A method for detecting the flatness, cone angle and sweep angle of a wind turbine blade root

Abstract

The invention discloses a method for detecting the flatness, cone angle and sweep angle of a blade root of a wind turbine blade, comprising placing the wind turbine blade in a blade posture and making the blade root end face a plumb plane; testing the three-dimensional coordinates of each bolt hole peripheral end face or bolt sleeve end face by a laser tracker to form a three-dimensional coordinate set, calculating the least square surface of the three-dimensional coordinate set, taking the distance between two inclusive planes parallel to the least square surface and having the minimum distance as the blade root flatness; taking the blade spanwise coordinates and calculating the average spanwise coordinates of the corresponding bolt hole peripheral end face or bolt sleeve end face, and calculating the cone angle α and the sweep angle θ respectively according to the corresponding spanwise coordinate averages; the invention can effectively improve the measurement accuracy of the blade root end face flatness, and can further measure its influence on the cone angle and sweep angle of blade installation, thereby improving the reliability and safety of the wind turbine.

Description

Technical Field

[0001] The present invention relates to the technical field of wind power generation, and in particular to a method for detecting the flatness, cone angle and sweep angle of a wind power blade root. Background Art

[0002] With the development of wind power technology, the diameter of wind rotors and the capacity of single units are getting larger and larger. In order to improve the reliability of wind turbines and obtain better power generation efficiency, higher requirements are put forward for the detection of relevant components of wind turbines.

[0003] The blades are connected to the hub through the blade root connector. Only when the connection is reliable can the blades transfer the captured wind energy to the generator, thereby generating the required electrical energy. This shows the importance of the blade root connection to the wind turbine. During the operation of the wind turbine, the wind rotor hub must bear the bending moment caused by the weight of the blades, the aerodynamic load caused by the wind, and the reaction force of the wind rotor shaft, and all these loads are cyclic alternating loads. In such a complex working state, in order to ensure the high-efficiency power generation needs, it is necessary to test the relevant indicators of the blade root.

[0004] The degree of inclination between the blade root end face and the pitch axis directly affects the installation posture of the blade on the whole machine, which will affect the blade performance, load, and the safety and reliability of the whole machine and the blade. Therefore, it is also crucial to detect the flatness of the blade root end face and evaluate its influence on the cone angle and sweep angle after the blade is installed. Summary of the invention

[0005] The technical problem to be solved by the present invention is how to improve the detection efficiency and accuracy of wind turbine blades to ensure the safety and reliability of wind turbine blades and the power generation efficiency.

[0006] The technical solutions adopted by the present invention to solve the problems of the prior art are as follows:

[0007] A method for detecting the flatness, taper angle and sweep angle of a wind turbine blade root is provided, comprising placing the wind turbine blade in a blade posture and making the blade root end surface a plumb plane, which can be used as a reference plane; after placing the wind turbine blade in a blade posture, for a punched blade, a hole must be cut and punched at the blade root, and for a pre-embedded blade, the bolt sleeve must be polished.

[0008] Furthermore, the three-dimensional coordinates of the end face around each bolt hole or the end face of the bolt sleeve are tested by a laser tracker to form a three-dimensional coordinate set, the least squares surface of the three-dimensional coordinate set is calculated, and the distance between two inclusive planes parallel to the least squares surface and with the minimum distance is taken as the blade root flatness.

[0009] Furthermore, the spanwise coordinates of the blade are taken and the average spanwise coordinates of the end face around the bolt hole or the end face of the bolt sleeve are calculated, which is recorded as Zi , where i is the bolt hole or bolt cap number, and the number increases in sequence from the zero-degree position in a counterclockwise direction; that is, the zero-degree position is numbered 1 in a counterclockwise direction, and the numbers are 1, ...N in sequence to the last hole in a counterclockwise direction.

