EP2606292B1 - Coolant condenser assembly - Google Patents

Description

The present invention relates to a refrigerant condenser assembly according to the preamble of claim 1 and a method for operating a refrigeration circuit of an automotive air conditioning system according to the preamble of claim 4. A refrigerant condenser assembly according to the preamble of claim 1 is from document EP 1 577 629 known.

In refrigerant condenser assemblies for an automotive air conditioning system, vaporous refrigerant is converted into a liquid state of aggregation, and then the liquid refrigerant is further "subcooled" in a subcooling region. The refrigerant condenser assembly forms part of a refrigeration circuit of an automotive air conditioning system with an evaporator, an expansion device and a compressor.

The DE 10 2007 018 722 A1 shows a condenser for the air conditioning system of a motor vehicle having two manifolds and a container arranged adjacent to the one collecting tube for receiving the desiccant of the refrigerant of the air conditioner.

When using the new refrigerant R1234yf in comparison to the previous refrigerant R134a, due to changed material properties of the new refrigerant R1234yf, the refrigeration cycle of an automotive air conditioning system is reduced by up to 10%. The performance of a refrigeration cycle in an automotive air conditioning system can be increased, among other things, that the already liquefied refrigerant is cooled more strongly at a subcooling region of the refrigerant condenser assembly.

In a refrigerant condenser assembly, the refrigerant in gaseous form enters the refrigerant condenser assembly at an inlet port and is cooled to a saturation temperature at an overheat region. Subsequently, the refrigerant flows in a condensation region and in this, the gaseous refrigerant is further cooled to a boiling temperature and liquefied with it. Subsequently, the liquid refrigerant flows into a supercooling zone and is cooled below the boiling point, for example to a temperature of 6 or 7 K below the boiling point of the refrigerant. By a greater cooling of the refrigerant in the subcooling below the boiling temperature of the refrigerant, a higher power of the refrigerant circuit can be achieved. In general, however, the refrigerant capacitor assembly within the motor vehicle, a predetermined space, for example given by a certain depth, height and width available, so that although a greater cooling of the refrigerant at the subcooling by a larger surface at the subcooling and a larger space associated therewith Although refrigerant condenser assembly is possible, but in general due to the predetermined dimensions of the space for the refrigerant condenser assembly no larger space is available.

To increase the performance of the refrigerant circuit or to compensate for the reduced power of the refrigerant, in particular the refrigerant R1234yf is sought to increase the subcooling, for example, 15 K. For this purpose, more cooling tubes or proportionally more area required by the capacitor. This has the consequence that less space is available for the condensation area, the cooling takes place at a higher saturation temperature and the associated saturation pressure increases. This causes a negative effect on the cooling capacity in the refrigerant circuit, which reduces or even nullifies the intended advantage.

For this the beats US Pat. No. 6,470,704 B2 a subcooling section, which is divided into a first and a second subcooler parallel section. The disadvantage of this arrangement is that the outlet opening and the collecting container are arranged on the same side of the refrigerant condenser assembly. In many installation situations, it is desirable for the outlet port and sump to be disposed on different longitudinal sides of the refrigerant condenser assembly.

Therefore, the object of the present invention is to provide a refrigerant condenser assembly, a method of operating a refrigeration cycle of an automotive air conditioning system, and an automotive air conditioner in which the refrigerant is strongly cooled in a subcooling region of the refrigerant condenser assembly without substantially increasing the condensing pressure in the refrigerant condenser assembly and that the outlet port and the reservoir are disposed on different longitudinal sides of the refrigerant condenser assembly.

This object is achieved with a refrigerant condenser assembly according to claim 1 or with a method according to claim 4.

The subcooling region of the refrigerant condenser assembly is thus subdivided into a total of three subcooler parallel sections which are each connected to one another by a subcooling intermediate flow channel. As a result, the refrigerant at the subcooling region can be cooled even further below the boiling point of the refrigerant.

