A protective dismantling construction method for onshore wind turbine generator system

Abstract

The present application belongs to the field of wind power generation technology, and particularly relates to a protective dismantling construction method of a land wind turbine generator set. The protective dismantling construction method of the land wind turbine generator set comprises the following steps: S1, preparation before dismantling; S2, installation of a wind rope and dismantling of internal components; S3, dismantling of a blade wheel; S4, ground placement of the blade wheel; S5, dismantling of a nacelle; S6, dismantling of a tower drum; S7, dismantling of a bottom tower drum; S8, equipment departure; and completion of the dismantling. The present application determines the number of high-strength connecting bolts or screw rods of the bottom tower drum and the foundation that are required to be reserved before dismantling each component, determines the number of bottom bolts that can be simultaneously dismantled when each large component of the wind turbine generator set is dismantled according to the number of the reserved bolts, thereby reducing the time consumption of the dismantling of the low-end tower drum and improving the rate of the dismantling of the whole machine. Under the premise of ensuring safety, the wind turbine generator set and the foundation connecting components are maximally protected from damage, and the dismantling construction cost is saved.

Description

Technical Field

[0001] This invention belongs to the field of wind power generation technology, and specifically relates to a protective dismantling method for onshore wind turbine generator sets. Background Technology

[0002] China's wind power development has spanned over 30 years, reaching a cumulative installed capacity of 338.31 GW by the end of 2021. Nearly 20 years have passed since the first batch of wind turbines were installed, and the upgrading and decommissioning of aging wind power projects are new challenges facing the industry. The dismantling of old wind turbines is a particularly dangerous sub-project. Whether it's upgrading or decommissioning, ensuring the reusability of the dismantled equipment and implementing protective dismantling measures are crucial, while also guaranteeing safety throughout the process.

[0003] Existing reverse-sequence dismantling methods require 3 days to dismantle a single unit, while methods based on simultaneously dismantling the bottom connecting bolts and top large components take 2 days. These methods result in low overall dismantling efficiency, and the wind turbine generator and foundation connection components are easily damaged during the dismantling process. A Chinese invention, wind turbine dismantling method (application publication number CN 105673348 A), dismantles the entire wind turbine generator by sequentially removing the rotor and nacelle, aiming to appropriately reduce the cost and difficulty of wind turbine maintenance and improve the economy and safety of wind farm construction. However, this method is designed for offshore wind turbine generators, primarily to prevent asymmetrical wave loads, which could lead to excessive tilting during dismantling, causing the entire wind turbine generator to overturn or even resulting in a complete loss of power. This method offers no benefit for the protective dismantling of onshore wind turbine generators. Summary of the Invention

[0004] To address the aforementioned problems, the purpose of this invention is to provide a protective dismantling method for onshore wind turbine generators. This method accelerates the dismantling efficiency of the entire wind turbine generator while ensuring safety, maximizes the protection of the wind turbine generator and its foundation connection components from damage, and saves on dismantling costs.

[0005] The technical solution of this invention is: a protective dismantling method for onshore wind turbine generator sets, the specific steps of which are as follows:

[0006] S1: Preparations before dismantling: Based on the design drawings, prepare the equipment and tools for dismantling.

[0007] S2: Installation of wind ropes and removal of internal components. Secure the two blades of the impeller with wind ropes and remove the connecting cables and other connecting components between the impeller and the nacelle.

[0008] S3: Impeller removal. Remove the connecting bolts between the impeller hub and the nacelle flange to separate the impeller from the nacelle.

[0009] S4: The impeller is placed on the ground and then placed on the impeller assembly fixture after being pulled horizontally by the tail crane, main crane and wind ropes. Then the blades are disassembled.

[0010] S5: Nacelle disassembly. Install the special steel wire rope for the nacelle on the nacelle lifting point, hang the hook, and then remove the connecting bolts between the nacelle and the tower.

[0011] S6: Tower dismantling. Remove the cables, ladders, and grounding wires inside the tower. Install the special tower lifting tools. After the main crane slowly lifts the hook and the lifting straps are under force, remove the connecting bolts between the tower sections.

[0012] S7: Bottom tower disassembly, remove the connecting bolts between the bottom tower and the foundation;

[0013] S8: Equipment leaves the site, dismantling complete.

