Humidifier stack, humidifier device and membrane for humidifier stack

Abstract

The invention relates to a humidifier stack (1) for a humidifier device (10). Comprising frame plates (8, 8 ') one after the other in the stacking direction in a plate stack comprising a dry gas channel (13) and a wet gas channel (14), and a membrane (9) separating the dry gas channel (13) and the wet gas channel (14), the membrane (9) enables moisture to be transferred from a fluid flow guided in the wet gas channel (14) to a fluid flow guided in the dry gas channel (13). The humidifier stack (1) further comprises an at least partially circumferentially extending seal (96) fixedly connected to the membrane (9), the at least partially circumferentially extending seal (96) comprising a flow channel sealing section (961) disposed along a circumferential edge of a moisture transfer surface (90) of the membrane (9) at a first surface (971) of the membrane (9).

Description

Technical Field

[0001] The invention relates to a humidifier stack, in particular for a fuel cell system, a humidifier device and furthermore to a membrane for a humidifier stack. Background Art

[0002] Humidifier devices for fuel cell systems are known from the prior art in various embodiments, wherein a distinction is made between two main technologies: hollow fiber humidifiers on the one hand and flat membrane humidifiers on the other hand.

[0003] The humidifier device is an indispensable component of the fuel cell system because it ensures that the electrolyte membrane used in the fuel cell stack is always in a moist state, so that the electrolyte therein is in a hydrated state. When the electrolyte membrane of the fuel cell system is not moist enough, the conductivity of the electrolyte decreases, which reduces the performance of the fuel cell. In order to operate the fuel cell stack at optimal performance and / or the optimal degree of efficiency, the humidifier device is therefore a core component.

[0004] All known humidifier devices have in common that they humidify a dry cathode air stream supplied to a fuel cell stack, in that moisture from a humid exhaust air stream from the fuel cells is supplied to the dry air stream. Typically, the dry air stream supplied to the fuel cell stack and the humid air stream from the fuel cell stack are directed in cross-flow or counter-flow through a moisture permeable membrane where moisture transfer occurs.

[0005] Known flat membrane humidifiers comprise a plurality of stacked frame plates which form a plurality of dry gas and humid gas channels which are each separated from one another by a moisture-permeable membrane.

[0006] In this context, the membranes are usually fixedly connected to the corresponding frame panels, for example glued or welded.

[0007] Such humidifier devices are known, for example, from DE 10 2016 014 895 A1 and DE 10 2019 123 534 A1.

[0008] Due to the high thermal loads (in the form of heat energy contained in the exhaust gas flow) and mechanical loads (in the form of pressure gradients acting across the membrane surface) that occur during the operation of the humidifier device in the fuel cell system, the connection of the membrane to the frame plate is a potential weak point, which can lead to premature failure of the humidifier device. The aforementioned problem is further exacerbated by the pressure peaks that occur under certain conditions during operation.

[0009] Furthermore, in known humidifier devices which rely on a direct connection of the membrane to the frame plate, there is the disadvantage that such a connection is complex and prone to failure during the manufacturing process and requires continuous quality control.

[0010] Finally, tolerance issues can lead to known concepts: Since a typical humidifier stack consists of up to 300 stacked layers, tolerances in the stacking direction accumulate; overall, this leads to dimensional deviations in the millimeter range, which are correspondingly difficult to compensate by compensating elements. Summary of the invention

[0011] The object of the present invention is therefore to provide a humidifier stack for a humidifier device, in particular for a fuel cell system, which comprises improved thermal and mechanical robustness and thus enables undisturbed operation over long periods of time and which, furthermore, is easier and cheaper to produce than known humidifier stacks.

[0012] This object is achieved by a humidifier stack having the features of independent claim 1 .

[0013] Another object is to provide a humidifier device, particularly for use in a fuel cell system.

[0014] This object is achieved by a humidifier device having the features of claims 26 and 27 .

[0015] Another object is to provide a membrane for a humidifier stack.

[0016] Advantageous embodiments and advantages of the invention emerge from the dependent claims, the description and the drawings.

[0017] A humidifier stack for a humidifier device, in particular for a fuel cell system, according to the present invention comprises a plurality of frame plates, which are arranged one after another in the stacking direction in the plate stack. In the plate stack, at least two groups of flow channels separated by membranes are formed. The first group of channels comprises a wet gas channel, and the second group of channels comprises a dry gas channel. The membrane allows moisture to be transferred from a fluid flow guided in the wet gas channel to a fluid flow guided in the dry gas channel. According to the present invention, the membrane is provided with a seal extending at least partially circumferentially, which seals at least in sections at adjacent frame plates. The circumferentially extending seal comprises at least two flow channel sealing sections, which are present at two or more circumferential edges of a moisture transfer surface provided by the membrane at the first surface of the membrane, wherein at least two other circumferential edges of the moisture transfer surface provided by the membrane at the first surface do not have a flow channel sealing section. The flow channel sealing section is now sealed relative to the adjacent frame plate so as to form one of the flow channels in the region defined by the membrane, by the adjacent frame plate, by another adjacent membrane and by the flow channel sealing section.

[0018] This film can comprise PTFE or PFSA film especially.This film is preferably framed or laminated into sandwich shape between two nonwoven layers, particularly between the nonwoven layers of PET, PPS or PA.The advantage of this lamination is to protect the film, and this film is very thin and therefore difficult to handle, and is not very robust mechanically.In addition, the nonwoven at the surface is conducive to the attachment of the seal extending circumferentially at least in part at the film, because the film has a very slippery surface and is therefore not too suitable as the point of action for the connection method.On the other hand, the nonwoven comprises porous or rough structure, and is therefore obviously more suitable for connection.

[0019] The flow channels formed by the plate stack can have a dimension of 0.5 mm to 3 mm in the stacking direction (height). In this context, the dry gas channels can have a greater height than the wet gas channels. This is advantageous because reduced pressure losses occur in the dry gas channels in this way; in the context of this system, this is beneficial for the efficiency of the fuel cell stack because in this way the cathode side of the fuel cell stack can be provided with a pressure level that is as high as possible.

[0020] Advantageously, the humidifier stack according to the invention is less susceptible to failures with respect to the thermal and mechanical loads occurring during operation than known humidifier stacks. This is achieved primarily in that, according to the invention, the flow channel sealing section of the seal extending at least partially circumferentially is present at the membrane and the membrane is embodied separately from the frame plate. The sealing effect of the membrane and the frame plate for forming the flow channel is advantageously achieved exclusively by compression of the plate stack, i.e. by friction. Taking into account the settling and creep behavior of the material of the seal extending at least partially circumferentially, the preload required for this can be determined without any problems.

[0021] However, the humidifier stack according to the invention is not only advantageous in terms of operation. It is also superior to the known humidifier stack in terms of manufacturing. This is also achieved again in particular due to the configuration of the flow channel sealing section of the seal that extends at least partially circumferentially. The circumferentially extending seal can be fastened to the membrane in a trouble-free, reliable and fast manner by means of established forming or one-shot forming methods. Since the tightness of the seal in the installed state is achieved purely by the friction forces generated by the compression of the plate stack, no increased requirements are imposed on the quality of the connection between the at least partially circumferentially extending seal and the membrane; in particular, no similarly complex quality control is required as in the humidifier stacks of the prior art that rely on a direct connection of the membrane to the frame plate.

[0022] In an embodiment, the plate stack can be held together by at least one clamping force generating device, in particular one or more tie rods, wherein the membrane in the plate stack is fastened exclusively by the clamping action. A stacking configuration in which the membrane is not glued to the frame plate is advantageous for significantly more reliable manufacturing (no gluing step prone to failure). In addition, there are advantages in terms of increased durability (particularly under the effects of heat, moisture and vibrations, adhesive connections are problematic) and there is a significant cost saving potential due to the manufacturing process that can be better automated. As an alternative to the tie rods (as clamping force generating device), tensioning belts or another device component that seems suitable to the person skilled in the art can also be used in order to load the humidifier stack in the stacking direction by the clamping force.

[0023] In another embodiment, the moisture transfer surface provided by the membrane may have a polygonal, in particular rectangular, shape. In this context, the flow channel sealing sections are positioned at two or more oppositely positioned circumferential edges of the moisture transfer surface at the first surface of the membrane, wherein at least two other oppositely positioned circumferential edges of the moisture transfer surface at the first surface of the membrane do not have a flow channel sealing section. In the case of a rectangular shape, a square shape may also be provided in a particular embodiment; this increases the possibility of using the same parts for the frame plate as well as for the membrane and thereby provides a significant cost saving potential.

[0024] In the region of the two other circumferential edges of the moisture transfer surface provided by the membrane which do not have flow channel sealing sections at the first surface, inflow and outflow cross sections are provided respectively into the flow channels of one of the two groups of flow channels.

[0025] Similarly, the membrane may not have a flow channel sealing section at the second surface, the second surface facing away from the first surface, where the flow channel sealing section is present at the first surface along at least the two circumferential edges. In this way, the corresponding inflow and outflow cross sections are provided in another set in the flow channel.

