Electrical heating of liquid for use in vehicle
By using an insulating interruption section to limit the heating conductor circuit and isolate the attachment area in the liquid heating element, the problem of high-pressure liquid electric heating element generating high heating power efficiently and quickly in a narrow space is solved, achieving a more durable heating effect.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-12
- Publication Date
- 2026-03-13
AI Technical Summary
In high-pressure liquid electric heating sections, how can high heating power be generated efficiently and quickly within a confined space while ensuring product durability and stability?
Design a liquid heating element in which the heating conductor circuit is limited by an insulating interruption in the plane of the heating conductor layer, the attachment area is separated from the electrical attachment side, and is separated from the heating conductor circuit section by the insulating interruption to reduce temperature gradient and mechanical stress.
By reducing temperature gradients and mechanical stress, the durability and heating efficiency of the liquid heating element are improved, ensuring stable operation under high pressure.
Smart Images
Figure CN121666877A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a liquid electric heating element for use in a vehicle and a vehicle electric heating element. Background Technology
[0002] In liquid electric heating units used in vehicles, there exist units where the heating element comprises a heating conductor layer disposed on a carrier element. The heating conductor layer has a heating conductor circuit and an attachment area for electrical contacts to connect the heating conductor circuit. There are many complex degrees of freedom in designing the heating conductor circuit. Furthermore, especially in high-pressure liquid heating units used in vehicles, operating at voltages greater than or equal to 400V, and particularly also at voltages greater than or equal to 700V, the challenge lies in generating very high heating power of 5kW, 8kW, 10kW, or higher as efficiently and quickly as possible within the narrowest possible space, while simultaneously achieving a durable and robust product. Summary of the Invention
[0003] The present invention is based on the objective of providing a liquid heating unit for a vehicle that can better address these requirements than known liquid heating units.
[0004] This task is addressed through the subject matter characterized by independent claims. Favorable configurations and extensions are derived from dependent claims.
[0005] A liquid electric heating element for use in a vehicle is described. The liquid electric heating element has a heating element comprising a carrier element and a heating conductor layer disposed on the carrier element. The heating conductor layer has a heating conductor circuit in a plane defined by at least one insulating interruption. The heating conductor circuit has a first attachment region and a second attachment region on an electrically attached side of the heating conductor layer, in which the heating conductor circuit is electrically connected to at least one electrically attached conductor, respectively. The first attachment region and the second attachment region are spaced apart by a distance d along a connecting line extending straight in the plane of the heating conductor layer, and the heating conductor circuit contacts and / or intersects the connecting line segmentally. A segment of the first heating conductor circuit extends in the plane of the heating conductor layer between the first attachment region and the electrically attached side.
[0006] It has been found that liquid heating elements with such a design can significantly reduce mechanical stress caused by temperature gradients in the material of the carrier element during heating operation, and improve the durability of the liquid heating element. Stress in the material is caused by the electrically attached regions of the heating resistor, which contribute little to heat generation. Heating of the heating conductor layer also occurs between the attached regions due to the crossing and / or contact of the connecting lines between the heating conductor circuit and the attached regions. Additional stress reduction is achieved by spacing at least the first attached region from the electrically attached side and extending a first heating conductor circuit segment between the first attached region and the electrically attached side. This also heats the first attached region on the attached side, unexpectedly and effectively reducing the temperature gradient and potential stress.
[0007] The electrical attachment side is the side of the heating conductor layer on or through which the electrical attachment conductor is electrically connected, either indirectly or directly, to an attachment electronics device, such as a power board or controller for a liquid electric heating unit. The electrical attachment conductor extends from the corresponding attachment area toward and beyond the attachment side. During heating operation, current is supplied to the heating conductor circuit through the electrical attachment conductor, and this current is converted into heating heat.
[0008] "On the electrical attachment side of the heated conductor layer" means that the distance between the first attachment region and the attachment side, as well as the second attachment region, is significantly smaller than the distance between the attachment side and the side opposite to the heated conductor layer. This distance is at least 40%, preferably at least 55%, and particularly preferably at least 65% smaller than the distance between the attachment side and the side opposite.
