CN108291780A - Heat exchanger - Google Patents

Abstract

A heat exchanger (3; 5) comprising: a flow path extending from a gas inlet side (4) to an opposite gas outlet side (6) of the heat exchanger; and at least one heat exchange coil (8; 8a, 8b) extending through the gas flow path and configured to allow heat exchange between a fluid flowing through the heat exchanger coil (8; 8a, 8b) and a gas flowing through the gas flow path. The at least one heat exchanger coil (8; 8a, 8b) comprises: a refrigerant inlet portion (10) having an inlet terminal end (12); a refrigerant outlet portion (14) having an outlet terminal (16); and a heat exchange portion (18) connected between the refrigerant inlet portion (10) and the refrigerant outlet portion (14) allowing a fluid to flow from the refrigerant inlet portion (10) through the heat exchange portion (18) into the refrigerant outlet portion (14). The refrigerant inlet portion (10), the refrigerant outlet portion (14) and the exchangerA hot portion (18) is arranged within the gas flow path such that gas entering at the gas inlet side (4) passes first through the refrigerant outlet portion (14), then through the refrigerant inlet portion (10) and finally through the heat exchange portion (18) before exiting the gas flow path at the gas outlet side (6). The refrigerant inlet portion (10) is provided by a single inlet tube section (9), the heat exchange portion (18) is provided by at least two heat exchange tube sections (20, 22) and the refrigerant outlet portion (14) is provided by at least two outlet tube sections (24, 26) connected in parallel, wherein the volume (Vin) of the refrigerant inlet portion (10) and the volume (V) of the heat exchange portion (18)_ex) And the volume (V) of the refrigerant outlet portion (14)_out) The volume ratio (R) of the sum of (A) is between 1: 3 and 1: 7, in particular between 1: 4 and 1: 6.

Description

Heat Exchanger

The present invention relates to a heat exchanger, in particular to a heat exchanger that can be used in refrigerated sales furniture and that operates efficiently at low charge conditions.

Refrigerated sales furniture is usually equipped with a refrigeration circuit configured to cool the refrigerated sales space of the refrigerated sales furniture and comprising, along the flow direction of the circulating refrigerant: a compressor, a heat rejection heat exchanger (condenser/gas cooler ), expansion device and heat receiving heat exchanger (evaporator).

In order to reduce the energy consumption of the refrigeration circuit, it would be beneficial in particular to increase the efficiency of the refrigeration circuit by providing an improved heat receiving heat exchanger, even under low charge conditions, i.e. when only a relatively low amount of refrigerant is in the The improved heat receiving heat exchanger also operates efficiently when circulating in a refrigeration circuit.

According to an exemplary embodiment of the present invention, a heat exchanger includes: a gas flow path extending from a gas inlet side to an opposite gas outlet side; and at least one heat exchange coil extending through the gas flow path, the at least A heat exchange coil is configured to allow heat exchange between fluid flowing through the at least one heat exchange coil and gas, in particular air, flowing through the gas flow path. The at least one heat exchange coil includes: a refrigerant inlet section having an inlet terminal; a refrigerant outlet section having an outlet terminal; and a heat exchange section fluidly connected between the refrigerant inlet section and the refrigerant outlet section, For allowing fluid refrigerant to flow from the refrigerant inlet section through the heat exchange section into the refrigerant outlet section. The refrigerant inlet section, the heat exchange section and the refrigerant outlet section are arranged within the gas flow path such that gas entering at the gas inlet side will first pass through the refrigerant outlet section, then pass through the refrigerant inlet section and finally exit at the gas outlet side The airflow path is preceded by the heat transfer section of the heat transfer coil. The refrigerant inlet section is provided by a single tube section. The heat exchange part and the refrigerant outlet part are respectively provided by at least two pipe sections connected in parallel, and the volume ratio between the volume of the refrigerant inlet part and the sum of the volumes of the heat exchange part and the refrigerant outlet part is 1:3 to In the range of 1:7, in particular in the range of 1:4 to 1:6.

