Heating element for temperating a flowing liquid and liquid circuit with a heating element arranged therein

Abstract

The invention relates to a liquid circulation circuit (22) for controlling the temperature of a liquid-cooled battery unit (16) of a drive and energy supply unit (10) of a vehicle drive (14). Liquid circulates in the liquid circulation circuit (22) by means of a pump (24) and can be conveyed through the liquid-cooled battery cell (16). According to the invention, at least one electrically operated heating element (28) is provided in a defined flow section (32) of the liquid circulation circuit (22), said heating element being equipped with flow channels (54), the channel walls of which are designed as planar heating conductors (44). The invention further relates to a heating element (28) for forming a flow section (32) for a liquid circulation circuit (22) provided for heat exchange with a drive battery (16). The heating element comprises at least one electrical heating conductor (44) and a carrier (46) on which the at least one electrical heating conductor (44) is arranged. According to the invention, the carrier (46) is a carrier layer or carrier film (48) which is wound and / or folded multiple times and thereby forms a space structure, one or more flow channels (54) for the liquid being provided between regions of the carrier layer or carrier film (48) which are spaced apart from one another in the radial direction.

Description

TECHNICAL FIELD

[0001] The present invention relates to a heating element for forming a flow section for a liquid circulation circuit, which is arranged for heat exchange with a drive battery. Furthermore, the present invention also relates to a liquid circulation circuit having a heating element arranged therein and flowed through by a liquid. BACKGROUND

[0002] Known drive and energy supply units for electrically operated vehicles, in which the electrical energy supply for one or more electric drive motors is ensured by rechargeable battery or accumulator units, generally require more or less comprehensive energy management, in which not only the output drive power is controlled or regulated in accordance with the current requirements of the driver, but also the electrical energy recovery process for recovering electrical energy in braking or coasting operation of the vehicle is controlled, in which the thermal components are taken into account in a sensible manner, since the accumulator has its highest performance in a temperature range above 15°C, but not too high, preferably below 30°C.

[0003] Since the battery units for vehicle drives are subjected to high loads not only in the charging operation, but also in their prescribed use as an electrical power source for the drive motors, it is generally sensible to thermoregulate the battery units. Especially at low temperatures, the electrical performance and the available capacity of the battery cells used in the battery units drop sharply, so that a rapid heating is expected before starting the journey and during the journey.

[0004] Since the rapid cooling requirements already necessary when the battery unit is strongly warmed up are generally premised on liquid cooling, this cooling circuit can in principle also be used for thermoregulating the battery unit at cold outside temperatures, wherein it is generally possible to use electrical heating elements which can be similar to immersion heaters. These electrical heating elements can be, for example, metal heating coils which can be heated by means of electrical energy, which are flushed by the circulating liquid and can thus heat the liquid as required if necessary.

[0005] Since such heating devices work relatively imprecisely and can only be controlled and regulated with a certain inertia, it is generally possible to achieve an accurate and rapid regulation of the temperature in the liquid.

[0006] A heating device, which is to be used in particular for the electric operation of a motor vehicle, is known from DE 10 2007 001 451 A1. The heating device has a structure which is flowed through by air, which structure is formed by an electrically conductive film for heating the air, which can be electrically heated. The film forms a plurality of channels, which are each flowed through by the air to be heated. The electrically conductive film can in particular have a wave shape, wherein the channels, which are flowed through by the air to be heated, are formed by the individual waves. Furthermore, it is proposed that the wave shape of the electrically conductive film forms a structure which is regionally wound or folded together.

[0007] Since the arrangement in DE 10 2007 001 451 A1 is very sensitive to local changes in the flow rate, here particularly temperature-resistant and thus expensive materials must be used in order that such a heating device can be used for heating passenger cabin air. SUMMARY

[0008] In contrast, it is desirable to improve the known prior art and to provide an efficient, safe and cost-effective heating device for driving batteries.

[0009] This object of the application is achieved by the subject matter of the independent claims. The features of advantageous refinements of the application result from the respective dependent claims.

[0010] In order to achieve this object, the application proposes a heating element for forming a flow section for a liquid circulation circuit, which is provided for heat exchange with a driving battery, wherein the heating element according to the application comprises at least one electrically conductive heating conductor and a carrier, wherein the at least one electrically conductive heating conductor is arranged on the carrier.

[0011] Such a heating element according to the application can be produced cost-effectively. By its embedding in a water circulation circuit, it can be operated here safely.

[0012] Since water has a significantly greater heat capacity than air; the heat capacity of water is approximately four times the heat capacity of air.

[0013] Due to its greater mass, water has a stronger inertia and is distributed more reliably and more uniformly when flowing through the heating channels.

[0014] Furthermore, there is also a safety buffer in the form of a phase converter, which makes it possible to at least partially absorb additional excess energy. Here, the gas that can theoretically occur would be an additional, easily monitored parameter, which can be used for safety in addition to temperature changes. And all the safety buffers mentioned are present, although in a liquid circulation circuit, even a slight deviation from the target temperature can be reliably detected.

[0015] Furthermore, no critical temperature values occur in any of the channels, since each channel wall is hit from both sides by the liquid flow, so that the temperature of the wall is automatically limited to the temperature of the surrounding liquid.

[0016] Furthermore, the heating element is usually only switched on in the initial phase of the operation of the vehicle until the battery has reached its operating temperature.

[0017] It can be provided in the heating element according to the application that the carrier is a carrier layer or a carrier film which is wound and / or folded multiple times and thereby forms a spatial structure, wherein one or more flow channels for the liquid are provided between regions of the carrier layer or the carrier film which are spaced apart from one another in the radial direction.

[0018] It can be provided, however, alternatively, that the carrier is a carrier layer or a carrier film which is at least section-wise wound helically or spirally around the longitudinal centre axis of the heating element, wherein one or more flow channels for the liquid are likewise provided between regions of the carrier layer or the carrier film which are spaced apart from one another in the radial direction.

[0019] According to a further embodiment variant of the heating element according to the application, the carrier layer or the carrier film constituting the carrier for the electrically heatable conductor can form a profile which is non-circular in cross section. By the term cross section used here is meant the cross-sectional direction transverse to the flow direction of the heating element. The profile which is non-circular in cross section can be, for example, a polygonal profile, in particular a quadrangular profile, which can be achieved alternatively by winding of the carrier layer, folding of the carrier layer or by a combination of winding and folding.

[0020] The carrier layer or the carrier film can thus be folded at least regionally and / or formed into the described spatial profile by a meandering shaping, which can be combined as desired or as intended with the winding of the segments of the carrier layer or the carrier film, respectively.

[0021] In such a regional folding and / or meandering shaping of the carrier layer or the carrier film, face segments of the carrier layer or the carrier film which are directly adjacent, for example, can be superimposed on one another, respectively.

