Anti-icing system and method for air inlet channel of engine and aero-engine

Abstract

The engine air inlet channel anti-icing system comprises air entraining pipelines, an air inlet channel temperature measuring unit and a control unit, all branch air entraining pipelines are communicated with different stages of an air compressor so as to introduce hot air at different temperatures from the different stages of the air compressor, and the air inlet channel temperature measuring unit is used for measuring the temperature of the air inlet channel. The two ends of the main air entraining pipeline are respectively communicated with each branch air entraining pipeline and the air inlet channel in an on-off manner; the air inlet channel temperature measuring unit is arranged on the air inlet channel to detect the temperature of the air inlet channel; the control unit is in signal connection with the first temperature measuring unit and the branch air entraining pipelines and adjusts the flow proportion of different stages of hot air of the air compressor conveyed by the branch air entraining pipelines according to the temperature of the air inlet channel. The invention further provides an anti-icing method for the air inlet channel of the engine and the aero-engine. According to the anti-icing system and method for the air inlet channel of the engine, the temperature of the air inlet channel serves as the reference, and the stability of the anti-icing system for the air inlet channel is remarkably improved by switching a multi-stage air entraining mixed temperature regulation mode or a single-stage air entraining mode.

Description

Technical Field

[0001] The present invention relates to the field of aero-engines, and in particular to the field of aero-engine anti-icing. Background Art

[0002] When an aircraft flies under icing weather conditions, ice will form on the air intake duct, inlet support plate, fairing cap, fan, low-pressure compressor and high-pressure compressor in the engine air intake components. The ice on these components will have a great impact on the engine performance. The ice on the engine air intake duct will reduce the flow area and reduce the engine thrust. In severe cases, it may even cause dangerous conditions such as compressor surge. The ice falling off the surface of the air intake duct will damage the fan or compressor blades, causing more serious safety accidents. In order to ensure the safe operation of the engine under icing conditions, most aircraft engine air intake ducts use hot gas anti-icing. Air is drawn from the engine high-pressure compressor, passes through the pressure regulating and flow regulating devices, and enters the device at the leading edge of the air intake duct to heat the leading edge of the air intake duct to achieve the purpose of anti-icing.

[0003] Most engine inlet hot air anti-icing systems draw air from a single stage of the high-pressure compressor. However, because the inlet hot air anti-icing system does not support protection surface temperature feedback and bleed air temperature control, the bleed air temperature may be too low under some low-power flight conditions. This will lead to insufficient anti-icing performance in some protected areas of the inlet, causing surface ice accumulation or backflow ice, affecting flight safety. In addition, the hot air anti-icing system draws air directly from the compressor. When the anti-icing system is turned on during takeoff, climb and other flight conditions, the bleed air temperature is high and cannot be adjusted, resulting in a high temperature on the inlet protection surface. Thermal fatigue is easily generated during system operation, thus affecting the service life of the inlet material. Summary of the invention

[0004] An object of the present invention is to provide an engine intake duct anti-icing system having better anti-icing performance.

[0005] To achieve the above-mentioned purpose, the engine intake duct anti-icing system includes an air bleed pipeline, an intake duct temperature measuring unit and a control unit. The air bleed pipeline includes a main air bleed pipeline and multiple branch air bleed pipelines. Each of the branch air bleed pipelines is connected to different stages of the compressor respectively to introduce hot air of different temperatures from different stages of the compressor. The two ends of the main air bleed pipeline can be connected to each branch air bleed pipeline and the intake duct in a disconnectable manner; the intake duct temperature measuring unit is arranged on the intake duct, for detecting the intake duct temperature; the control unit is connected to the intake duct temperature measuring unit and the branch air bleed pipeline signal, for adjusting the flow ratio of each branch air bleed pipeline conveying hot air of different stages of the compressor according to the intake duct temperature.

[0006] In one or more embodiments, the engine intake duct anti-icing system further includes a branch temperature measurement unit, which is disposed on each of the branch bleed air lines, and the branch temperature measurement unit is signal-connected to the control unit.

[0007] In one or more embodiments, the system further comprises a main valve assembly arranged on the main air duct and a branch valve assembly arranged on each of the branch air ducts, and the main valve assembly and the branch valve assembly are connected to the control unit by signal.

[0008] In one or more embodiments, the main bleed air line includes a throttling device.

[0009] In one or more embodiments, the main bleed air line is connected to a flared pipe in the inlet anti-icing cavity.

[0010] In one or more embodiments, each of the branch air bleed lines has the same diameter as that of the main air bleed line.

[0011] In one or more embodiments, the control unit is configured to control each of the branch air bleed lines to perform single-stage air bleed.

