CN116517696A

CN116517696A - Air inlet channel, turbofan engine and air inlet channel anti-icing method

Info

Publication number: CN116517696A
Application number: CN202210077936.9A
Authority: CN
Inventors: 林家坚; 余天竑; 朱琳; 任健
Original assignee: AECC Commercial Aircraft Engine Co Ltd
Current assignee: AECC Commercial Aircraft Engine Co Ltd
Priority date: 2022-01-24
Filing date: 2022-01-24
Publication date: 2023-08-01

Abstract

The air inlet comprises a lip, an inner wall plate, an outer wall plate and a front bulkhead, wherein a first cavity is formed by the inner wall plate, the outer wall plate and the front bulkhead, the air inlet further comprises a cooling system, the cooling system comprises an air inlet, an air outlet and a cooling pipeline, the cooling pipeline extends along the circumferential direction of the air inlet, a plurality of cooling holes are formed in the cooling pipeline, and the cooling holes are arranged towards the connection area of the lip and the inner wall plate; the cooling pipeline is arranged in the first cavity, cooling gas enters the cooling pipeline from the air inlet, is sprayed to the connecting area through the plurality of cooling holes, and is discharged out of the first cavity through the exhaust port. A turbofan engine and an air inlet anti-icing method are also provided.

Description

Air inlet channel, turbofan engine and air inlet channel anti-icing method

Technical Field

The invention relates to the field of turbofan aeroengine nacelle, in particular to an air inlet channel, a turbofan engine and an air inlet channel anti-icing method.

Background

The turbofan aeroengine nacelle has the main functions of fixing the engine on an aircraft, optimizing the aerodynamic flow field of the engine and protecting the engine from external damage. The engine nacelle mainly comprises an air inlet channel, a fan cover, a thrust reverser, a tail nozzle, a mounting system and the like, wherein the main function of the air inlet channel is to provide a stable and uniform air inlet flow field for the engine, and to carry out speed reduction and pressurization on the air inlet flow field so as to ensure the stable and reliable operation of the engine. The air inlet is mainly composed of a lip, a front partition frame, a rear partition frame, an inner wall plate, an outer wall plate, an anti-icing system, a butt joint ring and other components, wherein the lip is generally made of an aluminum alloy material, and the inner wall plate is generally made of a composite material, such as a honeycomb sandwich material.

In the running process of an aircraft, icing is usually caused at the lip of an air inlet of a turbofan engine due to low ambient temperature and high air humidity. The aerodynamic profile of the engine may become uneven due to the influence of icing of the inlet lip, so that the quality of the intake of the engine inlet may be deteriorated, resulting in a reduced performance of the engine. In order to prevent or eliminate ice formation on the inlet lip of an engine, high-temperature gas is usually led from the core of the engine through a bleed air line to a heating lip in a D-shaped cavity consisting of the inlet lip and a front bulkhead for deicing. In order to achieve the effect of quick anti-icing, when the air inlet anti-icing system works stably, the whole temperature of the lip reaches a high temperature of more than 200 ℃.

The inlet lip and the inner wall plate are of cylinder thin-wall structures, and the connecting structure form of the inlet lip and the inner wall plate is as follows: in order to ensure the smoothness of the inner flow passage surface of the air inlet passage, the front mounting edge of the inner wall plate is inwards recessed to leave a mounting space of the mounting edge of the lip, the lip is directly sleeved outside the front mounting edge of the inner wall plate, and the front mounting edge of the inner wall plate are riveted together through countersunk rivets. When the air inlet channel anti-icing system works, the thermal expansion amounts of the two parts are unequal due to the fact that the temperature of the lip opening is higher and the temperature of the front mounting edge of the inner wall plate is lower, and high thermal stress can be generated in a connecting area, so that the connecting structure is easy to fail; in addition, since the highest use temperature of the composite material is generally lower than 120 ℃, the mechanical properties of the composite material can be greatly reduced under the high temperature condition, and even layering of the laminated board occurs due to the high temperature.

In order to avoid the overhigh temperature of the installation edge of the inner wall plate, the prior technical scheme is to add a layer of rubber pad between the lip and the inner wall plate for heat insulation, and the technical scheme can avoid connection failure caused by overhigh temperature of the installation edge before the inner wall plate, but the rubber pad is easy to age and fall off after the repeated heating and cooling of the lip to cause the connection looseness of the lip and the inner wall plate.

Disclosure of Invention

An object of the present invention is to provide an air intake, which can avoid the problem of failure of the connection between the lip of the air intake and the wall plate.

