Humidifier, method for producing such humidifier, and fuel cell system having such humidifier

Abstract

The invention relates to a humidifier (1) for humidifying a dry cathode intake gas (2) by means of a moistened cathode exhaust gas (3), comprising a housing (4) and a membrane stack (5) consisting of a plurality of membranes (7) which are arranged one behind the other in a stacking direction (6). It is essential for the invention that the humidifier (1) has two end plates (11a, 11b) and support elements (12a, 12b), which are arranged in each case on a longitudinal side (8a, 8b) of the membrane stack (5) through which the flow can flow and are fastened to the two end plates (11a, 11b). The invention relates in particular to a method for producing a humidifier, and in particular to a fuel cell system having at least one humidifier.

Description

Technical Field

[0001] The invention relates to a humidifier according to the preamble of claim 1. The invention relates in particular to a method for producing such a humidifier and also in particular to a fuel cell system having at least one such humidifier. Background Art

[0002] The document DE 10 2021 207 424 A1 discusses the kind of humidifier mentioned at the beginning. The humidifier is arranged to humidify the dry cathode intake air by moistening the cathode exhaust gas in the fuel cell system, and is characterized by having a housing and a membrane stack inserted into the housing, the membrane stack having a plurality of membranes that are arranged one after another in the stacking direction. The membrane stack also has a plurality of longitudinal sides through which air can flow and two end sides that cannot flow and are opposite to each other. The humidifier is also equipped with two so-called sealing frames, which are arranged on the two longitudinal sides of the membrane stack opposite to each other and are connected to the two first air pipes of the housing that guide the air in a sealed manner in terms of flow technology, so that the dry cathode intake air can flow through the membrane stack along the first flow path. The housing also has two second air pipes for guiding air, which are assigned to the other two longitudinal sides of the membrane stack opposite to each other, so that the moist cathode exhaust gas can be guided through the membrane stack along the second flow path. These membranes alternately limit the intake channel through which the cathode intake air can flow and the exhaust channel through which the cathode exhaust gas can flow. The membrane is designed to be air-tight and water vapor-permeable, so that cathode feed gas and cathode exhaust gas flow through the membrane stack without mixing and water can be transferred from the cathode exhaust gas through the membrane to the cathode feed gas. This makes it possible to regulate the addition of water to the dry cathode feed gas relatively reliably.

[0003] A disadvantage of this known humidifier is that during operation of the humidifier, the cathode inlet gas and the cathode exhaust gas are guided through the inlet and exhaust channels of the membrane stack at a pressure that is elevated, for example, relative to the atmosphere surrounding the humidifier. The membrane stack is therefore subjected to a continuous pressure load, which manifests itself in particular in the form of a longitudinal expansion of the membrane stack, for example due to bulging of the inlet and exhaust channels. The longitudinal expansion of the membrane stack in the stacking direction is essentially limited only by the mechanical bonding between the membranes, so that, in particular after a certain operating time, increasingly severe delamination can occur in the region of the membranes of the membrane stack. This can lead in particular to leaks between the channels, which can lead to uncontrolled mixing of cathode exhaust gas and cathode inlet gas and power losses, which are undesirable. Summary of the invention

[0004] The object of the present invention is therefore to provide an improved or at least a different embodiment for a humidifier. In particular, a method for producing such a humidifier and also in particular a fuel cell system having such a humidifier are proposed.

[0005] In the invention, this object is achieved in particular by the subject matter of the independent claims. Advantageous embodiments are the subject matter of the dependent claims and the description.

[0006] The present invention has recognized that compressive stresses occurring on the membrane stack during operation of the humidifier or the resulting longitudinal expansion of the membrane stack in the stacking direction can be prevented or at least significantly reduced by means of a support element, which mechanically protects against the compressive forces acting on the membrane stack during operation of the humidifier. The risk of delamination and leaks can thus be eliminated or at least significantly reduced.

