Heat exchanger for a motor vehicle

Abstract

The invention relates to a heat exchanger (50) for a motor vehicle comprising: - a first heat exchange section (1) configured to allow heat exchange between a refrigerant fluid and an air flow (F), comprising a first bundle of tubes (3) forming a set of flow-through passages for the refrigerant fluid, - a second heat exchange section (2) configured to allow heat exchange between a heat transfer liquid and the air flow (F), comprising a second bundle of tubes (4) forming a set of flow-through passages for the heat transfer liquid, wherein the tubes (3) in the first bundle have a U-shape with a first branch (5) and a second branch (7) connected by a base (6), wherein the first branch (5) is arranged upstream of the second branch (7) in a flow direction of the air flow (F), and wherein the second bundle of tubes (4) is arranged between the first branch (5) and the second branch (7) of the tubes (3).

Description

Technical Field

[0001] This invention relates to the field of heat exchangers, and particularly to heat exchangers for motor vehicles. Such exchangers can be installed in a thermal control system mounted on a motor vehicle. In the case of electric vehicles, this thermal control system allows for ensuring thermal regulation of various parts of the vehicle, such as the interior or an energy storage battery. Heat exchange is primarily managed through the compression and expansion of the refrigerant flowing in a circuit in which multiple heat exchangers are arranged. A compressor enables the refrigerant to be pressurized and circulated in the circuit. Background Technology

[0002] A refrigerant circuit typically includes a first heat exchanger that ensures the condensation of the high-pressure refrigerant discharged from the compressor, or, in the case of a supercritical fluid, its cooling. The refrigerant flows through this first heat exchanger, releasing heat to the airflow passing through it.

[0003] Furthermore, it is also common to cool vehicle drivetrain components by circulating a heat transfer fluid. For this purpose, the heat transfer fluid receives heat from the drivetrain components and dissipates heat, for example, from the airflow, in a second heat exchanger.

[0004] Integrating these two heat exchangers in a vehicle can be tricky, especially due to their volume when they are offset from each other to receive the same airflow simultaneously. To limit volume, the two exchangers can also be aligned in the airflow direction so that they are continuously passed through by the same airflow. However, when air passes through the upstream exchanger, the heating of the air tends to impair the efficiency of the downstream exchanger.

[0005] The present invention aims to provide a solution that is easier to integrate due to its greater compactness and offers improved thermodynamic performance. Summary of the Invention

[0006] Therefore, the present invention proposes a heat exchanger for motor vehicles, comprising:

[0007] - The first heat exchange section is configured to allow heat exchange between the refrigerant and the airflow.

[0008] The first heat exchange section includes a first bundle of tubes forming a set of refrigerant flow channels configured in the airflow.

[0009] - The second heat exchange section is configured to allow heat exchange between the heat transfer liquid and the airflow.

[0010] The second heat exchange section includes a second bundle of tubes forming a set of heat transfer liquid flow channels arranged in the airflow.

[0011] The tube in the first bundle is U-shaped and includes a first branch and a second branch connected by a base.

[0012] The first branch is located upstream of the second branch in the direction of airflow, and

[0013] The second bundle tube is arranged between the first branch and the second branch of the first bundle tube in the direction of airflow.

[0014] The U-shape of the tubes in the first bundle allows for an increase in the length of heat exchanged in the first heat exchange section, while limiting the front surface area of ​​the heat exchanger. Since the second heat exchange section is arranged within the free volume formed by the spacing between the branches of each U-shaped tube in the first bundle, the presence of the second heat exchange section does not change the external volume of the heat exchanger. Therefore, the heat exchanger has a very compact shape.

[0015] Furthermore, for airflow, the first branch of the pipe is upstream of the second heat exchange section, and the second heat exchange section itself is upstream of the second branch of the pipe in the first heat exchange section. Therefore, each pipe or part of a pipe receives an airflow with a temperature adapted to the temperature of the fluid flowing inside. In other words, the first branch of the first heat exchange section receives fresh ambient airflow that is not heated by passing through the heat exchanger, which improves its efficiency. The airflow leaving the first branch of the first heat exchange section has a sufficiently low temperature to ensure good exchange efficiency with the second heat exchange section. Similarly, the airflow heated by passing through the second heat exchange section still has a sufficiently low temperature to ensure good exchange efficiency with the refrigerant flowing in the second branch of the first heat exchange section. Therefore, for a given volume, the efficiency of the heat exchanger is optimized. Furthermore, due to the proposed arrangement, any limitations regarding the maximum temperature of the heat transfer liquid at the outlet of the second heat exchange section can be met.

[0016] The functions listed in the following paragraphs can be implemented independently of each other, or in any technically possible combination:

[0017] According to one aspect of the proposed heat exchanger, the second bundle of tubes is located downstream of the first branch of the first bundle of tubes and upstream of the second branch of the first bundle of tubes.

[0018] According to one operating mode of the heat exchanger, the first heat exchange section operates as a condenser for the refrigerant.

[0019] According to one operating mode of the heat exchanger, the refrigerant flowing in the first heat exchange section releases heat into the airflow.

[0020] According to this operating mode, the refrigerant flows from the second branch of the pipe to the first branch of the pipe.

[0021] According to another operating mode of the heat exchanger, the first heat exchange section operates as an evaporator for the refrigerant.

[0022] According to one operating mode, the refrigerant flowing in the first heat exchange section receives heat from the airflow.

[0023] According to this operating mode, the refrigerant flows from the first branch of the pipe to the second branch of the pipe.

[0024] According to an example implementation of the heat exchanger, the airflow is the airflow outside the vehicle.

[0025] According to another example implementation of the heat exchanger, the airflow is the airflow inside the car.

[0026] In one application of heat exchangers, the refrigerant can be a chemical fluid, such as R1234yf or R134a.

[0027] In another application of heat exchangers, the refrigerant can be R744 or R290.

[0028] The heat transfer fluid can be a mixture of water and ethylene glycol.

[0029] According to one aspect of the heat exchanger, each tube in the first bundle of tubes extends in a plane.

[0030] The tubes in the first bundle are arranged in a parallel plane.

