A bleed air pre-cooling scheme and structure

Abstract

A bleed air pre-cooling scheme and structure relates to aircraft engines and gas turbines. The scheme includes a bleed air end manifold, a turbine end manifold, a left-end bleed air duct, a right-end bleed air duct, and a bleed air pre-cooler. Low-temperature compressed air within the outer duct is introduced into the outer vent cavity via the hood bleed air duct. After enhanced cooling of the outer wall of the inner bleed air duct, it is discharged from the hood exhaust duct into the straight section of the outer duct. Compressed air drawn from the compressor interstage bleed port enters the bleed air end manifold through the bleed holes. The compressed air is then introduced into the inner bleed air duct of the bleed air pre-cooler via the left-end bleed air duct. Under the enhanced cooling effect of the low-temperature compressed air within the outer vent cavity, the compressed air within the inner bleed air duct is cooled, reducing its temperature. The compressed air is then discharged into the turbine end manifold via the right-end bleed air duct, thereby achieving the purpose of cooling the compressor interstage bleed air. Using low-temperature air from the outer duct of an aircraft engine or gas turbine to pre-cool the compressor interstage bleed air provides a simple cooling scheme with high safety, as well as a simple structural scheme with high reliability.

Description

Technical Field

[0001] The present invention belongs to the technical field of aero engines and gas turbines, and in particular relates to a bleed air pre-cooling scheme and structure. Background Art

[0002] As a critical hot-end component of aircraft engines and gas turbines, turbine casing cooling is essential to prevent overheating. A typical turbine casing bleed air flow path draws compressed air of suitable temperature from the compressor interstages. This air is then transported to the turbine plenum via bleed pipes. This compressed air is then transported through the air system's secondary flow network to the turbine casing components requiring cooling. The compressed air is then discharged into the turbine flow path, thereby achieving cooling of the turbine casing components. With the continuous improvement of aircraft engine and gas turbine performance, turbine flow path pressures and temperatures are increasing, necessitating the use of higher-pressure bleed air from the compressor interstages. This detrimentally impacts the thermal cycle efficiency of aircraft engines and gas turbines, reducing compressor efficiency and increasing fuel consumption. Furthermore, the higher-pressure bleed air temperature also impairs turbine casing cooling, increasing safety risks. Therefore, pre-cooling the compressor interstage bleed air is essential.

[0003] To address the problem of reduced cooling of turbine casing components in aircraft engines and gas turbines due to increased bleed air temperatures, current solutions include high-performance heat exchangers (air-to-oil heat exchangers) and bleed air conversion. The high-performance heat exchanger (air-to-oil heat exchanger) requires fuel or lubricating oil as a cooling source, resulting in a complex system. Furthermore, any fuel or lubricating oil leak in the heat exchanger can cause fire or even explosion in the aircraft engine or gas turbine. The bleed air conversion solution requires a bleed air conversion valve, which can easily become stuck under high temperature conditions, causing the bleed air conversion function to fail. Summary of the Invention

[0004] The purpose of the present invention is to provide a bleed air pre-cooling scheme and structure with simple structure and high safety to address the technical problems of the existing bleed air pre-cooling scheme such as complex system, poor reliability and low safety.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] The present invention provides a bleed air pre-cooling structure, which sequentially comprises a bleed air collecting cavity at the bleed air end, a left bleed air pipe, a bleed air pre-cooler, a right bleed air pipe and a turbine end bleed air collecting cavity;

[0007] The bleed air collecting cavity at the bleed air end is used to collect and guide the compressor inter-stage bleed air, and the outlet of the bleed air collecting cavity is connected to the left end bleed air pipe;

[0008] One end of the left air bleed pipe is connected to the bleed air precooler, and the other end of the left air bleed pipe is connected to the bleed air collecting cavity at the bleed air end. The left air bleed pipe is used to guide the compressed air from the bleed air collecting cavity at the bleed air end to the bleed air precooler;

