Wind driven generator tower tube local reinforcing structure door opening buckling checking method

Abstract

The invention relates to the technical field of wind driven generators, and particularly discloses a wind driven generator tower tube local reinforcing structure door opening buckling checking method which specifically comprises the following steps: S1, determining design parameters of a tower tube in a wind driven generator set and the opening angle of a tower tube door opening; according to the design parameters and the size of the opening angle of the tower drum door opening, the bending reduction coefficient of the tower drum which is not locally thickened after opening is obtained; s3, the equivalent wall thickness of the locally thickened door opening part is obtained through calculation; s4, calculating an anti-buckling factor of the locally reinforced tower drum door opening; s5, calculating a reduction coefficient of the locally thickened door opening of the tower drum; s6, the critical buckling stress of the locally thickened door opening is obtained through calculation; and step S7, checking buckling of the locally thickened door opening. According to the method, the structural safety of the locally reinforced door opening can be checked, the structural design period of the tower drum door opening can be greatly shortened, a large amount of repeated calculation work in the early stage is avoided, the design redundancy is reduced, and the working efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of wind turbine technology, and more specifically, to a method for buckling verification of the portal opening in a locally reinforced structure of a wind turbine tower. Background Technology

[0002] As competition in the wind power industry intensifies, the cost-effectiveness of the entire wind turbine unit determines its competitiveness in the market. The tower is currently the most widely used support structure for wind turbine units, and its safety determines the optimal solution for the entire unit. The design of locally reinforced portal structures in towers has been widely applied in engineering projects. How to accurately and quickly assess the safety of this structure is an urgent problem to be solved. Summary of the Invention

[0003] The technical problem to be solved by this invention is to provide a method for buckling verification of the portal opening in a locally reinforced structure of a wind turbine tower. This method can verify the structural safety of the portal opening, significantly shorten the design cycle of the tower portal opening structure, avoid a large amount of repetitive calculation work in the early stage, reduce design redundancy, and improve work efficiency. The solution adopted by this invention to solve the technical problem is: A method for buckling check of the portal opening in a locally reinforced structure of a wind turbine tower, specifically including the following steps: Step S1: Determine the design parameters of the tower and the opening angle of the tower portal in the wind turbine generator set; Step S2: Based on the design parameters and the opening angle of the tower portal, calculate the buckling reduction coefficient after opening the portal without local thickening of the tower. ; Step S3: Obtain the equivalent wall thickness of the locally thickened doorway section according to the modified formula. ; Step S4: Utilizing local enhancement factors Calculate the buckling resistance factor of the portal opening of the locally reinforced tower. ; Step S5: Calculate the reduction factor for the locally thickened portal opening in the tower. ; Step S6: Based on the buckling resistance factor and reduction factor The critical buckling stress of the locally thickened doorway was calculated. ; Step S7: Based on the ratio D of the actual load on the tower and the critical buckling stress, perform buckling check on the locally thickened portal opening. If the ratio is ≤1, the design safety requirements are met, and the optimal solution is obtained.

[0004] In some possible implementations, step S1 specifically refers to: Simulation calculations were performed based on the wind resources at the project site to determine the load on the tower of the wind turbine generator set in the project. The load is evaluated, and the design parameters of the tower are determined using engineering algorithms in conjunction with the transportation conditions of the tower. The opening angle of the doorway is determined based on on-site operation and maintenance needs.

[0005] In some possible implementations, the design parameters of the tower include its diameter and wall thickness.

[0006] In some possible implementations, step S2 specifically refers to using an engineering algorithm to calculate the buckling reduction coefficient of the tower without local thickening of the opening, based on the tower radius and the wall thickness at the tower opening. , (1); Where r is the tower radius; t is the thickness of the cylinder wall at the tower portal opening; A1 is the doorway influence factor 1, A1 = 0.7~1.0; B1 is the doorway influence factor 2, B1=0.0019~0.0024.

