Heating system, first method for producing heating system, second method for producing heating system, and electrochemical energy converter

Abstract

The invention relates to a heating system (10) for indirectly heating a medium (12), in particular water, in at least one medium channel (14), comprising a medium container (16) for receiving the medium (12) to be heated, the medium container (16) having at least one medium channel (14) for discharging and / or supplying the medium (12) and a chamber (18), the invention relates to a medium container (16) comprising a medium channel (14) and a cavity (18) which extends at least partially parallel to the medium channel (14) and / or at least partially around the medium channel (14), and comprising a heating element (20) for heating the medium (12), the heating element (20) having a heating section (22) and a fastening section (24), the heating section (22) being arranged in the cavity (18), the fastening section (24) being used to fasten the heating element (20) to the medium container (16) such that the cavity (18) is closed. According to the invention, 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 means of an external power source (28), and in the heating section (22), the at least two electrical contacts (26) are surrounded by an electrically conductive elastomer (30).

Description

TECHNICAL FIELD

[0001] The invention relates to a heating system having the features of independent claim 1, to a first method for producing a heating system having the features of independent claim 8, to a second method for producing a heating system having the features of independent claim 10 and to an electrochemical energy converter having the features of independent claim 14. BACKGROUND

[0002] In the use of electrochemical energy converters, in particular in remote areas, freezing of the medium, here water, in the channels for supplying or discharging the medium can occur when the water separator provided is in a standstill state. For this purpose, heating elements made, for example, of electrically conductive plastic are currently provided. These heating elements are currently preformed and cured in a preheated mold.

[0003] In the use of these heating elements, it often occurs that the heat transfer is impaired because the heating elements do not correspond to the shape provided in the water separator or shrink during the curing process. As a result, there is a gap between the heating element and the housing, which leads to the fact that the medium in the supply channel or discharge channel cannot be thawed efficiently or elements provided along the channel, such as valves, sensors, etc., cannot be preheated.

[0004] This is particularly problematic in the use of water separators, since elements installed here along the channel can be damaged or their service life is shortened. In addition, the contained medium cannot be supplied or discharged quickly enough, so that the process is endangered. SUMMARY

[0005] The invention proposes a heating system having the features of independent claim 1, a first method for producing a heating system having the features of independent claim 8, a second method for producing a heating system having the features of independent claim 10 and an electrochemical energy converter having the features of independent claim 14. Further features and details of the invention result from the dependent claims, the description and the drawings. Here, the features and details described in connection with the heating system according to the invention are of course also associated with the first method according to the invention and / or the second method according to the invention and / or the electrochemical energy converter according to the invention, and vice versa, so that the disclosure with regard to the individual inventive aspects always refers to or is able to refer to each other.

[0006] The first aspect of the application is a heating system for indirectly heating a medium, in particular water, in at least one medium channel or in a medium container, the heating system having a medium container for receiving the medium to be heated. Here, the medium container has a cavity which extends at least partially around the medium container. Additionally or alternatively, the medium container has at least one medium channel for discharging and / or supplying the medium, and a cavity which extends at least partially parallel to the medium channel and / or at least partially around the medium channel. Additionally, the heating system comprises a heating element for heating the medium, the heating element having a heating section and a fixing section, wherein the heating section is arranged in the cavity of the medium container and / or in the cavity of the at least one medium channel of the medium container, and the fixing section serves to fix the heating element on the medium container such that the cavity is closed.

[0007] Here, the heating element has at least two electrical contacts, wherein the at least two electrical contacts are arranged in the heating section and are contactable by an external power source at the fixing section, and wherein, in the heating section, the at least two electrical contacts are surrounded by an electrically conductive elastomer.

[0008] The cavity is understood here as a receiving portion or a hollow space in the medium container. Here, it is advantageous for the heating of the medium that the wall thickness of the medium container between the cavity and the medium to be heated should be as small as possible in order to ensure an improved heat transfer. Here, a wall thickness in the range of 3 mm to 20 mm, preferably 4 mm to 15 mm, more preferably 5 mm to 10 mm, has proven to be particularly advantageous.

