HEATING BODY FOR A DEVICE FOR ELECTRICALLY HEATING AND CIRCULATING A LIQUID

Abstract

Heating body (I) for a device (16) for electrically heating liquid, said heating body (I) comprising at least one first helical heating element (4) defined by a diameter (di), a second helical heating element (5) defined by a diameter (d2), and a base (2) carrying the first and the second heating element (4, 5), characterized in that the first diameter (di) is greater than the second diameter (d2), and in that the first heating element is disposed around the second element. The heating body (I) can be configured so as to comprise three heating elements, or more, arranged such that the size in terms of length is limited, and could include a core, disposed so as to be surrounded by all of the different heating elements, reducing the volume of liquid inside the chamber (15) in which the heating body (I) is housed.

Claims

1. A heating body for an electric liquid-heating device, said heating body comprising: at least a first heating element of helical shape and defined by a first diameter; a second heating element of helical shape defined by a second diameter; and a base bearing the first heating element and the second heating element, wherein the first diameter is larger than the second diameter and the first heating element is disposed around the second heating element.

2. The heating body as claimed in claim 1, in which a winding axis of the first heating element is coincident with a winding axis of the second heating element.

3. The heating body as claimed in claim 1, wherein the first heating element and/or the second heating element comprises a first terminal section, followed by a wound portion, followed by a second, rectilinear terminal section, the first terminal section and the second terminal section extending between the wound portion and the base.

4. The heating body as claimed in claim 1, further comprising at least one third heating element, of helical shape and defined by a third diameter, the first heating element being disposed around the third heating element.

5. The heating body as claimed in claim 4, wherein the third heating element is disposed in the axial extension of the second heating element, and the second heating element and the third heating element wound around a common axis Y.

6. The heating body as claimed in claim 1, further comprising at least one third heating element, of helical shape and defined by a third diameter called the third diameter, the first heating element and the third heating element being disposed around the second heating element.

7. The heating body as claimed in claim 6, wherein the third heating element is disposed in the axial extension of the first heating element, such that the first heating element and the third heating element are wound around a common axis Y.

8. The heating body as claimed in claim 1, wherein the second terminal section of at least one of the heating elements extends toward the base, inside the wound portion of at least one heating element.

9. The heating body as claimed in claim 2, further comprising a core extending in the direction defined by a winding axis of the various heating elements, arranged such that the various heating elements are disposed around said core.

10. An electric heating device comprising: a heating body comprising: at least a first heating element of helical shape and defined by a first diameter, a second heating element of helical shape defined by a second diameter, and a base bearing the first heating element and the second heating element, wherein the first diameter is larger than the second diameter and the first heating element is disposed around the second heating element; and a housing fastened to the base, the heating body and the housing delimiting a chamber in which at least the first and second heating elements extend.

11. The heating body as claimed in claim 1, wherein the base is provided with orifices allowing the insertion and fastening, in a sealed manner, of at least the first and second heating elements.

12. The heating body as claimed in claim 11, wherein, in order to prevent deformation of the base bearing at least the first and second heating elements, said first and second heating elements comprise a non-heating zone located at sites of insertion in the base.

Description

[0038] Further characteristics, details and advantages of the invention will become more clearly apparent upon reading the detailed description given below, and several exemplary embodiments that are given by way of nonlimiting indication, with reference to the attached schematic drawings, in which:

[0039] FIG. 1 is a side view of the electric heating device, when its heating body comprises two heating elements;

[0040] FIG. 2 is a lateral view of the electric heating device, when its heating body comprises at least three heating elements;

[0041] FIG. 3 is a schematic representation of a heating body comprising two possible heating elements for the present invention;

[0042] FIG. 4 is a schematic representation of a heating body comprising three heating elements, arranged according to a first embodiment;

[0043] FIG. 5 is a schematic representation of a heating body comprising three heating elements, arranged according to a second embodiment;

[0044] FIG. 6 is a vertical cross section of a heating body comprising three heating elements arranged according to a first embodiment, as shown in FIG. 2;

[0045] FIG. 7 is a top view of the heating body, when the latter comprises a core.

[0046] FIG. 1 schematically illustrates an electric heating device 16, comprising a base 2 bearing at least two heating elements 4 and 5 and to which a housing 13 is fastened, thus delimiting a chamber 15 in which the various heating elements 4 and 5 extend. The base 2 and the heating elements 4 and 5 form the assembly that is called the heating body 1. In order to seal the chamber 15, an annular seal 17 is disposed at the bottom of the heating body 1, in a receiving groove situated between the base 2 and the housing 13.

