EP1794528A1

EP1794528A1 - Heat exchanger, particularly for a motor vehicle

Info

Publication number: EP1794528A1
Application number: EP05794801A
Authority: EP
Inventors: Walter Demuth; Wolfgang Geiger; Martin Kotsch; Michael Kranich; Karl-Heinz Staffa; Christoph Walter
Original assignee: Behr GmbH and Co KG
Current assignee: Mahle Behr GmbH and Co KG
Priority date: 2004-09-01
Filing date: 2005-09-01
Publication date: 2007-06-13
Anticipated expiration: 2025-09-01
Also published as: WO2006024528A1; DE502005009327D1; EP1794528B1; ATE462948T1

Abstract

The invention relates to a heat exchanger (1) comprising a block (2) consisting of tubes (3) and ribs (4). Said tubes (3) can be flowed through by a first medium in at least one direction and can be flowed around by a second medium. The heat exchanger also comprises at least one collecting and/or distributing device for the first medium that is connected to the tubes (3) in a communicating manner. The invention provides that the collecting and/or distributing device is provided in the form of at least one C-profile (5) with two limbs (5a, 5b) and with a web (5c), and that the C-profile (5) is closed by a strip (7) situated between the limbs (5a, 5b).

Description

BEHR GmbH & Co. KG Mauserstrasse 3, 70469 Stuttgart

Heat exchanger, in particular for a motor vehicle

The invention relates to a heat exchanger, in particular for a motor vehicle according to the preamble of claim 1.

By the DE-A 102 60 107 of the applicant, a heat exchanger, in particular for a motor vehicle was known, which is characterized by a pressure-stable construction, as used in particular in CO2-powered air conditioning use. The tubes, which can be flowed through by refrigerant, are designed as multi-chamber flat tubes which communicate with collecting and / or distribution devices as well as deflection devices. The collection and / or distribution devices are characterized by a pressure-stable plate construction, which essentially consists of a base plate, a distribution plate and a cover plate. The refrigerant, R744, is guided in the known heat exchanger in a very wide variety of ways through the tubes, with fundamentally deflections in the width (parallel to the end face) and in the depth (in or opposite to the flow direction of the air) being possible. A disadvantage of this heat exchanger is that the inlet and outlet channels or the refrigerant inlet and outlet are not optimally insulated from each other thermally, but rather are in wärmelei¬ tender connection over the common plates.

BESTÄTIGUNG5KOP1E From DE-A 199 06 289 a heat exchanger for a C02 refrigeration cycle was known, in which the refrigerant from the refrigerant inlet to the refrigerant outlet is deflected only in width, so that it flows through the entire heat exchanger block three-flow, ie in three passes. For reasons of internal pressure stability, the collecting boxes, which receive the pipe ends, are divided into two circular cross sections, which communicate with one another. A deflection of the refrigerant in the depth, ie a cross-counterflow with the air is not provided here, which limits the performance of this heat exchanger.

A similar construction was known from WO 98/51983, wherein a pressure-resistant heat exchanger of flat tubes and headers is built up, each of which is constructed of a plurality of communicating Kreisquer¬ sections. The headers can be produced as extruded parts and thus are particularly resistant to internal pressure, but are also associated with corresponding costs. Again, only a deflection of the refrigerant takes place in the width and not in the depth.

It is an object of the present invention, a heat exchanger of the type mentioned, in particular with deflection in the width and / or in depth with respect to its collection and / or Verteileinrichtun¬ conditions to improve, in particular, a thermal separation of flow channels with high temperature difference is given.

This object is solved by the features of patent claim 1. Er¬ invention provides that the collecting and / or Verteileinrich¬ device is formed as at least one C-profile, which is closed by a einge¬ raked rake. The C-profile can be obtained as a semifinished product or folded out of a flat sheet metal. The openings for receiving pipe ends, so-called passages can be easily produced by punching or stamping. The rake, ie a bar with recesses in the region of the passages can be formed as a flat stamped part with arbitrary shapes, for. B. with tongue-shaped Trennste¬ gene, which extend into the C-profile and cause a subdivision of the C-profile into individual chambers. The dividers, which act as partitions, can be arranged at any point between the passages. The C-profile is soldered to the rake and the pipe ends and thus represents a low-priced pressure-resistant solution.

