Electric liquid heating part for vehicle

Abstract

The invention relates to an electric heating device (10), in particular an electric liquid heater for a vehicle, comprising: a heating element (20, 60a, 60b, 60c), which is designed to convert electrical energy supplied to the heating element into heat; and a heat exchanger (10) which is thermally operatively connected to the heating element (20, 60a, 60b, 60c) and is designed to transfer heat supplied to the heat exchanger by the heating element (20, 60a, 60b, 60c) to a fluid (F) flowing through the heat exchanger. The invention relates to a heat exchanger (10) having a flat fluid chamber (120) which defines a heat exchanger region, a fluid inlet (12), a fluid outlet (14), and a turbulator (40) for heat transfer, the turbulator being arranged in the fluid chamber (120), the fluid chamber (120) being formed by delimiting walls (161-165, 181). In the heat exchanger region of the fluid chamber (120), in particular on the turbulator (40), and / or in the region of the delimiting wall opposite the turbulator, at least one flow diverting device is formed. The flow diverting device is designed to influence the flow direction of the fluid through the fluid chamber.

Description

TECHNICAL FIELD

[0001] The present invention relates to an electric heating device, in particular a liquid electric heating device for a vehicle. BACKGROUND

[0002] Known electric heating devices, in particular for vehicles, in particular electric and / or hybrid vehicles, generally comprise an electric heating conductor layer which is arranged adjacent to a heat exchanger and converts electrical energy supplied to the electric heating conductor layer into heat. The heat is transferred to the heat exchanger, which is traversed by a fluid, which is thus heated. The heated fluid is conveyed via a fluid outlet or outflow of the heating device, for example to a fluid circuit via which the fluid is transported to a place where it is desired to release heat in a desired manner. The cooled fluid is then conveyed via the fluid circuit again to the heat exchanger, into which it again enters via a fluid inflow or inlet, in order to be heated again therein.

[0003] The heating power is generally set by a controller. The setting of the heating power can be related to the temperature which the fluid has when it leaves the heat exchanger. This temperature can be determined or detected by means of a temperature sensor. The temperature sensor is therefore generally placed in the vicinity of the fluid outlet. For this purpose, essentially two process variants are available to date: On the one hand, the temperature sensor can be placed externally in the wall of the heat exchanger close to the fluid outlet for the coolant, preferably in a region in which the fluid which is traversed on the inside (during the traversal having a locally different temperature) has again mixed sufficiently due to the flow conditions. For this purpose, a corresponding recess, for example a blind hole or a similar structure, can be configured in the wall.

[0004] But this process variant presupposes that the coolant outlet region is correspondingly accessible around the fluid outlet and that a structural implementation with sufficient thermal and mechanical connection can be implemented on the wall of the heat exchanger. Furthermore, it must be ensured that on the inside of the implementation location the fluid is indeed mixed sufficiently due to the specific flow conditions in order to be able to detect the average coolant temperature. This is generally possible when there is a sufficiently large flow volume (fluid flow per time) and / or a sufficiently large space capacity between the heat exchanger region and the implementation location of the temperature sensor. However, meeting these requirements entails disadvantages in terms of space, weight and costs.

[0005] On the other hand, the temperature sensor can also be placed directly in the coolant or fluid, i.e. in the interior space of the heat exchanger. For this purpose, a perforation through the wall of the heat exchanger into its interior space or hydraulic region is required, again as close as possible to the fluid outlet region in order to obtain the temperature which is implemented for the regulation circuit in the heat transfer.

[0006] But this leads to the necessity of implementing a sealing bore for the cable connection or a sealing thread for a temperature sensor implemented directly in the coolant or the through-flowing fluid, which increases the costs and outlay. Furthermore, especially in the case of a high-voltage heater, if the sealing of this bore is insufficient or deteriorates, a leakage can always have a critical influence in terms of electrical short-circuit in the high-voltage region, for example the adjoining control electronics, thus influencing the safety of the entire system. In addition to this, even in the case of a bore, the coolant or the fluid must be mixed sufficiently in order to obtain a uniform temperature distribution over the flow cross-section at the location of the temperature sensor, so that the respective detection value is representative for the average temperature.

[0007] Overall, there is a need to reduce the costs and outlay necessary for the temperature detection necessary for regulating the heating power and to eliminate the restrictions in terms of installation space or weight required in the vehicle. SUMMARY

[0008] According to various aspects of the present application, an electric heating device, in particular a liquid electric heating unit for a vehicle, can contribute to meeting these needs, the electric heating device comprising at least one heating element, which is designed for converting electrical energy supplied to the heating element into heat, and a heat exchanger, which is in a heat-acting connection with the at least one heating element and is designed for transferring heat supplied to the heat exchanger by the heating element to a fluid through-flowing the heat exchanger.

[0009] The heat exchanger has a flat fluid chamber, which defines a heat exchanger region therein. Furthermore, the heat exchanger has a fluid inlet, a fluid outlet and a turbulator for heat transfer, which is arranged in the fluid chamber, wherein the fluid chamber is composed of a delimiting wall.

[0010] Within the heat exchanger region of the fluid chamber, in particular at the turbulator, and / or in the region of the delimiting wall opposite the turbulator, at least one flow deflection means is configured, which is designed for influencing the flow guidance of the fluid through the fluid chamber. According to embodiments, the flow deflection means can be formed in different ways. It has been found, however, that they particularly advantageously come into play when these structural measures for flow deflection are implemented within the heat exchanger region and not (only) externally.

