DE10257767A1 - Heat exchanger for condenser or gas cooler for air conditioning installations has two rows of channels for coolant with manifolds at ends and has ribs over which air can flow - Google Patents

Abstract

The heat exchanger (1) has at least two rows of channels (2,3) for coolant with manifolds (5-7) at the ends and has corrugated ribs over which air can flow. Air can flow through channels (4) between the ribs. Individual channels are arranged in a row. At least two rows of channels are divided into two blocks in one plane and each block is divided into two segments of flow channels. The fluid flows through the heat exchanger in a sinusoidal path.

Description

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

From the EP-B 0 414 433 Capacitors have become known in which two capacitors are arranged on the air side one behind the other and are mechanically connected to one another by additional fastening elements. On the refrigerant side, the two capacitors are flowed through either one behind the other or parallel to each other. In the series connection of the heat exchange takes place in the cross-counterflow, ie, the leeward condenser is first flowed through, the refrigerant then passes through a connecting line in the windward condenser and flows through this to the windward refrigerant outlet. Both capacitors are flowed through with multiple flow with decreasing flow cross-section (degressive circuit). A deflection of the refrigerant thus takes place only within the plane of each capacitor, ie only in width. A disadvantage of this known duplex capacitor is that two capacitors must be connected to each other both mechanically and on the refrigerant side, which requires additional components and assembly time. This means increased production costs. In addition, the known capacitor also thermodynamic potentials, since it is not optimally flowed through.

It is an object of the present invention to provide a Heat exchanger, in particular gas cooler or Capacitor to improve the type mentioned above, that the performance increased with the same face and / or the Weight and / or the manufacturing cost can be reduced.

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

The heat exchanger according to the invention, in particular Condenser or gas cooler, is preferably produced as a cohesive block, the preferably "in a shot "is soldered. This eliminates mechanical connectors, and the manufacturing costs are lowered. About that In addition, the capacitor is in the plane or in the planes of the flow channels, ie in width, in blocks and / or perpendicular to the planes, ie in depth, in segments divided, which are flowed through successively, with both a Deflection in depth or in width and also in depth and in width. By this division of the double row Condenser network results in optimal flow possibilities on the refrigerant side, which is an increase the performance of the capacitor results.

Advantageous embodiments of Inventions result from the subclaims.

The number of segments is advantageous straight, since each block consists of two segments with equal number of Flow channels exists. Advantageously, however, the number of segments may also be odd be, namely if one segment (or more) is divided into subsegments which is successively of refrigerant flows through become. Thus, the Durchströmungsmöglichkeiten of the capacitor still expanding, which adds extra Performance increases possible. It is also advantageous if the refrigerant inlet to a leeward or windward segment is arranged and the refrigerant outlet on a windward or leeward segment.

According to an advantageous embodiment According to the invention, the individual segments are flowed through one after the other in such a way that alternately a deflection of the refrigerant done in depth and in width. This results in the heat exchange between Air and refrigerant a cross countercurrent.

After a further advantageous Variant of the invention takes place after a deflection in depth a simultaneous deflection in depth and width. In order to arises for the heat exchange between air and refrigerant a cross-countercurrent, which has further thermodynamic advantages brings.

According to an advantageous embodiment the invention, the flow channels are formed as flat tubes, either in two, three or more rows or in a row, wherein the "continuous" flat tube is double-ended, flows through three or more flooded. The flat tubes point possibly arranged in parallel inner channels, flowing through in parallel become. Also, these can channels have interconnecting openings. Also can these flat tubes have turbulence inserts, which are in the flat tube be introduced.

Furthermore, it is advantageous if the Flat tube ends in a for more than one flat tube common manifold are attached, in which the deflection takes place in the depth. An advantageous solution exists further therein, when the flat tube ends on the other side in two Culvert pipes open, in which the deflection takes place in the width. It is advantageous if the two manifolds are either integrally formed and thus hold the block together or designed as separate headers are over the "continuous" flat tubes held together become. Advantageously, continuous between the flat tubes Corrugated ribs arranged, which due to their soldering with the flat tubes a ensure a compact and stable capacitor block.

