Heat exchanger

Abstract

Title: Heat Exchanger The invention relates to a heat exchanger (1), in particular of the internal heat exchanger type, also called IHX, comprising: a plurality of first-type plates (10) provided with corrugations (12), 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, the first-type plates (10) and the second-type plates (20) being assembled together by a plurality of contact plates (18, 28), the corrugations (12, 22) defining, between consecutive plates, channels (45, 47) allowing the passage of fluid, these channels (45, 47) being distributed between channels (45) to form a first fluid circuit and channels (47) to form a second fluid circuit, and the corrugations (12, 22) having heights (H1, H2) different when moving from one plate to the next. Figure for the abbreviation: Fig. 3

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 equipped with corrugations, - 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 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 divided into two sections: one to form a first fluid circuit for a first heat transfer fluid, and the other to form a second fluid circuit for a second heat transfer fluid. exhibit different heights when moving from one plate to the next.

[0008] 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.

[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 one aspect of the invention, the greatest height is, for example, at least twice the smallest height.

[0011] According to one aspect of the invention, in the stacking of plates, the plates with the corrugations of the smallest height are alternated with the plates with the corrugations of the greatest height.

[0012] Thus, once the contact plates have passed, the fluid enters a collection zone (namely the fluid inlet zone and / or the fluid outlet zone) which has different heights when passing from one plate to another.

[0013] Even if this difference in height of the corrugations (stamped areas) leaves an overall height of the channels substantially identical between the channels of the first section of fluid passage and the channels of the second section of fluid passage (therefore formed between the corrugations), this allows to have different heights in the collection areas of the two fluid circuits.

[0014] Thus, the height in the collection zones can be adapted to be of a larger volume for one fluid circuit (for example, on the low-pressure fluid circuit side) and of a smaller volume for the other fluid circuit (for example, on the high-pressure fluid circuit side). This results in an asymmetry between the two fluid circuits.

[0015] For example, in the case of an IHX type heat exchanger (which has a high-pressure (HP) circuit and a low-pressure (LP) circuit), the invention results in a reduction in fluid volume on the high-pressure (HP) side and an increase in volume on the low-pressure (LP) side due to the asymmetry between the two fluid circuits. On the high-pressure side, the refrigerant is in the liquid phase, resulting in a high fluid density and therefore a low fluid velocity. On the low-pressure side, the refrigerant is in the gaseous phase. To pass the same flow rate in the gaseous phase, a much higher velocity is required. This velocity creates a pressure drop. Thanks to the invention, this pressure drop is reduced on the low-pressure (LP) side (increased volume on the low-pressure side).

[0016] 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).

[0017] According to one aspect of the invention, the disturbance reliefs are distinct from the corrugations that form the channels.

[0018] According to one aspect of the invention, the disturbance reliefs, in particular made by stamped shapes, are rounded or oval in shape, for example in the shape of a cap.

[0019] According to one aspect of the invention, the contact plates may have an identical width so that the channels formed between the corrugations have an identical cross-section for all channels in both fluid circuits. In this case, the asymmetry between the two circuits is due to the difference in height in the collection zones, outside of the channels formed between the corrugations.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] According to one aspect of the invention, 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.

[0024] According to one aspect of the invention, the plates are made of aluminum.

[0025] 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.

[0026] 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.

[0027] 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:

[0028] [Fig.1] Fig.1 is a schematic, perspective representation of an IHX type heat exchanger;

[0029] [Fig.2] The [Fig.2] is a cross-sectional view of the heat exchanger of the [Fig.1];

[0030] [Fig.3] The [Fig.3] is a cross-sectional view of the plates of the heat exchanger of the [Fig.1];

[0031] [Fig.4] The [Fig.4] is a top view of a first type plate of the heat exchanger of the [Fig.1];

[0032] [Fig.5] The [Fig.5] illustrates the H1 / H3 and H2 / H4 correspondence of the heat exchanger of the [Fig.1].

[0033] 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.

[0034] Figures 1 and 2 show an internal heat exchanger 1 (IHX). This type of internal heat exchanger operates with a low-pressure side (LP side) and a high-pressure side (HP side). In this internal heat exchanger (IHX), the first and second heat transfer fluids are the same refrigerant (for example, propane for a heat pump) from the same fluid circuit, but at different pressures / states (liquid / gaseous). The heat exchanger 1 is generally a roughly rectangular block.

