Air entraining system

Abstract

The utility model provides an air entraining system, which comprises a first air entraining pipe and a second air entraining pipe, a first air entraining channel is defined by the first air entraining pipe, a second air entraining channel is defined by the second air entraining pipe, the first air entraining channel is separated from a rotor disc cavity by the first air entraining pipe, and the second air entraining channel is separated from the disc cavity by the second air entraining pipe; the first air entraining channel is connected between the air entraining port and the second air entraining channel, the air entraining port is formed in the high-pressure compressor, and the second air entraining channel is connected between the first air entraining channel and the bearing cavity.

Description

Technical Field

[0001] The utility model relates to the technical field of aviation engine bearing sealing, in particular to an air bleeding system. Background Art

[0002] To ensure the safe operation of the aviation engine bearing, lubricating oil needs to be supplied to the bearing cavity. Since the boundary of the bearing cavity is the interface between the rotating and stationary parts, there is a leakage gap. Usually, an air bleeding system is used to introduce sealing gas into the bearing cavity. The pressure of the sealing gas is greater than the pressure in the bearing cavity, forming a sealing pressure difference to achieve the purpose of sealing the bearing cavity and preventing lubricating oil from leaking from the bearing cavity. If the lubricating oil leaks, on the one hand, it will increase the lubricating oil consumption and reduce the economy of the engine. On the other hand, it may cause deflagration in the high-temperature area, affecting the safety of the engine.

[0003] For the bearing cavity near the hot-end components of the aviation engine, the air bleeding system for its sealing generally bleeds air from the high-pressure compressor, enters the high-pressure compressor rotor disc cavity channel through the flow holes on the high-pressure compressor journal, then forms a core flow, flows through each stage of the compressor disc cavity for purging, and finally enters the bearing cavity.

[0004] However, in the process of the existing air bleeding system bleeding air from the high-pressure compressor and then entering the rotor disc cavity channel to form a core flow, the sealing gas will be heated by each stage of the disc surface. The temperature of the sealing gas will increase with the increase of the number of rotor stages, and the higher the number of rotor stages, the greater the temperature rise along the way. If the temperature of the sealing gas entering the bearing cavity is too high, it will cause the temperature of the bearing cavity to rise, and there is a risk of coking of the lubricating oil in the cavity, affecting the lubrication and cooling effect of the lubricating oil in the bearing cavity. Summary of the Utility Model

[0005] The purpose of the utility model is at least to provide an air bleeding system, which can effectively reduce the temperature rise along the way of the sealing gas, significantly reduce the temperature of the sealing gas, and ensure the safe operation of the bearing in the bearing cavity.

[0006] The following gives a brief overview of one or more aspects to provide a basic understanding of these aspects. This overview is not an exhaustive survey of all conceived aspects, and neither is it intended to identify the key or decisive elements of all aspects nor to define the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description to follow.

[0007] One embodiment of the present utility model provides an air extraction system. The air extraction system includes a first air extraction pipe and a second air extraction pipe. The first air extraction pipe defines a first air extraction passage, and the second air extraction pipe defines a second air extraction passage. The first air extraction pipe isolates the first air extraction passage from the rotor disc cavity, and the second air extraction pipe isolates the second air extraction passage from the disc cavity. The first air extraction passage is connected between the air extraction port and the second air extraction passage. The air extraction port is opened on the high-pressure compressor, and the second air extraction passage is connected between the first air extraction passage and the bearing cavity.

[0008] In some embodiments, the first air extraction pipe and the second air extraction pipe are heat-insulating pipe bodies, and the heat-insulating pipe bodies are used to prevent or slow down heat transfer.

[0009] In some embodiments, the first air extraction pipe and the second air extraction pipe are arranged around the low-pressure shaft of the engine.

[0010] In some embodiments, the first end of the first air extraction pipe is connected to the air extraction port opened on the high-pressure compressor, and the second end of the first air extraction pipe is correspondingly arranged at any one of the 4th to 8th stage disc cavities of the high-pressure compressor.

[0011] In some embodiments, the first end of the second air extraction pipe is connected to the second end of the first air extraction pipe, and the second end of the second air extraction pipe is connected to the bearing cavity.

[0012] In some embodiments, an installation ring is arranged on the disc cavity. The first air extraction pipe, the second air extraction pipe, and the installation ring are arranged around the low-pressure shaft of the engine, and the second end of the first air extraction pipe and the first end of the second air extraction pipe are fixed on the installation ring.

[0013] In some embodiments, a first flow hole is opened near the first end of the first air extraction pipe. The first flow hole is used to extract cooling gas from the first air extraction pipe, and the cooling gas is used to cool the disc cavity.

