A blade frequency modulation method

Abstract

The present invention discloses a blade frequency modulation method. When the blade has a frequency modulation demand, especially when the frequency modulation demand is urgent and there is no time to modify the blade profile, the frequency modulation method can be used to achieve directional frequency modulation, including the following steps: a tenon and tenon groove initial mating surface parameter acquisition step: acquiring the tenon and tenon groove initial mating surface parameters, recorded as initial mating surface parameters; a modal analysis step: performing modal analysis on the blade to be frequency modulated in the tenon and tenon groove initial mating surface parameter acquisition step, and obtaining the modal analysis result; a frequency adjustment amount confirmation step: confirming the frequency adjustment amount of the blade to be frequency modulated according to the modal analysis step; a mating surface parameter adjustment step: adjusting the parameters of the initial mating surface according to the frequency adjustment amount in the frequency adjustment amount confirmation step to form first mating surface parameters; an output step: outputting the adjusted first mating surface parameters.

Description

Technical Field

[0001] The present invention relates to the field of heavy-duty gas engine compressor structure design, and in particular to a blade frequency modulation method. Background Art

[0002] The compressor blades of a heavy-duty gas turbine are connected to the outer edge of the disc through the blade root. When blade frequency adjustment is required, traditional methods often involve adjusting the blade profile and adding damping bosses. This is achieved by varying design parameters such as blade thickness and chord length, or by adding damping bosses to the flow path or blade surface to meet frequency requirements.

[0003] Prior art CN108757508A discloses a guide vane with a damping boss. The damping boss in the middle of the guide vane is connected to the blade after assembly to form a ring, constraining each other, increasing rigidity, and modifying the blade's natural frequency. However, the damping boss is located within the blade channel, which affects aerodynamic performance, requires aerodynamic CFD verification, and increases frequency modulation time. It also poses strength issues, increases manufacturing complexity, and increases the risk of structural failure.

[0004] In view of the above technical problems, the present invention is specially introduced. Summary of the Invention

[0005] The main purpose of the present invention is to provide a blade frequency modulation method to solve the problem of difficulty in blade frequency adjustment.

[0006] In order to achieve the above object, the present invention provides a blade frequency modulation method, comprising the following steps:

[0007] The step of obtaining the initial fitting surface parameters of the tenon and mortise: obtaining the initial fitting surface parameters of the tenon and mortise, which are recorded as the initial fitting surface parameters; the step of modal analysis: performing modal analysis on the blade to be frequency modulated in the step of obtaining the initial fitting surface parameters of the tenon and mortise, and obtaining the modal analysis results; the step of confirming the frequency adjustment amount: confirming the frequency adjustment amount of the blade to be frequency modulated according to the modal analysis step; the step of adjusting the fitting surface parameters: adjusting the parameters of the initial fitting surface according to the frequency adjustment amount in the step of confirming the frequency adjustment amount to form the first fitting surface parameters; the step of outputting the adjusted first fitting surface parameters. The blade frequency modulation method of the present invention does not change the line shape of the blade itself, but adjusts the blade frequency by adjusting the matching relationship between the blade and the wheel. When the blade has a frequency modulation requirement, especially when the frequency modulation requirement is more urgent, directional frequency modulation can be achieved by the circumferential blade profile frequency modulation method of the present invention.

[0008] The following is a further optimization of the above scheme by the present invention:

[0009] Furthermore, the step of obtaining the initial fitting surface parameters of the tenon and the tenon groove is a step of measuring the initial fitting surface parameters of the tenon and the tenon groove. For the blade to be frequency modulated, the parameters of the initial fitting surface of the tenon and the tenon groove are measured.

[0010] Furthermore, the step of obtaining the initial fitting surface parameters of the tenon and tenon groove is the step of preliminary designing the tenon and tenon groove profile lines. The preliminary design step of the tenon and tenon groove profile lines preliminarily designs the profile lines of the tenon and the tenon groove. The tenon profile lines and the tenon groove profile lines form an initial fitting surface to obtain the initial fitting surface parameters.

[0011] Furthermore, the frequency modulation method also includes a frequency calibration step, which calibrates whether the frequency meets the calibration requirements after the matching surface parameter adjustment step.

[0012] Furthermore, if the frequency does not meet the calibration requirements in the frequency calibration step, the process returns to the frequency adjustment amount confirmation step, and the output step is performed after the calibration frequency meets the calibration requirements.

