DE102016105592A1 - Heating device and method for heating a motor vehicle - Google Patents

Abstract

The invention relates to a heating device (20) for a motor vehicle having at least one heat exchanger (21) for heating a passenger compartment or a vehicle component, at least one evaporator (22, 41, 42) in which a working medium (31) is supplied by a heat source ( 25) and a heat exchanger (21) and the evaporator (22, 41, 42) connecting the heat conduction element. The heat conduction element comprises an outfeed line (23, 35, 43, 46) and a return line (24, 34, 42, 45) for transporting the working medium (31). Furthermore, the invention relates to a method for heating a passenger compartment or a vehicle component of a motor vehicle, wherein a working medium (31) transferred under heat by a heat source (25) in an evaporator (22, 41, 42) in a gaseous state and via a heat conduction element a heat exchanger (21) is passed, where the gaseous working medium (31) condenses with the release of heat. The gaseous working medium (31) is passed via an outfeed line (23, 35, 43, 46) from the evaporator (22, 41, 42) to the heat exchanger (21) and the condensed working medium (31) is conveyed via a return line (24, 34, 42, 45) from the heat exchanger (21) to the evaporator (22, 41, 42).

Description

The invention relates to a heating device for a motor vehicle having the features of patent claim 1 and to a method for heating a motor vehicle having the features of patent claim 15.

It is the endeavor in modern vehicle construction to transport heat as efficiently and inexpensively as possible to the points in the vehicle where it is needed. Thus, especially in the cold season, a rapid heating of the passenger compartment is desired to allow a comfortable ride. Even a vehicle battery or oil reservoirs should be well-tempered to allow optimal working behavior.

It is known from the prior art to heat a working medium and to transport it to the destination, where heat on cooling of the working medium is released again and can be used to heat the passenger compartment or a vehicle component. In this case, for example, the exhaust heat can be used. Especially at low ambient temperatures but also the exhaust gas temperature at the beginning of the trip is initially very low, so that a corresponding heater has a sluggish response in parallel. In electrically powered vehicles must be used for heating the working fluid in principle to an electric heater, if necessary, in combination with a heat pump.

The EP 2 407 328 A1 discloses a heating device for a motor vehicle, in which in a heating circuit, a liquid working medium, such as water, is heated and is brought into circulation by means of a pump. The heating takes place by means of an electrical heating element which is arranged in the circuit. The disadvantage of this design is initially the sluggish response of the system. It takes a relatively long time to heat the water volume in such a way to initiate a continuous, high heat transfer. This means that it takes a relatively long time to reach the desired temperature at the destination. Furthermore, the space requirement due to the plurality of individual components is relatively large. If you want to connect the heat exchanger, heater, pump and possibly a surge tank with each other, at least four lines for the working fluid necessary. Also, the lines for the working medium must be sufficiently large dimensions, since too small a surface-volume ratio, the heat loss to the lines by heat conduction and heat radiation is too large. Furthermore, the temperature window within which the liquid working medium can be heated, limited at the top by the boiling temperature of the working medium.

It is the object of the present invention to show a compact heater with fast, efficient response for a motor vehicle. Furthermore, it is the object of the invention to provide a fast and efficient method for heating a motor vehicle.

The objective part of the object is achieved by a heating device having the features of patent claim 1. Particular embodiments of the invention are subject of the dependent claims 2 to 14.

The procedural part of the object is achieved by a method having the features of patent claim 15. Particular embodiments of the method are the subject matter of subclaims 16 and 17.

The invention relates to a heating device for a motor vehicle with at least one heat exchanger for heating a passenger compartment or a vehicle component, at least one evaporator, in which a working fluid can be vaporized by supplying heat by a heat source and a heat conduction element connecting the heat exchanger and the evaporator. The invention is characterized in that the heat-conducting element comprises an outgoing line and a return line for transporting the working medium.

The working medium is first transferred here in an evaporator in a gaseous state. The heat is supplied to the working medium directly and locally and stored in the form of latent heat in the steam and released again in the heat exchanger. The transport of the gaseous working medium and thus the heat stored in the heat exchanger is carried out at high speed. This allows a very fast response of the system, so that at the target locations in the vehicle, where the heat exchanger is mounted, the expected target temperature is reached very quickly.

The destinations can be both a passenger compartment and a vehicle component. In the latter, the possibilities are varied and range from the vehicle battery via containers for liquids to be heated, such as gear oils, to cold-sensitive electronic devices.