The above-mentioned intake duct includes lip, interior wallboard, outer wallboard and preceding bulkhead, by interior wallboard outer wallboard and preceding bulkhead forms first cavity, and the intake duct still includes cooling system, cooling system includes: an air inlet; an exhaust port; the cooling pipeline extends along the circumferential direction of the air inlet channel, a plurality of cooling holes are formed in the cooling pipeline, and the cooling holes are arranged towards the connection area of the lip and the inner wall plate; the cooling pipeline is arranged in the first cavity, cooling gas enters the cooling pipeline from the air entraining port, is sprayed to the connecting area through the plurality of cooling holes, and is discharged out of the first cavity through the exhaust port.

In one or more embodiments, the cooling circuit includes a bleed air duct, the bleed air duct being provided through which a cooling gas is introduced into the cooling circuit from an inlet external flow channel or a nacelle external culvert.

In one or more embodiments, a plurality of the cooling holes are uniformly distributed on the cooling pipe.

In one or more embodiments, the exhaust port is disposed on a service cover of the intake duct.

In one or more embodiments, the air intake further includes a bracket having one end connected to the front bulkhead and the other end connected to the cooling pipe such that the cooling pipe is adjacent to the connection region.

In one or more embodiments, the lip is made of an aluminum alloy material and the inner wall plate is made of a composite material.

In one or more embodiments, the air intake further includes an anti-icing system, a second cavity is formed by the lip and the front bulkhead, and the anti-icing system is disposed in the second cavity to heat the lip.

In one or more embodiments, the anti-icing system includes a first valve for switching the anti-icing system on and off, and the cooling system includes a second valve for switching the cooling system on and off; wherein the second valve is synchronously operated with the first valve to maintain synchronous opening and closing.

The cooling system in the air inlet channel can directly spray cooling gas to the connection area of the lip and the inner wall plate, so that the temperature of the connection area is effectively reduced, the thermal stress generated in the connection area in the anti-icing process of the air inlet channel is reduced, the service life of the connection structure is prolonged, and the problem of connection failure caused by the thermal stress is avoided.

Another object of the present invention is to provide a turbofan engine that avoids the problem of failure of the connection of the inlet lip to the wall plate.

The turbofan engine comprises the air inlet channel.

The cooling system in the air inlet channel adopted by the turbofan engine can directly spray cooling gas to the connection area of the lip and the inner wall plate, so that the temperature of the connection area is effectively reduced, the thermal stress generated in the connection area in the anti-icing process of the air inlet channel is reduced, the service life of the connection structure is prolonged, and the problem of connection failure caused by the thermal stress is avoided.

It is still another object of the present invention to provide an air inlet anti-icing method, which can avoid the problem of failure of the connection between the lip and the wall plate during the air inlet anti-icing process.

The method for preventing ice of the air inlet is used for the air inlet of the nacelle, the air inlet comprises a lip, an inner wall plate, an outer wall plate and a front bulkhead, a first cavity is formed by the inner wall plate, the outer wall plate and the front bulkhead, a second cavity is formed by the lip and the front bulkhead, and the method for preventing ice comprises the following steps: providing an anti-icing system disposed in the second chamber, heating the lip by the anti-icing system; a cooling system is provided in the first chamber, by means of which the connection region of the lip and the inner wall plate is cooled.

In one or more embodiments, when the anti-icing system heats the lip, the connection region of the lip and the inner wall plate is synchronously cooled by the cooling system.

The method for preventing the air inlet from being iced can avoid the problem that the connecting structure of the lip and the inner wall plate is invalid due to overhigh temperature of the lip in the working process of the anti-icing system, and prolongs the service life of the connecting structure.

Drawings

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

FIG. 1 is a schematic diagram of an inlet according to an embodiment.

FIG. 2 is a schematic partial structure of an intake duct according to an embodiment.

FIG. 3 is a partial cross-sectional view of an intake port according to an embodiment.

FIG. 4 is a schematic diagram of a cooling circuit according to an embodiment.

Fig. 5 is a partial enlarged view of the region B in fig. 4.

FIG. 6 is a schematic structural view of an intake duct outer wall plate according to an embodiment.

Sign mark description

1 lip

2 inner wall plate

3 outer wall plate

4 front bulkhead

5 cooling pipeline

6 anti-icing pipeline

7 first chamber

8 second chamber

9 connection region

10 support

21 front mounting edge

31 exhaust port

32 maintenance cover plate

50 annular tube

51 bleed port

52 cooling holes

53 bleed air pipe

61 anti-icing hole

101 one end

102 another end

Direction a

Detailed Description

The present invention will be further described with reference to specific embodiments and drawings, in which more details are set forth in the following description in order to provide a thorough understanding of the present invention, but it will be apparent that the present invention can be embodied in many other forms than described herein, and that those skilled in the art may make similar generalizations and deductions depending on the actual application without departing from the spirit of the present invention, and therefore should not be construed to limit the scope of the present invention in terms of the content of this specific embodiment. It is noted that these and other figures are merely examples, which are not drawn to scale and should not be construed as limiting the scope of the invention as it is actually claimed.

