Media insert for a plate, which is to be protected from corrosion and / or erosion, of a fuel cell arrangement, and fuel cell arrangement having such a media insert
Patent Information
- Application Number
- EP2023723837
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-05-19
- Filing Date
- 2023-04-26
- Publication Date
- 2025-03-26
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
Fuel cell arrangements face challenges in protecting metallic and plastic plates from corrosion and erosion due to operating media, which can lead to material washout and damage to the fuel cell stack, and existing solutions are complex and difficult to handle during production.
A media insert made of elastic material with sleeve-shaped areas and sealing areas is used to seal operating media guide channels in fuel cell plates, providing a simple and reliable protection against corrosion and erosion by being easily integrated into the plate without additional fastening aids, using silicone or EPDM material for effective sealing and protection.
The media insert ensures easy assembly and complete protection of operating media guide channels, preventing corrosion and erosion, and provides a secure seal on both sides of the plate, effectively safeguarding the fuel cell stack from damage, while allowing for easy handling and production.
Smart Images
Figure 1.1
Abstract
Description
[0001] Media insert for a plate of a fuel cell assembly to be protected against corrosion and / or erosion, and fuel cell assembly with such a media insert
[0002] The present invention relates to a media insert for sealing at least one plate of a fuel cell arrangement to be protected against corrosion and / or erosion, which plate contains at least one first operating media guide channel and a second operating media guide channel for a respective operating medium for operating the fuel cell arrangement, as well as to a fuel cell arrangement with at least one fuel cell stack, a media connection arrangement for operating media and a metallic plate arranged therebetween with such a media insert.
[0003] Fuel cell arrangements typically comprise one or more fuel cell stacks in which several fuel cells are electrically connected in series, arranged one above the other or side by side (depending on the stack's spatial orientation). Fuel cells generate electrical energy from hydrogen as an anode operating gas and oxygen as a cathode operating gas. They also usually require a coolant, such as water or a glycol / water mixture, to cool the fuel cells and dissipate the generated heat. These fuel cell media must be supplied to the fuel cells and then removed again after flowing through the fuel cells.
[0004] In known fuel cell systems, supply and discharge lines for anode operating gas (e.g., hydrogen), cathode operating gas (oxygen or air), and coolant are fed to a fuel cell stack individually or collectively, e.g., by means of a plate-like arrangement, by means of a media connection arrangement. The individual fuel cells within a fuel cell stack are combined, e.g., clamped together, into a stack using stable plates. In one variant, metallic current collector plates, for example, are located between the two terminal fuel cells (edge cells) and the outer end plates of the fuel cell stack. These plates have connections for discharging the current generated by the fuel cell arrangement. Alternatively, the current collector plate and end plate can also be combined, i.e.,The end plates are at least partially made of a metallic material and serve both to collect current and to brace the fuel cell stack. The operating media supplied or discharged by the media connection arrangement must be routed through such an end plate or current collector plate to supply the fuel cell stack. For this purpose, such a metallic plate usually has several openings through which the respective operating media, such as hydrogen, air, and coolant, can be supplied or discharged to supply the fuel cell stack.
[0005] Such operating media guide channels in the form of such openings in a metallic plate, such as the end plate of a fuel cell stack, should be protected from corrosion and / or erosion (material removal) that may be caused by the respective operating medium. In this case, simple handling of a sealing device for one or more of the operating media guide channels during manufacture of the fuel cell assembly is desirable, as is reliable sealing against the operating media to protect the metallic plate from corrosion and / or erosion. Potential corrosion and / or erosion can occur not only in metallic plates, but also in plates made of plastic.Material erosion can, for example, result from leaching caused by the respective operating medium, which in turn can be harmful to the fuel cell stack if leached materials accumulate there.
[0006] JP 4775534 B2 relates to a fuel cell assembly capable of preventing corrosion of a terminal plate. A fuel cell consists of a switch-on plate 5, a terminal plate 7, an insulating plate 8, and an end plate 9, which are laminated in this order, and a supply channel 20 penetrating these four plates (5, 7, 8, 9) in a lamination direction. A sealing element 40, which acts as a media insert and seals at least one gap between the switch-on plate 5 and the terminal plate 7, is provided such that it covers a circumferential surface of the supply channel 20 of the terminal plate 7. The fuel cell assembly has the disadvantage that not all of the provided plates are protected against possible corrosion, and the sealing element must be arranged in the plate assembly in a comparatively complicated and complex manner.It is an object of the present invention to provide a media insert for at least one plate of a fuel cell arrangement to be protected from corrosion and / or erosion, as well as a fuel cell arrangement, which on the one hand enables simple handling during production of the fuel cell arrangement and on the other hand also enables reliable sealing of the operating media guide channels of the plate with respect to the operating media for protection against corrosion and / or erosion.