[0026] In a preferred embodiment, the circumferentially extending seal can be fixedly connected to the membrane, in particular can be injection molded or glued to the membrane. In particular, the circumferentially extending seal can include silicone or consist of silicone. In addition, in an embodiment, the seal can include EPDM or a thermoplastic elastomer or consist of EPDM or a thermoplastic elastomer. The adhesive connection of the circumferentially extending seal to the membrane can be achieved in particular by an adhesive strip. However, an adhesive connection using a curable liquid adhesive is also conceivable. In principle, it is sufficient for the concept according to the invention when the circumferentially extending seal is only fixed to the membrane in order to enable the humidifier stack to be assembled, because the sealing effect is mainly provided by friction via the compression of the humidifier stack.

[0027] Furthermore, at least one of the flow channel sealing sections can include at least one sealing lip, preferably two or more sealing lips. Due to the use of the sealing lips, an optimized relationship between compression force and sealing deformation is achieved, so that the compression force required to achieve a predetermined sealing effect is reduced due to this measure. This aspect is particularly important for stacking a plurality of frame plate-membrane units, since the compression forces are cumulative like a series connection.

[0028] In an embodiment, the thickness of the flow channel sealing section can be many times the thickness of the membrane, wherein the thickness of the flow channel sealing section is at least 3 times, preferably at least 5 times, in particular at least 7 times the thickness of the membrane. The channel size is also essentially defined by the height of the flow channel sealing section. The total height of the flow channel is derived from the (compressed) height of the flow channel seal and the thickness of the frame plate to which the flow channel seal is sealed.

[0029] Furthermore, at least one of the flow channel sealing sections can be guided around at least one circumferential edge of the moisture transfer surface provided by the membrane, in particular injection molded around the circumferential edge, and joined around the circumferential edge, in particular in a U-shape. This is advantageous because in this way the mechanical anchoring of the flow channel seal in / at the membrane material is improved. Furthermore, the membrane is protected from mechanical loads or wear at the rear side in this way; this further contributes to fail-safe operation. In an embodiment, the membrane can be perforated in the area where the flow channel seal is injection molded, so that the sealing material can penetrate the membrane; this further improves the attachment or anchoring of the seal to the membrane.

[0030] In another embodiment, the main flow direction in the wet gas channel can extend at an angle to the main flow direction in the dry gas channel, wherein the at least two flow channel sealing sections are respectively present at mutually different circumferential edges for membranes one behind the other in the plate stack. In this way, the humidifier stack according to the invention can preferably be operated with a crossflow, which on the one hand facilitates a transfer of moisture that is as efficient as possible, since the dry volume flow and the wet volume flow can be distributed particularly evenly over the moisture transfer surface of the membrane in this way. On the other hand, in embodiments of the humidifier device with a separate housing, the sealing action of the humidifier stack relative to the corresponding supply and discharge connectors for the dry and wet fluid flows is simplified.

[0031] In embodiments, in particular embodiments in which the basic shape of the membrane has rotational symmetry, i.e., for example, in the case of a square basic shape, the membrane can be identical in all stacking layers of the plate stack and the installation directions of the membrane in adjacent stacking layers of the plate stack can be rotated respectively, in particular respectively by 90°.

[0032] As an alternative or in addition, the mounting directions of the frame plates in adjacent stacking layers of the plate stack can each be rotated, in particular each by 90°, wherein the frame plates in all stacking layers of the plate stack are preferably identical.

[0033] The frame plate can comprise a metal-containing sheet metal material, in particular a sheet steel. Frame plates of sheet metal material, in particular in the form of stainless sheet steel, offer the advantages of excellent heat and chemical resistance and, moreover, can be produced with established and inexpensive production methods (punching, bending). The thickness of the sheet metal used can in particular be 0.2 mm to 0.8 mm, preferably 0.3 mm to 0.5 mm.

[0034] In an embodiment, at least one membrane support element and / or at least one flow mixing element, in particular a flow grid, may be present between at least two adjacent membranes. The membrane support element and / or the flow mixing element advantageously extend across the entire moisture transfer surface of the membrane and support the surface relative to the pressure gradient acting on the moisture transfer surface. The membrane support element and / or the flow mixing element may be specifically implemented as a one-piece configuration so that two functions are combined in one device component. The flow mixing element acts as a flow distributor and can cause turbulence in a targeted manner; this has the result that the available moisture transfer surface can be used as efficiently as possible for moisture exchange. Therefore, the flow mixing element may be a laminar mixer in particular. In addition to plastic materials, in particular PPS or PET, metals, in particular stainless steel, may also be conceivable as materials for membrane support elements and / or flow mixing elements, in particular flow grids. The membrane support element and / or the flow mixing element may particularly include a cross structure, which includes a plurality of webs or ribs that intersect each other at an angle. In this way, on the one hand, the support surface is maximized, and on the other hand, the flow mixing effect is optimized because a two-dimensional influence on the convection is achieved. The membrane support element and / or the flow mixing element can be a device component which is inserted separately into the plate stack. However, in an embodiment, the membrane support element and / or the flow mixing element can also be formed at the frame plate, in particular as a single part together with the frame plate. The membrane support element and / or the flow mixing element which is correspondingly integrated into the frame plate can be realized from a flat starting material provided for the frame plate, for example by a simple punching and bending method.

[0035] In another preferred embodiment, the frame plate may include at least one supporting element protruding away from the plate base plane. Between the end of the supporting element facing away from the plate base plane and the plate base plane, at least one flow opening is formed, which leads to one of the flow channels of the at least two groups of flow channels. In the region of at least two circumferential edges of the membrane, where the flow channel sealing section is present at the first surface, the supporting element is supported at the second surface of the membrane, which second surface faces away from the first surface and does not have the flow channel sealing section, so as to introduce the sealing preload into the flow channel sealing section.

[0036] The support element can be embodied in particular as a local protrusion raised from the plate base plane, in particular as a deep-drawn dome portion. In particular, a plurality of spaced-apart support elements can be present distributed along the circumferential edge. This is advantageous in order to transmit the compressive forces as evenly as possible and without local pressure peaks.

[0037] In a preferred special embodiment, the support element can be embodied as a pressure rod extending along the respective circumferential edge, wherein the pressure rod preferably contacts the circumferential edge of the membrane regionally. In this way, the uniformity of the introduction of the compressive force is further optimized and local damage of the membrane at the second surface is reliably prevented. With regard to production, the pressure rod can be produced from the plate-like basic material of the frame plate by a separation and forming process, such as stamping and bending, which can be well controlled and is inexpensive.

[0038] In another preferred embodiment, the pressure rod can be embodied as a folded section of the sheet material, in particular a bent section. In this context, the flow opening is particularly embodied between the spaced-apart bent sections of the frame sheet, which connect the sheet base plane to the pressure rod. The bent section can be understood as a web, which connects the sheet base plane to the pressure rod after the flow opening has been produced, for example by punching.

[0039] In a further preferred embodiment, the curved section can be designed to be elastically resilient and in particular to store the clamping force generated by the clamping force generating device. The elastic-elastic properties of the curved section are in particular dependent on the stacking direction. The reason for the elastic-elastic properties is the elastic deformation in the curved section, which in this way essentially acts as a leaf spring. This elastic-elastic property is particularly important for maintaining the compression of the seal in the plate stack, even in the case of a reduction in the inherent sealing preload over time due to settling processes in the material of the at least partially circumferentially extending seal. This is therefore an important measure in order to maintain the sealing tightness of the plate stack for as long a period of time as possible.

[0040] In an embodiment, the support element may also be formed at the membrane. In particular, the support element may be formed by a plurality of adjacent protrusions or projections, which are arranged along the circumferential edge of the membrane where the flow channel sealing section is not present at the first surface. Like the flow channel sealing section, the protrusions or projections are positioned at the first surface of the membrane. Between the membrane side support elements, a flow opening is formed, which leads to one of the flow channels of the at least two groups of flow channels. The membrane side support element may be supported at an adjacent frame plate. Advantageously, the membrane side support element may be made of the same material as the flow channel sealing section and may be produced together with the flow channel sealing section in a common process step, in particular by injection molding.

[0041] In an embodiment, at the second surface, along the at least two circumferential edges where the flow channel sealing sections are present at the first surface, the membrane may comprise a second seal which is in contact with at least one supporting element, in particular a pressure bar, of a respectively adjacent frame plate.

[0042] In particular, the secondary seal can be formed by a section of at least one flow channel sealing segment which is guided around the circumferential edge and in particular injection-molded. This enables the secondary seal to be provided together with the flow channel sealing segment in a common processing step, which makes the production of the humidifier stack according to the invention more cost-effective. Alternatively, the flow channel sealing segment and the secondary seal can also be applied only superficially on membrane surfaces facing away from each other without joining around the edge of the membrane.

[0043] It can in particular be provided that the thickness of the secondary seal is smaller than the thickness of the flow channel sealing section and / or that the secondary seal is embodied as a flat seal. The thickness of the secondary seal can in particular be half or even one third of the thickness of the flow channel sealing section.

[0044] In a further preferred embodiment, the plate stack may form supply and discharge channels which extend in the stacking direction and are fluidically connected to the at least two groups of flow channels. This embodiment of the humidifier stack together with the corresponding end plates can be used directly as a humidifier device without a housing separate from or outside the humidifier stack, because the supply and discharge of the dry volume flow and the wet volume flow are realized by a corresponding configuration within the plate stack.

