WO2004053411A1

WO2004053411A1 - Heat exchanger

Info

Publication number: WO2004053411A1
Application number: PCT/EP2003/012224
Authority: WO
Inventors: Martin Kaspar; Gerrit WÖLK
Original assignee: Behr Gmbh & Co. Kg
Priority date: 2002-12-10
Filing date: 2003-11-03
Publication date: 2004-06-24
Also published as: CN1723378A; JP2006509182A; DE10257767A1; US20050205244A1; BR0309404A; EP1573259A1; AU2003287988A1; MXPA04010517A; KR20050084778A

Abstract

The invention relates to a heat exchanger, especially a condenser or a gas cooler for air conditioning installations, especially for motor vehicles, said heat exchanger comprising at least two rows (2,3) of flow channels through which coolant can flow and which are received at the ends thereof by manifolds (5,6,7), and ribs which are arranged between the flow channels and over which air can flow. According to the invention, individual flow channels are arranged in a row, at least two rows (2,3) of flow channels (4) are divided into at least two blocks (1,11) in one plane, and each block is divided into at least two segments (1a, 1b; 11a,11b) of flow channels (4), perpendicularly to the planes of the heat exchanger. Said segments deviate perpendicularly to the planes (UT1, UT2), or in the plane (UB1, UB2), or deviate both in the plane and perpendicularly to the plane (UBT1, UBT2).

Description

BEHR GmbH & Co. KG Mauserstrasse 3, 70469 Stuttgart

Heat exchanger

The invention relates to a heat exchanger, in particular a condenser or gas cooler for air conditioning systems, in particular for motor vehicles, preferably according to the preamble of patent claim 1.

Capacitors have become known from EP-B 0 414 433, in which two capacitors are arranged one behind the other on the air side and are mechanically connected to one another by additional fastening elements. On the refrigerant side, the two condensers are flowed through either in series or in parallel. When connected in series, the heat exchange takes place in cross-counterflow, ie the leeward condenser is first flowed through, the refrigerant then passes through a connecting line into the windward condenser and flows through it to the refrigerant outlet located on the windward side. Both condensers are flowed through with multiple flows with a decreasing flow cross-section (degressive circuit). The refrigerant is therefore deflected only within the level of each condenser, ie only in width. A disadvantage of this known. Duplex condenser is that two condensers must be connected to each other both mechanically and on the refrigerant side, which requires additional components and assembly time. This means increased manufacturing costs. In addition, the known capacitor also has thermodynamic potential, since it is not optimally flowed through. It is an object of the present invention to improve a heat exchanger, in particular gas cooler or condenser, of the type mentioned at the outset in such a way that the power is increased with the same end face and / or the weight and / or the production costs are reduced.

The solution to this problem results from the features of claim 1.

The heat exchanger according to the invention, such as, in particular, a condenser or gas cooler, is preferably produced as an integral block which is preferably soldered “in one shot”. This eliminates mechanical connecting parts and reduces the manufacturing costs. In addition, the condenser is in the plane or in the levels of the flow channels, i.e. in the width, in blocks and / or perpendicular to the levels, i.e. in the depth, divided into segments which are flowed through in succession, both a deflection in the depth or in the width and both in the This division of the two-row condenser network results in optimal flow-through possibilities on the refrigerant side, which results in an increase in the performance of the condenser.

Advantageous refinements of the inventions result from the subclaims.

The number of segments is advantageous, since each block consists of two segments with the same number of flow channels. Advantageously, however, the number of segments can also be odd, namely when one segment (or more than one) is divided into sub-segments through which refrigerant flows in succession. This increases the flow through the condenser, which enables additional performance increases. It is also advantageous if the refrigerant inlet is arranged on a leeward or windward side segment and the refrigerant outlet on a windward or leeward side segment. According to an advantageous embodiment of the invention, the individual segments are flowed through one after the other in such a way that the refrigerant is alternately deflected in depth and in width. This results in a cross-countercurrent flow for the heat exchange between air and refrigerant.

According to a further advantageous variant of the invention, a deflection in depth results in a simultaneous deflection in depth and in width. This results in a cross-countercurrent for the heat exchange between air and refrigerant, which brings further thermodynamic advantages.

According to an advantageous embodiment of the invention, the flow channels are designed as flat tubes, either in two, three or more rows or in a row, with the “continuous” flat tube being flowed through in two-flow, three-flow or multiple flow. The flat tubes may have inner ones arranged in parallel Channels through which flow flows in parallel. These channels can also have connecting openings to one another. These flat tubes can also have turbulence inserts which are introduced into the flat tube.

