Heatable media line, clip element comprising at least one thermal protection device for such a media line, and fuel cell vehicle comprising at least one such media line

Abstract

The invention relates to a heatable media line (1) for conducting a medium, in particular for conducting a liquid medium, comprising at least one tube-shaped and / or hose-shaped media line (10), at least one line connector (11) which is arranged at the end face of the at least one tube-shaped and / or hose-shaped media line (10), at least one media line heating element (2, 3), and at least one line connector heating element (4, 41). The at least one media line heating element (2, 3) is paired with the at least one tube-shaped and / or hose-shaped media line (10) and is used to heat a medium flowing through the media line, and the at least one line connector heating element (4, 41) is paired with the at least one line connector (11) and is used to heat a medium flowing through the line connector. At least one thermal protection device (7) is provided for deactivating the heating process of the tube-shaped and / or hose-shaped media line (10) and / or of the line connector (11) on the basis of a temperature, and the thermal protection device is arranged in the region of the at least one line connector (11). At least the at least one line connector (11) is arranged in at least one exterior housing (13). According to the invention, in such a media line, the at least one thermal protection device (7) is a switch which is connected in series between the at least one media line heating element (2, 3) of the at least one tube-shaped and / or hose-shaped media line (10) and the at least one line connector heating element (4, 41) of the at least one line connector (11) and is arranged within the at least one exterior housing (13) of the at least one line connector (11), wherein the at least one thermal protection device (7) automatically interrupts and reestablishes the electrically conductive connection between the at least one media line heating element (2, 3) and the at least one line connector heating element (4, 41).

Description

[0001] Heatable media line, clip element with at least one thermal protection device for such a line and fuel cell vehicle with at least one such

[0002] The invention relates to a heatable media line for conducting medium, in particular for conducting liquid medium, such as water for water injection, preferably in automotive applications, such as in fuel cell vehicles, comprising at least one tubular and / or hose-shaped media line, at least one line connector arranged at the end of the at least one tubular and / or hose-shaped media line, at least one media line heating element and at least one line connector heating element, wherein the at least one media line heating element is assigned to the at least one tubular and / or hose-shaped media line and serves to heat medium flowing through it, and the at least one line connector heating element is assigned to the at least one line connector and serves to heat medium flowing through it,wherein at least one thermal protection device is provided for temperature-dependent deactivation of the heating of the tubular and / or hose-shaped media line and / or the line connector and is arranged in the region of the at least one line connector, and wherein at least the at least one line connector is arranged in at least one external housing, a clip element with at least one thermal protection device for such a heatable media line and a hydrogen-powered fuel cell vehicle comprising at least one such heatable media line.

[0003] Heatable media lines of this type are known in the art. In particular, in vehicles such as fuel cell vehicles, a number of media lines are usually provided for conducting media such as water, AdBlue®, deionized water (DI water). At low temperatures, the media flowing or flowable through the media lines threaten to freeze. For this reason, heating of the media lines is provided. Line connectors are used to connect at least two media lines to one another or to connect a media line to any desired unit. The length of the thawing time for thawing the medium in the tubular or hose-shaped media line or the line connector depends on the respective medium. A controller for controlling the voltage supply to the at least one media line heating element can enable continuous operation, i.e. permanent current supply orProvide a permanent power supply to the media line heating element for heating the tubular or hose-shaped media line and a shutdown when heating is terminated. The same applies to the line connector heating element. Typically, the power supply is shut off after a predefined period of time, which is based on the usual thawing time of the medium flowing through the heatable media line.

[0004] However, it is also known in the prior art to deactivate the power supply to the heating device, i.e., the at least one media line heating element and the at least one line connector heating element, as overheating protection when a predeterminable temperature is exceeded, wherein a temperature fuse is provided, as disclosed, for example, in DE 102 07 794 B4. Here, the heatable line has an inner core forming a flow path, a heating device surrounding the inner core, and thermal insulation surrounding the inner core and the heating device. In the immediate vicinity of the inner core, a heat sensor and / or a temperature fuse is provided, which deactivates the power supply to the heating device when a predefined temperature is exceeded. A tube extends in the longitudinal direction of the inner core on or below the heating device, into which tube the heat sensor or the temperature fuse can be inserted.

[0005] In order to effectively prevent the heatable media line from burning out, even with high power coupled along the media line and the line connector, a system is also known from DE 10 2012 022 232 A1, in which a control and regulation device for controlling and regulating the voltage supply to the heating element and a thermal protection device for temperature-dependent and / or voltage-dependent deactivation of the heating of the media line and / or the line connector are provided in the region of the line connector. The thermal protection device is arranged in or near a hotspot location, in particular integrated into a connection point between the heating element and its electrical supply conductor or arranged in series with the latter.Redundant protection of the heatable media line and of its at least one line connector is provided by the provision of the control and regulation device for controlling and regulating the voltage supply to the at least one heating element and the thermal protection device for protecting against a fault.

[0006] A high power input into the heating of a heatable media line is particularly necessary when rapid operational readiness is required, for example when using the heatable media line in combination with a hydrogen drive or a fuel cell. The required heating output of the at least one media line heating element and the at least one line connector heating element is significantly higher than when using a heatable media line in the SCR sector. A high power input is therefore necessary to achieve rapid operational readiness. In the automotive sector, the use of plastic components is common, i.e. line connectors and tubular or hose-shaped media lines made of at least one plastic material. With a high power input, hotspots can occur, i.e. particularly hot areas, which can be found particularly in the area of ​​a weld shaft orconnecting shaft of the power connector, which is used to connect to the tubular and / or hose-shaped media line, because two electrical conductors or heating elements are located very close to one another, on one another or adjacent to one another. This can lead to excessive local heating of the line connector if high power is coupled in. If the electrically heatable media line is subjected to too high a current, i.e. if high power is coupled into the heatable media line in a short period of time, the plastic components can melt. If the electrical conductors burn out, this happens in the area of ​​the hotspot. The more power is coupled in along the heatable media line, in particular along at least one of the line connectors, the higher the risk of the electrical heating elements burning out.

