GB2544585A

GB2544585A - Heating system for electrothermal temperature control, and method for the production of said heating system

Info

Publication number: GB2544585A
Application number: GB1614481.8A
Authority: GB
Inventors: During Denise; Pototzky Alexander
Original assignee: Deutsches Zentrum fuer Luft und Raumfahrt eV
Current assignee: Deutsches Zentrum fuer Luft und Raumfahrt eV
Priority date: 2015-08-26
Filing date: 2016-08-25
Publication date: 2017-05-24
Anticipated expiration: 2036-08-25
Also published as: FR3040580B1; GB2544585B; FR3040580A1; WO2017032803A1; DE102015114163A1; GB201614481D0

Abstract

A heating system for electrothermal temperature control comprises at least one areal heating element 5, 6 which is composed of a fibre composite material. By way of an electrical voltage source 3, a current flow through electrically conductive reinforcement fibres 8 of the fibre composite material can be effected. The heating system has multiple areal current bridges 9, 10, which, in subsections of the current path, can lie areally on the electrically conductive reinforcement fibres and thus form a current divider or a shunt, the current bridges having a lower specific electrical resistance than the electrically conductive reinforcement fibres.

Description

Heating system for electrothermal temperature control, and method for the production of said heating system

The invention relates to a heating system for electrothermal temperature control, wherein, upon energization of a material, the heat losses owing to the electrical resistance are utilized for the temperature control. The invention likewise relates to a method for the production of a heating system of said type for electrothermal temperature control. The invention likewise relates to a flow body having a heating system of said type and to a method for the production of a flow body of said type having a heating system of said type.

The use of fibre composite materials is nowadays commonplace in the modern aerospace sector. Specifically owing to the weight-specific strength and lightness, such fibre composite materials are specifically suitable for optimum utilization of the potential for lightweight construction. Therefore, it is not uncommon for even structurally critical components to be manufactured from such fibre composite materials.

Accordingly, nowadays, the use of carbon fibre reinforced plastics (CFRP) is already prior art even in the civilian aviation sector. In the newest models from the large aircraft manufacturers, such as for example the Airbus A350XWB and the Boeing 787 (Dreamliner), it is now even the case that large parts of the wing structure are composed of fibre-reinforced plastics.

Components made from fibre-reinforced plastics, known as fibre composite components, are produced by shaping of the reinforcement fibres of the fibre composite material, embedding of the reinforcement fibres into a matrix (matrix material, in particular thermoplastics or thermosetting plastics, resins) and curing of the matrix material in the embedded reinforcement fibres. The shaping of the reinforcement fibres in order to realize the subsequent component shape is generally realized by virtue of the reinforcement fibres being introduced into and draped in a moulding tool. Here, the reinforcement fibres may be dry fibres which are infused with the matrix material only after being draped in the moulding tool (so-called infusion method). The reinforcement fibres may however also be preimpregnated fibre material (so-called prepregs) which, already at the time of the shaping of the reinforcement fibres, that is to say normally during the draping of the reinforcement fibres in the moulding tool, are impregnated with the matrix material that cures at a later point in time.

Specifically in the case of aircraft structures which are impinged on by flow during flight (so-called flow bodies) such as for example wings, tail assemblies or aircraft nose structures, there is the risk of said aircraft structures icing up during flight. Icing-up of the wings or of the tail assembly is however particularly critical because the flight capability is severely impaired as a result of the accumulation of ice. For this reason, said structures are equipped with so-called anti-icing systems or de-icing systems in order to de-ice aircraft structures that have iced up, or in order to counteract the risk of icing.

The classic method of de-icing is the use of bleed air from the engines, so-called bleed air systems. These are however highly inefficient in terms of costs, because it is necessary to provide larger engines and more fuel in order to be able to generate an adequate amount of bleed air. In particular owing to high line losses in the pipelines, the efficiency is only approximately 30% to 40%. In the case of modern turbofan engines, it is furthermore no longer possible to discharge any desired amount of bleed air, because otherwise the admissible boundary conditions of said engines would no longer exist.

Secondly, the bleed air temperatures are, at approximately 180°C, very high. In the case of aircraft structures composed of fibre composite materials, this however leads to rapid degradation of the materials used, and thus of the fibre composite components, which thermally interact with said high bleed air temperatures.

