A method for dismantling a bottom tower of a wind turbine by prestressed anchor bolts

Abstract

The application provides a prestressed anchor bolt type fan bottom end tower tube dismounting method, which comprises the following steps: step S001: connecting the tower tube by using a crane, so that the crane keeps five tons of lifting force on the tower tube; step S002: dismounting the anchor bolt nut connected with the tower tube flange; step S003: digging a hole on the tower foundation concrete, installing a hydraulic jack in the hole, and making the hydraulic jack abut on the lower end surface of the tower tube flange; step S004: keeping the lifting force of the crane greater than the weight of the tower tube; step S005: starting to lift the tower tube flange by using the hydraulic jack until a gap is generated between the tower tube flange and the concrete; and step S006: dismounting the tower tube first, and then dismounting the hydraulic jack. The prestressed anchor bolt type fan bottom end tower tube dismounting method can release the bonding force between the tower tube flange and the tower foundation concrete first, and then the tower tube is dismounted by using the crane, so that the safety of construction is ensured.

Description

Technical Field

[0001] This invention belongs to the field of wind turbine dismantling and construction technology, specifically relating to a method for dismantling the bottom tower of a prestressed anchor bolt type wind turbine. Background Technology

[0002] The base of a wind turbine tower is typically an anchor-type structure, meaning the flange at the bottom of the tower is prestressed and connected to a concrete foundation using bolts. During operation, the prestressed anchors in the foundation may break to varying degrees, necessitating the complete dismantling of the turbine, followed by the re-casting of a gravity foundation and reinstallation. The biggest challenge in dismantling the entire wind turbine lies in removing the bottom tower. Because the bottom tower is installed using anchor bolts and high-strength grout, the adhesive force of the high-strength mortar to the bottom flange of the tower is not released after all the nuts on the prestressed anchor bolts are removed. Furthermore, the magnitude of this adhesive force cannot be accurately estimated, making it impossible to perform lifting operations on the bottom tower for the following reasons: According to the "Safety Regulations for Lifting Operations," lifting operations are strictly prohibited for heavy objects of unknown weight; the lifting capacity is 90 tons at the minimum operating radius of the crane, but the tower's own weight plus the adhesive force may exceed its lifting capacity, potentially leading to overloading; during the lifting process, the sudden release of the adhesive force causes a sudden and drastic reduction in the crane's load, which can cause a huge impact on the lifting machinery, potentially resulting in serious consequences such as broken booms or overturning. Summary of the Invention

[0003] This invention proposes a method for dismantling the bottom tower of a prestressed anchor bolt type wind turbine, which can overcome the above-mentioned problems or at least partially solve or alleviate them.

[0004] This invention proposes a method for dismantling the bottom tower of a prestressed anchor bolt type wind turbine, comprising the following steps:

[0005] Step S001: Use a crane to connect the tower, ensuring the crane maintains a lifting force of five tons on the tower;

[0006] Step S002: Remove the anchor bolt nuts connecting the tower flange;

[0007] Step S003: Drill holes in the concrete of the tower base, install hydraulic jacks in the holes, and place the hydraulic jacks on the lower end face of the tower flange.

[0008] Step S004: Maintain the crane lifting force at a level slightly greater than the tower's own weight;

[0009] Step S005: Use hydraulic jacks to begin lifting the tower flange until a gap is created between the tower flange and the concrete;

[0010] Step S006: Dismantle the tower and remove the hydraulic jacks.

[0011] In step S003, multiple holes are drilled in the tower base concrete below the tower flange on the side of the tower away from the crane, with the top of each hole reaching the lower surface of the tower flange.

[0012] In step S003, a hydraulic jack is placed in each hole, and oil pipes and hydraulic pump stations are connected to each hydraulic jack so that each hydraulic jack starts and stops simultaneously.

[0013] In step S004, the lifting force of the crane on the tower is gradually increased. When the lifting force is greater than the weight of the tower by one to two tons, the lifting force is stopped and kept constant. At this time, the tower will be in a static state due to the bonding force between the tower flange and the tower base concrete.

[0014] In step S005, all hydraulic jacks are controlled to simultaneously lift the tower flange, creating a gap between the tower flange and the tower base concrete.

[0015] The method for dismantling the bottom tower of a prestressed anchor bolt type wind turbine of the present invention mainly involves drilling holes in the concrete of the tower base and inserting hydraulic jacks. The hydraulic jacks are used to lift the tower flange to release the adhesion between the tower flange and the concrete of the tower base. Then, the tower is dismantled by hoisting with a crane, ensuring the safety of the construction. Attached Figure Description

[0016] Figure 1 This is a diagram of the bottom tower connection structure of a prestressed anchor bolt type wind turbine;

[0017] Figure 2 This is a schematic diagram of the dismantling of the bottom tower of a prestressed anchor bolt type wind turbine.

[0018] In the above diagram: 1. Tower base concrete; 101. Hole; 2. Embedded screw; 3. Tower tube; 4. Tower tube flange; 5. Hydraulic jack; 6. Hydraulic pump station; 7. Steel pad. Detailed Implementation

[0019] Example 1

[0020] refer to Figure 1 and Figure 2This invention proposes a method for dismantling the bottom tower of a prestressed anchor bolt type wind turbine, comprising the following steps: Step S001: First, dismantle all the sections above the bottom tower 3 of the wind turbine, then use a crane to connect the tower 3, maintaining a lifting force of five tons on the tower 3 and keeping it constant; Step S002: Remove the anchor bolt nuts from the connecting flanges 4 of the tower one by one; Step S003: Drill holes 101 in the concrete 1 of the tower base, install hydraulic jacks 5 in the holes 101, and use the hydraulic jacks to lift the tower 3. On the lower end face of the tower flange 4; Step S004: Keep the lifting force of the crane slightly greater than the weight of the tower 3; Step S005: Use hydraulic jacks 5 to start lifting the tower flange 4 until a gap is created between the tower flange 4 and the tower base concrete 1; Step S006: First remove the tower 3, lift and remove the tower 3 with a crane, so that the tower flange 4 at the bottom of the tower 3 leaves the tower base concrete 1 and continues to rise until the tower flange 4 is removed from the pre-embedded screws 2, and then remove the hydraulic jacks 5.

