EP2795230A2

EP2795230A2 - Heat exchanger

Info

Publication number: EP2795230A2
Application number: EP12810226.6A
Authority: EP
Inventors: Johannes Diem; Uwe FÖRSTER; Pedro Gonzàlez Rechea; Klaus Hassdenteufel; Herbert Hofmann; Martin Kaspar
Original assignee: Behr GmbH and Co KG
Current assignee: Mahle Behr GmbH and Co KG
Priority date: 2011-12-19
Filing date: 2012-12-18
Publication date: 2014-10-29
Also published as: US20140298853A1; US10240826B2; DE102011089091A1; WO2013092644A2; CN204255167U; WO2013092644A3

Abstract

The invention relates to a heat exchanger, comprising a first tube/fin block, first headers arranged on both sides of the first tube/fin block, which first headers communicate with the tubes of the first tube/fin block, and a second tube/fin block having second headers arranged on both sides of the second tube/fin block, which second headers communicate with the tubes of the second tube/fin block, wherein the first tube/fin block having the corresponding first headers is an air-cooled low-temperature coolant cooler and the second tube/fin block having the corresponding second headers is an air-cooled refrigerant cooler, wherein the headers of the first tube/fin block arranged on a respective side of the tube-fin block and a header of the second tube/fin block are connected to one another.

Description

Heat exchanger

Description Technical area

The invention relates to a heat exchanger, in particular according to the preamble of claim 1 and an arrangement of heat exchangers according to the preamble of claim 8.

State of the art

In automotive air conditioning systems in automobiles, automotive refrigerant circuits are used in which a condenser is used to cool and condense the refrigerant, which is pressurized by a compressor. The refrigerant thus condensed is then evaporated in an evaporator downstream of the condenser in the flow direction, so that it is cooled by a heat exchange between an air flowing through the evaporator and the refrigerant to temper or cool the vehicle interior of the motor vehicle. To increase the evaporator performance, the refrigerant is therefore cooled more strongly in the condenser than is necessary for pure condensation. This further reduces the enthalpy of entry into the evaporator. When using coolant-cooled capacitors, which are also called indirect capacitors, the waste heat of the capacitor is not delivered directly to the air, but to an interposed coolant in a coolant circuit, thereby the lowest temperature of the coolant in the coolant circuit is significantly higher than at air-cooled condensers, since the coolant used in the coolant circuit has a significantly higher coolant temperature than the ambient air which cools the refrigerant in air-cooled condensers. This means that in these so-called indirect capacitors, the enthalpy of entry on the evaporator is not lowered so far, so that it comes to power losses of the evaporator.

The air-cooled condenser does not have these problems, but it requires a relatively large amount of space in the front of the vehicle, which can not always or not always be provided to the required extent in modern motor vehicles.

The air-cooled capacitors have the problem that they are very often damaged in accidents with frontal damage to the vehicle and the refrigerant can escape, which leads to considerable costs in modern chemical refrigerants. In this respect, it is a desire to remove the air-cooled condenser from the front of the vehicle to protect it in an accident situation. However, this can not be done with air-cooled technology because, for example, at some other position in the engine compartment, there is not enough air available to cool the refrigerant. Therefore, it is advantageous that the condenser is operated coolant-cooled. As a solution to the problem, WO 2004/085810 proposes to provide a subcooler which is operated with a coolant of a low-temperature cooler. However, this has the disadvantage of a very high Verschaltungsaufwandes for the disposal of the Niedertemperaturkühimittels and often leads to a poorer controllability of the overall system,

Presentation of the invention, object, solution, advantages

It is the object of the invention to provide a heat exchanger which solves the above-mentioned problems and yet provides a condenser subcooler which cools the refrigerant downstream of the compressor to such an extent that it has an acceptable enthalpy of entry on the evaporator. It is a further object of the invention to provide an arrangement of heat exchangers which solves the above problems,

