Electrically heatable fluid piping for components of an electrochemical energy converter, system for an electrochemical energy converter, and electrochemical energy converter - Patent Application 20070122997

Abstract

An electrically heatable fluid pipe (10) for an electrochemical energy converter component (11) is made of a plastic (14) mixed with conductive particles (13), and has an outer jacket surface (15) and an inner jacket surface (16), and 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) being arranged on the outer jacket surface (15) at a distance from each other.

Description

[Technical Field]

[0001] The present invention relates to an electrically heatable fluid line for a component of an electrochemical energy converter, to a system for an electrochemical energy converter, and to an electrochemical energy converter. [Background technology]

[0002] Heating of pipes through which fluids / media flow is a frequent application: pipes of nozzles, injection valves, mixers, pumps, tanks, water separators, etc. must be heated in order to melt the media contained therein and thus make them pumpable, or to warm them up so that they reach a certain temperature level for subsequent processes without vaporizing.

[0003] Piping / tubes have proven to be advantageous for heating media passing through them due to their large surface area and the ease with which heat can be applied from the outside, allowing for a variety of heating techniques to be applied, such as electrical resistive heating elements, combustion, heat exchangers, etc.

[0004] Electrical resistance heaters can consist of a simple metal conductor, such as a length of cable wrapped around a tube, a ceramic-based PTC heating element, or a conductive plastic. Summary of the Invention

[0005] The present invention relates to an electrically heatable fluid pipe having the features of independent claim 1, a system having the features of independent claim 11 and an electrochemical energy converter having the features of independent claim 15. Further features and details of the invention will become apparent from the dependent claims, the description and the drawings, whereby features and details explained in the context of the electrically heatable fluid pipe according to the invention are naturally also valid in the context of the system according to the invention and / or the electrochemical energy converter according to the invention and vice versa, so that the disclosures relating to the individual inventive aspects are always cross-referenced or can be cross-referenced.

[0006] According to the present invention, an electrically heatable fluid pipe for a component of an electrochemical energy converter is provided, which is made of a plastic mixed with electrically conductive particles, and has an outer jacket surface, an inner jacket surface, and at least one first electrical contact and at least one second electrical contact, the at least one first electrical contact and the at least one second electrical contact being arranged on the outer jacket surface at a distance from each other.

[0007] Electrically heatable fluid lines serve to heat or melt fluids in electrochemical energy converters, for example in fuel cells or electrolyzers. The fluid may be frozen, for example due to the ambient temperature, and must be melted after a cold start in order to make the lines of the electrochemical energy converter available again or to make the valves of the electrochemical energy converter switchable again. This is the case, for example, in the water separators of electrochemical energy converters or in the discharge or metering valves of electrochemical energy converters. Frozen fluid remaining in front of or in the valves themselves can lead to malfunctions.

[0008] For melting of the fluid, the first and second electrical contacts are brought into contact with an electric current, so that an electric current flows through the wall of the electrically heatable fluid pipe, which heats up the electrically heatable fluid pipe (Joule heating) due to the electrically conductive particles. This heat is transferred to the fluid / medium located inside, i.e., the fluid flowing in the electrically heatable fluid pipe, and melts or at least heats it.

[0009] The inner jacket surface can be in direct contact with the fluid, which can be deionized water, for example. Since deionized water is not or only slightly conductive, the current does not flow through the deionized water, but rather through the electrically heatable fluid pipe. Particularly in the case of electrochemical energy converters, a small amount of electrolysis can occur. This results in the generation of hydrogen from the water, which remains in the system anyway and can be reacted again in the electrochemical energy converter and converted back into electrical current.

[0010] Electrically heatable fluid piping can be circular, square, or oval depending on the component. In addition, it can be made straight and / or curved to carry the fluid to its destination, allowing the electrically heatable fluid piping to be adapted to various geometries.

[0011] It is particularly preferred if at least one of the electrical contacts is arranged on the outer jacket surface in the region of the end face, so that the heat generated can be transferred to further components that are or can be connected to the fluid line.

[0012] Within the scope of the present invention, it may be preferable in electrically heatable fluid pipes for the electrically conductive particles to be arranged in sections in the axial direction or over the length of the fluid pipe and / or in sections in the radial direction or over the circumference of the fluid pipe.

[0013] Heat is generated based on the resistance of the conductive particles to electrical current, and the distribution and amount of conductive particles accordingly defines the locations or regions where heat is generated and transferred to the fluid.