[0009] A liquid heating element means that the heating element dissipates heat onto a liquid heat transfer medium that circulates through the heating element. This heat transfer medium can be, in particular, a liquid coolant in a vehicle that transfers heat within the vehicle and can dissipate heat at various points. Alternatively, the liquid heating element can also be a component of a vehicle's heat pump, such that the heat transfer medium can be, for example, a refrigerant of the heat pump. In this case, it is possible that the refrigerant exists only under specific conditions and only temporarily, or possibly never, in a completely liquid form, and in other cases is partially or completely gaseous. Nevertheless, this is also understood as a liquid heating element.
[0010] In principle, "vehicle" should be understood to encompass all possible mobile applications, particularly passenger cars, trucks, construction machinery, aircraft, and watercraft. This also includes, for example, construction machinery or cranes, as well as trailers that can be towed and transported by other vehicles, such as motorhomes.
[0011] Preferably, the liquid heating element has a heating power of at least 5 kW, preferably at least 7 kW, and for example at least 9 kW. This heating power is preferably less than or equal to 13 kW. The operating voltage used for the vehicle heating element, which can be the same as the on-board voltage of an electrically driven vehicle, is 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 and at least one heating conductor layer. Preferably, the liquid heating element has at least two heating conductor layers, particularly preferably at least three heating conductor layers, and corresponding heating conductor circuits. Here, the heating conductor layers and heating conductor circuits 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.
[0012] Preferably, the two attachment regions are arranged spaced apart from the surface edges of the carrier element and / or the heating conductor layer, respectively. Here, the surface edges of the carrier element can advantageously be defined by "bending" or "edges" of the surface of the carrier element. Thus, for example in the case of a plate-shaped carrier element, the surface edges of the carrier element can be defined by plate edges.
[0013] The heating conductor circuit can be considered as a region where current flows after a voltage is applied to an existing attachment region. The heating conductor circuit extends from a first electrical attachment region to a second electrical attachment region. Additional heating conductor circuits can be attached directly or seamlessly to the first or second end of the heating conductor circuit. That is to say, the term "end," like "attachment region," does not necessarily imply that the heating conductor circuit actually ends there. Rather, the heating conductor circuit can continue to extend from there, for example, towards a third attachment region. Such a third attachment region can, for example, be arranged at the actual end of the conductor circuit. The heating conductor circuit is particularly laterally defined in the plane of the heating conductor circuit by an insulation break, in which no current flows.
[0014] For example, the insulation interruption may be a region that does not have a heating conductor layer and divides the heating conductor layer into heating conductor circuit segments, which together form the path of the heating conductor circuit between a first end and a second end, and between two, three, or more attachment regions. However, the insulation interruption may also have the material of the heating conductor layer, which is electrically insulated from the heating conductor circuit.
[0015] For example, the attachment region can be defined and / or distinguished from the remainder of the heating conductor circuit by generating significantly less heat in the attachment region during heating operation (compared to a normal heating conductor circuit section of the same size in terms of area). Electrical contact with an external electrical energy source relative to the heating conductor is achieved in the attachment region. The necessary electrical contact connection can include contact connection methods such as laser welding, brazing, or thermal bonding. The heating conductor layer in the attachment region may have an additional coating and / or increased thickness compared to other regions to facilitate the contact connection method and to ensure durable and reliable electrical contact connection. The additional coating may be metallic and, for example, copper. The attachment region or end typically merges into the heating conductor circuit in one or both directions.
[0016] The heating conductor layer can be configured, for example, as a metallized portion made of a resistance alloy, which is the corresponding heating resistor. Insulation breaks can be created in the heating conductor layer, for example, by laser ablation, or have already been created during application using a screen printing process.
[0017] The heating conductor layer plane can represent the surface of the heating conductor supporting the carrier element. If the surface of the heating conductor supporting the carrier element is flat, then the heating conductor layer plane is, for example, a plane oriented parallel to the surface of the carrier element. Even if the surface of the heating conductor supporting the carrier element is curved, the heating conductor layer plane is still parallel to the surface of the heating conductor everywhere. However, the curved heating conductor layer plane is further defined at each point only by a tangential plane that can be determined at all points of the heating conductor layer, or a local plane at the corresponding point.
[0018] In an advantageous embodiment, the liquid electric heating section is configured such that the heating conductor circuit has a minimum heating conductor circuit width b, and the spacing d ≥ b, preferably ≥ 2b. Thus, the attachment area is advantageously distributed on the heating conductor layer, and large temperature gradients are further reduced.
