Aeroengine blade maintenance evaluation method and blade

Abstract

The application discloses an aero-engine blade maintenance evaluation method and a blade. The aero-engine blade maintenance evaluation method comprises the following steps: a plurality of wear marks are respectively arranged on each blade in an initial state, and each wear mark corresponds to a different blade tip wear amount; after use, the blades are checked, the blade tip wear interval corresponding to each blade is determined according to the blade tip after wear and the wear mark; the number of blades located in different blade tip wear intervals is counted respectively; and a maintenance plan is determined according to the counting condition of different blade tip wear intervals. The application is not only efficient, convenient, low in cost, wide in application range and high in reliability, but also has no influence on the blade structure and engine efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to an aero-engine blade maintenance evaluation method and a blade. BACKGROUND

[0002] During the operation of an aero-engine, due to the problem of thermal deformation incoordination between the rotor blade and the stator casing, etc., the honeycomb or coating at the corresponding position of the rotor blade tip and the casing often causes rubbing, which in turn easily leads to slight wear of the blade tip. As the number of aero-engine operation cycles increases, the wear of the rotor blade tip caused by rubbing will continuously accumulate, causing the rotor blade tip clearance to become larger, which in turn leads to a decrease in engine operation efficiency, an increase in EGT temperature, a decrease in the service life of high-temperature components of the engine, and an increase in the fuel consumption rate of the aero-engine, which has a great impact on the cost of the aero-engine during operation. Because the wear of the engine rotor blade or the increase in the blade tip clearance is positively correlated with the performance degradation of the engine, the rotor blade wear or the blade tip clearance is usually measured and analyzed to evaluate the performance degradation and health status of the in-service engine during maintenance, so as to determine the maintenance level of the engine, so as to ensure that the operation cost and safety of the engine are maintained within a reasonable range.

[0003] However, as the structure of the aero-engine is designed to be more and more compact and there are thousands of blades in one engine, it is difficult to measure and analyze the wear of the rotor blade or the blade tip clearance of the in-service engine during maintenance, and complex and expensive tooling equipment must be used for measurement, which not only limits the operation environment, but also is time-consuming, labor-intensive and costly. At the same time, the development of the repair scheme for the whole machine or parts of the in-service engine is usually based on the performance degradation state and the structural damage of the engine, and the measurement of the blade tip clearance also limits the rationality and effectiveness of the development of the repair scheme. SUMMARY

[0004] The technical problem to be solved by the present application is to overcome the defects in the prior art that the wear gap of the aero-engine blade must be measured by means of complex and expensive tooling equipment, which not only limits the operation environment, but also is time-consuming, labor-intensive and costly, and to provide an aero-engine blade maintenance evaluation method and a blade.

[0005] The present application solves the above technical problems by the following technical solutions:

[0006] An aero-engine blade maintenance evaluation method, the aero-engine blade maintenance evaluation method comprising:

[0007] Step 1, a plurality of wear marks are respectively provided on each blade in an initial state, and each wear mark corresponds to a different blade tip wear amount;

[0008] Step 2, after the step 1, check the blades, and determine the blade tip wear interval of each blade according to the blade tip and the wear mark of each blade after wear;

[0009] Step 3, count the number of blades in different blade tip wear intervals respectively;

[0010] Step 4, determine the maintenance plan according to the counting of different blade tip wear intervals.

[0011] Preferably, in step 1, the same blade has different distances between each wear mark and the blade tip, and / or the corresponding wear marks on different blades have the same distance from the blade tip of the blade where the wear mark is located.

[0012] Preferably, in step 2, the lower limit of the blade tip wear interval is determined by the closest wear mark that has been worn off or is 0, and the upper limit of the blade tip wear interval is determined by the closest wear mark that has not been worn off.

[0013] Preferably, in step 4, a reference calibration value is set for each blade tip wear interval, and the comparison between the counting value of each blade tip wear interval and the corresponding reference calibration value is used to determine the maintenance plan.

[0014] Preferably, in step 4, the step of determining the maintenance plan based on the comparison between the counting value of each blade tip wear interval and the corresponding reference calibration value includes: setting a corresponding maintenance measure for each comparison, and selecting a final maintenance measure from multiple maintenance measures.

[0015] Preferably, in step 4, the step of selecting a final maintenance measure from multiple maintenance measures includes: setting a priority for each maintenance measure, and selecting the maintenance measure with the highest priority.