[0014] The axial or radial distribution of the conductive particles allows for the targeted application of heat and its intensity to the electrically heatable fluid pipe. Furthermore, the conductive particles can be applied only to specific regions of the electrically heatable fluid pipe. This can be easily realized since such electrically heatable fluid pipes are manufactured by injection molding.

[0015] By disposing conductive particles along the length of the fluid pipe, i.e. throughout the entire length of the fluid pipe, the entire fluid pipe can be heated in a simple manner to ensure that various areas and undercuts are heated.

[0016] Within the scope of the present invention it is conceivable that in electrically heatable fluid lines the electrically conductive particles are soot and / or graphite and / or metal powder and / or metal fibres and / or carbon nanotubes.

[0017] High electrical conductivity is achieved by adding a sufficient number of conductive particles. The exact electrical conductivity can also be adjusted to adjust the internal resistance of the electrically heatable fluid pipe, and therefore the power consumption. Furthermore, a PTC effect (Positive Temperature Coefficient) can be generated in the plastic of the electrically heatable fluid pipe during heating due to the different thermal expansion coefficients of the plastic material and the filling substance, resulting in a temperature-dependent automatic regulation effect that limits the power consumption of the pipe heating element and prevents overheating.

[0018] Within the scope of the present invention, it may be provided that in the electrically heatable fluid pipe, 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.

[0019] This allows for a defined area of ​​the electrically heatable fluid piping in which heat is generated.

[0020] When at least two electrical contacts are attached radially to the outer diameter of the electrically heatable fluid pipe, current flows from the first electrical contact through a circumferential segment to the next, i.e., second, electrical contact, and at least one first electrical contact may be disposed at an angle to the second electrical contact, the angle being between 45° and 180°, preferably between 90° and 180°, and more preferably between 135° and 180°.

[0021] If at least two electrical contacts are arranged at a distance from one another on the outer diameter of the electrically heatable fluid pipe in the axial pipe direction, the current flows along the electrically heatable fluid pipe. Even with an axial arrangement of the electrical contacts, they may also be arranged offset from one another in the radial direction.

[0022] According to the present invention, it is conceivable that the at least one first electrical contact and / or the at least one second electrical contact have a contact layer for contacting each other, the contact layer being a conductive adhesive and / or sprayed metal particles and / or extrusion coated metal cable and / or punched grid.

[0023] The use of conductive adhesive and / or sprayed metal particles and / or extrusion-coated metal cables and / or punched grids ensures not only the electrical contact of the electrically heatable fluid pipes but also the local bonding of the electrically heatable fluid pipes. By conductive adhesive is meant herein an adhesive that conducts electricity.

[0024] The transmission of current through the contact layer can be ensured by means of press-fit terminal connections and / or stamped grids with contact springs and / or plugs.

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

[0026] The size of the contact area for joining the electrical contacts to the electrically heatable fluid pipe can thus be adjusted or defined, thereby adjusting or defining the heat generation area of ​​the electrically heatable fluid pipe and thus the heat generated. Accordingly, a specific circumferential segment of the electrically heatable fluid pipe in which heat should be generated can be easily defined, and the heat progression along the electrically heatable fluid pipe can also be determined.

[0027] Partially extending circumferentially is understood in the present case to mean that the contact surface, in terms of its circumferential extension, corresponds to at least 5%, preferably at least 25%, more preferably at least 50%, even more preferably at least 75% of the circumference of the outer jacket surface of the electrically heatable fluid pipe.

[0028] Within the scope of the present invention, it is optionally possible in the electrically heatable fluid pipe to have at least one outer undercut that circumferentially extends at least partially, in particular over the entire outer jacket surface of the electrically heatable fluid pipe.

[0029] The at least one outer undercut then suitably accommodates a seal, for example an O-ring, for sealing the electrically heatable fluid line from other components.

[0030] Additionally, the outer undercuts may be mounting means designed to accommodate corresponding mounting means of other components, such as other fluid lines or valves.

[0031] When the electrically heatable fluid line is assembled into a housing or other component, the at least one exterior undercut may also serve as a positioning aid during assembly into the housing.

[0032] It is also conceivable that in the electrically heatable fluid pipe the inner jacket surface is provided with at least one, preferably at least two, inner undercuts which are at least partially, in particular completely, circumferential.

[0033] The internal undercut serves to accommodate or couple other components or other fluid piping. The internal undercut allows for easy media-tight connections.

[0034] The inner undercut is preferably located on one of the end faces of the electrically heatable fluid pipe, so that a contact surface for the sealing seat can be created in a simple manner.

