Control method of engine nozzle throat area when measurement failure occurs

Abstract

The present application belongs to the technical field of engine nozzle throat area control, and relates to a method for controlling the throat area when a fault occurs in the measurement of the engine nozzle throat area, comprising: step one, determining the correspondence between the low-pressure converted speed and the nozzle throat area given value at different intake temperatures based on the engine control law; step two, determining the correspondence between the low-pressure converted speed and the high-pressure converted speed at different nozzle throat areas based on the engine test results; step three, when a fault occurs in the measurement of the engine nozzle throat area, using the current low-pressure converted speed and the high-pressure converted speed, based on the correspondence between the low-pressure converted speed and the high-pressure converted speed at different nozzle throat areas, to obtain the current nozzle throat area, and using the current low-pressure converted speed and the intake temperature, based on the correspondence between the low-pressure converted speed at different intake temperatures and the nozzle throat area given value, to obtain the nozzle throat area given value, and perform closed-loop control on the nozzle throat area.

Description

Technical Field

[0001] The present application belongs to the technical field of engine nozzle throat area control design, and specifically relates to a method for controlling the engine nozzle throat area when a throat area measurement failure occurs. Background Art

[0002] Engines with adjustable nozzle throat area, such as twin-rotor turbofan engines, usually control the nozzle throat area through an actuator.

[0003] There is a one-to-one correspondence between the displacement of the actuator and the nozzle throat area. After the engine is assembled, the size of the nozzle throat area is usually determined by calibrating the displacement of the actuator. When the engine is working, the displacement of the actuator is measured by a linear displacement sensor installed on the actuator, and the nozzle throat area is then obtained.

[0004] The linear displacement sensor installed on the actuator is prone to malfunction after long-term use, and can no longer measure the displacement of the actuator and obtain the nozzle throat area, resulting in nozzle throat area measurement failure and the inability to accurately control the nozzle throat area.

[0005] Currently, when a linear displacement sensor installed on the actuator fails, the nozzle throat area is usually controlled by comparing a given value of the nozzle throat area with a cutoff value. The given value of the nozzle throat area is an expected value based on the engine control law, and the cutoff value of the nozzle throat area is a fixed value selected between the maximum and minimum control areas of the nozzle throat. When the given value of the nozzle throat area is greater than the cutoff value, the nozzle throat area is controlled to the maximum value. When the given value of the nozzle throat area is less than the cutoff value, the nozzle throat area is controlled to the minimum value. This technical solution has the following drawbacks:

[0006] When the nozzle throat area measurement fails, based on the comparison between the nozzle throat area given value and the delimiter value, the nozzle throat area is simply controlled to the maximum value or minimum value, which can easily cause the nozzle throat area to be significantly larger or smaller than the nozzle throat area given value, causing changes in the overall engine matching. When the nozzle throat area is controlled to the maximum value, the fan working line will usually move down, greatly reducing the engine thrust. When the nozzle throat area is controlled to the minimum value, the fan working line will usually move up, greatly reducing the engine stability and causing a significant increase in the engine exhaust temperature.

[0007] This application is proposed in view of the above-mentioned technical defects. Summary of the Invention

[0008] The purpose of this application is to provide a method for controlling the throat area of ​​an engine nozzle when a measurement failure occurs, so as to overcome or alleviate at least one of the known technical defects.

[0009] The technical solution of this application is:

[0010] A method for controlling an engine nozzle throat area when a throat area measurement failure occurs, comprising:

[0011] Step 1: Based on the engine control law, determine the corresponding relationship between the low-pressure converted speed and the given value of the nozzle throat area at different intake temperatures;

[0012] Step 2: Based on the engine test results, determine the corresponding relationship between the low-pressure converted speed and the high-pressure converted speed under different nozzle throat areas;

[0013] Step 3. When there is a fault in the measurement of the engine nozzle throat area, the current low-pressure converted speed and high-pressure converted speed are used, and based on the corresponding relationship between the low-pressure converted speed and the high-pressure converted speed under different nozzle throat areas, the current nozzle throat area is obtained. Also, the current low-pressure converted speed and intake temperature are used, and based on the corresponding relationship between the low-pressure converted speed and the nozzle throat area given value under different intake temperatures, the nozzle throat area given value is obtained, and closed-loop control of the nozzle throat area is performed.

[0014] According to at least one embodiment of the present application, in the above-mentioned method for controlling the throat area of ​​the engine nozzle throat when the throat area measurement fails, the range of the low-pressure converted speed is set to the low-pressure converted speed of the engine from the slow state to the intermediate state.

[0015] According to at least one embodiment of the present application, in the above-mentioned method for controlling the throat area when the engine nozzle throat area measurement fails, in step two, the correspondence between the low-pressure converted speed and the high-pressure converted speed under different nozzle throat areas is determined based on the engine high-altitude platform test results.

