High-pressure turbine area bearing cavity device and ventilation pipe cooling method thereof

Abstract

The high-pressure turbine area bearing cavity device is beneficial to reducing the temperature of the inner wall face of a bearing cavity ventilation pipe and comprises a sealing air entraining cavity for sealing air flow on the periphery of a bearing cavity to flow and the ventilation pipe for exhausting sealing air leaked into the bearing cavity out of the bearing cavity. The ventilation pipe mounting seat is used for mounting the ventilation pipe and communicating the ventilation pipe with the bearing cavity; wherein the ventilation pipe mounting seat penetrates through the sealing air entraining cavity, and a ventilation hole is formed in the position, surrounding the connection position of the ventilation pipe, of the ventilation pipe mounting seat, so that the sealing airflow is exhausted from the ventilation hole. The invention discloses a ventilation pipe cooling method for a high-pressure turbine area bearing cavity device. The heating temperature of a ventilation pipe can be reduced.

Description

Technical Field

[0001] The invention relates to a bearing cavity device in a high-pressure turbine region of an aeroengine or a gas turbine and a ventilation pipe cooling method thereof. Background Art

[0002] The front and rear seals of the bearing cavity in the high-temperature area of ​​the high-pressure turbine of an aircraft engine or a gas turbine are grate seals, and a ventilation pipe is required to discharge the sealing gas leaking into the bearing cavity to the outside of the bearing cavity. The bearing cavity ventilation pipe is in a very hot environment.

[0003] The patent application with publication number "CN 114294112 A" records that the bearing cavity of an aircraft engine is generally composed of a bearing cavity housing, a bearing, a sealing device, a lubricating oil supply and return pipe, a ventilation pipe, etc. The bearing cavity pipelines are all single-layer structures, and their outer walls are wrapped with insulation materials and skins. However, this type of bearing cavity pipeline insulation structure is difficult to effectively meet the increasingly high temperature of the bearing cavity peripheral working environment. Therefore, a dual-channel pipeline device with a transition sealing structure is proposed to achieve the purpose of pipeline insulation and rapid cooling.

[0004] The inner wall temperature can be lowered by designing the ventilation pipe with double-layer pipe wall and spraying cooling lubricating oil into the ventilation pipe. However, these two methods alone cannot reduce the inner wall temperature of the ventilation pipe to below 204℃. The lubricating oil in the ventilation pipe will be seriously coked or even ignited, affecting the lubricating oil performance, so it is necessary to further reduce the inner wall temperature of the ventilation pipe. Summary of the invention

[0005] The object of the present invention is to provide a high-pressure turbine region bearing cavity device, which is beneficial to reducing the temperature of the inner wall surface of the bearing cavity ventilation pipe.

[0006] Another object of the present invention is to provide a ventilation pipe cooling method for a bearing cavity device in a high-pressure turbine area.

[0007] According to one aspect of the present invention, a high-pressure turbine region bearing cavity device comprises a sealing air bleed cavity for supplying a sealing air flow around the bearing cavity, a ventilation pipe for discharging the sealing air leaked into the bearing cavity to the outside of the bearing cavity, and a ventilation pipe mounting seat for installing the ventilation pipe and connecting the ventilation pipe with the bearing cavity; wherein the ventilation pipe mounting seat passes through the sealing air bleed cavity, and ventilation holes are arranged on the ventilation pipe mounting seat around the connection of the ventilation pipe so that the sealing air flow can be discharged from the ventilation holes.

[0008] In one embodiment, the ventilation hole is an annular hole surrounding the connection of the ventilation tube on the mounting base.

[0009] In one embodiment, the connection point of the ventilation pipe on the mounting seat is provided by a boss, and the mounting seat further includes an annular wall surrounding the boss, and the ventilation hole is arranged between the annular wall and the boss.

[0010] In one embodiment, the annular wall is higher than the boss.

[0011] In one embodiment, the sealed air bleed cavity is configured so that the sealed air flow therein can only be discharged through the ventilation hole.

[0012] In one embodiment, a flow passage cross-sectional area of ​​at least a portion of the ventilation pipe gradually decreases from the inside to the outside of the engine.

[0013] In one embodiment, the ventilation pipe has a double-layer wall.

[0014] In one embodiment, a cross-section of any layer of the tube wall has a major axis.

[0015] According to another aspect of the present invention, a ventilation pipe cooling method for a bearing cavity device in a high-pressure turbine area is provided, wherein the sealed airflow of the sealed bleed air cavity is used to cool the connection of the ventilation pipe on the mounting seat, so that the temperature of the connection of the ventilation pipe on the mounting seat is 80-100 degrees Celsius lower than the temperature of the peripheral cavity of the sealed bleed air cavity.

