Method for dismantling wind turbine towers for power generation

Abstract

To provide a method for dismantling wind turbine towers for power generation that can be transported by ordinary trucks or trailers, without using special vehicles that require wide construction roads, while avoiding the use of large cranes as much as possible.SOLUTION: A method for dismantling a wind turbine tower for power generation comprises a hoisting process for hoisting down a cylindrical block 10 that constitutes a wind turbine tower for power generation, a horizontal laying process for laying down the hoisted block 10 horizontally and supporting it on a plurality of support platforms 20, and a cutting process for cutting the block 10 while it is supported on the plurality of support platforms 20 horizontally, to form fragments 11a, etc. that have a semi-cylindrical shape with a dimension in a height direction of the tower half or less than the height of the block 10.SELECTED DRAWING: Figure 9

Description

[Technical field]

[0001] The present invention relates to a dismantling method for dismantling a power-generating wind turbine tower used as a support for a propeller and a nacelle of a power-generating wind turbine. [Background technology]

[0002] Due to the global trend towards adopting renewable energy, many wind turbines for power generation have been installed in Japan since around 2000. Most wind turbines for power generation have a design life of 20 years due to fatigue strength, and because they are depreciated over 17 years for tax purposes, many of them will be dismantled and removed in the future. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2023-002910 A Summary of the Invention [Problem to be solved by the invention]

[0004] Power-generating wind turbines are normally installed in windy locations, and because of noise issues, they are often installed in locations far from residential areas, for example by cutting open mountainous areas. For this reason, when constructing a power-generating wind turbine, in order to shorten the on-site construction period, a wide construction road is built and vacant land is developed around the construction site, after which large block parts are transported using special vehicles and assembled using large cranes.

[0005] However, when dismantling a wind turbine for power generation, trees may have grown around it 20 years after construction, and the only roads available may be those that are accessible only by general maintenance vehicles. Costs are incurred to prepare roads and vacant lots for construction that are the same size as those used during construction. For this reason, if there are no plans to reuse the dismantled parts, it is not realistic to simply dismantle the turbine in the reverse order of construction. Since reduction in total costs is required during dismantling rather than shortening the construction period, it is desirable to avoid using large cranes as much as possible during dismantling, and to transport the turbine using general trucks or trailers rather than using special vehicles that require wide construction roads.

[0006] Therefore, the inventors investigated a method for dismantling the tower section, which is the component part of a power-generating wind turbine that is least likely to be reused and is the heaviest and largest in volume, and came up with the present invention. [Means for solving the problem]

[0007] A method for dismantling a power-generating wind turbine tower according to one aspect of the present invention includes: a lowering process for lowering a cylindrical block constituting the tower of the power-generating wind turbine; a sideways laying step of laying the lowered block sideways and supporting it on a plurality of pedestals; a cutting step of cutting the block while the block is supported on the pedestals in a horizontal position to form a piece having a semi-cylindrical shape whose dimension in the height direction of the tower is half or less of the block; Includes. The demolition method of the present invention is as follows: a bending step of applying a pressing force to the piece from the outer periphery of the semi-cylinder to bend the piece along a bending line parallel to the height direction of the tower; It may further include: [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 shows the hoisting and lowering step S1a in the first embodiment. [Diagram 2]FIG. 2 shows the laying down step S1b in the first embodiment. [Diagram 3] FIG. 3 shows the laying down step S1c in the first embodiment. [Figure 4] 4A to 4C show the laying down step S1d in the first embodiment. [Diagram 5] FIG. 5 shows a cutting step S1e in the first embodiment. [Figure 6] FIG. 6 conceptually illustrates a self-propelled cutting machine 60 used in the cutting steps S1e, S1g, and S1h. [Figure 7] FIG. 7 shows an enlarged view of the start position Start and the end position End of one circumferential cutting line 12. [Figure 8] FIG. 8 shows a cutting step S1f in the first embodiment. [Figure 9] FIG. 9 shows the cutting step S1g in the first embodiment. [Figure 10] FIG. 10 shows a cutting step S1h in the first embodiment. [Figure 11] FIG. 11 shows the folding step S1i in the first embodiment. [Figure 12] FIG. 12 shows the folding step S1j in the first embodiment. [Figure 13] FIG. 13 shows step S1k of removing the fragment 11b. [Figure 14] FIG. 14 shows step S1m of removing the fragment 11b. [Figure 15] FIG. 15 shows step S1n of exporting the fragment 11b. [Figure 16] FIG. 16 shows how the lower piece 11c of the lying block 10 is lifted up after the cutting step S1g. [Figure 17] FIG. 17 shows the state in which the piece 11c is divided into two pieces 11d and placed on a wooden block for bending. [Figure 18] 18A to 18C show the laying down step S2d in the second embodiment. [Figure 19]19A and 19B show the cutting step S2e in the second embodiment. [Figure 20] FIG. 20 shows the cutting step S2g in the second embodiment. [Figure 21] FIG. 21 shows a cutting step S2h in the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, the embodiments of the present invention will be described in detail. Note that the embodiments described below do not unduly limit the contents of the present invention described in the claims. Furthermore, not all of the configurations described in the embodiments are necessarily essential as the means for solving the problems of the present invention. Furthermore, the same components are given the same reference symbols and descriptions thereof will be omitted.