[0009] The cavity can be a flat or concave or convex cavity here. Here, the cavity can have a horseshoe or U-shaped or L-shaped cross section, so that the channel is at least partially surrounded by the cavity. This ensures that, in use, the medium in the channel is heated and thus defrosted or can be defrosted by the periphery or sections of the periphery of the channel. In general, heating or defrosting of the medium is ensured when the cavity surrounds at least 50%, preferably at least 60%, more preferably at least 70% of the channel in cross section. A local heating of the medium in the channel can also be considered.

[0010] Here, the at least two electrical contacts can also be arranged in the cavity in such a way that the heat is quickly distributed to where it is most needed. Here, it is particularly advantageous in this case that the electrically conductive elastomer in the heating section of the heating element corresponds to the cavity. This has the advantage that little air remains in the cavity, so that the heat transfer of the medium can be carried out as optimally as possible.

[0011] It can be advantageous within the scope of the application that the medium container is a water separator of an electrochemical energy converter, in particular a fuel cell system, and that the medium supplied and / or discharged by the medium channel can be water.

[0012] The heating system is very suitable for water separators of electrochemical energy converters. Because these water separators are subjected to various temperature fluctuations in the long term and it is possible here to quickly and simply heat and thaw the medium, which is water for the water separator, in the medium channels for the supply or discharge of the medium from the medium container. This increases the service life of the surrounding components while ensuring an optimized operation of the electrochemical energy converter.

[0013] It can be considered within the scope of the present application that the outer contour of the heating section of the heating element corresponds to the inner contour of the cavity of the medium container and / or of the cavity of the at least one medium channel of the medium container.

[0014] If the inner contour of the cavity of the medium container and / or of the cavity of the at least one medium channel of the medium container corresponds to the outer contour of the heating section of the heating element, the fitting accuracy of the heating section is ensured. This reduces the air in the corresponding cavity or results in the absence of a gap between the heating section and the medium container, so that there is an optimized heat transfer from the heating element to the medium channel and / or to the medium container because there is no longer an air layer that insulates in the cavity.

[0015] It can be provided within the scope of the present application that the medium container and / or the fixing section has at least one injection channel, wherein the injection channel extends from the outside into the cavity, wherein the at least one injection channel is designed for the injection of an electrically conductive elastomer. It can also be considered that the injection mold for the production of the heating element has an injection channel.

[0016] By means of the injection channel at the outside of the cavity or the fixing section, an electrically conductive elastomer can be injected. This is particularly advantageous because by injecting the elastomer it can be ensured that the heating element fits accurately in the cavity. Thus, it is prevented that air is present between the heating section and the medium container. Thereby, on the one hand, the heat transfer can be homogenized and optimized over the entire surface of the cavity, while at the same time the production of the heating element is thereby simplified.

[0017] Furthermore, by injection it is also possible to utilize any shape of the cavity without creating a jump or inhomogeneity in the heat transfer.

[0018] Thereby, the cavity can also have a shape which cannot be achieved when only inserting the heating element into the cavity. For example, the cavity can now have a lateral recess in order to thereby be able to optimally match the shape of the medium channel. Thus, it is possible to design the cavity according to the area required for thawing or heating the medium in the medium channel.

[0019] It can also be considered that the electrically conductive elastomer has a share of 5% to 50%, preferably 7% to 40%, more preferably 10% to 35%, of electrically conductive fillers.

[0020] The use of an elastomer with an electrically conductive filler results in an optimally generated Joule heat, which is formed when an electrical current is applied to the electrical contacts in the heating section. The proportion of the electrically conductive filler can thus be selected in accordance with the amount of heat that is desired to be generated.

[0021] The elastomer can be a rubber, a fluoro rubber, a silicone, a fluorosilicone, a thermoplastic elastomer and an acrylate rubber.

[0022] It is also conceivable that the electrically conductive filler is at least one of the following: - carbon black, and / or - graphite, and / or - metal powder, and / or - metal fibers, and / or - carbon nanotubes.

[0023] These electrically conductive fillers are particularly well suited to being mixed with the elastomer. They not only produce the required electrical conductivity, but also distribute the Joule heat evenly in the heating section of the heating element.

[0024] Alternatively within the scope of the present application, the fixing section is able to be connected to the medium container in a medium-tight manner, in particular in a form-locked or material-locked manner.

[0025] This ensures that the heating element is always reliably connected to the medium container and cannot fall out in use.

