Modular heating unit and arrangement for a cooling circuit

Abstract

In order to create a heating unit (10) comprising at least one heating film (11) with at least one conductor track (12) and at least one guide element (21), in which the at least one heating film (11) and the at least one guide element (21) are shaped as a planar surface, which enables a technically simple and efficient heating of a heat-transferring fluid without local overheating of the fluid, it is proposed to connect the at least one heating film (11) and the at least one guide element (21) to each other in such a way that at least one flow channel (30) is formed between the at least one heating film (11) and the at least one guide element (21).

Description

[0001] The invention relates to a heating unit comprising at least one heating film with at least one conductive track and at least one guide element. Furthermore, the invention relates to an arrangement for a cooling circuit with at least one heating unit.

[0002] High-voltage heaters are typically used to regulate the temperature of the coolant in electric vehicles. These heaters are particularly important at low ambient temperatures to quickly heat the coolant. The heated coolant can then be used to regulate the temperature of both the vehicle interior and the traction battery, thereby increasing the battery's capacity. This ensures both passenger comfort and optimal battery operation at a specific temperature, preventing cell damage or performance loss.

[0003] The heaters mentioned can, for example, incorporate resistance heating elements to generate heat. These heating elements can be either PTC resistors, thin-film / thick-film heating elements, or tubular heaters. The coolant is heated indirectly via a heat transfer wall, as the heating elements are thermally connected to a metal body. The coolant flows through or around this metal body, allowing heat to be transferred to the coolant.

[0004] Theoretically, coolant heaters can be designed as high-voltage heaters with induction heating elements. Such heaters generate alternating electromagnetic fields for inductive heating. In particular, one or more metallic surface heating elements, for example in the form of hollow cylindrical bodies, are inductively heated by eddy currents induced within them. The resulting heat is transferred to a fluid flowing around or through these surface heating elements. Such heaters are not currently used in the automotive sector.

[0005] DE 10 2019 133 039 A1 discloses a fluid heater in which a heating element is formed by a circuit board that delimits part of a fluid space.

[0006] EP 3 799 523 A1 describes an electric flow heater. The flow heater has a thick-film heating element arranged in a housing. A fluid channel adjacent to the heating element is formed within the housing. The fluid channel has an inlet and an outlet.

[0007] A problem with existing solutions for heating the coolant is the excessively high surface temperature resulting from limited heat transfer area. This high surface temperature can damage the coolant. Furthermore, a significant pressure drop occurs when the coolant flows through the heaters, potentially necessitating an additional cooling circuit (bypass) and more powerful pumps. Such measures negatively impact the vehicle's range and cost-effectiveness. Moreover, the addition of heaters increases the number of components and the amount of installation space required within the vehicle.

[0008] The use of resistance heating elements requires a longer heating time due to the necessary heating of the heat transfer wall. Furthermore, a longer heating time may be required at certain operating points due to reduced heating power (derating).

[0009] The invention is based on the objective of creating a heating element, a heating unit and an arrangement for a cooling circuit that enables technically simple and efficient heating of the coolant or heat transfer fluid without local overheating of the coolant.

[0010] This problem is solved by the features specified in claim 1. Further advantageous embodiments of the invention are described in the dependent claims.

[0011] According to one aspect of the invention, a heating unit is provided. The heating unit comprises at least one heating film with at least one conductive track and at least one guide element. The at least one heating film and the at least one guide element are planar in shape, and the at least one heating film and the at least one guide element are connected to each other in such a way that at least one flow channel is formed between the at least one heating film and the at least one guide element.

[0012] The heating films can advantageously have at least one conductive track that is provided with electrical insulation on both sides. The electrical insulation can consist of a plastic, such as a PEN conductor.

[0013] The at least one guide element can, for example, be designed as a flow-guiding contour. In particular, the guide element can be manufactured in the form of a thin, corrugated sheet. For example, the guide element can be made of an aluminum alloy or another metal. This allows the guide element to exhibit good thermal conductivity and low weight. The thermal conductivity of a metal is advantageous because the plate-shaped guide elements separate the individual flow channels or coolant channels from one another, thus enabling heat transfer between the individual flow channels via the guide elements.

[0014] The heating unit enables a significantly larger heat transfer surface through the use of multiple heating films with flow around them on both sides. This increased heat transfer surface can result in a reduction of the required surface temperature for heat transfer, thus eliminating the risk of coolant decomposition. The direct placement of the heating films in the heat-transferring fluid allows for more dynamic temperature control and a shorter heating time.

[0015] The heating film, at least one of which, can be flexible or rigid. For example, the heating film can be designed as a rigid heating plate.

