EP3417673B1 - Heat exchanger system - Google Patents

Description

The invention relates to a heat exchanger system, in particular an oil-water heat exchanger system, in particular for connection to an internal combustion engine, preferably a motor vehicle, according to claim 1 and a method for producing such a heat exchanger system. For example EP 2 466 241 A1 describes an oil-water heat exchanger with several tub elements stacked one on top of the other and soldered together. Such oil-water heat exchangers are usually integrated into the cooling circuit of internal combustion engines and can be used, for example, to cool the engine oil.

Another oil-water heat exchanger is in U.S. 2015/0176913 A1 or JP2007016857A shown.

In a particular embodiment, an electric heater is proposed there in an interior space of the heat exchanger in order to heat one of the fluids of the heat exchanger that interact with one another.

In principle, it is felt to be disadvantageous in the known oil-water heat exchangers that preheating can either not take place at all or only in a comparatively complex and ineffective manner (in particular slowly). In particular, the reduction of pollutants that occur when the engine oil is not at operating temperature is seen as in need of improvement.

Furthermore, with regard to the state of the art, WO 2013/186106 A1 and WO 2013/030048 A1 referred. There, heaters are described which have an electrical heating layer which heats up when an electrical voltage is applied (or when a current flows).

Furthermore, with regard to the prior art DE 10 2011 006 248 A1 referred. A household refrigeration appliance with a heating device is described there. The heating device is made as a layer heater by painting and applied to a surface of an evaporator of the household refrigeration appliance. Concretely, the layer heating is according to DE 10 2011 006 248 A1 directly applied to a surface of the evaporator and hardly thermally insulating in order to impair the functionality of the evaporator as little as possible. However, it is considered to be disadvantageous that production according to this prior art is comparatively complex and appears to be tailored to a very specific application.

It is therefore the object of the invention to propose a heat exchanger system in which at least one fluid flowing in a heat exchanger can be heated in a simple manner and yet effectively. This object is achieved by a heat exchanger system having the features of claim 1.

In particular, the object is achieved by a heat exchanger system for connection to an internal combustion engine, comprising at least one oil-water heat exchanger module and a layered heating module that is mounted or can be mounted on an outside of the cover of the oil-water heat exchanger module. wherein the layer heating module comprises a substrate, in particular a carrier plate, and a heating coating applied to the substrate, in particular the carrier plate.

A core idea of the invention is to provide a layer heating module comprising a substrate and a heating coating for connection to a heat exchanger module, in particular an oil-water heat exchanger module. In a departure from the prior art, the heating coating is not applied directly to the heat exchanger, but to a separate substrate, which in turn is mounted (attached) to the heat exchanger (heat exchanger module). The advantages described in the prior art are deliberately (at least partially) dispensed with in favor of a simple and extremely variable (flexible) production. In particular, it should be noted that the provision of the substrate initially increases the overall installation space of the heat exchanger system. The heat transfer is also fundamentally less effectively. Nevertheless, according to the invention, the path was taken to provide a (separate) layer heating module in order to enable at least one fluid flowing in a heat exchanger to be heated effectively and with simple means. In particular, existing heat exchangers (of different types and/or different sizes) can be upgraded in a simple manner, possibly using one and the same layer heating module.

The substrate is preferably a plate-shaped substrate, in particular a carrier plate. The plate preferably has two (at least substantially) planar surfaces. Unevenness preferably has a maximum height of 5 mm, preferably 2 mm, even more preferably 0.5 mm. The substrate, in particular the carrier plate, can have a polygonal, in particular square, preferably rectangular outline or a (circular) round or elliptical or irregularly shaped outline. A thickness of the substrate, in particular of the carrier plate, is preferably at least 0.5 mm, preferably at least 1 mm, even more preferably at least 2 mm and/or at most 20 mm, preferably at most 12 mm, even more preferably at most 8 mm.

The layered heating module is preferably materially connected to the heat exchanger module, in particular glued to the heat exchanger module, and/or connected to the heat exchanger module in a non-positive and/or positive manner, in particular clamped on. As a result, a reliably functioning heat exchanger system is produced in a simple manner. Alternatively, the layer heating module can also be connected to the heat exchanger module in some other way, for example by mechanical fasteners (e.g. screws and/or bolts). A latching connection can also be provided as an alternative or in addition, for example in such a way that the layer heating module snaps into latching devices of the heat exchanger module.