[0007] Therefore, a humidifier for a fuel cell system is proposed, which is used to humidify dry cathode intake air by moist cathode exhaust gas, and the humidifier has a housing and a membrane stack, and the membrane stack is composed of a plurality of membranes that are arranged one after another in the stacking direction. The membrane stack has two first longitudinal sides that can flow and are opposite to each other, two second longitudinal sides that can flow and are opposite to each other, and two end sides that cannot flow and are opposite to each other. Here, the first longitudinal side and the second longitudinal side are oriented parallel to the stacking direction, and the end side is oriented transversely to the stacking direction. It is important that the humidifier has two end plates, which are respectively arranged on one end side, especially arranged in contact. In addition, it is important that the humidifier has a support element that is arranged to bear a force, especially a compressive force, that acts substantially along the stacking direction, and the support element is arranged in pairs on the first longitudinal side and / or the second longitudinal side and is also fastened to, especially only fastened to, the two end plates. Here, the support element and / or the end plate are preferably made of thermoplastics, such as polyamide (PA), polypropylene (PP) or polyethylene (PE).

[0008] The support element together with the end plate forms a stacking strap which wraps around the membrane stack, so to speak, like a belt, and which absorbs the compressive forces occurring in the membrane stack during operation of the humidifier, in particular acting in the stacking direction. The support element is therefore subjected to tensile loads. This can reduce the compressive stresses of the membrane stack occurring during operation of the humidifier and in particular reduce the longitudinal expansion of the membrane stack in the stacking direction, and achieve mechanical stabilization of the membrane stack. This has the advantage that damage to the membrane stack, in particular the aforementioned delamination of the membrane and / or detachment of the membrane stack from the end plate, can be prevented. The proposed humidifier is therefore relatively robust and has an improved product service life.

[0009] In particular, it can be provided that the membranes of the membrane stack are clamped against one another in the stacking direction by the support element. The membrane stack is thus compressed to a certain extent in the stacking direction and is prestressed, thereby counteracting the squeezing forces that occur during operation of the humidifier. However, if the components of the humidifier are geometrically designed adequately, i.e., for example, narrow tolerances are selected, clamping the membranes of the membrane stack using support elements is not absolutely necessary.

[0010] It can be expediently provided that the support element is respectively clamped or clipped to the end plate in a removable or non-removable manner. This allows, in particular, a quick and simple assembly of the support element by clamping or clipping the support element to the end plate, which can be carried out, for example, manually or automatically. In this case, the respectively designed clamping connection is designed to be removable or non-removable, removable so that the support element can be removed from the end plate if necessary, and non-removable so that a non-destructive removal of the support element is prevented.

[0011] Furthermore, it can be provided that the support element is clamped to the end plate in a removable or non-removable manner by means of a clamping or clipping connection, wherein the clamping or clipping connection is realized as a connection between the corresponding support plate and the end plate based on, in particular, only on a form fit or a form and force fit. In other words, the support element is fastened to the end plate by means of two or more clamping or clipping connections. In particular, this makes it possible to dispense with fastening screws or the like, so that the proposed humidifier can be manufactured in an overall cost-effective manner.

[0012] It can be expediently provided that the support elements are each formed by a plate parallel to the stacking direction or have such a plate. In this case, the plates each have clamping edge regions which are opposite each other in the stacking direction and are arranged in such a way that the respective support element can be clamped and fixed to the two end plates via its clamping edge regions in a removable or non-removable manner. Thus, the support elements can each be clamped and fixed or locked to the assembly consisting of the membrane stack and the end plates, wherein the clamping function is provided by the clamping edge regions of the plates of the support element.

[0013] The clamping region of a plate is expediently designed as an integrated component of the plate. In other words, the plate and the clamping region form an integral component. This component can be realized, for example, by producing the support element or the plate with the clamping region in the context of an injection molding or casting method, so that each component is integral. As a result, the plates can be provided relatively cost-effectively and in large quantities.