[0045] In particular, the first supply channel as a dry gas supply channel may be connected to the dry gas channel at the inlet side, and the second supply channel as a humid gas supply channel may be connected to the humid gas channel at the inlet side. Alternatively or additionally, the first exhaust channel as a dry gas exhaust channel may be connected to the dry gas channel at the outlet side, and the second exhaust channel as a humid gas exhaust channel may be connected to the humid gas channel at the outlet side.

[0046] The respective supply and discharge channels are formed in particular by corresponding flow cavities in the frame plates and / or the membranes, which form the supply and discharge channels when stacked. A flow cavity is to be understood as an individual recess in the structure of the frame plates and / or the membranes which, when stacked on top of one another in the stacking direction, forms a supply and discharge channel extending in the stacking direction. The flow cavities are present in particular in the region located outside the moisture transfer surface.

[0047] In a particular embodiment, in the region of the outer surrounding flow cavity, the membrane is respectively provided with a flow cavity seal, which seals in particular bidirectionally relative to an adjacent frame plate, wherein, in particular, the flow cavity seal is fixedly connected to the membrane, in particular injection molded or glued to the membrane. The flow cavity seal can also be provided in particular with one or more sealing lips in order to minimize the compression forces required to achieve the intended sealing action. A flow cavity seal formed directly at the membrane has the advantage that it can be produced in a common processing step together with the flow channel sealing section of the seal extending at least partially circumferentially; this further reduces the manufacturing costs.

[0048] In another embodiment, the flow cavity seal can also be embodied as a seal separate from the membrane and can be connected to one of the mutually adjacent frame plates in the region surrounding the flow cavity externally, or can be loosely inserted between the frame plates. Even in the latter case, in which the flow cavity seal is configured separate from the membrane, it nevertheless seals bidirectionally relative to the corresponding adjacent frame plates.

[0049] In yet another preferred embodiment, at least one compression limiting element can be arranged between two adjacent frame plates, which presets the minimum distance of adjacent frame plates and in this way limits the compression of the circumferentially extending seal of the membrane in the stacking direction. The compression limiting element can be formed in particular at one or more frame plates and can contact the adjacent frame plates. However, in other embodiments, the compression limiting element can be separated from the frame plate and can be inserted between two adjacent frame plates as an insert of a predetermined thickness. The insert can be a sheet metal strip of a predetermined thickness, in particular a gasket. The compression limiting element provides an effective measure to always ensure a predetermined preload of at least part of the circumferential seal during manufacturing, in particular a predetermined preload of its flow channel sealing section. In fact, in particular by a clamping force generating device such as a threaded rod, the plate stack can be so strongly compressed until the compression limiting elements respectively present between the two frame plates contact each other. With regard to measurement technology, this state can be determined simply by monitoring the tightening torque. Alternatively, the plate stack can also be preloaded by a controlled pressure generating device (e.g., a compression or tension testing machine), and the threaded rod can then be provided with a nut to maintain the adjusted preload. Another positive effect of the compression limiting element is that in this way effective tolerance management of the entire stack construction is possible. When using the compression limiting element, the length tolerance in the stacking direction no longer depends on the possibly varying seal compression, but exclusively on the dimensional tolerances of the frame plates, which can be significantly better controlled in terms of process technology, in particular their thickness and the dimensions of the compression limiting element in the stacking direction. This is therefore an important measure in order to enable large-scale production of humidifier stacks according to the invention.

[0050] Another aspect of the invention relates to a humidifier device, in particular a humidifier device for a fuel cell system, comprising a humidifier stack according to the invention, the humidifier stack comprising at least one membrane which enables the transfer of moisture from a wet fluid flow to a dry fluid flow and which is mounted between two end plates, in particular clamped. At least one end plate comprises at least one connector from the group comprising a supply connector for a dry fluid flow, a supply connector for a wet fluid flow, a discharge connector for a dry fluid flow and / or a discharge connector for a wet fluid flow. The supply connector for the dry fluid flow and the discharge connector for the dry fluid flow are fluidically connected to a second group of channels of the humidifier stack, including dry gas channels. The supply connector for the wet fluid flow and the discharge connector for the wet fluid flow are fluidically connected to a first group of channels of the humidifier stack, including wet gas channels.

[0051] The first embodiment of the humidifier device according to the invention can be referred to as a variant without a housing, since the humidifier stack itself forms the housing together with the end plates. With regard to this first embodiment of the humidifier device, a humidifier stack is particularly suitable in which the plate stack forms a supply and discharge channel which extends in the stacking direction and is fluidically connected to the at least two groups of flow channels. This embodiment of the humidifier stack together with the corresponding end plates can be used directly as a humidifier device without a housing separate from the humidifier stack or outside the humidifier stack, since the supply and discharge of the dry volume flow and the wet volume flow is achieved by a corresponding configuration within the plate stack.

[0052] In particular, the first supply channel as a dry gas supply channel may be connected to the dry gas channel at the inlet side, and the second supply channel as a humid gas supply channel may be connected to the humid gas channel at the inlet side. Alternatively or additionally, the first exhaust channel as a dry gas exhaust channel may be connected to the dry gas channel at the outlet side, and the second exhaust channel as a humid gas exhaust channel may be connected to the humid gas channel at the outlet side.

[0053] The respective supply and discharge channels are formed in particular by corresponding flow cavities in the frame plates and / or the membranes, which flow cavities form the supply and discharge channels when stacked. Flow cavities can be understood as individual recesses in the structure of the frame plates and / or the membranes, which are stacked on top of one another in the stacking direction and form supply and discharge channels extending in the stacking direction. The flow cavities are positioned in particular in the region lying outside the moisture transfer surface.

[0054] A connector formed on at least one end plate and comprising a supply connector for a dry fluid flow, a supply connector for a wet fluid flow, a drain connector for a dry fluid flow and / or a drain connector for a wet fluid flow is thus advantageously in contact with the supply and drain channel fluids provided by the plate stack itself, which in turn are in fluid communication with the at least two sets of flow channel fluids of the humidifier stack.

[0055] This variant without housing offers the advantage that different performance variants of the humidifier device according to the invention can be provided with minimal outlay and at lowest cost, since it is easily possible to increase or reduce the number of plates, by means of which the membrane surface area can be directly influenced. Thus, based on the same basic design, a whole range of application scenarios can be covered. Furthermore, a further advantage is that, with the variant without housing, installation space can be saved due to the high functional integration.

[0056] Another aspect of the invention relates to a humidifier device, in particular a humidifier device for a fuel cell system, the humidifier device having a housing, which comprises a supply connector for a dry fluid flow, a supply connector for a wet fluid flow, a discharge connector for the dry fluid flow and a discharge connector for the wet fluid flow. In the housing, a humidifier stack according to the invention is arranged, the humidifier stack comprising at least one membrane which enables the transfer of moisture from the wet fluid flow to the dry fluid flow. The supply connector for the dry fluid flow and the discharge connector for the dry fluid flow are fluidically connected to a second group of channels of the humidifier stack comprising dry gas channels, and the supply connector for the wet fluid flow and the discharge connector for the wet fluid flow are fluidically connected to a first group of channels of the humidifier stack comprising wet gas channels.

[0057] A second variant of the humidifier device according to the invention is a variant with a housing. In this variant, the humidifier stack may include at least one housing seal, which is present between the humidifier stack and the housing, for mutual sealing of the flow areas of the dry gas channel and the wet gas channel connected to the humidifier stack. In this context, at least some sections of the housing seal may be designed to mechanically hold the humidifier stack in the housing and at the same time seal the humidifier stack relative to the housing.

[0058] With regard to possible embodiments of the housing seal, reference has already been made to application DE 102021119892.5, the content of which is incorporated herein by reference.The suitability of the housing seal disclosed in the above-mentioned application according to the invention is not impaired by a correspondingly different internal configuration of the plate stack.

[0059] Finally, another aspect of the invention relates to a membrane for a humidifier stack according to the invention, which enables moisture to be transferred from a fluid flow guided in a wet gas channel to a fluid flow guided in a dry gas channel. The membrane is provided with a seal extending at least partially circumferentially, which is capable of forming a sealing contact at adjacent frame plates of the humidifier stack at least in sections. The seal extending at least partially circumferentially includes at least two flow channel sealing sections, which are present at two or more circumferential edges of a moisture transfer surface provided by the membrane at a first surface of the membrane. At least two other circumferential edges of the moisture transfer surface provided by the membrane do not have a flow channel sealing section at the first surface. The flow channel sealing section is configured to seal relative to an adjacent frame plate of the humidifier stack so as to form a flow channel of the humidifier stack in an area defined by the membrane, by an adjacent frame plate of the humidifier stack, by another adjacent membrane of the humidifier stack, and by the flow channel sealing section.

[0060] All features and feature combinations disclosed in connection with the inventive subject matter "Humidifier stack" and their specific advantages can be applied to the further inventive subjects "Humidifier device" and "Membrane" and vice versa.