The substrate, in particular the carrier plate, is preferably made at least partially from a (thermally and/or electrically) insulating material. A thermally insulating material is to be understood in particular as a material with a thermal conductivity (at 25° C.) of less than 10 W/mK or less than 2 W/mK or less than 0.8 W/mK or less than 0.5 W/mK. In particular, an electrically insulating material is a material with a specific resistance (at 25 °C) of at least 10 ⁵ Ω mm ² m ^-1 or at least 10 ⁹ Ω mm ² m ^-1 2 W/mK or at least 10 ¹² Ω mm ² m ^-1 . The substrate, in particular the support plate, can in particular be made of a (possibly insulating) ceramic. Alternatively, it is also conceivable that the substrate, in particular the carrier plate, is made of a conductor, for example metal. If necessary, an insulating layer can then be provided between the heating coating and the substrate, in particular the carrier plate. In general, however, it is particularly preferred if the electrical heating coating is applied directly to the substrate, in particular the carrier plate. Especially when the substrate, preferably the carrier plate, is made of an insulating material, the substrate can synergistically serve as a carrier for the additional module and as a structure that allows at least sectional insulation of the electrical heating coating from the heat exchanger module.

The heating coating and/or insulating layer is preferably applied to the (full) surface of the substrate. Furthermore, the heating coating and/or the insulation layer can have an (at least essentially) constant layer thickness. The heating coating or the insulating layer can be applied directly to the substrate. The heating coating and/or the insulating layer can be dimensionally unstable (or non-self-supporting) per se.

In a specific embodiment, the heating coating is arranged on the side of the substrate, in particular the carrier plate, that faces the heat exchanger module. In such an embodiment, the heat exchanger module can be effectively preheated.

In the installed state of the layer heating module, an intermediate space is preferably formed at least in sections between the layer heating module and the heat exchanger module. The intermediate space is preferably filled (at least in sections) with a filling material (“gap filler”), in particular a possibly compressible and/or elastically and/or plastically deformable film. The film is preferably (well) thermally conductive and more preferably has a thermal conductivity (at 25° C.) of at least 15 W/mK or at least 50 W/mK or at least 100 W/mK or at least 180 W/mK. Especially when the heating coating on the dem Heat exchanger module facing side of the substrate, in particular the support plate, is arranged, thereby a simple insulation (at least in sections) of the heating coating can be achieved with respect to the heat exchanger module. In principle, however, the heating coating (in the installed state) can also be in contact with a surface of the heat exchanger module (possibly over the entire surface). In such a case, an insulating layer or an insulating cover can optionally be arranged on the heating coating (specifically on the side of the heating coating that points away from the substrate, in particular the carrier plate). Optionally, however, the heat exchanger module can also have a corresponding insulating layer or generally have an insulating surface.

In a preferred embodiment, contacting of the heating coating runs through the substrate, in particular the carrier plate.

The contact can more preferably run through the substrate at least twice, preferably in such a way that a conductor section of the contact runs parallel to (touching) the heating coating.

In such embodiments, a simple yet reliable contacting, which at the same time saves space, is made possible.

In one embodiment, the heating coating is grounded via the heat exchanger module, in particular a housing of the heat exchanger module. Specifically, a ground contact (pad) or a spring or the like can be formed between the heating coating and the heat exchanger module. If the heating coating is arranged on the side of the substrate, in particular the carrier plate, that faces the heat exchanger module, a grounding line can also optionally be routed through the substrate, in particular the carrier plate, and then grounded either externally (i.e. not via the heat exchanger module) or via the heat exchanger module be. Overall, a comparatively simple closing of the circuit is made possible.

In a preferred embodiment, both sides of the substrate, in particular the carrier plate, are provided with a heating coating. This allows for particularly effective heating.

In further embodiments, at least two heat exchanger modules and/or at least two layer heating modules are provided. At least one layer heating module is preferably arranged between two heat exchanger modules. At least one heat exchanger module can also be arranged between two layer heating modules. In principle, several, for example at least two, or at least three layer heating modules can be arranged on a heat exchanger module. Overall, this allows an effective exchange of heat and a heating of at least one of the fluids to take place in a flexible manner.

