EP1859217A1

EP1859217A1 - Heat exchanger, in particular evaporator, of a motor vehicle air conditioning system

Info

Publication number: EP1859217A1
Application number: EP06706543A
Authority: EP
Inventors: Gottfried DÜRR; Frederik GÖTZ; Michael Kranich; Karl-Heinz Staffa; Christoph Walter
Original assignee: Behr GmbH and Co KG
Current assignee: Mahle Behr GmbH and Co KG
Priority date: 2005-03-07
Filing date: 2006-02-01
Publication date: 2007-11-28
Also published as: WO2006094583A1; JP2008531976A

Abstract

The invention relates to a heat exchanger, in particular an evaporator, of a motor vehicle air conditioning system, comprising a plurality of flow paths, each of which flow paths have at least one multi-duct tube (6) through which coolant flows, comprising an inlet line (1) and an outlet line (2) for the purpose of supplying and discharging the coolant to and from the heat exchanger, comprising at least one collecting region (3), at least sections of said collecting region (3) being connected to the plurality of flow paths, it being possible for cooling air to flow through the heat exchanger in a transverse direction for the purpose of cooling the coolant, the heat exchanger having a greater structural length in a longitudinal direction, which is substantially perpendicular to the transverse direction, than in the transverse direction, and the inlet line (1) being arranged, so as to be oriented in the longitudinal direction, on the collecting region (3) and being connected to the latter, and the inlet line having, in the region of the connection to the collecting region, an effective inlet line length in the longitudinal direction which is considerably smaller than an effective overall length of the collecting region (3).

Description

Heat exchangers, in particular evaporators of a motor vehicle

air conditioning

The invention relates to a heat exchanger according to the preamble of claim 1.

EP 1 459 026 A1 describes an evaporator for a motor vehicle air conditioning system, in which a number of flow paths for a coolant each open into a collecting area constructed from a plurality of plates. In the present application, the term Kählmittel is used synonymously for refrigerants, such as CO ₂ , R134a, etc. The coolant is supplied to the collecting area via a supply line which extends over substantially the entire length of the heat exchanger, wherein periodically spaced connecting holes between feed and Collection area are provided. The feed of the evaporator with coolant on its high pressure side thus takes place substantially parallel over the entire length. Quite generally and especially with long evaporators and with regard to the segregation of a gas phase and a liquid phase criti- see cooling, it is common that in the aforementioned feed already inhomogeneity of the coolant, for example, a favored by the high pressure side low flow velocity segregation of liquid Phase and gas phase occurs, which is why ultimately the temperature distribution or heat exchanger performance inhomogeneous in the longitudinal direction. This in turn leads to a deteriorated efficiency. loading knew measures such as the variation of the communication hole diameter over the length of the evaporator only unsatisfactory improvements.

It is the object of the invention to provide a heat exchanger mentioned above, in which an improved homogeneity of a temperature distribution over its length is made possible by simple means.

This object is achieved with the characterizing features of claim 1.

The retention of the effective lead length, i. the length of the supply line over which coolant flows in the longitudinal direction of the heat exchanger, behind the effective total length, i. The length of the heat exchanger through which the coolant flows allows the formation of even very long heat exchangers without phase separation of the coolant already taking place in the region of the supply line. As a result, overall a more homogeneous distribution of the liquid phase of the coolant and thus the evaporation relevant for the cooling capacity over the length of the heat exchanger or the number of flow paths is possible. In this case, the effective supply line length is preferably no greater than half the effective length of the collecting region, whereby the improvement achieved is particularly pronounced.

In a preferred embodiment of the invention, a circulating line connected to the collecting area is provided, wherein coolant enters the circulating line from a first subset of flow paths and exits from the circulating line into a second subset of flow paths. As a result, a sequential interconnection of groups of flow paths is made possible in a simple manner, so that ultimately the entire evaporator can be charged uniformly with liquid phase despite the shortened supply line.

In a further preferred embodiment, at least one of the group

Supply line, discharge line or circulation line have a separating element, by means of which at least two sections of the relevant line coolant-tight separated from each other. As a result, lines can be used in multiple ways, such as a supply line and at the same time as a circulation line, so that particularly space-saving and cost-effective versions are possible.

