Injection tube integrated in central vent tube

Abstract

The invention relates to an upstream part of an air discharge system for a turbomachine. The upstream part comprises a tube having an upstream end and a downstream end, and an inner tubular structure inside said tube and configured to form a narrowing of the cross section of the inner tubular structure therein. The inner tubular structure is integrated with the tube at the downstream end of the tube and the inner tubular structure is freely suspended at the upstream end of the tube. The invention also relates to a turbomachine having a device for discharging air from a bearing chamber, wherein the air is guided outside the turbomachine by said air discharge system. A method for manufacturing the air discharge system is proposed.

Description

Technical Field

[0001] This invention relates to a central ventilation pipe for a turbine. Background Technology

[0002] Turbines (such as turbojet engines) may include an exhaust system configured to draw in and direct pressurized air from the bearing housing and eject the pressurized air into the atmosphere. The exhaust system typically includes a central vent, with an internal tubular structure positioned within the central vent to form a narrowing section.

[0003] Vibration and thermal differences can cause cracks to appear between the central vent and the internal tubular structure, damaging the exhaust system. The central vent and the internal tubular structure are two separate components in contact. Static and vibrational stresses can cause cracks to appear in the internal tubular structure in the area in contact with the central vent, damaging the exhaust system.

[0004] Therefore, this invention proposes an air exhaust system that integrates an internal tubular structure into a central venting duct, and a method for manufacturing the system. The proposed exhaust system integrates the central venting duct and the internal tubular structure into a single component. Summary of the Invention

[0005] Therefore, the object of the present invention is to provide an upstream portion (40) of an air exhaust system (20) for a turbine (30), the upstream portion comprising:

[0006] - A pipe (70) having an upstream end (50) and a downstream end (60),

[0007] - An internal tubular structure (10) located inside (80) of the tube (70), and configured to form a narrowed portion (170) of the cross-section of the internal tubular structure therein.

[0008] The internal tubular structure (10) is integral with the pipe at the downstream end (60) of the pipe (10), and the internal tubular structure is freely suspended at the upstream end (50) of the pipe.

[0009] The upstream portion may include a free space (90) formed between the tube (70) and the inner tubular structure (10), such that the tube and the inner tubular structure are connected only at the downstream end, and the tube and the inner tubular structure are preferably connected only along the circumference of the downstream end.

[0010] According to a variation, the tube and the inner tubular structure may be separated at the upstream end by an annular slot (100), such that the inner tubular structure is freely suspended at the upstream end, the annular slot preferably having a size of 1.5 mm or greater.

[0011] The wall (110) of the tube may include at least one opening (120), the at least one opening being configured to allow removal of any unmelted powder located between the tube and the internal tubular structure.

[0012] The tube (70) may have a cylindrical shape with a longitudinal axis (220), and the first angle (140) between the wall of the internal tubular structure (10) and the longitudinal axis may be 50° or less.

[0013] The thickness (150) of the tube wall (110) and the wall of the internal tubular structure can be between 0.8 mm and 1.2 mm.

[0014] The present invention also relates to an air exhaust system, the air exhaust system comprising:

[0015] -The upstream portion, and

[0016] - Extension tube (160),

[0017] An extension tube is connected to the downstream end of the tube (70) to form an extension of the tube and to form the downstream portion of the air exhaust system.

[0018] The extension tube is preferably connected to the tube (70) via a weld (180).

[0019] In the air exhaust system, the extension pipe may include a material different from that of the upstream portion.

[0020] The present invention also relates to a turbine having a device (200) for discharging air from the bearing housing.

[0021] Air is directed to the outside of the turbine through the air exhaust system described above.

[0022] The present invention also relates to a method for manufacturing the upstream portion of an air exhaust system as described above by powder bed laser melting.

[0023] In the manufacturing process, laser melting can be performed from the upstream end to the downstream end.

[0024] The present invention also relates to a method for manufacturing an air exhaust system as described above, the method comprising the steps described above and the step of assembling an extension tube at an upstream portion by welding. Attached Figure Description

[0025] The invention will be better understood from the following description and accompanying drawings, in which:

[0026] - Figure 1 A turbine including a device (200) for discharging air from the bearing chamber is shown.

[0027] - Figure 2 The central vent pipe located within the jet cone is shown.

[0028] - Figure 3a , Figure 3b and Figure 3c A cross-section of the upstream section of the central vent is shown.

