An external bleed air structure for an aircraft engine

Abstract

This application belongs to the field of aero-engine design, and specifically relates to an external bleed air structure for an aero-engine. Replacing the bleed air pipe with a first and second interlayer channel can significantly reduce the space occupied by the bleed air pipe structure in the bypass, and reduce the restrictions on the arrangement of other structures. Compared with the bleed air pipe, the bleed air interlayer channel has a much larger surface area, and through heat conduction with the cold air in the bypass, it can achieve the effect of cooling the high-temperature gas in the channel, thus better cooling the high-temperature components of the turbine. By adding a throttling orifice plate to the bleed air pipe or changing the diameter of the bleed air pipe, the flow rate of the circulating gas can be controlled. Compared with the bleed air pipe, the replacement cost is low and the structure is simpler. The bleed air interlayer channel can be arranged in the inner or outer layer of the engine casing as needed. The bleed air interlayer can be divided or stacked for bleed air or exhaust at different locations, meeting the cooling requirements of multi-stage turbines.

Description

Technical Field

[0001] This application belongs to the field of aero-engine design, and specifically relates to an external bleed air structure for an aero-engine. Background Technology

[0002] The inlet temperature of modern aircraft engines is much higher than the temperature range that the engine's metal materials can withstand, so low-temperature cooling gas must be introduced to ensure that the high-temperature components of the engine can operate safely and reliably.

[0003] The structure of the engine's external bleed air section is as follows: Figure 1 As shown. Air is drawn from different blade tips of the compressor, connected to the turbine casing via multiple bleed air pipes, and then flows into the turbine collector chamber to cool the high-temperature components of the turbine. One end of the bleed air pipe is connected to the compressor casing, and the other end is connected to the turbine casing. The bleed air pipes are located in the engine's bypass space and are further enclosed by the engine casing.

[0004] In addition to the air intake pipe, numerous adjustment structures and fuel / lubricating oil pipes need to be arranged in the bypass space. Furthermore, the flow of bypass gas has a significant impact on afterburning and engine performance improvement.

[0005] As engine performance improves and gas inlet temperature rises, the amount of cold air required for turbine blade cooling also increases. This necessitates that the bleed pipes can circulate more cold air, which can be achieved by increasing the number of bleed pipes and increasing their diameter.

[0006] The specific drawbacks are:

[0007] 1. Air is drawn from a blade tip of the compressor and connected to the turbine casing. Cooling gas is then transported from the compressor to the high-temperature components of the turbine through an air duct located inside the outer casing.

[0008] 2. The bleed air pipe occupies a large space in the outer bypass, which on the one hand restricts the arrangement of key structures such as the adjustment mechanism and fuel pipe, and on the other hand increases the resistance to the flow of gas in the outer bypass, affecting engine performance.

[0009] Therefore, maintaining gas pressure, allowing more cool air to circulate, reducing the space occupied by the bypass, and ensuring the cooling needs of the turbine's high-temperature components have become design challenges. Summary of the Invention

[0010] The purpose of this application is to provide an external bleed air structure for an aircraft engine to solve the problem that existing designs struggle to maintain gas pressure and engine performance.

[0011] The technical solution of this application is: an external bleed air structure for an aero-engine, including an inlet bleed air pipe, a sandwich casing, and an outlet bleed air pipe; the inlet end of the inlet bleed air pipe is connected to the intermediate stage of the compressor, and the outlet end is connected to the sandwich casing; the sandwich casing is located inside the engine casing, and a bleed air sandwich channel is formed between the sandwich casing and the engine casing, and the outlet end of the inlet bleed air pipe is connected to the bleed air sandwich channel;

[0012] The inlet end of the outlet air intake pipe is connected to the air intake interlayer channel, and the outlet end is connected to the turbine air collection chamber.

[0013] Preferably, the outlet air intake pipe includes a first air outlet pipe and a second air outlet pipe, and the turbine air collection chamber includes a first air collection chamber and a second air collection chamber, wherein the first air outlet pipe is connected to the first air collection chamber, and the second air outlet pipe is connected to the second air collection chamber.