[0026] If the elastomer is injected, the medium-tightly connected fixing section ensures that the elastomer, which is still in a liquid state during the injection process, can no longer flow out of the cavity.

[0027] Medium-tightly connected is currently understood to mean a welding, a plug connection, a clamping or an adhesive bonding of the fixing section of the heating element to the container.

[0028] A second aspect of the present application is a first method for manufacturing a heating system according to the first aspect of the present application according to the present application, the method comprising the following steps: - providing a medium container with a cavity and / or at least one medium channel of the medium container, - fixing a fixing section of a heating element on the medium container to close the cavity of the medium container and / or the cavity of the at least one medium channel of the medium container, - introducing at least two electrical contacts into the cavity of the medium container and / or the cavity of the at least one medium channel of the medium container via the fixing section, so that the electrical contacts can be contacted by an external electrical power source, - introducing an electrically conductive elastomer into the cavity of the medium container and / or the cavity of the at least one medium channel of the medium container.

[0029] The order of the steps is not fixed here. It is also conceivable here, for example, to first introduce the elastomer and then to close the cavity of the heating element with the fixing section, and subsequently to introduce the electrical contacts.

[0030] The electrically conductive material is in the liquid state not only when the fixing section is fixed and the electrically conductive elastomer is introduced, but also when the fixing section is fixed and the electrically conductive elastomer is introduced. This ensures that the elastomer can adapt to the shape of the cavity in a simple manner.

[0031] Furthermore, it can be provided within the scope of the application that the electrically conductive elastomer is introduced, in particular injected, or directly introduced, in particular injected, into the cavity of the medium container and / or into the cavity of the at least one medium channel of the medium container via at least one injection channel of the medium container and / or of the fixing section.

[0032] The cavity can thus be filled quickly and reliably. The elastomer can reliably adapt to the shape of the cavity. If the elastomer shrinks slightly upon cooling or due to solidification, more material can be introduced via the injection channel.

[0033] A third aspect of the application is a second method for producing a heating system according to the first aspect of the application according to the application, comprising the following steps: - providing a medium container having a cavity and / or a medium container comprising at least one medium channel having a cavity, - providing an injection mold having a cavity for producing a heating element, wherein the cavity corresponds to the cavity of the medium container and / or the cavity of the at least one medium channel of the medium container, - closing the cavity of the injection mold with a fixing section of the heating element, - introducing at least two electrical contacts into the cavity via the fixing section, such that the electrical contacts can be contacted with an external power supply, - introducing an electrically conductive elastomer into the cavity, - allowing the elastomer to solidify in the injection mold, - demolding the heating element from the injection mold, - inserting the heating element into the cavity, such that the heating section of the heating element fills the cavity, - fixing the fixing section on the medium housing.

[0034] To this end, an injection mold corresponding to the shape of the cavity must first be produced. Depending on the elastomer used and its shrinkage properties, the injection mold can be designed to be larger, such that the shape and size of the elastomer after shrinkage corresponds to the cavity.

[0035] Furthermore, it can be considered that the electrically conductive elastomer is introduced, in particular injected, or directly introduced, in particular injected, into the injection mold via at least one injection channel of the fixing section.

[0036] This enables an optimized production of the shape of the heating section, such that all fillets or corners that the heating section can have are filled with the elastomer.

[0037] It can be advantageous within the scope of the present application that the electrically conductive elastomer introduced is cured by heating not only in the first method, but also in the second method. Here, the heat can be provided, inter alia, by energizing the electrical contacts by means of an external power source.

[0038] This allows the curing from the inside, so that the curing time can be shortened. At the same time, the functionality of the heating element can thereby be tested. Furthermore, it can also be determined whether the electrically conductive filler is uniformly distributed in the elastomer.

[0039] Here, the applied voltage can be used by the electrical consumer supplied by the electrochemical energy converter. The voltage source can provide a voltage of 12 V to 24 V. However, it is also conceivable to use a voltage source that can provide a voltage of 5 V to 220 V.

[0040] It can be considered within the scope of the present application that the fixing section of the heating element is fixed in a media-tight manner, in particular welded, bonded, plugged or clamped, form-locked and / or material-locked on the media container.