It is also advantageous if the flat tube ends are fastened in a manifold common to more than one flat tube, in which the deflection takes place at depth. An advantageous solution is also when the flat tube ends on the other side open into two header tubes, in which the deflection takes place in the width. It is advantageous here if the two header pipes are either formed in one piece and thus hold the block together or are designed as separate header pipes which are held together by the "continuous" flat tubes. Advantageously, continuous corrugated fins are arranged between the flat tubes, which due to their soldering to the Flat tubes ensure a compact, stable condenser block.

According to a further advantageous embodiment of the invention zusätzii- before deflecting between the ^'collecting pipes are provided, through which a simultaneous deflection of the refrigerant both in depth and in width is made possible. Through these deflection elements, for. B. Pipe bends are connected one behind the other flowable segments on the refrigerant side. These deflection elements can be soldered into the header pipes, so that this variant of the condenser according to the invention can also be soldered in one operation in the soldering furnace.

Embodiments of the invention are shown in the drawing and are described in more detail below. Show it

1 shows a two-row heat exchanger with deflection in depth and in width,

2 shows a two-row heat exchanger with deflection in depth and deflection both in width and in depth,

3 two integrally formed manifolds for two rows of flat tubes,

4 two separate manifolds for a row of double-flow flat tubes,

5 shows a first flow variant,

6 shows a second flow variant,

7 shows a third flow variant,

8 shows a fourth flow variant and

9 shows a performance diagram for a heat exchanger according to the invention, such as a condenser, in comparison with the prior art.

1 shows a two-row heat exchanger 1, such as a condenser or gas cooler, with a first row 2 and a second row 3 of flat tube ren 4, 4 known corrugated fins, not shown, are arranged between the flat tubes.

The fin height of the corrugated fins, that is to say the distance between two flat tubes in a row, is advantageously 4 mm to 12 mm. The rib density, that is to say the number of ribs per decimeter, is advantageously in the range from 45 to 95 ribs / dm, which corresponds to a rib spacing or a rib pitch of 1.05 to 2.33 mm. The fin or corrugated fin can advantageously be used from a band in which the band is inserted in waves or zigzag form between the flat tubes. The fin designed in this way will expediently have a thermal separation between different regions, so that the regions which are arranged between different flat tubes or flat tube regions are at least partially insulated thermally.

In a further advantageous embodiment, the rib can also consist of several individual strips which are inserted between the respective adjacent flat tubes. It is advantageous that the individual ribs of different rows have no thermal connection.

The flat tubes are advantageously designed in such a way that the tube width, that is to say the extension of the tubes in the direction of an adjacent tube of the same planes, is in the range from 1 mm to 5 mm, in particular advantageously from 1.2 mm to 3 mm. The expansion of the tubes in the direction perpendicular to the planes, the tube depth, is expediently in the range from 3 mm to 20 mm, advantageously in the range from 5 mm to 10 mm.

In one embodiment of the invention, the pipe depth can be substantially the same for the blocks of the heat exchanger. In another exemplary embodiment of the invention, however, the tube depth can also be selected differently from block to block. It is particularly expedient if the pipe depth in the windward plane is less than the pipe depth in the leeward plane. In the case of the heat exchangers shown in the figures, the tubes of different levels, viewed in the direction of air flow, are arranged one behind the other, that is to say they are arranged one behind the other at the same height.

In heat exchangers, not shown, the tubes of one level can be arranged offset with respect to the tubes of a further level. This staggered arrangement can preferably take place up to half the height of the ribs plus half the width of the tube. Intermediate values can also be assumed. In such an embodiment, different or identical fins can be used between the tubes of different levels, which are advantageously designed as independent bands.

