Heating system, a first method for producing the heating system, a second method for producing the heating system, and an electrochemical energy converter
Patent Information
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- ROBERT BOSCH GMBH
- Filing Date
- 2024-06-12
- Publication Date
- 2026-05-13
Smart Images
Figure EP2024066138_09012025_PF_FP_ABST
Abstract
Description
[0001] Description of the a second
[0002] The invention relates to a heating system having the features of independent patent claim 1, a first method for producing a heating system having the features of independent patent claim 8, a second method for producing a heating system having the features of independent patent claim 10, and an electrochemical energy converter having the features of independent patent claim 14.
[0003] When using electrochemical energy converters, especially in remote locations, the use of a water separator during downtime can lead to freezing of the medium (in this case, water) in a channel used to supply or discharge the medium. Heating elements made of electrically conductive plastics, for example, are currently being used for this purpose. These are currently being molded and cured in a pre-heated mold.
[0004] When using these heating elements, heat transfer is often impaired because the heating elements do not correspond to the shape intended in the water separator or shrink during the curing process. This creates a gap between the heating element and the housing, which means that the medium in the supply or discharge channel cannot be thawed efficiently, or that elements installed along the channel, such as valves, sensors, or similar, are not preheated. This is particularly problematic when using a water separator, as it can destroy the elements installed along the channel or reduce their lifespan. In addition, the contained medium cannot be supplied or discharged quickly enough, thus impairing the process.
[0005] The invention proposes a heating system having the features of independent patent claim 1, a first method for producing a heating system having the features of independent patent claim 8, a second method for producing a heating system having the features of independent patent claim 10, and an electrochemical energy converter having the features of independent patent claim 14. Further features and details of the invention emerge from the subclaims, the description, and the drawings.Features and details that are described in connection with the heating system according to the invention naturally also apply in connection with the first method according to the invention and / or in connection with the second method according to the invention and / or in connection with the electrochemical energy converter according to the invention and vice versa, so that with regard to the disclosure of the individual aspects of the invention, reference is or can always be made mutually.
[0006] A first aspect of the invention is a heating system for indirectly heating a medium, in particular water, in at least one media channel or in a media container, comprising the media container for receiving the medium to be heated. The media container has a cavity extending at least partially around the media container. Additionally or alternatively, the media container has the at least one media channel for discharging and / or supplying the medium and a cavity extending at least partially parallel to the media channel and / or at least partially around the media channel.In addition, the heating system comprises a heating element for heating the medium with a heating section and a fastening section, wherein the heating section is arranged in the cavity of the media container and / or the at least one media channel of the media container and the fastening section is provided for fastening the heating element to the media container so that the cavity is closed.
[0007] The heating element has at least two electrical contacts, wherein the at least two electrical contacts are arranged in the heating section and can be contacted at the fastening section by an external power source, and wherein the at least two electrical contacts are surrounded by an electrically conductive elastomer in the heating section.
[0008] The cavity is understood here as a receptacle or hollow space within the media container. For heating the medium, it is advantageous if the wall thickness of the media container between the cavity and the medium to be heated is as small as possible to ensure improved heat transfer. Wall thicknesses in the range of 3 mm to 20 mm, preferably 4 mm to 15 mm, and more preferably 5 mm to 10 mm, have proven particularly advantageous.
[0009] The cavity can be flat, concave, or convex. In cross-section, this cavity can have a horseshoe shape, a U-shape, or an L-shape, so that the channel is at least partially enclosed by the cavity. In use, this ensures that the medium located in this channel is heated over the circumference of the channel or in sections over the circumference of the channel, and thus is or can be thawed. Generally, heating or thawing of the medium is ensured when the cavity surrounds the channel by at least 50%, preferably at least 60%, preferably at least 70%, in cross-section. Local heating of the medium in the channel is also conceivable.
[0010] The at least two electrical contacts can also be accommodated in the cavity in such a way that the heat is quickly distributed to the areas most needed for it. In this case, it is particularly advantageous if the electrically conductive elastomer in the heating section of the heating element corresponds to the cavity. This has the advantage that less air remains in the cavity, so that the heat transfer to the medium is carried out as optimally as possible. Within the scope of the invention, it can be advantageous for the media container to be a water separator of an electrochemical energy converter, in particular a fuel cell system, and for the medium supplied and / or discharged via the media channel to be water.