[0035] The heat exchanger 1 comprises fluid inlet zones 15 and outlet zones 17. Figure 2 shows that the outlet zones 17 form a collection zone 83 of the heat exchanger 1 for the high-pressure (HP) side of the refrigerant. For this same high-pressure (HP) side, the inlet zones 15 also form a collection zone 83.

[0036] On the low-pressure (LP) side, the heat exchanger 1 comprises fluid inlet zones 25 and outlet zones 27. Figure 2 shows that the outlet zones 27 form a collection zone 85 of the heat exchanger 1. On this same low-pressure (LP) side, the inlet zones 25 also form a collection zone 85.

[0037] The heat exchanger 1 comprises, on the one hand, a plurality of first-type plates 10 provided with corrugations 12 and, on the other hand, a plurality of second-type plates 20 provided with corrugations 22, said corrugations 12, 22 being parallel to each other. The first-type plates 10 and second-type plates 20 are parallel to each other and are arranged alternately to form a stack.

[0038] Fig. 3 shows that the corrugations 12 are stamped areas of the first type plate 10. The corrugations 22 are stamped areas of the second type plate 20.

[0039] On the first type plates 10, the corrugations 12 have a straight, elongated shape, are parallel, and are spaced from each other at a regular pitch. Similarly, on the second type plates 20, the corrugations 22 have a straight, elongated shape, are parallel, and are spaced from each other at a regular pitch.

[0040] As illustrated in [Fig.4], the corrugations 12 of the first type plate 10 extend into a central area 30 of the heat exchanger 1, between the inlet areas 15 and 25 and the outlet areas 17 and 27. Similarly, the corrugations 22 of the second type plate 20 extend into the central area 30 of the heat exchanger 1, between the inlet areas 15 and 25 and the outlet areas 17 and 27.

[0041] On the first type plate 10, the corrugations 12 have a length at least twice less than the length of a larger side 6 of the perimeter of the heat exchanger 1. The corrugations 12 are set back from the fluid inlet zones 15 and 25 and outlet zones 17 and 27 and are arranged parallel to the side 6 of the perimeter of the heat exchanger 1.

[0042] Similarly, on the second type plate 20 (not shown), the corrugations 22 have a length at least twice less than the length of a larger side 6 of the perimeter of the heat exchanger 1. 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 the side 6 of the perimeter of the heat exchanger 1.

[0043] The fluid inlet zone 15 or 25 and the fluid outlet zone 17 or 27 have fluid flow disturbance features 70 (called "Dimples"). The disturbance features 70 are distinct from the corrugations 12 that form the channels 45 and 47. Similarly, the disturbance features 70 are distinct from the corrugations 22 that form the channels 45 and 47.

[0044] The disturbance reliefs 70 are made by stamped shapes and are rounded or oval in shape, for example in the shape of a cap.

[0045] Figures 2 and 4 show that, for the high pressure side 52, the outlet areas 17 are connected to each other by openings 71 in the first type plates 10 and second type plates 20 which form a fluid outlet conduit 75.

[0046] For the low pressure side 54, the outlet areas 27 are connected to each other by openings 73 in the first type plates 10 and second type plates 20 which form a fluid outlet conduit 77.

[0047] 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.

[0048] For the low pressure side 52, the inlet areas 15 are connected to each other by openings 72 in the first type plates 10 and second type plates 20 which form a fluid inlet conduit 76.

[0049] 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.

[0050] As illustrated in [Fig.3], the first type plates 10 and second type plates 20, made of aluminum, are brazed together by a plurality of contact plates which are here brazing plates 18 and 28 at the junction between two consecutive first type plates 10 and second type plates 20 of the stack.

[0051] The first type plates 10 have a plurality of brazing plates 18. The second type plates 20 have a plurality of brazing plates 28.

[0052] Corrugations 12 and 22 define channels 45 and 47 between consecutive first-type plates 10 and second-type plates 20. The channels 45 allow fluid to pass 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 47 allow fluid to pass between the fluid inlet zone 25 and the fluid outlet zone 27.

[0053] The corrugations 12 of the first-type plate 10 and the corrugations 22 of the second-type plate 20 have different heights. The corrugations 12 have the same small height called H1, and the corrugations 22 have the same large height H2. The heights H1 and H2 are measured perpendicular to the plane P of the plates.

[0054] This difference in height H1 and H2 of the corrugations 12 and 22 at the level of the embossed areas leaves an overall height HC of the channels 45 and 47 that is substantially identical between the channels 45 and 47 formed between the corrugations 12 and 22. The height HC of the channels 45 and 47 is equal to the sum of the small height H1 of the corrugation 12 and the large height H2 of the corrugation 22.