[0010] <1. First embodiment> <1-1. Overall explanation of demolition method> The power-generating wind turbine in the first embodiment is dismantled in the following procedure. (1) Secure working space around the power-generating wind turbines to be dismantled and prepare cranes and other equipment. (2) Remove the propeller (rotor) and hang it down. (3) Remove the nacelle (generator) and hoist it down. (4) The tower is dismantled into blocks and lowered (lowering process S1a). (5) The block is laid on its side (laying down steps S1b to S1d). (6) Cutting the block into pieces (cutting steps S1e to S1h). (7) The pieces are folded (folding steps S1i and S1j). (8) The fragments are transported by truck or trailer (S1k~S1n).

[0011] The blocks that make up the tower are assumed to be 20 m long (height dimension H of the tower), 4 m in diameter, weigh 40 t, and have steel plate thickness of 25 mm. The reason for setting the block length at 20 m is that it is thought that when constructing a wind turbine to generate electricity, large parts close to the upper limit for public road transportation (20 m) are often transported and assembled.

[0012] In step (8), for example, if a 10-ton truck is assumed for removal, the maximum weight is about 8 tons, and the truck is loaded so that the dimensions are 2.3 m wide x 7 m long x 3 m high. The reason for setting the maximum weight at about 8 tons is that even if it is a 10-ton truck, a fuel tank may be added or the loading platform may be reinforced, so it is not necessarily possible to load 10 tons of cargo onto a 10-ton truck.

[0013] In order to reduce the size of the large blocks as described above to a size that can be transported by truck or trailer, steps (4) to (6) are carried out, and more preferably step (7) is carried out.

[0014] <1-2. Step (4): Lifting and lowering process S1a> 1 shows the hoisting and lowering step S1a in the first embodiment. The tower of a power-generating wind turbine is assembled by bolting a number of blocks 10 together at their internal flanges (not shown). By removing the bolts from the top block 10 in order, the blocks 10 can be hoisted and lowered by a crane C500. Taking into consideration the weight of the blocks 10 and the height at which they are installed, for example, a 500 t class crane is used as the crane C500. The 500 t class crane C500 can also be used in steps (2) and (3) prior to step (4).

[0015] Block 10 is made of steel plates and has a roughly cylindrical shape. The direction parallel to the central axis of the cylinder of block 10 and the direction that will be the upper side when assembled into a tower is defined as the height direction H of the tower. If block 10 is tilted, the height direction H of the tower will also tilt (see Figures 2 and 3).

[0016] With the block 10 lowered to a height close to the ground, the rotating shafts 31 and 32 are fixed to the lower end of the block 10. The rotating shafts 31 and 32 are each a cylindrical rod, and are fixed to the block 10 via a fixing member (not shown) and a bolt hole in the internal flange of the block 10. The rotating shafts 31 and 32 are approximately parallel to each other, and are approximately the same distance from the lower end of the block 10.

[0017] Before the block 10 is lowered onto the ground, a two-stage platform 40 is installed on the ground. The two-stage platform 40 includes shaft support parts 41 and 42 that are at different heights from the ground. The shaft support parts 41 and 42 are configured to support the rotating shafts 31 and 32, respectively. The distance between the shaft support parts 41 and 42 is approximately equal to the distance between the rotating shafts 31 and 32.