[0019] The width of the heating conductor circuit can be substantially constant along its entire length, resulting in approximately uniform heat generation along the entire path of the heating conductor circuit between the two attachment regions during operation. However, the width of the heating conductor circuit can also vary. Preferably, the minimum heating conductor circuit width b can be greater than or equal to 1.5 mm and less than or equal to 7 mm. Here, it is particularly preferred that the minimum heating conductor circuit width b is between 2.5 mm (inclusive) and 6 mm (inclusive).
[0020] In the center or "center" of a pattern or "layout" constructed by a heated conductor circuit, the area not through which current flows can be located at a radial turning point, which serves to prevent localized overheating in that area of the heated conductor circuit. A connecting line represents a line that always extends within the plane of the heated conductor layer. If the heated conductor layer plane is planar, the connecting line is, for example, a normal straight line in that plane between two attachment regions, and therefore the shortest possible connection between the two attachment regions in that plane. If the heated conductor layer plane is a curved surface locally defined by a tangential plane at each point, the connecting line can be determined by the shortest distance (geodesic) between the two ends within the (curved) heated conductor layer plane, as can usually be determined using geodesic equations.
[0021] In an advantageous embodiment, the portion of the first heating conductor circuit segment extending between the electrical attachment side and the first attachment region is separated from the first attachment region by at least one insulation break. Alternatively, at this location, no insulation break extends, and the first attachment region transitions directly into the first heating conductor circuit segment. In this alternative, the first heating conductor circuit segment may extend, particularly at least partially, from the first attachment region toward the first attachment side.
[0022] In a preferred embodiment of the liquid heating section, the second heating conductor circuit section extends at least around a portion of the second attachment region in the plane of the heating conductor layer, and the second heating conductor circuit section is separated from that portion of the second attachment region by at least one insulating interruption.
[0023] "Extending around the end" means that the section of the heating conductor circuit involved is directly adjacent to the attachment area and / or the end of the heating conductor circuit, and is separated from the end only by at least one insulating break. This allows heat generated in the heating conductor circuit to be transferred to the center of the attachment area via a shorter line segment. This reduces the temperature gradient that occurs during the heating phase.
[0024] In another preferred embodiment of the liquid heating section, the second heating conductor circuit section extends between the second attachment region and the electrical attachment side, and the second heating conductor circuit section is separated from this portion of the second attachment region by at least one insulating interruption.
[0025] Alternatively, in an advantageous embodiment, the second attachment region is disposed directly on the electrical attachment side of the heated conductor layer. In this case, it is preferable to construct the second attachment region and the conductor circuit segment adjacent to it such that the second attachment region extends into the adjacent conductor circuit segment on its side facing away from the attachment side, such that the second attachment region and the conductor circuit segment are adjacent not only to the second attachment region on the side opposite to the attachment side, but also on both sides of the second attachment region laterally. These two sides of the second attachment region may extend substantially perpendicular to the main extension direction of the electrical attachment side. The second attachment region and the adjacent conductor circuit segment are separated from each other by an insulation break. Additionally or alternatively, the second attachment region may have a gap on its side facing the attachment side. All these measures can positively contribute to effectively reducing thermal stress during heating operation.
[0026] Advantageously, the first heating conductor circuit segment can be positioned abutting against the first end, and the second heating conductor circuit segment abutting against the second end. Here, abutting specifically means that the outer contour of the first or second heating conductor circuit segment, i.e., its edge, follows the outer edge of the corresponding end. Furthermore, the heating conductor circuit segments and their respective ends are separated from each other in the abutting segments only by at least one insulating break. In this way, more heat can be more quickly transferred from the heating conductor circuit to the attachment area, further reducing the temperature gradient.
[0027] Advantageously, two first points (A1; B1) can be defined on the edge of the first heating conductor circuit segment extending around a portion of the first attachment region and separated from that portion by at least one insulating interruption, such that a first connecting line VL1 extending straight between these two first points (A1; B1) in the heating conductor layer plane extends through the first end. Additionally or alternatively, two second points (A2; B2) can be defined on the edge of the second heating conductor circuit segment extending around a portion of the second attachment region and separated from that portion by at least one insulating interruption, such that a second connecting line VL2 extending straight between these two second points (A2; B2) in the heating conductor layer plane extends through the second end. That is, at least a section of the protruding edge of the first or second end is directly adjacent to the recessed edge of the corresponding heating conductor circuit segment. In this way, the temperature gradient in the attachment region can also be reduced during the operation of the heating element. It should be noted that not all point pairs (A1; B1) or (A2; B2) of the edge satisfy this condition. However, if the point pairs that meet the required conditions cannot be determined, the relevant heating conductor circuit segment is not attached to the corresponding end in the sense of this patent application.
