Repairing method for wind power installation platform rack

Abstract

The invention provides a method for repairing a rack of a wind power installation platform, which comprises the following steps of: S1, cleaning the surface of the rack before welding repair, and polishing a damaged part and the surface of the rack to be flat and smoothly transited; s2, a tooth-shaped electromagnetic heating piece is adopted to wrap the rack for preheating; s3, after preheating is completed, the rack is wrapped with heat preservation cotton, only the part needing to be welded is exposed, and welding is conducted; s4, after welding is completed, a tooth-shaped electromagnetic heating piece is immediately used for wrapping the welded rack, heat preservation cotton is adopted for wrapping after heat preservation is conducted for a certain time, and after slow cooling is conducted to the room temperature, the heat preservation cotton is removed; and S5, after hydrogen elimination is completed, polishing work is carried out. According to the welding repairing and polishing method for the ultrahigh-strength large thick plate rack, the welding repairing and polishing method is optimized, and the repairing quality is improved; the tooth-shaped electromagnetic heating piece wraps the rack for heating, and the problem of uneven heating is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of rack repair, and in particular relates to a method for repairing a rack of a wind power installation platform. Background Art

[0002] After a certain period of use, the racks of the pile legs of wind power installation platforms or liftable offshore platforms will be worn or broken during the lifting process, and need to be repaired on the platform. Due to the thick thickness of the racks and the high strength of the steel plates, the repair process generally requires preheating, welding, post-weld dehydrogenation, heat preservation and slow cooling, grinding, flaw detection and other steps. The existing repair methods have the following main problems:

[0003] 1. Since the rack is thick, it is generally made of 177.8mm 690-grade steel plate. It needs to be preheated to above 150°C before welding. Electromagnetic heating or flame heating is generally used before welding. When flame heating is used, the heating temperature is uneven, the temperature inside the steel plate may not reach the required temperature, and the temperature drops quickly after heating. When ordinary long strip electromagnetic heating sheets are used, the rack is tooth-shaped, and the heating sheet cannot completely wrap the rack, resulting in uneven heating.

[0004] 2. After welding, dehydrogenation treatment is required, which requires heating to 250℃-300℃ and maintaining this temperature for at least two hours. Ordinary long strip heating plates cannot maintain the temperature uniformity requirement. Summary of the invention

[0005] The embodiment of the present invention provides a method for repairing a rack of a wind power installation platform, which can solve the problems of uneven preheating and post-weld hydrogen removal temperature, poor welding quality and difficulty in grinding the tooth shape during rack welding repair.

[0006] The present invention provides a method for repairing a rack of a wind power installation platform, comprising:

[0007] Step S1: Clean the rack surface before welding and polish the damaged part and the rack surface to make a smooth transition;

[0008] Step S2: using a toothed electromagnetic heating sheet to wrap the rack for preheating;

[0009] Step S3: After preheating is completed, the rack is wrapped with thermal insulation cotton, leaving only the parts that need to be welded exposed, and welding is performed;

[0010] Step S4: After welding is completed, the welded rack is immediately wrapped with a toothed electromagnetic heating sheet, and after keeping warm for a certain period of time, it is wrapped with insulation cotton, and after slowly cooling to room temperature, the insulation cotton is removed;

[0011] Step S5: After the hydrogen removal is completed, polishing is performed.

[0012] Optionally, in step S1, cleaning the rack surface before welding repair includes: wiping or grinding away lubricating oil and rust on the rack surface before welding repair.

[0013] Optionally, in step S2, during preheating, the heating time is more than 2 hours, the temperature is heated to more than 150° C., and the temperature is kept stable for more than half an hour.

[0014] Optionally, in step S3, arc welding is adopted for welding, and the welding rod brand is L-80SN and the diameter is 3.2 mm.

[0015] Optionally, in step S3, the welding rod needs to be dried at 350° C. for 2 hours before welding, and the temperature is kept above 100° C. in a heat preservation barrel.

[0016] Optionally, in step S3, horizontal welding is adopted from bottom to top, and the length of each weld is not less than 50 mm.

[0017] Optionally, in step S3, during the welding process, the rack temperature must not be lower than 150°C and cannot exceed 250°C. If the temperature is too low, it needs to be reheated, and if the temperature is too high, it needs to wait for the temperature to drop.

[0018] Optionally, step S4 specifically includes:

[0019] After welding is completed, the toothed electromagnetic heating sheet is immediately wrapped around the welded rack, heated to 250℃-300℃, maintained at this temperature for 2-3 hours, then wrapped with insulation cotton, slowly cooled to room temperature, and then the insulation cotton is removed.

