PIPE HEATING SYSTEM FOR AN AIRCRAFT

Abstract

A heatable water pipe for an aircraft, having a heat-generating ply which extends in the pipe circumferential direction and the pipe longitudinal direction, at least in some section or sections. The heat-generating ply comprises a fiber composite layer containing fibers and a matrix surrounding the fibers, wherein at least some of the fibers are formed as conducting fibers. In this context, the conducting fibers are formed as carbon fibers with an electrically insulating coating. By virtue of the electrically insulating coating, leakage currents can be avoided. The carbon fibers serve both as heating elements and as reinforcing fibers in the fiber composite layer.

Claims

1. A heatable pipe for an aircraft, comprising a heat-generating ply, which extends in a pipe circumferential direction and a pipe longitudinal direction, at least in some section or sections, wherein the heat-generating ply comprises a fiber composite layer containing fibers and a matrix surrounding the fibers, wherein at least some of the fibers are formed as conducting fibers, and wherein the conducting fibers are formed as carbon fibers with an electrically insulating coating.

2. The pipe according to claim 1, wherein the conducting fibers form one or more closed circuits.

3. The pipe according to claim 1, wherein a form of an arrangement of the conducting fibers in the fiber composite layer is selected from a group consisting of: individual fibers, fiber bundles, fiber ribbons, non-crimped fibers, fiber mats, woven fibers and nonwoven fibers.

4. The pipe according to claim 1, wherein the conducting fibers are aligned in a unidirectional manner.

5. The pipe according to claim 1, wherein the conducting fibers are arranged parallel to the pipe longitudinal direction.

6. The pipe according to claim 1, wherein the heat-generating ply is arranged on a pipe inner side.

7. The pipe according to claim 1, wherein the electrically insulating coating has a thickness in a range of from 0.1 micrometer to 1 micrometer.

8. The pipe according to claim 1, wherein the conducting fibers are integrated into the fiber composite layer in such a way that the conducting fibers protrude from the fiber composite layer at a beginning of the pipe or at an end of the pipe.

9. The pipe according to claim 1, wherein the electrically insulating coating is formed as a polymer electrolyte coating.

10. A pipe heating system for an aircraft, comprising: a. a heatable pipe according to claim 1, b. a power source for supplying electric heating power, wherein the power source is connected electrically to the conducting fibers.

11. The pipe heating system according to claim 10, furthermore comprising a control unit which comprises temperature sensors and by means of which the heating power of the power source can be controlled.

12. An aircraft comprising a pipe heating system according to claim 10.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In the figures, identical reference signs are used for identical or at least similar elements, components or aspects. It is observed that the embodiment described in detail below is merely illustrative and not restrictive. In the claims, the word having does not exclude other elements and the indefinite article a/an does not exclude a plurality. The mere fact that certain features are mentioned in different dependent claims does not restrict the subject matter of the invention. Combinations of these features can also be employed to advantage. The reference signs in the claims are not intended to limit the scope of the claims. The figures should not be interpreted as being to scale and have only a schematic and illustrative character. In the drawing:

[0024] FIG. 1 shows a perspective view of a heatable pipe according to the invention,

[0025] FIG. 2 shows a perspective view of a conducting fiber according to the invention,

[0026] FIG. 3 shows a plan view of a pipe heating system according to the invention having a heat-generating ply which, by way of example, is rolled up, and

[0027] FIG. 4 shows an aircraft which has a pipe according to the invention or a pipe heating system according to the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] FIG. 1 shows a heatable pipe 10 for an aircraft. The pipe 10 has a heat-generating ply 16, which is arranged on a pipe inner side 4. In addition to the heat-generating ply 16, the pipe 10 according to the invention generally also has a basic pipe structure 11. In FIG. 1, the basic pipe structure 11 is formed by three fiber composite layers 5, 7, 9. These fiber composite layers 5, 7, 9 can be conventional plastics reinforced with glass fibers or carbon fibers (GFRP or CFRP), for example. The basic pipe structure 11 or fiber composite layers 5, 7, 9 can comprise or be formed by prepregs, for example, and can have different laying directions (e.g., +/45 relative to the pipe longitudinal direction).

[0029] The pipe 10 furthermore comprises a thermal insulation layer 15 on the outside 13 of the heat-generating ply 16. The insulating layer 15 can be formed by a foam material with a low thermal conductivity, for example. The thermal insulating layer 15 decouples the pipe 10 thermally almost completely from a structure supporting the pipe 10.