[0014] It can also be advantageously provided that the clamping edge region of a plate protrudes at least in sections and transversely to the stacking direction over the end plate. It is advantageous here that the end plate each has an outer surface that points away from the membrane stack, wherein the clamping edge region of the plate protrudes at least in sections and transversely to the stacking direction over the outer surface of the end plate and is supported at least in sections on the outer surface. This allows the assembly consisting of membrane stack and end plate to be gripped by means of the support element. This prevents the end plate and the membrane stack from being movable in the stacking direction in a form-fitting and / or force-fitting manner.

[0015] It can be suitably provided that the end plates each have an outer surface pointing away from the membrane stack. It is also provided that the clamping edge area each has at least one protrusion or is composed of at least one protrusion or a plurality of protrusions, wherein the protrusions of the plate each protrude above the outer surface of the end plate transversely to the stacking direction. In this provision, the protrusions of the plate are each supported on the outer surface of the end plate and / or cooperate with a complementarily configured mating protrusion or a complementarily configured groove of the corresponding end plate in order to achieve a clamping or clamping connection structure. It is conceivable that the protrusions each form a hook or the like and are hooked and locked on the outer surface of the end plate. The plate of the support element is thereby provided so that the support element is removably or non-removably clamped and fixed to the two end plates via its clamping edge area.

[0016] It can also be advantageously provided that the support elements are each formed by a plate extending parallel to the stacking direction or have such a plate, wherein the plates of the support elements are each penetrated by an opening through which flow can flow transversely to the stacking direction, in particular in the middle. During operation of the humidifier, dry cathode feed air flows through the openings of the plates, so that the openings of the support elements form so-called air channels.

[0017] It can also be conveniently provided that the plates each have a plate outer surface pointing away from the membrane stack, on which a sealing structure is provided, which completely surrounds the opening of the corresponding plate. Here, the sealing structure is respectively composed of a sealing channel provided for receiving a sealing device and a sealing device inserted into the sealing channel, and the sealing device is used to seal the opening of the corresponding plate relative to the housing of the humidifier. The sealing channel can be defined or formed, for example, between two parallel ribs arranged on the plate outer surface and adjacent to each other, and the sealing device is arranged at the ribs. Accordingly, the ribs can be manufactured cost-effectively and at the same time help to strengthen the corresponding plate. The sealing device can be realized, for example, by a sealing ring, a sealing belt or other suitable seals.

[0018] It can also be provided that the plates each have a plate inner surface pointing toward the membrane stack. An inner sealing structure can be provided on the plate inner surface, which completely surrounds the opening of the corresponding plate and can be used to seal the corresponding plate on the first longitudinal side and / or the second longitudinal side. As a result, a first gas flow, in particular cathode inlet gas or cathode exhaust gas, flows along a first flow path through the opening of the plate to the membrane stack, then passes through the membrane stack and flows downstream of the membrane stack through the opening of another plate, while a second gas flow, in particular cathode exhaust gas or cathode inlet gas, can flow through the membrane stack along a second flow path separated from the first flow path in an airtight manner.

[0019] It can be advantageously provided that the end plates are designed to be flow-proof. In other words, the end plates are designed to be airtight, for which purpose the end plates in particular do not have openings or through-holes which completely penetrate the respective end plate. This reliably prevents an undesired outflow of cathode inlet gas and / or cathode exhaust gas through the end sides of the membrane stack.

[0020] It can also be advantageously provided that the end plates and / or the supporting elements, ie in particular the plates thereof, are designed to be resistant to bending. That is, the end plates and / or the plates are resistant to mechanical loads and are strong against bending. This allows the membrane stack to be stabilized, ie the membrane stack has no or only little intrinsic mobility.

[0021] It can be expediently provided that the support elements are each formed by a plate extending parallel to the stacking direction or have such a plate, each having a plate outer surface pointing away from the membrane stack, wherein reinforcing ribs are arranged on the plate outer surfaces of the plates for reinforcing the corresponding plate. The reinforcing ribs can preferably be oriented parallel to the stacking direction and thus form longitudinal reinforcing ribs. Obviously, the reinforcing ribs can be oriented transversely to the stacking direction instead or in addition and thus form transverse reinforcing ribs. The mechanical load-bearing capacity of the plate, in particular its bending resistance, can be increased by corresponding reinforcing ribs. This allows for improved mechanical stability of the membrane stack.

