A method for replacing a broken blade of a wind turbine generator set

Abstract

The embodiment of the present invention discloses a method for replacing a broken blade of a wind turbine generator set, comprising: S1, drilling a hole at the root of the broken blade and installing a hanger; S2, drilling a hole in the unshed part of the broken blade and installing a hanger; S3, disassembling the broken blade in a vertical state; S4, disassembling a part of the air deflector; S5, installing and disassembling the wind rotor disassembly hanger; S6, installing a new blade and air deflector; S7, hoisting the wind rotor assembly and restoring the wind turbine set. The present invention can avoid the damage to the unit and the surrounding environment of the construction site caused by the accidental falling of the broken blade during the turning process, greatly improving the construction safety.

Description

Technical Field

[0001] The invention relates to the technical field of wind turbine generators, and in particular to a method for replacing broken blades of a wind turbine generator set. Background Art

[0002] At present, the rotors of wind turbines are mostly three-blade structures. Since the blades are prone to breakage after being struck by lightning, the rotor will lose balance after the blades are damaged. Under the influence of gravity, the rotor will automatically return to a balanced state, that is, the rotor will become a "human" shape, and the broken blades will be vertically upward. The blades in this form may exist in two states, one is that the broken part has fallen off, and the other is that the broken part droops but is still connected to the root of the blade. At this time, new blades need to be replaced to restore normal operation of the wind turbine.

[0003] At present, the main method for replacing broken blades at home and abroad is to use the turning method, which is generally to turn the broken blade to a horizontal state, and use a double crane or special clamp to replace the blade in the air, or to turn it to a vertical state, and use a "Y" shape to lift the wind wheel to the ground to replace the blade. For broken blade units, if there is no turning mechanism, it is not only difficult to turn the broken blade to a horizontal or vertical state in an unbalanced state, but there are also safety risks such as the broken blade falling off. Summary of the invention

[0004] The object of the present invention is to provide a method for replacing broken blades of a wind turbine generator set, which is used to solve at least one of the above-mentioned technical problems. It can avoid the damage to the unit and the surrounding environment of the construction site caused by the accidental falling of the broken blades during the turning process, thereby greatly improving the construction safety.

[0005] The embodiment of the present invention is achieved as follows:

[0006] A method for replacing a broken blade of a wind turbine generator set, comprising:

[0007] S1, drill a hole at the root of the broken blade of the wind turbine generator set, insert a steel wire rope, and connect an adjustable lifting chain to the steel wire rope.

[0008] S2, drill a hole in the part of the wind turbine generator set where the broken blade has not fallen off, insert a steel wire rope, and connect an adjustable lifting chain to the steel wire rope.

[0009] S3, connect the steel wire rope and adjustable chain inserted in S1 and S2 to the hook and tighten them to remove the damaged blade.

[0010] S4, install the lifting strap for removing the air deflector block assembly and connect it to the lifting hook to remove the air deflector block assembly at the damaged blade position.

[0011] S5. Install a lifting lug on the wind rotor and connect it to the lifting hook to lift the wind rotor away from the nacelle.

[0012] S6, reinstall the deflector and new blades.

[0013] S7, reinstall the wind wheel using the sling and the wind turbine resumes operation.

[0014] In a preferred embodiment of the present invention, in S1 of the above-mentioned method for replacing a broken blade of a wind turbine generator set, drilling a hole at the root of the broken blade of the wind turbine generator set comprises:

[0015] S11, remove the blade cover in the hub and access the blade break.

[0016] S12, drill holes at a distance A from the blade root. The number of holes is at least two and is a multiple of 2.

[0017] In a preferred embodiment of the present invention, in S1 of the above-mentioned method for replacing a broken blade of a wind turbine generator set, the inserting of the steel wire rope and connecting the adjustable suspension chain to the steel wire rope comprises:

[0018] S13, a steel wire rope is passed through every two holes.

[0019] S14, one end of each wire rope is connected to an adjustable lifting chain.

