Anti-icing system, compressor and turbofan engine

Abstract

This invention provides an anti-icing system, a compressor, and a turbofan engine, which have good anti-icing effects, can avoid losses caused by secondary flow, and can improve sealing performance. The turbofan engine includes the compressor, which includes the anti-icing system. At the inlet of the compressor, a first sealing chamber and a second sealing chamber are formed within the gap between the compressor rotor disc and the stator. A sealing structure is provided between the first and second sealing chambers. The anti-icing system includes a flow divider ring, an inlet guide vane, an bleed air pipe, and a guide vane channel. The flow divider ring includes an bleed air inlet and an bleed air outlet. The bleed air pipe is connected to the bleed air inlet and is used to introduce anti-icing bleed air from one of the compressor stages downstream of the flow divider ring into the flow divider ring. The guide vane channel is disposed inside the inlet guide vane and connects the bleed air outlet and the first sealing chamber.

Description

Technical Field

[0001] This invention relates to the field of anti-icing technology for aircraft engines, specifically to an anti-icing system, a compressor, and a turbofan engine. Background Technology

[0002] When an aircraft encounters cold clouds or operates on icy ground during a flight mission, certain surfaces at the engine inlet, such as the head of the splitter ring, may become icy. Without anti-icing measures, severe icing can occur, affecting engine performance and even damaging the engine, thus endangering flight safety. Airworthiness regulations require that icing on engine components during flight should not affect engine operation.

[0003] Traditional bleed-air anti-icing methods involve introducing high-temperature, high-pressure gas from a high-pressure compressor into the inner cavity of a splitter ring to raise its temperature and prevent icing. This gas is then discharged from the front end of the splitter ring into the inner cavity to heat the inner cavity airflow. This method introduces secondary flow, and given that the local flow field near the splitter ring is prone to turbulence (especially under off-design conditions), the introduction of this secondary flow increases the probability and severity of turbulence in the local flow field near the splitter ring, further causing additional losses. Summary of the Invention

[0004] One object of the present invention is to provide an anti-icing system for the compressor of a turbofan engine, which has a good anti-icing effect, can avoid losses caused by secondary flow, and can improve the sealing effect of the compressor.

[0005] An anti-icing system for a turbofan engine compressor, comprising: a first sealing chamber and a second sealing chamber formed within the gap between the compressor rotor disc and stator at the compressor inlet; a sealing structure provided between the first sealing chamber and the second sealing chamber; the anti-icing system including a flow divider ring, an inlet guide vane, an bleed air pipeline, and a guide vane channel; wherein: the flow divider ring includes an bleed air inlet and an bleed air outlet; the bleed air pipeline is connected to the bleed air inlet and is used to introduce anti-icing bleed air from one of the compressor stages downstream of the flow divider ring into the flow divider ring; the guide vane channel is disposed inside the inlet guide vane and connects the bleed air outlet and the first sealing chamber.

[0006] In one or more embodiments of the anti-icing system, the anti-icing system further includes an air collection chamber disposed inside the diversion ring, the interior of the air collection chamber being connected to the air intake pipe, and the cavity wall of the air collection chamber being provided with an impact hole, the impact hole penetrating the cavity wall and being opposite to the ring wall of the diversion ring.

[0007] In one or more embodiments of the anti-icing system, the air collection chamber is provided with a plurality of impact holes, which are distributed circumferentially along the diversion ring.

[0008] In one or more embodiments of the anti-icing system, the air collection chamber is provided with a plurality of impact holes, which are respectively opposite to different positions on the axial cross section of the ring wall.

[0009] In one or more embodiments of the anti-icing system, the duct ring includes a plurality of air inlets distributed circumferentially along the duct ring, and the air duct line includes a plurality of duct pipes distributed circumferentially along the duct ring and connected to each of the air inlets.

[0010] In one or more embodiments of the anti-icing system, the inner inlet guide vane is a hollow vane, and the inner cavity of the hollow vane provides the guide vane flow channel.

[0011] This anti-icing system, by setting a guide vane channel inside the inlet guide vane connecting the inside of the split ring and the first chamber, allows the anti-icing bleed air to sequentially achieve anti-icing of the split ring, anti-icing of the inlet guide vane, and gas sealing of the first chamber. It can fully utilize the anti-icing bleed air to achieve a better anti-icing effect and improve the sealing capability at the inlet of the inlet, without affecting the local flow field near the split ring, thus avoiding losses caused by secondary flow. This improves the performance and safety of the turbofan engine and the compressor. The anti-icing system has a simple structure, is easy to manufacture, and has a low cost.