[0022] While a carrier layer or a carrier film which is wound in the shape of a cylinder or approximately in the shape of a cylinder can be inserted well into a housing shape which is in the form of a pipe thickening, for example, a housing shape which is in the form of a cuboid is generally easier to manufacture and less costly and also enables a simpler insertion of the heating element by insertion into an opening which can be closed by means of a lid, which can extend over a large proportion of the entire side of such a housing cuboid. In order to bring the heating element into this configuration, which can be predetermined, in particular, by a housing shape which is in the form of a cuboid, the carrier layer or the carrier film can advantageously be folded multiple times, in particular with face segments which lie against one another between creases which extend over the entire length.

[0023] Accordingly, the overall wound, coiled and / or folded, i.e. multiply folded, carrier layer or carrier film, which constitutes a carrier for the electric heating conductor, can generally form an approximately cuboid-shaped spatial profile and be enclosed or accommodated in a cuboid-shaped housing. The electric heating conductor can preferably be equipped with a plurality of flow channels, which can be flowed through by the liquid to be tempered substantially parallel to a longitudinal central axis of the cuboid-shaped housing or heating conductor, in particular. The connections for the supply and the discharge of the liquid are expediently located on mutually opposite end faces of the typically elongate cuboid-shaped housing and can be connected to the flow, for example, by channel expansions there.

[0024] According to an alternative embodiment variant, however, the heating element can also be equipped with a cylindrical housing, which accommodates the electric heating conductor. The electric heating conductor can preferably be equipped with a plurality of flow channels, which can be flowed through by the liquid to be tempered substantially parallel to a longitudinal central axis of the cylindrical housing or heating conductor, in particular.

[0025] The flow channels of the heating element according to the application can preferably each extend with an approximately constant cross section along the longitudinal direction of the heating conductor. The heating element is suitable as a fast and precisely regulatable heating device in that at least a section of the channel wall of the flow channels is configured as a heatable surface, which can cause a fast and effective heat transfer to the liquid when the liquid flows past the heating conductor.

[0026] Alternatively, the heatable surface of the flow channels can extend over the entire length of the respective flow channel.

[0027] It is also conceivable, however, an embodiment of the electric heating element in which the heatable surface of the flow channels can have separately controllable regions in its longitudinal extension, which can be separated from one another and can be loaded with different temperatures. These separately controllable regions can be constituted, for example, by separately from one another sections of the surface heating conductor.

[0028] In principle, it is sensible if the plurality of channels of the heating element each have a similar cross section from the inlet end face to the outlet end face of the heating element, since in this way no significant flow influences are produced on the liquid conveyed through the heating element.

[0029] The heating element according to the application can comprise, for example, one wound and / or folded surface heating conductor, which is equipped with a wave-shaped cover layer, which is applied in a regular line contact on a planar first partial layer and forms flow channels regularly spaced apart from one another between the two layers.

[0030] As in practice different terms are also often used, it is to be clarified here that the wave-shaped layer with or without conductor tracks located thereon can be referred to as wave track or wave-shaped intermediate layer, while the non-wave-shaped layer above or below the wave track can be referred to as cover layer. According to a first embodiment variant of the electric heating element according to the application, the non-cover layer does not have conductor tracks; while according to an alternative embodiment variant of the heating element, the non-cover layer can likewise be equipped with conductor tracks which function as heating conductors.

[0031] Alternatively, the planar first partial layer, i.e. the straight or non-wave-shaped cover layer, and the wave-shaped cover layer or here possibly also referred to as wave-shaped intermediate layer, are respectively electrically conductively coated on both sides and configured as temperature control surfaces.

[0032] Alternatively, the planar first partial layer, i.e. the straight or non-wave-shaped cover layer, and the wave-shaped cover layer or here possibly also referred to as wave-shaped intermediate layer, are respectively electrically conductively coated on both sides and configured as temperature control surfaces.

[0033] Furthermore, in the heating element according to the application, it is advantageous if the electrically conductive coating of the partial layers is respectively equipped with conductor tracks which are narrowly spaced apart from one another and distributed over the layer surface, whereby an effective heat transfer to the liquid flowing through can be achieved.

[0034] In the heating element, the wound assembly of heating conductors can form a uniform spiral or a similar volute arrangement in cross section, i.e. transverse to the longitudinal central axis of the cylindrical housing, in which the distance between the wound layers lying on top of one another is largely constant. This in particular relates to the configuration of the heating element using a cylindrical housing.

[0035] In the above-mentioned oblong housing as a meaningful configuration alternative, the folded and / or wound sections can also be irregularly or unevenly spaced apart from one another or slightly compressed in places in order to match the housing shape, so that an uneven distance between the wound layers lying on top of one another and / or the folded layers lying against one another can be produced, but this generally does not negatively affect the heat transfer between the heating conductors and the liquid to be temperature-controlled.

[0036] Optionally, the heating element can additionally be equipped with at least one temperature measuring region, which is advantageously located in the region of the planar and / or undulating segments or partial layers and thus enables a relatively precise temperature detection within the heating element. In the at least one conductor track loop, for example, the temperature-dependent change in resistance can be used as a temperature sensor, so that the variable temperature coefficient of the metal can be utilized. A temperature sensor integrated into the heating element is thus provided, which does not change the flow pattern. If the sensor loop is distributed over the entire heating surface, it can measure the average temperature. If the sensor loop is placed only in the outflow region, the resulting water temperature can be detected.

[0037] The heating element constitutes a membrane water heater. The corrugated and spirally wound and / or multiply folded membrane heating element comprises a heating conductor track which can be heated by the application of a voltage. The heating conductor track can be particularly shaped or profiled with a varying distribution density on the heating membrane, so that the heating power density can be optimized locally if necessary. It can thus be advantageous, for example, to heat more strongly the region of the heating spiral or the section of the folded heating element in which the cold water or the liquid to be tempered first enters. In the case of inhomogeneous throughflow, the regions which are flowed through more strongly can also be heated more strongly, while the regions which are flowed through more slowly are heated more weakly, in order to achieve a uniform heat distribution in the liquid. In general, it is easier to adjust the local heating power ratio to profile the flow as uniformly as possible with increased effort.

[0038] A further option is to divide the heating conductor into a plurality of heating loops. The heating power can thus be easily increased or reduced by switching on or off more loops. In addition, expensive power semiconductor elements, which require a pulse width modulation control for their power adjustment, can be dispensed with in this way.

[0039] The heating element according to the application enables the heating of all types of water cooling systems for battery cells, in particular for traction batteries in vehicle drives.

[0040] As already mentioned above, some terms have been created, for example in corrugated paper materials, which include the term wave web, i.e. the undulating intermediate layer, and the term cover layer, i.e. the straight and non-undulating layer on or under the wave web. If a layer, a non-undulating layer or an undulating layer is mentioned in the present context, the terms web, wave web and carrier web can also be used instead, respectively. The term web is thus generally more purposeful than the term layer, since the term web can generally be understood more specifically than the term layer, which can generally also be understood as a synonym for the term non-physical plane.