The flat tubes 4 of both rows 2, 3 have flat tube ends 4a which open into a common header tube 5. On the other hand, the flat tubes 4 of both rows 2, 3 have flat tube ends 4b, which open into two separate header tubes 6, 7. The header pipe 7 has a refrigerant inlet 8. Both manifolds 6, 7 are divided into manifold sections by partitions, of which a partition 9 is shown only in manifold 6, which is shown open. The air flows through the condenser in the direction of arrow L, the air flow direction. The flow of the refrigerant in the condenser 1 is shown by a multi-angled line, starting with the refrigerant inlet KME and ending with the refrigerant outlet KMA. As will be explained in more detail later, the two rows 2, 3 of the flat tubes 4 are divided into three blocks 1, II, III, each block being divided into two segments 1 a, 1 a, 1 b; lla, llb and purple, lllb is divided. The refrigerant therefore first flows through the leeward segment la of the rear tube row 3, then reaches the header tube 5, where it is deflected in depth, represented by the arrow UT1, then reaches the windward segment Ib and the windward header tube 6, where it is redirected in width, represented by the arrow UB1. The refrigerant then flows through the next segment 11a back into the collecting tube 5, where it is again deflected in depth, but in the opposite direction as before, according to the arrow UT2. Then it flows through it leeward-side segment Ilb into the leeward-side manifold 7, is redirected there again in width, represented by the arrow UB2, flows through another segment purple back into the manifold 5, where it is again deflected in depth, represented by the arrow UT3 and finally flows through a last, windward segment lllb to the refrigerant outlet KMA. As a result of this flow of refrigerant on the one hand and air on the other hand, there is a cross countercurrent flow, because on the one hand the refrigerant and the air run in cross flow and on the other hand the deflections in depth, UT1, UT3 run against the air flow direction L- and UT2 in the air flow direction.

FIG. 2 shows a further exemplary embodiment of a capacitor 10 which is constructed essentially the same as the capacitor 1 according to FIG. 1, the same reference numbers being used for the same parts. In contrast to the exemplary embodiment according to FIG. 1, the condenser 10 has an additional partition 11 in the windward-side manifold 6 and two tubular deflection members 12, 13, which each connect sections of the windward-side manifold 6 to sections of the leeward-side manifold 7. The refrigerant flow path is again represented by a continuous, multi-angled line, starting at the refrigerant inlet KME and ending at the refrigerant outlet KMA. The refrigerant thus first flows through the leeward-side segment la, is deflected in depth in the collecting tube 5 in accordance with the arrow UT1 in the direction of the wind-side segment Ib and flows through it until the wind-up side collecting tube 6 is reached. Due to the position of the partition 11, the segments la and lb of the block I six flat tubes 4. Via the deflecting element 12, the refrigerant is then deflected into a section of the leeward collecting tube 7, i. H. there is a simultaneous deflection both in width and in depth, which is shown by the arrow UBT1. After this deflection, the refrigerant flows. through the leeward segment llb in

Direction of the collecting tube 5, is deflected there according to the arrow UT2 against the air flow direction and enters the windward segment 11a. After reaching the windward-side manifold 6, ie the section between the two partition walls 9, 11, the deflection member 13 redirects the width and depth, which is achieved by the arrow UBT2 is shown. Finally, the refrigerant flows through a further segment on the leeward side purple, is redirected again in the collecting pipe 5 in accordance with the arrow UT3 and finally flows through the last windward side segment 11b until the refrigerant outlet KMA. This flow pattern is a cross countercurrent because the deflection in the depth UT1, UT2, UT3 takes place in each case counter to the air flow direction L. This variant has thermodynamic advantages over the variant according to FIG. 1.

Fig. 3 shows the formation of the two manifolds 6, 7, here 6 ', T, to form a glasses-shaped double tube 14. The two manifolds 6', 7 'are formed from a continuous sheet metal strip 15 with end edges 16, 17, which in a web 18 connecting both manifolds 6 ', 7' is inserted and soldered to it. This results in a firm connection between the two manifolds 6 ', 7', which receive the flat tubes 4 with their flat tube ends 4b. This enables the production of the two-row capacitor in a soldered block.

Fig. 4 shows a further embodiment for the formation of the manifolds 6, 7, here called 6 ", 7", which are designed as separate manifolds. The

Flat tubes here are not arranged in two separate rows - as in the previous exemplary embodiments - but are formed by a "continuous" flat tube 19 which is flowed through in two passages, ie in a front (windward side) area 19a and a rear (leeward side) area 19b. The two areas 19a, 19b are separated from each other in terms of flow by a central separating area 19c. The continuous flat tube 19 has separate flat tube ends 19a 'and 19b' which are inserted into passages 20 of the two header tubes 6 ", 7" and soldered to them This also results in a coherent, compact, soldered capacitor block.