[0011] In particular, by providing at least one flow deflection device, a desired mixing of the coolant or fluid over the interior space of the fluid chamber can be achieved. More specifically, by means of the at least one flow deflection device, a sufficient mixing can be achieved at a desired, i.e. prescribed, location of the fluid chamber, which can be spaced apart from the fluid outlet concerned. This location can be adjacent to or in the vicinity of the mounting point of the temperature sensor, which is considered reasonable or appropriate for constructional reasons (e.g. as an external prescription). Here, the flow deflection device is so provided and arranged that the heat absorbed in the deflected flow up to this location is mixed by the flow and corresponds to an average temperature, which is representative for the thermal state of the fluid subsequently discharged.

[0012] The temperature sensor detecting this temperature now no longer needs to be mounted by means of a perforation through the delimiting wall of the interior space in order to detect as "close" to the fluid as possible, but can be placed externally in the vicinity of this selected location (or of several selected locations, even in a larger area in which a good mixing is achieved), thus saving costs and effort for the implementation and increasing the system safety, since it is now not necessary to worry about leaks.

[0013] Furthermore, an increased spacing from the fluid outlet is also possible, since by means of the improved mixing, a reliable temperature value can be taken which is in a fixed relationship in the vicinity of the temperature value which the fluid actually has when leaving the heat exchanger through the fluid outlet. For example, for a corresponding temperature difference of a maximum of 2°C, a wide area of the outer surface of the heat exchanger can be considered as a possible mounting point for the temperature sensor, if the flow guidance is influenced accordingly by implementing one or more (optionally also by a combination of different types of flow deflection devices). For a given heat exchanger layout and a given operating point (defined by heating power, fluid outlet temperature and volume flow), the positioning, size and orientation of the flow deflection device, etc. can be taken by means of, for example, simulations. For example, a desired location or desired area on the outer surface of the heat exchanger can be prescribed, and then based on this prescription, the exact implementation of the flow deflection device is calculated in a computer-aided simulation.

[0014] Various embodiments of the flow deflection device are described below. Their function can be to dampen the pressure and / or to influence the direction of the flow guidance only.

[0015] But first some terms should be explained: Vehicle is to be understood basically as all possible mobile applications, in particular passenger cars, lorries, construction machines, aircraft and ships. This also includes, for example, construction machines or cranes and trailers, which can be towed and transported by other vehicles, for example motor homes.

[0016] The term "liquid heating section" as used herein refers to a liquid heat transfer medium / fluid flowing through the heating section that transfers heat to the heat exchanger circuit. This heat transfer medium / fluid is particularly a liquid coolant in a vehicle, which carries heat within the vehicle and can release heat at different locations. Alternatively, the liquid heating section can also be a component of a vehicle heat pump, such that the heat transfer medium / fluid can be, for example, the refrigerant of the heat pump. It is possible here that the refrigerant may exist only under certain conditions and temporarily or possibly never in a completely liquid form, but may also be partially or completely gaseous. Nevertheless, this is also understood as a liquid heating section.

[0017] The liquid heating element preferably has a heating power of at least 5 kW, more preferably at least 7 kW, and for example at least 9 kW. The heating power is preferably less than or equal to 13 kW. The operating voltage of the vehicle heating element (which can be equivalent to the on-board voltage of an electric vehicle) can be greater than or equal to 400 V, preferably greater than or equal to 700 V, for example 800 V, 900 V, or 1000 V. The liquid heating element has at least one heating element. The heating element may include a heating conductor layer. Preferably, the liquid heating element has at least two heating elements, and particularly preferably at least three heating elements.

[0018] The heating conductor layer may have a preferred corresponding heating conductor circuit. The heating conductor layer and the heating conductor circuit can be arranged together on a single carrier element. Preferably, each heating conductor layer or each heating conductor circuit is applied to its own separate carrier element. This carrier element can also be the wall or plate of a heat exchanger, allowing the heat exchanger and heating element to share individual elements.

[0019] The heating element can be implemented in various ways, and the present invention is not limited to its defined embodiments. The heating element can, for example, be composed of a thermal spray coating. Atmospheric plasma spraying can be used as a coating method in manufacturing. It is also possible to apply the heating element to both sides, i.e., also on the bottom wall. Starting from the planar plate, the layer structure is formed first as an optional adhesive substrate, then as an insulating ceramic layer, the actual heating conductor layer, and, if necessary, a covering layer or protective layer. The heating conductor layer can be structured by laser or with the aid of masking. The material of the heating conductor can be a material with linear or PTC resistance characteristics.

[0020] In addition, polymer-based heating elements with PTC properties can be considered. These can be heating elements made of plastic films. Heating elements are typically constructed from an extruded or laminated polymer matrix, in which heating conductors and positive and negative electrodes are embedded.

[0021] In addition, the heating element can also be a ceramic heating element with PTC characteristics (positive temperature coefficient semiconductor element).

[0022] In addition, the heating element can be implemented as a thick-coated heating element. Here, the carrier element can also be a plate of a heat exchanger. A thick-coated heating element, which can be a dielectric and a heating conductor, is applied to the carrier element to form a flat heating resistor.

[0023] Alternatively, the heating element can be implemented as a ceramic substrate (as a carrier element), for example made of Al2O3, with a screen-printed heating conductor layer. Here, the heating conductor layer can be constructed, for example, as a metallization formed of a resistance alloy, which forms the corresponding heating resistor. Iron-nickel alloys or nickel-chromium alloys are considered. The insulating interruption section is responsible for structuring the long conductor circuit (which is otherwise a layer that is surface-coated and subsequently fired), and can be generated, for example, during the coating process by screen printing. The ceramic substrate can be a ceramic carrier plate. According to aspects of the invention, such an embodiment of the heating element is preferred.