[0029] - Figure 4a and Figure 4b A cross-section of the upstream portion of the central vent pipe with manufacturing support is shown. Detailed Implementation

[0030] Figure 1 A turbine is shown, which includes a device (200) for discharging air from the bearing chamber.

[0031] Turbines (such as twin-bypass turbojet engines) include an air intake with a fan, and the exhaust airflow from the intake is divided into an airflow that enters the engine and forms a hot or mainstream airflow and an airflow that flows around the engine and forms a cold or secondary airflow.

[0032] An engine typically includes at least one compressor, a combustion chamber, at least one turbine, and an injection device along the gas flow direction from upstream to downstream, in which the combustion gases exiting the turbine and forming the main stream are mixed with the secondary stream.

[0033] At the downstream end of the turbine, the turbine includes a cone (190) for injecting the main stream, or even a mixture of the main stream and secondary stream. The cone has an elongated shape, and its upstream end, with a larger diameter, is attached to turbine components (such as the casing).

[0034] A central vent pipe (20) extends longitudinally through the injection cone (190). The function of this central vent pipe (20) is to draw in and guide air from which oil has been removed by the turbine's air-oil separator, and to inject the air into the atmosphere through its downstream end, approximately at the downstream end of the injection cone (190). Thus, air from the turbine's bearing housing is directed to the outside via the central vent pipe (20).

[0035] The central vent includes an internal tubular structure (10) comprising a narrowing section (170), or in other words, a cross-section (170) with a reduced diameter, to create a Venturi effect on the air flowing within the internal tubular structure. A nozzle (300) draws purified air into the narrowing section (170), which generates a low-pressure suction through the Venturi effect, thereby drawing purified air from the nozzle and then ejecting it to the outside. Figure 2As shown in the figure, the direction of airflow from upstream to downstream in a running turbine is indicated by arrow 230.

[0036] Figure 2 A central vent (20) is shown within the jet cone (190). This vent includes an upstream section (40), followed downstream by an extension section (160), the inlet of which is indicated by arrow 280. The upstream section (40) itself includes an upstream end (50) and a downstream end (60).

[0037] The upstream portion includes a tube (70) having a longitudinal axis (220), which is preferably cylindrical in shape. An internal tubular structure (10) is located inside the tube (70) and forms a narrowing section (170) within the tube.

[0038] An extension tube (160) is connected to the downstream end (60) of the upstream portion (40) to form an extension of the tube (70). The extension tube can be connected to the upstream portion (40) via a weld (180). In this case, the extension tube may comprise a material different from that of the upstream portion. For example, the upstream portion may comprise a material particularly well-suited for manufacture by powder bed laser melting or another additive manufacturing method. The extension tube may comprise a material suitable for manufacture by other methods.

[0039] It is also conceivable, for example, to create a single piece from the upstream portion and the extended control via powder bed laser melting or another additive manufacturing method.

[0040] Figure 3a It shows Figure 2 The cross-section of the upstream portion (40) of the central vent (20) along the plane containing the longitudinal axis (220) of the tube (70). In this figure, the end (280) of the extension tube and the upstream portion (40), which includes the tube (70) between the upstream end (50) and the downstream end (60), can also be seen. The diameter of the tube can be 78 mm. An internal tubular structure (10) forms a narrowing section (170) inside the tube (80). In other words, air entering through the upstream end (50) and exiting through the downstream end must pass through a channel whose cross-section first narrows and then widens relative to the diameter of the tube. Advantageously, as Figure 3a As shown, the narrowing section (170) is asymmetrical with respect to the longitudinal axis (220) of the pipe, or more precisely, the narrowing section is off-center with respect to the longitudinal axis (220). In other words, air entering through the upstream end (50) is diverted from the longitudinal axis (220) by the asymmetrical narrowing section. The advantage of this asymmetrical form is that it avoids oil stagnation upstream of the narrowing area, which continuously ensures oil flow to the outside.

[0041] Figure 3c An enlarged view of the internal tubular structure and the downstream end (60) of the tube is shown. The internal tubular structure is integrally formed with the tube at the downstream end (60). Generally, "made" the first and second parts as a single unit means that the first and second parts are integrally manufactured as a single piece. In other words, the internal tubular structure and the tube are integrally manufactured, or at the downstream end, there is a continuity of material between the wall of the tube and the wall of the internal tubular structure. Preferably, the internal tubular structure is integrally formed with the tube over the entire circumference at the downstream end. In this way, the internal tubular structure and the tube are reliably and permanently connected, ensuring the service life of the central vent tube.