[0014] Preferably, the air intake interlayer channel is provided with an inner interlayer partition section. The inner interlayer partition section has multiple sets and is arranged at intervals along the circumference of the air intake interlayer channel to form multiple sets of first interlayer channels and second interlayer channels. The first interlayer channel is connected to the first air outlet pipe, and the second interlayer channel is connected to the second air outlet pipe.

[0015] Preferably, the first interlayer channel and the second interlayer channel are staggered, and the arc lengths of the first interlayer channel and the second interlayer channel are different.

[0016] Preferably, the intermediate stage of the compressor is provided with an air bleed chamber, and a compressor casing is provided on the outside of the air bleed chamber. The air bleed chamber is connected to the inlet air bleed pipe, the compressor casing is connected to the inlet air bleed pipe through a flange, and the sandwich casing is connected to the inlet air bleed pipe through a flange.

[0017] Preferably, the inlet air intake pipe includes a first air intake pipe and a second air intake pipe, the air intake chamber includes a first air intake chamber and a second air intake chamber, the first air intake pipe is connected to the first air intake chamber and the first interlayer channel, and the second air intake pipe is connected to the second air intake chamber and the second interlayer channel.

[0018] This application discloses an external bleed air structure for an aero-engine. By replacing the bleed air pipe with a first and second interlayer channel, the space occupied by the bleed air pipe structure can be significantly reduced, and the restrictions on the arrangement of other structures can be lessened. Compared with the bleed air pipe, the bleed air interlayer channel has a much larger surface area. Through heat conduction with the cold air in the outer casing, it can achieve the effect of cooling the high-temperature gas in the channel, thus better cooling the high-temperature turbine components. By adding a throttling orifice plate to the bleed air pipe or changing the diameter of the bleed air pipe, the flow rate of the circulating gas can be controlled. Compared with the bleed air pipe, the replacement cost is low and the structure is simpler. The bleed air interlayer channel can be arranged in the inner or outer layer of the engine casing as needed. The bleed air interlayer can be divided or stacked for bleed air or exhaust at different locations, meeting the cooling requirements of multi-stage turbines. Attached Figure Description

[0019] To more clearly illustrate the technical solutions provided in this application, the accompanying drawings will be briefly described below. Obviously, the drawings described below are merely some embodiments of this application.

[0020] Figure 1 This is a schematic diagram of the external bleed air structure of an engine in the background art;

[0021] Figure 2 This is a schematic diagram of the external bleed air structure and flow of the engine in this application;

[0022] Figure 3 This is a schematic diagram of the external bleed air structure and flow of the multi-stage bleed air engine of this application;

[0023] Figure 4 This is a schematic diagram of the segmented air-entraining interlayer channel of this application.

[0024] 1. Inlet air bleed pipe; 2. Sandwich casing; 3. Outlet air bleed pipe; 4. Engine casing; 5. First outlet air pipe; 6. Second outlet air pipe; 7. First air collection chamber; 8. Second air collection chamber; 9. Sandwich inner partition section; 10. First sandwich passage; 11. Second sandwich passage; 12. First air bleed pipe; 13. Second air bleed pipe; 14. First air collection chamber; 15. Second air collection chamber. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] An external bleed air structure for an aircraft engine, such as Figure 2It includes an inlet bleed pipe 1, a sandwich casing 2, and an outlet bleed pipe 3; the inlet end of the inlet bleed pipe 1 is connected to the intermediate stage of the compressor, and the outlet end is connected to the sandwich casing 2. The inlet bleed pipe 1 can receive high-pressure cold air from the compressor; the sandwich casing 2 is located inside the engine casing 4, and a bleed air sandwich channel is formed between the sandwich casing 2 and the engine casing 4. The outlet end of the inlet bleed pipe 1 is connected to the bleed air sandwich channel.

[0027] The inlet end of the outlet bleed pipe 3 is connected to the bleed interlayer channel, and the outlet end is connected to the turbine gas collection chamber.

[0028] The sandwich casing 2 can move left and right along the engine casing 4 to accommodate the installation of the inlet air pipe 1.