[0011] The heating system is ideal for the water separator of an electrochemical energy converter. Since these are exposed to various temperature fluctuations during continuous use, it allows the medium—in the case of the water separator, water—to be quickly and easily heated and thawed. This increases the service life of the surrounding components and simultaneously ensures the optimized operation of the electrochemical energy converter.
[0012] Within the scope of the invention, it is conceivable that an outer contour of the heating section of the heating element corresponds to an inner contour of the cavity of the media container and / or the cavity of the at least one media channel of the media container.
[0013] If the inner contour of the cavity of the media container and / or the cavity of at least one media channel of the media container corresponds to the outer contour of the heating section of the heating element, the precise fit of the heating section is ensured. This reduces the air in the respective cavity and results in no gap between the heating section and the media container, thus ensuring optimized heat transfer from the heating element to the media channel and / or the media container, since there is no longer an insulating air layer in the cavity.
[0014] Within the scope of the invention, it can be provided that the media container and / or the fastening section has at least one injection channel, wherein the injection channel runs from an outer side into the cavity, wherein the at least one injection channel is designed for injecting the electrically conductive elastomer. It is also conceivable for an injection mold for producing the heating element to have the injection channel. The electrically conductive elastomer can be injected through the injection channel in the outer side of the cavity or the fastening section. This is particularly advantageous because a precise fit of the heating element in the cavity can be ensured by injecting the elastomer. Accordingly, air is prevented from being present between the heating section and the media container. This makes it possible to even out and optimize heat transfer across the surface of the cavity.At the same time, this simplifies the production of the heating element.
[0015] Injection molding also allows any cavity shape to be used without creating a jump or unevenness in heat transfer.
[0016] This allows the cavity to have shapes that would not have been possible if the heating element had simply been inserted into the cavity. For example, the cavity can now have undercuts to optimally follow the shape of the media channel. This allows the cavity to be designed according to the areas required for thawing or heating the medium in the media channel.
[0017] It is further conceivable that the electrically conductive elastomer has a proportion of 5% to 50%, preferably 7% to 40%, more preferably 10% to 35%, of an electrically conductive filler.
[0018] The use of elastomers with electrically conductive fillers results in optimal generation of Joule heat, which is generated when a current is applied to the electrical contacts in the heating section. Accordingly, the proportion of electrically conductive fillers can be selected depending on the desired heat generation.
[0019] The elastomer can be rubber, fluorine rubber, silicone, fluorine silicone, thermoplastic elastomers, and acrylate rubber. It is also conceivable that the electrically conductive filler is at least one of the following materials:
[0020] - Soot and / or
[0021] - Graphite and / or
[0022] - metallic powders and / or
[0023] - metallic fibers and / or
[0024] - Carbon nanotubes.
[0025] These electrically conductive fillers are particularly well-suited for blending with an elastomer. They not only provide the required conductivity but also ensure a uniform distribution of Joule heat throughout the heating section of the heating element.
[0026] Within the scope of the invention, it is optionally possible for the fastening section to be connected to the media container in a media-tight manner, in particular in a form-fitting or material-fitting manner.
[0027] This ensures that the heating element is always securely connected to the media container and cannot come loose during use.
[0028] When the elastomer is injected, a media-tight fastening section ensures that the elastomer, which is still liquid during the injection process, cannot escape from the cavity again.
[0029] In this case, media-tight connection means welding, plugging, clipping or gluing the fastening section of the heating element to the container.
[0030] A second aspect of the invention is a first method according to the invention for producing a heating system according to a first aspect of the invention, comprising the following steps:
[0031] - Providing the media container and / or the at least one media channel of the media container with the cavity,
[0032] - Attaching the attachment portion of the heating element to the media container to close the cavity of the media container and / or the cavity of the at least one media channel of the media container,
[0033] - Inserting the at least two electrical contacts into the cavity of the media container and / or the at least one media channel of the media container via the fastening section, so that the electrical contacts can be contacted with an external power source,
[0034] - Introducing the electrically conductive elastomer into the cavity of the media container and / or the at least one media channel of the media container.