A heat exchanger with this configuration can operate very efficiently even under low charge conditions, i.e. when only a relatively small amount of refrigerant is circulating in the refrigeration circuit. This heat exchanger is therefore particularly suitable for use in refrigeration circuits using flammable refrigerants, since in this case the maximum amount of refrigerant circulating in the refrigeration circuit is limited by safety requirements.

Exemplary embodiments of the present invention will hereinafter be described in more detail with reference to the accompanying drawings.

Figure 1 schematically shows a heat exchanger according to a first embodiment of the invention;

Figure 2 schematically shows a heat exchanger according to a second embodiment of the invention; and

Fig. 3 shows a partial sectional view of a heat exchanger according to an exemplary embodiment of the present invention.

Figure 1 schematically shows a cross-sectional view of a heat exchanger 3 according to a first embodiment of the invention.

The heat exchanger 3 comprises: a gas inlet side 4 configured to receive a relatively warm air flow W, in particular warm return air; and an opposite gas outlet side 6 configured to deliver a relatively cold air flow that has been cooled by the heat exchanger 3 c.

In the configuration shown in FIG. 1 , the gas inlet side 4 is depicted at the bottom of FIG. 1 and the gas outlet side 6 is depicted at the top of FIG. 1 . Of course, the heat exchanger 3 can be oriented differently, resulting in a different orientation of the gas flow.

The two outer end plates 31 a , 32 b and the plurality of fins 30 arranged between the two end plates 31 a , 32 b extend parallel to the direction of the gas flow between the gas inlet side 4 and the gas outlet side 6 .

The heat exchanger 3 also includes a heat exchange coil 8 meandering through the heat exchanger 3 . The heat exchange coil 8 includes, in the flow direction of the refrigerant: a refrigerant inlet portion 10 having an inlet terminal 12 for receiving refrigerant; a heat exchange portion 18 arranged downstream of the refrigerant inlet portion 10; The agent outlet portion 14 is arranged downstream of the heat exchange portion 18 . The refrigerant outlet section 14 has an outlet terminal 16 for discharging the refrigerant after it has passed through the heat exchange coil 8 .

The refrigerant inlet section 10, heat exchange section 18 and refrigerant outlet section 14 are bounded by end plates 31a, 32b respectively and extend substantially normal to the direction of the fins 30 and airflow W, C. The heat exchange coil 8 also comprises a connecting portion 11 extending substantially parallel to the fins 30 outside the end plates 31a, 32b and connecting the refrigerant inlet portion 10, the heat exchange portion 18 and the refrigerant outlet portion 14 to each other. Fluid connections.

The heat exchange section 18 comprises two subsections 17, 19 extending parallel to each other between end plates 31a, 32b. A further connection portion 11 substantially parallel to the extension of the fins 30 outside the end plates 31a, 32b fluidly connects the subsections 17, 19 to each other. The number of the two subsections 17, 19 shown in Fig. 1 is only exemplary. A person skilled in the art will readily understand that the heat exchange section 18 may comprise any desired number of subsections 17 , 19 sequentially connected to each other by additional connecting sections 11 .

The refrigerant inlet part 10, the heat exchange part 18 and the refrigerant outlet part 14 are arranged along the flow path of the gas so that the gas entering at the gas inlet side 4 first passes through the refrigerant outlet part 14 (superheated part) for the refrigerant to pass through The outlet terminal 16 superheats the refrigerant before leaving the heat exchange coil 8 . After passing the refrigerant outlet section 14 , the gas will pass through the refrigerant inlet section 10 and finally pass through the heat exchange section 18 of the heat exchange coil 8 before leaving the gas flow path of the heat exchanger 3 at the gas outlet side 6 .

The refrigerant inlet section 10 is formed by a single inlet pipe section 9 .

