CN110300464B

CN110300464B - Electric heating device and system comprising same and device with body to be heated

Info

Publication number: CN110300464B
Application number: CN201910218979.2A
Authority: CN
Inventors: 安德列亚斯·司列福
Original assignee: Turk and Hillinger GmbH
Current assignee: Turk and Hillinger GmbH
Priority date: 2018-03-23
Filing date: 2019-03-21
Publication date: 2022-05-27
Anticipated expiration: 2039-03-21
Also published as: DE102019103751A1; CN110300464A; DE202018101632U1

Abstract

An electric heating device (100, 200) for heating a body (10, 20), the body (10, 20) having an outer diameter and a cross-section, wherein the electric heating device has a housing (110, 210), in the interior of which at least one electric heating element (130, 140, 230, 240) is arranged in such a way that it is electrically insulated from the housing, wherein the electric heating device has at least one section adapted to the outer diameter of the body, the curvature of the segments is adapted to the outer diameter of the body in such a way that the electric heating device can be placed on the body or can be pushed onto the body, in particular perpendicularly to the direction of extension of the body, so that there is a planar contact between a portion of the outer diameter and the adaptation section of the electric heating device and the electric heating element section has a corresponding curvature.

Description

Electric heating device and system comprising same and device with body to be heated

Technical Field

The present invention relates to an electric heating device for heating a body and a system consisting of a device having a body to be heated and an electric heating device for heating the body to be heated.

Background

An electrical heating device is a widely widespread solution that enables heating of a body, in particular a tube, and therefore also a fluid that is guided through the respective tube in the case of a tube.

However, there is still a need for improvement, in particular in respect of optimizing the surface loading of the electric heating elements of the electric heating device, especially in the case where the electric heating device should be able to be arranged afterwards on the body and the electric heating device can no longer be pushed onto the body in the extension direction.

Known classes of electrical heating devices of this type are, in particular, on the one hand, heating sleeves and heating bands which are composed of deformable material, are molded onto the main body when arranged thereon, and then (desirably) held in this position, and are band-type heating bodies by which the tubes to be heated are usually surrounded in the manner of a collar.

Disclosure of Invention

It is therefore an object of the present invention to provide an improved electric heating device for heating bodies, in particular tubes, and an improved system consisting of a device having a body to be heated, in particular a tube to be heated, and an electric heating device for heating the body or the tube, wherein a well-defined temperature profile can be achieved even in a narrow construction space using a compactly embodied and easily installable electric heating device, while at the same time providing a large planar contact with the body to be heated such that as high a heating power as possible is achieved with as low a surface loading of the electric heating element as possible.

This object is achieved by an electric heating device for heating a body, preferably a tube, and a system consisting of a device with a body to be heated, in particular a tube, and such an electric heating device. Advantageous developments of the invention are the subject matter of the respective dependent claims.

The electrical heating device according to the invention is used for heating a body having an outer diameter D and a cross section Q, and preferably defining a tube. The electric heating device has a housing, which is particularly preferably made of metal. At least one electric heating element is arranged in the interior of the housing in such a way that it is electrically insulated from the housing.

It is essential to the invention that the electric heating device has at least one section adapted to the outer diameter of the body, the curvature of which section is adapted to the outer diameter of the body such that the electric heating device can be placed onto the body or pushed onto the body (in particular from a direction perpendicular to the direction of extension of the body, which is predetermined by the central axis of the tube in the case of a tube) such that there is a planar contact between a portion of the outer diameter and the adapted section of the electric heating device, and the electric heating element has a corresponding curvature.

The electrical heating element has a corresponding curvature, in particular if it has sections which run substantially in the circumferential direction of the adapter section and thus of the body and at a substantially constant distance from the outer surface of the body, on which outer surface the curved section of the electrical heating element rests. In particular, therefore, curvature differences caused by the outer radius of the body and the actually small spacing between the electrical heating elements are also ignored here.

It has proven to be particularly advantageous if the electrical heating device has a U-shaped cross section with an arcuate section and two legs, wherein the outer contour of the U-shaped cross section is predetermined by a section of the housing, wherein the inner radius r of the arcuate section is half as large as the outer diameter D of the main body, the electrical heating device being used for heating the main body, such that, if the electrical heating device is arranged on the main body to be heated as intended, half of the cross section of the main body is accommodated in the arcuate section or rather in the inner arch thereof, and the legs extend approximately in the tangential direction to the outer contour of the main body.