[0016] In one embodiment, the cross-section of at least a portion of the inner wall of the ventilation pipe is designed to be tapered, that is, it gradually decreases from the inside to the outside of the engine, so that the flow rate of the oil-gas mixture in the ventilation pipe gradually decreases, accelerating convective heat exchange, thereby reducing the temperature of the inner wall of the ventilation pipe.

[0017] According to an embodiment of the present invention, heat exchange is accelerated by lowering the wall temperature at the connection point of the ventilation pipe for heat conduction and increasing the flow rate of the oil-gas mixture in the ventilation pipe, thereby lowering the wall temperature inside the ventilation pipe, thereby avoiding coking or ignition of the lubricating oil in the ventilation pipe and reducing the risk of spontaneous combustion of the lubricating oil pipeline. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and other features, properties and advantages of the present invention will become more apparent through the following description in conjunction with the accompanying drawings and embodiments, in which:

[0019] Figure 1 is a cross-sectional view of the bearing chamber arrangement in the high-pressure turbine region as a ratio;

[0020] Figure 2 is a partial view of the bearing chamber arrangement in the high-pressure turbine region as a pair of ratios;

[0021] Figure 3 It is a schematic diagram of the flow direction of the sealed airflow of the bearing cavity device in the high-pressure turbine area as a pair of ratios;

[0022] Figure 4 is a cross-sectional view of a bearing cavity device in a high-pressure turbine region according to an embodiment of the present invention;

[0023] Figure 5 is a partial view of a bearing cavity device in a high-pressure turbine region according to an embodiment of the present invention;

[0024] Figure 6 is a cross-sectional view of a ventilation pipe of a bearing chamber device in a high-pressure turbine region as a ratio;

[0025] Figure 7 is a cross-sectional view of a ventilation pipe of a bearing chamber device in a high-pressure turbine region according to an embodiment of the present invention;

[0026] Figure 8 is a cross-sectional view of a ventilation duct according to an embodiment of the present invention. DETAILED DESCRIPTION

[0027] Reference will now be made in detail to embodiments of the present invention, one or more examples of which are illustrated in the accompanying drawings. Each example is provided to explain the present invention, not to limit the present invention. In fact, it will be apparent to those skilled in the art that various modifications and variations may be made in the present invention without departing from the scope or spirit of the present invention. For example, a feature illustrated or described as part of one embodiment may be used together with another embodiment to produce yet another embodiment. Therefore, the present invention is intended to cover these modifications and variations within the scope of the appended claims and their equivalents.

[0028] As used herein, the terms “first,” “second,” and “third” may be used interchangeably to distinguish one component from another, and are not intended to indicate the position or importance of the respective components.

[0029] The terms "upstream" and "downstream" refer to relative directions relative to the flow of a fluid in a fluid path. For example, "upstream" refers to the direction from which the fluid is flowing, and "downstream" refers to the direction toward which the fluid is flowing.

[0030] correspond Figure 1 The sectioning position passes horizontally through Figure 2 The ventilation pipe 11 in the corresponding Figure 3 The sectioning position passes horizontally through Figure 2 The ventilation holes 12 in the.

[0031] like Figure 1As shown, the high-pressure turbine region bearing cavity device includes a bearing seat 1, a front air seal 2, a front oil seal 3, a front oil seal grate 4, a bearing 5, an oil collecting ring 6, an oil supply assembly 7, a rear oil seal grate 8 and a rear seal seat 9. These components surround and form a bearing cavity 40, and the outside of the bearing cavity 40 is a sealed air bleed cavity 30. The connection of the ventilation pipe 11 is located at the upper part of the bearing cavity 40. In one example, there is a ventilation pipe 11 at 2 o'clock and 10 o'clock along the course, which is connected to the ventilation pipe mounting seat 20 on the rear seal seat 9 by bolts 10.

[0032] The sealing air bleed cavity 30 is used to supply the sealing air flow around the bearing cavity. Figure 3 , where the areas through which the sealed airflow flows as indicated by the arrows are all included in the sealed air bleed cavity 30. The ventilation pipe 11 is used in the high-pressure turbine region bearing cavity device to discharge the sealed air leaking into the bearing cavity 40 to the outside of the bearing cavity 40, and the ventilation pipe mounting seat 20 is used to mount the ventilation pipe 11 and connect the ventilation pipe 11 with the bearing cavity 40.

