EP1717530B1 - Heat exchanger, more particularly rear evaporator for automotive vehicle - Google Patents

Description

The invention relates to a heat exchanger, in particular a rear evaporator for a motor vehicle, according to the preamble of claim 1. From the DE 102 60 107 A1 a heat exchanger is known which has tubes which can be flowed through by a first medium along a plurality of hydraulically parallel flow paths constructed from sections (flat tubes) and by a second medium. The heat exchanger has an inlet and an outlet section, wherein in each case a plurality of spaced-apart refrigerant inlet and outlet openings is provided in the inlet or outlet section. Through the refrigerant inlets, the refrigerant is distributed from the corresponding collection chamber to the flow paths, and through the refrigerant outlets, the refrigerant is collected in the corresponding collection chamber and supplied to the discharge section.

In Heckverdampfern is often the expansion element in the front of the vehicle (eg in the front of the engine compartment or in the cabin bulkhead), so that expanded refrigerant in the two-phase state long lines, if necessary over 2 m, must be led to the rear to the rear evaporator. Due to the length of the line, this leads to problems with regard to segregation of the gas and liquid phase. If the rear evaporator is operated superheated, it may happen in conventional designs that individual strands are preferably supplied with the segregated gas fraction, so that an unfavorable temperature profile may occur, whereby the performance and efficiency of the rear evaporator are impaired. This also applies, for example, in the case of a construction of the rear evaporator according to the aforementioned DE 102 60 107 A1 to.

An uneven temperature distribution is particularly undesirable in the generally relatively small designed Heckverdampfern (eg. 10 cm high and 15 cm wide), which are used in particular in high-quality, multi-zone air conditioning, the rear evaporator cooling the two zones, since they comfort can seriously affect the occupants.

It is therefore an object of the invention to provide a heat exchanger with an improved temperature profile available, so that even when separated at the heat exchanger inlet two-phase, i. not as a fine mist, refrigerant present a uniform temperature distribution can be ensured.

This object is achieved by a heat exchanger with the features of claim 1. Advantageous embodiments are the subject of the dependent claims.

For this purpose, a heat exchanger, in particular a rear evaporator for a motor vehicle is proposed, which is flowed through by refrigerant, and which is constructed such that the refrigerant flowing into the heat exchanger refrigerant flow through a distributor to exactly two from each other separated strands is distributed, such that there is no mutual mixing of each flowing therein refrigerant partial flow. A combination of the refrigerant partial streams, in particular in the output region of the heat exchanger should not be excluded. This configuration makes it possible, in particular in cases when the refrigerant is in a two-phase, segregated state at the evaporator inlet, a uniform temperature distribution across the heat exchanger, and thus also the largest possible cooling capacity with small dimensions of the heat exchanger. In other evaporators, such a two-phase, demixed refrigerant usually leads to a highly non-uniform temperature profile. By the uniform distribution of refrigerant so the comfort of the rear vehicle occupants can be significantly increased, the measures for this are very inexpensive. The above applies in particular to R744 (carbon dioxide) as a refrigerant, since it has been shown that the temperature distribution can be homogenized particularly well here.

According to the invention, a heat exchanger is provided, in particular a rear evaporator for a motor vehicle, with pipes and a collecting box, which comprises a distributor plate, a deflecting plate and a bottom plate, in which the tubes end with at least one of their ends, and which can be flowed through by refrigerant, wherein the collecting box has exactly one opening in the distributor plate, through which refrigerant passes into the collecting box and immediately after which the refrigerant flow is distributed to exactly two strands. The uniform refrigerant distribution due to the one opening in the distributor plate, which is provided with an injection distributor opening in the subsequently arranged baffle, allows a uniform distribution of the refrigerant, in particular even if the refrigerant is in a two-phase, segregated state, in others Evaporate to a strong inconsistent temperature profile leads. Due to the uniform distribution of refrigerant so the comfort of the rear vehicle occupants is significantly increased, the measures for this are very inexpensive. The above applies in particular to R744 (carbon dioxide) as a refrigerant, since it has been shown that the temperature distribution can be homogenized particularly well here.

The injection distributor opening adjoining the opening in the distributor plate is H-shaped. This form allows in a particularly simple and cost-effective manner a uniform distribution of the refrigerant on the two strands.