[0022] It is also suitable to provide that the end plate and / or the supporting element, ie, in particular, the plate thereof, is made of a metal material, a plastic material or a composite material, thereby ensuring a higher bending stiffness and making the manufacturing cost of the end plate lower.

[0023] The proposed humidifier expediently has exactly two support elements which are arranged in pairs opposite each other on the first longitudinal side or on the second longitudinal side and are fastened to the two end plates.

[0024] Obviously, in addition to the two supporting elements mentioned above, the proposed humidifier can also advantageously have two further supporting elements, i.e. the humidifier has exactly four supporting elements in total. Here, the four supporting elements are respectively fastened to the two end plates and are arranged in pairs opposite each other on the first longitudinal side and the second longitudinal side. In particular, this can further improve the mechanical stability of the membrane stack and further improve the bearing of the compressive forces occurring in the membrane stack during operation of the humidifier, in particular acting in the stacking direction.

[0025] The support elements can expediently be realized as identical parts. The end plates can also be realized as identical parts.

[0026] According to another basic concept of the present invention, a method for manufacturing the above-mentioned humidifier is provided. In the scope of the proposed manufacturing method, according to the successive steps:

[0027] - Provide housing,

[0028] - providing a film stack consisting of a plurality of films following one another in a stacking direction,

[0029] - providing two end plates and arranging them, in particular arranging them in a contacting manner, on mutually opposite end sides of the membrane stack which are impassable for flow,

[0030] - compressing the assembly formed by the membrane stack and the end plates in the stacking direction,

[0031] Providing a supporting element and fastening it in each case to the two end plates, in particular clamping or clamping the two end plates.

[0032] This provides an assembly-friendly and at the same time cost-effective route for producing a humidifier. By compressing the assembly consisting of membrane stack and end plate and then clamping it with the support element, the membranes are clamped or held clamped relative to each other in the stacking direction. In a subsequent step, the assembly consisting of membrane stack, end plate and support element can be placed in a housing of the humidifier.

[0033] According to another basic concept of the present invention, a fuel cell system is provided, in particular a motor vehicle fuel cell system or a stationary fuel cell system, which has at least one or more humidifiers for humidifying dry cathode intake air by moist cathode exhaust gas, the humidifiers being constructed as described above or manufactured according to the manufacturing method described above. Thus, an advantageous fuel cell system having at least one humidifier with a relatively long service life is proposed. Therefore, the proposed fuel cell system can be operated maintenance-free for a relatively long time, which is desirable in the automotive field.

[0034] In summary, the present invention mainly relates to a humidifier for humidifying dry cathode intake air by moistening cathode exhaust gas, the humidifier comprising a housing and a membrane stack, the membrane stack being composed of a plurality of membranes arranged one after another in a stacking direction. The key to the present invention is that the humidifier has two end plates, which are respectively arranged on one end side of the membrane stack, and the humidifier has supporting elements, which are respectively arranged on the longitudinal side of the membrane stack through which flow can pass and are fastened to the two end plates. The present invention particularly relates to a method for manufacturing a humidifier, and also particularly relates to a fuel cell system having at least one humidifier.

[0035] Further important features and advantages of the invention can be gathered from the dependent claims, the drawings and the associated description with reference to the drawings.

[0036] It is to be understood that the features mentioned above and the features to be explained below can be used not only in the respectively proposed combination but also in other combinations or alone without exceeding the scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] BRIEF DESCRIPTION OF THE DRAWINGS Preferred embodiments of the invention are shown in the drawings and are explained in more detail in the following description, wherein the same reference numerals refer to identical or similar or functionally identical parts.