[0033] In this comparative example, in order to reduce the temperature in the bearing cavity, a plurality of common ventilation holes 12 are opened on the rear sealing seat 9 to speed up the flow rate of the sealing gas. Figure 2 The arrow in the right figure indicates the direction of air flow. Part of the air in the sealed air bleed cavity enters the peripheral cavity through the common ventilation hole 12. Figure 1 It can be understood that the connection point of the ventilation pipe 11 on the ventilation pipe mounting base 20 is substantially located in the peripheral cavity.

[0034] The embodiment according to the present invention is improved on the basis of the comparative example. Figure 4 , Figure 5 , and 7 and Figure 8 Such an embodiment is shown. Figure 4 The sectioning position passes horizontally through Figure 5 The ventilation pipe 11 shown. Figure 4 As shown, the ventilation pipe mounting base 20 passes through the sealed air bleed cavity 30, and the ventilation hole 13 is arranged on the ventilation pipe mounting base 20 around the connection 21 of the ventilation pipe 11, so that the sealed air flow is discharged from the ventilation hole 13. The ventilation hole 13 is arranged at the connection 21 of the ventilation pipe, which not only realizes the function of the common ventilation hole 12 to accelerate the sealing air flow rate, but also reduces the wall temperature at the connection of the ventilation pipe 11. The thermal analysis boundary condition of the wall at the connection of the ventilation pipe 11 changes from the temperature of the peripheral cavity to the temperature of the sealed air bleed cavity, which can usually reduce 80℃ to 100℃. In this way, the wall temperature at the connection of the ventilation pipe is reduced, and the temperature of the inner wall of the ventilation pipe can be reduced through heat conduction.

[0035] In one embodiment, the ventilation hole 13 is an annular hole surrounding the connection 21 of the ventilation tube 11 on the mounting seat 20. This allows each location around the connection 21 to be further cooled.

[0036] like Figure 5 As shown, the connection 21 of the ventilation pipe 11 on the mounting seat 20 is provided by a boss 201, and the mounting seat 20 also includes an annular wall 202 surrounding the boss, and a ventilation hole 13 is arranged between the annular wall 202 and the boss 201. The annular wall 202 can further isolate the peripheral cavity and seal the air bleed cavity to increase the cooling effect.

[0037] like Figure 4 As shown, the annular wall 202 should be higher than the boss 201 so that the connection 21 is completely in the sealed air bleed cavity and its heating temperature is fully reduced.

[0038] Optionally, the sealed air bleed cavity is configured so that the sealed air flow therein can only be discharged through the vents 13, and the vents 12 described in the comparison are almost non-existent except for the vents 13. This further enhances the air flow rate and cooling effect of the vents 13, can reduce the ventilation area of ​​ordinary vents at other locations on the upper part of the sealed air bleed cavity, and can prevent thermal stress concentration.

[0039] The outer wall of the ventilation pipe is directly under the radiation of the high-temperature support plate. When the engine or gas turbine is operating normally, the temperature of the high-temperature support plate behind the turbine can generally reach more than 1000℃. The ventilation pipe around the center is directly affected by the strong heat radiation of the high-temperature support plate, causing the outer surface temperature of the ventilation pipe to be nearly 500-600℃. At the same time, the casing wall connected to the ventilation pipe will also directly transfer heat to the local surface of the ventilation pipe through heat conduction, thereby causing local overheating of the pipe. Therefore, under the action of the heat radiation of the high-temperature support plate and the heat conduction of the engine casing, the outer surface of the ventilation pipe always maintains a higher temperature. The high temperature on the outer surface of the ventilation pipe will be further transferred to the inner layer of the ventilation pipe, causing the temperature of the inner wall of the pipe to rise sharply. After the oil-gas mixture in the ventilation pipe passes through the high-temperature wall, it may cause the wall lubricating oil to coke, and may even cause the lubricating oil to spontaneously ignite in the pipe, causing damage to the engine or gas turbine. The flow pattern of the oil-gas mixture inside the bearing cavity ventilation pipe is an ascending annular flow pattern. In this flow pattern, the liquid film on the pipe wall is thick and contains oil bubbles, and the core part in the middle of the pipe is still mainly gas. Therefore, the heat exchange capacity of the pipeline based on this flow pattern is closely related to the proportion of oil-gas mixture in the pipeline, the flow rate of the oil-gas mixture and the gas content in the lubricating oil. From the perspective of the flow rate of the oil-gas mixture, when the flow rate in the pipeline is fast, it can effectively take away the heat of the inner wall of the pipeline, thereby reducing the temperature of the inner wall of the pipeline, thereby reducing the risk of lubricating oil coking, but at the same time it will cause a large amount of heat to be transferred to the lubricating oil, causing the heat load of the entire lubricating oil system to increase. When the flow rate in the pipeline is slow, the heat exchange capacity in the pipeline is weakened, causing the temperature of the pipeline wall to rise, the possibility of lubricating oil coking increases, and there is even a risk of self-ignition of the lubricating oil pipeline. In addition, the bearing cavity inlet conditions such as the lubricating oil supply and air leakage will also affect the proportion of the oil-gas mixture in the pipeline. Further, these factors will also affect the heat exchange in the pipeline.