The baffle preferably has not only an H-shaped injection manifold opening but also a plurality of H-shaped openings for deflecting the flow of refrigerant from one pipe to the adjacent pipe. Due to the H-shaped configuration, the refrigerant is mixed with each deflection in the collecting box, so that the temperature profile on the flat tubes itself is very even.

The baffle preferably also has an H-shaped refrigerant outlet opening, which is arranged after the corresponding opening in the distributor plate and through which the refrigerant is sucked out of the collecting box. The symmetrical design of the outlet opening supports a uniform temperature profile.

The H-shaped opening is designed to guide and optimize the flow with rounded corners.

The H-shaped opening is preferably formed rounded at its leg ends, wherein the width of the leg slightly widened. The leg itself preferably ends straight.

The H-shaped opening preferably has a leg width which corresponds approximately to the width of the transverse connection between the two legs. On the one hand, this embodiment enables a good mixing of the refrigerant in the region of the deflection and, on the other hand, it enables a sufficiently resilient design and solubility of the deflection plate.

The heat exchanger is preferably designed in two rows, wherein it is preferably also built very small.

In order to enable the most uniform possible temperature profile and a good efficiency of the heat exchanger, the injection manifold opening - seen in the flow direction of the heat exchanger through the air flowing - preferably arranged in the last row of tubes. Accordingly, the outlet opening is opposite on the other side, i. in the - viewed in the flow direction of the heat exchanger through the air flowing - arranged first row of tubes.

The heat exchanger is, in order to obtain a uniform temperature profile as possible, preferably mirror images to the central transverse axis and / or point symmetrical to the central axis formed, wherein - in the case of an unsuitable number of tubes - the corresponding inlet and outlet openings can also be arranged offset by one row. In the case of an a-symmetrical air inflow, however, it may also be advantageous to provide a different path length of the two strands through which the refrigerant flows through the heat exchanger. The same applies in other cases, for example, if due to the evaporator width or due to the installation conditions no symmetrical division is possible.

The injection tube and / or the suction tube are preferably soldered to the heat exchanger, resulting in a complete solution with as few soldering / connecting points. The soldering - including the collecting box - can be done in one step, so that the manufacturing costs can be minimized.

The connection points for the injection and suction pipe are preferably connected to the same center with respect to the width of the heat exchanger. In this case, preferably at least one, in particular both tubes run parallel to the direction of air flow.

In the refrigerant circuit, CO ₂ is preferably provided as the refrigerant, but any other refrigerant may be used.

Fig. 1

eine Ansicht eines Heckverdampfers mit Expansionsventil, Einspritzrohr und Saugrohr,

Fig. 2

eine Seitenansicht des Heckverdampfers von Fig. 1 mit Expansionsventil, Einspritzrohr und Saugrohr,

Fig. 3

eine Ansicht von unten auf den Heckverdampfer von Fig. 1 mit Expansionsventil, Einspritzrohr und Saugrohr,

Fig. 4

eine Ansicht des Einspritzrohres,

Fig. 5

eine Ansicht von unten auf das Einspritzrohr von Fig. 4,

Fig. 6

eine vergrößerte Darstellung eines Schnitts entlang der Linie VI-VI von Fig. 4,

Fig. 7

eine Detailansicht des Bereichs VII von Fig. 6,

Fig. 8

eine Darstellung eines Schnitts entlang der Linie Vlll-Vlll von Fig. 7,

Fig. 9

eine Ansicht des Saugrohrs,

Fig. 10

eine Ansicht von unten auf das Saugrohr von Fig. 9,

Fig. 11

eine vergrößerte Darstellung eines Schnitts entlang der Linie XI-XI von Fig. 10,

Fig. 12

eine Detailansicht des Bereichs XII von Fig. 11,

Fig. 13

eine Darstellung eines Schnitts entlang der Linie XIII-XIII von Fig. 12,

Fig. 14

eine Draufsicht auf die Verteilerplatte des Heckverdampfers von Fig. 1,

Fig. 15

einen Schnitt entlang der Linie XV-XV von Fig. 14,

Fig. 16

eine Draufsicht auf das Umlenkblech des Heckverdampfers von Fig. 1,

Fig. 17

eine Detailansicht des Bereichs XVII von Fig. 16,

Fig. 18

eine Seitenansicht des Umlenkblechs von Fig. 16,

Fig. 19

eine Draufsicht auf die Bodenplatte des Heckverdampfers von Fig. 1,

Fig. 20

eine Seitenansicht der Bodenplatte von Fig. 19,

Fig. 21

eine Ansicht der Anschlüsse einer Variante eines Heckverdampfers mit einer Breite von zwölf Flachrohren,

