Heat exchanger

Abstract

Title: Heat Exchanger The invention relates to a heat exchanger (1) comprising: - a plurality of first-type plates (10) which are flat, - a plurality of second-type plates (20) provided with corrugations (22), the first-type plates (10) and second-type plates (20) being arranged alternately, the first-type plates (10) and second-type plates (20) being assembled together by a plurality of contact plates (13, 19, 23, 29), - the corrugations (22) having a generally elongated shape and defining, between consecutive plates, channels (46, 48) allowing the passage of fluid, these channels (46, 48) being distributed between channels (46) of first fluid passage section and channels (48) of second passage section,the channels (46) of the first passage section being configured to form a first fluid circuit and the channels (48) of the second passage section being configured to form a second fluid circuit. Figure for the abbreviation: Fig. 2,

Description

Title of the invention: Heat exchanger

[0001] The field of the present invention relates to heat exchangers.

[0002] In an air conditioning loop, it is known to use an internal heat exchanger (IHX). This is used to ensure that the refrigerant is completely evaporated at the compressor inlet and also to increase evaporation capacity by increasing subcooling. This type of internal heat exchanger operates with a low-pressure side (also called the LP side) and a high-pressure side (also called the HP side).

[0003] Generally, a low pressure drop is required on the low-pressure side, namely the side where the fluid is in the vapor phase. To achieve this, a large flow area is needed to reduce the pressure drop.

[0004] During operation, pressures of 27 or 28 bar can be reached for certain refrigerants. For a refrigerant such as propane, even higher pressures are required, particularly above 30 bar. This necessitates a substantial increase in the burst pressure resistance of these heat exchangers.

[0005] Heat exchangers that meet this burst pressure constraint are, for example, plate exchangers with crossed and "dimple" chevrons that allow for brazing points that are regular.

[0006] The invention proposes in particular to further improve heat exchangers which include two fluid circuits.

[0007] The invention thus relates to a heat exchanger, in particular of the internal heat exchanger type, also called IHX, comprising: - a plurality of first-type plates that are flat, - a plurality of second-type plates equipped with corrugations, the plates of the first type and plates of the second type being arranged alternately in a stack of plates, the plates of the first type and plates of the second type being joined together, preferably brazed together, by a plurality of contact plates at the junction between two consecutive plates of the stack, - the corrugations of the second type of plates, generally elongated in shape, defining channels between consecutive plates that allow fluid to pass between a fluid inlet zone and a fluid outlet zone. These channels are distributed between first-section fluid passage channels and second-section fluid passage channels. The first-section passage channels of the exchanger heat being configured to form a first fluid circuit for a first heat transfer fluid and the second section passage channels of the heat exchanger being configured to form a second fluid circuit for a second heat transfer fluid.

[0008] According to the present invention, the plurality of first-type plates are flat in the sense that the plates are flat over most of their surface, in particular over the entire portion of the plate that defines the channels. Specifically, these first-type plates are flat everywhere except for a raised edge around the perimeter.

[0009] In the case where the first-type plates and the second-type plates are brazed, the contact surfaces are brazing surfaces. Instead of being brazed together, the plates can, in alternative configurations, be welded or bonded together.

[0010] According to the present invention, the first heat transfer fluid and the second heat transfer fluid can be the same heat transfer fluid from the same fluid circuit but at different pressures / states (liquid / gaseous), or be different heat transfer fluids belonging to two separate fluid circuits.

[0011] Thanks to the invention, with the flat plates, it can be seen that the fluid in the first circuit and the fluid in the second circuit are in thermal contact (by conduction) with each other over large areas.

[0012] According to one aspect of the invention, the first fluid passage section, in particular on the HP side, of the channels is smaller than the second fluid passage section, in particular on the LP side, of the channels.

[0013] According to one aspect of the invention, the first section passage channels of the heat exchanger and the second section passage channels of the heat exchanger alternate when moving transversely to the corrugations, in the plane of the first type flat plates.

[0014] According to one aspect of the invention, the contact plates have widths which vary from one contact plate to the next, the width being measured, in the plane of the plate, perpendicular to the direction of elongation of the corrugations of this plate.

[0015] The different widths of the contact plates allow in particular to have different widths between the channels of first passage section and the channels of second passage section.

[0016] This difference in width creates an asymmetry in the plates, resulting in a volume reduction in one fluid circuit and a volume increase in the other. By modifying the dimensions of the contact plates, different fluid volumes can be obtained for the two circuits of a heat exchanger of a given volume.