[0061] In an embodiment, each frame plate may further include a support grid interposed between and connecting the at least one support element.

[0062] The at least one support element may further include one or more pits, which are arranged in the at least one support element and distributed along the length of the at least one support element, each of the one or more pits being arranged into the top surface of the pressure rod, protruding from the bottom surface of the pressure rod, and extending toward the board base plane.

[0063] Each of the flow cavity seal and the seal that extends at least partially circumferentially may include: a left stopper portion, a right stopper portion, an intermediate raised portion inserted between the left stopper portion and the right stopper portion, and at least one cavity inserted between the intermediate raised portion and each of the left stopper portion and the right stopper portion, the intermediate raised portion having a height higher than the height of the left stopper portion and the right stopper portion, and the cavity passes through the top surface or bottom surface of the corresponding one of the flow cavity seal and the seal that extends at least partially circumferentially. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Further advantages are derived from the following description of the drawings. In the drawings, embodiments of the invention are illustrated. The drawings, description and claims contain many combinations of features. A person skilled in the art will also readily consider these features individually and combine them into convenient further combinations.

[0065] It is shown in an exemplary manner, where:

[0066] Figure 1 is an isometric view of a first embodiment of a humidifier device according to the present invention;

[0067] Figure 2 is an isometric exploded view of a humidifier device according to the present invention according to a first embodiment;

[0068] Figure 3 is a front view of a first embodiment of a humidifier device according to the present invention;

[0069] Figure 4 is a side view of a first embodiment of a humidifier device according to the present invention;

[0070] Figure 5 yes Figure 4 Longitudinal section AA;

[0071] Figure 6a yes Figure 5 Detailed view of Figure X ;

[0072] Figure 6b yes Figure 6a Detailed view of

[0073] Figure 7 is a plan view of a frame plate (wet side) of a humidifier stack according to the present invention;

[0074] Figure 8 yes Figure 7 Longitudinal section BB;

[0075] Fig. 9 is a plan view of a frame plate (dry side) of a humidifier stack according to the present invention;

[0076] Fig.10 yes Fig. 9 Longitudinal section FF;

[0077] Fig.11 yes Fig. 9 The longitudinal section CC;

[0078] Fig.12 It is a plan view of the replacement frame board (dry side);

[0079] Fig.13 yes Fig.12 Detail J, frame plate installed in humidifier stack;

[0080] Fig.14 is a plan view of a membrane stack of a humidifier according to the present invention;

[0081] Fig.15 yes Fig.12 Longitudinal section EE;

[0082] Fig.16 yes Fig.12 Longitudinal section DD;

[0083] Fig.17 is a plan view of the alternative membrane;

[0084] Fig.18 yes Fig.17 Section LL, detail N;

[0085] Fig.19 yes Fig.17 Section LL, detail N, of the membrane installed in the humidifier stack;

[0086] Fig. 20 is an isometric view of a humidifier stack according to a second embodiment;

[0087] Fig.21 is an isometric view of a humidifier device according to a second embodiment;

[0088] Fig. 22 is an isometric view of another alternative frame plate (dry side);

[0089] Fig.23 is an isometric view of yet another alternative frame plate (dry side);

[0090] Fig.24 yes Fig.23 Detailed view of Figure X ;

[0091] Fig.25 is an isometric view of another alternative membrane;

[0092] Fig.26 When the seal is compressed by a distance s1, the adjacent Fig.25 A schematic cross-sectional view of an alternative seal of another alternative membrane; and

[0093] Fig. 27 When the seal is compressed by a distance s greater than the distance s1, the adjacent Fig.25 Schematic diagram of a cross-section of an alternative seal with another alternative membrane. DETAILED DESCRIPTION

[0094] In the drawings, identical or identical types of components may be provided with identical reference numerals.The drawings illustrate examples only and are not to be construed as limiting.

[0095] Directional terms and terms such as "left", "right", "top", "bottom", "front", "rear", "after" and the like used hereinafter are only used for a better understanding of the drawings and should not be construed as limiting in any way. The components and elements shown, their design and use may vary within the context of consideration of a person skilled in the art and be suitable for the respective application.

[0096] exist Figure 1, a humidifier device 10 according to the invention according to a first embodiment is illustrated in an isometric view. The humidifier device 10 comprises a humidifier stack 1 also according to the invention and which is mounted between two end plates 4, 5. The end plates 4, 5 and the humidifier stack 1 are held together by threaded rods acting as clamping force generating means 2, wherein the preload force is generated by a removable nut 21. The end plates 4, 5 provide corresponding connectors, which can be connected to adjacent system components so that the humidifier stack can utilize the fluid flow provided for moisture exchange. In the end plate 4 on the left side in the illustration, a supply connector 42 for the wet fluid flow and a supply connector 41 for the dry fluid flow are formed. In the end plate 5 on the right side in the illustration, an exhaust connector 51 for the dry fluid flow and an exhaust connector 52 for the wet fluid flow are formed. The corresponding fluid flow is guided to the dry or wet gas channel formed in the humidifier stack 1 via the end plates 4, 5 and is separated by a membrane in the humidifier stack 1, respectively, which enables moisture to be transferred from the wet gas channel to the dry gas channel.

[0097] In the installed state in the fuel cell system, the supply connector 42 for the wet fluid flow is connected to the conduit from the exhaust side of the fuel cell stack and the supply connector 41 for the dry fluid flow is connected to the fresh gas intake conduit, which is typically located downstream of the cathode air filter.

[0098] The discharge connector 51 for the dry fluid flow is connected to the cathode air duct leading to the fuel cell stack, and the discharge connector 52 for the wet fluid flow ultimately leads to the environment, wherein further system components such as a water separator and / or at least one turbine of the cathode air compression device can often also be arranged upstream.

[0099] Within the humidifier stack 1 , the respective fluid flows are directed in cross-flow relative to each other; this is already evident from the positioning of the respective connectors 41 , 42 , 51 , 52 at the end plates 4 , 5 .

[0100] exist Figure 2 In the isometric view of FIG. 1 , a humidifier device 10 according to the invention is illustrated in an exploded view, wherein the separation between the humidifier stack 1 and the frame plates 4, 5 can be seen well. At its axial ends viewed in the stacking direction, the humidifier stack 1 is sealed relative to the end plates 4, 5, respectively, by end plate seals 6, 7. The unit of end plates 4, 5 and humidifier stack 1 is held together by a total of four threaded rods, which serve as clamping force generating means 2 and are guided through corresponding passage openings in the humidifier stack 1.

[0101] The humidifier stack 1 comprises an alternating stack of frame plates 8 on the wet side, frame plates 8' on the dry side and membranes 9 arranged between the respective frame plates. The membranes 9 are embodied separately from the frame plates 8, 8' and are held in the plate stack exclusively by clamping.

[0102] In the humidifier stack 1, a humidified gas channel 14 is formed (see Figure 6a , 6b ) and the dry gas channel 13 (see Figure 6a , 6b ), each wet gas channel 14 comprises an inflow cross section 16 and an outflow cross section 15, and each dry gas channel 13 (also comprises an inflow cross section 16 and an outflow cross section 15. The respective inflow cross sections 16 and outflow cross sections 15 of the wet gas channel 14 and the dry gas channel 13 are in fluid communication with the supply / discharge channel 11, which is formed by the plate stack itself through the flow recesses 81, 82, 83, 84 formed in the frame plates 8, 8' and the flow recesses 91, 92, 93, 94 formed in the membrane 9 The flow concave cavities 81 are formed to form a supply / exhaust channel 11 extending in the stacking direction in a stacked state. The channel formed by the flow concave cavities 81 is a wet inlet, which is connected to the wet gas channel 14 at the inlet side. The channel formed by the flow concave cavities 84 is a dry inlet, which is connected to the dry gas channel 13 at the inlet side. The channel formed by the flow concave cavities 82 is a wet outlet, which is connected to the wet gas channel 14 at the outlet side. The channel formed by the flow concave cavities 83 is a dry outlet, which is connected to the dry gas channel 13 at the outlet side.

[0103] Between two membranes 9 adjacent to each other in the plate stack, there is a membrane support element 12 spanning the moisture transfer surface 90 provided by the membrane 9. The membrane support element 12 supports the membrane 9 against the pressure difference acting thereon during operation so that the membrane 9 is not damaged. However, the membrane support element 12 also acts as a flow mixer, which influences the flow in the corresponding wet gas channel 14 and / or dry gas channel 13 and in particular ensures that mixing of the flow in the stacking direction is achieved, for which purpose the flow mixer is particularly designed as a laminar flow mixer. The membrane support element 12 is in particular a flow grid extending in two different directions in a plane and comprises several webs that cross each other. In Figure 2 In the exploded view of the humidifier device 10 or humidifier stack 1 shown, the membrane support element 12 is a device component separate from the frame plates 8, 8'. However, in an embodiment not shown, the membrane support element 12 can also be integrated in the frame plates 8, 8' and in particular be provided as a single part together with the respective frame plates 8, 8'. For this purpose, sheet steel as a starting material for the frame plates 8, 8' provides the best prerequisites.

[0104] exist Figure 3 and Figure 4 middle, Figure 1 The humidifier device 10 is shown in two different projections; Figure 3 It is shown from behind, and Figure 4 It is shown from the right side.

