Patent Application
20200161678
This application claims priority to German Application No. DE 10 2018 219 695.8 filed on Nov. 16, 2018, the contents of which are hereby incorporated by reference in its entirety.
The invention relates to a humidifying module for humidifying a fluid, in particular for humidifying an operating fluid of a fuel cell, in particular in a motor vehicle comprising a fuel cell, as well as a membrane liner for such a humidifying module.
Conventional devices for humidifying a fluid, hereinafter referred to as humidifying modules, have been known for some time. According to the prior art, such humidifying modules comprise membranes, which are impermeable for gas and which are permeable for humidity or water, respectively, or water vapor. In the humidifying module, a fluid to be humidified on the one hand, and a humid medium on the other hand, in each case flows over a membrane, which is formed in this way. The two fluids are thereby fluidically separated from one another by means of the membrane. A mixing of the two fluids, which flow through the humidifying module and which flow over the membrane liners, in terms of material, thus does not occur.
However, the humidity of the fluid, which has a higher humidity, can pass through the membrane and can be absorbed by the fluid having a lower humidity for the humidification thereof. The humidity of the two fluids thus adapts. In particular the process fluids of a fuel cell have to be humidified by means of such a humidifying module. The process fluids used in fuel cells, for example molecular hydrogen and oxygen, have to be humidified prior to flowing into the fuel cell, because the polymer electrolyte membranes, which are typically used in a fuel cell, would otherwise dry out. Such a dry-out, which can be avoided by means of the humidifying module, negatively impacts in particular the durability of the polymer electrolyte membranes as well as the efficiency of the fuel cell.
A humidifying module is known from DE 20 2013 003 566 U1, which can be used to humidify process gases for fuel cells. This humidifying module comprises a water-permeable and essentially gas-impermeable water transfer layer. The humidifying module furthermore has a thermoplastic protective layer, which is water- and gas-permeable at least in some areas. Towards its upper and lower side, the water transfer layer is fixedly connected to an afore-mentioned thermoplastic protective layer by means of a thermopressing process, so that a three-layered sandwich is formed. The water transfer layer and the protective layer are arranged in a stack so as to at least partially overlap one another. To humidify a process gas for a fuel cell, said process gas is guided past a side of the water transfer layer, and a further humid gas on the other side of the water transfer layer. Due to the water transfer layer, a humidity compensation can take place between the two gases, so that the humdities of the process gas as well as of the second gas adapt to one another.
A humidifying module is furthermore known from DE 10 2008 034 407 A1, which can be used to humidify a fluid in a fuel cell system of a motor vehicle. This humidifying module has two housing parts, between which at least one gas-tight and humidity-permeable membrane is arranged in a housing comprising the same membrane. This housing comprising the membrane is formed in the form of a cartridge and seals the membrane against the environment. To humidify a process fluid, which is supplied to the fuel cell and which flows past the membrane on the other side thereof, the humidity of a second fluid, which flows past the membrane on the other side thereof, can pass through the membrane by means of the humidifying module and can be absorbed by the process fluid of the fuel cell, without resulting in a mixing of the two fluids in terms of the material.
It is to thereby be considered to be a disadvantage of the known solutions that it is difficult to seal the membranes against the environment, so that a housing, which seals the membrane liners, is used for the most part. Even though there are also solutions, in the case of which such a housing can be forgone, sealing concepts used in the case of the afore-mentioned solutions prove to be comparatively cost-intensive. In addition, it has been shown that with conventional humidifying modules, the effectiveness of the gas-tight and humidity-permeable membranes used for humidity exchange is impaired if the humid fluid carries such a large amount of humidity that liquid is deposited on the membranes. Any liquid droplets carried along by the fluid can also deposit on the membranes, unduly reducing the effective area of the membranes.
It is thus an object of the present invention to show new ways in the development of humidifying modules for humidifying a fluid—in particular for eliminating the above-mentioned disadvantages.
This object is solved by means of the subject matter according to the independent patent claim(s). Preferred embodiments are subject matter of the dependent patent claims.