[0016] According to at least one embodiment of the present application, in the above-mentioned method for controlling the throat area of ​​the engine nozzle when the throat area measurement fails, in step two, the correspondence between the low-pressure converted speed and the high-pressure converted speed under different nozzle throat areas is determined based on the engine simulation test results.

[0017] According to at least one embodiment of the present application, in the above-mentioned method for controlling the engine nozzle throat area when a measurement failure occurs, in step three, closed-loop control of the nozzle throat area is performed, specifically:

[0018] Calculate the deviation between the current nozzle throat area and the given value of the nozzle throat area ,in, is the given value of the nozzle throat area; is the current nozzle throat area;

[0019] The control current is calculated by the PI control algorithm ,in, is the proportional control parameter, which is a constant; The balance current of the electro-hydraulic servo valve of the actuator is a constant; is the integral control parameter, which is a constant; For the points link;

[0020] Will control the current The output is sent to the electro-hydraulic servo valve of the actuator to control the actuator and adjust the nozzle throat area so that the deviation Δ between the current nozzle throat area and the given value of the nozzle throat area tends to 0.

[0021] This application has at least the following beneficial technical effects:

[0022] Provided is a method for controlling the nozzle throat area of ​​an engine when a nozzle throat area measurement failure occurs. When the nozzle throat area measurement failure occurs, based on slip limitation, the current low-pressure converted speed and the high-pressure converted speed are used, and based on the corresponding relationship between the low-pressure converted speed and the high-pressure converted speed under different nozzle throat areas, the current nozzle throat area is obtained. Furthermore, based on the current low-pressure converted speed and the intake air temperature, a given value of the nozzle throat area is obtained. The nozzle throat area is closed-loop controlled to control the nozzle throat area so that the nozzle throat area is close to the given value, so that the nozzle throat area and the whole engine match are close to the design state, thereby achieving effective control of the nozzle throat area. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 1 is a schematic diagram of a method for controlling the throat area of ​​an engine nozzle when a measurement failure of the throat area of ​​the engine nozzle is encountered, provided in an embodiment of the present application;

[0024] Figure 2 This is a control logic diagram for closed-loop control of the nozzle throat area provided in an embodiment of the present application.

[0025] In order to better illustrate this embodiment, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product. In addition, the drawings are only used for illustrative purposes and should not be understood as limiting this application. DETAILED DESCRIPTION

[0026] To make the technical solution and its advantages of this application more clear, the technical solution of this application will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described here are only some of the embodiments of this application and are only used to explain this application, not to limit this application. It should be noted that for ease of description, only the parts relevant to this application are shown in the accompanying drawings, and other relevant parts can refer to the general design.

[0027] In addition, unless otherwise defined, the technical terms or scientific terms used in the description of this application should have the usual meanings understood by those skilled in the art in the field to which this application belongs. The words indicating orientation used in the description of this application are only used to indicate relative directions or positional relationships. When the absolute position of the described object changes, its relative positional relationship may also change accordingly. The word "include" used in the description of this application means that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, but does not exclude other elements or objects.

[0028] In addition, it should be noted that, unless otherwise clearly stipulated and limited, the words "installation", "connection" and similar terms used in the description of this application should be understood in a broad sense. For example, the connection can be a fixed connection or a detachable connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. Technical personnel in the field can understand its specific meaning in this application according to the specific circumstances.

[0029] Engine slip is typically related to the fan inlet adjustable guide vane angle, the compressor adjustable guide vane angle, and the nozzle throat area. When the fan inlet adjustable guide vane angle and the compressor adjustable guide vane angle are fixed, engine slip is only related to the nozzle throat area.

[0030] In the engine control law, the angle of the adjustable guide vanes at the fan inlet is usually designed to change with the low-pressure converted speed, and the angle of the adjustable guide vanes at the compressor changes with the high-pressure converted speed, while the nozzle throat area changes with the engine's intake temperature and low-pressure converted speed. When the low-pressure converted speed is a constant, the high-pressure converted speed will change with changes in the engine's intake temperature. Therefore, when the nozzle throat area and the low-pressure converted speed are determined, the engine's slip is determined accordingly. Conversely, when the engine's slip and low-pressure converted speed are determined, the nozzle throat area is also determined accordingly.

[0031] Based on the above, the present application provides a method for controlling the throat area of ​​an engine nozzle when a measurement failure occurs. Figure 1 shown.

[0032] Step 1: Based on the engine control law, determine the corresponding relationship between the low-pressure converted speed and the given value of the nozzle throat area at different intake temperatures.

[0033] The range of the low-pressure converted speed can be set to the low-pressure converted speed of the engine from an idling state to an intermediate state.

[0034] The corresponding relationship between the low-pressure converted speed and the given value of the nozzle throat area at different inlet temperatures can be listed as follows:

[0035]

[0036] Step 2: Based on the engine test results, determine the corresponding relationship between the low-pressure converted speed and the high-pressure converted speed under different nozzle throat areas.

[0037] Specifically, the corresponding relationship between the low-pressure converted speed and the high-pressure converted speed under different nozzle throat areas can be determined based on the engine high-altitude bench test results or simulation test results.