[0105] Figure 5 by Figure 4 The longitudinal section AA of shows a humidifier device 10, wherein in particular the sealing effect of the humidifier stack 1 relative to the end plates 4, 5 by the end plate seals 6, 7 and the sealing positions at both sides can be well seen in this figure. The segmented top channel 11 is a supply channel for the moistening fluid formed by the flow recesses 81 of the frame plates 8, 8' and the flow recesses 91 of the membrane 9. The bottom channel 11 shown in the figure is a discharge channel for the moistening fluid formed by the flow recesses 82 of the frame plates 8, 8' and the flow recesses 92 of the membrane 9. The supply and discharge channels 11 are connected in fluid communication with a moist gas channel 14, which is formed by the plate construction of the humidifier stack 1, wherein in operation of the humidifier device 10 a flow from the top supply channel 11 to the bottom discharge channel 11 is provided.

[0106] However, in Figure 5 The connection of the dry gas channel 13 to the corresponding supply and exhaust channels 11 cannot be seen in the cross-sectional view of FIG. 1 , because they extend rotated 90°. However, in terms of function, it corresponds to the above-mentioned connection of the wet gas channel 14.

[0107] exist Figure 6a The detailed view shown (which shows Figure 5 In detail X) in FIG. 1 , the area of ​​the humidifier device 10 close to the wetting fluid outlet is shown in a cross-sectional view, wherein the internal structure of the humidifier stack 1 and its connection to the end plate 5 can be seen.

[0108] The humidifier stack 1 comprises alternately stacked wet side frame plates 8, membranes 9 and dry side frame plates 8'. In the area extending circumferentially around the moisture transfer surface 90 (see Fig.14 ), the membrane 9 is provided with an at least partially circumferentially extending seal 96. At the first surface 971 of the membrane 9, at two oppositely positioned circumferential edges of the moisture transfer surface 90, the at least partially circumferentially extending seal 96 comprises a respective flow channel sealing section 961. At least two other circumferential edges of the moisture transfer surface 90 provided by the membrane 9 do not have a flow channel sealing section 961 at the first surface 971.

[0109] The flow channel sealing section 961 is now sealed relative to the adjacent frame plates 8 , 8 ′ so that one of the flow channels 13 , 14 is formed in the area bounded by the membrane 9 , by the adjacent frame plates 8 , 8 ′, by the adjacent further membrane 9 and the flow channel sealing section 961 .

[0110] The other circumferential edge of the moisture transfer surface 90 provided by the membrane 9 which does not have a flow channel sealing section 961 at the first surface 971 provides respective inflow cross sections 16 and outflow cross sections 15 into the flow channels 13 , 14 .

[0111] With membranes 9 adjacent to one another, the circumferential edges of the moisture transfer surfaces 90 of the membranes 9 at which the flow channel sealing sections 961 are present are therefore alternately different circumferential edges in order to achieve an alternating sequence of wet gas channels 14 and dry gas channels 13 in the plate stack.

[0112] exist Figure 6a In the illustration of FIG. 1 , the connection of the wet-side discharge channel 11 to the outflow cross section 15 of the wet gas channel 14 is illustrated. In the illustrated edge region of the moisture transfer surface 90, the circumferential edge of every other membrane 9 at the first surface 971 does not have a flow channel sealing section, so that outflow from the wet gas channel 14 is possible. In the illustrated edge region of the moisture transfer surface 90 of this circumferential edge, the inserted membrane 9 has a flow channel sealing section 961, so that outflow from the dry gas channel 13 into the wet-side discharge channel 11 is prevented. In the dry gas channel 13, the flow is more precisely in the direction oriented to the illustrated plane, so that a flow guiding effect in a cross flow is generated in the dry gas channel 13 and the wet gas channel 14.

[0113] The wet side discharge channel 11 formed in the stacking direction by the flow recess 82 of the frame plates 8, 8' and the flow recess 92 of the membrane 9 is delimited at its outer side by a flow recess seal 95 formed at the membrane 9 and sealing the wet side discharge channel 11 relative to the environment. The flow recess seal 95 is effective in both directions, i.e. it seals relative to the frame plates 8, 8' adjacent on both sides. In order to provide protection for the flow recess seal 95, the frame plates 8, 8' each have a collar 88 at their outer circumference, which in the clamped state of the plate stack contacts the respective adjacent frame plate 8, 8' and in this way provides a substantially closed outer wall of the humidifier stack 1. The collar 88 is bent at an angle of less than 90° relative to the plate base plane, so that its distal end does not form a hard stop when contacting the adjacent frame plates 8, 8', but still provides sufficient movement play in the stacking direction so that the seal 96 extending at least partially in the circumferential direction can be reliably compressed. Furthermore, a hard stop of the collar 88 is undesirable since this would result in an uncertain relative position of the adjacent frame plates 8 , 8 ′ with respect to the stacking direction, which could lead to tolerance problems or partially incomplete sealing compression.

[0114] based on Figure 6b , Figure 6b As Figure 6a , showing three frame plates 8, 8' and two membranes 9, the function of the invention can be even better understood. In particular, the connection of the moist gas channel 14 to the moist side discharge channel 11 can be made clearer by means of the flow arrows. As explained, the flow is possible because the moisture transfer surface of the membrane 9 does not have a flow channel sealing section 961 at the circumferential edge shown in the figure, so that the flow can take place through the flow opening 851 of the support element 85. On the other hand, the adjacent membrane 9 has a flow channel sealing section 961 at the circumferential edge shown of its moisture transfer surface, so that outflow to the moist side discharge channel 11 is prevented here.

[0115] Of course, it is important to understand that Figure 5 and Figure 6a as well as Figure 6b All features and characteristics of the humidifier stack 1 explained in an exemplary manner for the connection of the wet gas channel 14 to the wet-side discharge channel 11 can also be applied mutatis mutandis to the connection of the wet gas channel 14 to the wet-side supply channel 11 and to the connection of the dry gas channel 13 to the dry-side supply and discharge channel.

[0116] exist Figure 7 In FIG. 8 , a plan view of the wet side frame plate 8 is shown, and Figure 8 The section BB is shown. In the assembled state, the flow path of the moistening fluid is from top to bottom relative to the illustration. The inflow is achieved via the flow cavity 81 which forms the moist-side supply channel 11 in the stacked state, while the outflow is similarly achieved via the flow cavity 82. In order to enable the inflow into the moistened gas channel 14, the support element 85 formed as a pressure rod 852 has a flow opening 851 which connects the area of ​​the respective supply / discharge channel 11 provided by the flow cavity 81, 82 to the moistened gas channel 14.

[0117] The pressure bars 852 are each formed as a single piece with the material of the frame plate 8, in particular as a bent edge, in which the flow openings 851 can be punched out. During assembly, the pressure bars 852 contact the second surface of the adjacent membrane 9, more precisely in the area of ​​the circumferential edge of the moisture transfer surface 90 provided by the membrane 9, where no flow channel sealing section is present. Due to the complete surface contact of the second surface 971 of the membrane 9 at the pressure bars 852, an optimal support of the membrane 9 is achieved and corrugations are prevented. Figure 8In section BB of , the pressure rod 852 is shown in a deformed state corresponding to the clamped installation in the plate stack. In principle, however, the pressure rod 852 is elastically resilient so that in the initial state of the frame plate 8, which is not installed, the latter does not extend parallel to the plate base plane, but is slightly angled relative to the plate base plane in order to provide a sufficient deformation stroke. Fig.11 This state is shown for the dry side frame plate 8 ′, however this can be similarly applied to the wet side frame plate 8 .

[0118] A passage opening 87 is provided for receiving a threaded rod or equivalent clamping force generating means.

[0119] Fig. 9 , Fig.10 and Fig.11 The dry side frame plate 8 ′ shown is constructed similarly to the wet side frame plate 8 . However, the difference is that the support elements 85 formed as pressure bars 852 are formed at different oppositely located edges in order to provide a flow path for the dry side that is separate from the wet side. When assembled, an inflow of the dry fluid is achieved through the flow recesses 84 , which in the stacked state form the dry side supply channel 11 , while an outflow is similarly achieved through the flow recesses 83 .

[0120] exist Fig.10 In the section FF shown, the compression limiting elements 86 present in the corner regions of the frame plates 8' can be seen, which are each formed as a local deep-drawn region of the plate material. In the clamped state of the plate stack, the compression limiting elements 86 contact the adjacent frame plates 8 in order to form a "hard" stop and thus predefine a predetermined sealing compression, which has a positive effect on the length tolerances in the stacking direction.

[0121] exist Fig.11 , the uncompressed initial state of the pressure rod 852 is shown. As can be seen, the pressure rod 852 extends at an angle relative to the plate base plane. When the plate stack is assembled, the pressure rod 852 elastically deforms (bends) until it extends parallel to the plate base plane. This resilient deformation correspondingly stores the clamping force and can therefore compensate for the sedimentation effects in the flow channel sealing section 961 of the seal 96 that extends at least partially circumferentially.