In a preferred heat exchanger, the collecting area has a plurality of plate elements, through the stacking of which the collecting area is at least partially buildable. This allows a cost-effective and pressure-resistant construction of the collecting area. In this case, the supply line is advantageously connected to an upper plate element of the collecting region, wherein a plurality of respectively corresponding openings are provided in the upper plate element and in the supply line. This allows a simple connection of supply and collection area.

In an advantageous embodiment, at least one opening of supply line and upper plate element opens into at least two flow paths, whereby the number of openings can be reduced. In a further, alternative or additional embodiment, however, exactly one opening of supply line and upper plate element can be assigned to exactly one flow path, which leads to a particularly secure fixing of the supply line because of the larger number of openings.

In a preferred embodiment, a plate-shaped distributor element is provided in the collecting region, wherein the coolant can be distributed to the plurality of flow paths by means of a plurality of apertures provided in the distributor element. By such a link-like shaped distribution element not only a simple construction of the collecting region of plates is made possible, but also a simple distribution of the coolant through the shape of the openings to the individual flow paths. The distribution can be done individually in parallel or sequentially. Further preferably, a lower plate member has a plurality of openings, wherein the flow paths are defined in the region of the openings on the lower plate member. This allows a particularly cost-effective and at the same time safe connection of the flow paths to the collecting area, for example by means of soldering.

Suitably, at least one of the flow paths is formed as a U-shaped flat tube with a plurality of chambers, whereby a large common surface of coolant and flow path is provided cost-effective and pressure-resistant.

In a particularly advantageous embodiment of the invention, the plurality of flow paths are grouped into a number of sections, each section having at least one flow path, wherein the sections are arranged side by side in the longitudinal direction of the heat exchanger and wherein between at least two of the sections to an intermediate collection of the coolant suitable volume is provided. This makes it possible to realize a group-wise sequential arrangement of the flow paths, which can be adapted particularly well to a shortened supply line. The intermediate collection results in a re-mixing of coolant segregated in the flow paths, which increases the efficiency and homogeneity of the heat exchanger. In addition, the use of known heat exchanger is possible with only small changes in the area of a distributor element cost-reducing.

In a preferred embodiment, the number of sections is a total of two. Alternatively, however, the number of sections may also have a different number, in particular a larger even number or an odd number greater than or equal to three.

Generally, the heat exchanger is an evaporator of a motor vehicle air conditioning system, wherein the coolant is carbon dioxide (R 744). Carbon dioxide is particularly critical in terms of the problems addressed in the prior art and also requires high pressures, which harmonizes particularly well with the proposed solutions. Generally, however, is the Combination of a conventional coolant such as R 134a with a heat exchanger according to the invention due to its good properties in terms of manufacturing costs and size advantageous.

In a further preferred embodiment, the supply line is laid over substantially the entire length of the heat exchanger. This may be appropriate depending on space requirements. It is essential in the context of the invention that the effective length of the supply line, ie the length over which coolant enters the collecting area, remains limited.

In a preferred embodiment, at least the supply line or the discharge line has a flattening (301b), wherein the flattening is soldered flat with the collecting area. As a result, a secure and tight fixing of the line at the collecting area is given in a simple manner. Particularly preferably, at least the supply line or the discharge has a substantially D-shaped cross-section. This cross section can be achieved by reworking a cost-effective circular tube or by extrusion or other known per se. Further preferably, the cross-section of at least the lead or the lead outside the area of the sheet soldering is substantially circular. As a result, standard tubes can be used, which are less expensive than cables with a special cross section, at least outside the areal soldering. The part with a D-shaped cross section may in particular be welded to the part with a circular cross section. But it can also be formed by flattening a completely round tube, so that circular part and D-shaped part have formed a uniform tube before the production of the lines.

Advantageously, at least the supply line or the discharge line has a shape which cooperates in a form-fitting manner with a formation of the collecting area for the purpose of positioning the supply line or discharge line, wherein the formation does not allow the passage of coolant. By such formations accurate positioning is made possible in particular during the production of the heat exchanger. Particularly advantageously, at least the supply line or the discharge line has a plurality of openings which are aligned with a plurality of openings of the collecting area for the purpose of passage of coolant, the openings not interacting in a form-fitting manner. As a result, there are hardly any strains in the area of the aligned perforations, so that there is little waste during production and a permanent impermeability of these critical joints.

