Heat transmitter for transferring heat between coolant and refrigerant in vehicle

Abstract

A heat transmitter for transferring heat between a coolant and a refrigerant, comprising: a heating device for heating the refrigerant and the coolant; a bottom wall forming a stacked end-side end of at least two flow volumes through which the refrigerant or coolant flows; a first flow volume adjoining the bottom wall and through which the refrigerant flows, the first flow volume being connected to a first fluid inlet and a first fluid outlet, the first fluid inlet and the first fluid outlet being designed to establish a connection to a refrigerant circuit, the first flow volume being additionally defined by a first partition wall opposite the bottom wall; and a second flow volume which is adjacent to the first partition wall, is opposite the first flow volume and is used for the coolant to flow through, the second flow volume is connected with a second fluid inlet and a second fluid outlet, and the second fluid inlet and the second fluid outlet are used for establishing a connection with the coolant circuit. The heating device is arranged on the bottom wall on the side opposite the first flow volume.

Description

TECHNICAL FIELD

[0001] The present invention relates to a heat exchanger for transferring heat between a coolant and a refrigerant, wherein the heat exchanger comprises a heating device for heating the refrigerant and the coolant. In particular, the present invention relates to such a heat exchanger for use in a thermal management system of a fully or partially electrically driven vehicle. BACKGROUND

[0002] In vehicles, in particular battery-operated electric motor vehicles (hybrid or fully electric), due to the complex thermal requirements, thermal management systems can be used more and more. For example, by omitting the internal combustion engine, on the one hand, an additional heating configuration for heating the passenger space at low temperatures can be required, the energy consumption of which is at the expense of the energy stored in the vehicle battery. On the other hand, the demand for fast charging capability has also increased significantly. Currently, direct current fast charging stations with up to 350 kW are provided. In conjunction therewith, the temperature of the vehicle battery must be maintained in a narrow range in order to be able to use the available charging power in the best possible way. Thus, depending on the current operating mode and the outside temperature, on the one hand, the vehicle battery must be cooled or, on the other hand, the vehicle battery must be heated. Higher fast charging powers also increase the requirements on the thermal management system. Here, the thermal management has the task of using the respectively assumed heat or temperature in the existing thermal circuit efficiently in order to keep the consumption of the additionally feedable power low and to comply with the predefined temperature ranges of the components, such as electric motor, vehicle battery and power electronics, in order to ensure the efficiency or durability of the components.

[0003] Such a thermal management system usually comprises a heat pump. The heat pump comprises at least one high-voltage compressor, a condenser, an expansion valve, an evaporator and a suitable working fluid or refrigerant, such as R134a, R1234yf, R744, R290, respectively. In the heating operation of such a heat pump, heat can be absorbed in a known manner from the environment or another fluid via the evaporator.

[0004] A heat management system is known from document DE 10 2016 214 623 A1, in which heat can be exchanged between different heat circuits. The heat circuits are each operated by means of a coolant. The respective heat exchange unit comprises a heat pump operated by means of a refrigerant, wherein, on the hot side (condenser) and on the cold side (evaporator), heat exchangers are each provided for transferring heat to or from one of the heat circuits to the other heat circuit. On the hot side or on the cold side, within the flow-through region of the associated heat exchanger, a PTC element can be provided as an additional heater. If the temperature in the flow-through region should be increased quickly, for example in the case of starting the heat management unit and / or in the case of low ambient temperatures, this additional heater can be activated as required.

[0005] It is known from document EP 3 739 276 B1 that a heat exchanger is connected with a line for a refrigerant, which can be integrated into a fluid circuit, and with a line for a coolant, which is arranged in a heat exchange connection with the coolant for this purpose and can be integrated into a further fluid circuit. Here too, this can be a fluid-fluid heat exchanger. The heat exchanger can be used in an air conditioning system for a vehicle. The line for the refrigerant extends coaxially within the line for the coolant. The line with the refrigerant is arranged in a low-pressure region of the respective fluid circuit, which has a compressor, a condenser and an expansion mechanism. An electrically operated heating element is arranged outside the line for the coolant. The heating element has heating wires wound around the line for the coolant or a heating foil which abuts against the surface of the heating element around the line.

[0006] In electrically operated vehicles, as described above, the vehicle battery is cooled in operation or when fast-charging, i.e. in a higher temperature range, via a refrigeration facility and a heat exchanger which is incorporated into the refrigeration facility in a heat- transferring manner. A heat exchanger set up in this way is also referred to as a chiller. By means of the heat exchanger, heat is transferred between a respective refrigerant circuit and a coolant circuit which interacts in a heat- transferring manner with the vehicle battery. In particular, in this case, the refrigerant is evaporated in the chiller or in front of it in the low-pressure region, wherein the refrigerant can absorb heat from the coolant in the chiller.

[0007] A heat exchanger operating as such a cooler is known from document DE 10 2022 111 067 A1 for at least partially electrically driven motor vehicles, which has a plurality of heat exchanger plates arranged next to one another or parallel to one another, which have a respective, fluid-technically separated refrigerant circuit and coolant circuit. The refrigerant circuit is connected to a refrigerant circuit of a refrigeration facility. The coolant circuit is connected to a coolant circuit of a cooling facility. The heat exchanger plates are designed in such a way that a heat transfer from the refrigerant to the coolant or vice versa can be realized. It is provided that the heat exchanger has an electric heating device, which can heat the refrigerant and the coolant simultaneously as required. The heating device can be embodied in a plate-like or mat-like manner and can be positioned in a sandwich / interlayer manner between two adjacent heat exchanger plates. Alternatively, the heating device can be arranged laterally between the housing of the heat exchanger and the heat exchanger plates. Here, the heating device can be mounted laterally on the inner wall of the housing or can be fastened relatively to the edge of the heat exchanger plates, but especially outside the heat exchanger plates. In addition, the heating device can also be integrated in the housing of the heat exchanger itself in a similar lateral position.

[0008] If the temperature is too low, the cooler has the function of transferring heat from the coolant to the refrigerant. In this case, heating of the passenger space is also often desirable. Therefore, the approach for implementing an additional heating device is generally to primarily heat the coolant. In the combination of the cooler and the additional heating, the refrigerant is heated by the additional heating device when required. SUMMARY

[0009] The task is to provide a heat exchanger for transferring heat between coolant and refrigerant, preferably for use in a vehicle, in which the efficiency of the heat transfer function is further improved.

[0010] According to an aspect, a heat exchanger for transferring heat between coolant and refrigerant, preferably for use in a vehicle, especially a motor vehicle, is proposed. The proposed heat exchanger can be a component of a thermal management system and is implemented in a vehicle that is operated electrically in its entirety or partially (hybrid). The heat exchanger can be implemented as a cooler and can have a heating device for heating the refrigerant and the coolant here.