The structure of the air inlet channel of the turbofan engine nacelle is shown in fig. 1, and comprises a lip, an outer wall plate, an inner wall plate and a front partition frame, wherein two ends of the lip are respectively connected with the inner wall plate and the outer wall plate, and the front partition frame is used for supporting the inner wall plate and the outer wall plate. In the running process of the aircraft, due to the fact that the ambient temperature is low and the humidity is high, icing can occur at the lip of the air inlet channel, air inlet quality is affected, and further engine performance is affected.

In order to prevent the situation of icing at the lip, an anti-icing pipeline is usually arranged in the air inlet channel, the anti-icing pipeline is arranged in a cavity formed by the lip and the front bulkhead, and high-temperature gas is introduced into the pipeline from a core engine of the engine to heat the cavity, so that the anti-icing function of the lip is realized. The gas introduced from the core machine has extremely high temperature, when the anti-icing system works, the lip can be heated to higher temperature, the temperature of the inner wall plate connected with the lip is lower, the thermal expansion of the lip and the inner wall plate is unequal, and the connecting area can generate extremely high thermal stress, so that the connection is invalid. Therefore, it is desirable to provide an air intake structure that can avoid the problem of failure of the lip to wall connection.

In order to achieve the above functions, the air inlet channel comprises a lip 1, an inner wall plate 2, an outer wall plate 3 and a front bulkhead 4, wherein a first chamber 7 is formed by the inner wall plate 2, the outer wall plate 3 and the front bulkhead 4, the air inlet channel further comprises a cooling system, the cooling system comprises an air inlet 51, an air outlet 31 and a cooling pipeline 5, the cooling pipeline 5 is arranged in the first chamber 7 and extends along the circumferential direction of the air inlet channel, a plurality of cooling holes 52 are formed in the cooling pipeline 5, and the cooling holes 52 are arranged towards a connection area 9 of the lip 1 and the inner wall plate 2, so that cooling air can be directly sprayed in the connection area 9 to cool the cooling air.

The cooling gas enters the cooling circuit 5 from the bleed port 51, is sprayed through the plurality of cooling holes 52 in the direction a shown by the arrow in fig. 2 to the connection region 9 of the intake lip 1 and the inner wall plate 2, and is discharged from the exhaust port 31 to the outside of the first chamber 7, so that the air pressure in the first chamber 7 is in a stable state.

In the embodiment shown in fig. 3, the front mounting edge 21 of the inner wall plate 2 is recessed radially inwards, and the lip 1 can be directly sleeved outside the front mounting edge 21 and fastened by means of fasteners. When the anti-icing system is started, the lip 1 part in the connecting area 9 can be heated to a higher temperature, the temperature of the front mounting edge 21 part is lower, the thermal expansion amounts of the lip and the front mounting edge are unequal, so that very high thermal stress can be generated in the connecting area 9, cooling gas can be directly sprayed to the connecting area 9 through the cooling system, the temperature of the connecting area 9 is effectively reduced, the thermal stress of the connecting area 9 is reduced, the service life of the connecting structure is prolonged, and the problem of connection failure caused by the thermal stress is avoided.

In other embodiments, the inlet lip 1 and the inner wall plate 2 may be connected by other means, and the connection area between the two is cooled by a cooling system, and the connection area refers to an area where thermal stress is induced at the connection between the lip 1 and the inner wall plate 2 due to heating during anti-icing.

As shown in fig. 3, the air inlet further includes a bracket 10, the cooling pipeline 5 is fixed in the first chamber 7 through the bracket 10, one end 101 of the bracket 10 is connected with the front bulkhead 4, the other end 102 is connected with the cooling pipeline 5, and the cooling pipeline 5 is arranged at a position close to the connection area 9, so that the cooling effect of the air flow is improved.

In one embodiment, one end 101 of the bracket 10 is in pin connection with the front bulkhead 4, the other end 102 of the bracket 10 is connected with the cooling pipeline 5 by adopting a joint bearing, so that the cooling pipeline 5 has a certain rotation space relative to the bracket 10, when the air inlet channel cooling system is started, the cooling pipeline 5 and the bracket 10 are affected by heat expansion and cold contraction, the thermal expansion amounts of the two are different, and the joint of the other end 102 of the bracket 10 and the cooling pipeline 5 is set to be in a structure with a certain movable space, so that allowance can be reserved for thermal expansion, and structural damage in the cooling process is avoided.