It is thus the basic idea of the invention to embody a humidifying module for humidifying a fluid with a humidifier block, in which first fluid paths through which the first fluid can flow for the exchange of humidity between a first and a second fluid and second fluid paths through which the second fluid can flow are fluidically separated from one another by means of gas-tight and humidity-permeable membranes, and with a liquid separator fluidically connected either to the first fluid paths or to the second fluid paths and thus through which the first or the second fluid can flow. The membranes thereby limit first and second fluid paths, which are fluidically separated from one another and through which two fluids can flow in such a way, that a humidity exchange between the fluids can take place through the membranes, without resulting in a mixing of the fluids in terms of material. The liquid separator also prevents the first or second fluid flowing through the liquid separator from having too much humidity or too much liquid. The liquid separator acts either as a pre-separator, so that a reduction in the effective area of the membranes that can be used for humidity exchange can be reduced or even completely avoided, or as a post-separator, so that the humidity or liquid carried along with the first or second fluid after flowing through the humidifier block can be prevented or at least reduced from escaping into the environment.
A humidifying module according to the invention for humidifying a fluid, preferably for humidifying an operating fluid of a fuel cell, particularly preferably in a motor vehicle with a fuel cell, comprises a humidifier block in which first fluid paths through which a first fluid can flow and second fluid paths through which a second fluid can flow are present. In the humidifier block, the first and second fluid paths are fluidically separated from each other by using gas-tight and humidity-permeable membranes. The membranes allow humidity exchange between the first and second fluids without material mixing of the first and second fluids. The humidifying module also comprises a (first) liquid separator which is fluidically connected to either the first or second fluid paths for passage of the first or second fluid. It is therefore advantageous to avoid too much humidity or too much liquid in the first or second fluid flowing through the separator, which, as already indicated, can ensure the effectiveness of the membranes or protect the environment.
According to a preferred embodiment of the humidifying module, the first liquid separator is fluidly connected to the same first or second fluid paths at a first end portion of the first or second fluid paths. The humidifying module also has a second fluid separator which is fluidly connected to the same first or second fluid paths in a second end portion of the first or second fluid paths connected to the first fluid separator opposite the first end portion. Depending on the direction of flow, the first fluid separator acts as a pre-separator and the second fluid separator as a post-separator or vice versa. This has the advantage that both the effectiveness of the membranes can be ensured and the unwanted introduction of humidity or liquid into the environment can be avoided or at least reduced.
The humidifying module expediently comprises further liquid separators which are preferably fluidically connected to the respective other end sections of the first and second fluid paths which are not already fluidically connected to the first or second liquid separator. The advantage of this is that the humidity or the liquid content of both the first and the second fluid can be limited to an optimum value.
According to a further advantageous embodiment of the humidifying module, at least one of the liquid separators has a fin structure in its separator interior. This fin structure serves to separate liquid from the first or the second fluid, respectively. The fin structure comprises a plurality of fins, which are spaced apart from one another. The fluid, which flows through the liquid separator, is deflected at the fins, and, as a result of the inertia of the liquid droplets entrained by this fluid, the afore-mentioned droplets are separated from the fluid stream. Liquid can thus be separated from the respective fluid by means of a comparatively simple construction. In terms of costs, a suitable separation of liquid from the respective fluid can also be ensured thereby to protect the environment or to protect the functionality of the membranes of the membrane liners.
In the case of a further preferred embodiment of the humidifying module, a nozzle plate comprising a first acceleration opening is arranged in the separator interior of one of the liquid separators. This nozzle plate divides the separator interior into two subregions. The first or the second fluid, depending on which one flows through the liquid separator, is accelerated through the first acceleration opening of the nozzle plate, and is directed towards a deflector plate, which is also arranged in the separator interior. The accelerated first or second fluid thus hits the deflector plate. As a result of the abrupt change in direction of the flow of the first or second fluid and as a result of the inertia of possible liquid droplets, which are entrained in this first or second fluid, the afore-mentioned droplets are separated from the fluid. A particularly effective liquid separation can thereby be attained in an advantageous manner.
According to a further advantageous embodiment of the humidifying module, the nozzle plate is embodied with at least one second acceleration opening. This second acceleration opening can be at least partially closed by means of a settable closure element. The second acceleration opening can thus be connected or disconnected. Due to this connection or disconnection of the second acceleration opening, the volume flow of the first or second fluid flowing through the respective liquid separator can thus be set. The level of separation can thus also be influenced. It can thus be ensured in an advantageous manner that an amount of liquid, which is as optimal as possible, is separated from the respective fluid.