[0013] Furthermore, the initial mating surface includes the bearing surface mating surface and / or the inlet and outlet groove mating surface, and the initial mating surface parameters include the mating length of the tenon and the tenon groove and / or the mating clearance of the tenon and the tenon groove. Accurate frequency modulation requirements can be achieved by controlling the mating length of the tenon and the tenon groove and / or the mating clearance.

[0014] Furthermore, the fitting length includes the horizontal fitting length of the tenon and the mortise in the circumferential direction, and the vertical fitting length of the tenon and the mortise in the radial direction; the fitting clearance includes the horizontal clearance between the tenon and the mortise in the circumferential direction, and the vertical clearance between the tenon and the mortise in the radial direction.

[0015] Furthermore, the horizontal fitting length includes a first horizontal fitting length, a second horizontal fitting length, and a third horizontal fitting length, wherein the first horizontal fitting length is the horizontal fitting length on one side of the bearing surface mating surface, the second horizontal fitting length is the horizontal fitting length on the other side of the bearing surface mating surface, and the third horizontal fitting length is the horizontal fitting length of the inlet and outlet groove mating surfaces.

[0016] Furthermore, the horizontal gap includes a first horizontal gap, a second horizontal gap, a third horizontal gap, and a fourth horizontal gap. The first horizontal gap is the horizontal gap on one side of the inlet and outlet groove mating surface, the second horizontal gap is the horizontal gap on the other side of the inlet and outlet groove mating surface, the third horizontal gap is the horizontal gap of the load-bearing surface mating surface close to the bottom of the blade, and the fourth horizontal gap is the horizontal gap of the load-bearing surface mating surface away from the bottom of the blade; the vertical gap includes a first vertical gap, a second vertical gap, and a third vertical gap. The first vertical gap is the vertical gap on one side of the inlet and outlet groove mating surface, the second vertical gap is the vertical gap on the other side of the inlet and outlet groove mating surface, and the third vertical gap is the vertical gap of the load-bearing surface mating surface.

[0017] Furthermore, in the modal analysis step, finite element analysis is used for modal analysis.

[0018] Furthermore, the modal analysis results include the multi-order intrinsic frequencies of the blade and the corresponding vibration shapes.

[0019] Furthermore, the modal analysis results are presented using campell diagrams.

[0020] Furthermore, the blade requiring frequency modulation has an avoidance rate, and the avoidance rate is a frequency range value that the blade requiring frequency modulation needs to avoid. The frequency adjustment amount confirmation step verifies whether the frequency of the present certificate falls within the avoidance rate.

[0021] Furthermore, the frequency adjustment amount includes any one or more of the frequency order, frequency value, and vibration mode.

[0022] Furthermore, in the mating surface parameter adjustment step, one or more parameters of the horizontal fitting length, the vertical fitting length, the horizontal gap, and the vertical gap are adjusted to form the first mating surface parameters.

[0023] Based on the above technical solution, the present invention has at least the following beneficial effects:

[0024] 1. The blade root tenon and mortise frequency tuning method of the present invention can meet the blade frequency tuning requirements by adjusting the tenon and mortise contact size and matching clearance;

[0025] 2. Since the contact surface position, area and clearance of the tenon and mortise are positively correlated with the frequency, the frequency modulation requirement can be accurately achieved by controlling the contact surface position, area and clearance of the tenon and mortise;

[0026] 3. When the blades need frequency modulation, they can be adjusted quickly without the need for multiple rounds of iterations with the aerodynamic design, thus reducing the manpower and material resources required for frequency modulation;

[0027] 4. There is no need to conduct strength verification again, which reduces the manpower and material resources required for strength verification;

[0028] 5. It does not affect the installation of circumferential blades and can ensure the preset assembly tolerance and blade root profile. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings, which constitute part of the present invention, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0030] Figure 1 is a schematic diagram of the tenon and mortise fit; and

[0031] Figure 2 is a frequency adjustment flow chart; and

[0032] Figure 3 is a diagram of the initial mating surface fit lengths of the tenon and mortise; and

[0033] Figure 4 is the initial mating surface clearance diagram; and

[0034] Figure 5 is the adjusted first mating surface mating length diagram; and

[0035] Figure 6 is the adjusted first mating surface fit clearance diagram; and

[0036] Figure 7 is to adjust the Campbell diagram of the front blade; and

[0037] Figure 8 is the adjusted leaf Campbell diagram.