For this reason, the trend for future aircraft generations is leading toward electrothermal de-icing systems in the case of which the heating is realized through the application of an electrical voltage to electrical resistance structures. An example of this is US 7,246,773 B2. Here, a metal foil is applied to the wing leading edge, which metal foil is then, by way of the application of electrical voltage, heated as a result of the electrical power losses in the resistance.

It is a disadvantage here that, as a result of the application of a metal foil to, for example, fibre composite materials, the advantage of such materials is in part annulled, because the metal foil gives rise to a considerable additional weight in relation to the fibre composite material. Furthermore, production-related problems arise in the combination of such materials. US 5,947,418 has disclosed an anti-icing system for wing leading edges, in the case of which electrically conductive reinforcement fibres of a fibre composite material are used to effect a thermal input of energy into the flow surface of the wing leading edge. For this purpose, the electrically conductive reinforcement fibres are connected to an electrical voltage source in order to energize the electrically conductive reinforcement fibres and, owing to the electrical resistance, then heat the surface by way of the electrical power losses.

It is however a disadvantage here that the input of thermal energy over the entire wingspan width cannot be reliably controlled in order to firstly ensure that the flow surface is correspondingly kept free from ice and to secondly prevent the fibre composite material from being damaged owing to an excessively high input of thermal energy. For this reason, it is necessary for several of said heating mats to be arranged at short intervals across the wingspan width, which greatly increases the cabling outlay and thus the production costs.

It is therefore an aim of the present invention to specify an improved heating system and an improved method for producing a heating system of said type, in particular for use as an anti-icing system on aircraft structures, which heating system can be adapted exactly to the geometry and icing conditions, reduces the cabling outlay and at the same time ensures that the fibre composite material of the aircraft structure is not damaged as a result of an excessively high input of thermal energy.

The inventionprovides a heating system as per claim 1 and a method for producing a heating system of said type as per claim 12. The invention furthermore provides a flow body as per claim 10 and a method for producing a flow body of said type as per claim 17.

According to claim 1, there is proposed a heating system for electrothermal temperature control, which heating system has at least one areal heating element which is formed from a fibre composite material. Here, the fibre composite material at least partially comprises electrically conductive reinforcement fibres which are embedded into a cured matrix material. The areal heating element formed from said fibre composite material is thus a fibre composite material composed of electrically conductive fibre material.

The electrically conductive reinforcement fibres of the areal heating element are in this case contacted or contactable with an electrical voltage source such that the electrically conductive reinforcement fibres through which current flows form an energization section.

According to the invention, it is now provided that the heating system has one or more areal current bridges which, in subsections of the energization section, lie areally on the electrically conductive reinforcement fibres and electrically contact these, wherein the current bridges have a lower specific electrical resistance than the electrically conductive reinforcement fibres.

Here, one of the current bridges may electrically contact the electrically conductive reinforcement fibres such that the current bridge forms a current divider together with the electrically contacted reinforcement fibres in the contacting region of the current bridge, whereby, owing to the lower specific electrical resistance of the current bridge, the electrical power losses in the contacting region of the current bridge are reduced.

As a result of the fact that the current bridges lie on the electrically conductive reinforcement fibres in order to form a current divider, it is thus possible in the heating system for the input of thermal energy to be controlled and adapted to the local conditions and geometry in targeted fashion, without each individual heating element of the heating system having to have a dedicated connection for this purpose and the cabling outlay thus being considerably increased. Rather, by virtue of the fact that the current bridges are laid on, and as a result of the formation of a current divider, an input of thermal energy can be reduced or prevented in targeted fashion, and adapted in targeted fashion to the component shape and the application.

Alternatively or in addition to this, it is also possible for one of the current bridges to be electrically contacted with the electrically conductive reinforcement fibres such that the current bridge forms a shunt in order to thus shunt electrically conductive reinforcement fibres which are insulated from one another, in order thereby to, for example, electrically connect two heating elements of the heating system to one another without the need for cumbersome cabling in the connecting region or without the generation of considerable heat input in the connecting region. Rather, with the current bridge as a shunt, it is possible for electrically conductive reinforcement fibres to be connected to one another without the risk of further heating in the shunt region.