[0020] In a preferred embodiment of the present invention, in S2 of the above-mentioned method for replacing a broken blade of a wind turbine generator set, the drilling of a hole in the portion of the broken blade of the wind turbine generator set that has not fallen off comprises:

[0021] S21, enter the blade fracture.

[0022] S22, drill holes on the main beam of the part where the broken blade has not fallen off, the number of holes shall be at least two and shall be a multiple of 2.

[0023] In a preferred embodiment of the present invention, in S2 of the above-mentioned method for replacing a broken blade of a wind turbine generator set, the inserting of the steel wire rope and connecting the adjustable suspension chain to the steel wire rope comprises:

[0024] S23, a steel wire rope is passed through every two holes.

[0025] S24, one end of each wire rope is connected to an adjustable lifting chain.

[0026] In a preferred embodiment of the present invention, in S3 of the above-mentioned method for replacing a broken blade of a wind turbine generator set, the step of connecting the steel wire rope and the adjustable chain inserted in S1 and S2 to the hook and tightening the hook comprises:

[0027] S31, connecting the steel wire rope at the root of the broken blade, the adjustable chain and the adjustable chain of the undetached part of the broken blade through the hook of the crane, lifting the hook, and tightening each of the adjustable chains.

[0028] S32, connecting the steel wire ropes at the roots of the broken blades in pairs.

[0029] In a preferred embodiment of the present invention, in S3 of the above method for replacing a broken blade of a wind turbine generator set, removing the damaged blade comprises:

[0030] S33, estimate the weight of the unbroken blade, add the lifting weight to the weight of the unbroken blade, and check and confirm that the blade root and skin of the unbroken blade are not cut by the wire rope.

[0031] S34, remove the bolts connecting the broken blade to the pitch bearing, check and confirm that there is no other damage, and then remove the broken blade.

[0032] The technical effect is that the present invention adopts a gravity-adjustable combined blade special hanger to realize multi-form disassembly of broken blades, and can be quickly disassembled and assembled with strong versatility.

[0033] In a preferred embodiment of the present invention, in S4 of the above-mentioned method for replacing a broken blade of a wind turbine generator set, the step of installing and removing the sling of the deflector block assembly and connecting it to the hook comprises:

[0034] S41, cut the sealant of each edge of the air deflector block assembly to be removed and the front end cover.

[0035] S42, the deflector block assembly is connected to the bolt holes of the front and rear brackets by two slings respectively, and connected to the hook of the crane.

[0036] In a preferred embodiment of the present invention, in S4 of the above-mentioned method for replacing a broken blade of a wind turbine generator set, the process of removing the deflector block assembly at the damaged blade portion comprises:

[0037] S43, remove the bolts connecting the air deflector block assembly to the front and rear brackets.

[0038] S44, remove the bolts connecting the air deflector block assembly and the front end cover.

[0039] S45, keep the sling straight and free from stress.

[0040] S46, after all the bolts connected to the air deflector block assembly are removed, the air deflector block assembly is lifted by a crane to be removed.

[0041] In a preferred embodiment of the present invention, in S5 of the above method for replacing a broken blade of a wind turbine generator set, the step of installing a lifting lug on the wind rotor and connecting the lifting lug to the lifting hook comprises:

[0042] S51, remove the studs at the installation position of the wind rotor's variable pitch bearing outer ring hanger.

[0043] S52, pad the lifting lug so that the lifting lug does not contact the outer ring of the pitch bearing, and fix the lifting lug to the outer ring of the pitch bearing with bolts.

[0044] In a preferred embodiment of the present invention, in S5 of the above method for replacing a broken blade of a wind turbine generator set, lifting the wind rotor off the nacelle comprises:

[0045] S53, use a crane to lift the hanging basket, tie the blade tip guard, tie the wind rope, install the blade tip trailing edge guard, and secure the auxiliary lifting sling.

[0046] S54, complete the tower hoist assembly on the ground, hang one end of the auxiliary hoisting strap on the main hook of the pulley, and the other end on the adjustable hoisting chain of the pulley.