[0007] Particularly when using the heatable media line in the area of ​​hydrogen drives and fuel cells or for conducting other highly flammable media, there is a risk of explosion. According to DE 10 2012 022 232 A1, a control strategy is provided which initially provides a temperature-dependent continuous energization, followed by at least a temporary intermittent energization and subsequently a de-energization, in order to enable timely shutdown of the heating of the heatable media line at higher temperatures in the area of ​​the media line and / or the installation location of the media line. Only at low temperatures does the heatable media line receive continuous heating by energizing at least one heating element. The temporary intermittent operation is carried out within a predetermined temperature range.According to DE 10 2012 022 232 A1, however, the problem arises that the thermal protection device is placed between the heating element and the electrical supply cable, as hotspots usually occur there. Over the entire service life of the heatable media line, environmental influences can cause the hotspots to migrate. The thermal protection device would then no longer be located at the hotspot and would therefore not trigger in a timely manner.

[0008] The problem with the arrangement in DE 102 07 794 B4 is, on the one hand, that this solution is quite complex, and, on the other hand, that the outer casing of the heatable line must be perforated at various points to position the thermal fuse and its surrounding pipe in the area of ​​the inner core with its surrounding heating device. Sealing is required in the area of ​​the insertion opening in any case, which, however, appears ill-suited for use with hydrogen-carrying media lines in the automotive sector.

[0009] The present invention is therefore based on the object of developing a heatable media line for conducting medium, in particular liquid medium, such as water for water injection, preferably for use in the automotive sector, in such a way that the structure of the heatable media line is less complex than in the known solutions of the prior art, a long service life of the heatable media line is possible and overheating of the heatable media line can be reliably prevented without temperature measurement and without providing a control and / or regulating unit.

[0010] The object is achieved for a heatable media line according to the preamble of claim 1 in that the at least one thermal protection device is a switch which is connected in series between the at least one media line heating element of the at least one tubular and / or hose-shaped media line and the at least one line connector heating element of the at least one line connector and is arranged within the at least one external encapsulation of the at least one line connector, wherein the at least one thermal protection device automatically interrupts and automatically re-establishes the electrically conductive connection between the at least one media line heating element and the at least one line connector heating element.The object is further achieved for a clip element with at least one thermal protection device for such a heatable media line, wherein the clip element comprises at least one receiving section for receiving the at least one thermal protection device and at least one connecting section for connecting to at least one line connector of the heatable media line.For a hydrogen-powered fuel cell vehicle, the object is achieved in that the latter comprises at least one such heatable media line, wherein at least one thermal protection device is designed as a switch as overheating protection, which is connected in series between at least one media line heating element of a tubular and / or hose-shaped media line of the heatable media line and at least one line connector heating element of at least one line connector of the heatable media line, wherein the at least one thermal protection device automatically interrupts and automatically restores the electrically conductive connection between the at least one media line heating element and the at least one line connector heating element depending on the temperature. Further developments of the invention are defined in the dependent claims.

[0011] This creates a heatable media line which is used, for example, to conduct hydrogen, nitrogen, DI water, i.e. deionized water, and is preferably used in the automotive sector, such as in fuel cell vehicles, which operates completely independently, i.e. without temperature measurement, without providing an additional control and / or regulating device for temperature control or regulation and without additional connections for the at least one thermal protection device designed as a switch and without any cabling located outside the heatable media line.This is made possible by the fact that the thermal protection device is designed as a switch and is interposed between the at least one media line heating element, which serves to heat the medium flowing or flowable through the at least one tubular and / or hose-shaped media line, and the at least one line connector heating element, which serves to heat the at least one line connector or the medium flowing through it. Depending on the temperature, the switch can independently interrupt and independently re-establish the electrically conductive connection between the at least one media line heating element and the at least one line connector heating element. The switch or the at least one thermal protection device is thus designed as a two-point switch.

[0012] The heatable media line comprises, on the one hand, the at least one tubular and / or hose-shaped media line, which is provided with the at least one media line heating element, which can be, for example, at least one media line heating strand, in order to enable heating of the medium flowing through the at least one tubular and / or hose-shaped media line, and, on the other hand, the at least one line connector arranged at the end of the at least one tubular and / or hose-shaped media line, which is provided with the at least one line connector heating element, which can be, for example, at least one line connector heating strand, for heating the medium flowing through it. In particular, it is possible to wrap the at least one tubular and / or hose-shaped media line and / or the at least one line connector with the at least one media line heating element or the at least one line connector heating element.Furthermore, any other arrangement forms, including mixed forms, on or on the at least one tubular and / or hose-shaped media line and / or the at least one line connector are possible, such as, for example, a meandering of the at least one media line heating element or the at least one line connector heating element.

[0013] The at least one thermal protection device designed as a switch makes it possible to automatically interrupt the electrically conductive connection between the at least one media line heating element and the at least one line connector heating element at a predeterminable first temperature and to automatically re-establish the electrically conductive connection at a predeterminable second temperature. This is possible without temperature measurement because the switch is designed such that it triggers at a predeterminable, in particular material-specific, first temperature or switch-off temperature, thereby interrupting the electrical connection between the at least one media line heating element and the at least one line connector heating element, and automatically re-establishes the electrical connection at a second temperature or switch-off temperature, which is also particularly material-specific.Switch-on temperature is triggered again and in doing so re-establishes the electrical connection between the at least one media line heating element and the at least one line connector heating element. The thermal protection device in the form of the switch is not arranged directly at a hotspot, so that the actual location of the hotspot is irrelevant. Rather, a switch-off temperature value is advantageously determined by empirical determination, which is present at the at least one thermal protection device in the form of the at least one switch when a maximum temperature is reached in the hotspot area, which should lead to a switch-off of the heating or an interruption of the electrically conductive connection between the at least one media line heating element and the at least one line connector heating element. For example, such a maximum temperature T. max at the hotspot is 130 °C, which then corresponds to a switch-off temperature value T at the switch, i.e. the thermal protection device, of 80 °C. At this temperature value, i.e. the first temperature, the thermal protection device in the form of the switch switches automatically, thus breaking the electrically conductive connection between the at least one media line heating element and the at least one line connector heating element. At a temperature at the hotspot of e.g. 80 °C, which corresponds to a second temperature at the switch of e.g. 55 °C, i.e. the switch-on temperature, the thermal protection device in the form of the switch switches again, so that the electrically conductive connection between the at least one media line heating element and the at least one line connector heating element is re-established. The heating of the heatable media line is thus made possible again. The interruption of the heating is therefore reversible.The temperature values ​​mentioned above are examples. The respective temperature differences between the temperature values ​​at the hotspot and at the switch, i.e., the thermal protection device, depend on the respective ambient temperature, the heating performance, and the components used in the specific application.