In the context of the following invention, an areal current bridge is to be understood to mean an electrically conductive element which is designed such that it can contact the electrically conductive reinforcement fibres of a heating element and, after curing of the matrix material, forms an integral unit with the heating element. Here, the areal current bridge has a two-dimensional dimension which greatly exceeds the thickness of the areal current bridge. The areal current bridge preferably has a smaller thickness than an electrical conductor of circular cross section provided for this application. Here, the areal current bridge is designed such that it can contact a multiplicity of individual electrically conductive reinforcement fibres of a heating element.

In an advantageous embodiment, the at least one current bridge, in order to form a current divider, is contacted with the electrically conductive reinforcement fibres in such a way that, upstream and downstream of the current divider section formed by the current divider in the direction of current flow (contacting section of the current divider with the electrically conductive reinforcement fibres), a heating section is formed by the electrically conductive reinforcement fibres. As a result of the energization of the electrically conductive reinforcement fibres, an energization section is formed in the areal heating elements, because, by way of the current bridge and the current divider thereby formed, the energization section is then divided into a heating section upstream of the current divider and a heating section downstream of the current divider.

Owing to the fact that the current bridge has a lower specific electrical resistance than the electrically conductive reinforcement fibres, relatively high electrical power losses are generated in the heating section in the event of energization of the electrically conductive reinforcement fibres, whereas, in the current divider section, owing to the relatively low specific resistance of the current bridge, the electrical power losses are considerably reduced, such that the input of thermal energy of the heating system is reduced overall. It is thus possible to develop heating strategies which are exactly adapted to the local conditions.

Here, it is very particularly advantageous for the current divider, in the current divider section, to form a heat sink in relation to the heating sections, in order thereby to greatly reduce the generation of hotspots in the heating sections, which greatly reduces the risk of damage to the underlying structure.

In a further advantageous embodiment, the heating system has at least two areal heating elements which are electrically insulated from one another and which are shunted by way of at least one current bridge and which are thus electrically connected to one another by way of the current bridge, wherein the at least one current bridge is electrically contacted at a first end to the electrically conductive reinforcement fibres of the first areal heating element and at an opposite, second end to the electrically conductive reinforcement fibres of the second areal heating element. In this way, it is possible for areal heating elements, which are each provided so as to exhibit electrically insulating characteristics, to be connected electrically in series with one another without the risk of structures being damaged as a result of an excessively high input of thermal energy. This is because, owing to the relatively low specific electrical resistance of the current bridges, the electrical power losses in the shunt region, and thus the overall input of thermal energy, are greatly reduced.

The advantage here is that the individual heating elements do not separately require a dedicated connection, whereby the cabling is greatly reduced; it is rather possible by way of the present invention for multiple heating elements to be connected in series with one another without separate cabling for each individual heating element.

It is advantageously also conceivable for one of the current bridges, at a first end at the start of the energization section of an areal heating element, to lie areally on the electrically conductive reinforcement fibres and electrically contact these, and at an opposite, second end, to be connected or connectable to the electrical voltage source. It is thus possible for the areal current bridges to also be used as connection elements for the purposes of connecting the heating system as a whole to the electrical voltage source.

In a further advantageous embodiment, the specific electrical resistance of the current bridges amounts to less than 1%, preferably less than 5%o, particularly preferably less than 2%0, of the specific electrical resistance of the electrically conductive reinforcement fibres, such that the current bridges exhibit considerably greater electrical conductivity, and thus considerably lower electrical power losses, then the electrically conductive reinforcement fibres.

In a further advantageous embodiment, the current bridges and the electrically conductive reinforcement fibres have a standard potential difference of at most 0.4 V, such that the current bridge and the electrically conductive reinforcement fibres can be combined with one another without a risk of corrosion.

The current bridges are advantageously formed from a material which comprises copper and/or aluminium. The current bridges are particularly preferably composed of copper and/or aluminium. Here, copper has the advantage that it exhibits a similar standard potential (+ 0.35 V) as carbon fibres (+ 0.75 V), such that the standard potential difference of 0.4 V is not exceeded, and thus there is no risk of corrosion. Furthermore, copper exhibits particularly high electrical conductivity in relation to the plastics fibres, and can thus greatly reduce the electrical power losses.

