Method and device for judging success of afterburner ignition in all-conditions engine

Abstract

The present application belongs to the field of engine control technology, and particularly relates to a method and device for determining whether afterburner ignition is successful under all engine operating conditions. The method comprises step S1, obtaining the throttle lever position and afterburner connection instruction; step S2, when the throttle lever is in the low afterburner area and the afterburner connection instruction is valid, obtaining the engine state; step S3, when the engine state is in the intermediate state, searching the corresponding turbine after-pressure change threshold in the first threshold table according to the current engine inlet total pressure; when the engine state is in the throttle state, searching the corresponding turbine after-pressure change threshold in the second threshold table according to the current engine inlet total pressure; step S4, determining the relationship between the current turbine after-pressure change amount and the turbine after-pressure change threshold, and determining whether afterburner ignition is successful if the current turbine after-pressure change amount is greater than the turbine after-pressure change threshold. The present application does not rely on onboard software and its calculation accuracy, can achieve successful afterburner ignition determination, and the method is simple.

Description

Technical Field

[0001] The present application belongs to the field of engine control technology, and in particular relates to a method and device for determining the success of afterburner ignition in all-conditions of an engine. Background Art

[0002] To meet the requirements of supersonic flight for aircraft, gas turbine engines with afterburners have emerged. These engines inject fuel into the turbine exhaust stream within the afterburner, further raising the gas temperature and increasing the nozzle exhaust velocity, thereby boosting engine thrust. Aircraft require engines to be capable of engaging afterburner throughout the afterburner envelope. Failure to detect afterburner engagement can degrade engine performance, impacting the mission and even causing serious problems such as runway overrun during takeoff. Therefore, reliably determining afterburner ignition success throughout the entire afterburner envelope is crucial.

[0003] A certain type of engine uses an ultraviolet flame detector to determine the success of afterburner ignition. The principle is: the flame detector senses the intensity of ultraviolet radiation from the afterburner flame, converts it into an electrical signal and sends it to the control system. When the signal intensity exceeds the specified threshold, the afterburner ignition is judged to be successful.

[0004] With a UV flame detector, after a successful afterburner ignition, if the afterburner flame axial position shifts forward (or backward) or dust or carbon deposits accumulate on the UV flame detector's observation window during use, the UV intensity may weaken and the output signal may fall below the threshold for afterburner ignition success, resulting in a false afterburner ignition failure. Manually adjusting the threshold or cleaning the flame detector and restarting the vehicle for verification is time-consuming and costly, making it inefficient.

[0005] In addition, there is a method based on the airborne mathematical model to judge the success of afterburner ignition, which uses the airborne mathematical model to calculate the nozzle throat area A8 and the turbine after-pressure P t6 By comparing A8, P t6 The measured values ​​are consistent with the A8 and P values ​​in the non-afterburner state. t6 Measured values, calculated A8 and P under boost state t6 value to determine whether the afterburner ignition is successful.

[0006] However, the method of comparing the calculated values ​​using the airborne mathematical model with the measured values ​​depends on the accuracy of the airborne model calculation. When there is no airborne model or the calculated values ​​of the airborne model differ greatly from the actual values, this method cannot be used for judgment. Summary of the Invention

[0007] In order to solve the above problems, the first aspect of the present application provides a method for determining whether the afterburner ignition of the engine under full working conditions is successful, mainly comprising:

[0008] Step S1, obtaining the throttle lever position and afterburner on instruction;

[0009] Step S2: When the throttle lever is in the low afterburner range and the afterburner-on command is valid, obtain the engine status;

[0010] Step S3: When the engine state is in the intermediate state, the corresponding turbine post-pressure change threshold value is searched in the first threshold value table according to the current engine inlet total pressure; when the engine state is in the throttle state, the corresponding turbine post-pressure change threshold value is searched in the second threshold value table according to the current engine inlet total pressure;

[0011] Step S4: Determine the relationship between the current change in the turbine post-pressure and the turbine post-pressure change threshold. If the current change in the turbine post-pressure is greater than the turbine post-pressure change threshold, determine that the afterburner ignition is successful.

[0012] Preferably, before step S3, the method further includes: obtaining the first threshold table and the second threshold table by means of experiments or simulation calculations.

[0013] Preferably, in step S3, the post-turbine pressure change threshold corresponding to the current engine inlet total pressure is interpolated from the first threshold table or the second threshold table by an interpolation method.

[0014] A second aspect of the present application provides a device for determining the success of afterburner ignition in all engine operating conditions, mainly comprising:

[0015] Afterburner command acquisition module, used to obtain the throttle lever position and afterburner connection command;

[0016] The engine status acquisition module is used to acquire the engine status when the throttle lever is in the low afterburner range and the afterburner-on command is valid;

[0017] a turbine post-pressure change threshold calculation module, configured to search a first threshold table for a corresponding turbine post-pressure change threshold based on the current engine inlet total pressure when the engine is in an intermediate state, and to search a second threshold table for a corresponding turbine post-pressure change threshold based on the current engine inlet total pressure when the engine is in a throttle state;

[0018] The afterburner state determination module is used to determine the relationship between the current turbine after-pressure change and the turbine after-pressure change threshold. If the current turbine after-pressure change is greater than the turbine after-pressure change threshold, it is determined that the afterburner ignition is successful.