This is achieved according to the invention with a heat exchanger having a heat exchanger with the features of claim 1. In particular, in cooperation with a coolant-cooled condenser, it is advantageous to use a heat exchanger, with a first tube / rib block and arranged on both sides of the first tube / rib block first Manifolds communicating with the tubes of the first tube / fin blocks; and a second tube / fin block having second manifolds disposed on either side of the second tube / fin block and communicating with the tubes of the second tube / fin block, wherein the first pipe / fin block with the respective first manifolds is an air side cooled low-temperature coolant radiator and the second tube / rib block with the related second manifolds is an air-side cooled refrigerant radiator, wherein each arranged on one side of the tube / fin block manifolds of the first and the manifolds of the second tube / rib biock are interconnected. The thus-designed low-temperature coolant radiator may be used to cool the refrigerant from the coolant-cooled condenser, followed by an air-side cooled refrigerant radiator as a subcooler to cool the refrigerant to a lower temperature from the low-temperature coolant-cooled condenser.

It is advantageous if the interconnected manifolds of the first and the second tube / rib block are integrally formed with each other. In this case, "integrally" merely means that the collecting pipes are formed connected to one another, wherein in the case of a one-part collecting pipe for the first and for the second pipe / fin block, the connected common collecting pipe is likewise formed in one piece a Sammelroh lid are the common manifolds so far in two parts, as they also consist of a tube sheet and a pipe cover.

Furthermore, it is advantageous if the first manifold of the first tube / fin block and the first manifold of the second tube / fin block are integrally formed and the second manifold of the first tube / fin block and the second manifold of the second tube / ribs - Blocks are integrally formed. With regard to the design of two-piece manifolds here is the same as the above.

It is also advantageous in another embodiment of the present invention, when the first and / or the second manifold of the first tube / fin block are provided with a first and / or a second fluid port, and the first and / or the second manifold of the second tube / fin blocks are provided with a third and / or fourth fluid connection. It may be advantageous depending on the interconnection be, if in a first embodiment, both manifolds are provided with an inlet or outlet as a fluid connection or at a deflection quite well, the inlet and the outlet of a tube / fin block can be arranged on a manifold.

Furthermore, it may be advantageous if the tube / rib block of the refrigerant radiator is preceded by a refrigerant collector in the fluid flow. It is also expedient if a collector is interposed between the tube / rib block of the refrigerant cooler. This means that the tube / fin block is divided and a collector is inserted in the fluid flow in the course of each fluid channel.

In this case, the refrigerant collector may be formed as a pure collector, but it may also include a filter and / or a dryer to filter and / or to dry the refrigerant flowing through the refrigerant collector.

It is advantageous if the collector is connected via a fluid connection with a manifold of the refrigerant radiator with the tube / fin block of the refrigerant radiator fluid. It is advantageous if the collector is connected via a flange or via a connecting pipe with the manifold. Advantageously, the fluid connection is designed as a flange or as a connecting pipe. The object of the arrangement of heat exchangers is achieved with the features of claim 8, according to which an arrangement is provided with a coolant-cooled condenser for defrosting and condensing of refrigerant, in particular in a refrigerant circuit of motor vehicles, further comprising an air-cooled refrigerant subcooler, in which the previously in the condenser cooled and condensed refrigerant is cooled further. It is advantageous if the coolant-cooled condenser is cooled by a low-temperature coolant from a low-temperature coolant circuit.

It is also advantageous if a collector is arranged in the fluid flow between the coolant-cooled condenser and the air-cooled subcooler.

It is also expedient if the air-cooled subcooler is designed as an assembly with an air-cooled low-temperature radiator of the low-temperature circuit.

It is also expedient if the air-cooled subcooler is formed separately from an air-cooled low-temperature radiator of the low-temperature circuit, but in particular is connected to it as a module.

It is also expedient if a manifold of the first tube / fin block and a manifold of the second tube-fin block are formed as a single-row tube.