[0009] The bleed air precooler is used to precool the compressed air in the inner bleed air pipe, and the bleed air precooler includes an air hood bleed air pipe, an air hood exhaust pipe, a sleeve, and an inner bleed air pipe; one end of the air hood bleed air pipe is provided with an air hood bleed air pipe flange, and the other end of the air hood bleed air pipe is connected to the sleeve; one end of the air hood exhaust pipe is connected to the air hood exhaust pipe flange, and the other end of the air hood exhaust pipe is connected to the sleeve; both ends of the sleeve are respectively provided with a left sleeve blocking cover and a right sleeve blocking cover; the left sleeve blocking cover is connected to the sleeve and to the inner bleed air pipe; the right sleeve blocking cover is also connected to the sleeve and the inner bleed air pipe; the two ends of the inner bleed air pipe are respectively provided with a left inner bleed air pipe flange and an inner bleed air pipe Right flange edge; an external ventilation cavity is formed between the inner wall of the casing and the outer wall of the inner bleed pipe; the external ventilation cavity is used to guide the low-temperature compressed air from the wind hood bleed pipe to enhance cooling of the outer wall of the inner bleed pipe, and then discharged from the wind hood exhaust pipe into the straight section of the outer duct; at the same time, the compressed air drawn out from the compressor interstage bleed port enters the bleed end air collecting cavity through the bleed hole, and then is introduced into the inner bleed pipe of the bleed air precooler through the left end bleed pipe. Under the enhanced cooling effect of the low-temperature compressed air in the external ventilation cavity, the compressed air in the inner bleed pipe is cooled and the temperature is reduced, thereby achieving cooling and lowering of the compressor interstage bleed air;

[0010] One end of the right-end bleed air pipe is connected to the bleed air precooler, and the other end of the right-end bleed air pipe is connected to the turbine-end air collecting chamber. The right-end bleed air pipe is used to guide the precooled compressed air from the bleed air precooler to the turbine-end air collecting chamber.

[0011] The turbine end air collecting cavity is used to receive the compressed air precooled by the bleed air precooler.

[0012] Furthermore, the left-end air duct includes a left-end air duct inlet flange, a left-end bent pipe section, and a left-end air duct outlet flange; the left-end air duct inlet flange is connected to the air duct end air collecting cavity, and the left-end air duct outlet flange is connected to the air duct precooler.

[0013] Furthermore, the right-end air bleed pipe comprises a right-end air bleed pipe inlet flange, a right-end curved pipe section, and a right-end air bleed pipe outlet flange; the right-end air bleed pipe inlet flange is connected to the bleed air precooler, and the right-end air bleed pipe outlet flange is connected to the turbine end air collecting chamber;

[0014] Furthermore, the left-end air bleed pipe, the right-end air bleed pipe and the bleed air precooler are respectively connected by bolts.

[0015] Preferably, the flange edge of the air hood air duct is welded to the air hood air duct, the flange edge of the air hood exhaust pipe is welded to the air hood exhaust pipe, the air hood air duct and the air hood exhaust pipe are welded to the sleeve, the left cover of the sleeve is welded to the sleeve, the sleeve is welded to the right cover of the sleeve, the left cover of the sleeve and the right cover of the sleeve are respectively welded to the inner air duct; the left flange edge of the inner air duct and the right flange edge of the inner air duct are respectively welded to the inner air duct.

[0016] Preferably, the left air duct inlet flange is welded to the left bent pipe section, and the left bent pipe section is welded to the left air duct outlet flange 40.

[0017] Preferably, the right-end air duct inlet flange is welded to the right-end curved pipe section, and the right-end curved pipe section is welded to the right-end air duct outlet flange.

[0018] During use, an installation window is provided on the wall of the rectifier casing on the inner side of the outer duct, and the wind hood bleed pipe and the wind hood exhaust pipe are arranged in the straight section of the outer duct through the installation window; the low-temperature compressed air in the outer duct is introduced into the outer ventilation cavity through the wind hood bleed pipe, and after the outer wall of the inner bleed pipe is enhanced cooled, it is discharged into the straight section of the outer duct from the wind hood exhaust pipe; at the same time, the compressed air drawn out from the compressor interstage bleed port enters the bleed end air collecting cavity through the bleed hole, and then the compressed air is introduced into the inner bleed pipe of the bleed air precooler through the left end bleed pipe. Under the enhanced cooling effect of the low-temperature compressed air in the outer ventilation cavity, the compressed air in the inner bleed pipe is cooled and the temperature is reduced, and then it is discharged into the turbine end air collecting cavity through the right end bleed pipe, thereby achieving the purpose of cooling the compressor interstage bleed air.