[0028] Furthermore, the first attachment region and / or the second attachment region can be configured such that they are completely surrounded by heating conductor circuit segments in the plane of the heating conductor layer. In this way, the heat input to the first and / or second ends can be maximized, minimizing the temperature gradient in the end regions during heating element operation. In particular, multiple heating conductor circuit segments can collectively and completely surround a single attachment region, such that different segments are directly adjacent to, extend around, or are in close contact with different regions of the corresponding ends. It should be noted that heating conductor circuit segments originating directly from the attachment region are always considered together, even if they are not separated from the attachment region by an insulation break.
[0029] Alternatively or additionally, at least one insulation interruption may be provided with a width b. I The width of the heating conductor circuit is less than 10%, preferably 5%, of the minimum heating conductor circuit width b. In this way, an insulation interruption with a small area can be provided, which only slightly reduces the overall usable heating surface of the heating conductor circuit, thereby increasing the heating power relative to the usable surface.
[0030] Alternatively, the heating conductor layer can be configured with a protruding surface in its plane, and at least one insulation interruption portion is located within this protruding surface. In this way, the heating conductor layer can be structured with at least one insulation interruption portion to create a heating conductor circuit extending between the attachment regions.
[0031] Advantageously, the area A suitable for heating the conductor layer can be set. S The area A of the heating conductor circuit B and at least one insulation interruption area A I The relationship is: A S = A B A I This, expressed in words, means that the area A of the heated conductor layer... S The area A of the heating conductor circuit B and the area A of at least one insulation interruption I The combined area is obtained. In this way, unused areas in the conductor layer can be avoided from being heated, thus maximizing the heating power relative to the usable surface.
[0032] Furthermore, the carrier element can be configured as a ceramic substrate. The ceramic substrate is advantageous and insulating, allowing the cost of the electric heating element to be kept low. Here, based on the present invention, disadvantages due to low fracture toughness and the potential power or dynamic limitations that may accompany heating can be avoided.
[0033] Here, the ceramic substrate can be configured as a plate. Therefore, the ceramic substrate is flat and level. Plate-shaped substrates are easy to manufacture and can also be easily processed in the heater.
[0034] In an advantageous extension, the ceramic substrate can be fastened to a metal heat exchanger through which the liquid to be heated in the liquid heating section can flow. Particularly preferably, this fastening is achieved by means of adhesive bonding. Attached Figure Description
[0035] The invention is described below by way of example with reference to the accompanying drawings.
[0036] The attached diagram shows: Figure 1 A top view of the first exemplary heating conductor layer of the liquid heating section is shown; Figure 2 Show Figure 1 A magnified view of the left half of the heated conductor layer in the image; Figure 3 A top view showing the second exemplary heating conductor layer of the liquid heating section; Figure 4 A cross-section of a segment of an exemplary heating element in a liquid heating section is shown; Figure 5 A simplified diagram of the vehicle's liquid electric heating section is shown; and Figure 6 A top view of the third exemplary heating conductor layer of the liquid heating section is shown.
[0037] In the following description of the accompanying drawings, the same reference numerals denote the same or similar parts. Detailed Implementation
[0038] Figure 1 A first top view of an exemplary heating conductor layer 16 is shown. Figure 2 Show Figure 1 An enlarged view of the left half of the heating conductor layer 16, in which... Figure 2 For clarity, the text is not shown. Figure 1 The electrically attached conductor 35 is shown in the figure. The heated conductor layer 16 is shown from above, such that the carrier element 14 located below it is almost completely covered by the heated conductor layer 16.