[0007] The invention relates to a media insert for at least one plate of a fuel cell assembly that is to be protected against corrosion and / or erosion, as well as a fuel cell assembly according to the appended patent claims. Advantageous embodiments and further developments are specified in the dependent claims.
[0008] According to a first aspect, the invention relates to a media insert for at least one plate of a fuel cell assembly to be protected against corrosion and / or erosion, said plate containing at least one first operating media guide channel and a second operating media guide channel for a respective operating media guide for operating the fuel cell assembly. The media insert has a first sleeve-shaped region made of elastic material for arrangement and sealing of the operating media in the first operating media guide channel and a second sleeve-shaped region made of elastic material for arrangement and sealing of the operating media in the second operating media guide channel of the plate, as well as a connecting region that connects the first and second sleeve-shaped regions and is formed flat between the first sleeve-shaped region and second sleeve-shaped region for bearing against a surface of the plate.Each of the first and second sleeve-shaped regions has a front-side first sealing region made of elastic material, which is designed to seal a respective operating media guide at a first parting line between the plate and a media connection arrangement, and a second sealing region made of elastic material, opposite the first sealing region, which is designed to seal a respective operating media guide at a second parting line, opposite the first parting line, between the plate and a fuel cell stack of the fuel cell arrangement.
[0009] According to a further aspect, the invention relates to a fuel cell arrangement which has at least one fuel cell stack, a media connection arrangement with connections for supplying the fuel cell arrangement with operating media for operating the fuel cell arrangement, and at least one plate to be protected against corrosion and / or erosion, which plate is arranged between the fuel cell stack and the media connection arrangement and contains at least one first operating media guide channel and a second operating media guide channel for a respective operating media guide for operating the fuel cell arrangement.Furthermore, the fuel cell arrangement has a media insert with a first sleeve-shaped region made of elastic material, which is arranged in the first operating media guide channel of the plate for sealing the operating media, a second sleeve-shaped region made of elastic material, which is arranged in the second operating media guide channel of the plate for sealing the operating media, and a connecting region which connects the first and second sleeve-shaped regions and is flat between the first sleeve-shaped region and second sleeve-shaped region and rests against a surface of the plate.Each of the first and second sleeve-shaped regions has a front-side first sealing region made of elastic material, which seals the respective operating media guide at a first parting line between the plate and the media connection arrangement, and a second sealing region made of elastic material, opposite the first sealing region, which seals the respective operating media guide at a second parting line between the plate and the fuel cell stack (in particular an edge plate of the fuel cell stack).
[0010] The media insert and the fuel cell assembly according to the invention enable simple assembly and thus easy handling during manufacture of the fuel cell assembly, while simultaneously reliably and completely protecting and sealing the operating media guide channels of the plate from the operating media to protect against corrosion and / or erosion, since the sleeve-shaped regions extend completely through the operating media guide channels. Furthermore, not only is the plate advantageously protected against corrosion and / or erosion, and thus the fuel cell stack against possible damage, but a seal is also created simultaneously, arranged and attached to both sides of the plate, which can seal the joints on both sides.Advantageously, the media insert according to the invention can be used to create a protective cover for the operating media guide channels and seal at least two of the operating media, such as hydrogen and air, with just one media insert. At the same time, a simple seal integrated into the media insert is achieved at the joints on both sides. For example, a media insert is provided that can be manually pressed into the end plate without separate fastening aids (such as screws or similar) and, due to its geometric shape, remains in a fixed position relative to and within the plate. Thanks to the first and second sealing areas made of elastic material on both sides, the media insert can simultaneously function as a seal on both sides of the plate, for example, against the environment.
[0011] According to one embodiment, the plate is designed as an end plate of the fuel cell assembly. This offers the advantage of a simple structure, as well as easy handling and manufacture of a fuel cell assembly and its sealing of the operating media from the environment, while simultaneously protecting the end plate from corrosion and / or erosion in the channels for the operating media.
[0012] 15
[0013] In one embodiment, the plate is formed as a metallic plate. However, it can also be formed at least partially from plastic. The invention is fundamentally suitable for any type of corrosion-prone or erosive plate used in a fuel cell arrangement of the type described.
