阅读说明：本技术 在次级路径中包括热交换器的涡轮机 (Turbomachine comprising a heat exchanger in the secondary path ) 是由 塞德里克·扎卡迪 克里斯托夫·马塞尔·卢西恩·佩德里根 凯瑟琳·皮科夫斯基 于 2020-02-06 设计创作，主要内容包括：本发明涉及一种涡轮机叶片(54),包括主要在一由主轴线B和纵向方向限定的平面内延伸的主体(60),所述主体由下表面壁(66)、上表面壁(68)、位于主体(60)的第一纵向端的前缘(70)以及位于主体(60)的第二纵向端的后缘(72)限定,其特征在于,叶片(54)的主体(60)包括用于气流循环的主要沿主轴线B的方向延伸的多个第一管道(74)和用于第二气流循环的主要沿纵向方向延伸的多个第二管道(76)。(The invention relates to a turbine blade (54) comprising a main body (60) extending mainly in a plane defined by a main axis B and a longitudinal direction, said main body being defined by a lower surface wall (66), an upper surface wall (68), a leading edge (70) at a first longitudinal end of the main body (60) and a trailing edge (72) at a second longitudinal end of the main body (60), characterized in that the main body (60) of the blade (54) comprises a plurality of first ducts (74) extending mainly in the direction of the main axis B for the circulation of an air flow and a plurality of second ducts (76) extending mainly in the longitudinal direction for the circulation of a second air flow.)

1. A turbine bucket (54) comprising a body (60) extending primarily in a plane defined by a major axis B and a longitudinal direction, the body (60) being bounded by an intrados wall (66), an extrados wall (68), a leading edge (70) at a first longitudinal end of the body (60), and a trailing edge (72) at a second longitudinal end of the body (60),

characterized in that the body (60) of the blade (54) comprises a plurality of first ducts (74) and a plurality of second ducts (76), the first ducts (74) carrying a circulation of an air flow mainly extending in the direction of the main axis B, the second ducts (76) carrying a circulation of a second air flow mainly extending in a longitudinal direction.

2. The blade (54) according to the preceding claim, characterized in that each first duct (74) comprises two ends open at least one end (56, 58) of the main body (60) along the main axis B.

3. The blade (54) according to the preceding claim, characterized in that the ends of said first duct (74) are arranged in such a way as to form a bundle that narrows as the distance from said at least one end (56, 58) of said body (60) decreases.

4. The blade (54) according to any one of the preceding claims, characterized in that each of the second ducts (76) comprises two ends that open in an intrados wall (66) or in an extrados wall (68) of the body (60).

5. The blade (54) according to any one of claims 1 to 3 wherein each of the second ducts (76) comprises two ends that are open at the leading edge (70) or trailing edge (72).

6. The paddle (54) of any preceding claim, wherein each of the second conduits (76) is corrugated in a transverse direction perpendicular to a vertical longitudinal plane, each of the first conduits (74) being located in a concave section of the second conduit (76).

7. The blade (54) according to the preceding claim, characterized in that said first duct (74) is arranged laterally on each side of each of said second ducts (76).

8. The blade (54) according to any of the preceding claims, characterized in that it is manufactured using an additive technology process.

9. An aircraft turbine (10) comprising a core stream fluid (16) passing through a low pressure compressor (30) and a high pressure compressor (32),

a bypass flow stream (20) located around the core flow stream (16) and coaxial with the core flow stream (16), comprising a stator vane assembly (52) for flow of the bypass flow stream (20), the stator vane assembly comprising a plurality of vanes (54) distributed around a major axis A of the turbine (10),

a pressurized air circuit (40), the pressurized air circuit (40) drawing air between the low pressure compressor (30) and the high pressure compressor (32) or in the high pressure compressor (32) to produce a pressurized airflow that feeds at least one component of a turbine (10),

-characterized in that said plurality of blades (54) comprises at least one blade (54) according to any one of the previous claims, the main axis B of which is oriented mainly radially from a main axis a of the turbomachine, the longitudinal direction being substantially parallel to said main axis a, comprising a first duct (74) and a second duct (76), the first duct (74) of said at least one blade (54) being crossed by a pressurized gas flow, the second duct (76) of said at least one blade (54) being crossed by a portion of the gas flow flowing in the bypass fluid (20).

