Manufacturing Method of Large Power Transformer Tank

Abstract

A method for manufacturing a large-scale power transformer oil tank includes S1: forming a box edge hole, a first strip of material used to form the box edge of the lower section oil tank and a second strip of material used to form the box edge of the upper section oil tank form a first temporary fixing structure correspondingly, and a plurality of box edge holes are set on the first temporary fixing structure before the first temporary fixing structure is removed; S2: forming a lower section oil tank, the box edge of the lower section oil tank is surrounded by a plurality of first strips of material, the box wall of the lower section oil tank is formed by a plurality of first side walls, and the box bottom of the lower section oil tank is formed by a bottom wall; S3: forming an assembly, a plurality of second strips of material are correspondingly welded with a plurality of second side walls to form an assembly; S4: forming a transformer oil tank, a plurality of assemblies are welded above the lower section oil tank to form an upper section oil tank, and the box edge holes are formed correspondingly with the box edge of the upper section oil tank and the box edge of the lower section oil tank. In the method for manufacturing a large-scale power transformer oil tank of the present invention, the setting of the box edge holes has low requirements on drilling machines and fixtures, and the manufacturing difficulty of the upper section oil tank is low.

Description

Technical Field

[0001] The present invention relates to the manufacture of transformer oil tanks, and particularly to a manufacturing method for a large power transformer oil tank. Background Art

[0002] A large power transformer oil tank generally consists of an upper part and a lower part. The transformer body is placed inside it and filled with insulating oil, and at this time its total weight can reach 100 - 400 tons.

[0003] The transformer oil tank mainly consists of an upper section oil tank, a lower section oil tank, and a tank rim. By providing tank rim holes on the tank rims of the upper and lower section oil tanks, the upper section oil tank and the lower section oil tank are connected into a sealed whole that can withstand vacuum and a maximum positive pressure of 0.1 MPa under the cooperation of the tank rims of the upper and lower section oil tanks and bolts. However, due to the large volume and mass of the transformer oil tank, and high requirements for assembly accuracy, welding deformation, and weld quality during the manufacturing process, thus, how to ensure that the tank rim does not deform and the tank rim holes are not misaligned while meeting the assembly accuracy of the transformer oil tank is a manufacturing difficulty of the transformer oil tank.

[0004] Currently, to solve the above problems, the manufacture of transformer oil tanks usually adopts the following two processes: First, the tank rims of the upper section oil tank and the lower section oil tank are assembled into a tank rim frame and clamped with a fixture for drilling. After the lower section oil tank is manufactured, the tank rims of the upper section oil tank and the lower section oil tank are fixed together with bolts. After the tank rims of the upper and lower section oil tanks are fixed, the wall of the upper section oil tank is formed on the inner wall of the tank rim frame of the upper section oil tank, and the tank cover is installed after welding is completed. Although this method can ensure the consistency of the tank rim holes of the tank rims of the upper section oil tank and the lower section oil tank, drilling after assembling into the tank rim frame requires high requirements for the fixture and the drilling machine and has low production efficiency. In addition, it is difficult to manufacture the wall of the upper section oil tank on the inner wall of the tank rim frame of the upper section oil tank and it is not easy to ensure the accuracy; Second, the tank rim of the upper section oil tank is drilled first and then assembled into a whole, and then the wall and the tank cover of the upper section oil tank are assembled to form a complete upper section oil tank. The tank rim of the lower section oil tank is not drilled temporarily and is assembled with the wall and the bottom of the lower section oil tank into a whole, and then the upper section oil tank is placed on the lower section oil tank, and the tank rim holes of the tank rim of the lower section oil tank are drilled along the tank rim holes of the tank rim of the upper section oil tank. Although this can also make the tank rim holes of the tank rims of the upper and lower section oil tanks consistent, it is inconvenient to drill and hoist the whole lower section oil tank, requires high requirements for the drilling machine and the fixture, and has low production efficiency. In addition, the same as the first process, there is a problem that after the tank rim frame of the upper section oil tank is formed, it is difficult to form the wall and it is not easy to ensure the accuracy. Summary of the Invention

[0005] The purpose of the present invention is to overcome the defects of the prior art and provide a manufacturing method for a large power transformer oil tank with lower manufacturing difficulty and lower requirements for the drilling machine and the fixture.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A manufacturing method of a large power transformer oil tank includes the following steps:

[0008] S1 Formation of the tank flange holes

[0009] The first material for forming the tank flange of the lower tank section and the second material for forming the tank flange of the upper tank section form a first temporary fixing structure correspondingly, and after setting a plurality of tank flange holes on the first temporary fixing structure, the first temporary fixing structure is removed. The part of the tank flange hole on the first material is the first perforation, and the part of the tank flange hole on the second material is the second perforation.