[0041] This aspect ensures that the cavity is media-tight for the injection process, so that no elastomer escapes; the other aspect ensures that the heating element does not fall out of the cavity in operation.

[0042] A fourth aspect of the present application is an electrochemical energy converter, in particular a fuel cell or a fuel cell system, having a heating system according to the first aspect of the present application, which is produced according to the method of the second or third aspect of the present application.

[0043] The advantages described in detail with respect to one aspect of the present application apply equally to the other aspects of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0044] Further advantages, features and details of the present application result from the following description with reference to the drawings, in which several embodiments of the present application are described in detail. Herein, the features mentioned in the claims and the specification can constitute essential content of the present application, both individually or in any combination. Herein, the present application is shown in the following figures: Figure 1 : Schematic representation of a first heating system according to the present application, Figure 2 : Schematic representation of a first heating system according to the present application in the A-A section, Figure 3 : Schematic representation of a second heating system according to the present application, Figure 4 schematic diagram of a first method according to the present application, Figure 5 schematic diagram of a second method according to the present application, Figure 6 schematic diagram of an electrochemical energy converter. DETAILED DESCRIPTION

[0045] In Figure 1 and Figure 2 a heating system 10 for indirectly heating a medium 12 in at least one medium channel 14 is shown. Here, the heating system 10 has a medium container 16 for receiving the medium 12 to be heated and a heating element 20 for heating the medium 12. The medium container 16 is currently a water separator 32 of an electrochemical energy converter 34, and thus the medium 12 is water.

[0046] The medium container 16 here has at least one medium channel 14 for discharging and / or supplying the medium 12 and has a cavity 18. The cavity 18 here extends at least sectionally parallel to the medium channel 14 and extends at least partially around the medium channel 14 due to its horseshoe shape.

[0047] The heating element 20 here has a heating section 22 and a fixing section 24. The heating section 22 is arranged in the cavity 18 here. The fixing section 24 for fixing the heating element 20 is provided on the medium container 16, so that the cavity 18 is closed.

[0048] The heating element 20 has at least two electrical contacts 26, which are arranged in the heating section 22 and are contactable by an external power source 28 at the fixing section 24. Here, in the heating section 22, the at least two electrical contacts 26 are surrounded by an electrically conductive elastomer 30. Here, the outer contour 38 of the heating section 22 of the heating element 20, i.e. the outer contour 38 of the elastomer with the at least two electrical contacts 26, corresponds to the inner contour 40 of the cavity 18 of the medium container 16. Thereby, an air gap between the heating section 22 and the medium container 16 is prevented, so that heat is optimally transferred from the heating element 20 into the housing wall of the medium container 16 in order to keep the medium channel 14 ice-free or to defrost frozen medium 12.

[0049] In Figure 3A second embodiment of the heating system is shown. A medium container 16 is provided, having a cavity 18 extending at least partially around the medium container 16. In this embodiment, a heating element 20 for heating the medium 12 is also provided, having a heating section 22 and a fixing section 24. Here, the heating section 22 is arranged in the cavity 18 of the medium container 16, and the fixing section 24 for fixing the heating element 20 is provided on the medium container 16, such that the cavity 18 is closed. The heating element 20 also has at least two electrical contacts 26, wherein the at least two electrical contacts 26 are arranged in the heating section 22 and are accessible by an external power source 28 at the fixing section 24, and wherein, in the heating section 22, the at least two electrical contacts 26 are surrounded by a conductive elastomer 30.

[0050] Because elastomers can be introduced in a liquid state, such as Figure 1 and Figure 2 An injection channel 42 is provided as shown. According to... Figure 1 and Figure 2 In an embodiment of the heating system 10, the injection channel 42 is disposed in the fixed section 24. In an embodiment not shown, the injection channel 42 may be disposed in the medium container 16. Here, the injection channel 42 extends from the outside 44 of the fixed section 42 into the cavity 18, wherein at least one injection channel 42 is designed for injecting an electrically conductive elastomer 30.

[0051] According to Figures 1 to 6 In the illustrated embodiment, the conductive elastomer 30 contains 30% metal fibers.

[0052] To ensure conductivity, a conductive filler should be provided in a proportion of 5% to 50%, preferably 7% to 40%, and more preferably 10% to 35%. These conductive fillers may also be carbon black and / or graphite and / or metal powder and / or carbon nanotubes.

