Brazing plate heat exchanger

Abstract

A brazed plate heat exchanger (10) includes a plurality of heat exchanger plates (12A, 12B) stacked onto each other. The heat exchanger plates (12A, 12B) are obtained by being formed from respective metal sheets and permanently joined to each other by brazing by means of a brazing material so as to form a plate group (30) provided with a first plate gap for a first fluid and a second plate gap for a second fluid. The plate group (30) comprises an alternation of first heat exchanger plates (12A) and second heat exchanger plates (12B). Each first heat exchanger plate (12A) and each second heat exchanger plate (12B) are provided with a plurality of port holes (P1, P2, P3, P4) and have a substantially rectangular shape with two long side edges (26), two short side edges (28) and a longitudinal axis (X) extending parallel to the long side edges (26) and transverse to the short side edges (28). Each first heat exchanger plate (12A) and each second heat exchanger plate (12B) have a corrugated pattern that forms at least one heat transfer region (36, 38; 40) extending along the longitudinal axis (X) and comprising mutually parallel ridges (32) and grooves (34) arranged in such a way that the ridges (32) of one of the first heat exchanger plates (12A) abut the grooves (34) of an adjacent one of the second heat exchanger plates (12B), so as to form a plurality of joining areas. Each ridge (32) and each groove (34) of at least one first heat transfer area (36) of each first heat exchanger plate (12A) are inclined with respect to the longitudinal axis (X) by a first angle (alpha) comprised between 0 DEG and 30 DEG. Each ridge (32) and each groove (34) of at least one heat transfer area (40) of each second heat exchanger plate (12B) are inclined relative to the longitudinal axis (X) by a second angle (beta) comprised between 90 DEG and 45 DEG. At least a portion of the ridge (32) and at least a portion of the groove (34) of at least the first heat transfer region (36) of each first heat exchanger plate (12A) extend uninterruptedly between opposite edges of the respective heat transfer region (36), wherein the opposite edges are parallel to the short side edges (28).

Description

Technical Field

[0001] The present invention generally relates to a plate heat exchanger and more particularly to a brazed plate heat exchanger in which the heat exchanger plates are provided with an improved corrugation pattern of ridges and grooves that facilitates drainage of liquid condensate. Background Art

[0002] A heat exchanger is a device for transferring heat between two or more fluids. A plate heat exchanger is a special type of heat exchanger in which metal plates are used to transfer heat between two fluids. A plate heat exchanger generally comprises a starting plate, an end plate and a plurality of intermediate plates stacked on each other so as to form flow channels between them. In a plate heat exchanger, two fluids at different temperatures (one of which is usually considered to be the refrigerant fluid) flow respectively through the plate channels obtained between the opposing surfaces of pairs of adjacent heat exchanger plates: in this way, the two fluids exchange their heat content. These fluids can flow in countercurrent or in parallel and their leak-free circulation is ensured by gaskets or by the bonds between the heat exchanger plates.

[0003] The flow channels between the heat exchanger plates are usually obtained by providing the two plate surfaces with a corrugated pattern. In other words, the two plate surfaces are provided with a pressed pattern of ridges and grooves. When the heat exchanger plates are stacked onto each other, the ridges of a first heat exchanger plate contact the grooves of an adjacent heat exchanger plate and thus the plates are kept at a distance from each other by the spacer elements. In this way, the flow channels are formed.

[0004] The usual way of manufacturing plate type heat exchangers is to braze the heat exchanger plates together. This way of manufacturing requires that the heat exchanger plates are provided with a brazing material. During manufacturing, the heat exchanger plates are stacked onto each other and placed in a furnace with a sufficiently high temperature to at least partially melt the brazing material. After the temperature of the furnace has been lowered, the brazing material will solidify, allowing the heat exchanger plates to become joined to each other to form a compact and strong heat exchanger.