[0018] When the block 10 is lowered by the crane C500, the height direction H of the tower faces almost straight up. In this state, as shown by the dashed line in Fig. 1, the higher shaft support part 41 can support the rotating shaft 31, but the lower shaft support part 42 is separated from the rotating shaft 32. The center of gravity G of the block 10 is not located directly above the rotating shaft 31, and is separated from the vertical plane 31p that extends the rotating shaft 31 in the direction opposite to the direction of gravity. Therefore, as the crane C500 is lowered, a rotational force is applied to the block 10 by the gravity acting on the block 10 and the reaction force that the shaft support part 41 exerts on the rotating shaft 31.

[0019] <1-3. Step (5): Laying down process S1b to S1d> FIG. 2 shows the sideways-tilting step S1b in the first embodiment. As the crane C500 is lowered, the block 10 tilts around the rotating shaft 31. When the rotating shaft 32 reaches the lower shaft support 42, if the center of gravity G of the block 10 is located between the vertical plane 32p extending the rotating shaft 32 in the direction opposite to the direction of gravity and the vertical plane 31p, the block 10 will not tilt any further. However, in this embodiment, since the center of gravity G passes the vertical plane 32p, as the crane C500 is lowered, a rotational force is applied to the block 10 by the gravity acting on the block 10 and the reaction force that the shaft support 42 gives to the rotating shaft 32. As a result, as shown by the dashed line in FIG. 2, the rotating shaft 31 moves away from the shaft support 41, and the block 10 tilts further around the rotating shaft 32.

[0020] Fig. 3 shows the laying down step S1c in the first embodiment. When the block 10 is laid down almost horizontally, the lower end side in the height direction H of the tower is supported by the shaft support part 42 via the rotating shaft 32. If the upper end side in the height direction H of the tower is supported by some kind of support, the crane C500 can be removed as shown by the dashed line in Fig. 3. In the first embodiment, by using the two-stage platform 40, it is not necessary to use large-scale equipment or a large work site for the laying down step, such as two large cranes for hoisting together.

[0021] 4A to 4C show the laying down step S1d in the first embodiment. FIG. 4B is a view seen in the direction of the arrow IVB shown in FIG. 4A, and FIG. 4C is a view seen in the direction of the arrow IVC shown in FIG. 4A. In the first embodiment, the block 10 is supported by a plurality of receiving tables 20 for the next cutting steps S1e to S1g. The plurality of receiving tables 20 may be installed in a work place other than the work place where the hoisting down step S1a is performed. A 200t class crane (not shown) may be used to move the block 10 (see FIG. 3) laid down by the two-stage platform 40 to the plurality of receiving tables 20. In that case, while the 200t class crane is in use, the crane C500 can be used for the hoisting down step S1a and the laying down steps S1b and S1c of the other block 10, improving the work efficiency.

[0022] 4B and 4C, the direction around the central axis of the cylinder of the block 10 is defined as the circumferential direction R. As will be described later with reference to Fig. 5, when the block 10 is divided into five pieces by cutting it into rings at four circumferential cutting lines 12, for example, the multiple receiving pedestals 20 include five receiving pedestals 20 as shown in Fig. 4A.

[0023] The block 10 has a slightly larger diameter at the lower end than at the upper end in the height direction H of the tower. The five pedestals 20 include adjustment members 21 of different sizes, and the adjustment member 21 included in the pedestal 20 at the upper end in the height direction H of the tower is larger than the adjustment member included in the pedestal 20 at the lower end in the height direction H of the tower. This allows the central axis of the cylinder of the block 10 to be approximately horizontal when the block 10 is supported by the five pedestals 20. The five pedestals 20 have a common configuration except for the adjustment member 21, and by making the adjustment member 21 replaceable, the materials can be shared. Note that the reference numerals in the drawings are omitted for the adjustment members 21 of the multiple pedestals 20 that are smaller in size.

[0024] <1-4. Step (6): Cutting steps S1e to S1h> 5 and 8 to 10 show cutting steps S1e to S1h in the first embodiment. In cutting steps S1e to S1g, while the block 10 is supported on its side by a plurality of receiving stands 20, the block 10 is cut into five rings along the circumferential cutting line 12, and further divided vertically into two along the axial cutting line 13a (see FIG. 9). This results in ten pieces 11a (see FIG. 10) each having a semi-cylindrical shape. However, the present invention is not limited to dividing the block 10 into five rings, and if the length of the block 10 is originally short, it may be divided into two or three.

