Electrically heatable fluid line for a component of an electrochemical energy converter, system for an electrochemical energy converter, and electrochemical energy converter

Abstract

The invention relates to an electrically heatable fluid line (10) for a component (11) of an electrochemical energy converter, said fluid line being made of a plastic (14) which is mixed with electrically conductive particles (13) and comprising an outer lateral surface (15), an inner lateral surface (16), at least one first electric contact (17), and at least one second electric contact (18). The at least one first electric contact (17) and the at least one second electric contact (18) are arranged on the outer lateral surface (15) in a mutually spaced manner.

Description

[0001] Description

[0002] Electrically heatable fluid line for a component of an electrochemical energy converter, system for an electrochemical energy converter and electrochemical energy converter

[0003] Heating pipes through which a fluid / medium flows is a common application. Lines for nozzles, injection valves, mixers, pumps, tanks, water separators, and much more need to be heated to thaw the media they contain and thus make them pumpable, or to heat them to a certain temperature level for subsequent processes without evaporation.

[0004] It turns out that it's advantageous to use the pipes / tubes to heat the media they carry, as they have a large surface area and can easily apply heat from the outside. Various heating technologies can be used for this, such as electrical resistance heating elements, combustion, or heat exchangers.

[0005] The electrical resistance heaters can consist of simple metallic conductors, e.g. cables of appropriate length wound around the pipe, of PTC heating elements on a ceramic basis or of electrically conductive plastics.

[0006] Disclosure of the invention

[0007] The invention relates to an electrically heatable fluid line having the features of independent patent claim 1, to a system having the features of independent patent claim 10, and to 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 described in connection with the electrically heatable fluid line according to the invention naturally also apply in connection with the system 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 to each other.

[0008] According to the invention, an electrically heatable fluid line is provided for a component of an electrochemical energy converter, made of a plastic mixed with electrically conductive particles, with an outer surface and an inner surface, and with at least one first electrical contact and at least one second electrical contact, wherein the at least one first electrical contact and the at least one second electrical contact are arranged at a distance from one another on the outer surface.

[0009] The electrically heated fluid line is used to warm or thaw a fluid in an electrochemical energy converter, such as a fuel cell or an electrolyzer. The fluid may, for example, be frozen due to outside temperatures and must be thawed after a cold start so that the lines of an electrochemical energy converter can be used again or so that the valves of an electrochemical energy converter can switch again. This is the case, for example, in the water separators of an electrochemical energy converter or in the drain or metering valves of an electrochemical energy converter. Frozen fluid remaining in front of or in the valves can lead to malfunctions.

[0010] To thaw the fluid, the first and second electrical contacts are contacted with current, thus flowing through the wall of the electrically heatable fluid line. The electrically conductive particles cause the electrically heatable fluid line to heat up (Joulian heating). This heat is transferred to the internal fluid / medium, i.e., the fluid flowing in the electrically heatable line, and this fluid is thawed or at least warmed up.

[0011] The inner surface of the casing can be in direct contact with the fluid. The fluid could be deionized water, for example. Deionized water is not or only slightly electrically conductive, so no current flows through the deionized water; instead, the current flows through the electrically heated fluid line. Particularly in the case of electrochemical energy converters, a small amount of electrolysis can also occur. This would produce hydrogen from the water, which is already present in the system and can react again in the electrochemical energy converter and be converted back into electricity.

[0012] The electrically heated fluid line can be round, square, or oval, depending on the component. It can also be straight and / or curved to guide the fluid to its destination. This allows the electrically heated fluid line to be adapted to various geometries.

[0013] It is particularly advantageous if at least one of the electrical contacts is located near the end face on the outer surface. This allows the generated heat to be transferred to other elements that are or may be connected to the fluid line.

[0014] Within the scope of the invention, it may be advantageous in an electrically heatable fluid line that the electrically conductive particles are arranged in sections in the axial direction or over a length of the fluid line and / or in sections in the radial direction or over a circumference of the fluid line.

[0015] The heat is generated due to the resistance the electrically conductive particles offer to the current. Accordingly, the distribution and quantity of the electrically conductive particles determine the location or area where the heat is generated and transferred to the fluid. By arranging the electrically conductive particles in sections in an axial or radial direction, the heat effect in the electrically heated fluid line and its intensity can be precisely controlled. Furthermore, it is possible to equip only certain areas of an electrically heated fluid line with electrically conductive particles. This is easily achieved due to the injection molding process used to manufacture this electrically heated fluid line.