[0005] Brazed plate heat exchangers, also known by the abbreviation "BHE", can be used as condensers in various applications such as air conditioning, heat pumps, etc. The condensation process usually takes place in vertical flow channels of the heat exchanger plates, where the refrigerant vapor flows from the top to the bottom of the channels generally according to gravity. This facilitates the drainage of liquid condensate by gravity, reducing the liquid film thickness on the surface of the plates and its associated thermal resistance.

[0006] Typically, a BHE unit used as a condenser is installed in a vertical position. This means that, since the heat exchanger plates typically have a substantially rectangular shape, the short sides of the plates are arranged horizontally and the long sides of the plates are arranged vertically. Several corrugation patterns of BHE plates are known in the prior art. For example, a known corrugation pattern provides a plurality of channels in a single or multiple herringbone shape, wherein one or more vertical ridges extend between the short sides of each heat exchanger plate. Other known corrugation patterns are disclosed, for example, in the prior art documents WO 2021 / 154152, EP 3832243, US 7669643, US2011 / 0083833, CN102519281 and JP 11037677.

[0007] Applicants have discovered that by tilting a BHE provided with plates having a known corrugation pattern at a predetermined angle relative to a vertical axis, the performance of the BHE condenser is improved for certain tilt angles (see Figures 7 and 8). A possible explanation is that the tilted BHE unit (at certain angles that may be related to the cross-corrugation angle and the direction of gravity) may allow liquid condensate to drain more easily to the bottom of the heat exchanger plates (where the subcooled liquid accumulates), making the liquid film thinner and thereby reducing its thermal resistance, with an ultimately improved condensation process (lower condensation temperature or lower temperature path). Therefore, there is a need to improve such prior art BHE units, as it is not convenient to install these BHE units in arrangements other than a vertical arrangement. Summary of the invention

[0008] It is therefore an object of the present invention to provide a brazed plate heat exchanger which solves the disadvantages of the prior art in a simple, inexpensive and particularly practical manner.

[0009] In detail, one object of the present invention is to provide a brazed plate heat exchanger in which liquid condensate can be discharged to the bottom of the heat exchanger plates in a simpler and faster manner compared to brazed plate heat exchangers according to the prior art, a good heat transfer being ensured by a suitable special choice of the corrugation angle of the plates.

[0010] Another object of the present invention is to provide a brazed plate heat exchanger, wherein the corrugation pattern of the heat exchanger plates is easier to manufacture relative to brazed plate heat exchangers according to the prior art.

[0011] According to the present invention, these objects are achieved by providing a brazed plate heat exchanger as set out in the appended claims.

[0012] Further characteristics of the invention are highlighted by the dependent claims which are an integral part of the present description.

[0013] A brazed plate heat exchanger according to the invention comprises a plurality of heat exchanger plates stacked on each other. The heat exchanger plates are obtained by forming from respective metal sheets. The heat exchanger plates are durably joined to each other by brazing by means of a brazing material so as to form a plate pack, the plate pack being provided with a first plate interspace for a first fluid and a second plate interspace for a second fluid. The plate pack comprises an alternation between first and second heat exchanger plates. Each of the first and second heat exchanger plates is provided with a plurality of port holes and has a substantially rectangular shape with two long side edges, two short side edges and a longitudinal axis extending parallel to the two long side edges and transverse to the two short side edges. Each of the first and second heat exchanger plates has a corrugated pattern forming at least one heat transfer region extending along the longitudinal axis. Each heat transfer region comprises mutually parallel ridges and grooves, the ridges and grooves being arranged in such a way that a ridge of one of the first heat exchanger plates abuts a groove of an adjacent one of the second heat exchanger plates so as to form a plurality of joining regions.

[0014] Each ridge and each groove of at least one first heat transfer area of ​​each first heat exchanger plate is inclined with respect to the longitudinal axis at a first angle comprised between 0° and 30°. Additionally, each ridge and each groove of at least one heat transfer area of ​​each second heat exchanger plate is inclined with respect to the longitudinal axis at a second angle comprised between 90° and 45°. Finally, at least a portion of the ridges and at least a portion of the grooves of at least the first heat transfer area of ​​each first heat exchanger plate extends without interruption between opposite edges of the respective heat transfer area, wherein these opposite edges are parallel to the short side edges.

