Aero-engine vibration fault positioning method based on multiple measuring points

Abstract

The invention discloses an aero-engine vibration fault positioning method based on multiple measuring points, and the method comprises the following steps: obtaining a rotating speed key phase signal of a rotor in an operation state of an aero-engine and a vibration signal of each measuring point of the aero-engine, the measuring points including an air inlet casing, an intermediate casing and a turbine rear casing, the vibration signals comprise an axial vibration signal, a radial vibration signal and a circumferential vibration signal; performing transient and steady state vibration phase analysis and order analysis on the rotating speed key phase signal and the vibration signal; and determining a fault type and / or an excitation source position according to phase analysis and order analysis results of each measuring point. According to the method, transient and steady state vibration phase analysis and order analysis are carried out on the vibration signals of the air inlet casing, the intermediate casing and the turbine rear casing of the aero-engine in the rotating state, then the fault type and the excitation source position are obtained, and the fault judgment accuracy is high.

Description

Technical Field

[0001] The invention belongs to the technical field of engine vibration fault positioning, and in particular relates to an aviation engine vibration fault positioning method based on multiple measuring points. Background Art

[0002] Using vibration testing technology to monitor the health status of the engine has become one of the conventional means in the industry, but due to the complex structure of the engine and the single analysis method, it can generally only identify vibration faults. For example, in the "A Vibration Fault Detection System and Method for Aircraft Engines" with application number CN202110056266.8, the test chamber is used to provide a test environment for the aircraft engine to cycle from low pressure to high pressure; the installation component is used to support the aircraft engine; the sensor network component is fixed on the aircraft engine shell and forms a monitoring network to monitor the vibration frequency of different points of the aircraft engine in real time; the sound wave collection component is used to determine the sound wave changes of the aircraft engine in the test environment from low pressure to high pressure; the data processing system judges the vibration fault according to the vibration amplitude of the monitoring data of the sensor network component from low pressure to high pressure and the sound wave change output by the sound wave collection component; the data processing system distinguishes the pure mechanical vibration of the aircraft engine from the sound wave interference vibration and judges the different faults of the aircraft engine by cyclically changing the test environment in the test chamber.

[0003] However, the existing methods are only unable to identify the specific fault and location. Summary of the invention

[0004] In order to solve the problem that the existing methods cannot identify the specific faults and positions, the present invention proposes an aero-engine vibration fault locating method based on multiple measuring points.

[0005] The objective of the present invention is achieved through the following technical solutions: The invention discloses an aero-engine vibration fault locating method based on multiple measuring points, comprising the following steps: Obtaining a speed key phase signal of a rotor in a running state of the aircraft engine and a vibration signal of each measuring point of the aircraft engine, wherein the measuring points include an air intake casing, an intermediate casing, and a turbine rear casing, and the vibration signal includes an axial vibration signal, a radial vibration signal, and a circumferential vibration signal; Perform transient and steady-state vibration phase analysis on the speed key phase signal and the vibration signal to obtain the change of the vibration phase of each measuring point with the speed; Performing order analysis on the speed key phase signal and the vibration signal to obtain the change of the vibration order of each measuring point with the speed; The fault type and / or excitation source location is determined based on the change of the vibration phase at each measuring point with the rotational speed and the change of the vibration order at each measuring point with the rotational speed.

[0006] The beneficial effects of the present invention are: The present invention performs transient and steady-state vibration phase analysis and order analysis on vibration signals at the air intake casing, intermediate casing and turbine rear casing of the aircraft engine in a rotating state, thereby obtaining the fault type and the location of the excitation source, and the fault judgment accuracy is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0008] Figure 1 This is a curve showing the speed of an engine and a vibration value changing with time. DETAILED DESCRIPTION

[0009] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0010] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0011] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features of the embodiments may be combined with each other.

[0012] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0013] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the invention is usually placed when in use, or the positions or positional relationships commonly understood by those skilled in the art, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0014] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0015] The first aspect of the present invention discloses a method for locating vibration faults of an aircraft engine based on multiple measuring points, including steps S11 to S14. It should be noted that the step identifiers in this scheme are only for the convenience of explaining the method, and do not constitute a limitation on the sequence. The sequence of each step is based on its language description and the sequence of each signal.

[0016] Step S11, obtaining the speed key phase signal of the rotor in the operating state of the aircraft engine and the vibration signal of each measuring point of the aircraft engine, the measuring points include the air intake casing, the intermediate casing, and the turbine rear casing, and the vibration signal includes the axial vibration signal, the radial vibration signal and the circumferential vibration signal.

