DE102023210867A1 - Cooler with two largely parallel plates - Google Patents

Abstract

A cooler (10) has at least two largely parallel plates (12, 14, 50, 54) shaped in this way and connected to one another, in particular soldered, and is characterized in that at least one flow channel (34) formed in one plate (50) is interrupted and this plate has at least one barrier such that a first fluid, in particular coolant flow, is diverted into a flow channel formed in the other plate (54), and at least two flow channels (34), preferably each flow channel (34), are assigned a separate inlet (26) and preferably also an outlet (26), and a closed flow space (56) for a second fluid, for example a coolant, is formed between the plates (12, 14, 50, 54).

Description

Technical area

The invention relates to a cooler with two largely parallel plates.

State of the art

For example, from the EN 10 2021 210 826 A1 A cooler with three largely parallel plates is known, of which the outer two are essentially flat. The middle plate defines the flow channels for coolant or refrigerant and is mechanically joined to the first-mentioned plates, usually soldered.

From the JP H 11-287580 A A similar cooler emerges, which is surrounded by air.

Finally, the EN 11 2021 004 917 T5 a heat exchanger between two fluids, in which each fluid within the heat exchanger is divided into several flow channels or spaces.

Description of the invention

Against this background, the object of the invention is to create a compact and/or improved cooler with regard to heat transfer.

This problem is solved by the subject matter of claim 1.

Accordingly, it has two largely parallel plates which are shaped and connected to one another, in particular soldered, in such a way that at least one flow channel formed in one plate is interrupted and this plate has at least one barrier such that a fluid, in particular coolant flow, is diverted into a flow channel formed in the other plate.

In other words, the flow channels are formed in sections and alternately in one and the other plate. The plates are parallel to one another and connected to one another with regard to the flat areas between any flow channels. In order to ensure the described deflection from a flow channel in one plate to a flow channel in the other plate, the flow channels formed in the respective plate overlap. The previously mentioned barriers, which essentially form the end of a flow channel section formed in a plate, thus act as guide elements for the diversion and as turbulators that improve the heat transfer. At the same time, the cooler or heat exchanger in general can be kept compact. As described in more detail below, the plates can also be connected to one another in such a way that they can withstand a particularly high load due to internal pressure.

If a gap between two plates is usually defined as a plane, a conventional fluid flow, in particular a coolant flow, can be described as two-dimensional. In contrast, the flow formed in the heat exchanger according to the invention is three-dimensional in that the fluid, in particular a coolant, flows at least in sections in a depression, a channel or a protrusion of a first plate, delimited by an adjacent flat region of the second plate, and in another section in a protrusion, depression or a channel of the second plate and delimited by an adjacent flat region of the first plate.

Viewed differently, if a layout of the one or more flow channels is marked with different colors corresponding to a flow in a recess or the like of one plate on the one hand and the other plate on the other hand, different colors appear in the course of the flow channel. A second fluid, for example a coolant, which gives off heat to the coolant flowing alternately in the plates, flows in the remaining plate spaces, which are delimited by a circumferential lateral web. Here, both a cocurrent, countercurrent, and cross-countercurrent flow can be formed in the heat exchanger.

Furthermore, the cooler typically has largely flat outer plates on the outside, which preferably have an inlet and outlet for a fluid that, for example, releases heat to a coolant. This essentially provides a connection option to the fluid system of a vehicle. In principle, a connection can be formed on both sides of the cooler and on each of the two outer plates.

For the sake of completeness, it should be mentioned that at least four plates, including the outer plates, are mechanically connected to one another in a suitable manner, in particular soldered, so that overall a cooler with high strength is created. This applies both to the strength against internal pressure and to external mechanical stress.

Furthermore, the cooler can be connected to the cooling system of a vehicle. Furthermore, the cooler according to the invention has a low pressure loss and, as mentioned, a high strength. Depending on requirements, the outer and/or any intermediate or separating plates can be completely flush with the plates in which flow channels are formed or can be offset inwards on at least one side.