[0015] Preferably, the first angle is 20° and the second angle is 70°.

[0016] Also preferably, the amount of ridges and hence grooves of the first heat transfer area of ​​each first heat exchanger plate extending without interruption between opposite edges of the respective heat transfer area is equal to at least 30% of the total amount of ridges and hence grooves of the first heat transfer area of ​​each first heat exchanger plate.

[0017] According to a preferred aspect of the invention, each of the first heat exchanger plates is provided with at least one second heat transfer area adjacent to the first heat transfer area. Each ridge and each groove of the second heat transfer area is preferably inclined relative to the longitudinal axis at a third angle comprised between 45° and 90°. More preferably, the third angle is 65°.

[0018] It is also preferred that at least a portion of the ridges and at least a portion of the grooves of the second heat transfer area extend seamlessly, i.e. without interruption, between opposite edges of the respective second heat transfer area, wherein these opposite edges are parallel to the short side edges. It is still preferred that the second heat transfer area has a longitudinal extension measured along the longitudinal axis which is equal to about 1 / 3 of the longitudinal extension of the first heat transfer area.

[0019] Each ridge and each groove of each heat transfer area of ​​both the first heat exchanger plate and the second heat exchanger plate is preferably straight and continuous along the respective heat transfer area.The longitudinal axis is preferably a vertical axis.

[0020] According to a preferred embodiment, each of the first and second heat exchanger plates is provided with four port holes.Then, each port hole is placed at a respective corner of the respective heat exchanger plate, ie at a contact point between a long side edge and a short side edge of the respective heat exchanger plate.

[0021] Preferably, at least one of the port holes may be placed at a distance from its nearest long side edge that is different from the distances of the remaining port holes from the respective nearest long side edges. More preferably, said distance of at least one port hole is greater than said distances of the remaining port holes. Still preferably, each corner of each heat exchanger plate is a rounded corner. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The characteristics and advantages of a brazed plate heat exchanger according to the invention will become more apparent from the following exemplary and non-limiting description, with reference to the attached schematic drawings, in which:

[0023] Figure 1 is a side view of a general embodiment of a brazed plate heat exchanger;

[0024] Figure 2 for Figure 1 A plan view of a brazed plate heat exchanger;

[0025] Figure 3 is a plan view of a heat exchanger plate according to the invention provided with a corrugated pattern of ridges and grooves of a first type;

[0026] Figure 4 for Figure 3 A side view of a heat exchanger plate;

[0027] Figure 5 is a plan view of a heat exchanger plate according to the invention provided with a corrugated pattern of ridges and grooves of a second type;

[0028] Figure 6 for Figure 5 A side view of a heat exchanger plate;

[0029] FIG. 7 is a graph showing the relationship between the condensation temperature and the inclination angle of a plate in a brazed plate heat exchanger according to the prior art.

[0030] FIG. 8 is a graph showing the condensation temperature and heat flux (in kW / m2) of a plate in a brazed plate heat exchanger according to the prior art. 2 Another diagram of the relationship between measurements).

[0031] FIG. 9 is a schematic diagram showing the tilt angles of plates in a brazed plate heat exchanger according to the prior art.

[0032] Fig.10 is a schematic diagram showing the corrugation pattern of ridges and grooves of a plate in a brazed plate heat exchanger according to the present invention. DETAILED DESCRIPTION

[0033] refer to Figure 1 and Figure 2 , a brazed plate heat exchanger 10 is shown. The heat exchanger 10 comprises a plurality of heat exchanger plates 12A, 12B stacked onto each other in a manner known per se. Typically, the heat exchanger plates 12A, 12B are stacked onto each other between a first end plate 14 and a second end plate 16 of the heat exchanger 10. The individual heat exchanger plates 12A, 12B are obtained by forming from respective metal sheets. The first end plate 14, the second end plate 16 and the heat exchanger plates 12A, 12B are durably joined to each other by brazing by means of a brazing material so as to form a plate group 30. Thus, the plate group 30 is provided with a first plate interspace for a first fluid and a second plate interspace for a second fluid. The first fluid and the second fluid may be any suitable heat transfer fluid.