10. Turbomachine (10) according to the preceding claim, characterised in that the main axis B of said at least one blade is mainly oriented radially from a main axis a of the turbomachine, the longitudinal direction of said at least one blade and the second duct (76) of said at least one blade (76) being substantially parallel to said main axis a corresponding to the direction of the gas flow in said bypass flow fluid (20).

Technical Field

The present invention relates to a turbine blade arranged to be able to cool under pressure a gas stream used to cool at least one component of a turbine or to pressurise a chamber containing a lubricant.

More particularly, the present invention relates to a turbine bucket that forms a heat exchanger between a pressurized gas stream and a gas stream circulating in a bypass flow fluid of the turbine.

Background

In existing turbines, there are many air circuits inside the engine. These loops perform different functions.

In these circuits, an air circuit performs the function of pressurizing the lubrication oil chambers to prevent oil from escaping from these chambers, while also performing the function of low-pressure shaft cooling.

Air from the circuit is fluidly discharged from the core stream downstream of the low pressure compressor, preferably between the low pressure compressor and the high pressure compressor.

This air is then discharged through the degreaser with respect to the air passing through the chamber, and downstream of the low pressure turbine with respect to the other air.

This circuit will suffer from head loss due to variations in radius, bore, seals, etc. Therefore, the pressure ratio (extraction pressure/outlet pressure) must be sufficiently large for the air to circulate satisfactorily at the required flow rate.

One of the limitations of this air circuit is that the air temperature must be low enough to cool the low pressure shaft and avoid overheating the oil in the chamber. The air pressure must be sufficiently high that the above-mentioned pressures are sufficiently high and capable of circulating a prescribed flow rate.

Also in some turbines, the thermodynamic cycle makes the pressure too low for the circuit to perform these functions. Therefore, an alternative solution must be found.

Document EP-0.743.435 describes a turbomachine comprising a heat exchanger integrated into the blades of a stator blade assembly located in the bypass flow fluid. According to this document, the blade comprises a through cavity at each radial end of the blade for the entry or exit of the air flow to be cooled.

Since the heat exchange surface area is limited, the cooling efficiency of the air flow to be cooled is limited.

The object of the invention is to disclose a turbine blade and a turbine for optimizing heat exchange.

Disclosure of Invention

The invention relates to a turbomachine blade comprising a body extending mainly in a plane defined by a main axis B and a longitudinal direction, said plane being delimited by an intrados wall, an extrados wall, a leading edge at a first longitudinal end of the body and a trailing edge at a second longitudinal end of the body, characterized in that the body of the blade comprises a plurality of first ducts carrying the circulation of an air flow extending mainly in the direction of the main axis B and a plurality of second ducts carrying the circulation of a second air flow extending mainly in the longitudinal direction.

Integrating the two sets of ducts into the body of the blade increases the heat exchange surface area between the two air flows, thereby improving the cooling of the second air flow.

Preferably, each first duct comprises two ends open at the same end of the body along the main axis B.

Preferably, the ends of the first conduit are arranged to form a bundle which narrows progressively with decreasing distance from said at least one end of the body.

Preferably, each second duct comprises two ends that open in the intrados wall or in the extrados wall of the body.

Preferably, each second duct comprises two ends open at the leading or trailing edge.

Preferably, each second duct has corrugations in a transverse direction perpendicular to the vertical longitudinal plane, and each first duct is located in a concave section of the second duct.

Preferably, the first conduits are arranged laterally on each side of each second conduit.

Preferably, the blade is manufactured using an additive technology process.

The invention also relates to an aircraft turbomachine comprising a core stream of gas passing through a low-pressure compressor and a high-pressure compressor,

a bypass flow stream located around and coaxial with the core flow stream, comprising a stator vane assembly for flow of the bypass flow stream therethrough, the stator vane assembly comprising a plurality of vanes distributed about a major axis A of the turbine,

a pressurized air circuit which extracts air between the low-pressure compressor and the high-pressure compressor or in the high-pressure compressor to produce a compressed air flow which is fed to at least one component of the turbine,

characterized in that said plurality of blades comprises at least one blade according to the invention, the main axis B of which is oriented mainly radially from the main axis A of the turbomachine and the longitudinal direction of which is substantially parallel to said main axis A, said blade comprising a first duct and a second duct, and in that the pressurized gas flow passes through the first duct of said at least one blade and part of the gas flow flowing in the bypass flow fluid passes through the second duct of said at least one blade.