[0019] Compared with the prior art, the advantages of the present invention are:

[0020] The present invention utilizes low-temperature air from the outer casing of aircraft engines and gas turbines to pre-cool the inter-stage bleed air of the compressor, effectively improving the quality of the inter-stage bleed air of the compressor. The cooling scheme has a simple structure and high safety. The introduction of a bleed air pre-cooler can pre-cool the compressed air in the inner bleed air duct while ensuring the flow resistance characteristics of the gas in the inner bleed air duct, which helps to improve the cooling efficiency and economy of the system. The design of the pre-cooler takes into account efficient enhanced heat exchange, and the cooling effect is enhanced through the simple structure of the wind hood bleed air duct and the wind hood exhaust duct. The various parts are connected by a combination of welding and bolting to ensure the reliability and sealing of the structure and reduce the risk of gas leakage. Through a simple structural design and a reliable welding process, effective cooling of the inter-stage bleed air of the compressor is achieved, thereby improving the overall performance and operational safety of aircraft engines and gas turbines. The bleed air pre-cooler has good sealing, a simple structure and high reliability. The system components are connected by flange edges and bolts, which is convenient for assembly and maintenance, and improves the flexibility and maintainability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1This is a schematic diagram of the typical interstage air bleed scheme and air bleed pipe location for aircraft engines and gas turbines;

[0022] Figure 2 This is a bleed air pre-cooling solution and structural diagram provided by the present invention;

[0023] Figure 3 is a structural cross-sectional view of the bleed air precooler 24 provided by the present invention;

[0024] Figure 4 This is a structural cross-sectional view of the left-end air duct 22 provided by the present invention;

[0025] Figure 5 This is a structural cross-sectional view of the right-end air duct 23 provided by the present invention;

[0026] Figure 6 1 is a schematic structural diagram of the improved outer duct inner rectifier casing 21 provided by the present invention;

[0027] Figure 7 This is a schematic diagram of the application of the present invention to an aircraft engine and a gas turbine;

[0028] Figure 8 yes Figure 7 A partial enlarged view of the pipe connection.

[0029] The marks in the figure are: 1-fan inlet, 2-fan rotor blades, 3-outer duct airflow inlet, 4-outer duct side support plate, 5-outer duct side support plate airflow outlet, 6-outer casing, 7-outer duct straight section, 8-outer duct straight section airflow outlet, 9-outer duct inner fairing casing, 10-compressor interstage bleed holes, 11-bleed air collecting cavity at the bleed end, 12-bleed pipe, 13-turbine end air collecting cavity, 14-inner duct airflow inlet, 15-inner duct side support plate, 16-compression component airflow inlet, 17-compression component airflow outlet, 18-combustion chamber, 19-combustion chamber inner wall, 20-combustion chamber outer wall, 21-improved outer duct inner fairing casing, 22-left end bleed pipe, 23-right end bleed pipe, 24-bleed air precooler, 25-improved The inner wall of the outer duct fairing casing, 26-installation window, 27-air hood air bleed pipe flange, 28-air hood air bleed pipe, 29-air hood exhaust pipe, 30-air hood exhaust pipe flange, 31-left flange of inner air bleed pipe, 32-left plugging cover of casing, 33-casing, 34-external ventilation cavity, 35-right plugging cover of casing, 36-right flange of inner air bleed pipe, 37-inner air bleed pipe, 38-left end air bleed pipe inlet flange, 39-left end bend section, 40-left end air bleed pipe outlet flange, 41-right end air bleed pipe inlet flange, 42-right end bend section, 43-right end air bleed pipe outlet flange, 44-connection structure between left end air bleed pipe outlet flange and inner air bleed pipe left flange, 45-connection structure between inner air bleed pipe right flange and right end air bleed pipe inlet flange. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the following embodiments will be further described in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0031] Comparative Example (Prior Art): Figure 1 As shown in Figure 2, typical interstage air bleed solutions for aircraft engines and gas turbines include:

[0032] The engine's duct airflow path is sequentially arranged as follows: fan inlet 1, fan rotor blades 2, duct airflow inlet 3, duct side support plate 4, duct side support plate airflow outlet 5, outer casing 6, duct straight section 7, duct straight section airflow outlet 8, and duct inner straightening casing 9. The inner straightening casing 9 straightens the airflow within the duct, ensuring smooth and uniform airflow and reducing flow losses within the duct. The annular space between the outer casing 6 and the inner straightening casing 9 forms the duct straight section 7. The air enters the engine through the fan inlet 1. After passing through the fan inlet, the air is initially compressed by the fan rotor blades 2. A portion of the air is guided into the duct through the duct airflow inlet 3. This portion of air is mainly used to generate duct thrust. The duct side support plate 4 is used to guide and rectify the airflow in the duct through the support plate to ensure the smoothness and uniformity of the airflow. The airflow after rectification by the support plate flows out from the duct side support plate airflow outlet 5, enters the duct straight section 7 to continue flowing, and is finally discharged from the duct straight section airflow outlet 8.

[0033] The inner duct airflow path is sequentially configured as follows: inner duct airflow inlet 14, inner duct side branch plate 15, compression component airflow inlet 16, compression component airflow outlet 17, and combustion chamber 18. The inner duct airflow inlet 14 is used to provide high-pressure and high-temperature air for combustion. The inner duct side branch plate 15 is used to guide and rectify the airflow within the inner duct. The compression component airflow inlet 16 is the airflow inlet of the compressor section, where the air is compressed. The compressed air flows out of the compression component airflow outlet 17 and enters the combustion chamber 18. The combustion chamber 18 includes the combustion chamber inner wall 19 and the combustion chamber outer wall 20. The compressor interstage bleed holes 10, located between different compressor stages, are used to extract high-pressure air. The high-pressure air extracted by the compressor interstage bleed holes 10 is collected in the bleed end plenum 11. The high-pressure air in the bleed end plenum 11 is guided to the area requiring cooling or sealing through the bleed pipe 12. The turbine end plenum 13, located at the turbine end, is used to collect and distribute bleed air.

[0034] A typical turbine casing component air bleed path draws out compressed air of suitable temperature from the compressor stage, and transports the compressed air to the turbine end air collecting chamber 13 through the air bleed pipe 12. The compressed air entering the turbine end air collecting chamber 13 is then transported to the interior of the turbine casing component that needs to be cooled through the air system secondary flow network, and then discharged into the turbine flow channel, thereby achieving the purpose of cooling the turbine casing components.

[0035] Example 1

[0036] like Figures 2 to 5 As shown, the embodiment of the present invention is provided with a bleed air collecting chamber 11, a left bleed air pipe 22, a bleed air precooler 24, a right bleed air pipe 23 and a turbine end bleed air collecting chamber 13;

[0037] The bleed air collecting chamber 11 is used to collect and guide the inter-stage bleed air of the compressor. One end of the bleed air collecting chamber 11 is connected to the left bleed air pipe 22 through the left bleed air pipe inlet flange 38; the other end of the bleed air collecting chamber 11 is connected to the original compression component.

[0038] The left air bleed pipe 22 is used to guide compressed air from the air bleed end collecting chamber 11 to the air bleed precooler 24. The left air bleed pipe 22 includes a left air bleed pipe inlet flange 38, a left curved pipe section 39, and a left air bleed pipe outlet flange 40. The left air bleed pipe inlet flange 38 is connected to the air bleed end collecting chamber 11, and the left air bleed pipe outlet flange 40 is connected to the air bleed precooler 24. The left air bleed pipe 22 is obtained by welding the left air bleed pipe inlet flange 38 and the left air bleed pipe outlet flange 40 to the left curved pipe section 39, respectively.

