Aero-engine take-off over-temperature protection control method

Abstract

The application provides an aero-engine take-off over-temperature protection control method, and belongs to the aero-engine control field.The method comprises the following steps: sequentially judging whether the engine is in a take-off state, whether the engine intake temperature is higher than a critical intake temperature, and whether the take-off height is lower than a critical height; when the engine is in the take-off state, the engine intake temperature is higher than the critical intake temperature, and the take-off height is lower than the critical height, entering an over-temperature protection state, and correcting the low-pressure rotating speed control value of the engine in an intermediate state and a boost state; obtaining the duration of the take-off state of the engine in the take-off process, and when the take-off state duration reaches a duration threshold or the engine exits the take-off state, the low-pressure rotating speed control value of the engine in the intermediate state and the boost state returns to normal control. The application solves the over-temperature problem in the take-off process of the engine, reduces the risk of over-temperature occurrence in the take-off process of the engine, and improves the reliability of the engine.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of aero-engine control, and particularly relates to an aero-engine take-off over-temperature protection control method. BACKGROUND

[0002] With the continuous development of aero-engine technology, the temperature before the turbine is higher and higher. For a certain generation of engine, the temperature load it can withstand is limited, and the higher the temperature level, the more sensitive the influence on the service life of the engine components. When the aero-engine is in use, the low-pressure turbine outlet temperature T6 is generally used as the main fuel control parameter. At present, the temperature sensor of the turbine outlet temperature T6 can accurately measure the steady-state exhaust temperature of the engine. However, when the engine is in a transient process, especially in the process of taking off in hot weather, the engine is not fully warmed up, and the component efficiency is low. Due to the lag in the dynamic response of the temperature sensor of the turbine outlet temperature T6, the engine state speed and thrust parameters increase first and then decrease, which is a "bulge" phenomenon, indicating that the measurement result of the turbine outlet temperature T6 is quite different from the actual temperature of the engine. If it is directly used for engine transient temperature control, it may cause the engine to overheat, increase the turbine thermal load and vibration stress, and even damage the structural integrity of the engine, directly threatening flight safety.

[0003] At present, some engines directly use the turbine outlet temperature T6 temperature sensor to collect values for transient temperature control, which ensures sufficient take-off thrust in hot weather. However, due to the large difference between the measurement result and the actual temperature of the engine, the engine will overheat, and the take-off may even exceed the maximum allowable value of the full envelope, which has a very serious impact on the service life of the turbine blades (analysis shows that the service life of the turbine blades will be reduced by about 10 times), greatly increasing the service life damage and maintenance cost of the engine. If the turbine outlet temperature T6 temperature sensor is used for advance correction, the time constant of the turbine outlet temperature T6 temperature sensor is related to the material and structure of the sensor itself, and is also related to the temperature, pressure, flow rate and other working environment parameters of the measurement position of the sensor. A large amount of sensor wind tunnel test and whole machine debugging work is needed, which has great technical difficulty and high development and use cost. SUMMARY

[0004] The purpose of the present application is to provide an aero-engine take-off over-temperature protection control method to solve or alleviate at least one problem in the background art.

[0005] The technical solution of the present application is: an aero-engine take-off over-temperature protection control method, comprising:

[0006] sequentially judging whether the engine is in a take-off state, whether the engine inlet temperature is higher than a critical inlet temperature, and whether the take-off height is lower than a critical height;

[0007] When the engine is in the take-off state, the engine intake temperature is higher than the critical intake temperature, and the take-off height is lower than the critical height, the over-temperature protection state is entered, and the low-pressure rotating speed control value n 1max is corrected so that the low-pressure rotating speed control value of the engine in the intermediate and afterburning states satisfies n 1max = n 1max - n 1-XZ , wherein n 1-XZ is a low-pressure rotating speed correction value of the engine in the intermediate and afterburning states.

[0008] The duration of the engine take-off state in the take-off process is obtained, and when the take-off state duration reaches a duration threshold or the engine exits the take-off state, the low-pressure rotating speed control value n 1max of the engine in the intermediate and afterburning states is restored to normal control.

[0009] Preferably, whether the engine is in the take-off state is determined according to characteristic parameters of the aircraft and the engine during take-off, and the characteristic parameters of the aircraft and the engine include an engine throttle lever angle PLA, an engine basic state, an aircraft landing gear state, and an aircraft ground speed V D .

[0010] Preferably, the critical temperature is determined according to an engine exhaust temperature margin and an engine warm-up degree before take-off.

[0011] Preferably, the critical height is two or more to adapt to plain airports and plateau airports at different altitudes.

[0012] Preferably, the low-pressure rotating speed correction value n 1-XZ of the engine in the intermediate and afterburning states is obtained through an overall test.