In a preferred embodiment, at least the supply line or the discharge openings for the purpose of the coolant passage, which are made by means of bore or materialwegnehmender punching. This makes it possible to maintain a line cross section in the region of the openings. Alternatively or additionally, it can also be provided that the supply line and / or the discharge have perforations (301a) for the purpose of passing through the coolant, which are produced by punching without material removal. Although this generally reduces the line cross-section at this point, there is a particularly high level of security against dissolving material residues which may enter the coolant during later operation of the heat exchanger.

Further advantages and features of a heat exchanger according to the invention will become apparent from the embodiments described below and from the dependent claims.

Hereinafter, three preferred embodiments and a number of modifications of a heat exchanger according to the invention will be described and explained in more detail with reference to the accompanying drawings.

Fig. 1 shows a plan view of a first embodiment of a heat exchanger from the front.

Fig. 2 shows a plan view of the heat exchanger of FIG. 1 from above.

Fig. 3 shows a plan view of the heat exchanger of Fig. 1 from the side.

Fig. 4 shows a sectional view through the heat exchanger of Fig. 1 in the region of a supply line. 5 shows a sectional view through the heat exchanger of Fig. 1 in the region of a derivative.

FIG. 6 shows a sectional view through the heat exchanger of FIG. 1 in FIG

Area of a circulation line. FIG. 7 shows a plan view of a distributor plate of the heat exchanger of FIG. 1. FIG.

FIG. 8 shows a plan view and a side view of an upper plate member of the heat exchanger of FIG. 1. FIG.

9 shows a plan view of a lower plate element of the heat exchanger from FIG. 1.

10 shows a sectional view of a flat tube of the heat exchanger from FIG. 1.

11 shows a plan view of a distributor plate of a heat exchanger according to a second exemplary embodiment. Fig. 12 shows an upper plate member of the second embodiment corresponding to the distributor plate of Fig. 11.

Fig. 13 shows a schematic representation of the principle of operation of the first and the second embodiment

FIGS. 14 to 36 each show a schematic representation of the functional principle of a heat exchanger according to the invention according to a first to correspondingly twenty-third modification.

Fig. 37 shows a top view of a third embodiment of a heat exchanger from the front. FIG. 38 shows a plan view of the heat exchanger of FIG. 37 from above. FIG.

Fig. 39 shows a plan view of the heat exchanger of Fig. 37 from the side.

FIG. 40 shows a scale-oriented plan view of a distributor plate of the heat exchanger of FIG. 37. FIG.

FIG. 41 is a plan view and a side sectional view taken along line AA of an upper plate member of the heat exchanger of FIG. 37; FIG. FIG. 42 is a plan view, a sectional view taken along the line A - A of the plan view, and a front end view of a lead of the heat exchanger of FIG. 37.

FIG. 43 shows a modification of the supply line from FIG. 42 in a sectional view and in a detailed view with a punching tool.

The heat exchanger according to the first embodiment is an evaporator for an automotive air conditioning system and comprises a tubular inlet 1 and a tubular outlet 2. Both lines 1, 2 are parallel to each other in a longitudinal direction of the evaporator above a collecting area extending over the entire evaporator length 3 arranged. Beyond the collecting area 3 lead 1 and 2 discharge are continued to a common flange 4, via which they are connected to the other air conditioning system of the vehicle (not shown). In the area of continuations 1a, 2a between collecting area 3 and flange plate 4, the lines have a number of kinks and bends, whereby they are adapted to the individual geometry of the installation space in the vehicle. As supply line 1 and discharge line 2 in the sense of the invention, therefore, only those sections of the lines are defined in which they are arranged directly on the evaporator.

Also parallel to the supply line 1 and the discharge line 2, a circulation line 5 is arranged above the collection area 3 at this and extends over the entire length of the evaporator. The circulation line 5 is designed as a tube section which is closed at its two ends and has approximately the same diameter as the supply line 1 and the discharge line 2. However, the diameters of the supply line, discharge line and circulation line can also have different diameters.

On a lower side of the collecting region 3, a plurality of a total of twenty U-shaped flat tubes 6 are arranged, wherein the leg heights of the U-shaped flat tubes plus the collecting area height and the inlet and discharge diameters result overall in the overall height of the evaporator. Each of the flat tubes 6 has a plurality of chambers or channels 6a (see cross section through one of the flat tube legs in FIG. 10). In the present example, only half of the chambers 6a of each of the flat tubes 6 together forms a flow path or is arranged hydraulically in parallel. In the direction of the cooling air flow, that is to say perpendicular to the plane of the drawing according to FIG. 1, there are thus in each case two flow paths in each flat tube in depth one behind the other.