The heat exchange portion 18 is provided by two heat exchange tube sections 20 , 22 fluidly connected in parallel and extending substantially parallel to each other. The refrigerant inlet side of each of the two heat exchange tube sections 20 , 22 is fluidically connected to the inlet tube section 9 .

On the refrigerant outlet side, each of the two heat exchange tube sections 20 , 22 transforms into a corresponding outlet tube section 24 , 26 which respectively extends through the gas inlet side 4 of the heat exchanger 3 .

The outlet pipe sections 24 , 26 merge downstream of the heat exchanger 3 providing a common outlet terminal 16 .

As shown in FIG. 1 , two tube sections 20 , 22 , 24 , 26 extending substantially parallel to each other can be arranged next to each other in the direction of the gas flow. However, they can also be arranged next to each other in a direction perpendicular to the section shown in FIG. 1 .

The volume V _in of the refrigerant inlet part 10 formed by the inlet pipe section 9 and the volume V _ex of the heat exchange part 18 (which is provided by the combined volume (V _ex = V ₂₀ + V ₂₂ ) of the heat exchange pipe sections 20, 22 ) The volume ratio R between the volume V _out of the refrigerant plus outlet portion 14 (which is provided by the combined volume of the outlet pipe sections 24, 26 (V _out = V ₂₄ +V ₂₆ )) is in particular between 1:3 and 1:3. Between 7, that is, R=V _in : (V _ex +V _out ).

It should be noted that the volume of the connecting portion 11 is not considered in calculating the volume ratio R.

It has been found that a heat exchanger 2 with this design allows a very efficient transfer of gas and The heat of the refrigerant flowing through the heat exchange coil 8.

Since only a single inlet pipe section 9 is used and thus the cross section of the inlet pipe section 9 is significantly smaller than the combined cross section of the heat exchange tube sections 20, 22, the flow velocity of the refrigerant within the inlet pipe section 9 is relatively high. Consequently, a considerable amount of refrigerant flowing through the inlet pipe section 9 is converted into gas by the warm gas flow W flowing to the heat exchanger 3 . Particularly when the heat exchanger is operated with a low refrigerant charge, the generation of a large amount of gas in the refrigerant inlet portion 10 is advantageous for increasing the efficiency of the heat exchanger 3 .

There may be further heat exchange sections 18 not depicted in the figures. This further heat exchange section 18 may be part of an additional serpentine heat exchange coil 8 of one or more further heat exchangers.

Two heat exchange tube sections 20 , 22 and two outlet tube sections 24 , 26 are depicted in FIG. 1 . However, those skilled in the art will readily understand that in other embodiments not explicitly shown in the drawings, more than two heat exchange tube sections 20, 22 and more than two outlet tube sections 24, 26 connected in parallel may be Used to set the desired volume ratio between the refrigerant inlet section 10 and the heat exchange section 18 .

The heat exchanger 3 according to the first exemplary embodiment may also be modified to include more than one heat exchange coil 8 .

Fig. 2 is a cross-sectional view of a heat exchanger 5 comprising two heat exchange coils 8a, 8b according to a second exemplary embodiment of the present invention. Like features are denoted with like reference signs and will not be discussed in detail.

For clarity of illustration, the two heat exchange coils 8a, 8b shown in FIG. 2 comprise only a single heat exchange tube section 20 and a single outlet tube section 24, respectively. However, each of the heat exchange coils 8a, 8b may be provided with a plurality of heat exchange tube sections 20, 22 and a plurality of outlet tube sections 24, 26, respectively, extending substantially parallel to each other, similar to the first shown in FIG. One and Second Embodiments.

