Electric heating device

Abstract

The present invention relates to an improved electric heating device (10) for heating a liquid medium, comprising a first heating chamber (100) and a second heating chamber (200) and an electric heating element (30) which is provided between the first heating chamber (100) and the second heating chamber (200) and is thermally coupled to the first heating chamber (100) and the second heating chamber (200), and with an inlet (11) and a distributor (40) downstream of the medium in the direction of flow, which divides the current introduced through the inlet (11) into a first partial current supplied to the first heating chamber (100) and a second partial current supplied to the second heating chamber (200), and with an outlet (13) and a connector (50) upstream of the medium in the direction of flow, which connects the partial currents discharged from the first and second heating chambers (100, 200).The first heating chamber (100) is formed by a first flow housing (106) comprising a first system component (102) thermally coupled to the heating device (30) and a first cover (104). The second heating chamber (200) is formed by a second flow housing (206) comprising a second system component (202) thermally coupled to the heating device and a second cover (204). The distributor (40) and / or the connector (50) is formed on a separate flow-conducting component (60) that is fluid-tightly connected to the first flow housing (106) and the second flow housing (206).

Description

[0001] The present invention relates to an electric heating device for heating a liquid medium comprising a first heating chamber and a second heating chamber and an electric heating element which is provided between the first heating chamber and the second heating chamber and is thermally coupled to the first heating chamber and the second heating chamber.

[0002] Such an electric heating device is known from EP 2 559 573 A1. In this prior art, the electric heating element is located between two heating chambers formed by different housing parts, which also contain the electric heating element. The connection between the different housing parts must be fluid-tight to seal at least one of the heating chambers. Furthermore, the layers of the electric heating element, which includes PTC elements and contact plates on both sides, must be reliably pressed against each other to achieve good electrical contact and heat dissipation. In the prior art described above, one of the heating chambers is covered by a control housing containing power transistors that are cooled via the corresponding heating chamber.The control housing is designed as a separate, self-contained component and forms the lid of the corresponding heating chamber. The medium to be heated is passed through one of the heating chambers and then through the other, flowing parallel to the layers of the electric heating element.

[0003] CN 108 592 383 A discloses an electric heating device with a self-contained housing in which several heating chambers are accommodated, which can be connected to a media circuit in a vehicle via connection ports provided on the housing and which accommodate an electric heating device between them.

[0004] An electric heating device of the aforementioned type, used in a motor vehicle, must meet certain requirements. As a mass-produced item, the electric heating device should be easy and reliable to manufacture. Furthermore, a low weight of the installed component is preferable in light of the overall low mass of the vehicle. The electric heating device must have a compact design. Since the electric heating system typically also includes a control unit, which, particularly when the electric heating device is used in an electric vehicle whose operating voltage is sometimes also used to power the electric heating device, must be protected against electromagnetic interference (EMI) to prevent electromagnetic interference from emanating from the electric heating device.

[0005] It goes without saying that the electric heating device should be operated as economically and efficiently as possible. This requires not only good thermal coupling between the electric heating element and the respective heating chambers, but also that the liquid medium be guided through the electric heating element with minimal loss. This necessitates a flow pattern that is as free of turbulence as possible, at least with regard to the macroscopic flow. This must be considered separately from micro-turbulence, which is sometimes promoted at the interface of the heating chamber to optimize heat transfer to the medium being heated. For efficient operation of the electric heating device, the heating element should be cooled via two opposing main surfaces, thus heating the medium on these two sides.Uniform heat dissipation on both sides is preferable. This is because, particularly with PTC elements, which can form part of the electrical heating element, even insufficient heat dissipation on one side leads to reduced efficiency.

[0006] The present invention aims to provide an electric heating device that meets these requirements as best as possible and solves all, or at least some, of the problems mentioned above.

[0007] The present invention proposes an electric heating device for heating a liquid medium, comprising a first heating chamber and a second heating chamber. An electric heating element is provided between these two heating chambers and is thermally coupled to them. The electric heating device also has an inlet and an outlet for the medium to be heated. These flow control components are typically each formed by a nozzle. These nozzles usually project beyond the outer surface of the housing of the electric heating device and are designed for connection to pipes or hoses for the liquid medium to be heated. A distributor is provided downstream of the inlet in the direction of medium flow.This distributor splits the flow of the medium to be heated, introduced through the inlet, into a partial flow directed to the first heating chamber and a partial flow directed to the second heating chamber. These two partial flows, designated as the first and second flows, are connected after passing through the two heating chambers by a connector located upstream of the outlet in the direction of flow. Thus, heating chambers are provided on both sides of the electric heating elements, which serve to dissipate heat from the electric heating elements and thereby enable relatively efficient operation of the heating elements.