[0017] Specifically, two measuring points are selected on the air intake casing, intermediate casing, and turbine rear casing of the aircraft engine, and a three-axis vibration sensor is installed to collect axial, radial, and circumferential vibration signals. The two measuring points on the air intake casing, intermediate casing, or turbine rear casing are installed on the same circular measurement section and are distributed at 90 degrees.

[0018] After the three-way vibration sensor is installed, start and run the engine to measure the vibration signal of each measuring point and the rotor speed key phase signal.

[0019] Step S12: Perform transient and steady-state vibration phase analysis on the speed key phase signal and the vibration signal to obtain the change of the vibration phase of each measuring point with the speed.

[0020] Specifically, in view of the situation that the engine speed increases rapidly and the vibration suddenly rises, the complex Simpson function is used to calculate the change of the vibration phase of each measuring point with the speed.

[0021] Step S13: performing order analysis on the speed key phase signal and the vibration signal to obtain the change of the vibration order of each measuring point with the speed.

[0022] Specifically, this step mainly analyzes the variation of the main orders with the rotation speed, wherein the main orders include but are not limited to integer orders of 1, 2, 3, 4 and fractional orders of 1 / 2, 1 / 3, 1 / 4.

[0023] To this end, we can further draw the vibration amplitudes of each main order of the engine, the vibration signal phase, amplitude and speed signal change trend diagram.

[0024] Step S14: determine the fault type and the excitation source location according to the change of the vibration phase of each measuring point with the rotational speed and the change of the vibration order of each measuring point with the rotational speed.

[0025] Specifically, when the fault type is determined: If the vibration change during the process of speed increase or decrease is greater than or equal to 80%, the fault is determined to be over-critical vibration of the rotor; if the phase difference of the vibration signals of two measuring points with a 90-degree distribution on the same circular measuring cross-section is 90°, the fault is determined to be unbalanced vibration of the rotor; if the first-order proportion of the vibration order at the same measuring point is greater than or equal to 40% and the second-order proportion is greater than or equal to 50%, the fault is determined to be rotor misalignment; if the radial vibration phase difference between the measuring points directly below the intake casing and the intermediate casing, the intermediate casing and the turbine rear casing is 180°, the fault is determined to be rotor misalignment.

[0026] For example, Figure 1 The curve of the speed and a certain vibration value of a certain engine changing with time. From the analysis of the figure, it can be seen that the vibration suddenly rises at a certain speed and suddenly drops after the speed, that is, the vibration change during the speed increase or decrease is greater than or equal to 80%, which can be judged as the rotor over-critical vibration. The vibration phase difference of the radial vibration signal at the two measuring points of the intake casing is 90°, which can be judged as the rotor unbalance vibration.

[0027] When the excitation source is determined: the vibration amplitude of each measuring point is converted into vibration displacement or vibration velocity by narrow-band tracking filtering, integration or differentiation of the rotor rotation frequency, and the position of the excitation source is determined by comparing the amplitude of the vibration displacement or vibration velocity.

[0028] Specifically, the low-pressure rotation frequency of the rotor is converted into vibration displacement by narrow-band tracking filtering of the signal of the measuring point of the air intake casing and the intermediate casing. If the vibration displacement of the air intake casing is greater than that of the intermediate casing, the excitation source is in the air intake casing, and the range is further narrowed to the front stage of the fan rotor; if the vibration displacement of the air intake casing is less than that of the intermediate casing, the excitation source is the rear stage of the fan rotor. The low-pressure rotation frequency of the rotor is converted into vibration displacement by narrow-band tracking filtering of the signal of the measuring point of the intermediate casing and the rear casing of the turbine. If the vibration displacement of the rear casing of the turbine is greater than that of the intermediate casing, the excitation source is close to the rear casing of the turbine, and the range is further narrowed to the low-pressure turbine rotor; if the vibration displacement of the rear casing of the turbine is less than that of the intermediate casing, the excitation source is the fan rotor. The low-pressure rotation frequency of the rotor is converted into vibration speed by narrow-band tracking filtering of the measurement point signals of the intermediate casing and the rear casing of the turbine. If the vibration speed of the intermediate casing is greater than the speed of the rear casing of the turbine, the excitation source is close to the intermediate casing, and the range is further narrowed to the high-pressure compressor rotor; if the vibration speed of the intermediate casing is less than the speed of the rear casing of the turbine, the excitation source is close to the rear casing of the turbine, and the range is further narrowed to the high-pressure turbine rotor.