FIG. 5 shows a schematic representation of the flow pattern of the exemplary embodiment according to FIG. 1, ie a cross countercurrent. The entire network of capacitor 1 according to FIG. 1 is divided into three blocks I, II, III, each block consisting of two segments Ia and Ib, Ila and IIb and llla and lllb exists. The segments of a block each have the same number of tubes and are located one behind the other in the air flow direction L. In the exemplary embodiment according to FIG. 5, the segments 1a, 1b each have nine flat tubes 4, the segments 11a, 11b each have seven flat tubes and the segments purple, 11bb each have five flat tubes 4. This results in a degressive circuit on the refrigerant side, that is to say the outlet cross section on the refrigerant side is smaller than the refrigerant inlet cross section, it is 5/9 or 56 percent of the inlet cross section. This is a favorable value for the gradation of the refrigerant-side flow channels with three blocks and six segments. The other alphanumeric names correspond to those of the

Embodiment of FIG. 1, d. H. the flow course has three deflections in depth UT1, UT2 and UT3 and two deflections in width UB1 and UB2.

6 shows the flow pattern which corresponds to the exemplary embodiment

Fig.2 is based, with the same alphanumeric names are adopted. The network of the capacitor 10 (FIG. 2) is again divided into three blocks I, II and III in width, and each block is divided into two equal segments la, Ib; lla, ilb and lilac, lllb divided. The number of tubes of block I is 2x nine, of block II 2x seven and of block III 2x five, so as in the previous embodiment. The deflection in the depth takes place with the same segments in the same direction, i. H. against the air flow direction L in the direction of arrows UT1, UT2 and UT3. In addition, there is a redirection both in width and in depth from the segments Ib to the segment Ilb, shown by the arrow UBT1, and a redirection both in width and in depth is also shown from the segment 11a to the segment purple by the arrow UBT2. In this respect, this type of flow is a cross-countercurrent, which brings advantages in performance over the cross-countercurrent.

FIG. 7 shows a further flow pattern in which the network of the capacitor is divided in width into two blocks I, II. The block I is divided into two equal segments la and Ib in depth, each of which has nine flat tubes 4. Block II is in a segment 11b with nine flat tubes 4 and two subsegments Ilaa with five flat tubes 4 and a subsegment Hab with four flat tubes. First the refrigerant flows through the leeward side segment la, then there is a deflection in depth, according to the arrow UT1, then the windward segment Ib is flowed through, then there is a deflection in the width, according to the arrow UB1, into the adjacent sub-segment llaa, then a redirection in depth UT2 to the leeward segment Ilb and from there another redirection in depth, according to arrow UT3, to the windward subsegment Hab. The division of a segment into two subsegments results in five flow paths, that is, an odd number. Such a variant with sub-segments can be particularly advantageous for subcooling the refrigerant in the last sub-segment Hab.

When using the division of a segment into sub-segments, a partition in the manifold is advantageously used. This partition can expediently be designed as a partition plate.

8 shows a further variant of the division of the capacitor network into seven flow paths. The width of the network is divided into three blocks I, II, III; block I- is divided into two identical segments 1 a, 1 b with nine flat tubes 4 each. Block II is divided into two identical segments Ha, Ilb, each with seven flat tubes, block III is divided into a segment purple with seven flat tubes and two subsegments lllba with four flat tubes, and a further subsegment lllbb with three flat tubes. The refrigerant is routed between the segments mentioned in the order of the following arrows: UT1, UB1, UT2, UB2, UT3 and UB3.

All • the variants described above (flow patterns with degressive switching) achieve the greatest performance if the ratio of the refrigerant outlet cross section to the refrigerant inlet cross section is in the range from 0.25 to 0.40. This ratio corresponds to the number ni of flat tubes from the last flowed through segment to the number n1 of flat tubes from the first flowed through segment (provided the same flat tube cross sections are used). FIG. 9 shows a performance comparison of the capacitors according to the invention with the prior art with variable air inflow velocity in m / s on the abscissa. The power of the capacitor in kW is plotted on the ordinate. The solid line S represents the performance of a conventional, multi-flow serpentine condenser with a degressive circuit. The first variant of the invention according to FIG. 1 is shown as a narrowly dotted line and is marked with KGG, which stands for cross-countercurrent. The second variant of the invention according to FIG. 2 is shown as a wide-dotted line and labeled KG, which stands for cross-countercurrent. It can be seen that the two inventive variants are significantly more powerful than the prior art, variant 2 being superior to variant 1 at higher air velocities. This results in a clear advantage in favor of the inventive division of the capacitor network into blocks and segments with deflection in depth. The curves S, KGG, KG shown result from calculations for capacitors with the same end face and the same fin density.