[0031] The tubes in the first bundle are aligned in a direction perpendicular to the tube plane.

[0032] According to one embodiment of the heat exchanger, the second bundle of tubes extends between two parallel planes perpendicular to the tube plane of the first bundle.

[0033] The heat exchanger thus has a compact shape, with the second heat exchange section filling the free space between all the first branches of the tubes of the first heat exchange section and all the second branches of the tubes.

[0034] The first branch of the tube in the first bundle is connected to the first branch of the adjacent tube via the first set of fins.

[0035] The second branch of the tube in the first bundle is connected to the second branch of the adjacent tube via a second set of fins.

[0036] The fins improve the heat transfer between the airflow and the refrigerant flowing in the tubes of the first heat exchange section.

[0037] The fins have slots for airflow.

[0038] According to one aspect of the heat exchanger, the base of the tubes in the first bundle of tubes is spaced apart from the base of the adjacent tubes.

[0039] When the first heat exchange section operates as an evaporator and the external temperature is below or near 0°C, ice will form on at least a portion of the tubes in the tube bundle. As the ice melts, water flows down the tubes to the base. The gap between two adjacent tubes allows water flow and prevents water from accumulating at the base of the tubes. This reduces the risk of frost re-forming on the first heat exchange section.

[0040] The outer periphery of the tubes in the first bundle has an elongated oval cross-section.

[0041] The tubes in the first bundle of tubes are, for example, microchannel tubes.

[0042] According to one embodiment of the heat exchanger, the outer periphery of the tubes in the first bundle of tubes has an oblong cross-section defining a major axis and a minor axis, and the major axis of the first branch of the tubes is parallel to the airflow.

[0043] According to one embodiment, the major axis of the second branch of the tube is parallel to the airflow.

[0044] The tubes in the first bundle can be twisted near the junction between the first branch and the base.

[0045] Similarly, the tubes in the first bundle can be twisted near the junction between the base and the second branch.

[0046] In this embodiment, the long axis of the base of the tube is perpendicular to the airflow.

[0047] According to an example embodiment of the heat exchanger, when the heat exchanger is in its nominal position installed in a vehicle, the base of the tubes in the first bundle of tubes defines the lower side of the heat exchanger.

[0048] According to this example embodiment of the heat exchanger, when the heat exchanger is in its nominal position installed in a vehicle, the first branch of the tubes in the first bundle of tubes extends along the vertical axis.

[0049] This configuration facilitates the drainage of water generated by defrosting the heat exchangers as ice deposits accumulate on the surfaces of the first and / or second heat exchange sections melt. Specifically, liquid water can flow along the pipes without encountering any obstacles that could cause it to be retained.

[0050] According to another example implementation, when the heat exchanger is in its nominal position installed in a vehicle, the base of the first bundle of tubes defines the lateral side of the heat exchanger.

[0051] According to this example embodiment of the heat exchanger, when the heat exchanger is in its nominal position installed in a vehicle, the first branch of the tubes in the first bundle of tubes extends along a horizontal axis.

[0052] This configuration prevents any corrosion of the lowest part of the heat exchanger due to moisture buildup. Furthermore, when the heat exchanger has a low height and a large width, this configuration allows for a limitation on the required number of tubes. When the exchanger is nominally installed in a vehicle, the height is understood as the dimension along the vertical axis, while the width is understood as the dimension along the vehicle's transverse axis. This facilitates the manufacture of exchangers for applications where vehicles have a low front end.

[0053] The first end of a tube in the first bundle of tubes leads to a first distributor, which is configured to distribute refrigerant among all tubes in the first bundle of tubes.

[0054] The first distributor extends transversely to the axis of the tubes in the first bundle.

[0055] The first distributor has a cylindrical shape.

[0056] The first distributor includes a refrigerant inlet.

[0057] The second end of the tube in the first bundle of tubes leads to the first manifold, which is configured to collect refrigerant from all the tubes in the first bundle of tubes.

[0058] The first manifold extends transversely to the axis of the tubes in the first bundle of tubes.

[0059] The first manifold has a cylindrical shape.

[0060] The first manifold includes the refrigerant outlet.

[0061] The first manifold and the first distributor extend in a parallel direction.

[0062] The tubes in the first bundle are identical.

[0063] According to one embodiment, the refrigerant inlet and the refrigerant outlet are opposite each other in a direction perpendicular to the axis of the first distributor.

[0064] According to an example embodiment of the heat exchanger, when the heat exchanger is in its nominal position installed in a vehicle, the first distributor is located downstream of the first manifold in the direction of airflow.

[0065] In another example implementation of the heat exchanger, when the heat exchanger is in its nominal position installed in a vehicle, the first manifold is located downstream of the first distributor in the direction of airflow.

[0066] According to one embodiment of the heat exchanger, a first branch and a second branch of the tubes in the first bundle of tubes have the same length. The lengths of the first and second branches of the tubes in the first bundle of tubes are, for example, between 300 mm and 600 mm.

[0067] According to another embodiment of the heat exchanger, the length of the first branch of the tubes in the first bundle is less than the length of the second branch of the tubes in the first bundle.

[0068] This reduces the amount of material used to manufacture the first bundle of tubes. Furthermore, portions of the tubes in the second bundle directly receive the airflow F, while none of the tubes in the first bundle are located upstream. This reduces the production cost of the exchanger without compromising its efficiency.

[0069] In this case, the length of the first branch of the tube in the first bundle is, for example, between 100 mm and 300 mm.

[0070] The length of the second branch of the tube in the first bundle is, for example, between 300 mm and 600 mm.

[0071] According to one embodiment, the tubes in the second bundle extend transversely to the tubes in the first bundle.

[0072] The tubes in the second bundle are parallel to each other.

[0073] The tubes in the second bundle are identical.

[0074] The second heat exchange section has a roughly parallelepiped shape.

[0075] The first end of the tube in the second bundle leads to the second distributor, which is configured to distribute the heat transfer fluid among all the tubes in the second bundle.

[0076] The second distributor extends transversely to the axis of the tube in the second bundle.

[0077] The second distributor includes a heat transfer liquid inlet.