[0038] The above drawings include the following reference numerals:

[0039] 1. Tenon; 2. Mortise; 3. Bearing surface and mating surface; 4. Inlet and outlet groove mating surface;

[0040] X1, first horizontal fitting length; X2, second horizontal fitting length; Z, third horizontal fitting length; Y, vertical fitting length;

[0041] A, first vertical gap; B, second vertical gap; F, third vertical gap; D, first horizontal gap; E, second horizontal gap; C, third horizontal gap; G, fourth horizontal gap. DETAILED DESCRIPTION

[0042] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0043] The present invention is further described in detail below with reference to specific embodiments. These embodiments are not to be construed as limiting the scope of protection claimed in the present invention. It should be noted that, in the description of the present invention, unless otherwise specified, "a plurality" means two or more; the steps of the present invention are not limited to the order listed, and the order of the steps can be adjusted as needed.

[0044] Gas turbine blades may require frequency modulation. When this is necessary, especially when the need is urgent and there is no time to modify the blade profile, a circumferential blade profile modulation method can be used to achieve directional frequency modulation.

[0045] The blade frequency modulation method of the present invention does not change the linear shape of the blade itself, but adjusts the blade frequency by adjusting the matching relationship between the blade and the wheel. Specifically, the frequency modulation function is achieved by changing the contact surface position, area size and matching gap size of the blade tenon 1 and the wheel tenon groove 2, thereby achieving the effect of directional frequency modulation. Changing the contact surface position, area size and matching gap size of the blade tenon 1 and the wheel tenon groove 2 is actually achieved by adjusting the matching surface of the tenon 1 and the wheel tenon groove 2. This frequency modulation method is as follows Figure 1 As shown, the following steps are included:

[0046] 1) Step of obtaining parameters of the initial fitting surface of the tenon and the mortise: obtaining the parameters of the initial fitting surface of the tenon and the mortise, which are recorded as initial fitting surface parameters;

[0047] 2) Modal analysis step: performing modal analysis on the blade to be frequency modulated in the step of obtaining parameters of the initial tenon and mortise mating surface, and obtaining modal analysis results;

[0048] 3) Frequency adjustment amount confirmation step: confirm the frequency adjustment amount of the blade to be frequency-modulated according to the modal analysis step;

[0049] 4) a mating surface parameter adjustment step: adjusting the parameters of the initial mating surface according to the frequency adjustment amount in the frequency adjustment amount confirmation step to form first mating surface parameters;

[0050] 5) Output step: output the adjusted first mating surface parameters, and use the first mating surface parameters to complete the adjustment of the tenon and mortise mating surface mating dimensions and mating clearance.

[0051] This frequency modulation method adjusts the mortise and tenon dimensions and clearances to meet the blade's frequency modulation requirements. Because it doesn't require changes to the blade's linear shape, it meets both frequency modulation requirements and blade strength requirements. Furthermore, this method allows for rapid frequency modulation, eliminating the need for multiple iterations of aerodynamic design, reducing the manpower and resources required for frequency modulation.

[0052] The frequency modulation method can solve the resonance problem of the gas turbine that has been put into operation, and can also improve the linear design efficiency of the gas turbine blade tenon 1 and the wheel tenon 2 in the new design stage.

[0053] For a gas turbine that has been put into operation, the step of obtaining the initial fitting surface parameters of the tenon and the tenon groove is the step of measuring the initial fitting surface parameters of the tenon 1 and the tenon groove 2. For blades that need frequency modulation, the parameters of the initial fitting surface of the tenon 1 and the tenon groove 2 are measured.

[0054] For gas turbines in the new design phase, the initial tenon and groove mating surface parameters are obtained through the preliminary tenon and groove profile design step. This involves initially designing the profiles of tenon 1 and tenon 2. The tenon 1 and tenon 2 profiles form an initial mating surface, resulting in the initial mating surface parameters. During the design phase, the aforementioned frequency modulation method is used to select different tenon 1 and tenon 2 profiles from the blade tenon 1 and tenon 2 profile libraries. The frequency value is then adjusted upward or downward based on the frequency adjustment amount. The tenon and tenon groove contact surface position, area, and mating clearance are then selected based on the frequency modulation amplitude to obtain the initial mating surface parameters.