[0007] In some possible implementations, step S3 specifically refers to: calculating the equivalent wall thickness of the locally thickened doorway using formula (2). : (2); in, This refers to the wall thickness of the unthickened portion of the cylinder. Angle for localized reinforcement of the cylinder body; η is a constant determined based on the thickness difference of the designed plate, and the value of η ranges from 15 to 35.

[0008] In some possible implementations, step S4 specifically refers to: The local strengthening factor is calculated using formula (3); (3); The buckling factor of the locally reinforced tower portal opening is calculated using formula (4). ; (4); in, For local strengthening factors; K is a constant determined based on the thickness difference of the design plate, and its value ranges from 0.1 to 0.3. Angle for localized reinforcement of the cylinder body; The turning angle of the cylinder is locally reinforced.

[0009] In some possible implementations, step S5 specifically refers to calculating the reduction factor for the locally thickened portal opening in the tower based on an engineering algorithm. ; (5); Where r is the tower radius; A1 is the doorway influence factor 1, A1 = 0.7~1.0; B1 is the doorway influence factor 2, B1=0.0019~0.0024.

[0010] In some possible implementations, in step S6, the critical buckling stress is determined using formula (6). Calculation; (6); in, This is the design value of the actual axial instability critical stress at the calculated section, without considering the influence of tower openings.

[0011] In some possible implementations, in step S7, the buckling of the locally thickened doorway is checked in conjunction with the calculation results of formula (7): (7); in, The actual load on the tower; like If so, the design safety requirements are met; like Then the opening angle of the tower portal will be re-determined.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention utilizes a local thickening region thickness correction method to obtain the corrected wall thickness used for buckling verification. Subsequently, it obtains the buckling resistance factor of the locally reinforced portal structure through a local strengthening factor, thereby correcting the buckling reduction coefficient at the portal. This reasonably evaluates the enhancement of the buckling resistance performance at the portal of the tower due to the local reinforcement structure, and solves the problem of calculation and verification of the locally reinforced portal structure of the wind turbine tower. This invention verifies the structural safety and reliability of locally reinforced doorways by combining specific parameters of the doorway structure with thickness correction formulas and local reinforcement factor formulas. This greatly shortens the design cycle of tower doorway structures, avoids a large amount of repetitive calculation work in the early stages, reduces design redundancy, and improves work efficiency. Attached Figure Description

[0013] Figure 1This is a flowchart of the present invention; Figure 2 This is a schematic diagram of the opening angle of the tower portal in this invention. Detailed Implementation

[0014] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. The terms "first," "second," and similar terms used in this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, "a" or "one," etc., do not indicate a quantity limitation, but rather indicate the existence of at least one. In the implementation of this application, "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. In the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more. For example, multiple positioning posts refer to two or more positioning posts. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0015] The present invention will now be described in detail.

[0016] The tower opening angle described in this invention is the angle formed by the two sides of the opening in the width direction and the center of the tower body, such as... Figure 2 As shown, the included angle The angle of the opening for the tower portal; like Figure 1 As shown, a method for buckling verification of the portal opening in a locally reinforced structure of a wind turbine tower includes the following steps: Step S1: Determine the design parameters of the tower and the opening angle of the tower portal in the wind turbine generator set; specifically: Simulation calculations were performed based on the wind resources at the project site to determine the load on the tower of the wind turbine generator set in the project. The load is evaluated, and the design parameters of the tower are determined using engineering algorithms in conjunction with the transportation conditions of the tower. The opening angle of the doorway is determined based on on-site operation and maintenance needs.

[0017] Furthermore, the design parameters of the tower include the diameter of the tower body and the wall thickness of the inner wall of the tower body.