Thus, the housing can be understood or described as a profile tube with a U-shaped tube interior space, even though it can be formed in a U-shape in other ways, in particular by shaping rectangular or oval tubes. The housing thus has a U-shaped inner contour, a U-shaped outer contour, which are connected to the connecting sections on the legs.

An arcuate section of the housing can therefore be understood as a circular ring section which covers in particular an angular range of 180 ° described in polar coordinates, wherein the inner radius of the circular ring section is adapted to the outer diameter of the body to be heated. The legs adjoining the ring segments then run approximately tangentially to the body to be heated and approximately parallel to one another, wherein "approximately" means that deviations below 5 ° are acceptable and, in view of the resulting spacing of the ends of the legs facing the arcuate segments from one another being greater than the deviations of the ends of the legs opposite these ends, are only reduced to such an extent that pushing onto the body to be heated from the radial direction is still possible, which may even be desirable.

This particular geometric design of the electric heating device has two effects: on the one hand, an electrical heating device of this design can be arranged easily and reliably on the main body, since the legs of the U-shape can facilitate the positioning of the electrical heating device and can be stable if necessary. On the other hand, although there is no longer direct contact with the body on the legs, the heating efficiency is significantly improved.

It is particularly preferred that at least two mutually independent electric heating elements are arranged in the housing, so that two independent heating circuits are present. This is always desirable in particular when different heating gears are to be realized, which can be switched on or off individually. Another important application is that which can operate under electrical operating conditions that are significantly different from each other, for example, optionally powered by the car grid of a caravan during driving, and powered by energizing a conventional power connection when the caravan is in a camp site.

In accordance with a preferred development of this feature, it is therefore proposed that at least two mutually independent electrical heating elements have different heating powers and/or different electrical properties.

Depending on the requirements of the respective application, it can be advantageous if at least two mutually independent electric heating elements are arranged offset from one another and/or partially overlap one another in the direction from the inner contour of the U-shaped cross section to the outer contour of the U-shaped cross section. In this arrangement, the electric heating elements are therefore arranged at least in sections one above the other in the housing.

However, it may also be advantageous to arrange at least two electrical heating elements that are independent of one another in different sections of the U-shaped cross section, i.e. adjacent to one another in the housing or even arranged in different polar regions relative to the central axis of the body, in a polar representation. These electric heating elements can be embodied in particular symmetrically; but it may also be expedient, in particular when using electric heating elements operating under different electrical operating conditions, for example various operating voltages at which the electric heating elements are operated independently of one another, to place differently sized sections with independent electric heating elements and thus to provide a different amount of construction space.

According to an advantageous development of the invention, which has a positive effect in particular on the available heating power, it is proposed that the at least one electric heating element is arranged partially in the arcuate section and partially in the legs of the U-shaped cross section.

A particularly advantageous variant of the invention provides that the at least one electrical heating element is a resistance wire wound onto the winding carrier. The winding frame may in particular be a mica board or a stack of mica boards.

Although it is in principle also possible to embed the electric heating elements in a powder or granulate of an electrically non-conductive but well heat-conducting material, such as magnesium oxide, it is proposed according to a preferred embodiment of the invention that at least one electric heating element is insulated from the housing and/or other electric heating elements by one or more insulating plates. The use of a plurality of insulating material plates is advantageous here because cracks occur in such plates during the shaping process for forming the curved bearing surface and the probability of the plates being positioned such that a penetrating crack occurs can be significantly reduced by the use of a plurality of plates. This risk can advantageously be further reduced when the sheets of insulating material also comprise at least one non-woven fabric of insulating material and/or one film of insulating material, for example made of Kapton (polyimide film material) or Nomex (aramid).

In order to fasten the electric heating device on the body, it is advantageous if the legs are mechanically pretensioned against each other such that a clamping action is exerted on the body arranged between them with the outer diameter D.

Here, the length of the leg portion may be particularly shorter than half of the outer diameter D of the body to be heated.

In particular, the electric heating device according to the invention is advantageously formed by a flat electric heating device by forming in a U-shape. This allows a very simple manufacturing of the electric heating device.

The system according to the invention is composed of a device having a body to be heated, which is particularly preferably a tube, and an electric heating device for heating the body to be heated, wherein the body to be heated has an outer diameter D and a cross section Q, characterized in that the electric heating device for heating the body to be heated is an electric heating device according to any of the embodiments just described.