In the area of overlap between two cooling channel sections in two different plates, this results in a flow channel height that is twice as large as the depth of the recess formed in one plate. The same applies to the flow space for the fluid in the remaining plate spaces, with the exception of the flow spaces for the fluid adjacent to the outer plates.

It should also be mentioned that for the inlets and outlets for the coolant, i.e. in the described inter-plate spaces, a diameter of 4.0 to 4.4 mm is preferred for a plate thickness of, for example, 0.6 mm, and a diameter of 2.8 to 3.2 mm is preferred for a plate thickness of 0.4 mm.

The cooler according to the invention is particularly pressure-stable in that at least two flow channels, preferably each flow channel in the respective plate, are assigned a separate inlet and preferably also an outlet, in other words that the fluid, in particular coolant flow, is already divided into several channels outside the plates, where stability can be more easily ensured.

Advantageously, heat transfer to a second, liquid fluid is efficiently achieved by forming a closed flow space for a second fluid, for example a coolant, between the plates.

Currently preferred areas of application of the cooler according to the invention are chillers, i.e. coolant coolers and direct refrigerant evaporators.

Preferred further developments are described in the further claims.

The design according to the invention can be advantageously implemented using a single type of plate with flow channels, which is used alternately rotated by 180° or installed in the heat exchanger. This means that only a single type of flow pattern, for example U-shaped or meandering, or multiple U-shaped, can be implemented inside the heat exchanger. Together with the outer plates as a further type of plate, two types of plates are therefore sufficient. Since it could be advantageous in certain applications to provide a second type of flow pattern in such a heat exchanger, this can also be implemented efficiently by using a maximum of two different types of plates with flow channels.

As already mentioned, the flow channels according to the invention can be realized by connecting one and the same type of plate together, one of them, for example, rotated by 180°.

At the same time, the thickness of at least one plate can be advantageously reduced to 0.6 mm or less without reducing the strength too much. Depending on the manufacturing process and the respective requirements, the plate thicknesses can differ from one another. 0.4 mm is currently preferred as the minimum thickness, and 0.65 to 0.8 mm have proven to be advantageous for the depth of a flow channel formed in a plate in initial simulations and tests. In the area of overlap between two flow channel sections in two plates lying on top of one another, this results in a total height or depth of 1.3 to 1.6 mm. Such dimensions are currently considered to be optimum with regard to a robust soldering process, pressure loss, heat transfer performance and strength.

With regard to the flow geometry, initial simulations have shown that a meander and/or possibly multiple, in particular triple U-shape and/or a straight-line flow are advantageous. The meanders can be relatively complex and thus be adapted to the requirements in a special way. A U-shape essentially has sections connected at right angles.

With regard to the mechanical internal pressure resistance of the cooler, it is currently preferred that it is resistant to an internal pressure corresponding to the maximum operating pressure of refrigerant R744 in order to form a particularly stable cooler. This value can be achieved in particular by minimizing free spanning areas between the plates by connecting the plates to one another at numerous points and/or parallel to numerous flow channels. The internal pressure resistance can then be ensured despite plate thicknesses of 0.6 mm or less.

The heat transfer can be advantageously improved by turbulators, which are preferably formed outside the flow channels, in other words, in the flow space for a coolant. The turbulators can be formed by notches, which can be round or oval. , and several such turbulators can be provided in series essentially parallel to the flow channels. The turbulators are preferably provided in one piece in the plates, as mentioned as notches or punched sections and/or bends. A maximum height of such turbulators can correspond to the height of the flow space, so that in other words they abut the upper boundary of a flow space.

With regard to efficient heat transfer, it is further preferred that the second fluid is guided in a V-shape and/or arcuate manner through a space between plates. As already indicated above, it can be advantageous to provide a different flow in different areas of a heat exchanger, so that in a first group of plates, the flow channels are designed in a first shape, for example straight, and in a second group of plates, the flow channels are designed in a second shape, for example U-shaped. This can in particular improve performance and at the same time make it possible to form any connections or as many connections as possible on a single side of the heat exchanger.