[0010] S2 Formation of the lower tank section

[0011] A plurality of first materials, a plurality of first side walls, and a bottom wall are welded together to form the lower tank section. The tank flange of the lower tank section is surrounded by a plurality of first materials provided with first perforations. The tank wall of the lower tank section is formed by a plurality of first side walls. The tank bottom of the lower tank section is formed by the bottom wall.

[0012] S3 Formation of the assembled body

[0013] A plurality of second materials are welded to a plurality of second side walls for forming the tank wall of the upper tank section correspondingly to form a plurality of assembled bodies.

[0014] S4 Formation of the upper tank section of the transformer

[0015] A plurality of assembled bodies are welded above the lower tank section to form the upper tank section, and the second perforations on the second materials forming the tank flange of the upper tank section are made to correspond to the first perforations on the first materials forming the tank flange of the lower tank section to form the tank flange holes.

[0016] Furthermore, the formation of the lower tank section in S2 includes the following steps:

[0017] S2.1 A plurality of first materials provided with first perforations are spliced and welded to surround the tank flange of the lower tank section.

[0018] S2.2 A plurality of first side walls for forming the tank wall of the lower tank section are erected on the inner wall of the tank flange of the lower tank section after the welding is completed, and after the erection of the first side walls is completed, the bottom wall for forming the tank bottom of the lower tank section is assembled.

[0019] S2.3 The first side walls are welded to the tank flange and the bottom wall of the lower tank section respectively to form the lower tank section.

[0020] Preferably, in S2.1, during the splicing of multiple first strips, an X-shaped groove is provided at the end of each first strip. Each first strip is fixed to the welding platform by multiple fixing members, and a support member is provided between two opposite first strips to avoid errors caused by the shrinkage of the weld seam.

[0021] Furthermore, the formation of the S3 splicing body includes the following steps:

[0022] S3.1 A plurality of second strips provided with second perforations are respectively spliced with a plurality of second side walls for forming the upper-section fuel tank wall, and the front sides of the second strips and the second side walls are positioned and welded to form a plurality of splicing bodies;

[0023] S3.2 Assemble and weld accessory components on the second side walls of the splicing bodies;

[0024] S3.3 After the accessory components are welded, weld the second strips forming the splicing bodies to the back sides of the second side walls.

[0025] Preferably, in S3.1, the front sides of the second strips and the second side walls are positioned and welded every 200 - 300 mm, and the weld length is 15 - 25 mm;

[0026] In S3.1, during the splicing of the second strips and the second side walls, the second side walls are fixed to the welding platform by multiple fixing members, and the interval between two fixing members is 300 - 500 mm;

[0027] In S3.3, after the accessory components are welded, flip the splicing body and raise the middle part of the second strip of the splicing body, with both ends of the second strip suspended. Weld the second strip forming the splicing body to the back side of the second side wall, with the fillet weld height being 5 - 6 mm, and leaving a range of 150 - 200 mm at both ends of the second strip without welding to the second side wall.

[0028] Furthermore, the formation of the S4 transformer fuel tank includes the following steps:

[0029] S4.1 Stand a plurality of splicing bodies on the upper wall of the lower-section fuel tank. The second strips of each splicing body correspond to the first strips forming the rim of the lower-section fuel tank, and the first perforations and the second perforations are aligned to form rim holes;

[0030] S4.2 Install temporary screws in the rim holes to form a second temporary fixing structure between the lower-section fuel tank and the spliced splicing bodies;

[0031] S4.3 Weld the plurality of splicing bodies of the second temporary fixing structure to form the upper-section fuel tank. The second strips of the splicing bodies surround the rim of the upper-section fuel tank, and the second side walls of the splicing bodies surround the wall of the upper-section fuel tank, and weld the front sides of the second side walls of the second temporary fixing structure to the second strips;

[0032] S4.4 Remove the temporary screw rods forming the second temporary fixing structure;

[0033] S4.5 Weld the upper-section fuel tank wall to form an integral body and assemble a cover for the upper-section fuel tank wall.