[0014] According to one embodiment, the first sealing area is formed by a sealing flange, and the second sealing area is formed by at least a portion of the connecting area. This achieves a simple seal at the separating joints on both sides, integrated into the media insert.
[0015] According to one embodiment, the media insert further comprises a third sleeve-shaped region made of elastic material for arrangement and for sealing the operating media in a third operating media guide channel of the plate 30, wherein the connecting region comprises the first, second and third sleeve-shaped
[0016] region and is formed flat between the first, second, and third sleeve-shaped regions for contact with the surface of the plate, and each of the first, second, and third sleeve-shaped regions has the first sealing region and the second sealing region. In this way, a protective cover for the operating media guide channels and a seal for all three operating media, such as hydrogen, air, and coolant, can be produced with only one media insert. According to one embodiment, the elastic material comprises at least one silicone and / or EPDM material. Such a material has advantageous properties with regard to handling, assembly, sealing properties, and corrosion and erosion protection.
[0017] According to one embodiment, the first operating media guide channel and / or the second operating media guide channel are designed to guide anode operating gas or cathode operating gas for the fuel cell assembly. The third operating media guide channel is designed, in particular, to guide coolant for the fuel cell assembly.
[0018] According to one embodiment, the media insert is arranged in the plate such that the elastic material of at least one of the first, second, and third sleeve-shaped regions is stretched and subjected to tensile stress between the first and second sealing regions. This allows a defined, tight fit to be achieved, which, for example, counteracts flexion movements in turbulent flows.
[0019] According to one embodiment, the expansion of the elastic material is caused by an overlap of the first sealing area of the media insert with an end wall of the corresponding operating media guide channel of the plate, which is compensated by the expansion in the final arrangement of the media insert in the plate.
[0020] According to one embodiment, the plate has at least one geometric shape on at least one of the first, second, and third operating media guide channels, by means of which the media insert is held in a fixed position in the plate. The at least one geometric shape has at least one elevation, depression, and / or undercut. The at least one elevation can be formed as one or more steps, and the at least one depression can be formed as one or more grooves.
[0021] According to one embodiment, the at least one geometric shape is configured such that at least one of the first sealing region and the second sealing region is compressed in a manner defined by the geometric shape. In particular, the media insert is configured such that it is held in a fixed position in the plate without a fastening means separate from the plate, such as a screw or adhesive. Secure fastening in the plate is possible in particular by the at least one geometric shape, which can be of various configurations as described.
[0022] According to one embodiment, at least one of the first, second and third sleeve-shaped regions of the media insert has at least one cross-sectional change along its longitudinal extent.
[0023] According to one embodiment, at least one of the first sealing region and the second sealing region comprises a first sealing device, such as a first sealing lip, and a second sealing device, such as a second sealing lip, which is provided redundantly to the first sealing device and assumes a sealing function in the event of a faulty first sealing device. Thus, a so-called cold redundancy in the seal can be created.
[0024] According to one embodiment, the media insert in at least one of the first, second, and third sleeve-shaped regions has an outer dimension, in particular an outer diameter, which, with an offset, is smaller than an inner dimension, in particular an inner diameter, of the corresponding first, second, or third operating media guide channel of the plate. By providing such an offset, greater ease of assembly can be achieved while reducing friction during assembly. Furthermore, manufacturing tolerances can also be compensated.
[0025] According to one embodiment, at least one of the first sealing region and the second sealing region is designed according to the principle of self-reinforcing. For example, a respective sealing device is provided whose sealing effect is amplified as a result of the pressure exerted by the respective operating medium. For example, a sealing ring is pressed against the plate or the fuel cell stack. The sealing effect of the sealing ring can be further amplified by the pressure inside the respective channel, exerted by the corresponding pressurized operating medium.
[0026] The invention is described in more detail below with reference to drawings. The drawings are merely exemplary. They are schematic, not to scale, and each show only the features essential to understanding the present invention. It is understood that further features, as are familiar to a person skilled in the art, may be present. In the drawings, like reference numerals designate like or corresponding elements. They show:
[0027] Fig. 1 shows a fuel cell assembly and a media insert according to an embodiment of the invention in a schematic exploded view; Fig. 2 shows a plan view of an embodiment of a fuel cell assembly according to Fig. 1, with a view of the media connection assembly;
[0028] Fig. 3 is a sectional view through an embodiment of a fuel cell arrangement according to Fig. 1 along the section line AA according to Fig. 2;
[0029] Fig. 4 is a detailed view of an embodiment of a fuel cell arrangement according to Fig. 1 in a section B according to Fig. 3.