[0011] The heat exchanger comprises a bottom wall which constitutes an end-side end of a stack consisting of at least two flow volumes which are traversed by a refrigerant or coolant. These flow volumes can be arranged alternately in the stack (or packet) for traversal by refrigerant and coolant. Other arrangements are likewise possible. The number of flow volumes for refrigerant and the number of flow volumes for coolant in the stack need not be identical, but can also be different. The bottom wall constitutes an end-side end, which means that the stack or a further stack with corresponding flow volumes does not extend beyond the bottom wall on the other side. The bottom wall constitutes a termination or end of the stack or packet with regard to traversal by the fluid.

[0012] A first flow volume (in the direction of the stack) for traversal by refrigerant which is adjoined by the bottom wall is connected with a first fluid inlet and with a first fluid outlet. The first fluid inlet and the first fluid outlet are provided for establishing a connection to a refrigerant circuit, wherein the first flow volume is additionally determined by a first partition wall which is opposite the bottom wall. Preferably, the flow volume determined by the bottom wall and the partition wall has a flat design, wherein the bottom wall and the partition wall are parallel to one another and have a spacing from one another in their direction of extension which is small compared to the dimensions of the bottom wall and the partition wall. The refrigerant can be, for example, a known working fluid, such as R134a, R1234yf, R744, R290, etc., but the embodiments are not limited to these particular fluids. As mentioned in the introduction, the refrigerant circuit can comprise, for example, mainly a compressor, a condenser, an expansion valve, an evaporator or vaporizer and further components (such as a collector, etc.). In summary, the refrigerant circuit can be part of a heat pump.

[0013] A second flow volume for traversal by coolant which is opposite the first flow volume is adjoined by the first partition wall. Heat can thus be transferred from the coolant to the refrigerant via the first partition wall and, depending on the operating mode, also vice versa, as required. The second flow volume is connected with a second fluid inlet and with a second fluid outlet which are provided for establishing a connection to a coolant circuit. The coolant circuit can ensure, for example, heating or cooling of a passenger interior, a vehicle battery or further components of the vehicle, such as a drive motor or a further electric motor. The coolant can be, for example, water or a similar, suitable, relatively highly heat-capacitive fluid.

[0014] The second fluid inlet and the second fluid outlet can have respective nipples which are configured in a known manner, for example as quick couplings, and thus ensure a quick, fluidically sufficiently reliable and foolproof mounting. This is different from the first fluid inlet and the first fluid outlet, which require a higher degree of robustness and sealing of the couplings and thus a more complex fastening primarily for reasons of durability, since the working fluid (refrigerant) must not get into the environment and a loss of this working fluid can lead to damaged components. In this respect, by configuring the fluid inlets and fluid outlets respectively for use with the fluids described, the first flow volume and the second flow volume are determined.

[0015] Furthermore, the second flow volume has a substantially similar flat configuration and substantially identical dimensions as the first flow volume. However, in particular, the dimensions of the flow volumes, in particular the height in the direction perpendicular to the bottom wall, can be completely different. Preferably, the fluid inlets and fluid outlets are respectively arranged diagonally relative to each other, which also applies to the first flow volume. Preferably, in the stacked configuration, the fluid inlets and fluid outlets extend in the height direction perpendicular to the bottom wall, wherein they can extend through adjacent flow volumes, if necessary.

[0016] According to an aspect according to the application, it is now proposed that, in such a configuration of the heat exchanger, the heating device is arranged on the bottom wall on the side opposite the first flow volume. In other words, the heating device is more or less directly thermally connected with the first flow volume, through which the refrigerant flows. This means that, in the (optional) heating operation, heat is first transferred to the refrigerant. Subsequently or indirectly, heat is also transferred to the second flow volume, which is located behind the first flow volume, viewed from the heating device. However, for this, these heat must pass through the first flow volume, more precisely the fluid (refrigerant) contained therein and the stationary mechanical components, for example its walls, and primarily through one or more turbulence generators, if any, provided therein.

[0017] This construction differs from the initially described primary heating of the coolant, since the heat capacity or heat absorption is here significantly higher in the refrigerant and thus a favorable concentration of the heat for the intended purpose can be expected. However, the following surprising advantages were shown in the carried out tests and calculations: The comparatively small heat capacity of the refrigerant compared to the coolant in particular leads to the fact that relatively little thermal energy of the heat fed in via the bottom wall by the heating power remains in the first flow volume (or is absorbed in the fluid) and thus there is still sufficient heat available to the second flow volume via the first flow volume in order to achieve the desired heating of the coolant. It has proven that in the conventional case, i.e. when the coolant is primarily heated and the refrigerant is secondarily heated, too much heat is dissipated from the coolant in operation. This can only be compensated for in general by reducing the flow speed, but this can have disadvantages and can lead to far too high coolant temperatures. By arranging the first flow volume, which is traversed by the refrigerant, in abutment with the bottom plate and thus in the immediate vicinity of the heating device, a particularly balanced balance between the degree of heating and the desired volume flow in the two fluid circuits is achieved.

[0018] According to an advantageous embodiment of the heat exchanger, at least one first turbulator is provided in the first flow volume for the refrigerant traversing it. Preferably, at least one second turbulator is also provided in the second flow volume for the coolant traversing it. Such turbulators not only have a high efficiency of swirling or mixing of the different fluid components in the flow, but also enable a high efficiency of heat transfer to the fluid, primarily by a large contact area with the fluid. In the present case, however, particular use is made of the fact that the turbulators are in thermal contact not only with the bottom wall, but also with the first partition wall between the first flow volume and the second flow volume. Thereby, the transport of heat from the bottom wall to the second flow volume is further improved compared to the case where the heat transport takes place only via the fluids (and if necessary via the lateral side walls connecting the bottom wall and the partition wall).

[0019] In a preferred embodiment, for the purpose of heat conduction from the bottom wall to the partition wall, at least one first turbulator is not only fastened to the bottom wall, but also to the opposite first partition wall, said fastening preferably being effected by brazing. Optionally, this embodiment can be further improved in such a way that the at least one first turbulator has a grid structure with a grid period (also referred to as pitch), which is formed by an accordion-like folding of a flat workpiece having a first wall thickness. This flat workpiece can be a plate made of a thermally conductive metal, such as an aluminum alloy. By introducing slits, a fine structure with a large surface can be achieved in the folded workpiece. From the initial shape of the flat workpiece, in the case of a suitable folding, the following possibility arises: a large-area contact section between the turbulator and the bottom wall or the first partition wall is established, which can then, if necessary, be brazed or can also be welded. The greater the contact area, the better the heat conduction through the turbulator to the second flow volume.

[0020] A preferred configuration provides for the wall thickness of the workpiece on which the turbulator is based to be implemented, in particular, to be thicker. The case is considered in which the bottom wall and the first partition wall are arranged substantially parallel to one another, wherein the heat conduction direction extends perpendicular to the bottom wall and the partition wall. Here, the bottom wall has a first thermal resistance R th1 with respect to its cross-sectional area perpendicular to the heat conduction direction, and the at least one first turbulator (in the case of a plurality of first turbulators, the entirety of the plurality of first turbulators) has a second thermal resistance R th2 with respect to the cross-sectional area of the first flow volume perpendicular to the heat conduction direction. Here, the second thermal resistance R th2 of the at least one first turbulator or the second thermal resistance of the entirety of the respective first turbulator is 10% or more, preferably 11% or more, further preferably 12% or more, of the first thermal resistance R th1 .