[0014] For example, the switch is designed as a bimetallic switch. Such a switch is capable of automatically interrupting or disconnecting the electrically conductive connection between the at least one media line heating element and the at least one line connector heating element when a predeterminable switch-on temperature is present, and of automatically restoring or reconnecting the electrically conductive connection between the at least one media line heating element and the at least one line connector heating element when a predeterminable switch-on temperature is present.Such a bimetallic switch switches automatically when a switch-off temperature is reached, thus automatically breaking the electrical connection between the at least one media line heating element and the at least one line connector heating element. It switches again when a second temperature value is reached at the switch, at which a harmless temperature is again present at the hotspot, in order to restore the electrically conductive connection between the at least one media line heating element and the at least one line connector heating element. The respective temperature value pairs of the temperatures at the hotspot and at the switch or the thermal protection device are advantageously determined empirically before commissioning the thermal protection device, and the thermal protection device or the switch is selected accordingly.With regard to a bimetal switch, this means a metal strip combination selected appropriately with regard to the switching temperatures.

[0015] The hotspot can be located away from or close to the area of ​​at least one thermal protection device in the form of a switch. Temperature measurement at the hotspot is not required, as the thermal protection device switches automatically when its specific switching values ​​or temperature values ​​are reached. The switch-off temperature value and the switch-on temperature value at the thermal protection device in the form of a switch are independent of the location of the expected hotspot(s). They are independent of the actual location of the hotspot(s) due to the adaptation to the temperature values ​​at the potential hotspot that require switch-off or allow later switch-on. Therefore, no wiring of the bimetallic switch is required, nor are any additional connections for the switch, as it does not require an additional electrical power supply.It is interposed between at least one media line heating element and at least one line connector heating element and reacts automatically to temperature changes without current. An additional control and / or regulation device or temperature measurement is therefore not required, since the switching operations are carried out automatically by the switch, which is designed in particular as a bimetallic switch, or by the thermal protection device. Further advantageously, the at least one thermal protection device can be arranged in the most heated or heatable area of ​​the at least one line connector, in particular directly on the at least one line connector heating element, or in the most uniform area with regard to temperature fluctuations, thus the most uniform with regard to temperature fluctuations related to the ambient temperature.This makes it possible for the at least one thermal protection device in the form of the switch to be exposed to hardly any temperature fluctuations, while at the same time a temperature increase will occur quickly there, thus enabling the switch or thermal protection device to react quickly. The at least one thermal protection device can be arranged in the area of ​​the cable connector in which tight windings and / or a large number of windings of the at least one cable connector heating element are arranged on or at the cable connector. It is precisely there that the tight windings per cm create a significant thermal shock. 2 or the large number of windings per cm 2The greatest heating power acting on the body of the cable connector. Furthermore, no major temperature fluctuations are expected there, and the temperature rise will occur comparatively quickly. Hotspots typically do not occur in this area. The thermal protection device is therefore not located directly on a hotspot area.

[0016] The thermal protection device is therefore primarily designed as a bimetallic switch, i.e., a temperature switch with automatic reset. This means that when the respective nominal temperature of the switch, i.e., the second temperature that correlates with a permissible (lower) temperature at the hotspot, is undershot, the switch automatically returns to its original position, allowing both the electrical connection between the at least one media line heating element and the at least one line connector heating element to be switched on and off quickly and safely. Such a resettable temperature switch, particularly in the form of a bimetallic switch, is thus a two-point switch or controller. Instead of a bimetallic switch, another type of two-point switch or controller can also be used.

[0017] The at least one bimetallic switch is formed from two firmly connected metal strips made of different metals with different thermal expansion coefficients. The bimetallic switch is advantageously mounted directly on electrical conductors or provided with these. These can be electrically connected to the at least one media line heating element on the one hand and to the at least one line connector heating element on the other, e.g. by crimping. A bimetallic switch or another two-point switch is advantageously used as a thermal protection device, which has a short response time, such as 60 s, and at the switching temperatures occurring in the area of ​​the line connector and are useful for switching the heating on and off. The switching temperatures, i.e. the switch-off temperature values ​​for switching off and the switch-on temperature values ​​for switching the heating on, depend on the respectively used orintended components of the heatable media line.

[0018] To avoid additional heating by the at least one thermal protection device, at least one of the electrical conductors of the at least one thermal protection device can advantageously have a larger diameter or cross-section than the at least one line connector heating element and / or the at least one media line heating element. As the diameter or cross-section increases, the electrical resistance of the line decreases and, accordingly, so does the voltage drop and thus the power loss or heating power of the line. Accordingly, additional heating by the at least one thermal protection device can be avoided by the correspondingly larger diameter or cross-section of the electrical conductors of the thermal protection device compared to the diameters of the at least one line connector heating element and the at least one media line heating element.Since the at least one thermal protection device in the form of a switch is not located at or in the area of ​​the hotspot, it is advisable for the thermal protection device to react quickly enough to avoid damage to the heatable media line or its individual components. Especially when the heatable media line is used to conduct hydrogen, for example, high safety requirements are placed on it, and the thermal protection device should react quickly and precisely. The reaction time of the thermal protection device should therefore not depend significantly on very high or very low temperatures prevailing outside the housing of the heatable media line, in particular of its at least one line connector in which the at least one thermal protection device is arranged.For this reason, it proves to be particularly advantageous to arrange the at least one thermal protection device directly on or at the most heated area of ​​the line connector, preferably directly on the at least one line connector heating element. To make this possible, at least one clip element can be provided with at least one receiving section for receiving the at least one thermal protection device and at least one connecting section, in particular a clamping section, for connecting to the at least one line connector. Particularly preferably, the shape of the at least one clip element can be adapted to the shape of the outside of the at least one line connector and / or its outer diameter in order to bear directly on the at least one line connector heating element arranged there.

