DE102022126383A1 - Heat exchanger consisting of two types of plates - Google Patents

Abstract

Heat exchanger (100), in particular for a motor vehicle, comprising at least one first plate (P1) and at least one second plate (P2). The at least two plates (P1, P2) each have at least one first opening (O11, O21). The at least two plates (P1, P2) each have at least one flat region (EB1, EB2) adjacent to the at least one first opening (O11, O21). The at least two plates (P1, P2) are arranged next to one another or one above the other along a stacking direction (SR). The at least one second flat region (EB2) of the second plate (P2) is connected to the at least one first flat region (EB1) of the first plate (P1) adjacent in the stacking direction (SR).

Description

The invention relates to a heat exchanger consisting of two types of plates, the production of the heat exchanger and the use of the heat exchanger in a motor vehicle.

The publication EN 10 2004 036 951 A1 describes a heat exchanger that is formed from interconnected plates that are arranged next to or on top of each other. Between the plates, cavities that are closed off from the outside are formed, through which a first medium and a second medium flow alternately from two first openings (an inlet line and an outlet line). The plates arranged between the cover plates are of the same design. A plate has structures (wave profiles). The structures are represented by channel-shaped elevations and depressions. Contact points (touch points) occur on the structures (wave profiles) between two adjacent plates. The contact points occur in the base plane of the adjacent plate. The adjacent plates are connected to each other at the contact points. The structures and are designed in such a way that the flow of the first and second medium from the corresponding first opening to the corresponding second first opening does not run in a straight line. In this way, turbulence is generated in the flow of the first and second medium. The structures also increase the surface area of a plate. With an increased surface area of the plate, the performance of the heat exchanger can be increased because a larger surface is available for the exchange of heat. The plate has two first openings and two second openings (a pair of holes for the inlet line and outlet line for the first and second medium). The second openings have a raised area. The plate has a raised (headed) edge all around. Adjacent plates are connected to one another at the edge and the raised areas. In this way, the cavity between two adjacent plates is fluidically separated from an adjacent cavity.

The plates are arranged between a lower cover plate and an upper cover plate along a stacking direction. An adjacent plate is arranged rotated by 0° or 180° around the stacking direction. In this way, two separate flow paths are created for the two media. The strength of a plate is heavily dependent on the flat areas adjacent to the openings. These areas have no structures. When the plate is loaded, these areas can sink or bulge. The flat areas are loaded by the pressure of the media. As a rule, the two media have different pressures. This pressure difference places additional strain on the flat areas adjacent to the openings. In order to produce a plate with sufficient strength, it is necessary to increase the thickness of the plate, which is disadvantageous. The thickness of a plate indicates the thickness of the material used. The thickness of the plate could also be viewed as the strength of the material used. In addition, it may be necessary to increase the thickness of the lower and upper cover plates in order to increase the strength of the plates in between. This disadvantageously increases the material used.

The device according to the invention with the features of the independent patent claim has the advantage that the plates of the heat exchanger have a high strength and the thickness of the plates at least does not increase and one of the two media can have a significantly higher pressure than media currently used in series.

The starting point of the invention is a heat exchanger consisting of plates. The heat exchanger can be used in particular in a motor vehicle. The heat exchanger can have at least one first plate and at least one second plate. The at least two plates can each have at least one first opening. The at least two plates can each have at least one flat area adjacent to the at least one first opening. The at least two plates can be arranged next to one another or one above the other along a stacking direction. The plates can be arranged between a lower and an upper cover plate next to one another or one above the other along a stacking direction. Along a stacking direction means that the plates are stacked one above the other or arranged next to one another from the lower cover plate to the upper cover plate. Cavities can be created between the plates arranged one above the other or next to one another. The at least one second flat area of the second plate can be connected to the at least one first flat area of the first plate adjacent in the stacking direction. Two media can flow through the heat exchanger. The two media can each have a different pressure. The heat exchanger can be used in a coolant circuit for a motor vehicle. Pressure is understood as the effect of a force distributed over the surface that acts perpendicularly on a flat surface. There is a discussion about requiring the use of carbon dioxide in a motor vehicle coolant circuit in a European directive. Carbon dioxide can be three to four times more pressure than current media used in series. This three to four times higher pressure can place a heavy load on the flat areas of the plates and greatly reduce the strength of the flat areas of the plates. Strength is understood to be the mechanical load-bearing capacity of a plate until the plate fails. A break or excessive permanent deformation of the plate can, for example, cause this failure. Since the second flat area and the first flat area can be connected to one another, the thickness of the material in the flat areas can advantageously increase. If the thickness of the first and second plates are the same, the thickness of the plate can double. In this way, the strength of the two plates can also advantageously increase and the plates can advantageously withstand the three to four times higher load caused by the use of carbon dioxide as a medium in the coolant circuit in which the heat exchanger is used. It is also possible for the flat areas to be touched by the carbon dioxide as a medium. This means that the at least one first flat area and also the at least one second flat area are subjected to the pressure of the carbon dioxide. The creation of a pressure difference between the flat areas of adjacent plates can thus advantageously be avoided. In this way, a load on the flat areas due to a pressure difference can advantageously be avoided. An increase in the thickness of the cover plates in order to increase the strength of the heat exchanger can also advantageously be avoided.