[0029] The inlet bleed pipe 1, bleed interlayer channel and outlet bleed pipe 3 deliver high-pressure cold air from the compressor to the turbine gas collection chamber. Low-temperature bypass gas can also be used to cool the high-temperature gas in the bleed structure and greatly reduce the space occupied by the bypass. This solves the problem of mutual restriction between the layout of the bleed pipeline and the fuel pipeline, control mechanism and other components in a small space.

[0030] Installing orifice plates at the inlet of the inlet air pipe 1 and at the outlet of the outlet air pipe 3, or changing the size of the air pipe, can control the flow rate through the air pipe, thus meeting the requirements of engine performance and cooling of high-temperature components.

[0031] The thickness of the sandwich casing 2 is selected based on the bleed air and bypass pressure difference to ensure casing strength. Appropriate temperature-resistant materials are selected for both the engine casing 4 and the sandwich casing 2 based on the bleed air temperature.

[0032] The fuel pipe and regulating mechanism, which need to pass through the casing, are designed according to the original plan. This part of the structure passes through the two casings, engine casing 4 and sandwich casing 2, and is fixed with bolts at the connection and sealed with gaskets.

[0033] The engine casing 4 and the sandwich casing 2 are fixed with bolts and sealed with gaskets.

[0034] To meet the cooling requirements of multiple stages, in a specific example, referring to the figure, the outlet exhaust pipe 3 includes a first exhaust pipe 5 and a second exhaust pipe 6, and the turbine gas collection chamber includes a first gas collection chamber 7 and a second gas collection chamber 8. The first exhaust pipe 5 is connected to the first gas collection chamber 7, and the second exhaust pipe 6 is connected to the second gas collection chamber 8. The first gas collection chamber 7 and the second gas collection chamber 8 are located at different turbine stages, so that the high-pressure cold air drawn out by the outlet exhaust pipe 3 can cool the turbines of different stages separately, meeting the cooling requirements of two or more turbine stages at different exhaust locations.

[0035] The two ends of the outlet air vent pipe 3 are connected to the engine casing 4 and the air collection chamber respectively via flanges. The position of the sandwich casing 2 can also be moved to accommodate the installation of the outlet air vent pipe 3.

[0036] Combination Figure 4 Preferably, an inner partition section 9 is provided in the air intake interlayer channel. The inner partition section 9 has multiple sets and is arranged at intervals along the circumference of the air intake interlayer channel to form multiple sets of first interlayer channels 10 and second interlayer channels 11. The first interlayer channel 10 is connected to the first air outlet pipe 5, and the second interlayer channel 11 is connected to the second air outlet pipe 6.

[0037] The different interlayer partition sections 9 are assembled using flanges, and the two ends of each interlayer partition section 9 are welded and sealed.

[0038] By setting up a partition section 9 in the interlayer, the cooling air in the air duct interlayer channel is diverted, so that cooling air at different temperatures can be delivered separately to meet the cooling needs of different locations.

[0039] Preferably, the first interlayer channel 10 and the second interlayer channel 11 are staggered, and the arc lengths of the first interlayer channel 10 and the second interlayer channel 11 are different, forming a symmetrical structure. This prevents the internal air pressure of the cooling gas from affecting each other and causing structural deformation.

[0040] Preferably, the intermediate stage of the compressor is provided with an air bleed chamber, and the compressor casing is provided on the outside of the air bleed chamber. The air bleed chamber is connected to the inlet air bleed pipe 1. The compressor casing is connected to the inlet air bleed pipe through a flange, and the sandwich casing 2 is connected to the inlet air bleed pipe 1 through a flange.

[0041] To meet multi-stage cooling requirements, in a specific example, preferably, the inlet air intake pipe 1 includes a first air intake pipe 12 and a second air intake pipe 13, and the air intake chamber includes a first air intake chamber 14 and a second air intake chamber 15. The first air intake chamber 14 and the second air intake chamber 15 are located at different positions in the intermediate stage of the compressor. The first air intake pipe 12 is connected to the first air intake chamber 14 and the first interlayer channel 10, and the second air intake pipe 13 is connected to the second air intake chamber 15 and the second interlayer channel 11. The inlet air intake pipe 1 can introduce cooling air of different temperatures through the first air intake chamber 14 and the second air intake chamber 15, and deliver it to the air intake interlayer channel to meet the air intake requirements at different temperatures.