[0019] The clip element can be at least partially approximately C-shaped in plan view with a projection in the form of the receiving section in which the at least one thermal protection device can be accommodated. The two arms of the otherwise C-shaped clip element, which form its clamping section, can be used to engage around the outside of the cable connector and to clamp the clip element onto it. This enables the at least one clip element to be held very securely on the outside of the at least one cable connector. The clip element can be pushed radially onto the cable connector, particularly in the region of the tightest windings of its at least one cable connector heating element or the largest number of its windings.Since the at least one thermal protection device is accommodated in the receiving section of the clip element, it thus lies closely on the outside of the at least one line connector heating element arranged there on the line connector.

[0020] Further advantageously, the at least one receiving section of the at least one clip element can be designed such that the thermal protection device is encapsulated therein, in particular is thermally sealed off from the outside. Furthermore, the at least one clip element or at least its at least one receiving section for receiving the at least one thermal protection device can consist of at least one material with poor thermal conductivity for thermally isolating the at least one thermal protection device. By providing such thermal sealing or by providing a material with poor thermal conductivity for the clip element or at least its at least one receiving section for receiving the at least one thermal protection device, independence from the temperatures prevailing outside the at least one housing of the at least one cable connector can be created.

[0021] Instead of arranging or receiving the at least one thermal protection device in the at least one clip element, the at least one thermal protection device can be or become received directly in the external housing of the at least one cable connector. The at least one thermal protection device can in particular be received and mounted in only one housing part, for example one housing half when the external housing is formed from two halves, or in two adjacent, joinable housing parts, e.g. housing halves. If the thermal protection device is received in two adjacent, joinable housing parts, such as two housing halves, the thermal protection device can be arranged such that it projects beyond a parting line between the two adjacent housing parts and is mounted in only one of the two housing parts.The adjacent second enclosure section can then be placed over the thermal protection device mounted on one of the enclosure sections and thus securely and directly accommodated within it. The thermal protection device is thus not mounted on a clip element in the external enclosure, but rather directly within the external enclosure.

[0022] To improve the thermal conductivity between the at least one cable connector heating element and the at least one thermal protection device, an auxiliary material, such as a thermal paste, a thermal pad, or butyl, may be provided. Butyl is suitable for adhesive bonding due to its adhesive and tough properties. A thin butyl layer as a bonding element can conduct heat better than air in an air gap, so that, supported by the achieved surface contact, heat conduction can be improved.

[0023] In this case, a heatable media line is provided that switches the heating of the media line off and on again completely independently. The thermal protection device of the heatable media line is not located at the hotspot, but in a housing of the at least one line connector of the heatable media line, preferably at a particularly hot point. In contrast to the

[0024] According to DE 102 07 794 B4, no breaking of the outer casing of the heatable media line is required, since the at least one thermal protection device is arranged within the at least one housing of the at least one line connector. This, as well as the arrangement of the thermal protection device away from the hotspot while still allowing a fast reaction time of the thermal protection device, means that the heatable media line is particularly suitable for conducting hydrogen or other highly flammable media, in particular when used with hydrogen drives in the automotive sector, such as in fuel cell vehicles. Since no temperature measurement is required and no control and / or regulation device is required, the design of the heatable media line with the at least one thermal protection device is superior to the solutions of the prior art, as described in particular in

[0025] DE 102 07 794 B4 and DE 10 2012 022 232 A1 are significantly less complex and therefore simpler. This also results in lower costs compared to the prior art solutions. The thermal protection device can be firmly accommodated not only in the at least one clip element or its receiving section by encapsulation, but also in the encapsulated housing of the at least one line connector of the heatable media line. Since the heating of the heatable media line is always automatically switched on again, it is not necessary to open the housing to replace the thermal protection device after it has been triggered and thus the heating of the heatable media line is switched off. Therefore, accommodation can easily take place within a encapsulated housing of the at least one line connector.

[0026] To further explain the invention, an embodiment of the invention is described in more detail below with reference to the drawings. These show:

[0027] Figure 1 is a partial sectional side view of a heatable media line according to the invention with a clip element according to the invention for receiving a thermal protection device according to the invention, Figure 2 is a partial sectional view of the heatable media line according to Figure 1 with a clip element and thermal protection device, rotated by 90° compared to the illustration in Figure 1,

[0028] Figure 3 is a partial sectional view of the heatable media line according to Figure 1 from the opposite direction,

[0029] Figure 4 is a perspective view of the clip element according to the invention for receiving the thermal protection device according to the invention,

[0030] Figure 5 is a side view of the clip element according to Figure 4, Figure 6 is a front view of the clip element according to Figure 4,

[0031] Figure 7 is a plan view of the clip element according to Figure 4, Figure 8 is a sketch of a circuit arrangement according to the invention of two media line heating elements, two line connector heating elements with a thermal protection device according to the invention connected in series between them,

[0032] Figure 9 is a perspective view of a second embodiment of a clip element according to the invention for receiving a thermal protection device according to the invention, and Figure 10 is a front view of the clip element according to Figure 9.

[0033] Figures 1 to 3 show a heatable media line 1. This comprises a tubular media line 10 and one or two line connectors 11 connected to the end thereof. Figures 1 and 3 show only one side of the heatable media line 10 and thus only one of the two line connectors 11 arranged at the end of the tubular media line 10. At the opposite end of the tubular media line 10, a line connector is usually also arranged, which, however, is not shown in Figures 1 to 3. By way of example, an angled line connector is shown in Figures 1 to 3. However, a straight line connector can also be arranged at the end of the tubular media line 10. The same line connectors or different ones can be arranged at the two ends of the tubular media line 10, such as, for example,an angled cable connector at one end and a straight cable connector at the other end.