[0042] Figure 3b An enlarged view of the upstream end (40) of the central vent is shown. The inner tubular structure hangs freely at this end. In other words, at the upstream end, the inner tubular structure is not connected to the tube. The tube and the inner tubular structure are connected only at the downstream end to leave a free space (90) between the wall (110) of the tube and the wall of the inner tubular structure. The tube and the inner tubular structure may be connected only along the circumference of the downstream end. At the upstream end, there is a space of dimension d between the inner tubular structure and the tube, such as... Figure 3a and Figure 3b As shown. An annular slot (100) can be formed at the upstream end of the space, allowing the internal tubular structure to be freely suspended within it. The annular slot can have a size of 1.5 mm or greater. The free space (90) communicates with the outside through the space between the internal tubular structure and the tube or through the annular slot (100). In this way, the upstream portion (40) is particularly well-suited for manufacturing as a single piece using a powder bed laser melting method. After the upstream portion is formed, the free space (90) is filled with unmelted powder to form the walls (110) and other components of the upstream portion (40). The powder can be discharged to the outside through a space of size d or the annular slot (100), such as... Figure 3a and Figure 3b As shown. Therefore, the tube and its internal tubular structure, which are integrally formed at the downstream end and free at the upstream end, are particularly well-suited for manufacturing as single pieces by powder bed laser melting. Advantageously, the wall (110) of the tube may include one or more lateral openings (120) configured to allow the removal of unmelted or unrefined powder.

[0043] The thickness (150) of the tube wall (110) and the wall of the inner tubular structure can be 0.8 mm, 1 mm, or 1.2 mm. It is also conceivable that the tube wall and the wall of the inner tubular structure have a thickness varying between 0.8 mm and 1 mm, between 1 mm and 1.2 mm, or between 0.8 mm and 1.2 mm. Therefore, one or more thicknesses can be selected for the upstream portion of the central vent tube. Thicknesses between 0.8 mm and 1.2 mm are particularly well-suited for fabrication by powder bed laser melting. The length (130) of the upstream portion (40) of the central vent tube can be 600 mm or less, a length compatible with simplified fabrication on a large-scale powder bed laser melting apparatus.

[0044] Figure 4a and Figure 4b It shows the line and Figure 3a Cross-sections in the same plane. These figures also show the powder (250) located between the tube and the internal tubular structure, and the manufacturing support (260) that does not form part of the central vent. Reference numeral 140 indicates the first orientation angle (140) of the wall of the internal tubular structure relative to the longitudinal axis (220). Reference numeral 240 indicates the orientation angle of the wall of the internal tubular structure relative to an axis perpendicular to the longitudinal axis (220).

[0045] The support (260) can be flat and supports the flange (90) at the upstream end of the tube. During flange formation, the support provides support for the flange-forming material by melting powder until the flange-forming material hardens. Generally, the support (260) facilitates the initiation of component construction. The support (260) can be made of the same material as the component. In this case, the first powder particles forming the flange are melted with the material of the support (260). In this case, the support must eventually be separated from the component, for example, by machining.

[0046] Preferably, the first angle (140) between the wall and the longitudinal axis is 50° or less. In other words, the sum of the first and second angles is 90°, and the second angle between the wall and the vertical axis is 40° or greater. The range of values ​​for the first or second wall angle is particularly suitable for manufacturing by powder bed laser melting. This range of values ​​is advantageous because a wall having a first angle of 50° or less with the longitudinal axis can be manufactured without the need for additional material (270) between the component and the support (260), such as... Figure 4b As shown.

[0047] For the first angle greater than 50°, additional material (270) is required. The additional material is formed on the same side as the air inlet, and it stabilizes the component or wall during the powder melting process. The additional material is then machined to form the wall. This material forming the additional material (270) can be manufactured using additive manufacturing, such as by powder melting. The parameters of the additional material can differ from those of the component, such as a lower density. The lower density of the additional material relative to the component facilitates machining, for example, forming the wall.

[0048] Therefore, the entire component can be manufactured as a single piece (including additional materials). In summary, it is necessary to distinguish between the manufacturing support (260) that enables the entire component to be supported from the beginning of manufacturing and any one or more additional materials (270) that may be needed to manufacture certain parts of the component due to the small manufacturing angle.

[0049] The manufacturing method involves fabricating the upstream portion (40) as a single piece using a powder bed laser melting method. Advantageously, this additive manufacturing by laser melting begins with the formation of the upstream end and ends with the fabrication of the downstream end. Thus, the flange (90) can be easily fabricated at the beginning of the method, while simultaneously supporting the flange on the support (260). Alternatively, fabrication can proceed from the downstream end (60) towards the upstream end (50).

