EP2144029A1 - Heat transfer unit, in particular that of a motor vehicle, for cooling a cooling agent and method for cooling a cooling agent - Google Patents

Abstract

The unit (1) has coolant pipes (3) flowing into lateral coolant collecting tanks (5, 6) of the heat-transfer unit. Wave-like ribs (4) are located between two directly adjacent coolant pipes. The coolant is circulated in a closed coolant circuit, where the coolant pipes have a supply line (19) and a return line (20) for the coolant of the coolant circuit. The supply line has a set of coolant outer channels, and the return line has a set of coolant inlet lines. The supply line and/or outer channels, and the return line and/or inner channels exhibit a common housing. An independent claim is also included for a method for cooling a coolant in a cooling circuit.

Description

The invention relates to a heat exchanger, in particular of a motor vehicle for cooling a refrigerant, with refrigerant pipes, which open into lateral refrigerant collecting boxes of the heat exchanger, and with corrugated fins, which are arranged between two immediately adjacent refrigerant tubes, wherein the refrigerant can circulate in a closed circuit. The invention also relates to a method for cooling a refrigerant in a refrigerant circuit.

Such heat exchangers are well known from the prior art and are used successfully especially in motor vehicles.

For this purpose, generic heat exchangers generally have a block which is essentially composed of refrigerant tubes and corrugated ribs, wherein the ends of the refrigerant tubes are in refrigerant collecting boxes of the heat exchanger open, so that a refrigerant introduced into a first refrigerant collecting box can flow through the refrigerant tubes into a second refrigerant collecting box of the heat exchanger.

Such a heat exchanger is for example from the published patent application DE 101 56 944 A1 in which a refrigerant flows into a first portion of a first refrigerant collecting case, passes through first refrigerant tubes into a first header section of a second refrigerant header, flows from there into a second header section of the second refrigerant header and from there back into the direction of further refrigerant tubes the first refrigerant collecting box flows and in this case passes into a second header section of the first refrigerant collecting box and from there, the heat exchanger leaves heated again. By such a forward and backward conduction of the refrigerant between the two refrigerant collecting boxes, the refrigerant can absorb heat energy from the ambient air particularly well, whereby the ambient air cooled very quickly and the effectiveness of the air conditioner shown there can be significantly improved.

It is an object of the present invention to be able to build generic heat exchangers even more compactly, wherein the heat exchangers can continue to represent a very torsionally rigid structural unit despite a material saving.

The object of the invention is achieved by a heat exchanger in particular of a motor vehicle for cooling a refrigerant with refrigerant pipes, which open into lateral refrigerant collecting boxes of the heat exchanger, and with corrugated fins, which are arranged between two immediately adjacent refrigerant tubes, wherein the refrigerant in a single Closed refrigerant circuit can circulate, and the heat exchanger is characterized in that a refrigerant pipe has both a flow and a return for the refrigerant of the refrigerant circuit.

The term "thermal silver carrier" describes any device by means of which heat can be transferred from a first medium to another medium, so that the first medium can be cooled in this case. In particular, in this case heat exchangers are detected by motor vehicles, such as cross-flow heat exchangers used there, in which a refrigerant to be cooled is passed as liquid through refrigerant pipes, which are in contact with corrugated fins, and in which the corrugated fins can be flowed around by ambient air, so that the heat energy the refrigerant can be discharged in particular via the corrugated fins in the ambient air. Here, the flow direction of the ambient air crosses the flow direction or the flow directions of the refrigerant.

The term "refrigerant collection boxes" describes means of the heat exchanger that provide cavities into which open ends of the refrigerant tubes may open, so that refrigerant can flow through the refrigerant tubes from a first refrigerant collection box of the heat exchanger into another refrigerant collection box of the heat exchanger and vice versa.

The term "corrugated ribs" in the present case means, preferably made of a good heat-conducting metal sheet, such as a rib shaft, which are in direct operative connection with the refrigerant tubes, so that contained in a refrigerant heat energy from the refrigerant tubes can go particularly well into the corrugated fins. The corrugated fins can then because of their relatively large surface providing this Heat energy particularly well to the environment, especially when they are flowed through by the ambient air or.