[0034] The tubular media line 10 can be tubular and / or hose-shaped, i.e. tubular or hose-shaped, optionally tubular in sections and hose-shaped in sections. To heat the tubular media line 10, two media line heating elements 2, 3 are arranged along the tubular media line 10. These extend helically around the tubular media line 10 on its outer side 15. To heat the line connector 11, in the example shown in Figures 1 to 3, a line connector heating element 4 is provided, which is arranged around the latter and partially coiled around it. The angled line connector 11 has a first section 110 or a first connection part, which is designed as a connecting shaft and is connected to the tubular media line 10, and a second section 111 or a second connection part, which is angled at a right angle to the first section 110.Connection part, which is designed here as a coupling part and serves for connecting to a plug part of another cable connector or to an assembly, neither of which is shown in the figures. The second section 111 or connection part of the cable connector 11 is provided with external, tight windings 40 of the cable connector heating element 4, as can be clearly seen in Figures 1 and 2.

[0035] The tubular media line 10 is provided with an external sheathing tube or corrugated tube 12 as a thermal protection device. The line connector 11 is provided with an external housing 13 as a thermal protection device. As can be seen in particular from Figures 1 and 3, a section of the corrugated tube 12 also extends into the external housing 13 of the line connector 11. Within the housing 13 of the line connector 11, the media line heating element 2 or 3 and the line connector heating element 4 are arranged closely adjacent to one another and electrically connected to one another. Hotspots 100 can arise in these areas. This can be seen from Figure 1.

[0036] The heatable media line 1 is therefore provided with a thermal protection device 7 in the form of a switch, in particular a bimetallic switch, as overheating protection. This is arranged in the region of the second section 111 or connection part of the line connector 11 on the tight windings 40 of the line connector heating element 4 located there. This can be seen in particular in Figure 2. The thermal protection device 7 is provided with two electrical conductors 70, 71, which are interposed between the media line heating elements 2 and 3 and the line connector heating element 4. Figure 8 shows a circuit arrangement 120 with such a series connection of the media line heating elements 2, 3 and two line connector heating elements 4, 41 with a thermal protection device 7 in the form of a thermal switch with its two electrical conductors 70, 71 connected therebetween.The media line heating elements 2, 3 and the line connector heating elements 4, 41 are each indicated by their electrical resistances R2, R3, R4, R41. These can be different. The media line heating element 3 and the line connector heating element 41 are connected to electrical supply conductors 130, 131 and an electrical connector 135 for connecting the series circuit of the heating elements 2, 3, 4, 41 to an electrical energy source. The electrical connection between the media line heating element 3 and the line connector heating element 41 is made via electrical connection points 132, 133, in particular crimp connections, which are provided or connected to the electrical connector 135 at the respective opposite ends. The electrical connection between the media line heating element 2 and the electrical conductor 70 is made at an electrical connection point 5 or by, for example,a crimp connection, the electrical connection of the media line heating element 3 and the line connector heating element 4 takes place at an electrical connection point 6 or by e.g. a crimp connection, the electrical connection between the line connector heating element 4 and the electrical conductor 71 of the thermal protection device 7 takes place at an electrical connection point 9 or by e.g. a crimp connection, and the electrical connection between the line connector heating element 41 and the media line heating element 2 takes place at an electrical connection point 134. The thermal protection device 7 is thus interposed between the media line heating element 2 and the line connector heating element 4, as can be seen particularly clearly in Figure 8.

[0037] The electrical conductors 70, 71 of the thermal protection device 7 have a larger cross-section or diameter d?o, d?i than the media line heating elements 2, 3 (with their respective diameter d2 or dg) and the line connector heating element 4 (with its diameter d4) in order to avoid additional heating, especially in the area of ​​the potential hotspots 100.

[0038] The thermal protection device 7 is accommodated in a clip element 8, which is clamped onto the outside of the tight windings 40 of the line connector heating element 4, which is applied to the outside of the second section 111 or connection part of the line connector 11. The clip element 8 is shown in detail in Figures 4 to 7. This comprises a receiving section 80 for receiving the thermal protection device 7 and a connecting section 81, which is designed as a clamping section and comprises two arms 82, 83, with which the connecting section 81 can be clamped onto the line connector 11 or its second section 111 or connection part. As can be further seen from Figures 4 to 7, the clip element 8 is approximately C-shaped in plan view with the projection in the form of the receiving section 80, in which the thermal protection device 7 is or is received.With the two arms of the otherwise C-shaped clip element, which form the connecting or clamping section 81 thereof, the cable connector 11 can be gripped on the outside and the clip element can be clamped thereto. This enables a very good hold of the at least one clip element 8 on the outside of the at least one cable connector 11. The clip element 8 can be pushed radially onto the cable connector 11 in the region of the tightest windings 40 or the largest number of turns of its at least one cable connector heating element 4 or 41 or of the two cable connector heating elements 4, 41.

[0039] The two arms 82, 83 of the connecting section 81 of the clip element 8 have slats 84 projecting outwardly from the outside thereof approximately perpendicularly. These serve in particular to stabilize the two arms 82, 83 in order to support the hold on the cable connector 11. Furthermore, they can serve for thermal insulation, since an air cushion can be enclosed between them to the external housing 13 of the cable connector 11. The thermal insulation can help to keep temperature fluctuations in the area of ​​the clip element 8 comparatively low. Furthermore, it is possible to form at least the receiving section 80, if necessary the entire clip element 8, from at least one material with poor thermal conductivity in order to thermally seal off the thermal protection device 7 from the outside, i.e., in the direction of the housing 13.Furthermore, the thermal protection device 7 can be encapsulated in the receiving section 80 of the clip element 8 to provide thermal insulation from the outside, or it can be encapsulated within itself. If necessary, the thermal protection device can also be glued into an encapsulated clip element without encapsulation. The thermal protection device 7 can also be inserted into the clip element 8 or held in the clip element 8 in a form-fitting manner in some other way.