[0030] Fig. 1 shows a fuel cell arrangement according to an embodiment of the invention in a schematic exploded view. The fuel cell arrangement 1 has at least one fuel cell stack 5, in which individual fuel cells (not shown) are combined to form a stack. This can be done in various ways in a known manner. For example, the fuel cell stack has 50 or more fuel cells. Each fuel cell of the fuel cell stack 50 has, for example, a membrane electrode
[0031] Arrangement (MEA), an anode flow field plate and a cathode flow field plate of known type, which serve to supply the respective fuel cells with anode and cathode operating gas, such as hydrogen and air, and to guide them within the fuel cell stack 5.
[0032] The fuel cell assembly 1 is bounded on both sides by end plates 4 and 6, which are clamped together, for example, using tie rods (not shown). The end plate 4 is an end plate with openings for operating media, as explained in more detail below, while the end plate 6 is an end plate without openings. Connections (not shown) on the end plates 4, 6 or on current collector plates adjacent to the end plates 4, 6 serve to take power from the fuel cell stack 5. The end plate 6 can be arranged on the fuel cell stack 5 using the respective rear seals 7.
[0033] The fuel cell assembly further comprises a media connection assembly 3 with connections 31-36 for supplying the fuel cell assembly 1 with operating media for operating the fuel cell assembly 1. The media connection assembly is designed, for example, as a so-called media connection plate or media adapter plate, which in the broader sense does not necessarily have to be plate-shaped, but essentially combines some of the connections required for operation and some of the peripheral equipment of the fuel cell assembly 1 in a common assembly. As such, the media connection assembly 3 is, in particular, an element or component, in particular plate-like, on which connections for supplying and / or removing operating media of the fuel cell assembly 1 are provided. For example, the media connection assembly 3 and the end plate 4 are screwed together (not shown).
[0034] The media connection arrangement 3 shown here has, among the number of connections 31 to 36, in particular two anode operating gas connections (e.g., for supply and outlet), two cathode operating gas connections (e.g., for supply and outlet), and two coolant connections (e.g., for supply and outlet). The connections 31 to 36 can, in principle, be used in different ways for the respective operating media, without requiring a specific geometric arrangement or distribution. The media connection arrangement 3 has a flat base body with opposing flat surfaces 37 and is typically made of metal or plastic.
[0035] During operation of the fuel cell arrangement 1, fresh anode operating gas, for example hydrogen, is fed from a (not shown) anode operating gas source through one of the connections 31-36 to the corresponding opposite connection 51-56 of the fuel cell stack 5. After being used up in the fuel cell stack 5, the gas flows, for example, from connection 55 or 56 (hidden in Fig. 1 ) to connection 35 or 36, where it leaves the media connection arrangement 3. A similar operating gas flow takes place via the corresponding remaining connections 31-36 and 51-56 with regard to the cathode operating gas (e.g. air) and with regard to the coolant, for example cooling water. The end plate 4 is provided between the media connection arrangement 3 and the fuel cell stack 5. This has the operating media guide channels 41 to 46, which correspond to the connections 31-36 of the media connection arrangement 3 andThe connections 51-56 of the fuel cell stack 5 are assigned and aligned accordingly in position and arrangement. The operating medium guide channels 41-46 each serve to guide a respective operating medium for operating the fuel cell arrangement 1, thus in the present example, the guidance or passage of anode operating gas, cathode operating gas, and coolant.
[0036] It should be noted that the described operating medium connections and channels are only examples in terms of shape, number and arrangement with regard to the median connection arrangement 3, end plate 4 and fuel cell stack 5 as well as with regard to the flow direction of the respective operating medium and can also have other geometric shapes (e.g. not circular), number and arrangement as well as flow directions. For example, under certain circumstances, depending on the area of application and power output, a coolant connection can be dispensed with and / or external air cooling can be used. Individual operating media can also be supplied in a different way than that shown in the fuel cell arrangement 1, for example via respective individual connections outside the media connection arrangement 3. Such connection and line types for operating media and those shown in Figure 1 are known to those skilled in the art in various ways.
