Double-flow heat exchanger

Abstract

The present invention relates to a heat exchanger (21) comprising a support arm (22) and a plurality of first fins (23), each of the first fins rising from an outer surface (24) of the support arm (22) and configured to allow a first airflow to pass over the plurality of first fins. According to the invention, the heat exchanger includes a plurality of second fins (25) downstream of the plurality of first fins (23), each of the second fins rising from an outer surface (24) of the support arm (22), the plurality of first fins and the plurality of second fins (23, 25) being separated by a distribution device (26) configured such that the first airflow flows outside the plurality of second fins (25), and a second airflow flowing outside the plurality of first fins passes through the plurality of second fins (25).

Description

Technical Field

[0001] This invention relates to the general field of aviation. In particular, the invention relates to heat exchangers for turbines. Background Technology

[0002] Turbines (especially those used in aircraft) comprise various components and / or equipment items that require lubrication and / or cooling, such as rolling bearings and gears. The heat released by these components is transferred via fluids and discharged to a cooling source available in the aircraft, where the amount of heat can be very high, depending on the power of the components and / or equipment items.

[0003] It is known to equip turbines with one or more heat exchange systems to perform heat exchange between a fluid (usually oil) and a cold source (air, fuel, etc.). There are even different types of heat exchange systems, such as fuel / oil heat exchangers commonly known as fuel-cooled oil coolers (FCOC) and air / oil heat exchangers known as air-cooled oil coolers (ACOC).

[0004] The FCOC heat exchanger has a dual function: heating the fuel before combustion in the turbine's combustion chamber and cooling the oil heated by the turbine's heat dissipation. However, the FCOC heat exchanger is insufficient to absorb all heat dissipation because the fuel temperature is limited for safety reasons.

[0005] Additional cooling is achieved through ACOC heat exchangers, particularly surface-type heat exchangers known by the abbreviation SACOC. Surface heat exchangers are typically arranged in the secondary ducts of a turbine to cool the oil flowing through the turbine using secondary airflow. These heat exchangers take the form of metallic surface components that allow oil to pass through machined channels. The secondary airflow is guided along fins supported by this surface component, which increase the contact surface with the secondary airflow and extract heat. However, a disadvantage of SACOC heat exchangers is that they generate additional pressure losses in the associated secondary ducts because they interfere with airflow, which affects turbine performance and fuel consumption.

[0006] The SACOC heat exchanger has very low aerodynamic thermal performance (the ratio between the dissipated heat power and the pressure loss caused on the secondary airflow side).

[0007] Furthermore, the cooling requirements for lubricating fluids are also increasing due to higher rotational speeds and power requirements that meet turbine specification trends. Summary of the Invention

[0008] The object of the present invention is to provide a heat exchanger that enables the optimization of its thermal performance while reducing mechanical energy loss.

[0009] According to the invention, this is achieved by a heat exchanger for a turbine, the heat exchanger comprising a support wall and a plurality of first fins, each of the first fins rising from an outer surface of the support wall and intended to be swept by a first airflow, the heat exchanger including a plurality of second fins downstream of the plurality of first fins, each of the second fins rising from an outer surface of the support wall, the plurality of first fins and the plurality of second fins being separated by a distribution device configured such that the first airflow flows outside the plurality of second fins, and a second airflow flowing outside the plurality of first fins passes through the plurality of second fins.

[0010] Therefore, this solution enables the achievement of the aforementioned objectives. Specifically, by allowing two separate airflows to circulate without intersecting, thermal performance increases when the second airflow replaces the first airflow that has already passed through the first fin. The second airflow circulating outside the heat exchanger is cooler, which increases the heat exchange capacity. Furthermore, the reduced path length of each airflow through the heat exchanger contributes to a reduction in induced drag.

[0011] The heat exchanger also includes one or more of the following features, either individually or in combination:

[0012] - The support wall extends along the longitudinal direction L.

[0013] - The distribution device is arranged at least partially between the plurality of first fins and the plurality of second fins along the flow direction of the first airflow and the second airflow in the fins.

[0014] The heat exchanger includes a first shaped wall and a second shaped wall. The first shaped wall is disposed upstream of a plurality of first fins and is configured to guide and slow down a first airflow entering the heat exchanger through the plurality of first fins. The second shaped wall is disposed downstream of a plurality of second fins and is configured to accelerate a second airflow leaving the heat exchanger through the plurality of second fins.

[0015] - The heat exchanger includes a first profiled panel and a first profiled wall covering a plurality of first fins. The first profiled wall is connected upstream to the first panel, disposed upstream of the plurality of first fins, and configured to guide and slow down a first airflow entering the heat exchanger through the plurality of first fins.