[0017] This difference between the fluid volumes also makes it possible to adjust the pressure losses between the first fluid circuit and the second fluid circuit, in particular to reduce the pressure losses at the level of the Low Pressure (LP) circuit by increasing the pressure losses at the level of the High Pressure (HP) circuit.

[0018] According to one aspect of the invention, the second type plate has a plurality of contact plates, including contact plates of a first width and contact plates of a second width, the second width being greater than the first width.

[0019] According to one aspect of the invention, on each plate of the second type, the first width contact plates and the second width contact plates are arranged alternately.

[0020] According to one aspect of the invention, the contact plates can each be located on a vertex of a corrugation of the second-type plate. The contact plates are thus formed at the junction between a corrugation of the second-type plate and the adjacent flat plate (i.e., the first-type plate).

[0021] We can also speak of contact surfaces on the first type of flat plate which are brazing areas at the junction with the corrugations of the second type of plate.

[0022] According to one aspect of the invention, the corrugations are stamped areas of the second type of plate.

[0023] Thus, a flat plate is retained and another plate is used which is stamped (to form the corrugations). In the invention, it is possible to vary the width of the contact plates, to have different fluid volumes between the first fluid circuit and the second fluid circuit.

[0024] According to one aspect of the invention, the corrugations are rectilinear.

[0025] According to one aspect of the invention, the corrugations are spaced apart from each other with a steady pace.

[0026] According to one aspect of the invention, the corrugations extend in a central area of ​​the heat exchanger, between the fluid inlet and outlet areas.

[0027] In other words, the corrugations have a length that is less than, for example at least twice less than, the length of the longest side of the perimeter of the heat exchanger.

[0028] According to one aspect of the invention, the corrugations are set back from the fluid inlet and outlet area.

[0029] These fluid inlet and outlet zones are also called the heat exchanger collection zones.

[0030] According to one aspect of the invention, the corrugations are arranged parallel to one side of the perimeter of the heat exchanger.

[0031] Alternatively, the corrugations can be arranged obliquely with respect to one side of the perimeter of the heat exchanger.

[0032] Thus, in the invention, it is possible to put the corrugations with the desired inclination, because these corrugations are in contact with a flat plate, and not with corrugations of an adjacent plate.

[0033] Preferably, the corrugations are parallel to each other.

[0034] According to one aspect of the invention, all the corrugations, and therefore the contact surfaces as well, of the heat exchanger are parallel to each other. In other words, all the corrugations and contact surfaces of the heat exchanger have the same orientation.

[0035] According to one aspect of the invention, the corrugations of the second type plate are formed for half the height on one side of the second type plate, and for half the height on the opposite side of the second type plate.

[0036] In other words, the second type of plate has a stamping plane that is approximately halfway up the corrugations. This allows fluid passages to be left at the fluid inlet and fluid outlet areas (collection areas).

[0037] According to one embodiment, the contact plate is not at mid-height. In particular, the corrugations are not of the same height from one face to the other of the plate, which allows for a fluid inlet zone and a fluid outlet zone of different heights in the alternation between the channels of the first fluid passage section and the channels of the second fluid passage section.

[0038] According to one aspect of the invention, the first section passage channels and the second section passage channels have an identical height.

[0039] Here, the height is measured perpendicular to the plane of the plates.

[0040] According to one aspect of the invention, the corrugations have an identical height.

[0041] According to one aspect of the invention, the fluid inlet zone and / or the fluid outlet zone have fluid flow disturbance reliefs (called "Dimples" in English).

[0042] According to one aspect of the invention, the disturbance reliefs are distinct from the corrugations that form the channels.

[0043] According to one aspect of the invention, the disturbance reliefs, in particular made by stamped forms, are rounded or oval in shape, for example in the shape of a cap.

[0044] According to one aspect of the invention, the disturbance reliefs are present only on the second type plate. The first type plate, which is flat, is devoid of any disturbance features. The manufacture of this flat plate can be very simple.

[0045] According to one aspect of the invention, the disturbance reliefs are all oriented towards the same side of the second type plate.

[0046] Alternatively, the plate disturbance reliefs are oriented, for some, on one side of the second type plate and, for other plate disturbance reliefs, on an opposite side.

[0047] According to one aspect of the invention, for each fluid circuit, all the fluid inlet areas of the plate stack are connected to each other by openings in the plates which form a fluid inlet conduit.