[0014] In step S2, the installation of the wind-guiding rope and the removal of internal components involve fixing the wind-guiding rope to the two blades of the impeller. Specifically, the impeller is yawed to the windward side, forming a "Y" shape, so that one blade is perpendicular to the ground. The impeller is locked, and the wind-guiding rope is fixed to the blade perpendicular to the ground with the assistance of a crane. The above process is repeated to install the wind-guiding rope on the other adjacent blade. The impeller is then rotated so that the blade without the wind-guiding rope is perpendicular to the ground. The wind-guiding rope completes the fixing of the two blades of the impeller.

[0015] In step S2, the connecting cable and other connecting components between the impeller and the nacelle are removed, making the impeller and the nacelle relatively independent. The connecting components and cables are then securely tied with cable ties and packed into a box.

[0016] In steps S3 to S7, the "cross-shaped" method is used to remove the connecting bolts between the wheel hub and the engine compartment, the engine compartment and the tower, the tower and the bottom section of the tower and the foundation.

[0017] In steps S3 to S7, when removing the connecting bolts between the hub and the nacelle, the nacelle and the tower, the towers and the bottom section of the tower and the foundation, after adjusting the torque value of the hydraulic torque pump to the required installation torque value, the bolts are removed by sequentially and symmetrically pressing in the opposite direction using the cross method.

[0018] In steps S4 to S6, when the impeller, nacelle, and tower are at a distance of ≥1 meter from the ground, they are placed on the ground after being leveled by a double-platform crane.

[0019] In steps S2 to S6, the overturning moment required before dismantling each section of the wind turbine generator set is determined based on the wind load combination and gravity. Then, based on the maximum yield strength of the high-strength bolts, the minimum number of high-strength connecting bolts or studs between the bottom tower and the foundation that must be retained before dismantling each component is determined. Based on the number of retained bolts, the number of bottom bolts that can be removed simultaneously during the dismantling of each major component of the wind turbine generator set is determined. The calculation formula is as follows:

[0020] M = 2W i A i h i

[0021] M 抗 =G i R i +nTL i

[0022] K = M / M 抗

[0023] In the formula, M is the overturning moment; M 抗 To resist overturning bending moment; W i Let A be the average wind load on the i-th tower segment; i h is the area of ​​the i-th tower segment; i G is the distance from the point of application of the wind load on the i-th tower segment to the calculated section; i R is the weight of the i-th tower segment; i The lever arm from the center of gravity to the overturning axis; n is the number of bolts that need to be retained; T is the tensile force of a single bolt; L i is the distance from the i-th retaining bolt to the rotating shaft; K is the safety factor, which is 2.

[0024] The technical advantages of this invention are as follows: 1. The wind ropes of this invention fix the two blades of the impeller respectively, assisting in positioning and fixing during disassembly, thereby reducing the swaying of the impeller during disassembly and descent, and ensuring construction safety; 2. This invention calculates and determines the minimum number of high-strength connecting bolts or screws between the bottom tower and the foundation that need to be retained before dismantling each component. Based on the number of retained bolts, it determines the number of bottom bolts that can be removed simultaneously when dismantling each major component of the wind turbine generator set, thereby reducing the dismantling time of the lower tower and increasing the dismantling speed of the entire machine; 3. The dismantling method of this invention minimizes dismantling time and saves dismantling costs while ensuring dismantling safety, and is highly efficient, safe, and reliable; 4. The dismantling method of this invention directly utilizes the original installation site, resulting in less damage to the environment and site, and is low-carbon and environmentally friendly.

[0025] The following will provide further explanation in conjunction with the accompanying drawings. Attached Figure Description

[0026] Figure 1This is a flowchart illustrating a protective dismantling method for onshore wind turbine generators according to an embodiment of the present invention.

[0027] Figure 2 This is a schematic diagram of the installation of the guy rope according to an embodiment of the present invention.

[0028] Figure 3 This is a schematic diagram illustrating the bolt removal sequence using the cross-symmetry method according to an embodiment of the present invention. Detailed Implementation

[0029] Example 1

[0030] like Figure 1 As shown, a protective dismantling method for onshore wind turbine generators includes the following specific steps:

[0031] S1: Preparations before dismantling: Based on the design drawings, prepare the equipment and tools for dismantling.

[0032] S2: Installation of wind ropes and removal of internal components. Secure the two blades of the impeller with wind ropes and remove the connecting cables and other connecting components between the impeller and the nacelle.

[0033] S3: Impeller removal. Remove the connecting bolts between the impeller hub and the nacelle flange to separate the impeller from the nacelle.

[0034] S4: The impeller is placed on the ground and then placed on the impeller assembly fixture after being pulled horizontally by the tail crane, main crane and wind ropes. Then the blades are disassembled.