[0016] - The distribution device includes a first ramp arranged downstream of a plurality of first fins and rising obliquely from the outer surface of the support wall, such that a first airflow exiting the plurality of first fins is guided to the outside of the heat exchanger.

[0017] - The dispensing device includes a deflector, which includes a first shaped wall portion connected downstream to a first panel and defined in a plane generally parallel to a first ramp. A plurality of stacked members extending between the first shaped wall portion and the first ramp are evenly spaced from each other to form a channel for a first airflow.

[0018] - Each stack includes a first opening and a second opening, the first opening leading to the outer surface of the first profiled wall portion and the second opening leading to the inner surface of the first ramp, opposite to a plurality of second fins, such that a second airflow flows through the plurality of second fins in the stack.

[0019] - The heat exchanger includes a second profiled panel and a second profiled wall covering a plurality of second fins. The second profiled wall is connected downstream to the second profiled panel, disposed downstream of the plurality of second fins, and configured to accelerate a second airflow exiting the heat exchanger through the plurality of second fins.

[0020] - The deflector includes a second irregular wall portion connected to a second panel, the second wall portion including a through-hole, a channel leading to the through-hole.

[0021] - The first wall portion includes a first flange that extends in a plane inclined to the first wall portion and at least partially covers the first opening of each stack.

[0022] - The second wall portion includes a second flange that extends in a plane inclined to the second wall portion and at least partially covers the orifice.

[0023] - The dispensing device includes a second ramp arranged upstream of a plurality of second fins and extending the second opening of the stacked member.

[0024] - The fins are either continuous and straight in a longitudinal direction, or discontinuous and arranged in staggered rows, or corrugated.

[0025] The heat exchanger is manufactured using additive manufacturing.

[0026] - The heat exchanger includes a deflector comprising an internal channel and an external channel formed by stacked elements. The internal channel is open on one side outside the heat exchanger and on the other side upstream of a plurality of second fins. The external channel is arranged between two adjacent stacked elements and is open on one side downstream of a first fin and on the other side outside the heat exchanger.

[0027] - The stacked components are arranged longitudinally between the first and second fins.

[0028] - The first irregular wall includes a first longitudinal end, which together with the support wall forms an air inlet with a first radial height. The second irregular wall includes a second longitudinal end, which together with the support wall forms an air outlet with a second radial height. The ratio between the first height and the second height is equal to or greater than 0.5.

[0029] - The first irregular panel extends from the outer surface to a maximum radial distance, which is greater than the first height of the first irregular wall and the second height of the second irregular wall.

[0030] - The first panel and the second panel are connected by a deflector.

[0031] The heat exchanger is manufactured using additive manufacturing.

[0032] - The first panel, the second panel, the first wall, the second wall, and the deflector are made into one piece.

[0033] - Multiple first fins are attached to the first panel.

[0034] - Multiple second fins are attached to the second panel.

[0035] - The fins of multiple first fins or second fins are respectively integrated with the first panel or the second panel.

[0036] - The heat exchanger is designed to be placed in the secondary piping of the turbine.

[0037] - The heat exchanger is of the air / fluid type, preferably of the surface type.

[0038] - The first airflow and the second airflow are the same.

[0039] - The first and second air flows originate from the secondary air flow circulating in the secondary duct.

[0040] The present invention also relates to a turbine module having a longitudinal axis X, the turbine module comprising an annular housing surrounding the longitudinal axis and a heat exchanger according to any of the foregoing features, wherein airflow flows through the annular housing, the heat exchanger is arranged in the annular housing, the annular housing comprising an annular wall that at least partially guides the airflow, and the annular wall having an opening or a recess in which a heat exchanger having a first shaped panel and a second shaped panel is mounted, the first wall being connected upstream of the first panel to a portion of the annular wall, the second wall being connected downstream of the second panel to a portion of the annular wall, the first panel and the second panel being connected by a deflector.

[0041] The heat exchanger is embedded in the wall of the annular shell.