Due to the presence of the working medium in gaseous form and the present utilization of latent heat and the heat losses through the pipe walls are extremely low. Thus, the lines can be made thinner and thus take less space, which saves weight. It Only two lines are necessary, which further reduces the space requirement.

As a working medium, for example, water or alcohols come into question. Methanol or ethanol have proven to be particularly suitable. The selection of the working medium depends on the intended temperature window during operation, to which the boiling temperature of the working medium is adjusted.

A further advantage is that the heating device according to the invention is a closed system with a closed circuit for the working medium, so that no regular maintenance of the system due to contamination or fluid loss is necessary.

In a particular embodiment of the invention it is provided that the forward line is used to transport a gaseous portion of the working medium from the evaporator to the heat exchanger and the return line serves to transport a liquid portion of the working medium from the heat exchanger to the evaporator.

The working medium is converted into a gaseous state in the evaporator and this steam is transported via the forward line to the heat exchanger. There, the gaseous working fluid is condensed with the release of heat and returned in the liquid state via the return line back to the evaporator. In this way, the full stored in the gaseous working fluid latent heat in the heat exchanger is released. Due to the separate lines, the gaseous and liquid fractions of the working medium are transported spatially separated from each other, so that no heat loss caused by cooling of the gas to the liquid. This additionally improves the efficiency of the heater.

Furthermore, the evaporator preferably comprises a capillary structure, which is arranged between the forward line and the return line. The capillary structure is a porous, preferably metallic, material, which is preferably produced in a sintering process. The capillary structure consists of a microscopic system of caverns and channels and preferably has a porosity between 40% and 60%, more preferably between 45% and 55%, particularly preferably between 48% and 52%.

The capillary structure is always saturated when starting the heater and during operation with liquid working fluid. The heat is preferably introduced into the evaporator on the upstream side of the capillary structure. There, the liquid working medium evaporates and flows in the direction of the forward line. On the return side of the capillary structure, however, the working medium is liquid. The two sides of the capillary structure are sealed against each other, so that gaseous and liquid portion of the working medium can not mix with each other. The two separate sides of the capillary structure are called the vapor side and the liquid side of the evaporator.

On the steam side of the evaporator prevails by the presence of the working medium as a gas and due to the higher temperature, a higher pressure than on the liquid side. Due to this pressure difference, which is maintained by counteracting capillary forces, the steam is then transported as described to the heat exchanger and condensed again, so that the liquid working medium can flow back to the evaporator on the liquid side. Capillary forces continuously draw liquid working fluid from the liquid side into the capillary structure and vaporize it on the steam side. In this way, a circuit for the working fluid is initiated without the need for an additional pump. This also reduces the space requirement leads to a further compactness of the heater. In addition, the power consumption is reduced by eliminating an electrically driven pump. The necessary to connect the pump to a circuit lines can also be saved.

Preferably, the capillary structure is arranged in a housing, wherein the housing between the return line of the capillary structure has a cavity for receiving the back-transported working medium.

As already mentioned, the capillary structure should be saturated with liquid working medium at any time during the operation of the heating device. If this is not the case and dries out the capillary structure, the working fluid is not effectively evaporated and the efficiency of the heater is lower. To ensure saturation, the entire surface of the capillary structure on the liquid side must be wetted with liquid working medium. This is achieved by a cavity which is formed in the housing between the capillary structure and the housing wall on the liquid side. In this cavity, the liquid transported back from the heat exchanger collects, so that always a sufficient wetting of the capillary structure is ensured.

Already in the design of the heater is to ensure that a sufficient amount of working fluid is provided in the system to ensure at any time saturation of the capillary structure can. Especially When starting the system, when the circulation of the working medium is only started, ensure a continuous flow of the working medium to the capillary structure.

In a particular embodiment of the invention, an electrical heater is arranged as a heat source on the outside of a first wall of the housing.

The electric heater is preferably brought into full-surface contact with the first wall of the housing. This can be done via a surface pressure, but also by a cohesive connection. As a result, the electrically generated heat is introduced directly into the evaporator and allows immediate evaporation of the working medium. This in turn increases the response and efficiency of the system.

An electric heater makes the heater in its operation independent of other possible heat sources, such as the exhaust line. In particular, in electrically powered vehicles, where there is no exhaust heat to exploit, an electric heater is advantageous. In addition, a continuous and controllable heat supply is possible.