The total of twenty flat tubes 6 are with their forty ends respectively in recesses 7a of a lower plate member 7 (see FIG. 9) inserted and soldered there. A central, extending in the longitudinal direction web 7b of the plate member 7 separates the two groups of chambers 6a from each other.

For further embodiment of the collecting region 3, a distributor plate 8 (see FIG. 7) is placed flat on the lower end plate 7 and soldered flatly, but at least along closed marginal lines with it. The distributor plate 8 has a number of slot-like openings 8 a, which are partially aligned with the openings 7 a of the lower end plate 7 and thus with the end faces of the flat tubes 6. Out of alignment portions of the apertures, e.g. H-shaped openings 8b of the distributor plate 8 are provided to connect different flow paths with each other. The H-shaped openings shown in this case each connect two adjacent flat tubes 6 or four flow paths with each other.

Above the distributor plate 8, an upper plate element 9 of the collecting region 3 is soldered flat on the distributor plate 8. The plate member 9 has a number of circular openings 9a made by punching each on the same side. By punching formed on the side facing away from the distributor plate in each case a protruding collar 9b (see side view of the plate member in Fig. 9), by means of which the supply line 1, 2 discharge line and 5 are particularly easy to attach. As can be seen from the scale drawing in FIG. 8, the holes 9a have different widths in groups on, so that the various pressures and coolant densities in the evaporator is taken into account.

As the illustrations in FIGS. 4 to 6 show, the tubular lines 1, 2 and 5 are each provided with bores which correspond to the above-described punches 9 a of the upper plate element 9. In the course of assembly of the evaporator, the lines 1, 2, 5 are thus attached to the collar 9b and soldered coolant-tight, whereby at the same time a mechanically secure connection between collecting area and line 1, 2, 5 is made.

The distances of the furthest holes result in an effective length of the respective line 1, 2, 5. An effective in terms of heat exchange evaporator length is useful as the largest distance between two flow paths defined in the longitudinal direction of the evaporator. It follows that in the present embodiment, the effective length of the feed line 1 is less than 40% of the effective evaporator length.

The invention now works as follows:

Through the supply line 1, the evaporator is supplied under high pressure from the liquid and gaseous phase of a coolant, which in the present case is carbon dioxide (R 744). The coolant enters through the punches 9a or holes of the supply line into a first group of eight flow paths. A transfer to the eight corresponding opposing flow paths takes place in the H-shaped apertures, each with a first and a subsequently traversed flow path belonging to the same flat tube ("in-depth transfer"), after passing 16 of the evaporator's total of forty flow paths The coolant enters through approximately larger holes in the circulation line 5. These 16 first flow paths, which correspond to the first eight flat tubes from the right in accordance with Fig. 1, are thus grouped into a first section.

The circulation line 5 has the function of an intermediate collector, so that the coolant of the different flow paths is remixed. at the same time flows to the left as shown in FIG. 1, wherein the flow velocity with respect to the supply line 1 is already significantly increased. By demixing related problems have already been significantly reduced at this point.

On the left side of the evaporator, the remaining twelve flat tubes form a second group or a second section of a total of twenty-four flow paths 6. In this case, the first entry of the circulation line in the first twelve flow paths of the second section and then by means of the H-shaped openings of the distributor plate in the second twelve flow paths of the second section through the holes 9a. The higher number of flow paths of the second section is taken into account in the circulating line 5, which is to be regarded as isobar, in that the diameter of the punches 9a of the second section is smaller than the diameter of the eight punches of the first section (see FIGS. 8 and 6). , However, the diameter of the punches may also have a different relative ratio.

Ultimately, the fully vaporized and expanded coolant from a particularly large twelve punches enters the discharge, in order to be fed from there to the wider refrigeration cycle.

According to the function of the evaporator, the flat tubes 6 are flowed around during the above-described operation of cooling air, which is subsequently used for air conditioning of a vehicle interior.

The second preferred embodiment according to FIG. 11 and FIG. 12 differs from the first example only in the formation of the punches 9a 'and their corresponding holes in the lines 1, 2, 6 and in the shape of the distributor plate 8'. In contrast to the first embodiment, here some of the openings 9a 'are each formed so that two flow paths 6a are each directly charged with coolant through a single bore. However, just as in the first embodiment, two flow paths are still flowed through per section of the evaporator, for which likewise H-shaped throughflows are used. Breaks 8a 'are responsible for the transition between the flow paths.