[0042] The present invention also relates to a turbine comprising at least one heat exchanger having any of the foregoing features and / or a turbine module as described above. Attached Figure Description

[0043] The invention will be better understood and other objects, details, features, and advantages of the invention will become clearer by reading the following detailed description of embodiments of the invention given as illustrative rather than limiting examples, with reference to the accompanying schematic diagrams:

[0044] [ Figure 1 ] Figure 1 This is an axial cross-sectional view of an example turbine to which the present invention is applied;

[0045] [ Figure 2 ] Figure 2 This is a perspective view of a heat exchange system for equipping a turbine according to the present invention;

[0046] [ Figure 3 ] Figure 3 It is based on Figure 2 A schematic axial cross-sectional view of the heat exchange system;

[0047] [ Figure 4 ] Figure 4 Another embodiment is a heat exchange system having discontinuous and staggered fins rising from the support wall of the heat exchanger according to the invention;

[0048] [ Figure 5 ] Figure 5 The intersecting regions of different heat exchange flows in an example of a heat exchange system according to the invention are shown schematically and in more detail, without mixing these heat exchange flows;

[0049] [ Figure 6 ] Figure 6 These are perspective and side views of an example of a heat exchange system, particularly a deflector, according to the present invention;

[0050] [ Figure 7 ] Figure 7 The path of the second flow through the stack in the axial cross-section of the heat exchange system according to the invention is shown;

[0051] [ Figure 8 ] Figure 8 These are perspective and rear views of the heat exchange system according to the present invention;

[0052] [ Figure 9 ] Figure 9 The first-order path through the heat exchange system according to the invention in the axial cross-section is shown; and

[0053] [ Figure 10 ] Figure 10 Another example of a heat exchange system according to the invention integrated into the turbine wall in the axial cross-section is shown. Detailed Implementation

[0054] Figure 1 An axial cross-sectional view of a turbine with a longitudinal axis X, to which the present invention is applied, is shown. The turbine shown is a two-flow turbine 1 intended for installation on an aircraft. Of course, the present invention is not limited to this type of turbine.

[0055] This type of dual-flow turbine 1 typically includes a gas generator or gas turbine engine 2, wherein a fan 3 is mounted upstream.

[0056] In this invention, the terms "upstream" and "downstream" are defined relative to the gas flow within the turbine, here along the longitudinal axis X and referring to... Figure 1 Defined from left to right. Similarly, turbines are typically composed of multiple modules that are manufactured independently of each other and then assembled together in a manner that facilitates the assembly, disassembly, and maintenance of the turbine.

[0057] The gas generator 2 includes a gas compressor assembly (hereinafter including a low-pressure compressor 4a and a high-pressure compressor 4b), a combustion chamber 5, and a turbine assembly (hereinafter including a high-pressure turbine 6a and a low-pressure turbine 6b). Typically, the turbine includes a low-pressure shaft 7 and a high-pressure shaft 8, the low-pressure shaft connecting the low-pressure compressor and the low-pressure turbine to form a low-pressure body, and the high-pressure shaft connecting the high-pressure compressor and the high-pressure turbine to form a high-pressure body. In this example, the low-pressure shaft 7, centered on the longitudinal axis, drives a fan shaft 9. As in this example, a reduction gear 10 may be provided between the fan shaft 9 and the low-pressure shaft 7. Upstream and downstream rotary guide bearings 11 enable the low-pressure shaft 7 to rotate relative to the stationary structure of the turbine.

[0058] Fan 3 is housed in the duct of fan housing 12, which is supported by nacelle 13, and generates a main airflow that flows through gas generator 2 in main duct 14 and a secondary airflow that flows in secondary duct 15 surrounding gas generator 2. The secondary airflow is ejected through secondary nozzle 16 terminating nacelle 13, while the main airflow is ejected to the outside of turbine via injection nozzle 17 located downstream of gas generator 2. Hereinafter, fan housing 12 and nacelle 13 are considered as a single unit.

[0059] In this example turbine configuration, the guide bearing 11 and the reducer 10 must be lubricated and / or cooled to ensure turbine performance. The power generated by these guide bearings and reducers is dissipated in fluid from a fluid supply source installed in the turbine, which enables the lubrication and / or cooling of the various components and / or equipment of the turbine. Of course, other equipment items of the turbine generate a significant amount of heat, which must be extracted from its environment.

[0060] For this purpose, the turbine includes a heat exchange system 20 that enables cooling of fluids used for lubricating and / or cooling these components and / or equipment items. In this example, the fluid is oil, and the cold source for cooling the oil is the airflow circulating within the turbine, particularly the secondary airflow. The heat exchange system includes a heat exchanger 21, which is carried by the turbine's fan housing, such as... Figure 1 As shown schematically. Specifically, heat exchanger 21 is arranged in secondary duct 15 such that secondary airflow passes through it. The heat exchanger is of the air / oil surface type.

[0061] Reference Figure 2 The heat exchanger 21 includes a support wall 22 extending along the longitudinal direction L. The support wall 22 is generally flat. This wall may not be perfectly flat, but rather curved to follow the contour of the wall of the fan housing 12, which is designed to support the heat exchanger 21 and is generally cylindrical (centered on the longitudinal axis X). The heat exchanger 21 may be annular and occupy the entire wall of the fan housing 12. Alternatively, the heat exchanger 21 may be arranged on a section of the fan housing 12.