[0010] Furthermore, the cone angle α and the sweep angle θ are calculated according to the average values ​​of the spanwise coordinates, and the calculation formulas are as follows:

[0011] When N is an integer multiple of 4,

[0012] When N is not an integer multiple of 4,

[0013]

[0014] Where D is the blade root pitch diameter, N is the total number of bolt holes or bolt caps, abs is the absolute value, (N / 2+1) / 2 and N / 2 are rounded up.

[0015] Furthermore, the number of coordinate points on the end surface around each bolt hole or the end surface of the bolt sleeve is 3, and the coordinates of each point are recorded as (x i1 ,y i1 , z i1 )、(x i2 ,y i2 , z i2 ) and (x i3 ,y i3 , z i3 ), where i is the bolt hole or bolt cap number.

[0016] Specifically, for punched blades, three points are taken on the peripheral end surface of each axial hole; for embedded blades, three points are taken on the end surface of each bolt sleeve.

[0017] The average spanwise coordinate of each bolt hole perimeter end face or bolt sleeve end face is recorded as: Where i is the bolt hole or bolt cap number.

[0018] Preferably, before testing with a laser tracker, the blade root end surface or the bolt sleeve is also polished.

[0019] Furthermore, it also includes setting up a placement tool, which includes at least 4 support frames, and the at least 4 support frames are arranged at equal intervals.

[0020] Furthermore, when the wind turbine blade is placed in a blade posture, the trailing edge of the wind turbine blade faces upward, the blade's stiffness in the swing direction is greater than its stiffness in the flapping direction, and the blade deformation is minimal when the trailing edge faces upward, thereby improving measurement accuracy.

[0021] The beneficial effects are as follows:

[0022] The present invention measures the flatness of the blade root end face by using a laser tracker, and improves the accuracy of flatness measurement by operations such as tool placement and polishing; the cone angle and sweep angle are further calculated using the spanwise coordinates, which can effectively evaluate the impact after the blade is installed, improve the reliability and safety of wind turbine blades, and further improve the power generation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the blade placement tooling of this embodiment 1;

[0024] Figure 2 This is a schematic diagram of the blade posture of this embodiment 1. DETAILED DESCRIPTION

[0025] The present invention will be further described below in conjunction with specific implementation modes.

[0026] Example

[0027] like Figures 1-2 As shown, this embodiment provides a method for detecting the flatness, cone angle and sweep angle of a wind turbine blade root, including placing a wind turbine blade 1 in a blade posture and making the end face of the blade root 2 a plumb plane 3, and the plumb plane 3 can be used as a reference plane; after placing the wind turbine blade 1 in a blade posture, for a punched blade, a hole must be cut and punched at the blade root, and for an embedded blade, the bolt sleeve must be polished.

[0028] It also includes setting up a placing tool 4. In this embodiment, the placing tool 4 includes four support frames, namely 41, 42, 43 and 44, and the four support frames are arranged at equal intervals.

[0029] In this embodiment, when the wind turbine blade 1 is placed in a blade posture, the trailing edge 5 of the wind turbine blade 1 faces upward, the blade's swing direction stiffness is greater than the swing direction stiffness, and the blade deformation is minimal when the trailing edge 5 faces upward, thereby improving measurement accuracy.

[0030] The specific detection method of this embodiment is as follows:

[0031] The three-dimensional coordinates of the end face around each bolt hole or the end face of the bolt sleeve are tested by a laser tracker to form a three-dimensional coordinate set, as shown in Table 1.

[0032] In this embodiment, the wind turbine blade is a perforated blade. Three points are taken on the peripheral end surface of each axial hole, as shown in Table 1. The coordinates of each point are recorded as (x i1 ,y i1 , z i1 )、(x i2 ,y i2 , z i2 》and (x i3,y i3 , z i3 ), where i is the bolt hole or bolt cap number; Figure 2 As shown, in this embodiment, the numbers increase in sequence from the zero-degree position A in the counterclockwise direction; that is, the zero-degree position A is numbered 1 in the counterclockwise direction, and the numbers are marked in sequence in the counterclockwise direction to the last hole, namely 1, ...N.