[0008] The distributor and connector are positioned within the flow path such that the flow is transferred from the inlet to the respective heating chambers with minimal loss and then merged from the heating chambers towards the outlet. The desirable configurations of the distributor and connector are explained in more detail below. While the present invention refers to first and second heating chambers or first and second partial flows, this does not preclude the electric heating device from also having additional heating chambers and / or the flow being divided into further partial flows, which may be supplied to the first or second heating chambers or – if present – ​​to further heating chambers.

[0009] According to the present invention, the first heating chamber is formed by a first flow housing. This housing has at least one first component, thermally coupled to the heating element, and a first cover. The flow housing can essentially consist of these two housing parts, which are typically sealed together. The two housing parts of the flow housing can be welded, soldered, or bonded together. The first component and the first cover can be made of plastic or metal, respectively. For optimal heat transfer, the first component is preferably made of a material with good thermal conductivity, and thus preferably of metal.

[0010] The second flow housing is designed in a similar manner. It comprises a second system component and a second cover. The details described for the first flow housing also apply to the second flow housing.

[0011] The first and second system components are thermally coupled to the heating element. Accordingly, the system components form contact surfaces that are in contact with the electric heating element as completely as possible.

[0012] At least the first and second parts of the system are identical, so that the electric heating device can be manufactured more economically using identical parts.

[0013] The distributor and / or connector are formed on a separate flow-guiding component, which is fluid-tightly connected to the first and second flow housings. This flow-guiding component can be connected to a part of the housing, preferably as an integral part thereof. However, the flow-guiding component can also be a separate component that serves only to guide and direct the flow and typically forms the inlet or outlet. It is preferable to form the flow-guiding component as an integral part of a housing section that also forms the connections.

[0014] To achieve the most uniform distribution of the partial flows possible with minimal pressure losses of the fluid to be heated within the electric heating device, a preferred embodiment proposes that the longitudinal axes of the nozzles extend parallel to a plane containing the heating chamber(s). The distributor has a dividing web extending in the plane containing the heating device, which divides the flow. The connector has a connecting web extending in the same plane, which connects the flow. The ratio of the first and second partial flows can be structurally adjusted via this connecting web, preferably such that, with identical heating chamber designs, the flow is divided equally between the two heating chambers, provided that only two such heating chambers are provided.The connector and distributor typically redirect the flow on both sides of the nozzle so that the flow is essentially perpendicular to the plane containing the heating element. This redirection preferably occurs at the level of the electric heating element. Each flow housing, in turn, has a deflection that transfers the flow with minimal loss from the plane perpendicular to the plane containing the electric heating element to the plane of the heating chamber, which typically extends perpendicular to the plane containing the electric heating element. Within this plane, the flow preferably follows a U-shaped path within the respective heating chamber and sweeps across the inner contact surface of the respective heating chamber, thereby heating the flow. The flow is then directed out of the heating chamber and transferred to the connector in the same manner. The flow-guiding surfaces between the inlet and outlet are designed to be highly efficient.The outlet nozzle and the inlet to the respective heating chamber or the outlet from the heating chamber are preferably designed identically, and are preferably optimized with regard to low-loss flow by means of uniform curved transitions that smoothly transfer the flow from one direction to the other.

[0015] As mentioned previously, the first and second components are preferably identical. The same applies to the cover parts. The respective cover parts can also initially be prepared as identical components, with one cover part, referred to below as the first cover part, preferably adapted to the requirements arising from its function as the base of a control or connection chamber. This chamber serves for the electrical connection of the electric heating device and the housing of a control unit. For example, the two cover parts can initially be manufactured together by casting, incorporating contours necessary solely for the connection chamber. These structures can then be machined or removed. Alternatively, the structures can be subsequently added to cover parts formed using ER-Plan technology.

[0016] According to a preferred embodiment of the present invention, the flow-guiding component-encompassing further housing part is a frame-shaped housing that circumferentially surrounds and accommodates at least the first flow housing and forms the inlet nozzle or the outlet nozzle. This frame-shaped housing can be made of plastic to reduce weight.