[0039] From the chosen viewing angle towards the heating conductor layer 16, the structuring of the heating conductor layer 16 via the insulation interruption 22 can be clearly seen. With the aid of the insulation interruption 22, a heating conductor circuit 20 with a minimum heating conductor circuit width b is provided in the heating conductor layer 16. (As in conjunction with...) Figure 4As can be seen more clearly, the insulation interruption section 22 is a region without the heating conductor layer 16, which divides the heating conductor layer 16 into heating conductor circuit segments 28, 30, 36, and 40 that are electrically insulated from each other in the lateral direction. These heating conductor circuit segments together form the path of the heating conductor circuit 20 between the first attachment region 32 and the second attachment region 34. The attachment regions may be arranged on the first end 24 and the second end 26 of the heating conductor circuit.
[0040] Two attachment regions 32 and 34 are arranged on the electrical attachment side 17 of the heated conductor layer 16. The distance between the first attachment region 32 and the attachment side 17 is only about the sum of the minimum circuit width b and the minimum width of the insulation interruption 22. The distance between the first attachment region and the side opposite the electrical attachment side 17 is more than 10 times greater. For example, this distance can be greater than or equal to 3 times, preferably greater than or equal to 8 times, and particularly preferably greater than or equal to 12 times.
[0041] A heating conductor circuit segment 28 extends between the first attachment side 17 and the first attachment region 32. This heating conductor circuit segment 28 also extends between the first attachment region 32 on a side that is away from the electrical attachment side 17 and connects the attachment side 17 to the side of the heating conductor layer 16 opposite to the electrical attachment side. Therefore, the first attachment region is not adjacent to the side or edge of the heating conductor layer, but is spaced apart from it. Conversely, in this embodiment, the second attachment region 34 is directly adjacent to the electrical attachment side of the heating conductor layer 16.
[0042] Two attachment regions 32 and 34 are used to connect the heating conductor circuit 20 via electrical contacts of the electrical attachment conductor 35, allowing electrical energy to be supplied to the heating conductor circuit 20, which is then converted into heat. The electrical attachment conductor 35 connects the attachment regions 32 and 34 to an attachment electronic device, which... Figure 1 and 2 Not shown. This could be a power board, a controller including power electronics, or the like. Each attachment region 32, 34 can be electrically connected to more than one electrical attachment conductor 35, wherein the number can vary between two attachment conductors. The attachment conductor 35 extends from the attachment regions 32, 34 in the direction of attachment side 17 and beyond the edge of the heated conductor layer 16 extending on attachment side 17. The electrical attachment conductor 35 is present in all embodiments, but only in Figure 1 It is shown schematically in the middle.
[0043] Just like the two ends 24, 26, the two attachment regions 32, 34 are arranged spaced apart from each other in the heating conductor layer 16. Here, the spacing d can be given by a straight connecting line defined in the plane of the heating conductor layer between the first end 24 and the second end 26 or between the first attachment region 32 and the second attachment region 34. The spacing d is in particular the shortest connecting line between the two ends 24, 26 or the attachment regions 32, 34, or more precisely, between the edges of the two ends 24, 26 or the attachment regions 32, 34 facing each other.
[0044] The heated conductor layer 16 can be constructed with a flat surface or a curved surface, such that (in the case of a curved surface) a locally defined plane of the heated conductor layer can be defined at each point. The shortest connecting line obtained in the curved heated conductor layer then also appears curved when viewed from the outside. This approach is well known to those skilled in the art and is applied in a wide variety of fields, where geodesics are commonly discussed. Thus, in Euclidean measurement, the straight line segment between two points is precisely a geodesic. However, on a sphere in space, a geodesic is typically the shorter portion of a great circle passing through the two points to be connected. Preferably, however, not only the main extending plane of the heated conductor layer 16 but also the main extending plane of the carrier element 14 is flat.
[0045] Here, the spacing is chosen such that d ≥ b, preferably d ≥ 2b, such that at least one heating conductor circuit segment can extend between the two attachment regions 32, 34 or the two ends 24, 26. This results in the two attachment regions 32, 34 not having a continuous and unheated surface, which leads to a smaller temperature difference between the interior of the two attachment regions 32, 34 and the surrounding area of the heating conductor circuit 20.
[0046] In addition Figure 2 As can be clearly seen, the first heating conductor circuit segment 28 is attached to the first attachment region 32, that is, the first heating conductor circuit segment follows the outer contour of the first attachment region in such a way that the first heating conductor circuit segment 28 is separated from the first attachment region 32 only by the insulation interruption portion 22. In the same manner, the second heating conductor circuit segment 30 is attached to the second attachment region 34.