[0055] The initial mating surface includes the load-bearing mating surface 3 and / or the inlet and outlet groove mating surface 4. The initial mating surface parameters include the mating length and / or the mating clearance between the tenon 1 and the tenon groove 2. The mating length includes the horizontal mating length of the tenon 1 and the tenon groove 2 in the circumferential direction and the vertical mating length Y of the tenon 1 and the tenon groove 2 in the radial direction. The mating clearance includes the horizontal clearance between the tenon 1 and the tenon groove 2 in the circumferential direction and the vertical clearance between the tenon 1 and the tenon groove 2 in the radial direction.

[0056] The horizontal fitting length includes a first horizontal fitting length X1, a second horizontal fitting length X2, and a third horizontal fitting length Z, wherein the first horizontal fitting length X1 is the horizontal fitting length on one side of the load-bearing surface mating surface 3, the second horizontal fitting length X2 is the horizontal fitting length on the other side of the load-bearing surface mating surface 3, and the third horizontal fitting length Z is the horizontal fitting length of the inlet and outlet groove mating surface 4.

[0057] The horizontal gap includes a first horizontal gap D, a second horizontal gap E, a third horizontal gap C, and a fourth horizontal gap G. The first horizontal gap D is the horizontal gap on one side of the inlet and outlet groove mating surface 4, the second horizontal gap E is the horizontal gap on the other side of the inlet and outlet groove mating surface 4, the third horizontal gap C is the horizontal gap of the load-bearing surface mating surface 3 close to the bottom of the blade, and the fourth horizontal gap G is the horizontal gap of the load-bearing surface mating surface 3 away from the bottom of the blade; the vertical gap includes a first vertical gap A, a second vertical gap B, and a third vertical gap F. The first vertical gap A is the vertical gap on one side of the inlet and outlet groove mating surface 4, the second vertical gap B is the vertical gap on the other side of the inlet and outlet groove mating surface 4, and the third vertical gap F is the vertical gap of the load-bearing surface mating surface 3.

[0058] After measuring the existing tenon and mortise profile parameters or completing the preliminary design of the tenon and mortise profile, the modal analysis step is performed. In the modal analysis step, finite element analysis is performed. Manual settings are required to obtain the modal analysis results. The modal analysis results include the multi-order intrinsic frequencies and corresponding vibration modes of the blade. The analysis results are displayed using a campell diagram, such as Figure 6 shown. Figure 6The horizontal axis is the rotation frequency of the fuel turbine, and the shaded area is the ideal rotation speed of the fuel turbine. The vertical axis is the frequency, including the 5-order intrinsic frequency, arranged from low to high; it also includes the excitation source frequency, Figure 6 The medium excitation source frequency is a slanted line starting from the origin. The excitation source frequency is the frequency of the entire gas turbine. For a fixed gas turbine, the excitation source frequency is basically fixed.

[0059] The blades that need frequency modulation have an avoidance rate, and the avoidance rate is the frequency range value that the blades that need frequency modulation need to avoid. Figure 6 When the frequency of the intermediate excitation source intersects with the third and fourth order (mode 3 and mode 4) intrinsic frequencies within the ideal speed range, resonance can occur. To avoid resonance, the blade frequency must be adjusted so that the blade's mode 3 and mode 4 intrinsic frequencies avoid the excitation source frequency near the gas turbine's operating speed. This frequency avoidance value is the blade avoidance rate.

[0060] During the frequency adjustment confirmation step, it is necessary to verify whether the blade's true frequency falls within the blade avoidance ratio. Specifically, after comparing the modal analysis results with the blade avoidance ratio, the frequency adjustment for each mode is determined. The frequency adjustment includes any one or more of the frequency order, frequency value, and corresponding vibration mode. When determining the frequency adjustment, it is necessary to ensure that the true frequency and the excitation source frequency do not intersect within the ideal speed range, thereby ensuring the avoidance ratio of the frequency-modulated blade.

