Method and device for maintaining stability margin during water ingestion of an aeroengine

Abstract

This application belongs to the field of engine control and relates to a method and device for maintaining the stability margin during water ingestion of an aeroengine. The method includes: Step S1, determining the fan temperature ratio based on the fan corrected speed; Step S2, determining the fan outlet temperature according to the fan inlet temperature and the fan temperature ratio; Step S3, correcting the fan outlet temperature to obtain the compressor inlet temperature; Step S4, determining the temperature difference between the calculated compressor inlet temperature and the measured compressor inlet temperature; Step S5, when the temperature difference exceeds the set value, determining the first compressor variable guide vane angle according to the calculated compressor inlet temperature and performing a low selection with the second compressor variable guide vane angle calculated from the fan inlet temperature; Step S6, determining the compressor variable guide vane correction value according to the temperature difference to perform a partial closing process on the low-selected compressor variable guide vane angle. This application ensures that the stability margin of the compression components does not decrease during the water ingestion process of the engine, reducing the engine performance loss.

Description

Technical Field

[0001] This application belongs to the field of engine control, and particularly relates to a method and device for maintaining the stability margin when an aeroengine swallows water. Background Technique

[0002] When an aircraft passes through a rain cloud, or when there is water on the runway during takeoff, landing, or ship landing in heavy rain, and the water splashed by the front wheel of the aircraft may be sucked into the engine. When the amount of water swallowed by the engine is within a certain range, the efficiency and pressure ratio of the compressor decrease as the amount of swallowed water increases, and the pressure ratio of each stage of the cascade also decreases accordingly. As the amount of swallowed water gradually increases, the surge margin of the compressor decreases, and the stability of the compressor drops significantly.

[0003] The liquid water inhaled by the engine enters the engine unevenly distributed. After passing through the fan, the liquid water vaporizes, causing the local temperature at the compressor inlet to decrease. Currently, when the engine swallows water, the angle of the adjustable guide vane of the compressor is controlled based on the measured compressor inlet temperature (usually a single sensor). If the sector where the water is inhaled coincides with the sector where the compressor inlet temperature sensor is located, it will cause the measured compressor inlet temperature to be lower than the average temperature of the entire cross-section, and the corrected speed of the compressor to be higher, resulting in the angle of the adjustable guide vane of the compressor being deflected, and the stability margin of the compressor decreasing.

[0004] At the same time, after the engine swallows water, it affects the working characteristics of the compressor, resulting in a decrease in the compressor surge boundary. The combined effect of the above factors makes the engine prone to surge after swallowing water, affecting the working safety of the engine. Summary of the Invention

[0005] In order to solve the above problems, this application provides a method and device for maintaining the stability margin when an aeroengine swallows water, so as to solve the problem of the reduction of the compressor stability margin when swallowing water.

[0006] The first aspect of this application provides a method for maintaining the stability margin when an aeroengine swallows water, mainly including:

[0007] Step S1: Determine the fan temperature ratio based on the corrected speed of the fan;

[0008] Step S2: Determine the fan outlet temperature according to the fan inlet temperature and the fan temperature ratio;

[0009] Step S3: Correct the fan outlet temperature to obtain the compressor inlet temperature;

[0010] Step S4: Determine the temperature difference between the calculated compressor inlet temperature and the measured compressor inlet temperature;

[0011] Step S5: When the temperature difference exceeds the set value, determine the first adjustable guide vane angle of the compressor according to the calculated compressor inlet temperature, and perform a low selection with the second adjustable guide vane angle of the compressor calculated from the fan inlet temperature;

[0012] Step S6: Determine the correction value of the adjustable guide vane of the compressor according to the temperature difference, and perform a partial closing process on the low-selected adjustable guide vane angle of the compressor based on the correction value.

[0013] Preferably, further included before step S1:

[0014] Obtain the relationship between the fan corrected speed and the fan temperature ratio through simulation calculation or test data statistics, and calculate the fan temperature ratio corresponding to the current fan corrected speed through this relationship.

[0015] Preferably, in step S5, determining the first adjustable guide vane angle of the compressor includes:

[0016] Calculate the first high-pressure turbine corrected speed according to the compressor speed and the calculated compressor inlet temperature, and calculate the first adjustable guide vane angle of the compressor according to the control law of the adjustable guide vane of the compressor related to the first high-pressure turbine corrected speed.