In an advantageous embodiment of the invention, two C-profiles are arranged at a distance next to each other for two rows of tubes, d. H. in Luftströmungsrich¬ direction behind the other. The distance between the two C-profiles results in the advantage of a thermal separation, ie. H. Heat is prevented from flowing from the higher temperature C-profile to the lower temperature C-profile, thereby degrading the efficiency of the heat exchanger.

In a further advantageous embodiment of the invention, deflecting devices are provided on the side of the block facing away from the C-profiles, which are preferably designed as a U-profile with an inserted wave profile, one "shaft" forming a deflection chamber and connecting two pipe ends to one another. The first flow medium, preferably carbon dioxide, thus initially enters a leeward C-profile, flows through a leeward row of tubes or on the leeward side arranged Strömungsungskanä¬ le, is deflected by the deflection opposite to the air flow direction and flows through a windward pipe row or flow channels until reaching the windward C-profile, where the refrigerant now has a significantly lower temperature than at the entrance Heat from the leeward C-profile can not flow to the windward C-profile between the two C-sections and the heating medium can be reheated there. This thermal separation thus has a particularly advantageous effect on gas coolers with falling or sliding temperature of the supercritical refrigerant. The lee- and windward flow channels can be used as separate rows of tubes, z. B. be formed two rows of flat tubes or as a continuous flat tube with opposite flow-through flow channels.

In a further embodiment of the invention, the C-profile can also be used as a deflecting device by providing a clamping between the two legs. - A -

te is inserted, which may have either the shape of a rake or a Plat¬ te with slots. The slots are formed as elongated holes and comprise the tube ends - they form in a two-row Rohranord¬ tion a crossing channel from one to the other row of tubes.

In a further advantageous embodiment of the invention, stops for limiting the insertion depth of the tubes are provided on the strips, rakes or plates, and preferably designed as paragraphs, which engage over the Röhren¬, preferably on the narrow sides. Thus, the tubes can be mounted in a simple manner always with the same insertion depth.

In a further advantageous embodiment of the invention, a collecting channel for refrigerant emerging from the tubes can be arranged in the strip, in particular of the plate, communicating with the oblong holes. Thus, a parallel connection of the tubes, be it possible for a two-row or a single-row arrangement.

In a further embodiment of the invention, both C-profiles can be subdivided into two chambers by separating webs arranged on the rake, so that four chambers arise for the entire heat exchanger, two of which are interconnected approximately diagonally opposite chambers by a transfer device. This results in the advantage that the heat exchanger can be flowed through twice, in each case half-side in countercurrent. This increases the heat transfer efficiency. It is also possible to create several chambers through several dividers, which are connected by a plurality of crossing means.

In a further advantageous embodiment of the invention, the Übertrittsein¬ direction each have a breakthrough in the web portion of the C-profile and a Übertrittsteil which forms a connection or transfer channel between bei¬ the C-profiles. The refrigerant thus enters the first leeseitig gelege¬ ne chamber, flows through after deflection in the depth of the second luvsei¬ tig chamber arranged, then enters the third leeseitig located chamber and leaves the heat exchanger on the fourth windward side chamber of the windward C. Profiles - this is the refrigerant inlet and - exit approximately diagonally opposite, ie they are largely isolated from each other thermally (a thermally conductive connection exists only in the middle crossing area).

The soldered heat exchanger according to the invention can be used advantageously in particular as a gas cooler of a CO2 air conditioning system because the collecting, distributing and deflecting devices according to the invention are on the one hand pressure-resistant and, on the other hand, variable in terms of flow guidance and thus deflections of the refrigerant both in width and in space depth, allowing effective cooling of the refrigerant from entry to exit.

Embodiments of the invention are illustrated in the drawings and will be described in more detail below. Show it

Fig. 1 shows a detail of a gas cooler with C-profile and inserted

Rake,

2 shows a cross section through the gas cooler with two C-profiles and transition area,

5 shows an alternative form of a deflection device with C-profile and Rohrinstecktiefenbegrenzung, Fig. 6 shows a section through a further deflection with 7 shows a single-row system with C-profile and rake, and FIG. 8 shows a single-row system with C-profile and slotted plate.

1 shows a section of a gas cooler 1 with a gas cooler block 2, consisting of flat tubes 3 and corrugated strips 4 arranged between them. The flat tubes 3 are arranged in two rows and are soldered to the corrugated strips 4. On a series of flat tubes 3, a C-profile 5 is attached, which has elongated openings 6, so-called passages, for receiving the tube ends of the flat tubes 3. In the open side of the C-profile is a Rake 7 used, which has in the region of the passages 6 recesses 7a for the pipe ends and a divider 7b. The C-profile 5 has two legs 5a, 5b formed as flat sides, which are connected by a web 5c. The C-profile can be produced by folding from a level sheet metal, whereby the passages 6 can be produced by stamping prior to folding.

