EP2428746B2 - Heat exchanger - Google Patents

Description

The invention relates to a heat exchanger according to the preamble of claim 1 and a motor vehicle air conditioning system according to the preamble of claim 11.

Motor vehicle air conditioning systems are used to heat and / or cool the air to be supplied to the interior of a motor vehicle. In motor vehicle air conditioning systems, heat exchangers are used as electrical heating devices in order to heat the air that is supplied to the interior. The electrical heating device comprises PTC elements. PTC elements (PTC: Positive Temperature Coefficient) are current-conducting materials that have an electrical resistance and can conduct electricity better at lower temperatures than at higher temperatures. Their electrical resistance increases as the temperature rises. The PTC element generally consists of ceramic and is a PTC thermistor. This means that regardless of the boundary conditions - such as B. applied voltage, nominal resistance or air volume on the PTC element - a very even surface temperature on the PTC element. Overheating can be prevented as it can e.g. B. could occur with a normal heat-emitting heating wire, since here, regardless of the boundary conditions, approximately the same resistance and thus an essentially identical electrical heating power is applied.

The heat exchanger comprises PTC elements, at least two electrical conductors by means of which electrical current is passed through the PTC element and heat conducting elements, in particular fins or corrugated fins, by means of which the surface for heating the air is enlarged. Increasingly, motor vehicles are being produced which have an exclusively electric drive or a hybrid drive. Motor vehicle air conditioning systems for these motor vehicles generally no longer have a heat exchanger for heating the air through which the cooling liquid flows. The entire heating output of the motor vehicle air conditioning system must therefore be provided by the electrical heating device or the PTC elements. For this reason it is necessary to also use the PTC elements with high voltage, e.g. B. in the range of 50 to 600 volts instead of low voltage with 12 volts to operate. However, high voltage in a motor vehicle air conditioning system poses a safety problem because, for example, human contact with parts that are under high voltage can cause damage to human health from the high voltage.

the U.S. 4,327,282 shows a heat exchanger with a PTC heating element. Current is passed through the PTC heating element by means of contact plates and an insulating layer is arranged on the contact plates. The components are held together with a U-shaped clip.

From the EP 1 768 458 A1 a heat-generating element of a heating device for heating air is known, comprising at least one PTC element and electrical conductor tracks resting on opposite side surfaces of the PTC element, the two electrical conductor tracks being surrounded on the outside by a non-electrically conductive insulating layer.

the EP 1 872 986 A1 discloses an electrical heating device for heating a flowing medium. The heating device has a housing in which the at least one electrical heating element of the electrical heating device is arranged. A heating chamber and a circulation chamber are formed in the housing. The medium that flows through the circulation chamber is completely kept away from the heating chamber by a partition. the US 2008/0173637 A1 discloses a heat exchanger according to the preamble of claim 1.

The object of the present invention is therefore to provide a heat exchanger and a motor vehicle air conditioning system in which an electric current under high voltage, for. B. more than 50 V, operated heat exchanger without endangering the environment, especially people, can be operated. The heat exchanger and the motor vehicle air conditioning system should be inexpensive to manufacture and operate reliably.

This object is achieved by the features of claim 1.

At least one electrical insulating element, at least one electrical resistance heating element as a PTC element, preferably several resistance heating elements, and the two conductors are arranged in the tubes which enclose the cavity. The at least one tube has only one tube opening at the upper end and in the remaining area of the tube, in particular at a lower end of the tube, the tube is closed in a fluid-tight manner, e.g. B. by means of a support plate or cover plate or due to the design of the tube. Thus, the pipe only has the (upper) pipe opening as its only opening, through which fluids can penetrate into the cavity enclosed by the pipe. The heat exchanger preferably has several tubes and the upper ends of the tubes with the tube openings are arranged at the openings of the adapter plate, so that, due to the fluid-tight arrangement of the tubes on the adapter plate, they can enter the cavity exclusively through the openings in the adapter plate and the tube openings Fluid could get. The adapter plate serves to connect an electronics housing to the adapter plate in a fluid-tight manner, so that the cavities of the tubes are completely opposite the environment are sealed because the electronics housing is fluid-tightly connected to the adapter plate. The adapter plate thus serves as an interface for connecting to other components, an electronics housing for electronics, in particular power electronics, and an air conditioning system housing. As a result, the components which are arranged in the cavity enclosed by the tube can be permanently sealed in a fluid-tight manner and, furthermore, the supply of electrical current to the electrical resistance heating elements is ensured. For example, the electronics housing connected to the adapter plate in a fluid-tight manner has contact elements with which electrical current can be conducted to the resistance heating elements, preferably two contact elements, and at least one or preferably two control current contact elements, with which the output of the resistance heating elements is controlled with the aid of the electronics arranged in the electronics housing and / or can be regulated. In this case, these contact elements and preferably control current contact elements are sealed fluid-tight with respect to the electronics housing, so that the cavities are sealed fluid-tight with respect to the environment.

In a supplementary embodiment, the tube is connected to the adapter plate on the outside in a fluid-tight manner.

The geometry of the at least one tube on the outside at the end with the tube opening preferably corresponds to the geometry of the opening of the adapter plate.

In a further embodiment, the adapter plate consists at least partially, in particular completely, of metal, e.g. B. aluminum, steel or stainless steel, or from, preferably thermoplastic, plastic and / or only through the opening of the adapter plate and the pipe opening, there is a connection in the cavity delimited by the at least one pipe with respect to the at least one pipe and the adapter plate and / or A sealing element is arranged between the adapter plate and the electronics housing and / or between the adapter plate and the air conditioning housing and, in particular, the sealing element is a seal, e.g. B. an O-ring seal, or glue or silicone. The at least one tube is connected to the adapter plate in a fluid-tight manner, so that when only the adapter plate and only the tube are taken into account, for example without taking into account, for example, a potting compound, a fluid only flows into the tube enclosed by the tube through the tube opening and only the opening of the adapter plate Cavity can get.