[0018] Step S2: Based on the design parameters and the opening angle of the tower portal, calculate the buckling reduction coefficient after opening the portal without local thickening of the tower. Specifically, this refers to using engineering algorithms to calculate the buckling reduction coefficient of the tower without local thickening after opening the portal, based on the tower's radius and the wall thickness at the portal opening. , (1); Where r is the tower radius; t is the thickness of the cylinder wall at the tower portal opening; A1 is the doorway influence factor 1, A1 = 0.7~1.0; B1 is the doorway influence factor 2, B1=0.0019~0.0024; Specifically: A1 and B1 can be determined based on the opening angle of the tower portal. The selection of tower material (Q235 and Q345) is shown in Table 1:

[0019] Table 1 Step S3: Obtain the equivalent wall thickness of the locally thickened doorway section according to the modified formula. Specifically, it refers to calculating the equivalent wall thickness of the locally thickened doorway using formula (2). : (2); in, This refers to the wall thickness of the unthickened portion of the cylinder. Angle for localized reinforcement of the cylinder body; η is a constant determined based on the thickness difference of the designed plate, and the value of η ranges from 15 to 35.

[0020] Step S4: Utilizing local enhancement factors Calculate the buckling resistance factor of the portal opening of the locally reinforced tower. Specifically, it refers to: The local strengthening factor is calculated using formula (3); (3); The buckling factor of the locally reinforced tower portal opening is calculated using formula (4). ; (3); in, For local strengthening factors; K is a constant determined based on the thickness difference of the design plate, and its value ranges from 0.1 to 0.3. A1 is the doorway influence factor 1, A1 = 0.7~1.0; B1 is the doorway influence factor 2, B1=0.0019~0.0024; Specifically: A1 and B1 can be determined based on the opening angle of the tower portal. The tower material can be selected from Table 1. If the opening angle of the tower door is between 20° and 30° or between 30° and 60°, the interpolation method can be used for conversion.

[0021] Step S5: Calculate the reduction factor for the locally thickened portal opening in the tower. Specifically, this refers to calculating the reduction factor for locally thickened portal openings in the tower based on engineering algorithms. ; (5); Where r is the tower radius; A1 represents the doorway influence factor of 1; B1 is the doorway influence factor 2.

[0022] Step S6: Based on the buckling resistance factor and reduction factor The critical buckling stress of the locally thickened doorway was calculated. Specifically, the critical buckling stress is determined using formula (6). Calculation; (6); in, This is the design value of the actual axial instability critical stress at the calculated section, without considering the influence of tower openings.

[0023] Step S7: Based on the ratio D of the actual load on the tower and the critical buckling stress, perform buckling check on the locally thickened portal. If the ratio is ≤1, the design safety requirements are met. Specifically, combine the calculation results of formula (7) to check the buckling of the locally thickened portal: (7); in, The actual load on the tower; like If this is achieved, the design safety requirements are met, and the optimal solution is obtained. like Then, the opening angle of the tower portal is re-determined, and steps S2-S7 are repeated until the optimal solution is obtained.

[0024] Example 1: This embodiment uses a specific project as an example to demonstrate how the present invention can be used to solve the design verification problem of a locally reinforced portal structure in a wind turbine tower. In this embodiment, the tower is made of Q345 steel, and the angle of the tower portal opening is... The angle is 30°, the diameter of the tower body is 4.9m, and the wall thickness of the unthickened part of the tower body is... The value is 40cm; η is 25, and the angle of the local reinforcement range of the cylinder is... The value is 60°; The value is 0.2. The value is taken as 200°, and the actual load on the tower is... =198, actual design value of critical stress for axial instability. =334.3; A1 selected from Table 1 is 0.95, and B1 selected is 0.0021; The equivalent wall thickness of the locally thickened doorway is calculated according to formula (2). , , The strengthening factor μ is calculated according to formula (3). ; The buckling resistance factor of the locally reinforced tower portal is calculated according to formula (4). , ; Calculate the buckling reduction coefficient according to formula (5). , ; The critical buckling stress is calculated according to formula (6). ; Right now: ; Comparison with the actual load on the tower and critical buckling stress The structural verification results that meet the conditions are obtained. It meets the design safety requirements.