Further, through the three subcooler parallel sections, the outlet port and the header tank are disposed on opposite longitudinal sides of the refrigerant condenser assembly. Thus, a collecting container with a larger collection volume can preferably be made available be as in the prior art. Furthermore, the inlet opening and outlet opening are preferably arranged on the same longitudinal side of the refrigerant condenser assembly.

The subcooling region of the refrigerant condenser assembly is thus subdivided into first and second and third subcooling parallel sections, and in the subcooling parallel sections, at least two cooling tubes are respectively hydraulically or fluidly urged in parallel with the refrigerant. In this case, the refrigerant exiting from the first subcooler parallel section is introduced into and mixed in a first subcooling intermediate flow channel, and the refrigerant is introduced into the second subcooler parallel section from the first subcooling intermediate flow channel. Subsequently, the refrigerant exiting from the second subcooler parallel portion is introduced into and mixed in a second subcool intermediate passage, and from the second subcool intermediate passage, the refrigerant is introduced into the third subcool parallel portion. Subsequently, the refrigerant is discharged through the discharge port from the refrigerant condenser assembly. Thus, the refrigerant can be cooled more advantageously at the subcooling, for example, to a temperature of 14 K below the boiling temperature of the refrigerant without thereby increasing the dimensions of the refrigerant condenser assembly and thus the refrigerant condenser assembly finds place in a given space of a motor vehicle. Thus, the performance of a refrigeration circuit of an automotive air conditioning system can be improved and thereby the power reduction when using the new refrigerant R1234yf be at least partially compensated.

An increased pressure drop in the subcooling region, which is generated by the three subcooling parallel sections, is not detrimental to the performance of the refrigerant condenser assembly or reduces its performance. This is due to the fact that the pressure drop takes place after the wet steam area, while the system's high pressure is oriented at the saturation temperature before the subcooling area or after the condensation area.

Preferably, and in particular for the utilization of the filling volume of a laterally arranged collecting container, the three subcooler parallel sections are flowed through from bottom to top. The third subcooling parallel section is thus arranged geodetically higher than the second subcooling parallel section, while the second subcooling parallel section is arranged geodetically higher than the first subcooling parallel section. Alternatively, of course, the three subcooler parallel sections can also be flowed through from top to bottom.

In a further refinement, one subcooler parallel section each has two, three or four cooling tubes acted upon in parallel and / or the surface of the cooling tubes and preferably the subcooling section headers is less than 50%, 40%, 35%, 30%, 25% or 15%. the surface of the heat exchanger of the refrigerant condenser assembly and in particular the heat exchanger consists of the cooling tubes and preferably the headers.

According to the invention, in the flow direction of the refrigerant upstream of the first subcooler parallel section, at least two cooling tubes act as fluid-conducting parallel first parallel section, the refrigerant flowing out of the first parallel section opens into a first intermediate flow channel and the first intermediate flow channel opens into at least two cooling tubes as second parallel section. In the flow direction of the refrigerant before the first subcooler parallel section, ie before the subcooling of the refrigerant condenser assembly, ie thus the overheating area and / or at the condensation region of the refrigerant condenser assembly, thus a first and a second parallel section is arranged. Thus, the overheating region and / or the condensation region are subdivided into the first and second parallel sections between which the refrigerant is conducted through the first intermediate flow channel.

In a supplementary embodiment, in the flow direction of the refrigerant before the first subcooler parallel section, the refrigerant flowing out of the second parallel section opens into a second intermediate flow channel and the second intermediate flow channel opens into at least two cooling tubes as the third parallel section. Before the subcooling area, d. H. Thus, at the overheating region and / or at the condensation region of the refrigerant condenser assembly, thus the refrigerant condenser assembly is divided into a total of three parallel sections with at least two, preferably at least four or six or eight, cooling tubes, which are each fluid-conductively connected to each other through the intermediate flow channel. Preferably, a parallel section has a greater number of cooling tubes than a subcooler parallel section, and preferably the number of cooling tubes of a parallel section is two, three, five or seven cooling tubes greater than the number of cooling tubes of a subcooler parallel section.