[0041] For this reason it is to be clarified here that the term "wave layer" is replaced by the term "wave web" which is used here to mean a wave-shaped planar element which is provided, inter alia, with the conductor tracks described above. Furthermore, it is to be clarified here that the term "carrier web" is used here to mean a planar element which serves for the mechanical stabilization of the wave web, possibly only sectionally effective mechanical stabilization of the wave web. Both web types can in turn each consist of a plurality of layers. The web types can thus each have one or a plurality of carrier layers or cover layers, if necessary.

[0042] Since wave webs which are provided with an upper carrier web and a lower carrier web are generally difficult to roll up and since such a composite will tend to buckle, the composite which is used here as a rollable and / or foldable structure of the heating element preferably has at least one carrier web and at least one wave web, wherein the carrier web and the wave web are arranged overlapping one another. Furthermore, the carrier web and the wave web are fixed to one another at least pointwise, preferably along lines. Finally, the wave web is preferably fixed to the carrier web only on one of its two surfaces, in order to achieve the flexibility of the resulting composite.

[0043] In particular, the composite can comprise exactly one carrier web and exactly one wave web, which are arranged overlapping one another and are fixed to one another at least pointwise, preferably along lines.

[0044] The greatest heating power in the smallest space is achieved when both the carrier web and the wave web carry heating resistors or are provided with conductor tracks and are thus embodied as electric heating elements, respectively.

[0045] However, other composite structures which likewise have a high heating density and which are therefore able to be used meaningfully in practice are producible more easily technically. In this alternative composite structure of the electric heating element according to the application, the wave web can carry heating resistors and be configured as a heating element, while the carrier web does not carry heating resistors and thus functions as a pure carrier web without heating function. In this variant, the carrier web thus has no electrically conductive and heating function and serves only as a pure mechanical carrier. Although this variant is not the technically possible optimum in terms of the maximum heating power achievable in a given volume, the cost-effectiveness ratio can be configured particularly advantageously in this variant.

[0046] Furthermore, technical solutions can be considered which do not employ the wave composite described above and which are also contained in the general inventive definition. In this variant, a planar heating element can be simply rolled up in a spiral. Since there is no wave as a spacer in order to separate the individual windings from one another. Linear spacers can therefore be installed at regular intervals in order to maintain the spacing between the different winding layers and to enable an essentially unimpeded flow of the liquid to be heated between these winding layers.

[0047] It is additionally required to be clarified here that the application can comprise a heating element as defined below in addition to the heating elements set forth above in the different embodiments. Thus, the application also relates to a heating element for heat exchange with a liquid circulation circuit, wherein the heating element comprises at least one heating web, at least one spatial arrangement pattern, at least one spacer element and at least one channel.

[0048] If at least one heating web of a heating element is mentioned here, the term heating web refers to a defined planar structure for heating, which planar structure converts electrical energy into thermal energy when energized.

[0049] If at least one spatial arrangement pattern of a heating element is mentioned here, it is required to be defined that the spatial arrangement pattern arranges at least two sections of a heating web overlapping one another in an overlapping area.

[0050] The above-mentioned spacer element is arranged between the overlapping sections of the heating web in the overlapping area.

[0051] Finally, if at least one channel of a heating element is mentioned here, it is required to be defined that the channel serves to guide a liquid along the heating web. Furthermore, the walls of the at least one channel are constituted by two overlapping sections of the heating web and the spacer element.

[0052] Preferably, the spatial arrangement pattern can comprise at least one of the following structures: - the heating web is wound helically around a central axis, - the zigzag fold is folded into a stack of cuboids, - the heating web is wound into a cuboid shape around a central axis.

[0053] Preferably, the spacer element is selected from: - a wave web that keeps two sections of the heating web apart, - a carrier web that keeps two wave-shaped sections of the heating web apart, - a plurality of elongated tabs or strips that keep two sections of the heating web apart.

[0054] Preferably, at least the heating web or the wave web is implemented in multiple layers. In this case, preferably at least one of the following layers: - a first cover layer, preferably waterproof and electrically non-conductive, - an electrical cover layer, preferably with a resistive material, - a second cover layer, preferably identical to the first cover layer.

[0055] To achieve the above-mentioned object, the application proposes, in addition to the electric heating element described in the different embodiments, a liquid circulation circuit for temperature regulation of a liquid-cooled battery unit of a drive and energy supply unit of a vehicle. The liquid is circulated in the liquid circulation circuit by means of a pump and can thus be conveyed through the liquid-cooled battery unit.

[0056] In the defined flow section of the liquid circulation circuit there is at least one electrically operated heating element, which is equipped with flow channels, the channel walls of which are configured as planar heating conductors, in order to enable heat transfer to the liquid circulating or flowing through these flow channels, which can then enter the battery unit and heat it up.

[0057] In the liquid circulation circuit according to the application, the at least one electric heating element can in particular be configured according to one of the previously described embodiments.

[0058] Furthermore, the liquid circulation circuit according to the application can advantageously be equipped with a control and / or regulation unit for temperature regulation, which can load the electric heating element with an adjustable supply voltage depending on the respective heating requirement of the liquid.

[0059] The electric heating element advantageously used in the liquid circulation circuit according to the application offers a particularly high heating power density due to its structure and configuration, which is up to 60 kW / m 2 or more. This high heating power density is essentially based on the properties of the cooling liquid, which can absorb and transfer significantly more energy even at slow throughflow than, for example, in the case of air to be heated. In air heat exchangers, the heating power density hardly reaches values of approx. 8 kW / m 2 , while the heating element according to the application offers heating power density values that are mostly multiples of those in air heating devices or air heat exchangers.

[0060] A further difference to air heat exchangers lies in the different materials that can be used. Since higher temperatures occur in air heating devices and since there is in principle a risk of overheating there, carbon materials and / or PTC materials, i.e. materials with a positive temperature coefficient, must be used there in particular, while in the electric heating element according to the application metal conductors, such as suitable aluminum alloys, can be used without further restrictions.

[0061] On the other hand, the liquid heat transfer medium used accordingly reasonably requires the metal material used to be resistant to the chemical reaction medium, which can contain ethylene glycol. The material should also be resistant to hydrolysis. This relates not only to the housing parts, but also to the films used as heating conductors accordingly. Furthermore, higher costs are required in terms of electrical insulation and sealing of the system for guiding the liquid compared to air-based systems. BRIEF DESCRIPTION OF DRAWINGS

[0062] Embodiments of the application and their advantages are explained in detail below with reference to the drawings. The dimensions of the various elements in the drawings are not necessarily to scale as some of the shapes are simplified and others are shown exaggerated in relation to the other elements for the sake of better understanding.