Drawings

The invention is explained in more detail below with reference to the drawings showing embodiments. In the drawings:

fig. 1a shows an external view of an electric heating device for heating a body;

figure 1b shows a partial view of a system consisting of a device with a body to be heated and the electric heating device for heating the body of figure 1 a;

FIG. 1c shows a schematic cross-sectional view of the system of FIG. 1 b;

FIG. 1d shows a detailed enlarged cut-away view of FIG. 1 c;

FIG. 1e shows the internal structure of the electric heating apparatus of FIGS. 1a-d before it is formed into a U-shape;

figure 2a shows a cross-sectional view of a second embodiment of a system consisting of a device with a body to be heated and an electric heating device for heating the body;

FIG. 2b shows a detailed enlarged cut-away view of FIG. 2 a; and

fig. 2c shows the internal structure of the electric heating device of fig. 2a and 2b before forming into a U-shape.

Detailed Description

Fig. 1a shows an external view of an electric heating device 100. The housing 110 with a U-shaped cross section can be seen from the outside, and the housing 110 can be made of metal, for example, and can be embodied in particular as a U-shaped profile tube, so that the housing 110 has an arcuate section 111 and two

legs

112, 113. The arcuate section 111 and the two

legs

112, 113 each consist of an outer contour 114 of U-shaped cross section and a corresponding section of an inner contour 116 formed by a housing wall section, which sections are each also U-shaped and are connected to one another by connecting

sections

117, 118. The connecting leads 120, 121, 122, 123 of the electric heating device can also be seen.

Fig. 1b shows a partial view of the system 1, namely a body to be heated 10 formed from a tube of a device having a body to be heated, which has an outer diameter D and a cross section Q, and the electrical heating device 100 of fig. 1a, which is arranged as intended on the body to be heated 10, for heating the tube.

As can be seen particularly well in the schematic cross-sectional view of fig. 1c, the inner radius r of the arcuate section 111 is half as large as the diameter D of the body to be heated 10 formed from a tube (and is therefore as large as its outer radius), so that in the case of an arrangement of the electric heating device 100 on the body to be heated 10 as intended in fig. 1c, half of the body cross-section Q of the body to be heated 10 is accommodated in the inner arch of the arcuate section 111, and the

legs

112, 113 extend approximately in the tangential direction towards the outer contour of the body 10.

It can also be seen that the

electrical heating elements

130, 140 are also curved. At least the arcuate section 111 is thus a section adapted to the outer diameter D of the body 10, the curvature of which section is adapted to the outer diameter D of the body 10 such that the electric heating device 100 can be placed onto the body 10 or can be pushed onto the body 10 perpendicular to the direction of extension of the body 10 such that there is a planar contact between a portion of the outer diameter and the adapted section of the electric heating device 100, wherein the

electric heating elements

130, 140 also have a corresponding curvature.

Fig. 1c is a schematic view, in particular, of the structure of the

electric heating elements

130, 140 of the electric heating device. In this example, the

electrical heating elements

130, 140 are formed by winding carriers 132, 133 around which

heating wires

131, 141 are wound, as can be seen in fig. 1e, which shows the

electrical heating elements

130, 140 used before shaping into the final shape, and in a cut-away enlarged view according to fig. 1 d. In fig. 1c, only the position of the

electric heating elements

130, 140 and their embedding in a thermally conductive insulating material 150 is shown, which insulating material 150 can be introduced either in the form of a plate, for example a mica plate, a non-woven fabric or a film, for example a Kapton film or a Nomex film, or in the form of a powder, for example magnesium oxide, and ensures the electrical insulation of the

electric heating elements

130, 140 or more precisely their

heating wires

131, 141 from the housing 110. As can be seen in fig. 1c, the two

electric heating elements

130, 140 are arranged adjacent to each other such that different sections of the U-shape are assigned to two mutually independent heating circuits.

The structure of the

heating elements

130, 140 can be seen in more detail, in particular of fig. 1e, in which the

heating elements

130, 140 are shown before forming. It can be seen in this figure that the

heating elements

130, 140 are each formed by a

heating wire

131, 141 wound on a winding

carrier

132, 142 in this example, which

heating wires

131, 141 are each led back and connected to the connecting leads 120, 121, 122, 123, except for the winding from the end of the winding to the beginning of the winding. The

heating elements

130, 140 can be introduced into the flat housing from an insulating material and then, if necessary, shaped into a U after closing the end faces of the housing. The

heating wires

131, 141 have distinctly different cross-sections and therefore differ in their heating power (which can also be achieved, for example, by different winding densities) and/or have different electrical properties and can therefore be optimized, for example, for operation with different voltages.