It is also advantageous if a manifold of the first tube / fin block and a manifold of the second tube-fin block are formed as a double-row tube, each one tube of the double-row tube forms the respective manifold.

It is also expedient for at least one tube of the first tube / fin block and at least one tube of the second tube / fin block to be designed in each case as a single-row tube. It is also advantageous if at least one tube of the first tube / rib block and at least one tube of the second tube-rib block as two-row tube is formed, wherein in each case a tube of the double-row tube forms the respective tube.

Furthermore, it is advantageous if a tube and / or a collection tube of the first tube / fin block are equal or unequal / are to a pipe and / or to a manifold of the second tube / fin block

Further advantageous embodiments are described by the following description of the figures and by the subclaims.

Brief description of the drawings

The invention will be explained in more detail on the basis of at least one embodiment with reference to the drawings. Show it:

Fig. 1 shows a first embodiment of an inventive

2, a second embodiment of a heat exchanger according to the invention,

3 shows another embodiment of a heat exchanger according to the invention »

Fig. 4 is a representation of a section of a heat exchanger according to the invention with tubes of a tube / rib block and a manifold and a con nection flange.

Fig. 5a to 5d each show a view of components for the composition of a manifold of a heat exchanger according to the invention, and

In each case a view of components for assembling a header of a heat exchanger according to the invention a schematic view of an arrangement of heat exchangers, and a schematic view of an arrangement of heat exchangers,

Preferred embodiment of the invention

1 shows a heat exchanger 1 with a first tube / rib block 2 and arranged on both sides of the first tube / rib block 2 first manifolds 3, 4. Furthermore, the heat exchanger 1 has a second tube / rib block 5, in which in turn, on both sides of the tube / rib block 5 second manifolds 6, 7 are arranged. The tubes 8 of the first tube / fin block 2 communicate on both sides with a manifold 3, 4, wherein the ends of the tubes 8 are inserted into openings of the manifolds and arranged there fluidly connected. The tubes 9 of the second tube / fin block communicate with the headers 6, 7 of the second tube / fin block 5, again with these tubes 9 on both sides are introduced with their end portions in openings of the manifolds 6, 7 and sealed and fluidly connected.

In this case, the first heat exchanger region with the first tube / fin block 2 and the manifolds 3, 4 according to the invention as a low-temperature coolant radiator and the second heat exchanger region with the tube / rib block 5 and the manifolds 6, 7 is designed as a refrigerant radiator, in particular refrigerant subcooler ,

It is particularly preferred if the manifolds 3 and 6, and the manifolds 4 and 7 are each formed integrally with each other. In the embodiment of Figure 1, the headers are designed as headers with bottom-lid configuration, so that they are basically formed as two-piece headers. In the case that the collecting pipes 3, 6 according to the invention are formed as one-piece collecting pipes, this means that these collecting pipes each have a one-piece cover or a one-piece bottom, which in each case übe the entire length of the collecting tube of the first and the second tube / rib Blocks extends.

The heat exchanger 1 has a first fluid port 10 for introducing a fluid into the low-temperature coolant radiator and a fluid port 11 serving as the outlet for the low-temperature coolant radiator. The two fluid ports 10, 11 are formed as pipe sockets, which are connected to the respective manifold 3.4.

Alternatively, a fluid connection can be arranged as a fluid inlet to a manifold and a second fluid port as an outlet on the same manifold, between these connected areas then typically a partition wall is provided for dividing the inlet side space portion of the manifold from the outlet side space portion of the manifold. The opposite header, which would be opposite the tube / fin block, would advantageously have no fluid connection. It then serves only to redirect the flow of fluid from one group of pipes to another group of pipes.