According to a further advantageous embodiment of the humidifying module, at least one of the liquid separators comprises an insert member, which particularly preferably has a liquid outlet. A particularly good accessibility of the respective liquid separator or of its interior, respectively, is attained, for example for maintenance purposes, by means of this insert member in an advantageous manner.
In another advantageous further embodiment of the humidifying module, the membranes of the humidifier block are essentially flat and arranged in a membrane stack. Such membranes offer a particularly cost-effective way of constructing the humidifier block.
The humidifier block of the humidifying module is conveniently equipped with a plurality of first and second membrane liners, which are arranged so as to alternate along a stack direction at a distance from one another. Two of these membrane liners, which are adjacent in the stack direction, in each case alternately limit one of the first fluid paths and one of the second fluid paths, wherein the first fluid path is arranged fluidically separated from the second fluid path. The first fluid path is formed in such a way that a first fluid can flow through it. The second fluid path is formed in such a way that a second fluid can flow through it. The membrane liners each comprise a holding part, wherein the first membrane liners each have a first holding part, and the second membrane liners each have a second holding part. One of the gas-tight and humidity-permeable membranes is arranged at this holding part of each membrane liner. The first fluid path is in each limited on the one side of the afore-mentioned membrane, and the second fluid path on the other side by means of this membrane. First and second fluid path are thus separated from one another by means of the gas-tight and humidity-permeable membrane. If the first fluid has a higher humidity than the second fluid, a transition of the humidity of the first fluid for humidifying the second fluid through the gas-tight and humidity-permeable membrane can thus take place when flowing through the humidifying module. A first fluid distribution duct for distributing the first fluid to the first fluid paths, and a first fluid collector duct for collecting the first fluid after flowing through the first fluid paths, are formed in the membrane liners or in the stack of the membrane liners, respectively. Analogous thereto, a second fluid distribution duct for distributing the second fluid to the second fluid paths, and a second fluid collector duct for collecting the second fluid after flowing through the second fluid paths, are formed in the membrane liners or in the stack of the membrane liners, respectively. It proves to be advantageous thereby that the fluid distributor as well as collectors as well as the fluid paths are arranged in the membrane liners or in the stack of the membrane liners, respectively, whereby in particular the number of necessary component parts for the humidifying module and thus also the expected production costs are reduced.
The membrane liners of the humidifier block in the stack of membrane liners are arranged fluid-tight to each other. This has the advantage that a separate housing enclosing the membrane stack and sealing it from an external environment surrounding the humidifier block can be completely dispensed with. However, such a housing can of course be provided to protect the membrane stack and the typically fragile membranes from external interference or to improve the necessary sealing of the membrane liners against this environment.
Two first apertures are in each case preferably present in each first holding part for forming the first fluid distribution duct and for forming the first fluid collector duct. Each first holding part furthermore comprises two second apertures for forming the second fluid distribution duct and for forming the second fluid collector duct. This means that the fluid distribution and fluid collector ducts are each formed by the first or second apertures, respectively, in some sections. All of the second holding parts each have two first apertures for forming the second fluid distribution duct and for forming the second fluid collector duct. Two second apertures are furthermore in each case arranged in each second holding part for forming the first fluid collector duct and the first fluid distribution duct. The first and second apertures of the first and second holding parts thus each form sections of the fluid distribution ducts or of the fluid collector ducts, respectively. This formation of the membrane liners or of the holding parts, respectively, provides a particularly installation space-saving option for designing the humidifying module in an advantageous manner, because all of the fluid-guiding cavities are formed in the membrane liners or the stack of the membrane liners, respectively. There are also cost advantages, because additional component parts, which include the fluid distribution ducts or the fluid collector ducts, respectively, can be forgone.