[0047] FIG. 1 presents, in particular, an electric heating device 16 of which the heating body 1 is configured to comprise two heating elements 4, 5, and shows the relative arrangement of the various heating elements 4, 5 within the electric heating device 16.

[0048] Each heating element 4, 5 is inserted and fastened, in a sealed manner, at orifices 3 made in the base 2, such that the liquid circulating in the chamber 15 cannot escape. Said heating elements 4, 5, are of tubular shape and are made up of a first terminal section 7, fastened to the base 2, continued by a wound portion 8 of helical shape, of which the helix extends in the direction defined by an axis Y, and ending with a second terminal section 9. Each terminal section 7, 9 is equipped at its end with a terminal 11 allowing the heating body 1 to be electrically connected to the electric power supply.

[0049] FIG. 1 shows a heating body 1 in which the second terminal sections 9 of each heating element 4, 5 extend in a rectilinear manner in a central zone 12, delimited by the inner surface of the wound portion of the second heating element 5. Alternatives to such an arrangement will nevertheless be discussed below.

[0050] The second terminal section 9 makes it possible to join the distal end, relative to the base 2, of the wound portion 8 to said base 2. In particular, a zone in which the distal end of the wound portion 8 and the second terminal section 9 are joined forms an elbow 10. The various elbows 10, and also the first and second terminal sections 7, 9 of each heating element 4, 5, are arranged such that there is no overlap or contact between the various terminal sections 7, 9. Such an arrangement will be illustrated in greater detail with FIGS. 6 and 7.

[0051] In the example shown in FIG. 1, the heating body 1 is configured so as to include only two heating elements 4 and 5. Said heating body 1 comprises a first heating element 4, defined by a first diameter d1, arranged such that this first heating element 4 is wound around the second heating element 5, defined by a second diameter d2 smaller than the diameter d1 of the first heating element 4.

[0052] The two heating elements 4, 5 can be arranged such that they are concentric, as illustrated in FIG. 1. The wound portions 8 of the various heating elements 4, 5 are then wound around a single axis Y. They extend in the chamber 15, over a height HA that is equal or substantially equal, measured along the same axis Y between the base and the distal end of the wound portion 8. The arrangement of the first and of the second heating element 4, 5 is defined such that these separate heating elements do not come into contact with each other, either at their own terminal sections 7 and 9 or at their wound portion 8.

[0053] When it is inserted into the housing 13, the heating body 1 is arranged such that, in a plane orthogonal to the axis Y, the points on the outer surface of the wound portion 8 of each heating element 4, 5 are equidistant, or substantially equidistant, from an inner surface of the housing 13, thus defining a space for circulation of the liquid in the chamber 15. In this way, the liquid circulates evenly through, around and inside the heating body 1, and rises in temperature upon contact with the various heating elements 4 and 5.

[0054] FIG. 2 and the schematic representation in FIG. 4 show a heating body 1 comprising three heating elements 4, 5 and 6, each of tubular and helical shape, and shows the arrangement of the various heating elements 4, 5, 6 according to a first embodiment. An alternative embodiment is shown schematically in FIG. 5.

[0055] In this first embodiment illustrated in FIG. 2, the heating body 1 comprises the first heating element 4, defined by the first diameter d1, which is wound around the second heating element 5, defined by the second diameter d2. The heating body 1 comprises a third heating element 6, defined by a third diameter d3. The various heating elements 4, 5, 6 are arranged such that this first heating element 4, defined by a first diameter d1 larger than d2 and d1 larger than d3, is wound around the second and the third heating element 5, 6. In particular, and as shown in FIG. 2, the third heating element 6 is disposed at the end of the second heating element 5 and these two heating elements have a common winding axis Y, which is coincident with the winding axis Z of the first element 4. The second and third heating elements 5, 6 are also defined by their equal diameters d2 and d3.

[0056] In such an arrangement, the various heating elements 4, 5 and 6 are at a non-zero distance from one another. In addition, the outer surface of the wound portion 8 of the second or of the third heating element 5, 6, and the inner surface of the wound portion 8 of the first heating element 4, delimit an intermediate annular zone 19, in the form of a more or less narrow ring, in which the liquid circulates.

[0057] The various heating elements 4, 5 and 6 extend in the chamber 15, which is delimited by the housing 13 and the base 2, in the direction defined by the axis Y. The first heating element 4 extends over a height H.sub.1, measured between the base 2 and the distal end of the wound portion 8 of the first element 4, along the axis Y. This height H.sub.1 is equal, or substantially equal, to the height H.sub.2,3, measured along the axis Y, between the base 2 and a distal end of a wound portion 8 of the third heating element 6. This height H.sub.2,3 is the sum of the length of the second and third heating elements 5 and 6, when they are disposed end to end, and is measured along the axis Y.