The layer heating module is preferably designed for operation in the low-voltage range (= preferably less than 100 V, more preferably less than 60 V (direct current), preferably 12 volts, 24 volts or 48 volts. Accordingly, electrical and/or electronic components that are required for a Operation of the layer heating module are necessary, be designed.As a result, any necessary insulation can be made comparatively simple.In particular, complex insulation, as is usually the case in the prior art (where work is carried out in the high-voltage range), is not necessary.

• Bereitstellung oder Herstellung eines Wärmetauschermoduls, insbesondere Öl-Wasser-Wärmetauscher-Moduls, sowie eines (separaten) Schichtheizmoduls, umfassend ein Substrat, insbesondere eine Trägerplatte, sowie eine auf dem Substrat, insbesondere der Trägerplatte, aufgebrachte elektrische Heizbeschichtung; und
• (stoff- und/oder kraft- und/oder formschlüssiges )Verbinden von Wärmetauschermodul und Schichtheizmodul, insbesondere durch Kleben und/oder Anklemmen.

The object mentioned above is also achieved by using a layer heating module having the features of claim 11 . Furthermore, the above object is achieved independently by a method for manufacturing a heat exchanger system with the features of claim 12, comprising the steps:

• Providing or producing a heat exchanger module, in particular an oil-water heat exchanger module, and a (separate) layer heating module, comprising a substrate, in particular a carrier plate, and an electrical heating coating applied to the substrate, in particular the carrier plate; and
• (Material and/or non-positive and/or form-fitting) connection of heat exchanger module and layer heating module, in particular by gluing and/or clamping.

The substrate, in particular the carrier plate, is preferably dimensionally stable or made from a dimensionally stable material.

The object mentioned above is also achieved by a layer heating module for a heat exchanger, in particular an oil-water heat exchanger, the layer heating module having the above and/or following features.

At least one hole is preferably made in the substrate, in particular the carrier plate, to produce the layered heating module. More preferably, contact is made with the heating coating through the at least one hole. In a specific embodiment, a blind hole is made in the substrate, in particular the carrier plate, in a first sub-step, the heating coating is applied to the substrate in a second sub-step (following the first sub-step) and in a third sub-step (following the second sub-step). a conductor portion is routed toward an end of the blind hole, preferably such that a bottom of the blind hole breaks so that the conductor portion comes into contact with the heater coating. Alternatively or additionally, two holes can be created in the substrate. Preferably, a contact for the heater coating is routed through both holes and more preferably runs (at least in sections) parallel to a plane defined by the heater coating (touching the heater coating). Insofar as features are described above (in connection with the heat exchanger system) which are at least also related to the production of the heat exchanger system, these process features are also proposed as preferred embodiments of the process.

A bimetal switch, possibly with two redundant switch devices, can be provided for controlling, in particular regulating, the electrically heated coating.

The heating coating can be applied to the substrate, in particular the carrier plate, indirectly, in particular via an insulating layer.

Such an insulating layer can be formed, for example, by an adhesion promoter layer. A polymer material can preferably be used for the insulating layer. However, the insulating layer is preferably provided by passivation, in particular oxidation, in particular anodizing (of aluminum or an aluminum alloy). Overall (particularly in low-voltage applications), simple yet adequate electrical insulation is provided. Alternatively, the heating coating can be applied directly to the substrate, in particular the carrier plate (for example in low-voltage applications and/or when the substrate is not electrically conductive or only poorly conductive). Overall, the complicated structure in the prior art, comprising a heating layer, a complex insulating layer and an adhesion promoter layer, can be reduced. In principle, the heating coating can be cohesively connected to a surface of the substrate, in particular the carrier plate.

In a specific embodiment, the layer heating module is arranged on a heat exchanger cover of the (oil-water) heat exchanger module. Particularly in the case of a low-voltage application, sufficiently safe use of the (oil-water) heat exchanger module (even without an additional protective element) is also possible when used on the outside of the cover (which can be advantageous, for example with regard to contacting). Overall, this proposes a simple yet reliably functioning structure.