Particularly in the automotive industry, R134a, which can circulate in the closed refrigerant circuit, is currently preferably used with regard to the refrigerant.

As a refrigerant pipes tubes can be used with different cross-sections. However, in a heat exchanger, preference is often given to using flat tubes which can be connected particularly well and over a large area to corrugated ribs of a heat exchanger.

Here, according to the present invention, such a refrigerant pipe has a single refrigerant flow and return of the aforementioned single closed refrigerant circuit, so that the refrigerant is preferably returned to a second refrigerant side box of the heat exchanger and back again with each of the existing refrigerant pipes from a first side refrigerant box of the heat exchanger can.

Advantageously, in this case the refrigerant is passed through the refrigerant pipe in a single refrigerant pipe in two opposite directions.

Characterized in that the refrigerant pipe simultaneously forms both a flow and a return, the refrigerant pipe is particularly resistant to bending, so that the heat exchanger can be designed to be particularly torsionally rigid and particularly solid.

Although there already exist heat exchangers in which an inner tube with a small diameter is arranged in an outer tube with a larger diameter, however, the inner tube and the outer tube are in this case approximately as a refrigerant tubes connected to different circuits, for example, a first fluid of a first cooling circuit can cool a second fluid of a second cooling circuit in the countercurrent flow through the refrigerant tubes.

However, such heat exchangers are not meant in the present case, since they have two separate closed circuits with respect to the inner tube and the outer tube, and therefore, because of the two required closed cooling circuits, they are also particularly complex and large.

In contrast, the refrigerant pipe according to the invention provides a flow and a return for a single refrigerant circuit, in which the refrigerant between two refrigerant collecting boxes can advantageously flow back and forth.

In particular, can be achieved by such a simple construction, a significant reduction in weight of the heat exchanger, since by means of the refrigerant pipe constructed in this way considerable material savings potentials are present with respect to the heat exchanger. This leads in particular to heat exchangers made of aluminum also to a significant cost reduction.

It is understood that the present refrigerant pipes having the flow and return for the single refrigerant passed through the refrigerant pipe can be tightly joined by known joining methods such as a soldering method or a sticking method, particularly to the refrigerant collecting boxes.

Advantageously, the refrigerant pipe with its flow and its return and related refrigerant pipe channels in an extrusion process be prepared, so that the provision of the refrigerant tubes can be done inexpensively. It is understood, however, that the refrigerant tubes can also be composed of several component components. For example, a welded tube is inserted into an extruded flat tube, so that the refrigerant tubes according to the invention can form a flow and a return for a common refrigerant.

A preferred embodiment provides that the flow has more than one refrigerant passage, preferably a plurality of refrigerant outer passages of the refrigerant pipe. Forms the flow more than a refrigerant channel, for example, in a wall of the refrigerant pipe, can be derived in the refrigerant heat energy particularly well in the wall of the refrigerant pipe and thus also particularly well in the corrugated fins of the heat exchanger. Preferably, a plurality of refrigerant outer channels are provided in the wall of the refrigerant pipe for this purpose.

Does the flow in particular a plurality of refrigerant outer channels, it is advantageous if the return has a refrigerant passage, preferably a refrigerant inner passage of the refrigerant pipe. This makes it possible that already cooled down refrigerant advantageous to return in the center of the refrigerant pipe again.

In this context, an advantageous embodiment provides that the refrigerant outer channels of the refrigerant tube and the refrigerant inner channel of the refrigerant tube are arranged in a common refrigerant circuit.

The refrigerant tube is particularly compact and torsionally rigid when the flow or the refrigerant outer channels of the refrigerant tube and the return or the refrigerant inner channel of the refrigerant tube have a common housing.

Are the flow or the refrigerant outer channels of the refrigerant pipe disposed in a wall of the return or the refrigerant inner channel of the refrigerant pipe, the refrigerant pipe has a particularly simple and effective structure.

The structure of the heat exchanger can be further simplified if only one of the refrigerant collecting boxes has a refrigerant inlet and a refrigerant outlet, by means of which the heat exchanger can be connected to further Kaftemittelkreislaufkomponenten.

