HEATING DEVICE FOR HEATING AIR

Abstract

The invention relates to a heating device for heating air, having a primary heat source (10) and a heat exchanger (2). The heat exchanger (2) has an interior space (22) for receiving the primary heat source (10) and transfers thermal energy generated by the primary heat source (10) to the air. The heat exchanger (2) includes a holding element (21) for receiving an electric heating element (11) as a secondary heat source (2). The heat exchanger (2) consists of a first heat exchanger unit (201) and a second heat exchanger unit (202).

Claims

1. (canceled)

2. (canceled)

3. (canceled)

4. (canceled)

5. (canceled)

6. (canceled)

7. (canceled)

8. (canceled)

9. (canceled)

10. (canceled)

11. A heating device for heating air, comprising a primary heat source (10), a heat exchanger (2) and a housing (3), wherein the heating device is configured for use in a travel trailer or a motorhome, wherein the primary heat source (10) is a gas or diesel burner, wherein the heat exchanger (2) surrounds the centrally arranged primary heat source (10), wherein the heat exchanger (2) comprises an interior space (22) for receiving the primary heat source (10) and transfers thermal energy generated by the primary heat source (10) to the air, and wherein the heat exchanger (2) includes a plurality of holding elements (21) that are radially spaced apart, arranged around the interior space (22), and serve to receive a respective electric heating element (11) as a secondary heat source (2), characterized in that the heat exchanger (2) consists of a first heat exchanger unit (201) and a plurality of second heat exchanger units (202), each for a respective electric heating element (11), in that the first heat exchanger unit (201) and the second heat exchanger units (202) include contact profiles (23) corresponding to each other for a releasable mechanical and/or direct thermal connection, in that the housing (3) and the first heat exchanger unit (201) define an air duct (30) for the air to be heated, and in that the first heat exchanger unit (201) is arranged within the housing (3) such that the plurality of second heat exchanger units (202) are insertable into the air duct (30) so as to be symmetrical to each other.

12. The heating device according to claim 1, wherein at least one placeholder (40) is provided, and wherein the placeholder (40) is insertable into the holding element (21) instead of the electric heating element (11).

13. The heating device according to claim 1, wherein the at least one holding element (21) has an annular shape that opens at least on one side, and wherein the holding element (21) has an elastic widening of the opening for receiving the electric heating element (11).

14. The heating device according to claim 1, wherein the electric heating element (11), surrounded by a thermally conductive insulation (4), is pressed into the holding element (21).

Description

[0032] In detail, there are a multitude of possibilities of configuring and further developing the heating device according to the invention. In this regard, reference is made, for one thing, to the claims dependent on claim 1 and, for another, to the following description of exemplary embodiments in conjunction with the drawings, in which:

[0033] FIG. 1 shows a schematic representation of a heating device according to the prior art,

[0034] FIG. 2 shows a section through a schematic representation of a first configuration of a heating device according to the invention,

[0035] FIG. 3 shows a section through a schematic representation of a second configuration of a heating device according to the invention,

[0036] FIG. 4 shows a section through a schematic representation of a third configuration of a heating device according to the invention,

[0037] FIGS. 5 a) and b) show a section through a schematic representation of a fourth configuration of a heating device according to the invention in two different component placement states,

[0038] FIG. 6 shows a section through a first configuration of a heat exchanger according to the invention,

[0039] FIG. 7 shows a section through a second configuration of a heat exchanger according to the invention, and

[0040] FIG. 8 shows a section through a third configuration of a heat exchanger according to the invention.

[0041] FIG. 1 shows a section through a schematic heating device according to the prior art.

[0042] The heat source 1 is formed by a combustion chamber in which an air-gas mixture is combusted. The combustion gases produced in the process are discharged through a heating chamber and then through an exhaust system (not illustrated here).

[0043] The substantially cylindrical heat source 1 is surrounded by a heat exchanger 2. To this end, the heat exchanger 2 comprises an interior space 22, which serves to accommodate the heat source 1. The heat exchanger 2 transfers the thermal energy of the heat source 1, or more specifically of the combustion or flue gases, to air which is conveyed along the outside of the heat exchanger 2, e.g. by means of a fan (not illustrated here). On its outside, the heat exchanger 2 features a plurality of ribs or fins 20, which increase the surface area that is effective for the transfer of heat and between which ducts for the air are formed.

[0044] The heat exchanger 2 is surrounded by a housing 3, which also co-defines the air duct 30 through which the air is guided around the heat exchanger 2.

[0045] The following Figures each show a section through a heating device according to the invention. For the sake of clarity, the illustration is greatly simplified. For example, only the respective outside of the various heat exchangers 2 is shown and described. Depending on the embodiment, however, fins protruding inwards may also be present, for example, or the fins—protruding inwards or outwards—may exhibit specially designed surfaces or contours.