[0048] According to one aspect of the invention, for each fluid circuit, all the fluid outlet areas of the plate stack are connected to each other by openings in the plates which form a fluid outlet conduit.

[0049] According to one aspect of the invention, for each fluid circuit, the fluid inlet area and the fluid outlet area can be diagonally opposite, or alternatively, can be on the same side of the heat exchanger.

[0050] The diagonal arrangement allows for improved performance because, in this case, the fluids of the two circuits have cross-flow directions, on either side of the stack plates.

[0051] According to one aspect of the invention, the plates are made of aluminum.

[0052] According to another aspect of the invention, the heat exchanger can be a A water-cooled condenser has two fluids circulating within it: a refrigerant and a coolant, such as a water-based liquid (particularly glycol water) or a dielectric fluid. In this case, the aim is to reduce the pressure drop on the coolant side to lower the pump's energy consumption on that side.

[0053] According to one aspect of the invention, the heat exchanger can also be a liquid evaporator, or "Chiller" in English, of an air conditioning loop.

[0054] Other features, details and advantages of the invention will become clearer upon reading the following description on the one hand, and several illustrative and non-limiting examples of embodiments given with reference to the accompanying schematic drawings on the other hand, in which:

[0055] [Fig.1] Fig.1 is a schematic, perspective representation of an IHX type heat exchanger;

[0056] [Fig.2] Fig.2 is a cross-sectional view of the plates of the heat exchanger heat of the [Fig.l];

[0057] [Fig.3] Fig.3 is a schematic representation of the plates of the heat exchanger heat of the [Fig.1].

[0058] The features, variants, and different embodiments of the invention can be combined in various ways, provided they are not incompatible or mutually exclusive. In particular, variants of the invention may be conceived comprising only a selection of features, described hereafter in isolation from the other described features, if this selection of features is sufficient to confer a technical advantage and / or to differentiate the invention from the prior art.

[0059] Figures 1 to 3 show an internal heat exchanger 1 (also called an IHX). This type of internal heat exchanger operates with a low-pressure side (also called the LP side) and a high-pressure side (also called the HP side). In the case of an internal heat exchanger (IHX), the first and second heat transfer fluids are the same refrigerant from the same fluid circuit but at different pressures / states (liquid / gaseous). The heat exchanger 1 is generally a block with a roughly rectangular perimeter.

[0060] The heat exchanger 1 includes inlet zones 15 and outlet zones 17 of fluid forming collecting zones of the heat exchanger 1 for the high pressure (HP) side of the refrigerant fluid.

[0061] Similarly, on the low pressure (LP) side, the heat exchanger 1 includes inlet zones 25 and outlet zones 27 of fluid forming collecting zones of the heat exchanger 1 for this low pressure (LP) side of the refrigerant fluid.

[0062] The heat exchanger 1 comprises, on the one hand, a plurality of first type plates 10 which are flat and on the other hand, a plurality of second type plates 20 provided with corrugations 22 parallel to each other.

[0063] Each first type plate 10 is flat over most of its surface except for a raised border 18 around its perimeter, visible in [Fig.3].

[0064] On the second type plates 20, the corrugations 22 are stamped areas of the second type plate 20. Thus, the first type plate 10 is kept flat and the second type plate 20 is used which is stamped to form the corrugations 22.

[0065] As can be seen in [Fig.3], the corrugations 22 are of straight, parallel, elongated shapes and are spaced from each other with a regular pitch.

[0066] The corrugations 22 extend into a central area 12 of the heat exchanger 1, between the inlet area 25 on the low pressure (LP) side and the outlet area 27 (not visible on [Fig.3]) on the low pressure (LP) side.

[0067] Similarly, on the high-pressure (HP) side, the corrugations 22 extend into the central zone 12 of the heat exchanger 1, between the inlet zone 15 (not visible on the [Fig.3]) on the high pressure (HP) side and outlet area 17 (not visible on the [Fig.3]) on this high pressure (HP) side.

[0068] The corrugations 22 have a length that is twice less than the length of the largest side 6 of the perimeter of the heat exchanger 1.

[0069] The corrugations 22 are set back from the fluid inlet zones 15 and 25 and outlet zones 17 and 27 and are arranged parallel to side 6 of the perimeter of the heat exchanger 1.

[0070] In an alternative (not shown), the corrugations 22 are arranged obliquely with respect to the side 6 of the perimeter of the heat exchanger 1. The corrugations 22 are inclined with the desired inclination.