[0039] The bleed air precooler 24 is used to precool the compressed air in the inner bleed air pipe 37. The bleed air precooler 24 includes a hood bleed air pipe flange 27, a hood bleed air pipe 28, a hood exhaust pipe 29, a hood exhaust pipe flange 30, an inner bleed air pipe left flange 31, a sleeve left plugging cover 32, a sleeve 33, a sleeve right plugging cover 35, an inner bleed air pipe right flange 36, and an inner bleed air pipe 37. One end of the hood bleed air pipe 28 is provided with a hood bleed air pipe flange 27, and the hood bleed air pipe flange 27 and the hood bleed air pipe 28 are welded together. The other end of the air hood duct 28 is connected to the sleeve 33; one end of the air hood exhaust pipe 29 is connected to the air hood exhaust pipe flange 30, and the air hood exhaust pipe flange 30 and the air hood exhaust pipe 29 are connected by welding; the other end of the air hood exhaust pipe 29 is connected to the sleeve 33; the air hood duct 28 and the air hood exhaust pipe 29 are respectively connected to the sleeve 33 by welding; the left sleeve cover 32 is connected to the sleeve 33 and is connected to the inner air duct 37; the right sleeve cover 35 is also connected to the sleeve 33 and the inner air duct 37; the inner air duct The two ends of the air pipe 37 are respectively provided with an inner air pipe left flange 31 and an inner air pipe right flange 36, which are connected by welding to the sleeve left cover 32, the sleeve 33, the sleeve right cover 35 and the inner air pipe 37; the inner air pipe left flange 31 and the inner air pipe right flange 36 are respectively connected to the inner air pipe 37 by welding, and an outer ventilation cavity 34 is formed between the inner wall of the sleeve 33 and the outer wall of the inner air pipe 37; the outer ventilation cavity 34 is used to guide the low-temperature compressed air from the wind hood air pipe 28 to the outer wall of the inner air pipe 37. After enhanced cooling of the wall, the compressed air is discharged from the air hood exhaust pipe 29 into the outer duct straight section 7; at the same time, the compressed air drawn out from the compressor interstage bleed port enters the bleed end plenum 11 through the bleed hole, and then is introduced into the inner bleed pipe 37 of the bleed air precooler through the left end bleed pipe 22. Under the enhanced cooling effect of the low-temperature compressed air in the outer ventilation cavity 34, the compressed air in the inner bleed pipe 37 is cooled and the temperature is reduced, thereby achieving cooling of the compressor interstage bleed air. The bleed air precooler 24 can be obtained through the above process.

[0040] The right-end air bleed pipe 23 is used to guide precooled compressed air from the bleed air precooler 24 to the turbine-end air collecting chamber 13. The right-end air bleed pipe 23 includes a right-end air bleed pipe inlet flange 41, a right-end curved pipe section 42, and a right-end air bleed pipe outlet flange 43. The right-end air bleed pipe inlet flange 41 is connected to the bleed air precooler 24, and the right-end air bleed pipe outlet flange 43 is connected to the turbine-end air collecting chamber 13. The right-end air bleed pipe 23 is obtained by welding the right-end air bleed pipe inlet flange 41 and the right-end air bleed pipe outlet flange 43 to the right-end curved pipe section 42.

[0041] The inlet of the turbine end air collecting chamber 13 is connected to the right end air bleed pipe 23 through the right end air bleed pipe outlet flange 43. The turbine end air collecting chamber 13 is used to receive the compressed air precooled by the bleed air precooler 24.

[0042] The left end bleed air pipe 22 is assembled on the mounting seat outside the bleed air collecting chamber 11 by connecting bolts; the right end bleed air pipe 23 is assembled on the mounting seat outside the turbine end bleed air collecting chamber 13 by connecting bolts, and the left end bleed air pipe 22, the bleed air precooler 24 and the right end bleed air pipe 23 are assembled into a bleed air precooler 24 by connecting bolts. Figure 2 The bleed air pre-cooling structure shown.