In an alternative embodiment, the heating coating is designed as a continuous (in particular unstructured and/or uninterrupted) layer. The heating coating may generally have at least one portion within which there are no breaks in the heating coating in two mutually perpendicular directions over a distance of at least 1 cm, preferably at least 2 cm, more preferably at least 4 cm. For example, the heating coating can comprise at least one rectangular section with a length and a width of at least 1 cm, preferably at least 2 cm, even more preferably at least 4 cm, within which there are no interruptions or any other structures in the heating coating. A "break" within the heater coating is understood to mean a section through which no current can flow, for example because this section is (entirely) free of material remains and/or is (at least partially) filled by an insulator. The heater coating can be thermally sprayed (regardless of whether it is unstructured or structured, in the final state). In this context, it has surprisingly been shown that even such a simply designed heating coating can bring about sufficient heating of the oil.

In a further alternative embodiment, the heating coating is designed as a structured layer. The heating coating is preferably structured by a masking process (preferably using silicone that can be embossed). Known masking methods of this type allow satisfactory structuring and are less complex than, for example, laser methods for structuring, which are used precisely in the high-voltage area. Overall, therefore, the advantages of a masking process with regard to the present heating coating are exploited in a synergistic manner.

The insulating layer described above can have a thickness of at least 50 μm, preferably at least 200 μm and/or at most 1000 μm, preferably at most 500 μm.

The heating coating preferably has a height (thickness) of at least 5 µm, preferably at least 10 µm and/or at most 1 mm, preferably at most 500 µm, more preferably at most 30 µm, even more preferably at most 20 µm. A conductor track defined by the heating coating can be at least 1 mm, preferably at least 3 mm, even more preferably at least 5 mm, even more preferably at least 10 mm, even more preferably at least 30 mm wide. "Width" is to be understood as meaning the extent of the conductor track perpendicular to its longitudinal extent (which usually also defines the direction of the current flow).

In an alternative embodiment, a protective covering, for example a silicone protective layer, is applied over the heating coating. Alternatively, however (in an embodiment that is particularly easy to produce), the heating coating can also define an outside of the layered heating module.

In a specific embodiment, the oil-water heat exchanger module has a number of sub-units, in particular pan elements, which more preferably, as in EP 2 466 241 A1 described, can be formed. Basically, the oil-water heat exchanger module (apart from the layer heating module according to the invention) as in EP 2 466 241 A1 or U.S. 2015/0176913 A1 described, be trained. The disclosure of these publications is hereby explicitly incorporated by reference. If several sub-units are provided, at least one layer heating module can optionally be arranged between two sub-units. If the oil-water heat exchanger module comprises a plurality of pan elements, at least one layer heating module can be arranged (applied) between two of these pan elements (on one of the pan elements). As a result, the preheating (additional heating) can be further improved with simple means.

The oil-water heat exchanger can have a turbulator. In such a case, the turbulator may be close, e.g. B. not more than 5 cm, in particular not more than 2 cm, be formed into a heating coating and / or be equipped with a heating coating. This, too, is a further possibility of improving the heating of the fluid in a simple manner (namely without the provision of further components). Here, synergistic use is made of the fact that in the area of a turbulator there can be increased heat transfer due to the turbulence generated.

In general, the insulating layer can be a ceramic material or a polymer material or can consist of such a material, Al ₂ O ₃ , for example, coming into consideration as the ceramic material.

The heating layer can be applied, for example, in a plasma coating process, in particular plasma spraying, or in a screen printing process or as a resistance paste, in particular on the insulating layer. In the plasma coating process, for example, an electrically conductive layer can first be applied, in particular to the insulating layer. Areas can then be cut out of the electrically conductive layer so that one or more conductor tracks remain. However, a masking technique is preferably used. The conductor tracks can then form the heating resistor or multiple heating resistors. The areas mentioned can alternatively to a masking technique, for example be cut out of the conductive layer by means of a laser. The heating coating can be a metal layer, for example, and optionally contain nickel and/or chromium or consist of these materials. For example, 70-90% nickel and 10-30% chromium can be used, with a ratio of 80% nickel and 20% chromium being found to work well.

The heating coating can, for example, occupy an area of at least 5 cm ² , preferably at least 10 cm ² and/or at most 200 cm ² , preferably at most 100 cm ² . The (oil-water) heat exchanger module or the (oil-water) heat exchanger system can have a total volume of preferably at least 200 cm ³ , more preferably at least 500 cm ³ , even more preferably at least 800 cm ³ and/or at most 5000 cm ³ , preferably at most 2000 cm ³ . For example, the (oil-water) heat exchanger module or the (oil-water) heat exchanger system can be 15-25 cm long and/or 8-12 cm wide and/or 3-7 cm high (thick).