Such additional refrigerant circuit components may be, for example, external refrigerant line strands to an internal combustion engine or from an internal combustion engine.

In this context, it is advantageous if a first of the refrigerant collecting boxes forms a terminal collecting box, by means of which the heat exchanger can be connected to the further refrigerant circuit components. Preferably, only the terminal collecting box has the refrigerant inlet and the refrigerant outlet. Thus, the weight of the heat exchanger can be further reduced.

In order to redirect the refrigerant well within the heat exchanger, it is advantageous if a second of the refrigerant collecting boxes forms a Umlenksammelkasten by means of which the refrigerant is deflected within the Umlenksammelkastens of the flow of the refrigerant pipe in the return of the refrigerant pipe.

A problem-free separation of the flow and the return of the refrigerant pipe in the area of the refrigerant collection boxes of the heat exchanger can be structurally easily achieved when a refrigerant collection box having an inner header and an outer header. For example, in this case, the refrigerant outer channels of the refrigerant pipe open into the outer header boxes of the refrigerant collecting boxes and the refrigerant inner channel into the inner header boxes of the refrigerant collecting boxes of the heat exchanger.

Thus, for example, the return can extend into the inner manifolds of the refrigerant collection boxes, it is advantageous if the return is designed to be longer than the flow.

It is also advantageous if the return flow of the refrigerant pipe is arranged at a distance from a cooling medium for cooling the refrigerant. This ensures that the flow and thus also the still warm refrigerant can advantageously come into contact with the cooling medium.

The object of the invention is also achieved by a method for cooling a refrigerant in a refrigerant circuit, in which the refrigerant from a first circulation line strand enters an inlet collecting chamber of a connection box of a heat exchanger, the refrigerant flows from there into a flow of a refrigerant pipe of the heat exchanger, the During the passage of the flow line of the refrigerant pipe, the refrigerant preferably releases heat energy to the environment via corrugations of the heat exchanger, the refrigerant passes into a first header chamber of a heat exchanger, and the refrigerant flows from the first header chamber to a second header chamber of the header box and from there through a connection port flows in a return line of the refrigerant pipe, the refrigerant is passed through the return passage into a drain collecting chamber of the terminal collecting box, and then ßend the refrigerant from the terminal box is introduced into a further circulation line of the refrigerant circuit.

By means of such a procedure, for example, a refrigerant can be directed and cooled in a confined space particularly effective in a heat exchanger of the motor vehicle.

Here, the first collecting chamber of the Umlenksammelkastens be formed for example by an outer Umlenksammelkasten the Umlenkksammelkastens and the second collection chamber of an inner Umlenksammelkasten the Umlenkksammelkastens.

Further advantages, objects and features of the present invention will be explained with reference to the appended drawing, in which an example of a heat exchanger with refrigerant tubes, each comprising a flow and a return for a common refrigerant of a closed refrigerant circuit, is shown.

Figur 1

schematisch eine Ansicht eines Wärmeübertragers mit Kältemittelrohren, welche einen Vorlauf und einen Rücklauf für ein gemeinsames Kältemittel aufweisen, zwischen zwei Kältemittelsammelkästen,

Figur 2

schematisch einen Querschnitt im Bereich eines der beiden Kältemittelsammelkästen mit einem inneren Sammelkasten und einem äußeren Sammelkasten des Wärmeübertragers,

Figur 3

schematisch einen weiteren Querschnitt eines weiteren Kältemittelsammelkastens des Wärmeübertragers mit eingezeichneten Strömungsrichtungen des Kältemittels,

Figur 4

schematisch einen Querschnitt eines der Kältemittelrohre des Wärmeübertragers,

Figur 5

schematisch eine geschnittene Ansicht eines Einlaufbereiches für Kältemittel an dem Wärmeübertrager, und

Figur 6

schematisch eine geschnittene Ansicht eines Ablaufbereiches für Kältemittel an dem Wärmeübertrager.