As already mentioned and as can be seen clearly in fig. 1c and 1d, the

electrical heating elements

130, 140 thus configured are arranged in the electrical heating device 100 in a bent state, wherein the curvature center point of the curvature lies on a central axis oriented parallel to the winding direction describing the progression of the individual windings on the winding carrier towards the body 10 embodied as a tube. As can be envisaged and at least additionally also seen in the detail drawing of fig. 1d, this also means that there are sections of the heating wire which run in relation to the direction of extent of the main body in its circumferential direction, in particular at a slope of less than 5 degrees, preferably less than 1 degree.

This general structure can also be understood in the detailed enlarged view of fig. 1 d. The true reason for adding this illustration is, however, that it emphasizes the additional design freedom of the electric heating device 100, i.e. how far the respective electric heating element, in the illustrated case the electric heating element 130, extends into the leg, here the leg 112 of the U-shape. In fig. 1d, the electrical heating element 130 terminates in an arcuate section 111. In contrast, as is apparent from fig. 2b, in the case of the electrical heating device 200 shown there, the

electrical heating elements

230, 240 project into this region.

Fig. 2a to 2c show views corresponding to the views of fig. 1c to 1e of a second embodiment of a system 2 consisting of a device with a body to be heated 20, which body to be heated 20 has an outer diameter D and a cross section Q, and an electric heating device 200 for heating the body 20, which body to be heated 20 is also embodied in this example as a tube.

Furthermore, the electric heating device 200 has a housing 220, the housing 220 having a U-shaped cross section, the housing 220 being made of metal, for example, and being embodied in particular as a U-shaped profile tube, so that the housing 220 has an arcuate section 211 and two legs 212, 213. These regions consist of housing sections as in the case of the electric heating device 100, and the inner radius r of the arcuate section 211 is half as large as the outer diameter D of the body 20 (and therefore as large as its outer radius), so that in the case of an arrangement of the electric heating device 200 on the body to be heated 20 as specified in fig. 2a, half of the body cross section Q of the body to be heated 20 is accommodated in the inner arch of the arcuate section 211, and the legs 212, 213 extend approximately in the tangential direction towards the outer contour of the body 20.

Furthermore, the electric heater 200 has two separate heating circuits in the form of correspondingly curved

electric heating elements

230, 240, which are only schematically shown in fig. 2 a. The important difference here with respect to the electric heating device 100 is the arrangement of the

electric heating elements

230, 240, which is here, on the one hand, that at least one partial region is arranged in the arcuate section 211 and one partial region in each case in the legs 212, 213 of the U-shaped cross section, and, on the other hand, that the

electric heating elements

230, 240 which are independent of one another are arranged offset from one another and overlap one another in the direction from the inner contour 214 of the U-shaped cross section to the outer contour 216 of the U-shaped cross section.

As can be seen in fig. 2c, which shows the

electric heating elements

230, 240 used before being shaped into the final shape, the

electric heating elements

230, 240 are in this example formed by winding carriers 232, 233 around which

heating wires

231, 241 are wound. A further difference with respect to the electric heating device 100 is, however, that the electrically insulating material 250 is realized here by insulating material plates, for example mica plates, which can be introduced together with the

electric heating elements

230, 240 first as a stack into a flat housing and then shaped into a U.

This general structure can also be understood in the detailed enlarged view of fig. 2 b. The true reason for adding this illustration is, however, that it emphasizes the additional design freedom of the electric heating device 200, i.e. how far the respective electric heating elements, in the illustrated case the

electric heating elements

230, 240, extend into the leg, here the leg 212 of the U-shape. In fig. 2b, the

electrical heating elements

230, 240 extend into the leg 212.