[0047] S55, connecting the tower hoist to the lifting lug on the pitch bearing through a shackle, checking that there is no interference between the steel wire ropes, and then lifting with a crane.

[0048] S56, connected and tightened by slings and hand winches at the pitch drive bracket of the downward blade.

[0049] S57, tighten the wind rope, remove the connecting bolts between the wind rotor and the nacelle, and lift the wind rotor away from the nacelle.

[0050] S58, when the downward blades are close to the ground, hang the slings fixed on the blade tips on the auxiliary crane, cooperate with the main crane to flip the wind wheel 90 degrees and fix it to the wind wheel transport frame.

[0051] The technical effect is that the present invention adopts a universal wind wheel disassembly lifting device to realize the disassembly of wind wheel assemblies of various models without turning the wheel, thereby reducing the turning workload and safety risks and improving replacement efficiency.

[0052] In a preferred embodiment of the present invention, in S6 of the above method for replacing a broken blade of a wind turbine generator set, reinstalling the deflector and the new blade comprises:

[0053] S61, reinstall the disassembled air deflector block assembly according to its position.

[0054] S62, install new blades.

[0055] In a preferred embodiment of the present invention, in S7 of the above-mentioned method for replacing a broken blade of a wind turbine generator set, reinstalling the wind rotor by using a hanger to resume operation of the wind turbine includes:

[0056] S71, install the special lifting equipment for the wind wheel assembly, lift the main crane and the auxiliary crane synchronously until the blades lifted by the auxiliary crane are vertically downwards 1m from the ground, and stop lifting at the same time.

[0057] S72, remove the auxiliary crane lifting device, and continue to lift with the main crane until the wind wheel assembly reaches the center of the main shaft, dock the wind wheel assembly, and complete the bolt tightening.

[0058] S73, install the unloaded electrical components, debug and connect to the grid, and start the machine.

[0059] The beneficial effects of the embodiments of the present invention are:

[0060] The present invention disassembles the broken blades of the wind turbine generator set in a vertically upward state without turning the wheel, and hoists the remaining wind wheel assembly to the ground for blade replacement, so as to solve the problem of blade replacement in old models without turning mechanisms or some wind turbines that cannot be turned, especially for blade replacement of units in which the broken blades have not fallen off, which is a very effective solution. At the same time, it can avoid the damage to the unit and the surrounding environment of the construction site caused by the accidental falling of the broken blades during the turning process, greatly improving the construction safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0062] Figure 1 A schematic flow chart of a method for replacing a broken blade of a wind turbine generator set according to the present invention;

[0063] Figure 2 A schematic diagram of the location of the drilling hole at the blade root in the method for replacing a broken blade of a wind turbine generator set according to the present invention;

[0064] Figure 3 A schematic diagram of inserting a steel wire rope into the root of a broken blade and installing an adjustable suspension chain in a method for replacing a broken blade of a wind turbine generator set according to the present invention;

[0065] Figure 4 A schematic diagram of inserting a steel wire rope into the unshed portion of a broken blade and installing an adjustable suspension chain in a method for replacing a broken blade of a wind turbine generator set according to the present invention;

[0066] Figure 5 This is a schematic diagram of the installation position of the wind wheel disassembly hanger in the method for replacing a broken blade of a wind turbine generator set of the present invention. DETAILED DESCRIPTION

[0067] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0068] Please refer to Figures 1 to 5 The embodiment of the present invention provides a method for replacing a broken blade of a wind turbine generator set, comprising: the method for replacing a broken blade of a wind turbine generator set, comprising:

[0069] S1, drill a hole at the root of the broken blade of the wind turbine generator set, insert a steel wire rope, and connect an adjustable lifting chain to the steel wire rope.

[0070] S2, drill a hole in the part of the wind turbine generator set where the broken blade has not fallen off, insert a steel wire rope, and connect an adjustable lifting chain to the steel wire rope.

[0071] S3, connect the steel wire rope and adjustable chain inserted in S1 and S2 to the hook and tighten them to remove the damaged blade.

[0072] S4, install the lifting strap for removing the air deflector block assembly and connect it to the lifting hook to remove the air deflector block assembly at the damaged blade position.