[0012] In one or more embodiments, each of the branch bleed air pipelines is respectively connected to the air collecting chamber of each stage of the compressor.

[0013] Another object of the present invention is to provide an aircraft engine, comprising a compressor and an air inlet, wherein the aircraft engine uses the above-mentioned engine air inlet anti-icing system to protect the air inlet from icing.

[0014] Another object of the present invention is to provide an engine intake anti-icing method, comprising the following steps: introducing hot air from different stages of the compressor to the main intake air pipeline; adjusting the hot air flow ratio of different stages according to the intake duct temperature; and introducing the adjusted mixed-stage hot air or single-stage hot air into the intake duct.

[0015] The above-mentioned engine inlet duct anti-icing system aims to address the problems of insufficient inlet duct anti-icing performance or excessive surface heat load caused by too low or too high bleed air temperature in the current single-stage bleed air. Based on the inlet duct temperature, the system switches between a multi-stage bleed air mixing temperature control method or a single-stage bleed air method to avoid the problem of insufficient heat load or excessive heat load, thereby significantly improving the stability of the inlet duct anti-icing system and the performance of the engine inlet duct anti-icing system. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and other features, properties and advantages of the present invention will become more apparent through the following description in conjunction with the accompanying drawings and embodiments, in which:

[0017] Figure 1 is a schematic diagram of an embodiment of an inlet ice protection system;

[0018] Figure 2 This is an example diagram of a circumferential installation of the temperature sensor in the intake duct;

[0019] Figure 3 Schematic diagram of the cross-sectional location of the temperature sensor in the intake duct;

[0020] Symbols and Markings

[0021] 1 Control unit

[0022] 2 Compressor

[0023] 3 Inlet duct temperature measurement unit

[0024] 4 Intake

[0025] 5 Second main valve

[0026] 6 First branch valve

[0027] 7. First temperature sensor

[0028] 8 First branch airway

[0029] 9 Second branch airway

[0030] 10 Third temperature sensor

[0031] 11 Second temperature sensor

[0032] 12 Second branch valve

[0033] 13 Third branch airway

[0034] 14 Third branch valve

[0035] 15 First main valve

[0036] 16 Main line temperature sensor

[0037] 17 Throttling device

[0038] 18 Main air duct

[0039] 19 Inlet anti-icing chamber pipeline

[0040] 20 Cables

[0041] 21 Branch airway DETAILED DESCRIPTION

[0042] The present invention is further described below in conjunction with specific embodiments and drawings. More details are elaborated in the following description to facilitate a full understanding of the present invention. However, the present invention can obviously be implemented in a variety of other ways different from the description herein. Those skilled in the art can make similar generalizations and deductions based on actual application situations without violating the connotation of the present invention. Therefore, the protection scope of the present invention should not be limited by the content of this specific embodiment.

[0043] It should be noted that these and other subsequent drawings are only examples and are not drawn to scale, and should not be used to limit the actual scope of protection required by the present invention.

[0044] Engine Inlet Anti-Ice System Reference Figure 1 As shown, it includes an air bleed line, an intake duct temperature measurement unit 3 and a control unit 1.

[0045] The bleed air pipeline includes a main bleed air pipeline 18 and a plurality of branch bleed air pipelines 21. Each branch bleed air pipeline is connected to a different stage of the compressor 2 to introduce hot air of different temperatures from different stages of the compressor. Figure 1 In one embodiment shown, the first branch bleed air line 8 is connected to the air collecting chamber of the 4th stage of the compressor, the second branch bleed air line 9 is connected to the air collecting chamber of the 7th stage of the compressor, and the third branch bleed air line 13 is connected to the air collecting chamber of the 10th stage of the compressor. The compressor is preferably a high-pressure compressor. It can be understood by those skilled in the art that the higher the number of stages, the higher the gas temperature. The selection of the number of stages of the compressor includes but is not limited to the above embodiments, and is determined comprehensively according to the specific engine model, operating conditions, etc.

[0046] In some embodiments, each branch air bleed pipe 21 is provided with a branch temperature measurement unit and a branch valve assembly which are signal-connected to the control unit 1. Figure 1 As shown, the first branch bleed air pipeline 8 is provided with a first temperature sensor 7 and a first branch valve 6, the second branch bleed air pipeline 9 is provided with a second temperature sensor 11 and a second branch valve 12, and the third branch bleed air pipeline 13 is provided with a third temperature sensor 10 and a third branch valve 14. Preferably, to prevent backflow, each branch valve is a one-way flow control shut-off valve, and the airflow direction is from the high-pressure compressor to the main bleed air pipeline. When the one-way control valve is opened, the hot gas of each stage flows from the high-pressure compressor to the main bleed air pipeline, and when the one-way control valve is closed, the hot gas of this stage is not introduced.