[0016] By arranging the electrically conductive particles over a length of the fluid line, i.e. the entire length of the fluid line, the entire fluid line can be heated in a simple manner to ensure that various areas and undercuts are heated.

[0017] Within the scope of the invention, in an electrically heatable fluid line, it is conceivable that the electrically conductive particles are soot and / or graphite and / or metal powder and / or metal fibers and / or carbon nanotubes.

[0018] By adding a sufficient number of electrically conductive particles, high electrical conductivity is achieved. Specific electrical conductivities can also be adjusted to adjust the internal resistance in the electrically heated fluid line and thus the power consumption. Furthermore, a PTC (positive temperature coefficient) effect can be induced in the plastic of the electrically heated fluid line due to the different thermal expansion coefficients of the plastic material and the fillers when heated. This creates a temperature-dependent, self-regulating effect that limits the power consumption of the tubular heating element and prevents overheating.

[0019] Within the scope of the invention, in an electrically heatable fluid line, it can be provided that the at least one first electrical contact and the at least one second electrical contact are arranged radially and / or axially offset from one another.

[0020] This allows the area in the electrically heatable fluid line in which the heat is generated to be defined. If the at least two electrical contacts are mounted radially on the outer diameter of the electrically heatable fluid line, the current flows from the first electrical contact across the circumferential segment to the next contact, i.e., the second electrical contact. The at least one first electrical contact can be arranged at an angle to the second electrical contact. The angle can be between 45° and 180°, preferably between 90° and 180°, more preferably between 135° and 180°.

[0021] If the at least two electrical contacts are arranged on the outer diameter of the electrically heatable fluid line at a distance from each other in the axial direction of the pipe, the current flows along the electrically heatable fluid line. Even with an axial arrangement of the electrical contacts, they can be arranged radially offset from each other.

[0022] It is conceivable according to the invention that the at least one first electrical contact and / or the at least one second electrical contact have a contacting layer for contacting one another, wherein the contacting layer is a conductive adhesive and / or sprayed-on metal particles and / or overmolded metallic cables and / or lead frames.

[0023] The use of conductive adhesive and / or sprayed-on metal particles and / or overmolded metallic cables and / or lead frames ensures both the electrical contact of the electrically heated fluid line and the local connection of the electrically heated fluid line. A conductive adhesive is defined as an electrically conductive adhesive.

[0024] The transmission of current via the contact layer can be ensured by means of an insulation displacement connection and / or by means of spring contacts and / or a lead frame with a plug.

[0025] It is also conceivable in the case of an electrically heatable fluid line that the at least one first electrical contact and / or the at least one second electrical contact has / have a contact surface, wherein the contact surface extends partially, in particular completely, along the length in the axial direction of the electrically heatable fluid line and / or along the circumference in the radial direction of the outer jacket surface of the electrically heatable fluid line.

[0026] By adjusting the size of the contact surface for connecting the electrical contacts to the electrically heatable fluid line, the area in the electrically heatable fluid line where heat is generated, and the amount of heat generated, can be controlled or specified. This makes it easier to specify specific circumferential segments of the electrically heatable fluid line where heat is to be generated. Furthermore, the heat distribution along the electrically heatable fluid line can also be determined.

[0027] By extending partially along the circumference, it is understood here that the contact surface in its circumferential extent corresponds to at least 5%, preferably at least 25%, more preferably at least 50%, more preferably at least 75%, of the circumference of the outer surface of the electrically heatable fluid line.

[0028] Within the scope of the invention, it is optionally possible for an electrically heatable fluid line to have at least one at least partially, in particular completely, circumferential outer undercut provided on the outer surface of the electrically heatable fluid line.

[0029] The at least one external undercut is suitable for accommodating seals, for example O-rings, in order to seal the electrically heatable fluid line from other components.

[0030] Furthermore, the outer undercut can be a fastening means which is designed to receive a counter-fastening means of another component, for example another fluid line or a valve.

[0031] If the electrically heatable fluid line is installed in a housing or another component, the at least one external undercut can also serve as a positioning aid during installation in the housing. It is also conceivable for an electrically heatable fluid line to have at least one, preferably at least two, at least partially, in particular completely, circumferential internal undercuts on the inner surface.

[0032] The internal undercut serves to accommodate or connect other components or additional fluid lines. This allows for a simple, media-tight connection.

[0033] Preferably, the inner undercut is located on one of the end faces of the electrically heated fluid line. This allows a contact surface for a sealing seat to be easily created.