[0019] Preferably, the first threshold table and the second threshold table are obtained by experiments or simulation calculations.

[0020] Preferably, the turbine post-pressure change threshold calculation module includes an interpolation unit for interpolating the turbine post-pressure change threshold corresponding to the current engine inlet total pressure from the first threshold table or the second threshold table by an interpolation method.

[0021] This application does not rely on onboard software and its calculation accuracy, can achieve successful judgment of afterburner ignition, and the judgment method is simple. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a flow chart of a preferred embodiment of the method for judging the success of afterburner ignition in all engine operating conditions of the present application. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solutions and advantages of the implementation of this application clearer, the technical solutions in the implementation of this application will be described in more detail below in conjunction with the drawings in the implementation of this application. In the drawings, the same or similar numbers throughout represent the same or similar elements or elements with the same or similar functions. The described implementation is a part of the implementation of this application, not all of the implementations. The implementation described below with reference to the drawings is exemplary and is intended to be used to explain this application, and should not be understood as a limitation on this application. Based on the implementation in this application, all other implementations obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. The implementation of this application is described in detail below in conjunction with the drawings.

[0024] This application provides a method for determining whether the engine is successfully ignited under full-load conditions. Figure 1 As shown, it mainly includes:

[0025] Step S1, obtaining the throttle lever position and afterburner on instruction;

[0026] Step S2: When the throttle lever is in the low afterburner range and the afterburner-on command is valid, obtain the engine status;

[0027] Step S3: When the engine state is in the intermediate state, the corresponding turbine post-pressure change threshold value is searched in the first threshold value table according to the current engine inlet total pressure; when the engine state is in the throttle state, the corresponding turbine post-pressure change threshold value is searched in the second threshold value table according to the current engine inlet total pressure;

[0028] Step S4: Determine the relationship between the current change in the turbine post-pressure and the turbine post-pressure change threshold. If the current change in the turbine post-pressure is greater than the turbine post-pressure change threshold, determine that the afterburner ignition is successful.

[0029] It is understandable that steps S1 and S2 are used to determine whether the engine has been connected to afterburner at the control level, and only when the throttle lever is in the low afterburner range and the host conditions meet the conditions for afterburner connection are determined, will it be determined whether the afterburner ignition is successful. That is, steps S3 and S4 are used to determine whether the actual afterburner ignition of the engine is successful.

[0030] According to the description of step S3 and step S4, this application is a method based on the turbine post-pressure change threshold P t6 dot is used to determine the method of afterburner ignition, and according to the engine state, different turbine post-pressure change thresholds P are given in the intermediate state and throttle state. t6 dot, thereby realizing the determination of successful afterburner ignition within the full envelope.

[0031] It should be noted that during the afterburner ignition process, the aerodynamic parameters of the afterburner turbofan engine will fluctuate, especially the turbine after-pressure P t6 During the afterburner ignition process, the nozzle throat area A8 generally remains unchanged or pre-opens. t6 When the afterburner ignition is successful, the area of ​​A8 decreases relative to the afterburner fuel flow rate, and P t6 Will rise rapidly, and its change P t6 The dot value is relatively large. t6 dot=(P t6(当前时刻) -P t6(前一时刻) ) / △t.

[0032] P corresponding to successful afterburner ignition t6 dot value and P during engine host acceleration t6 There are differences in the dot values, which can be used to determine the engine's full envelope afterburner ignition.

[0033] Considering the difference in the middle state of the full envelope range and the conditions for connecting the booster in the throttle state, different P t6 As shown in Table 1, several intermediate engine inlet total pressures P are given. t2 The corresponding turbine post-pressure change threshold P t6 The relationship between dot forms the first threshold table. Table 2 gives several engine inlet total pressures P in the throttle state. t2 The corresponding turbine post-pressure change threshold P t6 dot, a second threshold value table is formed, based on which the first threshold value table or the second threshold value table can be called according to the current state of the engine in step S3 to obtain a more accurate turbine post-pressure change threshold value P t6 dot.

[0034] Table 1 P under intermediate state and force condition t6dot threshold

[0035] <![CDATA[P t2 (kPa)]]> ≤20 40 70 90 ≥101.325 <![CDATA[P t6 dot(kPa / s)]]> Xx1 Xx2 Xx3 Xx4 Xx5

[0036] Table 2 P under throttling state and afterburner condition t6 dot threshold

[0037] <![CDATA[P t2 (kPa)]]> ≤20 40 70 90 ≥101.325 <![CDATA[P t6 dot(kPa / s)]]> Xx6 Xx7 Xx8 Xx9 Xx10

[0038] In some optional implementations, before step S3, the method further includes: obtaining the first threshold table and the second threshold table through experiments or simulation calculations.