In a further advantageous embodiment, the areal current bridges are of mesh-like, grid-like or net-like form, whereby an integral connection of the current bridges to the heating elements can be ensured.

The heating elements are advantageously arranged, together with the contacted current bridges, between electrically insulating glass fibre layers, in order thereby to insulate the heating elements from other structures in which the heating system is to be used.

Claim 10 proposes a flow body having a flow surface, wherein the flow surface is designed to be flowed around by a gaseous fluid. It is advantageously the case that at least the flow surface is produced from a fibre composite material or is composed of a fibre composite material of said type or has a fibre composite material of said type. Here, the flow body has a de-icing system for the de-icing of at least one part of the flow surface. According to the invention, the de-icing system is in this case a heating system as described above, which is contacted with an electrical voltage source for the application of an electrical voltage.

In an advantageous embodiment, the flow body is a wing leading edge of an aircraft wing, flaps of an aircraft wing, a tail assembly of an aircraft, rotor blades of a helicopter rotor, or rotor blades of a wind turbine.

It is also conceivable for the heating system as described above to be integrated into a moulding tool for the production of a fibre composite component for the purposes of curing the fibre composite component by temperature control for the curing of the matrix material diffused into the fibre material. In this case, such a heating system can be integrated in particular into the tool surface of the moulding tool.

Claim 12 proposes a method for producing a heating system for electrothermal temperature control, wherein firstly, electrically conductive reinforcement fibres of a fibre composite material are introduced into a moulding tool in order to form at least one areal heating element. The electrically conductive reinforcement fibres of the fibre composite material may in this case be dry or pre-impregnated fibre materials, for example fabrics or scrims, unidirectional fabric materials as strips or, for example, individual rovings.

The electrically conductive reinforcement fibres of the heating element which is to be produced by introduction of the electrically conductive reinforcement fibres into the moulding tool are then, at least in one subsection, electrically contacted with one or more areal current bridges by virtue of the at least one current bridge being laid on the electrically conductive reinforcement fibres. This may be realized for example by virtue of the current bridges being laid onto the corresponding subsections of the electrically conductive reinforcement fibres that have been introduced into the moulding tool. It is also conceivable for the current bridges to have previously been placed into the moulding tool at the corresponding positions, and the electrically conductive reinforcement fibres subsequently being correspondingly positioned over said current bridges.

Here, the current bridges contact the electrically conductive reinforcement fibres such that the current bridge forms a current divider or a shunt, wherein the current bridges have a lower specific electrical resistance than the electrically conductive reinforcement fibres.

Subsequently, electrical contact points for the contacting of the heating element with an electrical voltage source are formed, and then, the matrix material that has diffused into the electrically conductive reinforcement fibres is cured by temperature control and/or exertion of pressure.

Here, when the matrix material cures, the areal current bridges, in particular if they are of mesh-like, grid-like or net-like form, form an integral unit with the heating element as a fibre composite component, and here, simultaneously contact the electrically conductive reinforcement fibres of the subsequent fibre composite component (heating element). In this way, the current bridges can be manufactured together with the heating elements in one process step.

Advantageous refinements of the method can be found in the corresponding subclaims.

In particular, it is advantageous if the heating elements of the heating system are, during the production of a superordinate structure, produced at the same time together with said superordinate structure, in order to thereby form an integral unit of the superordinate structure together with the heating system. The superordinate structure may for example be a flow body within the context of the present invention, or a moulding tool.

The invention will be discussed by way of example on the basis of the appended figures, in which: figure 1 is a schematic illustration of a cross section through a flow profile; figure 2 is a schematic illustration of a heating element of the heating system; figure 3 shows an exemplary embodiment with two heating elements; figure 4 shows an exemplary embodiment with a parallel circuit.

Figure 1 shows a flow profile 100 in cross section, which flow profile may for example be an aircraft wing. The flow profile 100 has a flow surface 110 which can be impinged on by a flow of the surrounding air. In the front region, the flow profile 100 has a leading edge 120, which may be the most exposed point of the entire flow profile 100.