[0034] It is conceivable for an electrically heated fluid line to have an anti-twist device on the outer surface of the electrically heated fluid line. This ensures the fixed position of the electrically heated fluid line when installed in another component or housing of an electrochemical energy converter. The anti-twist device can, for example, be a projection on the outer surface of the electrically heated fluid line.

[0035] In addition, in the electrically heatable fluid line, a pipe, in particular a metallic pipe, can be arranged along the inner surface and is connected via the inner surface in a heat-transferring manner to the plastic mixed with electrically conductive particles.

[0036] It is particularly advantageous if the pipe or the material of the pipe has a high heat transfer coefficient, as this can optimize and accelerate the transfer of heat to the fluid.

[0037] Furthermore, the pipe, especially the metal pipe, is anodized and / or coated to create electrical and / or chemical insulation. It is conceivable that additional heat-conducting elements made of the same electrically conductive plastic or of mounted metal elements are provided to specifically conduct the heat generated in the pipe to other areas. For example, a metal pin can be arranged so that the pin extends from the electrically conductive plastic or the mounted metal element into a drain pipe. This allows even a more distant area to be thawed, thus ensuring the functionality of the entire system.

[0038] The above object is further achieved by a system according to the invention for an electrochemical energy converter with an electrically heatable fluid line as described above and a component, wherein the component and the electrically heatable fluid line are in contact with each other, in particular in heat-transferring contact.

[0039] In this context, "being in contact" means that the heat generated in the electrically heatable fluid line influences the component. This means that the electrically heatable fluid line and the component are in direct contact with each other, or that the fluid heated in the electrically heatable fluid line transfers this heat to the component.

[0040] Furthermore, within the scope of the invention, it can be provided in a system that an outer undercut of the outer surface of the electrically heatable fluid line is a fastening means and that the component has a counter-fastening means, wherein the counter-fastening means engages in the fastening means for fastening the component to the electrically heatable fluid line.

[0041] This ensures a secure connection between the component and the electrically heatable fluid line. This connection is preferably designed to be detachable. The connection can be a snap-in connection or a clip connection. For this purpose, the fastening element can be designed to be resilient. According to the invention, it is conceivable for a system to arrange the component and the electrically heatable fluid line in a housing.

[0042] The housing is a single unit. This allows for easy handling of the electrically heated fluid line, e.g., by arranging it on the component within the housing, and in particular, by fastening it to the component.

[0043] Within the scope of the invention, it is conceivable in the system that the component is a valve, wherein the valve has a valve housing with a counter-fastening means and a movable valve plug which, in the closed state, contacts a completely circumferential inner undercut of the inner jacket surface of the heatable fluid line.

[0044] The contact of the valve plug with the inner surface of the heatable fluid line ensures the mobility of the valve plug at low temperatures or, if the fluid is frozen, restores it.

[0045] The above object is further achieved by an electrochemical energy converter according to the invention having at least one electrically heatable fluid line as described above and / or a system as described above. The electrochemical energy converter is preferably a fuel cell or an electrolyzer, or a fuel cell system or an electrolyzer system.

[0046] Further advantages, features, and details of the invention will become apparent from the following description, which describes several embodiments of the invention 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 illustrated in the following figures:

[0047] Figure 1 is a schematic representation of an electrically heatable fluid line, Figure 2 is a schematic representation of an arrangement of the electrical contacts,

[0048] Figure 3 is a schematic representation of a second arrangement of the electrical contacts,

[0049] Figure 4 is a schematic representation of a first embodiment of the system,

[0050] Figure 5 is a schematic representation of a second embodiment of the system, and

[0051] Figure 6 is a schematic representation of an electrochemical energy converter.

[0052] Fig. 1 shows an electrically heatable fluid line 10 for a component 11 of an electrochemical energy converter (12), which is schematically shown in Fig. 5, made of a plastic 14 mixed with electrically conductive particles 13. The electrically heatable fluid line 10 has an outer surface 15 and an inner surface 16 as well as at least one first electrical contact 17 and at least one second electrical contact 18. The at least one first electrical contact 17 and the at least one second electrical contact 18 are arranged at a distance from one another on the outer surface 15.

[0053] The electrically conductive particles 13 are arranged in a section of length L in the axial direction of the electrically heatable fluid line 10 and in the radial direction over a circumference U of the electrically heatable fluid line 10. The electrically conductive particles 13 are carbon black and / or graphite and / or metal powder and / or metal fibers and / or carbon nanotubes.