[0017] Preferably, in step S5, determining the second adjustable guide vane angle of the compressor includes:

[0018] Calculate the second high-pressure turbine corrected speed according to the compressor speed and the fan inlet temperature, and calculate the second adjustable guide vane angle of the compressor according to the control law of the adjustable guide vane of the compressor related to the second high-pressure turbine corrected speed.

[0019] Preferably, further included after step S6:

[0020] Determine the correction value of the adjustable guide vane of the fan and the correction value of the nozzle throat area according to the temperature difference;

[0021] Perform a partial closing process on the adjustable guide vane angle of the fan according to the correction value of the adjustable guide vane of the fan, and perform an enlargement process on the nozzle throat according to the correction value of the nozzle throat area.

[0022] The second aspect of the present application provides a device for maintaining the stability margin when an aeroengine swallows water, mainly including:

[0023] A fan temperature ratio determination module for determining the fan temperature ratio based on the fan corrected speed;

[0024] A fan outlet temperature determination module for determining the fan outlet temperature according to the fan inlet temperature and the fan temperature ratio;

[0025] A compressor inlet temperature determination module for correcting the fan outlet temperature to obtain the compressor inlet temperature;

[0026] A temperature difference determination module, configured to determine the temperature difference between the calculated compressor inlet temperature and the measured compressor inlet temperature;

[0027] A low selection module for the adjustable guide vane angle of the compressor, configured to, when the temperature difference exceeds a set value, determine a first adjustable guide vane angle of the compressor according to the calculated compressor inlet temperature, and perform a low selection with a second adjustable guide vane angle calculated from the fan inlet temperature;

[0028] An over-close processing module for the adjustable guide vane angle of the compressor, configured to determine an adjustable guide vane correction value of the compressor according to the temperature difference, and perform an over-close processing on the low-selected adjustable guide vane angle of the compressor based on the correction value.

[0029] Preferably, the fan temperature ratio determination module includes:

[0030] A relationship acquisition unit for the fan corrected speed and the fan temperature ratio, configured to obtain the relationship between the fan corrected speed and the fan temperature ratio through simulation calculation or experimental data statistics.

[0031] Preferably, the low selection module for the adjustable guide vane angle of the compressor includes:

[0032] A first adjustable guide vane angle determination unit, configured to calculate a first high-pressure turbine corrected speed according to the compressor speed and the calculated compressor inlet temperature, and calculate a first adjustable guide vane angle of the compressor according to the compressor adjustable guide vane control law related to the first high-pressure turbine corrected speed.

[0033] Preferably, the low selection module for the adjustable guide vane angle of the compressor includes:

[0034] A second adjustable guide vane angle determination unit, configured to calculate a second high-pressure turbine corrected speed according to the compressor speed and the fan inlet temperature, and calculate a second adjustable guide vane angle of the compressor according to the compressor adjustable guide vane control law related to the second high-pressure turbine corrected speed.

[0035] Preferably, the stability margin maintaining device further includes:

[0036] A calculation unit for the adjustable guide vane angle correction value of the fan and the nozzle throat area correction value, configured to determine the adjustable guide vane correction value of the fan and the nozzle throat area correction value according to the temperature difference;

[0037] An adjustable guide vane angle and nozzle throat processing unit for the fan, configured to perform an over-close processing on the adjustable guide vane angle of the fan according to the adjustable guide vane correction value of the fan, and perform an enlargement processing on the nozzle throat according to the nozzle throat area correction value.

[0038] This application utilizes the existing measurement points of the engine without adding additional structures, and proposes a method for identifying engine water ingestion. The dual-redundancy method is adopted to effectively solve the problem of deviation in the control of the adjustable guide vane angle of the compressor during engine water ingestion. At the same time, according to the water ingestion influence amount, design differentiated stability enhancement measures are taken to further ensure that the stability margin of the compression components does not decrease during the engine water ingestion process. While enhancing stability, the engine performance loss is minimized as much as possible, ensuring the flight safety during the engine water ingestion process. Description of the Drawings

[0039] Figure 1 It is a flowchart of a preferred embodiment of the method for maintaining the stability margin during engine water ingestion of this application.