Within the flow profile 100 there is provided, according to the invention, the heating system 1, which in the region of the leading edge 120 has heating elements 2 (schematically illustrated). Here, the heating elements 2 interact with the flow surface 110 of the flow profile 100 such that, in the case of an input of thermal energy and heating of the heating elements 2, the thermal energy is released to the flow surface 110, and thus the leading edge 120 can be de-iced. In the exemplary embodiment of figure 1, the heating system 1 thus forms a de-icing system for the flow profile 100.

The one or more heating elements 2 of the heating system 1 is or are in this case connected to an electrical voltage source 3 such that the heating elements 2, more precisely the electrically conductive reinforcement fibres of the heating elements 2, can be energized in order thereby for the temperature of the heating elements 2 to be controlled.

To be able to correspondingly actuate the heating system 2, a control unit 4 is provided which is set up for controlling the energization of the heating elements 2 by way of the electrical voltage source 3.

For the sake of clarity, the current bridges of the heating system 1 are not shown in the exemplary embodiment of figure 1.

Figure 2 schematically shows the heating system 1 in detail in a first exemplary embodiment. Here, the heating system 1 firstly has a heating element 2 which can be contacted with an electrical voltage source 3.

In the exemplary embodiment of figure 2, the heating element 2 is of U-shaped form and has, in particular, two limbs 5 and 6 which, via a connecting web 7, form a U shape. Here, the heating element 2, with its first limb 5, its second limb 6 and its connecting web 7, has electrically conductive reinforcement fibres 8 which are indicated in figure 2.

If the heating element 2 is, as illustrated in figure 2, connected both at one end of the first limb 5 and at one end of the second limb 6 to the electrical voltage source, a current flows through the first limb 5 and through the connecting web 7 to the second limb 6, whereby all of the heating elements 2 are fully energized. In such an embodiment, electrical power losses would have the effect that the heating element 2 is intensely heated, whereby a large input of thermal energy into the heating element 2 can be realized in order to thereby be able to correspondingly control the temperature of other structures.

In order, in particular in conjunction with de-icing systems and flow profiles such as are known from figure 1, to be able to adapt the input of thermal energy correspondingly to the local conditions, it is schematically illustrated in the exemplary embodiment of figure 2 that the connecting web 7 is electrically contacted by a current bridge 9; more specifically, the electrically conductive reinforcement fibres 8 of the connecting web 7 are electrically contacted with the electrically conductive current bridge 9. The electrical contacting is in this case preferably realized such that the entire region of the current bridge 9 electrically contacts the electrically conductive fibres 8 of the connecting web 7.

It should be noted that the exemplary embodiment of figure 2 comprises merely a schematic illustration of the functional principle, and in practice, it is by all means possible for other shapes and coverage configurations of the current bridge to be provided in order to allow for the corresponding local conditions.

If the heating element 2 is now energized by the electrical voltage source, the current bridge 9 forms, in conjunction with the connecting web 7, a current divider, wherein, owing to the considerably lower electrical resistance of the current bridge 9, the current flows primarily through the current bridge 9, and less through the connecting web 7.

Thus, by way of the current bridge 9, a current divider is realized which has the effect that that region of electrically conductive reinforcement fibres which is covered by the current bridge 9 conducts considerably less current during the energization, whereby the thermal power losses are reduced in relation to the electrically conductive reinforcement fibres 8, such that, in this way, it is possible to realize that the region covered by the current bridge 9 as a current divider is not heated.

In the exemplary embodiment of figure 2, it is the case here that the current bridge 9 divides the U-shaped heating element 2 into a heating section situated upstream of the current bridge 9 and a heating section situated downstream of the current bridge 9, corresponding to the first limb 5 and the second limb 6. In other words, when the heating element 2 is energized, the first limb 5 and the second limb 6 form a heating section or a heating path, whereas the region of the connecting web 7 with the current bridge 9 arranged thereon constitutes a heat sink, which is not heated.

The current bridge 9 may for example be an areal element of mesh-like, grid-like or net-like form, which is preferably composed of copper (copper mesh).

At the diametrically opposite ends of the two limbs 5 and 6 in relation to the connecting web 7, there is furthermore likewise provided a current bridge 10 which contacts the reinforcement fibres 8 of the respective limbs 5 and 6 at their lower end. Via the current bridges 10, the electrical voltage source 3 is then contacted, such that contacting of the heating element 2 with the electrical voltage source 3 can be established via said current bridges 10.

