CN109973321A - The tower door opening of the wind power generating set, the tower and the wind generating set - Google Patents

Abstract

The present invention provides pylon door opening, pylon and the wind power generating set of a kind of wind power generating set.The pylon door opening of the wind power generating set includes curved portion symmetrical above and below, and the curved portion meets following equation: (x/a)^m+(y/b)ⁿ=1, wherein x, y respectively represent coordinate value of any point in X-axis and Y-axis in the curved portion, and a represents 1/2 value of width of the curved portion in X-axis, and b represents height value of the curved portion in Y-axis；Also, m, n meets respectively: 1.65≤m≤1.80,1.65≤n≤1.80.It can effectively reduce the factor of stress concentration of pylon door opening using pylon door opening, pylon and the wind power generating set of wind power generating set of the invention, reduce the pylon thickness at pylon doorway positions, to mitigate tower weight and reduce manufacturing cost.

Description

Tower door openings, towers and wind turbines for wind turbines

technical field

The present invention relates to the technical field of wind power generation, and more specifically, to a tower door opening of a wind power generator set capable of reducing the stress concentration factor of the tower door opening, a tower including the tower door opening, and a wind power generator set.

Background technique

The door opening at the bottom of the wind turbine tower is the main passage for maintenance operators and equipment to enter the wind turbine. Due to the opening of the tower door, the tower will experience a local increase in stress (stress concentration). Stress concentration can cause fatigue cracks in objects and static load fractures in parts made of brittle materials. In engineering, the stress concentration factor SCF (Stress Concentration Factor) is used to represent the degree of stress concentration. The SCF value can be calculated by dividing the maximum stress when the stress concentration occurs by the average stress, and the SCF value is greater than 1. Engineering experience shows that the more severe the section size changes, the larger the SCF value will be.

Therefore, when designing the tower door opening, the hole or slot with sharp corners should be avoided as much as possible, and the arc transition should be used in the design of the opening. From the point of view of manufacturing and processing technology, the current door opening cutting method adopts CNC cutting machine to directly cut the cylinder. This avoids the trouble of firstly transforming the coordinates of the shape of the tower door opening when using the method of first cutting the steel plate and then rolling it into a cylinder. In the operation of the CNC cutting machine, it is only necessary to take enough coordinate points on the curve shape projected on the XOY plane (ie, the front view), and the cutting machine can read the coordinates of these points and process to obtain the design used. shape. Therefore, in actual production, as long as the cutting shape function of the tower door opening can be obtained, enough points can be obtained, and the required shape can be obtained by processing.

In the existing tower door opening design, from the front view, the upper and lower ends of the door opening generally adopt an elliptical design (refer to FIG. 1 ). However, the SCF value near the door opening of the tower designed according to the ellipse is still relatively large, and generally can reach 1.40-1.50. Since the wall thickness of the tower is very sensitive to the SCF value, in order to make the design of the tower meet the strength requirements, now Some elliptical designs still need to thicken the wall thickness of the tower at the door opening of the tower, resulting in an increase in the quality of the tower.

Considering that the size of the SCF value directly affects the size of the tower wall thickness at the tower door opening, it is necessary to design a tower door opening that can reduce the SCF value at the current technological level, so as to reduce the tower wall thickness and lower the tower rack weight.

SUMMARY OF THE INVENTION

In order to solve the above technical problems, the present invention provides a tower door opening of a wind turbine that can reduce the SCF value of the tower door opening and reduce the tower thickness at the door opening position.

According to one aspect of the present invention, there is provided a tower door opening of a wind power generating set, the tower door opening of the wind generating set includes a vertically symmetrical arc portion, and the arc portion satisfies the following formula:

Among them, x and y represent the coordinate values of any point on the arc on the X-axis and the Y-axis respectively, a represents the 1/2 value of the width of the arc on the X-axis, and b represents the The height value of the arc portion on the Y axis; and, m and n respectively satisfy: 1.65≤m≤1.80, 1.65≤n≤1.80, so as to reduce the stress concentration factor of the tower door opening.

According to an exemplary embodiment of the present invention, in the formulas satisfied by the arc portion, m and n are respectively: m=1.70, n=1.69, so as to reduce the stress concentration factor of the tower door opening to a greater extent.

According to an exemplary embodiment of the present invention, a straight line segment is provided between the upper and lower arc portions of the tower door opening, so as to meet the design requirements for the size of the tower door opening.

According to another aspect of the present invention, a tower of a wind power generating set is provided, and the tower of the wind power generating set includes the above-mentioned tower door opening.

According to another aspect of the present invention, there is provided a wind turbine comprising a tower as described above.

The tower door opening, the tower and the wind generator set of the wind generator set of the present invention can effectively reduce the SCF value of the tower door opening, reduce the thickness of the tower at the door opening, thereby reducing the weight of the tower and reducing the manufacturing cost.