[0025] This invention is not limited to the specific embodiments described above. The invention extends to any new feature or combination disclosed in this specification, as well as any new method or process step or combination disclosed herein.

Claims

1. A method for checking the door hole buckling of a local reinforcement structure of a wind turbine tower, characterized in that, Specifically comprising the following steps: Step S1: determining the design parameters of the tower drum in the wind turbine generator set and the size of the tower drum door hole opening angle; Step S2: combining the design parameters and the opening angle of the tower drum door hole, the buckling reduction factor of the tower drum after opening is obtained ; Step S3: Obtain the equivalent wall thickness of the locally thickened door opening part according to the modified formula ; Step S4: Utilizing local stiffening factors , calculating the buckling resistance factor of the local stiffening tower drum door hole ; Step S5: Calculate the reduction factor of the local thickening door hole of the tower drum ; Step S6: Based on the buckling resistance factor and reduction factor The critical buckling stress of the locally thickened doorway was calculated. ; Step S7: according to the ratio D of the actual load of the tower drum and the critical buckling stress, the local thickening door hole buckling check is carried out, and if the ratio is ≤1, the design safety requirement is met.

2. The method according to claim 1, wherein, The step S1 specifically refers to: According to the simulation calculation of the wind resource of the project location, the load of the tower drum in the wind turbine generator set of the project is determined; The load is evaluated, and the design parameters of the tower drum are determined by using engineering algorithm combined with the transportation conditions of the tower drum; According to the on-site operation and maintenance requirements, the size of the door hole opening angle is determined.

3. The method according to claim 2, wherein, The design parameters of the tower drum include diameter and wall thickness of the drum.

4. The method according to claim 3, wherein, The step S2 specifically refers to obtaining the buckling reduction factor of the tower tube after the opening according to the radius of the tower tube and the thickness of the tube wall at the tower tube opening by using an engineering algorithm , （1）； Wherein, r is the radius of the tower drum; t is the thickness of the drum wall at the door hole; A1 is the door hole influence factor 1, A1=0.7~1.0; B1 is the door hole influence factor 2, B1=0.0019~0.0024.

5. A method of checking the local buckling of a door opening in a wind turbine tower according to claim 4, characterized in that The step S3 specifically refers to: using formula (2) to calculate the equivalent wall thickness of the locally thickened door opening part : （2）； Wherein, t is the wall thickness of the un-thickened portion of the cylinder; Angle of local reinforcement range for the cylinder η is a constant determined according to the design plate thickness difference, and the value range of η is 0.1~0.

3.

6. A method of checking the local buckling of a door opening in a wind turbine tower according to claim 4, characterized in that The step S4 specifically refers to: The formula (3) is used to calculate the local strengthening factor; （3）； The buckling resistance factor of the locally reinforced tower door is calculated by using formula (4) ; （4）； wherein is a local reinforcement factor; The constant two, K, determined according to the design plate thickness difference is in the range of 0.1-0.

3. Angle of local reinforcement range for the cylinder The cylinder is partially reinforced at the corner.

7. The method of claim 1, wherein the method further comprises: The step S5 specifically refers to calculating the reduction coefficient of the local thickening door hole of the tower drum based on an engineering algorithm ; （5）； Wherein, r is the radius of the tower drum; A1 is the door hole influence factor 1, A1=0.7~1.0; B1 is the door hole influence factor 2, B1=0.0019~0.0024.

8. The method of claim 1, wherein the method further comprises: In step S6, the calculation of the critical buckling stress is performed using equation (6) ; （6）； wherein, is the actual axial buckling critical stress design value at the cross section, not considering the influence of the tower opening.

9. The method of claim 1, wherein the method further comprises: determining a local buckling of the door opening of the tower of the wind turbine generator based on the determined stress and strain of the door opening of the tower of the wind turbine generator. In step S7, the calculation result of formula (7) is combined for local thickening door hole buckling check: （7）； wherein, is the actual loading on the tower section; If , then the design safety requirements are met; If the tower door opening angle is re-determined.

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