CN110863953A - Annular steel pipe concrete combined wind turbine generator tower structure - Google Patents

Abstract

The invention provides a tower structure of a circular-shaped concrete-filled steel tube combined wind turbine. The tower structure includes an upper steel tower and a lower concrete-filled steel tube tower, and the concrete-filled steel tube tower is composed of a multi-section annular concrete-filled steel tube. The tower section is connected and formed; the concrete-filled steel tube tower section includes inner and outer double-layer steel cylinders, and the inner and outer layer steel cylinders are connected at the upper and lower ends of the tower section, forming a grouting space between the two, and filling with concrete. The invention meets the requirements of high-altitude and large-scale wind turbines, the total height of the upper steel tower and the lower concrete-filled steel tube tower can reach no less than 150m, and the manufacturing, transportation and installation are convenient, reusable, and cost reduction.

Description

Circular-shaped CFST combined wind turbine tower structure

technical field

The invention belongs to the technical field of high towers of wind turbines in low wind speed areas.

Background technique

At present, most of the support structures of traditional wind turbines in my country are steel conical towers. However, with the rapid development of my country's wind power industry, the single-unit capacity of wind turbines is getting larger and larger. In order to effectively utilize wind energy resources in low wind speed areas, wind power The unit is gradually developing towards large-scale and high-altitude, and the requirements for the height and rigidity of the matching hub continue to increase. When the height of the hub exceeds 100m, the diameter of the bottom section of the traditional conical steel tower will exceed the size limit of conventional road transportation, and with the increase of the height of the steel cylinder, its overall stiffness will decrease, which will induce the bad vibration characteristics of the wind turbine, thus limiting the height of the wind turbine. The development of tower wind turbine technology. At this stage, prestressed steel-mixed towers and flexible towers have received certain attention and promotion in the field of high-tower wind power technology because they can meet the height and stiffness requirements of large-scale wind turbine hubs. However, factors such as the long construction period of the prestressed steel-concrete tower structure, the high cost of prestressed steel strands, and the complex tensioning operation and maintenance procedures restrict the development of the steel-concrete tower. As the height of the flexible tower increases with the height of the hub, the overall flexibility of the tower becomes larger, resulting in excessive tower top displacement, prominent fatigue damage, and seriously affecting the normal operation of the fan. In addition, the first-order natural vibration frequency of the flexible tower is low, which has entered the rotation of the impeller. Within the frequency range, resonance will occur at a certain speed of the impeller. Although the fan can quickly skip this speed by adjusting the control strategy, it will lose about 3% to 5% of the power generation. It can be seen that the existing technical solutions for high towers still have obvious limitations.

SUMMARY OF THE INVENTION

The purpose of the present invention is to solve the above-mentioned problems, to provide a circular ring-shaped concrete-filled steel tubular composite wind turbine tower structure, which can meet the requirements of high-altitude and large-scale wind turbines, and is convenient to manufacture, transport and install, and can be reused. cut costs. For this reason, the present invention adopts the following technical solutions:

The tower structure of a circular-shaped CFST combined wind turbine is characterized in that: the tower structure includes an upper steel tower and a lower CFST tower, and the CFST tower is composed of a multi-section annular CFST tower. The CFST tower section includes inner and outer double-layer steel cylinders, and the inner and outer layer steel cylinders are connected at the upper and lower ends of the tower section, forming a grouting space between the two, and filling with concrete.

The total height of the upper steel tower and the lower concrete-filled steel tubular tower of the present invention can reach not less than 150m.

On the basis of adopting the above-mentioned technical solutions, the present invention can also adopt the following further technical solutions or use these further technical solutions in combination:

Horizontal and vertical shear bonds are welded on the inner wall of the double-layer steel cylinder to enhance the shear resistance of the concrete.

The double-layer steel cylinders of the CFST tower section are prefabricated in batches in the factory, with a diameter of no more than 4.3m, which can meet the requirements of road transportation; the inner layer of the steel cylinder is provided with a number of grouting holes and grouting holes corresponding to the grouting space. The CFST tower sections are connected section by section using the procedure of pouring concrete on site and then hoisting.

Micro-expansion agent is added to the concrete grouting material to solve the problem of shrinkage during concrete setting.