The inlet terminal 12a and the outlet terminal 16a of the first heat exchange coil 8a are arranged on the first (left) lateral side 7a of the heat exchanger 5, and the inlet terminal 12b and the outlet terminal 16b of the second heat exchange coil 8b are arranged on the On the opposite second (right) lateral side 7b of the heat exchanger 5. Thus, the refrigerant flows through the first heat exchange coil 8a and the second heat exchange coil 8b in a countercurrent manner, in particular in the refrigerant inlet portion 10a, 10b and the refrigerant outlet portion 14a, 14b. This results in an almost even distribution of heat within the heat exchanger 5 and in particular avoids that one lateral side 7a, 7b of the heat exchanger 5 becomes significantly hotter than the other lateral side 7b, 7a in operation. Thus, heat transfer within the heat exchanger 5 is enhanced and the efficiency of the heat exchanger 5 is optimized.

Although only two heat exchange coils 8a, 8b are shown in FIG. 2, those skilled in the art will readily understand that more than two heat exchange coils 8a, 8b as depicted may be used, not explicitly shown in the figure. .

The additional heat exchange coils or the heat exchange parts 18 of the heat exchange coils 8 a , 8 b can in particular be arranged above or below the sections represented by FIGS. 1 and 2 , respectively.

In the case of providing an even number of heat exchange coils 8a, 8b, it is advantageous to provide the same number of inlet terminals 12a, 12b and outlet terminals 16a, 16b respectively on both sides of the heat exchanger 5 for generating heat in the heat exchanger. An almost uniform distribution between the first lateral side 7a and the second lateral side 7b of the heater 5, as previously described.

In case an odd number of heat exchange coils 8a, 8b are provided, the difference between the number of inlet terminals 12a, 12b and the number of outlet terminals 16a, 16b on both sides of the heat exchanger 5 can be chosen to be one, so that The heat distribution between the first lateral side 7a and the second lateral side 7b of the heat exchanger 5 is made as uniform as possible.

Fig. 3 shows a partial sectional view of the heat exchanger 3, 5 according to an exemplary embodiment of the invention, taken along a section S-S extending parallel to the fins 30 (see Fig. 2).

FIG. 3 in particular shows a portion of a fin 30 and four heat exchange tube sections 20 , 22 extending orthogonally across the fin 30 .

The heat exchange tube sections 20, 22 are arranged in a rectangular matrix arrangement comprising a plurality of columns extending perpendicular to the direction of air flow F (ie, vertically in FIG. 2 ) and parallel to the direction of air flow F (ie, in FIG. 2 ). Horizontally) a number of rows to extend.

The distance B of the heat exchange tube sections 20 , 22 along a (vertical) column is different from the distance A of the heat exchange tube sections 20 , 22 along a (horizontal) row. The ratio of the distance A along the rows to the distance B along the columns may be between 0.7 and 1.0, in particular between 0.8 and 0.9.

The distance A of the heat exchange tube sections 20, 22 along the rows may be between 35 mm and 45 mm, specifically between 38 mm and 42 mm, and the distance B of the heat exchange tube sections 20, 22 along the columns is between 45 mm and 55 mm. Between, specifically between 48mm and 52mm.

The diameter D of the tube sections 20 , 22 may in particular be in the range of 7 mm to 9.52 mm. In particular, the inner diameter D of the tube sections 20, 22 may be 7mm and the outer diameter of the tube sections 20, 22 may be 9.52mm.

When each of the fins 30 is (ideally) divided into a plurality of fin regions X of equal size, and each fin region X is assigned to one of the tube segments 20 , 22 , the tube segments 20 , 22 The perimeter πD relative to the dimension of the fin area X may be in the range of 1.0 mm/cm ² to 2.5 mm/cm ² , specifically between 1.5 mm/cm ² and 2.0 mm/cm ² for Efficient heat transfer between the gas flowing through the heat exchanger and the refrigerant flowing through the heat exchange coil 8 is allowed.

A number of optional features are set forth below. In particular embodiments, these features may be achieved alone or in combination with any other features.

In one embodiment, the refrigerant inlet portion, the heat exchange portion and the refrigerant outlet portion each extend between opposing end plates. The end plates in particular support the refrigerant inlet section, the heat exchange section and the refrigerant outlet section for providing a rigid structure of the heat exchanger. The end plates also define the volumes of the refrigerant inlet section, the heat exchange section and the refrigerant outlet section to be considered when calculating the volume ratio.