[0040] Figure 2 It is a schematic diagram of the numbering of the engine gas path cross-section.

[0041] Figure 3 It is a flowchart for calculating the angle of the adjustable guide vane of the compressor. Detailed Implementation Modes

[0042] To make the purpose, technical solutions, and advantages of the implementation of this application clearer, the technical solutions in the implementation modes of this application will be described in more detail below with reference to the drawings in the implementation modes of this application. In the drawings, the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions from beginning to end. The described implementation modes are part of the implementation modes of this application, rather than all of the implementation modes. The implementation modes described below with reference to the drawings are exemplary and are intended to explain this application and should not be construed as limiting this application. Based on the implementation modes in this application, all other implementation modes obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of this application. The implementation modes of this application will be described in detail below with reference to the drawings.

[0043] The first aspect of this application provides a method for maintaining the stability margin during engine water ingestion, as Figure 1 shown, mainly including:

[0044] Step S1: Determine the fan temperature ratio based on the fan corrected speed;

[0045] Step S2: Determine the fan outlet temperature according to the fan inlet temperature and the fan temperature ratio;

[0046] Step S3: Correct the fan outlet temperature to obtain the compressor inlet temperature;

[0047] Step S4: Determine the temperature difference between the calculated compressor inlet temperature and the measured compressor inlet temperature;

[0048] Step S5: When the temperature difference exceeds the set value, determine the first adjustable guide vane angle of the compressor according to the calculated compressor inlet temperature, and perform a low selection with the second adjustable guide vane angle of the compressor calculated from the fan inlet temperature;

[0049] Step S6: Determine the correction value of the adjustable guide vane of the compressor according to the temperature difference, and perform a partial closing process on the low-selected adjustable guide vane angle of the compressor based on the correction value.

[0050] For a fan component with a fixed technical state, according to the fan characteristics, under the condition of equal rotational speed, the total pressure ratio and total efficiency of the fan are determined, so the total temperature ratio of the fan is uniquely determined. At the same time, for a fixed intermediate casing, the relationship between the compressor inlet temperature and the fan outlet temperature is one-to-one correspondence. According to this feature, in Step S1 to Step S3, the nominal value T of the compressor inlet temperature at different fan rotational speeds can be obtained through simulation calculation or experimental data statistics t25_bc . For example, in some alternative embodiments, further comprising before Step S1: obtaining the relationship n between the fan corrected rotational speed and the fan temperature ratio through simulation calculation or experimental data statistics 1r ~T t21 / T t2 , then in Step S1, calculate the fan temperature ratio corresponding to the current fan corrected rotational speed through this relationship, and then in Step S2, use the fan inlet temperature T t2 to calculate the fan outlet temperature T t21 .

[0051] For the subscript representation method of the above parameters, refer to Figure 2 , Figure 2 gives the gas path section numbers of the engine. For example, the number on the far left of the entire engine is 1, that is, the engine inlet temperature is T1, and the engine inlet total pressure is P1. The number before the compressor is 25, that is, the compressor inlet temperature is T 25 , and the compressor inlet pressure is P 25 .

[0052] In Step S3, further consider the influence of performance decay and Reynolds number on the efficiency, the difference between the fan outlet temperature and the compressor inlet temperature and other factors to correct the fan outlet temperature, and then obtain the compressor inlet temperature, that is, the nominal value T of the compressor inlet temperature at different fan rotational speeds t25_bc . In this step, each correction coefficient can be obtained through the test results of the fan component and the test results of the whole machine.

[0053] After that, in Step S4, by comparing the measured compressor inlet temperature T t25 and the calculated compressor inlet temperature, that is, the nominal value T of the compressor inlet temperature t25_bc , when T t25 compared with T t25_bcReduce a certain value, and it can be determined in step S5 that the engine is in a water ingestion state.