[0021] However, a thicker wall thickness also increases the flow resistance. This can preferably be compensated by orienting the flow-preferred direction determined by the folding direction of the workpiece, which extends transversely to the folding direction, with respect to the flow direction, preferably parallel to the flow direction. The flow direction itself is determined by the position of the fluid inlet, the position of the fluid outlet, and by the position of possible partition walls that guide the flow.

[0022] In the above case, i.e. at least one first turbulator has a grid structure with a grid period, which is formed by an accordion-like folding of a flat workpiece with a first wall thickness, the grid period is in a ratio of 20:1 or less to the first wall thickness due to the larger wall thickness. Here, "larger" means in comparison to the wall thickness of a turbulator of the same structure type, which is used in the same size, for example in a fluid heater with pure additional heating (only heat exchange between the heating device and the sole fluid). If, for example, in the case of pure additional heating, the outer dimensions (length x width x height) are set similarly in terms of flow volume (the above ratio is, for example, approximately 30:1), a wall thickness of 0.3 mm for the turbulator provides an optimum compromise between flow resistance and heat transfer, whereas in the present case, a wall thickness of 0.4 to 0.5 mm can provide an optimum value in terms of heat transfer to the second fluid volume.

[0023] According to another special configuration, at least two, preferably three first turbulators are provided in the first flow volume for the passage of the refrigerant. Furthermore, at least one dividing wall (in the case of three first turbulators, for example two dividing walls connecting the bottom wall and the first partition wall) connecting the bottom wall and the first partition wall extends in the first flow volume. The one or more dividing walls divide the first flow volume in such a way that the refrigerant, starting from the first fluid inlet and up to the first fluid outlet, passes through the at least two or three first turbulators sequentially, i.e. in series, i.e. successively. The dividing walls do not necessarily have to connect the bottom wall and the partition wall to each other, but can, for example, have a small spacing from the bottom wall and / or the partition wall, which has a less flow-turning effect. In general, according to this embodiment, at least one dividing wall extending between the bottom wall and the first partition wall is contained in the first flow volume, and two dividing walls extending between the bottom wall and the first partition wall are contained in the case of three first turbulators. For example, the dividing walls can be integral components of the bottom plate or the partition wall and can be connected to the partition wall or the bottom plate on the other side by means of brazing. Thereby, a flow through the turbulators in sequence is achieved as uniform as possible and at the same time the greatest heat input (in the case of a given volume flow) is achieved. This flow in sequence increases the flow resistance, so that the division is preferably only necessary in the case of refrigerants. However, in the case of refrigerants, this flow in sequence offers the special advantage that the required heat can be introduced more easily, since there is a longer residence time in the relevant volume here. Furthermore, it is to be considered that the refrigerant is additionally also evaporated.

[0024] An extension in this connection provides that the cross-sectional area determined perpendicular to the respective flow direction in the sub-volumes formed by one or more partition walls and filled by the respective first turbulators increases from the first fluid inlet to the first fluid outlet. Thereby, the volume flow is slowed down towards the first fluid outlet, so that the distribution of the heat absorbed in the refrigerant over this cross-sectional area (parallel to the bottom wall or the first partition wall) is approximately constant, since the refrigerant in the vicinity of the fluid outlet has already been heated and therefore actually absorbs less heat. However, for this purpose, the residence time is also longer in the vicinity of the fluid outlet, which again increases the heat absorption. Thus, in total, the heat transfer towards the second flow volume is homogenized over this area. An additional aspect is that the refrigerant evaporates and subsequently occupies a larger volume. For this reason, too, the cross-section can be designed to increase gradually in the flow direction (with a correspondingly increasingly smaller flow speed).

[0025] According to another extension, the second wall thickness of the second turbulators for the second flow volume through which the coolant flows can be smaller than the first wall thickness of the first turbulators, in particular when no further flow volume is adjoined.

[0026] Furthermore, a third flow volume for the refrigerant is adjoined again by a second partition wall, which is parallel to the first partition wall, which together delimits the second flow volume, which is connected to the first fluid inlet and the first fluid outlet. Preferably, the first and third flow volumes are flowed through in parallel by the refrigerant. In the case of the third flow volume, a configuration with at least two, preferably three, third turbulators and the respective dividing walls can be implemented in the same way as in the first flow volume. Preferably, in the third flow volume, too, the flow preferential direction determined by the grid structure of the third turbulators is oriented parallel with respect to the respective flow direction. However, in an alternative configuration, the flow preferential direction determined by the grid structure of the third turbulators can be oriented transversely or obliquely with respect to the respective flow direction.

[0027] Alternatively or in addition thereto, in this case the third wall thickness of the at least one third turbulator (or of the plurality of third turbulators) can be smaller than the first wall thickness of the at least one first turbulator. Preferably, the ratio of the grid period to the third wall thickness of the at least one third turbulator is greater than 20:1. A thinner wall can be used, for example, distantly, since the wall thickness can be fully utilized, in particular for setting the thermal conductivity achieved by the material from passage to passage. Conversely, however, it is also possible in principle to consider increasing the wall thickness in the distal volume. Thereby, a higher pressure loss is obtained in the distal passages, and more heat can be introduced into the passages adjoining the heating device.

[0028] Preferably, in the second flow volume and, if necessary, in the fourth flow volume, which is traversed by the coolant, the second turbulator and, if necessary, the fourth turbulator are contained, which have an accordion-like folding structure and a flow-preferential direction perpendicular to the folding direction, wherein the turbulators are arranged such that their flow-preferential direction is oriented transversely to the main flow direction of the flow volume.

[0029] According to another expansion, the at least one second turbulator substantially fills the second flow volume, with the exception of two regions directly adjacent to the fluid inlet or the fluid outlet, which extend transversely to an imaginary connecting line between the second fluid inlet and the second fluid outlet. This can achieve a more uniform distribution of the flow over the turbulator cross section and ensure a substantially parallel flow direction in the flow volume. Here, the main flow direction extends between the main sides, along which the regions without turbulators extend.

[0030] As mentioned above, the at least one first turbulator, preferably all further turbulators, can also be formed from an aluminum alloy, which preferably has magnesium and / or silicon, for example the special aluminum alloys "3003" or "6060". Preferably, the bottom wall and the partition walls can be formed from the same material.

[0031] According to another expansion, the fluid inlet and the fluid outlet of the first flow volume for the traversing of the refrigerant are configured as a connector. Here, the connector of the fluid inlet is provided with a receptacle for an expansion valve of the refrigerant circuit. Alternatively or additionally, the connector of the fluid inlet and / or the fluid outlet is provided with a receptacle for a temperature sensor.

[0032] According to an embodiment, the heating device can comprise a heating conductor layer, which is formed on the bottom wall or on a substrate mounted on the bottom wall, in which a heating conductor circuit is configured.