Fig. 22

eine Draufsicht auf das Umlenkblech des Heckverdampfers von Fig. 21 mit durch Pfeilen angedeutetem Strömungsverlauf,

Fig. 23

eine erste Variante der Anschlüsse für den Heckverdampfer von Fig. 21,

Fig. 24

eine zweite Variante der Anschlüsse für den Heckverdampfer von Fig. 21,

Fig. 25

eine dritte Variante der Anschlüsse für den Heckverdampfer von Fig. 21,

Fig. 26

eine Ansicht der Anschlüsse einer zweiten Variante eines Heckverdampfers mit einer Breite von zwölf Flachrohren,

Fig. 27

eine Draufsicht auf das Umlenkblech des Heckverdampfers von Fig. 26 mit durch Pfeilen angedeutetem Strömungsverlauf,

Fig. 28

eine erste Variante der Anschlüsse für den Heckverdampfer von Fig. 26,

Fig. 29

eine zweite Variante der Anschlüsse für den Heckverdampfer von Fig. 26,

Fig. 30

eine dritte Variante der Anschlüsse für den Heckverdampfer von Fig. 26,

Fig. 31

eine Ansicht der Anschlüsse einer dritten Variante eines Heckverdampfers mit einer Breite von zwölf Flachrohren,

Fig. 32

eine Draufsicht auf das Umlenkblech des Heckverdampfers von Fig. 31 mit durch Pfeilen angedeutetem Strömungsverlauf,

Fig. 33

eine Ansicht der Anschlüsse einer Variante eines Heckverdampfers mit einer Breite von zehn Flachrohren,

Fig. 34

eine Draufsicht auf das Umlenkblech des Heckverdampfers von Fig. 33 mit durch Pfeilen angedeutetem Strömungsverlauf,

Fig. 35

eine Variante der Anschlüsse für den Heckverdampfer von Fig. 33,

Fig. 36

eine Draufsicht auf das Umlenkblech eines Heckverdampfers mit einer Breite von acht Flachrohren mit durch Pfeilen angedeutetem Strömungsverlauf,

Fig. 37

eine Draufsicht auf das Umlenkblech eines Heckverdampfers mit einer Breite von acht Flachrohren mit durch Pfeilen angedeutetem Strömungsverlauf gemäß einer Anschlussvariante bezüglich des Heckverdampfers von Fig. 36,

Fig. 38

eine Ansicht der Anschlüsse einer Variante eines Heckverdampfers mit zwölf Flachrohren, bei dem die beiden Stränge unterschiedlich lang sind,

Fig. 39

eine Draufsicht auf das Umlenkblech des Heckverdampfers von Fig. 38,

Fig. 40

eine weitere Variante der Anschlüsse für den Heckverdampfer,

Fig. 41

eine Fig. 40 entsprechende Variante der Anschlüsse für den Heckverdampfer mit umgekehrter Durchströmungsrichtung,

Fig. 42

eine weitere Variante der Anschlüsse für den Heckverdampfer,

Fig. 43

eine perspektivische Ansicht des Umlenkblechs,

Fig. 44

eine Detailansicht eines Ausschnitts des Umlenkblechs von Fig. 43,

Fig. 45

eine perspektivische Ansicht der Bodenplatte, und

Fig. 46

eine perspektivische Ansicht der Verteilerplatte.

In the following the invention will be explained with reference to an embodiment with several variants with reference to the drawings in detail. In the drawing show:

Fig. 1

a view of a rear evaporator with expansion valve, injection pipe and intake manifold,

Fig. 2

a side view of the rear evaporator of Fig. 1 with expansion valve, injection pipe and intake manifold,

Fig. 3

a view from below of the rear evaporator of Fig. 1 with expansion valve, injection pipe and intake manifold,

Fig. 4

a view of the injection tube,

Fig. 5

a view from below of the injection pipe of Fig. 4 .

Fig. 6

an enlarged view of a section along the line VI-VI of Fig. 4 .

Fig. 7

a detailed view of the area VII of Fig. 6 .

Fig. 8

a representation of a section along the line VIII-VIII of Fig. 7 .

Fig. 9

a view of the suction tube,

Fig. 10

a view from below of the suction pipe of Fig. 9 .