[0035] S5: Nacelle disassembly. Install the special steel wire rope for the nacelle on the nacelle lifting point, hang the hook, and then remove the connecting bolts between the nacelle and the tower.

[0036] S6: Tower dismantling. Remove the cables, ladders, and grounding wires inside the tower. Install the special tower lifting tools. After the main crane slowly lifts the hook and the lifting straps are under force, remove the connecting bolts between the tower sections.

[0037] S7: Bottom tower disassembly, remove the connecting bolts between the bottom tower and the foundation;

[0038] S8: Equipment leaves the site, dismantling complete.

[0039] In step S1, the preparation before dismantling involves preparing the equipment and tools for dismantling according to the design drawings.

[0040] The labor force required for dismantling a single wind turbine generator set is shown in Table 1, the materials used for dismantling are shown in Table 2, and the equipment and tools used for dismantling are shown in Table 3.

[0041] Table 1. Labor Allocation Table

[0042]

[0043] Table 2. List of materials needed for demolition

[0044]

[0045] Table 3. Equipment and Tools Required for Wind Turbine Generator Set Dismantling

[0046]

[0047]

[0048] In step S2, the installation of the wind-guiding ropes and the removal of internal components involve fixing the wind-guiding ropes to the two blades of the impeller. The specific process is as follows: Figure 2 As shown, first rotate the impeller to a positive "Y" shape and lock it. Then, using a crane and manual labor, install the protective sleeve for blade #1, perpendicular to the ground. Install the sleeve in the position specified by the manufacturer. After installation, rotate the impeller counterclockwise 120° and lock it. Install the protective sleeve for blade #2 in the same way, and then rotate it counterclockwise 120° to lock the impeller. Make blade #3 perpendicular to the ground. Guy ropes are used for auxiliary positioning and fixation during disassembly, thereby reducing swaying during impeller disassembly and descent.

[0049] In step S2, the connecting cables and other connecting components between the impeller and the nacelle are removed, making the impeller relatively independent from the nacelle. The connecting components and cables are then securely tied with cable ties before being packed into a box. This ensures that no internal collisions occur due to loose parts during the equipment lowering process.

[0050] In steps S3 and S4, the impeller is disassembled by removing the connecting bolts between the impeller hub and the nacelle flange, thus separating the impeller from the nacelle; the impeller is then placed on the ground. The specific process of impeller disassembly and ground placement is as follows:

[0051] 1. The main crane will place the special installation lifting tool in place. The installer will install the main crane lifting tool to the wheel hub lifting lug through the engine room skylight. Personnel and fixed traction measures at both ends of the guy ropes will be in place. The main crane will slowly lift the load so that the lifting straps are taut and under appropriate force.

[0052] 2. Mark the four symmetrical bolts connecting the impeller and the nacelle flange with a cross mark. Adjust the torque value of the hydraulic torque pump to the required installation torque value. Then, use the cross mark to press out the bolts in reverse symmetrically. Arrange the disassembled bolts and nuts neatly in a box.

[0053] 3. After the bolts are removed, the main crane quickly separates the impeller from the nacelle. During the separation process, the guy ropes are kept under tension, and the safe distance between the impeller and the crane and tower is adjusted as needed.

[0054] 4. Slowly lower the impeller. When the blade tip perpendicular to the ground is 2 meters away from the ground, install the tailing sleeve. Install the tailing sleeve and sling to the designated position. After the impeller is horizontally pulled by the tailing crane, main crane and wind rope, place it on the tooling frame for impeller assembly.

[0055] 5. Then the blades are disassembled and placed or hoisted onto blade transport vehicles and pulled off the site.

[0056] Step S5: Nacelle disassembly. Install the dedicated steel wire rope for the nacelle on the nacelle lifting point, attach the hook, and then remove the connecting bolts between the nacelle and the tower. The specific process is as follows:

[0057] 1. Inspect all components in the cabin, check whether the cable connections are loose, and whether there is any equipment that is not securely bundled. Securely tie the connecting parts and cables that need to be disassembled with cable ties before packing them into boxes.

[0058] 2. When dismantling the engine room, install the special steel wire rope for the engine room on the four lifting points of the engine room, hang the hooks, and only after checking that it is safe and secure can the engine room dismantling be carried out. First, tie two guy ropes to the head and tail of the engine room, and the ground staff will fix the rope ends to the ground anchor.