[0046] FIG. 2 shows a section through a schematic representation of a first configuration of the heating device according to the invention. Generally, the heat exchanger 2 has an oblong or cylindrical extent.

[0047] Located within the housing 3 is a heat exchanger 2, which in this case consists of a total of five heat exchanger units 201, 202: These are one first heat exchanger unit 201 and four second heat exchanger units 202.

[0048] The first heat exchanger unit 201 has an interior space 22 which comprises a primary heat source 10 in the form of a gas burner according to the prior art. This therefore corresponds to the configuration as illustrated and described with reference to FIG. 1.

[0049] Located between the first heat exchanger unit 201 and the inner wall of the surrounding housing 3 is an air duct 30 through which the air to be heated is passed.

[0050] The four second heat exchanger units 202 are provided for supplementing the primary heat source 10 by the secondary heat sources 11 in the form of heating rods, which are four in the illustrated embodiment. Alternatively, e.g., two, six, eight, and so on secondary heat sources 11 are provided. Integer multiples of two are favored for a symmetrical structure and/or a symmetrical heat distribution. The four second heat exchanger units 202 are inserted in the air duct 30 around the first heat exchanger unit 202 such that they fill the gaps, so to speak, between the first heat exchanger unit 201 and the inner wall of the housing 3. In the illustrated configuration, this insertion is simplified in that the housing 3 encompasses a rectangular interior space and in that the first heat exchanger unit 201 together with its fins 20 defines a circular cross-section.

[0051] The first heat exchanger unit 201 and the second heat exchanger units 202 as well as the second heat exchanger units 202 among each other here are free from thermal contact with each other, so that in the illustrated embodiment no thermal energy transfer occurs between or among the heat exchanger units 201, 202 themselves.

[0052] The second heat exchanger units 202 each have five fins 20 and an annular holding element 21. The air to be heated can circulate between the fins 20 of the second heat exchanger units 202. In addition, these fins 20 enlarge the interaction surface area. The electric heating elements 11 in the holding elements 21 are each surrounded by a thermally conductive insulation 4. In one configuration, the electric heating elements 11, for example a heating coil, and the insulation 4 are connected by a suitable pressing tool to form a finished unit. In an alternative configuration, the heating element 11 is placed in the holding element 21 without insulation.

[0053] In one configuration, instead of two separate electric heating elements 11, a heating rod bent in a U-shape is used, onto which two respective second heat exchanger units 202 are slid.

[0054] The second heat exchanger units 202 are introduced here along with the electric heating elements 11 after the first heat exchanger unit 201, thus allowing the heating power to be increased.

[0055] In the configuration of FIG. 3, a first heat exchanger unit 201 and a second heat exchanger unit 202 are provided as parts of the heat exchanger 2.

[0056] The two heat exchanger units 201, 202 each include a circular-cylindrical base body which, in section, appears as a ring. The second heat exchanger unit 202 coaxially surrounds the first heat exchanger unit 201 here. Inside the first heat exchanger unit 201 there still exists the interior space 22 for the primary heat source 10.

[0057] Arranged on the base body of the second heat exchanger unit 202, which thus functions as a holding element 21, there are four (in alternative configurations: any other number) electric heating elements 11, which are distributed symmetrically on the circumference.

[0058] The first heat exchanger unit 201, located inside, includes fins 20 that extend radially outward. The encompassing second heat exchanger unit 202 also features fins 20 that extend radially inward and thus toward the first heat exchanger unit 201. The distances between the fins 20 of the first heat exchanger unit 201 and between the fins 20 of the second heat exchanger unit 202 are each dimensioned such that the fins of the second heat exchanger unit 202 can be inserted between the fins 20 of the first heat exchanger unit 201. In this way, a direct mechanical contact between the fins 20 is avoided, and the two heat exchanger units 201, 202 can be slid into each other during manufacturing or subsequent component mounting.

[0059] The air duct 30 for the air to be heated is thus defined by the space between the second heat exchanger unit 202 and the inner wall of the housing 3 and by the space between the fins 20 of the first heat exchanger unit 201 and the second heat exchanger unit 202.

[0060] The configuration of FIG. 4 is similar to the configuration of FIG. 2.

[0061] Common to both configurations is that there is a first heat exchanger unit 201 with the interior space 22 for a primary heat source 10 and four second heat exchanger units 201 for an electric heating element 11 each. The first heat exchanger unit 201 and the four second heat exchanger units 202 together constitute the heat exchanger 2 inside the housing 3 and surrounded by the air duct 30 for the air to be heated. For the sake of clarity, the second heat exchanger units 202—specifically the holding elements 21—and the electric heating elements 11 are shown in one piece here.