[0035] The electrically heatable fluid pipe may be provided with a detent on its outer casing, which ensures a fixed position of the electrically heatable fluid pipe when it is mounted to other components or the housing of the electrochemical energy converter. The detent may be, for example, a protrusion on the outer casing of the electrically heatable fluid pipe.

[0036] Additionally, in electrically heatable fluid piping, a tube, in particular a metal tube, may be arranged along the inner jacket surface and be thermally coupled via the inner jacket surface to a plastic mixed with electrically conductive particles.

[0037] It is particularly advantageous here if the tubes or the tube material have a high heat transfer coefficient, since this allows for an optimized and rapid transfer of heat to the fluid.

[0038] Additionally, the tubes, particularly metallic tubes, may be anodized and / or coated to provide electrical and / or chemical insulation.

[0039] To properly guide the heat generated in the tube to other areas, it is conceivable to provide a further heat-conducting element made of the same conductive plastic or an integrated metal element. For example, a metal pin can be arranged, which leads from the conductive plastic or integrated metal element to the discharge tube. This allows melting even in remote areas, ensuring the functionality of the entire system.

[0040] The above-mentioned problem is further solved by the inventive system for an electrochemical energy converter, which comprises the above-described electrically heatable fluid pipe and a component, the component and the electrically heatable fluid pipe being in contact with each other, in particular in heat transfer contact.

[0041] In contact is understood in this case to mean that the heat generated in the electrically heatable fluid pipe influences the component, i.e. the electrically heatable fluid pipe and the component are in direct contact with each other, or the heated fluid in the electrically heatable fluid pipe releases this heat to the component.

[0042] Furthermore, within the scope of the present invention, it may be intended that in the system, the outer undercut of the outer jacket surface of the electrically heatable fluid pipe is the attachment means, and the component has a corresponding attachment means, which engages with the attachment means in order to attach the electrically heatable fluid pipe and the component.

[0043] This ensures a secure connection between the electrically heatable fluid line and the component. Such a connection is preferably designed to be removable. The connection can be a locking connection or a clip connection. For this purpose, the area of ​​the attachment means can be designed to be spring-elastic.

[0044] In the system, according to the invention, it is envisaged that the components and the electrically heatable fluid piping are arranged in a housing.

[0045] This housing is a common housing, which allows the electrically heatable fluid lines to be easily handled, i.e. arranged in components, for example, inside the housing, and in particular attached to one another.

[0046] Within the scope of the present invention, it is conceivable that the component in the system is a valve, which has a valve housing with corresponding mounting means and a movable valve plug that, when in the closed state, contacts a completely circumferential inner undercut on the inner outer jacket surface of the heatable fluid pipe.

[0047] The contact of the valve plug with the inner jacket surface of the heatable fluid pipe ensures the mobility of the valve plug at low temperatures or can be reestablished if the fluid freezes.

[0048] The above-mentioned object is further achieved by an electrochemical energy converter according to the invention, which comprises at least one electrically heatable fluid line as described above and / or a system as described above, preferably a fuel cell or an electrolyzer or a fuel cell system or an electrolyzer system.

[0049] 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, in which the features referred to in the claims and the description may each be part of the invention individually or in any combination, and in which the invention is illustrated in the following drawings: [Brief explanation of the drawings]

[0050] [Figure 1] FIG. 1 is a schematic diagram showing electrically heatable fluid piping. [Figure 2]FIG. 2 is a schematic diagram showing the arrangement of electrical contacts. [Figure 3] FIG. 10 is a schematic diagram showing a second arrangement of electrical contacts. [Figure 4] FIG. 1 is a schematic diagram illustrating a first embodiment of the system. [Figure 5] FIG. 10 is a schematic diagram illustrating a second embodiment of the system. [Figure 6] FIG. 1 is a schematic diagram showing an electrochemical energy converter. DETAILED DESCRIPTION OF THE INVENTION

[0051] Figure 1 shows an electrically heatable fluid pipe 10 made of plastic 14 mixed with electrically conductive particles 13 for a component 11 of an electrochemical energy converter (12) shown diagrammatically in Figure 5. The electrically heatable fluid pipe 10 has an outer jacket surface 15, an inner jacket surface 16, at least one first electrical contact 17, and at least one second electrical contact 18. Here, the at least one first electrical contact 17 and the at least one second electrical contact 18 are arranged on the outer jacket surface 15 at a distance from each other.