The bottom of the CFST tower is connected with the fan foundation, and the top of the top CFST tower is connected with the steel tower.

The bottom section of the CFST tower is provided with a T-shaped flange at the bottom of the CFST tower section, which is connected to the fan foundation through foundation anchor bolts; the bottom section of the CFST tower section is provided with a doorway, and the inner side of the doorway is provided with a door frame; The tower section is connected by an L-shaped flange and a bolt assembly; an L-shaped flange is arranged on the top of the top section of the CFST tower section, and is connected with the steel tower through a bolt assembly.

The outer diameter of the CFST tower remains the same, and the steel plate wall thickness of the inner and outer steel cylinders is controlled between 16mm and 20mm according to the overall stress characteristics; the upper and lower parts of the inner steel cylinder are welded with upper sealing plates respectively. and the lower sealing plate, so that the inner layer steel cylinder gradually transitions to intersect with the outer layer steel cylinder. In order to reserve the installation space of the bolt components for the connection of the CFST tower section under the premise of ensuring the strength requirements of the tower.

Further, the height of the lower concrete-filled steel tubular tower is greater than that of the upper steel tower.

The beneficial effects of the present invention are:

(1) The circular ring-shaped concrete-filled steel tubular composite wind turbine tower structure proposed by the present invention has reasonable design, reliable structure, firm connection, convenient transportation, batch process construction, modular installation, and can be recycled and reused in the post-wind power era. , which can greatly reduce the construction period on site, with significant economic and environmental benefits.

(2) The lower part adopts several concrete-filled steel tubular tower structures, and the upper part is connected with traditional steel towers. On the basis of ensuring the safe and stable operation of the wind turbine, the height of the hub of the wind turbine can be greatly increased, which can reach more than 150m, which can meet the large-scale wind turbine. , the development requirements of high-altitude, can effectively use the wind resources in the low wind speed area; at the same time, the diameter of the tower can be reduced to meet the needs of road transportation, without the need for prefabrication and transportation, on-site splicing like the previous concrete towers Maintenance can greatly facilitate transportation, reduce the difficulty of on-site construction, and greatly reduce the construction period and cost.

(3) The high-strength concrete is poured into the double-layer steel tube to enhance the overall rigidity of the tower and reduce the amplitude. On the one hand, it can effectively avoid the structural fatigue problem caused by the periodic large swing of the tower. Avoid the rotational frequency of the fan impeller to avoid resonance.

(4) It can fundamentally change the limitations of the long construction period of the prestressed steel mixed tower, the high cost of the prestressed steel strand, the small rigidity of the flexible tower, the large amplitude, the severe fatigue damage, and the frequency crossing, which can break through the existing high The bottleneck of the tower solution provides a new type of ultra-high tower solution in the low wind speed area in the future.

Description of drawings

FIG. 1 is an overall elevation view of an embodiment of a tower structure of a circular-ring concrete-filled steel tubular composite wind turbine according to the present invention.

FIG. 2 is an elevation view of a circular ring-shaped concrete-filled steel tubular tower in an embodiment of the present invention.

FIG. 3 is a partial schematic diagram of the connection between the bottom-section annular concrete-filled steel tubular tower and the foundation in the embodiment of the present invention.

FIG. 4 is a partial schematic diagram of the connection between the segments of the annular concrete-filled steel tubular tower in the embodiment of the present invention.

5 is a horizontal cross-sectional view of a circular-shaped concrete-filled steel tubular tower in an embodiment of the present invention.

Detailed ways

This embodiment is an ultra-high tower with a hub height of 150m, wherein the upper part is a 50m traditional steel tower 2, and the lower part is composed of 4 circular-shaped concrete-filled steel tubular towers 3 with a height of 25m. , the present invention will be described in further detail below in conjunction with the accompanying drawings.

As shown in FIGS. 1 to 5 , the tower structure of the circular-shaped CFST composite wind turbine in this embodiment includes 4 sections, each of which is 25 m high, and consists of 3 circular-shaped CFST tower sections. From top to bottom, the super-high tower wind turbine is composed of a fan head 1 , a steel tower 2 , a concrete-filled steel tubular tower section 3 and a fan foundation 4 .

The steel tower 2 is formed by connecting a plurality of steel tower sections.