[0017] The frame-shaped housing typically has the aforementioned inlet and outlet ports on its circumferential surface. The ports are preferably straight. Furthermore, interfaces in the form of connector housings for the power supply to operate the electric heating device and the control signals for controlling the control unit within the electric heating device are typically provided on the circumferential surface of the frame-shaped housing. Since, in the embodiment discussed here, the first flow housing is arranged within the frame-shaped housing, a space remains within the frame-shaped housing and between the first flow housing and a cover for it. This space is referred to as the connection chamber and may also contain the electric control unit in the form of a printed circuit board.The first flow housing and the control device are usually mounted and fastened in the frame-shaped housing.

[0018] The second flow housing usually forms the other lid of the frame-shaped housing and closes it off on the side opposite the connection chamber.

[0019] The first flow housing, which is at least partially made of metal, and the typically metal cover for the connection chamber, effectively shield the chamber from electromagnetic radiation. For example, the housing cover can have a metallic collar that extends into the connection chamber, completely surrounding the control unit and providing electromagnetic shielding in the circumferential direction as well. Alternatively, the frame-shaped housing, made of plastic, can be internally shielded. Such shielding can also be integrated into the frame-shaped plastic housing as an insert during injection molding.

[0020] To transfer the flow from the flow-conducting component to the respective heating chambers, the first and second system sections each have opposing heating chamber connections. These connections are sealed to the flow-conducting component and typically extend perpendicular to the plane containing the heating element. Preferably, the flow-conducting component also has housing connections extending in this direction, which are sealed against the heating chamber connections by means of a gasket. Accordingly, the heating chamber connections and the housing connections extend parallel to each other and perpendicular to the plane containing the heating element.It is understood that the inner circumferential surfaces defined by the nozzles typically have the same diameter and that the housing nozzles transition seamlessly into the heating chamber nozzles, thus ensuring the smoothest possible transfer of the medium from the flow-conducting component to the first and second flow housings. Each housing nozzle overlaps the heating chamber nozzle axially, usually to a certain extent, allowing a sealing ring to be positioned within this overlap area to seal the housing nozzle against the heating chamber nozzle.

[0021] The present invention is characterized by the following items: 1. An electric heating device with the features defined in claim 1 can comprise at least one, preferably two, flow housings, which are received in a frame-shaped housing made of plastic. This results in a weight saving. This frame-shaped housing need not necessarily include the flow-conducting component. The flow-conducting component can also be connected to the frame-shaped housing, in particular by bonding or welding. 2. An electric heating device with a first and a second heating chamber and an electric heating element, each thermally coupled to the electric heating chambers, can comprise first and second flow housings that are at least partially identical. Thus, each of the flow housings can have an identically designed component that is thermally coupled to the electric heating element. It is not necessary to split the incoming flow into two partial flows in parallel. Instead, the two heating chambers can also be connected in series.However, it is essential that the two flow housings are at least partially, preferably completely, made of identical components, with each housing part preferably consisting of only two components: a cover part which is identical for both flow housings, and a mounting part which is also identical for both flow housings. 3. The components that determine the flow can be essential to the invention in themselves, regardless of the design of the heating device. In particular, the division of the partial flows into two as identical partial flows is essential to the invention. With regard to identical flow conditions, the flow is preferably introduced and discharged in the plane containing the heating device. For this purpose, it is regularly required that the dividing bridge and the connecting bridge extend in the plane containing the electric heating device and divide the flow in this plane, deflecting it from this plane into a plane perpendicular to the plane containing the heating device. The flow is then deflected again into a plane containing the heating device in order to guide each partial flow parallel to the electric heating device and thus transfer the heat from the electric heating device to the medium to be heated.

[0022] The electric heating device preferably comprises PTC elements and conductor elements, preferably in the form of contact plates, which are electrically connected to the PTC elements and are energized with opposite polarity. The PTC elements are typically ceramic elements with a metallization on the surface intended for current introduction.

[0023] Further details and advantages of the present invention will become apparent from the following description of an exemplary embodiment in conjunction with the drawing. The drawing shows: Fig. 1 an exploded view of the essential components of the embodiment; Fig. 2 a partially cutaway perspective view of the embodiment according to Fig. 1 along the central longitudinal axis of the inlet nozzle and Fig. 3 a representation according to Fig. 2 along the central longitudinal axis of the outlet nozzle.

[0024] The Fig. Figure 1 shows the essential components of an electric heating device marked with reference numeral 10, which has a frame-shaped housing 20 and a correspondingly designed upper housing cover 22, which defines a connection chamber on its upper side.