According to a further advantageous embodiment of the invention, additional deflecting members are provided between the headers, by which allows a simultaneous deflection of the refrigerant both in depth and in width becomes. By this deflection, z. B. pipe bends are successively flowed through segments on the refrigerant side. These deflecting elements can be soldered into the headers, so that this variant of the capacitor according to the invention can be soldered in a single pass in the soldering oven.

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

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

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

3 two integral manifolds for two rows of flat tubes,

4 two separate headers for a series of double-flow flat tubes,

5 a first flow variant,

6 a second flow variant,

7 a third flow variant,

8th a fourth flow variant and

9 a performance diagram for a heat exchanger according to the invention, such as capacitor, compared to the prior art.

1 shows a double-row heat exchanger 1 , like condenser or gas cooler, with a first row 2 and a second row 3 from Flachroh ren 4 , being between the flat tubes 4 known corrugated ribs are arranged not shown.

The rib height of the corrugated ribs, so the Distance between two flat tubes in a row is advantageously 4 mm to 12 mm. The rib density, ie the number of ribs per decimeter is advantageous in the range of 45 to 95 ribs / dm, giving a rib distance or a rib pitch of 1.05 to 2.33 mm. The rib or corrugated fin can be advantageously used from a band, in which the tape used in waves or zig-zag shape between the flat tubes becomes. Appropriate way the rib thus formed becomes a thermal break between have different areas, so that the areas between arranged different flat tubes or flat tube areas are thermally at least partially isolated.

In a further advantageous embodiment The rib can also consist of several individual bands, the between the respective adjacent flat tubes are used. Advantageous is that the individual ribs of different rows no thermal connection respectively.

The flat tubes are advantageous in such a way designed that the Tube width, ie the extension of the tubes in the direction of an adjacent Tubes of the same levels in the range of 1 mm to 5 mm, in particular advantageously from 1.2 mm to 3 mm. The extension of the pipes in the direction perpendicular to the planes, the tube depth is expedient manner in the range of 3 mm to 20 mm, advantageously in the range of 5 mm to 10 mm.

In one embodiment of the invention can the pipe depth at the blocks of the heat exchanger be essentially the same. In another embodiment However, the invention can also the tube depth from block to block chosen differently his. It is particularly useful if the tube depth is less than in the windward plane the tube depth in the leeward plane.

In the illustrated in the figures heat exchangers the tubes of different planes are aligned in the direction of air flow arranged one behind the other, that is, they are at the same height one behind the other arranged.

In not shown heat exchangers, the Pipes facing a plane be arranged offset the tubes of another level. This staggered arrangement may preferably up to the height of half the rib height plus half the width of the pipe. Also intermediate values can be assumed become. In such an embodiment can different or equal ribs between the tubes of different levels are used, which are advantageously designed as independent bands.

The flat tubes 4 both rows 2 . 3 have flat tube ends 4a on, in a common collection tube 5 lead. On the other hand, the flat tubes 4 both rows 2 . 3 Flat tube ends 4b on that in two separate headers 6 . 7 lead. The manifold 7 has a refrigerant inlet 8th on. Both manifolds 6 . 7 are divided into collecting pipe sections by partitions, of which only in the manifold 6 , which is shown open, a partition 9 is shown. The air flows through the condenser in the direction of the 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, both are series 2 . 3 the flat tubes 4 divided into three blocks I, II, III, each block in each of two segments Ia, Ib; IIa, IIb and IIIa, IIIb is divided. Thus, the refrigerant first flows through the leeward segment Ia of the rear row of tubes 3 , then passes into the manifold 5 where it is deflected in the depth, represented by the arrow UT1, then enters the windward segment Ib and the windward manifold 6 , where it is deflected in the width, represented by the arrow UB1. The refrigerant then flows through the next segment IIa back into the manifold 5 , where it in turn in the depth, but in the opposite direction as before, according to the arrow UT2, is deflected. Thereafter, it flows through the leeward segment IIb into the leeward header 7 , is there again in the width, represented by the arrow UB2, deflected, flows through another segment IIIa again into the manifold 5 , is in turn deflected there in the depth, represented by the arrow UT3, and finally flows through a last, windward segment IIIb to the refrigerant outlet KMA. As a result of this flow of refrigerant on the one hand and air on the other hand results in a cross-countercurrent, and that is because on the one hand the refrigerant and the air in the cross flow and on the other hand, the deflections in the depth, UT1, UT3 run counter to the air flow direction L and UT2 in the air flow direction.