[0078] The second end of the tube in the second bundle leads to the second manifold, which is configured to collect the heat transfer fluid from all the tubes in the second bundle.

[0079] The second manifold extends transversely to the axis of the tubes in the second bundle.

[0080] The second manifold includes a heat transfer liquid outlet.

[0081] The tubes in the second bundle have an elongated oval cross-section around their periphery.

[0082] According to one embodiment, the heat exchanger includes a support between the base of at least a portion of the tubes arranged in a second bundle of tubes and at least a portion of the tubes in a first bundle of tubes.

[0083] The heat exchanger may include a support for the base of the tubes that connect the second heat exchange section to the first bundle of tubes.

[0084] The support member provides mechanical support to the base of the tube in the first heat exchange section relative to the second heat exchange section, which helps to reduce the propagation of vehicle vibrations in the tube in the first heat exchange section.

[0085] According to an example embodiment of the heat exchanger, the thermal conductivity of the support is lower than that of the first bundle of tubes, preferably lower than 10% of the thermal conductivity of the first bundle of tubes.

[0086] Therefore, the support insulates the base of the tube in the first heat exchange section from the second heat exchange section, preventing the formation of thermal bridges.

[0087] The support is made of plastic, for example, glass fiber reinforced polyamide (e.g., PA6 reinforced with 30% glass fiber) or glass fiber reinforced polypropylene (e.g., PP reinforced with 30% glass fiber).

[0088] The support can rigidly fix the second heat exchange section to the base of the tube in the first bundle of tubes.

[0089] According to an example embodiment, the second heat exchange section includes a surface arranged opposite to the base of the tubes in the first bundle of tubes, and a support connects the base of the tubes in the first bundle of tubes to the oppositely arranged surface.

[0090] According to one embodiment of the heat exchanger, the support includes a sealing wall that connects the second heat exchange section to the base of the tubes in the first bundle of tubes, thereby preventing airflow between the second heat exchange section and the base of the tubes in the first bundle of tubes.

[0091] The sealing wall prevents airflow from passing through the space between the base of the first bundle of tubes and the opposing surfaces of the second heat exchange section. Therefore, the sealing wall prevents a portion of the airflow F from leaving the exchanger without exchanging heat with the second heat exchange section.

[0092] The support member can have a trapezoidal cross section.

[0093] The smaller base of the trapezoid is opposite to the second heat exchange section. The larger base is opposite to the base of the tube in the first bundle.

[0094] Therefore, the support directs the airflow flowing near the base of the tubes in the first bundle of tubes to the second heat exchange section. Furthermore, water generated during the defrosting stage can also be directed to the bottom of the exchanger, facilitating its drainage.

[0095] According to an example embodiment, the support is rigidly fixed to the base of each tube in the first bundle of tubes.

[0096] The supports provide mechanical support to the tubes relative to each other, which limits the amplitude of vibration. This improves the mechanical strength of the heat exchanger.

[0097] Support members, for example, are overmolded onto the base of the tubes in the first bundle of tubes.

[0098] Alternatively, the surface of the second heat exchange section can be rigidly fixed to the base of the tube of the first heat exchange section, particularly by brazing.

[0099] According to an alternative embodiment, the tubes in the second bundle extend parallel to the first branch of the tubes in the first bundle.

[0100] This arrangement allows the second manifold or second distributor to be positioned opposite the base of the tubes in the first bundle. Therefore, the base of the refrigerant tubes can be attached to the second manifold or second distributor. This eliminates the need for supports that could rigidly fix the second heat exchange section to the base of the tubes in the first bundle.

[0101] Furthermore, one of the manifolds of the distributor and the second bundle can be aligned with the refrigerant manifold / distributor located upstream. Therefore, the airflow through the heat exchanger is less disturbed, which improves the efficiency for a given volume. Attached Figure Description

[0102] Further features, details, and advantages will become apparent from the following detailed description and study of the accompanying drawings, in which:

[0103] Figure 1 This is a schematic side sectional view of a heat exchanger according to a first embodiment of the present invention.

[0104] Figure 2 yes Figure 1 A schematic end view of a heat exchanger.

[0105] Figure 3 This is a schematic side sectional view of a heat exchanger according to a second embodiment of the present invention.

[0106] Figure 4 This is a schematic detailed side sectional view of a variation of the heat exchanger according to the present invention.

[0107] Figure 5 This is a schematic partial perspective view of a heat exchanger according to the present invention.

[0108] Figure 6 This is a schematic partial top view of three variations of the heat exchanger according to the present invention.

[0109] Figure 7 This is a schematic partial view of the tubes in the first bundle of tubes of a heat exchanger according to the present invention. Detailed Implementation

[0110] To make the accompanying drawings easier to read, various elements are not necessarily shown to scale. In these drawings, the same elements have the same reference numerals. Some elements or parameters may be indexed, that is, designated as, for example, first element or second element, or actually first parameter and second parameter, etc. The purpose of this indexing is to distinguish similar but not identical elements or parameters. This indexing does not imply that one element or parameter takes precedence over another, and the names are interchangeable.

[0111] In the following description, the expression "first element upstream of second element" means that the first element is located before the second element relative to the direction of fluid flow or travel. Similarly, the expression "first element downstream of second element" means that the first element is located after the second element relative to the direction of fluid flow or travel.

[0112] The statement "the second element is placed between the first element and the third element" means that the shortest path from the first element to the third element passes through the second element.

[0113] When a given subsystem has a given element, this does not preclude the existence of other elements in that subsystem.

[0114] The term "exchanger" is equivalent to the term "heat exchanger".

[0115] The heat exchanger 50 described below can be integrated into a thermal control system. The thermal control system includes a refrigerant circuit and a heat transfer fluid circuit. The refrigerant circuit forms a closed loop in which refrigerant can flow. When the refrigerant circuit is in its nominal operating condition, i.e., without defects or leaks, the refrigerant circuit is fluid-tight. Similarly, the heat transfer fluid circuit forms a closed and leak-proof circuit in which the heat transfer fluid can flow.