[0122] Fig.12An alternative embodiment of a dry-side frame plate 8' is shown, in which the support element 85 is not embodied as a pressure rod, but as a dome support portion 854. The dome support portion 854 can be deep-drawn from the sheet metal material of the frame plate 8' in a simple and reliable manner. Along two oppositely positioned edges of the frame plate 8', a plurality of dome support portions 854 are arranged spaced apart from one another, between which corresponding flow openings 851 are formed, which flow openings 851 enable flow into and out of corresponding flow channels of the humidifier stack. In the state installed in the humidifier stack, the section of the dome support portion 854 spaced apart from the plate base plane of the frame plate 8' is supported on the adjacent membrane 9, which in Fig.13 In other respects, the stacking construction is identical to the embodiment with pressure bars. The configuration of the support element 85 as a dome support portion 854 is a possibility which will be implemented as required and which has reduced equipment expenditure in production compared to bent pressure bars, since the bending and stamping steps are eliminated.

[0123] exist Fig.14 , Fig.15 and Fig.16 , finally the membrane 9 itself is shown, which represents the core component of the humidifier stack 1, where the moisture transfer takes place. The membrane 9 comprises a moisture transfer surface 90, which is provided with a corresponding flow channel sealing section 961 at the first surface 971, at two oppositely positioned circumferential edges, the flow channel sealing section 961 comprising a plurality of sealing lips. The flow channel sealing section 961 interacts with the adjacent frame plates 8, 8' in the manner described above, so as to laterally delimit the flow channels, i.e. the dry gas channels 13 or the wet gas channels 14, which are formed between the first surface 971 of the membrane 9 and the adjacent frame plates 8, 8'.

[0124] In the illustrated exemplary embodiment of the membrane 9, the first surface 971 adjoins the drying gas channel 13, i.e., in the illustration, the flow is effected from left to right. In the illustrated exemplary embodiment of the membrane 9, the flow channel sealing section 961 is present at the oppositely located short circumferential edge of the moisture transfer surface 90 (cf. section EE).

[0125] On the other hand, at the long circumferential edge of the moisture transfer surface 90, the first surface 971 of the membrane 9 has no flow channel sealing section 961 in order to enable the inflow and outflow of the drying fluid flow (see section DD).

[0126] The flow channel sealing section 961 of the at least partially circumferentially extending seal 96 is connected to the moisture transfer medium 97 of the membrane 9 by injection molding, but in other embodiments it can also be connected by bonding. The sealing material of the flow channel sealing section 961 is injection molded so as to engage around the corresponding circumferential edge and form a secondary seal 962 at the second surface 972 of the membrane 9 facing away from the first surface 971, which is embodied as a flat seal. When assembled, this secondary seal 962 contacts the support element 85 of the adjacent frame plate, in particular the pressure rod 852. On the one hand, this protects the moisture transfer medium 97 of the membrane 9 from wear and, on the other hand, improves the "anchoring" of the sealing material.

[0127] In the region outside the moisture transfer surface 90, the membrane 9 is provided with a flow cavity seal 95 which surrounds the flow cavities 91, 92, 93, 94 on the outside and forms a sealing lip at a first surface 971 and is configured as a flat seal at a second surface 972. When mounted, the flow cavity seal 95 seals bidirectionally with respect to the adjacent frame plates 8, 8' and thus closes off the supply / discharge channel 11 formed by the flow cavities 91, 92, 93, 94 in the stacked state with respect to the environment.

[0128] As is apparent based on the aforementioned flow conditions, the illustrated membrane 9 is a dry side membrane, which is associated with a dry side frame plate 8' (see Fig. 9 ). However, the wet side membrane 9 (not shown) is a simulated configuration, wherein, however, there is such a difference, that is, its flow channel sealing section 961 is not present at the short side of the moisture transfer surface 90 at the first surface 971 of the membrane 9, but is present at the relatively positioned long circumferential edge, so as to correspondingly achieve a flow from top to bottom relative to the illustration.

[0129] The moisture transfer medium 97 of film 9 comprises PTFE or PFSA film.This film forms frame or laminated sandwich shape between two layers of nonwoven material layers, particularly between nonwoven material layers of PET, PPS or PA.The advantage of this lamination is to protect the film, and this film is very thin, and therefore difficult to handle, and mechanically not very robust.In addition, nonwoven material helps to attach at least part of the seal 96 or flow channel sealing section 961 extending circumferentially at the surface, because film has very slippery surface, and therefore is not suitable as the point of action for the connection method.On the other hand, nonwoven material comprises porous or rough structure, and therefore is obviously more suitable for connection.

[0130] exist Fig.17 and Fig.18In FIG. 1 , an alternative membrane 9 is illustrated in plan view. The membrane 9 comprises an integrated membrane-side support element 963, which is formed as a bulge or protrusion. A plurality of spaced-apart bulges or protrusions are provided, which are present along two oppositely positioned circumferential edges of the moisture transfer surface 90 of the membrane 9. A flow channel sealing section 961 is present at two further circumferential edges of the moisture transfer surface 90 of the membrane 9. The membrane 9 shown is a dry-side membrane 9, which corresponds to the inflow and outflow regimes thereof. Fig.14 The membrane shown. The membrane side support element 963 is present at the same surface 971 of the membrane 9 where the flow channel sealing section 961 is also present. The membrane side support element 963 is particularly present at the first surface 971 of the membrane. The membrane side support element 963 can be provided alternatively or additionally to the frame plate side support element (pressure rod or dome pressure part). The membrane side support element 963 provides the advantageous possibility of providing the support element with minimal expenditure in terms of production.

[0131] Between the membrane side support elements 963, flow openings 964 are formed, which lead to one of the flow channels of at least two groups of flow channels of the humidifier stack. The membrane side support elements 963 can be supported at adjacent frame plates 8, 8'; this Fig.19 The membrane-side support element 963 can consist of the same material as the flow channel sealing section 961 and can be produced together with the flow channel sealing section in a common process step, in particular by injection molding a moisture transfer medium to the membrane 9 .

[0132] exist Fig. 20 In the figure, a second embodiment of a humidifier stack 1 according to the invention is illustrated, which differs from the first embodiment in that it does not have integrated supply / discharge channels for wet and dry fluid flows. This is achieved by eliminating the flow cavities 81, 82, 83, 84 of the frame plates 8, 8' and the flow cavities 91, 92, 93, 94 of the membrane 9. However, the internal structure of the plate stack is otherwise identical. The corresponding inflow cross-sections and outflow cross-sections of the dry and / or wet gas channels are exposed at the sides of the humidifier stack 1 and are only fluidically connected when installed in a corresponding housing with a corresponding supply / discharge connector. While the first embodiment does not require a separate housing, the second embodiment requires one.

[0133] The plate stack forming the humidifier stack 1 is again sandwiched between two end plates 4, 5. At a first pair of oppositely positioned side faces, there is an inflow cross section into the dry gas channel on the one hand and an outflow cross section out of the dry gas channel on the other hand. At a second pair of oppositely positioned side faces, there is an inflow cross section into the moist gas channel on the one hand and an outflow cross section out of the moist gas channel on the other hand. Thus, a flow through the humidifier stack in a crossflow is again provided.

[0134] In order to be able to guide the corresponding fluid flows individually - dry inlet, dry outlet, wet inlet, wet outlet - the corresponding housing seals 111 are present at the edges of the plate stack positioned between the sides and seal the corresponding sides to each other in the installed state. The housing seal 111 can be designed as a flat seal, which acts radially in the installed state. The plate stack can include corresponding bevels in its corner area, in particular about 45°, so that a fastening surface is provided for the housing seal 111. For example, the housing seal 111 can be glued to the plate stack. The housing seals 111 each extend to the corresponding end plates 4, 5, and intersect each other there in the form of a sealing cross 112 present at the corresponding end plates 4, 5, which seals axially relative to the corresponding wall of the housing 100 in the installed state.

[0135] Fig.21 The installation state of a humidifier stack 1 in a humidifier device 10 according to a second embodiment is illustrated. The humidifier device 10 comprises a housing 100 having a receiving space 102, the receiving space 102 being configured to receive the humidifier stack 1. The housing 100 further comprises a supply connector 41 for a dry fluid flow, a supply connector 42 for a wet fluid flow, a discharge connector 51 for a dry fluid flow and a discharge connector 52 for a wet fluid flow, each of which is fluidically connected to the receiving space 102. The housing 100 comprises four housing sealing grooves 101 adjacent to the receiving space 102, in which the housing seal 111 of the humidifier stack is sealingly received in the receiving space 102 in the installed state. The housing sealing grooves 101 are respectively arranged in the corner regions of the receiving space 102. Each of the housing sealing grooves 101 has a groove base, which can act as a radial sealing surface and is positioned obliquely relative to the main flow direction (dry or wet), in particular inclined at 45°. The housing sealing groove 101 comprises parallel groove walls which delimit a groove base at both sides and guide the humidifier stack 1 in the installation direction during installation. The position and arrangement of the supply / drain connectors 41 , 42, 51 , 52 are only examples and may deviate in embodiments.