In one embodiment, the heat exchange section comprises at least two subsections extending parallel to each other and fluidly connected by a connecting section. Providing a heat exchange section comprising a plurality of subsections allows increasing the capacity of the heat exchanger.

In one embodiment, the heat exchanger includes at least two heat exchange coils extending through the airflow path. Providing two or more heat exchange coils increases the capacity of the heat exchanger.

In one embodiment, the heat exchanger includes a first set of heat exchange coils and a second set of heat exchange coils. The inlet terminals of the first set of heat exchange coils are arranged on a first lateral side of the heat exchanger, and the inlet terminals of the second set of heat exchange coils are arranged on an opposite second lateral side of the heat exchanger. Therefore, the direction of refrigerant flowing through the refrigerant inlet portion of the first set of heat exchange coils is opposite to the direction of refrigerant flow through the refrigerant inlet portion of the second set of heat exchange coils. Consequently, the heat transfer is more evenly distributed over the entire width of the heat exchanger, and thus the efficiency of the heat transfer is increased.

In one embodiment, the outlet terminals of the first set of heat exchange coils are arranged on a first lateral side of the heat exchanger, and the outlet terminals of the second set of heat exchange coils are arranged on an opposite second lateral side of the heat exchanger. on the side. Therefore, the direction in which the refrigerant flows through the refrigerant outlet portion of the first set of heat exchange coils is opposite to the direction in which the refrigerant flows through the refrigerant outlet portion of the second set of heat exchange coils. Consequently, the heat transfer is more evenly distributed over the entire width of the heat exchanger, and thus the efficiency of heat transfer and superheating of the refrigerant in the refrigerant outlet portion is increased.

In one embodiment, the inner diameter of the tube section is greater than 6 mm, in particular at least 7 mm. In one embodiment, the outer diameter of the tube section is less than 10mm, in particular not greater than 9.52mm. In one embodiment, the inner diameter of the tube section is 7mm and the outer diameter of the tube section is 9.52mm. Tube sections with these diameters have been found to allow efficient heat transfer.

In one embodiment, the heat exchange tube segments are arranged in a plurality of columns and rows forming a rectangular matrix, wherein the distance of the heat exchange tube segments along the columns is different than the distance of the heat exchange tube segments along the rows. The ratio of the distance of the heat exchange tube sections along the rows to the distance of the heat exchange tube sections along the columns may in particular be between 0.7 and 1.0, in particular between 0.8 and 0.9. This configuration has been found to allow efficient heat transfer between the gas flowing through the heat exchanger and the fluid refrigerant flowing through the tube sections.

In one embodiment, the distance of the tube sections in a direction parallel to the gas flow is smaller than the distance of the tube sections in a direction normal to the gas flow. This arrangement has been found to allow efficient heat transfer between the gas flowing through the heat exchanger and the refrigerant flowing through the tube sections.

In one embodiment, the distance of the heat exchange tube sections along the rows is between 35mm and 45mm, and/or the distance of the heat exchange tube sections along the columns is between 45mm and 55mm.

In one embodiment, the heat exchanger further comprises a plurality of fins extending substantially parallel to the gas flow path and/or orthogonal to the inlet tube section to the outlet tube section and/or the heat exchange tube section. The fins guide the airflow flowing through the heat exchanger and enhance heat transfer between the airflow and the refrigerant flowing through the inlet tube section, through the outlet tube section and through the heat exchange tube section.

In one embodiment, the ratio of the circumference of the tube section to the fin area allocated to each tube section by mentally dividing the area of each fin into a plurality of fin areas of the same size is within 1.0 mm/cm In the range of ² to 2.5 mm/cm ² , in particular between 1.5 mm/cm ² and 2.5 mm/cm ² , each of the fin regions is centered at one of the tube sections. This arrangement has been found to allow efficient heat transfer between the gas flowing through the heat exchanger and the refrigerant flowing through the tube sections.