[0034] Preferably, in S4.3, weld the plate-shaped reinforcing iron to the upper edge of the upper-section fuel tank.

[0035] Preferably, a limit plate is provided on the cover. In S4.5, the upper-section fuel tank is flipped so that the upper-section fuel tank wall and the limit plate of the cover are first positioned and welded and then integrally welded.

[0036] Preferably, in S4.1, after the splicing body stands on the upper vertical wall of the lower-section fuel tank, the two second side walls of adjacent splicing bodies are positioned and welded every 200 - 300 mm, and the weld length is 15 - 25 mm.

[0037] Preferably, in step S1, four first strips and four second strips form four first temporary fixing structures that can enclose a rectangular frame. Each first temporary fixing structure includes a first strip and a second strip arranged in a stacked manner;

[0038] In step S2, four first strips are assembled into the upper edge of the lower-section fuel tank in a rectangular shape. The four first side walls are sequentially assembled with the first strips to form vertical walls, and a bottom wall is installed as the bottom of the lower-section fuel tank after the lower-section fuel tank wall is assembled;

[0039] In step S3, weld the four second side walls and the four second strips respectively to form four assembled bodies;

[0040] In step S4, weld the four assembled bodies above the lower-section fuel tank to form the upper-section fuel tank, and make the second perforations on the second strips correspond to the first perforations on the first strips to form the edge holes.

[0041] For a manufacturing method of a large power transformer fuel tank according to the present invention, in S1, first form the first temporary fixing structure with the first strips and the second strips, then set the edge holes, and remove the first temporary fixing structure after the edge holes are formed. The first temporary fixing structure does not directly form the complete upper-edge and lower-edge of the upper-section fuel tank, but only fixes the first strips and the second strips correspondingly. Therefore, the efficiency of setting the edge holes is relatively high and the requirements for the drilling machine and the fixture are relatively low; in S3, first weld the second strips and the second side walls to form the splicing body, and in S4, stand the wall above the lower-edge of the lower-section fuel tank, avoiding standing the wall inside the upper-edge of the upper-section fuel tank after forming the upper-edge of the upper-section fuel tank, reducing the manufacturing difficulty of forming the upper-section fuel tank wall. At the same time, since the edge holes are formed after the first strips and the second strips are fixed correspondingly, there will be no misalignment problem after assembly.

[0042] In addition, before welding, the first strip and the second side wall are fixed on the welding platform by fixtures to prevent flexural deformation during welding; during the manufacturing process, the assembly and welding sequence is specified, and the welding interval and weld length are fixed, which improves the manufacturing accuracy while ensuring the manufacturing standardization and guarantees the product quality. Brief Description of the Drawings

[0043] Figure 1 is a flowchart of a manufacturing method for a large power transformer tank of the present invention;

[0044] Figure 2 is a schematic structural diagram of a manufacturing method for a large power transformer tank of the present invention;

[0045] Figure 3 is Figure 2 an enlarged view of part A of Detailed Description of the Invention

[0046] The following Figures 1 to 3 given embodiments are used to further illustrate the specific implementation manners of a manufacturing method for a large power transformer tank of the present invention. The manufacturing method for a large power transformer tank of the present invention is not limited to the descriptions of the following embodiments.

[0047] A manufacturing method for a large power transformer tank includes the following steps:

[0048] S1 Formation of the tank rim holes

[0049] The first strip 1 for forming the tank rim of the lower tank section and the second strip 4 for forming the tank rim of the upper tank section form a first temporary fixing structure correspondingly, and after a plurality of tank rim holes are provided on the first temporary fixing structure, the first temporary fixing structure is removed. The part of the tank rim hole on the first strip is the first perforation, and the part of the tank rim hole on the second strip is the second perforation;

[0050] S2 Formation of the lower tank section

[0051] A plurality of first strips, a plurality of first side walls, and a bottom wall are welded together to form the lower tank section. The tank rim of the lower tank section is surrounded by a plurality of first strips 1 provided with first perforations, the tank wall of the lower tank section is formed by a plurality of first side walls 2, and the tank bottom of the lower tank section is formed by the bottom wall 3;

[0052] S3 Formation of the assembled body

[0053] A plurality of second strips 4 are welded to a plurality of second side walls 5 for forming the tank wall of the upper tank section correspondingly to form a plurality of assembled bodies;

[0054] S4 Formation of the upper tank section of the transformer

[0055] A plurality of assembled bodies are welded together above the lower-section fuel tank to form the upper-section fuel tank, and the second perforations on the second strip 4 forming the rim of the upper-section fuel tank correspond to the first perforations on the first strip 1 forming the rim of the lower-section fuel tank to form rim holes.