[0136] Fig. 22 8 ' (dry side). The frame plate 8 ' also includes a support grid 89 inserted between the support elements 85 and connecting them and inserted between the peripheral edges 811 and 821 of the flow cavities 81 and 82 and connecting them. The support grid 89 is further arranged above or below the moisture transfer surface 90 of the adjacent membrane 9.

[0137] The support grid 89 can be formed as a single piece with the material of the frame plate 8', through which openings can be punched out. During assembly, the support grid 89 can contact the moisture transfer surface 90 of the adjacent membrane 9, and due to this contact, an optimal support of the membrane 9 can be achieved, and corrugations can be prevented. As a result, a better positioning of the membrane 9 and the at least partially circumferentially extending seal 96 on the frame plate 8' can be achieved, thereby reducing pressure losses in the humidifier device 10. Fig. 22 The support grid 89 for the dry side frame plate 8' is shown in FIG. 1 , but can also be similarly applied to Figure 7 Wet side frame plate 8 in.

[0138] Fig.23 is an isometric view of another alternative frame plate 8' (dry side). Fig.24 yes Fig.23 Detailed view of Figure X The support member 85 further includes one or more dimples 855 disposed in the support member 85 and evenly distributed along the length of the support member 85. In detail, each dimple 855 is disposed in the top surface of the pressure bar 852, protrudes from the bottom surface of the pressure bar 852, and extends toward the plate base plane of the frame plate 8'.

[0139] The dimples 855 may be formed as a single piece with the material of the frame plate 8'. During assembly, the pressure rod 852 contacts the second surface of the adjacent membrane 9 to achieve optimal support of the membrane 9 and prevent corrugation. However, if too much pressure is applied to the pressure rod 852, it may contact the frame plate 8', causing the corresponding flow opening 851 to become blocked. The dimples 855 prevent this from happening by contacting the frame plate 8' and maintaining a space between the pressure rod 852 and the frame plate 8', thereby preventing the corresponding flow opening 851 from becoming blocked and thus reducing pressure losses in the humidifier device 10. The dimples 855 for the dry side frame plate 8' are formed in Fig.23 and 24 Figure 2, but can be applied similarly to Figure 7 Wet side frame plate 8 in.

[0140] Fig.25 is an isometric view of another alternative membrane 9.

[0141] refer to Fig.25 and Fig.26 , an alternative flow cavity seal 95 and an alternative at least partially circumferentially extending seal 96 are fixedly connected to the membrane 9. In detail, the flow cavity seal 95 is fixedly connected to the area surrounding the flow cavities 91, 92, 93, 94 on the outside, and the at least partially circumferentially extending seal 96 is arranged along the circumferential edge of the moisture transfer surface 90 of the membrane 9 at the first surface 971 of the membrane 9, similar to the Fig.14 The film 9 shown in the figure corresponds to Figure 7 The wet side membrane of the wet side frame plate 8. However, the dry side membrane 9 (not shown) has a similar configuration with the difference that its seal 96 is not present at the long sides but at the oppositely positioned short circumferential edges of the moisture transfer surface 90 to achieve a flow from left to right correspondingly with respect to the illustration.

[0142] However, Fig.25 and 26 The flow cavity seal 95 and the at least partially circumferentially extending seal 96 are connected to Fig.14 The difference between Fig.25 and 26 The flow cavity seal 95 and the at least partially circumferentially extending seal 96 have different geometries, with the middle raised portion having a height that is higher than the height of the left and right stopper portions.

[0143] Fig.26 When the seal 95 or 96 is compressed by a distance s1, the adjacent Fig.25 A schematic cross-sectional view of an alternative seal 95 or 96 of another alternative membrane 9 in FIG. Fig. 27 When the seal 95 or 96 is compressed by a distance s greater than the distance s1, the adjacent Fig.25 FIG. 2 is a schematic cross-sectional view of an alternative seal 95 or 96 of another alternative membrane 9 .

[0144] refer to Fig.26 Part (a) and Fig. 27 In part (a), the seal 95 or 96 includes a middle ridge 951, a left stopper part 952, a right stopper part 953 and a cavity 954. The middle ridge 951 is inserted between the left stopper part 952 and the right stopper part 953, and has a height higher than that of the left stopper part 952 and the right stopper part 953, that is, the height difference between the middle ridge 951 and the left stopper part 952 or the right stopper part 953 is a distance s1. The cavity 954 is inserted between the middle ridge 951 and each of the left stopper part 952 and the right stopper part 953, passing through the top surface and the bottom surface of the seal 95 or 96, respectively. The seal 95 or 96 is inserted between and in contact with the frame plates 8, 8', and initially, only the middle ridge 951 contacts the frame plate 8 above the seal 95 or 96. The middle raised portion 951 has a contact surface smaller than each of the left stopper portion 952 and the right stopper portion 953 .

[0145] refer to Fig.26Part (b), during assembly, the frame plate 8 first axially compresses the middle ridge 951 of the seal 95 or 96 by a distance s1. The first reaction force (first force-displacement curve) of the middle ridge 951 for the distance s1 is relatively very small, and increases at a relatively small first rate, thereby keeping the deformation in the thin frame plates 8, 8' as low as possible. Since the middle ridge 951 is decoupled from each of the left stopper portion 952 and the right stopper portion 953 (cavity 954), the first reaction force is not affected by the two large stopper portions 952 and 953. In addition, due to the small contact surface of the middle ridge 951, the seal 95 or 96 provides a high surface pressure (even at low forces) to achieve a very good sealing effect. In addition, the seal 95 or 96 and the frame plates 8, 8' are stabilized to prevent tilting.

[0146] refer to Fig. 27 In part (b), during assembly, the frame plate 8 then axially compresses the seal 95 or 96 by a distance s greater than the distance s1, i.e., the left stopper portion 952 and the right stopper portion 953. The second reaction force (second force-displacement curve) of the left stopper portion 952 and the right stopper portion 953 increases at a second rate that is much greater than the first rate. This results in a bilinear force-displacement curve for the seal 95 or 96. This characteristic affects the series connection of several seals of different flexibility. In detail, the seal with an intermediate raised portion and a stopper portion has a relatively small final compression expansion (the sum of the displacement distances) on all seals. On the other hand, the seal without a stopper portion has a relatively significantly larger final sealing compression expansion on all seals.

[0147] In the embodiments, again refer to Fig.26 Part (a) and Fig. 27 For part (a), for extreme tightness requirements, the seal 95 or 96 can be supplemented with a liquid sealant (not shown) in the cavity 954.

[0148] Reference numerals list

[0149] 100 Shell

[0150] 101 Housing sealing groove

[0151] 102 Receiving Space

[0152] 10 Humidifier device

[0153] 1 Humidifier stack

[0154] 11 Supply / discharge channels

[0155] 111 Housing seal

[0156] 112 Sealed Cross

[0157] 12Membrane support elements, flow mixing elements, flow grids

[0158] 13 Drying gas channel

[0159] 14 Humidified gas channel

[0160] 15 Outflow cross section of dry and / or wet gas channel

[0161] 16 Inflow cross section of dry and / or wet gas channel

[0162] 2 Clamping force generating device

[0163] 21 Nut

[0164] 4.5 End plate

[0165] 6, 7 End plate seals

[0166] 41 Supply connector for dry fluid flow

[0167] 42 Supply connector for wet fluid flow

[0168] 51 Discharge connector for dry fluid flow

[0169] 52 Discharge connector for wet fluid flow

[0170] 8 Frame plate on wet side

[0171] 8' dry side frame board

[0172] 81-84 Flow cavity of frame plate

[0173] 811, 821 Circumferential edge of the flow cavity

[0174] 85 Support element

[0175] 851 Flow openings in support elements

[0176] 852 Pressure rod

[0177] 853 Bend Section

[0178] 854 Dome support section

[0179] 855 pit

[0180] 86 Compression Limiting Element

[0181] 87 Access opening

[0182] 88 Ring

[0183] 89 Support Grid

[0184] 9 Film

[0185] 90 Moisture transfer surface

[0186] 91-94 Flow cavity of membrane

[0187] 95 Flow Cavity Seal

[0188] 951 Middle bulge

[0189] 952 Left stopper part

[0190] 953 Right stopper part

[0191] 954 Cavity

[0192] 96 A seal extending at least partially circumferentially

[0193] 961 flow channel sealing section

[0194] 962 Secondary Seal

[0195] 963 membrane side support element

[0196] 964 Flow openings of membrane side support elements

[0197] 97 Moisture transfer medium

[0198] 971 First Surface of Membrane

[0199] 972 Second surface of membrane

Claims

1. A humidifier stack (1) for a humidifier device (10), the humidifier stack (1) comprising: Frame plates (8, 8') arranged one behind the other in the stacking direction in a plate stack comprising dry gas channels (13) and wet gas channels (14); a membrane (9) separating the dry gas channel (13) and the wet gas channel (14), the membrane (9) enabling the transfer of moisture from a fluid flow guided in the wet gas channel (14) to a fluid flow guided in the dry gas channel (13); as well as an at least partially circumferentially extending seal (96) fixedly connected to the membrane (9), the at least partially circumferentially extending seal (96) comprising a flow channel sealing section (961) disposed along a circumferential edge of a moisture transfer surface (90) of the membrane (9) at a first surface (971) of the membrane (9), wherein the other circumferential edge of the moisture transfer surface (90) at the first surface (971) does not have a flow channel sealing section (961), The flow channel sealing section (961) is in sealing contact with an adjacent frame plate (8, 8') to form one of a dry gas channel (13) and a wet gas channel (14) in an area defined by the membrane (9), the adjacent frame plate (8, 8'), another membrane (9) and the flow channel sealing section (961), and Each of the flow passage sealing sections (961) engages around a respective one of the circumferential edges of the moisture transfer surface (90).