In particular, the adapter plate is made in one piece and / or outside the electronics housing and a heat sink for cooling the electronics is arranged inside the electronics housing on the electronics housing.

In a further embodiment, the at least one tube is connected to the adapter plate in a material and / or form-fitting and / or force-fitting manner.

In a supplementary variant, the at least one tube is connected to the adapter plate with a soldered, welded or adhesive connection and / or with a sealing element, e.g. B. a sealing ring, the at least one tube is sealed fluid-tight on the adapter plate, wherein the sealing element is preferably a separate component.

The adapter plate is preferably connected to the at least one tube with a latching, clip or crimped connection.

In a further variant, the at least one tube is in one or more parts in cross section, in particular in two parts, and / or the at least one tube is symmetrical or asymmetrical in cross section and / or the at least one tube is made up of two half-shells.

In a further embodiment, the at least one electrical insulating element is a, preferably hardenable and / or hardened, potting compound and / or the at least one electrical insulating element is a molded seal, e.g. B. a hose, a film or a plate, in particular a ceramic plate, and preferably the plate is firmly bonded to the at least one electrical resistance heating element.

In a supplementary embodiment, the potting compound is a liquid, e.g. B. a gel or a paste or a hardenable or a hardened liquid or an oil, in particular silicone oil, or a liquid organic compound or a solid, e.g. B. a powder or granules or a hardenable liquid plastic.

The potting compound and / or the molded seal, d. H. the at least one electrical insulating element with heat-transferring or heat-conducting particles, e.g. B. silicon carbide and / or boron nitride.

In particular, the adapter plate comprises a first connection section for connection to an electronics housing and / or the adapter plate comprises a second connection section for connection to an air conditioning system housing and / or the adapter plate is made of material and / or shape and / or material with the electronics housing and / or with the air conditioning system housing. or non-positively connected and / or the adapter plate is connected to the electronics housing and / or to the air conditioning system housing with a clip connection and / or a crimped connection and / or a screw connection. The adapter plate can thus be connected to an electronics housing at the first connection section of the adapter plate and the adapter plate can be connected to the air conditioning system housing at the second connection section. The geometry of the first connection section is preferably designed to be complementary to the geometry of the electronics housing, which is to be connected to the first connection section in this area and, in an analogous manner, the geometry of the adapter plate on the second connection section is complementary to that section of the air conditioning housing which is connected to the is to be brought into connection with the second connecting section of the adapter plate. The adapter plate with the electronics housing and / or with the air conditioning housing with a detachable connection, for. B. a screw or clip connection, or with a permanent connection, e.g. B. a crimped connection or a soldered or welded connection.

In a further variant, a sealing element, for. B. a seal, in particular O-ring seal, or adhesive or silicone arranged as a sealing element for fluid-tight sealing between the adapter plate and the electronics housing and / or between the adapter plate and the air conditioning housing.

In an additional embodiment, the electronics housing and / or the air conditioning housing consists at least partially, in particular completely, of metal, e.g. B. aluminum or steel, or made of, preferably thermoplastic, plastic.

The sealing element between the adapter plate and the electronics housing and / or the air conditioning system housing is preferably elastically pretensioned and / or overpressed in order to ensure a reliable seal.

In a supplementary embodiment, the at least one cavity wall as a wall of the at least one tube comprises two broad side walls and one or two narrow side walls in a cross section and / or the at least one cavity wall forms a closed tube, in particular a flat tube, in a cross section.

In a further embodiment, the at least one heat conducting element comprises the at least one cavity wall and / or the at least one heat conducting element comprises corrugated fins, which are arranged on the outside of the at least one cavity wall, in particular by means of soldering, and / or the at least two conductors have no direct contact with the at least one cavity wall.

In a further embodiment, the corrugated ribs and the at least one cavity wall are connected to one another by means of gluing.

In a supplementary embodiment, at least one heat conducting element, in particular the at least one cavity wall and / or the corrugated ribs, are at least partially, in particular completely, made of metal, for example aluminum or steel, or plastic.

The at least one molded seal is expediently elastic and / or the at least one molded seal consists at least partially of silicone or plastic or rubber and / or the at least one molded seal is non-positively and / or positively and / or cohesively connected to the at least one cavity wall. On the basis of elastic properties of the at least one molded seal, the at least one molded seal within the cavity, d. H. between the cavity walls, are clamped and thus positively connected.

In a further embodiment, the at least one molded seal comprises heat-transferring or heat-conducting particles, e.g. B. aluminum oxide and / or silicon carbide and / or boron nitride. As a result, the thermal conductivity of the at least one molded seal can be increased and, nevertheless, the at least one molded seal has a sufficiently large electrical insulation.

In particular, at least one electrical resistance heating element, the at least two conductors and the at least one electrical insulating element are connected to form at least one heating composite which is or are arranged in the at least one cavity.

A motor vehicle air conditioning system according to the invention comprises at least one heat exchanger described in this patent application.

The at least one molded seal is preferably arranged between each wall of the at least one pipe and a conductor, so that the at least two conductors are electrically insulated with respect to the at least one pipe.

The at least one tube is expediently closed in a fluid-tight manner by a lower cover plate at a lower, second end. The lower second end is the other end of the tube which is opposite the upper first end with the tube opening.

In a further embodiment, the at least one molded seal is designed as a shrink tube and the shrink tube is shrunk onto the at least two conductors by heating the shrink tube.

The at least one molded seal consists of an electrically insulating and thermally conductive material. Due to the geometric arrangement of the at least one molded seal within the heat exchanger, the at least two conductors and the at least one electrical resistance heating element are electrically insulated. The molded seal is in a solid aggregate state, i. H. not liquid or gaseous, even at high temperatures, e.g. B. 70 ° C or 100 ° C.

In a further embodiment, the at least one molded seal is a film or insulation film, e.g. B. a polyimide film (Kapton film), (elastic) ceramic-filled film or an (elastic) ceramic-filled silicone film.