[0047] Not only in the first heating conductor circuit segment 28, but also in the second heating conductor circuit segment 30, point pairs (A1, B1) and (A2, B2) can be selected on the corresponding edge segments of the first heating conductor circuit segment 28 or the second heating conductor circuit segment 30 that abut against the attachment regions 32 and 34, such that the connecting lines between these point pairs (A1, B1) and (A2, B2) intersect with the first attachment region 32 or the second attachment region 34. Therefore, in the first heating conductor circuit segment 28, the first point A1 and the second point B1 are connected by a first connecting line VL1, which intersects with the first attachment region 32. Similarly, the second attachment region 34 intersects with a second connecting line VL2, which extends between the second point A2 and another second point B2. It should be noted that this type of point pair can essentially only be selected from a set of points that form the edges of the corresponding heating conductor circuit segments 28, 30 abutting the first attachment region 32 or the second attachment region 34 and forming protruding edge segments. Not all points on the edge satisfy this condition. However, if a point pair satisfying this condition cannot be found, then the associated heating conductor circuit segments 28, 30 do not abut the corresponding ends 24, 26 in the sense of this patent application.
[0048] It can be considered, in Figure 1 The heating conductor circuit 20, shown with two attachment regions 32, 34, is horizontally mirrored on axis 48, resulting in two heating conductor circuits having a total of three attachment regions. This... Figure 6 As shown in the diagram. Here, the second attachment region 34 appears wider and extends into the heating conductor circuit section in two opposite directions. Preferably, the second attachment region 34 and the conductor circuit section adjacent to it and electrically separated from it by the insulation interruption 22 are constructed such that the second attachment region 34 extends into the heating conductor plane into the adjacent conductor circuit section on its side facing away from the attachment side 17, such that the conductor circuit section is adjacent not only to the second attachment region on its side opposite to the attachment side, but also to both sides of the second attachment region laterally. These two sides of the second attachment region extend substantially perpendicular to or slightly inclined to such a vertical line from the main extension direction of the electrical attachment side 17. Furthermore, the second attachment region 34 has a gap 39 in the heating conductor plane on its side facing the attachment side 17. The gap 39 has proven unexpectedly advantageous in avoiding thermal stress during heating operation. The third attachment region 33 is constructed in the same way as the first attachment region 32.
[0049] exist Figure 6In the illustrated embodiment, during heating operation, current flows in parallel between the second attachment region 34 and the first attachment region 32, and between the second attachment region 34 and the third attachment region 33. A liquid heating element having such a heating element typically has an operating voltage between 300V (inclusive) and 500V (inclusive). Specifically, the operating voltage is, for example, 400V. For example, liquid heating element 12 (see...) Figure 5 It has three such heating elements, each of which, for example, brings a heating power of 3 kW (1.5 kW for each of the two current paths for each heating element), such that the total maximum heating power is, for example, about 9 kW.
[0050] The same heating conductor circuit design can also be advantageously used in liquid heating sections with twice the operating voltage, specifically between 600V and 1000V. This is... Figure 3 As shown in the diagram. Specifically, the operating voltage is, for example, 800V. In this embodiment, the... Figure 6 In the middle, it serves as the attachment region of the second attachment region 34. Instead, it is based on... Figure 6 In the example, the attachment region 33 is the third attachment region according to Figure 3 In this example, the second attachment region 34 is used. Here, during heating operation, the current flows in a single, long current path between the first attachment region 32 and the second attachment region 34. For example, the liquid heating section 12 (see...) Figure 5 It has three such heating elements, each of which, for example, brings 3 kW of heating power in a single heating conductor current path, such that the total maximum heating power is, for example, about 9 kW.