[0034] The plate package 30 of the heat exchanger 10 comprises an alternation between first heat exchanger plates 12A and second heat exchanger plates 12B. In other words, starting from the first end plate 14 and up to the second end plate 16, a first heat exchanger plate 12A is joined to a second heat exchanger plate 12B, which in turn is joined to another first heat exchanger plate 12A, and so on. Thus, plate gaps are obtained between heat exchanger plates 12A, 12B of different types, i.e. first heat exchanger plates 12A and second heat exchanger plates 12B.

[0035] Each of the first heat exchanger plates 12A and the second heat exchanger plates 12B, and the first end plate 14 and the second end plate 16 are provided with a plurality of port holes, preferably four port holes P1, P2, P3 and P4. The first port hole P1 is connected to the first connecting pipe 18 and communicates with the first plate gap. The second port hole P2 is connected to the second connecting pipe 20 and communicates with the first plate gap. The third port hole P3 is connected to the third connecting pipe 22 and communicates with the second plate gap. Finally, the fourth port hole P4 is connected to the fourth connecting pipe 24 and communicates with the second plate gap. The connecting pipes 18, 20, 22 and 24 may be provided to extend from the first end plate 14 (such as Figure 1 ) and / or extending from the second end plate 16.

[0036] like Figure 2 As shown in FIG, each of the first and second heat exchanger plates 12A, 12B, and the first and second end plates 14, 16 have a substantially rectangular shape with two long side edges 26 and two short side edges 28. The longitudinal axis X extends parallel to the two long side edges 26 and transverse to the two short side edges 28.

[0037] Each of the first heat exchanger plates 12A and the second heat exchanger plates 12B has a corrugation pattern forming at least one heat transfer area 36, ​​38, 40 extending along the longitudinal axis X. Each heat transfer area 36, ​​38, 40 comprises mutually parallel ridges 32 and grooves 34 arranged in such a way that a ridge 32 of one of the first heat exchanger plates 12A abuts a groove 34 of an adjacent one of the second heat exchanger plates 12B so as to form a plurality of small joining areas, referred to as brazed joints.

[0038] According to the present invention, Figure 3 As shown in , each ridge 32 and therefore each groove 34 of at least one first heat transfer area 36 of each first heat exchanger plate 12A is inclined relative to the longitudinal axis X by a first angle α comprised between 0° and 30°. Figure 5 , each ridge 32 and thus each groove 34 of the heat transfer area 40 of each second heat exchanger plate 12B is instead inclined at a second angle β comprised between 90° and 45° relative to the longitudinal axis X. Preferably, the first angle α is 20° and the second angle β is 70°.

[0039] In addition, at least a portion of the ridges 32 and therefore at least a portion of the grooves 34 of the first heat transfer area 36 of each first heat exchanger plate 12A extends without interruption between opposite edges (i.e., opposite edges parallel to the short side edges 28 of the respective first heat exchanger plate 12A) of the respective heat transfer area 36. In other words, as shown in the figures, since the longitudinal axis X is preferably a vertical axis, at least a portion of the ridges 32 and therefore at least a portion of the grooves 34 of the first heat transfer area 36 of each first heat exchanger plate 12A extends seamlessly from the top to the bottom of the respective heat transfer area 36, ​​i.e., without interruption.