[0038] The figure schematically shows:

[0039] Figure 1 is a perspective view of a preferred embodiment of the humidifier of the present invention.

[0040] Figure 2 yes Figure 1 The humidifier part, press Figure 1 This is the top view of arrow II. DETAILED DESCRIPTION

[0041] Figure 1 A preferred embodiment of a humidifier for a fuel cell system (not shown) is shown, which is generally designated by reference numeral 1. The humidifier 1 is provided for humidifying a dry cathode inlet gas 2, which forms a first gas flow and is indicated schematically by arrows, by means of a moist cathode exhaust gas 3, which is also indicated schematically by arrows, of a second gas flow.

[0042] For this purpose, the humidifier 1 has a housing 4 , which is only schematically shown in sections, and a membrane stack 5 , which comprises a plurality of membranes arranged one behind the other in a stacking direction 6 , which for the sake of clarity is not shown. Figure 1 Only a few of the membranes are integrally marked with reference numeral 7. The membrane stack 5 can be completely inserted into the housing 4 along the stacking direction 6, and has first longitudinal side faces 8a, 8b opposite to each other, second longitudinal side faces 9a, 9b opposite to each other, and two end side faces 10a, 10b opposite to each other through which no flow passes. The first longitudinal side faces 8a, 8b and the second longitudinal side faces 9a, 9b are oriented parallel to the stacking direction 6 and are orthogonal to each other. The end side faces 10a, 10b are oriented transversely to the stacking direction 6, and together with the first longitudinal side faces 8a, 8b and the second longitudinal side faces 9a, 9b, form a cuboid. The membranes 7 delimit, in an alternating order, an intake channel through which the cathode intake gas 2 can flow and an exhaust channel through which the cathode exhaust gas 3 can flow. Here, the membrane 7 is designed to be air-tight and water vapor-permeable, so that in the operation of the humidifier 1, the first airflow formed by the cathode intake air 2 flows through the membrane stack 5 along the first flow path, and the second airflow formed by the cathode exhaust air 3 flows through the membrane stack 5 along the second flow path, and the first airflow and the second airflow do not mix during the flow. However, since water vapor can pass through the membrane 7, water can be transferred from the cathode exhaust air 3 to the cathode intake air 2.

[0043] from Figure 1As can be seen in FIG. 1 , the proposed humidifier 1 also has end plates 11a, 11b, which are arranged on the end sides 10a, 10b of the membrane stack 5. The two end plates 11a, 11b are designed to be flexurally rigid and for this purpose in particular have reinforcing ribs 11c, which respectively protrude from outer surfaces 16a, 16b of the end plates 11a, 11b pointing away from the membrane stack 5 (i.e. facing away from the membrane stack 5) and reinforce the respective end plates 11a, 11b.

[0044] from Figure 1 It can also be seen in the figure that the proposed humidifier 1 has two separate, identically designed support elements 12a, 12b. The support elements 12a, 12b are arranged in pairs on two first longitudinal sides 8a, 8b, transversely to the stacking direction 6, and are fastened to two end plates 11a, 11b. The support elements 12a, 12b are provided to absorb forces that act substantially in the stacking direction 6 during operation of the humidifier 1 and are caused in particular by compressive stresses of the membrane stack 5 and / or changes in the length of the membrane stack 5. The support elements 12a, 12b are each formed by a frame-shaped and flat plate 14a, 14b extending parallel to the stacking direction 6. The plates 14a, 14b of the support elements 12a, 12b each have clamping edge regions 15a, 15b, which are opposite in the stacking direction 6 and are provided to produce a clamping or clamping connection 13 between the corresponding plate 14a, 14b and the end plates 11a, 11b. Here, the clamping or clamping connection 13 is preferably designed to be removable or non-removable and is based only on form locking or only on form locking and force locking. In this way, the supporting elements 12a, 12b can be easily clamped and fixed on the end plates 11a and 11b and released again when necessary.