[0025] Reference number 200 designates a second heating chamber, which is essentially identical in design to the first heating chamber 100.

[0026] Both heating chambers 100, 200 have a first and second system section 102, 202, respectively, and a first and second cover 104, 204, respectively, connected to each of these sections around their perimeter. Between the respective system section 102, 202 and the cover 104, 204, the first and second heating chambers 100, 200 are formed by a flow housing designated 106 and 206, respectively, in the drawing. The second flow housing 206 simultaneously serves as the lower cover for the frame-shaped housing 20. Both this second flow housing 206 and the upper housing cover 22 are sealed to the frame-shaped housing 20, thus sealing the connection chamber 24 from the environment.

[0027] Reference numeral 26 designates a control device arranged between the first flow housing 106 and the upper housing cover 22. The electric heating device 30 is located on the side opposite the control device 26 with respect to the first flow housing 106. In the illustrated embodiment, the first flow housing 106 is mounted and held within the frame-shaped housing 20. However, the electric heating device is not separate from the control device 26. Both elements of the electric heating device 30 are located in the connection chamber 24.

[0028] How Fig. As can be seen from Figure 1, connecting lugs 32 protrude from the electric heating device 30, which penetrate a plane marked with reference numeral E1 containing the first heating chamber 100 and are electrically connected to the control device 26 by means of plug contacts, wherein the control device 26 is essentially formed by a circuit board 27 which is equipped with several and in Fig. The first flow housing 106 is equipped with two power transistors designated with reference numeral 28. These power transistors 28 are thermally connected to cooling benches 108 projecting from an outer surface of the first cover 104 via a retainer 25 mounted against the first flow housing 106, with an insulating film 29.2 interposed, so that the power dissipation of the power transistors 28 is thermally conducted via the first cover 104 into the first heating chamber 100 and is used to heat the medium to be heated in the electrical heating device 10.

[0029] For introducing this liquid medium, the electric heating device 10 has an inlet 11, formed by an inlet nozzle 12, and an outlet 13, formed by an outlet nozzle 14. The respective nozzles 12 and 14 are integrally molded onto the frame-shaped housing part 20, which is made of plastic and produced by injection molding. Fig. Figure 1 shows connector housings 15, one for connecting a cable through which the power current is introduced into the electric heating device 10, and the other for another cable for introducing the control signals. The control connector housing is designated by reference numeral 15a. Reference numeral 15b designates the power connector housing. In the illustrated embodiment, the connector housings 15 and the nozzles 12, 14 are located on a single end face of the frame-shaped housing 20 and project beyond it on one side.

[0030] The assembly of the in Fig. In the embodiment shown in Figure 1, the process begins after the first and second flow housings 106, 206 have been manufactured separately. The circuit board 27, typically equipped with the power transistors 28, is then pressed against the outer surface of the first cover 104. The power transistors 28 then rest against the cooling pads 108 with the insulating film 29 interposed. Reference numeral 110 indicates mounting bosses by which the retainer is connected to the first flow housing 106. This retainer resists compression elements (not shown) that pass through the recesses in the circuit board 27 and act against the individual power transistors 28 to thermally compress them against the cooling pads 108.

[0031] The second flow housing 206 is placed against the underside circumferential edge of the frame-shaped housing 20 and connected to it in a fluid-tight manner, for example by gluing. The electric heating device 30 is then placed against a contact surface of the second flow housing 206, marked with reference numeral 212, which is formed by the metallic contact part 202.

[0032] On the side opposite the second flow housing 206, the first flow housing 106, with its corresponding contact surface 112, is then placed against the electric heating element 30. The previously described layered assembly is clamped within the frame housing by means of retaining elements (not shown), which are supported on the inner circumferential surface of the frame housing 20 and act against the outer surface of the first cover 104, so that the two flow housings 106, 206 are thermally coupled to the electric heating element 30. The upper housing cover 22 is then placed onto the frame housing 20 and fluid-tightly connected to it. Contact tongues may protrude from the connector housings 15, which are plugged into the circuit board 27 mounted on it when the first flow housing 106 is inserted.This makes it easy to mount the electric heating device 10.