[0016] Preferably, the step of setting a priority for each maintenance measure includes determining the priority of each maintenance measure according to the distance between the corresponding blade tip wear interval and the initial state of the blade tip.

[0017] Preferably, the step of setting a corresponding maintenance measure for each comparison between the counting value of each blade tip wear interval and the corresponding reference calibration value includes: setting the corresponding maintenance measure when the counting value of each blade tip wear interval is greater than the corresponding reference calibration value, and / or not setting the corresponding maintenance measure when the counting value of each blade tip wear interval is less than or equal to the corresponding reference calibration value.

[0018] Preferably, a comprehensive impact factor is obtained based on the influence weight of the blade tip clearance on the engine performance decline, operation safety, work reliability and operating cost, and each wear mark is determined according to the comprehensive impact factor.

[0019] Preferably, the wear markings include one or more types of notches or grooves on the blade.

[0020] Preferably, steps 1-4 are performed on each blade of the same stage of the aero-engine. In step 4, a maintenance plan is determined based on the count of different tip wear intervals of all blades in the same stage.

[0021] A blade, the blade comprising a blade body and a plurality of wear marks, each wear mark corresponding to a different amount of blade tip wear, the wear marks being radially arranged notches on the trailing edge of the blade.

[0022] The positive and progressive effects of this invention are as follows: This invention allows for the intuitive and rapid measurement of the wear amount or tip clearance of engine blades, which can be efficiently and quickly completed during routine internal borescope inspections of the engine; it does not require any additional complex and expensive tooling equipment, the evaluation method is simple and does not require complicated operation or employee training, and it is applicable to any engine installation state. This invention is not only efficient, convenient, low-cost, widely applicable, and highly reliable, but it also does not affect the blade structure or engine efficiency. Attached Figure Description

[0023] Figure 1 This is a cross-sectional view of an aircraft engine according to a preferred embodiment of the present invention.

[0024] Figure 2 A schematic diagram of a partial structure of a blade with wear markings according to a preferred embodiment of the present invention.

[0025] Figure 3 A schematic diagram of the blade tip gap without blade tip wear according to a preferred embodiment of the present invention.

[0026] Figure 4 A schematic diagram of the blade tip gap in a preferred embodiment of the present invention, showing partial blade tip wear.

[0027] Figure 5 A schematic diagram of the blade tip gap during further blade tip wear according to a preferred embodiment of the present invention.

[0028] Figure 6 A schematic diagram of the blade tip gap in a preferred embodiment of the present invention, indicating increased blade tip wear.

[0029] Figure 7 A schematic diagram of a partial structure of a blade with wear markings according to a preferred embodiment of the present invention.

[0030] Figure 8 A flowchart of a preferred embodiment of the aircraft engine blade maintenance assessment method of the present invention. Detailed Implementation

[0031] The present invention will be further illustrated by way of embodiments below, but the present invention is not limited to the scope of the embodiments described herein.

[0032] This embodiment presents a method for evaluating the maintenance of aero-engine blades. This method can be applied to an aero-engine such as... Figure 1 As shown, the aero-engine gas turbine 1 is an axial-flow dual or triple-rotor engine mainly composed of a fan section 2, a compressor section 3, a combustion chamber section 4, and a turbine section 5. The minute radial clearances between the compressor rotor blades 6 and the compressor stator casing 7, and between the turbine blades 8 (turbine rotor blades) and the turbine stator casing 9, are referred to as blade tip clearances. Of course, in other embodiments, this aero-engine blade maintenance assessment method can also be used for other aero-engines with blade tip clearances.

[0033] like Figure 8 As shown, the aero-engine blade maintenance assessment method includes:

[0034] Step 1: Pre-set several wear marks on each blade in the initial state, with each wear mark corresponding to a different amount of blade tip wear;

[0035] Step 2: After use, inspect the blades and determine the corresponding blade tip wear range for each blade based on the worn blade tip and wear marks.

[0036] Step 3: Count the number of blades located in different tip wear zones;

[0037] Step 4: Determine the maintenance plan based on the count of different blade tip wear zones.

[0038] In this embodiment, step 1 can be set as follows: Figure 2 and Figure 7 This form. Further examples include... Figure 2 As shown, in one embodiment, three marking notches 310, 320, and 330 are radially machined on the trailing edge 112 near the leading edge tip 151 of the turbine blade 8 as wear marks. The three marking notches 310, 320, and 330 are arranged alternately from top to bottom, and the distance from notch 310 to the blade tip 151 is a; the distance from notch 320 to the blade tip 151 is b; and the distance from notch 330 to the blade tip 151 is c. The different distances to the blade tip can serve as indicators and references for different amounts of blade tip wear.