According to the invention, the second parallel section opens into a second intermediate flow channel and the second intermediate flow channel opens into the collecting container. Preferably, the third parallel section opens into a third intermediate flow channel and the third intermediate flow channel opens into the collecting container. If the overheating and / or condensation region of the refrigerant condenser assembly has the first and second parallel sections, the refrigerant discharged from the second parallel section is thus introduced into the collecting vessel and subsequently into the first subcooler parallel section introduced or the superheating and / or condensation region has three parallel sections, the discharged from the third parallel section refrigerant is introduced into the sump and then into the first subcooler parallel section. This also applies analogously if the overheating and / or condensation region is subdivided into more than three parallel sections, for example four or five parallel sections.

Alternatively, exactly one parallel section may be provided so that it opens exactly one parallel section into the collecting container, such an arrangement not falling within the scope of the claims.

• Überhitzungsbereich: 15 Kühlrohre
• Kondensationsbereich: 12 Kühlrohre (wobei der Kondensationsbereich in einen ersten Parallelabschnitt mit 7 Kühlrohren und einen zweiten Parallelabschnitt mit 5 Kühlrohren unterteilt ist)
• Unterkühlungsbereich: 9 Kühlrohre (wobei der Unterkühlungsbereich in einen ersten, zweiten und dritten Unterkühlparallelabschnitt mit jeweils 3 Kühlrohren unterteilt ist).

Through intensive measurements, it has been found that the following ratio of cooling tube number is preferable:

• Overheating range: 15 cooling tubes
• Condensation area: 12 cooling tubes (the condensation area being divided into a first parallel section with 7 cooling tubes and a second parallel section with 5 cooling tubes)
• Subcooling area: 9 cooling tubes (wherein the subcooling area is divided into first, second and third subcooler parallel sections each having 3 cooling tubes).

In one variant, the sum of the flow cross-sectional areas of the cooling tubes of a subcooler parallel section is smaller than the product of 0.7 or 0.5 or 0.3 or 0.1 and the sum of the flow cross-sectional areas of the cooling tubes of a parallel section and / or the cooling tubes are formed as flat tubes and between the flat tubes corrugated ribs are arranged. The flow cross-sectional area is the cross-sectional area of the cooling tubes for passing the refrigerant.

Conveniently, the refrigerant in the subcooling section is cooled by more than 7, 10, 12, or 14 K, and is preferably cooled by less than 30K or 20K. Due to the larger volumetric flow of the refrigerant in the cooling tubes of the subcooling region compared to a subcooling region having only exactly one subcooling parallel section and the associated greater flow velocity of the refrigerant in the subcooling region, a better heat transfer from the refrigerant to the air, which flows around the refrigerant condenser assembly, can thereby be achieved ,

In an additional embodiment, the refrigerant is R1234yf or R134a.

In a variant, the refrigeration medium condenser assembly has a closure device formed on the collecting container for closing a closure opening of the collecting container.

Preferably, a dryer and / or a filter are arranged in the collecting container.

Fig. 1

eine perspektivische Ansicht einer Kältemittelkondensatorbaugruppe,

Fig. 2

eine perspektivische Teilansicht der Kältemittelkondensatorbaugruppe gemäß Fig. 1 und

Fig. 3

ein Strömungsschaltbild des Kältemittels in der Kältemittelkondensatorbaugruppe gemäß Fig. 1.

In the following, an embodiment of the invention will be described in more detail with reference to the accompanying drawings. It shows:

Fig. 1

a perspective view of a refrigerant condenser assembly,

Fig. 2

a partial perspective view of the refrigerant condenser assembly according to Fig. 1 and

Fig. 3

a flow diagram of the refrigerant in the refrigerant condenser assembly according to Fig. 1 ,

In FIG. 1 and 2 a refrigerant condenser assembly 1 is shown in a perspective view. The refrigerant condenser assembly 1 is part of an automotive air conditioning system with an evaporator and a compressor (not shown). By horizontally arranged cooling tubes 2 as flat tubes 3 flows to be condensed and cooled refrigerant ( Fig. 1 and 2 ). The cooling tubes 2 open at their respective ends in a vertical manifold 5, that is, there are two manifolds 5 respectively at the ends of the cooling tubes 2. In Fig. 2 only one manifold 5 is shown. For this purpose, the collecting tube 5 has cooling tube openings through which the ends of the cooling tubes 2 project into the collecting tube 5. Within the manifolds 5 baffles (not shown) are formed with which a certain flow path of the refrigerant can be achieved through the cooling tubes 2, so that the refrigerant through the cooling tubes 2 according to the flow diagram in Fig. 3 flows through the cooling tubes 2.