[0033] In particular, the heating device can be realized in different ways, and the application is not limited to a certain embodiment of the heating device. For example, the heating device can consist of a thermally sprayed layer. At the time of manufacture, for example, atmospheric plasma spraying can be used as a coating method. It is also possible to apply the heating element on both sides, i.e. also on the bottom wall. As a layer construction, starting from a flat plate, first an optional adhesive base, then an insulating ceramic, a real heating conductor layer and, if necessary, a cover layer or a seal are applied. The heating conductor layer can be structured by means of a laser or with the aid of a mask. The material of the heating conductor can be a material having linear resistance properties or PTC resistance properties.

[0034] Furthermore, a polymer-based heating device having PTC properties is considered. This can involve a heating element made of a plastic foil. The heating element is usually composed of an extruded or laminated polymer matrix, into which a heating conductor and positive and negative electrodes are embedded.

[0035] In addition, the heating device can also comprise a ceramic heating element having PTC properties (Kaltleiter).

[0036] In addition to this, the heating device can be embodied as a thick-layer heating element. Here, the carrier element can again be the bottom wall of the heat transfer. The thick-layer heating element, which can be a dielectric and a heating conductor for forming a planar heating resistor, is applied to or on this carrier element.

[0037] Alternatively, the heating device can comprise a ceramic substrate (as a carrier element), which is made of, for example, AI2O3, which has a screen-printed heating conductor layer. Here, the heating conductor layer can be configured, for example, as a metallization made of a resistance alloy, which forms the respective heating resistor. Iron-nickel alloys or nickel-chromium alloys are primarily considered. Insulation interruptions ensure the structuring of the long conductor circuit, which is composed of a layer that is applied planarly in other sections and is subsequently calcined, and can have been produced by means of a screen printing process, for example, at the time of application. The ceramic substrate can be a ceramic carrier plate. This embodiment of the heating element is preferred according to the various aspects of the application.

[0038] In the case of the described polymer-based heating element having PTC properties, the ceramic heating element having PTC properties or the heating device with a ceramic substrate with a screen-printed heating conductor layer, the planar heating device can be applied to the preferably flat bottom wall by means of a thermal medium as an adhesive layer, for example a thermally conductive adhesive material. The thermal medium and the heating element or the heating device can be applied by means of a pressing device.

[0039] In all these cases, there is a heating device arranged over a large area on or against the bottom wall, which covers the bottom wall opposite the first flow volume or refrigerant. According to an embodiment, the area projected by the turbulator onto the bottom wall and the area projected by the heating device or the heating element or elements onto the bottom wall are substantially congruent (the degree of overlap of the projected heating element area relative to the projected turbulator area of the first channel is for example greater than 60%, greater than 70%, greater than 80% or even greater than 90%; preferably greater than or equal to 60% and less than or equal to 80%).

[0040] On the bottom wall, a circuit board with power electronics can also be arranged. The respective power switches can likewise be positioned on the bottom wall such that they are opposite the first flow volume in order to likewise participate in the heat transfer.

[0041] Alternatively or additionally, the side of the bottom wall with the heating device (optionally also with the power electronics) can be closed by a housing cover, which is protected from contamination and contact by body parts. As already mentioned, the flow volume of the participating fluid is arranged only on the side of the bottom wall or carrier plate facing away from the heating device and the housing cover.

[0042] The bottom wall can extend beyond the first flow volume opposite the heating device towards one or more sides. The expanded area region of the bottom wall is used on the one hand for mounting a control housing on the bottom wall, which accommodates or provides a control device (ECU) for the heating device as well as a power supply. One configuration provides that the control housing is mounted on the same side of the bottom wall as the stack of flow volumes. This has the advantage that not only the fluid connections, but also the electronic connections (HV (high voltage) for the power and LV (low voltage) for the communication) are arranged on the same side of the bottom wall, which now serves as a carrier plate, which significantly facilitates the implementation in the installation space of a vehicle, in particular a motor vehicle, since only an access for operation and maintenance from one side is required. For this purpose, the bottom wall can have one or more openings, which allow the respective lines (HV supply for the power electronics of the heating, LV lines for controlling the power switches for the temperature sensors, which are for example on a circuit board with power electronics) to be led from the control housing towards the heating device or the power electronics of the heating device to the other side.

[0043] The first flow volume can be delimited or defined in the height direction by a bottom wall and a first partition wall, which are oriented preferably parallel to one another in the manner described above. An advantageous configuration provides that a first side wall, which delimits the first flow volume, is also constructed in one piece on the bottom wall, for example by welding or brazing. The bottom wall or the carrier plate constituting the bottom wall thus comprises a basin-like construction, which is covered by the first partition wall. The first side wall, which is accordingly circumferential, can here be slightly inclined outwards continuously with respect to the height direction perpendicular to the bottom wall. That is, the basin widens upwards. A second basin, which is constructed in essentially the same manner, can be inserted into the first basin, said second basin being formed by the first partition wall and an upwards curved edge, for example by deep-drawing a flat blank. The upwards curved edge constitutes the respective second side wall for the subsequent second flow volume. This side wall also widens in the height direction, so that in this way the desired number of basins can be used. The circumferential walls, which meet respectively conically on the inside or on the outside in this process, can be brazed in a simple manner. The widening of the circumferential walls is dimensioned only in such a way that a respective flow volume remains between the mutually nested basins. The height of the circumferential walls corresponds to the respective turbulator mounted therein, so that these can be brazed or welded above and below. In summary, the following particular advantages arise: only two components (the next basin and the respective turbulator) have to be installed per flow volume and the manufacturing process is thereby significantly simplified. Furthermore, only one physical wall is produced between the flow volumes respectively. However, the invention does not exclude the case that each flow volume provides a circumferentially constructed, container-like, completely exclusive delimiting wall, so that the partition walls (and the bottom wall) according to the invention can be completely multilayered.

[0044] By means of the aspects, configurations and embodiments presented here, a heat exchanger can be realized overall, which allows three operating modes (values according to a preferred embodiment):

[0045] (a) a cooling power with the transfer of heat from the coolant circuit to the refrigerant circuit, which is for example up to 15 kW;

[0046] (b) an electrical heating power applied to the refrigerant (refrigerant circuit) by means of the heating device, which is dimensioned for example approximately 4-5 kW

[0047] (c) an electrical heating power applied to the coolant (coolant circuit) by means of the heating device, which is dimensioned for example approximately 6-7 kW.

[0048] Heating of the coolant can be effected without heating the refrigerant circuit in that the volume flow in the refrigerant circuit is set to zero. In this case, the first flow volume transfers the transferred heat only to the second flow volume.

[0049] According to another embodiment, the heat exchanger has at least five flow volumes. In an extension of this embodiment, the first, third and fifth flow volumes can be traversed by means of refrigerant and the second and fourth flow volumes can be traversed by means of coolant.

[0050] According to another embodiment, the heat exchanger has at least six flow volumes. In an extension of this embodiment, the first, third and fifth flow volumes can be traversed by means of refrigerant and the second, fourth and sixth flow volumes can be traversed by means of coolant.

[0051] According to another embodiment, the heat exchanger has at least seven flow volumes. In an extension of this embodiment, the first, third, fifth and seventh flow volumes can be traversed by means of refrigerant and the second, fourth and sixth flow volumes can be traversed by means of coolant. In principle, the heat exchanger can also have more than seven flow volumes.