According to a preferred embodiment of the humidifying module according to the invention, the membrane liners or the stack of membrane liners, respectively, are arranged between a first and a second closure part. The first as well as the second closure part each have a first and a second fluid connection for the first or the second fluid, respectively. The first fluid connection of the first closure part is thereby fluidically connected to the first fluid distribution duct. The second fluid connection of the first closure part is connected to the second fluid distribution duct so as to fluidically communicate therewith. Vice versa, the first fluid connection of the second closure part is connected to the second fluid collector duct so as to fluidically communicate therewith, and the second fluid connection of the second closure part is connected to the first fluid collector duct so as to fluidically communicate therewith. The fluid connections of the first or of the second closure part can be equipped with identical outside diameters or with standardized couplings, respectively, in an advantageous manner, whereby the humidifying module can be integrated in higher-level systems with comparatively little effort.
According to a further preferred embodiment of the humidifying module, at least two membrane liners, which are adjacent in the stack direction, are tightly connected to one another. The first and the second fluid collector duct as well as the first and the second fluid distribution duct are thereby also sealed against the external environment of the humidifying module. Advantageously, a separate housing, which seals the membrane liners or the first and the second fluid collector duct, respectively, as well as the first and the second fluid distribution duct, can thereby be foregone. Direct cost advantages can be derived from this foregoing of a separate housing.
A further preferred embodiment of the humidifying module provides that at least two holding parts, which are adjacent in the stack direction, of the respective membrane liners are tightly connected to one another by means of a press connection. An additional sealing medium, such as, for example, an adhesive is thus advantageously not required in order to seal the holding parts or the membrane liners, respectively, which include the fluid paths as well as the fluid collectors and fluid distributors, against the environment. Such a press connection is furthermore releasable, which is advantageously associated with the fact that the sealed component parts can optionally be separated from one another, without having to destroy the afore-mentioned component parts. On the one hand, this serves to save costs, because, first of all, the sealing medium can be forgone, and, secondly, because the membrane liners can readily be used again after a possible disassembly of the humidifying module, for example for maintenance purposes.
According to a preferred embodiment of the humidifying module, the membrane liners between the two closure parts are pressed by means of a screw connection. The screw connection is thereby formed between the two closure parts. To form this screw connection, the closure parts have, for example, a through-bore, through which a threaded rod is guided. The membrane liners can also have through-bores, which are embodied or arranged, respectively, according to a hole pattern, which is congruent with the closure part. The pressing force for sealing the holding parts or the membrane liners, respectively, or the humidifying module, respectively, is attained by means of a counter-screwing of screw nuts, starting at the two ends of the threaded rods.
It is also possible to design the screw connection for example by the use of a long screw, which has a screw head on one side, the bearing surface of which has a larger diameter than the diameter of the through-bore. To apply the sealing pressing force, only a nut is then screwed onto this screw. One of the closure parts can also have a threaded bore or an insert comprising a thread, instead of a through-bore. A large variety of further options for forming such a screw connection are known to the pertinent person of skill in the art, which is why a more detailed description is foregone at this point. The establishing of the press connection for sealing the adjacent holding parts or membrane liners, respectively, can be realized particularly cost-efficiently and in an easily producible manner with the use of such a screw connection.
In the case of a preferred embodiment of the humidifying module, the two closure parts are formed as identical parts. The first and second membrane liners can also be embodied as identical parts. This results in cost advantages, because the identical parts can each be produced by means of identical manufacturing processes and also on identical manufacturing lines or in series, respectively.
In the case of a further preferred embodiment of the humidifying module, the first and the second fluid paths of the humidifying module are formed in such a way that the first and the second fluid flows through them in cross-flow during operation of the humidifying module. This is to be understood in such a way that, viewed in a stack direction, the flow direction of the first fluid through the first fluid paths intersects a flow direction of the second fluid through the second fluid paths. A particularly good humidity exchange between the two fluids is attained thereby in an advantageous manner by means of the gas-tight and humidity-permeable membrane.
A further advantageous embodiment of the humidifying module provides that the holding part of at least one membrane liner is formed as plate-like holding frame. The afore-mentioned plate-like holding frame has a central aperture. This central aperture in the plate-like holding frame is closed by means of the gas-tight and humidity-permeable membrane. The central aperture is arranged laterally between the two first apertures. The two first apertures are thereby arranged at a distance from one another along a first transverse direction. This first transverse direction runs orthogonally to the stack direction. The plate-like formation of the holding frame of the holding part of a membrane liner results in a particularly good stackability of the membrane liners, whereby they can also be connected tightly particularly well by means of the already described press connection.