[0037] The operating medium guide channels 41-46 (hereinafter referred to as channels), which are designed here as openings or perforations in the end plate 4, should be protected from any corrosion and / or erosion caused by the respective operating medium during the operation of the fuel cell assembly over time. In principle, corrosion and / or erosion can occur in varying degrees depending on the material properties and / or composition of the plate 4 and the respective operating medium (e.g., properties, composition, pressure).In this case, on the one hand, simple handling of a sealing device to be provided for one or more of the operating media guide channels during manufacture of the fuel cell arrangement 1 is desirable, and on the other hand, reliable sealing of the inner surfaces of the channels with respect to the operating media and reliable sealing at the joints of the respective joints to protect the plate against corrosion and / or erosion. For this purpose, the present invention provides a media insert made of elastic material, which in the present exemplary embodiment is designed in two ways, namely in the form of a media insert 101 for the channels 41-43 and a media insert 102 for the channels 44-46. The media inserts 101 and 102 are essentially the same, differing only in the respective distance between the sleeve-shaped regions 11, 12, 13.Thus, in the media insert 101, the sleeve-shaped regions 11, 12 are arranged at a shorter distance from one another, corresponding to the channels 41, 42 (Fig. 1), whereas in the media insert 102, the sleeve-shaped regions 12, 13 are arranged at a shorter distance from one another, corresponding to the channels 45, 46 (Fig. 3). This distance does not play a significant role in the function of the media inserts, but only serves to adapt to the arrangement and spacing of the channels 41-46 from one another, so that in the following reference is made only to one of the media inserts 101, 102, and the same applies to the other media insert. In particular, the properties of the sleeve-shaped regions 11, 12, 13 and the connecting region 15, as well as the sealing regions 21, 22, are the same, as explained in more detail below with reference to Figures 3 and 4.In the present exemplary embodiment, a media insert with three sleeve-shaped regions 11, 12, 13 is described for the exemplary operating media hydrogen, air, and coolant. As described above, more or fewer connections for operating media of the fuel cell assembly 1 can also be provided. Accordingly, the number of sleeve-shaped regions can also vary. For example, a media insert has only two sleeve-shaped regions, such as 11 and 13, e.g., for the operating media hydrogen and air, which are connected to one another via the connecting region 15.
[0038] In the following, a structure and function of a media insert according to the invention in an embodiment of a fuel cell arrangement of the invention are described in more detail with reference to the embodiments of Figures 1 to 3:
[0039] The media insert 101, 102 has a first sleeve-shaped region 11, which is arranged in the channel 41 or 44 of the end plate 4, a second sleeve-shaped region 13, which is arranged in the channel 43 or 46 of the end plate 4, and a third sleeve-shaped region 12, which is arranged in the channel 42 or 45 of the end plate 4. The sleeve-shaped regions 11, 12, 13 are each made of an elastic material, such as silicone and / or EPDM (well-known abbreviation for ethylene-propylene-diene (monomer) rubber), and serve to seal the respective inner surfaces of the channel against the operating media (i.e., sealing them against the operating media that are conducted in the respective channel) in order to prevent corrosion and / or erosion. For example, corrosion can occur if these or the plate are metallic. Metallic means that the plate or the respective channel inner surfaces are at least partially made of a metallic material.Potential corrosion and / or erosion can occur not only in metal plates, but also in plates made of plastic. Material erosion can, for example, result from leaching caused by the respective operating medium, which in turn can be harmful to the fuel cell stack if leached materials accumulate there.
[0040] The sleeve-shaped regions 11, 12, 13 are connected to one another via a connecting region 15, which can also be made of silicone and / or EPDM. The connecting region 15 is arranged between the regions 11, 12 and 12, 13. And in these sections, at least in some areas, it is flat and rests against a surface 48 of the end plate 4. Thus, a flat or compact arrangement of the media insert 101, 102 and the end plate 4 is possible without the media insert 101, 102 contributing significantly to increasing the thickness of the fuel cell arrangement 1. The media insert 101, 102 is inserted, for example, as an integrated component from one side of the end plate 4 into the respective channels 41-46 and, due to its elasticity and shape, as described in more detail below, is arranged and secured in the end plate without additional fastening means separate from the end plate.
[0041] Each of the sleeve-shaped regions 11 to 13 has a first sealing region 21 on the end face, which seals the respective operating media guide at a first parting line 81 between the end plate 4 and the media connection arrangement 3, and a second sealing region 22 opposite the first sealing region 21, which seals the respective operating media guide at a second parting line 82 between the end plate 4 and the fuel cell stack 5. Both sealing regions 21, 22 are made of elastic material, for example, silicone and / or EPDM. According to the illustrated embodiment, the first sealing region 21 is formed by a sealing flange 25, which bears against a facing surface 37 of the media connection arrangement 3. The sealing flange 25 can, for example, be annular and have a larger diameter and outer circumference than the adjacent sleeve-shaped region 11, 12, or 13.