Overall, this reduced the number of holes or punches 9a '. There are only twenty-four punches 9a 'present, in each case six for each exit or entry of the coolant into the lines 1, 2, 5. Thus, in the second embodiment, the two sequential sections or groups of flow paths are the same size, but what can be easily modified depending on requirements.

In the second embodiment, the effective lead length is slightly less than half the effective total length of the evaporator, as shown by the corresponding maximum bore spacing of lead 1 and longitudinal evaporator.

In order to clarify the scope of the inventive concept, twenty-three modifications according to FIGS. 14 to 36 will be described below. These are only the conceptual arrangement of supply line, discharge line and possibly further circulating lines. Outlets of coolant from a line are each symbolized by a crossed circle, whereas entries are each symbolized by a dotted circle. Flow paths for the coolant are symbolized by connecting lines between the lines.

Fig. 14 shows a modification according to the principle of the two embodiments described in detail with a feed line, a drain, a circulation line and two sections of flow paths, wherein the second section has twice the number of flow paths.

Fig. 15 shows the modification of Fig. 14 with supply and discharge on opposite sides.

Fig. 16 shows the modification of Fig. 15 with two equal sections. Fig. 17 shows a modification with three sections, wherein a second circulating line is provided for feeding the third section.

Fig. 18 shows the modification of Fig. 17 with shortened circulation lines.

Fig. 19 shows a modification with three sections, wherein in each case a circulation line is formed by means of separating a portion of the supply line and the discharge line by a coolant-tight separating element. As a result, a particularly narrow evaporator can be realized, since only two line pipes run parallel to one another.

Fig. 20 shows a modification with three sections and a separate circulation pipe, wherein the discharge has a separating element for the separation of another circulation pipe and leads away in the opposite direction to the supply line from the evaporator.

Fig. 21 shows a modification with three sections and two separate circulation tubes, wherein supply and discharge are arranged on the same side.

Fig. 22 shows a similar to Fig. 21 modification with short circulation lines.

FIG. 23 shows a modification with three sections, a separate circulating line and separating elements in the supply line and discharge line, with the supply line and the discharge leading away in opposite directions.

FIG. 24 shows a modification with five sections, wherein two separate circulating lines, each having a separating element, are provided for generating virtually four circulating lines.

Fig. 25 shows a solution for five sections with a total of three parallel lines, which is realized by corresponding separating elements in the supply line and circulation line. Fig. 26 shows a solution with four parallel lines and five sections, wherein additional separating elements are provided.

Fig. 27 shows a modification with four sections, wherein three conduits are provided and continue supply and discharge opposite. The solution is in principle expandable to 6 or more even-numbered sections.

Fig. 28 shows a modification with four or more even-numbered sections, wherein supply and discharge are provided by means of separating elements in the same conduit and vorrt only one circulation line.

FIG. 29 shows the modification from FIG. 28 with only two sections and thus only one separating element between the feed line and the discharge line.

Fig. 30 shows a solution having four or more sections in a supply line, a mutual discharge line and a circulation line.

Fig. 31 shows a variant in which supply and discharge have their connections in the longitudinal direction in the middle and are continued perpendicular to the longitudinal direction. There are two sections and one circulation line.

FIG. 32 shows a variant of FIG. 29 with asymmetrical division of the sections and at the evaporator ends in each case angled infeed and outfeed.

Fig. 33 shows the variant of Fig. 32 with separate pipes for supply and discharge, so that no separator is required.

FIG. 34 shows the variant from FIG. 33 with feed and discharge continued in the opposite direction relative to the flow of air.

FIG. 35 shows a variant with two sections, in which the first section is distributed in half with respect to the individual flow paths on the end regions of the evaporator, the second section being between the two subgroups of flow paths of the first section is located. This allows a fine adjustment to a distribution of the air flow.

FIG. 36 shows an arrangement modified from FIG. 35, in which subgroups of flow paths of the second section are respectively arranged at the evaporator ends. The subgroups are a-symmetrically distributed for more accurate adaptation, with only one flow path at one end and three flow paths of the second section at the other end.