[0040] Figures 9 and 10 show a further embodiment of the clip element 8. This has ribs 86 on its inner side 85, which protrude into the defined interior space 87 of the receiving section 80 of the clip element 8. The ribs 86 serve, on the one hand, to enclose an insulating layer of air when the clip element 8 is pushed onto the tight windings 40 of the second section 111 or connecting part of the cable connector 11. On the other hand, the ribs 86 can create the smallest possible contact area between the thermal protection device 7, which is arranged in the receiving section 80 between the mutually facing ribs 86, and the clip element 8.The two arms 82, 83 of the clip element 8 according to Figures 9 and 10 have an even greater difference in height than the two arms 82, 83 in the embodiment of the clip element 8 according to Figures 4 to 7, as can also be clearly seen from the comparison of Figures 4 to 7 with Figures 9 and 10. The second arm 83 in the embodiment according to Figures 9 and 10 is significantly narrower than the first arm 82. It has only two lamellae 84 or external ribs on the outside, whereas the first arm 82 of the clip element 8 according to Figures 9 and 10 corresponds to the first arm 82 of the clip element 8 in the embodiment according to Figures 4 to 7 and has three lamellae 84 or external ribs on the outside.The second arm 83 of the respective clip element 8 is positioned in the direction of the first section 110 of the line connector 11 when arranged on an angled cable connector according to Figures 1 to 3, so that due to the angular shape and the associated limited space conditions, the second arm 83 has a lower height there, a particularly low height in the embodiment of the clip element 8 according to Figures 9 and 10.

[0041] Since a static temperature is established precisely in the tight windings of the cable connector heating element 4 on the second section 111 or the connecting part of the cable connector 11, thus minimizing temperature fluctuations, arranging the clip element 8 with the thermal protection device 7 in this area is particularly suitable. Furthermore, a temperature increase will occur particularly quickly there, since the greatest heating power is generated there anyway. Accordingly, the thermal protection device can then react particularly quickly, effectively, and reliably.

[0042] The shape of the clip element 8, particularly in the area of ​​its connecting section 81, is adapted to the external shape of the second section 111 or connecting part of the cable connector 11. Furthermore, a shape adaptation can also be provided to the tight windings of the cable connector heating element 4 on the second section 111 or connecting part of the cable connector 11. In any case, particularly close contact between the thermal protection device 7 and the windings of the cable connector heating element 4 is possible.

[0043] Instead of arranging the thermal protection device 7 in the clip element 8 and subsequently enclosing the line connector 11 provided with the clip element 8 and thermal protection device 7 in the external housing 13, the thermal protection device 7 can also be accommodated directly in the external housing 13 of the line connector 11. In this case, it can be accommodated and mounted in only one of the housing parts, in particular housing halves, of the external housing 13. Furthermore, it can be accommodated in two adjacent, joinable housing parts of the housing 13, such as two housing halves similar to those shown in Figures 1 to 3. If the thermal protection device 7 is accommodated in two adjacent housing or housing parts, the thermal protection device 7 can protrude beyond a parting line between the two housing or housing parts and can only be attached to orbe mounted in one of the two adjacent housing or casing parts. The second housing or casing part, or the one adjacent to the first, is then placed over the thermal protection device 7, and the adjacent housing parts are connected to one another. The thermal protection device can thus be accommodated directly in the housing 13, without being accommodated in a clip element. The positioning of the thermal protection device 7 on the outer circumference of the cable connector 11 or of its second section 111 or second connection part can differ in this embodiment from that shown in Figures 1 to 3.

[0044] The thermal protection device 7 functions in such a way that when a cut-off temperature value occurs in the area of ​​the thermal protection device 7, thus in the area of ​​the tight windings of the line connector heating element 4 on the second section 111 or connection part of the line connector 11, the thermal protection device 7, designed as a switch, switches and thereby separates or interrupts the electrical connection. Since the thermal protection device 7 is interposed between the media line heating element 2 and the line connector heating element 4, the heating of the heatable media line is interrupted. Accordingly, the arrangement area of ​​the thermal protection device 7 in the area of ​​the second section 111 or connection part of the line connector 11 subsequently cools down again.As soon as the temperature there falls below a switch-on temperature value specific to the thermal protection device 7, the thermal protection device 7 switches again, so that the electrically conductive connection between the media line heating element 2 and the line connector heating element 4 is restored. This can also be clearly seen in Figure 8. The thermal protection device 7 is thus designed as a two-point switch or controller, in particular as a bimetallic switch. The switch-off temperature value of the thermal protection device 7 correlates with a maximum temperature value at the hotspot 100 requiring switch-off, and the switch-on temperature of the thermal protection device 7 correlates with a second temperature value at the hotspot 100, which allows the heating to be switched on again.The respective switch-off temperature and the respective switch-on temperature of the thermal protection device 7 can be determined empirically in relation to the respective maximum temperature value and the second temperature value at the hotspot 100, and the materials of the thermal protection device 7 can be selected accordingly, in particular the metals of a bimetallic switch. A specific selection of the thermal protection device 7 can be made for the respective application of the heatable media line 1, so that a rapid response of the thermal protection device 7 is possible. During the empirical determination of the temperature values, it is first determined which critical temperatures can occur at the hotspots 100 of the heatable media line, such as a temperature of 130°C at the hotspot, whereby the temperature value depends on the pipe material, i.e., on the material of the tubular media line 10 or the line connector.Subsequently, the temperatures prevailing at the time in the region of the positioning of the thermal protection device 7, thus in the region of the second section 111 or connection part of the line connector 11 and the tight windings of the line connector heating element 4 arranged there, are determined. For example, in the region of the second section 111 or connection part, on which the clip element 8 with the thermal protection device 7 is arranged, a temperature of 80 °C can occur, while at the hotspot 100 a temperature of 130 °C prevails. The thermal protection device 7 then switches at a temperature of, for example, 80 °C. These temperature values ​​are determined for a respective application of the heatable media line 1, and the materials of the thermal protection device 7 are selected accordingly. Further correlating temperature value pairs for possible switch-off temperatures and switch-on temperatures of the thermal protection device 7 can, for example,be 140 °C at hotspot 100 and 80 °C at the thermal protection device 7 or the clip element 8, 130 °C at hotspot 100 and 80 °C or 70 °C or 60 °C at the thermal protection device 7, 120 °C at hotspot 100 and 80 °C at the thermal protection device 7, etc. Of course, various other temperature value pairs can also arise depending on the application.