[0025] 5 (cutting step S1e), cutting is performed along circumferential cutting lines 12 and axial cutting lines 13. When cutting along axial cutting lines 13, if an attempt is made to completely cut the sliced ​​block 10 pieces vertically, the weight of the piece will close the cut edge and cutting will become impossible, so instead of cutting completely vertically, uncut portions are left at the top and bottom ends of the tower height direction H.

[0026] 6 conceptually illustrates a self-propelled cutting machine 60 used in the cutting steps S1e, S1g, and S1h. The self-propelled cutting machine 60 includes a magnet (not shown) that generates an attractive force between the self-propelled cutting machine 60 and the surface of the block 10, a plurality of wheels 61 that enable the self-propelled cutting machine 60 to travel on the surface of the block 10, a motor (not shown) that drives the wheels 61, and a gas nozzle 62 that sprays a flame of flammable gas and high-pressure oxygen gas. The flammable gas may be any fuel, such as acetylene, propane, or hydrogen. The operation of the motor is remotely controlled by a signal from a controller (not shown) held by the operator.

[0027] FIG. 7 shows an enlarged view of the start position Start and the end position End of one circumferential cutting line 12. Since the block 10 has a tapered shape with a diameter that varies slightly depending on the position in the height direction H of the tower, it is difficult to match the start position Start of cutting the block 10 in the circumferential direction R with the end position End of cutting the block 10 one revolution from the start position Start. Therefore, before starting cutting from the start position Start, a cut 14 is made in a direction that intersects with the circumferential cutting line 12. The cut 14 may be made at a height that is within reach of the hand using a manually operated gas cutting machine (not shown). By making the cut 14, even if the start position Start and the end position End are slightly misaligned, the block 10 can be reliably cut into rings by cutting one or more revolutions in the circumferential direction R. Each of the five pieces obtained by cutting into rings is hereinafter referred to as a ring-cut piece.

[0028] FIG. 8 (cutting step S1f) shows a state in which a crane C50 is connected to a portion of the block 10 that will become the semi-cylinder fragment 11a. For example, a 50 ton class crane is used as the crane C50. The crane C50 is less expensive than the crane C500, requires a smaller installation space, and requires fewer workers. The crane C50 pulls the sliced ​​pieces upward with a pulling force roughly equivalent to the weight of the fragments 11a, but since the sliced ​​pieces are twice as heavy as the fragments 11a, the sliced ​​pieces do not lift up. A wire may be used to pull the fragments 11a upward, but more simply, a lifting magnet may be used to attract the fragments 11a.

[0029] 9 (cutting step S1g), the sliced ​​piece is cut at both ends of the axial cutting line 13a while being pulled upward by the crane C50, thereby lifting the fragment 11a. The fragment 11a is moved by the crane C50 to a work site where the cutting step S1h and the subsequent bending steps S1i and S1j are performed.

[0030] In this embodiment, the 20m block 10 is cut into 5 rings, so the length of the pieces 11a is 4m, which is still too large to be transported by a 10-ton truck. However, if the block 10 is cut into, for example, 10 rings, the length of the pieces 11a will be 2m, and if the pieces are further cut along the axial cutting line 13a to form semi-cylinders, they will be able to be transported by a 10-ton truck. In this case, the cutting step S1h and the bending steps S1i and S1j can be omitted.

[0031] In FIG. 10 (cutting step S1h), the piece 11a is placed on a block, and cut along the circumferential cutting line 15 to divide the piece 11a into two semi-cylindrical pieces 11b, and then cut along the axial cutting line 16. The axial cutting line 16 constitutes the folding line in the folding steps S1i and S1j. Since the semi-cylindrical piece 11a is placed on the block, if there is a self-propelled cutting machine 60 and a scaffolding with a height of about 1.8 m, a worker can perform the cutting step S1h while visually checking. The axial cutting line 16 does not completely divide the piece 11b, but cuts the piece 11b leaving the upper and lower ends of the piece 11b in the height direction H of the tower. The length of the axial cutting line 16 is set to a length that will not crush the piece 11b even if a person stands on it after cutting, and for example, an uncut area of ​​about 200 mm is left at the upper and lower ends.

[0032] <1-5. Step (7): Folding process S1i, S1j> 11 and 12 show bending steps S1i and S1j in the first embodiment. The bending steps S1i and S1j are steps in which a cylindrical weight 70 is placed on the fragment 11b so as to be parallel to the axial cutting line 16, and a pressing force F is applied to the fragment 11b from the outer periphery of the semicylinder, thereby bending the fragment 11b along the axial cutting line 16. The weight 70 includes, for example, concrete and has a weight of, for example, 1500 kg, and is placed on the fragment 11b by a crane S50.