[0045] The plates 14a, 14b of the support elements 12a, 12b are respectively penetrated by an approximately rectangular central opening 18. Here, each opening 18 leads to a plate outer surface 19a, 19b of the corresponding plate 14a, 14b pointing away from the membrane stack 5 on the one hand, and to a plate inner surface 19c of the corresponding plate 14a, 14b on the other hand, so that air can flow through the support elements 12a, 12b through the corresponding opening 18. In addition, the plates 14a, 14b each have a sealing structure 21, which completely surrounds the corresponding opening 18 on the outside, through which the support elements 12a, 12b can be arranged in a sealed manner on the housing 4 of the humidifier 1. The sealing structure 21 each has a continuous sealing channel 22 for receiving a sealing device 23, which is used to seal the corresponding opening 18 relative to the housing 4. The support elements 12a and 12b also have a plurality of reinforcing ribs 25 on their plates 14a, 14b, which are provided for reinforcing the corresponding plates 14a, 14b. Here, the reinforcing ribs 25 protrude from the plate outer surfaces 19a, 19b of the corresponding plates 14a, 14b transversely to the stacking direction 6 and extend in their corresponding main extension directions along the stacking direction 6, so that they form longitudinal reinforcing ribs. It is understood that in other embodiments of the present invention not shown here, the supporting elements 12a, 12b can be implemented without reinforcing ribs, with longitudinal reinforcing ribs and / or with transverse reinforcing ribs extending transversely to the longitudinal reinforcing ribs without departing from the scope of the present invention.

[0046] exist Figure 2 , it is shown that the clamping edge regions 15a, 15b of the plates 14a, 14b have, by way of example, at least one protrusion 17a, 17b, respectively, or are formed by such a protrusion. The protrusions 17a, 17b protrude transversely to the stacking direction 6 onto the outer surfaces 16a, 16b of the end plates 11a, 11b and are clamped and fixed on the outer surfaces 16a, 16b, respectively, and are suitably matched with the mating protrusions 26a of the corresponding end plates 11a, 11b, respectively, to form a clamping or clamping connection 13.

Claims

1. A humidifier (1) for a fuel cell system, the humidifier being used to humidify dry cathode inlet gas (2) by moistening cathode exhaust gas (3), the humidifier comprising: a housing (4) and a membrane stack (5), the membrane stack (5) comprising a plurality of membranes (7) arranged one behind the other in a stacking direction (6), -in, The membrane stack (5) has two first longitudinal sides (8a, 8b) through which flow can pass and which are opposite to each other. wherein the membrane stack (5) has two second longitudinal sides (9a, 9b) through which flow can pass and which are located opposite one another, wherein the membrane stack (5) has two end sides (10a, 10b) which are not flow-throughable and are located opposite one another, wherein the first longitudinal side surface (8a, 8b) and the second longitudinal side surface (9a, 9b) are oriented parallel to the stacking direction (6), and the end side surfaces (10a, 10b) are oriented transversely to the stacking direction (6), It is characterized in that The humidifier (1) has two end plates (11a, 11b), each of which is arranged on an end side (10a, 10b). The humidifier (1) has support elements (12a, 12b) configured to bear forces acting essentially in the stacking direction (6), the support elements (12a, 12b) being arranged in pairs opposite to each other on the first longitudinal side (8a, 8b) and / or the second longitudinal side (9a, 9b) and being fixed to the two end plates (11a, 11b).

2. The humidifier (1) according to claim 1, It is characterized in that The films (7) are clamped to one another in the stacking direction (6) by means of supporting elements (12a, 12b).

3. A humidifier (1) according to claim 1 or 2, It is characterized in that The supporting elements (12a, 12b) are respectively clamped and fixed on the end plates (11a, 11b) in a detachable or non-detachable manner.

4. A humidifier (1) according to any one of the preceding claims, It is characterized in that - the supporting elements (12a, 12b) are respectively clamped and fixed on the end plates (11a, 11b) in a removable or non-removable manner via a clamping or holding connection structure (13), -in, The clamping or clamping connection structure (13) is based on a form fit between the corresponding support plate (12a, 12b) and the end plate (11a, 11b) or on a form fit and force fit between the corresponding support plate and the end plate.