[0052] In an embodiment having three flow volumes which can be traversed by means of coolant, these flow volumes can be connected in such a way in terms of flow technology that the flow volumes can be traversed by means of coolant in parallel.

[0053] In another advantageous embodiment, the heat exchanger has at least two flow volumes which can be traversed by means of refrigerant, which flow volumes are connected in such a way in terms of flow technology that at least one of the flow volumes can be traversed sequentially with the other flow volumes.

[0054] In an embodiment having first, third and fifth flow volumes, these flow volumes are connected in such a way in terms of flow technology that at least the fifth flow volume can be traversed by means of refrigerant sequentially with the first and third flow volumes. Here, the first and third flow volumes can be connected in such a way in terms of flow technology that these flow volumes can be traversed by means of refrigerant in parallel with one another.

[0055] In an embodiment having first, third, fifth and seventh flow volumes which can be traversed by means of refrigerant, respectively, the first and third flow volumes and the fifth and seventh flow volumes can be traversed in parallel with one another, respectively. In addition, the fifth and seventh flow volumes can be traversed by means of refrigerant sequentially with the first and third flow volumes.

[0056] Further embodiments of the application result from the attached subclaims. BRIEF DESCRIPTION OF DRAWINGS

[0057] Embodiments of the application are explained below in more detail according to the accompanying drawings. Shown here is:

[0058] Figure 1 A heat transfer device with electrical high-voltage heating devices is shown in perspective view according to an embodiment;

[0059] Figure 2 The heat transfer device in Figure 1 is shown from another angle;

[0060] Figure 3 A bottom wall of the heat transfer device in Figure 1 is shown in top view, the bottom wall having heating elements of the heating devices mounted on the bottom wall;

[0061] Figure 4 The heat transfer device is shown in perspective view with the control housing removed;

[0062] Figure 5 A cross-sectional view of a bottom wall is shown in very schematic cross-sectional view, the bottom wall having a stack of flow volumes mounted on the bottom wall;

[0063] Figure 6 A turbulator pertaining to a flow volume is shown in perspective view, the bottom wall and the partition wall being removed, but the fluid inlet and the fluid outlet being included;

[0064] Figure 7 The turbulator in Figure 6 is shown in exploded schematic view;

[0065] Figure 8 A fragment of a first turbulator of a first flow volume closest to the bottom wall is shown in enlarged perspective view;

[0066] Figure 9 As in Figure 8 but relating to a second turbulator of a second flow volume in the stack that adjoins the first flow volume;

[0067] Figure 10 As in Figure 8 or Figure 9 but with a comparison of the first turbulator to a third turbulator of a third flow volume in the stack that adjoins the second flow volume;

[0068] Figure 11 A cross-sectional view of a bottom wall is shown in very schematic cross-sectional view according to an alternative embodiment, the bottom wall having a stack of flow volumes mounted on the bottom wall, and a flow path of refrigerant through the flow volumes is shown;

[0069] Figure 12in a very schematic cross-sectional view with Figure 11 Similarly, a cross-section of a bottom wall is shown, which has a stack of flow volumes mounted on the bottom wall, and a flow path of refrigerant through the flow volumes is shown.

[0070] In the following description of the preferred embodiments, it is to be understood that the disclosure of the various aspects is not limited to the details of construction and arrangement of the components shown in the following description and drawings. In practice, the embodiments can be carried out or implemented in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. Furthermore, in the following description, identical or similar features or items are denoted by the same reference signs, so that in some cases, repeated detailed description is omitted in order to keep the drawing compact and clear. DETAILED DESCRIPTION

[0071] In Figure 1 and Figure 2 a heat transfer device 1 with a (high-voltage) electric heating device 51 according to an embodiment is shown in perspective view. This is in particular a fluid-to-fluid heat transfer device with a heating device, for example for a thermal management system in a purely electrically operated or hybrid operated vehicle, in particular a motor vehicle. The fluids can be on the one hand a refrigerant of a refrigerant circuit of a heat pump and on the other hand a coolant of a coolant circuit or of multiple coolant circuits, which can be configured by a three-way valve depending on the operating mode, for example.

[0072] The heat transfer device 1 comprises a control module 10, a heat transfer module 20 and a heating module 50. The control module 10 has a control housing 11, preferably formed from plastic, in which a control circuit board (not shown) is accommodated, which serves as an ECU (Electronic Control Unit; controller). The control circuit board can be connected to a vehicle network for power supply and for communication with a BCM (Body Control Module; vehicle network controller) via a high-voltage connection socket 12 and a low-voltage connection socket 13. The control housing 11 can be closed by a control housing cover 14 (see Figure 2 ).

[0073] The heat exchanger module 20 comprises a bottom wall 30 which also serves as a carrier plate for the components and modules. The bottom wall 30 is configured as a flat, planar and essentially rectangular plate (with rounded edges) which is made of a material with high thermal conductivity, in particular an aluminum alloy. A first side wall 31 is configured in one piece with the bottom wall 30, which encloses or forms a planar rectangular area (again with rounded edges) on the bottom wall 30. The first side wall 31 extends approximately perpendicular to the bottom wall 30, but widens slightly upwards. This planar rectangular area forms a first flow volume 21 for the flow-through of a coolant, which is delimited in the Figure 5 simplified schematic cross-sectional view.

[0074] A second component is placed on this component formed by the first bottom wall 30 and the first side wall 31, which is formed by a first partition wall 81 and a second side wall 32. Here, the first partition wall 81 extends parallel to the bottom wall 30, opposite it and delimits the first flow volume 21 upwards. Like the first side wall 31, the second side wall 32 extends approximately perpendicular to the first partition wall 81 and forms a second flow volume 22 for the flow-through of a coolant. Due to the widening of the first side wall 31, the lower end of the second side wall 32 can be accommodated in the upper edge area of the first side wall 31 and brazed to it in order to seal the first flow volume 21. Like the first side wall 31, the second side wall 32 also widens upwards or conically outwards.

[0075] In the same way, a third component is placed on this component formed by the first partition wall 81 and the second side wall 32, which is formed by a second partition wall 82 and a third side wall 33. Here, the second partition wall 82 extends parallel to the first partition wall 81 and the bottom wall 30, opposite the first partition wall and delimits the second flow volume 22 upwards. Like the first and second side walls 31, 32, the third side wall 33 extends approximately perpendicular to the second partition wall 81 and forms a third flow volume 23 for the flow-through (again of a coolant). Due to the widening of the second side wall 32, the lower end of the third side wall 33 can be accommodated in the upper edge area of the second side wall 32 and brazed to it in order to seal the second flow volume 22. Like the first and second side walls 31, 32, the third side wall 33 also widens upwards or conically outwards.

