommodated; a cap case coupled to the middle case; a potting part formed at the end portions of the plurality of hollow fiber membranes; and an assembling member disposed between the end portions of the cap case and the middle case, and simultaneously coupling, so as to be airtight, a gap between the cap case and the middle case and a gap between the cap case and the potting part.

A humidifier having a multiplicity of metallic flow plates and a multiplicity of water transfer membranes, in particular for humidifying process gas for an electrochemical system or for HVAC applications is described. The humidifier has a construction in which the metallic flow plates and the water transfer membranes are arranged such that in each case at most one of the single-layer flow plates is arranged between adjacent water transfer membranes of the stack; and at least one of the water transfer membranes is in each case accommodated in a sealing manner, in particular clamped in a sealing manner, between the mutually facing sealing lines of adjacent flow plates of the stack. The humidifier has lower production costs, greater efficiency and lower weight.

The present invention relates to a humidifier for a fuel cell, the humidifier comprising: a humidifying module for humidifying a dry gas, supplied from the outside, by using a wet gas discharged from a fuel cell stack; and a first cap coupled to one end of the humidifying module. The humidifying module includes: a mid-case; and at least one cartridge disposed in the mid-case and accommodating a plurality of hollow fiber membranes. The humidifier for a fuel cell further includes a first packing member which is air-tightly coupled to at least one end of the humidifying module through mechanical assembly so that the first cap is in fluid communication with only the hollow fiber membranes.

A device for controlling compensation for an air flow rate upon discharge of hydrogen off-gas and a method for controlling compensation for an air flow rate using the same is an air flow rate control device configured to control a flow rate of air supplied to a fuel cell cathode through an air supply unit of a fuel cell system, wherein the air flow rate control device is configured to determine whether a fuel discharge valve of the fuel cell system is opened and determine a fuel diffusion amount per unit time, wherein the fuel diffusion amount corresponds to an amount of the hydrogen off-gas discharged through the fuel discharge valve and diffused into an air supply unit through a humidifier, and compensate a target air flow rate depending on an oxygen concentration reduction proportion, determined according to the determined fuel diffusion amount per unit time and flow rate information of the air supply unit.

A humidifier is provided having a humidifier module which is arranged between end plates and has a steam-permeable membrane, wherein on each of the two sides of the membrane, a flow field frame having a plurality of bridges defining a flow field is arranged, and between each flow field frame and the membrane a seal is arranged. A motor vehicle with a fuel cell device having a humidifier is also provided.