Finally, it has proven advantageous for the stable connection of the plate to connect them together, in particular to solder them, in the area of inlets and outlets and/or on the outer edge. Furthermore, alternatively or additionally, at least one stiffening plate and/or a fold can be provided at least in sections or places on at least one outer edge. A stiffening plate can be provided in particular in the area of the inlet and outlet for the coolant and/or a tie rod can be designed in such a way that it is inserted through additional holes formed with a collar and soldered to each plate. In this way, a tensile force is distributed from the top plate to several plates, down to all plates including a bottom plate. Such a tie rod can be round, oval or rectangular or have any other shape. Furthermore, several such tie rods can be provided. Alternatively or additionally, the plate stack forming the heat exchanger can be enclosed, in particular in an area subject to the greatest mechanical stress, by a band, for example made of aluminum, which can be soldered to the plate stack. Finally, one or more C-shaped clamps can be provided on the outside of the plate stack to hold the plate stack together. At least one such clamp can contain one or more connections; in any case, at least one such clamp is preferably provided in the area of the connections because these areas are critical with regard to the pressure loads that occur.

In view of favorable properties, it is further preferred that all inlets and outlets for the first fluid have a diameter of 4.0 to 4.4 mm, in particular with a plate thickness of about 0.6 mm, or a diameter of 2.8 to 3.2 mm, in particular with a plate thickness of about 0.4 mm.

It is also advantageous for the stability of the plate stack if all inlets and outlets for the first fluid are surrounded by an elevation or depression formed from the plate material.

This also applies to the preferred measure, whereby the elevation or depression is followed by an elevation or depression that forms a flow channel. All elevations and depressions can be formed efficiently, and the structures mentioned promote the flow to and in the channels.

The production and connection of the panels is particularly easy if all elevations or depressions are the same height or depth.

This also applies to the preferred measure that sections of flow channels formed in different plates are at least partially the same length. This also improves the flow pattern.

Particularly good properties are also expected if a flow channel is connected to each inlet and outlet in each plate, so that in other words the fluid flow is not diverted immediately after entering an adjacent plate.

Short description of the drawings

• 1 den grundsätzlichen Aufbau des erfindungsgemäßen Kühlers,
• 2 eine erste Art von Platte in dem in 1 gezeigten Kühler in einer Draufsicht,
• 3 eine zweite Art von Platte in dem in 1 gezeigten Kühler in einer Draufsicht,
• 4 einen Teil einer weiteren Ausführungsform eines erfindungsgemäßen Kühlers,
• 5 einen Teil einer weiteren Ausführungsform eines erfindungsgemäßen Kühlers,
• 6 einen Teil einer weiteren Ausführungsform eines erfindungsgemäßen Kühlers,
• 7 einen Teil einer weiteren Ausführungsform eines erfindungsgemäßen Kühlers,
• 8-12 die in den Ausführungsformen von 4-7 verwendeten Platten,
• 13 ein Detail des erfindungsgemäßen Kühlers,
• 14 eine weitere Ausführungsform einer in dem Kühler verwendeten Platte,
• 15 die in 14 gezeigte Platte um 180° gedreht,
• 16 bis 18 Schnitte durch zwei Plattenpaare mit den enthaltenen Volumina gemäß 14 und 15, wobei 16 einen Schnitt senkrecht zu einem Strömungskanal zeigt, und 17 und 18 Schnitte parallel zu einem Strömungskanal,
• 19 einen Schnitt durch zwei Plattenpaare zusammen mit Außenplatten,
• 20-22 die Strömung in der ersten, der zweiten und in den beiden Platten kombiniert,
• 23 eine weitere Ausführungsform einer Platte,
• 24 einen ersten Schnitt durch einen Plattenstapel mit mehreren der in 23 gezeigten Platten, und
• 25 einen zweiten Schnitt durch den Plattenstapel mit mehreren der in 23 gezeigten Platten.