[0062] The heat exchanger 21 also includes a plurality of first fins 23, each of which rises from the outer surface 24 of the support wall 22. The fins 23 extend in a radial direction R perpendicular to the longitudinal direction. Specifically, we use the term "direction" to describe the heat exchanger 21. The radial direction is parallel to the radial axis extending from the longitudinal axis of the turbine. In the installed case, the longitudinal direction is parallel to the longitudinal axis of the turbine.

[0063] from Figure 2 and Figure 3 As can be seen, the fins 23 are continuous and straight. Advantageously, the fins 23 are rectangular in shape. Each fin extends along the longitudinal direction L (generally parallel to the flow or movement of air in the turbine, particularly in the heat exchanger). More specifically, each fin 23 is flat. The fins 23 are arranged successively and regularly on the radial outer surface 24 along a transverse direction T perpendicular to both the longitudinal direction L and the radial direction R. The fins remain generally parallel to each other. Figure 3In the middle, each of the plurality of first fins 23 has a leading edge 23a and a trailing edge 23b that are opposite to each other in the direction of airflow.

[0064] from Figure 2 and Figure 3 It can also be seen that the heat exchanger 21 includes a plurality of second fins 25, each of which rises radially from the outer surface 24 of the support wall 22. The fins 25 are arranged downstream of the plurality of first fins 23 (in the direction of airflow). Figure 3 As shown, the fins 25 of a plurality of first fins 23 are arranged downstream of the plurality of first fins along the longitudinal direction L. In this example, the fins 25 of a plurality of second fins are similar to the fins 23 of the plurality of first fins. In other words, these fins 25 are continuous, straight, and flat. These fins are also rectangular in axial cross-section. Each fin 25 has a leading edge 25a and a trailing edge 25b.

[0065] exist Figure 4 In the partial cross-sectional view, the fins of the plurality of first fins 23 and / or the plurality of second fins 25 may also be discontinuous and arranged in staggered rows (offset spacing) in the radial or longitudinal direction. The fins 23, 25 extend from the outer surface 24 of the support wall 23 along the flow directions of the airflows F1, F2. There are rows of fins in the longitudinal and transverse directions T. Fins arranged in this way allow for reinforcement of the thermal boundary layer through interruption and reconstruction, which allows for a significant reduction in the exchange surface for a given dissipation power or allows for an increase in the power that can be dissipated within a given total dimension. Alternatively, the fins 23, 25 may also be corrugated in the radial or longitudinal direction. Alternatively, the fins 23, 25 may be trapezoidal.

[0066] Two airflows, namely the first airflow F1 and the second airflow F2 (see...) Figure 2 , Figure 3 The first airflow F1 and the second airflow F2 are used to sweep across fins 23 and 25 without intersecting each other. These first airflows F1 and second airflows F2 originate from the secondary airflow, which enters the fan housing 12 (in the secondary duct 15) and is split into two streams. The first airflow and the second airflow are identical. The first airflow F1 and the second airflow F2 circulate outside the heat exchanger 21 and flow through fins 23 or 25.

[0067] For this purpose, a plurality of first fins 23 and a plurality of second fins 25 are separated by a distribution device 26 for a first airflow F1 and a second airflow F2, the distribution device being configured such that the first airflow F1 flows outside the plurality of second fins 25, and the second airflow F2, flowing outside the plurality of first fins 23, passes through the plurality of second fins 25. It should be understood that the distribution device is arranged at least partially between the plurality of first fins and the plurality of second fins along the flow direction of the first and second airflows in the fins (or along the longitudinal direction L). The first airflow F1 is intended to flow only through the fins 23. Conversely, the second airflow F2 is intended to flow only through the fins 25 (flowing between the fins 25). This configuration is compact and allows for both axial and radial benefits.

[0068] In particular, Figure 2 and Figure 3 In the heat exchanger 21, a first shaped wall 27 is disposed upstream of the fins 23 (along the airflow direction along the outer surface 24), and the first shaped wall 27 is configured to guide and direct a first airflow F1 into the heat exchanger 21, particularly into the fins 23. The first wall 27 is also configured to slow the airflow entering the heat exchanger. The first wall has a gradually widening profile. The first wall 27 extends over a width l1, which is at least equal to the distance occupied by the fins. Specifically, the l1 of the first shaped wall 27 is greater than the width occupied by the fins (along the lateral direction T).