Fig. 11

an enlarged view of a section along the line XI-XI of Fig. 10 .

Fig. 12

a detailed view of the area XII of Fig. 11 .

Fig. 13

a representation of a section along the line XIII-XIII of Fig. 12 .

Fig. 14

a plan view of the distributor plate of the rear evaporator of Fig. 1 .

Fig. 15

a section along the line XV-XV of Fig. 14 .

Fig. 16

a plan view of the baffle of the rear evaporator of Fig. 1 .

Fig. 17

a detailed view of the area XVII of Fig. 16 .

Fig. 18

a side view of the baffle of Fig. 16 .

Fig. 19

a plan view of the bottom plate of the rear evaporator of Fig. 1 .

Fig. 20

a side view of the bottom plate of Fig. 19 .

Fig. 21

a view of the connections of a variant of a rear evaporator with a width of twelve flat tubes,

Fig. 22

a plan view of the baffle of the rear evaporator of Fig. 21 with flow path indicated by arrows,

Fig. 23

a first variant of the connections for the rear evaporator of Fig. 21 .

Fig. 24

a second variant of the connections for the rear evaporator of Fig. 21 .

Fig. 25

a third variant of the connections for the rear evaporator of Fig. 21 .

Fig. 26

a view of the connections of a second variant of a rear evaporator with a width of twelve flat tubes,

Fig. 27

a plan view of the baffle of the rear evaporator of Fig. 26 with flow path indicated by arrows,

Fig. 28

a first variant of the connections for the rear evaporator of Fig. 26 .

Fig. 29

a second variant of the connections for the rear evaporator of Fig. 26 .

Fig. 30

a third variant of the connections for the rear evaporator of Fig. 26 .

Fig. 31

a view of the connections of a third variant of a rear evaporator with a width of twelve flat tubes,

Fig. 32

a plan view of the baffle of the rear evaporator of Fig. 31 with flow path indicated by arrows,

Fig. 33

a view of the connections of a variant of a rear evaporator with a width of ten flat tubes,

Fig. 34

a plan view of the baffle of the rear evaporator of Fig. 33 with flow path indicated by arrows,

Fig. 35

a variant of the connections for the rear evaporator of Fig. 33 .

Fig. 36

a plan view of the baffle of a rear evaporator with a width of eight flat tubes with flow indicated by arrows,

Fig. 37

a plan view of the baffle of a rear evaporator with a width of eight flat tubes with flow indicated by arrows according to a connection variant with respect to the rear evaporator of Fig. 36 .

Fig. 38

a view of the connections of a variant of a rear evaporator with twelve flat tubes, in which the two strands are of different lengths,

Fig. 39

a plan view of the baffle of the rear evaporator of Fig. 38 .

Fig. 40

another variant of the connections for the rear evaporator,

Fig. 41

a Fig. 40 corresponding variant of the connections for the rear evaporator with reverse flow direction,

Fig. 42

another variant of the connections for the rear evaporator,

Fig. 43

a perspective view of the baffle,

Fig. 44

a detailed view of a section of the baffle of Fig. 43 .

Fig. 45

a perspective view of the bottom plate, and

Fig. 46

a perspective view of the distributor plate.

A heat exchanger 1, in this case a rear evaporator of a motor vehicle, which is connected via an injection pipe 2 and a suction pipe 3 with an expansion element 4, according to the present embodiment, a collecting box 5 and a plurality of double-row arranged, U-shaped flat tubes 6. The collecting box 5 has a distributor plate 7, each with an opening 8 with slightly outwardly projecting to the outside Edge 9 for the injection and suction of the refrigerant by means of the injection tube 2 and the suction tube 3, a deflector 10 soldered to the distributor plate 7 and a bottom plate 11 soldered to the baffle 10 with a plurality of slot-like openings 12, into which the ends the flat tubes 6 are inserted.

The injection tube 2 is closed at its end with a closure cap 13. The refrigerant outlet from the injection tube 2 into the heat exchanger 1 is provided in the form of exactly one bore 14, which is arranged in the joining seam of the tube and has a bore diameter which is smaller than the inner diameter of the injection tube 2 (see. Fig. 8 ). The bore 14 is arranged in alignment with the corresponding opening 8 in the distributor plate 7.