The invention is explained in more detail below using exemplary embodiments. They show:

• 1 the basic structure of the cooler according to the invention,
• 2 a first type of plate in the 1 shown cooler in a top view,
• 3 a second type of plate in the 1 shown cooler in a top view,
• 4 a part of another embodiment of a cooler according to the invention,
• 5 a part of another embodiment of a cooler according to the invention,
• 6 a part of another embodiment of a cooler according to the invention,
• 7 a part of another embodiment of a cooler according to the invention,
• 8-12 which in the embodiments of 4-7 used plates,
• 13 a detail of the cooler according to the invention,
• 14 another embodiment of a plate used in the cooler,
• 15 in the 14 shown plate rotated by 180°,
• 16 to 18 Sections through two pairs of plates with the contained volumes according to 14 and 15 , where 16 shows a section perpendicular to a flow channel, and 17 and 18 Cuts parallel to a flow channel,
• 19 a section through two pairs of plates together with outer plates,
• 20-22 the flow in the first, the second and in the two plates combined,
• 23 another embodiment of a plate,
• 24 a first section through a stack of plates with several of the 23 shown plates, and
• 25 a second section through the plate stack with several of the 23 plates shown.

Detailed description of preferred embodiments of the invention

As from 1 As can be seen, the cooler 10 according to the invention consists of numerous plates, which are described in more detail below. All plates are typically substantially rectangular, and the outer plates 14 are substantially flat at least on their outer sides. The intermediate plates 12 have structures for forming flow channels, which are described in more detail below. In the case shown, the upper outer plate in the figure also has inlets and outlets 16-22, which are also described in more detail below and can be adapted to customer specifications.

In detail, in the case shown, the upper outer plate 14 has an inlet 16 and an outlet 18, for example for coolant, which is to be cooled by the cooler 10 according to the invention. As indicated by the arrows A and B, the coolant essentially flows in the orientation shown from top to bottom through all the plate gaps described in more detail below and from the underside of the cooler 10 upwards to the outlet 18. In detail, the coolant is distributed through the passages 36 formed in all the plates to all the plate gaps and flows here in a U-shape, essentially from the front left to the back right, from there to the front right and finally to the front left, in order to reach the outlet 18 through the passages 36 which can again be seen. In the 2 and 3 In this respect, the flow channels 34 for the coolant are interrupted and described in more detail below. The coolant essentially flows between them, in particular in a U-shape due to the central boundary 58. The inlet 16 and outlet 18 are essentially cylindrical with a tapering section approximately in the middle and can be soldered to the outer plate 14.

This also applies to the block 24 which can be seen and which has an inlet 20 and an outlet 22 for a coolant. Due to the higher pressure load in this area, the block 24 can be formed by milling, for example.

In the right-hand area of the outer plate 14, numerous openings 26 can be seen through which the coolant enters numerous flow channels, which are described in more detail below. 1 It should be explained that the coolant initially flows to the front left in accordance with the arrows C in the left area of the plate stack 28 that can be seen. As can be seen from the vertical arrow C, this happens in parallel in the entire plate stack 28. For clarity, only the two lowest plates of this plate stack 28 are shown separated from each other. The part of the plate stack 28 that can be seen above consists of identical plates, which are shown stacked.

This also applies to the lower plate stack 30, which is separated from the upper plate stack 28 by a separating or intermediate plate 32. For the upper plate stack 28, a straight-line flow was described in accordance with the arrows C pointing from the right rear to the left front. In contrast, in the lower plate stack 30, a U-shaped flow is formed in such a way that the coolant flows in all flow channels of this plate stack 30 in parallel, first according to the arrows D from the left front to the right rear, then according to the arrows E from the left rear to the right rear and then according to the arrows F from the right rear to the left front. From here, the coolant flows upwards, now into the right part of the upper plate stack 28 and here, again in all flow channels in parallel according to the arrows len G from left front to right rear, thus in a straight line and from there according to the arrow H to its outlet 22.

After the coolant entering through the inlet 16 flows in the upper plate stack, in its left area from the front left to the rear right, a counterflow to the coolant occurs here. In the lower plate stack, a parallel, U-shaped flow occurs. Furthermore, a counterflow also forms in the right part of the upper plate stack 28. This advantageously lengthens the flow paths and improves the heat transfer. This applies in particular to the counterflow in the right area of the upper plate stack 28, which is particularly advantageous for the cooling of the coolant subsequently leaving the cooler 10. At the same time, with the 1 In the cooler 10 shown, all inlets and outlets 16, 18, 20 and 22 can advantageously be arranged on one side, which offers advantages for connecting the cooler to the cooling system of a vehicle, for example.