[0073] S5. Install a lifting lug on the wind rotor and connect it to the lifting hook to lift the wind rotor away from the nacelle.

[0074] S6, reinstall the deflector and new blades.

[0075] S7, reinstall the wind wheel using the sling and the wind turbine resumes operation.

[0076] In a preferred embodiment of the present invention, in S1 of the above-mentioned method for replacing a broken blade of a wind turbine generator set, drilling a hole at the root of the broken blade of the wind turbine generator set comprises:

[0077] S11, remove the blade cover in the hub and access the blade break.

[0078] S12, use a hand drill to drill holes at a distance of A1.7m from the blade root. The number of holes should be at least two, which is a multiple of 2. The diameter of the hole is 30mm. Drill 4 holes. The horizontal position of the 4 holes depends on the bending direction of the broken part of the blade, such as Figure 3 As shown, the two holes located on the bent side of the broken part of the blade should be about 30cm away from the blade joining line in the circumferential direction, and the glass fiber thickness at the drilling position should not be less than 15mm.

[0079] In a preferred embodiment of the present invention, in S1 of the above-mentioned method for replacing a broken blade of a wind turbine generator set, the inserting of the steel wire rope and connecting the adjustable suspension chain to the steel wire rope comprises:

[0080] S13, insert a steel wire rope into every two holes, and insert two φ24mm steel wire ropes through the holes.

[0081] S14, one end of each wire rope is connected to a 10T adjustable lifting chain.

[0082] In a preferred embodiment of the present invention, in S2 of the above-mentioned method for replacing a broken blade of a wind turbine generator set, the drilling of a hole in the portion of the broken blade of the wind turbine generator set that has not fallen off comprises:

[0083] S21, enter the blade fracture through the hanging basket.

[0084] S22, drill holes on the main beam of the part where the broken blade has not fallen off. The number of holes shall be at least two, which shall be a multiple of 2 and have a diameter of 24 mm.

[0085] In a preferred embodiment of the present invention, in S2 of the above-mentioned method for replacing a broken blade of a wind turbine generator set, the inserting of the steel wire rope and connecting the adjustable suspension chain to the steel wire rope comprises:

[0086] S23, insert a steel wire rope into every two holes, and insert two φ24mm steel wire ropes into the holes.

[0087] S24, such as Figure 4 As shown, one end of each wire rope is connected to a 10T adjustable lifting chain.

[0088] In a preferred embodiment of the present invention, in S3 of the above-mentioned method for replacing a broken blade of a wind turbine generator set, the step of connecting the steel wire rope and the adjustable chain inserted in S1 and S2 to the hook and tightening the hook comprises:

[0089] S31, connecting the steel wire rope at the root of the broken blade, the adjustable chain and the adjustable chain of the undetached part of the broken blade through the hook of the crane, lifting the hook to a lifting weight of about 1 t, and tightening each of the adjustable chains.

[0090] S32, use short guy ropes to connect the steel wire ropes at the roots of the broken blades in pairs to prevent the blades from tipping over in the air after the roots are pulled out.

[0091] In a preferred embodiment of the present invention, in S3 of the above method for replacing a broken blade of a wind turbine generator set, removing the damaged blade comprises:

[0092] S33, estimate the weight of the unbroken blade, slowly add the lifting weight to the weight of the unbroken blade, and check and confirm that the blade root and skin of the unbroken blade are not cut by the wire rope.

[0093] S34, use a hydraulic tensioner to remove the bolts connecting the broken blade to the pitch bearing, check and confirm that there is no other damage, and then remove the broken blade.

[0094] The technical effect is that the present invention adopts a gravity-adjustable combined blade special hanger to realize multi-form disassembly of broken blades, and can be quickly disassembled and assembled with strong versatility.

[0095] In a preferred embodiment of the present invention, in S4 of the above-mentioned method for replacing a broken blade of a wind turbine generator set, the step of installing and removing the sling of the deflector block assembly and connecting it to the hook comprises:

[0096] S41, the operator uses safety clothing or safety ropes, or a hanging basket, and uses a cutter to cut the sealant on each edge of the air deflector block assembly to be removed and the front end cover to ensure that there is no adhesion during subsequent disassembly.