[0033] Before being folded, each piece 11b has a size of, for example, 2 m wide × 4 m long × 2 m high, but by folding as shown in Fig. 12, the size becomes approximately 2 m wide × 5.6 m long × 0.6 m high. Since the axial cutting lines 16 are formed in advance and then the pieces are folded along the axial cutting lines 16, the shape of the folded pieces 11b becomes almost constant, and the pieces can be stacked compactly as will be described later with reference to Fig. 14.

[0034] <1-6. Step (8): Steps S1k to S1n for carrying out the fragment 11b> Figures 13 to 15 show steps S1k to S1n for carrying out the pieces 11b. As shown in Figure 13, the folded pieces 11b are lifted by a crane C50, and multiple pieces 11b are piled up in a temporary storage area as shown in Figure 14. As shown in Figure 15, multiple pieces 11b can be loaded onto the bed of a 10-ton truck. The weight of the pieces 11b is about 2 tons, and for example, four pieces 11b, i.e., a total of 8 tons, can be transported by one 10-ton truck.

[0035] <1-7. When reversing fragment 11c: S3g, S3h> 16 shows how the fragment 11c located at the bottom of the fallen block 10 is lifted after the cutting step S1g. The fragment 11c is supported by the support 20 with the outer circumferential surface of the semi-cylinder facing downward. Before lifting the fragment 11c, if there is an object such as a ladder installed inside the block 10, it is disassembled and removed.

[0036] A hanging piece 17 is welded and fixed to a part of the outer circumferential surface of the piece 11c, and the piece 11c can be turned upside down by lifting it up with a crane C50.

[0037] Fig. 17 shows a state where the piece 11c is divided into two pieces 11d and placed on a block to be folded. The subsequent folding process and the process of carrying out the pieces 11d are the same as those described with reference to Figs. 11 to 15.

[0038] <1-8. Effects of the First Embodiment> (I) According to the first embodiment, the method for dismantling a power-generating wind turbine tower includes a hanging / lowering process S1a, in which a cylindrical block 10 constituting the tower of the power-generating wind turbine is hung down, sideways laying processes S1b to S1d, in which the hung / lowered block 10 is laid on its side and supported by a plurality of receiving stands 20, and cutting processes S1e to S1h, S3h, in a state in which the block 10 is laid on its side and supported by the plurality of receiving stands 20, to cut the block 10 to form pieces 11a, 11b, 11c, 11d having a semi-cylindrical shape whose dimension in the height direction H of the tower is less than half that of the block 10.

[0039] According to this method, the cylindrical block 10 is lowered, turned sideways, and cut into pieces 11a, 11b, 11c, and 11d while supported by a plurality of pedestals 20, so that the huge tower can be dismantled safely. Also, by making the dimension of the tower in the height direction H less than half that of the block 10, and further cutting the block 10 into semi-cylindrical pieces 11a, 11b, 11c, and 11d, the pieces 11a, 11b, 11c, and 11d can be stacked, and transportation from the dismantling site can be realized at low cost.

[0040] (II) According to the first embodiment, the method for dismantling a power-generating wind turbine tower further includes bending processes S1i and S1j in which a pressing force F is applied to the pieces 11b and 11d from the outer periphery of the semi-cylinder to bend the pieces 11b and 11d at bending lines 16 parallel to the height direction H of the tower.

[0041] According to this, the semi-cylindrical fragments 11b and 11d are deformed into a shape of two quarter cylinders combined (see FIG. 12), so that the fragments 11b and 11d are not bulky even when stacked, and the center of gravity of the fragments 11b and 11d is low, so that transportation by truck or trailer can be easily performed. In addition, when the fragments 11b and 11d are completely cut and separated at the bending line (axial cutting line) 16, the inside of the semi-cylindrical fragments 11b and 11d must be supported in advance so that they do not collapse when cutting is completed, but by folding them without cutting them, the work can be performed safely without taking special measures to prevent collapse. When the fragments 11b and 11d are completely cut and separated at the bending line (axial cutting line) 16, the size of the fragments is halved but the number is doubled, so that the amount of work in the process S1k to carry them out by the crane C50 may be doubled, but by folding them without cutting them, the increase in the amount of work is suppressed.