In an additional variant, the heat exchanger has an IP protection class of 67, so that it is sufficiently watertight and dustproof.

In a further embodiment, the corrugated fins and the at least one tube are connected to one another by means of gluing and / or soldering and / or non-positively under pretension.

In a further embodiment, the at least one heat conducting element and / or the at least one electrical insulating element has a thermal conductivity of at least 1 W / mK, in particular at least 15 W / mK.

In a further embodiment, the at least one electrical insulating element has electrical insulation of at least 1 kV / mm, in particular at least 25 kV / mm.

In one variant, the at least one electrical insulating element, preferably in cross section, has a dielectric strength of at least 1 kV.

In a further embodiment, the at least one electrical insulating element has a thermal conductivity of at least 1 W / mK, in particular at least 15 W / mK. The at least one electrical insulating element can thus, on the one hand, provide good electrical insulation and, on the other hand, can conduct the heat sufficiently well from the electrical resistance heating element to the heat-conducting element or the heat-conducting elements.

Fig. 1

einen Querschnitt einer Kraftfahrzeugklimaanlage,

Fig. 2

eine Explosionsdarstellung eines Wärmeübertragers bzw. Heizregisters in einem ersten Ausführungsbeispiel,

Fig. 3

eine perspektivische Ansicht mehrerer Heizregister des Wärmeübertragers gemäß Fig. 2,

Fig. 4

eine Seitenansicht des Wärmeübertragers gemäß Fig. 3,

Fig. 5

eine Draufsicht des Wärmeübertragers gemäß Fig. 3,

Fig. 6

einen Querschnitt des Heizregisters gemäß Fig. 2,

Fig. 7

einen Querschnitt mehrerer Flachrohre,

Fig. 8

einen Querschnitt von drei Flachrohren und einem Heizverbund,

Fig. 9

einen Querschnitt des Flachrohres mit dem Heizverbund in dem Flachrohr als Heizregisters bzw. Wärmeübertrager,

Fig. 10

eine perspektivische Ansicht einer Adapterplatte in einem ersten Ausführungsbeispiel,

Fig. 11

eine perspektivische Ansicht der Adapterplatte gemäß Fig. 10 mit Rohren in Öffnungen der Adapterplatte,

Fig. 12

eine perspektivische Ansicht der Adapterplatte in einem zweiten Ausführungsbeispiel mit Rohren in Öffnungen der Adapterplatte,

Fig. 13

eine perspektivische Ansicht der Adapterplatte gemäß Fig. 12,

Fig. 14

eine perspektivische Ansicht der Adapterplatte gemäß Fig. 12 mit Heizregistern,

Fig. 15

eine perspektivische Teilansicht der Adapterplatte in einem dritten Ausführungsbeispiel mit Heizregistern und einem Elektronikgehäuse mit einer Krimmverbindung zur Verbindung der Adapterplatte mit dem Elektronikgehäuse,

Fig. 16

eine perspektivische Ansicht eines Wärmeübertragers mit der Adapterplatte, dem Elektronikgehäuse und einem Klimaanlagengehäuse,

Fig. 17

einen Längsschnitt des Wärmeübertragers gemäß Fig. 16,

Fig. 18

einen Querschnitt des Heizregisters in einem zweiten Ausführungsbeispiel,

Fig. 19

einen Querschnitt des Heizregisters in einem dritten Ausführungsbeispiel,

Fig. 20

einen Längsschnitt des Heizregisters in einem vierten Ausführungsbeispiel,

Fig. 21

Längsschnitt der Rohre mit der Adapterplatte in einem nicht erfindungsgemäßen Beispiel,

Fig. 22

eine perspektivische Teilansicht der Adapterplatte in einem vierten Ausführungsbeispiel mit Heizregistern und einem Elektronikgehäuse mit einer Clipsverbindung zur Verbindung der Adapterplatte mit dem Elektronikgehäuse,

Fig. 23

einen Längsschnitt der Clipsverbindung gemäß Fig. 22 zwischen der Adapterplatte und dem Elektronikgehäuse,

Fig. 24

eine weitere Teilansicht der Adapterplatte gemäß Fig. 22 mit dem Elektronikgehäuse, das mit einem Kühlkörper versehen ist,

Fig. 25

einen Längsschnitt des Kühlkörpers gemäß Fig. 24,

Fig. 26

eine weitere perspektivische Teilansicht der Adapterplatte in dem dritten Ausführungsbeispiel gemäß Fig. 15 mit Heizregistern und dem Elektronikgehäuse mit der Krimmverbindung zur Verbindung der Adapterplatte mit dem Elektronikgehäuse,

Fig. 27

einen Längsschnitt der Krimmverbindung gemäß Fig. 26,

Fig. 28

eine perspektivische Teilansicht der Adapterplatte in einem fünften Ausführungsbeispiel mit Heizregistern und dem Elektronikgehäuse mit einer Schraubverbindung zur Verbindung der Adapterplatte mit dem Elektronikgehäuse und

Fig. 29

einen Längsschnitt der Schraubverbindung gemäß Fig. 28.