[0063] Figure 1 A schematic line diagram of a liquid circulation circuit is shown, which has an electric heating element arranged therein, which can be used to temper the liquid circulating through the battery cells.

[0064] Figure 2A A schematic and perspective view of a heating element according to Figure 1 through which liquid can flow is shown.

[0065] Figure 2B An internal structure of a heating element according to Figure 2A is shown, which has a plurality of flow channels through which liquid to be heated can flow.

[0066] Figure 2C A layer structure of a heating conductor which can be inserted into a heating element is shown.

[0067] Figure 2D An end face view of a heating conductor having a plurality of flow channels is shown.

[0068] Figure 3 A first embodiment variant of a conductor track structure of a planar heating conductor is shown in a schematic top view.

[0069] Figure 3 A conductor track structure according to Figure 3 A in a wound structure, which can be located in a heating element, is shown in a schematic and perspective view.

[0070] Figure 3 A second embodiment variant of a conductor track structure of a planar heating conductor is shown in a schematic top view.

[0071] Figure 3 A wound structure of a conductor track as can be found in a heating element is shown in a schematic and perspective view.

[0072] Figure 3 A third embodiment variant of a conductor track structure of a planar heating conductor is shown in a schematic top view.

[0073] Figure 3 A wound structure of a conductor track according to Figure 3 E as can be found in a heating element is shown in a schematic front view.

[0074] Figure 4A An alternative configuration of the heating element is shown in a schematic and perspective view, in which the wound carrier layer forms an approximately cuboid profile.

[0075] Figure 4B An embodiment variant of the heating element according to the application is shown, which is packed into a cuboid housing. Figure 4A

[0076] Figure 5A and 5B An embodiment variant of the electrical line connection is shown, which is guided through the housing wall of the heat exchanger by means of a sealing element.

[0077] Figure 6A and 6B Another alternative configuration of the heating element is shown in a schematic and perspective view, in which an optional support film and a multiply folded carrier layer form an approximately cuboid profile.

[0078] Figure 7A A first variant of the planar heating conductor layer structure is shown.

[0079] Figure 7B A second variant of the planar heating conductor layer structure is shown.

[0080] Figures 8A to 8F Different variants of another alternative design variant of the heating conductor of the electric heating element are shown, which do not require the above-described wave compound, but have spacers configured between the heating conductors wound on one another.

[0081] The same reference signs are used for elements of the same or identical action of the application. Furthermore, for the sake of clarity, only the reference signs required for the description of the respective figure are shown in the individual figures. The shown embodiments are merely examples to illustrate how the device according to the application can be realized and are not an exhaustive limitation. DETAILED DESCRIPTION

[0082] Figure 1 A schematic diagram shows a drive and energy supply unit 10 for an electric vehicle drive 12, which has at least one electric drive motor 14, the electrical energy supply of which is ensured by a rechargeable battery or accumulator unit 16 having a plurality of battery cells 18. The battery cells 18 together form the battery or accumulator unit 16 and for this are in a reasonable arrangement grouped in series in order to be able to provide the desired output voltage. Furthermore, usually a plurality of such battery cell groups are connected in parallel to ensure the desired total electrical power. The construction of such a battery or accumulator unit 16 is not shown here in detail, since it can be assumed to be known to the person skilled in the art.

[0083] ​Between the drive motor 14 and the battery or accumulator unit 16 there is at least one control and regulating unit 20, by means of which not only the output driving power is controlled or regulated in accordance with the current requirements of the driver, but which control and regulating unit 20 is also generally responsible for the electric energy recovery in the braking or coasting operation of the vehicle. Furthermore, the entire energy and charging management can be monitored, controlled and regulated by means of this control and regulating unit 20, if necessary. The complex functional range of such a control and regulating unit 20 is not considered in detail here, but is likewise considered to be fully known to the person skilled in the art.

[0084] Since such a battery unit 16 or accumulator module (as shown here schematically and as part of the drive and energy supply unit 10 of the drive motor 14 of the vehicle drive 12) is subjected to relatively high electrical, thermal and possibly mechanical loads not only in the charging operation but also in its prescribed use as an electrical power source, and since the battery units 18 generally used for this purpose can best develop their electrical properties and achieve their maximum capacity within a limited temperature range, it is generally meaningful to temperature-regulate the battery units 18 or the entire battery unit 16. Furthermore, significant heat is generated not only in the charging operation (especially in the case of fast charging processes with high power), but also in the case of high power requirements by means of the driving operation, so that temperature regulation is often required during the entire operation.

[0085] In Figure 1 The drive and energy supply unit 10 shown here schematically comprises a liquid circulation circuit 22, which has at least one pump 24 for circulating a liquid circulating in the liquid circulation circuit 22. This liquid circulating by means of the pump 24 flows through the battery unit 16 and can optionally flow through a heat exchanger 26, by means of which the circulating liquid and thus also the battery unit 16 can be cooled as required when the battery units 18 are strongly heated as a result of the charging process or because of high power requirements by means of the drive motor 14 of the vehicle drive 12.

[0086] However, since the temperature range for the high performance of the battery units 18 does not lie significantly below approximately 15 to 20°C, there is also a controllable and / or regulatable electric heating element 28 in the liquid circulation circuit 22, which is also flowed through by the circulating liquid. This electric heating element 28 (which obtains a controlled supply voltage 30 from the control and regulating unit 20) is explained in detail below in terms of its construction and function as part of the drive and energy supply unit 10 and as part of the liquid circulation circuit 22 coupled therewith.

[0087] Thus, the electric heating element 28 shown here serves to quickly and efficiently heat the liquid circulating in the liquid circulation loop 22, in which a defined flow section 32 is formed within the liquid circulation loop 22 and thus can be responsible for heat exchange with the battery cells 18 of the battery unit 16.

[0088] Figure 2A and 2B The perspective view shows an embodiment of an electric heating element 28 through which liquid flows, which can be used for targeted and controllable heating of the liquid circulating in the liquid circulation loop 22 (see Figure 1 ). The heating element 28 comprises a housing 34 having a cylindrical body 36 and mouth funnels 38 tapering towards both ends, which mouth funnels open into pipe connections 40, respectively.

[0089] The two tapering mouth funnels 38, for example, each have a length in the direction of the longitudinal center axis 42, which corresponds approximately to one quarter of the length of the cylindrical body 36. The cylindrical body 36, for example, can have a diameter corresponding to half the length of the cylindrical body. The reasonable cross section of the flow section 32 shown in Figure 1 with the electric heating element 28 arranged therein between the two pipe connections 40 can be approximately one quarter or less of the outer diameter of the cylindrical body 36.

[0090] In order to reduce the flow resistance, the pipe connections 40, which open into the housing 34 on both sides, can be aligned with each other, preferably simultaneously with the longitudinal center axis 42 of the housing 34 and its cylindrical body 36, as exemplarily shown in Figure 2A .

