A method and apparatus for detecting turbine engine blade clearance and tip damage

Abstract

The application discloses a turbine engine blade gap and tip damage detection method and device, which is used for eddy current monitoring detection of defects of blades (121a, 121b, 121c,..., 121n) of a turbine engine rotor (12) of a turbine engine (1) such as an aviation turbine engine or gaps between the blades (121a, 121b, 121c,..., 121n). A monitoring device (2) is attached to the peripheral surface of a casing (11) of the aviation turbine engine (1) in a circular array. A piece of tip detection data obtained by each sensor in the arrayed eddy current detection sensor is combined and analyzed for comparison, and a monitoring detection method for evaluating defects and hidden dangers existing in the blades is provided. Therefore, defects and abnormalities can be monitored and detected early, and safety hazards of the aviation turbine engine and the like can be prevented in advance.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of non-destructive testing, in particular to a method and device for eddy current monitoring or detection of rotor blades and their gaps, such as in an aero turbine engine, and more particularly to a method and device for detecting turbine engine blade gap and tip damage. BACKGROUND

[0002] The development process and in-service maintenance and repair of an aero engine necessarily involve tip gap measurement. In particular, in-service health management and fault diagnosis, tip gap and blade damage are important monitoring and detection parameters. Although there are many methods for monitoring tip gap, such as X-ray, ultrasonic wave, microwave, capacitance method and eddy current method, from the perspective of engineering practice, the eddy current detection method has good application prospects because it uses the principle of cutting magnetic lines and does not require holes to be opened in the engine casing for installation (i.e. it can penetrate the casing).

[0003] The applicant of the present application has previously applied for and been granted an invention patent "CN108267504B A method for dynamically monitoring the in-situ of ferromagnetic engine casing internal blades", which discloses a technical solution for detecting the gap of the tip of a high-speed rotating blade inside a ferromagnetic casing, and simultaneously obtaining the relative position between the blades, including the signal amplitude weakening caused by tip loss and other faults.

[0004] To address the above problems, the present application uses the following technical solutions for further improvement. SUMMARY

[0005] The present application provides a method and device for detecting turbine engine blade gap and tip damage, and the disclosed technical solution is as follows:

[0006] A method for detecting turbine engine rotor blade gap and tip damage, for monitoring and detecting defects of the blades (121a, 121b, 121c,..., 121n) of a turbine engine rotor (12) of a turbine engine (1), such as an aero turbine engine, or the gap between the blades (121a, 121b, 121c,..., 121n), etc., a monitoring device (2) is attached to the peripheral surface of the casing (11) of the aero turbine engine (1) in a circular array, and the detection data of a piece of tip obtained by each sensor in the arrayed eddy current detection sensor is combined and analyzed for comparison, and a monitoring and detection method for evaluating the defects and hidden dangers of the blades is provided, and the specific steps are as follows:

[0007] a. Actual detection: place the arrayed eddy current detection sensor device on the outer casing of the detected turbine engine rotor blade, and detect each eddy current sensor by operating a multi-channel arrayed eddy current detector, and the eddy current detector acquires the detection signal data of each eddy current detection sensor;

[0008] b. Data analysis: comparative analysis of the signal values detected by different eddy current detection sensors to evaluate the damage and hidden defect conditions of the detected blades.

[0009] For example, the analysis of the voltage signal parameter values, the amplitude of the detection signal curve is used to evaluate the detection signals of different blades. The arrayed eddy current detection sensors are distributed on the casing of the turbine engine, and different sensors detect the detection signals of the turbine engine blades at different positions. In many cases, metal fatigue stress or other damage causes cracks or deformation, which may not necessarily produce large cracks or direct rupture in a short period of time. Elastic deformation or some adhesive cracks of the metal, or loose installation of the blade, are not easy to be detected under normal and static conditions. However, the adhesive deformation of the blade at different positions may be different due to the effect of gravity, such as the cracks at different directions and positions may be aggravated when the blade is vertical, or the loose parts may fall off more obviously, etc. Therefore, the comparison of the signal parameter values of the eddy current detection sensors at different positions can better reflect the differences between the blades under normal conditions and with defects, especially some adhesive defects that are not easy to be detected. The subtle differences can be amplified due to the effect of gravity at different positions, and some defects that cannot be detected by a single sensor at the same position can be detected.