[0061] After determining the frequency adjustment amount, the frequency modulation order, frequency adjustment amount and corresponding vibration mode are proposed, and the position of the tenon and mortise fitting surface, the size of the fitting surface area and the size of the fitting clearance are selected according to the above adjustment amounts. Among them, the position of the tenon and mortise fitting surface and the size of the fitting surface area are reflected in the fitting length of the tenon and mortise. Figure 2 As shown, the fitting length of the tenon and the mortise includes a first horizontal fitting length X1, a second horizontal fitting length X2, a third horizontal fitting length Z, and a vertical fitting length Y; the fitting clearance of the tenon and the mortise includes a first horizontal clearance D, a second horizontal clearance E, a third horizontal clearance C, a fourth horizontal clearance G, a first vertical clearance A, a second vertical clearance B, and a third vertical clearance F. The fitting surface parameter adjustment step adjusts the fitting length parameters of the tenon 1 and the mortise 2, and the fitting clearance parameters of the tenon 1 and the mortise 2, wherein, Figure 2-Figure 3 The length of the tenon 1 and the tenon groove 2 before adjustment, and the clearance of the tenon 1 and the tenon groove 2 before adjustment; Figure 4-Figure 5 It is the fitting length of the tenon 1 and the tenon groove 2 and the fitting clearance of the tenon 1 and the tenon groove 2 after adjustment.

[0062] After determining the contact surface and fit clearance of the tenon and mortise according to the design requirements, the fit length parameter and fit clearance parameter are adjusted. In the fit surface parameter adjustment step, one or more parameters of the horizontal fit length, vertical fit length Y, horizontal gap, and vertical gap are adjusted to form the first fit surface parameter, such as Figure 4-Figure 5 As shown in the figure, the adjusted first mating surface parameters show significant differences in the tenon-mortise contact area and clearance compared to the initial parameters before adjustment. Because the position, area, and clearance of the tenon-mortise contact surface are positively correlated with frequency, frequency modulation requirements can be accurately achieved by controlling the position, area, and clearance of the tenon-mortise contact surface.

[0063] The frequency modulation method also includes a frequency calibration step. After the matching surface parameter adjustment step, the frequency is calibrated to see whether it meets the calibration requirements. If it does not meet the calibration requirements, it will be continuously iterated according to the calibration results until the frequency calibration requirements are met. Figure 7 This is a Campbell diagram of the blade after adjusting the mating surface. It can be seen that after adjusting the mating surface parameters, the blade's fourth-order intrinsic frequency, or mode 4, is significantly reduced, avoiding intersection with the excitation source frequency within the ideal speed range, thus meeting the frequency adjustment requirements. The frequency adjustment method of the present invention is simple and easy to operate. It eliminates the need for re-strength verification, reducing the manpower and material resources required for strength verification. It does not affect the installation of circumferential blades, and can ensure the preset assembly tolerances and blade root profile. Furthermore, during the adjustment process, the radial contact area is not reduced, the stress on the radial contact surface of the blade root is not increased, and the strength verification time is not increased.

[0064] If the frequency does not meet the calibration requirements during the frequency calibration step, the process returns to the frequency adjustment confirmation step. The calibration results are iterated until the calibration frequency meets the calibration requirements. Once the calibration frequency meets the requirements, the output step is performed.

[0065] In summary, from the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0066] 1. The blade root tenon and mortise frequency tuning method of the present invention can meet the blade frequency tuning requirements by adjusting the tenon and mortise contact size and matching clearance;

[0067] 2. Since the contact surface position, area and clearance of the tenon and mortise are positively correlated with the frequency, the frequency modulation requirement can be accurately achieved by controlling the contact surface position, area and clearance of the tenon and mortise;

[0068] 3. When the blades need frequency modulation, they can be adjusted quickly without the need for multiple rounds of iterations with the aerodynamic design, thus reducing the manpower and material resources required for frequency modulation;

[0069] 4. There is no need to conduct strength verification again, which reduces the manpower and material resources required for strength verification;

[0070] 5. It does not affect the installation of circumferential blades and can ensure the preset assembly tolerance and blade root profile.

[0071] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A blade frequency modulation method, characterized in that: The following steps are involved: The step of obtaining parameters of the initial fitting surface of the tenon and the tenon groove is as follows: obtaining the parameters of the initial fitting surface of the tenon and the tenon groove, which are recorded as initial fitting surface parameters; Modal analysis step: performing modal analysis on the blade to be frequency modulated in the step of obtaining parameters of the initial mating surface of the tenon and mortise, and obtaining modal analysis results; Frequency adjustment amount confirmation step: confirming the frequency adjustment amount of the blade to be frequency-modulated according to the modal analysis step; A mating surface parameter adjustment step: adjusting the parameters of the initial mating surface according to the frequency adjustment amount in the frequency adjustment amount confirmation step to form first mating surface parameters; Output step: output the adjusted first mating surface parameters.

