AIR HEATING DEVICE

Abstract

An electrical air heater, in particular for a motor vehicle, including a first heating element and at least one second heating element The heating elements each include a first conductive layer, in particular a first metal layer, a second conductive layer, in particular a second metal layer (11a, 11b), and a polymer layer. The polymer layer contains a polymer component and a conductive carbon component. An interspace is formed between the heating elements, through which interspace air is able to flow for the heating thereof.

Claims

1. Electrical air heater for a motor vehicle, comprising a first heating element and at least one second heating element, wherein the heating elements each comprise a first conductive layer, a second conductive layer, and a polymer layer, wherein the polymer layer contains a polymer component and a conductive carbon component, wherein an interspace is formed between the heating elements, through which interspace air is able to flow for the heating thereof.

2. Air heater according to claim 1, wherein first and/or second heating element extend(s) at least substantially along an air flow direction and/or extend(s) at an angle relative to the air flow direction.

3. Air heater according to claim 1, wherein the respective first and/or second conductive layer are/is embodied as a plate.

4. Air heater according to claim 1, wherein the respective first and/or second conductive layer and/or the polymer layer are/is embodied in at least substantially planar fashion.

5. Air heater according to claim 1, wherein at least three heating elements with corresponding interspaces are provided.

6. Air heater according to claim 1, wherein a diameter of the interspace between the first and the second heating element is greater than a thickness of the first and/or second heating element.

7. Air heater according to claim 1, wherein at least one protrusion is provided on the respective conductive layer, for the purpose of enlarging the heat transfer area.

8. Air heater according to claim 1, wherein the carbon component is present in particle form and/or as a carbon backbone.

9. Air heater according to claim 1, wherein the carbon component is present in the form of carbon black and/or graphite and/or graphene and/or carbon fibres and/or carbon nanotubes.

10. Air heater according to claim 1, wherein the polymer component is embodied in the form of an electrically insulating polymer component and/or comprises a first polymer subcomponent based on ethylene acetate or ethylene acetate copolymer and/or ethylene acrylate or ethylene acrylate copolymer and/or a second polymer subcomponent based on polyolefin and/or polyester and/or polyamide and/or fluoropolymer.

11. Air heater according to claim 1, wherein the polymer layer is in contact with the first conductive layer over at least 20% of its side facing the first conductive layer and/or is in contact with the second conductive layer over at least 20% of its side facing the second conductive layer.

12. Air heater according to claim 1, wherein the polymer layer is a PTC resistor.

13. Method for operating an air heater according to claim 1, wherein air flows through the at least one interspace and is heated in the process.

14. A motor vehicle comprising an air heater according to claim 1 for heating air in an interior of the motor vehicle.

15. Electrical air heater of claim 1, wherein the first conductive layer is a metal layer and the second conductive layer is a metal layer.

16. Air heater according to claim 2, wherein the heating element extend(s) at an angle relative to the air flow direction at an angle of less than or equal to 90 and greater than 0. in particular greater than 10.

17. Air heater according to claim 2, wherein the heating element extend(s) at an angle relative to the air flow direction at an angle of less than or equal to 90 and greater than 10.

18. Air heater according to claim 1 wherein the respective first and/or second conductive layer are/is embodied as a metal plate and/or have/has a thickness of at least 0.1 mm and/or at most 5.0 mm.

19. Air heater according to claim 1, wherein the protrusion is at least one rib and/or at least one fin.

20. Air heater according to any of the preceding claims claim 10, wherein the second polymer subcomponent is based on polyethylene and/or polypropylene.

Description

[0049] The disclosure is described below on the basis of exemplary embodiments which are explained in greater detail with reference to the accompanying figures, in which:

[0050] FIG. 1 shows a schematic frontal view of an electrical air heater according to the disclosure;

[0051] FIG. 2 shows a schematic side view of the embodiment in accordance with FIG. 1 in a sectional illustration; and

[0052] FIG. 3 shows a schematic side view of an alternative embodiment of an electrical air heater according to the disclosure in a sectional illustration analogous to FIG. 2.

[0053] In the following description, the same reference signs are used for identical and identically acting parts.

[0054] FIG. 1 shows a frontal view of an air heater according to the disclosure. Said air heater comprises a plurality of heating elements 9a-9f (specifically six, although this is not mandatory). Each of the heating elements 9a comprises a first conductive layer 10a-10f, a second conductive layer 11a-11f and a polymer layer 12a-12f. The respective first and second conductive layers are connected to electrical contacts 15a, 15b. Interspaces (fluid channels) 16a-16e are formed between the heating elements 9a-9f. The air flows through said interspaces 16a-16e for the heating of said air (in FIG. 1 into the plane of the drawing or out of the plane of the drawing). A further interspace 16f can optionally be provided outside a (marginal) heating element (heating element 9f in this case).

[0055] In the sectional illustration in accordance with FIG. 2, in particular the air flow is also indicated by an arrow 14.

[0056] The respective conductive layer is, in particular, a metal layer (preferably composed of aluminium or an aluminium alloy). The respective polymer layer is a layer based on polymer comprising a carbon fraction. The polymer layer has a PTC behaviour.

[0057] The alternative embodiment in accordance with FIG. 3 differs from the embodiment in accordance with FIG. 1 in that the heating elements here do not extend along the air flow direction (see FIG. 2), but rather perpendicularly thereto, such that only one heating element 9a is discernible in the illustration in accordance with FIG. 3 since the other heating elements are concealed by this heating element. Here, too, once again six heating elements can be present, for example. The interspaces are likewise concealed by the heating element 9a.

[0058] It should be pointed out at this juncture that all parts described above, considered by themselves and in any combination, in particular the details illustrated in the drawings, are claimed as essential to the disclosure. Modifications thereof are familiar to the person skilled in the art.

LIST OF REFERENCE SIGNS

[0059] 9a-9f Heating element [0060] 10a-10f First conductive layer (metal layer) [0061] 11a-11f Second conductive layer (metal layer) [0062] 12a-12f Polymer layer [0063] Arrow [0064] 15a, 15b Contact [0065] 16a-16f Interspace (fluid channel)