Preferably, the main axis B of said at least one blade is oriented mainly radially from the main axis a of the turbomachine and corresponds to the direction of the gas flow in the bypass flow fluid, the longitudinal direction of said at least one blade and the second duct of said at least one blade being substantially parallel to the main axis a.

Drawings

Other features and advantages of the present invention will become apparent upon reading the following detailed description, which is to be better understood with reference to the accompanying drawings, wherein:

figure 1 is a schematic axial section of an aircraft turbine comprising a pressurized air circuit made according to the invention;

figure 2 is a view similar to figure 1, showing a variant embodiment of the pressurized air circuit;

figure 3A is a schematic perspective view of a blade according to the invention;

figure 3B is a perspective cross-section of the blade shown in figure 3A, showing the first and second ducts;

figure 4 is a section through the blade shown in figure 3A along a longitudinal plane;

figure 5A is a detailed perspective view of a blade manufactured according to a second embodiment of the invention;

FIG.5B is a perspective cross-section of the blade shown in FIG.5A, showing the first and second ducts;

figure 6 is a section through the blade shown in figure 5B along a longitudinal plane.

Detailed Description

The vertical, longitudinal and transverse orientations according to the V, L, T coordinate system shown on the drawings will be used to describe the present invention.

Fig.1 shows an aircraft turbine 10 comprising a main axis a.

The turbine 10 includes, in order of distance from its major axis a, a low pressure shaft 12, a high pressure shaft 14, a core stream flow 16, a bypass stream flow 20, a core compartment 18 separating the core stream flow 16 and the bypass stream flow 20, and an intermediate housing 22.

Core compartment 18, also referred to as a "flow-fluid compartment", is radially bounded from major axis a by a radially inner wall 24 and a radially outer wall 26, the radially inner wall 24 bounding the exterior of core flow fluid 16, the radially outer wall 26 bounding the interior of bypass flow fluid 20. The housing 22 includes a radially inner wall 28 defining an exterior of the bypass flow stream 20.

Along the airflow direction and along the main axis, the core flow 16 includes, in order from upstream to downstream, in other words, from left to right with reference to fig.1, a low pressure compressor 30, a high pressure compressor 32, a combustor 34, a high pressure turbine, and a low pressure turbine (not shown).

The bypass flow stream 20 includes a paddle assembly 22, and the paddle assembly 22 will redirect the flow of the bypass flow stream 20 such that its flow is oriented substantially in an axial direction, in other words, substantially in a direction parallel to the primary axis a.

To this end, the paddle assembly 52 comprises a plurality of paddles 54 evenly distributed around the main axis a of the turbine 10, which act on the gas flow circulating in the bypass flow fluid 20.

Each blade 54 extends mainly in a plane defined by a main axis B and a longitudinal direction. When the blade 54 is mounted in the blade assembly 52, the main axis B is oriented substantially radially from the main axis a, in other words, the main axis B is significantly inclined from the radial orientation, and the longitudinal direction is parallel to the main axis a.

Each blade 54 has a first end, referred to as root 56, along the main axis B for its connection to the core compartment 18, and a second end, referred to as tip 58, along the main axis B for its connection to the casing 22. When the blade 54 is mounted in the blade assembly 52, the first end 56 is radially inward of the principal axis a and the second end is radially outward of the principal axis a.

The turbine 10 also comprises a pressurized air circuit 40, which pressurized air circuit 40 is designed firstly to cool the low-pressure shaft 12 and secondly to supply pressurized air to the chambers containing the lubricating oil for the moving parts which are located on the low-pressure shaft and pressurize these chambers.

This pressurized air may also be directed to a speed reducer (not shown) located between the low pressure shaft 12 and the turbine fan to ventilate or cool the turbine.

The speed reducer will separate the rotational speed of the fan from the rotational speed of the low pressure shaft 12 driving the fan.

In particular, this reduces the rotational speed of the blades of the fan with respect to the rotational speed of the blades of the low pressure compressor, thereby optimizing the efficiency of each low pressure compressor and therefore improving the propulsion efficiency. Such a retarder is particularly advantageous for turbojet engines with high dilution ratios, in other words for which the ratio of the air flowing in the bypass flow fluid to the air flowing in the core flow fluid is high.