In the following, exemplary embodiments of the invention are described in more detail with reference to the accompanying drawings. It shows:

Fig. 1

a cross section of a motor vehicle air conditioning system,

Fig. 2

an exploded view of a heat exchanger or heating register in a first embodiment,

Fig. 3

a perspective view of several heating registers of the heat exchanger according to FIG Fig. 2 ,

Fig. 4

a side view of the heat exchanger according to Fig. 3 ,

Fig. 5

a plan view of the heat exchanger according to Fig. 3 ,

Fig. 6

a cross section of the heating register according to Fig. 2 ,

Fig. 7

a cross section of several flat tubes,

Fig. 8

a cross-section of three flat tubes and a heating system,

Fig. 9

a cross section of the flat tube with the heating compound in the flat tube as a heating register or heat exchanger,

Fig. 10

a perspective view of an adapter plate in a first embodiment,

Fig. 11

a perspective view of the adapter plate according to Fig. 10 with tubes in openings of the adapter plate,

Fig. 12

a perspective view of the adapter plate in a second embodiment with tubes in openings of the adapter plate,

Fig. 13

a perspective view of the adapter plate according to Fig. 12 ,

Fig. 14

a perspective view of the adapter plate according to Fig. 12 with heating registers,

Fig. 15

a perspective partial view of the adapter plate in a third embodiment with heating registers and an electronics housing with a crimped connection for connecting the adapter plate to the electronics housing,

Fig. 16

a perspective view of a heat exchanger with the adapter plate, the electronics housing and an air conditioning housing,

Fig. 17

a longitudinal section of the heat exchanger according to Fig. 16 ,

Fig. 18

a cross section of the heating register in a second embodiment,

Fig. 19

a cross section of the heating register in a third embodiment,

Fig. 20

a longitudinal section of the heating register in a fourth embodiment,

Fig. 21

Longitudinal section of the pipes with the adapter plate in an example not according to the invention,

Fig. 22

a perspective partial view of the adapter plate in a fourth embodiment with heating registers and an electronics housing with a clip connection for connecting the adapter plate to the electronics housing,

Fig. 23

a longitudinal section of the clip connection according to Fig. 22 between the adapter plate and the electronics housing,

Fig. 24

a further partial view of the adapter plate according to Fig. 22 with the electronics housing, which is provided with a heat sink,

Fig. 25

a longitudinal section of the heat sink according to Fig. 24 ,

Fig. 26

a further perspective partial view of the adapter plate in the third embodiment according to Fig. 15 with heating registers and the electronics housing with the crimping connection for connecting the adapter plate to the electronics housing,

Fig. 27

a longitudinal section of the crimping connection according to Fig. 26 ,

Fig. 28

a perspective partial view of the adapter plate in a fifth embodiment with heating registers and the electronics housing with a screw connection for connecting the adapter plate to the electronics housing and

Fig. 29

a longitudinal section of the screw connection according to Fig. 28 .

Fig. 1 shows a motor vehicle air conditioning system 24. A fan 25, an air filter 30, a refrigerant evaporator 31 and a heat exchanger 1 as an electrical heating device are arranged in an air conditioning system housing 26 with a bottom wall 27 and an outlet section 29. The air conditioning housing 26 thus forms a channel 35 for the air to pass through. Walls 28 of the air conditioning system housing 26 have a surface 36 on the inside which delimits the duct 35. The air for the interior of a motor vehicle is passed through the air filter 30, the refrigerant evaporator 31 and the heat exchanger 1 by means of the fan 25.

The motor vehicle air conditioning system 24 is therefore not provided with a heat exchanger through which coolant flows for heating the air conducted through the motor vehicle system 24. The air conducted through the motor vehicle air conditioning system 24 is heated electrically exclusively by means of the heat exchanger 1. The motor vehicle air conditioning system 24 is preferably used in a motor vehicle with an exclusively electric drive or with a hybrid drive (not shown). In order to achieve the necessary electrical heating power by means of the heat exchanger 1, the heat exchanger must be operated with high voltage, e.g. B. be operated with more than 50 volts, for example with 60 V or 600 V, in order not to get too high currents and thus too thick power lines (not shown).

In the Fig. 2 to 9 a first embodiment of the heat exchanger 1 for the motor vehicle air conditioning system 24 without an adapter plate 34 is shown. The heat exchanger 1 in the first exemplary embodiment, however, comprises the adapter plate 34 (not shown). A tube 18 made of aluminum designed as a flat tube 13 has two broad side walls 20 and two narrow side walls 21 ( Fig. 2 and 6th ) on. The wide and narrow side walls 20, 21 represent cavity walls 17 which enclose a cavity 19 within the tube 18. A narrow side wall 21 is connected to one another by means of a tongue and groove connection 15. Two molded seals 23 are arranged as electrical insulating elements 22 within the flat tube 13. The two molded seals 23 are made of elastic silicone and each have a recess 14 on one side. Within these two recesses 14 of the two molded seals 23, which form a receiving cavity when the two molded seals 23 lie on top of one another, two conductors 4, namely a first printed circuit board 6 and a second printed circuit board 7, are arranged. Between the two circuit boards 6, 7, three electrical resistance heating elements 2 designed as PTC elements 3 are arranged. The PTC elements 3 are connected to the two circuit boards 6, 7 with adhesive. The two molded seals 23 each have a slot 16 ( Fig. 2 ), through each of which an electrical contact plate 5 of the circuit board 6, 7 is passed. The tube 18 has an upper end 38 with a tube opening 37. At the lower end, the tube 18 is closed in a fluid-tight manner.

The two printed circuit boards 6, 7 are thus completely enclosed by the two molded seals 23 because the molded seals 23 lie directly on top of one another at the edges outside the recess 14 and also seal due to their elastic properties. As a result, the two circuit boards 6, 7 with the three PTC elements 3 arranged between them are electrically insulated due to the electrical insulation of the molded seals 23 and also sealed off in a fluid-tight manner due to the sealing properties of the two superposed molded seals 23. The two circuit boards 6, 7 are electrically contacted by means of electrical lines (not shown) on the contact plates 5. The two circuit boards 6, 7 with the three PTC elements 10 represent a heating unit 10. After the heating unit 10 has been enclosed with the two molded seals 23, these form a heating assembly 8. After the heating assembly 8 has been introduced into the flat tubes 13 with the corrugated fins 12, a heating register 9 or the heat exchanger 1 is present. Several heating registers 9 as shown in Fig. 4 can also be connected to one another to form a heat exchanger 1 with a larger number of heating registers 9 ( Figures 3 to 5 ).