[0056] A manufacturing method of a large power transformer fuel tank according to the present invention. In S1, after the first strip 1 and the second strip 4 form the first temporary fixing structure, rim holes are set, and the first temporary fixing structure is removed after the rim holes are formed. The first temporary fixing structure does not directly form the complete rims of the upper-section fuel tank and the lower-section fuel tank, but only fixes the first strip 1 and the second strip 4 correspondingly. Therefore, the efficiency of setting the rim holes is relatively high and the requirements for the drilling machine and the fixture are relatively low. In S3, the second strip 4 is first welded to the second side wall 5 to form a splicing body, and in S4, a vertical wall is erected above the rim of the lower-section fuel tank, avoiding erecting a wall inside the rim of the upper-section fuel tank after the rim of the upper-section fuel tank is formed first, and reducing the manufacturing difficulty of forming the wall of the upper-section fuel tank. At the same time, since the rim holes are formed after the first strip 1 and the second strip 4 are fixed correspondingly, there will be no misalignment problem after assembly.

[0057] The formation of the rim holes in S1 specifically includes the following steps:

[0058] S1.1 The first strip 1 for forming the rim of the lower-section fuel tank and the second strip 4 for forming the rim of the upper-section fuel tank correspondingly form the first temporary fixing structure;

[0059] S1.2 Drill a plurality of rim holes on the first temporary fixing structure. The part of the rim hole on the first strip 1 is the first perforation, and the part of the rim hole on the second strip 4 is the second perforation. The first perforation and the second perforation are docked to form the rim hole;

[0060] S1.3 Remove the first temporary fixing structure after the rim holes are set;

[0061] Among them, the first temporary fixing structure in S1.1 is preferably four first temporary fixing structures that can enclose a rectangular frame. Each first temporary fixing structure includes the first strip 1 and the second strip 4 stacked. Of course, the number of the first temporary fixing structures in S1.1 may not be limited to four. A plurality of first strips 1 and second strips 4 may be stacked together to form a first temporary fixing structure. Of course, the specifications of the first strip 1 and the second strip 4 should be the same at this time, and the intervals and sizes of the rim holes are preferably the same. It should be noted that the shapes of the rims of the lower-section fuel tank and the upper-section fuel tank formed by a plurality of first strips 1 and second strips 4 are not limited to rectangles, but may also be polygons and other shapes, but their formation principles are the same. Further, to ensure the welding quality of the rim strip, the end of the first strip 1 is preferably set as an X-shaped port.

[0062] The formation of the lower-section fuel tank specifically includes the following steps:

[0063] S2.1 A plurality of first strips 1 provided with first perforations are spliced and welded to form the rim of the lower-section fuel tank.

[0064] S2.2 A plurality of first side walls 2 for forming the wall of the lower-section fuel tank are erected on the inner wall of the rim of the lower-section fuel tank after the splicing and welding are completed, and a bottom wall 3 for forming the bottom of the lower-section fuel tank is assembled after the erection of the first side walls 2 is completed.

[0065] S2.3 The first side walls 2 are respectively welded to the rim and the bottom wall 3 of the lower-section fuel tank to form the lower-section fuel tank.

[0066] To prevent flexural deformation during the welding process, in S2.1, during the splicing process of the plurality of first strips 1, the first strips 1 are fixed to the welding platform by a plurality of fixing members, and the interval between two fixing members is 300 - 500 mm; in S3.1, during the splicing process of the second strip 4 and the second side wall 5, the second side wall 5 is fixed to the welding platform by a plurality of fixing members, and the interval between two fixing members is 300 - 500 mm.

[0067] Especially when the first temporary fixing structure in S1.1 is four first temporary fixing structures that can enclose a rectangle, each first temporary fixing structure includes a first strip 1 and a second strip 4 arranged in a stacked manner. Furthermore, in S2.1, a plurality of first strips 1 are spliced to form a rectangular frame structure, and each first strip 1 is fixed to the welding platform by a plurality of fixing members to prevent flexural deformation. A support member for avoiding errors caused by the shrinkage of the weld seam is provided between two opposite first strips 1 to ensure the quality and accuracy of the rim of the lower-section fuel tank.