As shown in fig. 4 and 5, in one embodiment, the cooling pipeline 5 includes an annular pipe 50 and a bleed air pipe 53, a plurality of cooling holes 52 are formed in the annular pipe 50, one end of the bleed air pipe 53 is communicated with the annular pipe 50, and a bleed air port 51 is provided at the other end of the bleed air pipe 53, and cooling air flow can flow into the annular pipe 50 from the bleed air port 51 through the bleed air pipe 53 and then be sprayed at the connection area 9 through the cooling holes 52 to cool the annular pipe. The air introduction port 51 may be provided at an air intake passage outer flow passage or a nacelle outer flow passage, from which cooling air is introduced into the cooling pipe 5.

In the embodiment shown in fig. 4, a plurality of cooling holes 52 are uniformly distributed on the annular pipe 50, so that uniform cooling of the connection region 9 between the inlet lip 1 and the inner wall plate 2 is realized, and the cooling effect is improved.

As shown in fig. 6, in one embodiment, the air inlet outer wall plate 3 is provided with a maintenance cover plate 32, during maintenance, the maintenance cover plate 32 can be opened to inspect the cooling pipeline 5, the air outlet 31 is arranged on the maintenance cover plate 32, the air outlet structure is simplified, and when the cooling system is opened, air flow in the first chamber 7 can be discharged from the air outlet 31, so that the pressure in the chamber is in a stable state. In other embodiments, an exhaust pipe may be provided in the first chamber 7 to enable the cooling air flow to be exhausted to the outside of the chamber.

In the above embodiment, the inlet lip 1 is made of an aluminum alloy material, the inner wall plate 2 is made of a honeycomb sandwich material, the maximum use temperature of the honeycomb sandwich material is 100 ℃, the lip 1 is heated to above 200 ℃ in the normal working state of the anti-icing system, heat is transferred from the lip 1 to the front mounting edge 21 in the connecting area 9, the inner wall plate 2 is heated, the cooling system is arranged in the first cavity 7 to cool the connecting area 9, the mechanical property of the honeycomb sandwich material is prevented from being reduced in the high temperature state, the layering problem of the laminated plate is avoided, and the stability of the inlet structure is ensured.

As shown in fig. 3, in one embodiment, the air intake further includes an anti-icing system, which forms a second chamber 8 with the lip 1 and the front bulkhead 4, and is disposed in the second chamber 8 to heat the lip 1. The anti-icing system comprises an anti-icing pipeline 6, the anti-icing pipeline 6 is connected to the front bulkhead 4 through a bracket, a plurality of anti-icing holes 61 are formed in the anti-icing pipeline 6, high-temperature gas can be introduced into the anti-icing pipeline 6 from an engine core machine and is sprayed into the second cavity 8 through the plurality of anti-icing holes 61, and anti-icing of the lip of the air inlet channel is achieved.

In one embodiment, the anti-icing system comprises a first valve for switching the anti-icing system on and off, and the cooling system comprises a second valve for switching the cooling system on and off, wherein the second valve is operated in synchronization with the first valve to maintain synchronized switching.

In a specific embodiment, the first valve and the second valve are on-off valves, and have an open state and a closed state, wherein the first valve opens a pipeline of the anti-icing system in the open state, and closes the pipeline of the anti-icing system in the closed state. Likewise, the second valve opens the cooling system piping in the open state and closes the cooling system piping in the closed state.

In a specific embodiment, the opening and closing of the first valve and the second valve may be controlled by a control system that effects a synchronized actuation of the two, e.g., the control system opens the second valve in response to the opening of the first valve. Or the first valve and the second valve can be provided with a linkage mechanism, and the second valve is driven to be opened when the first valve is opened, so that synchronous action of the first valve and the second valve is realized. The cooling system can be synchronously started along with the anti-icing system to timely cool the connection area 9 of the lip 1 and the inner wall plate 2, so that the failure of the connection structure caused by overheat of the inner wall plate 2 is prevented; the cooling system will only be turned on when the anti-icing system is on, and will remain off in other situations, avoiding cooling in unnecessary situations. In other embodiments, the switches of the anti-icing system and the cooling system may be controlled separately as desired by the design.