[0024] In the case of polymer-based heating elements with PTC properties, ceramic heating elements with PTC properties, or heating elements on ceramic substrates with screen-printed heating conductor layers, the surface heating element can be applied as an adhesive layer to the outside of a cover wall typically implemented as a flat plate using a heat transfer medium, such as a thermally conductive adhesive. The heat transfer medium and the heating element can be applied using a clamping device.

[0025] It is worth noting that, according to embodiments of the present invention, heating elements can also be applied to both sides of the heat exchanger, i.e., applied to the cover wall and the bottom wall.

[0026] The heat exchanger itself can be made of, for example, steel or aluminum, preferably aluminum. According to a particular embodiment, the boundary walls constituting the flat fluid chamber of the heat exchanger include a cover wall, a bottom wall opposite the cover wall, and narrow side walls connecting them, wherein the fluid inlet and fluid outlet are constructed in the bottom wall. According to embodiments, the basic structure can be formed in a flat cubic shape, but it is not required that the opposing walls be parallel to each other. Instead, they can also be formed at an angle. Furthermore, the boundary walls do not necessarily have to be planar, but may have arched or rounded shapes. The cover wall and bottom wall are preferably formed planarly and extend substantially along the plane defined by the heat exchanger.

[0027] The heat exchanger may also be referred to as a plate heat exchanger or implemented as a plate heat exchanger. This means that the structural height perpendicular to the cover wall, which is essentially constructed as a flat plate (on which the heating element may be mounted, or which itself forms the heating element), is significantly smaller than its width and length extending parallel to the cover wall. The ratio of the structural height to the length / width of the heat exchanger may, for example, be less than 1:2, preferably less than 1:4, more preferably less than 1:8, and in some cases even less than 1:16. However, for the purposes of this document, a plate heat exchanger should not be construed as an embodiment consisting of a plurality of corrugated profile plates in some places, wherein the medium to be heated and the medium to be exothermic flow alternately in successive gaps. For the purposes of this document, a plate heat exchanger preferably comprises only one fluid chamber, such that the plate heat exchanger is only suitable for heat transfer of one fluid and not for heat transfer between two fluids. The heat exchanger is preferably a metal plate heat exchanger.

[0028] According to an embodiment, the heat exchanger is preferably constructed as a two-piece unit. The heat exchanger may have a bottom component and a cover component, which are connected to each other, material-locked, and if necessary, form-locked and / or force-locked, together with the turbulence generator described below, particularly by brazing or fusion welding. The bottom wall may form part of the bottom component together with the side walls, and the cover wall may form part of the cover component, preferably constructed as a flat plate. The cover wall and the cover component may be identical.

[0029] The turbulence generator can have a preferably fine structure and may include a mesh structure. The turbulence generator preferably has at least thermal conductive contact with the cover wall so that heat transferred through the cover wall is directed into the mesh structure around which the flow passes, allowing the fluid to efficiently absorb heat due to the large contact area between the fluid and the mesh. The turbulence generator can transform fluid flow into the interior space into turbulence, allowing for better mixing of the fluid flowing through the interior space, thereby further improving the efficiency of the heat exchanger. The mesh-like turbulence generator can be made, for example, from a single metal plate. For manufacturing, slots can first be stamped into the metal plate. Subsequently, the mesh structure of the turbulence generator is formed, for example, by "accordion-like" folding. The turbulence generator can be made of the same material as the bottom wall and / or the cover wall. Preferably, the turbulence generator is also fastened to the bottom wall to prevent dynamic arching under the high pressure of the flowing fluid and thus altering the hydrodynamic conditions. The material thickness of the turbulence generator can, for example, correspond to, the wall thickness of the bottom wall and / or the cover wall, or at least be within a similar range. Instead of using a coherent grid-like turbulence generator, the bottom wall and / or cover wall can also have multiple protrusions that extend into the internal space in the assembled state, thus forming a grid-like turbulence generator there as well. Other embodiments for the heat transfer mechanism are also possible. In a top view perpendicular to the cover wall direction, the turbulence generator and the heating element are preferably substantially identical in their area coverage, i.e., completely overlapping.

[0030] According to one embodiment, the flow diversion device is configured as an outwardly pointing bulge that enlarges the fluid chamber within one or more boundary walls. This bulge then forms a channel within the heat exchanger region, internally bounded by a turbulence generator, through which fluid can flow across the turbulence generator. This is, in part, a flow bypass that affects the overall flow distribution within the turbulence generator.

[0031] Embodiments of the present invention enable the near elimination of non-turbulent inflow or outflow regions, resulting in a very compact, flat structure for the heat exchanger. Internally, only space is required for the heat exchanger region, into which the fluid inlet and outlet can directly converge. However, this typically also eliminates the free space for pre-distributing the flow, thus the heat exchanger can no longer be traversed with the same degree of uniformity (parallel flow with substantially the same intensity across the cross-section).

[0032] However, more complex geometries can now be achieved. For example, the fluid inlets no longer need to be positioned at opposite ends, but can be laterally, particularly perpendicular to the plane defined by the cover wall, directly introducing the fluid into the heat exchanger region, where it diffuses from the inlet. Due to symmetry, the flow is no longer inherently uniform, but can be, for example, partially directed towards the opposite fluid outlet, and possibly also initially towards the sidewall (then these flows also turn towards the fluid outlet). The channels formed by the ridges function here in such a way that they influence the flow conditions, causing the flow components to mix more uniformly, thereby reducing temperature differences. In particular, a favorable reduction in pressure loss in the heat exchanger region is achieved through these channels.