As in 2 As shown, the plates 12 of the upper plate stack 28 have openings 26 for the coolant on the one hand, and interrupted and described in more detail below, for example four to six parallel flow channels 34 and passages 36 for the coolant on the one hand and the coolant on the other hand. 2 The plate shown is designed for a straight-line flow, in the case shown from right to left at the top and from left to right at the bottom with regard to the coolant. Furthermore, in the example shown, turbulators 38 are shown in the upper area between the flow channels, which are described in more detail below. As in 2 As can be seen, in this case they are elongated according to the flow direction of the refrigerant and in series with the flow channels 34 for the refrigerant.

This applies equally to the 3 shown plate 40 of the lower plate stack 30. As can be seen particularly in the right-hand area, a deflection of the coolant takes place here in its flow channels 34 and thus an overall U-shaped flow.

At the 4 In the alternative embodiment shown, the flow is essentially triple U-shaped, as explained in more detail below. Here, the middle U is upside down and its two legs coincide with the inner legs of the outer U. Inlet 20 and outlet 22 for the coolant are separate in this case, and the coolant initially flows into the individual flow channels according to arrow C, then, as described, in a triple U-shape or meandering shape according to arrow D to the right and from there to the outlet 22. The inlet and outlet for the coolant can again be seen as essentially cylindrical and can be used both in parallel and counterflow to the coolant.

5 essentially shows a duplication of the 4 shown flow, according to which in the two upper plates the flow is essentially from left to right, and in the two lower plates from right to left, after the flow has been directed from the second plate from above into the third plate from above. The flow after another pair of plates, for example according to the 4 The return flow to the outlet 22 shown below is indicated by the arrow H.

In 6 It is indicated how inlet 20 and outlet 22 for the coolant can advantageously be arranged on one side of the cooler, namely by providing a lower group 42 (cf. 8th ) of openings is used, and the refrigerant in the 7 to be recognized upper pair of plates from left to right, in the middle pair of plates from right to left and in the bottom pair of plates from 7 again flows from left to right. The total resulting backflow after flowing through the 6 The connection of the plate pair shown below to the outlet 22 is indicated by the arrow H. For the concepts according to 4-7 It should be emphasized that they advantageously allow the arrangement of all inlets and outlets 16-22 on one side. This simplifies the integration of the cooler into the cooling system of a vehicle, for example, without the need for external redirection of the coolant, for example. A combination of the 4 and 5 allows an odd number of deflections, and a combination of the 6 and 7 an even number of deflections.

As shown by 8th As can be seen more precisely, the upper plate in each plate pair corresponds to 7 the in 8th The first plate type shown in 9 The second plate type shown forms the lower plate of the upper and lower plate pair, and the one in 10 The plate type shown is the lower plate of the middle plate pair. Arrows I are indicated in the 8 to 12, 14 and 15 the essentially inverted V-shaped flow of the second fluid in the flow space between two plates from one to the other passage 36 is shown in the orientation shown. The flow space extends on all sides up to the outer boundary 60. The second fluid, typically a coolant, in particular water, is cooled and gives off heat to the in this case in countercurrent and essentially according to the figure The coolant flows in a U-shape from the top left to the top right, causing it to evaporate. The heat transfer ideally takes place evenly along the respective flow path.

The remaining plate types according to 11 and 12 correspond to the 4 and 6 plates shown below, whereby the plate type according to 12 The two upper pairs of plates of 7 the in 5 to be recognized plate pairs, and in 4 , below is the plate type according to 11 as upper, and the one according to 12 as the lower plate. As in 8-12 As can be seen, different openings 26 are closed in different plate types in order to realize the flow paths described above using the plates shown. Groups of openings, such as those in 8th The group 42 indicated form collector areas which can be used advantageously for heat transfer. For all plate types, it can be seen that their respective flow channels for the coolant are interrupted, and the operation of the cooler formed in this way is described in more detail below. Due to the respective central boundary 58, the coolant flows essentially in an inverted V or arc shape from one passage 36 to the other.