[0054] In step S5, the set value A can be determined according to the water ingestion simulation analysis or the results of the water ingestion test. When the engine is in a water ingestion state, the nominal value T of the compressor inlet temperature is used t25_bc Control the angle α of the compressor variable guide vane c (i.e., n 2r25_bc ~α c ), which is not affected by the uneven temperature distribution during water ingestion. At the same time, based on the characteristic that the measured temperature T at the fan inlet during water ingestion t2 is not affected, increase the use of the measured temperature T at the fan inlet t2 to control α c rule, (i.e., n 2r ~α c ), α c takes the deviation value of the two sets of control rules for control to ensure that the angle α of the compressor variable guide vane during water ingestion c does not appear to be deviated open control.

[0055] Specifically, in some alternative embodiments, in step S5, determining the first angle of the compressor variable guide vane includes: calculating the first high-pressure turbine conversion speed according to the compressor speed and the calculated compressor inlet temperature, and calculating the first angle of the compressor variable guide vane according to the compressor variable guide vane control rule related to the first high-pressure turbine conversion speed.

[0056] In some alternative embodiments, in step S5, determining the second angle of the compressor variable guide vane includes: calculating the second high-pressure turbine conversion speed according to the compressor speed and the fan inlet temperature, and calculating the second angle of the compressor variable guide vane according to the compressor variable guide vane control rule related to the second high-pressure turbine conversion speed.

[0057] The above two embodiments refer to Figure 3 , on the one hand, calculating n 25_bc according to the compressor speed N2 and the compressor inlet temperature T 2r25 , and calculating the first angle α of the compressor variable guide vane based on the nominal temperature of the compressor inlet according to the compressor variable guide vane control rule (n 2r25 ~α c ). On the other hand, calculating n c_T25 according to the compressor speed N2 and the fan inlet temperature T t2 , and calculating the second angle α of the compressor variable guide vane based on the fan inlet temperature according to the compressor variable guide vane control rule (n 2r ~α 2r ~α c ). Finally, take α c_Tt2 and α c_T25 and αc_Tt2 Control both of them at Pianguan to ensure the stability margin of the compressor during the water swallowing process to the greatest extent.

[0058] Finally, in step S6, when it is recognized that the engine is in the water swallowing state, by closing the adjustable guide vane angle α of the compressor c , further expand the stability margin of the compression component. Determine the adjustment amount for stability expansion according to the water swallowing influence amount. When the water swallowing influence is large, increase the adjustment amount for stability expansion. The water swallowing influence amount is characterized by the decrease amount △T of the measured inlet temperature of the compressor compared with the nominal temperature 25 = T t25_bc - T t25 The adjustment amount for stability expansion is set according to the decrease amount △T of the compressor inlet temperature, that is, △α 25 = △T c / A * B 25 . In the formula, A is the set value determined according to the water swallowing simulation analysis or the water swallowing test result in step S5, and B αC is the stability expansion adjustment coefficient of the compressor, which is comprehensively determined according to the influence of water swallowing on the stability margin of the compression component and the stability expansion effect under the unit geometric adjustment amount of different stability expansion components. αC

[0059] In some alternative embodiments, further comprising after step S6:

[0060] Determine the correction value of the adjustable guide vane of the fan and the correction value of the nozzle throat area according to the temperature difference;

[0061] Perform a closing control on the adjustable guide vane angle of the fan according to the correction value of the adjustable guide vane of the fan, and perform an enlargement process on the nozzle throat according to the correction value of the nozzle throat area.

[0062] In this embodiment, in addition to performing a closing control on the adjustable guide vane angle of the compressor, it further includes closing the adjustable guide vane angle α of the fan f and enlarging the nozzle throat area A8 to further expand the stability margin of the compression component. Similarly, determine the adjustment amount for stability expansion according to the water swallowing influence amount. When the water swallowing influence is large, increase the adjustment amount for stability expansion. △α f = △T 25 / A * B αf , △A8 = △T 25 / A * B A8 . In the formula, B αf , B A8 are respectively the stability expansion adjustment coefficient of the fan and the stability expansion adjustment coefficient of the nozzle, which are comprehensively determined according to the influence of water swallowing on the stability margin of the compression component and the stability expansion effect under the unit geometric adjustment amount of different stability expansion components.