The pressurized air circuit 40 includes at least one air discharge point 42 located on the radially inner wall 24 of the core compartment 18. The discharge point 42 is located between the low pressure compressor 30 and the high pressure compressor 32, or in the high pressure compressor 32, as shown in fig. 1.

In the latter case, the discharge point is located at a stage of the high-pressure compressor 32, which is determined according to the pressure of the pressurized air, its temperature, and the possibility of discharge at the first stage of the high-pressure compressor 32 despite the presence of Variable Stator Vanes (VSV).

The pressure of the displaced air is high enough to pressurize the oil chamber. However, the temperature of this air is too high to cool the low pressure shaft 12 and to have good operating conditions for the lubrication circuit.

To this end, the pressurized air circuit 40 includes a heat exchanger 44 that reduces the temperature of the pressurized air.

The heat exchanger 44 is of the air-air type, the source of cold air comprising air circulating in the bypass flow fluid 20.

In this case, a heat exchanger 44 is formed in at least one blade 54 of the blade assembly 52, through which heat exchanger 44 pressurized air circulates to exchange heat with air circulating in the bypass flow fluid 20.

The pressurized air circuit 40 includes, in the direction of airflow in the circuit, an upstream section 46 extending from the air discharge point 42 to the blades 54, a downstream section 48 extending from the blades 54 to the low pressure shaft 12, and a device (not shown) that distributes pressurized air toward the low pressure shaft 12 and cooling points of the oil pressurization chamber.

Thus, the upstream section 46 of the pressurized air circuit 40 extends through the core compartment 18, from the radially inner wall 24 thereof, where the upstream section 46 is connected to the exhaust point 42, to the radially outer wall 26 of the core compartment 18, where the core compartment 18 is connected to the blades 54.

The downstream section 48 of the pressurized air circuit extends through the core compartment 18, starting from its radially outer wall where it is connected to the blades 54 and where it also flows through the core flow fluid 16 in profiled arms (not shown) advantageously positioned between the low pressure compressor 30 and the high pressure compressor 32.

In the second embodiment shown in fig.2, the downstream section 48 of the pressurized air circuit 40 is connected to the outer radial end 58 of the blade 54, it passes through the secondary flow fluid 20 and the core compartment 18, for example, through a segment arm (not shown), and then it also passes through the core flow fluid 16 in a segment arm (not shown) advantageously positioned between the low pressure compressor 30 and the high pressure compressor 32.

As described above, the source of cold air for the blades 54 comprises air circulating in the bypass flow fluid 20.

Therefore, heat exchange is performed by the constituent material of the blade 54.

The blade 54 comprises a body 60 with a vertical main direction, a lower end 56, called root, and an upper end 58, called tip.

The body 60 is laterally bounded by an inner arcuate wall 66 and an outer arcuate wall 68. These two walls (inner arcuate wall 66 and outer arcuate wall 68) are connected to the first longitudinal end of the body at a leading edge 70, said leading edge 70 being the upstream edge of the body in the direction of airflow in the bypass flow stream 20, and they are connected to the second longitudinal end of the body at a trailing edge 72, said trailing edge 72 being the downstream edge of the body 60 in the direction of airflow in the secondary flow stream 20.

As described above, the pressurized airflow is circulated through the blades 54. To this end, the body 60 comprises a plurality of ducts 74, said ducts 74 being oriented in the body 60 in a direction defined by the main axis B of the blade 54.

According to the embodiment shown in fig.1, the duct 74 is open only at the root 56 of the blade 54. They then have a curved U-shape at the tip 58 of the blade 54, in other words comprising two branches substantially parallel to the main axis B and a curved section connecting these two branches, said curved section being located at the tip 58 of the blade 54.

According to the embodiment shown in fig.2, the ducts 74 open at their ends at the root 56 and tip 58 of the blade 54. To this end, the root and tip of the blade 54 include attachment devices (not shown) at the upstream and downstream sections 46, 48. Moreover, to facilitate the connection of the first conduits 74, all the ends of the first conduits 74 are inclined to each other and to the main direction of the axis B to form a bundle that progressively tightens as the distance from the tip 58 or root 56 of the blade 54 decreases.