In one embodiment, the heat exchanger is configured to flow R290 through at least one heat exchange coil. The use of R290 as refrigerant allows refrigeration circuits to operate very efficiently and economically.

While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements of the exemplary embodiments without departing from the scope of the invention. . In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed, but that the invention will include all embodiments falling within the scope of the claims.

reference symbol

3 heat exchanger (first embodiment)

4 Gas inlet side

5 heat exchanger (second embodiment)

6 Gas outlet side

7a First (left) lateral side of heat exchanger

7b Second (right) lateral side of heat exchanger

8, 8a, 8b heat exchange coil

9 Inlet pipe section

10, 10a, 10b Refrigerant inlet section of the heat exchange coil

11 Connecting part of the heat exchange coil

12, 12a, 12b Entry Terminals

14, 14a, 14b Refrigerant outlet section of the heat exchange coil

16, 16a, 16b Exit Terminals

17 Subsections of the heat exchange section

18 Heat Exchange Section of Heat Exchange Coil

19 Subparts of the heat exchange section

20, 22 heat exchange tube section

24, 26 Outlet pipe section

30 fins

31a, 31b end plate

A Distance between pipe sections in the first direction

B Distance between pipe sections in the second direction

C cold air

D the diameter of the pipe section

F Direction of airflow

R volume ratio

S-S section

V _ex the volume of the heat exchange part

V _in the volume of the refrigerant inlet section

V _out is the volume of the refrigerant outlet portion

Volume of V ₂₀ and V ₂₂ heat exchange tube sections

Volume of V ₂₄ , V ₂₆ outlet pipe sections

W Thermal

X fin area

Claims (15)