According to a further advantageous embodiment of the humidifying module, this central aperture is arranged laterally between the two second apertures. The two second apertures are arranged at a distance from one another along a second transverse direction. The second transverse direction also runs orthogonally to the stack direction, but not congruent to the first transverse direction. It is attained thereby in an advantageous manner that the gas-tight and humidity-permeable membrane is flown over across an effective length, which is a large as possible. The humidity exchange can thus be realized particularly well by means of the gas-tight and humidity-permeable membrane.
In the case of a further preferred embodiment, the first apertures in the holding part are each fluidically connected to the central aperture so as to communicate therewith by means of a first connecting section. The two second apertures can also each be fluidically connected to the central aperture so as to communicate therewith by means of a connecting section. By means of these connecting sections, a distribution of the first or of the second fluid, respectively, to the first or second fluid paths, respectively, as well as a collecting of the first or second fluid, respectively, from the first or second fluid paths, respectively, can take place particularly easily after the fluids have flown through the fluid paths.
In the case of an advantageous further development of the humidifying module, the two first connecting sections are formed to be open towards an upper side of the holding part. The two second connecting sections can analogously be formed to be open towards a lower side of the holding part. This embodiment of the connecting sections or of the holding parts, respectively, can be produced with particularly little effort, which is thus associated with manufacturing cost advantages.
In the case of a further advantageous embodiment of the humidifying module, a sealing surface of the first closure part as well as a sealing surface of the second closure part and a cross section of at least one of the membrane liners, viewed in the stack direction, have an essentially identical outer contour. All membrane liners particularly preferably have such an essentially identical outer contour, viewed in the stack direction. A particularly compact outer shape of the humidifying module can thus be attained in an advantageous manner, whereby said humidifying module can thus be integrated particularly well and in a space-saving manner in a higher-level system.
According to a further preferred embodiment of the humidifying module, this contour is axially- or point-symmetrical. It is thereby ensured in an advantageous manner that the force, which is applied by means of the screw connection to sealingly press the membrane liners between the connecting parts, is distributed as evenly as possible to all membrane liners as well as the closure parts or the sealing surfaces thereof, respectively. Membrane liners, which are embodied as identical parts, can thus also be arranged in the stack so as to be rotated relative to one another in such a way that, depending on their alignment, they either form a first membrane liner or a second membrane liner.
In the case of a further preferred embodiment of the humidifying module, the first closure part has a bypass fluid duct, which can be closed at least partially. This bypass fluid duct can be closed at least partially by means of an adjustable valve device. The bypass fluid duct connects either the first or the second fluid connection of the first closure part to the first or the second fluid collector duct as to fluidically communicate therewith, past the first or second fluid paths, respectively, so. The second closure part can also comprise such a bypass fluid duct comprising an adjustable valve device, which can at least partially close the afore-mentioned bypass fluid duct. This bypass fluid duct of the second closure part connects either the first or the second fluid connection past the first or second fluid paths, respectively to either the first or the second fluid distribution duct so as to fluidically communicate therewith. The bypass fluid duct of the first closure part or the bypass fluid duct of the second closure part, respectively, thus serves to bridge the first or second fluid paths, respectively. In the case that the adjustable valve device is open, a flow-through of the fluid paths and thus also a humidity exchange between the first and the second fluid thus does not occur. It follows as an advantage from this that the level of the humidification of one of the first or of the second fluid, depending on which one is the fluid, which is to be humidified, can be set by means of the at least partial closing of the respective bypass fluid duct by means of the adjustable valve device. The setting of the valve device can take place during the operation of the humidifying module and continuously. It can be ensured thereby that the fluid to be humidified always has an optimal level of humidity.