[0069] The first wall 27 is flat and defined in a plane inclined relative to the longitudinal direction L. More specifically, the first wall 27 includes an upstream first longitudinal end 27a, which, together with the support wall 22, forms an air inlet having a first predetermined height he in the radial direction. The first height he is less than the radial height hi of the fin. The fin height hi is between 5 mm and 30 mm. The first wall 27 includes a downstream second longitudinal end 27b, which is connected to the top of the leading edge 23a of each fin 23. In other words, the first wall 27 is inclined by expanding downstream. In particular, the distribution device includes an air inlet for a second airflow and an air outlet for a first airflow. The air inlet of the distribution device is different from the air inlet at the first fin.

[0070] The heat exchanger 21 includes a first shaped panel 28 covering fins 23. In this way, the first panel allows for control of airflow within the heat exchanger 21 without the risk of airflow bypassing the heat exchanger. Therefore, the fins 23 are arranged radially between the support wall 22 and the first shaped panel 28. In this example embodiment, the first panel 28 is connected to the first wall 27 and extends along the longitudinal direction L (downstream). The first panel 28 also has the same width as the first wall 27 (along the transverse direction). Figure 3 As shown, the first panel 28 is flat. However, panel 28 is generally circular or curved (around the longitudinal axis X when mounted in a turbine). Specifically, panel 28 includes a first longitudinal edge 28a that connects to a first longitudinal end 27b of the first wall 27. As shown, the outer peripheral surface 29 of panel 28 has surface continuity with the outer surface 30 of the first wall 27. Panel 28 extends at a radial distance equal to or greater than the radial distance of the fins 23. In other words, this radial distance is greater than the first height he of the air inlet of the first wall 27.

[0071] The first wall 27 and the panel 28 are advantageously formed as a single unit, and are formed as a single unit, for example by an additive manufacturing method (or 3D printing) such as a laser melting method on a powder bed.

[0072] Advantageously, but not limitingly, the fins 23 are attached to the panel 28 and / or support wall 22, for example, by brazing. Thus, they are assembled. Alternatively, the fins 23 and support wall 22 are formed integrally (i.e., formed of one material and are monolithic) and advantageously formed by additive manufacturing. Similarly, the fins 23 and panel 28 can be made as a single piece. For example, additive manufacturing is performed in the direction from upstream to downstream of the heat exchanger. In this case, to facilitate additive manufacturing, especially in the absence of support, the leading edge 23a of the fins 23 has an angle inclined to the radial direction.

[0073] Of course, the heat exchanger 21 as a whole can be manufactured by other manufacturing methods such as forging.

[0074] Furthermore, placing the panel 28 on the fins 23 can improve the mechanical strength of the heat exchanger 21, thereby reducing the thickness of the fins 23. However, the reduction in the thickness of the fins 23 also makes it possible to reduce the weight of the heat exchanger 21.

[0075] like Figures 2 to 4As shown, multiple second fins 25 are also covered by the second panel 31 to control the airflow within the heat exchanger 21 without the risk of bypassing. The fins 25 are arranged radially between the support wall 22 and the second profiled panel 31. Like the first panel 28, the second panel 31 extends in width l2, which is at least equal to the distance occupied by the fins 25. The panel 31 is also flat, but may be circular in radial cross-section, or curved around the longitudinal axis X in the installation case. The second panel 31 is connected downstream to the second profiled wall 32. The second profiled wall is positioned downstream of the fins 25 to reduce reflow occurring downstream of the fins. The second profiled wall 32 is also configured to accelerate the flow at the outlet of the heat exchanger 21. As described below, a distribution device connects the first panel 28 and the second panel 31.

[0076] The second wall 32 has a substantially similar construction to the first wall 27. However, the second wall has a converging profile. The width of the second wall 32 is the same as the width (l1) of the first wall 27 and also the width (l2) of the second panel 32 (and wider than the width occupied by the fins arranged in the transverse direction T). The second wall 32 also includes a first end portion 32a, which is connected to the second longitudinal edge 31b of the second panel 31. The outer peripheral surface 33 of the second panel 31 is surface continuous with the outer surface 34 of the second wall 32. The second wall includes a second downstream end portion 32b, which, together with the support wall 22, forms an air outlet having a second predetermined height hs in the radial direction. The second height hs is less than the height hi of the fins. The first end portion 32a of the second wall 32 is connected to the top of the trailing edge 25b of the fins 25. In other words, the second wall 32 is inclined by expanding upwards. The radial distance of the panels is equal to or greater than the first height he and the second height hs of the walls 27 and 32. The air outlets downstream of the multiple second fins used for the second airflow are different from the air outlets of the distribution device.

[0077] In this example, the ratio between the first height he and the second height hs is between 0.5 and 1.