Furthermore, the collecting pipe 6 and the collecting pipe 7 also each have a fluid connection 12, 13, the fluid connection 12 being connected as an inlet fluid connection to the collecting pipe 6 and the fluid connection 13 as outlet-side fluid connection to the collecting pipe 7. The fluid connections 12, 13 are more advantageous designed as connecting flanges and serve the connection of a connecting pipe with the manifold. It may also be expedient for the refrigerant cooler or refrigerant subcooler if both the fluid connection for the enclosure and the fluid connection for the outlet are connected to a collecting tube, whereby once again between the spatial regions within the collecting tube which are connected to the respective fluid connections , a partition is provided. The in turn the tube / rib block opposite collecting tube then would in turn have the function of a deflection of the refrigerant or fluid from one group of tubes into another group of tubes, There would be preferably no fluid connection provided.

As can be seen, the entire tube / fin block 2.5 has a number of tubes 8 or a number of tubes 9, which are the tube / fin block 2 of the low-temperature coolant cooler or the tube / rib block 5 associated with the refrigerant radiator. Thus, it can be seen in FIG. 1 that a multiplicity of tubes 8 are assigned to the tube / fin block 2 of the low-temperature coolant cooler and only a smaller one Number of tubes 9 associated with the tube / fin block 5 of the refrigerant cooler or refrigerant subcooler.

Furthermore, it can be seen _'that between the tube / fin block 2 of the low-temperature coolant radiator and the tube / fin block 5 of the

Refrigerant, a pipe or a web or a spacer 14 is arranged, which separates the tube / rib block 2 of the low-temperature coolant radiator from the 'tube / rib block 5 of the refrigerant radiator This element 14 may be formed as a tube or metal strip, which in the Pipe / rib block is inserted as if it were a pipe. However, the tube 14 or the strip 14 is not integrated in the refrigerant circuit or the low-temperature coolant circuit. For this purpose, 4,7 and 3,6 partitions 15, 16, 17, 18 are arranged on both sides of the tube in the region of the collecting pipes, which divides the region into which the pipe or strip 14 penetrates into a passage or into an opening of the collecting pipe, separated from the fluid stream.

Furthermore, the headers 3, 6, 4, 7 on end plates 19, 20, 21, 22, which serve to complete the headers 3, 6, 4, 7 on one side.

FIG. 2 shows a further exemplary embodiment of an inventive heat exchanger 30 with a first tube / rib block 31 and a second tube / rib block 32, on both sides of the tube / rib blocks 31, 32 a collecting tube 33, 34 and 35, 36 is arranged. The manifolds 33, 34 and 35, 36 Fluidanschiüsse 37 and 38 and 39 and 40 are assigned. In this case, as already described for the exemplary embodiment of FIG. 1, a respective fluid connection can be assigned to a collecting pipe, as is also shown in FIG. Alternatively, one of these two manifolds can be assigned two Fluidanschiüsse, in which case preferably no fluid connection must be assigned to the opposite manifold. In the event that from the opposite manifold yet a fluid should be branched off, there could be provided as well as a 3. Fluidanschiuss there. This could be applicable to both the low-temperature coolant radiator and the refrigerant radiator, depending on how the needs would be in the motor vehicle used or in the refrigeration or refrigerant circuit used.

The embodiment of Figure 2 shows in addition to the heat exchanger 30 and a refrigerant accumulator 41, which is preferably supplied via a fluid flange 42 with a fluid with refrigerant. The fluid flows through the inlet port 43 to the fluid flange 42 in the accumulator 41. There, the fluid can preferably be collected and flowed through a fluid outlet 44 into the inlet 45 of the heat exchanger. The Fluideiniass 45 for the heat exchanger forms the Fluidanschiuss for the refrigerant radiator or refrigerant subcooler, so that a fluid, preferably refrigerant can flow through the Fluidanschius 42 into the collector, before there from the collector back out through the Fluidanschiuss 39 into the inlet port 45 through the tube / fin block 32 of the heat exchanger to flow before it flows into the manifold 36 and flows out of the Fluidanschius 40 again from the heat exchanger.