[0042] According to one embodiment, the sealing flange 25 is such that it corresponds to a geometric shape in the end plate at the corresponding channel or
[0043] breakthrough is adapted. For example, at least one geometric formation 47 is provided in the respective channel (shown as an example in the channel 44 according to Fig. 4), by means of which the media insert 101, 102 is held in a fixed position in the end plate 4. In the present exemplary embodiment, the geometric formation 47 is designed as one or more depressions, here a groove, in which the sealing flange 25 is arranged. However, alternatively or additionally, other geometric shapes are also possible, such as one or more elevations (e.g. steps) and / or undercuts which, like the groove 47, support fixing of the media insert in the respective channel. As shown in more detail in Fig. 3 and Fig. 4, the at least one geometric formation 47, here in the form of a depression, is designed such that at least a part of the sealing flange 25 is compressed in a manner defined by the geometric formation 47.The sealing function is promoted and defined by defined compression. In the illustrated embodiment, compression occurs in a pressure zone DR. A defined compression of the sealing regions 21, 22 can be produced, for example, by respective tie rods (not shown), with which the end plates 4, 6 of the fuel cell arrangement 1 are clamped together. The same applies analogously to the second sealing region 22, which in the present embodiment is formed by at least a section of the connecting region 15, which rests on the one hand against a surface 58 of the fuel cell stack 5 and on the other hand against a surface 48 of the end plate 4. The surface 58 of the fuel cell stack is formed, for example, by an edge plate of the fuel cell stack 5 (not shown).Such an edge plate seals off the outermost fuel cell (edge cell) of the fuel cell stack 5 to the outside (here on the side of the end plate 4). An edge plate has a flow channel structure for a cathode or anode flow field on its surface facing inward into the fuel cell stack 5. Here, too, one or more geometric shapes 47 can be provided according to one or more of the described types, which support the fixation of the media insert to the end plate 4. Likewise, the elastic material in the sealing area 22 is compressed in a pressure zone DR to achieve improved sealing and improved seating in the end plate 4.
[0044] As further illustrated in Figures 3 and 4, the media insert is arranged in the end plate 4 such that the elastic material of the respective first, second, or third sleeve-shaped region between the first and second sealing regions 21, 22 is stretched and subjected to tensile stress. This, in turn, also promotes fixation in the end plate 4, regardless of the geometric shape 47. In particular, the respective sleeve-shaped region is subjected to tensile stress in a respective tensile region Z, favored by the elastic material from which it is made.
[0045] According to the illustrated embodiment, the stretching of the elastic material is caused by an overlap (so-called offset) d2 of the first sealing area 21 of the media insert with an end wall of the corresponding channel (here 44) of the end plate 4, which is compensated for by the stretching in the final arrangement of the media insert in the end plate 4. This means that the sealing flange 25 is pressed to the left upon insertion into the channel 44, so that the sleeve-shaped area 11 is stretched and thus subjected to tensile stress (tensile area Z). Fig. 4 graphically shows a state in which the sealing flange 25 and the end wall of the channel 44 overlap in order to illustrate the principle of insertion and material displacement under stretching and tensile stress. In the final arrangement, the sealing flange 25 and the end wall of the channel lie flat against one another. A comparable overlap can also be provided on the side of the sealing area 22.A defined, firm fit achieved in this way counteracts, for example, flexion movements in turbulent flows.
[0046] To facilitate assembly, according to the embodiment of Figures 3 and 4, the media insert in the sleeve-shaped region 11, 12 or 13 has an outer dimension, in particular an outer diameter in the case of a round shape, which, with an offset d1 (so-called offset), is smaller than an inner dimension, in particular an inner diameter, of the corresponding channel of the end plate 4. This allows the media insert in the respective sleeve-shaped region to be inserted into the corresponding channel without significant friction. This also makes it possible to compensate for manufacturing tolerances. A further embodiment of the invention, which is not shown in the figures, provides that at least one of the sleeve-shaped regions 11, 12, 13 of the media insert has at least one cross-sectional change along its longitudinal extent. For example, the cross-section changes along the respective sleeve-shaped region from, for example,a smaller to a larger cross-section. Additionally or alternatively, the cross-section can also change in shape along the longitudinal extent of at least one of the sleeve-shaped regions 11, 12, 13, e.g. from a circular to an elliptical shape. A further embodiment of the invention, which is not shown in the figures, provides that at least one of the sealing regions 21, 22 has a first sealing device and a second sealing device, e.g. in the form of respective sealing lips or sealing rings. In this case, the second sealing device is provided redundantly to the first sealing device and only takes over a sealing function if the first sealing device is faulty. In this way, what is known as cold redundancy can be achieved when sealing the joints.