[0042] (III) According to the first embodiment, the cutting steps S1e to S1h include cutting the block 10 in the circumferential direction R from the start position Start, after making a slit 14 between a start position Start and an end position End at which the block 10 has been cut one revolution from the start position Start.

[0043] According to this, even if the start position Start and the end position End are misaligned when cutting the block 10 one revolution, the block 10 can be reliably sliced ​​into a ring.

[0044] <2. Second embodiment> <2-1. Differences from the first embodiment> Figures 18A to 18C show the laying down step S2d in the second embodiment. Figure 18B is a view seen in the direction of the arrow XVIIIB shown in Figure 18A, and Figure 18C is a view seen in the direction of the arrow XVIIIC shown in Figure 18A. Instead of the multiple support pedestals 20 in the first embodiment, in the second embodiment, the block 10 is supported by multiple support pedestals 80. The multiple support pedestals 80 include five support pedestals 80.

[0045] As shown in Fig. 18A, two turning rolls 82 are arranged on each of the multiple receiving tables 80. As shown in Fig. 18B and Fig. 18C, each of the turning rolls 82 is a jig that places the block 10 between two rollers having parallel rotation axes and rotates the rollers, thereby rotating the block 10 around the rotation axis Ax parallel to the height direction H of the tower (in the circumferential direction R).

[0046] Some of the ten turning rolls 82 are equipped with roller drive mechanisms 83. If there are only one or two turning rolls 82 equipped with drive mechanisms 83, the turning rolls 82 equipped with drive mechanisms 83 may not come into contact with the block 10 due to distortion or bending of the block 10. Therefore, three turning rolls 82 located at both ends and near the center of the ten turning rolls 82 are equipped with drive mechanisms 83.

[0047] Of the ten turning rolls 82, the turning rolls 82 located at both ends are fixed to the respective receiving tables 80. Slide plates (not shown) are disposed between the eight turning rolls 82 and the respective receiving tables 80 so that the eight turning rolls 82 other than those at both ends can move relative to the receiving tables 80. In addition, the distance between the two rollers included in each of these eight turning rolls 82 can be manually adjusted, thereby making it possible to average out the load applied to the ten turning rolls 82.

[0048] The five receiving bases 80 include adjustment members 81 of different sizes, and the adjustment member 81 included in the receiving base 80 at the upper end in the height direction H of the tower is larger than the adjustment member included in the receiving base 80 at the lower end in the height direction H of the tower. The five receiving bases 80 have a common configuration except for the adjustment member 81, and by making the adjustment member 81 replaceable, it is possible to standardize materials.

[0049] 18C shows a cutting torch 90 used in the cutting step S2e (see FIG. 19). The cutting torch 90 has a gas nozzle 92 fixed to a tripod 91. By spraying a flame and high-pressure oxygen gas toward the block 10 while rotating the block 10 around the rotation axis Ax by the turning roll 82, the block 10 can be cut along the circumferential cutting lines 15 and 12.

[0050] 19 to 21 show cutting steps S2e, S2g, and S2h in the second embodiment. Fig. 19A is a view seen in the direction of the arrow XIXA shown in Fig. 19B. In Fig. 19 (cutting step S2e), in a state where the block 10 is supported on a plurality of receiving pedestals 80 in a laid-down state, a plurality of cuts are formed to obtain a plurality of pieces 11b (see Fig. 21). The plurality of cuts are formed by cutting along the axial cut lines 13 (see Fig. 19B) and 16 (see Fig. 19A) and the circumferential cut line 15, respectively.

[0051] The cutting along the axial cutting lines 13, 16 and the circumferential cutting line 15 is not performed completely, but rather, an uncut portion is left at both ends of each cutting line. After the cutting along the axial cutting lines 13, 16 and the circumferential cutting line 15, the cutting along the circumferential cutting line 12 is performed.

[0052] The cutting at the circumferential cutting lines 15, 12 can be performed using a cutting torch 90 while the block 10 is rotated by the turning roll 82. If multiple cutting torches 90 are prepared, it is possible to cut multiple locations per one rotation of the block 10. Since the position of the block 10 shifts in the axial direction when the block 10 is rotated multiple times, for example, it is desirable to simultaneously cut at four locations at the circumferential cutting line 12 by rotating the block 10 once.