[0040] like Figure 7 As shown, the cross-sectional area of ​​the flow passage of at least a portion 15 of the ventilation pipe gradually decreases from the inside to the outside of the engine. Figure 6 As shown, the cross-sectional area of ​​at least a portion 14 of the ventilation pipe remains almost constant from the inside to the outside of the engine. According to the embodiment of the present invention, the flow rate of the lubricating oil in the ventilation pipe is gradually increased, so that the convective heat transfer can be accelerated, thereby reducing the temperature of the inner wall of the ventilation pipe, reducing the coking of the lubricating oil and the natural risk of the pipeline.

[0041] like Figure 8 As shown, the ventilation pipe has a double-layer pipe wall. Optionally, the cross section of any layer 15a, 15b of the pipe wall has a major axis. In other embodiments, the cross section of the inner wall of the ventilation pipe can be in various shapes, such as waist-shaped, circular, etc.

[0042] In combination with the aforementioned embodiments, it can be understood that the ventilation duct cooling method uses the sealed airflow of the sealed air bleed cavity to cool the connection of the ventilation duct on the mounting seat, so that the temperature of the connection of the ventilation duct on the mounting seat is 80-100 degrees Celsius lower than the temperature of the peripheral cavity of the sealed air bleed cavity.

[0043] Furthermore, the cross-section of at least a portion of the inner wall of the ventilation pipe is designed to be tapered, that is, gradually shrinking from the inside to the outside on the engine, so that the flow rate of the oil-gas mixture in the ventilation pipe gradually decreases, accelerating convective heat exchange, thereby reducing the inner wall temperature of the ventilation pipe.

[0044] Although the present invention is disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, any modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope defined by the claims of the present invention.

Claims

1. High-pressure turbine area bearing cavity device, including: A sealed air bleed cavity for supplying sealed air flow around the bearing cavity. A vent pipe for discharging the sealing air leaking into the bearing cavity to the outside of the bearing cavity, and A ventilation pipe mounting seat for mounting the ventilation pipe and connecting the ventilation pipe to the bearing cavity; It is characterized in that The ventilation pipe mounting seat passes through the sealed air ducting cavity, and a ventilation hole is arranged on the ventilation pipe mounting seat around the connection of the ventilation pipe, so that the sealed airflow is discharged from the ventilation hole.

2. The high-pressure turbine region bearing cavity device according to claim 1, characterized in that: The ventilation hole is an annular hole surrounding the connection of the ventilation pipe on the mounting seat.

3. The high-pressure turbine region bearing chamber device according to claim 1 or 2, characterized in that: The connection point of the ventilation pipe on the mounting seat is provided by a boss, and the mounting seat also includes an annular wall surrounding the boss, and the ventilation hole is arranged between the annular wall and the boss.

4. The high-pressure turbine region bearing cavity device according to claim 3, characterized in that: The annular wall is higher than the boss.

5. The high-pressure turbine region bearing cavity device according to claim 1, characterized in that: The sealed air bleed cavity is arranged so that the sealed air flow therein can only be discharged through the ventilation hole.

6. The high-pressure turbine region bearing cavity device according to claim 1, characterized in that: The cross-sectional area of ​​the flow passage of at least a portion of the ventilation pipe gradually decreases from the inside to the outside of the engine.

7. The high-pressure turbine region bearing chamber device according to claim 1 or 5, characterized in that: The ventilation pipe has a double-layer pipe wall.

8. The high-pressure turbine region bearing cavity device according to claim 7, characterized in that: A cross section of any layer of the tube wall has a major axis.

9. A ventilation pipe cooling method for a bearing cavity device in a high-pressure turbine region, characterized in that: The sealed airflow of the sealed air bleed cavity is used to cool the connection of the ventilation pipe on the mounting seat, so that the temperature of the connection of the ventilation pipe on the mounting seat is 80-100 degrees Celsius lower than the temperature of the peripheral cavity of the sealed air bleed cavity.

10. The ventilation duct cooling method according to claim 9, characterized in that: The cross section of at least a portion of the inner wall of the ventilation pipe is designed to be tapered, that is, it gradually decreases from the inside to the outside on the engine, so that the flow rate of the oil-gas mixture in the ventilation pipe gradually decreases, accelerating convective heat exchange, thereby reducing the inner wall temperature of the ventilation pipe.

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