Here, there is the advantage firstly that, by way of the current bridges 10, no additional cables of relatively large cable cross section have to be incorporated into the overall structure in order to connect the heating element 2 to the electrical voltage source 3. Furthermore, the current bridges 10, which may for example be composed of a copper material with a very low specific resistance, make it possible to realize that there is no prior input of thermal energy into heating element 2 owing to the electrical power losses of the connection elements.

Thus, the input of thermal energy is restricted exclusively to the remaining limbs 5 and 6 of the heating element 2, and is thus controlled in a defined manner.

Figure 3 shows an exemplary embodiment in which two heating elements are connected to one another by way of a current bridge 11 in the form of a connecting current bridge. Here, one end of the second limb 6 of the first heating element 2a is contacted with one end of the first limb 5 of the second heating element 2b by way of the current bridge 9, such that an electrically conductive connection is formed between the first heating element 2a and the second heating element 2b. Owing to the high conductivity of the current bridge 11, only a very small input of thermal energy occurs here, which is considerably reduced in relation to the input of thermal energy of the heating sections of the limbs 5 and 6 of the heating elements 2a, 2b.

It is thus possible for multiple heating elements to be connected in series with one another without the overall input of thermal energy becoming too great for the underlying structure or for the heating element itself. By way of the continuous introduction of heat sinks by way of the current bridges 9, 10 and 11, it is possible for the input of thermal energy to be controlled in a defined manner.

Figure 4 schematically shows an exemplary embodiment in which the heating system is formed by way of a parallel circuit. For this purpose, a first current bridge 11a and a second current bridge 11b are provided, between which the limbs 5a to 5c with the electrically conductive reinforcement fibres are arranged. Here, the current bridges 11a and 11b contact the electrically conductive reinforcement fibres of the limbs 5a to 5c at their respective upper ends, such that in these regions, the current bridges 11a, 11b lie areally, in partial sections, on the electrically conductive reinforcement fibres.

If, by way of the voltage source 3, a current flow is now effected in the current bridges 11a and 11b and in the limbs 5a to 5c, it is the case in particular that the limbs 5a to 5c are heated to a considerably greater extent, owing to the higher specific electrical resistance, than the current bridges 11a and 11b with a lower specific electrical resistance than the electrically conductive reinforcement fibres. In this way, it is possible to realize a defined input of thermal energy.

List of reference designations: 1 Heating system 2 Heating elements 2a First heating element 2b Second heating element 3 Voltage source 4 Control unit 5, 6 Limbs 7 Connecting web 8 Reinforcement fibres 9 Current bridge 10 Current bridges 11 Current bridge 100 Flow profile 110 Flow surface 120 Leading edge

Claims

Claims:

1. A heating system (1) for electrothermal temperature control, having at least one areal heating element (2) which is formed from a fibre composite material which at least partially comprises electrically conductive reinforcement fibres (8) which are embedded into a cured matrix material, wherein the electrically conductive reinforcement fibres (8) of the areal heating element (2) are contacted or contactable with an electrical voltage source (3) such that the electrically conductive reinforcement fibres (8) through which current flows form an energization section, the heating system (1) having one or more areal current bridges (10) which, in subsections of the energization section, lie areally on the electrically conductive reinforcement fibres (8) and electrically contact these such that the current bridge (9) forms a current divider and/or a shunt, wherein the at least one current bridge (9) has a lower specific electrical resistance than the electrically conductive reinforcement fibres (8).

2. A heating system (1) according to Claim 1, wherein the at least one current bridge (9), in order to form a current divider, contacts the electrically conductive reinforcement fibres (8) in such a way that, upstream and downstream of the current divider section formed by the current divider as viewed in a current flow direction, a heating section is formed by the electrically conductive reinforcement fibres (8).

3. A heating system (1) according to Claim 2, wherein the current divider, in the current divider section, forms a heat sink in relation to the heating sections.

4. A heating system (1) according to one of the preceding claims, wherein at least two areal heating elements (2) are provided which are electrically insulated from one another and which are shunted by way of at least one current bridge (9), wherein the at least one current bridge (9) is electrically contacted at a first end to the electrically conductive reinforcement fibres (8) of the first areal heating element (2a) and at an opposite, second end to the electrically conductive reinforcement fibres of the second areal heating element (2b).