Between the cooling tubes 2 meandering corrugated fins 4 are arranged, which are in thermal communication with the cooling tubes 2 by means of heat conduction. This increases the area available for cooling the refrigerant. The cooling tubes 2, the corrugated fins 4 and the two manifolds 5 are generally made of metal, in particular aluminum, and are materially connected to one another as a solder joint. In four corner regions of the refrigerant condenser assembly 1, a fastening device 8 is arranged, with which the refrigerant condenser assembly can be attached to a motor vehicle, in particular to a body of a motor vehicle.

At the manifold 5, also vertically aligned, a collecting container 6 is arranged on a first longitudinal side ( Fig. 1 . 2 ). The collecting container 6 is by means of two overflow openings (not shown) in fluid communication with the collecting tube 5 and thus also indirectly in fluid communication with the cooling tubes 2. In the collecting container 6, a dryer and a filter (not shown) is arranged. The dryer is hygroscopic and can absorb water or moisture from the refrigerant. The collecting container 6 is mechanically connected to the collecting tube 5 at the lower and upper ends with a concave support region. At the lower end of the collecting container 6 is closed by a closure device 7 fluid-tight. The removable closure device 7 allows an exchange of the dryer and the filter in the collecting container 6.

The refrigerant condenser assembly 1 has an inlet port 9 for introducing the refrigerant R1234yf into the refrigerant condenser assembly 1, and an outlet port 10 for discharging the refrigerant from the refrigerant condenser assembly 1 (FIG. Fig. 1 and 3 ). The ends of the cooling tubes 2 terminate in the manifolds 5. In the manifolds 5 baffles or flow guide plates, not shown, are arranged with the help of which a certain predetermined flow diagram of the refrigerant can be achieved, ie with which flow path, the refrigerant flows through the plurality of superimposed cooling tubes 2 of the refrigerant condenser assembly 1. This in Fig. 3 shown flow diagram is only for illustrative representation of the flow path of the refrigerant through the cooling tubes 2 and does not represent the geometric orientation of the cooling tubes 2 to each other in the refrigerant condenser 1. A first intermediate flow passage 20, a second intermediate flow passage 22, a third intermediate flow passage 24 and a first sub-cooling intermediate flow passage 15th and a second sub-cooling intermediate passage 17, which in Fig. 3 are shown are thus formed within the manifolds 5 of the flow guide plates, not shown.

The refrigerant condenser assembly 1 constitutes a heat exchanger for transferring heat from the refrigerant to air surrounding and circulating around the refrigerant condenser assembly 1. In this case, the heat exchanger is essentially formed by the cooling tubes 2 and the two manifolds 5. The heat exchanger as part of the refrigerant condenser assembly 1 in this case has an inlet opening 9 through which gaseous refrigerant is passed from a compressor, not shown, to the refrigerant condenser assembly 1. The gaseous refrigerant is thereby cooled at an overheating region 11 to a saturation temperature, ie at the saturation temperature occurs in accordance with the existing pressure, a condensation of the refrigerant. In the flow direction of the refrigerant after the overheating region 11, a condensation region 12 connects, in which the refrigerant is condensed and thus liquefied. The refrigerant liquefied in the condensation region 12 is supplied as a liquid to the subcooling region 13 and cooled in the subcooling region 13 below the boiling temperature of the refrigerant. In the Fig. 3 given clear separation in the overheating region 11, condensation region 12 and subcooling region 13 may differ slightly during operation of an automotive air conditioning system, so that, for example, in modification of the illustration in Fig. 3 the overheating region 11 is slightly larger and thereby the condensation region 12 becomes smaller, so that, for example, a second parallel section 21 also partially forms the overheating region 11. This applies analogously to the separation between the condensation region 12 and the subcooling region 13, which can either shift into a first subcooling parallel section 14 in the flow direction of the refrigerant or in a third parallet section 23 against the flow direction of the refrigerant.

