Tower drum door frame installation position optimization method and system based on wind direction probability

Abstract

The invention discloses a tower drum door frame installation position optimization method and system based on wind direction probability, and the method comprises the steps: dividing the circumferential region of a tower drum every certain angle, obtaining n wind directions, and obtaining the wind frequency corresponding to each wind direction; when the tower drum door frame is located at different positions of the tower drum, the total damage of weld joints in the door frame positions corresponding to different wind directions in the life cycle is obtained; based on the total damage in the life cycle of the weld joint at the door frame position corresponding to different wind directions and the corresponding wind frequency, the total fatigue damage of the weld joint when the tower door frame is located at different positions of the tower is obtained; and selecting the position with the minimum total welding line fatigue damage as the mounting position of the tower drum door frame. The mounting position of the tower door frame can be optimized, and the weight of the tower door can be reduced.

Description

Technical Field

[0001] The present invention mainly relates to the field of wind power technology, and in particular to a method and system for optimizing the installation position of a tower door frame based on wind direction probability. Background Art

[0002] like Figure 1 As shown in the figure, the typical structure of the wind turbine tower door frame is composed of three welded parts: the door frame, the reinforcement plate and the tower body. The calculation of the fatigue strength of the tower door frame weld is mainly for Figure 1 The fatigue strength of six welds in the calculation is calculated, including weld 1 (weld between door frame and reinforcement plate, including two inner and outer welds), weld 2 (lower weld between reinforcement plate and tower body, close to tower bottom, including two inner and outer welds) and weld 3 (upper weld between reinforcement plate and tower body, close to tower top, including two inner and outer welds). The passing standard is that the cumulative fatigue damage of each weld should be less than 1 during the life cycle of the wind turbine.

[0003] The general method currently used by wind power main engine manufacturers to calculate the fatigue strength of tower door frame welds is as follows:

[0004] 1. Assume that during the life cycle of the wind turbine, the wind always blows from the north direction ( Figure 2 0° direction) blows toward the tower;

[0005] 2. Take the first section of the tower as the calculation object and place the tower door at a relative position of 0° ( Figure 2 In the 180° direction, because My plays a major role in fatigue load, when the tower door is placed in this position, the door frame weld is subjected to the maximum stress), and the model is meshed;

[0006] 3. Establish a load point at the center of the top of the first section of the tower and couple the load point with all the nodes at the top of the tower by rigid beams. At the same time, place the load point in the wind direction coordinate system (the wind direction coordinate system refers to the coordinate system in which the X axis points to the direction of the wind, the Z axis is along the height direction of the tower, and the Y axis and the X axis and the Z axis conform to the right-hand rule. For details, see Figure 2 The coordinate system indicated in );

[0007] 4. Fix the bottom of the tower and apply fatigue unit load at the load application point to calculate the unit stress at the tower door frame weld;

[0008] 5. Substitute the unit stress of the tower door frame weld, the SN curve value of the weld and the fatigue time series load at the load loading point into the relevant software to calculate the total damage of the tower door frame weld during its life cycle.

[0009] The above method for calculating the fatigue strength of the tower door frame weld is particularly conservative because the following two assumptions are made:

[0010] (1) It is too conservative to assume that the wind always blows from the north to the tower during the life cycle of the wind turbine. In actual wind farms, the wind comes from all directions and will not blow from the north to the tower during the entire life cycle of the wind turbine.

[0011] (2) When calculating, the tower door frame is deliberately placed in a relative position in the north direction ( Figure 2 If the fatigue strength of the tower door frame weld meets the requirements at this position, then the fatigue strength of the tower door frame weld also meets the requirements when the tower door frame is located at any position on the tower circumference. However, this is too conservative. Because when installing the tower in an actual wind farm, the orientation of the tower door frame can be specified by the drawings, and it does not have to be installed at the position with the greatest force (i.e. Figure 2 This will result in a heavier tower design, which does not meet the economic requirements of the wind turbine manufacturer. Summary of the invention

[0012] In view of the technical problems existing in the prior art, the present invention provides a tower door frame installation position optimization method and system based on wind direction probability, which can optimize the tower door frame installation position and reduce the tower door weight.