The at least two plates can each have a structure. The first structure of the first plate can be formed in the stacking direction. The second structure of the second plate can be formed against the stacking direction. In this way, the flat areas can be connected to one another. The structures of the at least two plates can be formed by channel-shaped elevations or depressions. Alternatively, it is conceivable that the structures are formed by knobs or cones. The structures can increase the surface area of the plates. This means that a larger surface area is available for the exchange of heat. Turbulence can also be generated in the flow of the media.

The second structure of the second plate can be connected to the first structure of the first plate adjacent in the stacking direction. Contact points can occur between the structures. In this way, the cavities between adjacent plates can be divided into individual channels. In this way, the distribution of a medium to a plate can be improved and thus the exchange of heat between the two media.

The at least two plates can each have a base plane. The contact points that occur between the structures can each have a distance from the base plane. The contact points between the structures of two adjacent plates can occur not only at the base planes. The contact points can occur in all areas of the structures, for example on the channel-shaped elevations. In this way, the flow of the media between the plates can have a freely selectable component in or against the flow direction. In this way, the turbulence that occurs in the flow can advantageously be increased or adjusted.

In a first embodiment according to the invention, the at least two plates can each have at least one second opening. The at least one second opening can each have a dome-like edge. The first dome-like edge of the first plate can be formed in the stacking direction. The second dome-like edge of the second plate can be formed against the stacking direction. The dome-like edges can be connected to one another. In this way, adjacent cavities between plates can be fluidically separated from one another. Fluidically separated means that no or only negligible amounts of a medium can pass through the connection. It is conceivable that the plates consist of an aluminum alloy and are produced by deep drawing. If the dome-like edges and the structures of the plates are each formed in the same direction (in or against the stacking direction), the production of the plates is advantageously simplified.

In a second embodiment according to the invention, the at least one first plate can have at least one second opening. The at least one second opening can have a first dome-like edge. The first dome-like edge can be formed in or against the stacking direction. It is conceivable that the first dome-like edge is formed in the stacking direction. The first structure can be formed in the stacking direction. This can advantageously simplify the manufacture of the first plate. Alternatively, it is conceivable that the first dome-like edge is formed against the stacking direction. The first dome-like edge can be connected to an adjacent second plate. A second plate can have at least one second opening. The at least one second opening of the second plate can be designed without a dome-like edge. Advantageously, this simplifies the production of the second plate.

In this way, the adjacent cavities between plates can be fluidically separated.

In a further embodiment according to the invention, the at least one second plate can have at least one second opening. The at least one second opening can have a second dome-like edge. The second dome-like edge can be formed in or against the stacking direction. Since the second structure can be formed against the stacking direction. It is conceivable that the second dome-like edge is formed against the stacking direction in order to simplify the production of the second plate. Alternatively, the second dome-like edge can be formed in the stacking direction. The second dome-like edge can be connected to an adjacent first plate. A first plate can have at least one second opening. The at least one second opening of the first plate can be designed without a dome-like edge. This can advantageously simplify the production of the first plate. In this way, the adjacent cavities between plates can be fluidically separated.

The plates can have a raised edge all around. The edge of the plates can be formed in the stacking direction. Two adjacent plates can be connected at the edges in order to fluidically separate the heat exchanger from the environment.