[0010] Further, the comparative analysis of the detection signal values in step b is set to extract the signal values of the turbine engine rotor blades at two different angular positions detected by different eddy current detection sensors of the arrayed eddy current detection sensor. The signal values of the sensors at different angles can be selected for analysis to evaluate the hidden subtle defects of the blade through the range covered by the arrayed eddy current detection sensor.

[0011] Further, the comparative analysis of the signal values of the different position sensors in step b is set to comparative analysis of the signal values of two different eddy current detection sensors when the turbine engine rotor blade is at the upper and lower positions in the vertical direction. Generally, when the turbine engine rotor blade is loose, the gravity acting on the turbine shaft position is completely different when the eddy current blade is at the upper and lower positions in the vertical direction. The blade at the vertical downward position completely bears the pulling force of the blade, while the blade at the vertical upward position completely bears the downward thrust of the blade. The subtle difference between the turbine engine rotor blade and the engine casing can be more clearly shown by comparative analysis of the data detected by two arrayed eddy current detection sensors, and the safety hazard can be easily found in the early stage.

[0012] Further, the detection signal value of the comparative analysis in step b is set as the two detection signal values of the comparative analysis of the horizontal position and the vertical position of the turbine engine rotor blade.

[0013] Generally, when the turbine engine rotor blade produces a cohesive crack, the gravity of the blade in the horizontal and vertical positions is different in the direction angle, the deformation crack is pulled by the gravity of different angles, and the cohesion degree is also different. The two data of the eddy current detection sensor in the two positions are compared and analyzed, and the difference is obviously increased, which is more conducive to detecting the hidden fine cohesive crack of the turbine engine rotor blade. When the blade has a safety hazard, the hidden hazard is eliminated as soon as possible.

[0014] The vertical position can be vertically downward or vertically upward, and the gravity angle direction formed thereby is different, which can be used as a fine difference for comparative analysis to evaluate and determine the hidden stress deformation crack of the turbine engine blade and other defects, and to early check the safety hazards of the aviation turbine engine and other safety hazards. The comparative analysis is easier to realize the clearance fine difference caused by the fine loosening of the blade deformation or the installation device.

[0015] Further, the detection signal value of the comparative analysis in step b is set as the two detection signal values of the comparative analysis of the horizontal position and the vertical position of the turbine engine rotor blade.

[0016] Further, the detection signal value of the comparative analysis in step b is set as the two detection signal values of the comparative analysis of the horizontal position and the vertical position of the turbine engine rotor blade.

[0017] Further, the detection signal value of the comparative analysis in step b is set as the two detection signal values of the comparative analysis of the horizontal position and the vertical position of the turbine engine rotor blade.

[0018] The application also discloses a device for detecting the clearance and tip damage of a turbine engine rotor blade, which is used for detecting the defects of the blade (121a, 121b, 121c,..., 121n) of a turbine engine rotor (12) of an aero turbine engine (1) or the clearance between the blades (121a, 121b, 121c,..., 121n) and the like. A monitoring device (2) is attached to the peripheral surface of the casing (11) of the aero turbine engine (1) in a circular array. The monitoring device (2) comprises a multi-channel eddy current detector (3), a flexible diaphragm (22) and an arrayed eddy current detection sensor (21). The multi-channel eddy current detector (3) is electrically connected to the arrayed eddy current detection sensor (21). The arrayed eddy current detection sensor (21) is arranged on the flexible diaphragm (22). The flexible diaphragm (22) is a long strip-shaped diaphragm structure which is made of a semi-flexible material and can be magnetically attracted to an arc surface. Each sensor unit (211a, 211b, 211c,..., 211n) of the arrayed eddy current detection sensor (21) is uniformly arranged on the flexible diaphragm (22).

[0019] The multi-channel eddy current detector (3) has different eddy current detection channels, which respectively extract the signal values of each sensor unit (211a, 211b, 211c,..., 211n) of the arrayed eddy current detection sensor (21) and perform comparative analysis. That is, each channel of the multi-channel eddy current detector (3) can realize the function of individually extracting the detection signal of a single eddy current detection sensor in the arrayed detection sensor device.