[0097] S42, the deflector block assembly is connected to the bolt holes of the front and rear brackets by two slings respectively, and connected to the hook of the crane.

[0098] Among them, the sling is not subjected to stress.

[0099] In a preferred embodiment of the present invention, in S4 of the above-mentioned method for replacing a broken blade of a wind turbine generator set, the process of removing the deflector block assembly at the damaged blade portion comprises:

[0100] S43, remove the bolts connecting the air deflector block assembly to the front and rear brackets.

[0101] S44, remove the bolts connecting the air deflector block assembly and the front end cover.

[0102] S45, keep the slings straight and free from stress to prevent the deflector block assembly from slipping off.

[0103] S46, after all the bolts connected to the air deflector block assembly are removed, the air deflector block assembly is lifted by a crane to be removed.

[0104] In a preferred embodiment of the present invention, in S5 of the above method for replacing a broken blade of a wind turbine generator set, the step of installing a lifting lug on the wind rotor and connecting the lifting lug to the lifting hook comprises:

[0105] S51, remove the studs at the installation position of the wind rotor's variable pitch bearing outer ring hanger.

[0106] S52, pad the lifting ears. Use pads under each lifting ear to pad the lifting ears so that the lifting ears do not contact the outer ring of the pitch bearing. Fix the lifting ears to the outer ring of the pitch bearing with bolts.

[0107] Among them, 8 special bolts for lifting ears are used to fix the lifting ears. The four points where the lifting ears are installed are evenly distributed, and the tightening torque of the bolts is 300N.m~500N.m.

[0108] Among them, the installation direction of the four lifting ears requires that the two round holes on each lifting ear must point upward, and the long slot hole with limiting teeth points obliquely downward.

[0109] In a preferred embodiment of the present invention, in S5 of the above method for replacing a broken blade of a wind turbine generator set, lifting the wind rotor off the nacelle comprises:

[0110] S53, use a crane to lift the hanging basket, tie the blade tip guard belt at the lifting points of the blade tips of the two downward-slanting blades, tie the wind rope, install the blade tip trailing edge guard, and fix the auxiliary lifting strap.

[0111] S54, complete the tower hoist assembly on the ground, hang one end of the auxiliary hoisting belt on the main hook of the pulley, and hang the other end on the 10t×3m adjustable hoisting chain of the pulley;

[0112] Among them, the tower hoist includes 45t×1.5m sling, 35t shackle, 35t pulley, φ48mm×13m wire rope, and 10t×6m sling.

[0113] S55, connect the tower hoist and the lifting lug on the pitch bearing through a 25t shackle, check that there is no interference between the steel wire ropes, and then use a crane to lift.

[0114] The lifting weight is about 26t. Pay attention to the direction of the shackle pin to avoid interference with the lifting equipment when turning over.

[0115] S56, connected and tightened at the pitch drive bracket of the downward blade by two 10t×5m slings and a 10t hand winch.

[0116] S57, tighten the wind rope, remove the connecting bolts between the wind rotor and the nacelle, and lift the wind rotor away from the nacelle.

[0117] S58, when the downward blades are close to the ground, hang the slings fixed on the blade tips on the auxiliary crane, cooperate with the main crane to flip the wind wheel 90 degrees and fix it to the wind wheel transport frame.

[0118] The technical effect is that the present invention adopts a universal wind wheel disassembly lifting device to realize the disassembly of wind wheel assemblies of various models without turning the wheel, thereby reducing the turning workload and safety risks and improving replacement efficiency.

[0119] In a preferred embodiment of the present invention, in S6 of the above method for replacing a broken blade of a wind turbine generator set, reinstalling the deflector and the new blade comprises:

[0120] S61, reinstall the disassembled air deflector block assembly according to its position.

[0121] S62, install new blades.