[0016] In one embodiment, the at least one guide element and / or the at least one heating film are corrugated, folded, or bent, or have a surface structure to form the at least one flow channel. The folded or corrugated structure or shape of the guide element and / or the heating film can create one or more areas that can function as flow channels. In a particularly simple embodiment, the heating film or the guide element can be flat or sheet-like.

[0017] Depending on the design, at least one guide element can be made of metal or plastic. The heating film can have at least one conductive track that is electrically insulated by silicone, PPS, or similar materials. In the area of ​​the interface, the conductive track can protrude from the electrical insulation and thus be contactable.

[0018] The heating films and guide elements can be modularly combined to form a unit or heating package if the at least one heating film and the at least one guide element are connected by an adhesive bond and / or by at least one fastener. The at least one fastener can be in the form of screws, clamps, clips, straps, or similar devices that join the heating element into a single component. This approach enables particularly simple manufacturing through a stacking process of heating films and guide elements or flow-guiding contours for assembly.

[0019] In one embodiment, the at least one heating film and the at least one guide element are connected to each other at least partially along their edges. This allows for a seal between the guide elements and the heating films.

[0020] In a further embodiment, at least one seal and / or an adhesive is arranged between the at least one heating film and the at least one guide element. Advantageously, the at least one seal and / or the adhesive is applied circumferentially. The heating film assembly or the heating element thus has a seal between the respective plates or guide elements and heating films, so that the heat-transferring fluid can only circulate within a defined area and the heating element itself is fluid-tight. Depending on the design, the seal can also be fixed in place using the adhesive. The adhesive can be a curing or a permanently elastic adhesive, which can also have a sealing function.

[0021] Sealing can be achieved by means of an injection-molded sealant applied to the edge of the guide elements. The electrical contacting of the individual conductor tracks of the heating films can be accomplished via a common mounting rail, in which the individual electrical connections or interfaces of the heating films can be bundled, with each heating film preferably having plug contacts or interfaces.

[0022] Depending on the design, the seal can be a molded seal, O-ring seal, paper seal, adhesive bond, and the like.

[0023] The electrical regulation of the heating unit can be particularly efficient if at least one heating film has at least one temperature sensor.

[0024] In one embodiment, the at least one temperature sensor is arranged in or on the heating film, or the at least one conductor track can be used, at least temporarily, as a temperature sensor. Consequently, temperature sensors, such as NTCs, can be used to detect the temperature of the heat-transferring fluid. In a particularly simple solution, the temperature can be determined using a temperature measurement loop in the form of an additional conductor track or the conductor track used for heating.

[0025] According to one embodiment, the at least one heating film is configured to transfer heat to a fluid flowing through the at least one flow channel. The delivered heat output can be scaled or adjusted particularly easily if the nominal heat output can be set by means of a number of interconnected heating films and guide elements. The conductive traces of the heating films can thus be designed for a specific heat output, so that, depending on the required heat output of the cooling system or arrangement, the corresponding number of heating films can be stacked and bundled in combination with the guide elements. This measure enables power variability and a modular design of the heating unit.

[0026] According to a further embodiment, the heating unit has at least one inlet for introducing a fluid into the at least one flow channel and at least one outlet for discharging the fluid from the at least one flow channel. The inlet and / or the outlet are formed in the form of an opening in the at least one heating film and / or in the at least one guide element.

[0027] In another embodiment, the inlets of all heating films and all guide elements are fluid-conducting and interconnected. These inlets and guide elements can be stacked on top of each other. Similarly, the outlets of all heating films and all guide elements can be fluid-conducting and, for example, stacked on top of each other.

[0028] Advantageously, the inlets and outlets are spaced apart by flow channels, which connect the inlets and outlets, carrying the fluid. After the heat-transferring fluid or coolant is introduced into the heating unit via the inlets, the fluid can distribute itself through the parallel flow channels and flow to the outlets. As it passes through the flow channels, heat is transferred to the fluid. The fluid can then exit the heating unit through the outlets.

[0029] The at least one inlet and / or the at least one outlet can be designed with or without conductor tracks, so that the heating effect can be extended over the entire cross-section of the heating films or limited to the flow channels.

[0030] According to a further aspect of the invention, an arrangement for a cooling circuit is provided. The arrangement comprises at least one heating unit, wherein the heating unit is arranged in a housing connectable to a coolant circuit or fluid circuit, or in a component of the coolant circuit. The at least one flow channel of the heating unit is configured to guide a heat-transferring fluid at least on one side along at least one heating film. This allows the fluid to be heated and thermally conditioned in a particularly simple manner.

[0031] For the installation of the heating unit, the heating unit, designed as a heating package, is inserted into a coolant-carrying or fluid-carrying housing, which can then be closed by placing an electronics housing or electronics unit or a cover on top.