Even with conventionally operated vehicles occur situations in which little or no exhaust heat is available. For example, at low outdoor temperatures, as long as the exhaust gas temperature is too low for effective operation of the heater, the electric heater can take over the heat input to the evaporator. Preferably, both the electric heater and the exhaust gas line are then arranged on the outside of a first wall of the housing.

A further application is the vehicle battery in particular in an electrically powered vehicle. If, for example, a battery is charged when the motor vehicle is stationary and a temperature control of the battery is necessary, a heating device according to the invention with an electric heater can also be used for this purpose.

It is preferably provided that the capillary structure is arranged on the inside of the first wall of the housing. This further optimizes the heat input into the capillary structure and makes the evaporation of the working medium even more effective. At the same time, the above-described cavity between the capillary structure and the housing wall is produced by this arrangement in a simple manner and the vapor and liquid side of the evaporator are very easy to separate from each other by a seal on the liquid side of the capillary structure.

Furthermore, a special embodiment of the invention provides that the capillary structure has on its surface lying against the first wall in its longitudinal and / or transverse direction running integrally and material-uniform, formed steam grooves. These steam grooves are therefore on the steam side of the capillary structure and serve to quickly divert the gaseous working fluid to the outgoing line. In addition, a steam collecting space may be provided immediately before the forward line into which the steam grooves open. This will make the evaporation of the working fluid more effective.

Alternatively it can be provided that between the capillary structure and the inside of the first wall of the housing spacers are arranged, which form together with the capillary structure and the first wall in the longitudinal and / or transverse direction of the capillary extending steam grooves.

In this variant, the capillary structure can be made simpler. The spacers may be formed, for example, as webs or beads of the housing wall. Alternatively, it can also be provided pins, which may be integrally formed from the wall or positively and / or non-positively and / or materially connected to the wall.

Another particular embodiment of the invention provides that a compensation volume for the working medium is provided.

As already described above, it must be ensured that the capillary structure is saturated at all times with liquid working medium. It is therefore in principle desirable to use the largest possible amount of the working medium in the system in order to ensure a continuous flow to the capillary structure. Accordingly, a compensation volume is provided which receives the working medium not in direct circulation.

At the start state, it is imperative that a residual amount of liquid working medium be present in the equalizing volume so that there is an immediate flow to saturate the capillary structure.

However, the total volume must be such that at any point in time, the system is only loaded by the vapor pressure and not by hydrostatic pressure, even if the entire working medium has gone into the gaseous state. Otherwise, there is a risk of bursting the system.

The compensation volume for the working medium is preferably in or directly on the housing intended. This compact design further optimizes the required installation space.

Particularly preferably, the compensation volume is designed as a protuberance of a second wall of the housing. This also allows a space-optimized design of the evaporator, since the compensation volume can be formed almost arbitrarily and adapted to the available space.

A one-piece design of the compensation volume in the housing wall also allows an ideal tightness of the compensation volume.

The protuberance for the compensating volume is preferably formed opposite the capillary structure on the second wall of the housing and forms a roof-like structure. This design allows vapor which has formed undesirably on the liquid side of the evaporator to collect there at the highest point of the protuberance. This avoids that the steam collects in the vicinity of the capillary structure and allows a supersaturation of the capillary structure. The vapor collected in the protuberance may also be directed to the outgoing conduit via a separate conduit.

A further embodiment of the invention provides that on the first wall of the housing flanges are formed, which surround the heat source at least partially. This embodiment improves the utilization of the heat source and thus the heat input into the evaporator. The flanges may, for example, be corrugations formed in the wall or fins which are formed in one piece from the wall or are materially connected to the wall.

It is particularly preferably provided that two evaporators are preferably arranged symmetrically on a heat source and are connected in each case via a heat conduction element with one or each with a heat exchanger.

Further preferably, the flanges of the housing of the two evaporators are formed so that the heat source is completely encompassed.

These embodiments also serve to optimize the use of heat. The voltage applied to the heat source walls of the evaporator and respective flanges then form a cavity in which the heat source is disposed over the entire surface. In this way, almost all of the heat provided by the heat source can be introduced into the circulation of the working medium. Both evaporators can be connected via their heat-conducting elements with a single heat exchanger and thus increase the amount of heat available locally. On the other hand, different locations in the vehicle can be supplied with heat by each evaporator is connected to a separate heat exchanger.