[0051] In principle, Figure 3 The heating conductor circuit 20 shown is composed of the above-described combination. Figure 1The previously mentioned mirror image on axis 48 is derived, but in which, as described above, the second attachment region 34 is omitted. Instead, a continuous, longer heating conductor circuit 20 is obtained, which now extends between the first end 24 and the second end 26 having the first attachment region 32 and the second attachment region 34, such that these attachment regions 32, 34 are completely surrounded by the heating conductor circuit segments 28, 36, 40 or 30, 38, 42. In this way, the attachment regions 32, 34 of the heating conductor circuit 20 are not only dispersedly "heated" in the heating conductor layer 16, but also simultaneously "heated" from all sides (and not located on the edges of the heating conductor layer 20 or the carrier element 14), so that the possible temperature difference between the heated heating conductor circuit segments 28, 30, 36, 38, 40, 42 and the interior of the corresponding attachment regions 32, 34 can be reduced again. Therefore, the first attachment region 32 is completely surrounded by the first heating conductor circuit segment 28, the additional heating conductor circuit segment 36, and the additional first heating conductor circuit segment 40. In the same manner, the second attachment region 34 is completely surrounded by the second heating conductor circuit segment 30, the additional heating conductor circuit segment 38, and the additional second heating conductor circuit segment 42.
[0052] Heating conductor circuit sections 40 and 42 originate from / begin at corresponding ends 24 and 26 of heating conductor circuit 20. The difference between these heating conductor circuit sections and their corresponding ends is particularly that in these sections 40 and 42, electrical energy is converted into heat to the same extent as in sections of heating conductor circuit 20 that are further away from their corresponding ends. This is a suitable criterion for determining whether a portion of heating conductor circuit 20 should belong to one of the two ends 24 and 26 / one of the two attachment regions 32 and 34, or should belong to a heating conductor circuit section.
[0053] Figure 4 A cross-section of an exemplary segment of the heating element 10 is shown. Figure 4 In the image, the heating element 10 is shown in a segmented, laterally cut view. This cut is made perpendicular to the plane 18 of the heating conductor layer.
[0054] For simplicity, the surface provided by the carrier element 14 is flat, on which the heating conductor layer 16 is disposed. However, a curved surface is also possible, except that the heating conductor layer plane 18 is then defined as consisting of local tangential planes at various points in the heating conductor layer and follows the surface of the carrier element 14. This affects the shortest connecting lines (geodesics) in the heating conductor layer 16.
[0055] The heating conductor circuit 20 in the heating conductor layer plane 18 has a width b and is limited on both sides by insulating interruptions 22. The insulating interruptions 22 are in the heating conductor layer 16 having a width b. I The linear grooves. The carrier element is electrically insulating, or has a corresponding electrically insulating portion on its surface where the heating conductor layer 16 is arranged. Here, the width b of the heating conductor circuit 20 is much larger than the width b of the insulation interruption portion 22. I This means that almost the entire surface of the heating conductor layer 16 can be used to construct one or more heating conductor circuits 20.
[0056] In all the exemplary descriptions of the electric heating element 10 in the liquid heating section 12, the heating conductor circuit 20 is constructed such that most of the parallel sub-segments of the conductor circuit are advantageously energized by current flowing through them in opposite directions. Therefore, the electromagnetic fields generated during heating operation can at least partially cancel each other out.
[0057] Figure 5 A simplified diagram of a liquid electric heating unit 12 for a vehicle is shown. In addition to the electric heating element 10, in... Figure 5 The vehicle electric heating unit 12 shown also includes a liquid heat exchanger 44 and a controller 46 for operating an electric heating element 10, which is disposed on the liquid heat exchanger, and from which heat generated during heating operation is transferred to the liquid heat exchanger. For this purpose, the controller 46 is connected to the electric heating element 10 via an electrical attachment line 50. The vehicle electric heating unit 12... Figure 5 Other components not shown (these other components are omitted for simplicity) Figure 5 (Not explicitly shown) is well known to those skilled in the art and is supplemented by those skilled in the art to ensure the functionality of the vehicle electric heating unit 12.
[0058] The features disclosed in the above description, in the drawings and in the claims are important for the implementation of the present invention, not only individually but also in any combination.
[0059] List of reference numerals 10 Electric heating elements 12 Vehicle electric heating unit 14 Carrier Components 16 Heating conductor layer 17. Electrical attachment side of the heated conductor layer 18. Heating conductor layer plane 20 Heating conductor circuit 22 Insulation interruption section 24 First end 26 Second end 28 First heating conductor circuit section 30 Second heating conductor circuit section 32 First Attachment Area 33 Third Attachment Area 34 Second Attachment Area 35 Electrically attached conductor 36. Additional heating conductor circuit sections 38. Additional heating conductor circuit sections 39. Empty space 40. Another first heating conductor circuit section 42. The other second heating conductor circuit section 44 Heat exchanger 46 Controller 48 axis 50 electrical attachment lines b. Heating conductor circuit width d Spacing A1 First point B1 Another first point VL1 First Connection Line A2 Second point B2 Another second point VL2 Second Connector b I The width of the insulation interruption.