[0058] As mentioned above for a heating body 1 comprising two heating elements 4, 5, the assembly of these three heating elements 4, 5 and 6 is preferably arranged such that, in a plane orthogonal to the axis Y, the points on a respective outer surface of a wound portion 8 of the various heating elements 4, 5, 6 are equidistant, or substantially equidistant, from an inner surface of the housing 13, so as to define a space for circulation of the liquid in the chamber 15 that is equally distributed.

[0059] The wound portion 8 of the first element 4, of diameter d1, which is larger than the diameters d2 and d3 of the second and third heating elements 5 and 6, in this embodiment has a pitch P.sub.1 larger than the pitches P.sub.2 or P.sub.3 observed in the wound portion 8 of the second or third heating element 5, 6. The second and third heating elements 5, 6 illustrated in the heating body 1 in FIG. 2 have identical pitches P.sub.2 and P.sub.3. An alternative in which these pitches differ will nevertheless be conceivable.

[0060] Each heating element 4, 5, 6, comprises an elbow 10 extending, in a plane substantially perpendicular to the winding axis Y, toward the central zone 12 delimited by the inner surface of the wound portions of the second and third heating elements 5, 6. The elbow 10 of the third heating element is thus arranged such that the second terminal section 9 that is attached to it can extend rectilinearly in the central zone 12, from the wound portion 8 to a vacant space in the base 2, similarly to what has been explained above for the first and second heating elements 4, 5.

[0061] In the example shown in FIG. 6, the elbows 10 of each heating element 4, 5 and 6 extend toward the central zone 12, such that the second terminal sections 9 of each heating element 4, 5, 6 extend in this same central zone 12. It will nevertheless be possible to envisage alternatives in which one or more of the second terminal sections extend in the intermediate annular zone 19, which is located between the various heating elements 4, 5, 6.

[0062] This cross section along the Y axis illustrates a succession of turns that are vertically aligned on an axis V, belonging to the first heating element 4, followed by a succession of turns of the second and third heating element 5, 6, which are aligned vertically along an axis W that is separate from the axis V. The section of each heating element 4, 5, 6 is identical, illustrating the fact that they are composed of resistive strands of similar, or substantially similar, diameter.

[0063] FIG. 7 schematically illustrates a heating body 1 comprising a core 14 disposed at the center of the various heating elements 4, 5, 6. Such a core 14 can be integrated in all the configurations and embodiments of the heating body 1 as described above, regardless of the number of heating elements of which it is made up. This core 14 fills, at least partially, the central zone 12 of the heating body 1 and thus contributes to reducing the volume of the chamber 15, to increasing the disturbance of the flow of the heat-transfer liquid present in the chamber 15 and to accelerating the speed of movement of the liquid within this chamber 15. The presence of this core 14 thereby improves the performance of the heating body 1.

[0064] The core 14 is disposed in the central zone 12 and extends in the direction defined by the winding axis Y of the various heating elements 4, 5, 6 in the chamber 15. This core can be of variable height and extends over all or some of the length of the longest heating element. Nevertheless, a core of height approaching the height of the heating body 1 assembly surrounding said core 14 will preferably be adopted, so as to optimize the effect of the core 14.

[0065] FIG. 7 also illustrates fastening means 21, integrated in the base 2, which will make it possible to fasten the electric heating device of the present invention to the vehicle or to a support thereof.

[0066] It will be understood from reading the foregoing that the present invention proposes a heating body intended for an electric heating device, this heating body being configured to reduce the bulk of the electric heating device, while at the same time maintaining or increasing its thermal performance. The dimensions of this heating body, which is intended in particular to cooperate with a heating and/or air-conditioning apparatus for an electric or hybrid vehicle, are optimized as a result of the particular arrangement of the various heating elements. The addition of a core, disposed within this heating body, also has the effect of increasing the efficiency of the heat transfer that takes place between the heating elements and the liquid. The efficiency of the energy transfer is thereby increased, while the bulk of the electric heating device is reduced compared with the fluid-heating devices of the prior art.

[0067] The invention is not limited to the means and configurations described and illustrated herein, however, and also extends to all equivalent means or configurations and to any technically functional combination of such means. In particular, the number of heating elements, the pitch of the wound portions of said heating elements, the diameter of said heating elements can be modified without harming the invention, insofar as the electric heating device for a vehicle ultimately fulfills the same functionalities as those described in this document.

[0068] It will for example be possible to envisage a configuration in which one or more of the second terminal sections of the heating elements extend in the intermediate annular zone, and not in the central zone.