[0063] This application utilizes the existing measurement points of the engine without adding additional structures, and proposes a method for identifying engine water ingestion. The dual-redundancy method is adopted to effectively solve the problem of deviation in the control of the adjustable guide vane angle of the compressor during engine water ingestion. At the same time, according to the water ingestion influence amount, design differential stability enhancement measures are taken to further ensure that the stability margin of the compression components does not decrease during the engine water ingestion process. While enhancing stability, the engine performance loss is minimized as much as possible, ensuring flight safety during the engine water ingestion process.

[0064] The second aspect of this application provides a device for maintaining the stability margin when an aeroengine ingests water corresponding to the above method, mainly including:

[0065] A fan temperature ratio determination module, configured to determine the fan temperature ratio based on the fan corrected speed.

[0066] A fan outlet temperature determination module, configured to determine the fan outlet temperature according to the fan inlet temperature and the fan temperature ratio.

[0067] A compressor inlet temperature determination module, configured to correct the fan outlet temperature to obtain the compressor inlet temperature.

[0068] A temperature difference determination module, configured to determine the temperature difference between the calculated compressor inlet temperature and the measured compressor inlet temperature.

[0069] A low-selection module for the compressor adjustable guide vane angle, configured to, when the temperature difference exceeds a set value, determine a first compressor adjustable guide vane angle according to the calculated compressor inlet temperature, and perform a low-selection with a second compressor adjustable guide vane angle calculated from the fan inlet temperature.

[0070] A deviation closing processing module for the compressor adjustable guide vane angle, configured to determine a correction value for the compressor adjustable guide vane according to the temperature difference, and perform a deviation closing process on the low-selected compressor adjustable guide vane angle based on the correction value.

[0071] In some alternative embodiments, the fan temperature ratio determination module includes:

[0072] A relationship acquisition unit for the fan corrected speed and the fan temperature ratio, configured to obtain the relationship between the fan corrected speed and the fan temperature ratio through simulation calculation or experimental data statistics.

[0073] In some alternative embodiments, the low-selection module for the compressor adjustable guide vane angle includes:

[0074] A first compressor adjustable guide vane angle determination unit, configured to calculate a first high-pressure turbine corrected speed according to the compressor speed and the calculated compressor inlet temperature, and calculate a first compressor adjustable guide vane angle according to the compressor adjustable guide vane control law related to the first high-pressure turbine corrected speed.

[0075] In some alternative embodiments, the low selection module for the adjustable guide vane angle of the gas turbine includes:

[0076] A second compressor adjustable guide vane angle determination unit, configured to calculate a second high-pressure turbine corrected speed according to the compressor speed and the fan inlet temperature, and calculate a second compressor adjustable guide vane angle according to the compressor adjustable guide vane control law related to the second high-pressure turbine corrected speed.

[0077] In some alternative embodiments, the stability margin maintaining device further includes:

[0078] A fan adjustable guide vane angle correction value and nozzle throat area correction value calculation unit, configured to determine a fan adjustable guide vane correction value and a nozzle throat area correction value according to the temperature difference;

[0079] A fan adjustable guide vane angle and nozzle throat processing unit, configured to perform a partial closing process on the fan adjustable guide vane angle according to the fan adjustable guide vane correction value, and perform an enlargement process on the nozzle throat according to the nozzle throat area correction value.

[0080] As described above, the above are only specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed in the present application should be covered by the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A method for maintaining stability margin when an aircraft engine swallows water, characterized in that: include: Step S1, determining the fan temperature ratio based on the fan converted speed; Step S2, determining the fan outlet temperature according to the fan inlet temperature and the fan temperature ratio; Step S3, correcting the fan outlet temperature to obtain the compressor inlet temperature; Step S4, determining the temperature difference between the corrected compressor inlet temperature and the measured compressor inlet temperature; Step S5, when the temperature difference exceeds the set value, determining the first compressor adjustable guide vane angle according to the corrected compressor inlet temperature, and performing a low selection with the second compressor adjustable guide vane angle calculated according to the fan inlet temperature; Step S6: determining a compressor adjustable guide vane correction value according to the temperature difference, and performing a bias-closing process on the low-selected compressor adjustable guide vane angle based on the correction value.