In the collector 41, preferably not only a collecting function can be realized, but also a dryer and / or filter function can be realized. For this purpose, a filter may be provided in the collector, which is preferably forcibly flowed through between the inflow opening and the outflow opening. Furthermore, the dryer function can be realized by the arrangement of desiccant. However, it is not absolutely necessary for the desiccant to be in direct flow between the inflow and outflow openings. Since the desiccant exerts its effect due to a partial pressure, it is not necessary for it to be circulated directly, but it may well be sufficient for it to be located in the stored liquid volume. FIG. 3 shows a further exemplary embodiment of the heat exchanger according to the invention, again showing a heat exchanger 50, with a first tube / rib block 51 and a second tube / rib block 52, whereby manifolds 53 and 54 again follow the tube / rib Block 51 are assigned and manifolds 55 and 58 associated with the tube / rib block 52.

In this Ausführungsbeispie! 3, the tube / rib-block 52 is flowed through in two bends, that is, that the tube / rib block is divided into two floods 57 and 58, wherein the tube / rib block is longitudinally provided with a fluid port 59 through which a fluid in the tube / rib block

57 and flows through the relevant collection tube 80. From the manifold, the fluid is flowed into the tube / fin block 57, then in the tube / fin block 61 again collected in the area 62 of the manifold 56 deflected, from there again fed into the tubes of the tube / fin block 58 and merged into the manifold 61 of the manifold 55 before it is discharged from the heat exchanger at the fluid port 64.

The double-flow design of the tube / fin block 52 with the floods 57 and

58 is achieved in that the manifold 55 is divided by a partition wall 65 into two areas 60, 63 and the fluid flows into the heat exchanger in the area 60 and flows out of the heat exchanger from the area 63 again. At the same time, the collection tube 56 serves the regions 61 and 62, which, however, are not separated by a partition, as a pure diversion manifold, which collects the fluid flowing from the tube / fin block 57 _» and into the tube / fin block 58 eintässt. Furthermore, a collector 66 can be seen in FIG. 3, which is provided with a fluid connection 67, so that a fluid flows through the inlet opening of the fluid connection 67 can flow into the collector, where it can be collected before it flows in via the fluid connection 59 into the tube / fin block 57 via the collecting tube 85. The collector 66 may in turn be provided with a collecting function corresponding to the collector of Figure 2, in addition, a drying and / or a filter function is also feasible.

4 shows a view of an arrangement of a manifold 70 with a fluid port 71 and tubes 72 of the tube / fin block,

The tubes 72 of the tube / fin block are divided into three different tube types. The tubes 73 are part of the second tube / fin block and the tubes 74 are part of the first tube / fin block. The tube 75 serves as a side part and does not participate in the fluid transport between the headers. The tube 76 serves as a separation between the two tube / rib blocks and also does not participate in the fluid transport. This can be seen in that the two partitions 77 the upper part 78 of the manifold separated from the lower part 79 of the manifold. The space area 80 between the two partition walls 77 does not participate in the function as a collecting tube, but serves as a distance between the two headers for the different fluids and can serve as leakage detection space, in the event that one of the two partitions 77 should be leaking, so that from an opening in the region of the volume 80 then the outflowing fluid can emerge and be observed. Furthermore, the separating web 81 serves to terminate the collecting tube.

The fluid connection 82 to the collection tube is realized by the flange 71, which has a connection opening 83 into which a connection tube can be fitted. FIGS. 5a to 5d show ways in which a collection tube with an integrated connection flange can be formed as a fluid connection. 5a shows in a flat tube which is made of a flat tube bottom and a flat tube lid, the flat tube sheet which is part _"in which the tube holes are present, and the flat tube cover is the part in which no pipe openings are introduced. The part 100 represents an integral flange 101 with a manifold cover 102, this manifold cover being so ^" integrated ^" that the side cheeks 103 of the cover project from the flange and the connection 104 between the sidewalls 103 is formed by the body of the flange 101. In the upper area, a lid 105 is used, which is placed on the flange component according to Figure 5b, so that the side walls 103 are aligned with the side walls 106 of the lid in the axial direction.Figures 5c and 5d show this again in a different perspective the flange component 100 can be combined with the cover 105 to form a solderable unit.