[0040] Preferably, the amount of ridges 32, and therefore the amount of grooves 34, of the first heat transfer area 36 of each first heat exchanger plate 12A extending without interruption between the opposite edges of the respective heat transfer area 36 is equal to at least 30% of the total amount of ridges 32, and therefore the total amount of grooves 34, of the first heat transfer area 36 of the respective first heat exchanger plate 12A. For example, a preferred first angle α of 20° of each first heat exchanger plate 12A ensures that at least 40% of the respective ridges 32, and therefore the respective grooves 34, extend seamlessly from top to bottom of the first heat transfer area 36 of the respective first heat exchanger plate 12A.

[0041] The second angle β of the second heat exchanger plate 12B comprised between 90° and 60° and preferably equal to 70° is chosen in such a way that a good heat exchange coefficient is obtained. In fact, in heat exchanger plates according to the prior art with a standard pattern, i.e. with a small corrugation angle (e.g. 20°), two drawbacks occur on pairs of adjacent heat exchanger plates: a low heat exchange coefficient and incorrect distribution of the fluid within the corresponding channels.

[0042] Preferably, if Figure 3 As shown in , each first heat exchanger plate 12A is provided with at least one second heat transfer area 38 adjacent to the first heat transfer area 36. More specifically, in the case where the longitudinal axis X is a vertical axis, the second heat transfer area 38 is arranged below the first heat transfer area 36. Each ridge 32 and therefore each groove 34 of this second heat transfer area 38 is inclined relative to the longitudinal axis X by a third angle γ comprised between 45° and 90°. Preferably, the third angle γ is 65°.

[0043] Similar to the first heat transfer areas 36, at least a portion of the ridges 32 and thus at least a portion of the grooves 34 of the second heat transfer areas 38 preferably extend without interruption between opposite edges of the respective second heat transfer areas 38 (i.e. opposite edges parallel to the short side edges 28 of the respective first heat exchanger plates 12A). Figure 3As shown in , the second heat transfer area 38 of each first heat exchanger plate 12A has a longitudinal extension measured along the longitudinal axis X which is equal to about 1 / 3 of the longitudinal extension of the first heat transfer area 36 of the respective first heat exchanger plate 12A.

[0044] Fig.10 The above-mentioned corrugation pattern of the first heat exchanger plate 12A and the second heat exchanger plate 12B is schematically shown in FIG. The corrugation pattern allows one of the fluids processed by the heat exchanger 10 (e.g., liquid condensate in the case where the heat exchanger 10 is used as a condenser) to move along the almost vertical gaps so as to more easily reach the bottom area of ​​the heat exchanger plates 12A, 12B. In addition, this advantageous feature is enhanced by the fact that the individual ridges 32 and the individual grooves 34 of the individual heat transfer areas 36, 38, 40 of both the first heat exchanger plate 12A and the second heat exchanger plate 12B are straight and continuous along the respective heat transfer areas 36, 38, 40. In other words, the heat exchanger plates 12A, 12B are not provided with any vertical ridges or other discontinuities in the respective heat transfer areas 36, 38, 40, thereby improving the ability of the liquid condensate to more easily reach the bottom area of ​​the heat exchanger plates 12A, 12B.

[0045] Preferably, each of the four port holes P1, P2, P3, P4 of the heat exchanger plates 12A, 12B is placed at a corresponding corner of the corresponding heat exchanger plate 12A, 12B. In other words, as shown in the figure, each of the four port holes P1, P2, P3, P4 of the heat exchanger plates 12A, 12B is placed at a contact point between the long side edge 26 and the short side edge 28 of the corresponding heat exchanger plate 12A, 12B. More preferably, each corner of each heat exchanger plate 12A, 12B is a rounded corner.

[0046] According to a preferred aspect of the present invention, at least one of the port holes P4 of each heat exchanger plate 12A, 12B, namely Figure 3 and Figure 5 The port hole P4 at the upper left in the middle is placed at a distance D1 from its nearest long side edge 26, which is different from the distances D2, D3 of the remaining port holes P1, P2, P3 from the respective nearest long side edges 26. Preferably, but not exclusively, the distance D1 of the at least one port hole P4 is greater than the distances D2, D3 of the remaining port holes P1, P2, P3. This preferred technical feature is due to the fact that the specific and innovative combination of corrugation angles α and β requires an equally specific fluid port arrangement in order to have a uniform fluid distribution along the width of the heat exchanger plates 12A, 12B (in order to maximize heat transfer).