[0068] The formation of the splicing body specifically includes the following steps:

[0069] S3.1 A plurality of second strips 4 are respectively spliced with a plurality of second side walls 5 for forming the wall of the upper-section fuel tank, and the front surfaces of the second strip and the second side wall 5 are tack-welded to form a plurality of splicing bodies.

[0070] S3.2 An accessory component is assembled and welded on the second side wall 5 of the splicing body.

[0071] S3.3 After the accessory component is welded, the second strip 4 forming the splicing body is welded to the back surface of the second side wall 5.

[0072] Preferably, the second strip 4 and the second side wall 5 are first tack-welded and then erected, and then the second strip 4 and the second side wall 5 are completely welded together. The second strip 4 and the second side wall 5 are first tack-welded to determine their assembly positions and form a temporary fixing structure. If they are welded together at this time, it will cause a problem of large gaps between the tank walls when using temporary screws for fixing later.

[0073] The welding of the accessory components can be carried out synchronously with the tack welding of the second strip 4 and the second side wall 5, and the two can be carried out in any order. The accessory components on the splicing body include accessory components such as channel-shaped reinforcing irons, brackets, and pipe joints. Among them, the reinforcing irons include plate-shaped reinforcing irons and channel-shaped reinforcing irons. As Figure 2 shown, the channel-shaped reinforcing irons are arranged uniformly along the longitudinal direction of the second side wall 5, and plate-shaped reinforcing irons are also provided below each channel-shaped reinforcing iron. Preferably, each channel-shaped reinforcing iron corresponds to two plate-shaped reinforcing irons, but the plate-shaped reinforcing irons are not welded first in step S3.2.

[0074] Specifically, in S3.1, the second strip 4 and the front of the second side wall 5 are tack welded every 200 - 300 mm, and the weld length is 15 - 25 mm.

[0075] The specific process of S3.3 is that after the welding of the accessory components is completed, the splicing body is flipped and the middle of the second strip 4 of the splicing body is raised, and both ends of the second strip 4 are suspended. Then, the back of the second strip 4 forming the splicing body and the second side wall 5 are welded, which is beneficial to reducing the later welding workload, and the fillet weld height is 5 - 6 mm. The smaller fillet weld results in less welding deformation and has less impact on the later operation difficulty; a range of 150 - 200 mm is left at both ends of the second strip 4 without welding to the second side wall 5, which is beneficial to reducing welding deformation.

[0076] The formation of the upper tank of the S4 transformer includes the following steps:

[0077] S4.1 Stand multiple splicing bodies on the upper wall of the lower tank. The second strip 4 of each splicing body corresponds to the first strip 1 forming the tank edge of the lower tank, and the first perforation and the second perforation are aligned to form a tank edge hole;

[0078] S4.2 Install temporary screws in the tank edge holes to form a second temporary fixing structure between the lower tank and the spliced splicing bodies;

[0079] S4.3 Weld the multiple splicing bodies of the second temporary fixing structure to form the upper tank. The second strip 4 of the splicing body surrounds the tank edge of the upper tank, and the second side wall of the splicing body surrounds the tank wall of the upper tank, and the front of the second side wall of the second temporary fixing structure is welded to the second strip 4;

[0080] S4.4 Remove the temporary screws forming the second temporary fixing structure;

[0081] S4.5 Weld the tank wall of the upper tank to make it integral and assemble a tank cover 6 for the tank wall of the upper tank.

[0082] Preferably, a plate-shaped reinforcing iron is provided on the splicing body, and the welding between the plate-shaped reinforcing iron and the second strip 4 is not carried out first after the welding of the auxiliary components in step S3.3, but is carried out in S4.3. Specifically, in S4.1, after the splicing body stands on the upper vertical wall of the lower fuel tank, the adjacent two second side walls 5 are tack-welded every 200-300 mm, and the weld length is 15-25 mm. The final completion of the plate-shaped reinforcing iron is in S4.3, where the plate-shaped reinforcing iron is welded to the edge of the upper fuel tank to prevent the edge of the fuel tank from deflecting and deforming after welding, resulting in the inability to fix the edge of the upper fuel tank and the edge of the lower fuel tank as a whole due to local gaps.