[0091] Thus, the liquid circulating in the liquid circulation loop 22 can enter the housing 34 of the heating element 28 from the first pipe connection 40 and flow out of the housing 34 again from the opposite second pipe connection 40, wherein the liquid flowing out can be tempered, i.e. heated, as required, relative to the inlet side. In order to achieve this, the liquid flowing through the heating element 28 can be tempered or heated within the cylindrical body section 36 of the housing 34 by means of the electric heating conductor 44 arranged there.

[0092] As Figure 2B , 2C and 2D overview diagram can visually show that there are actually electric heating conductors 44 within the housing 34 of the electric heating element 28 (see Figure 2A ), which electric heating conductors form electrically conductive layers on the surface of a face carrier 46 that is compactly wound together. The shown carrier 46, on which the electric heating conductors 44 are arranged, is a two-part face carrier layer 48 or carrier film 48, whose first partial layer 50 is first oriented planarly in order to apply a second partial layer 52 thereon, asFigure 2C As visually illustrated.

[0093] Not only located Figure 2C The first portion layer 50 is a plane below the side view, and a second portion layer 52 disposed thereon and fixed to the first portion layer 50 is equipped with heating conductors 44, which are described in more detail below, so as to form a heatable flow channel 54. Because the second portion layer 52 has a corrugated structure with a uniformly meandering extended surface, the second portion layer can be placed on the first portion layer 50 in line contact and then fixed to the first portion layer 50, which is in Figure 2C It is also clearly visible in the middle.

[0094] Because the two side-facing surfaces of the carrier 46, the two partial layers 50 and 52, are respectively equipped with heating conductors 44, and because the cavity formed between the two joined partial layers 50 and 52 forms flow channels 54 respectively (according to...) Figure 2D All these flow channels extend parallel to the longitudinal central axis 42 of the heating element 28, so by selectively applying electrical energy to the heating conductor 44, the liquid flowing through the flow channel 54 can be heated to the desired increased temperature.

[0095] from Figure 2D As can be seen, the double-layered carrier 46 is spirally wound or coiled around the longitudinal central axis 42 of the heating element 28, thereby providing numerous flow channels 54 for the liquid flowing through the heating element 28 between the radially spaced regions of the carrier 46 or carrier film 48. Because the meandering, wavy second layer 52 applied to the first portion layer 50 of the carrier 46 defines a certain thickness of the carrier 46 thus formed, for example, it produces... Figure 2D The coiled structure of the carrier film 48, which is rolled up according to the diameter of the housing 34, shown in the figure, wherein the wave structure of the second layer 52 and the distance between the troughs and crests predetermine not only the opening cross-section of the flow channel 54, but also predetermines the distance between the troughs and crests according to the diameter of the housing 34. Figure 2D The distance between consecutive wound layers in the spirally wound carrier membrane 48.

[0096] The total number of possible flow channels 54 is also determined by the number of winding layers of a double-layer carrier film 48, consisting of two joined partial layers 50 and 52, that fits into the cylindrical housing 34, forming a carrier 46 having an electrically heated conductor 44 applied thereto. (See from...) Figure 2DAs can be seen, the interior of the cylindrical housing 34 is thus equipped with the mentioned plurality of flow channels 54, which can be flowed through by the liquid to be tempered parallel to the longitudinal central axis 42 of the cylindrical housing 34. An alternative embodiment variant will be set forth and illustrated in the figures below, in which the flow channels 54 extend meander-like due to the structurally different second partial layer 52, which can be desired for flow-technical reasons.

[0097] Since the wave structure of the second partial layer 52 is according to Figure 2C uniformly distributed over its entire area, the flow channels 54 thus formed each extend with approximately constant cross section along the longitudinal direction of the housing 34 of the heating element 28. The desired heat transfer onto the liquid flowing through the flow channels 54, which is used to temper the battery cells 18 of the drive and energy supply unit 10 (see Figure 1 ), is achieved by the electrical heating conductors 44, which are formed at least in partial regions of the channel walls, which will be set forth in detail below.

[0098] Preferably, the surface heating conductors 44 extend over the entire length of the respective flow channels 54 within the housing 34. This requires an entire-area coating of the respective carrier film 48, preferably on the first partial layer 50 and on the wave-shaped second partial layer 52 bonded thereto.

[0099] For the surface heating conductors 44, which are applied on the respective carrier film 48, i.e. on the first partial layer 50 and the second partial layer 52, as conductor tracks 56 which are closely bonded to one another, have a parallel course and are turned through 180° at the end sides, it is possible according to Figure 3 A, Figure 3 C or Figure 3 E to have different additional functions. Thus, Figure 3 A intuitively shows an embodiment variant in which one narrow partial section of the conductor tracks 56, i.e. the right partial section in the top view of the carrier film 48 shown on the left, is configured as a temperature measurement region 58, which can provide a corresponding temperature signal to the control and regulation unit 20 shown in Figure 1 , so that a temperature regulation of the unit 20 can be achieved.

[0100] The conductor tracks 56 applied to the carrier film 48 cause a desired heating upon current flow through the conductor tracks 56 due to their internal electrical resistance. Since the conductor tracks largely cover the entire surface of the carrier film 48, this surface serves as a surface heating device.

[0101] In the right-hand view of Figure 3 A (here the carrier 46 is shown in the unfolded state), this temperature measurement region 58 is located in the right-hand section of the carrier 46, i.e. close to the downstream mouth funnel 38 of the heating element 28 (seeFigure 2A ), so that the temperature after flowing through the flow channel 54 of the heating element 28 can be effectively detected and provided as an electrical signal to the control and regulation unit 20 (cf. Figure 1 ).

[0102] Furthermore, Figure 3 The schematic top view of C shows an embodiment variant in which one narrow partial section of the conductor track 56, namely the one located on the left in the top view of the shown carrier film 48, is configured as an independently controllable subregion 60, whereby a graduated temperature regulation can preferably be achieved. Thus, this independently controllable subregion 60 of the conductor track 56 can be controlled separately from the rest and can in particular be loaded with a different temperature, so that for example this subregion 60 can be heated more intensively.

[0103] In Figure 3 The schematic top view of C shows an embodiment variant in which one narrow partial section of the conductor track 56, namely the one located on the left in the top view of the shown carrier film 48, is configured as an independently controllable subregion 60, whereby a graduated temperature regulation can preferably be achieved. Thus, this independently controllable subregion 60 of the conductor track 56 can be controlled separately from the rest and can in particular be loaded with a different temperature, so that for example this subregion 60 can be heated more intensively. Figure 3 The perspective view of D (in which the carrier 46 is shown in the wound state) shows, according to one preferred configuration of the heating element 28, that this independently controllable subregion 60 is located in the left section of the carrier 46, namely close to the upstream mouth funnel 38 of the heating element 28, so that after flowing through the flow channel 54 of the heating element 28, the temperature can first be increased more intensively and then further increased with moderate heating.