[0045] The hotspots 100 are located away from the location of the thermal protection device 7, so that no temperature measurement is performed at the hotspot 100. Instead, the appropriate design of the thermal protection device 7 reliably switches the thermal protection device 7 when the shutdown temperature, e.g., 80 °C, is reached. A loss of function of the electrical lines in the form of the media line heating elements 2, 3 or the line connector heating element(s) 4, 41 due to leakage, e.g., at the melted media line 10, can thus be successfully avoided.

[0046] In order to enable even better heat transfer between the line connector heating element 4 and the thermal protection device 7, further aids can be provided, such as a thermal pad, butyl, a thermal paste, etc. By further improving the thermal conduction between the line connector heating element 4 and the thermal protection device 7, an even faster response can be enabled when the switch-off temperature value is reached, since the heat transfer is improved accordingly.

[0047] As an alternative to the embodiment shown in Figure 2, the thermal protection device 7 itself can be directly wound on the outside with the cable connector heating element 4. The windings, particularly tight windings, of the cable connector heating element 4 then extend externally over the thermal protection device 7. This enables even better temperature transfer to the thermal protection device and thus more precise switching operations. However, the heat transfer into the medium flowing through the cable connector 11 is then poorer in this area than in the embodiment shown in Figure 2.

[0048] A further alternative embodiment of the clip element 8 can consist in that it is provided on its outer side, specifically in the region of its receiving section 80, with grooves or another type of track guide elements for arranging the cable connector heating element 4. This provides for an indirect wrapping of the thermal protection device 7 by the cable connector heating element 4 arranged on the outer side of the clip element 8, wherein the clip element 8 continues to enclose or accommodate the thermal protection device 7 in its receiving section 80. In comparison to the previously described embodiments of the arrangement of the thermal protection device on the

[0049] However, this cable connector allows for poorer temperature transfer to the thermal protection device, at least depending on the design of the clip element 8 or its material.

[0050] A further alternative embodiment consists in that the cable connector 11 has a groove or pocket into which the thermal protection device 7 can be received. In particular, the thermal protection device 7 can be fixed in such a pocket in the cable connector using at least one adhesive or bonding agent or fixing agent. After the thermal protection device 7 has been arranged in the pocket in the cable connector 11, the latter is wound with the cable connector heating element 4 so that the winding also encompasses the thermal protection device 7. Instead of providing such a pocket in the wall of the cable connector 11, the thermal protection device 7 can also be arranged at the desired location and overmolded directly during the manufacture of the cable connector 11. Instead of a pocket, the thermal protection device 7 can thus be injected or overmolded directly during the manufacturing process of the cable connector 11.

[0051] Since the thermal protection device 7 is designed as a two-point switch, in particular a bimetallic switch, both the shutdown and the re-energization, i.e. the restoration of the electrical connection of the electrical heating of the heatable media line 1 by the media line heating elements 2, 3 and the line connector heating element 4, occur automatically and completely independently. The heatable media line 1 or its heating is thus completely self-sufficient and does not require control by a control and / or regulating device. The heatable media line can therefore have a long service life without the risk of its heating failing.

[0052] In addition to the embodiments of the heatable media line described above and shown in the figures, which are used in particular for conducting liquid media, especially in the field of automotive applications, such as a fuel cell vehicle, numerous others can be provided, in particular any combinations of the above-mentioned features thereof, wherein in each case at least one thermal protection device is provided for temperature-dependent deactivation and subsequent activation of the heating of the tubular and / or hose-shaped media line and / or the line connector of the heatable media line, the thermal protection device is designed as a switch, in particular as a two-point switch, which is connected in series between the at least one media line heating element of the at least one tubular and / or hose-shaped media line and the at least one line connector heating element of the at least one line connector.Advantageously, the at least one thermal protection device is arranged within the at least one external housing of the at least one line connector of the heatable media line. The electrical connection between the at least one media line heating element of the tubular and / or hose-shaped media line and the at least one line connector heating element of the at least one line connector is automatically interrupted and automatically restored by the thermal protection device in the form of a two-point switch.

[0053] List of reference symbols

[0054] 1 Heatable media line

[0055] 2 media line heating element

[0056] 3 Media line heating element

[0057] 4 cable connector heating element

[0058] 5 electrical connection point / crimp connection

[0059] 6 electrical connection point / crimp connection

[0060] 7 thermal protection device

[0061] 8 clip element

[0062] 9 electrical connection point / crimp connection

[0063] 10 tubular media line

[0064] 11 cable connectors

[0065] 12 corrugated pipe / sheath pipe

[0066] 13 external enclosure

[0067] 15 outside of 10

[0068] 40 tight wraps

[0069] 41 Cable connector heating element

[0070] 70 electrical conductors

[0071] 71 electrical conductor

[0072] 80 recording section

[0073] 81 connecting section

[0074] 82 first arm

[0075] 83 second arm

[0076] 84 slats

[0077] 85 Inside of 8

[0078] 86 rib

[0079] 87 Interior

[0080] 100 Hotspot

[0081] 110 first section / first connecting part of 11

[0082] 111 second section / second connecting part of 11

[0083] 120 Circuit arrangement

[0084] 130 electrical supply cable

[0085] 131 electrical supply conductor 132 electrical connection point / crimp connection