[0038] The corresponding relationship between the low-pressure converted speed and the high-pressure converted speed under different nozzle throat areas can be listed as follows:

[0039]

[0040] Step 3. When there is a fault in the measurement of the engine nozzle throat area, the current low-pressure converted speed and high-pressure converted speed are used, and based on the corresponding relationship between the low-pressure converted speed and the high-pressure converted speed under different nozzle throat areas, the current nozzle throat area is obtained. Also, the current low-pressure converted speed and intake temperature are used, and based on the corresponding relationship between the low-pressure converted speed and the nozzle throat area given value under different intake temperatures, the nozzle throat area given value is obtained, and closed-loop control of the nozzle throat area is performed.

[0041] The nozzle throat area is closed-loop controlled, and the control logic is as follows: Figure 2 For details, please refer to the following:

[0042] Calculate the deviation between the current nozzle throat area and the given value of the nozzle throat area ,in, is the given value of the nozzle throat area; is the current nozzle throat area;

[0043] The control current is calculated by the PI control algorithm ,in, is the proportional control parameter, which is a constant; The balance current of the electro-hydraulic servo valve of the actuator is a constant; is the integral control parameter, which is a constant; For the points link;

[0044] Will control the current The output is sent to the electro-hydraulic servo valve of the actuator to control the actuator and adjust the nozzle throat area so that the deviation Δ between the current nozzle throat area and the given value of the nozzle throat area tends to 0.

[0045] The above-mentioned embodiment discloses a method for controlling the nozzle throat area of ​​an engine when a nozzle throat area measurement failure occurs. When the nozzle throat area measurement failure occurs, based on the slip limit, the current low-pressure conversion speed and high-pressure conversion speed are used, and based on the correspondence between the low-pressure conversion speed and the high-pressure conversion speed under different nozzle throat areas, the current nozzle throat area is obtained. In addition, the current low-pressure conversion speed and the intake temperature are used to obtain a given value of the nozzle throat area. The nozzle throat area is closed-loop controlled, and the nozzle throat area can be controlled to be close to the given value, so that the nozzle throat area and the overall matching are close to the design state, thereby achieving effective control of the nozzle throat area.

[0046] So far, the technical solution of the present application has been described in conjunction with the preferred embodiments shown in the accompanying drawings. Those skilled in the art should understand that the scope of protection of the present application is obviously not limited to these specific embodiments. Without departing from the principles of the present application, those skilled in the art can make equivalent changes or replacements to the relevant technical features, and the technical solutions after these changes or replacements will fall within the scope of protection of the present application.

Claims

1. A method for controlling the throat area of ​​an engine nozzle when a measurement failure occurs, characterized in that: include: Step 1: Based on the engine control law, determine the corresponding relationship between the low-pressure converted speed and the given value of the nozzle throat area at different intake temperatures; Step 2: Based on the engine test results, determine the corresponding relationship between the low-pressure converted speed and the high-pressure converted speed under different nozzle throat areas; Step 3: When the engine nozzle throat area measurement fails, the current low-pressure converted speed and high-pressure converted speed are used, and based on the corresponding relationship between the low-pressure converted speed and the high-pressure converted speed under different nozzle throat areas, the current nozzle throat area is obtained. Furthermore, the current low-pressure converted speed and intake air temperature are used, and based on the corresponding relationship between the low-pressure converted speed and the nozzle throat area given value under different intake air temperatures, the nozzle throat area given value is obtained, and closed-loop control of the nozzle throat area is performed, specifically as follows: Calculate the deviation between the current nozzle throat area and the given value of the nozzle throat area: Δ = A8Dem - A8, where A8Dem is the given value of the nozzle throat area; A8 is the current nozzle throat area; The control current is calculated by the PI control algorithm Among them, Kp is the proportional control parameter, which is a constant; I 平衡 K is the balance current of the electro-hydraulic servo valve of the actuator, which is a constant; i is the integral control parameter, which is a constant; For the points link; The control current I is output to the electro-hydraulic servo valve of the actuator to control the actuator and adjust the nozzle throat area so that the deviation Δ between the current nozzle throat area and the given value of the nozzle throat area tends to 0.

2. The method for controlling the engine nozzle throat area when a measurement failure occurs according to claim 1, characterized in that: The range of the low-pressure converted speed is set to the low-pressure converted speed of the engine from an idling state to an intermediate state.

3. The method for controlling the engine nozzle throat area when a measurement failure occurs according to claim 1, characterized in that: In step 2, based on the engine high-altitude test results, the corresponding relationship between the low-pressure converted speed and the high-pressure converted speed under different nozzle throat areas is determined.

4. The method for controlling the engine nozzle throat area when a measurement failure occurs according to claim 1, characterized in that: In step 2, based on the engine simulation test results, the corresponding relationship between the low-pressure converted speed and the high-pressure converted speed under different nozzle throat areas is determined.

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