[0078] Alternatively, not shown, the first wall 27 and the second wall 32 each have a generally corrugated or curved shape in a plane RL (formed by the vertical longitudinal direction L and the radial direction R) perpendicular to the plane LT of the supporting wall 22.

[0079] exist Figures 5 to 9In this embodiment, the distributing device 26 between two plurality of fins 23, 25 includes a deflector 35 supported at least by a first panel 28. The deflector 35 has an X-shaped axial cross-section. Specifically, the deflector 35 includes a first shaped wall portion 36 having an upstream end 36a connected to a second longitudinal edge 28b of the first panel 28. The first wall portion 36 slopes downstream. In this example, the first wall portion 36 is defined in a plane substantially parallel to the plane of a first ramp 37. The plane of the ramp 37 slopes at an angle between 20° and 70°. The first ramp 37 includes a first longitudinal end 37a connected to a support wall 22 and a second longitudinal end 37b connected to a first longitudinal edge 31a of the second panel 31. The first longitudinal end 37a rises axially (along the longitudinal direction L) downstream of the root of the trailing edge 23b of the fin 23 from the outer surface 24 of the support wall 22. The second longitudinal end 37b is also connected to the top of the leading edge 25a of the fin 25. In other words, the first ramp 37 slopes downstream. In this way, the airflow leaving the plurality of first fins 23 is guided to the outside of the heat exchanger 21 via the first ramp 37.

[0080] Between the first wall portion 36 and the first ramp 37, a plurality of stacked members 38 extend generally radially. The stacked members 38 are evenly spaced apart from each other to form a channel 50 for a first airflow F1. In this way, the airflow flows and is individually distributed in the distribution device. The first airflow flows, on the one hand, between the first ramp 37 and the first wall portion 36, and on the other hand, through the channel 50 (between each adjacent stacked member 38 in the lateral direction T). In the distribution device, the arrangement of the stacked members between their walls and a plurality of first fins and a plurality of second fins forms a compact arrangement. Each stacked member 38 includes an upstream side 38a and a downstream side 38b, which are connected by two lateral sides 38c. Each stacked member 38 is hollow. Each stacked member 38 includes a first opening 40 defined in the first wall portion 36 of the deflector 35. The first opening 40 opens to the outer surface 41 of the first wall portion 36. The first opening 40 passes through the walls of the first wall portion on both sides. Each stack 38 also includes a second opening 42 defined in the first ramp 37 (in) Figure 6 (shown as dashed lines). More specifically, such as Figure 7 As shown, the second opening 42 leads to the inner surface 43 of the first ramp 37. This inner surface 43 is oriented towards the leading edge 25a of the fin 25. The second opening 42 extends through the ramp 37 on both sides. Sides 38a, 38b, and 38c define the first opening 40 and the second opening 42. In other words, each stack 38 (forming an internal conduit) is in fluid communication with the exterior of the heat exchanger 21 and the interior of the fin 25. More specifically, each opening 40, 42 leads to the internal conduit of the stack 38. In this way, as... Figure 7As shown, a second airflow F2 that flows outside the heat exchanger and sweeps across the outer surface 29 of the panel 28 passes through the stack 38 via the first opening 40 and through a plurality of second fins 25 via the second opening 42.

[0081] Reference Figure 6 and Figure 8 The deflector 35 includes a second wall portion 44 defined in a plane transverse to the plane of the first wall portion 36. The second wall portion 44 is connected to the first portion 36 at a central connection (at the center of the upper X). The second wall portion 44 includes a second end portion 44a connected to (or near the longitudinal edge of) a first longitudinal edge of the second panel 31. In this way, the deflector 35 is also carried by the second panel 31.

[0082] from Figure 8 As can be seen, the first wall portion 44 includes a plurality of segments 44b evenly distributed in the transverse direction T. An upstream side portion 38a is defined in (or defined by) each segment 44b of the second wall portion 44. The second wall portion 44 also includes orifices 48 that pass through the wall of the second wall portion on both sides in a direction transverse to the plane defining the second wall portion 44. Each orifice 48 is transversely arranged between two stacked members 38. More specifically, each orifice 48 is configured to be opposite and aligned with a channel 50 formed between two adjacent stacked members 38. However, the first or last stacked member in the transverse direction is spaced a distance from the side edge 49 of the first ramp 37. Similarly, from... Figure 6 It can be seen that the second wall portion 44 does not extend to the side edge 49. In other words, the second wall portion 44 extends in a straight line with the lateral side portion 38c of the first stack or the second stack 38 in the lateral direction. In this way, as... Figure 9 As shown, the first airflow F1 flowing through the fins 23 leads to the ramp 37, passes through one or more channels 50, and flows to the outside of the heat exchanger via the orifice 48. The first airflow can pass through the channel 50 closest to the side edge 49 and flow towards the outside of the heat exchanger.