[0033] One particularly advantageous embodiment features a recessed, outwardly pointing, enlarging bulge in the fluid chamber that is a dome-shaped structure constructed within the bottom wall and forms a channel adjacent to the fluid inlet or outlet above the turbulent. This dome-shaped structure allows fluid to flow locally across the turbulent, thus efficiently introducing it from the fluid inlet into the turbulent, or conversely, exiting it from the fluid outlet.

[0034] The dome-shaped structure preferably extends in a predetermined direction from the fluid inlet or fluid outlet. In particular, the dome-shaped structure can extend toward the middle region of the bottom wall. These embodiments have proven particularly advantageous, especially when the fluid outlet and / or fluid inlet are oriented perpendicular to the plane of the heat exchanger or the cover wall, and positioned toward the corners of the bottom wall.

[0035] Furthermore, according to a particular embodiment, the cross-section of the dome-shaped structure can continuously decrease as the distance from the fluid inlet or outlet increases. This results in a gradual change in flow conditions across the cross-section away from the inlet or towards the outlet. Preferably, the fluid inlet and fluid outlet are each associated with a dome-shaped structure. More preferably, the arrangement of the walls, fluid inlet and fluid outlet, and dome-shaped structures is symmetrical, particularly mirror-symmetrical or point-symmetrical.

[0036] An alternative (or advantageously combined with a domed structure in the heat exchanger) implementation is provided in which the recessed, outwardly pointing, enlarging bulge of the fluid chamber is configured as a Überstrom, which is constructed in one of the sidewalls extending along or parallel to the line connecting the fluid inlet and outlet. This enables Überstrom between the edge of the turbulent and the sidewall, allowing fluid components that would otherwise have flowed a longer path through the turbulent to flow more rapidly, thus conveying them to a location of faster mixing. In particular, this also reduces undesirable pressure losses.

[0037] Instead of, or advantageously added to, such an outward bulge to reduce pressure loss within the heat exchanger, a flow diversion device can also be a section that narrows the cross-section of the fluid chamber in a direction perpendicular to the connecting line between the fluid inlet and outlet. This intervention itself leads to an increase in pressure loss. However, it can bring further advantages. The liquid heater operates at a predetermined operating point, which involves heating power, fluid outlet temperature, and volumetric flow rate. The volumetric flow rate does not necessarily need to be known in control, as the heating power is usually regulated by temperature. For heaters with high volumetric flow rates (e.g., 900 L / h or higher), the geometry (size, design) of the heat exchanger may already be designed so that even the feature of a flow diversion device that narrows the cross-section is unnecessary, because sufficient flow has already occurred in the internal space or heat exchanger region at such high volumetric flow rates. Now, in practice, electric heaters with lower volumetric flow rates (e.g., 600 L / h) can use heat exchangers of essentially the same structure (same geometry, size, design). This saves development costs and allows for the manufacture of the same components in larger batches. Furthermore, it offers vehicle manufacturers the possibility of providing the same installation space for all vehicle models involved, where the selection of the specific volumetric flow rate of the liquid heating element only needs to be made during installation. In this case, where the current volumetric flow rate is low, the flow conditions inside the heat exchanger can change significantly. In this case, it has been shown that by taking measures (narrowing sections) on individual components of the heat exchanger shortly before assembly to narrow the cross-section, the desired effect can be achieved: better mixing of fluid components, thus providing a larger external surface area available for placing the temperature sensor.

[0038] As a specific embodiment, this section can be constructed within a turbulence generator. The turbulence generator can have a structure with an overall mesh format as described above, wherein the section is provided in particular by a continuous, pin-like closed grid of dots. In the example of stamping a slotted metal sheet, slotted sheets are produced in the sheet, which are alternately pressed outward and inward during manufacturing in an accordion-like folded state. For example, the corresponding sheets can be additionally pressed back before the turbulence generator plate is inserted and secured in the internal space (on the cover and / or bottom components), thereby forming a closed pin-like portion that, in the inserted state, is transverse to the flow direction present in other cases. This thus redirects the flow. The advantage of this variant is that only the insert needs to be modified, and the workload is minimal.

[0039] According to other embodiments not shown, such locking pins may have been formed from two or three adjacent sheets pressed in the same manner to one side or the other. Alternatively or additionally, multiple such small locking pins may be alternately combined with the permeable areas of unchanged sheets (grid points) to achieve, overall, a locking pin with a certain degree of permeability, i.e., increased flow resistance. For example, in an alternating arrangement of sheets, defined sheets may be pressed to opposite sides to form double or triple locking pins together with one or two adjacent sheets. The next sheet in a row transverse to the flow direction remains pressed in the opposite direction, allowing flow to pass through. Subsequently, the row, as described above, continues again with double or triple locking pins. It should be noted that it will be apparent to those skilled in the art that, due to structural reasons, such as stamping used to form a general grid structure, it may also result in restricted flow permeability between sheets or grid points that are also positioned in a locking pin.

[0040] Alternatively or additionally, this section can be provided by an embossed portion extending from one sidewall of the bottom wall, especially when the embossed portion is part of the deep-drawn shape forming the bottom component. In particular, the embossed portion can be formed in a sidewall extending along or parallel to the connecting line between the fluid inlet and the fluid outlet.