[0116] The thermal regulation system includes a compressor that places the refrigerant under high pressure and high temperature. The high-pressure, high-temperature refrigerant can be sent to the first heat exchange section 1 of a heat exchanger 50, where the refrigerant releases heat to the airflow F. The heat exchanger 50 is, for example, located at the front of the vehicle and receives the airflow F from outside the vehicle interior, particularly generated by the vehicle's forward movement. The cooled refrigerant can then pass through an expansion valve and become a low-pressure refrigerant, which then evaporates in a second heat exchanger. The second heat exchanger is, for example, located in the vehicle's HVAC (heating, ventilation, and air conditioning) system. Therefore, the second heat exchanger allows for the cooling of the vehicle interior. Alternatively, the second heat exchanger can be a cooling exchanger thermally coupled to an electrical energy storage battery. Therefore, the second exchanger allows the battery to be cooled, especially during fast charging.

[0117] Depending on other operating modes of the thermal control system, the heat exchanger 50 can receive low-pressure refrigerant and perform refrigerant evaporation. The heating or dehumidification stages of the air inside the vehicle correspond to these operating modes.

[0118] The heat transfer fluid circuit of the thermal regulation system allows for the cooling of components of the vehicle's electric drive system. These components may include an energy storage battery, an electronic module for controlling the vehicle's electric drive motor, or the motor itself. The heat transfer fluid thus receives heat from the drive system components, and this heat dissipates in the second heat exchange section 2 of the heat exchanger 50.

[0119] Figure 1 A heat exchanger 50 according to a first embodiment is shown. The heat exchanger 50 is, for example, a heat exchanger for a motor vehicle. In the various figures, the X-axis corresponds to the longitudinal axis of the vehicle, the Y-axis corresponds to the transverse axis, and the Z-axis corresponds to the vertical axis.

[0120] Heat exchanger 50 for motor vehicles includes:

[0121] - First heat exchange section 1, configured to allow heat exchange between the refrigerant and the airflow F.

[0122] The first heat exchange section 1 includes a first bundle of 11 tubes 3 forming a set of refrigerant flow channels arranged in the airflow F.

[0123] - The second heat exchange section 2 is configured to allow heat exchange between the heat transfer liquid and the air flow F.

[0124] The second heat exchange section includes a second bundle of 12 tubes 4 forming a set of heat transfer liquid flow channels arranged in the airflow F.

[0125] The tube 3 in the first bundle of 11 tubes has a U-shape and includes a first branch 5 and a second branch 7 connected by a base 6.

[0126] The first branch 5 is positioned upstream of the second branch 7 in the direction of airflow F, and

[0127] The second bundle of 12 tubes is arranged in the direction of airflow F between the first branch 5 and the second branch 7 of tube 3 in the first bundle of 11 tubes.

[0128] The U-shape of tube 3 in the first bundle of 11 tubes 3 allows for an increase in the length of heat exchanged in the first heat exchange section, while limiting the front surface area of ​​the heat exchanger 50. Furthermore, a portion of the tube forming the first branch 5 directly receives ambient air that has not been heated by another heat exchanger, which increases the efficiency of heat exchange. The second heat exchange section 2 is arranged in the free volume formed by the spacing between the branches 5, 7 of each U-shaped tube 3 in the first bundle of 11 tubes. The presence of the second heat exchange section 2 does not change the external volume of the heat exchanger 50. The heat exchanger 50 thus has a very compact and thermally optimized shape.

[0129] Furthermore, the first branch 5 of pipe 3 is positioned upstream of the second heat exchange section 2 relative to the airflow F, and the second heat exchange section 2 itself is positioned upstream of the second branch 7 of pipe 3 in the first heat exchange section 1. Therefore, each pipe or portion of a pipe receives an airflow with a temperature adapted to the temperature of the fluid flowing within it. In other words, the first branch 5 of the first heat exchange section 1 receives fresh ambient airflow that is not heated by passing through the heat exchanger, which increases its heat exchange efficiency. The airflow exiting the first branch 5 of the first heat exchange section 1 has a sufficiently low temperature to ensure good exchange efficiency with the fluid flowing in the second heat exchange section 2. Similarly, the airflow heated by passing through the second heat exchange section 2 still has a sufficiently low temperature to ensure good exchange efficiency with the refrigerant flowing in the second branch 7 of the first heat exchange section 1. Therefore, for a given volume, the efficiency of the heat exchanger 50 is optimized.

[0130] The fact that the tubes of the first bundle 11 are U-shaped is understood to mean that the tubes include a first straight portion called the first branch 5, which is fluidly connected to a second straight portion called the second branch 7 via an intermediate portion called the base 6. The first branch 5 and the second branch 7 extend parallel to each other and opposite to each other. The intermediate portion 6 extends transversely to the first branch 5 and the second branch 7. In this case, the intermediate portion is straight. The first branch 5, the second branch 7, and the intermediate portion 6 are arranged in the same plane.

[0131] According to a variant not shown, the middle portion may have a curved shape.

[0132] The second bundle 12 is located downstream of the first branch of the tube 3 of the first bundle 11 and upstream of the second branch 7 of the tube 3 of the first bundle 11.

[0133] According to one operating mode of the heat exchanger 50, the first heat exchange section 1 operates as a condenser for the refrigerant.

[0134] According to this operating mode of the heat exchanger 50, the refrigerant flowing in the first heat exchange section 1 releases heat to the airflow F. This is also true when the refrigerant used is in a supercritical state. In this case, the heat exchanger 50 operates as a cooler for the refrigerant, without any condensation. This operation occurs, for example, when the refrigerant used is R744.

[0135] According to this operating mode as a condenser and / or cooler, the refrigerant flows from the second branch 7 of pipe 3 to the first branch 5 of pipe 3. In other words, the hottest refrigerant reaches the first heat exchange section 1 through the downstream section of the pipe relative to the airflow F.

[0136] According to another operating mode of heat exchanger 50, the first heat exchange section 1 operates as an evaporator for refrigerant.

[0137] In this operating mode, the refrigerant flowing in the first heat exchange section 1 receives heat from the airflow F. This operating mode corresponds, for example, to a heat pump mode.