[0020] Optionally, the grinding in step S5 specifically includes: grinding after welding and post-weld dehydrogenation are completed, and tooth grinding is performed with a toothed template made of aluminum alloy and a plumb line; first, the weld surface is polished flat, and then the aluminum alloy template is inserted between the racks for comparative grinding until the template and the rack are completely fitted and the internal grinding of the rack is completed.

[0021] Optionally, the grinding in step S5 specifically includes: grinding the tooth tip by pulling down a line from the intact tooth tip above to ensure that all rack tooth tips are in the same straight line, and grinding the tooth tip chamfer by fitting a template on the tooth tip to ensure that the chamfer angle is consistent.

[0022] The beneficial effects brought by the present invention are as follows:

[0023] 1. The present invention optimizes the welding repair and grinding method for ultra-high strength thick plate racks. After preheating, the rack is wrapped with insulation cotton, and only the parts that need to be welded are exposed for welding; after welding, the welded rack is immediately wrapped with a toothed electromagnetic heating sheet, and after a certain period of insulation, it is wrapped with insulation cotton. After slowly cooling to room temperature, the insulation cotton is removed, thereby improving the repair quality;

[0024] 2. The present invention adopts a toothed electromagnetic heating sheet to wrap the rack for heating, thereby solving the problem of uneven heating.

[0025] It can be seen from the above scheme that the embodiment of the present invention provides a kind of. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A diagram showing a damaged rack structure according to an embodiment of the present invention;

[0027] Figure 2 A diagram showing the matching relationship between a rack and a toothed electromagnetic heating sheet according to an embodiment of the present invention;

[0028] Figure 3 A schematic diagram showing the processing of a weld during welding according to an embodiment of the present invention;

[0029] Figure 4 A schematic diagram showing internal grinding of teeth according to an embodiment of the present invention;

[0030] Figure 5 A schematic diagram of tooth tip grinding according to an embodiment of the present invention is shown.

[0031] In the figure, 1. rack; 2. damaged part; 3. toothed electromagnetic heating plate; 4. heating power supply; 5. part to be welded; 6. toothed template; 7. tooth tip chamfering template. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] The problems existing in the prior art mainly include the following three points:

[0034] 1. Since the rack is thick, it is generally made of 177.8mm 690-grade steel plate. It needs to be preheated to above 150°C before welding. Electromagnetic heating or flame heating is generally used before welding. When flame heating is used, the heating temperature is uneven, the temperature inside the steel plate may not reach the required temperature, and the temperature drops quickly after heating. When ordinary long strip electromagnetic heating sheets are used, the rack is tooth-shaped, and the heating sheet cannot completely wrap the rack, resulting in uneven heating.

[0035] 2. After welding, dehydrogenation treatment is required, which requires heating to 250℃-300℃ and maintaining this temperature for at least two hours. Ordinary long strip heating sheets cannot maintain the uniform temperature requirement;

[0036] 3. After welding, the weld needs to be polished smooth because each surface of the rack needs to mesh with the gear. However, the shape and size of the rack have corresponding requirements. It can only be polished manually on the platform and cannot be processed by machining. It is difficult to control the tooth shape during manual polishing.

[0037] In view of the technical problems existing in the prior art, the present invention provides a method for repairing a rack 1 of a wind power installation platform, comprising:

[0038] Step S1: Clean the surface of the rack 1 before welding and polish the damaged part 2 and the surface of the rack 1 to make them smooth;

[0039] Furthermore, in step S1, cleaning the surface of the rack 1 before welding repair includes: wiping or grinding away lubricating oil and rust on the surface of the rack 1 before welding repair.

[0040] Specifically, Figure 1 As shown, step S1: before welding repair, the lubricating oil and rust on the surface of the rack 1 need to be wiped off or polished away, and then the damaged part 2 and the surface of the rack 1 need to be polished flat and smoothly transitioned to facilitate subsequent welding and ensure full penetration of the welding;

[0041] Step S2: using the toothed electromagnetic heating sheet 3 to wrap the rack 1 for preheating;

[0042] Furthermore, in step S2, during preheating, the heating time is more than 2 hours, the temperature is heated to more than 150° C., and the temperature is kept stable for more than half an hour.