[0039] Among them, such as Figures 2-6In the diagram, notch 311 represents the worn state of the notch portion, corresponding to the unworn notch 310. Notch 322 represents the worn state of the notch portion, corresponding to the unworn notches 320 and 321. Notch 333 represents the worn state of the notch portion, corresponding to the unworn notches 330, 331, and 332. Specifically... Figure 3 Marking notch 310 and Figure 4 The notch 311 in the text represents the same notch under different wear conditions. Figure 3 Marking notch 320 and Figure 4 Marking gap 321 in Figure 5 The notch 322 in the text represents the same notch under different wear conditions. Figure 3 Marking notch 330 and Figure 4 Marking gap 331 in Figure 5 Marking gap 332 in Figure 6 The notch 333 in the text represents the same notch under different wear conditions.

[0040] This embodiment utilizes radially arranged marking notches 310, 320, and 330 on the trailing edge 112 of the blade as wear markers to measure the tip wear depth. To avoid stress concentration and other defects that could affect blade strength due to machining the marking notches 310, 320, and 330 at the trailing edge 112, in a further embodiment, the marking notches 310, 320, and 330 are designed with smooth curved surfaces. Furthermore, for both the compressor rotor blade 6 and the turbine blade 8, creating small notches on the trailing edge 112 prevents additional incoming gas from leaking from the blade facet 100 to the blade back 110, thus reducing the compressor or turbine's working efficiency. It also avoids the impact of additional structures on the blade's aerodynamic performance.

[0041] In a preferred embodiment, in step 1, the wear marks on the same blade are at different distances from the blade tip, and / or corresponding wear marks on different blades are at the same distance from the blade tip of their respective blades. Specifically, for the same blade, wear marks at different distances are needed to indicate different degrees of wear. However, for all blades, a unified standard is needed to assess the degree of wear. For example, the wear marks closest to the blade tip on each blade are set at the same distance to ensure that each blade is evaluated under the same wear judgment standard.

[0042] In a preferred embodiment, in step 2, the lower limit of the blade tip wear range is determined by the nearest worn-out wear marker or is 0, and the upper limit of the blade tip wear range is determined by the nearest unworn wear marker. Specifically, when no wear marker has been worn away, the value of the blade tip wear range is 0.

[0043] An example of the preferred embodiments described above is as follows: Figure 2 As shown, in this embodiment, since the radial heights of the marking notch 310, marking notch 320 and marking notch 330 decrease sequentially, a correspondence can be established between their radial positions and the size of the engine blade tip clearance.

[0044] For example, such as Figure 3 When a brand new engine leaves the factory, the clearance between the tip 150 of the turbine blade 8 and the inner wall 200 of the casing 9 is A, which is the optimal tip clearance value. The position of the notch 310 can represent the amount of tip wear or the green line value of the tip clearance (less wear), that is, the tip 151 gradually wears down after the engine runs for a certain number of cycles.

[0045] like Figure 4 As shown, when the small notch 310 is worn away, the resulting marked notch 311 is worn away and just becomes invisible, corresponding to a blade tip clearance value of B. The blade tip clearance is between blade tip wear intervals A and B, which is within a reasonable range and has minimal impact on engine performance degradation and health; it is within an acceptable range. The position of the marked notch 320 can represent the amount of blade tip wear or the yellow line value of the blade tip clearance.

[0046] like Figure 5 As shown, when the tip 152 of turbine blade 8 is worn down to the point where the marked notch 322 is barely visible, it indicates a decline in engine performance and a drop in engine health to a warning level. The tip clearance is within the tip wear range B to C, which is of concern. While the engine may operate normally within this range, leading to a slight increase in fuel consumption, the engine remains in a safe and reliable state, requiring only regular routine maintenance. The position of the marked notch 330 can represent the tip wear amount or the red line value of the tip clearance (significant wear).

[0047] like Figure 6As shown, when the tip 153 of turbine blade 8 is worn down to the point where the marked notch 333 is just no longer visible, the tip clearance value D at this point is the maximum tip clearance value that the engine can accept. The tip clearance value between the tip wear range C and D is within the warning range. The increase in tip clearance has already affected the normal operating condition of the engine to a certain extent. There is a certain risk in operating within the engine flight profile. It needs to be closely monitored and major overhaul inspection should be carried out within the specified number of cycles. When the tip clearance value exceeds D, it is defined as a dangerous range. If the tip clearance is too large, the engine will not be able to complete the flight mission normally. It needs to be scrapped and the blades replaced immediately. Otherwise, it may cause greater danger.