Description of drawings

The above and other features and advantages of the present invention will become more apparent from the following detailed description of exemplary embodiments of the present invention in conjunction with the accompanying drawings, in which:

FIG. 1 is a diagram showing an elliptic function curve;

2 is a schematic diagram illustrating a hyperelliptic function curve according to an exemplary embodiment of the present invention;

3 is a diagram schematically illustrating the shape of a tower door opening in a superelliptical design according to an exemplary embodiment of the present invention;

Fig. 4 is a schematic diagram illustrating the shape of a tower door opening of a super-elliptical design according to an exemplary embodiment of the present invention;

Fig. 5 is a stress cloud diagram when an axial force Fz is applied to the super-elliptical designed tower opening shown in Fig. 4;

Fig. 6 is a stress cloud diagram when a bending moment Mxy is applied to the superelliptic designed tower opening shown in Fig. 4;

Fig. 7 is a schematic diagram of the shape of the existing ellipse-designed tower door opening;

Figure 8 is a stress contour plot when an axial force Fz is applied to the elliptical designed tower portal shown in Figure 7; and

FIG. 9 is a stress contour diagram when a bending moment Mxy is applied to the elliptical designed tower opening shown in FIG. 7 .

Explanation of reference numbers:

1: Tower; 10: Tower door opening; 11: Upper arc; 12: Lower arc; 13: Straight line.

Detailed ways

Embodiments of the invention will now be described more fully with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown.

The present invention optimizes the shape of the doorway opened in the bottom section tower 1 of the wind power generating set to make the stress as small as possible, thereby achieving the purpose of reducing the SCF value. An exemplary embodiment of the present invention provides a tower door opening 10 of a wind power generating set and a tower including the tower door opening 10 , and also provides a wind power generating set including the tower door opening 10 .

The tower door opening 10 according to the exemplary embodiment of the present invention includes vertically symmetrical arc portions 11 and 12, and the arc portions 11 and 12 satisfy the following formula (1):

Among them, x and y represent the coordinate values of any point on the arc-shaped parts 11 and 12 on the X-axis and the Y-axis, respectively, a represents the 1/2 value of the width of the arc-shaped parts 11 and 12 on the X-axis, and b represents the The height values of the arc-shaped portions 11 and 12 on the Y axis; and, m, n respectively satisfy: 1.65≤m≤1.80, 1.65≤n≤1.80.

Here, a Cartesian coordinate system XOY is established with the center O of the tower door opening 10 of the wind turbine as the origin, and the horizontal axis and the vertical axis are respectively defined as the X axis and the Y axis, wherein m and n are positive numbers.

Here, the formula (1) is called a hyperelliptic function formula. As shown in Figure 3, the hyperelliptic function formula is a new shape function formula proposed based on the elliptic function, and a family of curves including ellipses can be drawn through two variables m and n. The curve drawn according to the hyperelliptic function is called hyperelliptic curve. When m=n=2, the hyperelliptic curve degenerates into an elliptic curve; when m=n=1, the hyperelliptic curve degenerates into a straight line. Due to the introduction of variables m and n, the scope of the design domain becomes larger. Therefore, in the shape optimization process, the purpose of reducing the SCF value can be achieved by setting appropriate m and n values.

When m and n satisfy respectively: 1.65≤m≤1.80, 1.65≤n≤1.80, the tower door opening designed according to the above shape function formula (1) can effectively reduce the stress concentration factor SCF, thereby reducing the tower door opening The thickness of the tower at the location reduces the overall weight of the tower and reduces the production cost.

If m and n are outside the above ranges, the above effects cannot be achieved. In detail, when m and n are less than 1.65, the shape of the tower door opening tends to be rhombus, so that the tower door opening has obvious sharp edges and corners, so that the stress concentration factor SCF of the corresponding position becomes larger, resulting in the corresponding position The wall thickness of the tower increases, the overall weight of the tower increases, and the production cost increases. When m and n are greater than 1.80, the shape of the tower doorway tends to be a rectangle with corners, so that the stress concentration factor SCF at the corresponding position becomes larger, resulting in an increase in the wall thickness of the tower at the corresponding position, and the tower's Overall weight increases and production costs increase.

According to an exemplary embodiment of the present invention, a straight line 13 is provided between the upper and lower arcs 11 and 12 of the tower door opening 10, the height of the straight line 13 on the Y axis is 2h, and the straight line 13 is symmetrical about the X axis, Then the upper arc portion 11 and the lower arc portion 12 respectively satisfy the following formulas (2) and (3):

Among them, x and y represent the coordinate values of any point on the arc-shaped parts 11 and 12 on the X-axis and the Y-axis respectively, a represents the 1/2 value of the width of the arc-shaped parts 11 and 12 on the X-axis, and b represents the The height value of the arc parts 11 and 12 on the Y axis, h represents the 1/2 value of the height of the straight line segment 13 on the Y axis; and, m, n respectively satisfy: 1.65≤m≤1.80, 1.65≤n≤1.80 .