[0043] Figure 6 A schematic structural diagram of the improved outer duct inner fairing casing provided by the present invention is provided; an installation window 26 is provided on the improved outer duct inner fairing casing wall 25, and the installation window 26 is used to install and secure the bleed air duct and bleed air exhaust pipe of the bleed air precooler. This design ensures that the normal flow of gas in the outer duct is not affected during the operation of the aircraft engine and gas turbine, avoiding the generation of unnecessary aerodynamic resistance or turbulence. At the same time, it facilitates the inspection and maintenance of the bleed air precooler 24 when necessary, without the need for large-scale disassembly of the outer duct.

[0044] Figure 7 A schematic diagram of the application of the present invention to an aircraft engine and a gas turbine is given. Figure 8 yes Figure 7 A partial enlarged view of the pipe connection. Figure 7 The annular space between the outer casing 6 and the inner rectifying casing 9 of the outer duct forms the outer duct straight section 7. The air flow flows out from the air flow outlet 5 of the outer duct side support plate and continues to flow along the outer duct straight section 7. The wind hood air bleed pipe 28 and the wind hood exhaust pipe 29 of the bleed air precooler 24 are arranged in the outer duct straight section 7 through the installation window 26; the low-temperature compressed air in the outer duct is introduced into the outer ventilation cavity 34 by the wind hood air bleed pipe 28 of the bleed air precooler 24, and after the outer wall of the inner bleed pipe 37 is enhanced cooled, it is discharged into the outer duct straight section from the wind hood exhaust pipe 29 and discharged from the outer duct straight section air flow outlet 8. At the same time, the compression component airflow inlet 16 serves as the compressor section's airflow inlet, where air is compressed. The compressed air then flows out of the compression component airflow outlet 17. The compressed air drawn from the compressor interstage bleed port enters the bleed end manifold 11 through the bleed holes 10. It is then introduced into the inner bleed duct 37 of the bleed air precooler 24 via the left bleed duct 22. Under the enhanced cooling effect of the low-temperature compressed air within the external ventilation chamber 34, the compressed air within the inner bleed duct 37 is cooled (by up to 20°C) and then discharged into the turbine end manifold 13 via the right bleed duct 23, thereby cooling the compressor interstage bleed air. The connection between the left bleed duct 22 and the bleed air precooler 24 is equipped with a connecting structure 44 between the left bleed duct outlet flange and the left flange of the inner bleed duct, which are bolted together. The connection between the right end bleed air pipe 23 and the bleed air precooler 24 is provided with a connection structure 45 between the right flange of the inner bleed air pipe and the flange of the right end bleed air pipe inlet and connected by bolts. Figure 7 In the figure, mark 21 is the improved inner rectifier casing of the outer duct.

[0045] The present invention mainly improves the original bleed air cooling system by:

[0046] 1. Added a new air hood bleed pipe 28 and an air hood exhaust pipe 29: One end of the air hood bleed pipe 28 is connected to the outer duct, and the other end is connected to the bleed air precooler 24. The air hood bleed pipe 28 introduces low-temperature compressed air into the outer ventilation cavity 34, enhancing cooling of the outer wall of the inner bleed pipe 37. The air is then discharged into the straight section of the outer duct through the air hood exhaust pipe 29. This improves the cooling efficiency of the existing system and utilizes the low-temperature air resources in the outer duct.

[0047] 2. Design of bleed air precooler 24: This is the core component of the present invention. The bleed air precooler 24 includes a hood bleed air pipe flange 27, a hood bleed air pipe 28, a hood exhaust pipe 29, a hood exhaust pipe flange 30, an inner bleed air pipe left flange 31, a sleeve left plugging cover 32, a sleeve 33, a sleeve right plugging cover 35, an inner bleed air pipe right flange 36, and an inner bleed air pipe 37; the hood bleed air pipe flange 27 is connected to the hood bleed air pipe 28, and the hood exhaust pipe flange 30 is connected to the hood exhaust pipe 29, and The wind hood exhaust pipe flange 30 and the wind hood exhaust pipe 29 are respectively connected to the sleeve 33; the left sleeve cover 32 is connected to the sleeve 33 and to the inner air duct 37; the right sleeve cover 35 is also connected to the sleeve 33 and the inner air duct 37; the left inner air duct flange 31 and the right inner air duct flange 36 are respectively connected to the inner air duct 37; the inner air duct 37 passes through the outer ventilation cavity 34, so that the high-temperature compressed air in the inner air duct can be cooled by the low-temperature air in the outer ventilation cavity, thereby reducing the bleed air temperature.