The heat exchanger module, in particular the oil-water heat exchanger module, preferably has one or more first fluid channels for conducting a first fluid, in particular the oil, and one or more second fluid channels for conducting a second fluid, in particular the water.

Fig. 1

eine schematische Ansicht eines Wärmetauschers;

Fig. 2

einen schematischen Ausschnitt eines Schichtheizmoduls gemäß einer ersten Ausführungsform;

Fig. 3

einen schematischen Ausschnitt einer weiteren Ausführungsform des Schichtheizmoduls;

Fig. 4

einen schematischen Ausschnitt eines (noch nicht fertiggestellten) Schichtheizmoduls gemäß einer weiteren Ausführungsform;

Fig. 5

einen schematischen Ausschnitt einer weiteren Ausführungsform des Schichtheizmoduls.

The invention is described below using exemplary embodiments which are explained in more detail using the figures. Here show:

1

a schematic view of a heat exchanger;

2

a schematic section of a layer heating module according to a first embodiment;

3

a schematic section of a further embodiment of the layer heating module;

4

a schematic section of a (not yet completed) layer heating module according to a further embodiment;

figure 5

a schematic section of a further embodiment of the layer heating module.

In the following description, the same reference numbers are used for the same parts and parts with the same effect.

1 shows an oil-water heat exchanger module 10 and a layer heating module 11. The oil-water heat exchanger module 10 can, for example as in EP 2 466 241 A1 described, be constructed, in particular several (possibly soldered together) pan elements have.

The layered heating module 11 comprises a support plate 12 and an electrical heating coating 13. The layered heating module 11 is preferably mounted on a cover 28 of the oil-water heat exchanger 10.

The electrical heating coating 13 is (which is not mandatory) applied to a side 14 of the carrier plate 12 facing the oil-water heat exchanger module 10 . The reference number 15 shows a first variant for producing a ground contact, specifically by a pad 15 that connects the heating coating 13 to the oil-water heat exchanger module 10 (in particular a housing thereof). A further alternative is indicated by the reference number 16, which specifically shows a pipe 16 which also connects the electric heating coating to the oil-water heat exchanger module 10 (in particular a housing thereof). Alternatively, the line 16 could also be grounded externally (ie not via the oil/water heat exchanger module 10). A contact corresponding to the ground contact is not shown. However, such a second contact could also be formed by a line analogous to line 16 if this is corresponding (deviating from 1 ) connected.

In 2 a first embodiment of a contacting of the electrical heating coating is shown. Here too (which is not mandatory), the electric heating coating 13 is located on a side 14 facing the carrier plate (not shown). A side facing away from the carrier plate is identified by the reference number 17 . The carrier plate 12 has a hole 18 through which a conductor section 19 forming the contact is passed. To facilitate contacting, one end 20 of the conductor section 19 is designed as a widening and in or above a recess 21 arranged. The end 20 is then preferably overmolded when the heating coating 13 is produced, so that a contact is formed.

In 3 is an embodiment similar to 2 shown, in which, however, no widening end 20 and no recess 21 is provided.

4 shows a schematic section of the layer heating module before final completion. Specifically, a conductor section 19 is shown here, which is inserted into a blind hole 22 . A second blind hole 23 is provided opposite (or adjoining) the first blind hole 22 (which is not mandatory). In a next step, the heating coating 13 is applied and then a predetermined breaking point 24 between the two blind holes 22, 23 is broken through, so that the conductor section 19 can come into contact with the heating coating 13. The predetermined breaking point 24 is preferably defined by a web.

In figure 5 another possibility of contacting the heating coating 13 is shown. In this embodiment, a first hole 25 and a second hole 26 are made in the support plate 12 . A conductor section 19 is guided both through the first hole 25 and through the second hole 26, so that a conductor sub-section 27 runs parallel to the heating layer 13, touching it. As a result, particularly simple and reliable contacting is implemented. Here, too, the electrical heating coating is preferably applied (sprayed on) after the conductor section 19 has been attached.