Here, the purpose of designing the straight section 13 is mainly to allow related equipment to pass through the tower door opening 10 without touching the door opening. Therefore, according to actual needs, the height of the straight section 13 can be adjusted to meet the size of the door opening. design requirements.

As an example, if the height (2b+2h) of the tower doorway 10 on the Y axis is 4000mm, the width (2a) of the tower doorway 10 on the X axis is 1700mm, and the height (2h) of the straight section 13 on the Y axis is 1100mm, and the height value (b) of the arc parts 11 and 12 on the Y axis is 1450mm, then the upper arc part 11 and the lower arc part 12 satisfy the following formulas (4) and (5) respectively:

Using the parameters of the tower doorway 10 mentioned above, the tower doorway designed with the super elliptic function according to the present invention is compared with the existing tower doorway designed with the standard ellipse function. Specifically, the shape of the tower door opening according to the present invention is designed using the hyperelliptic function when m=1.70, n=1.69, and the shape of the existing tower door opening is designed using the standard elliptic function (m=2, n=2 ) made.

The following table 1 shows the size of the tower door opening and the nominal stress calculation results, and the following table 2 shows the difference between the tower door opening adopting the super elliptic function design according to the present invention and the existing one adopting the standard ellipse function design SCF calculation results of tower door openings.

Table 1

Table 2

5 and 6 are compared with FIGS. 8 and 9 respectively, and combined with the calculation results shown in Table 2, it can be known that when m=1.70, n=1.69, the tower designed by the hyperelliptic function according to the present invention The maximum stress concentration factor SCF=1.328 of the frame door opening, and the maximum stress concentration factor SCF=1.400 when the existing tower frame door opening using standard elliptic function design is used. It can be seen that, compared with the existing tower door opening using the standard elliptic function design, the tower door opening using the hyperelliptic function design according to the present invention reduces the maximum stress concentration factor by 5.14%. From the results, compared with the conventional standard elliptical-shaped tower door opening, the super-ellipse-shaped tower door opening according to the present invention is more beneficial to reduce the stress concentration factor SCF. Therefore, under the existing process conditions, using the hyperelliptic function to optimize the shape of the doorway can effectively reduce the SCF value, thereby reducing the tower thickness of the tower in the doorway section, and achieving the effect of reducing the weight of the tower.

Based on the calculation results shown in Table 2, the SCF value of the standard ellipse-shaped tower door opening can reach 1.400, and the SCF value of the super-ellipse-shaped tower door opening according to the present invention can be reduced to 1.328, then for a diameter of 7m, the door opening For a tower with a tower height of 10m, compared with the existing tower doorway designed with a standard elliptic function, the tower doorway designed with a hyperelliptic function according to the present invention can reduce the weight of about 5t; A wind farm is equipped with 50 wind turbines, and it is estimated that each ton of steel plates is quoted at 10,000 yuan, which can save about 2.5 million yuan. 2.5 million yuan.

The tower door opening of the wind power generating set, the tower and the wind power generating set of the present invention can effectively reduce the stress concentration factor SCF of the tower door opening, reduce the thickness of the tower at the door opening, thereby reducing the weight of the tower and reducing the manufacturing cost.

While the invention has been particularly shown and described with reference to exemplary embodiments of the invention, it should be understood by those skilled in the art that modifications may be made thereto without departing from the spirit and scope of the invention as defined by the claims. Various changes in form and detail.

Claims (5)

1. A tower door opening of a wind power generating set, characterized in that, the tower door opening (10) of the wind generating set includes vertically symmetrical arc portions (11, 12), and the arc portions (11, 12) 12) Satisfy the following formula: Wherein, x and y represent the coordinate values of any point on the X-axis and the Y-axis respectively on the arc portion (11, 12), and a represents the width of the arc portion (11, 12) on the X-axis 1/2 value, b represents the height value of the arc portion (11, 12) on the Y axis; and m, n satisfy respectively: 1.65≤m≤1.80, 1.65≤n≤1.80. 2. The tower door opening of a wind power generating set according to claim 1, characterized in that, in the formulas satisfied by the arc-shaped portions (11, 12), m and n are respectively: m=1.70, n=1.69 . 3. The tower door opening of a wind power generating set according to claim 1 or 2, wherein a straight line segment (13) is provided between the upper and lower arc parts (11, 12) of the tower door opening. 4. A tower of a wind turbine, characterized in that the tower of the wind turbine comprises the tower door (10) according to any one of claims 1-3. 5 . A wind power generating set, wherein the wind power generating set comprises the tower of claim 4 . 6 .