[0053] The cutting at the axial cutting lines 13, 16 may be performed using a self-propelled cutting machine 60 (see FIG. 6) after the block 10 is rotated by a turning roll 82 so that the positions of the axial cutting lines 13, 16 are at a height where they can be visually recognized. Alternatively, the cutting may be performed using a manually operated gas cutting machine (not shown) after the block 10 is rotated by a turning roll 82 so that the positions of the axial cutting lines 13, 16 are at a height where they can be reached by hand.

[0054] When cutting along the circumferential cutting lines 12, as described with reference to FIG. 7, cuts 14 may be made in advance in a direction intersecting with the circumferential cutting lines 12.

[0055] The operation of connecting the crane C50 to the portion of the block 10 that will become the semi-cylinder piece 11a is similar to that described with reference to FIG. 8 (cutting step S1f).

[0056] In FIG. 20 (cutting step S2g), the sliced ​​piece is cut at both ends of the axial cutting line 13a while being pulled upward by the crane C50, thereby lifting the piece 11a.

[0057] In Fig. 21 (cutting step S2h), the piece 11a is placed on a block and the circumferential cutting line 15 is extended and cut to separate the piece 11a into two semi-cylindrical pieces 11b. The uncut area of ​​the circumferential cutting line 15 is at a height that can be reached by hand, so the cutting step S2h can be performed without scaffolding. Cutting at the axial cutting line 16 is not performed in Fig. 21 because it has already been performed in Fig. 19A.

[0058] The subsequent steps are the same as those in the first embodiment. Folding steps S1i and S1j (Fig. 11 and Fig. 12) Steps S1k to S1n for carrying out the fragment 11b (FIGS. 13 to 15) Inversion (FIGS. 16 and 17) of the fragment 11c, folding process, and process of carrying out the fragment 11d

[0059] <2-2. Effects of the Second Embodiment> (IV) According to the second embodiment, the cutting steps S2e, S2g, and S2h include cutting the block 10 in the circumferential direction R while rotating the block 10 about a rotation axis Ax parallel to the height direction H of the tower.

[0060] This makes it possible to cut the block 10 without constructing a large scaffolding for cutting the block 10. Also, since cutting is possible even when the cutting torch 90 is in a fixed position, the burden of checking safety when working with fire is reduced. [Explanation of symbols]

[0061] 10...block, 11a, 11b, 11c, 11d...fragment, 12...circumferential cutting line, 13, 13a...axial cutting line, 14...slit, 15...circumferential cutting line, 16...axial cutting line, 17...hanging piece, 20...support, 21...adjusting member, 31, 32...rotating shaft, 31p, 32p...vertical surface, 40...two-stage stand, 41, 42...shaft support, 60...self-propelled cutting machine, 61...wheel, 62...gas nozzle, 70...weight, 80...support, 81...adjusting member, 82...turning roll, 83...drive mechanism, 90...cutting Cutting torch, 91...tripod, 92...gas nozzle, Ax...rotating axis, C50, C500...crane, Start...starting position, End...end position, F...pressing force, G...centre of gravity, H...tower height direction, R...circumferential direction, S1a...lowering process, S1b, S1c, S1d...tilting process, S1e, S1f, S1g, S1h...cutting process, S1i, S1j...bending process, S1k, S1m, S1n...transporting process, S2d...tilting process, S2e, S2g, S2h...cutting process, S3g...inverting process, S3h...cutting process

Claims

1. a lowering process for lowering a cylindrical block constituting the tower of the power-generating wind turbine; a sideways laying step of laying the lowered block sideways and supporting it on a plurality of pedestals; a cutting step of cutting the block while the block is supported on the pedestals in a horizontal position to form a piece having a semi-cylindrical shape whose dimension in the height direction of the tower is half or less of the block; A method for dismantling wind turbine towers, including:

2. In claim 1, a bending step of applying a pressing force to the piece from the outer periphery of the semi-cylinder to bend the piece along a bending line parallel to the height direction of the tower; The present invention further includes a method for dismantling a power generating wind turbine tower.

3. In claim 1 or 2, the cutting step includes forming a cut between a start position for cutting the block in a circumferential direction and an end position at which the block has been cut one revolution from the start position, and then cutting the block in the circumferential direction from the start position. Dismantling method for power generating wind turbine towers.

4. In claim 1 or 2, The cutting step includes cutting the block in a circumferential direction while rotating the block about a rotation axis parallel to a height direction of the tower. Dismantling method for power generating wind turbine towers.

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