[0076] In the same manner, a fourth component is placed on the component formed by the second partition wall 82 and the third side wall 33, which fourth component is formed by a third partition wall 83 and a fourth side wall 34. Here, the third partition wall 83 extends parallel to the second partition wall 82, the first partition wall 81 and the bottom wall 30, opposite the second partition wall and bounds the third flow volume 23 upward. Like the first, second and third side walls 31, 32, 33, the fourth side wall 34 extends approximately perpendicular to the second partition wall 82 and constitutes a fourth flow volume 24 for the (again cooled) flow-through. Due to the widening of the third side wall 33, the lower end of the fourth side wall 34 can be accommodated in the upper edge region of the third side wall 33 and soldered thereto in order to seal the third flow volume 23. Like the first, second and third side walls 31, 32, 33, the fourth side wall 34 also widens upward or conically outward.

[0077] An upper top wall parallel to the third partition wall 83 is arranged on the fourth side wall 34, which upper top wall bounds the fourth flow volume 24 upward and closes the resulting stack of four flow volumes 21-24. Thus, viewed from the bottom wall 30, the four flow volumes are arranged in an alternating manner for the flow-through of refrigerant and coolant, starting from the refrigerant. Apart from the slight widening of the side walls 31-34, which enables the mutual nesting of the pot-shaped components (Ineinanderschachteln), the side walls are essentially aligned with one another, so that the sum of the fluid chambers results in an overall closed, cuboid-shaped stack configuration. The stack direction is perpendicular to the plane formed by the bottom wall 30.

[0078] The first flow volume 21 and the third flow volume 23 are open via a first fluid inlet 61 and a first fluid outlet 62, respectively, and are incorporated into a refrigerant circuit of a heat pump (not shown). For this purpose, a respective one of the first fluid inlet 61 and the first fluid outlet 62 also extends through the partition walls 81, 82, 83 and the upper top wall 35. The connections are positioned on diagonally opposite corners of the flow volumes or the stack. The first fluid inlet 61 and the first fluid outlet 62 are configured in terms of their construction for coupling to the refrigerant circuit of the heat pump. The first fluid inlet and the first fluid outlet have a first receptacle 65 for an expansion valve (not shown) and a second receptacle 66 for a temperature sensor (not shown). Via the expansion valve, the first flow volume 21 and the third flow volume 23 obtain the function of an evaporator in the refrigerant circuit. By means of the temperature sensor, which can be connected to a control circuit board (not shown), suitable monitoring of the heat transfer and control or regulation, etc. can be carried out, for example, by adjusting the heating power and / or the volume flow not only in the refrigerant circuit but also in the coolant circuit.

[0079] The second flow volume 22 and the fourth flow volume 24 are open by a second fluid inlet 71 and a second fluid outlet 72, respectively, and are incorporated in a coolant circuit (not shown) of a vehicle. The second fluid inlet 71 and the second fluid outlet 72 each have a connection piece for connection to a coolant hose, which connection piece is configured as a quick coupler. These connection pieces are positioned on the remaining two diagonally opposite corners of the flow volume or stack. These connection pieces also extend at least through the partition walls 82, 83 and the upper top wall 35.

[0080] Figure 3 A top view of the bottom wall 30 is shown. The bottom wall 30 has a side surface 39 facing the stack of fluid chambers (flow volumes) through which the fluid is flowed (heat exchanger side) and a side surface 38 facing the heating device 51. Figure 3 A top view of the side surface 38 facing the heating device 51 is shown. The three heating elements 52 of the heating device 51 are positioned on the side of the bottom wall 30 opposite the first flow volume 21. The heating elements 52 each have a heating conductor layer applied to a ceramic substrate and a heating conductor circuit structured in a thick layer technology (Dickschichttechnik), which serves as a heating resistor when a high-voltage voltage is applied or switched. The heating conductor circuit can have a meandering layout (not shown) on the ceramic substrate. Power switching elements can be arranged on an additional circuit board (not shown) mounted on the bottom wall 30 or can be arranged in the control housing 11, for example on a control circuit board.

[0081] Furthermore, the bottom wall has an aperture 36, which enables mounting of the control housing 11 on the bottom wall 30 on the side surface 39 facing the stack of fluid chambers. An opening 37 is provided in order to allow the passage of high-voltage lines and control lines to the heating elements 52 or possible temperature sensors.

[0082] Figure 4 The bottom wall 30 with the stack of fluid chambers is shown in a perspective view looking towards the side surface 39. Figure 5 The cross-sectional view shows that the heating device 51 is positioned opposite the first flow volume for the coolant to be flowed through in such a way that there is a large overlap, for example an overlap of more than 80%, 90% of the degree of overlap. From the perspective of the side surface 39, the heating device 51 is positioned in the first flow volume 21. Figure 5 As can also be seen schematically in the cross-sectional view in Figure 10 Each fluid chamber or each flow volume 21-24 has a turbulator 41-44. The turbulators 41-44 are firmly connected, for example by brazing, to the respective lower wall, for example the bottom wall 30, and the upper wall, for example the first partition wall 81, by a large-area contact surface 49 (see

[0083] According to this embodiment, the heat transfer allows three modes of operation for the heat transfer:

[0084] (a) a cooling power with heat transfer from the coolant circuit (flow volumes 22, 24) to the refrigerant circuit (flow volumes 21, 23), which is for example up to 15 kW;

[0085] (b) an electrical heating power applied to the refrigerant (refrigerant circuit: flow volumes 21, 23) by means of the heating device 51, which is for example in the order of 4-5 kW in size;

[0086] (c) an electrical heating power applied to the coolant (coolant circuit: flow volumes 22, 24) by means of the heating device 51, which is for example in the order of 6-7 kW in size.

[0087] Figure 6 The arrangement of the turbulators 41-44 is shown in the case of removal of the separating walls and side walls, etc. The turbulators 41-44 fill a large part of the interior space of the flow volumes 21-24 and thus reproduce their stacked arrangement in projection in the height direction 26 perpendicular to the heat conduction direction of the bottom wall 30. The flow volumes 21-24 and the turbulators 41-44 substantially overlap in projection in the height direction 26 perpendicular to the heat conduction direction of the bottom wall 30. Figure 6

[0088] However, here, in the case of the first and third flow volumes 21, 23 for the refrigerant to flow through, a comparatively large volume area is still not filled by turbulators 41, 43, as can be gathered from the exploded schematic view in Figure 7 . The first and third flow volumes 21, 23 each comprise three individual first turbulators 41a, 41b, 41c or third turbulators 43a, 43b, 43c and are divided here in addition by means of dividing walls 46 or 48, so that the turbulators are sequentially flowed through by the refrigerant. Here, the dividing walls 46 or 48 constitute three subspaces from the respective fluid inlet 61, which are separated from one another by turning areas (indicated in Figure 7 by turning arrows). These turning areas are not provided with first and third turbulators in order to effect an efficient turning and to avoid dead angles with only slowly exchanging fluid. For the same reason, the area around the respective fluid inlet and outlet 61, 62 is also kept free.

[0089] It should also be noted that the cross-sectional area or width b1, b2, b3 of the first or third turbulators 41a, 41b, 41c, 43a, 43b, 43c or of the respective subspaces perpendicular to the respective flow direction increases from the fluid inlet 61 towards the fluid outlet 62.