Claims
1. A liquid electric heating unit (12) for use in a vehicle, the liquid electric heating unit having a heating element (10), wherein, The heating element (10) includes: - Carrier element (14); and - A heating conductor layer (16) is disposed on the carrier element (14); - Wherein, the heating conductor layer (16) has a heating conductor circuit (20) in the heating conductor layer plane (18), and the heating conductor circuit is limited in the heating conductor layer plane (18) by at least one insulation interruption (22); - Wherein, the heating conductor circuit (20) has a first attachment region (32) and a second attachment region (34) on the electrical attachment side (17) of the heating conductor layer (14), and in the first attachment region and the second attachment region, the heating conductor circuit is electrically connected to at least one electrical attachment conductor (35) respectively. - Wherein, the first attachment region (32) and the second attachment region (34) are spaced apart by a distance d along a connecting line extending straight in the plane (18) of the heating conductor layer, and the heating conductor circuit (20) contacts and / or crosses the connecting line in sections; - wherein the first heating conductor circuit segment (28) in the heating conductor layer plane (18) extends between the first attachment region (32) and the electrical attachment side (17).
2. The liquid electric heating unit (12) according to claim 1, wherein, The portion of the first heating conductor circuit section (28) extending between the electrical attachment side (17) and the first attachment region (32) is separated from the first attachment region (32) by the at least one insulation interruption portion (22).
3. The liquid electric heating unit (12) according to claim 1 or 2, wherein, The second heating conductor circuit segment (30) in the heating conductor layer plane (18) extends at least around a portion of the second attachment region (34), and the second heating conductor circuit segment (30) is separated from that portion of the second attachment region (34) by the at least one insulation interruption (22).
4. The liquid electric heating unit (12) according to claim 3, wherein, The second heating conductor circuit segment (30) extends between the second attachment region (34) and the electrical attachment side (17), and the second heating conductor circuit segment (30) is separated from this portion of the second attachment region (34) by the at least one insulation interruption portion (22), or the second attachment region is directly disposed on the electrical attachment side (17) of the heating conductor layer (14).
5. The liquid electric heating unit (12) according to any one of the preceding claims, wherein, The heating conductor circuit (20) has a minimum heating conductor circuit width b, and the spacing d ≥ b, preferably ≥ 2b.
6. The liquid electric heating unit (12) according to any one of the preceding claims, wherein, The first heating conductor circuit segment (28) is attached to the first attachment area (32), and / or the second heating conductor circuit segment (30) is attached to the second attachment area (34).
7. The liquid electric heating unit (12) according to any one of the preceding claims, wherein, Two first points (A1; B1) can be defined on the edge of the first heating conductor circuit segment (28) extending around a portion of the first attachment region (32) and separated from that portion by the at least one insulation interruption (22), such that a first connecting line VL1 extending straight between the two first points (A1; B1) in the heating conductor layer plane (18) extends through the first attachment region (32).
8. The liquid electric heating unit (12) according to any one of the preceding claims, wherein, Two second points (A2; B2) are defined on the edge of the second heating conductor circuit segment (30) extending around a portion of the second attachment region (34) and separated from that portion by the at least one insulation interruption (22), such that a second connecting line VL2 extending straight between the two second points (A2; B2) in the heating conductor layer plane (18) extends through the second attachment region (34).
9. The liquid electric heating unit (12) according to any one of the preceding claims, wherein, The first attachment region (32) and / or the second attachment region (34) are completely surrounded in the heating conductor layer plane (18) by heating conductor circuit segments (28, 36; 30, 38).
10. The liquid electric heating unit (12) according to any one of the preceding claims, wherein, The width b of the at least one insulation interruption (22) I It is less than 10% of the minimum heating conductor circuit width b, preferably 5%.
11. The liquid electric heating unit (12) according to any one of the preceding claims, wherein, The carrier element (14) is a ceramic substrate.
12. The liquid electric heating unit (12) according to the preceding claim, wherein, The ceramic substrate is fastened to the metal heat exchanger.