[0083] Preferably, a limiting plate is provided on the tank cover 6. After the edge and wall of the upper fuel tank are completed, as in S4.5, the upper fuel tank is turned over so that the wall of the upper fuel tank and the limiting plate of the tank cover 6 are first tack-welded and then welded integrally.

[0084] The following is an optimal manufacturing solution provided, and the steps are as follows.

[0085] S1 Formation of the edge holes of the fuel tank

[0086] S1.1 Fix four first strips 1 and four second strips 4 with C-clamps to form a first temporary fixing structure. Each first temporary fixing structure includes a first strip 1 and a second strip 4 arranged in a stacked manner, and the centers of the first strip 1 and the second strip 4 are kept consistent, with a deviation of less than 2 mm.

[0087] S1.2 Drill a plurality of edge holes on the first temporary fixing structure. The part of the edge hole located on the first strip 1 is the first perforation, and the part of the edge hole located on the second strip 4 is the second perforation. The first perforation and the second perforation are docked to form the edge hole.

[0088] S1.3 Remove the first temporary fixing structure after the edge holes are set up.

[0089] S2 Formation of the lower fuel tank

[0090] S2.1 Lay the four first-section materials 1 that have been drilled flat on the platform for assembly and welding. Each end of the first-section material 1 is provided with an X-shaped groove to ensure welding quality, ensure the welding penetration depth, and make it penetrate. The four first-section materials 1 are assembled into the lower-section fuel tank rim in a rectangular shape. The inner length deviation of the lower-section fuel tank rim ≤ ±2 mm, the width deviation ≤ ±1 mm, and the diagonal deviation ≤ ±S2.5 mm. To prevent the lower-section fuel tank rim from deflecting and deforming during welding, use pressing plates as fixing parts to fix the assembled lower-section fuel tank rim before welding. The interval between adjacent two pressing plates is 300 - 500 mm, and the pressing plates are 50 - 100 mm away from both sides of the splicing weld. Further, to prevent the inner size deviation of the lower-section fuel tank rim caused by the shrinkage of the splicing weld, C-shaped tooling can also be spot-welded inside the splicing weld before welding, and 2 - 3 positive and negative lead screws are evenly used as support parts on the parallel part inside the lower-section fuel tank rim.

[0091] S2.2 Assemble and erect the four first side walls 2 in sequence with the lower-section fuel tank rim formed by the first-section materials 1, and install the bottom wall 3 as the bottom of the lower-section fuel tank after the lower-section fuel tank wall is assembled.

[0092] S2.3 Weld the welds between the lower-section fuel tank rim, the lower-section fuel tank wall, and the lower-section fuel tank bottom to form the lower-section fuel tank.

[0093] S3 Formation of the assembled body

[0094] S3.1 Fix the four second side walls 5 serving as the upper-section fuel tank walls on the welding platform with pressing plates respectively. The distance between adjacent two pressing plates is 300 - 500 mm. Assemble each second side wall 5 with a second-section material 4 provided with a second perforation. The center line of a second-section material 4 is aligned with a second side wall 5, and the center mutual difference ≤ ±1 mm. Then, position-weld the front of the second-section material 4 and the second side wall 5 to form four assembled bodies. The distance between the position-welds is 200 - 300 mm, and the length of the weld is about 20 mm.

[0095] S3.2 Assemble and weld accessory parts such as channel-shaped stiffeners, pipe joints, and brackets on the second side wall 5 of the assembled body.

[0096] S3.3 After the accessory parts are welded, remove the pressing plates used to fix the second side wall 5 on the welding platform. Use a crane to flip the assembled body and lay sleepers at the center position of the second-section material 4 so that both ends of the second-section material 4 are in a suspended state. Weld the reverse side weld of the second-section material 4 and the second side wall 5 of the assembled body. The fillet weld height is 5 - 6 mm, and leave a non-welding area of 150 - 200 mm at both ends of the second-section material 4.