This arrangement can basically be extended as desired. In an elongated heat source such as an exhaust line or a correspondingly designed electrical heater, a plurality of evaporators can be arranged one behind the other and a plurality of destinations in the vehicle can be supplied with heat.

Furthermore, the invention relates to a method for heating a passenger compartment or a vehicle component of a motor vehicle, wherein a working fluid is transferred under heat supply by a heat source in an evaporator in a gaseous state and passed through a heat conducting element to a heat exchanger, where the gaseous working fluid with release of heat condensed. The gaseous working medium is passed via an outgoing line from the evaporator to the heat exchanger and the condensed working medium is passed via a return line from the heat exchanger to the evaporator.

An advantage of this method is in particular the direct heat input into the working medium and the local storage in the form of latent heat. The stored heat is thus very quickly transported to the heat exchangers and a passenger compartment or a vehicle component can be brought very quickly to the desired target temperature. The system thus has a faster response than merely heating a working medium which remains in its present state of aggregation. Further aspects and advantages of the method have already been explained above in connection with the heating device.

The heat transfer in the form of latent heat, the heat loss is kept low in the lines, resulting in a high energy-saving efficiency of the process.

It is preferably provided that the condensed working medium is conducted by capillary forces from a liquid side of the evaporator through a capillary structure arranged between the outfeed line and the return line to a vapor side of the evaporator.

As described above in the context of the heating device itself, the evaporation of the working medium on the steam side of the evaporator leads to a pressure difference between the steam side and the liquid side, whereby the steam to is transported to the heat exchanger. The pressure difference is maintained by counteracting capillary forces. Due to capillary forces liquid working fluid is drawn into the capillary structure and thus driven a circuit for the working fluid. An additional pump is obsolete, which further improves the efficiency of the system, since no additional energy is needed to operate the pump.

Particularly preferably, the working medium is evaporated at a temperature between 50 ° C and 200 ° C, preferably between 60 ° C and 130 ° C, more preferably between 70 ° C and 110 ° C.

The temperature window provided in the respective application depends on the desired target temperature at the heat exchanger and the working medium used.

The invention will be explained below with reference to exemplary embodiments in the figures.

Show it:

1 a schematic drawing of a known from the prior art heater,

2 a schematic drawing of a heating device according to the invention,

3 a sectional view of an evaporator,

4 a sectional view of an evaporator with a compensation volume and

5 a sectional view of an embodiment with two evaporators.

The 1 shows a heater 10 for a motor vehicle, as known from the prior art, in a schematic representation. The heater consists of a resistance heating element 11 in which the in the circuit of the heater 10 contained water is heated. About a first line 12 the water enters a heat exchanger 13 Where the water is cooled and the heat released in their intended place, such as the passenger compartment, is discharged. The cooled water is via a second line 14 through a surge tank 15 led, in turn, via a third line 16 with a pump 17 connected is. From the pump 17 the water is via a fourth pipe 18 back into the resistance heating element 11 and the cycle starts again.

In the resistance heating element 11 it may be, for example, a so-called PTC heater, with a power of up to several kilowatts, for example 5 Kilowatts of warming water. As an additional power consumer is the pump 17 to see that in this heater 10 is imperative to keep the water cycle running. In addition, heat absorption and heat transport lead to a relatively slow response of the system.

In practice, this heater is 10 also very space-consuming, which in addition to the individual components on the four lines 12 . 14 . 16 . 18 lies. If these are designed too thin, the heat loss through the pipe walls is too high because of the large surface-to-volume ratio. A minimum volume for these lines 12 . 14 . 16 . 18 is therefore essential. In addition to the claimed total volume, this is also associated with a lower flexibility in the wiring.

Water boils under normal conditions at 100 ° C, so that the amount of heat that can be introduced is limited. In addition, the temperature-related volume change makes an additional large-volume expansion tank 15 necessary.

A heating device according to the invention 20 for a motor vehicle, however, shows 2 , This has a heat exchanger 21 for heating a passenger compartment or a vehicle component (not shown in detail) on. The vehicle component is a component of the motor vehicle that is to be heated permanently or in certain situations. Examples include the battery or a container for transmission oil. Furthermore, the heater has an evaporator 22 on, in which a working medium 31 with heat supplied by a heat source 25 is vaporizable. Furthermore, a heat conduction element is present, which is an outgoing line 23 and a return 24 for transporting the working medium 31 includes. The heat source 25 may, as in this exemplary illustration, be an electrical heater that has a voltage source 19 is powered. But other heat sources are conceivable, such as an exhaust pipe.