[0052] In this example, the conductive particles 13 are arranged in an axial section of the electrically heatable fluid pipe 10 having a length L and in a radial section around the circumference U of the electrically heatable fluid pipe 10. In this case, the conductive particles 13 are soot and / or graphite and / or metal particles and / or metal fibers and / or carbon nanotubes.

[0053] 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 jacket surface 15 of the electrically heatable fluid pipe 10, exemplarily at an angle of 180° between the first and second electrical contacts 17, 18. Here, both contacts 17, 18 are arranged axially offset from one another. Each of the at least one first electrical contact 17 and the at least one second electrical contact 18 has a contact surface 29, which is square and extends partially axially along a length L and radially along a circumference U of the outer jacket surface 15. The circumferential lengths of the contact surfaces 29 each correspond to approximately 5% of the circumference U.

[0054] 3, the at least one first electrical contact 17 and the at least one second electrical contact 18 are arranged offset from one another in the axial and radial directions. The at least one first electrical contact 17 and / or the at least one second electrical contact 18 have a contact surface 29 that extends partially, in particular entirely, in the axial direction along the length L and / or in the radial direction of the outer jacket surface 15 along the circumference U. Here, the at least one first electrical contact 17 extends along the entire circumference U, and the second electrical contact 18 extends only partially along the circumference U. The circumferential extension of the second electrical contact 18 corresponds to approximately 10% of the circumference U of the electrically heatable fluid pipe 10.

[0055] 1 and 2, at least one first electrical contact 17 and / or at least one second electrical contact 18 have a contact layer 19 for contact, which is preferably a conductive adhesive 30. In a second embodiment, metal particles 31 are sprayed onto the second electrical contact 18 for contact. At least one first electrical contact 17 is preferably an extrusion-coated metal cable 32. In the embodiment of FIG. 5, the contacts 17, 18 are contact springs 38.

[0056] The outer jacket surface 15 of the electrically heatable fluid pipe 10 is at least partially, in particular completely, provided with at least one circumferential outer undercut 20. Here, the outer undercut 20 is configured as a circumferential groove 33 that serves as the mounting means 24. Another outer undercut 20 serves as the area in which the electrically conductive particles 13 are distributed, i.e., as the abutment surface for the contact surface 29. Furthermore, the outer undercut 20 is provided with an abutment surface for the sealant 26. Furthermore, these outer undercuts 20 themselves provide positioning aids 34 or surround positioning aids 34 between themselves.

[0057] The inner jacket surface 16 is provided in this example with a completely circumferential inner undercut 21 in the region of the end face 37 of the electrically heatable fluid pipe 10 in order to accommodate components 11, such as valves 28 and seals 26, as shown in FIG.

[0058] Additionally, the electrically heatable fluid pipe 10 of FIG. 1 has a detent 22 on the outer jacket surface 15.

[0059] Figures 4 and 5 respectively show a system for an electrochemical energy converter 12 having an electrically heatable fluid pipe 10 as shown in Figures 1 to 3 and a component 11, where the component 11 and the electrically heatable fluid pipe 10 are in contact with each other, in particular in heat transfer contact.

[0060] Here, the outer undercuts 20 in the outer jacket surface 15 of the electrically heatable fluid pipe 10 can serve as attachment means 24, as shown in Figure 4. In addition to this, the component 11 has counterattachment means 25, which then engage with the resilient attachment means 24 for attachment of the electrically heatable fluid pipe 10 to the component 11. This can be designed as a kind of clip or locking connection.

[0061] For improved handling, the component 11 and the electrically heatable fluid pipe 10 are arranged in a housing 27. For this purpose, it is preferable if the component 11 and the electrically heatable fluid pipe 10 are already connected and the seal 26 is positioned in the groove 33 or outer undercut 20 provided for this purpose before being inserted into the housing 27. It is also conceivable to insert the housing 27 into a housing half, after which a second housing half is placed on top and screwed in. Positioning aids 34 are provided for positioning the component 11 on the electrically heatable fluid pipe 10 or for positioning the electrically heatable fluid pipe 10 in the housing 27.

[0062] 4-5, the component 11 is a valve 28. Here, the valve 28 comprises a valve housing 35 with corresponding mounting means 25 and a movable valve plug 36 which, when in the closed position, contacts the fully circumferential inner undercut 21 of the inner jacket surface 16 of the electrically heatable fluid pipe 10.

[0063] Additionally, metal pins 40 are placed in the electrically heatable fluid pipe 10 to transfer heat from the plastic 14 mixed with conductive particles 13 to the fluid outlet pipe 41.

