Assembling method of assembled oil storage tank structure

Abstract

The invention discloses an assembly method of an assembly type oil storage tank structure. The assembly method comprises the steps of (1) foundation construction, (2) oil storage tank prefabrication, (3) tank bottom plate assembly, (4) auxiliary equipment installation, (5) top ring tank wall assembly, (6) tank top assembly, (7) other tank wall assembly and (8) bottom layer tank wall and tank bottom plate assembly. The oil storage tank assembled through the method is high in installation precision, the installation precision is convenient to detect, the position posture of an installation part is convenient to adjust, lifting is stable, the construction cost is low, and the repair rate of the welded oil storage tank is low.

Description

Technical Field

[0001] The invention relates to the technical field of on-site assembly of metal oil tanks, and in particular to an assembling method of an assembled oil storage tank structure. Background Art

[0002] With the expansion of production scale and technological upgrading in various industries, especially in the chemical, food, pharmaceutical, petroleum, natural gas and other industries, the demand for metal tanks continues to increase due to their corrosion resistance, easy cleaning, high strength and other characteristics. Due to their large size and weight, metal tanks are usually assembled on-site. The most difficult and labor-intensive steps in on-site assembly are on-site assembly and welding operations, which mainly include the assembly of tank wall panels, the position adjustment of tank wall panels and bottom plates, and the reservation of shrinkage joints. At present, on-site installation is mainly carried out by multiple manual coordination for splicing and welding operations, which requires high coordination and cooperation capabilities and increases construction costs. The invention patent with authorization announcement number CN115106623B discloses a method for assembling the side walls of large storage tanks using a BOP process, which includes the following steps: 1) installing a circular operating platform vehicle for the storage tank; 2) welding the enclosure, assembly and longitudinal seams of the first circle of wall panels under the tank top; 3) installing a synchronous hydraulic jacking device for the storage tank;

[0003] 4) The enclosure of the second circle wall panel under the tank top; 5) The overall lifting of the first circle wall panel under the tank top; 6) The assembly and longitudinal seam welding of the enclosure of the second circle wall panel under the tank top; 7) The circumferential seam welding of the first and second circle wall panels under the tank top; 8) Repeat steps 4) to 7) until the overall welding of the tank side wall is completed. It effectively reduces the demand for senior welding talents and reduces the workload of construction personnel in high-altitude operations. It improves the efficiency of tank construction while ensuring the welding quality. The overall work efficiency is increased to 3 times the existing construction efficiency, which accelerates the application of automatic welding technology in the third-generation nuclear power market. However, the platform vehicle used in its construction is complex to install and has high requirements for installation accuracy, which increases the cost of construction. Summary of the invention

[0004] The purpose of the present invention is to provide an assembly method for an assembled oil storage tank structure, wherein the oil storage tank assembled by the method has high installation accuracy, convenient installation accuracy detection, and is easy to adjust the position and posture of the installation components, and the lifting is stable, the construction cost is low, and the rework rate of the oil storage tank after welding is low.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] An assembling method of an assembled oil storage tank structure, the assembling method comprising the following steps:

[0007] Step 1: foundation construction: construct multiple foundation piles at the bottom of the oil storage tank installation area, lay a perlite concrete cushion layer in the area, lay an asphalt sand insulation layer on top of the perlite concrete cushion layer; set position marks on the asphalt sand insulation layer;

[0008] Step 2: prefabricate the oil storage tank, divide the tank bottom plate into multiple edge plates and middle plates; the tank wall is composed of multiple wall panels, and the cutting line, standard line, and three-equal grouping lines of the plate length of each wall panel are marked on the steel plate, and the size and number are marked on the wall panel; the tank top plate includes multiple melon skin plates and reinforcing ribs fixed on the inner wall of the melon skin plates. After the melon skin plates are cut, they are integrally formed using an arch forming mold;

[0009] Step 3: Assemble the tank bottom plate. First, lay the pad on the foundation. After the pad is laid into a circle, lay the edge plate on the pad. When laying, use the spacing limit block to adjust the interval between two adjacent edge plates. After the overall adjustment is completed, use the gantry clamp to fix it; then lay the middle plate. The middle plates are laid piece by piece from the center of the tank bottom to both ends. After the middle row is laid, the middle row is used as the basis to lay rows on both sides. Each row of middle plates is laid from the middle to both sides in sequence; after the overall laying of the tank bottom plate is completed, the joint seams of the two adjacent middle plates are welded; the lap welds between the edge plate and the middle plate are used as contraction seams and are not welded for the time being;