[0035] The order of the steps is not specified. It would also be conceivable, for example, that the elastomer is introduced first, then the cavity of the heating element is sealed with the mounting section, and finally the electrical contacts are inserted.
[0036] Whether the electrically conductive elastomer is introduced after the fastening section has been secured, or before, the electrically conductive elastomer is introduced, the electrically conductive material is in a liquid state. This ensures that the elastomer can easily assume the shape of the cavity.
[0037] Furthermore, it can be provided within the scope of the invention that the electrically conductive elastomer is introduced, in particular injected, via the at least one injection channel of the media container and / or the fastening section or directly into the cavity of the media container and / or into the cavity of the at least one media channel of the media container.
[0038] This allows the cavity to be filled quickly and reliably. The elastomer can reliably assume the shape of the cavity. Should the elastomer shrink slightly during cooling or solidification, additional material can be introduced through the injection channel. A third aspect of the invention is a second method according to the invention for producing a heating system according to a first aspect of the invention, comprising the following steps:
[0039] - Providing the media container with the cavity and / or the media container with the at least one media channel with the cavity,
[0040] - Providing an injection mold with a cavity for producing the heating element, wherein the cavity corresponds to the cavity of the media container and / or the cavity of the at least one media channel of the media container,
[0041] - Closing the cavity of the injection mold with the fastening section of the heating element,
[0042] - Inserting the at least two electrical contacts into the cavity via the fastening section so that the electrical contacts can be contacted with an external power source,
[0043] - Introducing the electrically conductive elastomer into the cavity,
[0044] - Curing of the elastomer in the injection mold,
[0045] - demoulding the heating element from the injection mould,
[0046] - Inserting the heating element into the cavity so that the heating section of the heating element fills the cavity,
[0047] - Attach the mounting section to the media housing.
[0048] For this, an injection mold must first be created that matches the shape of the cavity. Depending on the elastomer used and its shrinkage behavior, the injection mold can be designed larger so that the shape of the elastomer after shrinking matches the shape and size of the cavity.
[0049] Furthermore, it is conceivable that the electrically conductive elastomer is introduced, in particular injected, via the at least one injection channel of the fastening section or directly into the injection mold.
[0050] This enables optimal creation of the shape of the heating section, so that all curves or corners that the heating section may have are filled with the elastomer. Within the scope of the invention, it can be advantageous for the introduced electrically conductive elastomer to be cured by applying heat in both the first and second processes. This heat can be supplied, in particular, by applying current to the electrical contacts from an external electrical source.
[0051] This allows for curing from the inside out, thus reducing the curing time. At the same time, it allows testing of the heating element's functionality. Furthermore, it can be determined whether the electrically conductive fillers are evenly distributed throughout the elastomer.
[0052] The applied voltage can be used by a load supplied by the electrochemical energy converter. The voltage source can provide between 12V and 24V. However, it is also conceivable to use a voltage source that can provide a voltage of 5V to 220V.
[0053] Within the scope of the invention, it is conceivable that the fastening section of the heating element is fastened to the media container in a media-tight manner in a form-fitting and / or material-fitting manner, in particular by welding or gluing or plugging or clipping.
[0054] This ensures that, on the one hand, the cavity is media-tight for the injection process so that no elastomer escapes and, on the other hand, that the heating element cannot become detached from the cavity during operation.
[0055] A fourth aspect of the invention is an electrochemical energy converter, in particular a fuel cell or a fuel cell system, with a heating system according to a first aspect of the invention, produced according to the second or third aspect of the invention.