[0097] S4 Formation of the upper-section fuel tank of the transformer

[0098] S4.1 Place the lower-section fuel tank on the welding platform. Use a crane to lift the four splicing bodies and place them on the corresponding edges of the lower-section fuel tank. Align the first perforation of the first strip 1 with the second perforation of the second strip 4 to form a rim hole. Use positioning pins to position and assemble from the center line to both sides so that the four assembled bodies are successively on the upper vertical wall of the lower-section fuel tank;

[0099] S4.2 After removing the positioning pins in the rim hole, install temporary screws to form a second temporary fixing structure between the lower-section fuel tank and the four spliced splicing bodies;

[0100] S4.3 Weld the four splicing bodies of the second temporary fixing structure to form the upper-section fuel tank. The second strip 4 of the splicing body forms the rim of the upper-section fuel tank, and the second side wall 5 of the splicing body forms the wall of the upper-section fuel tank. That is, adjacent two assembled bodies of the second temporary fixing structure are positioned and welded to form the wall of the upper-section fuel tank. Specifically, adjacent two second side walls 5 are positioned and welded every 200 - 300 mm, and the weld length is about 20 mm. Weld the splicing joints of the four second strips 4 of the second temporary fixing structure, and use double-person symmetric welding for the weld between the front of the second side wall 5 and the second strip 4. At this time, weld the plate-shaped reinforcing iron to the second strip 4 of the second temporary fixing structure;

[0101] S4.4 After the weld cools, remove the temporary screws used to form the second temporary structure;

[0102] S4.5 Further weld the wall of the upper-section fuel tank to weld adjacent two second side walls 5 into one body; Lift the welded upper-section fuel tank by 500 mm and place it flat on the fixture. Adjust the flatness of the tank cover 6 to be less than 5 / 1000 and weld limit plates at the four corners of the tank cover 6. Use a crane to turn the upper-section fuel tank 180°. Then lower the upper-section fuel tank so that the upper-section fuel tank is close to the limit plate, first perform positioning welding, and then weld the wall of the upper-section fuel tank and the tank cover 6 as a whole.

[0103] The above content is a further detailed description of the present invention in combination with specific preferred embodiments. It cannot be determined that the specific implementation of the present invention is only limited to these descriptions. For those of ordinary skill in the technical field to which the present invention belongs, without departing from the concept of the present invention, several simple deductions or substitutions can still be made, and all should be regarded as belonging to the protection scope of the present invention.

Claims

1. A manufacturing method of a large power transformer oil tank, characterized in that: It includes the following steps, S1 Formation of the tank flange holes, The first material for forming the tank flange of the lower section of the oil tank and the second material for forming the tank flange of the upper section of the oil tank form a first temporary fixing structure correspondingly, and after setting a plurality of tank flange holes on the first temporary fixing structure, the first temporary fixing structure is removed. The part of the tank flange hole on the first material is the first perforation, and the part of the tank flange hole on the second material is the second perforation; S2 Formation of the lower section of the oil tank, A plurality of first materials, a plurality of first side walls, and the bottom wall are welded together to form the lower section of the oil tank. The tank flange of the lower section of the oil tank is surrounded by a plurality of first materials provided with the first perforations. The tank wall of the lower section of the oil tank is formed by a plurality of first side walls, and the tank bottom of the lower section of the oil tank is formed by the bottom wall; S3 Formation of the assembled body, A plurality of second materials are welded correspondingly with a plurality of second side walls for forming the tank wall of the upper section of the oil tank to form a plurality of assembled bodies; S4 Formation of the upper section of the transformer oil tank, A plurality of assembled bodies are welded above the lower section of the oil tank to form the upper section of the oil tank, and the second perforations on the second materials forming the tank flange of the upper section of the oil tank correspond to the first perforations on the first materials forming the tank flange of the lower section of the oil tank to form the tank flange holes.

2. The manufacturing method of a large power transformer oil tank according to claim 1, characterized in that: The formation of the lower section of the oil tank in S2 includes the following steps: S2.1 A plurality of first materials provided with the first perforations are spliced and welded to surround the tank flange of the lower section of the oil tank; S2.2 A plurality of first side walls for forming the tank wall of the lower section of the oil tank are erected on the inner wall of the tank flange of the lower section of the oil tank after the welding is completed, and after the erection of the first side walls is completed, the bottom wall for forming the tank bottom of the lower section of the oil tank is assembled; S2.3 The first side walls are welded to the tank flange and the bottom wall of the lower section of the oil tank respectively to form the lower section of the oil tank.