After the composition of the components according to FIGS. 5a to 5d, FIGS. 8a to 6d show the insertion of the partitions according to FIG. 4 into the manifold and the connection to the tubesheet and the insertion of the flat tubes into the tube openings of the tubesheet. In FIGS. 6c and FIG. 6d shows how the flange component 100 can be inserted into a dividing wall 110, wherein the lower dividing wall 110, which is arranged at the end-side end of the flange, corresponds to the dividing wall 81 of FIG. The two upper dividing walls, comparable to the two dividing walls 77 of FIG. 4, serve as a separation between the first and the second tube / fin block,

Figures 6a and 6b show a configuration according to Figures 6c and 6d, the placement of the tube sheet 111 and the insertion of the flat tubes 1 12. It can be seen in Figure 6b that the lowest flat tube 1 13 as Side panel is the subsequent flat tubes 114 serve the first tube / rib block, the next coming pipe 1 15 causes a separation of the two tube / rib blocks and the subsequent tubes 16 form the first tube / rib block.

FIG. 7 schematically shows an arrangement of heat exchangers 200, in which a coolant-cooled condenser 201 receives a refrigerant from a line 202 from a compressor, not shown, which is de-condensed and condensed in the condenser 201 _", at which a low-temperature coolant, which flows through the condenser 201 flows, is heated. Subsequently, the refrigerant flows through the line 203 to the collector 204, where it can be at least partially collected and optionally filtered and dried. Subsequently, the fluid flows through the conduit 205 to the subcooler 206, where it is further cooled. The subcooler 206 is preferably an air cooled subcooler. Thereafter, the refrigerant flows through the conduit 207 to the expansion valve and to the evaporator.

The low-temperature coolant for cooling the refrigerant in the condenser is guided in a low-temperature circuit 208 and cooled in a low-temperature radiator 209, which is an air-cooled radiator. The subcooler 206 and the low temperature radiator 209 are two different components in this embodiment.

FIG. 8 schematically shows an arrangement of heat exchangers 300, in which a coolant-cooled condenser 301 receives a refrigerant from a line 302 from a compressor, not shown, which is de-condensed and condensed in the condenser 301, at which time a low-temperature coolant, which flows through the condenser 301 flows, is heated. Subsequently, the refrigerant flows through the conduit 303 to the collector 304 where it can be at least partially collected and optionally filtered and dried. Subsequently, the fluid flows through the conduit 205 to subcooler 306, where it is cooled further. The subcooler 306 is preferably an air cooled subcooler. Thereafter, the refrigerant flows through the conduit 307 to the expansion valve and to the evaporator. The low-temperature coolant for cooling the refrigerant in the condenser is passed in a low-temperature circuit 308 and cooled in a low-temperature radiator 209, which is an air-cooled radiator. The subcooler 306 and the low temperature radiator 309 are formed in this embodiment as a unit.

It is particularly advantageous if the subcooler has no deflection, so that the refrigerant flows in the I-flow through the subcooler and enters on one side, flows through the subcooler and exits again on the other side, as shown in FIG. 1 or 2 is. It is also particularly advantageous if the subcooler has at least one deflection, so that the refrigerant flows through the subcooler in the U flow, thereby entering on one side, flowing through the subcooler, being deflected on the other opposite side, and passing through the subcooler again and also exits at the side of the entrance, as shown in FIG. It is also particularly advantageous if the subcooler has more than one deflection, for example at least two deflections, so that the refrigerant enters the subcooler on one side, flows through the subcooler, is deflected, flows through the subcooler again, is deflected, flows through the subcooler again, etc. and exits again on one side.