In 13 Firstly, the connection of the block 24 with the inlet 20 and/or outlet 22 for the coolant to the outer plate 14, as well as the latter with an intermediate plate 12 and the connection of several intermediate plates 12 to one another is shown. This is advantageously done by soldering, and it should be emphasized that the resulting circumferential and double soldering of the plates in the areas marked 44 ensures particular strength. As indicated by the folds 46, the strength can optionally be further increased by lateral folds. The double circumferential soldering in the areas marked 44 ensures additional protection against corrosion, since it is outside, according to 13 to the left of the soldering sufficient for the cooler to function is provided in the area of the mutually directed curvatures of the plates 12. Corrosion in the areas 44 cannot lead to coolant or fluid leakage, since the previously mentioned soldering necessary for the cooler to function is provided further inside than these areas 44.

This applies equally to the 14 indicated measure, according to which local dimples 48 can be provided in one or more corners of the plates 12, which can be soldered together continuously for all plates.

In 15 is the 14 The plate shown is shown rotated by 180° around a vertical axis parallel to the plate plane, which accordingly also has interrupted flow channels. However, if the 14 shown plate in this orientation with the one in 15 shown plate, also in the orientation shown, is soldered, resulting in continuous flow channels, which are partially formed in only one of the two plates. The coolant can flow from one plate to the other in the area of overlapping flow channels of both plates. The ends of the flow channel sections form barriers for the deflection into the other plate.

In 16 In this regard, it can be seen from the section, for example, that the coolant initially flows only in the upper plate 50 after entering the second opening 26 from the left. However, as it continues, the flow channel 34 formed therein ends and the coolant enters a flow channel 34 formed in the lower plate 54 in the form of a recess in the area of the overlap. In the case shown, each flow channel 34 is assigned an opening 26 which is formed in further plates 50, 54 and in this respect acts as a distributor for the flow channels 34 of several pairs of plates 50, 54.

This overlap is in 16 by way of example, the second flow channel 34 from the right and the flow channel 34 located furthest to the left are indicated. In this area, the coolant thus flows in the channels of both plates 50, 54. For the flow channel 34 located furthest to the right, it can be seen that in this area the coolant only flows in a channel 34 formed in the lower plate 54, while above this the flow channel 34 formed to a limited extent in the upper plate 50 can be seen.

As in 17 Thus, it can be seen in addition that in the case shown, the coolant changes from a flow only in the upper plate 50 in the region of the overlap 52 into the flow channel of the lower plate 54, and from there in the region of a further overlap 52 back into the flow channel in the upper plate 50.

This is complementary in 18 and are marked with the identical reference numbers. The flow of the coolant to be cooled, which can be seen in the remaining plate gaps 56, is also indicated here.

In 19 is additionally shown as an example how an arrangement of two pairs of plates, each with an upper plate 50 and a lower plate 54, is separated by the essentially flat outer plates 14. can be closed, and there are further flow spaces 56 for the coolant adjacent to the outer plates 14. For the flow channel 34 located furthest to the left in the section shown, it can be seen that it is only located in the upper plate 50, the second flow channel 34 from the left only in the lower plate 54, and the third from the left in both plates 50, 54.

Out of 20 arise according to the 14 The flow channels of the upper plate 50 which can be recognized are those interrupted regions in which the refrigerant flows in this upper plate 50.

21 shows the same for the flow in the lower plate 54 according to the 15 to be recognized flow channels, and 22 shows the resulting overall flow alternating between the two plates through the different hatching of the flow channel in different plates.

23 Finally, shows, by way of example for a plate with the described triple U-shaped flow, how turbulators 38 can also be formed in series and parallel to the flow channels 34.