3. The manufacturing method of a large power transformer oil tank according to claim 2, characterized in that: Wherein, In S2.1, during the splicing process of a plurality of first materials, the ends of the first materials are provided with X-shaped grooves, each first material is fixed to the welding platform through a plurality of fixing parts, and a support part for avoiding errors caused by the shrinkage of the welding seam is provided between two opposite first materials.

4. The manufacturing method of a large power transformer oil tank according to claim 1, characterized in that: The formation of the spliced body in S3 includes the following steps: S3.1 A plurality of second materials provided with the second perforations are spliced correspondingly with a plurality of second side walls for forming the tank wall of the upper section of the oil tank, and the front surfaces of the second materials and the second side walls are welded by positioning to form a plurality of spliced bodies; S3.2 Assemble and weld the accessory parts on the second side walls of the spliced body; S3.3 After the welding of the accessory parts is completed, weld the back surfaces of the second materials and the second side walls forming the spliced body.

5. The manufacturing method of a large power transformer oil tank according to claim 4, characterized in that: wherein, in S3.1, the front surfaces of the second materials and the second side walls are welded by positioning every 200 - 300 mm, and the weld length is 15 - 25 mm; In S3.1, during the splicing process of the second materials and the second side walls, the second side walls are fixed to the welding platform through a plurality of fixing parts, and the interval between two fixing parts is 300 - 500 mm; In S3.3, after the auxiliary components are welded, turn over the splicing body and raise the middle part of the second strip of the splicing body, with both ends of the second strip suspended. Weld the second strip forming the splicing body to the back of the second side wall, with the fillet weld height being 5 - 6 mm, and leave a range of 150 - 200 mm at both ends of the second strip without welding to the second side wall.

6. A manufacturing method of a large power transformer oil tank according to claim 1, characterized in that: The formation of the S4 transformer oil tank includes the following steps: S4.1 Stand multiple splicing bodies on the upper vertical wall of the lower section of the oil tank. The second strip of each splicing body corresponds to the first strip forming the tank edge of the lower section of the oil tank, and the first perforation and the second perforation are aligned to form a tank edge hole; S4.2 Install temporary screws in the tank edge hole to form a second temporary fixing structure between the lower section of the oil tank and the spliced splicing bodies; S4.3 Weld the multiple splicing bodies of the second temporary fixing structure to form the upper section of the oil tank. The second strips of the splicing bodies enclose the tank edge of the upper section of the oil tank, and the second side walls of the splicing bodies enclose the tank wall of the upper section of the oil tank, and weld the front of the second side wall of the second temporary fixing structure to the second strip; S4.4 Remove the temporary screws forming the second temporary fixing structure; S4.5 Weld the tank wall of the upper section of the oil tank to form an integral body and assemble a tank cover for the tank wall of the upper section of the oil tank.

7. A manufacturing method of a large power transformer oil tank according to claim 6, characterized in that : In S4.3, weld the plate - type strengthening iron to the tank edge of the upper section of the oil tank.

8. A manufacturing method of a large power transformer oil tank according to claim 6, characterized in that: A limiting plate is provided on the tank cover. In S4.5, the upper section of the oil tank is turned over so that the tank wall of the upper section of the oil tank and the limiting plate of the tank cover are first positioned - welded and then integrally welded.

9. A manufacturing method of a large power transformer oil tank according to claim 6, characterized in that: wherein, In S4.1, after the splicing bodies are stood on the upper vertical wall of the lower section of the oil tank, the two second side walls of adjacent splicing bodies are positioned - welded every 200 - 300 mm, and the weld length is 15 - 25 mm.

10. A manufacturing method of a large power transformer oil tank according to claim 1, characterized in that: In step S1, four first strips and four second strips form four first temporary fixing structures that can enclose a rectangular frame. Each first temporary fixing structure includes a first strip and a second strip arranged in a stacked manner; In step S2, four first strips are assembled into a rectangular tank edge of the lower section of the oil tank. The four first side walls are sequentially assembled and stood corresponding to the first strips, and a bottom wall is installed as the tank bottom of the lower section of the oil tank after the tank wall of the lower section of the oil tank is assembled; In step S3, weld the four second side walls to the four second strips respectively to form four assembled bodies; In step S4, weld the four assembled bodies above the lower section of the oil tank to form the upper section of the oil tank, and align the second perforation on the second strip with the first perforation on the first strip to form a tank edge hole.

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