2 shows a further embodiment of a capacitor 10 which is essentially the same as the capacitor 1 according to 1 is constructed, wherein the same reference numerals are used for the same parts. In contrast to the embodiment according to 1 indicates the capacitor 10 an additional partition 11 in the windward manifold 6 and two tubular deflecting members 12 . 13 on, each section of the windward manifold 6 with sections of the leeward header 7 connect. The refrigerant flow path is in turn 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 segment Ia, is in the manifold 5 deflected in the depth in the direction of the windward side Ib according to the arrow UT1 and flows through this until reaching the windward manifold 6 , Due to the position of the partition 11 Thus result for the segments Ia and Ib of the block I six flat tubes 4 , About the deflecting element 12 The refrigerant is then in a section of the leeward header 7 deflected, ie there is a simultaneous deflection both in width and in depth, which is represented by the arrow UBT1. After this deflection, the refrigerant flows through the leeward segment IIb in the direction of the manifold 5 , is deflected there according to the arrow UT2 against the air flow direction and enters the windward segment IIa. After reaching the windward manifold 6 ie the section between the two partitions 9 . 11 a redirection takes place in the width and in the depth by the deflecting member 13 , which is represented by the arrow UBT2. Finally, the refrigerant flows through another leeward segment IIIa, is again in the manifold 5 deflected according to the arrow UT3 and finally flows through the last windward side segment IIIb to the refrigerant outlet KMA. This flow pattern is a countercurrent flow, because the deflection in the depths UT1, UT2, UT3 takes place counter to the direction of air flow L in each case. This variant has compared to the variant according to 1 thermodynamic advantages.

3 shows the formation of the two manifolds 6 . 7 , here 6 ', 7' called, to a spectacle-shaped double tube 14 , The two manifolds 6 ' . 7 ' are made of a continuous sheet metal strip 15 with end edges 16 . 17 Shaped in a two headers 6 ' . 7 ' connecting footbridge 18 plugged in and soldered to it. This results in a firm connection between the two headers 6 ' . 7 ' holding the flat tubes 4 with their flat tube ends 4b take up. This enables the production of the double-row capacitor in a soldered block.

4 shows a further embodiment for the formation of the manifolds 6 . 7 , here 6 '', 7 '' called, which are designed as separate manifolds. The flat tubes are not here in two separate rows - as in the previous embodiments - arranged, but by a "continuous" flat tube 19 formed, which is flowed through in two bends, ie in a front (windward) area 19a and a rear (leeward) area 19b , Both areas 19a . 19b are through a middle separation area 19c fluidly separated. The continuous flat tube 19 has separate flat tube ends 19a ' and 19b ' on that in passages 20 the two headers 6 '' . 7 '' used and soldered with these. In this way also results in a contiguous, compact soldered capacitor block.

5 shows a schematic representation of the flow pattern of the embodiment according to 1 . d , H. a cross countercurrent. The entire network of the capacitor 1 according to 1 is divided into three blocks I, II, III, each block consisting of two segments Ia and Ib, IIa and IIb and IIIa and IIIb. The segments of a block each have the same number of tubes and are in the air flow direction L seen one behind the other. In the embodiment according to 5 the segments Ia, Ib each have nine flat tubes 4 , the segments IIa, IIb each seven flat tubes and the segments IIIa, IIIb five flat tubes 4 , Thus, a degressive circuit results on the refrigerant side, ie, the refrigerant-side outlet cross section 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 in three blocks and six segments. The remaining alphanumeric designations correspond to those of the exemplary embodiment according to FIG 1 ie, the flow path has three deflections in the depth UT1, UT2 and UT3 and two deflections in the width UB1 and UB2.