[0053] In the heating system 10 shown, the stationary section 24 is connected to the medium container 16 in a medium-sealed manner. Here, the stationary section 24 is welded to the medium container 16, and thus is locked in place with the medium container material.

[0054] exist Figure 4 The diagram shows the materials used for manufacturing according to... Figure 1 and Figure 2 A first method 100 for a heating system 10, the method comprising the following steps: - Provides a media container 16 having a cavity 18, 110 - Fix the fixing section 24 of the heating element 20 to the medium container 16 to seal the cavity 18. - introducing 140 at least two electrical contacts into the cavity 18 by means of the fixation section 24, such that the electrical contacts can be contacted by an external power source 28, - introducing 150 an electrically conductive elastomer 30 into the cavity 18.

[0055] Here, the electrically conductive elastomer 30 is introduced 150, i.e. injected, through at least one injection channel 42 of the medium container 16. In another embodiment, the injection channel 42 can also be provided in the fixation section 24. It is also conceivable to introduce 150, i.e. inject, the electrically conductive elastomer directly into the cavity 18 and subsequently close 130 the cavity 18 with the fixation section 24.

[0056] In Figure 5 a second method 200 according to the application for manufacturing a heating system 10 according to Figure 1 and Figure 2 is shown in the following. Here, the method first manufactures a heating element 20, which is subsequently inserted into the cavity 18. The method 200 comprises the following steps: - providing 210 a medium container 16 having a cavity 18, - providing 210 an injection mold 46 having a hollow space for manufacturing a heating element 20, wherein the hollow space corresponds to the cavity 18, - closing 220 the hollow space of the injection mold 46 with a fixation section 24 of a heating element 20, - introducing 230 at least two electrical contacts 26 into the hollow space via the fixation section 24, such that the at least two electrical contacts 26 can be contacted by an external power source 28, - introducing 240 an electrically conductive elastomer 30 into the hollow space, - curing 280 the elastomer 30 in the injection mold 46, - demolding 250 the heating element 20 from the injection mold 46, - inserting 260 the heating element 20 into the cavity 18, such that the heating section 22 of the heating element 20 fills the cavity 18, - fixing 270 the fixation section 24 on the medium housing.

[0057] In the method 200, at least one injection channel 42 can also be provided in the injection mold 46. Here, however, it is also conceivable to introduce 240, in particular inject, the elastomer having an electrically conductive filler directly into the injection mold 46.

[0058] In both the first method 100 and the second method 200, the electrically conductive elastomer 30 introduced 150, 240 is cured 160, 280 by supplying heat. For this purpose, heat is provided by energizing the electrical contacts 26 by means of an external power source.

[0059] Here, not only in the first method 100 but also in the second method 200, the fixing section 24 of the heating element 20 is fixed 120, 270 in a media-tight manner material-lockingly on the media container 16. Here, the fixing section 24 is welded to the media container 16.

[0060] Figure 6 An electrochemical energy converter 34 in the form of a fuel cell system 36 is shown, which has a heating system 10 according to Figure 1 and Figure 2 .

Claims

1. A heating system (10) for indirectly heating a medium (12), particularly water, in at least one medium channel (14) or medium container (16), said heating system comprising: A medium container (16) for receiving the medium (12) to be heated, the medium container having a cavity (18) extending at least partially around the medium container (16), and / or, A medium container (16) for receiving a medium (12) to be heated, the medium container having at least one medium channel (14) for discharging and / or supplying the medium (12) and a cavity (18) extending at least sectionally parallel to and / or at least partially around the medium channel (14), and A heating element (20) for heating the heating medium (12) has a heating section (22) and a fixing section (24), wherein the heating section (22) is arranged in a cavity (18) of the medium container (16) and / or at least one medium channel (14) of the medium container (16), and the fixing section (24) is configured to fix the heating element (20) to the medium container (16) such that the cavity (18) is closed. Its features are, 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 are accessible by an external power source (28) at the fixed section (24), and wherein the at least two electrical contacts (26) are surrounded by an conductive elastomer (30) in the heating section (22).