[0032] The individual heating foils can be connected simultaneously if their conductor tracks terminate in electrical interfaces, and these interfaces can be electrically connected via a mounting rail. The mounting rail is advantageously electrically connected to an electronic unit. Alternatively, the mounting rail is integrated into the electronic unit. The individual heating foils are thus connected together via the mounting rail, which bundles the individual electrical connections of the heating foils, with each foil having plug contacts.

[0033] The heating unit can be integrated into a cooling circuit particularly efficiently if the housing can be sealed fluid-tight by a closure or by the electronic unit.

[0034] Exemplary embodiments of the invention are explained in more detail below with reference to the drawings. The drawings show: Fig. 1 a top view of a heating film of a heating unit according to an embodiment, Fig. 2 a perspective view of a guide element of a heating unit according to an embodiment, Fig. 3 a sectional view of a heating unit according to one embodiment, Fig. 4 a perspective view of a heating unit according to a further embodiment, Fig. 5 perspective views of an arrangement according to one embodiment, and Fig. 6 a sectional view of an arrangement according to a further embodiment.

[0035] In the figures, the same constructive elements each have the same reference numerals.

[0036] The Fig. Figure 1 shows a top view of a heating film 11 of a heating unit 10 (see Figure 1). Fig. 3) according to one embodiment. The heating unit 10 has one or more heating foils 11. In the illustrated embodiment, the heating foil 11 has a conductor track 12 which can be supplied with a defined voltage and a defined current to generate heat. The electrical power of the conductor track 12 can be variable or constant.

[0037] Furthermore, the heating film 11 has a first opening 13 and a second opening 14. The conductive track 12 extends in a meandering pattern between the first opening 13 and the second opening 14. The conductive track 12 is embedded in a plastic or silicone material, which serves as electrical insulation 15 for the conductive track 12. The first opening 13 and the second opening 14 are incorporated into the electrical insulation 15. The electrical insulation 15 of the heating film 11 thus extends laterally beyond the conductive track 12.

[0038] The conductor track 12 can, for example, be made of aluminium and terminates in an interface 16 located at the edge of the heating film 11.

[0039] The first opening 13 is designed as part of an inlet 33 and the second opening 14 as part of an outlet 34 (see figure). Fig. 4).

[0040] Furthermore, the heating unit 10 has at least one guide element 21. Fig. Figure 2 shows an exemplary perspective view of a guide element 21 of the heating unit 10 according to one embodiment. In the illustrated embodiment, the guide element 21 is partially shaped as a corrugated sheet-like plate. The dimensions of the guide element 21 essentially correspond to the dimensions of the heating film 11 in order to enable precise stacking of several heating films 11 and guide elements 21.

[0041] The guide element 21 has a first opening 23 and a second opening 24, analogous to the heating film 11. The openings 23 and 24 of the guide element 21 have corresponding positions and dimensions to the openings 13 and 14 of the heating film 11.

[0042] A section 22 of the guide element 21, which is shaped as a corrugated sheet, is arranged between the openings 23, 24. A wave-like profile runs in the structured section 22 transversely to a distance between the openings 23, 24.

[0043] In the Fig. Figure 3 shows a sectional view of a heating unit 10 according to one embodiment. The heating unit 10 has two heating films 11, which are spaced apart from each other by a guide element 21. The heating films 11 and the guide element 21 are stacked and fluid-tightly connected to each other. Fig. Figure 4 shows a perspective view of a heating unit 10 according to a further embodiment with a larger number of stacked heating foils 11 and guide elements 21.

[0044] Between each heating film 11 and the guide element 21, flow channels 30 are formed by the structured area 22 of the guide element 21. The interfaces 16 project side by side beyond the guide element 21.

[0045] The sealing of the flow channels 30 can be achieved, for example, by a circumferential seal 31. In the illustrated embodiment, the seal 31 is applied to both sides of the guide element 21 and extends completely around the edge.

[0046] A fluid introduced through openings 13 and 23 can thus enter the flow channels 30 and cannot escape from the edges of the heating element 10. After passing through the flow channels 30, the fluid can flow out of the heating element 10 through the second openings 14 and 24.

[0047] The Fig. Figure 4 illustrates the formation of the first openings 13, 23 as an inlet 33 and the second openings 14, 24 as an outlet 34 of the heating unit 10.

[0048] In the Fig. Figure 5 shows perspective views of an arrangement 100 according to one embodiment. The arrangement 100 may be part of a cooling system or coolant circuit (not shown) or connected to the cooling system. Fig. Figure 5 shows one option of the arrangement 100, which can be connected to a cooling system.