Fig. 1a shows the rake 7 (partially) as a single part with the divider 7b, as shown in Fig. 1. The C-profile, which is soldered to the tube ends of the flat tubes 3 and the rake 7, forms a Sammel¬ or distribution channel, which is interrupted by the divider 7b. Thus, two or more chambers can be formed within the C-profile. The C-profile 5 is closed at the end by an end web 7 c at the end of the rake 7.

Fig. 2 shows a cross section in the upper region of the gas cooler 1 with a first row of tubes I and a second row of tubes II. The direction of air flow is shown by an arrow L; Thus, the row of tubes I is the leeward (downstream) and the tube row Il the windward (upstream). On the windward tube row II, the C-profile 5 and on the lee side tube row I is another C-profile 8 is arranged, which is also completed by a rake 9 to the outside and mirror image to the C-profile 5 with rake 7 is formed. Both C-profiles form Strömungska¬ channels 10, 11, which are interconnected by a transfer channel 12. Between both C-profiles 5, 8, there is a distance a, in which a T-shaped formed transition part 13 is inserted and soldered to the two C-profiles 5, 8. The crossing channel 12 is - as shown in the drawing - formed by openings in the web areas of the C-profiles 5, 8 and the T-shaped crossing part 13. Such a transition region is preferably arranged in the middle of the heat exchanger or in the middle region of the two C-profiles 5, 8, so that a passage of the refrigerant from the windward chamber 10 into the leeward chamber 11 is made possible. Depending on the number of deflections of the refrigerant in the depth, it is also possible to provide a plurality of such transition areas on a heat exchanger. FIG. 3 shows the transition region according to FIG. 2 in a view from above of the two C-profiles 5, 8 which are cut in the area of their webs 5c, 8c. The distance a between the two C-profiles 5, 8 causes a thermal decoupling. The front C-profile 5 is divided into two flow chambers 11, 15 by the separating web 7b of the compute 7 into two flow chambers 10, 14 and the rear C-profile 8 through a dividing web 9b of the rake 9. The two separating webs 7b, 9b are arranged offset from one another, so that an overlap is formed between the chambers 10, 11, within which the transfer channel 12 is arranged, which in the region of the distance a is formed by the T-shaped crossing part 13 becomes. Thus, a Z-shaped flow deflection of the refrigerant from the chamber 10 into the chamber 11 takes place. The flow chamber 15 is the inlet chamber for the refrigerant and the flow chamber 14 is the outlet chamber for the refrigerant from the gas cooler 1. The refrigeration unit, not shown - Teteneintritt and the refrigerant outlet also not shown are thus almost diagonally opposite and have a maximum distance, which proves favorable for the efficiency of the gas cooler, ins¬ also in connection with the thermal decoupling by the distance a both C-profiles 5, 8.

FIG. 4 shows the side of the gas cooler 1 facing away from the C-sections 5, 8 with a deflection device 16, which consists essentially of a U-profile 17 with a wave profile 18. The U-profile 17 has a flat Stegbe¬ rich 17a, which acts as a tube sheet and punched passages 19 for receiving the pipe ends of the flat tubes 3. On both sides of the tube bottom 17a, U-legs 17b, 17c are bent at right angles, which receive the wave profile 18 between them and are soldered tightly thereto. The wave profile 18 has a multiplicity of "waves" 18a, 18b ..., which respectively form deflection chambers and communicate with tubes of the first and second row of tubes I ₁ Il The wave profile 18 is soldered on the one end to the two legs 17b, 17c and on the other hand, with its wave crests, not shown, with the tube bottom 17a. This deflecting device 16 thus effects a deflection in the depth. The embodiment described above represents only one possibility of many for the flow guidance of the refrigerant within the gas cooler 1 according to the invention. For example, the transfer area described in FIGS. 2 and 3 can be dispensed with, so that both C-profiles 5, 8 do not exist on the refrigerant side interconnected, rather are completely separate. The arrangement of the separating webs could be modified, for example, to the effect that only the leeward rake 9 has an approximately central separating web 9b, whereas the windward rake 7 has no separating web. This would mean that the refrigerant, which enters the inlet chamber 15, reaches the second chamber 10 after deflection by the deflection device 16 and would then be distributed to the chamber 14. After the deflection in the depth of the deflection 16 so would be done by the flow from the chamber 10 into the chamber 14, a deflection in the width. After renewed deflection at depth, now in the air flow direction L, the chamber 11 would be reached by the refrigerant, which would now be the outlet chamber. Other flow guides in the invention are possible.