[0041] According to another aspect of the invention, an electric heating device, particularly a liquid electric heating unit for a vehicle, may include: at least one heating element configured to convert electrical energy supplied to the heating element into heat; and a heat exchanger thermally connected to the at least one heating element and configured to transfer heat supplied from the heating element to the heat exchanger to a fluid flowing through the heat exchanger.

[0042] The heat exchanger is a heat exchanger and accordingly has a flat fluid chamber that defines a heat exchanger region therein. Furthermore, the heat exchanger has a fluid inlet, a fluid outlet, and a turbulence generator for heat transfer, which is arranged within the fluid chamber, wherein the fluid chamber is formed by boundary walls.

[0043] As described above, the heat exchanger has a cover wall, which may be part of a planar, preferably plate-shaped cover component. This cover wall or cover component is thermally connected to a heating element for heat transfer. The electric heating device also includes a temperature sensor. This temperature sensor may be mounted on a circuit board, which is also thermally connected to the cover component or cover wall.

[0044] This is particularly advantageous because the circuit board is thermally connected to the cover wall, much like a heating element. Therefore, the temperature of the fluid can also be approximated at or on the circuit board. The circuit board can also be configured to receive a power switching element for operating the heating element, so that heat generated during the switching process can also be conducted into the fluid. This creates a synergistic effect, namely, the circuit board itself is advantageously provided, and it is also used to implement the temperature sensor with very low overhead, since the attachment for electrical contact already exists or can be implemented with very low overhead.

[0045] According to the embodiments, this aspect can be combined with the above aspects and embodiments, because in particular it also provides the possibility of no longer placing the temperature sensor in the fluid or at the fluid outlet. However, even without the flow diversion device, mounting the temperature sensor on the circuit board has the aforementioned advantages, and this is also possible.

[0046] In a further improvement of this aspect, a controller may be provided, which is connected to a temperature sensor and configured to determine the actual temperature of the fluid flowing out of the fluid outlet during operation based on the temperature value detected by the temperature sensor.

[0047] In another further improvement, the controller can be configured to read an offset value for temperature and add it to the detected temperature value. This offset value preferably corresponds to the difference between the actual temperature value present at the fluid outlet and the detected temperature value, and can be determined experimentally beforehand and stored in a memory accessed by the controller, or as part of the controller itself. This offset value is preferably related to the detected temperature value and / or the current heating power. This can be achieved through a lookup table or through parameters in a simple calculation formula. Attached Figure Description

[0048] The invention described above will now be illustrated by way of example with reference to the accompanying drawings and preferred embodiments.

[0049] The attached diagram shows: Figure 1 A perspective view of the heat exchanger of the electric heating device 1 according to an embodiment of the present invention is shown; Figure 2 Show Figure 1 A schematic perspective view of the cover component of the heat exchanger, on which heating elements are formed; Figure 3 Detailed Figure 2 Top view of the cover component; Figure 4 A schematic cross-sectional view of the electric heating device is shown. Figure 5 Show Figure 1 A perspective view of the bottom component of the heat exchanger, with the inserted turbulence generator; Figure 6 Show Figure 5 A partial perspective view of the turbulence generator; Figure 7 Show Figure 1 A cross-sectional view of the heat exchanger, wherein the fluid inlet and fluid outlet are shown in a partial side view; Figure 8 Show Figure 1 A cross-sectional view of the heat exchanger, in which the fluid inlet and fluid outlet are also shown in cross-section; Figure 9 Show Figure 8 An enlarged view of the cross-section of a fluid inlet, showing a VDA connector with a nominal width of 16. Figure 10 similar Figure 9 However, another VDA connector for the fluid inlet is shown, which has a nominal width of 20. Figure 11 similar Figure 9 Or 10, but shows a conventional fitting for the fluid inlet (for assembly with hose clamps), with a freely selectable profile of 19 mm in diameter; Figure 12 Show Figure 6 turbulence generator; Figure 13 Show Figure 12 The turbulence generator modification scheme includes increasing the grid period in the main flow direction; and Figure 14 Show Figure 13 The modified turbulence generator also increases the grid period in the secondary flow direction. Detailed Implementation

[0050] In the following description of preferred embodiments, it should be noted that various aspects of this disclosure are not limited to the details of the structures and component arrangements shown in the following description and drawings. All embodiments, including those not shown in the drawings, can be practiced or implemented in different ways. Furthermore, it should be noted that the expressions and terminology used herein are for descriptive purposes only and should not be construed as limiting by those skilled in the art. Additionally, in the following description, the same reference numerals in the drawings denote the same or similar features or objects; therefore, in some cases, repeated detailed descriptions of them have been omitted to maintain conciseness and clarity of description.

[0051] Figure 1 A perspective view of a heat exchanger 10 of an electric heating device 1 according to an embodiment of the present invention is shown. The heat exchanger 10 includes a bottom component 16 and a cover component 18, which form a brazed structural assembly and surround a fluid chamber 120 (see [link to documentation]). Figure 4 , Figure 5 , Figure 7 and Figure 8 The fluid chamber 120 includes a fluid inlet 12 and a fluid outlet 14. Furthermore, a turbulence generator 40 (see schematically) is provided within the fluid chamber 120. Figure 4 And in the partially open state of the fluid chamber Figure 5 ).