[0042] Multiple segments are set within the channel, allowing air intake tubes at different locations to be installed as follows: Figure 4 The connection to the interlayer channel is shown, and the corresponding outlet air duct 3 is connected at the outlet position to guide the appropriate gas to different gas collection chambers to cool the high-temperature components.

[0043] In summary, this application has the following advantages:

[0044] Replacing the bleed pipe with the first interlayer channel 10 and the second interlayer channel 11 can significantly reduce the space occupied by the bleed pipe structure in the outer bypass and reduce the restrictions on the arrangement of other structures. Compared with the bleed pipe, the bleed pipe interlayer channel has a huge surface area. Through heat conduction with the cold air in the outer bypass, it can achieve the effect of cooling the high-temperature gas in the channel, and better achieve the cooling of the high-temperature components of the turbine. By adding a throttle plate to the bleed pipe or changing the diameter of the bleed pipe, the flow rate of the gas can be controlled. Compared with the bleed pipe, the replacement cost is low and the structure is simpler. The bleed pipe interlayer channel can be arranged in the inner or outer layer of the engine casing 4 as needed. The bleed pipe interlayer can be divided or stacked for bleed or exhaust in different positions to meet the cooling needs of multi-stage turbines.

[0045] Finally, it should be noted that the accompanying drawings of the embodiments disclosed in this invention only involve the structures involved in the embodiments disclosed in this invention. Other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of this invention can be combined with each other.

[0046] In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An external bleed air structure for an aircraft engine, characterized in that: It includes an inlet bleed pipe (1), a sandwich casing (2), and an outlet bleed pipe (3); the inlet end of the inlet bleed pipe (1) is connected to the intermediate stage of the compressor, and the outlet end is connected to the sandwich casing (2); the sandwich casing (2) is located inside the engine casing (4), and a bleed air sandwich channel is formed between the sandwich casing (2) and the engine casing (4), and the outlet end of the inlet bleed pipe (1) is connected to the bleed air sandwich channel; The inlet end of the outlet air intake pipe (3) is connected to the air intake interlayer channel, and the outlet end is connected to the turbine air collection chamber. The outlet air intake pipe (3) includes a first air outlet pipe (5) and a second air outlet pipe (6), and the turbine air collection chamber includes a first air collection chamber (7) and a second air collection chamber (8). The first air outlet pipe (5) is connected to the first air collection chamber (7), and the second air outlet pipe (6) is connected to the second air collection chamber (8). The gas-drawing interlayer channel is provided with an interlayer partition section (9). The interlayer partition section (9) has multiple sets and is arranged at intervals along the circumference of the gas-drawing interlayer channel to form multiple sets of first interlayer channels (10) and second interlayer channels (11). The first interlayer channel (10) is connected to the first air outlet pipe (5), and the second interlayer channel (11) is connected to the second air outlet pipe (6). The first interlayer channel (10) and the second interlayer channel (11) are staggered, and the arc lengths of the first interlayer channel (10) and the second interlayer channel (11) are different; The intermediate stage of the compressor is provided with an air intake chamber, and the compressor casing is provided on the outside of the air intake chamber. The air intake chamber is connected to the inlet air intake pipe (1). The compressor casing is connected to the inlet air intake pipe (1) through a flange. The sandwich casing (2) is connected to the inlet air intake pipe (1) through a flange. The inlet air intake tube (1) includes a first air intake tube (12) and a second air intake tube (13), and the air intake chamber includes a first air intake chamber (14) and a second air intake chamber (15). The first air intake tube (12) is connected to the first air intake chamber (14) and the first interlayer channel (10), and the second air intake tube (13) is connected to the second air intake chamber (15) and the second interlayer channel (11).

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