[0062] The addition to the configuration of FIG. 4 consists in the mechanical and preferably also thermally conductive connection between the first heat exchanger unit 201 and the four second heat exchanger units 202. This connection or direct coupling takes place here via mutually corresponding contact profiles 23, which are applied onto the fins 20 of the first heat exchanger unit 201 or those of the second heat exchanger units 202. The fins 20 in question each have contours on the face side which can be introduced into corresponding mating contours. Here, combinations of profiles (ball shape) and associated negative profiles (half shells with corresponding inside diameters) are shown.

[0063] The second heat exchanger units 202 thus generate satellite-like continuations of the first heat exchanger unit 201 here by way of the contact profiles 23.

[0064] In the configuration of FIG. 5, one first heat exchanger unit 201 and two second heat exchanger units 202 are provided. The three heat exchanger units 201, 202 thus form the heat exchanger 2 within the housing 3.

[0065] The two second heat exchanger units 202 have a fin structure such that they largely encompass the first heat exchanger unit 201 laterally. The two second heat exchanger units 202 are opposite each other here.

[0066] The holding elements 21 are arranged centrally in the second heat exchanger units 202 and are formed jointly by the first heat exchanger unit 201 and the second heat exchanger units 202. The contact profiles 23 within the meaning of the configuration of FIG. 4 are thus realized here by the shared holding elements 21.

[0067] FIG. 5 a) illustrates the case in which the second heat exchanger units 202 are connected to the first heat exchanger unit 201 and they jointly form the heat exchanger 2, but located within the holding elements 21 are only placeholders 40 for the electric heating elements 11 proper.

[0068] In FIG. 5 b), the electric heating elements 11 are inserted instead of the placeholders 40.

[0069] In this configuration, the placeholders 40 serve to make sure that the same internal geometry and also the same weight distributions are given in the heating device with and without the heating element 11. Thus, for example, the same flow behavior of the air is produced inside the housing 3 in each case.

[0070] FIG. 6 illustrates a one-piece heat exchanger 2.

[0071] Fins 20, which are corrugated here, project into the interior space 22 and, starting from the ring of the heat exchanger 2, further fins 20 extend radially outward. The heat exchanger 2 has a rectangular outer contour due to the dimensions of the fins 20.

[0072] Four of the fins 20 have a respective holding element 21 which allows an electric heating element to be placed therein.

[0073] The holding element 21 is substantially ring-shaped here and has an opening directed radially outward. The edges of the opening flare radially. In this case, the dimensions of the holding elements 21 and the nature or quality of the fins concerned are selected and adapted to each other such that the heating element can be inserted laterally during manufacture and that the holding element 21 expands elastically when an appropriate pressure is applied. In this way, the heating element is received and subsequently securely held.

[0074] FIG. 7 shows a heat exchanger 2 which, similar to the configuration of FIG. 5, consists of one first heat exchanger unit 201 and two second heat exchanger units 202.

[0075] The two second heat exchanger units 202 are located opposite each other, thus flanking the first heat exchanger unit 201, and have an oblong extent. In addition, here the second heat exchanger units 202 each have two holding elements 21.

[0076] As in the other configurations, the first heat exchanger unit 201 is essentially of a circular cylindrical design so that, in section, a ring shape is obtained. The ring encompasses the interior space 22. Fins 20 extend radially outwards, with four fins 20 having a respective contact profile 23 on the face side.

[0077] The two second heat exchanger units 202 feature corresponding contact profiles 23 at their end portions, so that a respective mechanical contact can be produced between the first heat exchanger unit 201 and the second heat exchanger units 202. In this case, the contact profiles 23 consist of balls and half shells.

[0078] The second heat exchanger units 202 also have fins 20, some of which are directed towards the first heat exchanger unit 201 and some of which are directed away from it.

[0079] FIG. 8 shows the second heat exchanger units 202 of FIG. 7, which are directly connected to each other, jointly constituting the heat exchanger 2.

[0080] This variant is made possible by the contact profiles 23, which are constructed such that they can be connected not only with the first heat exchanger unit, but also with each other. Therefore, the two ends of the second heat exchanger units 202 also differ with respect to the shape of the contact profiles 23.

[0081] The two second heat exchanger units 202 enclose an interior space 22; the air to be heated can flow through the interior space 22 as well as through the outer air duct 30. The fins 20 which project inwards and, in the configuration shown, are in direct contact with one another, reach through the interior space 22 here.

[0082] The four holding elements 21 allow the insertion of up to four electric heating elements, which in this configuration thus form the primary and single heat source.

LIST OF REFERENCE NUMBERS

[0083] 1 heat source [0084] 2 heat exchanger [0085] 3 housing [0086] 4 insulation [0087] 10 primary heat source [0088] 11 electric heating element [0089] 20 fin [0090] 21 holding element [0091] 22 interior space [0092] 23 contact profile [0093] 30 air duct [0094] 40 placeholder [0095] 201 first heat exchanger unit [0096] 202 second heat exchanger unit