In the heater 20 it is not necessary to heat up a complete volume of liquid, it becomes a working medium 31 evaporates and the heat introduced in the form of latent heat in the gaseous working medium 31 saved. At the working medium 31 it may be, for example, water, but also alcohols such as methanol or ethanol. The working medium used 31 depends significantly on the temperature window at which the heat exchanger is to be operated. Adapted to this is namely to choose the evaporation point of the working medium.

The evaporated working medium 31 is about the forwarding 23 to the heat exchanger 21 guided. There, the steam is condensed and releases the heat that is supplied to the destination. The liquid working medium 31 will be on the return line 24 back to the evaporator 22 transported. Since the heat transfer takes place in the form of latent heat, the heat loss through the walls of the forward line 23 much lower than in the described prior art. The wires 23 . 24 can be made thinner, which makes them smaller in volume, lighter and more flexible. There are only two lines 23 . 24 necessary, what the heater 20 makes it more compact overall.

Already during the design, the system can with regard to the required amount of the working medium 31 be conceived. It should be considered, which volume the entire evaporated working medium 31 has. At no time, however, is the heater 20 completely with liquid working medium 31 filled. This eliminates a large-volume, separate expansion tank 15 , Although a smaller compensation volume 37 necessary, but without any problems in the immediate vicinity of the evaporator 22 can be arranged or formed in this itself. So also a high compactness in the construction is made possible.

Finally, by the evaporation of the working medium 31 and the transport of the gaseous working medium 31 the heat transport accomplished very quickly. This allows a very fast response of the system. Through the heat exchanger 21 the passenger compartment or the vehicle component can be heated quickly, especially in the cold season, this leads to a significantly improved ride comfort.

In 3 is a possible embodiment of the evaporator 22 shown in more detail. Between the forwarding 35 and the return 34 is a capillary structure 28 arranged. This consists of a porous material, wherein the porosity is between 40% and 60%, preferably between 45% and 55%, particularly preferably between 48% and 52%. It is a sintered metallic material, such as copper. The capillary structure 28 is in a housing 26 housed, in which the return line 34 in and out 35 out leads.

The capillary structure 28 is on an inside of a first wall 27 of the housing 26 arranged. The first wall 27 at the same time forms a cover of the housing 26 , On the opposite outside of the first wall 27 is a heat source 25 arranged.

Between the capillary structure 28 and a second wall 30 of the housing 26 is a cavity 36 educated. In this cavity 36 can the liquid working medium 31 gather, so that (on the presentation in 3 relative) the top of the capillary structure 28 , also called its liquid side, is always wetted and the capillary structure 28 even with liquid working medium 31 is saturated. Through seals 32 is the liquid side of the capillary structure 28 sealed from the opposite so-called steam side.

The heat source 25 heats the working medium 31 that is located on the vapor side in the capillary structure 28 is located and evaporates this. The steam collects in steaming grooves 29 that are in the capillary structure 28 at her on the first wall 27 adjacent surface, so the steam side, are integrally formed and of uniform material.

On the steam side of the evaporator there is a higher pressure than on the liquid side due to the higher temperature. By capillary forces, the liquid working fluid 31 further from the liquid side through the capillary structure 28 sucked on the steam side and there again evaporated. Due to the prevailing pressure difference, which is held up by counteracting capillary forces, the steam flows into a vapor collecting space 33 from there the forwarding 35 for the heat exchanger, not shown here 21 leads (flow direction B of the gaseous working medium). There, the vapor condenses and gets over the return line 34 back to the cavity 36 in the case 26 directed (flow direction A of the liquid working medium). This shows a further advantageous aspect of the heating device according to the invention 20 , The driven by the pressure difference current of the working medium 31 leads to an automatic circulation of the working medium 31 in the heater 20 , As a result, an additional pump, thus an additional energy consumer, superfluous and at the same time saves additional space.

When heating the working medium 31 this is evaporated at a temperature between 50 ° C and 200 ° C, preferably between 60 ° C and 130 ° C, more preferably between 70 ° C and 110 ° C. The vapor volume is usually greater than the liquid volume of the working medium 31 , This is in the design of the overall system of the heater 20 to take into account.