The overheating region 11 is formed by the first parallel section 19. The first parallel section 19 has eleven cooling tubes, which are connected in parallel or flow through in a fluid-conducting or hydraulic manner. After flowing out of the refrigerant from the eleven cooling tubes 2 of the first parallel section 19, the refrigerant is introduced into the first intermediate flow passage 20 and introduced from the first intermediate flow passage 20 into the second parallel section 21. The second parallel section 21 has eight cooling tubes 2, through which the refrigerant flows simultaneously in parallel. The refrigerant flowing out of the second parallel section 21 is introduced into the second intermediate flow passage 22 and introduced therefrom into the third parallel section 23 with likewise eight cooling tubes 2.

The refrigerant flowing out of the third parallel portion 23 is introduced into the third intermediate flow passage 24, and then, after passing through the reservoir 6, is supplied to the subcooling portion 13 of the refrigerant condenser assembly 1. The subcooling region 13 comprises a first subcooler parallel section 14, a second subcooler parallel section 16 and a third subcooler parallel section 18. The three subcool parallel sections 14, 16 and 18 each have three cooling tubes 2. The first subcooler parallel section 14 is connected to the second subcooler parallel section 16 through the first subcooling intermediate flow channel 15 and analogously, the second subcooling parallel section 16 is connected to the third subcooling parallel section 18 through the second subcooling intermediate flow channel 17. Thus, in the refrigerant condenser assembly 1, the parallel sections 19, 21 and 23 and the subcooler parallel sections 14, 16 and 18 are fluidly connected in series and the cooling tubes 2 at the parallel sections 19, 21 and 23 and the subcool parallel sections 14, 16 and 18 are hydraulically or fluid-conducting connected in parallel.

The entire refrigerant passed through the refrigerant condenser assembly 1 thus flows through the respective parallel sections 19, 21 and 23 and the subcooler parallel sections 14, 16 and 18. The subcooler parallel sections 14, 16 and 18 have a significantly smaller number of cooling tubes 2 than the parallel sections 19, 21 and 23. Due to the fluid-conducting or hydraulic circuit of the refrigerant condenser assembly 1 is thus the refrigerant at the subcooler parallel sections 14, 16 and 18, a much smaller flow cross-sectional area than at the parallel sections 19, 21 and 23, because the cooling tubes 2 have the same flow cross-sectional area. As a result, a greater flow velocity of the refrigerant or a larger volume flow of the refrigerant occurs at the subcool parallel sections 14, 16 and 18 than at a subcooling region with only exactly one subcool parallel section. Due to this larger flow rate or the larger volume flow of the refrigerant to the subcooling region 13, the heat transfer from the refrigerant to the air in the subcooling region 13 can be increased and thereby more heat is transferred from the refrigerant to the air flowing around the refrigerant condenser assembly 1 and thus the refrigerant in the Subcooler 13 are cooled more below the boiling temperature of the refrigerant, for example, cooled to 14 K below the boiling temperature of the refrigerant become. This can be increased advantageously the COP of a refrigerant circuit. Due to the adequately dimensioned flow cross-sectional area at the subcooling region 13, the pressure drop in the refrigerant condenser assembly 1 is not or only very slightly increased, so that the high pressure at the inlet opening 9 only slightly increases and thus the performance increase of the refrigerant circuit due to the greater cooling at the subcooling region 13 substantially larger is, as the power reduction due to the eventual increase of the high pressure at the inlet opening 9 is. After flowing through the subcooling region 13, the refrigerant is discharged through the outlet opening 10 from the refrigerant condenser assembly. Due to the formation of three subcool parallel sections, the outlet opening is arranged on a second longitudinal side of the refrigerant condenser assembly. Thus, outlet port and sump 6 are disposed on different longitudinal sides of the refrigerant condenser assembly.