[0021] Example 2

[0022] like Figure 2 As shown, in step S003, multiple holes 101 are drilled in the tower base concrete 1 below the tower flange 4 on the side of the tower 3 away from the crane, with the top of each hole 101 reaching the lower surface of the tower flange 4.

[0023] On the side of tower 3 furthest from the crane, at a distance of 1m, drill three holes 101 in the concrete base 1 below tower flange 4. The holes 101 are about 30cm high and extend about 20cm into the tower directly below tower flange 4. The tower flange 4 above the holes 101 should be exposed and cleaned of concrete debris.

[0024] Example 3

[0025] like Figure 2 As shown, in step S003, a hydraulic jack is placed in each hole, and oil pipes and hydraulic pump stations are connected to each hydraulic jack so that each hydraulic jack can be started and stopped simultaneously.

[0026] Place a hydraulic jack 5 in each of the three holes 101. The hydraulic jack 5 must be a large-tonnage, small-stroke model. Place a 200mm×200mm×20mm steel pad 7 between the upper surface of the piston of each hydraulic jack 5 and the tower flange 4 to prevent the piston of the hydraulic jack 5 from damaging the surface of the tower flange 4. Then connect the oil pipe and hydraulic pump station 6 and other accessories.

[0027] Example 4

[0028] In step S004, the lifting force of the crane on the tower 3 is gradually increased, and stopped when the lifting force is greater than the weight of the tower by one to two tons.

[0029] Gradually increase the lifting force of the crane on tower 3. Stop when the lifting force exceeds the weight of tower 3 by one to two tons and keep it constant. At this time, tower 3 will be in a static state due to the adhesion between tower flange 4 and tower base concrete 1. Before lifting operations, a load test should be performed on the crane, and the lifting capacity display on the instrument panel should be calibrated to ensure that the error of the lifting capacity displayed by the crane is less than one ton.

[0030] Example 5

[0031] like Figure 2 As shown, in step S005, all hydraulic jacks 5 are controlled to simultaneously lift the tower flange 4, so that a slight gap is formed between the tower flange 4 and the tower base concrete 1.

[0032] Control all hydraulic jacks 5 to simultaneously lift the tower flange 4, gradually applying lifting force until a slight gap is formed between the tower flange 4 and the tower base concrete 1. At this time, the hydraulic jacks maintain pressure and do not release pressure temporarily.

[0033] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims. Components and structures not described in detail in this embodiment are well-known components and common structures or common means in the industry, and will not be described in detail here.

Claims

1. A method for dismantling the bottom tower of a prestressed anchor bolt type wind turbine, used to dismantle the bottom tower of a wind turbine generator that is connected to the tower base concrete by prestressed anchor bolts and high-strength grouting, and where there is adhesive force between the tower flange and the tower base concrete, characterized in that... Includes the following steps: Step S001: First, dismantle the part above the bottom section of the wind turbine tower, and use a crane to connect the tower, so that the crane maintains a lifting force of five tons on the tower and keeps it constant. Step S002: Remove the anchor bolt nuts connecting the tower flange; Step S003: Drill multiple holes in the tower base concrete below the tower flange on the side of the tower away from the crane, ensuring that the top of each hole reaches the lower surface of the tower flange; place a hydraulic jack in each hole, so that each hydraulic jack rests on the lower end face of the tower flange, and connect each hydraulic jack to the hydraulic pump station through oil pipes so that each hydraulic jack can start and stop simultaneously. Step S004: Before lifting operations, perform a load test on the crane and calibrate the lifting capacity display; then slowly increase the lifting force of the crane on the tower. When the lifting force is greater than the weight of the tower by one to two tons, stop increasing the force and keep the lifting force constant so that the tower remains stationary due to the bonding force between the tower flange and the tower base concrete. Step S005: Control all hydraulic jacks to simultaneously lift the tower flange and gradually apply lifting force until a gap is formed between the tower flange and the tower base concrete to release the adhesive force between the tower flange and the tower base concrete; after the gap is formed, each hydraulic jack maintains pressure and does not release pressure temporarily. Step S006: First, use a crane to lift and dismantle the tower, so that the tower flange at the bottom of the tower is removed from the tower base concrete and then continue to rise until the tower flange is detached from the pre-embedded screws, and then remove the hydraulic jacks.

2. The method for dismantling the bottom tower of a prestressed anchor bolt type wind turbine according to claim 1, characterized in that, In step S003, three holes are drilled in the tower base concrete below the tower flange on the side of the tower farthest from the crane, spaced 1m apart. The holes are 30cm high and extend 20cm into the tower flange directly below it. The tower flange above the holes is exposed and the concrete debris is cleaned off.

3. The method for dismantling the bottom tower of a prestressed anchor bolt type wind turbine according to claim 1, characterized in that, In step S003, the hydraulic jacks are of the large tonnage, small stroke type. A 200mm×200mm×20mm steel pad is placed between the upper surface of the piston of each hydraulic jack and the tower flange to prevent the piston of the hydraulic jack from damaging the surface of the tower flange.

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