Fig. 5 shows a further embodiment of a deflection device 20, which is designed as a C-profile 21 with two parallel legs 21a, 21b and a web 21c. Between the two legs 21a, 21b, a plate 22 is inserted, which has slots 23 in the form of elongated holes. Within the slots open pipe ends 24, 25, which are through the lower leg 21 a, which acts as a tube sheet, are pushed through. The block of the heat exchanger, consisting of tubes and fins, is not shown here. On the side facing the leg 21a of the plate 22 paragraphs 26, 27 are arranged, which partially overlap the tube ends 24, 25 on their narrow sides and thus act as a limitation for the insertion depth of the tubes. The oblong holes 23 form a crossover channel for the tubes 24, 25 or the first and the second row of tubes. The assembly of the deflecting device 20 takes place in such a way that first the plate 22 is pushed into the gap between the two legs 21a, 21b and fixed in this position, which can be done positively or non-positively. Thereafter, the deflection device 20 is attached to the tube ends 24, 25 of the finished block, not shown, wherein the tube ends 24, 25 come with their upper edges in attack with the paragraphs 26, 27. Da¬ after the heat exchanger can be soldered.

Fig. 6 shows a further embodiment of a deflection device 28 in a sectional view. The C-profile 29 is shown here by dashed lines. Within the profile 29 there is a plate 30 which has at its lower side four shoulders 31a, 31b, 31c, 31d, which respectively overlap the narrow side edges of the two flat tubes 32, 33 and thus form an insertion depth limitation , Above the tubes 32, 33, two elongated holes 34, 35 and above a perpendicular to the plane ver¬ running collection channel 36 are arranged in the plate 30 for emerging from the tubes 32, 33 in the direction of the arrows P refrigerant. This arrangement with collecting channel 36 allows a parallel flow of the tubes 32, 33, d. H. in the same direction as shown by the arrows P. The escaping refrigerant is then supplied via the collecting channel 36 to the outlet of the heat exchanger zuge¬.

Fig. 7 shows a heat exchanger 37 as a single-row system, i. H. with only one row of flat tubes 38, which are received by the lower leg 39a of the C-profile 39. In the C-profile 39 is a rake 40 - as described above - inserted. The plate-shaped rake 40 has on its underside a shoulder 41, which engages over the narrow side of the pipe end 38 and thus forms a stop for (one-sided) Be¬ limitation of the insertion. Laterally, the heat exchanger 37 can be completed by side parts, not shown, which are inserted with their ends by slots, not shown in the C-profile 39.

FIG. 8 shows a further exemplary embodiment of a single-row heat exchanger 42 with C-profile 43 and inserted plate 44, which has slots in the form of oblong holes 46 in the region of the tube ends 45. In the region of the narrow sides of the pipe ends 45 paragraphs 47, 48 are provided as beid¬ sided Einstecktiefenbegrenzung. The invention is not limited to the refrigerant R747 (CO2), but also extends to heat exchangers, which are operated with the refrigerant R134a or R152.

Claims

Patent claims

1. Heat exchanger (1) with a tube (3) and in particular ribs (4) existing block (2), wherein the tubes (3) flowed through by a first medium in at least one direction and by ei¬ NEM second medium flowed around and at least one collecting and / or distributing device for the first medium, which communicates with the tubes (3), characterized gekenn¬ characterized in that the collecting and / or distribution device as at least one C-profile ( 5) with two legs (5a, 5b) and a web (5c) is formed and that the C-profile (5) by a between the legs (5a, 5b) arranged bar (7) is closed.

2. Heat exchanger according to claim 1, characterized in that in one of the two legs (5 b) openings (6) for receiving pipe ends of the tubes (3) are arranged.

3. Heat exchanger according to claim 2, characterized in that the strip as a rake (7) with recesses (7a) in the region of Öff¬ openings (6) is formed for the pipe ends.

4. Heat exchanger according to claim 1, 2 or 3, characterized in that the tubes (3) have two or more rows (I, II) of tube ends and that a row (I, II) each with a C Profile (5, 8) is connected.