Claims

Claims 1. A heat exchanger having a first tube / fin block and first manifolds disposed on either side of the first tube / fin block communicating with the tubes of the first tube / fin block and a second tube / fin block having both sides of the second tube / Rib blocks arranged second manifolds, which communicate with the tubes of the second tube / fin block, wherein the first tube fin block with the respective first manifolds is an air side cooled low-temperature coolant radiator and the second tube-fin block with the related second manifolds an air side Refrigerated refrigerant cooler, wherein each disposed on one side of the tube / rib block

Collecting tubes of the first and a manifold of the second tube / rib block are connected together.

2. Heat exchanger according to claim 1, characterized in that the interconnected manifolds are integrally formed with each other.

3. Heat exchanger according to claim 2, characterized in that the first manifold of the first tube / fin block and the first manifold of the second tube / fin block are integrally formed and that the second manifold of the first tube / rib block and the second Collecting tube of the second tube / rib block are integrally formed.

4. Heat exchanger according to at least one of the preceding claims, characterized in that a collecting tube of the first Tube / fin blocks and a manifold of the second tube-fin block are formed as a single-row tube,

5. Heat exchanger according to at least one of the preceding claims, characterized in that a collecting tube of the first tube / fin block and a collecting tube of the second tube-fin block are formed as a double-row tube, wherein in each case a tube of the double-row tube forms the respective collecting tube ,

6. Heat exchanger according to at least one of the preceding claims, characterized in that an at least one tube of the first tube / fin block and at least one tube of the second tube-fin block are each formed as a single-row tube.

7. Heat exchanger according to at least one of the preceding claims, characterized in that at least one tube of the first tube / fin block and at least one tube of the second tube-fin block is formed as a double-row tube, wherein in each case one tube of the double-row tube the respective Pipe forms.

8. Heat exchanger according to at least one of the preceding claims, characterized in that a tube and / or a collecting tube of the first tube / fin block are equal or unequal to a tube and / or to a collecting tube of the second tube / rib block.

9. Heat exchanger according to at least one of the preceding claims, characterized in that the first and / or the second manifold of the first tube / fin block are provided with a first and / or a second fluid port and the first and / or the second manifold of the second tube / fin blocks are provided with a third and / or fourth fluid connection.

10, heat exchanger according to at least one of the preceding claims, characterized in that the tube / rib block of the refrigerant radiator, a collector is connected upstream.

1 1.Härmeübertrager according to at least one of the preceding claims, characterized in that the tube / rib block of the refrigerant radiator, a collector is interposed.

12. Heat exchanger according to at least one of the preceding claims, characterized in that the collector is fluidly connected via a fluid connection to a manifold of the refrigerant radiator with the tube / fin block of the refrigerant radiator.

13. Heat exchanger according to at least one of the preceding claims, characterized in that the fluid connection is designed as a flange or as a connecting pipe.

14. Arrangement of heat exchangers, with a coolant-cooled condenser for defrosting and condensing of refrigerant, in particular in a refrigerant circuit of motor vehicles, further comprising an air-cooled refrigerant radiator, wherein the previously cooled in the condenser and condensed refrigerant is further cooled.

15. The arrangement according to claim 14, characterized in that the coolant-cooled condenser is cooled by a low-temperature coolant from a low-temperature coolant circuit.

16. Arrangement according to one of claims 14 or 15, characterized in that between the coolant-cooled condenser and the air-cooled subcooler, a collector is arranged in the fluid flow.

17, arrangement according to one of claims 14 or 15, characterized in that the air-cooled refrigerant radiator or subcooler is formed with an air-cooled low-temperature radiator of the low-temperature circuit as a structural unit.

18. Arrangement according to one of claims 14 or 15, characterized in that the air-cooled refrigerant radiator or subcooler is formed separately from an air-cooled low-temperature radiator of the low-temperature circuit, but in particular is connected to it as a module.