[0104] Furthermore, Figure 3 The schematic top view of E visually shows a further embodiment variant in which defined longitudinal sections 62 of the carrier film 46 can be configured as independently controllable subregions of the conductor track 56, whereby again a graduated temperature regulation can be achieved, but here for the case of a non-uniformly flowing channel 54, so that the liquid passing there is also heated non-uniformly. By means of such independently controllable longitudinal sections 62, which for example can be temperature-regulated more intensively, the more weakly flowing flow channels 54 can be heated more intensively, so that a more uniform temperature regulation of the liquid can be achieved over the entire cross section of the heating element 28 within the housing 34.

[0105] However, such a graduated temperature regulation requires a correspondingly spatially resolved temperature measurement, which can be ensured by a correspondingly divided temperature measurement region 58 (cf. Figure 3 A). The different temperatures in different subregions of the flow channel 54 can for example be determined according to Figure 3 The schematic front view of the wound structure of the conductor track shown on the right of the top view of E (according to Figure 3 F) is visualized. Thus, Figure 3 F shows a top view of the wound carrier 46 with the differently measured temperature profile of the liquid flowing through the channel 54 (cf. Figure 3 The graphic supplement on the right of F).

[0106] The different regions 58, 60 and 62 of the conductor track structure 56 can also be selectively combined with one another, so that different temperature measurement regions 58 (cf. Figure 3 A) can be combined in an arbitrary and accordingly purpose- appropriate manner with sub-regions 60 (cf. Figure 3 B) which can be more strongly temperature-regulated in the flow direction and / or with longitudinal sections 62 of the conductor track 56 which can be more strongly or more weakly temperature-regulated and accordingly independently controllable.

[0107] The arrows to the right of Figure 3 A, 3C and 3E, pointing to the right Figure 3 B, 3D and 3F, are intended to illustrate the deformation process of the planar carrier 46, in which the two partial layers 50 and 52 are joined to one another, first according to Figure 2C A, and then according to Figure 2B B and C. 2D The carrier 46 is wound in the manner shown, so that it assumes the barrel-shaped profile shown in A and

[0108] B and C, and can be inserted into the interior of the cylindrical housing 34. Figure 4A A schematic and perspective view is intended to illustrate one alternative configuration of the heating element 28, in which the double-layered carrier 46 is not precisely helically wound or wound around the longitudinal center axis 42 of the heating element 28. The carrier 46 or carrier film 48 can be configured, in particular, in the same or a similar manner as shown with reference to Figure 2D A and described above. In the carrier film 48 shown in Figure 2C A, the distribution of the conductor tracks 56 and / or temperature measurement regions 58 can be configured, in particular, according to Figure 4A A, 3C and / or 3E. Figure 3 According to the variant shown in

[0109] A, the winding of the carrier 46 can preferably result in a cuboid-shaped outer contour of the entire electrically heated conductor 44, so that between the regions of the planar carrier 46 or carrier film 48 which are spaced apart from one another in the radial direction, although a large number of flow channels 54 are provided for the liquid flowing through the heating element 28. However, due to the different distances between the layers of the carrier film 48 which are superposed on one another, the flow channels 54 in the successively wound layers of the wound carrier 46 can have different effective cross sections. However, this effect can be overall negligible or technically acceptable due to the small overall cross section difference. Figure 4A Since the serpentine undulating second partial layer 52 applied to the first partial layer 50 of the carrier 46 defines a certain thickness of the thus formed carrier 46, for example, a

[0110] A cuboid-shaped housing 35 which is available for use is shown in Figure 4A A, for which reference is made to Figure 4BThe size of the wound structure is determined by the dimensions of the second layer 52, wherein the waveform structure of the second layer 52 and the distance between each trough and crest are predetermined not only by the opening cross-section of the flow channel 54, but also by the dimensions of the wound structure. Figure 4A The distance between the continuously wound layers in the carrier film 48, which is spirally wound around the longitudinal central axis 42 only in the internal region, and the carrier film 48 exhibits a certain distance from the longitudinal central axis 42 as the radial distance increases. Figure 4A The visible outline is a coiled shape resembling a cuboid.

[0111] Alternatively, the configuration of the completed heating conductor 44 can be maintained in the desired profile and mechanically stable by means of a support strip 64 that is wound or tightened around the periphery of the heating conductor 44.

[0112] Figure 4B The schematic and three-dimensional view intuitively shows the... Figure 4A Possible mounting configurations include a heating conductor 44 wound in an approximately cuboid shape, which is inserted into a cuboid housing 35. The housing 35 may preferably have a housing opening 66 of a correspondingly designed size, for example, the size of the entire side of the housing 35, such that a heating conductor can be inserted through this housing opening 66 according to... Figure 4A The heating conductor 44 is formed by the wound carrier film 48.

[0113] Figure 4B The illustration shows a rectangular housing 35, but the housing cover (not shown here) has been removed, thus exposing the housing opening 66 and the heating conductor 44 inserted into the housing 35.

[0114] The configuration of the funnel 38 located on the opposite end faces of the cuboid shell 35 and the pipe joints 40 respectively connected to the funnel can be referred to above. Figure 2A The described implementation is carried out in a corresponding manner, but the opening funnel 38 should be matched in a reasonable manner to the profile of the cuboid shell configuration and its respective rectangular or square end faces.

[0115] Figure 5A and 5B The perspective view shows a possible embodiment of an electrical wiring connection 68 for supplying electrical power to the electrically heated conductor 44 and transmitting electrical signals. This is because the entire electrically heated conductor 44 is located within a cylindrical housing 34 through which liquid flows (see [reference]). Figure 2A ) or rectangular shell 35 (see Figure 4B Therefore, reliable sealing should be ensured for the wiring connections entering and exiting the housings 34 and 35.

[0116] This can be achieved, for example, by following... Figure 5A and / orFigure 5B The configuration of the electrical connection line 68 ensures that, in this configuration, the electrical connection line 68 is equipped with an elongated sealing element 70, which can achieve the desired sealing effect when the line connection 68 is installed and the housings 34 and 35 are closed.

[0117] Figure 6A and 6B The schematic and three-dimensional view also visually illustrates an alternative embodiment of the heating conductor 44, in which the layers of the heating conductor are not wound but folded, such that they are formed in... Figure 6B The structure of the heating conductor 44 shown includes carrier layers 72, each consisting of a carrier film 48 folded 180° along its longitudinal edges and stacked on top of each other. To stabilize this layer structure in its shape, it can be reused according to... Figure 4A Support straps and / or supportive wrapping 74 (see Figure 6B )wait.