[0071] The first type plates 10 and the second type plates 20 are arranged alternately, forming a stack of these first type plates 10 and second type plates 20. These first type plates 10 and second type plates 20, which are made of aluminum, are brazed together by a plurality of contact plates, which are here brazing plates 13, 19, 23 and 29 at the junction between two consecutive first type plates 10 and second type plates 20 of the stack, as can be seen in [Fig.2].

[0072] The corrugations 22 define, between the consecutive first-type plates 10 and second-type plates 20, channels 46 and 48. The channels 46 allow the passage of fluid between a fluid inlet zone 15 and a fluid outlet zone 17 on the high-pressure (HP) side. Similarly, on the low-pressure (LP) side, the channels 48 allow the passage of fluid between a fluid inlet zone 25 and a fluid outlet zone 27.

[0073] Thus, the channels 46 of the first passage section of the heat exchanger 1 are configured to form the high-pressure side 52. Conversely, the channels 48 of the second passage section are configured to form the low-pressure side 54.

[0074] The first fluid passage section, relating to the high pressure (HP) side of the channels 46, is smaller than the second fluid passage section, relating to the low pressure (LP) side of the channels 48.

[0075] The channels 46 of the first passage section and the channels 48 of the second passage section are alternated when moving transversely to the corrugations 22, in the plane of the first type 10 flat plates.

[0076] The second type plate 20 has a plurality of brazing plates 23 and 29, including brazing plates 23 of a first width and brazing plates 29 of a second width, the second width being greater than the first width. On each second type plate 20, the first-width brazing plates 23 and the second-width brazing plates 29 are arranged alternately.

[0077] The width is measured in the plane P of the second type plate 20 and perpendicular to an elongation direction EL of the corrugations 22 of this second type plate 20.

[0078] The brazing plates 23 and 29 are each on a vertex 200 of the corrugation 22 and are thus each formed at the junction between the corrugation 22 and the adjacent flat first-type plate 10.

[0079] On the other hand, the first type flat plate 10 includes brazing plates 13 and 19 which are brazing areas at the junction with the corrugations 22. The brazing plates 13 have a first width and the brazing plates 19 have a second width which is greater than the first width.

[0080] All the corrugations 22, and therefore the brazing plates 23 and 29 as well, are parallel to each other and consequently in the same orientation.

[0081] The different widths between the brazing plates 13, 19, 23, and 29 allow for different widths between the channels 46 of the first flow section and the channels 48 of the second flow section. This difference in width creates an asymmetry in the first-type plates 10 and the second-type plates 20, resulting in a reduction in volume on the high-pressure side 52, which passes through the channels 46 of the first flow section, and an increase in volume on the low-pressure side 54, which passes through the channels 48 of the second flow section. These volume differences also affect the pressure losses on the high-pressure and low-pressure sides. Thus, the different widths between the brazing plates 13, 19, 23, and 29 can be dimensioned according to the acceptable pressure losses on the high-pressure and low-pressure sides.

[0082] With the first type 10 flat plates, the fluid in the high pressure side 52 and in the low pressure side 54 are in thermal contact by conduction mutually over large surfaces.

[0083] The second type plate 20 has a PE stamping plane that is substantially at mid-height of the corrugations 22. The corrugations 22 of the second type plate 20 are formed for half their height on one side 201 of the second type plate 20, and for half their height on an opposite side 202 of this second type plate 20. The corrugations 22 have the same height. This allows fluid passages at the fluid inlet zones 15 and 25 and the fluid outlet zones 17 and 27, defined as the collection zones.

[0084] The channels 46 of the first passage section and the channels 48 of the second passage section have the same height. The height is measured perpendicular to the plane P of the first type plates 10 and second type plates 20.

[0085] The fluid inlet zones 15 and 25 and / or the fluid outlet zones 17 and 27 have fluid flow disturbance features 70, called "Dimples". Figure 3 shows that the disturbance features 70 are distinct from the corrugations 22 that form the channels 46 and 48. The disturbance features 70, formed by stamped shapes, are rounded or oval, for example, cap-shaped.

[0086] The disturbance reliefs 70 are present only on the second type plate 20. The disturbance reliefs 70 are all oriented towards the same side of the second type plate 20.

[0087] The first type plate 10, which is flat, is free of disturbance reliefs 70. The manufacture of this first type plate 10 is very simple.