2. The method for maintaining stability margin of an aircraft engine when swallowing water according to claim 1, characterized in that: Before step S1, the method further comprises: The relationship between the fan converted speed and the fan temperature ratio is obtained through simulation calculation or test data statistics, and the fan temperature ratio corresponding to the current fan converted speed is calculated based on the relationship.

3. The method for maintaining stability margin of an aircraft engine when swallowing water according to claim 1, characterized in that: In step S5, determining the adjustable guide vane angle of the first compressor includes: The first high-pressure turbine converted speed is calculated based on the compressor speed and the corrected compressor inlet temperature, and the first compressor adjustable guide vane angle is calculated based on the compressor adjustable guide vane control law related to the first high-pressure turbine converted speed.

4. The method for maintaining stability margin when an aircraft engine swallows water according to claim 1, characterized in that: In step S5, determining the adjustable guide vane angle of the second compressor includes: The second high-pressure turbine converted speed is calculated according to the compressor speed and the fan inlet temperature, and the second compressor adjustable guide vane angle is calculated according to the compressor adjustable guide vane control law related to the second high-pressure turbine converted speed.

5. The method for maintaining stability margin of an aircraft engine when swallowing water according to claim 1, characterized in that: Step S6 further includes: Determine a correction value for the fan's adjustable guide vanes and a correction value for the nozzle throat area according to the temperature difference; The angle of the fan adjustable guide vane is offset according to the correction value of the fan adjustable guide vane, and the nozzle throat is enlarged according to the correction value of the nozzle throat area.

6. A device for maintaining stability margin when an aircraft engine swallows water, characterized in that: include: A fan temperature ratio determination module, used to determine the fan temperature ratio based on the fan converted speed; A fan outlet temperature determination module, used to determine the fan outlet temperature according to the fan inlet temperature and the fan temperature ratio; A compressor inlet temperature determination module, used to correct the fan outlet temperature to obtain the compressor inlet temperature; A temperature difference determination module, used to determine the temperature difference between the corrected compressor inlet temperature and the measured compressor inlet temperature; A compressor adjustable guide vane angle low selection module, used to determine the first compressor adjustable guide vane angle according to the corrected compressor inlet temperature when the temperature difference exceeds the set value, and to perform low selection with the second compressor adjustable guide vane angle calculated by the fan inlet temperature; The compressor adjustable guide vane angle bias closing processing module is used to determine the compressor adjustable guide vane correction value according to the temperature difference, and perform bias closing processing on the low selected compressor adjustable guide vane angle based on the correction value.

7. The device for maintaining stability margin of an aircraft engine when swallowing water according to claim 6, characterized in that: The fan temperature ratio determination module comprises: The fan converted speed and fan temperature ratio relationship acquisition unit is used to obtain the relationship between the fan converted speed and the fan temperature ratio through simulation calculation or test data statistics.

8. The device for maintaining stability margin of an aircraft engine when swallowing water according to claim 6, characterized in that: The air turbine adjustable guide vane angle low selection module comprises: The first compressor adjustable guide vane angle determination unit is used to calculate the first high-pressure turbine converted speed based on the compressor speed and the corrected compressor inlet temperature, and calculate the first compressor adjustable guide vane angle based on the compressor adjustable guide vane control law related to the first high-pressure turbine converted speed.

9. The device for maintaining stability margin of an aircraft engine when swallowing water according to claim 6, characterized in that: The air turbine adjustable guide vane angle low selection module comprises: The second compressor adjustable guide vane angle determination unit is used to calculate the second high-pressure turbine converted speed according to the compressor speed and the fan inlet temperature, and calculate the second compressor adjustable guide vane angle according to the compressor adjustable guide vane control law related to the second high-pressure turbine converted speed.

10. The device for maintaining stability margin of an aircraft engine when swallowing water according to claim 6, characterized in that: The stability margin maintaining device also includes: A fan adjustable guide vane angle correction value and nozzle throat area correction value calculation unit, used to determine the fan adjustable guide vane angle correction value and nozzle throat area correction value according to the temperature difference; The fan adjustable guide vane angle and nozzle throat processing unit is used to perform a bias-closing process on the fan adjustable guide vane angle according to the fan adjustable guide vane correction value, and to perform a magnifying process on the nozzle throat according to the nozzle throat area correction value.

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