According to a further idea according to the invention, the heat exchanger can be flowed through from top to bottom or from bottom to top. Bottom and top are defined by the installation position of the heat exchanger. For example, one level of the heat exchanger can also be flowed through from bottom to top and another level from top to bottom. The flow channels are preferably arranged horizontally.

In a further advantageous exemplary embodiment, the flow channels are expediently aligned vertically and the header tubes are aligned horizontally.

Claims

P atent claims

1. Heat exchanger, in particular condenser or gas cooler for air conditioning systems, in particular for motor vehicles, with at least two rows of flow channels through which refrigerant can flow and are accommodated in collecting pipes at the ends, with between the

Ribs arranged in flow channels and over which air can flow, with individual flow channels being arranged in a row and defining a plane, the main air flow direction being perpendicular to the plane and and the at least two rows being arranged one behind the other in the air flow direction, characterized in that at least two rows (2,

3) of flow channels (4) in the plane are divided into at least two blocks (I, II) and each block (I, II) perpendicular to the planes into at least two segments (la, Ib; lla, Ilb) of flow channels

(4) are divided, with the segments (la, lb, lla, Ilb) one behind the other on the refrigerant side

Flow can be flowed through in such a way that between individual segments there is a deflection perpendicular to the planes (UT1, UT2) or a deflection in the plane (UB1, UB2) or a deflection both in the plane and perpendicular to the plane (UBT1, UBT2).

Heat exchanger according to claim 1, characterized in that part of the segments (lla, lllb), in particular the one arranged downstream on the coolant side, is divided into sub-segments (llaa, Hab; lllba, lllbb) in the plane.

Heat exchanger according to claim 1 or 2, characterized in that a refrigerant inlet (8, KME) is arranged on a leeward segment (la). ^'

. Heat exchanger according to claim 1 or 2, characterized in that a refrigerant inlet (8, KME) is arranged on a windward segment (la).

5. Heat exchanger according to one of claims 1 to 4, characterized in that a refrigerant outlet is arranged on a windward segment (lllb).

6. Heat exchanger according to one of claims 1 to 4, characterized in that a refrigerant outlet is arranged on a leeward segment (lllb).

7. Heat exchanger according to one of claims 1 to 6, characterized in that the number of blocks (I, II, III) is three, four, five or more.

8. Heat exchanger according to one of claims 1 to 7, characterized in that the deflections from segment to segment take place alternately perpendicular to the planes (UT1) and in the planes (UB1).

9. Heat exchanger according to one of claims 1 to 7, characterized in that the deflections from segment to segment take place alternately perpendicular to the planes (UT1) and both in the planes and perpendicular to the planes (UBT1).

10. Heat exchanger according to one of claims 1 to 9, characterized in that the flow channels are designed as flat tubes (4).

11. Heat exchanger according to one of claims ¹ to 9, characterized in that the at least two rows (2, 3) of flow channels are formed by a series of continuous flat tubes (9) through which flow can flow in two or more flows (19a, 19b). .

12. Heat exchanger according to one of claims 1 to 11, characterized in that the deflection takes place perpendicular to the planes (UT1, UT2) in a common collecting pipe (5), which has the ends (4a) of both rows (2, 3). of flow channels or flat tubes (4).

13. Heat exchanger according to one of claims 1 to 12, characterized in that the deflection in the levels (UB1, UB2) takes place in a respective collecting pipe (6, 7) by means of partitions (9, 11), with each row (2, 3 ) of flow channels or flat tubes (4) a collecting pipe (6, 7) is assigned.

14. Heat exchanger according to one of claims 1 to 12, characterized in that the simultaneous deflection takes place both in the planes and perpendicular to the planes (UBT1, UBT2) via deflection elements (12, 13), which flow through segments one after the other (Ib , Ilb; lla, purple) connect with each other.

15. Heat exchanger according to claim 10 and 13, characterized in that the collecting tubes (6 ', T) are connected to one another to form a double tube (14) by a web (18) for deflection in the planes.

16. Heat exchanger according to claim 11 and 13, characterized in that the collecting pipes (6", 7") are designed as separate collecting pipes (6", 7") for deflection in the planes, which are connected to the ends (19a ¹ , 19b' ) of the continuous flat tubes (19) are attached.

17. Heat exchanger according to one of the preceding claims, characterized in that the heat exchanger is a gas cooler or condenser (1, 10), which is designed as a soldered tube/fin block with collecting tubes arranged on both sides,