In a further embodiment (not shown and not falling within the scope of the claims), the subcooling region 13 has only the first and second subcooler parallel sections 14, 16 and not the third subcooler parallel section 18. In an additional embodiment, not shown, the subcooling region 13 may also be divided into a total of four or five subcooler parallel sections. However, the subcooling region 13 preferably has an odd number of subcooling parallel portions, so that the sump 6 and the outlet port 10 are disposed on different sides of the refrigerant-capacitor assembly.

Overall, significant advantages are associated with the inventive refrigerant capacitor assembly 1. The flow velocity or the volume flow at the subcooling region 13 is due to greatly increased, so that a greater undercooling or cooling of the refrigerant at the subcooling 13 can be achieved without the refrigerant capacitor assembly 1 requires more space or surface, because due to the greater flow rate, the heat transfer from the refrigerant to the air per surface unit of Refrigerant capacitor assembly 1, in particular on the cooling tubes 2, the corrugated fins 4 or the manifolds 5 as a heat exchanger of the refrigerant condenser assembly 1, is increased. As a result, with an unchanged installation space for the refrigerant condenser assembly 1, the COP of a refrigeration circuit with the refrigerant condenser assembly 1 can be increased without requiring additional space for the refrigerant condenser assembly 1. Thus, the reduction in COP due to the use of the refrigerant R1234yf can be at least partially compensated.

Bezugszelchenliste

1

Refrigerant condenser assembly

2

cooling pipe

3

flat tube

4

corrugated fin

5

manifold

6

Clippings

7

Closing device on the collecting container

8th

fastening device

9

inlet port

10

outlet

11

overheating area

12

condensation region

13

Supercooling region

14

First subcooler parallel section

15

First subcooler intermediate flow channel

16

Second subcooler parallel section

17

Second subcooler intermediate flow channel

18

Third subcooler parallel section

19

First parallel section

20

First intermediate flow channel

21

Second parallel section

22

Second intermediate flow channel

23

Third parallel section

24

Third intermediate flow channel

Claims (5)

1. A refrigerant condenser assembly (1) for a motor vehicle air-conditioning system, comprising

   - an inlet opening (9) for the introduction of a refrigerant,

   - an outlet opening (10) for the discharge of a refrigerant,

   - cooling tubes (2) for conducting a refrigerant,

   - two collecting tubes (5) for fluidically connecting the cooling tubes (2),

   - a collecting tank (6) having at least one flow transfer opening via which the collecting tank (6) is fluidically connected to the cooling tubes (2) and/or to the collecting tube (5), wherein the collecting tank is arranged at a first longitudinal side of the refrigerant condenser assembly,

   - wherein the cooling tubes (2) have a superheat region (11) for cooling the vaporous refrigerant, a condensation region (12) for condensing the refrigerant, and a supercooling region (13) for cooling the liquid refrigerant, wherein,