[0047] According to the invention, an improved media insert and an improved fuel cell arrangement are thus provided, with which not only a plate, such as an end plate, of the fuel cell arrangement, which may comprise at least partially metallic and / or plastic material, is effectively protected against corrosion and / or erosion, but also represents an elastomer seal fastened to both sides of the plate. In particular, the media insert extends from the edge plate of the fuel cell stack to the media connection arrangement. The media insert is manufactured, for example, by injection molding. The elastic material is preferably a silicone or EPDM material or a mixture of these. The media insert can be pressed manually into the plate without separate fastening aids (such as screws, adhesive, etc.) and, due to its geometric shape, remains in a fixed position relative to and in the plate.Thanks to the elastic material, the media insert can function as a seal on both sides of the plate simultaneously. Through its integral design as a single component, whose sleeve-shaped sections completely line the respective channels or openings in the plate, an effective protective cover / sealing of all three described operating media (hydrogen, coolant, air) or two media (hydrogen, air) and the openings in the plate from media can be achieved, thus providing effective corrosion and / or erosion protection with a single media insert.
Claims
Patent claims 1.Media insert (101, 102) for at least one plate (4) of a fuel cell assembly (1) to be protected against corrosion and / or erosion, comprising at least one first operating media guide channel (41, 44) and a second operating media guide channel (43, 46) for a respective operating media guide for the operation of the fuel cell assembly (1), comprising: - a first sleeve-shaped area (11) made of elastic material for arrangement and sealing of the operating media in the first operating media guide channel (41, 44) and a second sleeve-shaped area (13) made of elastic material for arrangement and sealing of the operating media in the second operating media guide channel (43, 46) of the plate (4), - a connecting area (15) which connects the first and second sleeve-shaped areas (11, 13) and is formed flat between the first sleeve-shaped area (11) and second sleeve-shaped area (13) for contact with a surface (48) of the plate (4). is,. - wherein each of the first and second sleeve-shaped area (11 , 13) has an end-face first sealing area (21) made of elastic material, which is designed to seal a respective operating media guide at a first separation joint (81) between the plate (4) and a media connection arrangement (3), and has a second sealing area (22) made of elastic material opposite the first sealing area (21), which is designed to seal a respective operating media guide at a second separation joint (82) opposite the first separation joint (81) between the plate (4) and a fuel cell stack (5) of the fuel cell arrangement (1 ).
2. Media insert according to claim 1, wherein the first sealing area (21) is formed by a sealing flange (25) and the second sealing area (22) is formed by at least one section of the connection area (15).
3. Media use according to claim 1 or 2, further comprising: - a third sleeve-shaped area (12) made of elastic material for arrangement and sealing of the operating media in a third operating media guide channel (42, 45) of the plate (4), - wherein the connecting area (15) connects the first, second and third sleeve-shaped areas (11 , 12, 13) and is designed to be flat between the first, second and third sleeve-shaped areas to rest on the surface (48) of the plate (4), - wherein each of the first, second and third sleeve-shaped area (11 , 12, 13) has the first sealing area (21 ) and the second sealing area (22).
4. Media application according to one of claims 1 to 3, wherein the elastic material comprises at least a silicone and / or EPDM material.
5. Fuel cell order (1) comprising the following: - at least one fuel cell stack (5), - a media connection arrangement (3) with connections (31-36) for supplying the fuel cell arrangement (1) with operating media for the operation of the fuel cell arrangement (1 ), - at least one plate (4) to be protected against corrosion and / or erosion, which is arranged between the fuel cell stack (5) and the media connection arrangement (3), with at least one first operating media supply channel (41, 44) and a second operating media supply channel (43, 46) for a respective operating media supply for the operation of the fuel cell arrangement (1), - a media insert (101, 102) with a first sleeve-shaped area (11) made of elastic material, which is arranged in the first operating media guide channel (41, 44) of the plate for sealing the operating media, and a second sleeve-shaped area (13) made of elastic material, which is arranged in the second operating media guide channel (43, 46) of the plate for sealing the operating media, and a connecting area (15) which connects the first and second sleeve-shaped areas (11, 13) and is flat between the first sleeve-shaped area (11) and second sleeve-shaped area (13) and rests against a surface (48) of the plate (4), - wherein each of the first and second sleeve-shaped areas (11, 13) has an end-face first sealing area (21) made of elastic material, which seals the respective operating media guide at a first separation joint (81) between the plate (4) and the media connection arrangement (3), and has a second sealing area (22) made of elastic material opposite the first sealing area (21), which seals the respective operating media guide at a seals the second separation joint (82) between the plate (4) and the fuel cell stack (5).