[0088] For the high pressure side 54, the inlet areas 25 are connected to each other by openings 74 in the first type plates 10 and second type plates 20 which form a fluid inlet conduit 78.

[0089] Similarly, for the low pressure side 52, the inlet areas 15 are connected to each other by openings (not shown) in the first type plates 10 and second type plates 20 which form a fluid inlet conduit (not shown).

[0090] Conversely, for the high-pressure side 52, the outlet zones 17 are connected to each other by openings (not shown) in the first-type plates 10 and second-type plates 20, which form a fluid outlet conduit (not shown). Similarly, for the low-pressure side 54, the outlet zones 27 are connected to each other by openings (not shown) in the first-type plates 10 and second-type plates 20, which form a fluid outlet conduit (not shown).

[0091] Finally, the fluid inlet zones 15 and 25 and the fluid outlet zones 17 and 27 are diagonally opposite. The diagonal arrangement allows for improved performance because, in this case, the high-pressure side 52 and low-pressure side 54 have cross flow directions, on either side of the first-type plates 10 and second-type plates 20 of the stack.

Claims

Demands

1. Heat exchanger (1), in particular of the internal heat exchanger type, also called IHX, comprising: - a plurality of first-type plates (10) which are flat, - a plurality of second-type plates (20) provided with corrugations (22), the first-type plates (10) and the second-type plates (20) being arranged alternately in a stack of plates, the first-type plates (10) and the second-type plates (20) being joined together, in particular brazed together, by a plurality of contact plates (13, 19, 23, 29) at the junction between two consecutive plates of the stack, - the corrugations (22) of the second-type plates (20) having a generally elongated shape and defining, between consecutive plates, channels (46, 48) allowing the passage of fluid between a fluid inlet zone (15, 25) and an outlet zone (17, 27) of fluid, these channels (46,48) being distributed between first section fluid passage channels (46) and second section fluid passage channels (48), the first section passage channels (46) of the heat exchanger (1) being configured to form a first fluid circuit for a first heat transfer fluid and the second section passage channels (48) of the heat exchanger (1) being configured to form a second fluid circuit for a second heat transfer fluid.

2. Heat exchanger (1) according to claim 1, wherein the first fluid passage section, in particular on the HP side, of the channels (46) is smaller than the second fluid passage section, in particular on the LP side, of the channels (48), and preferably, the channels (46) of the first passage section of the heat exchanger (1) and the channels (48) of the second passage section of the heat exchanger (1) are alternated when moving transversely to the corrugations (22), in the plane of the first type flat plates (10).

3. Heat exchanger (1) according to any one of the preceding claims, wherein the contact plates (13, 19, 23, 29) have widths which vary from one contact plate (13, 19, 23, 29) to the next, the width being measured, in the plane of the plate, perpendicular to the direction of the corrugations (22) of this plate.

4. Heat exchanger (1) according to claim 3, wherein the second type plate (20) has a plurality of contact plates (23, 29), including contact plates (23) of a first width and contact plates (29) of a second width, the second width being greater than the first width, and preferably, on each second type plate (20), the first width contact plates (23) and the second width contact plates (29) are arranged alternately.

5. Heat exchanger (1) according to claim 4, wherein the contact plates (23, 29) can each be on a vertex (200) of the corrugation (22) of the second type plate (20), and the contact plates (13, 19, 23, 29) are thus each formed at the junction between the corrugation (22) of the second type plate (20) and the adjacent flat plate, i.e. the first type plate (10).

6. Heat exchanger (1) according to any one of the preceding claims, wherein the corrugations (22) are stamped areas of the second type plate (20).

7. Heat exchanger (1) according to any one of the preceding claims, wherein the corrugations (22) are straight, and preferably, the corrugations (22) extend in a central area (12) of the heat exchanger (1), between the fluid inlet area (15, 25) and the fluid outlet area (17, 27).

8. Heat exchanger (1) according to any one of the preceding claims, wherein the corrugations (22) of the second type plate (20) are formed for half the height on one side of the second type plate (20), and for half the height on the opposite side of the second type plate (20).

9. Heat exchanger (1) according to any one of the preceding claims, wherein the channels (46) of first passage section and the channels (48) of second passage section have an identical height.

10. Heat exchanger (1) according to any one of the preceding claims, wherein the fluid inlet zone (15, 25) and / or the fluid outlet zone (17, 27) have fluid flow disturbance reliefs (70), and these disturbance reliefs (70) are distinct from the corrugations (22) which form the channels (46, 48).

Images