5. A heating system (1) according to one of the preceding claims, wherein at least one of the current bridges (10), at a first end at the start of the energization section of an areal heating element, lies areally on the electrically conductive reinforcement fibres (8) and electrically contacts these, and at an opposite, second end, is connected or connectable to the electrical voltage source (3).

6. A heating system (1) according to one of the preceding claims, wherein the specific electrical resistance of the at least one current bridge (10) amounts to less than 1 percent, preferably less than 5 tenths of a percent, particularly preferably less than 2 tenths of a percent, of the specific electrical resistance of the electrically conductive reinforcement fibres (8), and/or in that the at least one current bridge (10) and the electrically conductive reinforcement fibres (8) have a standard potential difference of at most 0.4 V.

7. A heating system (1) according to one of the preceding claims, wherein at least one the current bridge (10) is formed from a material which comprises copper and/or aluminium.

8. Heating system (1) according to one of the preceding claims, wherein at least one of the areal current bridges (10) is of mesh-like, grid-like or net-like form.

9. Heating system (1) according to one of the preceding claims, wherein the at least one heating element (1) is arranged, together with the at least one contacted current bridge (10), between electrically insulating glass fibre layers.

10. A flow body having a flow surface (110) which is designed to be flowed around by a gaseous fluid, wherein the flow body has a de-icing system for the de-icing of at least one part of the flow surface (110), and wherein the de-icing system has a heating system (1) according to one of the preceding claims, which heating system is contacted with an electrical voltage source (3) for the application of an electrical voltage.

11. A flow body according to Claim 10, comprising a leading edge of an aircraft wing, flaps of an aircraft wing, a tail assembly of an aircraft, rotor blades of a helicopter, or rotor blades of a wind turbine.

12. A method for producing a heating system (1) for electrothermal temperature control, having the steps: introducing electrically conductive reinforcement fibres (8) of a fibre composite material into a moulding tool in order to form at least one areal heating element (2), contacting the electrically conductive reinforcement fibres (8) of the heating element (2) with one or more areal current bridges (10) by laying the at least one current bridge (9) onto the electrically conductive reinforcement fibres (8) in at least one subsection such that the current bridge (9) forms a current divider or a shunt, wherein the at least one current bridge (10) has a lower specific electrical resistance than the electrically conductive reinforcement fibres (8), forming electrical contact points for the contacting of the heating element (2) with an electrical voltage source (3), and curing a matrix material that has diffused into the electrically conductive reinforcement fibres (8) by way of temperature control and/or exertion of pressure.

13. A method according to Claim 12, wherein the at least one current bridge (9), in order to form a current divider, is contacted with the electrically conductive reinforcement fibres (8) in such a way that, upstream and downstream of the current divider section formed by the current divider as viewed in a current flow direction, a heating section is formed by the electrically conductive reinforcement fibres (8) when the electrically conductive reinforcement fibres (8) are energized.

14. A method according to Claim 13, wherein a heat sink in relation to the heating sections is formed by the current divider in the current divider section.

15. A method according to one of Claims 12 to 14, wherein at least two heating elements (2) which are provided so as to be electrically insulated from one another are formed by virtue of the electrically conductive reinforcement fibres (8) being introduced into the moulding tool, wherein the electrically conductive reinforcement fibres (8) of the heating elements (2) are shunted by way of at least one current bridge (9) which is electrically contacted at a first end to the electrically conductive reinforcement fibres of the first areal heating element (2a) and at an opposite, second end to the electrically conductive reinforcement fibres of the second areal heating element (2b).

16. A method according to one of Claims 12 to 15, wherein the electrically conductive reinforcement fibres (8) are applied to a first glass fibre layer in the moulding tool, wherein, after the introduction of the electrically conductive reinforcement fibres (8) and of the current bridges (10) into the moulding tool, a second glass fibre layer is applied to the introduced electrically conductive reinforcement fibres (8).

17. A method for producing a flow body having a de-icing system, wherein the de-icing system is produced in accordance with the method according to one of Claims 12 to 16 when the flow body is produced.

18. A heating system for electrothermal temperature control, substantially as described herein with reference to one of Figures 2, 3 or 4 of the accompanying drawings.