[0020] Further, the flexible diaphragm (22) is a structure which can be elastically stretched to adjust the length and be attached to the surface of the detected object. During the stretching and contraction, the spacing between each sensor unit (211a, 211b, 211c,..., 211n) is uniformly adjusted. By adjusting the size of the spacing between each sensor unit (211a, 211b, 211c,..., 211n), the flexible diaphragm (22) is more suitable for the tip clearance of the turbine engine rotor blade of the aero engine.

[0021] Further, the flexible diaphragm (22) is provided as a plurality of free connection structures. While the spacing between each sensor unit (211a, 211b, 211c,..., 211n) is adjusted, the length of the monitoring device is also adjusted, which is more suitable for the peripheral surface of the turbine engine rotor blade of the aero engine and can calculate more appropriate detection data requirements of the turbine engine rotor blade at different angle positions.

[0022] According to the above technical scheme, the present application has the following beneficial effects: the turbine engine blade gap and tip damage detection method and device improves the original single electromagnetic eddy current sensor, uses an array type eddy current detection sensor, combines and analyzes the detection data of each blade obtained by each sensor, and compares the data, so that the gap change and tip deformation of the aero-engine blade can be more accurately reflected, especially when the tip has a crack and has not yet been damaged (the detection method of the previous single eddy current detection sensor can only detect the tip after the damage), the detection data of each sensor obtained by the array sensor are combined, analyzed and compared in terms of subtle differences in signal amplitude, so that it can be known in advance whether the tip of the blade has a damage crack or the like, or whether the installation of the blade is loose through the subtle change of the blade gap, so that the defect anomaly can be detected early, the safety hidden danger of the aero turbine engine is prevented in advance, and the present application can also be used for detecting other similar mechanical devices with blades. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 The monitoring device usage state schematic diagram of the best embodiment of the present application is shown in the figure;

[0024] Figure 2 The monitoring device usage state schematic diagram of the best embodiment of the present application is shown in the figure;

[0025] Figure 3 The signal analysis schematic diagram of the monitoring device of the best embodiment of the present application is shown in the figure;

[0026] Figure 4 The detection position schematic diagram of the best embodiment of the present application is shown in the figure;

[0027] Figure 5 The detection position schematic diagram of the best embodiment of the present application is shown in the figure;

[0028] Figure 6 The detection position direction schematic diagram of the best embodiment of the present application is shown in the figure;

[0029] Figure 7 The detection position direction schematic diagram of the best embodiment of the present application is shown in the figure;

[0030] Figure 8 The detection position direction schematic diagram of the best embodiment of the present application is shown in the figure;

[0031] Figure 9 The turbine engine rotor blade different position signal analysis schematic diagram of the best embodiment of the present application is shown in the figure;

[0032] Figure 10 The flexible diaphragm stretching structure schematic diagram of the best embodiment of the present application is shown in the figure;

[0033] Figure 11 Figure 1 is a schematic diagram of a flexible membrane multi-connection structure according to a preferred embodiment of the present application. DETAILED DESCRIPTION

[0034] The application will be further described with reference to the drawings and specific embodiments.

[0035] As Figures 1 to 10 shown, a method for detecting the gap and tip damage of a turbine engine rotor blade, for the eddy current monitoring detection of defects of the blades 121a, 121b, 121c, …, 121n of a turbine engine rotor 12 such as an aero turbine engine 1 or the gap between the blades 121a, 121b, 121c, …, 121n, a monitoring device 2 is attached to the peripheral surface of the casing 11 of the aero turbine engine 1 in a circular array, and the tip detection data obtained by each sensor in the arrayed eddy current detection sensor is combined and analyzed for comparison, and the monitoring method for evaluating the defects and hidden dangers existing in the blades is as follows:

[0036] a. Actual detection: Place the arrayed eddy current detection sensor device on the outer shell of the detected turbine engine rotor blade, and detect each eddy current sensor by operating the multi-channel arrayed eddy current detector, and the eddy current detector obtains the detection signal data of each eddy current detection sensor;

[0037] b. Data analysis: Compare and analyze the signal values detected by different eddy current detection sensors to evaluate and determine the defect and hidden danger state of the detected blade.