[0083] The first wall portion 36 of the deflector 35 includes a first flange 51 that at least partially overlaps the first wall portion 36 with a first opening 40. The free end of the first flange 51 is radially spaced from the first wall portion 36. Similarly, the second wall portion 44 includes a second flange 52 that partially overlaps the second wall portion 44 with an orifice 48. The first and second flanges extend in opposite directions. The first flange 51 allows a second airflow to be directed to the stack 38. The second flange 52 allows the first airflow to be directed at the outlet of the orifice 48. The free end 36b of the second flange is radially spaced from the second panel 31. Figure 6As shown, the outer surfaces 46 and 47 of the first flange and the second flange have surface continuity.

[0084] The distribution device 26 also includes a second ramp 45 extending from the inner surface 43 of the first ramp 37 to the root of the fin 25. Advantageously, but not limitingly, the second ramp 45 extends downstream of the second opening 42 to guide airflow into the interior of the fin 25.

[0085] Panels 28 and 31 and deflector 35 can be manufactured as a single unit to simplify the fabrication and installation of the heat exchanger. Additive manufacturing is one method to achieve this. It is anticipated that fins 23 and 25 will also be manufactured as a single unit with the panels and deflector 35, following the same manufacturing method.

[0086] Therefore, the first airflow F1 entering the heat exchanger 21 sweeps across the outer surface 24 of the support 22, passes through the first fins 23, passes through one or more channels 50 arranged between (or on both sides) the stack 38, and is discharged to the outside of the heat exchanger through one or more orifices 48. The first airflow sweeps across the outer surface of the second panel at the outlet of the orifice 48. Regarding the second airflow F2 flowing outside the heat exchanger 21, this second airflow enters the heat exchanger at the first opening 40, penetrates into the interior of the stack 38, and then is discharged into the second fins 25 through the second opening 42. The second airflow then exits the heat exchanger through the outlet and sweeps across the outer surface 24 of the support wall 22. Each of the first and second flows travels a short path through the heat exchanger, which reduces drag. In fact, the respective paths of the first and second flows are substantially the same as those of a conventional exchanger with only one type of multi-fin 23 or 25.

[0087] Figure 10An embodiment of a heat exchanger embedded in the annular walls 60, 61 of a turbine is shown. Here, the annular wall is the annular wall of the secondary duct and at least partially guides the secondary airflow. The heat exchanger 21 is swept and / or passed through by the secondary airflow of the turbine in its arrangement. The secondary duct 15 is defined by a radially inner annular wall 60 and a radially outer annular wall 61. The radially outer annular wall is at least partially supported by the fan housing 12. According to an example embodiment, the annular wall 60 includes an opening or recess 63 in which the heat exchanger 21 is mounted. In particular, a first wall 27 upstream of the first panel 28 is connected to a section of the annular wall 60, and a second wall 32 downstream of the second panel 31 is connected to a section of the annular wall. The first and second panels are connected by a deflector 35. The panels 28, 31 are offset radially inward from the wall 60. In this way, the fins 23, 25 are at least partially embedded in the wall 60 of the secondary duct 15, which makes it possible to minimize interference with the flow of air in the secondary duct. Furthermore, as in the previous embodiment, the first and second flows pass through the heat exchanger 21 via internal channels and conduits of the deflector 35. For this purpose, the deflector 35 includes stacks extending axially (or longitudinally) between the first fins 23 and the second fins 25. Adjacent stacks form channels 50 that allow the plurality of first fins 23 to fluidly communicate with the outside of the heat exchanger 21 via orifices 48. The stacks also form internal conduits in fluid communication with the plurality of second fins 25. Each stack extends between a wall portion and a ramp of the exchanger, uniformly spaced from each other to form an external channel for the first airflow. The wall portion includes a first opening 40 communicating with the outside of the exchanger (in this case, duct 15) and a second opening 42 opening upstream of the second fins 25. In this way, the first airflow F1 flowing through the fins 23 leads to the ramp 37, passes through one or more channels 50, and leads to the outside of the heat exchanger (in the secondary duct) via the orifice 48, and the second airflow F2 flowing outside the heat exchanger (in the second duct) passes through the stack 38 via the first opening 40 and through the plurality of second fins 25 via the second opening 42.