[0090] ​In contrast, in the case of the second and fourth flow volumes 21, 23, which are to be traversed by the coolant, only the regions directly below the associated connection pieces 42a, 42c, 42e and 42f or 44a, 44c, 44e and 44f and the volume regions 42b, 42d or 44b, 44d, which extend from these regions on the end side and in the vicinity of the second and fourth side walls 32, 34, remain open, said volume regions are to ensure a better, i.e. more uniform, traversal of the fluid through the turbulators 42 or 44.

[0091] Figure 8 and Figure 9 A comparison between one of the first turbulators 41, for example the first turbulator 41a, 41b or 41c, and the second turbulator 42 is shown in more detail. In this embodiment, the turbulators are manufactured from flat, plate-like workpieces with a uniform wall thickness, in that a slit is introduced into the turbulators and the workpiece is then periodically folded along a folding direction 47. The slit enables an alternating bending out of the tabs formed by the slit. It can be seen that the wall thickness of the workpiece is greater in the case of the first turbulators 41 than in the case of the second turbulators 42. For example, the wall thickness of the first turbulators 41 is approximately 0.45 mm, while the wall thickness of the second turbulators 42 is approximately 0.3 mm. In both cases, the grid period 45 is approximately 9 mm. The ratio of the grid period 45 to the wall thickness is therefore approximately 20:1 in the case of the first turbulators 41 and approximately 30:1 in the case of the second turbulators 42.

[0092] Figure 10 A comparison between one of the first turbulators 41, for example the first turbulator 41a, 41b or 41c, and one of the third turbulators 43, for example the third turbulator 43a, 43b or 43c, is shown. Here, the wall thickness can, but need not, be chosen to be the same. In contrast, here the grid period 45 varies between the turbulators 41 and 43. The grid of the third turbulators 43 has a substantially increased grid period 45, which leads to a significantly reduced flow resistance in the third flow volume 23, since there are fewer fine structures per volume which impede the flow.

[0093] In Figure 11 and Figure 12 An alternative embodiment shown in is a heat exchanger 1 which has seven flow volumes. In comparison with the embodiment according to Figures 1 to 10 the heat exchanger additionally has a fifth flow volume 27, a sixth flow volume 28 and a seventh flow volume 29. It is shown by means of dashed arrows how the coolant can flow through the flow volumes in Figure 11 Figure 12 ​How the coolant can flow through the flow volumes, i.e. how the flow volumes are fluidically connected to each other.

[0094] In Figure 12 , the dotted arrows show the coolant flow path 75. The second flow volume 22, the fourth flow volume 24 and the sixth flow volume 28 are fluidically connected in such a way that the second, fourth and sixth flow volumes can be traversed in parallel by coolant.

[0095] In Figure 11 , the dotted arrows show the refrigerant flow path 74. The first flow volume 21, the third flow volume 23, the fifth flow volume 27 and the seventh flow volume 29 are fluidically connected in such a way that the first and third flow volumes 21, 23 and the fifth and seventh flow volumes 27, 29 can be traversed by refrigerant parallel to each other, respectively. In addition, the fifth and seventh flow volumes 27, 29 can be traversed by refrigerant sequentially with the first and third flow volumes 21, 23.

[0096] In Figure 11 , all features not shown in Figure 12 can be implemented in a similar way as in the embodiment shown in Figures 1 to 10 , wherein the fifth and seventh flow volumes 27, 29 can be designed in a similar way as the third flow volume 23 and the sixth flow volume 28 can be designed in a similar way as the fourth flow volume 24, especially with respect to the internal flow path, the side wall and the turbulator. Unlike in the embodiment shown according to Figures 1 to 10 , in the embodiment shown in Figure 11 and Figure 12 , the fluid outlets 61, 61 are configured on the bottom wall 30 (not shown).

[0097] Completely different embodiments are possible. For example, it can be provided that, instead of the fluid chamber stacks being finally closed with a bottom wall in the manner described above, no housing cover is arranged on the other side of the heating device 51, but rather there is rather an additional bottom wall from which the respective fluid chamber stack continues in the opposite direction. In any case, in a sandwich / layer construction of the flow volumes, the heating device is arranged between two flow volumes. Here, the planar heating device 51 can release its heat in both (opposite) directions. The associated flow volumes for refrigerant and coolant can be connected to one another respectively correspondingly between the stacks. In principle, this is a heating device 51 integrated in a single stack in a manner located in the middle, which is directly adjacent to the flow volume guiding refrigerant on at least one side. It is also possible and preferred that the flow volume guiding refrigerant is adjacent to the heating device 51 on both sides across the associated wall, so to speak, the arrangement is mirror-symmetrical with respect to the heating device. These embodiments for a sandwich / layer construction specifically can be combined with all features given for example in the attached claims.

[0098] List of reference signs

[0099] 1 heat transfer

[0100] 10 control module

[0101] 11 control housing

[0102] 12 high-voltage plug-in connection socket

[0103] 13 low-voltage plug-in connection socket

[0104] 14 control housing cover

[0105] 20 heat transfer module

[0106] 21 first flow volume (refrigerant circuit)

[0107] 22 second flow volume (coolant circuit)

[0108] 23 third flow volume (refrigerant circuit)

[0109] 24 fourth flow volume (coolant circuit)

[0110] 26 heat conduction direction or height direction

[0111] 27 fifth flow volume (refrigerant circuit)

[0112] 28 sixth flow volume (coolant circuit)

[0113] 29 seventh flow volume (refrigerant circuit)

[0114] 30 bottom wall

[0115] 31 first side wall

[0116] 32 second side wall

[0117] 33 third side wall

[0118] 34 fourth side wall

[0119] 35 upper top wall

[0120] 36 hole for mounting control housing

[0121] 37 opening for passing through a line

[0122] 38 side surface of bottom wall (facing fluid chamber stack)

[0123] 39 side surface of bottom wall (facing heating device)

[0124] 41 first turbulator

[0125] 42 second turbulator

[0126] 43 third turbulator

[0127] 44 fourth turbulator

[0128] 45 grid period

[0129] 46 dividing wall

[0130] 47 flow preferential direction

[0131] 48 dividing wall

[0132] 49 contact surface

[0133] 51 heating device

[0134] 52 heating element

[0135] 61 first fluid inlet

[0136] 62 first fluid outlet

[0137] 65 first accommodation (for expansion valve)

[0138] 66 second accommodation (for temperature sensor)

[0139] 71 second fluid inlet

[0140] 72 second fluid outlet

[0141] 73 main flow direction

[0142] 74 refrigerant flow path

[0143] 75 coolant flow path

[0144] 81 first partition wall

[0145] 82 second partition wall

[0146] 83 third partition wall

[0147] 90 cross-sectional area perpendicular to the main flow direction in the flow volume or partitioned space, respectively.