[0052] The cover member 18 and the bottom member 16 may be made of steel or aluminum, preferably aluminum. The terms bottom member and cover member are subjectively chosen to distinguish them from each other and may be used interchangeably. The chosen terms should not be interpreted restrictively. The bottom member 16 is made of a deep-drawn plate in an internal region. Thus, the bottom member includes a generally cuboid deep-drawn region 17 with sidewalls 161, 162, 163 and 164 and a substantially flat, preferably planar, bottom wall 165, and the bottom member includes a plate-like, completely planar edge region 171. Unlike a strictly cuboid shape, the sidewalls 161-164 are slightly inclined and the edges are rounded.

[0053] The cover component 18 is formed of a completely planar plate in the illustrated embodiment. The cover component 18 forms a cover wall 181. The bottom component 16 and the cover component 18 are bonded together at their edges, in the completely planar regions on both sides, to form an internal space or fluid chamber 120. The cover wall 181, the bottom wall 165, and the side walls 161-164 that connect them form the fluid chamber 120 on the inside.

[0054] Figure 2 With Figure 1 The orientation of the cover component 18 or cover wall 181 is shown relative to its flipped state. A heating element 20 is shown in the purely schematic diagram, which is mounted on the outer surface and arranged opposite the internal space or fluid chamber 120. Figure 2The heating element 20 is not drawn to scale.

[0055] Figure 3 The outer side of the cover component 18 or cover wall 181 is shown in more detail. The heating element 20 is formed by three heating element units 60a, 60b, and 60c, each of which includes a preferably ceramic substrate 42 on which a heating conductor circuit 50 is constructed by screen printing. The heating conductor circuit is formed in a meandering shape in a heating conductor layer made of a resistance alloy by means of insulating breaks. Other forms of heating conductor circuits and other types of heating elements, such as the variations described above, are also possible.

[0056] The attachment point of the conductor circuit 50 is connected to the circuit board 48 via the connecting line 44. Figure 3 The power switching element arranged on the circuit board is not shown, and the heating element units 60a-c can be operated (switched, e.g., PWM) by means of the power switching element. The power switching element can be switched by the controller 46 of the electric heating device 1 via the connection line 47. In addition, power is supplied from the controller 46 via the connection line 47.

[0057] Figure 4 The electric heating device 1 described herein is shown schematically in cross-section.

[0058] exist Figure 1 as well as Figure 5 The image shows flow deflection devices formed in the bottom component 16 and the turbulence generator 40. These are the dome structures 30 and 31, the overflow channel 32, the imprint section 34, and the pin-shaped closed grid point region 405 in the turbulence generator 40. The dome structures 30 and 31, the overflow channel 32, and the imprint section 34 are constructed in the bottom component 16.

[0059] The dome-shaped structure 30 extends from the area of ​​the fluid inlet 12 located near the corner of the bottom wall 165 toward the middle section of the bottom wall 165. The turbulence generator 40 is provided as a grid stamped and accordion-folded on a metal plate, such as... Figure 6 As shown, the turbulence generator has multiple alternating inward and outward pressed fins 401. The mesh is regularly constructed and has a constant thickness in its length and width. A flat, confined channel is thus formed above the turbulence generator 40 by an outwardly pointing, i.e., recessed, raised dome-shaped structure 30 constructed in the bottom wall 16, through which fluid F is fed into the turbulence generator 40 located below. The cross-section of the dome-shaped structure continuously decreases from the fluid inlet 12. A dome-shaped structure 31 is formed in the same manner and in a mirror-symmetrical arrangement on the side of the fluid outlet 14, which is located near another corner of the bottom wall 165. These two corners are connected by a side wall 164.

[0060] likeFigure 7 and Figure 8 As shown, the fluid inlet 12 has an inlet nozzle with a first central axis Z1, and the fluid outlet 14 has an outlet nozzle with a second central axis Z2. The first central axis Z1 and the second central axis Z2 are substantially perpendicular to the plane orientation defined by the flat fluid chamber 120 and, in particular, the cover wall 181. Therefore, the flat dome-shaped structures 30, 31 extend in directions perpendicular to the central axes Z1 and Z2. Here, the first central axis Z1 and the second central axis Z2 extend through the turbulence generator 40 along their extension lines. Since the fluid inlet 12 and the fluid outlet 14 are no longer located in the plane of the bottom wall or the cover wall, a very compact and particularly flat structure without separate inlet or outlet regions is formed. Instead, the dome-shaped structures 30, 31 form only a flat channel that allows flow across the turbulence generator 40.

[0061] Due to the interaction between the dome-shaped structures 30, 31 and the turbulence generator 40 (forming a channel between them), the dome-shaped structures 30, 31 are arranged in the heat exchanger region. This heat exchanger region is characterized by the overlapping projections of the turbulence generator 40 and the heating element 20 in a top view (along the central axes Z1, Z2 of the fluid inlet 12 or fluid outlet 14), wherein the circuit board 48 itself also participates as a heat dissipation element. Therefore, in this case, the entire fluid chamber 120 is defined as the heat exchanger region.

[0062] It is important to note that Figure 7 and Figure 8 The cross section along Figure 1 The AA line extends from it. This line does not intersect with any flow deflectors except in the grid point region 405 within the turbulence generator 40, therefore these flow deflectors (although present) are... Figure 7 or Figure 8 It is not visible in the middle.

[0063] Figures 9 to 11 A variant of the fitting for fluid outlet 14 is shown as an example only. Fluid inlet 12 is provided with a similar fitting design accordingly. Figure 9 It was shown in detail again. Figure 7 and 8 The nozzle at fluid outlet 14. Due to Figures 9 to 11 Along the middle Figure 1 The line of sight of the cross section AA is in the same direction as Figure 7 and Figure 8 Conversely, the vaulted structure 30 can now also be seen. The flange 166, which is formed in the deep-drawn bottom wall 165 of the bottom member 16 and receives the lower, for example, columnar section of the nozzle of the fluid outlet 14, can also be clearly seen.