The manufacturing steps for arranging the heating assembly 8 in the flat tubes 13 are shown in FIG Figures 7 to 9 shown. The flat tubes 13 are connected to one another with the corrugated fins 12 by means of soldering in a soldering furnace. In the area of the tongue and groove connection 15, a spacer (not shown) is introduced into the tongue and groove connection 15 during soldering, so that the flat tubes 13 are not soldered to one another at the tongue and groove connection 15, ie not connected to one another in a materially bonded manner , will. After removing the spacers (not shown), the flat tubes 13 are opened in the area of the tongue and groove connection 15, so that the flat tubes 13 deform, in particular bend, in the area of the lower narrow side walls 21. The flat tubes 13 with the corrugated fins 12 are opened in the manner of an accordion as shown in FIG Fig. 7 to Fig. 8 . In the in Fig. 8 The open position of the flat tube 13 shown, the heating assemblies 8 in the direction of the tube depth, ie perpendicular to one on the plane of the drawing Fig. 8 perpendicular longitudinal axis of the tube 18 into which the flat tubes 13 are inserted. After the heating assembly 8 has been pushed into the flat tubes 13, the flat tubes 13 are connected to one another again at the tongue and groove connection 15 and the tongue and groove connection 15 is permanently fastened by pressing the tongue and groove connection 15 are made of silicone and elastically deformable and the size of the molded seals 23 is matched to the heating unit 10 so that the heating assembly 8 is slightly larger than the closed flat tube 13. As a result, the molded seals 23 are elastically deformed when the tongue and groove connections 15 are closed and prestressed, so that the heating composite 8 is clamped under prestress between the cavity walls 17 of the flat tube 13, in particular between the broad side walls 20 of the flat tube 13, and is thus connected to the flat tube 13 in a non-positive manner. For this purpose, a correspondingly directed force F is applied to the broad side walls 20 ( Fig. 9 ).

The network height H _{N of} the heat exchanger 1 as shown in FIG Fig. 4 is approx. 50 to 300 mm, preferably 100 to 200 mm and the mesh width B _N is approx. 50 to 300 mm, preferably 100 to 200 mm. The transverse division Q, ie the distance between the flat tubes 13 as shown in FIG Fig. 5 , is between 5 and 30 mm, preferably 9 to 18 mm, and the network depth T _N as shown in FIG Fig. 5 is 6 to 60 mm, preferably 10 to 40 mm.

The cavity 19 enclosed by the cavity walls 17 of the flat tube 13 is an empty space 32 in the area of the narrow side walls 21, that is, in the empty space 32 there is only air ( Fig. 6 ). Deviating from this, in the empty spaces 32 according to the illustration in FIG Fig. 6 the molded seal 23 can also be arranged in the case of a corresponding different geometric design of the molded seal 23 ( Fig. 8 ). At the upper end 38 of the tubes 18, the tubes 18 are arranged in openings 39 of the adapter plate 34, not shown, analogously to the following exemplary embodiments.

In Fig. 10 and 11 a first embodiment of the adapter plate 34 with openings 39 is shown. The adapter plate 34 consists of thermoplastic synthetic material or of metal, in particular aluminum, and is produced with deep drawing when it is designed as aluminum. The geometry of the openings 39 of the adapter plate 34 corresponds to the geometry of the tubes 18 at the upper end 38 ( Fig. 2 ) of the tubes 18. The tubes 18 are inserted with the end 38 into the openings 39 of the adapter plate 34 ( Fig. 11 ) and integrally connected to the adapter plate 34, for example by means of soldering or gluing. In Fig. 11 of the heating register 9, only the tubes 18 are shown, but not the conductors 4, the electrical contact plates 5 and the electrical insulating element 22. The heating composite 8 is thus shown in FIG Fig. 11 not shown. As a result, in the cavity 19 enclosed by the tube 18, due to the fluid-tight connection of the tubes 18 to the adapter plate 34, there is a fluid-conducting connection into the cavity 19 only through the opening 39 of the adapter plate 34 and the tube openings 37 Fig. 11 The tube 18 shown is in one piece in cross section and has two narrow side walls 21 and two broad side walls 20.

In Figures 12, 13 and 14th a second embodiment of the adapter plate 34 is shown. The geometry of the openings 39 of the adapter plate 34 corresponds to the outside geometry of the tube 18 according to FIG Fig. 12 and 14th . The tube 18 is constructed in two parts in cross section from two asymmetrical half-shells. The geometry of the openings 39 of the adapter plate 34 is also designed accordingly. In Fig. 14 is the adapter plate 34 according to Figures 12 and 13 shown with the heating register 9.

The adapter plate 34 serves as an interface for connection to an electronics housing 43 with electronics (not shown), in particular power electronics for controlling and / or regulating the power of the electrical resistance heating elements 2 in the individual heating registers 9 Fig. 15 The partial view shown is an exploded view of the electronics housing 43 and the heat exchanger 1 with the adapter plate 34 in a third exemplary embodiment. By means of the adapter plate 34, the individual heating registers 9 are connected to one another and by means of a Seal 45 as a sealing element 44, for example an elastic O-ring seal made of rubber, a fluid-sealing connection can be established between the electronics housing 43 and the adapter plate 34, and the electronics housing 43 is also mechanically connected to the adapter plate 34 with a crimped connection 53. The electronics housing 43 is completely closed and has no openings or gaps in the environment, so that with a fluid-tight connection of the electronics housing 34 with the adapter plate 34, the cavity 19 is sealed fluid-tight with respect to the environment due to the fluid-tight connection of the tubes 18 with the adapter plate 34 is. In Fig. 15 the electrical contact plates 5 and the molded seal 23 formed as a hose 46 or film 47 are also shown. The hose 46, which completely surrounds the heating unit 10, is led slightly beyond the upper end 38 of the tubes 18 so that there is a sufficient distance from the two circuit boards 6, 7 to the tube 18. This distance is preferably 4 mm. Furthermore, in Fig. 15 in contrast to the previous ones Figures 10-14 the corrugated fins 12 are also shown as heat-conducting elements 11 between the tubes 18.