6 shows the flow pattern, which according to the embodiment according to 2 underlying the same alphanumeric designations. The network of the capacitor 10 ( 2 ) is again divided into three blocks I, II and III in width, and each block is divided in depth into two equal segments Ia, Ib; IIa, IIb and IIIa, IIIb divided. The number of tubes of the block I is 2x nine, the block II 2x seven and the block III 2x five, so as in vorheri gene embodiment. The deflection in the depth takes place in each case with the same segments in the same direction, ie against the direction of air flow L in the direction of the arrows UT1, UT2 and UT3. Incidentally, from the segments Ib to the segment IIb there is a deflection both in the width and in the depth, represented by the arrow UBT1, and from the segment IIa to the segment IIIa likewise a deflection both in the width and in the depth by the arrow UBT2. In this respect, this type of flow is a cross-countercurrent, which brings advantages in terms of performance over the cross-countercurrent flow.

7 shows another 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 Ia and Ib in the depth, each with nine flat tubes 4 respectively. The block II is in a segment IIb with nine flat tubes 4 and two subsegments IIaa with five flat tubes 4 and a subsegment IIab with four flat tubes subdivided. First, the leeward segment Ia flows through the refrigerant, then there is a deflection in the depth, corresponding to the arrow UT1, then the windward side Ib is flowed through, then there is a deflection in the width, corresponding to the arrow UB1, in the adjacent subsegment IIaa, then a deflection in the depth UT2 to the leeward segment IIb and from there again a deflection in the depth, corresponding to the arrow UT3, the windward subsegment IIab. Due to the subdivision of a segment into two subsegments, there are five flow paths here, ie an odd number. Such a variant with subsegments may be advantageous in particular for the subcooling of the refrigerant in the last subsegment IIab.

When using the division a segment in subsegments will be beneficial a partition in used the manifold. This partition can be useful as Particle be formed.

8th shows a further variant of the division of the capacitor network in seven flow paths. The network is divided in width into three blocks I, II, III; the block I is in two equal segments Ia, Ib, each with nine flat tubes 4 divided. The block II is divided into two equal segments IIa, IIb, each with seven flat tubes, the block III is divided into a segment IIIa with seven flat tubes and two sub-segments IIIba with four flat tubes and another sub-segment IIIbb with three flat tubes. The refrigerant flow between the mentioned segments takes place in the order of the following arrows: UT1, UB1, UT2, UB2, UT3 and UB3.

All variants described above (Flow pattern with degressive circuit) achieve the greatest performance when the ratio of Refrigerant outlet cross section to refrigerant inlet cross section is in the range of 0.25 to 0.40. This ratio corresponds to the number ni of the flat tubes from the last segment flown through to the number n1 the flat tubes of the first flowed through segment (same flat tube cross sections provided).

9 shows a performance comparison of the prior art capacitors according to the invention with variable Luftanströmgeschwindigkeit 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 degressive circuit. The first variant of the invention according to 1 is shown as a narrow dotted line and labeled KGG, which stands for cross countercurrent. The second variant of the invention according to 2 is shown as a long dotted line and denoted by KG, which stands for cross countercurrent. It can be seen that both inventive variants in terms of performance significantly above the prior art, the variant 2 at higher air speeds of the variant 1 is superior. Thus, there is a clear advantage in favor of the inventive division of the capacitor network into blocks and segments with deflection in depth. The illustrated curves S, KGG, KG result from calculations for capacitors with the same end face and the same fin density.

According to a further inventive concept can the heat exchanger be flowed through from top to bottom or from bottom to top. Below or above are defined by the mounting position of the heat exchanger. Also For example, a plane of the heat exchanger from bottom to top flow through his and another level from top to bottom. The flow channels are preferably arranged horizontally.