[0138] According to this operating mode, the refrigerant flows from the first branch 5 of pipe 3 to the second branch 7 of pipe 3. In other words, the refrigerant reaches the first heat exchange section 1 through the upstream pipe portion relative to the airflow F. Preferably, the direction of refrigerant flow is reversed depending on whether the heat exchanger 50 operates as a condenser or an evaporator. This reversal of the flow direction is optional depending on the operating mode using the heat exchanger.

[0139] According to an example embodiment of the heat exchanger 50, the airflow F is the airflow outside the vehicle. In this case, the exchanger 50 is arranged, for example, at the front of the vehicle, behind the radiator grille.

[0140] According to another example embodiment of the heat exchanger 50, the airflow F is the airflow inside the vehicle. The heat exchanger 50 is then arranged in the vehicle's heating, ventilation, and / or air conditioning system.

[0141] In one application of heat exchanger 50, the refrigerant can be a chemical fluid, such as R1234yf or R134a. In another application of the heat exchanger, the refrigerant can be R744 or R290.

[0142] The refrigerant flows in parallel through tube 3 in the first bundle of 11 tubes.

[0143] Similarly, the heat transfer fluid flows in parallel through tube 4 in the second bundle of 12 tubes. The heat transfer fluid can be a mixture of water and ethylene glycol.

[0144] Figure 5The first heat exchange section 1 and the second heat exchange section 2 are shown separately. In other words, the second heat exchange section 2 and the first heat exchange section 1 have been moved along the transverse axis Y for easier differentiation. As schematically shown in the figure, each tube 3 in the first bundle 11 extends in plane P1.

[0145] Tube 3 in the first bundle of 11 tubes is arranged in a parallel plane. Figure 5 The image depicts nine tubes 3. More generally, the first bundle 11 may include any number of tubes 3.

[0146] Tube 3 in the first bundle of 11 tubes is aligned along direction D, which is perpendicular to the tube plane.

[0147] The tube 3 of the first bundle 11 can be made of aluminum or copper, for example. Similarly, the tube 4 of the second bundle 12 can be made of aluminum or copper, for example.

[0148] According to the example shown, the second bundle 12 tubes 4 extends between two parallel planes P2 and P2', which are perpendicular to the plane of the first bundle 1 tubes 3. Plane P2 is in Figure 6 As shown in the figure, Figure 6 This is a schematic top view of heat exchanger 50.

[0149] The heat exchanger 50 thus has a compact shape, with the second heat exchange section 2 filling the free space between all the first branches 5 and all the second branches 7 of the tube 3 of the first heat exchange section 1.

[0150] Especially Figure 2 As shown, the first branch 5 of tube 3 in the first bundle of 11 tubes is connected to the first branch of the adjacent tube via a first set of fins 23. In other words, two adjacent tubes in the first bundle of 11 tubes are connected by a set of fins 23.

[0151] Similarly, the second branch 7 of tube 3 in the first bundle 11 tubes is connected to the second branch of the adjacent tube via the second set of fins 24.

[0152] Fins 23 and 24 improve heat transfer between the airflow F and the refrigerant flowing in the tube 3 of the first heat exchange section 1.

[0153] Fins 23 and 24 have slots 25 for airflow F to pass through. Slots 25 improve heat transfer between airflow F and fins 23 and 24.

[0154] Similarly, tube 4 in the second bundle of 12 tubes is connected to the adjacent tube by a set of fins 32. These fins improve heat transfer between the airflow F and the heat transfer fluid flowing in the second heat exchange section 2. Figure 2 In the image, only a portion of the first bundle 11 tubes is shown to make a portion of the second heat exchange section 2 visible.

[0155] The base 6 of tube 3 in the first bundle of 11 tubes is spaced apart from the base of the adjacent tube 3. In other words, the bases of tube 3 in the first bundle of 11 tubes are spaced apart from each other. The free space between the bases 6 of two adjacent tubes can be constant.

[0156] When the first heat exchange section 1 operates as an evaporator and the external temperature is below or close to 0°C, ice will form on at least a portion of the tubes in the bundle 11. As the ice melts, water flows along the tubes 3 to the base 6 of the tubes. The gap between two adjacent tubes 3 allows water flow and prevents water from accumulating at the base 6 of the tubes. This reduces the risk of frost re-forming on the first heat exchange section 1.

[0157] The outer periphery of tube 3 in the first bundle of 11 tubes has an elongated oval cross-section. Tube 3 in the first bundle of 11 tubes is, for example, a microchannel tube. In other words, each tube 3 comprises multiple parallel channels. The microchannel tube is formed by extrusion and then shaped to obtain the desired U-shape. The outer periphery of tube 3 in the first bundle of 11 tubes has an elongated oval cross-section, defining a major axis a and a minor axis b. The major axis a of the first branch 5 of the tube is parallel to the airflow F. The major axis 7 of the second branch 7 of the tube 3 is also parallel to the airflow F. Figure 7 This is a schematic detailed view of the external shape of tube 3. Microchannels are not shown in this figure.

[0158] Tube 3 in the first bundle of 11 tubes can be twisted near the junction 35 between the first branch 5 and the base 6. Similarly, tube 3 in the first bundle of 11 tubes can be twisted near the junction 36 between the base 6 and the second branch 7. In other words, in the region of the junction 35 between the first branch 5 and the base 6, the major axis a of the cross-section of tube 3 gradually rotates 90° about the extension axis D5 of the first branch 5 of tube 3. This deformation of the tube allows for the creation of a U-shape without excessive deformation of the tube material.

[0159] In this embodiment, the major axis a of the base 6 of the tube 3 is perpendicular to the airflow F.

[0160] According to an example embodiment of the heat exchanger 50, when the heat exchanger 50 is in its nominal position installed in a vehicle, the base 6 of the tube 3 in the first bundle 11 tubes defines the lower side of the heat exchanger 50. In other words, the base 6 extends in a plane parallel to the planes X and Y. The various figures illustrate the exchanger 50 oriented in this manner.

[0161] When the heat exchanger 50 is in its nominal position installed in the vehicle, the first branch 5 of the tube 3 in the first bundle 11 extends along the vertical axis Z.