[0013] In order to solve the above technical problems, the technical solution proposed by the present invention is:

[0014] A tower door frame position optimization method based on wind direction probability comprises the following steps:

[0015] The tower circumference is divided at certain angles to obtain n wind directions, and the wind frequency corresponding to each wind direction is obtained;

[0016] Obtain the total damage of the weld in the life cycle at the door frame position corresponding to different wind directions when the tower door frame is at different positions of the tower;

[0017] Based on the total damage of the weld at the door frame position corresponding to different wind directions during the life cycle and the corresponding wind frequency, the total fatigue damage of the weld at different positions of the tower door frame is obtained;

[0018] Select the position with the smallest total weld fatigue damage as the tower door frame installation position.

[0019] Preferably, the specific process of obtaining the total damage of the weld in the life cycle at the door frame position corresponding to different wind directions when the tower door frame is at different positions of the tower is:

[0020] Fix the bottom of the tower and apply fatigue unit load at the load loading point, calculate the unit stress of the weld at the door frame position corresponding to each direction when the tower door frame is at this position and the wind blows from each direction;

[0021] Based on the unit stress of the weld at the door frame position corresponding to each direction, the total damage of the weld at the door frame position corresponding to each direction during the life cycle when the tower door frame is located at this position and the wind blows from each direction is calculated.

[0022] Preferably, the total damage of the tower door frame weld in each wind direction during the life cycle is calculated based on the unit stress of the door frame weld in each wind direction, the weld stress-life curve value and the fatigue time series load at the load loading point.

[0023] Preferably, the load loading point is located at the center of the tower top of the first section of the tower, the loading point is rigidly coupled with all nodes at the top of the tower, and the loading point is placed in different wind direction coordinate systems respectively;

[0024] The wind direction coordinate system refers to a coordinate system in which the X-axis points to the direction of wind, the Z-axis is along the height direction of the tower, and the Y-axis, the X-axis, and the Z-axis conform to the right-hand rule.

[0025] Preferably, when calculating the unit stress of the weld at the door frame position corresponding to each direction, the wind direction coordinate system corresponds to the corresponding wind direction.

[0026] Preferably, based on the total damage of the weld at the door frame position corresponding to different wind directions during the life cycle and the corresponding wind frequency, the specific process of obtaining the total fatigue damage of the weld when the tower door frame is at different positions of the tower is:

[0027] When the tower door frame is at a certain position, the total fatigue damage of the weld = the total damage of the weld in the first wind direction × the wind frequency in the first wind direction + the total damage of the weld in the second wind direction × the wind frequency in the second wind direction + ... + the total damage of the weld in the nth wind direction × the wind frequency in the nth wind direction;

[0028] The total weld damage in the nth wind direction is the total weld damage corresponding to the nth wind direction, and the wind frequency in the nth wind direction is the wind frequency corresponding to the nth wind direction.

[0029] Preferably, based on the measured data of the wind tower, the frequency of occurrence of each wind direction in the life cycle of the wind turbine is counted as the wind frequency.

[0030] The present invention also discloses a computer program product, comprising a computer program, wherein the computer program executes the steps of the method described above when executed by a processor.

[0031] The present invention further discloses a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the method described above are executed.

[0032] The present invention also discloses a tower door frame installation position optimization system based on wind direction probability, comprising an interconnected memory and a processor, wherein a computer program is stored on the memory, and when the computer program is run by the processor, the steps of the method described above are executed.

[0033] Compared with the prior art, the advantages of the present invention are:

[0034] The present invention divides the tower into zones along the circumferential area according to the measured data of the wind measuring tower, and uses the actual load of the wind along each zone to calculate the fatigue of the tower door frame weld; since the load comes from various directions, the force on the same point of the tower door frame weld position will be reduced, thereby reducing the fatigue damage of the weld; the present invention calculates the tower door frame at various positions in the circumferential direction, so as to find out all positions from the smallest to the largest fatigue damage of the tower door frame, and subsequently, according to the calculation results, it can be required on the drawings that the tower door frame be installed in a specific direction in the wind field. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a typical tower door frame structure diagram of the prior art; (a) is a three-dimensional structure diagram; (b) is a main view structure diagram.

[0036] Figure 2 The figure is a calculation diagram of fatigue strength of tower door frame weld in the prior art; (a) is a three-dimensional structure diagram; (b) is an orientation diagram.

[0037] Figure 3 This is a tower wind direction division diagram in the present invention.