In the case of a further advantageous embodiment of the humidifying module, a first liquid separator is arranged between the sealing surface of one of the first or of the second closure part as well as the upper or lower side facing the same first or second closure part of the closest membrane liner. This first liquid separator has a separator interior, which connects the first fluid connection of the first or second closure part to the first fluid distribution duct so as to fluidically communicate therewith. The first liquid separator can also be an integral part of the respective first or second closure part. A second liquid separator can be arranged between the sealing surface of the respective other one of the first or second closure part as well as the upper or lower side of the closest membrane liner facing the same other first or second closure part. This second liquid separator has a separator interior, which connects the second fluid connection of this other one of the first or second closure part to the first fluid collector duct so as to communicate therewith. The second liquid separator can also be an integral part of this other one of the first or of the second closure part. It can advantageously be prevented in this way that liquid drops, which are too large, reach into the first or second fluid paths, respectively, with the humid fluid and wet the membranes of the membrane liners there, whereby the efficiency thereof would be impacted. It can thus be ensured by means of the first liquid separator that the function of the humidifying module is also ensured when the humid fluid entrains liquid comprising a droplet size, which is too large. The second liquid separator advantageously serves the purpose that prior to the escape of the humid fluid, the liquid entrained by this fluid can be separated. It is thus prevented that liquid reaches into the surrounding area in an unwanted manner.
According to a further advantageous embodiment of the humidifying module, the gas-tight and humidity-permeable membranes arranged in the humidifier block of the humidifying module are designed as hollow-fiber membranes. Such hollow-fiber membranes enable a particularly effective humidity exchange between the first and the second fluid.
The humidity-permeable and gas-tight membranes of the humidifier block, which are designed as hollow-fiber membranes, each enclose a cavity. The cavities of the membranes each form one of the first fluid paths. The cavities of the hollow-fiber membranes can therefore be flowed through by the first fluid along the first fluid paths. The hollow-fiber membranes limit the second fluid paths at outer sides of the hollow-fiber membranes facing away from the cavities. This means that the second fluid paths are defined by spaces between the hollow-fiber membranes. As the fluid flows through the second fluid paths, the second fluid flows around the outer sides of the hollow-fiber membranes. The advantage of this is that it is particularly easy to constructively separate the first and second fluid paths in the humidifier block of the humidifying module using the hollow-fiber membranes.
In the case of an advantageous embodiment of the humidifying module, the hollow-fiber membranes of the humidifier block extend along a common longitudinal direction and are arranged essentially parallel and at a distance from each other. This results in a particularly uniform arrangement of the hollow-fiber membranes, which has a positive effect on the effectiveness of the humidifying module due to the particularly uniform formation of the second fluid paths.
Another preferred further embodiment of the humidifying module is that the humidifier block of the humidifying module has a housing which extends in the longitudinal direction to delimit a housing interior. The housing interior comprises a central chamber as well as a fluid distributor chamber and a fluid collector chamber. The central chamber of the housing interior is fluidically separated from the fluid distributor chamber of the housing interior and the fluid collector chamber of the housing interior by means of two sealing plates lying opposite each other in the longitudinal direction. This implies that the central chamber of the housing interior is arranged in the longitudinal direction between the fluid collector chamber of the housing interior and the fluid distributor chamber of the housing interior. The hollow-fiber membranes each have two end sections which lie opposite each other in the longitudinal direction and which each merge into a central section of the respective hollow-fiber membranes arranged between the end sections. The hollow-fiber membranes are arranged in the interior of the housing in such a way that the central section of the hollow-fiber membranes limits the second fluid paths on the outside of the hollow-fiber membranes in the central chamber of the interior of the housing. This means that the second fluid paths are present in the central chamber of the housing interior. The housing as well as the two sealing plates and the outer sides of the hollow-fiber membranes conveniently limit the second fluid paths in a fluid-tight manner. The two end sections of one of the hollow-fiber membranes each penetrate one of the sealing plates, so that the fluid distributor chamber and the fluid collector chamber are fluidically connected via the cavities of the hollow-fiber membranes, which form the first fluid paths. The first fluid can thus be distributed via the fluid distributor chamber to the cavities of the hollow-fiber membranes forming the first fluid paths and collected again via the fluid collector chamber after flowing through the first fluid paths. The humidity exchange through the humidity-permeable and gas-tight hollow-fiber membranes takes place in the central chamber of the housing. Such a design of the humidifier block of the humidifying module allows a particularly efficient humidity exchange between the first and the second fluid.