As finally in 24 and 25 As can be seen in the figures, which are sections running perpendicular to each other, the turbulators 38 can extend over the entire height of the flow gap and accordingly abut against the respective upper plate or an outer plate 14. As can be seen in the right-hand area of the 25 As can be seen, the turbulators 38 can extend in both directions and can be punched out of the plate material in such a way that when two plates are connected, the plate thickness is single in the area of the turbulators 38, while in other areas and in particular between flow channels 34 the plate thickness is double.

QUOTES INCLUDED IN THE DESCRIPTION

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

Cited patent literature

• DE 102021210826 A1 [0002]
• JP H11287580 A [0003]
• EN 112021004917 T5 [0004]

Claims (16)

Cooler (10) with at least two largely parallel plates (12, 14, 50, 54) shaped in this way and connected to one another, in particular soldered, wherein at least one flow channel (34) formed in one plate (50) is interrupted and this plate (50) has at least one barrier such that a first fluid, in particular coolant flow, is diverted into a flow channel formed in the other plate (54), at least two flow channels (34), preferably each flow channel (34) is assigned a separate inlet (26) and preferably also an outlet (26), and a closed flow space (56) for a second fluid, for example a coolant, is formed between the plates (12, 14, 50, 54). Cooler (10) after Claim 1 , characterized in that a maximum of three, preferably two different types of plates (12), two, preferably one type thereof with flow channels (34) therein, are provided. Cooler (10) after Claim 1 or 2 , characterized in that at least one type of plate (12) is installed in at least two different orientations, preferably rotated by 180°. Cooler (10) according to one of the Claims 1 until 3 , characterized in that at least one plate (12,14) has a thickness of 0.4 to 0.6 mm and/or at least one flow channel in a plate (12, 14) has a depth of 0.65-0.8 mm. Cooler (10) according to one of the Claims 1 until 4 , characterized in that the first fluid is guided in a meandering and/or in at least a simple, in particular triple U-shape and/or in a straight line through the cooler (10) and/or the flow channels. Cooler (10) according to one of the Claims 1 until 5 , characterized in that it has a mechanical internal pressure resistance corresponding to a maximum operating pressure of refrigerant R744. Cooler (10) according to one of the Claims 1 until 6 , characterized in that turbulators (38) are provided in particular outside the flow channels (34) for the coolant. Cooler (10) according to one of the Claims 1 until 7 , characterized in that the second fluid is passed in a V-shape and/or arc-shaped through a space between the plates. Cooler (10) according to one of the Claims 1 until 8th , characterized in that in a first group (28) of plates (12, 14, 50, 54) the flow channels are formed in a first shape, for example rectilinear, and in a second group (30) of plates (12, 14, 50, 54) in a second shape, for example U-shaped. Cooler (10) according to one of the Claims 1 until 9 , characterized in that the plates (12, 14, 50, 54) are connected to one another in the region of inlets and outlets (16-22) and/or at the outer edge and/or at least one stiffening plate and/or at least one fold (46) at least in sections or places is provided on the outer edge. Cooler (10) according to one of the Claims 1 until 10 , characterized in that all inlets and outlets (26) for the first fluid have a diameter of 4.0 to 4.4 mm, in particular with a plate thickness of approximately 0.6 mm, or a diameter of 2.8 to 3.2 mm, in particular with a plate thickness of approximately 0.4 mm. Cooler (10) according to one of the Claims 1 until 11 , characterized in that all inlets and outlets (26) for the first fluid are surrounded by an elevation or depression formed from the plate material. Cooler (10) after Claim 12 , characterized in that the elevation or depression is followed by an elevation or depression which forms a flow channel (34). Cooler (10) after Claim 12 or 13 , characterized in that all elevations or depressions are of the same height or depth. Cooler (10) according to one of the Claims 1 until 14 , characterized in that sections of flow channels (34) formed in different plates (12, 14, 50, 54) are at least partially of equal length. Cooler (10) according to one of the Claims 1 until 15 , characterized in that in each plate (12, 14, 50, 54) a flow channel (34) is connected to each inlet and outlet (26), so that in other words the fluid flow is not diverted immediately after entering an adjacent plate (12, 14, 50, 54).

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