In Fig. 16 is a perspective view of the heat exchanger 1 in the air conditioning housing 26 is shown. The adapter plate 34 is connected to the electronics housing 43 in a fluid-tight manner and to the air-conditioning system housing 26 in a fluid-tight manner. The type of design of the fluid-tight connection between the adapter plate 34 and the electronics housing 43 and the fluid-tight connection between the adapter plate 34 and the air-conditioning system housing 26 is identical. This makes it possible to seal the cavity 19 enclosed by the tubes 18 in a fluid-tight manner with respect to the environment and to ensure reliable electrical insulation with respect to the environment when high voltage is used in the electrical resistance heating elements 2. In Fig. 17 is a longitudinal section of the heat exchanger 1 according to Fig. 16 shown. The adapter plate 34 has a first connection section 41 for connecting the adapter plate 34 to the electronics housing 43 and a second connection section 42 for connecting the adapter plate 34 to the air conditioning system housing 26. The Kümaanlage housing 26 and / or the electronics housing 43 are positively and / or cohesively and / or non-positively connected to the adapter plate 34, for example with an adhesive or soldered connection or with the aid of a screw or snap connection (not shown). A sealing element 44, in particular a seal 45, is arranged both between the adapter plate 34 and the electronics housing 43 on the first connection section 41 and between the adapter plate 34 and the air conditioning housing 26 on the second connection section 42. In this case, the seal 45 is preferably designed as an O-ring seal, which completely surrounds the first and / or second connection section 41, 42, so that a fluid-tight connection is thereby created both on the first and on the second connection section 41, 42 with respect to the air-conditioning system housing 26 and the electronics housing 43 is guaranteed. The sealing element 44 can either be a separate component or it can already be attached to the electronics housing 43 and / or the air conditioning housing 46 or be integrated, for example by inserting the sealing element 44 into the injection molding tool during the injection molding of the electronics housing 43 or the air conditioning housing 26 in the injection molding tool or the sealing element 44 is produced on the rest of the air conditioning system housing 26 and / or the rest of the electronics housing 43 in a 2K injection molding process. The tubes 18 are connected to the adapter plate 34 in a fluid-tight manner, for example with an adhesive connection, and are arranged in the openings 39 of the adapter plate 34.

In Fig. 18 a cross section of the heating register 9 is shown in a second embodiment. The heating unit 10 is enclosed by a hose 46 or a foil bag and the wall of the hose is designed as a foil 47. As a result, the heating unit 10 is completely enclosed (the foil bag or hose 46 only has an opening at the top of the contact plates 5) by the hose 46 or foil bag and thus electrically insulated with respect to the pipe 18 or the walls of the pipe 18. The seal 45 or the molded seal 23 can also be provided with electrically conductive particles in order to ensure, in addition to the required electrical insulation, also a sufficient thermal conductivity of the molded seal 23.

In Fig. 19 a third embodiment of the heating register 9 is shown. In the following, only the differences from the second exemplary embodiment are essentially described in accordance with FIG Fig. 18 described. The molded seal 23 is a plate 48 designed as a ceramic plate 49, and a positioning strip 50 is also present within the tube 18. The position strip 50 prevents the heating unit 10 from slipping within the tube 18, so that sufficient electrical insulation is ensured. Deviating from this (not shown), the position output 50 can also be dispensed with, provided that the ceramic plates 49 are connected to the two conductors 24 in a materially bonded manner, for example by means of gluing, and there is therefore no longer any risk of the heating unit 10 slipping inside due to the sufficient rigidity of the ceramic plate 49 of the tube 18 consists.

In Fig. 20 a fourth embodiment of the heating register 9 is shown in a longitudinal section. A potting compound 51 is used as the electrical insulating element 22. After the heating unit 10 has been introduced into the cavity 19 and the pipes 18 have been mechanically and fluid-tightly connected to the adapter plate 34, the potting compound 51 is applied to the top of the adapter plate 34. The flowable or liquid potting compound 51 can thus flow into the cavities 19 inside the tubes 18 and fill the empty cavities 19 outside the heating unit 10 and thereby enable electrical insulation. Due to its geometry, the adapter plate 34 serves as an "overflow pool" for the potting compound 51 and only the electrical contact plates 5 and possibly a small part of the circuit boards 4 protrude from the potting compound 51. After the potting compound 51 has hardened, permanent electrical insulation of the heating unit 10 is available and, furthermore, the potting compound 51 is used to seal the cavity 19 fluid-tight with respect to the environment, because no liquid or a fluid can flow into the cavity 19. Only the electrical contact plates 5 and possibly the conductors 4 outside the potting compound 51 must be permanently electrically isolated from the environment, for example by placing the electronics housing 43 on the adapter plate 34 and connecting it to the adapter plate 34 in a fluid-tight manner (not shown).

In Fig. 21 an example of the adapter plate 34 not according to the invention is shown. The tubes 18 of the heating register 9 are not inserted into the openings 39 of the adapter plate 34, but the adapter plate 34 is provided with a groove 40 completely encircling the openings 39 and the ends 38 of the tubes 18 are arranged in the groove 40 and with the adapter plate 34 mechanically connected to the groove 40 and also connected in a fluid-tight manner. The connection can be made with a material fit, for example by means of gluing, welding or soldering.