[0059] 3. The dismantling of the engine room shall be carried out in strict accordance with the manufacturer's technical documents;

[0060] 4. After the weight of the nacelle reaches a certain value, the crane adjusts the center of gravity and adjusts the torque value of the hydraulic torque pump to the required installation torque value. Then, the bolts are removed by symmetrically and in reverse using the cross method. The disassembled bolts and nuts are neatly placed in a box. When all the bolts are removed, the crane slowly lifts the hook. The ground workers pull the guy ropes and the person in charge pays attention to adjusting the center point. The hook is slowly lifted to lift the nacelle away from the tower.

[0061] 5. Slowly lower it onto the prepared tooling on the ground, then secure it with positioning bolts, and finally protect the cabin with special protective equipment.

[0062] Step S6: Tower dismantling. Remove the cables, ladders, and grounding wires inside the tower. Install the special tower lifting equipment. After the main crane slowly lifts the hook and the lifting straps are under load, dismantle the connecting bolts between the tower sections. The specific process is as follows:

[0063] 1. Before dismantling, remove the cables, ladders, and grounding wires inside the tower. Securely tie the dismantled components and cables with cable ties and pack them into boxes to ensure that no parts loosen and cause internal collisions during the equipment lowering process. Install the special lifting tools, and after the main crane slowly lifts the hook and the lifting straps are under force, remove the bolts. The removed bolts and nuts are neatly arranged and packed into boxes.

[0064] 2. After adjusting the hydraulic torque pump to the required installation torque value for the tower, use the cross method to symmetrically and in reverse pressurize and remove the bolts. Once all removal is complete, slowly lift and move the tower away.

[0065] 3. Slowly lower the tower section. When the tower section is ≥1 meter off the ground, hang the tailing hoist to the bottom of the tower section. Use the auxiliary hoisting lugs to flip the tower section down. The dismantling method for the middle section of the tower section is the same.

[0066] Step S7: Disassembly of the bottom tower section, including removing the connecting bolts between the bottom tower section and the foundation; the specific process is as follows:

[0067] 1. The disassembly steps for the bottom tower and foundation connection in the form of a base ring are the same as those for the tower disassembly described above. For the foundation connection in the form of a base ring, the bolts are disassembled directly using the cross-symmetry method. For the foundation in the form of anchor bolts, the left and right nuts are removed using an anchor bolt tensioner and a torque wrench according to the cross-symmetry principle. The disassembled bolts and nuts are neatly arranged and packed into a box.

[0068] 2. After removing the connecting bolts or nuts, proceed to step S6: Tower disassembly process to disassemble the bottom tower.

[0069] In steps S3 to S7, the "cross-shaped" method is used to remove the connecting bolts between the wheel hub and the nacelle, the nacelle and the tower, the towers, and the bottom tower section and the foundation. The "cross-shaped" method for removing the connecting bolts between the wheel hub and the nacelle, the nacelle and the tower, the towers, and the bottom tower section and the foundation is as follows: Figure 3 As shown.

[0070] In steps S3 to S7, when removing the connecting bolts between the hub and the nacelle, the nacelle and the tower, the towers and the bottom section of the tower and the foundation, after adjusting the torque value of the hydraulic torque pump to the required installation torque value, the bolts are removed by sequentially and symmetrically pressing in the opposite direction using the cross method.

[0071] In steps S4 to S6, when the impeller, nacelle, and tower are at a distance of ≥1 meter from the ground, they are placed on the ground after being leveled by a double-platform crane.

[0072] In steps S2 to S6, the overturning moment required before dismantling each section of the wind turbine generator set is determined based on the wind load combination and gravity. Then, based on the maximum yield strength of the high-strength bolts, the minimum number of high-strength connecting bolts or studs between the bottom tower and the foundation that must be retained before dismantling each component is determined. Based on the number of retained bolts, the number of bottom bolts that can be removed simultaneously during the dismantling of each major component of the wind turbine generator set is determined. The calculation formula is as follows:

[0073] M=∑W i A i h i

[0074] M抗 =G i R i +∑nTL i

[0075] K = M / M 抗

[0076] In the formula, M is the overturning moment; M 抗 To resist overturning bending moment; W i Let A be the average wind load on the i-th tower segment; i h is the area of ​​the i-th tower segment; i G is the distance from the point of application of the wind load on the i-th tower segment to the calculated section; i R is the weight of the i-th tower segment; i The lever arm from the center of gravity to the overturning axis; n is the number of bolts that need to be retained; T is the tensile force of a single bolt; L i is the distance from the i-th retaining bolt to the rotating shaft; K is the safety factor, which is 2.