It shows

FIG. 1

2 schematically shows a view of a heat exchanger with refrigerant tubes, which have a feed and a return for a common refrigerant, between two refrigerant collecting boxes,

FIG. 2

FIG. 2 schematically shows a cross section in the region of one of the two refrigerant collecting boxes with an inner collecting box and an outer collecting box of the heat exchanger, FIG.

FIG. 3

2 schematically shows a further cross section of a further refrigerant collecting box of the heat exchanger with drawn flow directions of the refrigerant,

FIG. 4

schematically a cross section of one of the refrigerant tubes of the heat exchanger,

FIG. 5

schematically a sectional view of an inlet region for refrigerant to the heat exchanger, and

FIG. 6

schematically a sectional view of a drain area for refrigerant to the heat exchanger.

The Indian FIG. 1 shown heat exchanger 1 is used for cooling a refrigerant 2. For this purpose, the refrigerant 2 can flow through a plurality of refrigerant tubes 3 therethrough. For better heat dissipation, the heat exchanger 1 in addition corrugated fins 4 (here only exemplified) on.

In this exemplary embodiment, the refrigerant tubes 3 and the corrugated fins 4 extend approximately horizontally between a first refrigerant collecting box 5 and a second refrigerant collecting box 6 of the heat exchanger 1. The first refrigerant collecting box 5 of the heat exchanger 1 is in this embodiment a terminal collecting box 7, by means of which the heat exchanger 1 at another Not shown here refrigerant circuit components of a likewise not shown here in detail single refrigerant circuit can be connected.

For this purpose, the connection collecting box 7 has an inlet 8 and a drain 9. The inlet 8 is connected to an inlet collecting chamber 10 of the connection collecting box 7 and the outlet 9 is accordingly connected to a drain collecting chamber 11 of the connecting collecting box 7. Here, the inlet collection chamber 10, an outer collection box 12 (see FIG. 2 ) of the first refrigerant header 5 and the drain collection chamber 11 has an inner header 13 (see FIG FIG. 2 ) of the first refrigerant collecting box 5. By means of the outer Collection box 12 and the inner header tank 13, the inlet collection chamber 10 and the drainage collection chamber 11 is spatially separated from each other, so that between them, the refrigerant 2 can not flow directly.

In contrast to the first refrigerant collecting box 5, the second refrigerant collecting box 6 does not constitute a terminal collecting box 7 but a deflecting collecting box 14 by means of which the refrigerant 2 inside the heat exchanger 1 can be deflected.

For this purpose, the Umlenksammelkasten 14 an inner Umlenksammelkasten 15 and an outer Umlenksammelkasten 16, which are connected in this embodiment in a lower portion 17 of the heat exchanger 1 by means of a connection opening 18 spatially directly with each other. Through this connection opening 18, an exchange of the refrigerant 2 between the inner Umlenksammelkasten 15 and the outer Umlenksammelkasten 16 take place directly.

According to the invention, the refrigerant tubes 3 of the heat exchanger 1 both a flow 19 and a return 20.

This makes it possible for the refrigerant 2 to take the following advantageous flow path through the heat exchanger 1.

The refrigerant 2 flows via the inlet 8 into the inlet collecting chamber 10 of the first refrigerant collecting box 5. From the inlet collecting chamber 10, the refrigerant 2 flows further into the respective headers 19 of the refrigerant tubes 3 of the heat exchanger 1. Here, the refrigerant 2 flows through each of the existing refrigerant tubes 3 according to a flow direction 21, so that from the refrigerant 2 via the refrigerant tubes 3 and the connected refrigerant fins 4 can deliver heat energy to the environment 22.

From the respective headers 19 of the refrigerant tubes 3, the refrigerant 2 reaches the second refrigerant collecting box 6 of the heat exchanger 1, where it enters the outer Umlenksammelkasten 16 Umlenksammelkastens 14 and flows through the connection opening 18 in the inner Umlenksammelkammer 15 Umlenksammelkastens 14, rises there and flows into the returns 20 of the refrigerant tubes 3. In this case, flows through the refrigerant 2, the refrigerant tubes 3 a second time, and contrary to the flow direction 21, in the return flow direction 23 until the refrigerant 2 enters the drain collection chamber 11 of the first refrigerant tank 5 and from there via the outlet 9 again in the here not further shown refrigerant circuit is fed.