2. The frequency modulation method according to claim 1, wherein: The step of obtaining the parameters of the initial fitting surface of the tenon and the tenon groove is a step of measuring the parameters of the initial fitting surface of the tenon (1) and the tenon groove (2). For the blade to be frequency modulated, the parameters of the initial fitting surface of the tenon (1) and the tenon groove (2) are measured.

3. The frequency modulation method according to claim 1, wherein: The step of obtaining the parameters of the initial fitting surface of the tenon and the tenon groove is a step of preliminary designing the profile of the tenon and the tenon groove. The preliminary designing step of the tenon and the tenon groove profile preliminarily designs the profile of the tenon (1) and the profile of the tenon groove (2). The profile of the tenon (1) and the profile of the tenon groove (2) form the initial fitting surface, and the initial fitting surface parameters are obtained.

4. The frequency modulation method according to claim 1, wherein: The frequency modulation method further includes a frequency calibration step, which is to calibrate whether the frequency meets the calibration requirements after the mating surface parameter adjustment step.

5. The frequency modulation method according to claim 4, characterized in that: If the frequency does not meet the calibration requirement in the frequency calibration step, the process returns to the frequency adjustment amount confirmation step, and the output step is performed after the calibration frequency meets the calibration requirement.

6. The frequency modulation method according to claim 5, characterized in that: The initial fitting surface includes a load-bearing fitting surface (3) and / or an inlet and outlet groove fitting surface (4), and the initial fitting surface parameters include a fitting length between the tenon (1) and the tenon groove (2) and / or a fitting clearance between the tenon (1) and the tenon groove (2).

7. The frequency modulation method according to claim 6, characterized in that: The fitting length includes the horizontal fitting length of the tenon (1) and the tenon groove (2) in the circumferential direction, and the vertical fitting length of the tenon (1) and the tenon groove (2) in the radial direction; the fitting clearance includes the horizontal clearance between the tenon (1) and the tenon groove (2) in the circumferential direction, and the vertical clearance between the tenon (1) and the tenon groove (2) in the radial direction.

8. The frequency modulation method according to claim 7, characterized in that: The horizontal fitting length includes a first horizontal fitting length, a second horizontal fitting length, and a third horizontal fitting length, wherein the first horizontal fitting length is the horizontal fitting length on one side of the bearing surface matching surface (3), the second horizontal fitting length is the horizontal fitting length on the other side of the bearing surface matching surface (3), and the third horizontal fitting length is the horizontal fitting length of the inlet and outlet groove matching surface (4).

9. The frequency modulation method according to claim 7, characterized in that: The horizontal gap includes a first horizontal gap, a second horizontal gap, a third horizontal gap, and a fourth horizontal gap. The first horizontal gap is the horizontal gap on one side of the inlet and outlet slot mating surface (4), the second horizontal gap is the horizontal gap on the other side of the inlet and outlet slot mating surface (4), the third horizontal gap is the horizontal gap between the load-bearing surface mating surface (3) and the bottom of the blade, and the fourth horizontal gap is the horizontal gap between the load-bearing surface mating surface (3) and the bottom of the blade; the vertical gap includes a first vertical gap, a second vertical gap, and a third vertical gap. The first vertical gap is the vertical gap on one side of the inlet and outlet slot mating surface (4), the second vertical gap is the vertical gap on the other side of the inlet and outlet slot mating surface (4), and the third vertical gap is the vertical gap between the load-bearing surface mating surface (3).

10. The frequency modulation method according to claim 1, wherein: In the modal analysis step, the modal analysis adopts finite element analysis.

11. The frequency modulation method according to claim 10, characterized in that: The modal analysis results include the multi-order intrinsic frequencies of the blade and the corresponding vibration modes.

12. The frequency modulation method according to claim 11, characterized in that: The modal analysis results are presented using a Campell diagram.

13. The frequency modulation method according to claim 12, characterized in that: The blade requiring frequency modulation has an avoidance rate, and the avoidance rate is a frequency range value that the blade requiring frequency modulation needs to avoid. The frequency adjustment amount confirmation step verifies whether the current frequency falls within the avoidance rate.

14. The frequency modulation method according to claim 13, characterized in that: The frequency adjustment amount includes any one or more of a frequency order, a frequency value, and a vibration mode.

15. The frequency modulation method according to claim 8, characterized in that: In the mating surface parameter adjustment step, one or more parameters of the horizontal fitting length, the vertical fitting length, the horizontal gap, and the vertical gap are adjusted to form the first mating surface parameters.

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