2. The humidifier stack (1) according to claim 1, wherein: The plate stack is held together by tie rods (2), and The membrane (9) is secured exclusively by clamping.

3. A humidifier stack (1) according to any one of the preceding claims, wherein: The moisture transfer surface (90) of the membrane (9) has a rectangular shape, The flow channel sealing section (961) is arranged along two oppositely positioned circumferential edges of the moisture transfer surface (90) at the first surface (971) of the membrane (9), and Two other oppositely located circumferential edges of the moisture transfer surface (90) at the first surface (971) are free of flow channel sealing sections (961).

4. A humidifier stack (1) according to any one of the preceding claims, wherein: The other peripheral edge of the moisture transfer surface (90) of the membrane (9) comprises inflow and outflow cross sections (15, 16) into one of the dry gas channel (13) and the wet gas channel (14).

5. A humidifier stack (1) according to any one of the preceding claims, wherein: The at least partially circumferentially extending seal (96) is injection moulded or glued to the membrane (9).

6. A humidifier stack (1) according to any one of the preceding claims, wherein: Each flow channel sealing section (961) includes one or more sealing lips.

7. A humidifier stack (1) according to any one of the preceding claims, wherein: The thickness of the flow channel sealing section (961) is several times the thickness of the membrane (9).

8. A humidifier stack (1) according to any one of the preceding claims, wherein: The main flow direction in the wet gas channel (14) extends at a certain angle to the main flow direction in the dry gas channel (13), and The humidifier stack (1) further comprises another at least partially circumferentially extending seal (96) fixedly connected to the other membrane (9), the other at least partially circumferentially extending seal (96) comprising two other flow channel sealing segments (961), the other two flow channel sealing segments (961) being arranged along two circumferential edges of another moisture transfer surface (90) of the other membrane (9) at another first surface (971) of the other membrane (9), At the first surface (971) of the membrane (9), the two circumferential edges correspond to the other circumferential edges of the moisture transfer surface (90) of the membrane (9).

9. The humidifier stack (1) according to one of the preceding claims, wherein: Each frame plate (8, 8') comprises sheet steel.

10. A humidifier stack (1) according to any one of the preceding claims, wherein: It also comprises a membrane support element (12) interposed between the membrane (9) and the other membrane (9).

11. A humidifier stack (1) according to any one of the preceding claims, wherein: Each frame plate (8, 8') includes at least one supporting element (85) protruding away from the plate base plane, and the at least one supporting element (85) includes at least one flow opening (851) leading to one of the dry gas channel (13) and the wet gas channel (14) between the end of the supporting element (85) facing away from the plate base plane and the plate base plane, and the at least one supporting element (85) is supported at the second surface (972) of the membrane (9), the second surface facing away from the first surface (971) of the membrane (9) and having no flow channel sealing section (961), and a flow channel sealing section (961) is arranged in the area of ​​the circumferential edge of the moisture transfer surface (90) of the membrane (9) to introduce a sealing preload force into the flow channel sealing section (961).

12. The humidifier stack (1) according to claim 11, wherein: Each frame plate (8, 8') also comprises a support grid (89) interposed between and connecting the at least one support element (85).

13. The humidifier stack (1) according to claim 11, wherein: The at least one support element (85) includes a deep drawn dome portion (854) which is raised from the plane of the base plate and is distributed along the circumferential edge of the moisture transfer surface (90) of the film (9).

14. The humidifier stack (1) according to claim 11, wherein: The at least one supporting element (85) comprises a pressure bar (852) extending along and in regional contact with a respective one of the circumferential edges of the moisture transfer surface (90) of the membrane (9).

15. The humidifier stack (1) according to claim 14, wherein: The pressure rod (852) is a folded section of a respective frame plate (8, 8'), and The at least one flow opening (851) is arranged between spaced apart curved sections (853) of the respective one frame plate (8, 8'), which connect the plate base plane to the pressure rod (852).

16. The humidifier stack (1) according to claim 15, wherein: The spaced apart curved sections (853) are configured to be elastically resilient and to store a clamping force.

17. The humidifier stack (1) according to claim 14, wherein: The at least one support element (85) also includes one or more recesses (855) arranged in the at least one support element (85) and distributed along the length of the at least one support element (85), each of the one or more recesses (855) being arranged in the top surface of the pressure rod (852), protruding from the bottom surface of the pressure rod (852) and extending toward the board base plane.

18. The humidifier stack (1) according to any one of claims 11 to 17, further comprising a secondary seal (962) arranged at the second surface (972) along other circumferential edges, wherein the flow channel sealing section (961) is not arranged at the first surface (971) at the other circumferential edges, and the secondary seal (962) is in contact with at least one supporting element (85) of an adjacent frame plate (8, 8').

19. The humidifier stack (1) according to claim 18, wherein: The secondary seal (962) has a thickness smaller than that of the flow passage sealing section (961) and is flat.

20. A humidifier stack (1) according to any one of the preceding claims, wherein: The plate stack further comprises a supply and discharge channel (11) which extends in the stacking direction and is in fluid communication with the dry gas channel (13) and the wet gas channel (14).

21. The humidifier stack (1) according to claim 20, wherein: The supply and discharge channel (11) comprises: a first supply passage (11) connected to the inlet side of the drying gas passage (13) as a drying gas supply passage; a second supply channel (11) connected to the inlet side of the humidified gas channel (14) as a humidified gas supply channel; a first exhaust passage (11) connected to the outlet side of the dry gas passage (13) as a dry gas exhaust passage; and A second exhaust passage (11) is connected to the outlet side of the moist gas passage (14) as a moist gas exhaust passage.

22. A humidifier stack (1) according to claim 20 or 21, wherein: The supply and discharge channels (11) are formed by corresponding flow cavities (81, 82, 83, 84, 91, 92, 93, 94) in the stacked frame plates (8, 8') and the membrane (9).

23. A humidifier stack (1) according to claim 22, further comprising a flow cavity seal (95) which is fixedly connected to a region of the flow cavity (91, 92, 93, 94) externally surrounding the membrane (9), the flow cavity seal (95) sealing in both directions relative to the frame plate (8, 8'), in, The flow cavity seal (95) is injection moulded or glued to the membrane (9).

24. The humidifier stack (1) according to claim 23, wherein: Each of the flow cavity seal (95) and the at least partially circumferentially extending seal (96) comprises: a left stopper portion (952); right stopper portion (953); a middle raised portion (951) interposed between the left stopper portion (952) and the right stopper portion (953), the middle raised portion (951) having a height higher than the heights of the left stopper portion (952) and the right stopper portion (953); and At least one cavity (954) is interposed between the intermediate raised portion (951) and each of the left stopper portion (952) and the right stopper portion (953), extending through a top surface or a bottom surface of a corresponding one of the flow cavity seal (95) and the at least partially circumferentially extending seal (96).

25. A humidifier stack (1) according to any one of the preceding claims, further comprising at least one compression limiting element (86), which is inserted between the frame plates (8, 8'), the at least one compression limiting element (86) presetting a minimum distance between the frame plates (8, 8') and thereby defining the compression of the at least partially circumferentially extending seal (96) in the stacking direction, and the compression limiting element (86) is formed at the first of the frame plates (8, 8') and contacts the second of the frame plates (8, 8').

26. A humidifier device (10) comprising a humidifier stack (1) according to any one of the preceding claims, in, The humidifier stack (1) is sandwiched between two end plates (4, 5), at least one of the two end plates (4, 5) includes any one or any combination of the following: a supply connector (41) for a dry fluid flow, a supply connector (42) for a wet fluid flow, an exhaust connector (51) for a dry fluid flow and an exhaust connector (52) for a wet fluid flow, the supply connector (41) for a dry fluid flow and the exhaust connector (51) for a dry fluid flow are fluidically connected to a dry gas channel (13) of the humidifier stack (1), and the supply connector (42) for a wet fluid flow and the exhaust connector (52) for a wet fluid flow are fluidically connected to a wet gas channel (14) of the humidifier stack (1).

27. A humidifier device (10), comprising: A housing (100) comprising a supply connector (41) for a dry fluid flow, a supply connector (42) for a wet fluid flow, a discharge connector (51) for a dry fluid flow and a discharge connector (52) for a wet fluid flow; and A humidifier stack (1) according to any one of claims 1 to 25 and arranged in the housing (100), a supply connector (41) for a dry fluid flow and a discharge connector (51) for a dry fluid flow being fluidically connected to a dry gas channel (13) of the humidifier stack (1), and a supply connector (42) for a wet fluid flow and a discharge connector (52) for a wet fluid flow being fluidically connected to a wet gas channel (14) of the humidifier stack (1).

Images