5. Humidifier (1) according to one of the preceding claims, It is characterized in that the supporting elements (12a, 12b) are each formed by a plate (14a, 14b) extending parallel to the stacking direction (6) or each have a plate extending parallel to the stacking direction, wherein the plates (14a, 14b) each have clamping edge regions (15a, 15b) which are located opposite each other in the stacking direction (6), - wherein the clamping edge areas (15a, 15b) of the plates (14a, 14b) are arranged so that the corresponding support elements (12a, 12b) can be clamped and fixed to the end plates (11a, 11b) via their clamping edge areas (15a, 15b) in a detachable or non-detachable manner.

6. The humidifier (1) according to claim 5, It is characterized in that The clamping edge regions (15a, 15b) of the plates (14a, 14b) each protrude beyond the end plates (11a, 11b) at least in sections and transversely to the stacking direction (6).

7. The humidifier (1) according to claim 5 or 6, It is characterized in that the end plates (11a, 11b) each have an outer surface (16a, 16b) pointing away from the membrane stack (5), the clamping edge regions (15a, 15b) each have at least one projection (17a, 17b) or are formed by at least one projection (17a, 17b), wherein the projections (17a, 17b) of the plates (14a, 14b) protrude above the outer surfaces (16a, 16b) of the end plates (11a, 11b), respectively, transversely to the stacking direction (6), - wherein the protrusions (17a, 17b) of the plates (14a, 14b) are supported on the outer surface (16a, 16b) of the end plates (11a, 11b), respectively, and / or cooperate with the complementary configured mating protrusions (26a) of the corresponding end plates (11a, 11b) in order to achieve a clamping or clamping connection structure (13a, 13b), respectively.

8. Humidifier (1) according to one of the preceding claims, It is characterized in that the supporting elements (12a, 12b) are each composed of a plate (14a, 14b) extending parallel to the stacking direction (6) or each have a plate extending parallel to the stacking direction, - wherein the plates (14a, 14b) are each penetrated by an opening (18) through which flow can pass transversely to the stacking direction (6).

9. The humidifier (1) according to claim 8, It is characterized in that the plates (14a, 14b) each have a plate outer surface (19a, 19b) pointing away from the membrane stack (5) and into which corresponding openings (18) open, - the plates (14a, 14b) each have a sealing structure (21) which completely surrounds the corresponding opening (18), -in, The sealing structures (21) each have a sealing channel (22) for receiving a sealing device (23) and a sealing device (23) inserted into the sealing channel (22), wherein the sealing device is used to seal the corresponding opening (18) relative to the housing (4) of the humidifier (1).

10. The humidifier (1) according to claim 9, It is characterized in that The plates (14a, 14b) each have a reinforcing rib (25) for reinforcing the corresponding plate (14a, 14b).

11. Humidifier (1) according to one of the preceding claims, It is characterized in that The end plates (11a, 11b) and / or the support elements (12a, 12b) have at least one of the following features: - it is designed to be resistant to bending, -It is made of metal material, plastic material or composite material.

12. A method for producing a humidifier (1), in particular a humidifier (1) according to one of the preceding claims, within the scope of the method: - providing a housing (4), - providing a film stack (5) comprising a plurality of films (7) following one another in a stacking direction (6), - providing two end plates (11a, 11b) and arranging them on mutually opposite, non-flowing end sides (10a, 10b) of the membrane stack (5), - compressing the assembly formed by the membrane stack (5) and the end plates (11a, 11b) in the stacking direction (6), - Two supporting elements (12a, 12b) are provided and fastened to the two end plates (11a, 11b), respectively, in particular clamped or clamped to the two end plates.

13. A fuel cell system, in particular a motor vehicle fuel cell system or a stationary fuel cell system, comprising at least one humidifier (1), which is designed according to one of the device claims 1 to 11 or is produced according to method claim 12.

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