[0122] In a preferred embodiment of the present invention, in S7 of the above-mentioned method for replacing a broken blade of a wind turbine generator set, reinstalling the wind rotor by using a hanger to resume operation of the wind turbine includes:

[0123] S71, install the special lifting equipment for the wind wheel assembly, lift the main crane and the auxiliary crane synchronously until the blades lifted by the auxiliary crane are vertically downwards 1m from the ground, and stop lifting at the same time.

[0124] S72, remove the auxiliary crane lifting equipment, and continue to lift with the main crane until the wind wheel assembly reaches the center of the main shaft, slowly dock the wind wheel assembly, and complete the bolt tightening.

[0125] S73, install the unloaded electrical components, debug and connect to the grid, and start the machine.

[0126] The embodiment of the present invention aims to provide a method for replacing a broken blade of a wind turbine generator set, which has the following effects:

[0127] 1. The present invention has a small number of split components, a small number of lifting times, and improved lifting efficiency of a single unit.

[0128] 2. When the present invention is disassembled, the nacelle cover does not need to be disassembled, and the adverse weather such as rain and snow has little impact on the nacelle body after hoisting.

[0129] 3. The split components of the present invention have lower lifting capacity requirements for the main crane, which can be met by mainstream cranes in the market, reducing the lifting cost by 5% and greatly improving the on-time delivery capability of the unit.

[0130] 5. The present invention can provide strong technical support for the subsequent design and installation of higher and larger power units, and can also provide technical reference for the separate installation of large units in the wind power industry, thereby improving the overall installation technology level of the industry and having high economic and market value.

[0131] It should be understood that the above specific embodiments of the present invention are only used to illustrate or explain the principles of the present invention, and do not constitute a limitation of the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc. made without departing from the spirit and scope of the present invention should be included in the protection scope of the present invention. In addition, the appended claims of the present invention are intended to cover all changes and modifications that fall within the scope and boundaries of the appended claims, or the equivalent forms of such scope and boundaries.

Claims

1. A method for replacing a broken blade of a wind turbine generator set, characterized in that: include: S1, drilling a hole at the root of the broken blade of the wind turbine generator set, inserting a steel wire rope, and connecting an adjustable lifting chain to the steel wire rope; S2, drilling a hole in the part of the wind turbine generator set where the broken blade has not fallen off, inserting a steel wire rope, and connecting an adjustable lifting chain to the steel wire rope; S3, connect the steel wire rope and adjustable chain inserted in S1 and S2 to the hook and tighten them to remove the damaged blade; S4, installing a lifting strap for removing the air deflector block assembly and connecting it to the lifting hook to remove the air deflector block assembly at the damaged blade position; S5, installing a lifting lug on the wind rotor and connecting it to the lifting hook, and lifting the wind rotor away from the nacelle; S6, reinstall the deflector and new blades; S7, reinstall the wind wheel through the lifting device, and the wind turbine resumes operation; The root drilling of the broken blade of the wind turbine generator set comprises: S11, remove the blade cover in the hub and enter the blade fracture; S12, drill holes at a distance A from the blade root, the number of holes is at least two and is a multiple of 2; The drilling of the portion of the wind turbine generator set that has not fallen off the broken blade comprises: S21, entering the blade break; S22, drilling holes on the main beam of the part where the broken blade has not fallen off, the number of holes being at least two and being a multiple of 2; The step of connecting the steel wire rope and the adjustable chain inserted into S1 and S2 to the hook and tightening the hook comprises: S31, connecting the steel wire rope at the root of the broken blade, the adjustable chain and the adjustable chain of the undetached part of the broken blade through a hook of a crane, lifting the hook, and tightening each of the adjustable chains; S32, connecting the steel wire ropes at the roots of the broken blades in pairs.

2. The method for replacing a broken blade of a wind turbine generator set according to claim 1, characterized in that: In S1, the inserting of the steel wire rope and the connecting of the adjustable lifting chain to the steel wire rope include: S13, a steel wire rope is inserted into every two holes; S14, one end of each wire rope is connected to an adjustable lifting chain.