In the third exemplary embodiment according to FIGS. 37 to 43, the feed line 301 is laid almost over the entire housing length of the heat exchanger and arranged between a discharge line 302 and a circulation line 305. The effective length Lz of the feed line results as a maximum distance of a total of five in the feed direction successively arranged openings 301a, via which the refrigerant enters the heat exchanger. An effective length Ls of a collecting region 303 results from a maximum distance between two flow paths in the longitudinal direction of the heat exchanger. In the present case, the effective supply line length Lz is approximately 43% of the effective evaporator length Ls. The drawings Fig. 37 to Fig. 43 are each in scale.

The collecting region 303 is constructed analogously to the first exemplary embodiments of an upper plate element 309, a distributor plate 308 and a lower plate element 307 for receiving flat tubes 306. The distributor plate 308 differs in the exact arrangement of their openings 308a from the previous embodiments, but works on the same principle. The plate elements 307, 308, 309 are soldered flat on their abutting surfaces. The lower plate member corresponds to that of the first embodiment. Overlaying the drawings in FIGS. 40 and 41 results directly in the intended flow paths of the coolant within the heat exchanger. Just as in the previous embodiments are in accordance with the decreasing pressure, the openings in the Lines and running in the upper plate member 309 in the course of the flow path of the coolant increasingly larger.

The supply line 301, the discharge line 302 and the circulation line 305 each have a flattening 301 b in the area of their contact with an upper plate element 309, so that the lines have a D-shaped cross section over this section (see FIGS. 39, 42 ). Outside the contact area, supply line 301 and discharge line 302 are circular in cross section.

In addition, the lines 301, 302, 305 in the region of the flattening 301b perforations 301c, which correspond with embossed elevations 309b of the upper plate member 309. Since the elevations 309b do not provide a passage for the refrigerant (see FIG. 41), the engagement of the elevations 309b in the perforations 301c, ie the positive engagement of corresponding formations, merely serves to position and retain the lines 301, 302, 305 in FIG During the production of the heat exchanger. In this case, the upper side of the upper plate element 309 is plated flat with solder. After aligned arrangements of the lines 301, 302, 305 they are soldered flat in their contact area 301b with the upper plate member 309, while aligned openings 309a of the upper plate member with the respective apertures 301a, without the openings 301a, 309a as in the first embodiment form-fitting manner need to grab. Suitably, in each case one of the apertures 301 a is dimensionally accurate with respect to the predetermined passage cross-section for the refrigerant, and the respective other of the apertures 309 a has an excess in order to take account of unavoidable tolerances in the positioning of the lines.

According to FIG. 42, the openings 301a have no burrs or excess material residues. This can be achieved by drilling or usually more cost-effective punching and subsequent deburring and removal of the punched-out material. This can be done using compressed air, for example. In general, there remains a certain risk of loose burrs or material remnants that are not completely removed, which could later enter the refrigeration cycle. In a modification according to FIG. 43, the line 301 is therefore punched by means of a suitable tool 310 without removal of material, that is to say in a material-preserving manner, in order to produce the openings 301a, 301b. In this case, the removed from the opening material 301 d of the conduit wall is disposed within the conduit and firmly connected to the rest of the wall. In this way, a high level of security against entry of material waste is achieved in the refrigeration cycle. However, in principle, the cross-section of the line 301, 302, 305 is reduced, which has a corresponding pressure drop result. Appropriately, it can therefore be provided that only line parts with high pressure and low flow velocity, in particular the feed line 301, are produced by punching without material removal.

Claims

P a n t a n s p r e c h e

1. A heat exchanger, in particular evaporator of a motor vehicle air conditioning system, comprising a plurality of flow paths, each of the flow paths at least one of a coolant flowed through multi-channel tube (6), a supply line (1) and a derivative (2) for supplying and discharging the

Coolant to the heat exchanger, at least one collecting area (3), wherein at least portions of the collecting area (3) are connected to the plurality of flow paths, wherein the heat exchanger in a transverse direction of cooling air for cooling the coolant is flowed through, wherein the heat exchanger in a to the transverse direction substantially longitudinal longitudinal direction has a greater structural length than in the transverse direction, and wherein the supply line (1) oriented in the longitudinal direction of the collecting area (3) and is connected thereto, characterized in that the supply line in the region of the connection with the collecting area has an effective lead length in the longitudinal direction, which is significantly smaller than an effective total length of the collecting region (3).

2. Heat exchanger according to claim 1, characterized in that the effective supply line length is not greater than half the effective length of the collecting region (3). 3. Heat exchanger according to claim 1 or 2, characterized in that with the collecting area (3) connected to circulating line (5) is provided, wherein coolant from a first subset of flow paths out into the circulation line (5) and from the

Circulation line (5) exits in a second subset of flow paths.