[0064] Flange 166 has an inner diameter of, for example, 22 or 24 mm. According to embodiments, the nozzle is particularly a separate component. This structure allows for the use of nozzles of different types or sizes (especially those with different inner diameters) without fundamentally altering the heat exchanger for the respective application. The nozzle can advantageously be fastened as required by the customer during heat exchanger assembly, so that "variant forming" is only required in the final process step. The available nozzles only need to have a lower section with an outer diameter matching the inner diameter of flange 166, but other aspects can arbitrarily differ from each other.

[0065] For different nozzles, the fastening part of the nozzle on the bottom part 16 can be brazed to the material of the nozzle in the same step, for example, the bottom part 16 is brazed to the flat, plate-shaped cover part 18.

[0066] Figure 9 The nozzle for the fluid outlet 14 is, for example, a VDA nozzle with an inner diameter (nominal width) of 16 mm. In the case of this particular nozzle, the inner diameter of the nozzle tapers from the receiving section to the opening, for which a nominal width is given. Figure 10 A variant (fluid outlet 14') is shown, which takes the form of a VDA nozzle with an inner diameter (nominal width) of 20 mm.

[0067] Figure 11 It shows the relationship with Figure 9 and Figure 10 The same heat exchanger has a conventional nozzle with hose clamps (fluid outlet 14'', not corresponding to the VDA nozzle). It can be clearly seen here that not only the inner diameter can be different (19 mm), but other designs of the nozzle can also be different.

[0068] exist Figure 1 and 5 As can be seen, an elongated flow passage 32 is arranged on the side wall 162 of the deep-drawing area 17 of the bottom component 16. This flow passage also allows fluid (in this case, lateral) flow to pass over or around the turbulence generator 40.

[0069] Furthermore, starting from the middle region of the opposing sidewall 164, approximately in the middle between the fluid inlet 12 and the fluid outlet 14, the bottom wall 165 is provided with an embossed portion 34 (as an example of a flow diversion device), thereby locally increasing the contact area with the cover wall 181. This causes a narrowing of the cross-section of the fluid chamber, thereby altering, i.e., affecting, the flow guidance within the fluid chamber.

[0070] like Figure 5As shown, in the turbulence generator 40, a row of grids along the extension of the imprinted section 34 is locked in a pin-like manner. This pin-like closed grid dot region 405 extends to the center of the fluid chamber 120, resulting in a further narrowing of the cross-section available for flow, thereby further altering, and thus affecting, the flow direction within the fluid chamber. The pin-like closed grid dot region 405 in the imprinted section 34 and the turbulence generator 400 leads to pressure suppression.

[0071] Figure 1 and Figure 5 The flow diversion devices shown in the diagram collectively induce a defined flow field in the fluid chamber 120. Other combinations, additions, or omissions also significantly affect the flow guidance. These can be adjusted through simulation to achieve good mixing depending on the operating point, thereby providing additional areas on or near the surface of the heat exchanger for temperature sensing, with a temperature difference of only 2°C or less from the fluid outlet temperature.

[0072] exist Figure 3 and Figure 4 As can be seen, temperature sensor 52 is arranged on circuit board 48. This temperature sensor detects the temperature and transmits it to controller 46 via connection line 49. Reference numeral 54 indicates a stamped mesh that provides portions of connection lines 45, 47, and 49 to / from controller 46. Controller 46 can adjust the control of power switching elements (not shown) on circuit board 48 based on the detected temperature. As described above, controller 46 can determine the actual fluid outlet temperature by adding stored offset values, and also by using a lookup table if necessary.

[0073] exist Figures 12 to 14 Another example of a flow steering device is shown in the figure. Figure 12 As the starting point, it is shown Figure 5 or Figure 6 Turbulence generator 40. In Figure 13 In the main flow direction X, the pitch or grid period starts from Px1 ( Figure 12 ) increases to Px2 ( Figure 13 This reduces flow resistance in that direction. Figure 14 In addition, in the secondary flow direction Y, the pitch or grid period changes from Py1 ( Figure 12 Increase to Py2 ( Figure 14 This reduces flow resistance in that direction as well. When applied locally, this effect is similar to that in a crossflow channel.

[0074] The features of the invention disclosed in the foregoing description, drawings, and claims, whether individually or in any combination, may be crucial for realizing the invention. This is particularly true for cumulative considerations of flow diversion devices (as shown), but also for implementing them individually. Furthermore, the temperature sensor may be arranged in other locations than schematically indicated. Figure 4 Neutralization specifically in Figure 3 The location shown is, in particular, on or near the outer surface of the heat exchanger, which does not correspond to circuit board 34, but is also not immediately adjacent to the fluid outlet. In other embodiments, the temperature sensor may be located near or directly at the fluid outlet, or it may be omitted entirely.

[0075] List of reference signs 1. Electric heating equipment, liquid heating equipment 10. Heat exchangers, plate heat exchangers 12 Fluid inlet 14,14',14'' Fluid outlet 16 Bottom Components 161-164 Sidewalls 165 bottom wall 166. Flange in the bottom wall for connecting pipes 17 Deep Drawing Area 171 Planar edge region 18. Cover components 181 Cover Wall 20 Heating elements 30. Arched structure 31. Arched structure 32. Overflow channel 34 Imprinting Section 36 Circuit Boards 40,40a Turbulence generator 40b (Main flow direction) Turbulent flow device with increased pitch 40c (secondary flow direction) turbulent flow device with increased pitch 401 thin film 405 Locking pin 42 Substrate 44 Connection lines (circuit board - heating element) 45. Connection wiring (controller-circuit board: control signals for switching) 46 Controller 47 Connection lines (controller-circuit board: power supply) 48 Circuit Boards 49 Connection wiring (controller-circuit board: temperature detection) 50 Heating conductor circuit 52 Temperature Sensor 54 Stamped Mesh 60a-c Heating element unit.