[0012] Another objective of this invention is to provide a compressor with better anti-icing effect, which can avoid losses caused by secondary flow and improve sealing effect.

[0013] The compressor for achieving the aforementioned purpose includes the aforementioned anti-icing system.

[0014] In one or more embodiments of the compressor, the compressor includes a low-pressure compressor and a high-pressure compressor, and the bleed pipe leads the anti-icing bleed air from the high-pressure compressor.

[0015] In one or more embodiments of the compressor, the compressor includes a low-pressure compressor, a medium-pressure compressor, and a high-pressure compressor, and the bleed air pipe draws out the anti-icing bleed air from the medium-pressure compressor or the high-pressure compressor.

[0016] Another objective of this invention is to provide a turbofan engine with better anti-icing performance, which can avoid losses caused by secondary flow and improve sealing performance.

[0017] A turbofan engine for achieving the aforementioned purpose includes the aforementioned compressor.

[0018] By adopting this anti-icing system, the turbofan engine and the compressor can achieve better anti-icing effect and improve the sealing capability at the inlet of the compressor without affecting the local flow field near the splitter ring. This avoids losses caused by secondary flow, thereby improving the performance and safety of the turbofan engine and the compressor. Attached Figure Description

[0019] The above and other features, properties and advantages of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings and embodiments, wherein:

[0020] Figure 1 This is a partial schematic diagram of a compressor according to one embodiment.

[0021] Figure 2 This is a partial schematic diagram of an anti-icing system according to one embodiment. Detailed Implementation

[0022] The following discloses various implementation methods or embodiments of the described subject matter. To simplify the disclosure, specific examples of the elements and arrangements are described below. These are merely examples and are not intended to limit the scope of protection of the present invention. It should be noted that the accompanying drawings are for illustrative purposes only and are not drawn to scale, and should not be used to limit the actual scope of protection claimed by the present invention. Furthermore, certain features, structures, or characteristics in one or more embodiments of this application can be appropriately combined.

[0023] A turbofan engine according to one embodiment of the present invention includes, as follows: Figure 1 The compressor 1 shown includes a low-pressure compressor 10, a high-pressure compressor (not shown), and an anti-icing system 20.

[0024] The low-pressure compressor 10 includes a booster stage 11, which includes a stator casing 13, a stator inner ring 14, a rotor hub 15, multi-stage rotor blades 16, and multi-stage guide vanes (stator blades) 17. The stator casing 13 is located radially outside the stator inner ring 14 and the rotor hub 15. The rotor blades 16 are mounted on the rotor hub 15. The radial sides of the guide vanes 17 are connected to the stator casing 13 and the stator inner ring 14, respectively.

[0025] The upstream end of the stator casing 13 has a flow splitting ring 18, which is located downstream of the fan blades 19. The flow splitting ring 18 is used to separate the inlet airflow into two paths: the outer bypass airflow and the inner bypass airflow. The inner bypass airflow flows downstream of the compressor 1 and is compressed by the low-pressure compressor 10 and the high-pressure compressor in succession, and the temperature and pressure of the airflow gradually increase.

[0026] In the description of this invention, the terms "upstream" and "downstream" refer to the relative flow directions of fluid flow within a fluid path. For example, "upstream" refers to the direction from which the fluid flows, while "downstream" refers to the direction to which the fluid flows.

[0027] Reference Figure 1 and Figure 2 The anti-icing system 20 includes a flow divider ring 18, an inner inlet guide vane 171 (i.e., the first-stage guide vane closest to the upstream in the multi-stage guide vane 17), an air intake pipe 21, an air collection chamber 22, a guide vane flow channel (not shown), and a guide vane outlet (not shown).

[0028] The flow divider ring 18 includes an annular wall 181, an air inlet 182, and an air outlet 183, with the air inlet 182 and air outlet 183 penetrating the annular wall 181. Multiple air inlets 182 are distributed circumferentially along the flow divider ring 18, and multiple air outlets 183 are also distributed circumferentially along the flow divider ring 18. The air outlets 183 are located radially outside the inner inlet guide vane 171.

[0029] The bleed gas line 21 is connected to the bleed gas inlet 182. The bleed gas line 21 is used to draw compressed gas from one of the stages of the compressor 1 located downstream of the split ring 18 as anti-icing bleed gas, and deliver the anti-icing bleed gas to the interior of the split ring 18 to heat the split ring 18 and achieve the anti-icing effect.