Two media can flow through the heat exchanger. The at least one first flat area and the at least one second flat area can be touched by the first medium. The at least one first flat area and the at least one second flat area can be touched by an amount of the second medium that approaches zero. It is conceivable that carbon dioxide is used as the first medium. In this case, the at least one first flat area and the at least one second flat area are touched by the carbon dioxide. Advantageously, this means that no pressure difference can arise in the area of the flat areas and a load on the flat areas can be avoided.

The plates can comprise a metal material. It is conceivable that the plates consist of an aluminum material. Alternatively, it is conceivable that stainless steel is used to manufacture the plates. The plates can be made in one piece. It is conceivable to manufacture the plates by embossing. However, it is also conceivable to manufacture the plates by deep drawing. The edge, the structures, the first openings, the second openings and the dome-like edges on the second openings can be manufactured in a single process step. Alternatively, in a further embodiment according to the invention, the plates could be manufactured in two pieces. For example, the structures could be inserted into the plates as a separate component and then connected to the plates.

Two adjacent plates can be connected in a material-locking manner at the contact points. Contact points can occur on the peripheral edge, on the dome-like edges of the second openings and the structures. Preferably, a soldering process, in particular brazing, can be used. If a soldering process is used, the plates are usually solder-plated to enable the individual plates to be soldered tightly together. However, it is also conceivable to connect the plates to one another using a welding process, such as laser welding. However, it is also conceivable to connect the plates to one another using an adhesive. For this, the plates are covered with an adhesive layer and then connected to one another.

The heat exchanger according to the invention can be manufactured in the following way. The plates can be embossed. Another conceivable possibility for producing the plates can be deep drawing. It is conceivable to emboss or deep draw the peripheral edge, the first openings, the second openings, the dome-like edges, the structures in one process step. The plates can be arranged between a lower cover plate and an upper cover plate along a stacking direction. A first plate and a second plate can always be arranged alternately one above the other along a stacking direction. Along a stacking direction means that the plates are stacked one above the other or arranged next to one another from the lower cover plate to the upper cover plate. The following methods for firmly connecting the plates are conceivable: soldering, welding and gluing. The plates can be connected at the following contact points: the peripheral edge, the dome-like edges and the structures.

In a first use according to the invention, the heat exchanger can be used in a coolant circuit of a motor vehicle. It is conceivable that the heat exchanger is used as an oil cooler. In order to prevent the oil in the motor vehicle from aging, it is necessary to dissipate the heat as constantly as possible. To do this, it may be necessary to increase the volume flow of the oil. This leads to an increase in the pressure of the oil. It is conceivable to design the heat exchanger such that the flat areas are touched by the oil. In a second use according to the invention, the heat exchanger can be used in a coolant circuit of a motor vehicle. In a vehicle with an electric or predominantly electric drive, it is necessary to dissipate a lot of heat in a short period of time. To do this, it may be necessary to increase the volume flow of a medium in the heat exchanger. This leads to an increase in the pressure occurring in the heat exchanger and thus increases the load on the flat areas of the plates. It is conceivable to design the heat exchanger such that the medium with the higher pressure touches the flat areas. This enables the plates to withstand the increased loads.

• 1 eine erste Platte in einer ersten erfindungsgemäßen Ausführung
• 2 eine zweite Platte in einer ersten erfindungsgemäßen Ausführung
• 3 Schnitt von drei ersten Platten sowie drei zweiten Platten in Bereich der Strukturen entlang einer Stapelrichtung übereinander angeordnet
• 4 Schnitt von drei ersten Platten sowie drei zweiten Platten im Bereich der Öffnungen entlang einer Stapelrichtung übereinander angeordnet
• 5 Wärmeübertrager, bestehend aus Platten die entlang einer Stapelrichtung übereinander angeordnet sind

In a further use according to the invention, the heat exchanger can be used in a refrigerant circuit of a motor vehicle. There is discussion that the use of carbon dioxide as a refrigerant in refrigerant circuits of motor vehicles should be prescribed in a European directive. This can mean a three- to four-fold increase in the pressure of the refrigerant (carbon dioxide) in the circuit compared to refrigerants currently used in series, such as R-1234ylf. The heat exchanger can be designed so that carbon dioxide can be used as the first medium. Flat areas of the plates are then advantageously touched by the carbon dioxide. The creation of a pressure difference between the flat areas of adjacent plates can thus advantageously be avoided. In this way, the plates of the heat exchanger can withstand the significantly increased loads compared to current series applications.