[0056] Advantages described in detail for one aspect of the invention also apply to the other aspects of the invention. Further advantages, features, and details of the invention will become apparent from the following description, in which several embodiments of the invention are described in detail with reference to the drawings. The features mentioned in the claims and in the description may be essential to the invention individually or in any combination. The invention is shown in the following figures:
[0057] Figure 1 is a schematic representation of a first heating system according to the invention,
[0058] Figure 2 is a schematic representation of the first heating system according to the invention in a section AA,
[0059] Figure 3 is a schematic representation of a second heating system according to the invention,
[0060] Figure 4 is a schematic representation of the first method according to the invention,
[0061] Figure 5 is a schematic representation of the second method according to the invention,
[0062] Figure 6 is a schematic representation of an electrochemical energy converter.
[0063] Fig. 1 and Fig. 2 show a heating system 10 for indirectly heating a medium 12 in at least one media channel 14. The heating system 10 comprises a media container 16 for receiving the medium 12 to be heated and a heating element 20 for heating the medium 12. In this case, the media container 16 is a water separator 32 of an electrochemical energy converter 34, which is why the medium 12 is water. The media container 16 comprises at least one media channel 14 for discharging and / or supplying the medium 12 and a cavity 18. The cavity 18 runs at least partially parallel to the media channel 14 and, due to its horseshoe shape, at least partially around the media channel 14.
[0064] The heating element 20 has a heating section 22 and a fastening section 24. The heating section 22 is arranged in the cavity 18. The fastening section 24 for fastening 120 the heating element 20 is provided on the media container 16, so that the cavity 18 is closed.
[0065] The heating element 20 has at least two electrical contacts 26, which are arranged in the heating section 22 and can be contacted at the fastening section 24 by an external power source 28. In the heating section 22, the at least two electrical contacts 26 are surrounded by an electrically conductive elastomer 30. An outer contour 38 of the heating section 22, i.e. the outer contour 38 of the elastomer with the at least two electrical contacts 26, of the heating element 20 corresponds to an inner contour 40 of the cavity 18 of the media container 16. This prevents an air gap from occurring between the heating section 22 and the media container 16, so that the heat is optimally transferred from the heating element 20 into the housing wall of the media container 16 in order to keep the media channel 14 free of ice and to thaw the frozen medium 12.
[0066] Fig. 3 shows a second embodiment of the heating system. It includes a media container 16 having a cavity 18 extending at least partially around the media container 16. This embodiment also includes a heating element 20 for heating the medium 12, comprising a heating section 22 and a fastening section 24. The heating section 22 is arranged in the cavity 18 of the media container 16, and the fastening section 24 for fastening the heating element 20 is provided on the media container 16, such that the cavity 18 is closed. Here, too, the heating element 20 has at least two electrical contacts 26, wherein the at least two electrical contacts 26 are arranged in the heating section 22 and can be contacted at the fastening section 24 by an external power source 28, and wherein the at least two electrical contacts 26 in the heating section 22 are surrounded by an electrically conductive elastomer 30.
[0067] Since the elastomer is or can be introduced in the liquid state, as shown in Fig. 4 and Fig. 5, an injection channel 42 is provided. In the exemplary embodiment of the heating system 10 according to Fig. 1 and Fig. 2, the injection channel 42 is provided in the fastening section 24. In an exemplary embodiment not shown, it is conceivable that the injection channel 42 is provided in the media container 16. The injection channel 42 runs from an outer side 44 of the fastening section 42 into the cavity 18, wherein the at least one injection channel 42 is designed to inject the electrically conductive elastomer 30.
[0068] In the embodiment according to Fig. 1 to Fig. 6, the electrically conductive elastomer 30 is mixed with metallic fibers in a proportion of 30%.
[0069] To ensure electrical conductivity, a proportion of 5% to 50%, preferably 7% to 40%, and more preferably 10% to 35%, of an electrically conductive filler should be provided. These electrically conductive fillers can also be carbon black and / or graphite and / or metallic powders and / or carbon nanotubes.
[0070] In the illustrated heating system 10, the fastening section 24 is connected to the media container 16 in a media-tight manner. The fastening section 24 is welded to the media container 16 and thus firmly connected to it.