[0038] As Figure 3 shown, the analysis of the voltage signal parameter value, the amplitude of the detection signal curve is used to evaluate the detection signal of different blades. Each detection sensor of the arrayed eddy current detection sensor is distributed on the outer shell of the turbine engine, and different sensors detect the detection signals of the turbine engine blades at different positions, as shown in the attached Figure 3The subtle difference in the amplitude of the eddy current detection sensor 211a position signal value is evaluated for defects. In many cases, metal cracks or deformation due to fatigue stress or other damage do not necessarily produce large cracks or direct fractures in a short period of time. Elastic deformation or some adhesive cracks of the metal, or loose installation of the blade, are not easily detected under normal and static conditions. However, the adhesive deformation cracks or looseness of the blade at different positions will be different due to the effect of gravity, such as the effect of gravity in different directions, the cracks in the vertical direction will be aggravated, or the loose parts will fall off more obviously, etc. Therefore, by comparing the signal parameter values of the eddy current detection sensors at different positions, the differences between the blade under normal conditions and with defects can be better reflected, especially some adhesive defects that are not easily detected. The subtle difference can be amplified due to the effect of gravity at different positions, and some defects that cannot be easily detected by a single sensor at the same position can be detected.

[0039] As shown in Figure 4 and Figure 5 , the detection signal value of the comparative analysis in step b is set to compare and analyze the signal values detected by different eddy current detection sensors of the arrayed eddy current detection sensor for the turbine engine rotor blade at two different angle directions. The signal values detected by sensors at different angles can be selected for analysis to evaluate the subtle defects hidden in the blade by the range covered by the arrayed eddy current detection sensor.

[0040] As shown in Figure 4 , the signal values of the different position sensors detected in step b of the comparative analysis are set to compare and analyze the signal values detected by two different eddy current detection sensors when the turbine engine rotor blade is in the upper and lower positions in the vertical direction. Generally, when the turbine engine rotor blade is loose, the gravity acting on the turbine shaft position is completely different when the eddy blade is in the upper and lower positions in the vertical direction. The blade in the vertical downward position completely bears the pulling force of the blade, while in the vertical upward position, it completely bears the downward blade thrust force. The subtle difference in the gap between the turbine engine rotor blade and the engine casing can be more clearly displayed by comparing and analyzing the data detected by two arrayed eddy current detection sensors, and safety hazards can be easily detected at an early stage.

[0041] As shown in Figure 5As shown, the comparative analysis in step b involves comparing two detection signal values ​​for the turbine engine rotor blade in the horizontal and vertical directions. When adhesive cracks occur in the turbine engine rotor blade, the gravity acting on the blade in the horizontal and vertical positions differs in direction and angle. The deformation crack is stretched by gravity at different angles, resulting in varying degrees of adhesion. Comparing the two sets of data from the eddy current detection sensors at these two positions significantly increases the difference, making it easier to detect hidden, minute adhesive cracks in the turbine engine rotor blade. This allows for early elimination of potential safety hazards. The vertical position, which can be vertically downward or vertically upward, results in different gravity angles, which can be used for comparative analysis of subtle differences. This helps assess and determine hidden stress deformation cracks and other defects in the turbine engine blade, enabling early detection of safety hazards in aero-turbine engines. Furthermore, comparative analysis makes it easier to detect subtle differences in clearance caused by blade deformation or minor loosening of mounting devices.

[0042] like Figure 6 , Figure 7 and Figure 8 As shown, the detection signal values ​​for comparative analysis in step b are set to extract and compare the signal values ​​detected by different eddy current detection sensors at different positions of the same blade. Using the number of turbine engine blades and the rotor blade speed, the corresponding eddy current detection sensors at different positions of the blade are calculated. The array-type eddy current detection sensors extract the detection data of the same blade at corresponding positions for different channels, and comparative analysis is performed to evaluate subtle defects, enabling targeted analysis of subtle defects on the same blade.