[0014] In some embodiments, a second flow hole is opened near the second end of the first air extraction pipe. The second flow hole is used to introduce the cooling gas in the disc cavity into the first air extraction pipe to mix with the sealing gas in the first air extraction pipe.

[0015] In some embodiments, a second flow hole is opened near the second end of the first air extraction pipe. The second flow hole is used to extract cooling gas from the first air extraction pipe, and the cooling gas is used to cool the disc cavity.

[0016] In some embodiments, a plurality of second flow holes are opened near the second end of the first air extraction pipe, and the shapes of the second flow holes include long strip, circular, square, and square-round.

[0017] The air extraction system involved in the present utility model isolates the first air extraction pipe and the second air extraction pipe, separating the first air extraction channel and the second air extraction channel from the rotor disc cavity, avoiding the direct contact between the sealing gas and the disc cavity, reducing the heating of the sealing gas by each stage of the disc inside the rotor, which is beneficial to reducing the temperature of the sealing gas, thereby facilitating the reduction of the temperature of the bearing cavity and avoiding the coking of the lubricating oil in the bearing cavity;

[0018] A flow hole is opened near the first end or the second end of the first air extraction pipe, and a stream of cooling gas is led out from the first air extraction pipe into the disc cavity channel outside the first air extraction pipe and the second air extraction pipe, realizing the cooling purge of the disc cavity channel, which can significantly reduce the temperature of the sealing gas in the bearing cavity. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] After reading the detailed description of the embodiments of the present disclosure in conjunction with the following drawings, the above features and advantages of the present utility model can be better understood. In the drawings, the components are not necessarily drawn to scale, and components with similar related characteristics or features may have the same or similar reference numerals. Among them:

[0020] Figure 1 is a schematic structural view of the first air extraction pipe shown in some embodiments;

[0021] Figure 2 is a schematic structural view of the second air extraction pipe shown in some embodiments;

[0022] Figure 3 is a schematic structural view of the first air extraction pipe shown in some other embodiments. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] The present utility model will be described in detail below in conjunction with the drawings and specific embodiments. It should be noted that the aspects described below in conjunction with the drawings and specific embodiments are only exemplary and should not be construed as imposing any limitation on the protection scope of the present utility model.

[0024] It can be understood that the technical terms that may be involved in the description of this specification, such as "center", "longitudinal", "transverse", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or position relationship based on the orientation or position relationship shown in the drawings. It is only for the convenience of describing the embodiments and does not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation on the protection scope of the utility model.

[0025] It should be noted that the terms "first", "second", etc. are used in the text to limit the features only for the convenience of distinguishing the corresponding features. Without additional statements, these terms have no special meanings, and thus should not be construed as limiting the protection scope of the present utility model.

[0026] An embodiment of this specification provides an air extraction system. As Figure 1 and Figure 2 shown, the air extraction system includes a first air extraction pipe 110 and a second air extraction pipe 120. The first air extraction pipe 110 defines a first air extraction passage, and the second air extraction pipe 120 defines a second air extraction passage. The first air extraction passage and the second air extraction passage are used to guide the sealing gas 130 to pass through. The first air extraction pipe 110 isolates the first air extraction passage from the rotor disk cavity, and the second air extraction pipe 120 isolates the second air extraction passage from the disk cavity, which can prevent the sealing gas 130 from directly contacting the disk cavity, reduce the heating of the sealing gas 130 by the various disk surfaces inside the rotor, is beneficial to reducing the temperature of the sealing gas 130, and thus is beneficial to reducing the temperature of the bearing cavity and avoiding the coking of the lubricating oil in the bearing cavity.

[0027] In some embodiments, the first air extraction passage is connected between the air extraction port and the second air extraction passage. Among them, the air extraction port is opened on the high-pressure compressor, and the second air extraction passage is connected between the first air extraction passage and the bearing cavity. The air extraction port extracts the gas inside the high-pressure compressor to form the sealing gas 130. The sealing gas 130 flows along the first air extraction passage, passes through the first air extraction passage, continues to pass through the second air extraction passage, and enters the bearing cavity connected to the second air extraction passage. The pressure of the sealing gas 130 is greater than the pressure inside the bearing cavity 140, realizing the sealing of the bearing cavity 140. It should be noted that Figure 1 and Figure 2 the arrows shown in

[0028] indicate the flow direction of the gas.

[0029] In some embodiments, the first air extraction pipe 110 and the second air extraction pipe 120 are arranged around the low-pressure shaft 150 of the engine. In some embodiments of this specification, the first air extraction pipe 110 and the second air extraction pipe 120 are used to isolate the central region of the disk cavity channel formed inside the rotor. The central region of the disk cavity channel is relatively far from the disk surface, that is, the middle region relatively close to the low-pressure shaft 150. The formed first air extraction channel and the second air extraction channel are relatively far from the rotor disk surface, which is beneficial to reducing the heating effect of the rotor disk surface on the sealing gas and is beneficial to reducing the temperature of the sealing gas 130.