[0162] This configuration facilitates the drainage of water generated during heat exchanger defrosting as ice deposits on the surfaces of the first heat exchange section melt. Specifically, liquid water can flow along the pipes without encountering any obstacles that could cause it to be retained.

[0163] According to another example embodiment (not shown), when the heat exchanger 50 is in its nominal installation position in the vehicle, the first branch 5 of the tube 3 in the first bundle 11 extends along a horizontal axis. This horizontal axis is, for example, the vehicle's transverse axis Y.

[0164] When the heat exchanger 50 is in its nominal position installed in the vehicle, the base 6 of the tubes 3 of the first bundle 11 defines the lateral side of the heat exchanger 50. In other words, the base 6 then extends in a plane parallel to the Y and Z planes. This configuration is particularly suitable for applications where the vehicle has a low and wide front end.

[0165] like Figure 5 As shown, the first end 15 of tube 3 in the first bundle of 11 tubes leads to a first distributor 9, which is configured to distribute refrigerant among all tubes 3 in the first bundle of 11 tubes. The first distributor 9 extends transversely to the axis of tube 3 in the first bundle of 11 tubes.

[0166] The first distributor 9 has, for example, a cylindrical shape. The first distributor 9 includes a refrigerant inlet 13.

[0167] The second end 16 of tube 3 in the first bundle 11 leads to the first manifold 10, which is configured to collect refrigerant from all tubes 3 in the first bundle 11. The first manifold 10 extends transversely to the axis of tube 3 in the first bundle 11.

[0168] The first manifold 10 has, for example, a cylindrical shape. The first manifold 10 includes a refrigerant outlet 14.

[0169] The first manifold 10 and the first distributor 9 extend in a parallel direction.

[0170] Pipe 3 is sealed at its first end 15 to the first distributor 9. Similarly, pipe 3 is sealed at its second end 16 to the first manifold 10. Pipe 3 is, for example, brazed to the first distributor 9 and the first manifold 10.

[0171] In the example shown, especially Figure 5 In the first bundle of 11 tubes, tube 3 is the same.

[0172] The refrigerant inlet 13 and the refrigerant outlet 14 can be arranged relative to each other in different ways. Figure 6 Several possible configurations are illustrated schematically.

[0173] According to the example shown, the refrigerant inlet 13 and the refrigerant outlet 14 are opposite each other in a direction perpendicular to the axis of the first distributor 9. In other words, the refrigerant inlet 13 and the outlet 14 are arranged on the same side edge of the exchanger 50.

[0174] According to a variant not shown, the refrigerant inlet 13 and the refrigerant outlet 14 may be arranged on opposite side edges along the axis of the first distributor 9.

[0175] The refrigerant inlet 13 and refrigerant outlet 14 can also be arranged near the middle of the first distributor 9 and the first manifold 10 relative to their main extension direction. This arrangement reduces refrigerant pressure loss and improves refrigerant distribution. Specifically, the distance between the refrigerant inlet and the farthest pipe is thus reduced. The same applies to the distance between the refrigerant outlet and the farthest outlet.

[0176] Note that the refrigerant inlet 13 and outlet 14 are not inherently defined by the heat exchanger 50, but can be changed according to the refrigerant flow pattern within the heat conditioning system in which the heat exchanger is integrated. In other words, the portion corresponding to the refrigerant inlet 13 in one operating mode may become the refrigerant outlet 14 in another operating mode. Specifically, once the heat exchanger 50 has been integrated into the heat conditioning system, the refrigerant flow direction is controlled by a set of valves that can be selectively opened or closed. By controlling the various valves, the refrigerant flow direction in the first heat exchange section 1 can be reversed. Therefore, the refrigerant flow direction can be changed according to the desired operating mode, such as in condenser or evaporator mode.

[0177] according to Figure 6 In the example embodiment of the heat exchanger 50 shown in Part A, when the heat exchanger 50 is in its nominal position installed in the vehicle, the first distributor 9 is located downstream of the first manifold 10 in the direction of airflow F. This configuration is preferred when the heat exchanger 50 operates as a condenser or gas cooler. In other words, in this operating mode, the refrigerant inlet is located on one side of the first branch 5 of the pipe 3, upstream in the direction of airflow.

[0178] exist Figure 6 In another example embodiment of the heat exchanger 50 schematically shown in Part B, when the heat exchanger 50 is in its nominal position installed in the vehicle, the first manifold 10 is located downstream of the first distributor 9 in the direction of airflow F. This configuration is preferred when the heat exchanger 50 operates as an evaporator, particularly for heat pump mode. In other words, in this operating mode, the refrigerant inlet is located on one side of the second branch 7 of pipe 3, downstream in the direction of airflow.

[0179] In specific terms, such as Figure 1 and Figure 2In the first embodiment shown, the first branch 5 and the second branch 7 of the tubes 3 in the first bundle 11 have substantially the same length. This length is, for example, between 300 mm and 600 mm. The tubes 4 of the second bundle 12 extend along the axis Z and along the entire length of the first branch 5 and the second branch 7. In other words, the entire second bundle 12 is arranged between the first branch 5 and the second branch 7 of the tubes 3 in the first bundle 11 in the direction of airflow F.

[0180] Figure 3 A second embodiment of the heat exchanger 50 is shown. In this embodiment, the length L1 of the first branch 5 of the tube 3 in the first bundle 11 is less than the length L2 of the second branch 7 of the tube 3 in the first bundle 11. In other words, only a portion of the tube 4 of the second heat exchange section 2 is opposite to the first branch 5 of the tube 3 of the first heat exchange section 1.

[0181] The amount of material used to manufacture the first bundle of tubes 11 is thus reduced. Furthermore, a portion of tube 4 in the second bundle of tubes 12 directly receives the airflow F, while none of the tubes in the first bundle of tubes 11 are located upstream. Therefore, this portion of tube 4 is particularly efficient in terms of heat exchange. The production cost of the exchanger 50 can be reduced without compromising its efficiency.

[0182] In this case, the length L1 of the first branch 5 of tube 3 in the first bundle 11 tubes 3 is, for example, between 100 mm and 300 mm. The length L2 of the second branch 7 of tube 3 in the first bundle 11 tubes 3 is, for example, between 300 mm and 600 mm.