In another aspect, the present application further provides an anti-icing method for an air intake duct of a nacelle, the air intake duct including a lip 1, an inner wall plate 2, an outer wall plate 3 and a front bulkhead 4, a first cavity 7 being formed by the inner wall plate 2, the outer wall plate 3 and the front bulkhead 4, and a second cavity 8 being formed by the lip 1 and the front bulkhead 4, the anti-icing method comprising:

providing an anti-icing system arranged in the second chamber 8, and heating the lip 1 through the anti-icing system;

a cooling system is provided which is arranged in the first chamber 7 and by means of which the connection region 9 of the lip 1 with the inner wall plate 2 is cooled.

In one embodiment, the method for preventing ice in the air inlet can be realized through the air inlet structure shown in fig. 3, so that the problem that the connecting structure of the lip 1 and the inner wall plate 2 is invalid due to overhigh temperature of the lip 1 in the working process of the anti-ice system is avoided, and the service life of the connecting structure is prolonged. In other embodiments, the cooling of the connection region 9 can also be achieved by other cooling structures than those shown in the figures.

In one embodiment, when the anti-icing system heats the lip 1, the cooling system synchronously cools the connection region 9 of the lip 1 and the inner wall plate 2, so that the cooling system can be synchronously started along with the anti-icing system, and the connection region 9 of the lip 1 and the inner wall plate 2 is timely cooled, so that the connection structure failure caused by overheating of the connection region 9 is prevented.

In another embodiment, the cooling system further comprises a temperature sensor arranged on the connection area 9 and a control system receiving data measured by the sensor and controlling the cooling system, the control system being provided with a temperature threshold value which can be set in dependence on the maximum thermal stress that can be tolerated by the connection area 9 and the properties of the composite material used. When the temperature detected by the temperature sensor exceeds the threshold value, the control system starts the cooling system to cool the connection area 9, so that the problems of failure of the connection structure or layering of the laminated plate caused by overheat of the connection area 9 are prevented.

While the invention has been described in terms of preferred embodiments, it is not intended to be limiting, but rather to the invention, as will occur to those skilled in the art, without departing from the spirit and scope of the invention. Therefore, any modification, equivalent variation and modification of the above embodiments according to the technical substance of the present invention fall within the protection scope defined by the claims of the present invention.

Claims

1. An air inlet comprising a lip, an inner wall panel, an outer wall panel and a front bulkhead, a first chamber being defined by the inner wall panel, the outer wall panel and the front bulkhead, the air inlet further comprising a cooling system comprising:

an air inlet;

an exhaust port; and

the cooling pipeline extends along the circumferential direction of the air inlet channel, a plurality of cooling holes are formed in the cooling pipeline, and the cooling holes are arranged towards the connection area of the lip and the inner wall plate;

the cooling pipeline is arranged in the first cavity, cooling gas enters the cooling pipeline from the air entraining port, is sprayed to the connecting area through the plurality of cooling holes, and is discharged out of the first cavity through the exhaust port.

2. The intake duct of claim 1, wherein the cooling circuit includes a bleed duct providing the bleed port through which cooling gas is introduced into the cooling circuit from an intake exterior flow passage or a nacelle exterior culvert flow passage.

3. The air intake duct of claim 1, wherein a plurality of the cooling holes are uniformly distributed on the cooling circuit.

4. The intake duct of claim 1, wherein the exhaust port is provided on a service cover of the intake duct.

5. The air intake of claim 1, further comprising a bracket having one end connected to the front bulkhead and another end connected to the cooling conduit such that the cooling conduit is proximate the connection region.

6. The air intake of claim 1, wherein said lip is made of an aluminum alloy material and said inner wall plate is made of a composite material.

7. The air intake of claim 1, further comprising an anti-icing system defining a second chamber with the lip and the front bulkhead, the anti-icing system disposed within the second chamber for heating the lip.

8. The air intake of claim 7, wherein the anti-icing system includes a first valve for switching the anti-icing system on and off, and the cooling system includes a second valve for switching the cooling system on and off;

wherein the second valve is synchronously operated with the first valve to maintain synchronous opening and closing.

9. A turbofan engine comprising an inlet duct according to any one of claims 1 to 8.

10. An inlet anti-icing method for a nacelle inlet, the inlet including a lip, an inner wall, an outer wall, and a front bulkhead, a first cavity being defined by the inner wall, the outer wall, and the front bulkhead, the lip and the front bulkhead defining a second cavity, the anti-icing method comprising:

providing an anti-icing system disposed in the second chamber, heating the lip by the anti-icing system;

a cooling system is provided in the first chamber, by means of which the connection region of the lip and the inner wall plate is cooled.

11. The inlet anti-icing method of claim 10, wherein said lip and said inner wall panel connection area is cooled synchronously by said cooling system as said anti-icing system heats said lip.