Claims

1. Heat exchanger (21) for a turbomachine, comprising a support wall (22) extending along a longitudinal direction L and a plurality of first fins (23) each raised from an outer surface (24) of the support wall (22) and intended to be swept by a first air flow, characterized in that, The heat exchanger includes a plurality of second fins (25) downstream of the plurality of first fins (23) along the longitudinal direction. Each of the plurality of second fins rises from the outer surface (24) of the support wall (22). The plurality of first fins (23) and the plurality of second fins (25) are at least partially separated in the longitudinal direction by a distribution device (26) configured such that a first airflow flows outside the plurality of second fins (25), and a second airflow flowing outside the plurality of first fins passes through the plurality of second fins (25). The heat exchanger (21) also includes a first shaped wall (27) and a second shaped wall (32), the first shaped wall being disposed upstream of the plurality of first fins (23) and configured to guide and slow down the first airflow entering the heat exchanger (21) through the plurality of first fins (23), and the second shaped wall being disposed downstream of the plurality of second fins (25) and configured to accelerate the second airflow leaving the heat exchanger through the plurality of second fins (25).

2. The heat exchanger (21) according to claim 1, characterized in that The heat exchanger includes a first profiled panel (28) covering the plurality of first fins (23), and the first profiled wall (27) is connected upstream to the first profiled panel (28).

3. The heat exchanger (21) according to claim 2, characterized in that, The distribution device (26) includes a first ramp (37) arranged downstream of the plurality of first fins (23) and rising obliquely from the outer surface (24) of the support wall (22) such that a first airflow exiting the plurality of first fins (23) is guided to the outside of the heat exchanger.

4. The heat exchanger (21) according to claim 3, characterized in that, The dispensing device (26) includes a deflector (35) including a first shaped wall portion (36) connected downstream to the first shaped panel (28), the first shaped wall portion being defined in a plane substantially parallel to the plane of the first ramp (37), and a plurality of stacks (38) extending between the first shaped wall portion (36) and the first ramp (37) being evenly spaced from each other to form a channel (50) for the first airflow.

5. The heat exchanger (21) according to claim 4, characterized in that, Each stack (38) includes a first opening (40) and a second opening (42), the first opening leading to the outer surface (41) of the first irregular wall portion (36), and the second opening leading to the inner surface (43) of the first ramp (37) on one hand and opposite to the plurality of second fins on the other, such that the second airflow flows through the plurality of second fins in the stack.

6. The heat exchanger (21) according to claim 2, characterized in that, The heat exchanger includes a second profiled panel (31) covering the plurality of second fins (25), and a second profiled wall (32) is connected downstream to the second profiled panel (31).

7. The heat exchanger (21) according to claim 4, characterized in that, The heat exchanger includes a second profiled panel (31) covering the fins of the plurality of second fins (25), a second profiled wall (32) being connected downstream to the second profiled panel (31), the deflector (35) including a second profiled wall portion (44) connected to the second profiled panel (31), the second profiled wall portion (44) including a through-hole (48), and the channel (50) leading to the through-hole.

8. The heat exchanger (21) according to claim 5, characterized in that, The first irregular wall portion (36) includes a first flange (51) that extends in a plane inclined to the first irregular wall portion (36) and at least partially covers the first opening (40) of each stack (38).

9. The heat exchanger (21) according to claim 7, characterized in that, The second irregular wall portion (44) includes a second flange (52) extending in a plane inclined to the second irregular wall portion (44), the second flange at least partially covering the through opening (48).

10. The heat exchanger (21) according to claim 5, characterized in that, The dispensing device (26) includes a second ramp (45) arranged upstream of the plurality of second fins and extending the second opening (42) of the stack (38).

11. The heat exchanger (21) according to claim 1 or 2, characterized in that, The plurality of first fins (23) and the plurality of second fins (25) are each continuous and straight in the longitudinal direction, or discontinuous and arranged in staggered rows, or corrugated.

12. The heat exchanger (21) according to claim 1 or 2, characterized in that, The heat exchanger is manufactured using additive manufacturing.

13. A turbine module having a longitudinal axis X, the turbine module comprising an annular housing (12) and a heat exchanger (21) according to claim 2, the annular housing (12) being annular about the longitudinal axis and through which an airflow passes, the heat exchanger being disposed in the annular housing (12), the annular housing (12) comprising annular walls (60, 61) at least partially guiding the airflow, and the annular walls having openings or recesses (63) in which a heat exchanger (21) having a first profiled panel (28) and a second profiled panel (31) is mounted, the first profiled wall (27) being connected upstream of the first profiled panel (28) to a portion of the annular wall, the second profiled wall (32) being connected downstream of the second profiled panel (31), the distribution device (26) comprising a deflector (35) through which the first profiled panel and the second profiled panel are connected.

14. A turbine (1) comprising at least one heat exchanger (21) according to any one of claims 1 to 12 and / or a turbine module according to claim 13.

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