6. Fuel cell arrangement according to claim 5, wherein the first operating media supply channel (41 , 44) and / or the second operating media supply channel (43, 46) are designed to supply anode operating gas or cathode operating gas for the fuel cell arrangement (1 ).
7. Fuel cell arrangement according to claim 5 or 6, wherein - the plate (4) has a third operating media supply channel (42, 45) for operating media supply for the operation of the fuel cell arrangement (1), - the media insert (101 , 102) further comprises a third sleeve-shaped area (12) made of elastic material, which is arranged in the third operating media guide channel (42, 45) of the plate for sealing the operating media, - wherein the connecting area (15) connects the first, second and third sleeve-shaped areas (11 , 12, 13) and is flat between the first, second and third sleeve-shaped areas (11 , 12, 13) and rests against the surface (48) of the plate (4), - wherein each of the first, second and third sleeve-shaped area (11 , 12, 13) has the first sealing area (21 ) and the second sealing area (22).
8. Fuel cell arrangement according to claim 7, wherein the third operating media supply channel (42, 45) is designed to supply coolant for the fuel cell arrangement (1).
9. Fuel cell arrangement according to one of claims 5 to 8, wherein the first sealing area (21 ) is formed by a sealing flange (25) which abuts a surface (37) of the media connection arrangement (3), and the second sealing area (22) is formed by at least a section of the connection area (15) which abuts a surface of the fuel cell stack (5).
10. Fuel cell arrangement according to one of claims 5 to 9, wherein the plate (4) is designed as an end plate of the fuel cell arrangement (1).
11. Fuel cell arrangement according to one of claims 5 to 10, wherein the plate (4) is designed as a metallic plate.
12. Fuel cell arrangement according to one of claims 5 to 11, wherein the media insert (101, 102) is arranged in the plate (4) such that the elastic material of at least one of the first, second and third sleeve-shaped region (11, 12, 13) between the first and second sealing region (21, 22) is stretched and subjected to tensile stress.
13. Fuel cell arrangement according to claim 12, wherein the elongation of the elastic material is caused by an overlap (d2) of the first sealing area (21) of the media insert with an end wall of the corresponding operating media guide channel (44) of the plate, which is compensated by the elongation in the final arrangement of the media insert (101 , 102) in the plate (4).
14. Fuel cell arrangement according to one of claims 5 to 13, wherein the plate (4) has at least one geometric shape (47) on at least one of the first, second and third operating media guide channel (41-46) by means of which the media insert (101 , 102) is held in a fixed position in the plate (4), wherein the at least one geometric shape (47) has at least one elevation, in particular step, depression, in particular groove, and / or an undercut.
15. Fuel cell arrangement according to claim 14, wherein the at least one geometric shape (47) is designed such that at least one of the first sealing area (21) and second sealing area (22) is compressed in a manner defined by the geometric shape (47).
16. Fuel cell arrangement according to one of claims 5 to 15, wherein the media insert (101 , 102) is held in a fixed position in the plate (4) without a fastening means separate from the plate (4).
17. Fuel cell arrangement according to one of claims 5 to 16, wherein at least one of the first, second and third sleeve-shaped regions (11 , 12, 13) of the media insert has at least one change in cross-section along its longitudinal extent.
18. Fuel cell arrangement according to one of claims 5 to 17, wherein at least one of the first sealing area (21) and second sealing area (22) has a first sealing device and a second sealing device which is used for The first sealing device is redundantly designed and takes over a sealing function in the event of a faulty first sealing device.
19. Fuel cell arrangement according to one of claims 5 to 18, wherein the media insert (101 , 102) has in at least one of the first, second and third sleeve-shaped area (11 , 12, 13) an outer dimension, in particular an outer diameter, which is smaller by an offset (d1 ) than an inner dimension, in particular an inner diameter, of the corresponding first, second or third operating media guide channel (41-46) of the plate.
20. Fuel cell arrangement according to one of claims 5 to 19, wherein at least one of the first sealing area (21) and second sealing area (22) are designed according to the principle of self-reinforcement.