• 1 a first plate in a first embodiment according to the invention
• 2 a second plate in a first embodiment according to the invention
• 3 Section of three first plates and three second plates in the area of the structures arranged one above the other along a stacking direction
• 4 Section of three first plates and three second plates arranged one above the other in the area of the openings along a stacking direction
• 5 Heat exchanger consisting of plates arranged one above the other along a stacking direction

In the 1 a plan view of the first plate P1 is shown in a first embodiment according to the invention. The first plate P1 has a circumferential raised edge RA. The edge RA is pronounced in the stacking direction SR. The first plate P1 has two first openings O11 and two second openings O12. The two second openings O12 each have a first dome-like edge DO1. The first dome-like edge DO1 is pronounced in the stacking direction SR. The first plate P1 has a first structure ST1. The first structure ST1 is pronounced in the stacking direction SR. The first structure ST1 is represented by channel-shaped elevations and depressions. The first structure ST1 enlarges the surface of the first plate P1 for the exchange of heat. The first structure ST1 also creates turbulence in the flow of a medium (not shown). The first plate P1 has a first flat region EB1 adjacent to a first opening. The first flat region EB1 encloses the first opening O11. In the first flat area EB1, the first plate has no channel-shaped elevations and depressions. The first plate P1 has a first base plane EB1. The channel-shaped elevations of the first structure ST1 are spaced from the first base plane EB1. The first plate P1 can have a metallic material. It is conceivable that the first plate P1 consists of an aluminum alloy. Alternatively, it is conceivable that the first plate P1 consists of stainless steel. The first plate P1 is in one piece and can be produced, for example, by embossing. Alternatively, the plate could also be produced by deep drawing.

The 2 shows a plan view of the second plate P2 in a first embodiment according to the invention. The second plate P2 has a circumferential raised edge RA. The edge RA is pronounced in the stacking direction SR. The second plate P2 has two first openings 012 and two second openings 022. The two second openings 022 each have a second dome-like edge DO2. The second dome-like edge DO2 is pronounced against the stacking direction SR. The second plate P2 has a second structure ST2. The second structure ST2 is pronounced against the stacking direction SR. The second structure ST2 is represented by channel-shaped elevations and depressions. The second structure ST2 enlarges the surface of the second plate P2 for the exchange of heat. The second structure ST2 also creates turbulence in the flow of a medium (not shown). The second plate P2 has a second flat region EB2 adjacent to a first opening. The second flat area EB2 encloses the first opening 021. In the second flat area EB2, the first plate has no groove-shaped elevations and depressions. The second plate P2 has a second base plane EB2. The groove-shaped elevations The second plate P2 can comprise a metallic material. It is conceivable that the second plate P2 consists of an aluminum alloy. Alternatively, it is conceivable that the second plate P2 consists of a stainless steel. The second plate P2 is in one piece and can be manufactured by embossing, for example. Alternatively, the plate could also be manufactured by deep drawing.

In 3 the section of three first plates P1 and three second plates P2 is shown. The plates P1, P2 are each shown in a first embodiment according to the invention. The plates P1, P2 are arranged one above the other along the stacking direction SR. The bottom plate is a second plate P2, above which a first plate P1 is arranged. The plates P1, P2 each have a structure ST1, ST2. The first structure ST1 of the first plate P1 is pronounced in the stacking direction SR. The second structure of the second plate P2 is pronounced against the stacking direction SR. The structures ST1, ST2 are shown by groove-shaped elevations and depressions. The plates P1, P2 each have a flat area EB1, EB2. The plates P1, P2 each have a peripheral edge RA. The plates P1, P2 are materially connected to the flat areas EB1, EB2, the edge RA and the structures. For example, the plates can be connected by the following material-bonding processes: brazing, welding and gluing. The plates P1, P2 each have a base plane BE1, BE2. The contact points at which the structures ST1, ST2 are connected have a first distance AB1 to the first base plane BE1 of the first plate P1 and a second distance AB2 to the second base plane BE2 of the second plate P2.