[0064] 5, a metal tube 39 is arranged along the inner jacket surface 16 of the electrically heatable fluid pipe 10 and is connected in a heat-transfer manner via the inner jacket surface 16 to the plastic 14 mixed with electrically conductive particles 13. In this embodiment, the electrically conductive particles 13 are distributed over the entire length of the electrically heatable fluid pipe 10 in order to also heat the undercuts 21, thereby preventing, for example, freezing or partial freezing of the valve plug.

[0065] Figure 6 shows an electrochemical energy converter 12 having at least one electrically heatable fluid line 10 as shown in Figures 1 to 3 and / or a system 23 as shown in Figure 4. Here, the electrochemical energy converter 12 may be a fuel cell system or an electrolyzer system. [Explanation of symbols]

[0066] 10 Electrically heatable fluid piping 11 Components 12 Electrochemical energy converters 13 Conductive particles 14 Plastic 15 Outer mantle surface 16 Inner mantle surface 17 First electrical contact 18 Second electrical contact 19 Contact layer 20 Outer Undercut 21 Medial Undercut 22 Anti-rotation 23 System 24 Mounting means 25 Corresponding mounting means 27 Housing 28 valves 29 Contact surface 35 Valve housing 36 Valve plug 39 tube L length U circumference

Claims

1. An electrically heatable fluid line (10) for a component (11) of an electrochemical energy converter, It is made of a plastic (14) mixed with conductive particles (13), The device has an outer mantle surface (15) and an inner mantle surface (16), at least one first electrical contact (17) and at least one second electrical contact (18), The electrically heatable fluid pipe, wherein the at least one first electrical contact (17) and the at least one second electrical contact (18) are arranged on the outer jacket surface (15) at intervals from each other.

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

3. 3. An electrically heatable fluid pipe (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. 4. An electrically heatable fluid pipe (10) according to claim 1, wherein the at least one first electrical contact (17) and the at least one second electrical contact (18) are arranged offset from one another in the radial and / or axial direction.

5. 5. An electrically heatable fluid pipe (10) according to claim 1, characterized in that at least one first electrical contact (17) and / or at least one second electrical contact (18) have a contact layer (19) for contacting each other, the contact layer (19) being a conductive adhesive and / or sprayed metal particles and / or extrusion-coated metal cable and / or a punched grid.

6. 6. An electrically heatable fluid pipe (10) according to claim 1, characterized in that at least one first electrical contact (17) and / or at least one second electrical contact (18) have a contact surface (29) which extends partially, in particular entirely, in the axial direction along a length (L) and / or in the radial direction along a circumference (U) of the outer jacket surface (15).

7. 7. An electrically heatable fluid pipe (10) according to claim 1, characterized in that the outer jacket surface (15) is provided with at least one outer undercut (20) that runs around the outer jacket surface (15) at least partially, in particular over the entire surface.

8. 8. An electrically heatable fluid pipe (10) according to claim 1, characterized in that the inner jacket surface (16) is provided with at least one circumferential inner undercut (21) at least partially, in particular over the entire surface.

9. 9. An electrically heatable fluid pipe (10) according to any one of claims 1 to 8, characterized in that the outer jacket surface (15) is provided with a detent (22).

10. 10. An electrically heatable fluid pipe (10) according to claim 1, characterized in that a pipe (39), in particular a metal pipe (39), is arranged along the inner jacket surface (16) and is heat-transferably connected via the inner jacket surface (16) to the plastic (14) mixed with the electrically conductive particles (13).

11. 11. A system (23) for an electrochemical energy converter (12) comprising an electrically heatable fluid pipe (10) according to any one of claims 1 to 10 and a component (11), wherein the component (11) and the electrically heatable fluid pipe (10) are in contact with each other, in particular in heat transfer contact.

12. 12. The system (23) of claim 11, wherein the outer undercut (20) of the outer jacket surface (15) of the electrically heatable fluid pipe (10) is an attachment means (24), and the component (11) has corresponding attachment means (25) that engage with the attachment means (24) to attach the electrically heatable fluid pipe (10) and the component (11).

13. 13. A 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).

14. 14. A system (23) according to claims 11 to 13, characterized in that the component (11) is a valve (28) comprising a valve housing (35) with corresponding mounting means (25) and a movable valve plug (36) which, when in a closed state, contacts a fully circumferential inner undercut (21) of the inner jacket surface (16) of the heatable fluid pipe (10).

15. Electrochemical energy converter (12) comprising at least one electrically heatable fluid pipe (10) according to claims 1 to 10 and / or a system (23) according to claims 11 to 14.

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