4. Heat exchanger according to one of claims 1 to 3, characterized in that at least one of the group supply line (1), discharge line (2) or circulation line (5) has a separating element, by means of which at least two sections of the relevant line coolant-tight separated from each other.

5. Heat exchanger according to one of the preceding claims, characterized in that the collecting area (3) comprises a plurality of plate elements (7, 8, 9), by the stacking of the collecting area (3) is at least partially buildable.

6. Heat exchanger according to claim 5, characterized in that the feed line (1) with an upper plate member (9) of the collecting region (8) is connected, wherein a plurality of respective corresponding openings (9 a) in the upper plate member (9) and in the supply line (1) are provided.

7. Heat exchanger according to claim 6, characterized in that at least one opening (9a) of supply line (1) and upper plate member (9) opens into at least two flow paths.

8. Heat exchanger according to claim 6 or 7, characterized in that at least one of the flow paths is associated with exactly one opening (9 a) of the supply line (1) and upper plate element (9). 9. Heat exchanger according to one of claims 5 to 8, characterized in that a plate-shaped distributor element (8) is provided, wherein the coolant by means of a plurality of in the distributor element (8) provided openings (8a) can be distributed to the plurality of flow paths.

10. Heat exchanger according to one of claims 5 to 9, characterized in that a lower plate member (7) has a plurality of openings (7a), wherein the flow paths in the region of the openings (7a) fixed to the lower plate member (7) are.

11. Heat exchanger according to one of the preceding claims, characterized in that at least one of the flow paths as a U-shaped flat tube (6) with a plurality of chambers (6 a) is formed.

12. A heat exchanger according to one of the preceding claims, characterized in that the plurality of flow paths is grouped into a number of sections, each section having at least one flow path, wherein the sections in the longitudinal direction of the heat exchanger are arranged side by side and wherein fluidically between at least two the portions of a suitable volume for an intermediate collection of the coolant volume is provided.

13. Heat exchanger according to claim 12, characterized in that the number of sections is two or a larger even number.

14. Heat exchanger according to claim 12, characterized in that the number of sections a total of three or a larger odd

Number is.

15. Heat exchanger according to one of the preceding claims, characterized in that the coolant is carbon dioxide (R 744). 16. Heat exchanger according to at least one of the preceding claims, characterized in that the supply line in the region of the connection with the collecting region has an effective supply line length in the longitudinal direction, which is shorter than the length of the supply line itself.

17. Heat exchanger according to at least one of the preceding claims, characterized in that the supply line is divided in the region of the connection with the collecting area to a plurality of pipes, pipe sections or partial pipe sections.

18. Heat exchanger according to at least one of the preceding claims, characterized in that the supply line (301) is laid over substantially the entire length of the heat exchanger.

19. Heat exchanger according to one of the preceding claims, characterized in that at least the feed line (301) or the discharge line (302) has a flattening (301 b), wherein the flattening (301b) is soldered flat with the collecting area (303).

21. Heat exchanger according to claim 19, characterized in that at least the supply line (301) or the discharge line (302) have a substantially D-shaped cross-section.

22. A heat exchanger according to claim 21, characterized in that the cross section of at least the supply line (301) or the discharge line (302) outside the region of the planar soldering is substantially circular.

23. Heat exchanger according to one of the preceding claims, characterized in that at least the feed line (301) or the discharge (302) has a formation (301c) which is positively connected to a formation (309b) of the collecting area for the purpose of positioning the feed line (301 ) or derivative (302) interacts, wherein the formation (301c, 309b) does not allow the passage of coolant.

24. Heat exchanger according to one of the preceding claims, characterized in that at least the supply line (301) or the discharge line (302) has a plurality of openings (301 a) which with a plurality of openings (309 a) of the collecting area (303) for the purpose of passage are aligned by coolant, wherein the openings (301a, 309a) do not interact positively.

25. Heat exchanger according to one of the preceding claims, characterized in that at least the supply line (301) or the discharge line (302) have openings (301 a) for the purpose of coolant passage, which are produced by means of bore or material wegnehmen- punching.

26. Heat exchanger according to one of the preceding claims, characterized in that at least the supply line (301) or the discharge (302) have openings (301a) for the purpose of coolant passage, which are made by punching without material removal.