[0118] Figure 6A Visually illustrating a pre-manufacturing stage in which the carrier membrane 48 is covered at least on one side (preferably both sides) by the support membrane 76, which may be particularly associated with the carrier membrane 48, i.e. with the first and second partial layers 50 and 52 (see...). Figure 2C Adhesive or otherwise attached there. Fold lines, i.e., creases, can be pre-defined by means of the longitudinal side seams 78 or weakened portions arranged at defined intervals, where the carrier film 48 should be folded 180° to obtain according to Figure 6B The heating conductor 44 has a folded and layered structure.

[0119] According to Figure 4A Compared to the rectangular coil required for the transformation, according to Figure 6A and 6B An additional advantage of implementing the modified heating conductor 44 is that it is easier to implement in terms of manufacturing technology.

[0120] at last, Figure 7A and 7B Two alternative implementation variations are visually illustrated. Therefore, a front view from the end face of the double-layered carrier 46 ( Figure 7A As can be seen from above, the longitudinal extension direction of the regularly spaced crests and troughs of the wavy second layer 52 (which is connected to the planar lower layer 50 and together with the lower layer forms a flow channel 54) is perpendicular to the planar carrier membrane 48. Figure 7A (Below) the side edge.

[0121] In this variant, the winding direction is transverse to the longitudinal direction of the crests and troughs of the second layer 52, such that when the carrier 46 is wound or rolled up (see... Figure 2Band Figure 2D The longitudinal extension direction of all parallel flow channels 54 is also parallel to the entire heating element 28 (see...). Figure 2A The longitudinal extension direction 42 extends. Therefore, the temperature-regulating liquid flowing through the flow channel 54 is not deflected.

[0122] Conversely, according to Figure 7B In the second embodiment, the longitudinal extension direction of the regularly spaced crests and troughs of the wavy second portion layer 52 (which is connected to the planar lower portion layer 50 and together with the lower portion layer forms the flow channel 54) is not precisely perpendicular to the side edge of the still planar carrier film 48, but forms an acute angle with the side edge, for example, from 10° to about 25° (see [link to embodiment]). Figure 7B (below).

[0123] However, even in this implementation variant, the winding direction is transverse to the side edges of the rectangular carrier 46, so that an acute angle is obtained that is the same as the longitudinal direction of the crests and troughs of the second part layer 52.

[0124] Thus, in the state of the carrier 46 being wound or rolled up (see...) Figure 2B and Figure 2D The longitudinal extension direction of all parallel flow channels 54 also extends at an acute angle of about 10° to 25° with the longitudinal extension direction 42 of the entire heating element 28. As a result, the temperature-regulating liquid flowing through the flow channels 54 is deflected obliquely and thus a vortex-shaped flow is obtained.

[0125] Other implementation variations may be considered, which can be combined with... Figure 7A and Figure 7B The variations are different; for example, they do not have the straight longitudinal extension direction of the flow channel 54, but have a moderately wavy or meandering direction.

[0126] It should be noted that membrane materials, for example, that have durable resistance or tolerance to water and / or ethylene glycol alcohol are suitable as the carrier layer 48 or carrier membrane 48. Therefore, a PEN carrier membrane with the desired properties can be used as the carrier membrane 48, for example.

[0127] Furthermore, the conductor rail 56 and the carrier membrane 48 should be able to operate and function sustainably at voltages in the high-voltage range (e.g., about 300 to 1000 volts, particularly about 400 to 900 volts). Additionally, it is essential to ensure, through the selection of suitable materials and dimensions, that short circuits between the heating rail (i.e., conductor rail 56) and the sensor rail (i.e., the conductor rail of the temperature measurement area 58) are avoided, as exemplarily in… Figure 3 As visually illustrated in A, 3C, and 3E.

[0128] also, Figures 8A to 8FThe schematic diagrams illustrate different variations of an alternative design for the heating conductor 44 of the electric heating element 28, variations that do not require the wave complex described above. In the variations shown, the surface-constructed heating conductors 44 are simply spirally wound. Since there are no waves as spacers to separate the individual windings from each other, linear spacers 80 are introduced at regular intervals, which hold the different winding layers at a constant distance from each other, thereby allowing the liquid to be heated to flow largely unimpeded within the flow channels 54 thus formed.

[0129] The electrical contact points 82 are respectively guided outward so as to be able to connect with the conductor rail 56 of the heated conductor 44 (see...). Figure 3 A, 3C and 3E) establish conductive connections. Figure 8A and 8B A top view of the wound structure of two overlapping heating conductors 44 shows a variant of an electric heating element 28 with a large total current-carrying cross-section, because the heating conductors 44 are wound more than five times. Figure 8A A variation is shown in which the heating conductor 44 terminates at a certain point on the outside, in which the electrical contact heads 82 are thus brought close to each other. Figure 8B This illustrates a variation of the electric heating element 28, in which the heating conductor 44 terminates in an opposite region on the outer periphery, such that the respective electrical contact heads 82 are also arranged in opposite regions on the outer periphery of the heating element 28.

[0130] Figure 8C and 8D Another variation of the electric heating element 28 with an average total current cross-section is shown in a top view of the wound structure of two overlapping heating conductors 44, since the heating conductors 44 are wound only two or three times. Figure 8C A variation is shown in which the heating conductor 44 terminates at a certain point on the outside, where the electrical contact heads 82 are thus brought close to each other. Figure 8D This illustrates a variation of the electric heating element 28, in which the heating conductor 44 terminates in an opposite region on the outer periphery, such that each electrical contact 82 is also arranged in an opposite region on the outer periphery of the heating element 28.

[0131] at last, Figure 8E and 8F Another variation of the electric heating element 28 with a small total current-carrying cross-section is shown in a top view of the wound structure of two overlapping heating conductors 44, since the heating conductors 44 are wound only once. Figure 8E A variation is shown in which the heating conductor 44 terminates at a certain point on the outside, where the electrical contact heads 82 are thus brought close to each other. Figure 8FThis illustrates a variation of the electric heating element 28, in which the heating conductor 44 terminates in an opposite region on the outer periphery, such that each electrical contact 82 is also arranged in an opposite region on the outer periphery of the heating element 28.

[0132] As a result, the present invention provides an effective, temperature-adjustable surface, for example, about a quarter square meters, which can be accommodated within a heating element 28 with a housing length, for example, possibly only about fifteen to twenty centimeters and a reasonable housing diameter of less than ten centimeters. Such a heating element 28 can be seamlessly integrated into a liquid circulation loop 22 for temperature regulation of the battery cell 16, as described above. Figure 1 As described with respect to electric vehicle drive 14 as an example.

[0133] Preferred analytical and evaluation electronic devices (especially those configured or implemented via the control unit 20 mentioned above) (see Figure 1 It can also detect the resistance of at least one conductor rail loop and determine the temperature of the currently present water or temperature-regulating liquid, or carrier liquid, using the known temperature coefficient of aluminum or the aluminum alloy used accordingly. Furthermore, the analytical evaluation electronics can be configured to induce additional heating of the conductor rail loop involved, for example, by approximately 5°C, and determine the electrical energy consumed for this purpose (calculated as the product of the applied voltage and the corresponding current flowing through the conductor rail loop). The faster the water or temperature-regulating liquid, or carrier liquid, flows through the conductor rail loop, the more energy is required to maintain the desired temperature difference (e.g., approximately 5°C).