4 show a section of three first plates P1 and three second plates P2, each in a first embodiment according to the invention. The section is along the first openings O11, O21 and second opening O12, O22. The plates P1, P2 are arranged one above the other along the stacking direction SR between a second plate P2 and a first plate P1. The plates P1, P2 each have a surrounding edge RA. The flat areas EB1, EB2 are arranged adjacent to the first openings O11, O21. The second openings 012, 012 have a dome-like edge DO1, DO2. The plates P1, P2 each have structures ST1, ST2. The first dome-like edge DO1 and the first structure ST1 of a first plate P1 are pronounced in the stacking direction. The second dome-like edge DO2 and the second structure ST2 are pronounced against the stacking direction ST2. A cavity is pronounced between the plates P1, P2. A first medium M1 or a second medium M2 flows through these cavities alternately. The first medium is distributed or collected again via the first openings O11, O21 into a cavity between two plates P1, P2. The second medium M2 is distributed via the second openings O12, O22 into a cavity between two plates P1, P2. The structures ST1, ST2 divide these cavities into individual channels. In this way, the surface area for the exchange of heat between the two media M1, M2 is increased. In this way, turbulence can be generated in the flow of the two media M1, M2. The plates P1, P2 are materially connected at the dome-like edges DO1, DO2. In this way, the cavities are fluidically separated from one another. The plates P1, P2 are materially connected at the edges RA and to the structures ST1, ST2. The flat areas EB1, EB2 are connected to one another. The flat areas EB1, EB2 are touched by the first medium M1. There is currently discussion about whether the use of carbon dioxide in motor vehicle refrigeration circuits should be prescribed in a European directive. When carbon dioxide is used, the pressure is three to four times higher than the pressures currently encountered in media currently used in series in motor vehicle refrigeration circuits. Carbon dioxide can be used as the first medium M1 and can have a significantly higher pressure. The materially bonded plates P1, P2 have twice the material thickness in the flat areas EB1, EB2. In this way, the strength of the plates P1, P2 is advantageously increased. The pressure of the first medium M1 acts on the flat areas EB1, EB2. Since the pressure for the flat areas EB1, EB2 is the same, a load resulting from a pressure difference is advantageously avoided. This increases the strength of the plates P1, P2. The second medium M2 can usually have a significantly lower pressure than the first medium M1.

In 5 the heat exchanger 100 is shown in a first embodiment according to the invention. The plates P1, P2 are arranged one above the other along the stacking direction SR between a lower cover plate UAP and an upper cover plate OAP. Plates P1, P2 are always arranged alternately with each other. In this way, two fluidically separated flow paths are created for two media (not shown). The plates P1, P2, the lower cover plate UPD and the upper cover plate ODP are connected to each other in a materially bonded manner. The upper cover plate ODP has a first inlet connection ZA1 and a first outlet connection AA1 for a first medium (not shown). The upper cover plate ODP has a second inlet connection ZA2 and a second drain connection AA2 for a second medium, not shown.

List of reference symbols

P1

first plate according to the invention

P2

Second inventive plate

SR

Stacking direction of the plates on top of each other or next to each other

R.A.

circumferential raised edge of the at least two plates according to the invention

ST1

first structure of the first plate according to the invention

ST2

second structure of the second plate according to the invention

O11, O21

first opening of the at least two plates according to the invention

O21, O22

second opening of the at least two plates according to the invention

EB1

first flat area, adjacent to a first opening

EB2

second flat area, adjacent to a first opening

DO1

first dome-like edge of a second opening

DO2

second dome-like edge of a second opening

BE1

first floor level of the first plate according to the invention

BE2

second floor level of the second plate according to the invention

AB1

first distance of the contact points of the two structures to the first floor level

STARTING AT 2

Second distance of the contact points of the two structures to the second floor plane

M1

first medium

M2

second medium

100

Heat exchangers according to the invention consist of plates

OAP

upper cover plate of the heat exchanger

UAP

lower cover plate of the heat exchanger

ZA1

first inlet connection of the heat exchanger for a first medium

ZA2

second inlet connection of the heat exchanger for a second medium

AA1

first drain connection of the heat exchanger for a first medium

AA2

second drain connection of the heat exchanger for a second medium

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 102004036951 A1 [0002]