[0029] Those skilled in the art will appreciate that the embodiments described herein are intended to help readers understand the principles of the present invention, and should be understood that the protection scope of the present invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific variations and combinations that do not deviate from the essence of the present invention based on the technical revelations disclosed by the present invention, and these variations and combinations are still within the protection scope of the present invention.

Claims

1. A method for locating vibration faults of an aircraft engine based on multiple measuring points, characterized in that: The following steps are involved: Obtaining the speed key phase signal of the rotor in the running state of the aircraft engine and the vibration signal of each measuring point of the aircraft engine, wherein the measuring points include two measuring points distributed at 90 degrees on a circular measuring section of the air intake casing, the intermediate casing, and the turbine rear casing, and the vibration signal includes an axial vibration signal, a radial vibration signal, and a circumferential vibration signal; Perform transient and steady-state vibration phase analysis on the speed key phase signal and the vibration signal to obtain the change of the vibration phase of each measuring point with the speed; Performing order analysis on the speed key phase signal and the vibration signal to obtain the change of the vibration order of each measuring point with the speed; The fault type and excitation source location are determined based on the change of vibration phase at each measuring point with the rotational speed and the change of vibration order at each measuring point with the rotational speed.

2. The method for locating aero-engine vibration faults based on multiple measuring points according to claim 1, characterized in that: The transient and steady-state vibration phase analysis of the speed key phase signal and the vibration signal comprises: The complex Simpson function is used to calculate the vibration phase change of each measuring point with the rotational speed.

3. The method for locating aero-engine vibration faults based on multiple measuring points according to claim 1, characterized in that: Determining the fault type and the excitation source location according to the change of the vibration phase of each measuring point with the rotation speed and the change of the vibration order of each measuring point with the rotation speed includes: If the vibration change is greater than or equal to 80% during the speed increase or decrease, the fault is determined to be overcritical vibration of the rotor; If the phase difference of the vibration signals of two measuring points with a 90-degree distribution on the same circular measuring cross section is 90°, the fault is determined to be rotor unbalance vibration; If the first order of vibration at the same measuring point accounts for 40% or more and the second order accounts for 50% or more, the fault is judged to be rotor misalignment; If the radial vibration phase difference between the intake casing and the intermediate casing, and between the intermediate casing and the measuring point directly below the turbine rear casing is 180°, the fault is determined to be rotor misalignment.

4. The method for locating aero-engine vibration faults based on multiple measuring points according to claim 1, characterized in that: Determining the fault type and the excitation source location according to the change of the vibration phase of each measuring point with the rotation speed and the change of the vibration order of each measuring point with the rotation speed includes: The vibration amplitude of each measuring point is converted into vibration displacement or vibration velocity by performing narrow-band tracking filtering, integration or differentiation on the rotation frequency of the rotor, and the position of the excitation source is determined by comparing the amplitude of the vibration displacement or vibration velocity.

5. The method for locating aero-engine vibration faults based on multiple measuring points according to claim 1, characterized in that: The vibration amplitude of each measuring point is converted into vibration displacement or vibration velocity by performing narrow-band tracking filtering, integration or differentiation on the rotation frequency of the rotor, and the position of the excitation source is determined by comparing the amplitude of the vibration displacement or vibration velocity, including: The low-pressure rotation frequency of the rotor is converted into vibration displacement by narrow-band tracking filtering of the measuring point signals of the air intake casing and the intermediate casing. If the vibration displacement of the air intake casing is greater than that of the intermediate casing, the excitation source is the front stage of the fan rotor. If the vibration displacement of the air intake casing is less than that of the intermediate casing, the excitation source is the rear stage of the fan rotor. The low-pressure rotation frequency of the rotor is converted into vibration displacement by narrow-band tracking filtering of the measurement point signals of the intermediate casing and the rear casing of the turbine. If the vibration displacement of the rear casing of the turbine is greater than that of the intermediate casing, the excitation source is the low-pressure turbine rotor. If the vibration displacement of the rear casing of the turbine is less than that of the intermediate casing, the excitation source is the fan rotor. The low-pressure rotation frequency of the rotor is converted into vibration speed by narrow-band tracking filtering of the measurement point signals of the intermediate casing and the rear casing of the turbine. If the vibration speed of the intermediate casing is greater than the speed of the rear casing of the turbine, the excitation source is the high-pressure compressor rotor. If the vibration speed of the intermediate casing is less than the speed of the rear casing of the turbine, the excitation source is the high-pressure turbine rotor.

Images