[0033] Details of the routing of the medium to be heated within the exemplary embodiment are described in the Fig. 2 and Fig. Level 3, next to the level containing the first heating chamber, is labelled E1, with E2 indicating the level containing the second heating chamber. Reference symbol EH designates the level containing the heating device 30. This level is defined by the average height of PTC elements located in Fig. 2 and 3 are marked with reference numeral 34 and are electrically conductive in contact with contact plates 36, which form the aforementioned connecting lugs 32 in one piece and are covered on the side opposite the PTC elements 34 with an insulating layer 38, which is in direct contact with the respective contact surface 112, 212. The respective heating chambers 100, 200 are identical. Thus, the levels E1, E2 containing the heating chambers 100, 200 are each the same distance from the level EH containing the heating device 30. Three-dimensional structures 114, 214 project from the inner wall of the plant section 102, 202, which limits the respective heating chamber 100, 200. These structures serve to increase the heat-transferred surface area in the respective heating chamber 100, 200 and cause micro-turbulence in the area of ​​the heat-transferring inner surface, which improves heat transfer.

[0034] As well as Fig. As can be seen in Figure 1, the respective system components 102, 202 each form two heating chamber nozzles 116, 216, which extend perpendicular to the planes E1, E2. The outer end of each of these heating chamber nozzles 116, 216 is closed by cover segments 118, 218 of the respective covers 104, 204, which form convex ramp surfaces 120, 220 curved towards the heating chamber nozzles 116, 216, which gently and continuously transfer the flow from the heating chamber nozzles 116, 216 into the respective heating chamber 100, 200 (cf. Figure 1). Fig. 2) or derive from it (cf. Fig. 3).

[0035] The elements of the electric heating device that guide the flow between the nozzles 12 and 14 are identically designed, although the flow in Fig. 2 in the opposite direction to the current Fig. 3 flows. Like the nozzles 12, 14, a flow is created through the plastic material of the housing 20. Fig. 2 Distributors designated with reference numeral 40 are formed with a distribution rib 42. The dividing rib 42 lies in and extends within the plane EH containing the heating element 30. Starting from a leading edge 43 in the direction of flow, the distributor 40 forms concave flow-guiding surfaces 44, which deflect the flow introduced into the plane EH through the inlet nozzle 12 at right angles to the plane EH containing the heating element 30, so that it flows axially towards the heating chamber nozzles 116, 216. The flow-guiding surfaces 44 extend on both sides of the plane EH into housing nozzles 45, the cylindrical ends of which extend at right angles to the plane EH and project towards each other from the system components 102, 202.

[0036] In Fig.Reference numeral 3 50 designates a connector corresponding to the distributor 40, which has a connecting web 52 shaped according to the design of the dividing web 42 and deflects the flow discharged from the two heating chambers 100, 200 over flow-guiding surfaces 54, so that the partial flows discharged from the respective flow housings 106, 206 are connected downstream of a connecting edge 53 and directed towards the outlet nozzle 14. Here too, the flow-guiding surfaces 54 extend on both sides of the plane EH into housing nozzles 55, the cylindrical ends of which extend perpendicular to the plane EH.

[0037] The flow is evidently introduced and discharged identically through the respective nozzles 12 and 14, so that, due to identically designed heating chambers 100 and 200 and thus identical flow resistances within the flow housings 106 and 206, identical partial flows are guided past both sides of the electric heating device 30. The heating of the partial flow passed through the first heating chamber 100 can be slightly greater, depending on the amount of power dissipated by the power transistors 28 into this heating chamber 100. However, by adapting the design of the distributor 40 and the connector 50, the partial flows can be adjusted so that identical temperatures are achieved at the outlet of the respective heating chambers 100 and 200 with an average expected power dissipation.

[0038] The housing nozzle 45, the distributor 40, and the inlet nozzle 12 together form a flow-initiating segment 46. The housing nozzle 55, the connector 50, and the outlet nozzle 14 together form a flow-outward segment 56. These two segments 46 and 56 are each integrally integrated with the frame-shaped housing 20. However, they can also be provided as separate flow-guiding components, which are designated by reference numeral 60 to clarify the concept according to the invention.