[0038] Figure 4 This is one of the tower door frame orientation diagrams in the present invention (when the tower door frame is at 180°).

[0039] Figure 5 This is the second tower door frame orientation diagram in the present invention (when the tower door frame is located at 202.5°).

[0040] Figure 6 It is a schematic diagram of equivalent rotation in the present invention.

[0041] Figure 7 This is the tower door layout diagram of the present invention.

[0042] Figure 8 The present invention is a flow chart of a tower door frame weld fatigue strength calculation method in an embodiment. DETAILED DESCRIPTION

[0043] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0044] like Figure 8As shown, the tower door frame installation position optimization method based on wind direction probability provided by an embodiment of the present invention includes the steps of:

[0045] The tower circumference is divided at certain angles to obtain n wind directions, and the wind frequency corresponding to each wind direction is obtained;

[0046] Obtain the total damage of the weld in the life cycle at the door frame position corresponding to different wind directions when the tower door frame is at different positions of the tower;

[0047] Based on the total damage of the weld at the door frame position corresponding to different wind directions during the life cycle and the corresponding wind frequency, the total fatigue damage of the weld at different positions of the tower door frame is obtained;

[0048] Select the position with the smallest total weld fatigue damage as the tower door frame installation position.

[0049] Specifically, the specific process of obtaining the total damage of the weld in the life cycle at the door frame position corresponding to different wind directions when the tower door frame is at different positions of the tower is as follows:

[0050] Fix the bottom of the tower and apply fatigue unit load at the load loading point, calculate the unit stress of the weld at the door frame position corresponding to each direction when the tower door frame is at this position and the wind blows from each direction;

[0051] Based on the unit stress of the weld at the door frame position corresponding to each direction, the value of the weld stress-life curve and the fatigue time series load at the load loading point, the total damage of the weld at the door frame position corresponding to each direction during the life cycle when the wind blows from each direction when the tower door frame is located at this position is calculated.

[0052] The present invention divides the tower into zones along the circumferential area according to the measured data of the wind measuring tower, and uses the actual load of the wind along each zone to calculate the fatigue of the tower door frame weld; since the load comes from various directions, the force on the same point of the tower door frame weld position will be reduced, thereby reducing the fatigue damage of the weld; the present invention calculates the tower door frame at various positions in the circumferential direction, so as to find out all positions from the smallest to the largest fatigue damage of the tower door frame, and subsequently, according to the calculation results, it can be required on the drawings that the tower door frame be installed in a specific direction in the wind field.

[0053] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0054] like Figure 8 As shown, the method for calculating the fatigue strength of the tower door frame weld based on wind direction probability according to an embodiment of the present invention comprises the following steps:

[0055] S1. Divide the circumference of the tower into a wind direction at a certain angle of N° (the value of N depends on whether the divided wind direction can represent the typical value of the wind tower in the wind direction. In this example, 22.5° is taken). The entire circumference is divided into 16 wind directions, such as Figure 3 As shown;

[0056] S2. According to the measured data of the wind tower, the frequency of each wind direction in the life cycle of the wind turbine is calculated (hereinafter referred to as wind frequency). For example, if the life cycle of the wind turbine is 20 years, and the cumulative time of wind blowing from 22.5° is 1 year, then the wind frequency of the 22.5° wind direction is 1 / 20=0.05), as shown in Table 1:

[0057] Table 1: Wind frequency table

[0058]

[0059] S3. Take the first section of the tower as the calculation object, and first place the tower door in the relative position of the 0° wind direction, such as Figure 4 The south direction or the position indicating 180°;

[0060] S4. Establish a load loading point at the center of the top of the first section of the tower, and couple the loading point with all the nodes at the top of the tower by rigid beams. At the same time, place the loading point in different wind direction coordinate systems (the wind direction coordinate system refers to a coordinate system in which the X-axis points to the direction of wind, the Z-axis is along the height direction of the tower, and the Y-axis, the X-axis and the Z-axis conform to the right-hand rule; therefore, this calculation method has 16 corresponding wind direction coordinate systems);

[0061] S5. Fix the bottom of the tower and apply fatigue unit load at the load loading point. Calculate the unit stress of the weld at the door frame position corresponding to each direction when the wind blows from 16 directions when the tower door frame is at this position (using finite element calculation, the calculation coordinate system is Figure 4 The wind direction coordinate system indicated in the figure. When calculating the unit stress of the weld corresponding to different directions, the coordinate system must be calculated according to the wind direction coordinate system of that direction. For example, when calculating the unit stress of the weld at the tower door frame position at a wind direction of 22.5°, it is necessary to Figure 4 The XY coordinate system in the figure is rotated 22.5° clockwise for loading calculation, and the rest of the angles are calculated by analogy).