   in the supercooling region (13), at least two cooling tubes (2) as a first supercooling parallel portion (14) are charged with the refrigerant in parallel in terms of fluid conduction, the refrigerant flowing out of the first supercooling parallel portion (14) issues into a first supercooling intermediate flow duct (15), and the first supercooling intermediate flow duct (15) issues into at least two cooling tubes (2) as a second supercooling parallel portion (16), wherein, in the supercooling region (13), the second supercooling parallel portion (16) issues into a second supercooling intermediate flow duct (17) and the second supercooling intermediate flow duct (17) issues into at least two cooling tubes (2) as a third supercooling parallel portion (18), such that the outlet opening (10) is arranged on a second longitudinal side of the refrigerant condenser assembly, wherein, upstream of the first supercooling parallel portion (14) as viewed in the flow direction of the refrigerant, at least two cooling tubes (2) as a first parallel portion (19) are charged in parallel in terms of fluid conduction, the refrigerant flowing out of the first parallel portion (19) issues into a first intermediate flow duct (20), and the first intermediate flow duct (20) issues into at least two cooling tubes (2) as a second parallel portion (21) and the second parallel portion (21) issues into a second intermediate flow duct (22) and the second intermediate flow duct (22) issues into the collecting tank (6) (14), characterised in that the sum total of the flow cross-sectional areas of the cooling tubes (2) of a supercooling parallel portion (14, 16, 18) is less than the product of 0.7 or 0.5 or 0.3 or 0.1 and the sum total of the flow cross-sectional areas of the cooling tubes (2) of the respective parallel portion (19, 21, 23), and wherein the cooling tubes (2) are formed as flat tubes (3) and corrugated fins (4) are arranged between the flat tubes.
2. The refrigerant condenser assembly as claimed in claim 1, characterised in that in each case one supercooling parallel portion (14, 16, 18) has two, three or four cooling tubes (2) which are charged in parallel, and/or the surface area of the cooling tubes (2) and preferably of the collecting tubes (5) of the supercooling region (13) amounts to less than 50%, 40%, 35%, 30%, 25% or 15% of the surface area of the heat exchanger of the refrigerant condenser assembly (1), and in particular, the heat exchanger is composed of the cooling tubes (2) and preferably the collecting tubes (5).
3. The refrigerant condenser assembly as claimed in one or more of the preceding claims, characterised in that the third supercooling parallel portion (18) is arranged geodetically higher than the second supercooling parallel portion (16), and the second supercooling parallel portion is arranged geodetically higher than the first supercooling parallel portion (14).
4. A method for operating a refrigeration circuit of a motor vehicle air-conditioning system, having the steps:

   - conducting refrigerant through lines of a refrigerant circuit,

   - compressing the gaseous refrigerant in a compressor, such that the pressure of the gaseous refrigerant is increased,

   - cooling and condensing the gaseous refrigerant in a refrigerant condenser assembly (1), which refrigerant is conducted through cooling tubes (2), by virtue of the gaseous refrigerant being cooled to a saturation temperature in a superheat region (11), the gaseous refrigerant subsequently being cooled to a boiling temperature and liquefied in a condensation region (12), and the liquid refrigerant being cooled below the boiling temperature in a supercooling region (13),

   - expanding the liquid refrigerant at an expansion element such that the pressure of the liquid refrigerant is reduced,

   - heating and evaporating the refrigerant in an evaporator,

   - conducting the gaseous refrigerant emerging from the evaporator to the compressor,

   characterised in that,
   in the supercooling region (13), the refrigerant is conducted in parallel through at least two cooling tubes (2) of a first supercooling parallel portion (14), the refrigerant flowing out of the first supercooling parallel portion (14) is conducted into a first supercooling intermediate flow duct (15), and the refrigerant conducted through the first supercooling intermediate flow duct (15) is subsequently conducted in parallel through at least two cooling tubes (2) of a second supercooling parallel portion (16), and the second supercooling parallel portion (16) issues into a second supercooling intermediate flow duct (17), and the second supercooling intermediate flow duct (17) issues into at least two cooling tubes (2) as a third supercooling parallel portion (18), and/or, in the supercooling region (13), the refrigerant is conducted through cooling tubes (2) with a smaller flow cross-sectional area than the refrigerant that is conducted through the cooling tubes (2) of the superheat region and/or of the condensation region (12), such that the refrigerant conducted through the cooling tubes (2) in the supercooling region (13) has a greater volume flow rate than the refrigerant conducted through the cooling tubes (2) in the superheat region (11) and/or in the condensation region (12), wherein the volume flow rate of the refrigerant in the cooling tubes (2) of the supercooling region (13) is 1.2 or 1.5 or 2 times greater than the volume flow rate of the refrigerant in the cooling tubes (2) of the superheat region (11) and/or of the condensation region (12).
5. A motor vehicle air-conditioning system, comprising

   - a refrigerant condenser assembly (1),

   - an evaporator,

   - a compressor,

   - preferably a fan,

   - preferably a housing for accommodating the fan and the evaporator,

   characterised in that
   the refrigerant condenser assembly (1) is designed as claimed in one or more of claims 1 to 3 and/or a method as claimed in claim 4 can be implemented by the motor vehicle air-conditioning system.

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