[0030] The inside of the first air extraction pipe 110 is the first air extraction channel, and the second air extraction pipe 120 is the second air extraction channel. Figure 1 The structure of the first air extraction pipe 110 is mainly shown. Figure 2 The structure of the second air extraction pipe 120 is mainly shown.

[0031] Due to the axial direction along the low-pressure shaft 150 (see Figure 1 ), as the number of rotor stages increases, the temperature of its disk surface rises. The disk surface temperatures of the front stages of the high-pressure compressor rotor, the front stages of the disk cavity, for example, the 2nd to 7th stage disk cavities, corresponding to Figure 1 101, 102, 103, 104, and 105 shown, are lower than the disk surface temperatures of the rear stages of the high-pressure compressor rotor disk cavities. The rear stages of the disk cavity, for example, the 8th to 10th stage disk cavities, corresponding to Figure 1 106, 107, 108, and 109 shown, and are lower than the disk surface temperatures of the high-pressure turbine rotor disk cavities (such as Figure 1 1091 and 1092 shown). Therefore, in some embodiments, the first air extraction pipe 110 is arranged corresponding to the front stages of the high-pressure compressor rotor disk cavities, the second air extraction pipe 120 is arranged corresponding to the rear stages of the high-pressure compressor rotor disk cavities and the high-pressure turbine rotor disk cavities. The heat insulation coefficient of the first air extraction pipe 110 can be lower than that of the second air extraction pipe 120. The first air extraction pipe 110 and the second air extraction pipe 120 can be separately manufactured, which is beneficial to reducing the manufacturing difficulty and the manufacturing cost.

[0032] In some embodiments, such as Figure 1 and Figure 2As shown, the first end of the first air extraction pipe 110 is connected to the air extraction port opened on the high-pressure compressor, and the second end of the first air extraction pipe 110 is correspondingly arranged at any one of the 4th to 8th stage disk cavities of the high-pressure compressor, so that the first air extraction pipe 110 is arranged corresponding to the front-stage disk cavities of the high-pressure compressor rotor. In some embodiments, the second end of the first air extraction pipe 110 is correspondingly arranged at any one of the 5th to 7th stage disk cavities of the high-pressure compressor. In some embodiments, the first end of the second air extraction pipe 120 is arranged at the same stage disk cavity of the high-pressure compressor as the second end of the first air extraction pipe 110 to realize the connection between the second air extraction pipe 120 and the first air extraction pipe 110. The second end of the second air extraction pipe 120 is connected to the bearing cavity, so that the second air extraction pipe 120 is arranged corresponding to the rear-stage disk cavities of the high-pressure compressor rotor and the high-pressure turbine rotor disk cavity.

[0033] In some embodiments, as Figure 1 shown, a mounting ring 160 is installed at any one of the 4th to 8th stage disk cavities of the high-pressure compressor. The mounting ring 160 is arranged around the low-pressure shaft 150 and is located outside the first air extraction pipe 110 and the second air extraction pipe 120 away from the low-pressure shaft 150. The second end of the first air extraction pipe 110 and the first end of the second air extraction pipe 120 are fixed on the mounting ring 160. In some embodiments, the mounting ring 160 has an axial dimension along the axial direction, which is convenient for the installation of the first air extraction pipe 110 and the second air extraction pipe 120.

[0034] In some embodiments, in order to reduce the temperature rise of the sealing gas along the way, the temperature of the disk surface of the rotor disk cavity can be reduced to reduce the heating of the sealing gas by the rotor disk cavity, so as to reduce the temperature of the sealing gas in the bearing cavity. In some embodiments, a first flow hole (not shown in the figure) is opened near the first end of the first air extraction pipe 110. The first flow hole is used to extract the cooling gas 170 from the first air extraction pipe 110, and the cooling gas 170 purges the disk cavity channel located outside the first air extraction pipe 110 and the second air extraction pipe 120 to reduce the temperature of the disk surface of the rotor disk cavity. In some embodiments, as Figure 3 shown, a second flow hole 111 is opened near the second end of the first air extraction pipe 110. The second flow hole 111 is used to extract the cooling gas 170 from the first air extraction pipe 110, and the cooling gas 170 purges the disk cavity channel located outside the first air extraction pipe 110 and the second air extraction pipe 120 to reduce the temperature of the disk surface of the rotor disk cavity. In some embodiments, holes are opened on the journal of the high-pressure compressor for discharging the cooling gas 170.