[0062] S6, calculate the total damage of the weld in the life cycle of the door frame position corresponding to each direction when the wind blows from 16 directions when the tower door frame is located at this position (the unit stress of the door frame weld in each wind direction of step S5, the value of the weld stress-life (SN) curve and the fatigue time series load at the load loading point are substituted into the relevant software to calculate the total damage of the tower door frame weld in the life cycle of each wind direction);

[0063] S7, finally calculate the tower door frame at the 0° relative position according to the formula (i.e. Figure 4 Total fatigue damage of weld at 180° position as shown:

[0064] When the tower door frame is at the relative position of 0°, the total fatigue damage of the weld = 0° weld total damage × 0° wind frequency + 22.5° weld total damage × 22.5° wind frequency + ... + 337.5° weld total damage × 337.5° wind frequency;

[0065] S8. Place the tower door frame at a relative position with a wind direction of 22.5° (i.e. Figure 5 The position marked with 202.5° in the middle);

[0066] S9. When the tower door is in this position, it can be found that its actual effect is equivalent to Figure 6 (That is, the tower door is located in the south direction and does not move, and the wind direction rotates 22.5° counterclockwise). If only one wind direction is considered, the total fatigue damage of the weld at the position corresponding to the tower door frame facing the 22.5° wind direction during the life cycle is equal to the total fatigue damage of the weld at the tower door frame facing the 22.5° wind direction during the life cycle. Figure 4 The total fatigue damage during the life cycle of the weld when the wind direction is 0° at the marked 180° position.

[0067] S10, according to step S9 analysis, when the tower door frame is located Figure 6 When the position is 202.5° as shown, the total fatigue damage calculation formula is as follows:

[0068] The tower door frame is located at a relative position of 22.5° ( Figure 6 =0° weld total damage (0° weld total damage calculated in step S6) × 22.5° wind frequency + 22.5° weld total damage (22.5° weld total damage calculated in step S6) × 45° wind frequency + ... + 337.5° weld total damage (337.5° weld total damage calculated in step S6) × 0° wind frequency;

[0069] S11. By analogy, the total fatigue damage of the weld when the tower door is located at the relative position of 45°, 67.5°..., 337.5° wind direction is calculated and formed into Table 2:

[0070] Table 2 Weld fatigue damage of tower door frame at different circumferential angles

[0071]

[0072] S12. According to Table 2, when the tower door frame is located at the relative position of the wind direction, the weld fatigue strength damage meets the strength. For example: in Table 2, when the tower door is located at the relative position of the wind direction of 0°, 22.5°, 90°, 157.5°, 180°, 202.5°, 270°, and 337.5°, the weld fatigue strength meets the requirements;

[0073] S13. Draw the safe installation position of the tower door into a tower door distribution map to specify the installation position of the wind farm tower door, such as Figure 7 As shown, Figure 7 The position shown in the middle circle is a dangerous position, that is, a position where the tower door cannot be placed.

[0074] The present invention applies the load according to the data measured by the actual wind tower, rather than always applying the load in one direction, thereby avoiding excessive fatigue damage of the door frame weld calculated; the present invention sets requirements for the installation position of the tower door, and does not require the fatigue strength of the tower door weld to meet the requirements when the tower door is located at any position of the circumference, but only needs to meet the requirements at certain specific positions of the tower door. In this way, the weight of the tower door can be further reduced, thereby reducing the weight of the tower, meeting the economic requirements of the wind turbine main engine manufacturer.

[0075] The present invention also discloses a computer program product, including a computer program, which executes the steps of the above method when executed by a processor. The present invention further discloses a computer-readable storage medium, on which a computer program is stored, which executes the steps of the above method when executed by a processor. The present invention also discloses a tower door frame installation position optimization system based on wind direction probability, including an interconnected memory and a processor, on which a computer program is stored, which executes the steps of the above method when executed by a processor. The product, medium and system of the present invention correspond to the above method and also have the advantages described in the above method.