It is basically the largest possible amount of the working medium 31 in the system desirable to provide a continuous flow to the capillary structure 28 ensure that they are always through the liquid working medium 31 remains saturated. However, the one available too standing space and the total weight of the system to pay attention.

At the same time, it must be ensured that at any point in time the system is only loaded by the vapor pressure and not by hydrostatic pressure, even if the entire working medium 31 has gone into the gaseous state. Otherwise, there is a risk of bursting the system. Accordingly, the filling of the entire system is minimized and it is a compensation volume 37 provided, which is not in direct circulation working medium 31 receives.

Such a compensation volume 37 can be provided as a separate container in the circuit, but also directly from the housing 26 of the evaporator 22 be shaped as in 4 shown. There is the equalization volume 37 from a second wall 30 of the housing 26 formed. It is made up of sloping walls 38 . 39 , in the picture plane from the second wall 30 be led upwards. The compensation volume is completed 37 through a deck area 40 ,

In principle, it is also possible that gaseous working medium 31 also forms on the liquid side of the capillary structure. This is undesirable and may result in poor saturation of the capillary structure 28 with working medium 31 to lead. In this case, the embodiment of the compensation volume shown here has 37 Other advantages. The resulting vapor collects in the area below the top surface 40 and thus as far away as possible from the capillary structure 28 , resulting in complete wetting of the capillary structure 28 with liquid working medium 31 is maintained. It is also possible the compensation volume 37 with an additional, on the top surface 40 attached pipe with the steam storage room 33 or directly with the forward line 35 connect to the under the deck area 40 directly return the collected steam to the circulation.

To make even more effective use of the heat source 25 To achieve the heat available, two evaporators can be used 41 . 44 symmetrical at the heat source 25 be arranged, like 5 this shows. The first evaporator 41 and the second evaporator 44 each have two flanges 47 . 48 . 49 . 50 on, on the housings of the evaporator 41 . 44 are attached. These flanges 47 . 48 . 49 . 50 embrace the heat sources 25 Completely. Thus, the entire circumferentially radiated heat of the heat source 25 recorded and the working medium 31 be supplied. The evaporators 41 . 44 each have an inbound line 43 . 46 and a return 42 . 45 through the gaseous working medium 31 in the flow direction B, B 'removed and the liquid working medium 31 in the direction of flow A, A 'is recycled.

This can be the first forwarding 43 and the second forward 46 each lead to different receivers for the transported heat, but it can also both Hinleitungen 43 . 46 lead to one and the same heat exchanger. For the first and second return 42 . 45 this applies analogously.

LIST OF REFERENCE NUMBERS

10

 heater

11

 resistance

12

 first line

13

 heat exchangers

14

 second line

15

 surge tank

16

 third line

17

 pump

18

 fourth line

19

 voltage source

20

 heater

21

 heat exchangers

22

 Evaporator

23

 forward line

24

 return

25

 heat source

26

 casing

27

 first wall

28

 capillary

29

 steam grooves

30

 second wall

31

 working medium

32

 poetry

33

 Steam-collecting chamber

34

 return

35

 forward line

36

 cavity

37

 compensating volume

38

 sloping wall

39

 sloping wall

40

 gable

41

 Evaporator

42

 return

43

 forward line

44

 Evaporator

45

 return

46

 forward line

47

 flange

48

 flange

49

 flange

50

 flange

A

flow direction

A '

 flow direction

B

flow direction

B '

 flow direction

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 2407328 A1 [0004]

Claims (17)