2. The heating system (10) according to claim 1. Its features are, The medium container (16) is a water separator (32) of the electrochemical energy converter (34), particularly the fuel cell system (36), and the medium (12) supplied and / or discharged through the medium channel (14) is water.

3. The heating system (10) according to claim 1 or 2. Its features are, The outer contour (38) of the heating section (22) of the heating element (20) corresponds to the inner contour (40) of the cavity (18) of the medium container (16) and / or the cavity (18) of at least one medium channel (14) of the medium container (16).

4. The heating system (10) according to any one of the preceding claims. Its features are, The medium container (16) and / or the fixed section (24) have at least one injection channel (42), wherein the injection channel (42) extends from the outside (44) into the cavity (18), wherein the at least one injection channel (42) is designed for injecting the conductive elastomer (30).

5. The heating system (10) according to any one of the preceding claims. Its features are, The conductive elastomer (30) has a 5% to 50%, preferably 7% to 40%, more preferably 10% to 35% share of conductive filler.

6. The heating system (10) according to claim 5. Its features are, The conductive filler is at least one of the following substances: carbon black and / or graphite and / or metal powder and / or metal fiber and / or carbon nanotubes.

7. The heating system (10) according to any one of the preceding claims. Its features are, The fixed section (24) is connected to the medium container (16) in a medium-sealed manner, particularly in a shape-locking or material-locking manner.

8. A method (100) for manufacturing a heating system (10) according to any one of the preceding claims, comprising the following steps: - Provide (110) the media container (16) having a cavity (18) and / or at least one media channel (14) of the media container (16). - Fix (120) the fixed section (24) of the heating element (20) to the medium container (16) to close (130) the cavity (18) of the medium container (16) and / or the cavity (18) of at least one medium channel (14) of the medium container (16). - At least two electrical contacts (26) are introduced (140) via the fixed section (24) into the cavity (18) of the medium container (16) and / or at least one medium channel (14) of the medium container (16), such that the at least two electrical contacts (26) can contact an external power source (28). - Introduce (150) an electrically conductive elastomer (30) into the cavity (18) of the medium container (16) and / or at least one medium channel (14) of the medium container (16).

9. The method (100) according to claim 8. Its features are, An electrically conductive elastomer (30) is introduced (150), particularly injected or directly introduced, particularly injected into the cavity (18) of the medium container (16) and / or the cavity (18) of at least one medium channel (14) of the medium container (16) via the medium container (16) and / or the fixed section (24).

10. A method (200) for manufacturing a heating system (10) according to any one of claims 1 to 7, comprising the following steps: - Provide (210) a media container (16) having a cavity (18) and / or a media container (16) including at least one media channel (14) having a cavity (18). - Provide (210) an injection mold having a cavity for manufacturing a heating element (20), wherein the cavity corresponds to the cavity (18) of the medium container (16) and / or the cavity (18) of at least one medium channel (14) of the medium container (16), - The cavity of the injection mold is sealed (220) by the fixed section (24) of the heating element (20). - At least two electrical contacts (26) are introduced into the cavity (230) via the fixed section (24) so ​​that the at least two electrical contacts (26) can contact an external power source (28). - Introduce an electrically conductive elastomer (30) into the cavity (240). - The elastomer (30) is cured (280) in the injection mold. - Demold the heating element (20) from the injection mold (250). - Insert the heating element (20) into the cavity (18) (260) such that the heating section (22) of the heating element (20) fills the cavity (18). - Fix the fixed section (24) (270) on the medium housing.

11. The method (200) according to claim 10. Its features are, The conductive elastomer (30) is introduced (240), particularly injected or directly introduced (240), particularly injected into the injection mold via at least one injection channel (42) of the fixed section (24).

12. The method (100, 200) according to any one of claims 8 or 11. Its features are, The introduced (150, 240) conductive elastomer (30) is cured by providing heat (160, 280), especially by energizing the electrical contacts with the aid of an external power source.

13. The method (100, 200) according to any one of claims 8 to 12. Its features are, The fixing section (24) of the heating element (20) is fixed in a medium-sealed manner by shape locking and / or material locking (120, 270), especially by welding, bonding, plugging or clamping onto the medium container (16).

14. An electrochemical energy converter (34), particularly a fuel cell or fuel cell system (36), having a heating system (10) according to any one of claims 1 to 7.

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