[0047] It can thus be seen that the brazed plate heat exchanger according to the invention achieves the objectives outlined previously.

[0048] The brazed plate heat exchanger of the invention thus conceived is in any case susceptible to numerous modifications and variations, all falling within the same inventive concept; moreover, all the details may be replaced by technically equivalent elements. In practice, the materials used, as well as the shapes and sizes, may be of any type according to the technical requirements.

[0049] Therefore, the protection scope of the present invention is defined by the appended claims.

[0050] Reference List

[0051] 10: Heat exchanger;

[0052] 12A: first heat exchanger plate;

[0053] 12B: second heat exchanger plate;

[0054] 14: first end plate;

[0055] 16: second end plate;

[0056] 18: first connecting pipe;

[0057] 20: second connecting pipe;

[0058] 22: third connecting pipe;

[0059] 24: fourth connecting pipe;

[0060] 26: long side edge of the board;

[0061] 28: short side edge of the board;

[0062] 30: Plate group;

[0063] 32: ridge;

[0064] 34: groove;

[0065] 36: a first heat transfer region of a first heat exchanger plate;

[0066] 38: second heat transfer region of the first heat exchanger plate;

[0067] 40: heat transfer area of ​​the second heat exchanger plate;

[0068] α: first angle;

[0069] β: second angle;

[0070] γ: third angle;

[0071] P1: first port hole;

[0072] P2: second port hole;

[0073] P3: third port hole;

[0074] P4: fourth port hole;

[0075] D1: distance between the fourth port hole and the edge of the corresponding long side of the plate;

[0076] D2: distance between the first port hole and the third port hole and the edge of the corresponding long side of the plate;

[0077] D3: Distance between the second port hole and the edge of the corresponding long side of the plate.

Claims

1. A brazed plate heat exchanger (10) comprising a plurality of heat exchanger plates (12A, 12B) stacked on each other, wherein the heat exchanger plates (12A, 12B) are obtained by forming from respective metal sheets, wherein the heat exchanger plates (12A, 12B) are durably joined to each other by brazing by means of a brazing material so as to form a plate pack (30), the plate pack being provided with first plate interspaces for a first fluid and second plate interspaces for a second fluid, wherein the plate pack (30) comprises an alternation between first heat exchanger plates (12A) and second heat exchanger plates (12B), wherein each between the first heat exchanger plates (12A) and the second heat exchanger plates (12B) is provided with a plurality of port holes (P1, P2, P3, P4) and has a substantially rectangular shape with two long sides A heat exchanger (10) comprising a first heat exchanger plate (12A) and a second heat exchanger plate (12B) having a first edge (26), two short side edges (28) and a longitudinal axis (X) extending parallel to the two long side edges (26) and transverse to the two short side edges (28), wherein each of the first heat exchanger plates (12A) and the second heat exchanger plates (12B) has a corrugated pattern, the corrugated pattern forming at least one heat transfer area (36, 38; 40) extending along the longitudinal axis (X), and wherein each heat transfer area (36, 38; 40) comprises mutually parallel ridges (32) and grooves (34), the ridges and the grooves being arranged in such a way that a ridge (32) of one of the first heat exchanger plates (12A) abuts a groove (34) of an adjacent one of the second heat exchanger plates (12B) so as to form a plurality of joined areas, the heat exchanger (10) being characterized in that: - each ridge (32) and each groove (34) of at least one first heat transfer area (36) of said first heat exchanger plate (12A) is inclined at a first angle (α) comprised between 0° and 30° with respect to said longitudinal axis (X); - each ridge (32) and each groove (34) of at least one heat transfer area (40) of said second heat exchanger plate (12B) is inclined relative to said longitudinal axis (X) at a second angle (β) comprised between 90° and 45°; - at least a portion of the ridges (32) and at least a portion of the grooves (34) of at least a first heat transfer area (36) of the first heat exchanger plate (12A) extend without interruption between opposite edges of the respective heat transfer area (36), wherein the opposite edges are parallel to the short side edges (28).