[0013] Preferably, the low-pressure rotating speed correction value of the engine in the intermediate and afterburning states is 1% to 2% of the low-pressure rotating speed control value n 1max of the engine in the intermediate and afterburning states according to the engine intake temperature.

[0014] Preferably, the transition time to the normal control is linearly transitioned.

[0015] Preferably, the duration threshold and the transition time are respectively set to 25s and 3s.

[0016] The take-off over-temperature protection control method of the aero-engine provided in the application solves the over-temperature problem in the take-off process of the engine, reduces the risk of over-temperature in the take-off process of the engine, improves the reliability of the engine, and ensures flight safety. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions provided by the present application, the accompanying drawings will be briefly introduced. Obviously, the accompanying drawings described below are only some embodiments of the present application.

[0018] Figure 1 The figure is a schematic diagram of the take-off over-temperature protection control method of the aero-engine of the present application. DETAILED DESCRIPTION

[0019] In order to make the purposes, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be described in more detail below with reference to the accompanying drawings in the embodiments of the present application.

[0020] Since there is a lag in the dynamic response of the temperature sensor of the turbine outlet temperature T6, when the engine is from the idle state to the maximum take-off state, the engine has a "bulge" feature that the parameters such as thrust and speed first increase and then decrease. In order to avoid the over-temperature influence of the "bulge" feature on the engine, the present application proposes an aero-engine take-off over-temperature protection control method according to the parameter characteristics of the engine during take-off and considering the specific scenarios of take-off.

[0021] As shown in Figure 1 , the aero-engine take-off over-temperature protection control method provided by the present application includes the following processes:

[0022] S10, determining whether the engine is in a take-off state.

[0023] According to the characteristic parameters of the airplane and the engine during take-off, it is determined whether the engine is in a take-off state.

[0024] Generally, the characteristic parameters of the airplane and the engine during take-off include the engine throttle lever angle PLA, the engine basic state, the airplane landing gear state, the airplane ground speed V D , etc. That is, the engine throttle lever angle PLA, the engine basic state, the airplane landing gear state, the airplane ground speed, etc. can be used for judgment. For example, when the throttle lever angle PLA of a certain engine is ≥65°, the engine is in an intermediate and above intermediate state, the landing gear state signal is in a lowered state, and the airplane ground speed V D ≥5.5 m / s, it can be determined that the engine is in a take-off state.

[0025] S20, determining whether the engine inlet temperature T2 is higher than the critical inlet temperature.

[0026] The engine intake air temperature T2 at takeoff is obtained, and it is determined whether the engine intake air temperature T2 exceeds the critical intake air temperature. When the engine intake air temperature T2 at takeoff is lower than the critical intake air temperature, the engine is generally controlled according to the speed, and there is no over-temperature problem. When the engine intake air temperature T2 at takeoff is higher than the critical intake air temperature, the engine is generally controlled according to the exhaust temperature. At this time, over-temperature protection is achieved by reducing the engine low-pressure relative physical speed n1.

[0027] In this application, the selection of the critical intake temperature is related to factors such as the engine exhaust temperature margin and the degree of engine warm-up before takeoff. For example, in some embodiments, the critical intake temperature of a certain engine is set to 283K (i.e., about 10°C).

[0028] S30 determines whether the takeoff altitude H is below the critical altitude.

[0029] In this application, to adapt to plains airports and plateau airports at different altitudes, there can be two or more critical altitudes, and the same or different control rules can be set for plains airports and plateau airports corresponding to different altitudes. For example, in one embodiment of this application, the critical altitude can be set to 0km, 1km, 3km, and 4.5km.

[0030] S40, when the engine is in takeoff condition, the intake air temperature is higher than the critical temperature, and the takeoff altitude is lower than the critical altitude, it enters the over-temperature protection state. At this time, the low-pressure speed control value n of the engine in intermediate and afterburner states is adjusted. 1max The correction is performed by reducing the low-pressure speed control value n during engine intermediate and afterburner states. 1max That is, n 1max =n 1max -n 1-XZ In the formula, n 1-XZ This is the low-pressure speed correction value for the engine during intermediate and afterburner states.

[0031] In this application, the low-pressure speed correction value n for engine intermediate and afterburner states 1-XZ The value can be obtained through whole-aircraft testing. The testing process is as follows: adjust the aircraft and engine parameters, simulate the takeoff process, and when the engine speed, thrust, and other parameters no longer exhibit the "bulge" phenomenon of first rising and then falling when pushed up from idle to maximum, or when the "bulge" is small, the low-pressure speed correction value n for the engine in the intermediate and afterburner states can be obtained. 1-XZ .