After FIG. 2 it can be seen well that the shorter flow 19 of the refrigerant pipe 3 opens into the inlet collecting chamber 10 and the longer return 20 of the refrigerant pipe 3 into the drain collecting chamber 11 of the terminal collecting box 7.

In the present case, the refrigerant tubes 3 can be connected to the refrigerant collecting boxes 5 and 6 using the known joining methods. On a side facing away from the refrigerant tubes 3 side 24 of the terminal box 7 is still a part of the inlet 8, in which a fastening means 25 is screwed, by means of which the heat exchanger 1 to a corresponding holding device (not shown here) can be attached.

After the presentation of the FIG. 3 shows how a refrigerant pipe 3 on the one hand in the outer Umlenksammelkasten 16 and on the other hand into the inner Umlenksammelkasten 15 opens. Here ends of the shorter flow 19 of the refrigerant pipe 3 in the outer Umlenksammelkasten 16, so that the refrigerant 2 can flow in unhindered there. Has the refrigerant 2 in the FIG. 1 Passes through the opening 18, it passes into the inner Umlenksammelkasten 15 of the second refrigerant tank 6 and the Umlenksammelkastens 14. From there, the refrigerant 2 flows in the return line 20 of the refrigerant pipe. 3

The example in the FIG. 4 shown refrigerant tube 3 has a housing 26 which forms both the flow 19 of the refrigerant tube 3 and the return 20 of the refrigerant tube. The flow 19 in this case comprises a plurality of refrigerant outer channels 27 (numbered here only by way of example), whereas, on the other hand, the return 20 only has a single refrigerant inner channel 28. Here, the refrigerant outer channels 27 of the flow 19 in the wall 29 of the return 20 and the refrigerant inner channel 28 are arranged. As a result, the refrigerant pipe 3 is particularly compact and extremely rigid, especially since additional dividers 30 are provided between the individual refrigerant outer channels. The refrigerant 2 flows in the refrigerant outer passages 27 in the forward flow direction 21. As shown in FIG FIG. 4 directed into the paper plane. In the refrigerant internal passage 28, the refrigerant 2 flows in the reverse return flow direction 23, as shown in FIG FIG. 4 thus directed out of the paper plane.

After the presentation of the others FIG. 5 the inlet 8 of the heat exchanger 1 is shown again in detail, it being well recognized that the inlet 8 extends into the inlet collecting chamber 10, in which also the open ends 31 of the refrigerant outer channels 27 open, the terminal collecting box 7. Accordingly, in each case an open end 32 of the refrigerant inner channel 28 opens into the drainage collection chamber 11 of the terminal collecting box 7.

Both the inlet collecting chamber 10 and the drainage collecting chamber 11 of the terminal collecting box 7 are axially closed in the region above the inlet 8 by means of an upper closure 33. Accordingly, the inlet collecting chamber 10 and the drainage collection chamber 11 are axially closed below the outlet 9 by means of a lower closure 34.

After the presentation of the FIG. 6 flows the refrigerant 2, after it has flowed through the refrigerant tubes 3 of the heat exchanger 1, from the outlet 9, which is connected to the drainage collection chamber 11, again from the heat exchanger 1 from. The outlet 9 is equipped with further fastening means 35, by means of which the heat exchanger 1 can be permanently secured to a suitable holding device, for example a motor vehicle, in a reliable manner. In the lower part of the heat exchanger 1, the corrugated fins 4 are still indicated schematically.