Reference List

10

Oil-water heat exchanger module

11

layer heating module

12

backing plate

13

electric heating coating

14

Page

15

Pads

16

Director

17

Page

18

Hole

19

ladder section

20

End

21

recess

22

first blind hole

23

second blind hole

24

predetermined breaking point

25

first hole

26

second hole

27

ladder subsection

28

Lid

Claims (13)

1. A heat exchanger system for connection to an internal combustion engine, preferably of a motor vehicle, comprising at least one oil water heat exchanger module (10) and a layer heating module (11), which is mounted or mountable on an outer surface of the cover of the oil water heat exchanger module, wherein the layer heating module (11) comprises a substrate, in particular a carrier plate (12), and an electric heating coating (13) applied to the substrate, in particular the carrier plate (12).
2. The heat exchanger system according to claim 1, characterized in that the layer heating module is connected in material-locking fashion to the oil water heat exchanger module (10), in particular adhesively bonded to the oil water heat exchanger module (10), and/or connected in particular clamped, in non-positively locking and/or positively locking fashion to the oil water heat exchanger module (10).
3. The heat exchanger system according to claims 1 or 2, characterized in that the substrate, in particular the carrier plate (12), is manufactured from an electrically and/or thermally insulating material, in particular ceramics.
4. The heat exchanger system according to one of the preceding claims, characterized in that the heating coating (13) is arranged on that side of the substrate, in particular the carrier plate (12), which faces towards the oil water heat exchanger module (10).
5. The heat exchanger system according to one of the preceding claims, characterized in that in the mounted state of the layer heating module, an intermediate space is formed between the layer heating module (11) and the oil water heat exchanger module (10), wherein the intermediate space is preferably filled with a filler material.
6. The heat exchanger system according to one of the preceding claims, characterized in that a contacting of the heating coating (13) extends through the substrate, in particular the carrier plate (12), wherein the contacting extends preferably twice through the substrate, in particular the carrier plate (12), preferably such that a conductor section (27) of the contacting extends parallel to the electric heating coating (13) so as to make contact therewith.
7. The heat exchanger system according to one of the preceding claims, characterized in that the electric heating coating (13) is grounded via the oil water heat exchanger module (10), in particular a housing of the oil water heat exchanger module.
8. The heat exchanger system according to one of the preceding claims, characterized in that both sides of the substrate, in particular the carrier plate (12), are provided with an electric heating coating (13).
9. The heat exchanger system according to one of the preceding claims, characterized in that at least two oil water heat exchanger modules and/or at least two layer heating modules are provided, wherein preferably at least one layer heating module is arranged between two oil water heat exchanger modules.
10. The heat exchanger system according to one of the preceding claims, characterized in that the layer heating module (11) is designed for an operation in a low-volt range, preferably 12 volts, 24 volts or 48 volts.
11. Use of a layer heating module (11), comprising a substrate, in particular a carrier plate (12), and an electric heating coating (13) applied to the substrate, in particular the carrier plate (12), for warming at least one fluid of an oil water heat exchanger, wherein the heating layer module is arranged on an outer surface of the cover of the oil water heat exchanger.
12. A method for producing an oil water heat exchanger module according to one of claims 1 to 10, comprising the steps:

    - providing or producing an oil water heat exchanger module (10), and a layer heating module (11), comprising a substrate, in particular a carrier plate (12), and an electric heating coating (13) applied to the substrate, in particular the carrier plate (12); and

    - connecting the oil water heat exchanger module (10) and the layer heating module (11) on an outer surface of the cover of the oil water heat exchanger, in particular by adhesive bonding and/or clamping.
13. The method according to claim 12,
    characterized in that

    to produce the layer heating module (11), at least one hole (18, 25, 26) is formed in the substrate, in particular the carrier plate (12), wherein a contacting to contact the electric heating coating is led through the at least one hole,

    wherein preferably in a first sub-step a blind hole (22) is produced in the substrate, in particular the carrier plate (12), in a second sub-step the electric heating coating (13) is applied to the substrate, and in a third sub-step a conductor section is guided against one end of the blind hole, such that a base of the blind hole breaks, such that the conductor section comes into contact with the electric heating coating (13), and/or wherein preferably two holes (25, 26) are created in the substrate, in particular the carrier plate (12), wherein a conductor section of the contacting runs preferably in parallel to the electric heating coating (13) while making contact therewith.

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