In a further advantageous embodiment the flow channels are expedient manner vertically aligned and the headers are aligned horizontally.

Claims (17)

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, which are traversed by refrigerant and end taken in headers, arranged between the flow channels, can be overflowed by air ribs, wherein individual flow channels are arranged in a row and define a plane, wherein the main air flow direction is perpendicular to the plane and and the at least two rows are arranged one behind the other in the air flow direction, characterized in that at least two rows ( 2 . 3 ) of flow channels ( 4 ) are divided in the plane into at least two blocks (I, II) and each block (I, II) perpendicular to the planes into at least two segments (Ia, Ib; IIa, IIb) of flow channels len ( 4 ), wherein the segments (Ia, Ib, IIa, IIb) are flowed through one behind the other in the manner that between individual segments a deflection perpendicular to the planes (UT1, UT2) or a deflection in the plane (UB1, UB2) or a deflection takes place both in the plane and perpendicular to the plane (UBT1, UBT2). Heat exchanger according to claim 1, characterized in that a part of the segments (IIa, IIIb), especially the refrigerant side downstream, divided into subsegments in the plane (IIaa, IIab, IIIba, IIIbb) is. Heat exchanger according to claim 1 or 2, characterized in that a refrigerant inlet ( 8th , KME) is arranged on a leeward segment (Ia). Heat exchanger according to claim 1 or 2, characterized in that a refrigerant inlet ( 8th , KME) is arranged on a windward segment (Ia). Heat exchanger according to one of claims 1 to 4, characterized in that a refrigerant outlet on a windward side Segment (IIIb) is arranged. Heat exchanger according to one of claims 1 to 4, characterized in that a refrigerant outlet to a leeward Segment (IIIb) is arranged. Heat exchanger according to one of claims 1 to 6, characterized in that the number of blocks (I, II, III) three, four, five or more. Heat exchanger according to one of claims 1 to 7, characterized in that the deflections of segment to segment alternately perpendicular to the planes (UT1) and in the Layers (UB1) take place. Heat exchanger according to one of claims 1 to 7, characterized in that the deflections of segment to segment alternately perpendicular to the planes (UT1) and both in the planes as well as perpendicular to the planes (UBT1). Heat exchanger according to one of claims 1 to 9, characterized in that the flow channels as flat tubes ( 4 ) are formed. Heat exchanger according to one of claims 1 to 9, characterized in that the at least two rows ( 2 . 3 ) of flow channels through a series of continuous flat tubes ( 19 ), which are double-flowed or multi-flowed ( 19a, 19b ) can be flowed through. Heat exchanger according to one of claims 1 to 11, characterized in that the deflection perpendicular to the planes (UT1, UT2) in a common manifold ( 5 ), which ends ( 4a ) of both rows ( 2 . 3 ) of flow channels or flat tubes ( 4 ). Heat exchanger according to one of claims 1 to 12, characterized in that the deflection in the planes (UB1, UB2) in each case a collecting tube ( 6 . 7 ) by means of partitions ( 9 . 11 ), each row ( 2 . 3 ) of flow channels or flat tubes ( 4 ) a collecting pipe ( 6 . 7 ) assigned. Heat exchanger according to one of claims 1 to 12, characterized in that the simultaneous deflection both in the planes and perpendicular to the planes (UBT1, UBT2) via deflecting organs ( 12 . 13 ), which successively flow through segments (Ib, IIb, IIa, IIIa) with each other. Heat exchanger according to claim 10 and 13, characterized in that the collecting pipes ( 6 ' . 7 ' ) for deflection in the planes by a web ( 18 ) with each other to a double tube ( 14 ) are connected. Heat exchanger according to claim 11 and 13, characterized in that the collecting pipes ( 6 '' . 7 '' ) for deflection in the planes as separate headers ( 6 '' . 7 '' ) are formed on the ends ( 19a ' . 19b ' ) of the continuous flat tubes ( 19 ) are plugged. 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 mutually arranged collecting tubes,