[0183] According to the embodiment shown in the figure, tube 4 in the second bundle 12 extends transversely to tube 3 in the first bundle 11. The tubes 4 in the second bundle 12 are parallel to each other. The tubes 4 in the second bundle 12 are, for example, identical. Figure 5 As schematically shown, tube 4 in the second bundle of 12 tubes extends along the transverse axis Y.

[0184] The second heat exchange section 2 has a roughly parallelepiped shape.

[0185] In the longitudinal direction X, there is a gap between the first branch 5 of tube 3 in the first bundle 11 and tube 4 in the second bundle 12. Similarly, in the same longitudinal direction X, there is a gap between tube 4 of the second bundle 12 and the second branch 7 of tube 3 in the first bundle 11.

[0186] The first end 17 of tube 4 in the second bundle of 12 tubes leads to a second distributor 19, which is configured to distribute heat transfer fluid among all tubes 4 in the second bundle of 12 tubes. The second distributor 19 extends transversely to the axis of tube 4 in the second bundle of 12 tubes. The second distributor 19 includes a heat transfer fluid inlet 21.

[0187] The second end 18 of tube 4 in the second bundle of 12 tubes leads to the second manifold 20, which is configured to collect the heat transfer fluid from all tubes 4 in the second bundle of 12 tubes. The second end of tube 4 and the second manifold 20 are located at... Figure 2 They are not visible because they are arranged behind the first branch 5 of the tube 3 shown.

[0188] Tube 4 in the second bundle of 12 is sealed at its first end 17 to the second distributor 19. Similarly, tube 4 in the second bundle of 12 is sealed at its second end 18 to the second manifold 20. Tube 4 in the second bundle of 12 is, for example, brazed to the second distributor 19 and the second manifold 20.

[0189] The second manifold 20 extends transversely to the axis of tube 4 in the second bundle 12. The second manifold 20 includes a heat transfer liquid outlet 22. The second manifold 20 and the second distributor 19 extend along the vertical axis Z.

[0190] According to various examples of the embodiments, the relative positions of the heat transfer liquid inlet 21 and outlet 22 can be varied. Figure 5 , Figure 2 and Figure 6 In part C of the example, the heat transfer liquid inlet 21 and the heat transfer liquid outlet 22 are arranged on opposite lateral sides of the heat exchanger 50. Figure 6 In the examples of parts A and B, inlet 21 and outlet 22 are on the same transverse side. The flow of the heat transfer fluid in the manifold and distributor is adjusted accordingly.

[0191] The outer periphery of tube 4 in the second bundle of 12 tubes has an elongated oval cross-section.

[0192] Figure 4 An alternative embodiment is shown, wherein the heat exchanger 50 includes a support 30 disposed between at least a portion of the tube 4 in the second bundle 12 and at least a portion of the base 6 of the tube 3 in the first bundle 11.

[0193] In the example shown, the heat exchanger 50 includes a support 30 that connects the second heat exchange section 2 to the base 6 of the tube 3 in the first bundle 11 tubes.

[0194] The support member 30 provides mechanical support to the base 6 of the pipe 3 of the first heat exchange section 1 relative to the second heat exchange section 2, which helps to reduce the propagation of vehicle vibration in the pipe 3 of the first heat exchange section 1.

[0195] The thermal conductivity of the support 30 is lower than that of the tube 3 of the first bundle 11, preferably 10% lower than that of the tube 3 of the first bundle 11.

[0196] Therefore, the support member 30 thermally insulates the base 6 of the pipe 3 in the first heat exchange section 1 from the second heat exchange section, preventing the formation of thermal bridges.

[0197] The support 30 is made of plastic, for example, glass fiber reinforced polyamide (e.g., PA6 reinforced with 30% glass fiber) or glass fiber reinforced polypropylene (e.g., PP reinforced with 30% glass fiber).

[0198] The support member 30 can rigidly fix the second heat exchange section 2 to the base 6 of the tube 3 in the first bundle 11 tubes.

[0199] exist Figure 6 In the example shown, the second heat exchange section 2 includes a surface 26 arranged opposite to the base 6 of the tube 3 in the first bundle 11 tubes, and the support member 30 connects the base 6 of the tube 3 in the first bundle 11 tubes to the oppositely arranged surface 26.

[0200] In this case, the support 30 includes a sealing wall 27 that connects the second heat exchange section 2 to the base 6 of the tube 3 in the first bundle 11 tubes, thereby preventing airflow F from flowing between the second heat exchange section 2 and the base 6 of the tube 3 in the first bundle 11 tubes.

[0201] The sealing wall 27 prevents airflow from passing through the space between the base of the tube 3 of the first bundle 11 and the surface 26 of the second heat exchange section positioned opposite each other. Therefore, the sealing wall 27 prevents part of the airflow F from leaving the exchanger 1 without exchanging heat with the second heat exchange section 2.

[0202] In this configuration, the support member 30 has a trapezoidal cross-section. The smaller base 28 of the trapezoid is opposite to the second heat exchange section 2. The larger base 29 is opposite to the base 6 of the tube 3 in the first bundle 11 tubes.

[0203] Therefore, the support 30 directs the airflow F flowing near the base 6 of the tube 3 in the first bundle 11 tubes to the second heat exchange section 2. Furthermore, water generated during the defrosting stage can also be directed by the sealing wall 27 to the bottom of the exchanger 50, which facilitates the drainage of this water.

[0204] According to an example of an embodiment, the support 30 is rigidly fixed to the base 6 of each tube 3 in the first bundle 11 tubes.

[0205] Support member 30 provides mechanical support to tubes 3 relative to each other, which limits the amplitude of vibration. This improves the mechanical strength of heat exchanger 50.

[0206] The support member 30 is, for example, overmolded onto the base 6 of the tube 3 in the first bundle of tubes 11.

[0207] According to a variant not shown, the surface 26 of the second heat exchange section 2 can be rigidly fixed to the base 6 of the tube 3 of the first heat exchange section 1, particularly by brazing. In this case, the support 30 is not present. There is no gap along the axis Z between the surface 26 of the second heat exchange section 2 and the base 6 of the tube 3 of the first heat exchange section 1.