[0047] Each temperature sensor is preferably a K-type thermocouple, which is inserted into a pre-opened through hole on the branch air duct through a mounting seat, and is used to measure the air flow temperature in the branch air duct and transmit the signal to the engine controller through the cable 20.

[0048] The two ends of the main air bleed pipe 18 can be connected to each branch air bleed pipe 21 and the intake duct 4 in an on-off manner, for example, by means of valves. The first end of the main air bleed pipe 18 is connected to each branch air bleed pipe 21, and the second end is connected to the flute in the anti-icing chamber of the intake duct. The main air bleed pipe 18 also includes a main valve assembly and a main line temperature sensor 16 connected to the control unit 1 signal. The main valve assembly includes a first main valve 15 and a second main valve 5, and the second main valve 5 is close to one side of the intake duct. The second end of the main air bleed pipe 18 is connected to the intake duct anti-icing chamber pipeline 19, as shown in FIG. Figure 3 As shown, the main valve assembly on the main air inlet line regulates the pressure to supply the flute tube in the intake duct, and the jet flows through the small holes on the flute tube and sprays onto the heated intake duct surface, thereby achieving the effect of heating the intake duct.

[0049] The main valve is preferably a pressure regulating control valve to achieve a pressure regulation effect, such as increasing the bleed air pressure of the high-pressure compressor. The main line temperature sensor 16 is preferably a K-type thermocouple, which is inserted into the main bleed air line 18 to measure the temperature of the air flow finally delivered to the inlet duct 4, and transmit the temperature data to the control unit 1 in real time.

[0050] The main bleed air pipeline 18 also includes a throttling device 17, which is arranged between the first main valve 15 and the second main valve 5 and is used to limit the flow of the intake duct anti-icing system.

[0051] In some embodiments, the diameter of each branch air bleed line 21 is the same as that of the main air bleed line 18 .

[0052] The intake duct temperature measuring unit 3 is arranged on the intake duct 4 and is used to detect the temperature of the intake duct 4. Figure 2 and Figure 3 As shown, 16 temperature measurement sensors are arranged circumferentially on the inner surface of the inlet anti-icing chamber. The temperature measurement sensors are K-type thermocouples, which are pasted or welded on the surface of the inlet duct. The average inlet duct temperature at different annular positions is measured and the signal is transmitted to the engine control unit 1 through cables.

[0053] The control unit 1 is connected to the intake duct temperature measuring unit 3 and the branch bleed air pipeline 21 by wired signal connection, such as by a cable 20, or by wireless signal connection. The control unit 1 adjusts the flow ratio of hot air of different stages of compressors delivered by each branch bleed air pipeline according to the intake duct temperature, and switches the mode of bleed air from different stages of high-pressure compressors or bleed air from multiple stages of compressors.

[0054] Specifically, the control unit 1 determines the opening or closing of each branch pipeline valve according to the temperature data transmitted by the intake duct temperature measurement unit 3, and then realizes the single-stage bleed air or multi-stage mixed bleed air mode of different stages of compressors according to the preset control law and the intake duct temperature feedback value. It can be understood that the multi-stage mixed bleed air plays a role in regulating the airflow temperature. Since the traditional single-stage bleed air has the problem of too low or too high bleed air temperature, which leads to insufficient anti-icing performance or too high surface heat load, by using mixed bleed air as an optional method, it can achieve more accurate temperature control and achieve better anti-icing effect.

[0055] Table 1 and Table 2 show the matching relationship between the two intake duct temperatures and the bleed air mode.

[0056] Table 1 Inlet duct temperature and bleed air mode matching table (I)

[0057]

[0058]

[0059] Table 2 Inlet duct temperature and bleed air mode matching table (II)

[0060]

[0061]

[0062] When the engine intake does not need anti-icing, all valves in the system are in a closed state. After the anti-icing command is turned on, the engine control unit 1 controls the 4-stage bleed air pipeline one-way control valve, opens the first main valve 15 and the second main valve 5, and the intake duct anti-icing system bleeds air from the 4-stage high-pressure compressor of the engine. The bleed air pipeline temperature measurement sensor and the intake duct temperature sensor transmit signals to the engine control unit 1 in real time. When the bleed air mode is determined, the control unit 1 controls the branch valve opening of each branch bleed air pipeline, and then adjusts the mixed gas flow ratio to achieve single-stage bleed air or mixed bleed air.