Claims (14)

Heat exchanger (100), in particular for a motor vehicle, comprising: - at least one first plate (P1) - at least one second plate (P2) - wherein the at least two plates (P1, P2) each have at least one first opening (O11, O21) - wherein the at least two plates (P1, P2) each have at least one flat region (EB1, EB2) adjacent to the at least one first opening (O11, O21) - wherein the at least two plates (P1, P2) are arranged next to one another or one above the other along a stacking direction (SR), characterized in that the at least one second flat region (EB2) of the second plate (P2) is connected to the at least one first flat region (EB1) of the first plate (P1) adjacent in the stacking direction (SR). Heat exchanger (100) to Claim 1 , characterized in that the at least two plates (P1, P2) each have a structure (ST1, ST2), wherein the first structure (ST1) of the first plate (P1) is formed in the stacking direction (SR), wherein the second structure (ST2) of the second plate (P2) is formed counter to the stacking direction (SR). Heat exchanger (100) to Claim 1 and 2 , characterized in that the second structure (ST2) of the second plate (P2) is connected to the first structure (ST1) of the first plate (P1) adjacent in the stacking direction (SR). Heat exchanger (100) to Claim 1 , 2 and 3 , characterized in that the at least two plates (P1, P2) each have a ground plane (BE1, BE2), wherein the contact points occurring between the structures (ST1, SR2) each have a distance (AB1, AB2) to the ground plane (BE1, BE2). Heat exchanger (100) to Claim 1 , 2 , 3 and 4 , characterized in that the at least two plates (P1, P2) each have at least one second opening (O21, O22), wherein the at least one second opening (O21, O22) each has a dome-like edge (DO1, DO2), wherein the first dome-like edge (DO1) of the first plate (P1) is formed in the stacking direction (SR), wherein the second dome-like edge (DO2) of the second plate (P2) is formed against the stacking direction (SB), wherein the dome-like edges (DO1, DO2) are connected to one another. Heat exchanger (100) to Claim 1 , 2 , 3 and 4 , characterized in that the at least one first plate (P1) has at least one second opening (O21), wherein the at least one second opening (O21) has a first dome-like edge (DO1), wherein the first dome-like edge (DO1) is formed in or against the stacking direction (SR), wherein the first dome-like edge (DO1) is connected to an adjacent second plate (P2). Heat exchanger (100) to Claim 1 , 2 , 3 and 4 , characterized in that the at least one second plate (P2) has at least one second opening (O22), wherein the at least one second opening (O22) has a second dome-like edge (DO2), wherein the second dome-like edge (DO2) is formed in or against the stacking direction (SR), wherein the second dome-like edge (DO2) is connected to an adjacent first plate (P1). Heat exchanger (100) according to one of the preceding claims, characterized in that the plates (P1, P2) have a circumferential raised edge (RA), wherein the edge (RA) of the plates (P1, P2) is each formed in the stacking direction (SR). Heat exchanger (100) according to one of the preceding claims, characterized in that the heat exchanger (100) is flowed through by two media (M1, M2), wherein the at least one first flat region (EB1) and the at least one second flat region (EB2) are touched by the first medium (M1), wherein the at least one first flat region (EB1) and the at least one second flat region (EB2) are touched by an amount of the second medium (M2) approaching zero. Heat exchanger (100) according to one of the preceding claims, characterized in that the plates (P1, P2) each comprise a metal material, wherein the plates (P1, P2) are designed in one piece. Heat exchanger (100) according to one of the preceding claims, characterized in that two adjacent plates (P1, P2) are materially connected at the contact points. Method for producing a heat exchanger (100) according to at least one of the preceding Claims 1 - 11 comprising the following process steps: - embossing or deep drawing of the plates (P1, P2) - stacking of the plates (P1, P2) - materially bonding the plates (P1, P2) Heat exchanger (100) for a refrigerant circuit or a coolant circuit of a power vehicle according to at least one of the preceding Claims 1 - 11 . Heat exchanger (100) for a coolant circuit of a motor vehicle according to at least one of the preceding Claims 1 - 11 characterized in that carbon dioxide is used as the first medium (M1).

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