5. Heat exchanger according to claim 4, characterized in that the two C-profiles (5, 8) are arranged in parallel and at a distance (a) to each other an¬.

6. Heat exchanger according to claim 4 or 5, characterized gekennzeich¬ net, that a C-profile (5) as an inlet channel and the adjacent C-profile (8) formed as an outlet channel and the tubes (3) in two directions Rich¬ with a deflection can be flowed through in parallel in the depth.

7. Heat exchanger according to claim 4, 5 or 6, characterized gekenn¬ characterized in that the C-profiles (5, 8) remote from the pipe ends with a deflection device (16, 20, 28) are connected.

8. Heat exchanger according to claim 7, characterized in that the deflection device (16) is formed as a U-profile (17) with a tube bottom designed as a web (17a) for receiving the tube ends and two side surfaces (17b, 17c) between which a wave-shaped deflector (wave profile 18) is arranged.

9. Heat exchanger according to claim 8, characterized in that the wave profile (18) has wave crests, which are connected to the tube plate (17 a) to form deflection chambers.

10. Heat exchanger according to claim 7, characterized in that the deflection device (20, 28) as a C-profile (21, 29) is formed, in which a bar (22, 30) can be inserted.

11. Heat exchanger according to claim 10, characterized in that the strip is designed as a rake.

12. Heat exchanger according to claim 10, characterized in that the strip as a plate (22) with slots, in particular Langlö¬ Chern (23) is formed, in which the pipe ends (24, 25) open.

13. Heat exchanger according to claim 10, 11 or 12, characterized gekenn¬ characterized in that the strip (22, 30) stops (26, 27, 31 a - 31 d) for limiting the insertion depth of the tubes (24, 25, 32, 33) having.

14. Heat exchanger according to claim 13, characterized in that the stops as paragraphs (26, 27, 31 a - 31 d) in the strip (22, 30) are formed, which engage over the pipe ends (24, 25, 32, 33) partially ,

15. Heat exchanger according to claim 14, characterized in that the paragraphs (26, 27, 31 a - 31 d) in the region of at least one of the narrow sides of the tubes (24, 25, 32, 33) are arranged.

16. Heat exchanger according to one of claims 10 to 15, character- ized in that the strip (30) has a collecting channel (36) for from the tubes (32, 33) exiting refrigerant.

17. Heat exchanger according to one of the preceding claims, in particular according to claim 16, characterized in that the tubes are arranged in one or two rows (32, 33) and can be flowed through in parallel.

18. Heat exchanger according to one of claims 3 to 17, characterized ge indicates that at least one C-profile (5) by one or more on the rake (7) arranged separating webs (7b) is subdivided in the longitudinal direction.

19. Heat exchanger according to claim 18, characterized in that both C-profiles (5, 8) to form four or more chambers (10, 11, 14, 15) divided in the longitudinal direction and that two chambers

(10, 11) are connected by a transfer channel (12) between the C-profiles (5, 8).

20. Heat exchanger according to claim 19, characterized in that the transfer channel (12) by a respective breakthrough in the webs (5c, 8c) and between the webs (5c, 8c) arranged Über¬ kicking part (13) is formed.

21. Heat exchanger according to claim 20, characterized in that the crossing part (13) T-shaped, has a T-bar with Durch¬ outlet opening and that the T-bridge bridges the distance a between the C-profiles (5, 8) ,

22. Heat exchanger according to one of claims 1 to 21, character- ized in that the first medium is a refrigerant, in particular

R744 (CO2) and the second medium is a gas, in particular air.

23. Heat exchanger according to claim 22, characterized in that the heat exchanger is designed as a gas cooler (1) of a CO2-powered air conditioning system.

24. Heat exchanger according to claim 22 or 23, characterized gekenn¬ characterized in that the refrigerant CO2 and the air are guided in cross-counterflow to each other.

25. Heat exchanger according to one of the preceding claims, da¬ characterized in that it can be produced by soldering.

26. Heat exchanger according to one of the preceding claims, character- ized in that the transition part (13) is tubular ausge¬ forms.

27. Heat exchanger according to one of the preceding claims, da¬ characterized in that the transition part (13) protrudes into at least one C-profile.

28. Heat exchanger according to one of the preceding claims, da¬ characterized in that in at least one C-profile a Kam¬ mer is formed, the tubes of a first flow direction and tubes with a second, different from the first through-flow mung direction connects to each other, wherein the first and the second flow direction are in particular opposite to each other.