Heating device ( 20 ) for a motor vehicle with at least one heat exchanger ( 21 ) for heating a passenger compartment or a vehicle component, at least one evaporator ( 22 . 41 . 42 ), in which a working medium ( 31 ) with heat supplied by a heat source ( 25 ) is vaporized and the heat exchanger ( 21 ) and the evaporator ( 22 . 41 . 42 ) connecting the heat conduction element, characterized in that the heat conduction element is an outgoing line ( 23 . 35 . 43 . 46 ) and a return ( 24 . 34 . 42 . 45 ) for transporting the working medium ( 31 ). Heating device ( 20 ) according to claim 1, characterized in that the forward line ( 23 . 35 . 43 . 46 ) for transporting a gaseous portion of the working medium ( 31 ) from the evaporator ( 22 . 41 . 42 ) to the heat exchanger ( 21 ) and the return line ( 24 . 34 . 42 . 45 ) for transporting a liquid portion of the working medium ( 31 ) from the heat exchanger ( 21 ) to the evaporator ( 22 . 41 . 42 ) serves. Heating device ( 20 ) according to one of claims 1 or 2, characterized in that the evaporator ( 22 . 41 . 42 ) a capillary structure ( 28 ) between the forward line ( 23 . 35 . 43 . 46 ) and the return line ( 24 . 34 . 42 . 45 ) is arranged. Heating device ( 20 ) according to claim 3, characterized in that the capillary structure ( 28 ) in a housing ( 26 ), wherein the housing ( 26 ) between the return line ( 24 . 34 . 42 . 45 ) of the capillary structure ( 28 ) a cavity ( 36 ) for receiving the back-transported working medium ( 31 ) having. Heating device ( 20 ) according to one or more of claims 1 to 4, characterized in that on the outside of a first wall ( 27 ) of the housing ( 26 ) an electric heater as a heat source ( 25 ) is arranged. Heating device ( 20 ) according to claim 4 or 5, characterized in that the capillary structure ( 28 ) on the inside of the first wall ( 27 ) of the housing ( 26 ) is arranged. Heating device ( 20 ) according to claim 6, characterized in that the capillary structure ( 28 ) at her on the first wall ( 27 ) adjoining surface extending in its longitudinal and / or transverse direction in one piece and of uniform material, formed steam grooves ( 29 ) having. Heating device ( 20 ) according to claim 4 or 5, characterized in that between the capillary structure ( 28 ) and the inside of the first wall ( 27 ) of the housing ( 26 ) Spacers are arranged, which together with the capillary structure ( 28 ) and the first wall in the longitudinal and / or transverse direction of the capillary structure ( 28 ) running steam grooves ( 29 ) train. Heating device ( 20 ) according to one or more of the preceding claims, characterized in that a compensation volume ( 37 ) for the working medium ( 31 ) is provided. Heating device ( 20 ) according to claim 9, characterized in that the compensating volume ( 37 ) for the working medium ( 31 ) in or directly on the housing ( 26 ) is provided. Heating device ( 20 ) according to claim 10, characterized in that the compensating volume ( 37 ) as a protuberance of a second wall ( 30 ) of the housing ( 26 ) is trained. Heating device ( 20 ) according to one or more of claims 5 to 11, characterized in that on the first wall ( 27 ) of the housing ( 26 ) Flanges ( 47 . 48 . 49 . 50 ) are formed, the heat source ( 25 ) at least partially embrace. Heating device ( 20 ) according to one or more of the preceding claims, characterized in that two evaporators ( 22 . 41 . 42 ) preferably symmetrically at a heat source ( 25 ) are arranged and in each case via a heat conduction element with one or each with a heat exchanger ( 21 ) are connected. Heating device ( 20 ) according to claim 13, characterized in that the flanges ( 47 . 48 . 49 . 50 ) of the housing ( 26 ) of the two evaporators ( 22 . 41 . 42 ) are designed so that the heat source ( 25 ) is completely encompassed. Method for heating a passenger compartment or a vehicle component of a motor vehicle, wherein a working medium ( 31 ) with heat supplied by a heat source ( 25 ) in an evaporator ( 22 . 41 . 42 ) is transferred in a gaseous state and via a heat conducting element to a heat exchanger ( 21 ), where the gaseous working medium ( 31 ) condensed with release of heat, characterized in that the gaseous working medium ( 31 ) via an outgoing line ( 23 . 35 . 43 . 46 ) from the evaporator ( 22 . 41 . 42 ) to the heat exchanger ( 21 ) and the condensed working medium ( 31 ) via a return line ( 24 . 34 . 42 . 45 ) from the heat exchanger ( 21 ) to the evaporator ( 22 . 41 . 42 ). A method according to claim 15, characterized in that the condensed working medium ( 31 ) by capillary forces from a liquid side of the evaporator ( 22 . 41 . 42 ) by an interim the forwarding ( 23 . 35 . 43 . 46 ) and the return line ( 24 . 34 . 42 . 45 ) arranged capillary structure ( 28 ) to a vapor side of the evaporator ( 22 . 41 . 42 ). Method according to claim 15 or 16, characterized in that the working medium ( 31 ) is evaporated at a temperature between 50 ° C and 200 ° C, preferably between 60 ° C and 130 ° C, more preferably between 70 ° C and 110 ° C.

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