[0076] The present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by hardware related to computer program instructions. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned method embodiment when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. Computer-readable storage media include: any entity or device that can carry computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electric carrier signal, telecommunication signal and software distribution medium. The memory is used to store computer programs and / or modules, and the processor implements various functions by running or executing computer programs and / or modules stored in the memory, and calling data stored in the memory. The memory may include high-speed random access memory and may also include non-volatile memory, such as a hard disk, an internal memory, a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card (Flash Card), at least one disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0077] The above are only preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should be regarded as the protection scope of the present invention.

Claims

1. A tower door frame installation position optimization method based on wind direction probability, characterized in that: Includes steps: The tower circumference is divided at certain angles to obtain n wind directions, and the wind frequency corresponding to each wind direction is obtained; Obtain the total damage of the weld in the life cycle at the door frame position corresponding to different wind directions when the tower door frame is at different positions of the tower; Based on the total damage of the weld at the door frame position corresponding to different wind directions during the life cycle and the corresponding wind frequency, the total fatigue damage of the weld at different positions of the tower door frame is obtained; Select the position with the smallest total weld fatigue damage as the tower door frame installation position.

2. The tower door frame installation position optimization method based on wind direction probability according to claim 1 is characterized in that: The specific process of obtaining the total damage of the weld in the life cycle at the door frame position corresponding to different wind directions when the tower door frame is at different positions of the tower is as follows: Fix the bottom of the tower and apply fatigue unit load at the load loading point, calculate the unit stress of the weld at the door frame position corresponding to each direction when the tower door frame is at this position and the wind blows from each direction; Based on the unit stress of the weld at the door frame position corresponding to each direction, the total damage of the weld at the door frame position corresponding to each direction during the life cycle when the tower door frame is located at this position and the wind blows from each direction is calculated.

3. The tower door frame installation position optimization method based on wind direction probability according to claim 2 is characterized in that: Based on the unit stress of the door frame weld in each wind direction, the value of the weld stress-life curve and the fatigue time series load at the load loading point, the total damage of the tower door frame weld in the life cycle of each wind direction is calculated.

4. The tower door frame installation position optimization method based on wind direction probability according to claim 2 or 3, characterized in that: The load application point is located at the center of the top of the first tower section. The load application point is coupled with all nodes at the top of the tower by a rigid beam, and the load application point is placed in different wind direction coordinate systems. The wind direction coordinate system refers to a coordinate system in which the X-axis points to the direction of wind, the Z-axis is along the height direction of the tower, and the Y-axis, the X-axis, and the Z-axis conform to the right-hand rule.

5. The tower door frame installation position optimization method based on wind direction probability according to claim 2 or 3, characterized in that: When calculating the unit stress of the weld at the door frame position corresponding to each direction, the wind direction coordinate system corresponds to the corresponding wind direction.

6. The tower door frame installation position optimization method based on wind direction probability according to claim 1, 2 or 3, characterized in that: Based on the total damage of the weld in the life cycle at the door frame position corresponding to different wind directions and the corresponding wind frequency, the specific process of the total fatigue damage of the weld of the tower door frame at different positions of the tower is obtained as follows: When the tower door frame is at a certain position, the total fatigue damage of the weld = the total damage of the weld in the first wind direction × the wind frequency in the first wind direction + the total damage of the weld in the second wind direction × the wind frequency in the second wind direction + ... + the total damage of the weld in the nth wind direction × the wind frequency in the nth wind direction; The total weld damage in the nth wind direction is the total weld damage corresponding to the nth wind direction, and the wind frequency in the nth wind direction is the wind frequency corresponding to the nth wind direction.

7. The tower door frame installation position optimization method based on wind direction probability according to claim 1, 2 or 3, characterized in that: Based on the measured data from the wind tower, the frequency of each wind direction in the life cycle of the wind turbine is calculated as the wind frequency.

8. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are performed.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the computer program performs the steps of the method according to any one of claims 1 to 7.

10. A tower door frame installation position optimization system based on wind direction probability, comprising a memory and a processor connected to each other, wherein a computer program is stored in the memory, characterized in that: When the computer program is executed by a processor, the computer program performs the steps of the method according to any one of claims 1 to 7.

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