[0048] like Figure 7 As shown, in other embodiments, marking notches 310, 320, and 330 can also be formed on the blade tip 150, and the bottom of marking notches 310, 320, and 330 may not be set as a semi-circular transition. The marking method thus achieved can also be used to display the wear condition of the blade tip 150.

[0049] In a preferred embodiment, in step 4, reference calibration values ​​are set for different blade tip wear intervals, and a maintenance plan is determined by comparing the count values ​​of each blade tip wear interval with the corresponding reference calibration values. Specifically, one approach is to target... Figure 2 The figure shows the X values ​​corresponding to the wear intervals A~B, B~C, C~D, and greater than D obtained for each blade. AB X BC X CD and X D Wear intervals smaller than A are not counted. The reference calibration values ​​for these wear intervals can be set as X3, X2, X1, and X0, respectively. The wear interval count is then compared to the corresponding reference calibration value. Some implementations directly compare the wear interval count with the corresponding reference calibration value, while others compare their ratio, etc.

[0050] In a preferred embodiment, step 4, which involves comparing the count values ​​of each blade tip wear interval with the corresponding reference calibration values ​​to determine the maintenance plan, includes: setting corresponding maintenance measures for each blade tip wear interval based on the comparison of the count values ​​with the corresponding reference calibration values, and selecting the final maintenance measure from multiple maintenance measures.

[0051] In a preferred embodiment, the step of prioritizing each maintenance measure includes determining the priority of each maintenance measure based on the distance between the corresponding blade tip wear range and the blade tip in its initial state.

[0052] In a preferred embodiment, the step of setting corresponding maintenance measures based on the comparison between the count value of each blade tip wear interval and the corresponding reference calibration value includes: setting corresponding maintenance measures when the count value of each blade tip wear interval is greater than the corresponding reference calibration value, and / or not setting corresponding maintenance measures when the count value of each blade tip wear interval is less than or equal to the corresponding reference calibration value.

[0053] One approach is to target Figure 2 The wear intervals obtained for each blade are A~B, B~C, and C~D. The corresponding X values ​​are counted respectively. AB X BC X CD and X D With the reference calibration values ​​set to X3, X2, X1, and X0 respectively, the settings are as follows:

[0054] When X D When X > X0, the engine cannot operate normally, and the maintenance measure is to carry out a major overhaul, and the corresponding blades need to be scrapped and replaced; when Xc D When X1 > X1, the engine can still operate normally, but there is a certain risk. The maintenance measure is to perform a major overhaul and blade replacement within a certain number of cycles, but the specific number of cycles can vary depending on the value of X1; when X... BC When x > X2, the engine can operate safely and reliably. Maintenance measures include periodic routine maintenance checks, the specific maintenance cycle of which varies depending on the magnitude of x2. When X AB When the value is >X0, the engine is still in good health and no maintenance is required.

[0055] In a preferred embodiment, step 4, the step of comprehensively selecting a final maintenance measure from multiple maintenance measures, includes: assigning priorities to each maintenance measure, and selecting the maintenance measure with the highest priority among all maintenance measures. Since a larger blade tip clearance value has a greater impact on engine health, the maintenance plan has a higher priority. The maintenance is ordered from highest to lowest absolute priority, for example, in X... AB >X0 or Xc D If X1 is satisfied, then Xc D The maintenance measures for >X1 are of a higher priority, therefore the maintenance measures adopted are to carry out major overhaul inspections and blade replacements within a certain number of cycles, rather than X. AB > The maintenance measures corresponding to X0.

[0056] In a preferred embodiment, a comprehensive influence factor is obtained based on the weights of the impact of tip clearance on the degree of engine performance degradation, operational safety, working reliability and operating costs, and each wear mark is determined based on the comprehensive influence factor.

[0057] In a preferred embodiment, steps 1-4 are performed on each blade of the same stage of the aero-engine. In step 4, a maintenance plan is determined based on the count of different tip wear intervals of all blades in the same stage.