[0030] The heat-generating ply 16 comprises at least one fiber composite layer 20, which, for its part, has fibers and a matrix surrounding the fibers (not shown specifically). In contrast to conventional plastics reinforced with glass fibers or reinforced with carbon fibers, at least some of the fibers in the at least one fiber composite layer 20 are formed as conducting fibers 22 (cf. FIG. 2). For this purpose, the conducting fibers 22 are formed as carbon fibers 24 with an electrically insulating coating 26. The conducting fibers 22 can be used as electric conductors and thus as electric heating elements for heating the pipe 10. In this case, the conducting fibers 22 are integrated into the pipe 10, wherein a power source 46 (cf. FIG. 3) can be applied to the conducting fibers 22 in order to pass a heating current through the fibers. By virtue of the electrically insulating coating 26 of the conducting fibers 22, leakage currents are avoided. The conducting fibers 22 can also touch and, at the same time, can serve not only as current conductors but simultaneously also as reinforcing fibers for the fiber composite layer 20.

[0031] The electrically insulating coating 26 illustrated in FIG. 2 can have a thickness in a range of from 0.1 micrometer to 1 micrometer. The carbon fibers 24 can have a diameter of between 6 and 7 micrometers, for example, giving a diameter of the conducting fibers 22 of about 7 to 8 micrometers. The electrically insulating coating 26 is formed as a polymer electrolyte coating, for example. Polymer electrolyte coatings of this kind can have a temperature stability of at least 700 degrees Celsius but, at the same time, can have excellent bonding properties for incorporation into fiber-reinforced components.

[0032] FIG. 3 shows a pipe heating system 40 for an aircraft, wherein, by way of simplification and by way of example, only the fiber composite layer 20 with the conducting fibers 22 in a rolled up view is illustrated. The pipe heating system 40 comprises the power source 46 for supplying electric heating power. The power source 46 is connected in an electrically conductive manner to the fiber composite layer 20. The pipe heating system 40 furthermore has a control unit 50 having temperature sensors 48, by means of which the heating power of the power source 46 can be controlled. By means of the control unit 50, the current conducted electrically in the conducting fibers 22 can be continuously adapted if there is a deviation from a desired target temperature and there is a desire to compensate the deviation.

[0033] The conducting fibers 22 are integrated into the fiber composite layer 20 in such a way that the conducting fibers 22 protrude from the fiber composite layer 20 and can be electrically connected at the start of the pipe or at the end of the pipe. The conducting fibers 22 form a closed circuit 30, wherein the power source 46 is connected in an electrically conductive manner to the closed circuit 30.

[0034] In FIG. 3, the conducting fibers 22 forming the closed circuit 30 are selected and illustrated in the fiber composite layer 20 purely by way of example in the form of a meandering and continuous individual fiber 22. Although, in FIG. 3, the continuous individual fiber 22 is illustrated by way of example as spaced apart in the mutually parallel longitudinal sections, it is possible to place the continuous individual fiber 22 so close together, at least in some section or sections, that it corresponds to unidirectional alignment of the conducting fibers 22. The conducting fibers 22 are then aligned unidirectionally. It is then possible, in particular, for the conducting fibers 22 to be arranged parallel to the pipe longitudinal direction 6 (cf. FIG. 1). As an alternative, the form of the arrangement of the conducting fibers 22 in the fiber composite layer 20 can be selected from the group comprising: fiber bundles, fiber ribbons, non-crimped fibers, fiber mats, woven fibers or nonwoven fibers. It is then also possible in principle to implement a multiplicity of closed circuits 30 for heating the pipe 10.

[0035] FIG. 4 illustrates the aircraft 12 having the heatable pipe 10 or the pipe heating system 40. The heatable pipe 10 or pipe heating system 40 provides a multifunctional and lightweight solution for use in commercial aircraft, particularly in unheated areas of commercial aircraft. By virtue of the relatively small number of individual components, the pipe 10 or pipe heating system 40 can furthermore be produced or manufactured easily and quickly. The direct integration of the heating capability into the pipe 10 also allows quick and easy installation.

[0036] While at least one exemplary embodiment of the present invention(s) is disclosed herein, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any adaptations or variations of the exemplary embodiment(s). In addition, in this disclosure, the terms comprise or comprising do not exclude other elements or steps, the terms a or one do not exclude a plural number, and the term or means either or both. Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise. This disclosure hereby incorporates by reference the complete disclosure of any patent or application from which it claims benefit or priority.