[0054] 1 and 2, the at least one first electrical contact 17 and the at least one second electrical contact 18 are arranged radially offset from one another on the outer circumferential surface 15 of the electrically heatable fluid line 10, here for example at an angle of 180° between the first and second electrical contacts 17, 18. The two contacts 17, 18 are arranged offset from one another in the axial direction. Both the at least one first electrical contact 17 and the at least one second electrical contact 18 have a contact surface 29, wherein the contact surface 29 is square and extends partially along the length L in the axial direction and along the circumference U in the radial direction of the outer circumferential surface 15. The circumferential length of the contact surface 29 corresponds in each case to approximately 5% of the circumference U.

[0055] According to an embodiment shown in Fig. 3, the at least one first electrical contact 17 and the at least one second electrical contact 18 are arranged axially and radially offset from one another. The at least one first electrical contact 17 and / or the at least one second electrical contact 18 has a contact surface 29, wherein the contact surface 29 extends partially, in particular completely, along the length L in the axial direction and / or along the circumference U in the radial direction of the outer circumferential surface 15. The at least one first electrical contact 17 extends along the entire circumference U, and the second electrical contact 18 extends partially along the circumference U. The circumferential extent of the second electrical contact 18 corresponds to approximately 10% of the circumference U of the electrically heatable fluid line 10.

[0056] The at least one first electrical contact 17 and / or the at least one second electrical contact 18 of the first embodiment of Figs. 1 and 2 have a contacting layer 19 for contacting, wherein the contacting layer 19 is preferably a conductive adhesive 30. In the second embodiment, metal particles 31 were sprayed on to contact the second electrical contact 18. The at least one first electrical contact 17 is preferably an overmolded metallic cable 32. In the embodiment according to Fig. 5, the contacts 17, 18 are spring contacts 38.

[0057] On the outer surface 15 of the electrically heatable fluid line 10, at least one at least partially, in particular completely, circumferential outer undercut 20 is provided. One of the outer undercuts 20 is designed as a circumferential groove 33, which serves as a fastening means 24. Another outer undercut 20 serves as a section in which the electrically conductive particles 13 are distributed, and thus as a contact surface for the contact surfaces 29. Furthermore, contact surfaces for seals 26 are provided on the outer undercuts 20. Furthermore, the outer undercuts 20 either themselves provide a positioning aid 34 or enclose a positioning aid 34 between them.

[0058] In this case, a completely circumferential inner undercut 21 is provided on the inner surface 16. This is provided in a region of an end face 37 of the electrically heatable fluid line 10 in order to accommodate a component 11, for example, a valve 28 or a seal 26, as shown in Fig. 5.

[0059] Furthermore, the electrically heatable fluid line 10 according to Fig. 1 has an anti-twist device 22 on the outer surface 15.

[0060] Fig. 4 and Fig. 5 each show a system for an electrochemical energy converter 12 with an electrically heatable fluid line 10 according to Figs. 1 to 3 and a component 11. The component 11 and the electrically heatable fluid line 10 are in contact with each other, in particular in heat-transferring contact.

[0061] The outer undercut 20 of the outer surface 15 of the electrically heatable fluid line 10 can serve as a fastening means 24, as shown in Fig. 4. Additionally, the component 11 has a counter-fastening means 25. To secure the component 11 to the electrically heatable fluid line 10, the counter-fastening means 25 engages the spring-elastic fastening means 24. This can be designed as a type of clip or snap-in connection.

[0062] For easier handling, the component 11 and the electrically heatable fluid line 10 are arranged in a housing 27. For this purpose, it is advantageous if the component 11 and the electrically heatable fluid line 10 are already connected and the seals 26 are positioned in the grooves 33 or external undercuts 20 provided for this purpose and then pushed into the housing 27. It would also be conceivable to insert it into one housing half of the housing 27, with a second housing half then being placed on top and screwed in. Positioning aids 34 are provided for positioning a component 11 on the electrically heatable fluid line 10 or the electrically heatable fluid line 10 in a housing 27.

[0063] In the embodiment according to Fig. 4 or Fig. 5, the component 11 is a valve 28. The valve 28 has a valve housing 35 with a counter-fastening means 25 and a movable valve plug 36 which, in the closed state, contacts a completely circumferential inner undercut 21 of the inner jacket surface 16 of the electrically heatable fluid line 10.

[0064] Furthermore, a metallic pin 40 is arranged on the electrically heatable fluid line 10 in such a way that the heat is transferred from the plastic 14 mixed with electrically conductive particles 13 into a drain pipe 41 of the fluid.