[0077] Economic Benefit Analysis

[0078] The application of this method effectively improved the overall dismantling efficiency, reduced dismantling costs, and ensured a safe and reliable dismantling process. Compared to the dismantling time of the first two machines in this project, this method reduced the overall dismantling time from 3 days to 2 days, saving a significant amount of labor and machine shifts (one day). A detailed analysis of the benefits per unit is shown in Table 4.

[0079] Table 4. Economic Benefits Analysis of Single Wind Turbine Removal

[0080]

[0081] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for protective dismantling of onshore wind turbine generator sets, characterized in that: Includes the following steps: S1: Preparations before dismantling: Based on the design drawings, prepare the equipment and tools for dismantling. S2: Installation of wind ropes and removal of internal components. Secure the two blades of the impeller with wind ropes and remove the connecting cables and components between the impeller and the nacelle. S3: Impeller removal. Remove the connecting bolts between the impeller hub and the nacelle flange to separate the impeller from the nacelle. S4: The impeller is placed on the ground and then placed on the impeller assembly fixture after being pulled horizontally by the tail crane, main crane and wind ropes. Then the blades are disassembled. S5: Nacelle disassembly. Install the special steel wire rope for the nacelle on the nacelle lifting point, hang the hook, and then remove the connecting bolts between the nacelle and the tower. S6: Tower dismantling. Remove the cables, ladders, and grounding wires inside the tower. Install the special tower lifting tools. After the main crane slowly lifts the hook and the lifting straps are under force, remove the connecting bolts between the tower sections. S7: Bottom tower disassembly, remove the connecting bolts between the bottom tower and the foundation; S8: Equipment departs, dismantling completed; In steps S2-S6, the overturning moment required before dismantling each section of the wind turbine generator set is determined based on the wind load combination and gravity. Then, based on the maximum yield strength of the high-strength bolts, the number of high-strength connecting bolts or studs between the bottom tower and the foundation that must be retained before dismantling each component is determined. Based on the number of retained bolts, the number of bottom bolts that can be removed simultaneously during the dismantling of each major component of the wind turbine generator set is determined. The calculation formula is as follows: K=M / M 抗 In the formula, M is the overturning moment; M 抗 To resist overturning bending moment; This represents the average wind load on the i-th tower segment; Let i be the area of ​​the i-th tower segment; The distance from the point of application of the wind load on the i-th tower segment to the calculated section; Let be the weight of the i-th tower segment; The lever arm is the distance from the center of gravity to the axis of rotation that causes the overturning. The number of bolts to be retained; T is the tensile force of a single bolt; is the distance from the i-th retaining bolt to the rotating shaft; K is the safety factor, which is 2.

2. The protective dismantling method for onshore wind turbine generators according to claim 1, characterized in that: In step S2, the installation of the wind-guiding rope and the removal of internal components involve fixing the wind-guiding rope to the two blades of the impeller. Specifically, the impeller is yawed to the windward side, forming a "Y" shape, so that one blade is perpendicular to the ground. The impeller is locked, and the wind-guiding rope is fixed to the blade perpendicular to the ground with the assistance of a crane. The above process is repeated to install the wind-guiding rope on the other adjacent blade. The impeller is then rotated so that the blade without the wind-guiding rope is perpendicular to the ground. The wind-guiding rope completes the fixing of the two blades of the impeller.

3. The protective dismantling method for onshore wind turbine generators according to claim 1, characterized in that: In step S2, the connecting cable and connecting components between the impeller and the nacelle are removed, making the impeller and the nacelle relatively independent. The connecting components and cables are then securely tied with cable ties before being packed into a box.

4. The protective dismantling method for onshore wind turbine generators according to claim 1, characterized in that: In steps S3 to S7, the "cross-shaped" method is used to remove the connecting bolts between the wheel hub and the nacelle, the nacelle and the tower, the towers, and the bottom tower section and the foundation.

5. The protective dismantling method for onshore wind turbine generators according to claim 4, characterized in that: In steps S3 to S7, when removing the connecting bolts between the hub and the nacelle, the nacelle and the tower, the towers and the bottom section of the tower and the foundation, after adjusting the torque value of the hydraulic torque pump to the required installation torque value, the bolts are removed by sequentially and symmetrically pressing in the opposite direction using the cross method.

6. The protective dismantling method for onshore wind turbine generators according to claim 1, characterized in that: In steps S4 to S6, when the impeller, nacelle, and tower are at a distance of ≥1 meter from the ground, they are placed on the ground after being leveled by a double-platform crane.

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