[0043] like Figure 6 As shown, the comparative analysis of the detection signal values ​​in step b is set as follows: the signal values ​​detected by two different eddy current detection sensors are compared and analyzed when the same turbine engine rotor blade 121a is in the upper and lower positions in the vertical direction. By specifically analyzing the subtle differences between the two detection signals of the same blade 121a in the two vertical directions, the minute defects of deformation gaps caused by loose installation or fatigue stress of the same blade 121a can be more accurately assessed and analyzed. This allows for the early detection of safety problems in aero-turbine engines and other applications, enabling the early elimination of potential safety hazards. And as... Figure 3 As shown, defects are assessed and determined by subtle signal differences within the same blade 121a. And as... Figure 9 As shown, the detection signals of the same blade 121a at different positions are different from those of different detection sensors 211a and 211n. The detection signal at the detection sensor 211n, which is located vertically above the blade, may be normal, while the detection signal at the detection sensor 211a, which is located vertically below the blade, is a detection signal with slight differences.

[0044] As shown in Figure 7 and Figure 8 , the detection signal value of the comparative analysis in step b is set to compare and analyze the signal values detected by two different eddy current detection sensors in the horizontal direction position and the vertical position direction of the same blade 121a. The targeted analysis and evaluation determines the hidden stress deformation cracks and other defects of the same blade 121a of the turbine engine, and the safety hazards of the aviation turbine engine are checked as soon as possible. And as shown in Figure 3 , the hidden defects are evaluated and analyzed by the subtle signal difference of the same blade 121a. It can be vertically downward or vertically upward, as shown in Figure 7 , the detection signal comparison of the vertically upward position and the horizontal direction position, and as shown in Figure 8 , the detection signal comparison of the vertically downward position and the horizontal direction position. Similarly, as shown in Figure 9 , the same blade 121a has a difference in the detection signal of the different detection sensors 211a and 211n at different positions. The detection signal of the detection sensor 211n, that is, the vertical position of the blade, may be normal, and the detection signal of the detection sensor 211a, that is, the horizontal transverse direction of the blade, is a detection signal with a subtle difference. Through comparative analysis, the hidden defects are evaluated.

[0045] As shown in Figure 1 , Figure 2 , Figure 10 and Figure 11As shown, the present application also discloses a turbine engine rotor blade gap and tip damage detection device for eddy current monitoring detection of defects of the blades 121a, 121b, 121c,..., 121n of a turbine engine rotor 12 of an aircraft turbine engine 1 or gaps between the blades 121a, 121b, 121c,..., 121n, etc. The monitoring device 2 is attached to the peripheral surface of the casing 11 of the aircraft turbine engine 1 in a circular array fit, and comprises a multi-channel eddy current detector 3, a flexible diaphragm 22 and an arrayed eddy current detection sensor 21. The multi-channel eddy current detector 3 is electrically connected to the arrayed eddy current detection sensor 21, the arrayed eddy current detection sensor 21 is arranged on the flexible diaphragm 22, the flexible diaphragm 22 is a long strip-shaped diaphragm structure made of a semi-flexible material and can be magnetically attracted to fit an arc surface, and each sensor unit 211a, 211b, 211c,..., 211n of the arrayed eddy current detection sensor 21 is uniformly arranged on the flexible diaphragm 22. The multi-channel eddy current detector 3 has different eddy current detection channels, respectively extracts the signal values of each sensor unit 211a, 211b, 211c,..., 211n of the arrayed eddy current detection sensor 21, and performs comparative analysis. That is, each channel of the multi-channel eddy current detector 3 can realize the function of individually extracting the detection signal of a single eddy current detection sensor in the arrayed detection sensor device.

[0046] As shown in the drawings, Figure 10 The flexible diaphragm 22 is a structure that can be elastically stretched to adjust the length to fit the surface of the object to be detected, and in the process of stretching and contracting, the spacing between each sensor unit 211a, 211b, 211c,..., 211n is uniformly adjusted. By adjusting the size of the spacing between each sensor unit 211a, 211b, 211c,..., 211n, it is more suitable for the tip gap of the turbine engine rotor blade of the aircraft engine.