The CFST tower section 3 is provided with inner and outer double-layer steel cylinders 6 and 7, and the wall thickness of the inner and outer double-layer steel cylinders is 18 mm; Shear key 20 to enhance the shear resistance of concrete. The double-layer steel cylinder part of the CFST tower structure is prefabricated in batches in the factory. The outer diameter of the tower is 4.3m, which can meet the requirements of road transportation; the main wall thickness of the CFST tower section 3 is 300mm, and the inner steel cylinder and outer A grouting space is formed between the layers of steel cylinders; corresponding to the grouting space, two grouting holes 12 are opened near the bottom and the middle of the inner steel plate of each section of the steel cylinder, and two grouting holes are opened near the top of the inner steel plate. Hole 13, the grouting space in the double-layer steel cylinder is filled with high-strength concrete 8 by high-pressure grouting to increase the overall rigidity of the tower.

The high-strength concrete grouting material has micro-expansion, self-compacting, low bubble and high fluidity at the same time, so as to solve the shrinkage problem in the concrete setting process and ensure that the concrete grouting material can self-compact to the design without adding vibration. Require.

As a preferred solution, C50 concrete grouting material is used in this embodiment. Considering that the height of each CFST tower section 3 is 25m, the first-stage pumping scheme directly lifts the concrete from the bottom of the tower section to the top, which is difficult to continuously pour, and the compactness of the concrete is difficult to guarantee; The concrete pouring plan is as follows: (1) Before pouring concrete, first pump clean water to make the inner wall of the grouting space of the double-layer steel pipes 6 and 7, keep it clean and moist to reduce the effect of pumping resistance, and remove it 1 hour before grouting (2) Place the primary pump and the secondary pump near the grouting holes 12 at the bottom and the middle of the CFST tower section 3 respectively; (3) Keep the 2 grouting holes 12 in the middle and the 2 grouting holes at the top 13 Open the state, use the first-stage pump to simultaneously pour high-strength concrete grouting material through the two grouting holes 12 near the bottom, until the two grouting holes in the middle appear grout; (4) Close the two grouting holes 12 near the bottom and keep close The two grouting holes 13 at the top are open, and the secondary pump is used to pour synchronously through the two grouting holes in the middle until the 2 grouting holes 13 on the top are all slurried; (5) The concrete does not need to be vibrated during the jacking process. Only rely on the pumping pressure and the vibration-free self-tightness of the concrete to achieve compaction; during the pumping process, the concrete jacking height can be determined by the hammering method, and the concrete pumping progress difference at the same tower elevation can be ensured by controlling the pumping pressure and flow rate No more than 1m; (6) Concrete pouring in the steel pipe should be carried out continuously; (7) After the slurry emerges from the slurry hole, use a plug-in vibrating rod to vibrate several times, and the concrete in the pipe will no longer sink and bubble. Stop pumping grouting, and seal the grouting hole 12 and the grouting hole 13. The grouting of the concrete-filled steel tubular tower sections 3 of each segment can be performed synchronously or continuously if the on-site construction equipment and site permit.

The CFST tower section 3 is installed by section-by-section hoisting from bottom to top. The CFST tower section 3 of each segment is grouted and the hoisting can be carried out after the concrete 8 has set to the design strength.

As shown in FIG. 3 , a T-shaped bottom flange 16 is arranged at the bottom of the bottom section of the CFST tower section 3 with a flange thickness of 100 mm. Both sides of the T-shaped flange 16 are connected to the fan foundation 4 through foundation anchor bolts 17 .

As shown in Figure 1, the bottom section of the CFST tower section 3 is provided with a door opening 5, the center of the door opening is located 3m on the upper surface of the foundation, and an oval door frame 18 is installed on the inside of the door opening 5. The thickness of the door frame is 40 mm. .

The CFST tower sections 3 are connected to bolt assemblies 15 through L-shaped flanges 9, as shown in FIG. 4, and the flange thickness is 100 mm. In order to reserve the installation space of the bolt assembly 15 between the CFST tower sections, the inner steel plate 7 of the CFST tower is welded with the upper sealing plate 11 and the lower sealing plate 10 at a distance of 1m from the upper and lower flanges, so that the inner steel cylinder 7 Gradually transition to the intersection with the outer layer steel cylinder 6, and the thickness of the steel plate 14 after the intersection is 36mm is the sum of the thickness of the inner and outer layer steel cylinders, so as to ensure the overall strength and stiffness requirements of the tower.