In the case of a further preferred embodiment of the humidifying module, a spacer device is attached to the membrane of a membrane liner. This spacer device ensures that the membrane is also secured in its position during operation of the humidifying module. The membrane as well as the spacer device of this membrane liner can be fixedly connected to the holding part. This fixed connection is particularly preferably attained by means of a screen printing process or by means of high-frequency welding. The position of the typically flexurally limp membrane is also ensured during operation of the humidifying module by means the spacer device in an advantageous manner. It is thus prevented that for example the membrane, which is provided with the spacer device, comes into contact with the membrane of the closest membrane liner. On the one hand, such a contact would possibly damage the membrane, and, on the other hand, reduce the effective surface for the humidity exchange via the membrane.
The scope of the present invention furthermore extends to a membrane liner for a humidifying module, preferably for a humidifying module as already described above.
A membrane liner according to the invention thus comprises a holding part, at which a gas-tight and humidity-permeable membrane is arranged. The holding part furthermore has two first apertures as well as two second apertures. The holding part is formed as plate-like holding frame, which has a central aperture. The membrane closes the afore-mentioned central aperture in a gas-tight and liquid-permeable manner. In the case of such a membrane liner according to the invention, the holding part can be produced particularly cost-efficiently due to its plate-shaped design, because common semi-finished products can be fallen back on.
A preferred embodiment of the membrane liner provides that the central aperture is arranged laterally between the two first apertures. These two first apertures are spaced apart from the central aperture. The two first apertures and the central aperture are arranged along a first transverse direction of the plate-shaped holding part. Analogously, the central aperture is arranged laterally between the two second apertures. The two second apertures are arranged spaced apart from the central aperture. The two second apertures as well as the central aperture are arranged along a second transverse direction of the plate-shaped holding part. A particularly good stackability of the membrane liners results due to the plate-like formation of the holding frame of the holding part of a membrane liner, whereby they can also be connected tightly particularly well by means of the already described press connection.
In the case of an advantageous embodiment of the membrane liner, the first transverse direction runs orthogonally to the second transverse direction. It is attained thereby in an advantageous manner that he gas-tight and humidity-permeable membrane is flown over across an effective length, which is a large as possible. The humidity exchange can thus be realized particularly well by means of the gas-tight and humidity-permeable membrane.
In the case of an advantageous embodiment of the membrane liner, the two first apertures in the holding part are each fluidically connected to the central aperture so as to communicate therewith by means of a connecting section. The two second apertures can also each be fluidically connected to the central aperture so as to communicate therewith by means of a second connecting section. By means of these connecting sections, a distribution of the first or of the second fluid, respectively, to the first or second fluid paths, respectively, can take place particularly easily for flowing over the membrane of a membrane liner, as well as a collecting of the first or second fluid, respectively, after the fluids have flown through membrane.
A further preferred embodiment of the membrane liner provides that the first connecting sections are each formed to be open towards the upper side of the holding part. Analogously, the two second connecting sections can be formed so as to be open towards the lower side of the holding part. This embodiment of the connecting sections or of the holding parts, respectively, can be produced with particularly little effort, which is thus associated with manufacturing cost advantages.
In the case of a preferred embodiment, a spacer device is attached to the membrane of a membrane liner. The membrane or the spacer device, respectively, is fixedly connected to the holding part. This fixed connection of the membrane or of the spacer device, respectively, with the holding part is preferably attained by means of a screen printing process or by means of high-frequency welding. The position of the typically flexurally limp membrane is also ensured during operation of the humidifying module by means the spacer device in an advantageous manner. It is thus avoided that for example the membrane, which is provided with the spacer device, comes into contact with the membrane of the closest membrane liner. On the one hand, such a contact would possibly damage the membranes, and, on the other hand, reduce the effective surface for the humidity exchange via the membrane.
Further important features and advantages of the invention follow from the subclaims, from the drawings, and from the corresponding figure description on the basis of the drawings.
It goes without saying that the above-mentioned features and the features, which will be described below, cannot only be used in the respective specified combination, but also in other combinations or alone, without leaving the scope of the present invention.
Preferred exemplary embodiments of the invention are illustrated in the drawings and will be described in more detail in the following description, whereby identical reference numerals refer to identical or similar or functionally identical components.