[0048] 3. Design the left and right air bleed pipes 22 and 23: Connect the inlet and outlet flanges of the left and right air bleed pipes 22 and 23 by welding, and assemble them on the mounting bases outside the air bleed end collecting cavity 11 and the turbine end collecting cavity 13 respectively using connecting bolts to form a complete air bleed pre-cooling structure.

[0049] 4. All components are connected by welding, including the hood air bleed pipe flange 27, hood air bleed pipe 28, hood exhaust pipe flange 30, hood exhaust pipe 29, sleeve 33, inner bleed pipe 37, etc. The left bleed pipe 22, the right bleed pipe 23 and the bleed air precooler 24 are connected by bolts respectively to improve the strength and sealing of the overall structure.

[0050] Through a simple structural design and reliable welding process, this invention effectively cools the compressor interstage bleed air, improving the cooling efficiency and structural stability of the bleed air cooling system, ensuring effective temperature control of the compressor interstage bleed air, and thereby enhancing the overall performance, operating efficiency, and safety of aircraft engines and gas turbines. This invention utilizes low-temperature air from the outer casing of aircraft engines and gas turbines to pre-cool the compressor interstage bleed air, resulting in a simple cooling solution with high safety and a simple structural solution with high reliability.

[0051] Through a simple structural design and reliable welding process, this invention pre-cools compressor interstage bleed air using low-temperature air from the outer liner, effectively improving the quality of this air and ensuring enhanced overall performance, operating efficiency, and safety of aircraft engines and gas turbines. This invention utilizes low-temperature air from the outer liner of aircraft engines and gas turbines to pre-cool compressor interstage bleed air, resulting in a simple cooling solution with high safety, a simple structural solution, high reliability, and easy maintainability.

[0052] The above embodiments are only preferred embodiments of the present invention and should not be considered to limit the scope of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent of the present invention.

Claims

1. A bleed air pre-cooling structure, characterized in that The air collecting chamber at the bleed end, the air bleed pipe at the left end, the air bleed precooler, the air bleed pipe at the right end and the air collecting chamber at the turbine end are sequentially provided; The air collecting cavity at the bleed end is used to collect and guide the inter-stage bleed air of the compressor, and the outlet of the air collecting cavity at the bleed end is connected to the left end bleed pipe; One end of the left air bleed pipe is connected to the bleed air precooler, and the other end of the left air bleed pipe is connected to the bleed air collecting cavity at the bleed air end. The left air bleed pipe is used to guide the compressed air from the bleed air collecting cavity at the bleed air end to the bleed air precooler; The bleed air precooler is used to precool the compressed air, and the bleed air precooler includes an air hood bleed pipe, an air hood exhaust pipe, a casing, and an inner bleed pipe; the air hood bleed pipe is provided with an air hood bleed pipe flange, and the air hood bleed pipe is connected to the casing; the air hood exhaust pipe is connected to the air hood exhaust pipe flange, and the air hood exhaust pipe is connected to the casing; both ends of the casing are respectively provided with a left casing cover and a right casing cover; the left casing cover is connected to the casing and to the inner bleed pipe; the right casing cover is also connected to the casing and the inner bleed pipe; the two ends of the inner bleed pipe are respectively provided with a left inner bleed pipe flange and a right inner bleed pipe flange; an outer ventilation cavity is formed between the inner wall of the casing and the outer wall of the inner bleed pipe; the outer ventilation cavity is used to guide the low-temperature compressed air from the air hood bleed pipe to enhance the cooling of the compressed air in the inner bleed pipe, and then discharge the low-temperature compressed air from the air hood bleed pipe into the straight section of the outer duct through the air hood exhaust pipe; One end of the right-end bleed air pipe is connected to the bleed air precooler, and the other end of the right-end bleed air pipe is connected to the turbine-end air collecting chamber. The right-end bleed air pipe is used to guide the precooled compressed air from the bleed air precooler to the turbine-end air collecting chamber. The turbine end air collecting cavity is used to receive the compressed air precooled by the bleed air precooler.