[0033] As shown in Table 1, the least square surface of the data in the three-dimensional coordinate set in Table 1 is calculated, and the distance between two inclusive planes parallel to the least square surface and with the minimum distance is taken as the blade root flatness.

[0034] Take the spanwise coordinates of the blade and calculate the average spanwise coordinates of the end face around the bolt hole or the end face of the bolt sleeve, which is recorded as Where i is the bolt hole or bolt cap number.

[0035] In this embodiment, the cone angle α and the sweep angle θ are calculated according to the average values ​​of the spanwise coordinates, and the calculation formulas are as follows:

[0036] When N is an integer multiple of 4,

[0037] When N is not an integer multiple of 4,

[0038]

[0039] Where D is the blade root pitch diameter, N is the total number of bolt holes or bolt caps, abs is the absolute value, (N / 2+1) / 2 and N / 2 are rounded up.

[0040] The cone angle and sweep angle are obtained to evaluate the impact of blade installation.

[0041] Table 1

[0042]

[0043] In this embodiment, the flatness of the end face of the blade root 2 is measured by using a laser tracker, and the accuracy of the flatness measurement is improved through operations such as tool placement and polishing. The cone angle and sweep angle are further calculated using the spanwise coordinates, which can effectively evaluate the impact after the blade is installed, improve the reliability and safety of the wind turbine blades, and further improve the power generation efficiency.

[0044] Obviously, the above embodiments are merely examples for clearly explaining the technical solutions of the present invention, and are not intended to limit the implementation methods of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the protection of the claims of the present invention.

Claims

1. A method for detecting the flatness, cone angle and sweep angle of a wind turbine blade root, characterized in that: The method comprises placing the wind turbine blade in a blade posture and making the blade root end surface a plumb plane; The three-dimensional coordinates of the end surface around each bolt hole or the end surface of the bolt sleeve are measured by a laser tracker to form a three-dimensional coordinate set, the least square surface of the three-dimensional coordinate set is calculated, and the distance between two inclusive planes parallel to the least square surface and with the minimum distance is taken as the blade root flatness; Take the spanwise coordinates of the blade and calculate the average spanwise coordinates of the end face around the bolt hole or the end face of the bolt sleeve, which is recorded as Wherein, i is the number of the bolt hole or bolt cap, and the number increases in a counterclockwise direction from the zero position; The cone angle α and the sweep angle θ are calculated according to the average spanwise coordinates. The calculation formulas are as follows: When N is an integer multiple of 4, When N is not an integer multiple of 4, Where D is the blade root pitch diameter, N is the total number of bolt holes or bolt caps, abs is the absolute value, (N / 2+1) / 2 and N / 2 are rounded up.

2. The method for detecting the flatness, cone angle and sweep angle of a wind turbine blade root according to claim 1, characterized in that: The number of coordinate points on the end surface around each bolt hole or the end surface of the bolt sleeve is 3, and the coordinates of each point are recorded as (x i1 ,y i1 , z i1 )、(x i2 ,y i2 , z i2 ) and (x i3 ,y i3 , z i3 ), where i is the bolt hole or bolt cap number.

3. The method for detecting the flatness, cone angle and sweep angle of a wind turbine blade root according to claim 2, characterized in that: The average spanwise coordinate of each bolt hole perimeter end face or bolt sleeve end face is recorded as: Where i is the bolt hole or bolt cap number.

4. The method for detecting the flatness, cone angle and sweep angle of a wind turbine blade root according to claim 1, characterized in that: Before the laser tracker test, the blade root end surface or the bolt sleeve is polished.

5. The method for detecting the flatness, cone angle and sweep angle of a wind turbine blade root according to claim 1, characterized in that: It also includes setting up a placement tool, which includes at least 4 support frames, and the at least 4 support frames are arranged at equal intervals.

6. The method for detecting the flatness, cone angle and sweep angle of a wind turbine blade root according to claim 1, characterized in that: When the wind turbine blade is placed in the blade posture, the trailing edge of the wind turbine blade faces upward.

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