[0043] Specifically, Figure 2 As shown, step S2: since the rack 1 of the wind power installation platform or the offshore platform is generally 690-grade steel with a thickness of 177.8 mm, it needs to be preheated before welding. Therefore, a toothed electromagnetic heating plate is used to wrap the rack 1 for preheating. The heating time is more than 2 hours, heated to more than 150°C, and the temperature is kept stable for more than half an hour; the toothed heating plate can preheat one tooth, or preheat multiple teeth in series; the toothed electromagnetic heating plate 3 is powered by a heating power supply 4 to generate heat.

[0044] Step S3: After preheating is completed, the rack 1 is wrapped with heat-insulating cotton, leaving only the part to be welded exposed, and welding is performed;

[0045] Furthermore, in step S3, arc welding is adopted during welding, and the welding rod brand is L-80SN and the diameter is 3.2 mm.

[0046] Furthermore, in step S3, the welding rod needs to be dried at 350°C for 2 hours before welding, and the temperature should be kept above 100°C in a heat preservation barrel.

[0047] Furthermore, in step S3, horizontal welding is adopted from bottom to top, and the length of each weld is not less than 50 mm.

[0048] Furthermore, in step S3, during the welding process, the temperature of the rack 1 must not be lower than 150°C and must not exceed 250°C. If the temperature is too low, it needs to be reheated, and if the temperature is too high, it needs to wait for the temperature to drop.

[0049] Specifically, Figure 3 As shown in Table 1, in step S3, after preheating, the rack 1 is wrapped with insulation cotton, leaving only the part to be welded to prevent the temperature from dropping; arc welding is adopted during welding, the welding rod brand is L-80SN, the diameter is 3.2 mm, the welding rod needs to be dried at 350°C for 2 hours before welding, and the insulation barrel is used to keep the temperature above 100°C; horizontal welding is adopted from bottom to top during welding, and the length of each weld is not less than 50 mm; during welding, the temperature of the rack 1 shall not be lower than 150°C and shall not exceed 250°C. If the temperature is too low, it needs to be reheated, and if the temperature is too high, it needs to wait for the temperature to drop;

[0050] Table 1 Welding parameters

[0051]

[0052] Step S4: After welding is completed, the welded rack 1 is immediately wrapped with the toothed electromagnetic heating sheet 3, and after keeping warm for a certain period of time, it is wrapped with insulation cotton, and after slowly cooling to room temperature, the insulation cotton is removed;

[0053] Furthermore, step S4 specifically includes:

[0054] After welding is completed, the toothed electromagnetic heating sheet 3 is immediately wrapped around the welded rack 1, heated to 250°C-300°C, maintained at this temperature for 2-3 hours, and then wrapped with insulation cotton. After slowly cooling to room temperature, the insulation cotton is removed.

[0055] Specifically, step S4: immediately after welding is completed, the toothed heating sheet is wrapped around the welded rack 1, heated to 250°C-300°C, maintained at this temperature for 2-3 hours, then wrapped with heat-insulating cotton, slowly cooled to room temperature, and then the heat-insulating cotton is removed;

[0056] Step S5: After the hydrogen removal is completed, polishing is performed.

[0057] Furthermore, the grinding in step S5 specifically includes: grinding after welding and post-weld dehydrogenation are completed, and the tooth profile is ground by using a tooth profile template made of aluminum alloy and a plumb line; first, the weld surface is ground flat, and then the aluminum alloy template is inserted between the racks 1 for comparative grinding until the template and the rack 1 are completely fitted, and the internal grinding of the rack 1 is completed.

[0058] Furthermore, the grinding in step S5 specifically includes: grinding the tooth tip by pulling down a line from the intact tooth tip above to ensure that the tooth tips of all racks 1 are in the same straight line, and grinding the tooth tip chamfer by fitting a template on the tooth tip to ensure that the chamfer angle is consistent.

[0059] Specifically, Figure 4 and Figure 5 As shown, step S5: after welding and post-weld dehydrogenation are completed, grinding work is performed, and the tooth profile is polished with a tooth tip grinding template made of aluminum alloy and a plumb line; first, the weld surface is polished flat, and then the aluminum alloy tooth profile template 6 is inserted between the racks 1 for comparative polishing until the tooth tip is polished, the tooth profile template 6 is completely fitted with the rack 1, and the internal polishing of the rack 1 is completed; the tooth tip is polished by pulling down the plumb line from the intact tooth tip above to ensure that all the tooth tips of the racks 1 are in the same straight line, and the tooth tip chamfer is polished by the tooth tip chamfering template 7 fitted on the tooth tip to ensure the chamfer angle.