References list

1

Heat exchanger

2

refrigerant

3

Refrigerant pipes

4

corrugated fins

5

first refrigerant collecting box

6

second refrigerant collection box

7

Connection collection box

8th

enema

9

procedure

10

Inlet plenum

11

Outlet collection chamber

12

outer collection box

13

inner collection box

14

Umlenksammelkasten

15

inner diverting box

16

outer diverter box

17

lower area

18

connecting opening

19

leader

20

returns

21

Forward flow direction

22

Surroundings

23

Reverse flow direction

24

opposite side

25

fastener

26

casing

27

Refrigerant outer channels

28

Refrigerant inner channel

29

wall

30

dividers

31

open ends of the refrigerant outer channels

32

open end of the refrigerant channel

33

upper closure

34

lower closure

35

further fasteners

Claims (12)

Heat exchanger (1), in particular of a motor vehicle, for cooling a refrigerant with refrigerant tubes (3), which open into lateral refrigerant collecting boxes (5, 6) of the heat exchanger (1), and with corrugated fins (4), which between two immediately adjacent refrigerant tubes (3 ), wherein the refrigerant can circulate in a single closed refrigerant circuit, characterized in that a refrigerant pipe (3) has both a flow (19) and a return (20) for the refrigerant of the refrigerant circuit. Heat exchanger (1) according to claim 1, characterized in that the flow (19) has more than one refrigerant channel, preferably a plurality of refrigerant outer channels (27) of the refrigerant tube (3). Heat exchanger (1) according to claim 1 or 2, characterized in that the return (20) has a Käftemittelkanal, preferably a refrigerant inner channel (28) of the refrigerant pipe (3). Heat exchanger (1) according to claim 2 or 3, characterized in that the refrigerant outer channels (27) of the refrigerant tube (3) and the refrigerant inner channel (28) of the Käftemittelrohres (3) are arranged in a common refrigerant circuit. Heat exchanger (1) according to any one of the preceding claims, characterized in that the flow (19) or refrigerant outer channels (27) of Käitemittelrohres (3) and the return (20) or the refrigerant inner channel (28) of the refrigerant tube (3) a common Have housing (26). Heat exchanger (1) according to one of the preceding claims, characterized in that the flow (19) or refrigerant outer channels (27) of the refrigerant pipe (3) in a wall (29) of the return (20) and a refrigerant inner channel (28) of the refrigerant pipe (3) are arranged. Heat exchanger (1) according to one of the preceding claims, characterized in that only one of the refrigerant collecting boxes (5, 6) has a refrigerant inlet (8) and a refrigerant outlet (9), by means of which the heat exchanger (1) can be connected to further refrigerant circuit components. Heat exchanger (1) according to one of the preceding claims, characterized in that a first of the refrigerant collecting boxes (5, 6) forms a terminal collecting box (7), by means of which the heat exchanger (1) can be connected to further refrigerant circuit components. Heat exchanger (1) according to one of the preceding claims, characterized in that a second (6) of the refrigerant collecting boxes (5, 6) forms a Umlenksammelkasten (14), by means of which the refrigerant (2) within the Umlenksammelkastens (14) of the flow ( 19) of the refrigerant pipe (3) in the return (20) of the refrigerant pipe (3) is deflected. Heat exchanger (1) according to one of the preceding claims, characterized in that the return (20) of the refrigerant pipe (3) spaced from a cooling medium for cooling the refrigerant (2) is arranged. Heat exchanger (1) according to one of the preceding claims, characterized in that a refrigerant collecting box (5, 6) has an inner collecting box (13, 15) and an outer collecting box (12, 16). A method for cooling a refrigerant (2) in a refrigerant circuit, wherein the refrigerant (2) from a first circulation line strand in an inlet collecting chamber (10) of a terminal collecting box (7) of a heat exchanger (1) enters, the refrigerant (2) from there into a flow (19) of a refrigerant pipe (3) of the heat exchanger (1) flows in, the refrigerant (2) during the flow through the flow (19) of the refrigerant pipe (3) heat energy preferably via corrugated fins (4) of the heat exchanger (1) to the environment (22), the refrigerant (2) further into a first collecting chamber (16) of a Umlenksammelkastens (14) of the heat exchanger (1) passes, the refrigerant (2) over a connection port (18) from the first collection chamber (16) into a second collection chamber (15) of the Umlenksammelkastens (14) and from there into a return (20) of the refrigerant pipe (3) flows, the refrigerant (2) through the return (20 ) is passed through into a drainage collection chamber (11) of the terminal collecting box (7), and then the refrigerant (2) is introduced from the terminal collecting box (7) into another circulation pipe string of the refrigerant cycle.

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