[0047] As shown in the drawings, Figure 11 The flexible diaphragm 22 is arranged as a plurality of free connection structures. While achieving the spacing between each sensor unit 211a, 211b, 211c,..., 211n, the length of the monitoring device is adjusted, which is more suitable for the peripheral surface of the turbine engine rotor blade of the aircraft engine, and the detection data requirements of the turbine engine rotor blade at different angle positions are more appropriate.

[0048] The above is one embodiment of the present application. In addition, it should be noted that any equivalent or simple changes made in accordance with the structure, features and principles described in the present patent concept are included in the protection scope of the present patent.

Claims

1. A method for detecting blade clearance and tip damage in a turbine engine rotor, characterized in that... A monitoring and detection method for assessing blade defects and potential hazards is employed, which combines, analyzes, and compares data obtained from individual sensor units in an array-type eddy current detection sensor. The specific steps are as follows: a. Actual testing: The array-type eddy current detection sensor is placed on the outer shell of the rotor blade of the turbine engine under test. Each sensor unit is operated by a multi-channel eddy current detector to detect the signal data of each sensor unit. b. Data analysis: Compare and analyze the signal values ​​detected by different sensor units to assess and determine the defects and potential hazards of the detected blades; Among them, the signal values ​​detected by different sensor units are compared and analyzed. The method is to extract the signal values ​​detected by different sensor units of the array-type eddy current detection sensor from two turbine engine rotor blades at two different angular positions and compare and analyze them. Alternatively, it can be configured to extract and compare signal values ​​detected by different sensor units at different positions of the same turbine engine rotor blade.

2. The method for detecting turbine engine rotor blade clearance and tip damage according to claim 1, characterized in that... The comparative analysis in step b, which compares the detected signal values ​​at two different angular positions, is set as a comparative analysis of the signal values ​​detected by two different sensor units when the turbine engine rotor blades are at the upper and lower positions in the vertical direction.

3. The method for detecting turbine engine rotor blade clearance and tip damage according to claim 1, characterized in that... The comparative analysis in step b, which compares the detected signal values ​​at two different angular positions, is set as a comparative analysis of the signal values ​​detected by two different sensor units when the turbine engine rotor blades are in horizontal and vertical positions.

4. The method for detecting turbine engine rotor blade clearance and tip damage according to claim 1, characterized in that... The detection signal value for comparative analysis in step b is set as the signal value detected by two different sensor units when the rotor blade of the same turbine engine is at the upper and lower positions in the vertical direction.

5. The method for detecting turbine engine rotor blade clearance and tip damage according to claim 1, characterized in that... The detection signal value for comparative analysis in step b is set as the signal value detected by two different sensor units when the rotor blade of the same turbine engine is in the horizontal and vertical positions, and then compared and analyzed.

6. A detection device for turbine engine rotor blade clearance and tip damage, comprising a multi-channel eddy current detector (3), a flexible diaphragm (22), and an array-type eddy current sensor (21), wherein the multi-channel eddy current detector (3) is electrically connected to the array-type eddy current sensor (21), and the array-type eddy current sensor (21) is disposed on the flexible diaphragm (22), characterized in that... The flexible diaphragm (22) is a long strip diaphragm structure made of semi-flexible material that can be magnetically attracted to conform to the arc surface. The sensor units (211a, 211b, 211c, ..., 211n) of the array eddy current detection sensor (21) are uniformly arranged and attached to the flexible diaphragm (22). The multi-channel eddy current detector (3) has different eddy current detection channels, and extracts the signal values ​​of each sensor unit (211a, 211b, 211c, ..., 211n) of the array-type eddy current detection sensor (21) for comparative analysis.

7. The device for detecting turbine engine rotor blade clearance and tip damage according to claim 6, characterized in that... The flexible diaphragm (22) is a structure that can be elastically stretched and adjusted to fit the surface of the object being tested. During the stretching and shrinking process, the spacing between each sensor unit (211a, 211b, 211c, ..., 211n) is adjusted evenly.

8. The device for detecting turbine engine rotor blade clearance and tip damage according to claim 7, characterized in that... The flexible diaphragm (22) is configured as multiple freely connected structures.

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