The suction pipe 3 is formed according to the injection pipe 2 and arranged with respect to the distributor plate 7, however, the bore 14 at the end of the suction pipe 3 has a bore diameter corresponding to the inner diameter of the suction pipe 3 (see. Fig. 13 ).

The injection tube 2 as well as the suction tube 3 are presently connected directly to the distributor plate 7, for which the respective slightly outwardly projecting edge 9 of the openings 8 in the distributor plate 7 projects into the corresponding bore 14 in the respective tube. Here, the height of the edge corresponds approximately to the pipe wall thickness.

Alternatively, the tubes can also be introduced into the distributor plate with their ends or can be provided a multi-part embodiment, in which case the firmly connected to the distributor plate or possibly also integrally formed part in terms of its function as a part of the injection tube or Suction tube is called.

In the following, the baffle 10 will be explained in more detail. The function of the baffle 10 is primarily the deflection of the effluent from a flat tube 6 refrigerant to the adjacent flat tube 6, wherein the refrigerant is to be mixed in addition, so that a uniform temperature profile is possible. This takes place here within the rows with the aid of the double row arranged H-shaped openings 15 in the baffle 10. In principle, however, would be another embodiment of the openings 15, only the deflection of a flat tube 6 to the adjacent flat tube 6 and possibly also the discharge from serve the last two flow-through flat tubes 6 in the suction tube 3, possible. However, due to the strength required by the high pressures, an H-shaped configuration is particularly advantageous.

At both longitudinal ends of the baffle 10 each have a slot-like opening 16 is provided, which extends in length over both rows of H-shaped openings 15 and the refrigerant from one row into the other row passes (see Fig. 16 ).

The H-shaped configuration of an injection Verteiferöffnung 15 a, which is arranged opposite to the refrigerant inlet of the distributor plate 7, in the present case corresponds exactly to that of the other openings 15, which is precisely this embodiment in view of a uniform distribution of the refrigerant on the two strands is particularly advantageous. In the present case, the discharge opening 15b of the deflection plate 10, which is opposite the refrigerant outlet of the distributor plate 7, is likewise designed accordingly.

The H-shape of the openings 15, 15a and 15b has rounded edges in all areas, wherein the ends of the legs are provided with outwardly projecting rounded portions, so that the leg width is slightly enlarged at the ends (see. Fig. 17 ). The cross connection has the same Width as the thighs up. The leg width corresponds approximately to the width of the opening of the flat tubes 6, the leg length is formed accordingly.

The present rear evaporator has, as is common practice, compared to conventional evaporators, as used for front-side motor vehicle air conditioners, reduced dimensions. While conventional front evaporator dimensions are in the range of 180 mm to 310 mm for the width, 180 mm to 260 mm for the height, and 40 mm to 50 mm for the depth, the present evaporator has a width of 130 mm and a height of 130 mm at a depth of 40 mm. However, all values in the range of 100 mm to 160 mm, in particular 110 mm to 150 mm, especially 120 mm to 140 mm for height and / or width of the rear evaporator are particularly favorable.

FIGS. 21 and 22 show a variant of a double-row rear evaporator, which has twelve tubes in width. In this case, the refrigerant supply and removal takes place parallel in the longitudinal direction of the collecting tank in the middle of the same (see. Fig. 22 ). The refrigerant flow is evenly distributed in both directions after the injection due to the symmetrical configuration (mirror image embodiment with respect to the central transverse axis of the heat exchanger) of the injection manifold opening 15a, so that there is a relatively uniform temperature profile.

The FIGS. 23, 24 and 25 show a different arrangement of the injection and suction pipe, namely in Fig. 23 a parallel arrangement in which the flow direction in the two tubes is the same, in Fig. 24 a lateral arrangement, in which both tubes have a bend (45 ° bend) relatively shortly before the connection to the rear evaporator, and in Fig. 25 a lateral arrangement in which a tube is formed straight and the other tube provided with a kink. The basic structure of the collecting tank however, including the injection manifold opening 15a is identical to that in FIG Fig. 22 shown.