[0071] In Fig. 4, the first method 100 for producing a heating system 10 according to Fig. 1 and Fig. 2 is shown, comprising the following steps:
[0072] - Providing 110 the media container 16 with the cavity 18,
[0073] - Attaching 120 the attachment portion 24 of the heating element 20 to the media container 16 to close 130 the cavity 18, - Inserting 140 the at least two electrical contacts into the cavity 18 via the attachment portion 24 so that the electrical contacts can be contacted with an external power source 28,
[0074] - Inserting 150 the electrically conductive elastomer 30 into the cavity 18.
[0075] The electrically conductive elastomer 30 is introduced 150 or injected via the at least one injection channel 42 of the media container 16. In another embodiment, the injection channel 42 can also be provided in the fastening section 24. Direct introduction 150 (injection) into the cavity 18 and subsequent closure 130 of the cavity 18 with the fastening section 24 is also conceivable.
[0076] Fig. 5 illustrates the second method 200 according to the invention for producing a heating system 10 according to Fig. 1 and Fig. 2. The heating element 20 is first manufactured and then inserted into the cavity 18. The method 200 comprises the following steps:
[0077] - Providing 210 the media container 16 with the cavity 18,
[0078] - Providing 210 an injection mold 46 with a cavity for producing the heating element 20, wherein the cavity corresponds to the cavity 18,
[0079] - Closing 220 the cavity of the injection mold 46 with the fastening section 24 of the heating element 20,
[0080] - Inserting 230 the at least two electrical contacts 26 into the cavity via the fastening section 24, so that the at least two electrical contacts 26 can be contacted with an external power source 28,
[0081] - introducing 240 the electrically conductive elastomer 30 into the cavity,
[0082] - Curing 280 of the elastomer 30 in the injection mold 46,
[0083] - demoulding 250 of the heating element 20 from the injection mould 46,
[0084] - Inserting 260 the heating element 20 into the cavity 18 so that the heating section 22 of the heating element 20 fills the cavity 18,
[0085] - Attaching 270 the attachment portion 24 to the media housing.
[0086] In this method 200, the at least one injection channel 42 can also be provided in the injection mold 46. However, it is also conceivable here that the elastomer with the electrically conductive fillers is introduced 240, in particular injected, directly into the injection mold 46.
[0087] In both the first method 100 and the second method 200, the introduced 150, 240 electrically conductive elastomer 30 is heated by supplying
[0088] Heat cured 160, 280. For this purpose, the heat is supplied by energizing the electrical contacts 26 with an external electrical source.
[0089] In both the first method 100 and the second method 200, the fastening section 24 of the heating element 20 is fastened 120, 270 in a media-tight manner to the media container 16. Here, the fastening section 24 is welded to the media container 16.
[0090] In Fig. 6, an electrochemical energy converter 34 in the form of a fuel cell system 36 with a heating system 10 according to Fig. 1 and Fig.
[0091] 2 shown.
Claims
Claims 1. Heating system (10) for indirectly heating a medium (12), in particular water, in at least one media channel (14) or in a media container (16), comprising the media container (16) for receiving the medium to be heated (12) with a cavity (18) extending at least partially around the media container (16), and / or the media container (16) for receiving the medium (12) to be heated, with the at least one media channel (14) for discharging and / or supplying the medium (12) and a cavity (18) extending at least partially parallel to the media channel (14) and / or at least partially around the media channel (14), and a heating element (20) for heating the medium (12), with a heating section (22) and a fastening section (24), wherein the heating section (22) is arranged in the cavity (18) of the media container (16) and / or the at least one media channel (14) of the media container (16), and the fastening section (24) is provided for fastening the heating element (20) to the media container (16), so that the cavity (18) is closed, characterized in that Heating element (20) has at least two electrical contacts (26),wherein the at least two electrical contacts (26) are arranged in the heating section (22) and can be contacted at the fastening section (24) by an external power source (28), and wherein in the heating section (22) the at least two electrical contacts (26) are surrounded by an electrically conductive elastomer (30).
2. Heating system (10) according to claim 1, characterized in that that the media container (16) is a water separator (32) of an electrochemical energy converter (34), in particular a fuel cell system (36), and that the medium (12) supplied and / or discharged via the media channel (14) is water.