1. A heat exchanger (3; 5) comprising a gas flow path extending from a gas inlet side (4) of said heat exchanger (3; 5) to an opposite gas outlet side (6); and At least one heat exchange coil (8; 8a, 8b) extending through the airflow path and configured to allow fluid flowing through the heat exchange coil (8; 8a, 8b) to flow through the airflow path heat exchange between gases; Wherein said at least one heat exchange coil (8; 8a, 8b) comprises: a refrigerant inlet section (10) having an inlet terminal (12); a refrigerant outlet section (14) having an outlet terminal (16); and a heat exchange portion (18) fluidly connected between said refrigerant inlet portion (10) and said refrigerant outlet portion (14) for allowing fluid to pass from said refrigerant inlet portion (10) through said The heat exchange portion (18) flows into the refrigerant outlet portion (14); wherein said refrigerant inlet portion (10), said heat exchange portion (18) and said refrigerant outlet portion (14) are arranged in said gas flow path such that the gas entering at said gas inlet side (4) Gas first passes through the refrigerant outlet section (14), then through the refrigerant inlet section (10) and finally through the heat exchange coil ( 8; said heat exchange portion (18) of 8a, 8b); and wherein said refrigerant inlet section (10) is provided by a single inlet tube section (9), said heat exchange section (18) is provided by at least two heat exchange tube sections (20, 22), and said refrigerant outlet section (14) is provided by at least two outlet pipe sections (24, 26) connected in parallel, wherein the volume (V _in ) of the refrigerant inlet section (10) is related to the volume (V _ex ) and the sum of the volume of the refrigerant outlet portion (14) (V _out ) has a volume ratio (R) between 1:3 and 1:7, in particular between 1:4 and 1:6. 2. The heat exchanger (5) according to claim 1, wherein said refrigerant inlet section (10), said heat exchange section (18) and said refrigerant outlet section (14) are respectively at opposite ends The plates (31a, 32b) extend between them. 3. The heat exchanger (5) according to claim 1 or 2, wherein the heat exchange section (18) comprises at least two subsections (17, 19) extending parallel to each other and fluidly connected by a connecting section (11) ). 4. The heat exchanger (5) according to any one of claims 1 to 3, comprising at least two heat exchange coils (8a, 8b) extending through the gas flow path. 5. The heat exchanger (5) according to claim 4, comprising a first set of heat exchange coils (8a) and a second set of heat exchange coils (8b), wherein the first set of heat exchange coils The inlet terminal (12a) of (8a) is arranged on the first lateral side (7a) of the heat exchanger (5) and the inlet terminal (12b) of the second set of heat exchange coils (8b) ) is arranged on the opposite second lateral side (7b) of the heat exchanger (5) such that the direction of the refrigerant inlet portion (10a) flowing through the first set of heat exchange coils (8a) The direction of the refrigerant inlet portion (10b) flowing through the second set of heat exchange coils (8b) is opposite. 6. The heat exchanger (5) according to claim 4 or 5, comprising a first set of heat exchange coils (8a) and a second set of heat exchange coils (8b), wherein the first set of heat exchange coils (8b) The outlet terminal (12a) of the coil (8a) is arranged on the first lateral side (7a) of the heat exchanger (5) and the outlet terminal of the second set of heat exchange coils (8b) (12b) is arranged on the opposite second lateral side (7b) of the heat exchanger (5) such that the refrigerant outlet portion (14a) flowing through the first set of heat exchange coils (8a) The direction of the refrigerant is opposite to the direction of the refrigerant outlet portion (14b) flowing through the second group of heat exchange coils (8b). 7. The heat exchanger (3; 5) according to any one of the preceding claims, wherein the inner diameter of the tube sections (9, 20, 22, 24, 26) is greater than 6 mm, in particular at least 7 mm, and /or wherein the outer diameter of the tube section (9, 20, 22, 24, 26) is smaller than 10 mm, in particular not larger than 9.52 mm. 8. The heat exchanger (3; 5) according to any one of the preceding claims, wherein the heat exchange tube sections (20, 22) are arranged in a plurality of columns and rows forming a rectangular matrix. 9. The heat exchanger (3; 5) according to claim 8, wherein the heat exchange tube sections (20, 22) have a different distance (B) along the column than the heat exchange tube sections (20 , 22) The distance (A) along the row. 10. The heat exchanger (3; 5) according to claim 9, wherein the distance (A ) is less than the distance (B) of said pipe section (9, 20, 22, 24, 26) in a direction normal to said air flow (F). 11. The heat exchanger (3; 5) according to any one of claims 8 to 10, wherein said distance (A) of said heat exchange tube sections (20, 22) along said row is relative to The ratio of said distances (B) of said heat exchange tube sections ( 20 , 22 ) along said columns is between 0.7 and 1.0, in particular between 0.8 and 0.9. 12. The heat exchanger (3; 5) according to any one of claims 8 to 11, wherein said inner diameter D of said tube sections (9, 20, 22, 24, 26) is 7 mm, said The outer diameter D of the tube sections (9, 20, 22, 24, 26) is 9.52mm, and the distance (A) of the heat exchange tube sections (20, 22) along the row is between 35mm and 45mm Between, and/or said distance (B) of said heat exchange tube sections (20, 22) along said row is between 45mm and 55mm. 13. The heat exchanger (3; 5) according to any one of the preceding claims, further comprising fins (30) extending substantially parallel to the gas flow path. 14. The heat exchanger (3; 5) according to claim 14, wherein the circumference of the tube sections (9, 20, 22, 24, 26) is relative to that assigned to each tube section (9, 20, 22) , 24, 26) the ratio of the fin area (X) is in the range of 1.0 mm/cm ² to 2.5 mm/cm ² , specifically between 1.5 mm/cm ² and 2.5 mm/cm ² , said Each tube section is constructed by dividing the total area of each fin (30) into a plurality of fin areas (X) of equal size. 15. The heat exchanger (3; 5) according to any one of the preceding claims, configured to flow R290 through the at least one heat exchange coil (8; 8a, 8b).