The FIGS. 26 and 27 show a second variant of a double-row rear evaporator, which has twelve tubes in width. Here, the refrigerant supply and discharge takes place diagonally offset, in each case at the laterally outermost H-shaped opening. The refrigerant flow is in turn distributed evenly on both strands, wherein the strand downstream in the air flow direction, the corresponding series of flat tubes flows through and the other part flow is deflected after flowing through the corresponding side most rear flat tube in the depth direction of the rear evaporator and then flows through the front row until it reaches the last H-shaped opening passes to the suction pipe. The injection and the suction pipe can be arranged to extend parallel in the direction of the longitudinal extension of the collecting tank, as in Fig. 26 shown. Alternative embodiments are in the FIGS. 28 to 30 shown. Particularly advantageous here is the embodiment accordingly Fig. 30 according to which the refrigerant supply and removal is provided at different corners of the heat exchanger, and in which one of the two pipes, in this case the suction pipe, is arranged to extend parallel to and adjacent to the collecting tank of the heat exchanger.

FIGS. 31 and 32 show a second variant of a double-row rear evaporator with twelve tubes in width, in which the injection manifold opening between that of the two variants described above. The connection is designed according to the variant described above. Other connection possibilities correspond to those of FIGS. 28 to 30.

In the FIGS. 33 and 34 is a variant of a double row rear evaporator with ten tubes shown in width, in Fig. 35 a connection variant for connection of Fig. 33 , but also a different arrangement of the injection and suction pipes is possible, in particular as in the Figures 23-25 shown. Of course, a further apart supply and discharge of the refrigerant is possible, ie with respect to the representation of Fig. 34 each offset by an H-shaped opening 15 to the right or to the left.

In the FIGS. 36 and 37 Two variants of the refrigerant supply and discharge for a double-row rear evaporator with eight pipes each are shown in width. The arrangement of the injection and suction pipes may be formed according to the previous variants.

The Figures 38 and 39 show a variant of a rear evaporator with different path length of the two strands. A different path length of the two strands may be useful in an unequal distribution of air flow through the rear evaporator to optimize the temperature profile.

As can be seen from all the variants described above, the injection distributor opening 15a is preferably arranged in the second (or the rearmost) row when viewed in the air flow direction, but the outlet opening 15b is arranged in the first row. This enables optimization of the cooling capacity.

The heat exchanger according to the embodiment described above is at operating pressures of 90 bar here, but at least 50 bar, designed (test pressure in this case 160 bar), so that in particular R744, ie CO ₂ , can be used as a refrigerant.

In the FIG. 40 a particularly advantageous variant of the arrangement of the connections for a rear evaporator is shown, wherein the injection and suction pipe - apart from an end portion of the injection pipe, in which one of the two tubes at the end is slightly bent to allow connection at the same height - are arranged parallel to each other. The tubes are substantially parallel to the direction of air flow, wherein the connection points are arranged centrally on the rear evaporator. This embodiment is particularly advantageous with regard to the temperature distribution over the rear evaporator.

Fig. 41 shows a variant that is substantially the embodiment of Fig. 40 corresponds, but the flow direction of the refrigerant is reversed, so that the injection and suction pipe are reversed. The dimensions of Einsprüz- and suction tube are not shown to scale in the figures.

As shown by Fig. 42 in turn, the connection points are arranged centrally with respect to the rear evaporator, but in the present case only the injection tube is aligned parallel to the air flow direction. The suction pipe runs perpendicular to this and is bent only laterally of the rear evaporator.

Any other arrangements of the injection and suction pipes are possible, but a (possible) central arrangement of the connection points in terms of a uniform temperature distribution is advantageous.

In the following, the baffle 10 and its function in the collection box 5 will be explained in more detail. The function of the baffle 10 is primarily the deflection of the effluent from a flat tube 6 refrigerant to the adjacent flat tube 6, wherein the refrigerant is to be mixed in addition, so that a uniform temperature profile is possible. This takes place here within the rows by means of the double row arranged H-shaped openings 15 in the baffle 10, wherein the refrigerant through a leg of the H-shaped opening 15 on, through the connecting web and over the second leg of the H-shaped opening 15 flows out again into the adjacent U-shaped flat tube 6. At both longitudinal ends of the baffle 10 each have a slot-like opening 16 is provided, which extends in length over both rows of H-shaped openings 15 and directs the refrigerant from one row to the other row.

In principle, however, would also be another embodiment of the openings 15, which serve only the deflection of a flat tube 6 to the adjacent flat tube 6 and possibly also the discharge of the last two flow-through flat tubes 6 in the suction pipe, possible. However, due to the strength required by the high pressures, an H-shaped configuration is particularly advantageous.