[0058] Without the method of this invention, assessing performance degradation would require processing and analyzing engine operating data and using engine performance models. Furthermore, operational cost and safety analyses also necessitate evaluation using a long-established data model, which is highly specialized, lacks rapid results, and is difficult to implement. This invention, however, provides a direct and rapid measurement of engine blade tip wear or tip clearance, efficiently and quickly performed during routine engine internal borescope inspections. It eliminates the need for any additional complex and expensive tooling, simplifies the assessment method without requiring complex operations or employee training, and is applicable to any engine installation state. It reduces engine maintenance decision-making time by at least 30%, improves the efficiency of engine performance degradation assessment by at least 50%, and significantly enhances engine safety during operation. This invention is not only highly efficient, convenient, low-cost, widely applicable, and highly reliable, but also does not affect blade structure or engine efficiency.

[0059] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. A method for evaluating the maintenance of aero-engine blades, characterized in that, The aforementioned aero-engine blade maintenance assessment method includes: Step 1: Pre-set several wear marks on each blade in the initial state, with each wear mark corresponding to a different amount of blade tip wear; wherein, the wear marks include green line marks, yellow line marks, and red line marks; Step 2: After use, inspect the blades and determine the blade tip wear interval for each blade based on the worn blade tip and wear mark. The blade tip wear interval includes a first interval between the green line mark and the blade tip, a second interval between the green line mark and the yellow line mark, a third interval between the yellow line mark and the red line mark, and a fourth interval beyond the red line mark. Step 3: Count the number of blades in different tip wear intervals within the same blade class; denoted as X for the number of blades in the first interval. AB Let X be the number of leaves located in the second interval. BC Let X be the number of leaves located in the third interval. CD Let X be the number of leaves located in the fourth interval. D ; Step 4: Determine the maintenance plan based on the count of different tip wear zones within the same blade stage; The steps for determining a maintenance plan based on the wear count of different blade tip zones include: Reference calibration values ​​are set for different blade tip wear intervals; wherein, the reference calibration value for the first interval is X3, the reference calibration value for the second interval is X2, the reference calibration value for the third interval is X1, and the reference calibration value for the fourth interval is X0. Based on the comparison between the count value of each blade tip wear zone and the corresponding reference calibration value, corresponding maintenance measures are set; where, when X D When the value is greater than X0, the maintenance measure is to carry out a major overhaul, and the corresponding blades must be scrapped and replaced; when X... CD When X > X1, the maintenance measures are to perform a major overhaul inspection and blade replacement within a certain number of cycles; when X BC When the value is greater than X2, the maintenance measures are to perform routine maintenance and inspections periodically at several intervals; when X... AB When the value is greater than X0, the maintenance measure is to take no maintenance measures.

2. The aero-engine blade maintenance assessment method as described in claim 1, characterized in that, In step 1, the wear marks on the same blade have different distances relative to the blade tip, and / or the corresponding wear marks on different blades have the same distance relative to the blade tip of their respective blades.

3. The aero-engine blade maintenance assessment method as described in claim 1, characterized in that, In step 2, the lower limit of the blade tip wear range is determined by the closest wear mark that has been worn away or is 0, and the upper limit of the blade tip wear range is determined by the closest wear mark that has not been worn away.

4. The aero-engine blade maintenance assessment method as described in claim 1, characterized in that, In step 4, if more than one of the count values ​​is greater than the corresponding reference calibration value, then a final maintenance measure is selected from multiple maintenance measures, including: setting priorities for each maintenance measure and selecting the maintenance measure with the highest priority among all maintenance measures.

5. The aero-engine blade maintenance assessment method as described in claim 4, characterized in that, The steps for prioritizing each maintenance measure include determining the priority of each maintenance measure based on the distance between the corresponding blade tip wear range and the blade tip in its initial state.

6. The aero-engine blade maintenance assessment method as described in claim 1, characterized in that, A comprehensive influence factor is obtained based on the weights of the impact of tip clearance on engine performance degradation, operational safety, working reliability, and operating costs, and each wear mark is determined based on the comprehensive influence factor.

7. The method for evaluating the maintenance of aero-engine blades as described in any one of claims 1-6, characterized in that, Setting several wear marks includes one or more of the following: setting notches or grooves on the blade.

8. A blade, characterized in that, The blade includes a blade body and several wear marks, each wear mark corresponding to a different amount of blade tip wear. The wear marks are radially arranged notches on the trailing edge of the blade, and the blade is maintained using the aero-engine blade maintenance assessment method as described in any one of claims 1-7.

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