3. Heating system (10) according to claim 1 or 2, characterized in that an outer contour (38) of the heating section (22) of the heating element (20) corresponds to an inner contour (40) of the cavity (18) of the media container (16) and / or the cavity (18) of the at least one media channel (14) of the media container (16).
4. Heating system (10) according to one of the preceding claims, characterized in that the media container (16) and / or the fastening section (24) has at least one injection channel (42), wherein the injection channel (42) runs from an outer side (44) into the cavity (18), wherein the at least one injection channel (42) is designed for injecting the electrically conductive elastomer (30).
5. Heating system (10) according to one of the preceding claims, characterized in that the electrically conductive elastomer (30) has a proportion of 5% to 50%, preferably 7% to 40%, more preferably 10% to 35%, of an electrically conductive filler.
6. Heating system (10) according to claim 5, characterized in that the electrically conductive filler is at least one of the following substances: carbon black and / or graphite and / or metallic powders and / or metallic fibers and / or carbon nanotubes.
7. Heating system (10) according to one of the preceding claims, characterized in that that the fastening section (24) is connected to the media container (16) in a media-tight manner, in particular in a form-fitting or material-fitting manner.
8. A method (100) for producing a heating system (10) according to any one of the preceding claims, comprising the following steps: Providing (110) the media container (16) and / or the at least one media channel (14) of the media container (16) with the cavity (18), Fastening (120) the fastening section (24) of the heating element (20) to the media container (16) for closing (130) the cavity (18) of the media container (16) and / or the cavity (18) of the at least one media channel (14) of the media container (16), Inserting (140) the at least two electrical contacts (26) into the cavity (18) of the media container (16) and / or the at least one media channel (14) of the media container (16) via the fastening section (24) so that the at least two electrical contacts (26) can be contacted with an external power source (28), introducing (150) the electrically conductive elastomer (30) into the cavity (18) of the media container (16) and / or the at least one media channel (14) of the media container (16).
9. Method (100) according to claim 8, characterized in that the electrically conductive elastomer (30) is introduced (150), in particular injected, via the at least one injection channel (42) of the media container (16) and / or the fastening section (24) or directly into the cavity (18) of the media container (16) and / or into the cavity (18) of the at least one media channel (14) of the media container (16).
10. Method (200) for producing a heating system (10) according to one of the Claims 1 to 7, comprising the following steps: Providing (210) the media container (16) with the cavity (18) and / or the media container (16) with the at least one media channel (14) with the cavity (18), Providing (210) an injection mold with a cavity for producing the heating element (20), wherein the cavity corresponds to the cavity (18) of the media container (16) and / or the cavity (18) of the at least one media channel (14) of the media container (16), closing (220) the cavity of the injection mold with the fastening section (24) of the heating element (20), Inserting (230) the at least two electrical contacts (26) into the cavity via the fastening section (24) so that the at least two electrical contacts (26) can be contacted with an external power source (28), Introducing (240) the electrically conductive elastomer (30) into the cavity, Curing (280) the elastomer (30) in the injection mold, demolding (250) the heating element (20) from the injection mold, inserting (260) the heating element (20) into the cavity (18) so that the heating section (22) of the heating element (20) fills the cavity (18), fastening (270) the fastening section (24) to the media housing.
11. Method (200) according to claim 10, characterized in that the electrically conductive elastomer (30) is introduced (240), in particular injected, via the at least one injection channel (42) of the fastening section (24) or directly into the injection mold.
12. Method (100, 200) according to one of claims 8 or 11, characterized in that the introduced (150, 240) electrically conductive elastomer (30) is cured (160, 280) by supplying heat, in particular that the heat is supplied by energizing the electrical contacts with an external electrical source.
13. Method (100, 200) according to one of claims 8 to 12, characterized in that that the fastening section (24) of the heating element (20) is fastened (120, 270) to the media container (16) in a media-tight manner in a form-fitting and / or material-fitting manner, in particular by welding or adhesive bonding or by plugging or clipping.
14. Electrochemical energy converter (34), in particular a fuel cell or a fuel cell system (36), with a heating system (10) according to one of claims 1 to 7.