Claims

1. An electric heating device (1), in particular a liquid electric heating unit for a vehicle, comprising: - a heating element (20, 60a, 60b, 60c) which is designed to convert electrical energy supplied to the heating element into heat; and - a heat exchanger (10) which is in thermal action connection with the heating element (20, 60a, 60b, 60c) and which is designed to transfer heat supplied by the heating element (20, 60a, 60b, 60c) to a fluid (F) flowing through the heat exchanger; - wherein the heat exchanger (10) has a flatly configured fluid chamber (120) which defines a heat exchanger area, a fluid inlet (12), a fluid outlet (14) and a turbulator (40) for heat transfer, which turbulator is arranged in the fluid chamber (120), wherein the fluid chamber (120) is composed of delimiting walls (161-165, 181), - wherein, within the heat exchanger area of the fluid chamber (120), in particular at the turbulator (40), and / or in the area of the delimiting walls opposite the turbulator, at least one flow deflection means is configured, which flow deflection means is designed to influence the flow direction of the fluid through the fluid chamber.

2. The electric heating device (10) according to claim 1, wherein The delimiting walls (161-165, 181) which compose the flatly configured fluid chamber (120) comprise a cover wall (181), a bottom wall (165) opposite the cover wall (181) and narrow side walls (161-164) connecting the cover wall and the bottom wall, wherein the fluid inlet (12) and the fluid outlet (14) are configured in the bottom wall (165).

3. The electric heating device (1) according to claim 1, wherein A further flow deflection means is provided, which is a recessed, outwardly pointing, fluid chamber (120) enlarging bulge in one or more of the delimiting walls (161-165, 181), which bulge constitutes a passage which is delimited internally by the turbulator (40), through which the fluid (F) can flow over the turbulator (40).

4. The electric heating device (1) according to claim 3, wherein The recessed, outwardly pointing, fluid chamber (120) enlarging bulge is a vaulted structure (30, 31) which is configured in the bottom wall (165) and constitutes a passage adjoiningly to the fluid inlet (12) or the fluid outlet (14) above the turbulator (40).

5. The electric heating device (1) according to claim 4, wherein The vaulted structure (30, 31) extends in a predetermined direction from the fluid inlet (12) or the fluid outlet (14).

6. The electric heating device (1) according to claim 5, wherein The vaulted structure (30, 31) extends towards a middle area of the bottom wall (165).

7. An electric heating device (1) according to claim 5 or 6, wherein The cross section of the vaulted structure (30, 31) continuously decreases with increasing distance from the fluid inlet (12) or the fluid outlet (14).

8. An electric heating device (1) according to any one of claims 4 to 7, wherein Preferably, the fluid inlet (12) and the fluid outlet (14) are each assigned a vaulted structure (30, 31).

9. The electric heating device (1) according to claim 3, wherein The recessed, outwardly pointing, enlarged bulge of the fluid chamber (120) is a cross-flow channel (32) which is configured in one of the side walls (162) which extends along or parallel to a connection line between the fluid inlet (12) and the fluid outlet (14).

10. The electric heating device (1) according to claim 2, wherein The flow-turning device is a section which narrows the cross section of the fluid chamber in a direction perpendicular to a connection line between the fluid inlet (12) and the fluid outlet (14).

11. The electric heating device (1) according to claim 10, wherein The section is configured in the turbulence generator (40), wherein the turbulence generator has a generally mesh format, wherein the section is provided by a mesh point area (405), wherein this area is preferably coherent and / or configured as a latch and / or further preferably closed.

12. The electric heating device (10) according to claim 10, wherein The section is provided by an embossing (34) of the bottom wall (165) from one side wall (164), which is preferably a side wall (164) which extends along or parallel to a connection line between the fluid inlet (12) and the fluid outlet (14).

13. An electric heating device (1) according to any one of claims 1 to 9, wherein, The cover wall (181) is part of a cover part (18) which is planar, preferably configured as a plate, which is thermally connected with the heating element (60a, 60b, 60c) for transferring heat, the electric heating device further comprising a temperature sensor (52) which is arranged on a circuit board (48), which is likewise thermally connected with the cover part (18).

14. The electric heating device (1) according to claim 13, further comprising a controller (46) connected with the temperature sensor (52) and arranged for deriving an actual temperature of the fluid (F) flowing out of the fluid outlet (14) in operation from the temperature value detected by the temperature sensor (52), wherein, The controller (46) is preferably set up for reading an offset value for the temperature and adding this value to the detected temperature value, wherein the offset value is further preferably related to the detected temperature value and / or the current heating power.

15. An electric heating device (1) according to any one of the preceding claims, wherein The fluid inlet (12) has an inlet connection with a first central axis (Z1), the fluid outlet (14) has an outlet connection with a second central axis (Z2), - wherein the first central axis (Z1) and the second central axis (Z2) are oriented essentially perpendicular to a plane defined by the flat fluid chamber (120), and / or - wherein the first central axis (Z1) and the second central axis (Z2) extend on an extension line through the turbulence generator (40).

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