[0063] In some embodiments, when the air intake duct is within a specific temperature range, there are multiple bleed air modes. For example, when the average surface temperature of the air intake duct is within the range of 20 to 200°C, a 4-stage and 7-stage mixed bleed air mode or a 7-stage single bleed air mode can be used. Taking into account various factors such as bleed air time and compressor working state, the control unit 1 assigns priorities to different bleed air modes. For example, a single 7-stage bleed air mode is preferentially used within the range of 20 to 200°C. When the air intake duct cooling rate exceeds the expected value, it can be changed to a 4-stage and 7-stage mixed bleed air mode. The 4-stage and 7-stage bleed air ratio can also be determined according to actual conditions to adjust the intake air temperature to a suitable range.

[0064] The above-mentioned system bleeds air from different stages of the engine's high-pressure compressor or bleeds air from multiple stages according to the inlet temperature sensor signal and the current working status of the system, avoiding the problems of insufficient inlet anti-icing performance or excessive surface heat load caused by too low or too high inlet temperature in a single-stage bleed air, thereby achieving better anti-icing performance.

[0065] Combined with the introduction of the above anti-icing system, we can also understand an aircraft engine that uses the above anti-icing system to protect the air intake duct, and an engine air intake duct anti-icing method. The method introduces hot air from different stages of the compressor to the main air bleed pipeline, adjusts the hot air flow ratio of different stages according to the air intake duct temperature, and finally introduces the adjusted mixed-stage hot air or single-stage hot air into the air intake duct, realizing precise control of the airflow temperature according to the air intake duct temperature feedback value, overcoming the problems existing in single-stage air bleed.

[0066] It should be noted that the above content uses words such as "first" and "second" to limit components, which is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above words have no special meaning and therefore cannot be understood as limiting the scope of protection of this application.

[0067] At the same time, the present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

[0068] Although the present invention is disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, any modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope defined by the claims of the present invention.

Claims

1. The engine air intake anti-icing system is characterized by: include: An air bleed pipeline comprises a main air bleed pipeline (18) and a plurality of branch air bleed pipelines (21), each of the branch air bleed pipelines being connected to a different stage of the compressor (2) so as to introduce hot air of different temperatures from different stages of the compressor, and both ends of the main air bleed pipeline (18) being connected to each of the branch air bleed pipelines (21) and the air inlet (4) in a disconnectable manner; An air intake duct temperature measuring unit (3), arranged on the air intake duct (4) and used for detecting the temperature of the air intake duct (4); The control unit (1) is connected to the intake duct temperature measurement unit (3) and the branch bleed air pipeline (21) by signal, and is used to adjust the flow ratio of hot air of different stages of the compressor transported by each branch bleed air pipeline according to the intake duct temperature.

2. The engine air intake anti-icing system according to claim 1, characterized in that: The engine air intake anti-icing system further comprises a branch temperature measurement unit, which is arranged on each of the branch air bleed pipes (21), and the branch temperature measurement unit is connected to the control unit (1) by signal.

3. The engine intake duct anti-icing system according to claim 1, characterized in that: The system further comprises a main valve assembly arranged on the main air bleed pipeline (18) and a branch valve assembly arranged on each of the branch air bleed pipelines (21), wherein the main valve assembly and the branch valve assembly are connected to the control unit by signals.

4. The engine intake anti-icing system according to claim 1, characterized in that: The main air inlet pipeline comprises a throttling device (17).

5. The engine intake duct anti-icing system according to claim 1, characterized in that: The main air bleed pipeline (18) is connected to a flute in the anti-icing cavity of the air inlet duct (4).

6. The engine intake anti-icing system according to claim 1, characterized in that: The diameter of each branch air bleed pipe (21) is the same as that of the main air bleed pipe (18).

7. The engine intake anti-icing system according to claim 1, characterized in that: The control unit is configured to control each of the branch air bleed pipelines (21) to perform single-stage air bleed.

8. The engine air intake anti-icing system according to claim 1, characterized in that: Each of the branch air bleed pipelines (21) is respectively connected to the air collecting chambers of each stage of the compressor.

9. An aircraft engine, comprising a compressor and an air inlet, characterized in that: The engine air intake anti-icing system as claimed in any one of claims 1 to 8 is used to protect the air intake from icing. 10.An engine intake duct anti-icing method, characterized in that: The steps include: Lead hot air from different stages of the compressor to the main bleed air line; Adjust the hot gas flow ratio of different stages according to the inlet duct temperature; The regulated mixed-stage hot gas or single-stage hot gas is introduced into the intake duct.

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