In the Figures 22 to 24 a fourth embodiment of the adapter plate 34 is shown. In this exemplary embodiment of the heat exchanger 1, the adapter plate 34 is connected to the electronics housing 43 by means of a clip connection 52. The adapter plate 34 is provided with a total of six adapter plate tabs 57, three adapter plate tabs 57 on each side of the adapter plate 34. Furthermore, the electronics housing 43 also has six electronics housing tabs 56 on the lower edge, three electronics housing tabs 56 on one side. Both the electronics housing tabs 56 and the adapter plate tabs 57 each have a tab opening 58 ( Fig. 23 ) on. Fig. 22 FIG. 13 shows a disconnected state of the electronics housing 43 with the adapter plate 34 and FIG Fig. 22 FIG. 4 shows a connected state of the adapter plate 34 with the electronics housing 43. In each case, the connected state according to FIG Fig. 23 a clip 59 is arranged with its ends at the upper end in the tab opening 58 of the electronics housing tab 56 and at the lower end of the tab opening 58 of the adapter plate tab 57. The clip 59, for example made of metal or plastic, is pretensioned here and the electronics housing tab 56 is pressed onto the adapter plate tab 57 as a result. The seal 45 between the electronics housing 43 and the adapter plate 34 is oversized with respect to a recess in the electronics housing 43 or the electronics housing tab 56, so that in the in Fig. 23 The mechanical connection state shown between the electronics housing 43 and the adapter plate 34, the seal 45 is pretensioned as an elastic O-ring seal made of rubber, thereby ensuring a permanent and reliable fluid-tight seal between the electronics housing 43 and the adapter plate 34. The O-ring seal 45 is arranged around the entire circumference between the electronics housing 43 and the adapter plate 34.

In Fig. 24 and 25th is a complement to that in the Fig. 22 and 23 illustrated embodiment shown. The electronics housing 43 is provided with a heat sink 64 ( Fig. 24 and 25th ) Mistake. The cooling body 64 is sealed in a fluid-tight manner with respect to the electronics housing 43 and is arranged both inside the electronics housing 43 and outside the electronics housing 43. By means of the heat sink 54 arranged outside the electronics housing 43, heat can thus be given off from electronics (not shown), in particular power electronics, to the ambient air by means of heat conduction through the heat sink 64. This is possible without any problems because the heat exchanger 1 is surrounded by ambient air.

In Fig. 26 and 27 is in addition to Fig. 15 the adapter plate 34 shown in the third embodiment. It is in the adapter plate 34 in the third embodiment according to Fig. 15 , 26th and 27 the adapter plate 34 is connected to the electronics housing 43 by means of a crimped connection 53. The adapter plate 34 has a vertically aligned adapter wall 61 on the outer edge. The completely circumferential and vertically aligned adapter wall 61 has only a small extent in the vertical direction and a multiplicity of elongated holes 60 are arranged in this adapter wall 61. The part of the adapter wall 61 which, or above the adapter wall 61 delimits the elongated hole 60, represents a part 62 of the adapter wall 61. This part 62 of the adapter wall 61 can be deformed in the process. The fluid-tight seal between the electronics housing 43 and the adapter plate 34 takes place in a manner analogous to that in the previous exemplary embodiment by means of a seal 45 as an elastic O-ring seal, which is elastically pretensioned. To produce the crimped connection 53, the electronics housing 43 with the opening at the bottom must first be introduced into the area or space between the vertically aligned adapter wall 61 and placed on the seal 45 and pressed on until the seal 45 is elastically pretensioned. Then on the part 62 of the adapter wall 61 above the elongated hole 60 (in Fig. 27 the non-deformed state of the part 62 of the adapter wall 61 is shown) to apply a force, so that the part 62 is deformed to the effect that the part 62 rests above the electronics housing 43 as shown in FIG Fig. 26 . As a result, a permanent mechanical connection can be established between the electronics housing 43 and the adapter plate 34.

In Fig. 28 and 29 a fifth embodiment of the adapter plate 34 is shown. In the fifth exemplary embodiment of the adapter plate 34, the adapter plate 34 is detachably connected to the electronics housing 43 by means of a screw connection 54. The adapter plate 34 has in a manner analogous to the fourth embodiment according to Figures 22 to 24 a total of six adapter plate tabs 57, three being arranged on each side. In an analogous manner, the electronics housing 43 has a total of six electronics housing tabs 56, three of which are arranged on one side and in Fig. 28 only three electronics housing tabs 56 are visible due to the perspective view. The electronics housing tabs 56 each have a blind hole with a thread. The adapter plate tabs 57 have a hole through which a screw 63 can be inserted from below, and due to a screw head that has a larger diameter than the hole in the adapter plate tab 57, the head of the screw 63 rests on the adapter plate tab 57. For the mechanical connection by means of the screw connection 54, the electronics housing 43 is to be placed on the adapter plate 34 in such a way that the blind holes in the electronics housing tabs 56 are aligned with the bores in the adapter plate tabs 57 and then the screw 63 with an external thread can be inserted with the internal thread using a screwdriver Blind holes of the electronics housing tabs 56 are screwed. A lower end of the tubes 18 of the heat exchanger 1 is secured by means of a cover plate 55 as shown in FIG Fig. 28 and 29 sealed fluid-tight. The cover plate 55 is connected to the tubes 18 by means of a soldered connection, for example. This also applies to the tubes 18 of the heat exchanger 1 in the in Fig. 22 illustrated embodiment.

The details of the various exemplary embodiments can be combined with one another, unless otherwise stated.

Viewed overall, the heat exchanger 1 according to the invention is associated with significant advantages. The individual heating registers 9 of the heat exchanger 1 can be mechanically connected to the adapter plate 34 to form a heat exchanger 1 with a plurality of heating registers 9. The heating registers 9 or the tubes 18 of the heating registers 9 are arranged in a fluid-tight manner at the openings 39 of the adapter plate 34, so that a fluid-tight sealing of the heating registers 9 with respect to the environment is thereby possible in a simple manner. An electronics housing 43 is attached to the adapter plate 34 in a fluid-tight manner and this enables permanent electrical insulation of the heat exchanger 1 with little technical effort. This enables permanent protection against contact with the electrically conductive parts of the heat exchanger 1.