In the following description, reference will be made to the embodiment shown in fig.2, according to which the duct 74 opens radially at each end 56, 58 of the blade 54. It will be understood that the invention is not limited to this embodiment and that it is also applicable to U-shaped curved ducts as shown in figure 1.

As can be seen in particular in fig.2, the ducts 74 are oriented mainly in the direction of the main axis B and are longitudinally offset so as to be distributed longitudinally over the entire length of the body 60.

The large number of these conduits 74 allows a large heat exchange surface area between the body 60 of the blade 54 and the pressurized airflow, and maximizes the surface area and volume of the blade.

The airflow circulating through the bypass flow 20 contacts the inner and outer arcuate walls 66, 68 to exchange heat with the body 60 of the blade 54.

In order to further increase the heat exchange surface area between the body 60 of the paddle 54 and the gas flow circulating in the bypass flow fluid 20, the body 60 of the paddle 54 comprises a plurality of further ducts 76 having mainly a longitudinal orientation, said further ducts 76 being designed to carry the circulation of a part of the gas flow circulating in the bypass flow fluid 20.

In the following description, the conduit 74 through which the pressurized gas stream fluid passes will be designated as the "first conduit" and the conduit 76 through which the fresh gas stream circulates in the bypass flow fluid 20 will be designated as the "second conduit".

The second conduits 76 are oriented in the main longitudinal direction and are distributed in the main body 60 in the direction of the main axis B.

The combination of the first conduit 74 and the second conduit 76 forms a mesh in the body 60 of the paddle 54, thus facilitating heat exchange between the two airflow fluids.

According to the first embodiment shown in fig.3A to 4, a second conduit 76 is formed between the extrados wall 68 and the first conduit 74.

In addition, both ends of each second duct 76 are open in the extrados wall 68.

This configuration makes it possible to discharge a portion of the air flowing along the extrados wall 68 and to discharge the hot air along the extrados wall 68 in the same flow direction, while generating low aerodynamic disturbances.

Thus, the relative position of the second conduit 76 with respect to the extrados wall 68 and with respect to the first conduit 74 makes it possible to place the first conduit 74 at a distance from the extrados wall 68, which extrados wall 68 is the wall of the blade 54 that is most susceptible to external attack (e.g., hail).

It will be understood that the present invention is not limited to this embodiment, and that the second conduit 76 may be formed between the inner arcuate wall 66 and the first conduit 74, and both ends thereof may be open in the inner arcuate wall 66.

In a second embodiment shown in fig.5A through 6, a second conduit 76 passes longitudinally through the entire body 60 of the bucket 54 from the leading edge 70 to the trailing edge 72.

This embodiment may limit the creation of perturbations on either the intrados wall 66 or the extrados wall 68. Venting the portion of the gas stream circulating in the bypass flow stream 20 minimizes gas flow disturbances through the secondary flow stream 20. The air flowing through these second ducts 76 also becomes straight and emerges in the longitudinal direction.

According to a first embodiment of another aspect of the invention, with respect to the relative arrangement of the different ducts 74, 76, a second duct 76 is arranged laterally between the first duct 74 and the extrados wall 68 to promote heat exchange, as shown in detail in fig. 4.

According to a second embodiment of this further aspect of the invention, and as shown in detail in fig.6, each second duct 76 has corrugations in its main longitudinal transverse plane.

These corrugations allow the second conduit 76 to pass between the first conduits.

Thus, each first conduit is associated with a curved segment of each second conduit 76 and is located inboard of the concave portion of the curved segment.

This enables a better distribution of the heat exchange in the blades 54 and a greater number of first conduits 74 in the same body 60 for the same distance between two adjacent first conduits 74.

Therefore, the material from which the blades 54 are made is selected to have good heat transfer properties. The material may also be selected based on the mechanical properties of the blade 54, particularly when the blade 54 performs a structural function that provides a mechanical connection between the shell 22 of the center housing and the core compartment 18.

Moreover, the material from which the blades 54 are made is selected to facilitate their manufacture. Preferably, the paddle 54 is manufactured by additive techniques, as this technique can be used to manufacture the different conduits 74, 76 in the paddle 54. Therefore, the material from which the blade 54 is made must be suitable for use with this method of manufacture.

Other methods of manufacturing the blades 54 are contemplated, such as molding and/or machining.

Aluminum is cited as a non-limiting example of a material having good thermal conductivity properties.