[0039] The heating chamber nozzles 116, 216 and the housing nozzles 45 associated with the inlet side are axially aligned and, during assembly of the flow housing 106, are connected in a partially axially overlapping manner and with a fluid-tight seal 62 in the form of a permanently elastic O-ring, supported by an intermediate bearing. The same applies to the heating chamber nozzles 116, 216 associated with the outlet side in relation to the housing nozzles 55. Reference symbol list 10 Electric heating device 11 Admission 12 inlet nozzles 13 Outlet 14 outlet nozzles 15 connector housings 15a Control connector housing 15b Power connector housing 20 frame-shaped housings 22 upper case cover 24 Connection chamber 26 Control unit 25 hold-down devices 27 printed circuit board 28 Power transistor 29 Insulating film 30 Electric heating device 32 Connection flag 34 PTC elements 36 Contact plate 38 Insulation layer 40 distributors 42 Dividing Bridge 43 Leading edge 44 Flow guidance surface 45 Housing connectors 46 flow-initiating segment 50 connectors 52 Connecting bridge 53 Connecting edge 54 Flow guidance surface 55 Housing connectors 46 Flow-draining segment 60 flow-conducting components 62 Seal 100 first heating chamber 102 first plant section 104 first cover 106 first flow housing 108 Cooling bench 110 Mounting dome 112 m² of installation area 114 3D structure 116 Heating chamber nozzles 118 Cover segment 120 ramp area 200 second heating chamber 202 second plant section 204 second cover 206 second flow housing 212 Plant area 214 3D structure 216 Heating chamber nozzles 218 Cover segment 220 ramp area E1 the first heating chamber containing 100 levels E2 the second heating chamber containing 200 level EH the electric heating device 30 containing level 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] EP 2 559 573 A1

[0002] CN 108 592 383 A

[0003]

Claims

[1] Electric heating device (10) for heating a liquid medium comprising a first heating chamber (100) and a second heating chamber (200) and an electric heating element (30) which is provided between the first heating chamber (100) and the second heating chamber (200) and is thermally coupled to the first heating chamber (100) and the second heating chamber (200), and with an inlet (11) and a distributor (40) downstream of the medium in the direction of flow, which divides the current introduced through the inlet (11) into a first partial current supplied to the first heating chamber (100) and a second partial current supplied to the second heating chamber (200), and with an outlet (13) and a connector (50) upstream of the medium in the direction of flow, which connects the partial currents discharged from the first and the second heating chamber (100, 200), characterized by, that the first heating chamber (100) is formed by a first flow housing (106) comprising a first system part (102) thermally coupled to the heating device (30) and a first cover (104), that the second heating chamber (200) is formed by a second flow housing (206) comprising a second system part (202) thermally coupled to the heating device and a second cover (204), and that the distributor (40) and / or the connector (50) is formed on a separate flow-conducting component (60) which is fluid-tightly connected to the first flow housing (106) and the second flow housing (206). [2] Electric heating device (10) according to claim 1, characterized by, that the inlet (11) is formed by an inlet nozzle (12), that the outlet (13) is formed by an outlet nozzle (14), that the longitudinal axes of the nozzles (12, 14) extend parallel to a plane (E1, E2) containing the first and / or the second heating chamber (100, 200), and that the distributor (40) has a dividing web (42) extending in the plane (EH) containing the heating device (30) and / or that the connector (50) has a connecting web (52) extending in the plane (EH) containing the heating device (30) [3] Electric heating device (10) according to claim 1 or 2, characterized by , that the first plant part (102) is identical to the second plant part (202) and / or that the first cover part (104) is identical to the second cover part (204). [4] Electric heating device (10) according to any one of the preceding claims characterized bya frame-shaped housing (20) that fully surrounds at least the first flow housing (106) and forms the flow-guiding component (60) and an inlet nozzle (12) forming the inlet (11) and an outlet nozzle (14) forming the outlet (13). [5] Electric heating device (10) according to claim 4, characterized by , that the frame-shaped housing (20) is made of plastic. [6] Electric heating device (10) according to claim 4 or 5, characterized by , that the frame-shaped housing (20) includes a control device (26) with at least one power transistor (28) thermally coupled to the first heating chamber (100) and that the frame-shaped housing (20) is covered on one side by a housing cover (22) and on the other side by the second flow housing (206). [7] Electric heating device (10) according to any one of the preceding claims characterized by, that the first plant part (102) and the second plant part (202) and / or that the first cover part (104) and the second cover part (204) are made of metal. [8] Electric heating device (10) according to any one of the preceding claims, characterized by , that the first system part (102) and the second system part (202) each form opposing heating chamber nozzles (116, 216) which are sealed and connected to the flow-conducting component (60) and which extend perpendicularly to the plane (EH) containing the heating device (30). [9] Electric heating device (10) according to any one of the preceding claims, characterized by , that the flow-conducting component (60) forms housing nozzles (45, 55) extending perpendicularly to the plane (EH) containing the heating device (30), which are sealed against the heating chamber nozzles (116, 216) by means of an interposed seal.

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