Description of reference numerals:

1, 2 systems

10, 20 main body

100, 200 electric heating device

110, 210 casing

111, 211 arcuate section

112, 113, 212, 213 legs

114, 214 outer contour

116, 216 inner contour

117, 118, 217, 218 connecting section

120，121，122，123，

220, 221, 222, 223 connecting lead

130, 140, 230, 240 electric heating element

131, 144, 231, 241 heating wire

132, 142, 232, 242 winding carriers

150, 250 insulating material

D outside diameter

Q cross section

r inner radius

Claims

1. An electric heating device (100, 200) for heating a body (10, 20), the body (10, 20) having an outer diameter (D) and a cross-section (Q), wherein the electric heating device (100, 200) has a housing (110, 210), in the inner space of which housing (110, 210) at least one electric heating element (130, 140, 230, 240) is arranged such that it is electrically insulated from the housing (110, 210), characterized in that the electric heating device (100, 200) has at least one section adapted to the outer diameter (D) of the body (10, 20), the curvature of which section is adapted to the outer diameter of the body (10, 20) such that the electric heating device (100, 200) can be placed onto the body (10, 20) or can be pushed onto the body (10) perpendicular to the direction of extension of the body, 20) such that there is a planar contact between a portion of the outer diameter and the adapted section of the electric heating device (100, 200) and the section of the electric heating element (130, 140, 230, 240) also has a corresponding curvature,

the electric heating device has a U-shaped cross section with an arcuate section (111, 211) and two legs (112, 113, 212, 213), wherein the outer contour of the U-shaped cross-section is predefined by a section of the housing (110, 210), wherein the inner radius (r) of the arcuate section (111, 211) is half as large as the outer diameter (D) of the body (10, 20), the electric heating device (100, 200) being applied for heating of the body (10, 20), so that, in the case of an electrical heating device (100, 200) arranged on the body (10, 20) as intended, half of the cross section (Q) of the body (10, 20) is received in the inner arch of the arcuate section (111, 211), and the leg portions (112, 113, 212, 123) extend substantially in a tangential direction towards the outer contour of the body (10, 20) and run substantially parallel to each other.

2. An electric heating device (100, 200) according to claim 1, characterized in that at least two mutually independent electric heating elements (130, 140, 230, 240) are arranged in the housing (110, 210) such that there are two independent heating circuits.

3. Electric heating device (100, 200) according to claim 2, characterized in that at least two electric heating elements (130, 140, 230, 240) independent of each other have different heating powers and/or different electrical characteristics.

4. Electric heating device (200) according to claim 2 or 3, characterized in that at least two mutually independent electric heating elements (230, 240) are arranged offset from each other and/or partially overlapping in a direction from an inner contour (216) of the U-shaped cross-section to an outer contour (214) of the U-shaped cross-section.

5. An electric heating device (100) according to any of claims 2-3, characterized in that at least two mutually independent electric heating elements (130, 140) are arranged in different sections of the U-shaped cross-section.

6. An electric heating device (200) according to any of claims 1-3, characterized in that at least one electric heating element (230, 240) is arranged partly in the arcuate section (211) and partly in the legs (212, 213) of the U-shaped cross-section.

7. An electric heating device (100, 200) according to any of claims 1-3, characterized in that at least one electric heating element (130, 140, 230, 240) is a resistance wire (131, 141, 231, 241) wound on a winding frame (132, 142, 232, 422).

8. An electric heating device (100, 200) according to any of claims 1-3, characterized in that at least one electric heating element (130, 140, 230, 240) is insulated from the housing and/or other electric heating elements (140, 130, 240, 230) by an insulating plate.

9. Electric heating device (100, 200) according to any one of claims 1-3, characterized in that the legs (111, 112, 211, 212) are mechanically pretensioned against each other such that a clamping action is exerted on a body (10, 20) arranged between them having an outer diameter (D).

10. An electric heating device (100, 200) according to any of claims 1-3, characterized in that the length of the leg (111, 112, 211, 212) is shorter than half the outer diameter (D) of the body (10, 20).

11. Electric heating device (100, 200) according to any of claims 1-3, characterized in that the electric heating device (100, 200) is a U-shaped electric heating device (100, 200).

12. A system (1, 2) consisting of a device with a body to be heated (10, 20) and an electric heating device (100, 200) for heating the body to be heated (10, 20), wherein the body to be heated (10, 20) has an outer diameter (D) and a cross-section (Q), characterized in that the electric heating device (100, 200) for heating the body to be heated (10, 20) is an electric heating device (100, 200) according to any one of claims 1 to 11.

13. System (1, 2) according to claim 12, characterized in that the connecting leads (120, 121, 122, 123, 220, 221, 222, 223) of the electric heating device (100, 200) are led out downwards from the electric heating device (100, 200) when the body to be heated (10, 20) is oriented in space as prescribed.