3. The method for replacing a broken blade of a wind turbine generator set according to claim 1, characterized in that: In S2, the inserting of the steel wire rope and the connecting of the adjustable chain to the steel wire rope include: S23, a steel wire rope is inserted into every two holes; S24, one end of each wire rope is connected to an adjustable lifting chain.

4. The method for replacing a broken blade of a wind turbine generator set according to claim 1, characterized in that: In S3, removing the damaged blades includes: S33, estimating the weight of the unbroken blade, adding the lifting weight to the weight of the unbroken blade, and checking and confirming that the blade root and skin of the unbroken blade are not cut by the wire rope; S34, remove the bolts connecting the broken blade to the pitch bearing, check and confirm that there is no other damage, and then remove the broken blade.

5. The method for replacing a broken blade of a wind turbine generator set according to claim 1, characterized in that: In S4, the step of installing and removing the sling of the deflector block assembly and connecting it to the hook includes: S41, cutting the sealant of each edge of the air deflector block assembly to be removed and the front end cover; S42, the deflector block assembly is connected to the bolt holes of the front and rear brackets by two slings respectively, and connected to the hook of the crane.

6. The method for replacing a broken blade of a wind turbine generator set according to claim 5, characterized in that: In S4, the removal of the guide cover block assembly at the damaged blade portion includes: S43, remove the bolts connecting the air deflector block assembly to the front and rear brackets; S44, remove the bolts connecting the air deflector block assembly and the front end cover; S45, keep the sling straight and free from stress; S46, after all the bolts connected to the air deflector block assembly are removed, the air deflector block assembly is lifted by a crane to be removed.

7. The method for replacing a broken blade of a wind turbine generator set according to claim 1, characterized in that: In S5, the step of installing a lifting lug on the wind rotor and connecting the lifting lug to the lifting hook comprises: S51, remove the studs at the installation position of the hanger of the outer ring of the variable pitch bearing of the wind rotor; S52, pad the lifting lug so that the lifting lug does not contact the outer ring of the pitch bearing, and fix the lifting lug to the outer ring of the pitch bearing with bolts.

8. The method for replacing a broken blade of a wind turbine generator set according to claim 7, characterized in that: In S5, lifting the wind rotor away from the nacelle includes: S53, use a crane to lift the hanging basket, tie the blade tip guard, tie the wind rope, install the blade tip trailing edge guard, and secure the auxiliary lifting strap; S54, complete the tower hoist assembly on the ground, hang one end of the auxiliary hoisting strap on the main hook of the pulley, and hang the other end on the adjustable hoisting chain of the pulley; S55, connecting the tower hoist to the lifting lug on the pitch bearing through a shackle, checking that there is no interference between the steel wire ropes, and then lifting with a crane; S56, connected and tightened at the pitch drive bracket of the downward blade by a sling and hand chain hoist; S57, tighten the wind rope, remove the bolts connecting the wind rotor and the nacelle, and lift the wind rotor away from the nacelle; S58, when the downward blades are close to the ground, hang the slings fixed on the blade tips on the auxiliary crane, cooperate with the main crane to flip the wind wheel 90 degrees and fix it to the wind wheel transport frame.

9. The method for replacing a broken blade of a wind turbine generator set according to claim 1, characterized in that: In S6, reinstalling the guide cover and the new blades includes: S61, reinstall the disassembled air deflector block assembly according to its position; S62, install new blades.

10. The method for replacing a broken blade of a wind turbine generator set according to claim 1, characterized in that: In S7, reinstalling the wind wheel by the sling to resume the operation of the wind turbine includes: S71, install the special hoisting equipment for the wind rotor assembly, lift the main crane and the auxiliary crane synchronously until the blades lifted by the auxiliary crane are vertically downward and 1m off the ground, and stop lifting at the same time; S72, remove the auxiliary crane lifting device, and continue to lift with the main crane until the wind rotor assembly reaches the center of the main shaft, dock the wind rotor assembly, and complete the bolt tightening; S73, install the unloaded electrical components, debug and connect to the grid, and start the machine.

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