[0065] In the second exemplary embodiment according to Fig. 5, a metallic tube 39 is arranged along the inner surface 16 of the electrically heatable fluid line 10 and is connected via the inner surface 16 in a heat-transfer manner to the plastic 14, which is provided with electrically conductive particles 13. In this exemplary embodiment, the electrically conductive particles 13 are also distributed over the entire length of the electrically heatable fluid line 10 in order to also heat the undercut 21, thereby preventing, for example, the valve plug from freezing or freezing solid.

[0066] Fig. 6 shows an electrochemical energy converter 12 with at least one electrically heatable fluid line 10 according to Figs. 1 to 3 and / or a system 23 according to Fig. 4. The electrochemical energy converter 12 can be a fuel cell system or an electrolyzer system.

Claims

Claims 1 . Electrically heatable fluid line (10) for a component (11) of an electrochemical energy converter, made of a plastic (14) mixed with electrically conductive particles (13), with an outer surface (15) and an inner surface (16), and with at least one first electrical contact (17) and at least one second electrical contact (18), wherein the at least one first electrical contact (17) and the at least one second electrical contact (18) are arranged at a distance from one another on the outer surface (15).

2. Electrically heatable fluid line (10) according to claim 1, characterized in that the electrically conductive particles (13) are arranged in the axial direction in sections or over a length (L) of the fluid line (10) and / or in the radial direction in sections or over a circumference (U) of the fluid line (10).

3. Electrically heatable fluid line (10) according to claim 1 or 2, characterized in that the electrically conductive particles (13) are soot and / or graphite and / or metal powder and / or metal fibers and / or carbon nanotubes.

4. Electrically heatable fluid line (10) according to one of the preceding claims, characterized in that the at least one first electrical contact (17) and the at least one second electrical contact (18) are arranged radially and / or axially offset from one another. Electrically heatable fluid line (10) according to one of the preceding claims, characterized in that the at least one first electrical contact (17) and / or at least one second electrical contact (18) have a contacting layer (19) for contacting one another, wherein the contacting layer (19) is a conductive adhesive and / or sprayed-on metal particles and / or overmolded metallic cables and / or lead frames. Electrically heatable fluid line (10) according to one of the preceding claims, characterized in that the at least one first electrical contact (17) and / or at least one second electrical contact (18) has a contact surface (29), wherein the contact surface (29) extends partially, in particular completely, along the length (L) in the axial direction and / or along the circumference (U) in the radial direction of the outer circumferential surface (15).Electrically heatable fluid line (10) according to one of the preceding claims, characterized in that at least one at least partially, in particular completely, circumferential outer undercut (20) is provided on the outer surface (15). Electrically heatable fluid line (10) according to one of the preceding claims, characterized in that at least one at least partially, in particular completely, circumferential inner undercut (21) is provided on the inner surface (16). Electrically heatable fluid line (10) according to one of the preceding claims, characterized in that an anti-twist device (22) is provided on the outer surface (15). Electrically heatable fluid line (10) according to one of the preceding claims, characterized in that a tube (39), in particular a metallic tube (39), is arranged along the inner surface (16) and is connected via the inner surface (16) in a heat-transferring manner to the plastic (14) mixed with electrically conductive particles (13). System (23) for an electrochemical energy converter (12) with an electrically heatable fluid line (10) according to one of claims 1 to 10 and a component (11), wherein the component (11) and the electrically heatable fluid line (10) are in contact with one another, in particular in heat-transferring contact.System (23) according to claim 11, characterized in that an outer undercut (20) of the outer circumferential surface (15) of the electrically heatable fluid line (10) is a fastening means (24) and in that the component (11) has a counter-fastening means (25), wherein the counter-fastening means (25) engages in the fastening means (24) for fastening the component (11) to the electrically heatable fluid line (10). System (23) according to claim 11 or 12, characterized in that the component (11) and the electrically heatable fluid line (10) are arranged in a housing (27). System (23) according to claims 11 to 13. characterized in that the component (11) is a valve (28), wherein the valve (28) has a valve housing (35) with a counter-fastening means (25) and a movable valve plug (36) which, in the closed state, is provided with a completely circumferential inner undercut (21) of the Contacted with the inner surface (16) of the heatable fluid line (10). Electrochemical energy converter (12) with at least one electrically heatable fluid line (10) according to claims 1 to 10 and / or a system (23) according to claims 11 to 14.

Images