[0032] In a preferred embodiment of this application, the low-pressure speed correction value for the engine in intermediate and afterburner states is typically taken as the low-pressure speed control value n for the engine in intermediate and afterburner states. 1max1% to 2% of the low-pressure rotating speed control value n of the engine in the intermediate and afterburning states, which is adjusted according to the engine intake temperature T2. Meanwhile, considering the special scenario of plateau airport use, the modification can be omitted. Table 1 shows the low-pressure rotating speed modification value n of the engine in the intermediate and afterburning states obtained by an embodiment of the present application 1-XZ The low-pressure rotating speed control value n of the engine in the intermediate and afterburning states is not modified when the intake temperature is below the critical intake temperature (283K). 1max The low-pressure rotating speed modification value n of the engine in the intermediate and afterburning states is modified when the intake temperature is 10K higher than the critical intake temperature (i.e. 293K). 1-XZ The low-pressure rotating speed modification value n of the engine in the intermediate and afterburning states is modified by taking 1% of the low-pressure rotating speed control value n of the engine in the intermediate and afterburning states when the intake temperature is 20K higher than the critical intake temperature (i.e. 303K or above). 1-XZ The low-pressure rotating speed modification value n of the engine in the intermediate and afterburning states is modified by taking 2% of the low-pressure rotating speed control value n of the engine in the intermediate and afterburning states.

[0033] Table 1 Low-pressure rotating speed modification value n of the engine in the intermediate and afterburning states 1-XZ

[0034]

[0035] S50, return to normal control:

[0036] The duration X1 of the engine in the takeoff state in the actual takeoff process is obtained, and the low-pressure rotating speed control value n of the engine in the intermediate and afterburning states is returned to normal control (i.e. control without modification) when the duration X1 of the engine in the takeoff state reaches a duration threshold or the engine exits the takeoff state. 1max The low-pressure rotating speed control value n of the engine in the intermediate and afterburning states is returned to normal control (i.e. control without modification).

[0037] In the preferred embodiment of the present application, to ensure smooth changes of engine parameters during the recovery process, the transition time X2 of the return to normal control is linearly transitioned.

[0038] In some embodiments of the present application, the duration threshold of the engine in the takeoff state and the transition time can be set to 25s and 3s, respectively.

[0039] The takeoff over-temperature protection control method for an aero-engine provided by the present application solves the over-temperature problem in the takeoff process of the engine by setting takeoff over-temperature protection control logic, reduces the risk of over-temperature in the takeoff process of the engine, improves the reliability of the engine, ensures flight safety, and provides a new method for solving similar problems in the development of the engine, thereby ensuring the smooth development of the type development and reducing the cost of the type development. In addition, the method is simple to implement, easy to improve, and widely adaptable.

[0040] The above merely provides the specific implementation of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of the changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. An aircraft engine takeoff overtemperature protection control method, characterized in that, Comprise: In turn, determine whether the engine is in the state of take-off, whether the engine intake temperature is higher than the critical intake temperature, and whether the take-off height is lower than the critical height, wherein the critical intake temperature is determined according to the engine exhaust temperature margin and the engine warm-up degree before take-off; When the engine is in a takeoff state, the engine intake air temperature is higher than a critical intake air temperature, and the takeoff height is lower than a critical height, an over-temperature protection state is entered, and the low-pressure rotating speed control value n 1max of the engine in an intermediate and afterburning state is corrected to satisfy n 1max =n 1max -n 1-XZ , wherein n 1-XZ is a low-pressure rotating speed correction value of the engine in the intermediate and afterburning state, the low-pressure rotating speed correction value n 1-XZ of the engine in the intermediate and afterburning state is obtained through an overall test, and the low-pressure rotating speed correction value of the engine in the intermediate and afterburning state is 1% to 2% of the low-pressure rotating speed control value n 1max of the engine in the intermediate and afterburning state according to the engine intake air temperature. acquiring a duration of the takeoff state of the engine during the takeoff, and when the duration of the takeoff state reaches a duration threshold or the engine exits the takeoff state, causing the low-pressure spool speed control value n 1max to return to normal control.

2. The aircraft engine takeoff overtemperature protection control method of claim 1, wherein, According to the characteristic parameters of the aircraft and the engine at the time of takeoff, it is determined whether the engine is in a takeoff state, the characteristic parameters of the aircraft and the engine including an engine throttle lever angle PLA, an engine basic state, an aircraft landing gear state, an aircraft ground speed V D .

3. The aircraft engine takeoff overtemperature protection control method of claim 1, wherein, The critical height is two or more to adapt to different height of plain airport and plateau airport.

4. The aircraft engine takeoff overtemperature protection control method of claim 1, wherein, The transition time to restore to normal control is linearly transitioned.

5. The turbofan engine takeoff overtemperature protection control method of claim 4, wherein, The duration threshold and the transition time are set to 25s and 3s respectively.

Images