In each case schematically,
Flow directions of the two fluids 2a and 2b, which cross one another, are illustrated by means of flow arrows in
As can be seen in
The second fluid distribution duct 8b and the second fluid collector duct 9b are analogously formed by means of the two second apertures 11 of the first holding parts 6a and the two first apertures 10 of the second holding parts 6b. The membrane liners 4 are arranged between a first closure part 13a and a second closure part 13b. Each of the closure parts 13 thereby has a first fluid connection 14a and a second fluid connection 14b. The first fluid connection 14a of the first closure part 13a fluidically communicates with the first fluid distribution duct 8a in the humidifying module 1. The second fluid connection 14b of the first connector part 13a is connected to the second fluid distribution duct 8b so as to fluidically communicate therewith. The first fluid connection 14a of the second closure part 13b fluidically communicates with the second fluid collector duct 9b in the humidifying module 1. The second fluid connection 14b of the second closure part 13b is connected to the first fluid collector duct 9a so as to fluidically communicate therewith. According to an alternative of the humidifying module 1, at least two membrane liners 4, which are adjacent in the stack direction 3, are tightly connected to one another. The first and second fluid collector duct 9a and 9b as well as the first and the second fluid distribution duct 8a and 8b are thereby sealed against the external environment of the humidifying module 1. In a further development of the humidifying module 1, two membrane liners 4, which are adjacent to one another in the stack direction 3, can be tightly connected to one another by means of a press connection. The press connection is advantageously created by means of a screw connection, which connects the two closure parts 13a and 13b and presses the membrane liners 4 between the closure parts 13a and 13b. In
As can additionally be seen by means of
In
In an alternative of the humidifying module 1, the first closure part 13a, as shown in
A further development of the humidifying module 1 is illustrated in an exemplary manner in
According to
The housing 37 may have a liquid drain 47, which can be used to drain any liquid from the inside of the housing 38. Humidifying module 1 may have a first fluid connection 14a through which the first fluid 2a enters humidifying module 1 or humidifier block 23 during operation of humidifying module 1 and into the cavities 35 of the membranes 7. The first fluid 2a flowing through the cavities 35 via the first fluid paths 5a can flow out of humidifying module 1 through a second first fluid connection 14a′ of humidifying module 1. In addition, a second fluid 2b can flow through humidifying module 1 or humidifier block 23, which flows around the hollow-fiber membranes 35 on their outer sides 36. This is to say that spaces between the hollow-fiber membranes 34 can form the second fluid paths 5b for the second fluid 2b. Humidifying module 1 may have a first second fluid connection 14b through which the second fluid 2b enters humidifying module 1. The second fluid 2b can flow through a second second fluid port 14b′ of humidifying module 1 out of humidifying module 1. Here the first first fluid connection 14a and the second first fluid connection 14a′ can be arranged on humidifier sides of humidifying module 1 opposite along the longitudinal direction 25, while the second second fluid connection 14b and the second second fluid connection 14b′ can be arranged on humidifier sides of humidifying module 1 opposite in a height direction 45 running transversely to the longitudinal direction 25. The first fluid 2a can flow along the longitudinal direction 25 according to the extension of the hollow-fiber membranes 34, while the second fluid 2b flows around the hollow-fiber membranes 34 on the outside and thus has a flow direction transverse to the longitudinal direction 25, in particular in the height direction 45. The humidity-permeable design of the membranes 7 designed as hollow-fiber membranes 34 allows a humidity exchange between the first fluid 2a and the second fluid 2b. It is conceivable that the first fluid 2a will absorb humidity from the second fluid 2b. It is also conceivable that the second fluid 2b absorbs humidity from the first fluid 2a.
In principle, it is also possible to use humidifying module 1 as a dehumidifier if cathode gas 52 is too humid. Excess humidity can be transferred from cathode gas 52 to the less humid fuel cell exhaust gas 51. In this case, humidity can be transferred from the first fluid 2a, i.e. from the cathode gas 52, to the second fluid 2b, i.e. to the fuel cell exhaust gas 51. It is also conceivable to use humidifying module 1 in front of a reformer of the fuel cell system 48 not shown here to generate the anode gas 53 in order to humidify a fluid or gas to be supplied to the reformer, for example air.
The scope of the present invention furthermore extends to a membrane liner 4 for a humidifying module 1, as it is illustrated in an exemplary manner in
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2018 219 695.8 | Nov 2018 | DE | national |