The top of the top section CFST tower section 3 is provided with an L-shaped flange 9 with a thickness of 100 mm, and is connected with the upper conventional steel tower 2 through bolt assemblies 15 .

Further, in the embodiment, all welds need to be ground to eliminate residual stress, all bolt assemblies 15 and foundation anchor bolts 17 need to be treated with anti-corrosion, and each segment tower connection needs to be coated with waterproof sealant.

The above embodiment is only a preferred technical solution of the present invention. Those skilled in the art should understand that the technical solutions or parameters in the embodiments can be modified or replaced without departing from the principle and essence of the present invention. should be included within the protection scope of the present invention.

Claims (9)

1. The tower structure of circular-shaped concrete-filled steel tubular composite wind turbine is characterized in that: the tower structure comprises an upper steel tower and a lower concrete-filled steel tubular tower, and the concrete-filled steel tubular tower is composed of a multi-section annular concrete-filled steel tubular structure. The tower section is connected and formed; the concrete-filled steel tube tower section includes inner and outer double-layer steel cylinders, and the inner and outer layer steel cylinders are connected at the upper and lower ends of the tower section, forming a grouting space between the two, and filling with concrete to increase the tower section. Overall stiffness of the barrel. 2 . The annular CFST composite wind turbine tower structure according to claim 1 , wherein the horizontal and vertical shear keys are welded on the inner wall of the double-layer steel cylinder to enhance the shear resistance of the concrete. 3 . 3. The annular CFST composite wind turbine tower structure according to claim 1, characterized in that: the double-layer steel cylinders of the CFST tower section are prefabricated in batches at the factory, and its diameter is no more than 4.3m , can meet the requirements of road transportation; the inner steel cylinder has a number of grouting holes and grouting holes corresponding to the grouting space, and each CFST tower section is connected section by section by the procedure of pouring concrete on site and then hoisting. 4 . The annular CFST composite wind turbine tower structure according to claim 1 , wherein a micro-expansion agent is added to the concrete grouting material to solve the shrinkage problem during the concrete setting process. 5 . 5. The annular CFST composite wind turbine tower structure according to claim 1, wherein the bottom of the CFST tower is connected with the fan foundation at the bottom of the bottom section of the CFST tower, and the top section of the CFST tower is connected to the fan foundation. The top of the tower section is connected to the steel tower. 6 . The annular CFST composite wind turbine tower structure according to claim 1 , characterized in that: the bottom section of the CFST tower is provided with a T-shaped flange at the bottom of the CFST tower section, and through the foundation anchor bolts It is connected to the fan foundation; the bottom section of the CFST tower section is provided with a door opening, and the door frame is set on the inside of the door opening; the upper and lower adjacent CFST tower sections are connected by L-shaped flanges and bolt assemblies; the top section of the CFST tower section is provided with L-shaped Flange and connected to the steel tower via bolt assemblies. 7. The annular CFST combined wind turbine tower structure according to claim 1 is characterized in that: the outer diameter of the CFST tower remains the same, and the steel plate wall thickness of the inner layer steel cylinder and the outer layer steel cylinder is subject to the overall The force characteristics are controlled between 16mm and 20mm; the upper and lower sealing plates of the inner steel cylinder are welded to the upper and lower sealing plates respectively, so that the inner steel cylinder gradually transitions to intersect with the outer steel cylinder, and the intersection position is far from the concrete filled steel tube. There is still a distance from the end of the tower, and it is ensured that the thickness of the overall steel plate after the intersection is the sum of the thickness of the inner and outer steel cylinders, so as to reserve the concrete-filled steel tubular tower section on the premise of ensuring the strength requirements of the tower. Installation space for bolt assemblies for connection. 8 . The annular CFST composite wind turbine tower structure according to claim 1 , wherein the total height of the upper steel tower and the lower CFST tower can reach no less than 150m. 9 . 9 . The annular CFST combined wind turbine tower structure according to claim 1 , wherein the height of the lower CFST tower is greater than that of the upper steel tower. 10 .

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