[0050] At the end of the laser melting process, the powder (250) remains in the free space (90) and must be removed. This is a powder not used to form a wall. This powder can be removed (210) through the space located at the upstream end, between the tube and the internal tubular structure. Unmelted powder can be removed through an annular slot (100). Advantageously, the powder can also be discharged through one or more openings (120) in the wall (110) of the tube.

[0051] Therefore, the tube and the internal tubular structure are manufactured as a single piece by additive manufacturing methods (preferably by powder bed laser melting as described above).

[0052] The upstream portion manufactured by powder bed laser melting can be produced by "Inconel 718" (registered trademark). In certain forms, Inconel 718 may comprise, by weight percentage: 50% to 55% nickel, 17% to 21% chromium, 15% to 21% iron, 4.75% to 5.5% niobium, 2.8% to 3.3% molybdenum, 0.65% to 1.15% titanium, and 0.2% to 0.8% aluminum. This material is particularly well-suited for manufacture by powder bed laser melting.

[0053] Extension tubes can also be manufactured by Inconel 718. Alternatively, extension tubes can be manufactured by "Inconel 625" (registered trademark). In certain forms, Inconel 625 may comprise, by weight percentage: 58% or more nickel, 20% to 23% chromium, 5% or less iron, 8% to 10% molybdenum, 3.15% to 4.15% niobium, 1% or less cobalt, 0.5% or less manganese, 0.4% or less aluminum, 0.4% or less titanium, 0.5% or less silicon, 0.1% or less carbon, 0.015% or less sulfur, and 0.015% or less phosphorus.

Claims

1. An upstream portion (40) of an air exhaust system (20) for a turbine (30), said upstream portion comprising: - A pipe (70) having an upstream end (50) and a downstream end (60). - An internal tubular structure (10) located inside (80) of the tube (70), and the internal tubular structure is configured to form a narrowed portion (170) of the cross-section of the internal tubular structure. The internal tubular structure (10) is integral with the tube at the downstream end (60) of the tube (70), and the internal tubular structure is freely suspended at the upstream end (50) of the tube.

2. The upstream portion according to claim 1, wherein A free space (90) is formed between the tube (70) and the internal tubular structure (10), such that the tube and the internal tubular structure are connected only at the downstream end.

3. The upstream portion according to claim 1 or 2, wherein The tube and the internal tubular structure are separated at the upstream end by an annular slot (100), such that the internal tubular structure is freely suspended at the upstream end.

4. The upstream portion according to claim 1 or 2, wherein The wall (110) of the tube includes at least one opening (120) configured to remove any unmelted powder located between the tube and the internal tubular structure.

5. The upstream portion according to claim 1 or 2, wherein - The tube (70) has a cylindrical shape, the cylindrical shape having a longitudinal axis (220), and - The first angle (140) between the wall of the internal tubular structure (10) and the longitudinal axis is 50° or less.

6. The upstream portion according to claim 4, wherein The thickness (150) of the wall (110) of the tube and the wall of the inner tubular structure is between 0.8 mm and 1.2 mm.

7. The upstream portion of claim 2, wherein, The tube and the internal tubular structure are connected only along the circumference of the downstream end.

8. The upstream portion of claim 3, wherein, The annular slot has a size of 1.5 mm or greater.

9. An air exhaust system, said air exhaust system comprising: - The upstream portion according to any one of claims 1 to 8, and - Extension tube (160) The extension tube is connected to the downstream end of the tube (70) to form an extension of the tube and to form the downstream portion of the air exhaust system. The extension tube is connected to the tube (70).

10. The air exhaust system according to claim 9, wherein The extension tube is made of a different material than the upstream portion.

11. The air discharge system of claim 9, wherein, The extension tube is connected to the tube (70) via a weld (180).

12. A turbine having means (200) for discharging air from a bearing housing. Air is directed to the outside of the turbine via an air exhaust system according to any one of claims 9 to 11.

13. A method for manufacturing the upstream portion of an air exhaust system according to any one of claims 1 to 8 by means of powder bed laser melting.

14. The manufacturing method according to claim 13, wherein the laser melting is performed from the upstream end to the downstream end.

15. A method for manufacturing an air exhaust system according to any one of claims 9 to 11, the method comprising the manufacturing method according to claim 13 or 14 and the step of assembling the extension tube at the upstream portion by welding.

Images