[0086] 133 electrical connection point / crimp connection

[0087] 134 electrical connection point / crimp connection

[0088] 135 electrical connector d2 diameter of 2 dg diameter of 3 d4 diameter of 4 d 70 Diameter of 70 d 7i Diameter of 71

[0089] R2 electrical resistance

[0090] R3 electrical resistance

[0091] R4 electrical resistance

[0092] R41 electrical resistance

Claims

Claims 1. Heatable media line (1) for conducting medium, in particular for conducting liquid medium, comprising at least one tubular and / or hose-shaped media line (10), at least one line connector (11) arranged at the end of the at least one tubular and / or hose-shaped media line (10), at least one media line heating element (2, 3) and at least one line connector heating element (4, 41), wherein the at least one media line heating element (2, 3) is assigned to the at least one tubular and / or hose-shaped media line (10) and serves to heat medium flowing through it, and the at least one line connector heating element (4, 41) is assigned to the at least one line connector (11) and serves to heat medium flowing through it,wherein at least one thermal protection device (7) is provided for temperature-dependent deactivation of the heating of the tubular and / or hose-shaped media line (10) and / or the line connector (11) and is arranged in the region of the at least one line connector (11), and wherein at least the at least one line connector (11) is arranged in at least one external housing (13), characterized in that the at least one thermal protection device (7) is a switch which is connected in series between the at least one media line heating element (2, 3) of the at least one tubular and / or hose-shaped media line (10) and the at least one line connector heating element (4, 41) of the at least one line connector (11) and is arranged within the at least one external housing (13) of the at least one line connector (11),wherein the at least one thermal protection device (7) automatically interrupts and automatically re-establishes the electrically conductive connection between the at least one media line heating element (2, 3) and the at least one line connector heating element (4, 41).

2. Heatable media line (1) according to claim 1, characterized in that the at least one thermal protection device (7) is designed such that, when a predeterminable first temperature is present, it automatically interrupts or switches off the conductive connection between the at least one media line heating element (2, 3) and the at least one line connector heating element (4, 41) and, when a predeterminable second temperature is present, it automatically restores or switches on the conductive connection between the at least one media line heating element (2, 3) and the at least one line connector heating element (4, 41).

3. Heatable media line (1) according to claim 1 or 2, characterized in that the at least one thermal protection device (7) is a two-point switch or regulator, in particular a bimetal switch.

4. Heatable media line (1) according to one of the preceding claims, characterized in that the at least one thermal protection device (7) can be arranged or is arranged in the most strongly and / or most uniformly heated or heatable area of ​​the at least one line connector (11) with respect to temperature fluctuations, in particular directly on the at least one line connector heating element (4, 41).

5. Heatable media line (1) according to one of the preceding claims, characterized in that the at least one thermal protection device (7) is arranged in a region of the line connector (11) in which close windings (40) and / or a large number of windings of the at least one line connector heating element (4, 41) are arranged on or at the line connector (11).

6. Heatable media line (1) according to one of the preceding claims, characterized in that in order to avoid additional heating by the at least one thermal protection device (7), at least one of the electrical conductors (70, 71) of the at least one thermal protection device (7) has a larger diameter (d?o, d?i) than the at least one line connector heating element (4, 41) and / or the at least one media line heating element (2, 3).

7. Heatable media line (1) according to one of the preceding claims, characterized in that at least one clip element (8) is provided with at least one receiving section (80) for receiving the at least one thermal protection device (7) and at least one connecting section (81), in particular a clamping section, for connecting to the at least one line connector (11).

8. Heatable media line (1) according to claim 7, characterized in that the at least one clip element (8) is adapted with regard to its shape to the shape of the outside of the at least one line connector (11) and / or its outer diameter in order to bear directly on the at least one line connector heating element (4, 41) arranged there.

9. Heatable media line (1) according to claim 7 or 8, characterized in that the at least one receiving section (80) of the at least one clip element (8) is designed such that the thermal protection device (7) is encapsulated therein, in particular is thermally sealed off from the outside.

10. Heatable media line (1) according to one of claims 7 to 9, characterized in that the at least one clip element (8) or at least its at least one receiving section (80) for receiving the at least one thermal protection device (7) for thermally isolating the at least one thermal protection device (7) consists of at least one material with poor heat conduction.

11. Heatable media line (1) according to one of claims 1 to 6, characterized in that the at least one thermal protection device (7) is accommodated in the external housing (13) of the at least one line connector (11), in particular in one housing part or in two adjacent housing parts that can be joined together.

12. Heatable media line (1) according to one of the preceding claims, characterized in that an aid for improving the thermal conduction is arranged between the at least one line connector heating element (4, 41) and the at least one thermal protection device (7), in particular at least one thermally conductive pad, at least one thermally conductive paste, at least one butyl.

13. Clip element (8) with at least one thermal protection device (7) for a heatable media line (1) according to one of claims 1 to 10 or 12, wherein the clip element (8) comprises at least one receiving section (80) for receiving the at least one thermal protection device (7) and at least one connecting section (81) for connecting to at least one line connector (11) of the heatable media line (1).

14. Clip element (8) according to claim 13, characterized in that the at least one receiving section (80) of the at least one clip element (8) is designed such that the thermal protection device (7) is encapsulated therein, in particular thermally outwardly is sealed off, and / or that the at least one clip element (8) or at least its at least one receiving section (80) for receiving the at least one thermal protection device (7) for thermally sealing off the at least one thermal protection device (7) consists of at least one material with poor heat conduction.

15. A fuel cell vehicle with hydrogen drive, comprising at least one heatable media line (1) according to one of claims 1 to 12, wherein as overheating protection at least one thermal protection device (7) is designed as a switch which is connected in series between at least one media line heating element (2, 3) of a tubular and / or hose-shaped media line (10) of the heatable media line (1) and at least one line connector heating element (4, 41) of at least one line connector (11) of the heatable media line (1), wherein the at least one thermal protection device (7) automatically interrupts and automatically restores the electrically conductive connection between the at least one media line heating element (2, 3) and the at least one line connector heating element (4) depending on the temperature.

Images