[0208] According to another alternative embodiment, tube 4 in the second bundle 12 extends parallel to the first branch 5 of tube 3 in the first bundle 11.

[0209] This arrangement allows the second manifold 20 or the second distributor 19 to be positioned opposite the base 6 of the tube 4 in the first bundle 11 tubes. Therefore, the base 6 of the refrigerant tube can be attached to the second manifold 20 or the second distributor 19 to provide support for the U-shaped tube in the bundle 11 tubes of the first heat exchange section 1.

[0210] Since the tube 3 of the first bundle 11 of refrigerant tubes can be horizontal or vertical, and the tube 4 of the second bundle 12 of heat transfer liquid tubes can also be horizontal or vertical, four arrangements are possible.

Claims

1. A heat exchanger (50) for a motor vehicle, comprising: - The first heat exchange section (1) is configured to allow heat exchange between the refrigerant and the airflow (F). The first heat exchange section (1) includes a first bundle (11) of tubes (3) forming a set of refrigerant flow channels arranged in the airflow (F). - The second heat exchange section (2) is configured to allow heat exchange between the heat transfer liquid and the air flow (F). The second heat exchange section includes a second bundle (12) of tubes (4) forming a set of heat transfer liquid flow channels arranged in the airflow (F). The tube (3) in the first bundle (11) has a U-shape, the U-shape including a first branch (5) and a second branch (7) connected by a base (6). Wherein, the first branch (5) is positioned upstream of the second branch (7) in the flow direction of the airflow (F), and The second bundle (12) tube is arranged in the direction of airflow (F) between the first branch (5) and the second branch (7) of the tube (3) in the first bundle (11) tube.

2. The heat exchanger (50) as claimed in claim 1, wherein, Each tube (3) in the first bundle (11) extends in a plane. In the first bundle (11) of tubes, tubes (3) are arranged in a parallel plane, and In the first bundle (11) of tubes, the tubes (3) are aligned in a direction (D) perpendicular to the plane of the tubes.

3. The heat exchanger (50) as claimed in claim 2, wherein, The second bundle (12) tube (4) extends between two parallel planes (P2, P2') that are perpendicular to the plane of the first bundle (11) tube (3).

4. The heat exchanger (50) as described in any of the preceding claims, wherein, The base (6) of the tube (3) in the first bundle (11) is spaced apart from the base of the adjacent tube (3).

5. The heat exchanger (50) as described in any one of claims 1 to 3, wherein, The outer periphery of the tube (3) in the first bundle (11) has an elongated oval cross-section defining the major axis and the minor axis, wherein the major axis of the first branch (5) of the tube is parallel to the airflow (F). Wherein, the major axis of the second branch (7) of the tube (3) is parallel to the airflow (F), and The long axis of the base (6) of the tube (3) is perpendicular to the airflow (F).

6. The heat exchanger (50) as claimed in any one of claims 1 to 3, wherein, When the heat exchanger (50) is in its nominal position installed in the vehicle, the base (6) of the tube (3) in the first bundle (11) of tubes defines the lower side of the heat exchanger (50), and When the heat exchanger (50) is in the nominal position installed in the vehicle, the first branch (5) of the tube (3) in the first bundle (11) extends along the vertical axis (Z).

7. The heat exchanger (50) as claimed in any one of claims 1 to 3, wherein, When the heat exchanger (50) is in its nominal position installed in the vehicle, the base (6) of the tube (3) in the first bundle (11) of tubes defines the lateral side of the heat exchanger (50), and When the heat exchanger (50) is in its nominal position in the vehicle, the first branch (5) of the tube (3) in the first bundle (11) extends along the horizontal axis.

8. The heat exchanger (50) as claimed in any one of claims 1 to 3, wherein, The first end (15) of the tube (3) in the first bundle (11) leads to a first distributor (9), which is configured to distribute the refrigerant among all the tubes (3) in the first bundle (11). Wherein, the second end (16) of the tube (3) in the first bundle (11) leads to the first manifold (10), the first manifold (10) being configured to collect the refrigerant from all the tubes (3) in the first bundle (11), and When the heat exchanger (50) is in its nominal position in the vehicle, the first distributor (9) is positioned downstream of the first manifold (10) in the direction of airflow (F).

9. The heat exchanger (50) as claimed in any one of claims 1 to 3. in, The first end (15) of the tube (3) in the first bundle (11) leads to a first distributor (9), which is configured to distribute the refrigerant among all the tubes (3) in the first bundle (11). Wherein, the second end (16) of the tube (3) in the first bundle (11) leads to the first manifold (10), the first manifold (10) being configured to collect the refrigerant from all the tubes (3) in the first bundle (11), and When the heat exchanger (50) is in its nominal position in the vehicle, the first manifold (10) is positioned downstream of the first distributor (9) in the direction of airflow (F).

10. The heat exchanger (50) as claimed in any one of claims 1 to 3, wherein, The length (L1) of the first branch (5) of the tube (3) in the first bundle (11) is less than the length (L2) of the second branch (7) of the tube (3) in the first bundle (11).

11. The heat exchanger (50) as claimed in any one of claims 1 to 3, comprising a support (30) for connecting the second heat exchange section (2) to the base (6) of the tube (3) in the first bundle (11) tubes.

12. The heat exchanger (50) as claimed in claim 11, wherein, The thermal conductivity of the support (30) is lower than that of the tube (3) of the first bundle (11).

13. The heat exchanger (50) as claimed in claim 12, wherein, The support (30) includes a sealing wall (27) that connects the second heat exchange section (2) to the base (6) of the tube (3) in the first bundle (11) tube, thereby preventing the airflow (F) from flowing between the second heat exchange section (2) and the base (6) of the tube (3) in the first bundle (11) tube.

14. The heat exchanger (50) as claimed in any one of claims 1 to 3, wherein, The tube (4) in the second bundle (12) extends transversely to the tube (3) in the first bundle (11).

15. The heat exchanger (50) as claimed in any one of claims 1 to 3, wherein, The tube (4) in the second bundle (12) extends parallel to the first branch (5) of the tube (3) in the first bundle (11).

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