[0030] Optionally, the anti-icing bleed air is drawn from one stage of the high-pressure compressor, which has a high temperature and pressure, so that only a small amount of bleed air is needed to achieve a good anti-icing effect and the sealing effect described later.

[0031] In some other embodiments, compressor 1 also includes an intermediate-pressure compressor (not shown) located between the low-pressure compressor 10 and the high-pressure compressor, and bleed air line 21 leads out anti-icing bleed air from the intermediate-pressure compressor or the high-pressure compressor.

[0032] Continue to refer to Figure 1 and Figure 2 The bleed gas line 21 includes a control valve 211, a bleed gas distribution pipe 212, and multiple branch pipes 213. The control valve 211 is used to control the opening and closing of the bleed gas line 21 and / or control the gas flow rate within the bleed gas line 21. The bleed gas distribution pipe 212 is used to distribute the gas drawn from the compressor 1 to the multiple branch pipes 213. The multiple branch pipes 213 are distributed circumferentially along the branching ring 18 and are respectively connected to each bleed gas inlet 182 to improve the circumferential temperature uniformity of the branching ring 18 and improve the anti-icing effect.

[0033] The gas collecting chamber 22 is located inside the flow divider ring 18 and is fixedly connected to the ring wall 181 of the flow divider ring 18 via a support column (not shown) or other means. The interior of the gas collecting chamber 22 is connected to the flow divider pipe 213. The chamber wall 220 of the gas collecting chamber 22 is provided with multiple impact holes 221. The impact holes 221 penetrate the chamber wall 220 of the gas collecting chamber 22 and are opposite to the ring wall 181 of the flow divider ring 18, so that the anti-icing induced air in the gas collecting chamber 22 impacts the ring wall 181 through the impact holes 221, thereby further improving the anti-icing effect through impact heat exchange.

[0034] The gas collecting chamber 22 is provided with multiple impact holes 221. In the circumferential direction, the multiple impact holes 221 are distributed along the circumference of the flow divider ring 18, thereby making the temperature more uniform in the circumferential direction of the flow divider ring 18 and improving the anti-icing effect. In the axial section of the flow divider ring 18, the multiple impact holes 221 are respectively opposite to different positions of the ring wall 181, for example, opposite to the radially outer side, radially inner side, and the leading edge located on the upstream side of the ring wall 181. It can be understood that... Figure 2 The location and number of impact holes 221 shown are for illustrative purposes only. The specific location and number of impact holes 221 on the axial section should be determined by calculation.

[0035] The guide vane channel is located inside the inner inlet guide vane 171 and extends from the radially outer side to the radially inner side of the inner inlet guide vane 171. For example, the inner inlet guide vane 171 is a hollow vane, and the inner cavity of the hollow vane provides the guide vane channel, thereby simplifying the structure and reducing weight.

[0036] The guide vane channel is connected to the interior of the split ring 18 through the air outlet 183, so that the anti-icing air after the impact heat exchange is completed enters the guide vane channel from the split ring 18, thereby increasing the temperature of the inner inlet guide vane 171 and achieving anti-icing of the inner inlet guide vane 171. Moreover, the anti-icing air flows inside the inner inlet guide vane 171 and will not affect the local flow field near the split ring 18, thus avoiding losses caused by secondary flow.

[0037] In aircraft engines, gaps inevitably exist between rotating and stationary parts, leading to gas leakage. Gas usually leaks from the high-pressure side to the low-pressure side through these gaps. Sealing is necessary to reduce the amount of leakage. Sealing and controlling leaking gas is an essential component of modern engines.

[0038] At the inlet of the low-pressure compressor 10, a first sealing chamber 111 and a second sealing chamber 112 are formed in the gap between the stator inner ring 14 and the rotor hub 15. The first sealing chamber 111 and the second sealing chamber 112 are adjacent to each other in the axial direction of the low-pressure compressor 10.

[0039] The first sealing chamber 111 is connected to the inlet airflow upstream of the inner inlet guide vane 171, and the second sealing chamber 112 is connected to the inner duct airflow downstream of the inner inlet guide vane 171. Since the pressure of the inner duct airflow is greater than the pressure of the inlet airflow, a sealing structure 113 is provided between the first sealing chamber 111 and the second sealing chamber 112 to prevent gas leakage from the second sealing chamber 112 to the first sealing chamber 111. This sealing structure can be a comb-like structure or another type of sealing structure.

[0040] Grate seals are a widely used sealing technology in modern aero engines. Currently, the design of grate seals mainly focuses on reducing leakage by designing tooth shape and reducing gap, but this has limited effect on improving sealing capability.