2. The bleed air pre-cooling structure according to claim 1, characterized in that The left-end air bleed pipe includes a left-end air bleed pipe inlet flange, a left-end bent pipe section, and a left-end air bleed pipe outlet flange; the left-end air bleed pipe inlet flange is connected to the air bleed end air collecting cavity, and the left-end air bleed pipe outlet flange is connected to the air bleed precooler.

3. The bleed air pre-cooling structure according to claim 1, characterized in that The right-end air bleed pipe includes a right-end air bleed pipe inlet flange, a right-end bent pipe section, and a right-end air bleed pipe outlet flange; the right-end air bleed pipe inlet flange is connected to the bleed air precooler, and the right-end air bleed pipe outlet flange is connected to the turbine end air collecting chamber.

4. The bleed air pre-cooling structure according to claim 1, characterized in that The left-end air bleed pipe, the right-end air bleed pipe and the bleed air precooler are respectively connected by bolts.

5. The bleed air pre-cooling structure according to claim 1, characterized in that The air hood air duct comprises an air hood air duct flange, a straight section, and a curved section; the air hood air duct flange is connected to the straight section.

6. The bleed air pre-cooling structure according to claim 1, characterized in that The wind hood exhaust pipe comprises a wind hood exhaust pipe flange, a straight section, and a curved pipe section; the wind hood exhaust pipe flange is connected to the straight section.

7. The bleed air pre-cooling structure according to claim 1, characterized in that The flange edge of the air hood air duct is welded to the air hood air duct, the flange edge of the air hood exhaust pipe is welded to the air hood exhaust pipe, the air hood air duct and the air hood exhaust pipe are welded to the casing, the left blocking cover of the casing is welded to the casing, the casing is welded to the right blocking cover of the casing, the left blocking cover of the casing and the right blocking cover of the casing are respectively welded to the inner air duct; the left flange edge of the inner air duct and the right flange edge of the inner air duct are respectively welded to the inner air duct.

8. The bleed air pre-cooling structure according to claim 2, characterized in that The left-end air duct inlet flange edge is welded to the left-end curved pipe section, and the left-end curved pipe section is welded to the left-end air duct outlet flange edge.

9. The bleed air pre-cooling structure according to claim 3, characterized in that The right-end air duct inlet flange edge is welded to the right-end curved pipe section, and the right-end curved pipe section is welded to the right-end air duct outlet flange edge.

10. The bleed air pre-cooling structure according to claim 1, characterized in that An installation window is provided on the wall of the rectifier casing on the inner side of the outer duct, and the straight section of the wind hood bleed pipe and the straight section of the wind hood exhaust pipe are arranged in the straight section of the outer duct through the installation window; the low-temperature compressed air in the outer duct is introduced into the outer ventilation cavity through the wind hood bleed pipe, and after the outer wall of the inner bleed pipe is enhanced cooled, it is discharged into the straight section of the outer duct from the wind hood exhaust pipe; at the same time, the compressed air drawn out from the compressor interstage bleed port enters the bleed end air collecting cavity through the bleed hole, and then the compressed air is introduced into the inner bleed pipe of the bleed air precooler through the left end bleed pipe. Under the enhanced cooling effect of the low-temperature compressed air in the outer ventilation cavity, the compressed air in the inner bleed pipe is cooled and the temperature is reduced, and then it is discharged into the turbine end air collecting cavity through the right end bleed pipe, thereby realizing the cooling of the compressor interstage bleed air.

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