Claims

1. A heat transfer device (1) for transferring heat between a coolant and a refrigerant, preferably for use in a vehicle, wherein, The heat exchanger (1) comprises a heating device (51) for heating refrigerant and coolant, the heat exchanger furthermore comprising: a bottom wall (30) which constitutes an end-side end of a stack consisting of at least two flow volumes (21, 22) which are traversed by refrigerant or coolant; a first flow volume (21) for being traversed by refrigerant, which first flow volume adjoins the bottom wall (30), which first flow volume is connected with a first fluid inlet (61) and with a first fluid outlet (62), which first fluid inlet and first fluid outlet are intended for establishing a connection to a refrigerant circuit, wherein the first flow volume (21) is additionally determined by a first partition wall (81) which opposes the bottom wall (30); a second flow volume (22) for being traversed by coolant, which second flow volume adjoins the first partition wall (81) and opposes the first flow volume (21), which second flow volume is connected with a second fluid inlet (71) and with a second fluid outlet (72), which second fluid inlet and second fluid outlet are intended for establishing a connection to a coolant circuit, characterized in that the heating device (51) is arranged on the bottom wall (30) on a side which opposes the first flow volume (21).

2. Heat exchanger (1) according to claim 1, wherein at least one first turbulator (41; 41a, 41b, 41c) is intended in the first flow volume (21) for being traversed by refrigerant; and preferably, at least one second turbulator (42) is also intended in the second flow volume (22) for being traversed by coolant.

3. Heat exchanger (1) according to claim 2, wherein for the purpose of heat conduction from the bottom wall (30) to the partition wall (81), the at least one first turbulator (41; 41a, 41b, 41c) is fastened not only on the bottom wall (30) but also on the opposing first partition wall (81), the fastening preferably being effected by brazing.

4. Heat exchanger (1) according to claim 3, wherein the bottom wall (30) and the first partition wall (81) are arranged substantially parallel to one another, wherein a heat conduction direction (26) extends perpendicular to the bottom wall (30) and to the partition wall (81), and The bottom wall (30) has a first thermal conductance value (G th1 ) with respect to its cross-sectional area perpendicular to the heat conduction direction (26), and the at least one first turbulator (41 ; 41 a, 41 b, 41 c) has a second thermal conductance value (G th2 ) with respect to the cross-sectional area of the first flow volume perpendicular to the heat conduction direction, in case of a plurality of first turbulators, the totality of the plurality of first turbulators has a second thermal conductance value with respect to the cross-sectional area of the first flow volume perpendicular to the heat conduction direction, wherein the second thermal conductance value (G th2 ) of the at least one first turbulator (41 ; 41 a, 41 b, 41 c) or respectively the second thermal conductance value of the totality of the first turbulators is 10% or more, preferably 11 % or more, further preferably 12% or more of the first thermal conductance value (G th1 ).

5. Heat exchanger (1) according to claim 3 or 4, wherein the at least one first turbulator (41; 41a, 41b, 41c) has a grid structure with a grid period (45), which grid structure is formed by an accordion folding of a flat workpiece having a first wall thickness.

6. Heat exchanger (1) according to claim 5, wherein the ratio of the grid period (45) to the first wall thickness is 20:1 or less.

7. Heat exchanger (1) according to any one of claims 2 to 6, wherein At least two, preferably three first turbulators (41a, 41b, 41c) are established in the first flow volume (21) for the refrigerant to flow through, Furthermore, in the first flow volume (21) at least one dividing wall (48) is comprised which extends between the bottom wall (30) and the first partition wall (81), in the case of three first turbulators (41a, 41b, 41c) two dividing walls (48) are comprised which extend between the bottom wall (30) and the first partition wall (81), the dividing walls dividing the first flow volume (21) in such a way that the refrigerant from the first fluid inlet (61) to the first fluid outlet (62) sequentially flows through the at least two or three first turbulators (41a, 41b, 41c).

8. Heat transfer (1) according to claim 7, wherein The cross-sectional area (90) determined perpendicular to the respective flow direction in the sub-volume of the first flow volume (21) formed by the bottom wall (30), the first partition wall (81) and the dividing wall (48) and filled by the respective first turbulator (41a, 41b, 41c) increases from the first fluid inlet (61) to the first fluid outlet (62), respectively.

9. Heat transfer (1) according to claim 7 or 8, wherein The at least two first turbulators (41a, 41b, 41c) have a grid structure with a grid period (45), the grid structure preferably being formed by an accordion folding of a flat workpiece along a folding direction, The grid structure respectively determines a flow preferential direction (46) perpendicular to the folding direction, in which flow preferential direction the flow resistance is minimal, and The at least two first turbulators (41a, 41b, 41c) are arranged in such a way that their respective flow preferential direction (46) is oriented parallel to the respective existing flow direction of the refrigerant.

10. Heat transfer (1) according to any one of claims 2 to 9, wherein In the second flow volume (22) for the coolant to flow through at least one second turbulator (42) is also established, the second turbulator (42) having a grid structure with a grid period (45), the grid structure preferably being formed by an accordion folding of a flat workpiece along a folding direction, The grid structure respectively determines a flow preferential direction (46) perpendicular to the folding direction, in which flow preferential direction the flow resistance is minimal, and The second turbulator (42) is arranged in such a way that its flow preferential direction (46) is oriented transversely to the main flow direction (73) of the coolant.

11. Heat transfer (1) according to claim 5 or 6, wherein The second flow volume (22) is delimited by a second partition wall (82) opposite the first partition wall, a third flow volume (23) for the passage of refrigerant is adjoined to the second partition wall (82), the third flow volume being connected to the first fluid inlet (61) and the first fluid outlet (62), and in the third flow volume (23), a configuration with at least one third turbulator (41; 41a, 41b, 41c) is implemented in the same way as in the first flow volume (21), but wherein, a third wall thickness of the third turbulator (43; 43a, 43b, 43c) is smaller than a first wall thickness of the at least one first turbulator (41; 41a, 41b, 41c), wherein, preferably, the ratio of the grid period (45) of the at least one third turbulator (43; 43a, 43b, 43c) to the third wall thickness is greater than 20:

1.

12. Heat transfer (1) according to any one of claims 2 to 11, wherein the at least one second turbulator (42) substantially fills the second flow volume (22), except for two areas immediately adjacent to the fluid inlet (71) or the fluid outlet (72) which extend transversely to an imaginary connecting line between the second fluid inlet (71) and the second fluid outlet (72).

13. Heat transfer (1) according to any one of claims 2 to 11, wherein at least the at least one first turbulator (41; 41a, 41b, 41c) is formed from an aluminum alloy, which preferably has magnesium and / or silicon.

14. Heat transfer (1) according to any one of claims 2 to 12, wherein the fluid inlet (61) and the fluid outlet (62) of the first flow volume (21) for the passage of refrigerant are configured as a stub, wherein at least the stub of the fluid inlet (61) is provided with a receptacle (65) for an expansion valve of a refrigerant circuit; and / or wherein the stub of the fluid inlet (61) and / or the stub of the fluid outlet (62) is provided with a receptacle (66) for a temperature sensor.

15. Heat transfer (1) according to any one of claims 1 to 14, wherein the heating device (51) comprises one or more heating elements (52) having a heating conductor layer, which is formed on the bottom wall (30) or on a substrate mounted on the bottom wall, in which a heating conductor circuit is configured.

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