[0049] The arrangement 100 has at least one heating unit 10. In the illustrated embodiment, the heating unit 10 is arranged in a housing 110, which is connected to the coolant circuit.

[0050] The arrangement 100 further comprises an electronic unit 120, which serves to contact the interfaces 16 of the heating films 11 and may include further electrical components for controlling and regulating the heating films 11. In the illustrated embodiment, the electronic unit 120 can be mounted on the bottom of the housing 110, with the housing 110 being sealed fluid-tight by the electronic unit 120.

[0051] The electronic unit 120 can have plug connections 121 or electrical connections to control the heating unit 10.

[0052] The housing 110 has an inlet 33 and an inlet 34, which lead fluid into the first openings 13, 23 and the second openings 14, 24 of the heating foils 11 and guide elements 21.

[0053] The Fig. Figure 6 shows a sectional view of an arrangement 100 according to a further embodiment. In contrast to the one in Fig. In the arrangement 100 shown in Figure 5, the heating unit 10 of the arrangement 100 is integrated into a component or part 130 of the coolant circuit. The part 130 can be sealed fluid-tight by a cover (not shown) or by the electronic unit 120. Reference symbol list 100 arrangement 110 cases 120 electronic units 121 electrical connections 130 components 10 heating units 11 Heating film 12 conductor tracks 13. First opening of the heating film 14 second opening of the heating film 15 electrical insulation 16 Interface 21 Guide element 22 structured area / surface structure of the guide element 23 First opening of the guide element 24 second opening of the guide element 30 Flow channel 31 Seal 33 Admission 34 Outlet QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2019 133 039 A1

[0005] EP 3 799 523 A1

[0006]

Claims

[1] Heating unit (10) comprising at least one heating film (11) with at least one conductor track (12) and at least one guide element (21), wherein the at least one heating film (11) and the at least one guide element (21) are shaped as a planar surface, wherein the at least one heating film (11) and the at least one guide element (21) are connected to each other in such a way that at least one flow channel (30) is formed between the at least one heating film (11) and the at least one guide element (21). [2] Heating unit according to claim 1, wherein the at least one guide element (21) and / or the at least one heating film (11) are corrugated or folded or bent or have a surface structure (22) to form the at least one flow channel (30). [3] Heating unit according to claim 1 or 2, wherein the at least one heating film (11) and the at least one guide element (21) are connected to each other by an adhesive connection and / or by at least one fastening means, wherein the at least one heating film (11) and the at least one guide element (21) are connected to each other at least partially at the edges. [4] Heating unit according to one of claims 1 to 3, wherein at least one seal (31) and / or an adhesive is arranged between the at least one heating film (11) and the at least one guide element (21), wherein the at least one seal (31) and / or the adhesive is designed circumferentially. [5] Heating unit according to one of claims 1 to 4, wherein the at least one heating film (11) has at least one temperature sensor, wherein the at least one temperature sensor is arranged in the heating film (11) or on the heating film (11) or the at least one conductor track (12) can be used at least temporarily as a temperature sensor. [6] Heating unit according to one of claims 1 to 5, wherein the at least one heating film (11) is configured to deliver heating power to a fluid flowing through the at least one flow channel (30), wherein the nominal heating power is adjustable by a number of interconnected heating films (11) and guide elements (21). [7] Heating unit according to any one of claims 1 to 6, wherein the heating unit (10) has at least one inlet (33) for introducing a fluid into the at least one flow channel (30) and at least one outlet (34) for discharging the fluid from the at least one flow channel (30), wherein the inlet (33) and / or the outlet (34) are formed in the form of an opening (13, 14, 23, 24) in the at least one heating film (11) and / or in the at least one guide element (21), wherein the inlets (13, 23) of all heating films (11) and all guide elements (21) are fluid-carrying connected to each other, and wherein the outlets (14, 24) of all heating films (11) and all guide elements (21) are fluid-carrying connected to each other. [8] Arrangement (100) for a cooling circuit, comprising at least one heating unit (10) according to one of claims 1 to 7, wherein the heating unit (10) is arranged in a housing (110) connectable to a coolant circuit or in a component (130) of the coolant circuit, wherein the at least one flow channel (30) of the heating unit (10) is configured to guide a heat-transferring fluid at least on one side along at least one heating film (11). [9] Arrangement according to claim 8, wherein conductor tracks (12) of the heating films (11) terminate in electrical interfaces (16), wherein the electrical interfaces (16) can be electrically contacted by means of a plug-in rail, wherein the plug-in rail is electrically connected to an electronic unit (120) or wherein the plug-in rail is integrated into the electronic unit (120). [10] Arrangement according to claim 9, wherein the housing (110) or the component (130) of the coolant circuit can be closed fluid-tight by a closure or by the electronic unit (120).

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