[0060] Step S6: After grinding is completed, ultrasonic flaw detection and magnetic particle flaw detection are performed on the entire rack 1 72 hours after welding is completed to ensure that there are no defects inside and near the surface of the rack 1 after welding.

[0061] The present invention can be used for welding and repairing the rack 1 of the lifting system of steel structures, wind power installation ships, offshore platforms, etc., to improve the welding quality and be used for repair work during ship repair or construction. The present invention has been applied to the repair of the rack 1 of the pile leg of a wind power installation ship, which can ensure that the wind power installation ship can carry out the lifting test on time, and can also be used for repairing the rack 1 of the lifting system of the corresponding platform after receiving orders for ship repair.

[0062] 1. The present invention optimizes the welding repair and grinding method of the ultra-high strength thick plate rack 1, thereby improving the repair quality;

[0063] 2. The present invention adopts a new type of heating plate to solve the problem of uneven heating;

[0064] 3. The present invention solves the problem of grinding the tooth profile of the rack 1 after welding, ensuring that the rack 1 is consistent after grinding and the tooth tips are in the same plane.

[0065] The above are preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for repairing a rack of a wind power installation platform, characterized in that include: Step S1: Clean the rack surface before welding and polish the damaged part and the rack surface to make a smooth transition; Step S2: wrapping the rack with a toothed electromagnetic heating sheet for preheating; Step S3: After the preheating is completed, the rack is wrapped with heat-insulating cotton, leaving only the part 5 to be welded exposed, and welding is performed; Step S4: After welding is completed, the welded rack is immediately wrapped with the toothed electromagnetic heating sheet, and after keeping warm for a certain period of time, it is wrapped with insulation cotton, and after slowly cooling to room temperature, the insulation cotton is removed; Step S5: After the hydrogen removal is completed, polishing is performed.

2. The method for repairing a rack of a wind power installation platform according to claim 1, characterized in that: In the step S1, cleaning the rack surface before welding repair includes: wiping or grinding away lubricating oil and rust on the rack surface before welding repair.

3. The method for repairing a rack of a wind power installation platform according to claim 1 or 2, characterized in that: In the step S2, during preheating, the heating time is more than 2 hours, the temperature is heated to more than 150° C., and the temperature is kept stable for more than half an hour.

4. The method for repairing a rack of a wind power installation platform according to claim 1 or 2, characterized in that: In step S3, arc welding is adopted during welding, and the welding rod brand is L-80SN and the diameter is 3.2 mm.

5. The method for repairing a rack of a wind power installation platform according to claim 4, characterized in that: In step S3, the welding rod needs to be dried at 350° C. for 2 hours before welding, and the temperature is kept above 100° C. in a heat preservation barrel.

6. The method for repairing a rack of a wind power installation platform according to claim 5, characterized in that: In step S3, horizontal welding is adopted from bottom to top, and the length of each weld is not less than 50 mm.

7. The method for repairing a rack of a wind power installation platform according to claim 6, characterized in that: In step S3, during the welding process, the rack temperature must not be lower than 150°C and cannot exceed 250°C. If the temperature is too low, it needs to be reheated, and if the temperature is too high, it needs to wait for the temperature to drop.

8. The method for repairing a rack of a wind power installation platform according to claim 1 or 2, characterized in that: The step S4 specifically includes: After welding is completed, the toothed electromagnetic heating sheet is immediately wrapped around the welded rack, heated to 250℃-300℃, maintained at this temperature for 2-3 hours, then wrapped with insulation cotton, slowly cooled to room temperature, and then the insulation cotton is removed.

9. The method for repairing a rack of a wind power installation platform according to claim 1 or 2, characterized in that: The grinding described in step S5 specifically includes: grinding after welding and post-weld dehydrogenation are completed, and the tooth profile is ground by using a tooth profile template made of aluminum alloy and a plumb line; first, the weld surface is ground flat, and then the aluminum alloy template is inserted between the racks for comparative grinding until the template and the rack are completely fitted and the internal grinding of the rack is completed.

10. The method for repairing a rack of a wind power installation platform according to claim 9, characterized in that: The grinding in step S5 specifically includes: grinding the tooth tip by pulling down a line from the intact tooth tip above to ensure that all rack tooth tips are in the same straight line, and grinding the tooth tip chamfer by fitting a template on the tooth tip to ensure that the chamfer angle is consistent.

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