[0041] The first sealing chamber 111 is at least partially located radially inside the inlet guide vane 171 of the inner chamber. The guide vane outlet penetrates the root of the inlet guide vane 171 and the stator inner ring 14. The guide vane outlet connects the guide vane flow channel with the first sealing chamber 111 to introduce anti-icing induced gas from the guide vane flow channel into the first sealing chamber 111. This can increase the pressure in the first sealing chamber 111, reduce the pressure difference between the first sealing chamber 111 and the second sealing chamber 112, and reduce the gas leakage from the second sealing chamber 112 to the first sealing chamber 111, thereby further improving the sealing effect, reducing flow field loss, increasing compression efficiency, and making full use of the anti-icing induced gas, avoiding direct discharge into the inner chamber and the introduction of secondary flow.

[0042] The anti-icing system 20, by setting a guide vane channel inside the inner core inlet guide vane 171 that connects the inside of the split ring and the first sealing chamber 111, allows the anti-icing bleed air to sequentially achieve anti-icing of the split ring 18, anti-icing of the inner core inlet guide vane 171, and gas sealing of the first sealing chamber 111. This can fully utilize the anti-icing bleed air to achieve a better anti-icing effect and improve the sealing capability at the inner core inlet, without affecting the local flow field near the split ring 18, thus avoiding losses caused by secondary flow. This can improve the performance and safety of the turbofan engine and the compressor 1.

[0043] The anti-icing system 20 has a simple structure, is easy to manufacture, and has a low cost. It is suitable for... Figure 1 and Figure 2 The turbofan engine and compressor 1 shown are also applicable to turbofan engines and compressors 1 with other structural forms.

[0044] By employing the anti-icing system 20, the turbofan engine and the compressor 1 can achieve better anti-icing effect and improve the sealing capability at the inlet of the internal cavity, without affecting the local flow field near the splitting ring 18, thus avoiding losses caused by secondary flow and improving the performance and safety of the turbofan engine and the compressor 1.

[0045] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Any variations and modifications can be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention, without departing from the scope of the invention, fall within the protection scope defined by the claims of the present invention.

Claims

1. Anti-icing system, used in the compressor of a turbofan engine, including: At the inlet of the compressor, a first sealing chamber and a second sealing chamber are formed in the gap between the compressor rotor disc and the stator, and a sealing structure is provided between the first sealing chamber and the second sealing chamber; The anti-icing system includes a flow divider ring, an inner inlet guide vane, an air duct, and a guide vane flow channel, wherein: The shunt ring includes an air inlet and an air outlet; The bleed air pipeline is connected to the bleed air inlet, and the bleed air pipeline is used to introduce anti-icing bleed air from one of the stages of the compressor located downstream of the split ring into the split ring; The guide vane channel is located inside the inner inlet guide vane and connects to the air outlet and the first sealing chamber.

2. The anti-icing system of claim 1, wherein, The anti-icing system also includes an air collection chamber disposed inside the diversion ring. The interior of the air collection chamber is connected to the air intake pipe. The cavity wall of the air collection chamber is provided with an impact hole that penetrates the cavity wall and is opposite to the ring wall of the diversion ring.

3. The anti-icing system of claim 2, wherein, The gas collecting chamber is provided with a plurality of impact holes, which are distributed circumferentially along the diversion ring.

4. The anti-icing system of claim 2, wherein, The gas collecting chamber is provided with a plurality of impact holes, which are respectively opposite to different positions on the axial cross section of the ring wall.

5. The anti-icing system of any one of claims 1 to 4, wherein, The shunt ring includes a plurality of air intake inlets, which are distributed circumferentially along the shunt ring. The air intake pipeline includes a plurality of shunt pipes, which are distributed circumferentially along the shunt ring and connected to each of the air intake inlets.

6. The anti-icing system of any one of claims 1 to 4, wherein, The inner inlet guide vane is a hollow vane, and the inner cavity of the hollow vane provides the guide vane flow channel.

7. A compressor characterized by, Including the anti-icing system as described in any one of claims 1 to 6.

8. The compressor of claim 7, wherein The compressor includes a low-pressure compressor and a high-pressure compressor, and the bleed air pipe leads out the anti-icing bleed air from the high-pressure compressor.

9. The compressor as described in claim 7, characterized in that, The compressor includes a low-pressure compressor, a medium-pressure compressor, and a high-pressure compressor, and the bleed pipe leads out the anti-icing bleed air from the medium-pressure compressor or the high-pressure compressor.

10. A turbofan engine characterised in that, Includes the compressor as described in any one of claims 7 to 9.

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