[0055] Fig. 2 shows that once the brazing plates 18 and 28 have passed, the fluid enters the collection zones 83 and 85 which have different heights.

[0056] For the high-pressure side 52, the collection zones 83 relating to the inlet zones 15 and outlet zones 17 have a height H3. On the other hand, for the low-pressure side 54, the collection zones 85 relating to the inlet zones 25 and outlet zones 27 have a height H4. The height H4 is greater than the height H3. The heights H3 and H4 of the collection zones 83 and 85 are measured perpendicular to the plane P of the plates.

[0057] The height H4 of the collection zones 85 is adapted for a larger volume on the low-pressure side 54. The high-pressure side 52, corresponding to the height H3 for the collection zones 83, is, on the other hand, adapted for a smaller volume. This results in an asymmetry between the high-pressure side 52 and the low-pressure side 54.

[0058] The brazing plates 18 and 28 have an identical width so that the channels 45 and 47 formed between the corrugations 12 and 22 have an identical cross-section for all channels 45 and 47, high-pressure side 52 and low-pressure side 54. The asymmetry between the high-pressure side 52 and the low-pressure side 54 is due to the difference in height H3 and H4 in the collection zones 83 and 85 outside of channels 45 and 47 formed between the corrugations 12 and 22.

[0059] In particular, as illustrated in [Fig. 5], the height H3, H4 of each of the collection zones 83, 85 corresponds to the height H1, H2 of the corresponding corrugations. Thus, the corrugations 12 with a small height H1 correspond to the height H3 of the collection zones 83 relating to the inlet zones 15 and outlet zones 17, for the high-pressure side 52. The corrugations 22 with a large height H2 correspond to the height H4 of the collection zones 85 relating to the inlet zones 25 and outlet zones 27, for the low-pressure side 54.

Claims

Demands

1. A heat exchanger (1), in particular of the internal heat exchanger type, also called IHX, comprising: - a plurality of first-type plates (10) provided with corrugations (12), - 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 plate stack, the first-type plates (10) and the second-type plates (20) being joined together, in particular brazed together, by a plurality of contact plates (18, 28) at the junction between two consecutive plates of the stack, - the corrugations (12, 22) of the plates having a generally elongated shape and defining, between consecutive plates, channels (45, 47) allowing the passage of fluid between a fluid inlet zone (15, 25) and a fluid outlet zone (17, 27). fluid, these channels (45,47) being distributed between channels (45) to form a first fluid circuit for a first heat transfer fluid and channels (47) to form a second fluid circuit for a second heat transfer fluid, and the corrugations (12, 22) have different heights (H1, H2) when moving from one plate to the next.

2. Heat exchanger (1) according to claim 1, wherein the plates with corrugations (12, 22) of smaller height (H1) are alternated with the plates with corrugations (12, 22) of greater height (H2), and preferably, the greater height (H2) is for example at least twice the smaller height (H1).

3. Heat exchanger (1) according to any one of the preceding claims, comprising a collection zone (83, 85), preferably of the fluid inlet zone (15, 25) and / or the fluid outlet zone (17, 27), which has different heights (H3, H4) when passing from one plate to the other.

4. Heat exchanger (1) according to claims 2 and 3, wherein the difference in height (H1, H2) of the corrugations (12, 22) leaves an overall height (HC) of the channels (45, 47) substantially identical between the channels (45) of the first fluid passage section and the channels (47) of the second passage section allowing to have different heights (H3, H4) in the collection zones (83, 85) of the two fluid circuits.

5. 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 that form the channels (45, 47).

6. Heat exchanger (1) according to any one of the preceding claims, wherein the contact plates (18, 28) have an identical width so that the channels (45, 47) formed between the corrugations (12, 22) have an identical cross-section for all the channels (45, 47) of the two fluid circuits.

7. Heat exchanger (1) according to any one of the preceding claims, wherein the plates are made of aluminium.

8. Heat exchanger (1) according to any one of the preceding claims, defining an internal heat exchanger, also called IHX.

9. Heat exchanger (1) according to any one of claims 1 to 7, defining a water condenser in which two fluids circulate within it, preferably refrigerant and a coolant-type liquid, in particular comprising water, in particular glycol water.

10. Heat exchanger (1) according to any one of claims 1 to 7, defining a liquid evaporator of an air conditioning loop.

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