[0039] It should also be noted that before step S3, cumulative test verification (on the ground platform and the high-altitude platform) within the full envelope is carried out based on the parameters in Tables 1 and 2. According to the test results, the afterburner ignition judgment threshold can be modified as appropriate.

[0040] In some optional embodiments, in step S3, the turbine post-pressure change threshold corresponding to the current engine inlet total pressure is interpolated from the first threshold table or the second threshold table by an interpolation method. In addition, as shown in Tables 1 and 2, truncation is also performed by boundary values.

[0041] According to the parameter change characteristics of the engine afterburner ignition, the application adopts the turbine after-pressure P t6 The rate of change P t6 dot is used to judge the success of afterburner ignition, and the ignition success threshold is set differently according to the engine status and engine inlet pressure, so as to adapt to the afterburner ignition judgment under the full envelope and different afterburner states.

[0042] A second aspect of the present application provides a device corresponding to the above method for determining the success of afterburner ignition in all engine operating conditions, mainly comprising:

[0043] Afterburner command acquisition module, used to obtain the throttle lever position and afterburner connection command;

[0044] The engine status acquisition module is used to acquire the engine status when the throttle lever is in the low afterburner range and the afterburner-on command is valid;

[0045] a turbine post-pressure change threshold calculation module, configured to search a first threshold table for a corresponding turbine post-pressure change threshold based on the current engine inlet total pressure when the engine is in an intermediate state, and to search a second threshold table for a corresponding turbine post-pressure change threshold based on the current engine inlet total pressure when the engine is in a throttle state;

[0046] The afterburner state determination module is used to determine the relationship between the current turbine after-pressure change and the turbine after-pressure change threshold. If the current turbine after-pressure change is greater than the turbine after-pressure change threshold, it is determined that the afterburner ignition is successful.

[0047] In some optional implementations, the first threshold table and the second threshold table are obtained through experiments or simulation calculations.

[0048] In some optional embodiments, the turbine post-pressure change threshold calculation module includes an interpolation unit for interpolating the turbine post-pressure change threshold corresponding to the current engine inlet total pressure from the first threshold table or the second threshold table through an interpolation method.

[0049] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A method for determining whether afterburner ignition is successful under full-load conditions of an engine, characterized in that: include: Step S1, obtaining the throttle lever position and afterburner on instruction; Step S2: When the throttle lever is in the low afterburner range and the afterburner-on command is valid, obtain the engine status; Step S3: When the engine state is in the intermediate state, the corresponding turbine post-pressure change threshold value is searched in the first threshold value table according to the current engine inlet total pressure; when the engine state is in the throttle state, the corresponding turbine post-pressure change threshold value is searched in the second threshold value table according to the current engine inlet total pressure; Step S4: Determine the relationship between the current change in the turbine post-pressure and the turbine post-pressure change threshold. If the current change in the turbine post-pressure is greater than the turbine post-pressure change threshold, determine that the afterburner ignition is successful.

2. The method for determining whether the afterburner ignition of the engine under full operating conditions is successful according to claim 1, characterized in that: Before step S3, the method further includes: obtaining a first threshold table and a second threshold table by means of experiments or simulation calculations.

3. The method for determining whether the afterburner ignition of the engine under full operating conditions is successful according to claim 1, wherein: In step S3, a post-turbine pressure change threshold corresponding to the current engine inlet total pressure is interpolated from the first threshold table or the second threshold table by an interpolation method.

4. A device for determining whether afterburner ignition is successful under full-operation conditions of an engine, characterized in that: include: Afterburner command acquisition module, used to obtain the throttle lever position and afterburner connection command; The engine status acquisition module is used to acquire the engine status when the throttle lever is in the low afterburner range and the afterburner-on command is valid; a turbine post-pressure change threshold calculation module, configured to search a first threshold table for a corresponding turbine post-pressure change threshold based on the current engine inlet total pressure when the engine is in an intermediate state, and to search a second threshold table for a corresponding turbine post-pressure change threshold based on the current engine inlet total pressure when the engine is in a throttle state; The afterburner state determination module is used to determine the relationship between the current turbine after-pressure change and the turbine after-pressure change threshold. If the current turbine after-pressure change is greater than the turbine after-pressure change threshold, it is determined that the afterburner ignition is successful.

5. The device for determining whether the afterburner ignition of the engine under full working conditions is successful according to claim 4, characterized in that: The first threshold value table and the second threshold value table are obtained by experiments or simulation calculations.

6. The device for determining whether afterburner ignition is successful under full engine conditions according to claim 4, characterized in that: The turbine post-pressure change threshold calculation module includes an interpolation unit for interpolating a turbine post-pressure change threshold corresponding to the current engine inlet total pressure from the first threshold table or the second threshold table by an interpolation method.

Images