[0134] Therefore, a fluid sensor with a simple construction and reliable operation can be implemented in the manner described. If the fluid sensor detects a cessation of flow or an excessive reduction in flow rate, all heating circuits can be shut off to prevent overheating of the heating element 28 and / or the entire circuit through which the liquid flows.

[0135] The present invention has been described with reference to a preferred embodiment. However, those skilled in the art will appreciate that modifications or alterations can be made to the invention without departing from the scope of the appended claims.

[0136] List of Reference Numerals 10 Drive and power supply units 12 Vehicle Drive 14. Drive motor, electric drive motor 16. Battery cells, storage battery cells, battery modules, storage battery modules 18 battery cells 20. Control unit, regulating unit, control and / or regulating unit 22 Liquid circulation loop 24 pumps 26 Heat Exchanger 28. Heating elements, electric heating elements 30 Supply voltage 32. Flowing Section 34. Shell 35. A rectangular shell 36. Main body, columnar main body, main body section 38. Funnel at the mouth 40 Pipe joint 42. Longitudinal central axis 44. Heating conductor, electric heating conductor 46 carriers 48. Carrier layer, carrier membrane 50 First layer 52. Second part layer, wavy second part layer, wavy cover layer 54 Flow Channel 56 Conductor Rails 58 Temperature Measurement Area 60 independently controllable sub-regions 62. Longitudinal sections, independently controllable longitudinal sections. 64 Support belt 66. Shell opening 68 Electrical connection lines 70 Sealing elements 72 Carrier Layer 74 packages 76 Supporting membrane 78 seam opening 80 spacers 82 Electrical contact head

Claims

1. A heating element (28) for forming a flow section (32) for a liquid circulation loop (22), the liquid circulation loop being configured for heat exchange with a drive battery (16), the heating element comprising: - At least one electrically heated conductor (44), and - Carrier (46), on which at least one electrically heating conductor (44) is arranged, The carrier (46) is characterized in that it is a carrier layer or carrier film (48) which is wound and / or folded multiple times to form a spatial structure, wherein a flow channel (54) or a plurality of flow channels (54) for liquid is provided between radially spaced regions of the carrier layer or carrier film (48).

2. The heating element (28) according to claim 1, wherein the carrier layer or carrier film (48) of the heating element forming the carrier (46) of the electric heating conductor (44) is spirally wound around the longitudinal central axis (42) of the heating element (28) at least in a region.

3. The heating element (28) according to claim 1 or 2, wherein the heating element is formed for the carrier layer or carrier film (48) of the carrier (46) of the electric heating conductor (44) to form a non-circular profile, especially a polygonal profile, particularly preferably an approximate quadrilateral profile, especially by winding the carrier layer or carrier film (48).

4. The heating element (28) according to claim 1, wherein, The carrier layer or carrier membrane (48) is at least partially folded and / or formed by a meandering shape to create the spatial structure.

5. The heating element (28) according to claim 4, wherein, The directly adjacent surface segments of the carrier layer or carrier film (48) are stacked on top of each other.

6. The heating element (28) according to any one of claims 1 to 5, wherein, The entire wound, coiled and / or folded carrier layer or carrier film (48) forms a cuboid spatial structure and is wrapped and / or contained by a cuboid shell (34), which forms a carrier (46) for the electric heating conductor (44).

7. The heating element (28) according to claim 1 or 2, wherein the housing (34), particularly the cylindrical housing, of the heating element houses the electric heating conductor (44).

8. The heating element (28) according to any one of claims 1 to 7, wherein, The electric heating conductor (44) is equipped with a plurality of flow channels (54) through which the liquid to be heated can flow substantially parallel to the longitudinal central axis (42) of the rectangular or cylindrical housing (34) or the heating conductor (44).

9. The heating element (28) according to any one of claims 1 to 8, wherein, The flow channels (54) extend along the longitudinal direction of the heating conductor (44) with approximately constant cross-sections.

10. The heating element (28) according to any one of claims 1 to 9, wherein, At least a section of the channel wall of the flow channel (54) is constructed as a heatable surface that can cause heat transfer to the liquid as the liquid flows past the heating conductor (44).

11. The heating element (28) according to claim 10, wherein, The heatable surface of the flow channel (54) extends along the entire length of the corresponding flow channel (54).

12. The heating element (28) according to claim 10 or 11, wherein, The heatable surface of the flow channel (54) has separately controllable regions in its longitudinal extension direction, these regions being separate from each other and capable of being loaded at different temperatures.

13. The heating element (28) according to any one of claims 1 to 12, the heating element comprising a wound surface heating conductor (44) equipped with a corrugated cover layer (52) applied in a regular line contact manner on a first portion layer (50) of a plane, and forming regularly spaced flow channels (54) between the two layers (50, 52).

14. The heating element (28) according to claim 13, wherein, Not only the first portion layer (50) of the plane, but also the wavy covering layer (52) is electrically coated at least on its mutually facing surfaces and is configured as a temperature-regulating surface.

15. The heating element (28) according to claim 13, wherein, Not only the first portion layer (50) of the plane, but also the wavy cover layer (52) is electrically coated on both sides and constructed as a temperature-regulating surface.

16. The heating element (28) according to claim 14 or 15, wherein, The conductive layers of the partial layers (50, 52) are respectively equipped with conductor rails (56), which are narrowly spaced apart from each other and distributed on the surface of the layers (50, 52).

17. The heating element (28) according to any one of claims 1 to 16, wherein the heating element is equipped with at least one temperature measuring area (58) located in a planar and / or wavy section or in a region of the partial layers (50, 52).

18. A liquid circulation loop (22) for regulating the temperature of a battery cell (16) for liquid cooling of a drive and energy supply unit (10) of a vehicle drive (14), wherein, The liquid can be circulated in the liquid circulation loop (22) by means of a pump (24) and can be transported through the liquid-cooled battery cell (16), wherein there is at least one electrically operated heating element (28) in a defined flow section (32) of the liquid circulation loop (22), the heating element being equipped with flow channels (54) the channel walls of which are constructed as surface heating conductors (44).

19. The liquid circulation loop (22) according to claim 18, wherein, The at least one electric heating element (28) is constructed according to any one of claims 1 to 17.

20. The liquid circulation loop (22) according to claim 18 or 19, wherein the liquid circulation loop is equipped with a control and / or regulation unit (20) for temperature regulation, the control and / or regulation unit being capable of applying an adjustable supply voltage (30) to the electric heating element (28).

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