2. The brazed plate heat exchanger (10) according to claim 1, characterized in that: The first angle (α) is 20°.

3. The brazed plate heat exchanger (10) according to claim 1 or claim 2, characterized in that: The second angle (β) is 70°.

4. The brazed plate heat exchanger (10) according to any one of claims 1 to 3, characterized in that: The amount of ridges (32) and therefore the amount of grooves (34) of the first heat transfer area (36) of each first heat exchanger plate (12A) extending without interruption between opposite edges of the respective heat transfer area (36) is equal to at least 30% of the total amount of ridges (32) and therefore the total amount of grooves (34) of the first heat transfer area (36) of the first heat exchanger plate (12A).

5. The brazed plate heat exchanger (10) according to any one of claims 1 to 4, characterized in that: Each of the first heat exchanger plates (12A) is provided with at least one second heat transfer area (38) adjacent to the first heat transfer area (36).

6. The brazed plate heat exchanger (10) according to claim 5, characterized in that Each ridge (32) and each groove (34) of the second heat transfer zone (38) is inclined relative to the longitudinal axis (X) at a third angle (γ) comprised between 45° and 90°.

7. The brazed plate heat exchanger (10) according to claim 6, characterized in that: The third angle (γ) is 65°.

8. The brazed plate heat exchanger (10) according to any one of claims 5 to 7, characterized in that: At least a portion of the ridges (32) and at least a portion of the grooves (34) of the second heat transfer area (38) extend seamlessly, i.e. without interruption, between opposite edges of the respective second heat transfer area (38), wherein the opposite edges are parallel to the short side edges (28).

9. The brazed plate heat exchanger (10) according to any one of claims 5 to 8, characterized in that: The second heat transfer zone (38) has a longitudinal extension, measured along the longitudinal axis (X), which is equal to about 1 / 3 of the longitudinal extension of the first heat transfer zone (36).

10. The brazed plate heat exchanger (10) according to any one of claims 1 to 9, characterized in that: Each ridge (32) and each groove (34) of each heat transfer area (36, 38; 40) of both the first heat exchanger plate (12A) and the second heat exchanger plate (12B) is disposed along the respective heat transfer area (36, 38; 40) is straight and continuous.

11. The brazed plate heat exchanger (10) according to any one of claims 1 to 10, characterized in that: The longitudinal axis (X) is a vertical axis.

12. The brazed plate heat exchanger (10) according to any one of claims 1 to 11, characterized in that: Each of the first heat exchanger plates (12A) and the second heat exchanger plates (12B) is provided with four port holes (P1, P2, P3, P4), wherein each port hole (P1, P2, P3, P4) is placed at a corresponding corner of the corresponding heat exchanger plate (12A, 12B), that is, at a contact point between a long side edge (26) and a short side edge (28) of the corresponding heat exchanger plate (12A, 12B).

13. The brazed plate heat exchanger (10) according to any one of claims 1 to 12, characterized in that: At least one of the port holes (P4) is placed at a distance (D1) from its nearest long side edge (26) that is different from the distances (D2, D3) of the remaining port holes (P1, P2, P3) from the respective nearest long side edges (26).

14. The brazed plate heat exchanger (10) according to claim 13, characterized in that The distance (D1) of the at least one port hole (P4) is greater than the distances (D2, D3) of the remaining port holes (P1, P2, P3).

15. The brazed plate heat exchanger (10) according to any one of claims 12 to 14, characterized in that Each corner of each heat exchanger plate (12A, 12B) is a rounded corner.

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