List of reference symbols

1

Heat exchanger

2

Electric resistance heating element

3

PTC element

4th

ladder

5

Electrical contact plate

6th

First printed circuit board

7th

Second circuit board

8th

Heating network

9

Heating register

10

Heating unit

11

Heat conducting element

12th

Corrugated ribs

13th

Flat tube

14th

Recess in molded seal

15th

Tongue and groove connection

16

Slot in molded seal for contact plate

17th

Cavity wall

18th

Tube 19 cavity

20th

Broad side wall

21

Narrow side wall

22nd

Electrical insulating element

23

Molded seal

24

Automotive air conditioning system 25 fans

26th

Air conditioner housing

27

Bottom wall

28

Wall

29

Exit section

30th

filter

31

Refrigerant evaporator

32

Empty space within the flat tube

33

Mushroom-shaped compression on the molded seal

34

Adapter plate

35

channel

36

surface

37

Pipe opening

38

End of the pipe with a pipe opening

39

Opening of the adapter plate

40

Groove in adapter plate

41

First connection section on adapter plate for connection to an electronics housing

42

Second connection section on adapter plate for connection to an air conditioning housing

43

Electronics housing

44

Sealing element

45

poetry

46

hose

47

foil

48

Tile

49

Ceramic plate

50

Position bar

51

Potting compound

52

Clip connection

53

Krimm connection

54

Screw connection

55

Cover plate

56

Electronics housing tab

57

Adapter plate tab

58

Flap opening

59

Clips

60

Long hole

61

Adapter wall

62

Part of the adapter wall

63

screw

64

Heat sink

HN

Net height

BN

Mesh width

Q

Transverse division

TN

Net depth

Claims (11)

1. A heat exchanger (1), comprising

   - at least one electrical resistance heating element (2) as a PTC element (3),

   - at least two conductors (4), in particular conductor plates (6, 7), electrically conductively connected to the at least one electrical resistance heating element (2) to conduct electrical current through the at least one electrical resistance heating element (2) and thereby heat the electrical resistance heating element (2),

   - at least one heat-conducting element (11, 12) for transferring heat from the at least one electrical resistance heating element (2) to a fluid to be heated,

   - at least one electrical insulating element (22) that insulates electrically the at least two conductors (4) and preferably the at least one electrical resistance heating element (2),

   - at least one tube (18) having a tube opening (37), wherein

   - the at least two conductors (4), the at least one electrical insulating element (22), and the at least one electrical resistance heating element (2) are arranged within at least one cavity (19) bounded by the at least one tube (18),

   wherein
   the heat exchanger (1) comprises an adapter plate (34) having at least one opening (39), and each tube (18) is arranged with one end (38) at the tube opening (37) within a respective opening (39) of the adapter plate (34) and each tube opening (37) is arranged at a respective opening (39) of the adapter plate (34) and the at least one tube (18) is connected fluid-tight to the adapter plate (34), characterised in that the adapter plate (34) is connected fluid-tight to an electronics housing (43) and an HVAC housing (26).
2. The heat exchanger according to claim 1, characterised in that the tube (18) is connected fluid-tight on an outer side to the adapter plate (34) .
3. The heat exchanger according to claim 1 or 2, characterised in that the geometry of the at least one tube (18) on an outer side at the end (38) with the tube opening (37) corresponds to the geometry of the opening (39) of the adapter plate (34).
4. The heat exchanger according to one or more of the preceding claims, characterised in that the adapter plate (34) is formed at least partially, particularly totally, of metal, for example aluminium, steel or stainless steel, or of plastic, preferably thermoplastic, and/or there is a connection in the cavity (19) bounded by the at least one tube (18) only through the opening (39) of the adapter plate (34) and the tube opening (37) with respect to the at least one tube (18) and the adapter plate (34) and/or a sealing element (44) is arranged between the adapter plate (34) and the electronics housing (43) and/or between the adapter plate (34) and the HVAC housing (26) and in particular the sealing element (44) is a seal (45), for example an O-ring seal, or adhesive or silicone.
5. The heat exchanger according to one or more of the preceding claims, characterised in that the adapter plate (34) is formed as a single piece and/or a cooling element (64) for cooling the electronics within the electronics housing (43) is arranged outside the electronics housing (43) and on the electronics housing (43).
6. The heat exchanger according to one or more of the preceding claims, characterised in that the at least one tube (18) is connected to the adapter plate (34) by bonding and/or form-fittingly and/or force-fittingly.
7. The heat exchanger according to one or more of the preceding claims, characterised in that the at least one tube (18) is connected to the adapter plate (34) with solder, weld, or glued joint and/or the at least one tube (18) is sealed fluid-tight to the adapter plate (34) with a sealing element (44), for example a sealing ring.
8. The heat exchanger according to one or more of the preceding claims, characterised in that the at least one tube (18) is made up of one or many parts, particularly two parts, in cross section, and/or the at least one tube (18) is symmetric or asymmetric in cross section and/or the at least one tube (18) is made up of two half-shells.
9. The heat exchanger according to one or more of the preceding claims, characterised in that the at least one electrical insulating element (22) is a preferably hardenable and/or hardened sealing compound (51) and/or the at least one electrical insulating element (22) is a moulded seal (23), for example a tubing (46), a film (47) or a plate (48), in particular a ceramic plate (49), and the plate (48) is preferably connected to the at least one electrical resistance heating element (2) by bonding.
10. The heat exchanger according to one or more of the preceding claims, characterised in that the adapter plate (34) comprises a first connection section (41) for connecting to an electronics housing (43) and/or the adapter plate (34) comprises a second connection section (42) for connecting to an HVAC housing (26) and/or the adapter plate (34) is connected to the electronics housing (43) and/or to the HVAC housing (26) by bonding and/or form-fittingly and/or force-fittingly and/or the adapter plate (34) is connected to the electronics housing (43) and/or to the HVAC housing (26) with a clip connection and/or a press connection (53) and/or a screw connection (54).
11. A vehicle HVAC system (24), characterised in that the vehicle HVAC system (24) comprises at least one heat exchanger (1) according to one or more of the preceding claims.

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