The H-shaped configuration of an injection manifold opening 15a, which is arranged opposite to the refrigerant inlet of the distributor plate 7, corresponds in the present case exactly to that of the other openings 15, exactly this embodiment is particularly advantageous with regard to a uniform distribution of the refrigerant to the two strands. In the present case, the discharge opening 15b of the deflection plate 10, which is opposite the refrigerant outlet of the distributor plate 7, is likewise designed accordingly.

The H-shape of the openings 15, 15a and 15b has rounded edges in all areas, wherein the centrally disposed ends of the legs are provided with outwardly projecting rounded portions, so that the leg width is slightly enlarged at the ends (see. Fig. 44 ). The cross-connection has twice the width as the legs. The leg width corresponds approximately to the width of the opening of the flat tubes 6, the leg length is formed accordingly.

The present rear evaporator has, as is common practice, compared to conventional evaporators, as used for front-side motor vehicle air conditioners, reduced dimensions. While conventional front evaporator dimensions range from 180 mm to 310 mm for the width, 180 mm to 260 mm for the height and 40 mm to 50 mm for the depth, the present heat exchanger has a width of 130 mm and a height of 130 mm at a depth of 40 mm. However, all values in the range of 100 mm to 160 mm, in particular 110 mm to 150 mm, especially 120 mm to 140 mm for height and / or width of the rear evaporator are particularly favorable.

The heat exchanger according to the embodiment described above is at operating pressures of 90 bar here, but at least 50 bar, designed (test pressure in this case 160 bar), so that in particular R744, ie CO ₂ , can be used as a refrigerant.

The heat exchanger according to the embodiment described above is at operating pressures of 90 bar here, but at least 50 Bar, designed (test pressure in this case 160 bar), so that in particular R744, ie CO ₂ , can be used as a refrigerant.

Claims (12)

1. A heat exchanger, in particular a rear evaporator for a motor vehicle, with tubes (6) and a collecting tank (5) which comprises a distributor plate (7), a baffle (10) and a bottom plate (11), in which the tubes (6) terminate with at least one of their ends, and which can be flowed through by refrigerant, characterised in that the collecting tank (5) has exactly one opening (8) in the distributor plate (7) through which refrigerant passes into the collecting tank (5) and directly after which the refrigerant flow is distributed between exactly two strands, wherein the refrigerant is evenly distributed between exactly two strands, wherein a distributor injection opening (15a) is formed in the baffle (10) and wherein the distributor injection opening (15a) adjacent to the opening (8) is H-shaped, wherein the two strands are respectively formed by at least one of the tubes (6) to which the refrigerant can be supplied via the common H-shaped distributor injection opening (15a).
2. The heat exchanger according to claim 1, characterised in that the baffle (10) has several H-shaped openings (15) for redirecting the refrigerant flow from one of the tubes (6) to the adjacent tube (6).
3. The heat exchanger according to one of the preceding claims, characterised in that the baffle (10) has an H-shaped refrigerant outlet opening (15b).
4. The heat exchanger according to one of claims 2 to 3, characterised in that the H-shaped openings (15, 15a, 15b) are formed with rounded corners.
5. The heat exchanger according to one of claims 2 to 4, characterised in that the H-shaped openings (15, 15a, 15b) are rounded on their leg ends, wherein the width of the leg expands.
6. The heat exchanger according to one of claims 2 to 5, characterised in that the H-shaped openings (15, 15a, 15b) have a leg width which corresponds to the width of the cross connection between the two legs.
7. The heat exchanger according to one of the preceding claims, characterised in that the heat exchanger is formed in two rows.
8. The heat exchanger according to one of the preceding claims, characterised in that the distribution injection opening (15a), as seen in the flow direction of the air flowing through the heat exchanger, is arranged in the last tube row.
9. The heat exchanger according to one of the preceding claims, characterised in that exactly one refrigerant outlet opening (15b) is provided, which, as seen in the flow direction of the air flowing through the heat exchanger, is arranged in the first tube row.
10. The heat exchanger according to one of the preceding claims, characterised in that the heat exchanger (1) is formed inversely to the central transverse axis and/or point-symmetrically to the central axis.
11. The heat exchanger according to one of the preceding claims, characterised in that an injection tube (2) and/or a suction tube (3) is soldered to the heat exchanger (1).
12. The heat exchanger according to claim 11, characterised in that the connection points of the injection tube (2) and/or of the suction tube (3) are centrally connected to the heat exchanger (1) with respect to the width thereof.

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