[0035] In some embodiments, as Figure 2As shown in the figure, in order to reduce the temperature rise along the way of the sealing gas 130, a first flow hole is opened near the first end of the first gas guide pipe 110. The first flow hole is used to draw out the cooling gas 170 from the first gas guide pipe 110. Since the temperatures of the front-stage disk cavities of the high-pressure compressor rotor are still within an acceptable range, a second flow hole 111 is also opened near the second end of the first gas guide pipe 110. After the cooling gas 170 sweeps through the front-stage disk cavities of the high-pressure compressor rotor, it enters the first gas guide pipe 110 through the second flow hole 111 and mixes with the sealing gas 130 in the first gas guide pipe 110, so as to increase the gas extraction flow rate of the sealing gas 130 and significantly reduce the temperature rise along the way of the sealing gas 130. After the cooling gas 170 is mixed with the sealing gas 130 in the first gas guide pipe 110, a new sealing gas 130 is formed. The new sealing gas 130 enters the bearing cavity 140 through the second gas guide pipe 120. The pressure of the sealing gas 130 in the second gas guide pipe 120 is greater, which is beneficial to improving the sealing performance of the sealing gas 130 for the bearing cavity 140.

[0036] In some embodiments, the second flow hole 111 is correspondingly arranged at the disk cavities of the 4th to 6th stages of the high-pressure compressor. In some embodiments, in order to increase the amount of the cooling gas entering the first gas guide pipe 110 so as to increase the gas extraction flow rate of the sealing gas 130, a plurality of second flow holes 111 are opened near the second end of the first gas guide pipe 110. In some embodiments, the shape of the second flow hole 111 includes strip-shaped, circular, square, and square-round.

[0037] The basic concepts have been described above. Obviously, for those skilled in the art, the above detailed disclosure is only an example and does not constitute a limitation to this specification. In addition, unless clearly stated in the claims, the order of elements and sequences, the use of numerical letters, or the use of other names in this specification are not used to limit the order of the processes and methods in this specification. Although some useful utility model embodiments have been discussed through various examples in the above disclosure, it should be understood that such details only serve the purpose of illustration. The appended claims are not limited to the disclosed embodiments. On the contrary, the claims are intended to cover all modifications and equivalent combinations that conform to the essence and scope of the embodiments of this specification.

Claims

1. An air bleeding system, characterized in that, The bleed air system includes a first bleed air pipe and a second bleed air pipe. The first bleed air pipe defines a first bleed air passage, and the second bleed air pipe defines a second bleed air passage. The first bleed air pipe isolates the first bleed air passage from the rotor disk cavity, and the second bleed air pipe isolates the second bleed air passage from the disk cavity; The first bleed air passage is connected between the bleed air port and the second bleed air passage. Among them, the bleed air port is opened on the high-pressure compressor, and the second bleed air passage is connected between the first bleed air passage and the bearing cavity.

2. The air bleeding system according to claim 1, characterized in that The first bleed air pipe and the second bleed air pipe are heat-insulating pipe bodies, and the heat-insulating pipe bodies are used to prevent or slow down heat transfer.

3. The air bleeding system according to claim 1, wherein, The first bleed air pipe and the second bleed air pipe are arranged around the low-pressure shaft of the engine.

4. The air extraction system according to claim 1, characterized in that, The first end of the first bleed air pipe is connected to the bleed air port opened on the high-pressure compressor, and the second end of the first bleed air pipe is correspondingly arranged at any one of the 4th to 8th stage disk cavities of the high-pressure compressor.

5. The air bleeding system according to claim 4, wherein The first end of the second bleed air pipe is connected to the second end of the first bleed air pipe, and the second end of the second bleed air pipe is connected to the bearing cavity.

6. The air bleeding system according to claim 5, wherein An installation ring is arranged on the disk cavity. The first bleed air pipe, the second bleed air pipe and the installation ring are arranged around the low-pressure shaft of the engine, and the second end of the first bleed air pipe and the first end of the second bleed air pipe are fixed on the installation ring.

7. The bleed air system according to claim 4, characterized in that, A first flow hole is opened on the first bleed air pipe near its first end, and the first flow hole is used to draw out cooling gas from the first bleed air pipe, and the cooling gas is used to cool the disk cavity.

8. The air bleeding system according to claim 7, characterized in that A second flow hole is opened on the first bleed air pipe near its second end, and the second flow hole is used to introduce the cooling gas in the disk cavity into the first bleed air pipe to mix with the sealing gas in the first bleed air pipe.

9. The air bleed system according to claim 4, characterized in that, A second flow hole is opened on the first bleed air pipe near its second end, and the second flow hole is used to draw out cooling gas from the first bleed air pipe, and the cooling gas is used to cool the disk cavity.

10. The air bleeding system according to claim 8 or 9, characterized in that, A plurality of the second flow holes are opened on the first bleed air pipe near its second end, and the shapes of the second flow holes include long strip, circular, square, and square-round.

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