[0010] Step 4: Installation of auxiliary equipment: Install a positioning assembly at the center of the tank bottom. The positioning assembly is used to measure the position and horizontality of each wall panel relative to the center of the tank bottom; install a lifting assembly on the tank bottom and inside the tank wall. The lifting assembly is used to lift the assembled tank wall; the positioning assembly includes a support column fixedly installed at the center of the tank bottom plate and a support seat rotatably arranged on the support column. A level and a laser displacement sensor are fixedly installed on the support seat. Two photosensitive elements are horizontally arranged on the inside of each wall panel. The photosensitive elements are used to receive light signals from the level and the laser displacement sensor and convert them into electrical signals;

[0011] Step 5, assembling the top ring tank wall, through the positioning of the positioning component, draw the inner circumference line and the outer circumference line of the top ring tank wall on the tank bottom plate, and place several adjustable positioning parts along the inner side of the inner circumference. The wall panels are assembled according to the number marks and corresponding orientation marks. During assembly, the positioning component and the square ruler are used to detect the installation position, horizontality and verticality of the wall panels. When the verticality, arc and circumference of the entire circle of the tank wall meet the requirements, the vertical seams of the two adjacent wall panels are spot welded, leaving a vertical seam as a vertical contraction seam. After the spot welding is completed, the vertical seams are welded as a whole, and finally the vertical contraction seams are welded; the adjustable positioning parts include an L-shaped support bottom plate fixedly mounted on the tank bottom plate and two adjusting bolts adjustably mounted on the L-shaped support bottom plate, and also include an adjusting rod hingedly mounted between the wall panel and the tank bottom plate, and the verticality of the wall panel is adjusted by adjusting the length of the adjusting rod;

[0012] Step 6: Roof assembly: first assemble two melon skin boards at the axially symmetrical position, adjust them evenly and then weld them, then assemble other melon skin boards and adjust the overlap width to 60mm; after the melon skin boards are assembled, they are welded by step-back welding, and then the intermittent welds on the inner side of the arch and the connecting welds of the ribs are welded; finally, the hemming angle steel is welded and the roof opening machine accessories are installed;

[0013] Step seven, assemble the remaining tank walls, install the inner expansion ring on the inner side of the top ring tank wall, and use the gantry plate to fix the inner expansion ring on the inner side of the wall plate; install the secondary top ring tank wall on the outer side of the top ring tank wall according to the corresponding position, and reserve a live opening; connect the inner expansion ring with the lifting assembly, lift the top ring tank wall to above the assembly position of the two rings of tank walls through the lifting assembly, and assemble the secondary top ring tank wall according to the method of step three. After the welding of the secondary top ring tank wall is completed, the top ring tank wall and the secondary top ring tank wall are spliced ​​by the lifting assembly, and the position and posture of the two are adjusted and then spot welded and fixed. The tank wall is checked for shape and size. After the inspection is qualified, the annular weld of the top ring tank wall and the secondary top ring tank wall is welded; the third and fourth rings of tank walls from top to bottom are lifted and assembled and installed according to the above operations until the bottom tank wall is assembled;

[0014] Step eight, assemble the bottom tank wall and the tank bottom plate. After the installation of the bottom tank wall is completed, construct the tank body opening, pipe connection and top plate installation; first spot weld the bottom tank wall and the tank bottom plate, measure the size and shape of the tank body and then perform full welding; after welding, weld the shrinkage seams between the edge plate and the middle plate and between the edge plates; after welding, perform vacuum inspection.

[0015] Preferably, cutting lines and standard lines of each edge plate and middle plate are drawn on the steel plate, and each edge plate and middle plate is numbered and marked; one end of the edge plate is arc-shaped, and the minimum dimension of the edge plate along the radius direction of the tank bottom is greater than or equal to 700mm; the middle plate is rectangular, and the width of the middle plate is greater than or equal to 1000mm, and the length is greater than or equal to 2000mm.

[0016] Preferably, in step three, the middle plate and the edge plate are temporarily welded via a temporary positioning plate to control the welding deformation.

[0017] Preferably, in step three, before the tank bottom plate is laid, an anti-corrosion coating should be applied to the lower surface of the tank bottom plate, and no coating shall be applied within 50 mm of the edge of each tank bottom plate.

[0018] Preferably, in step 4, the lifting assembly includes a lifting column fixedly mounted on the tank bottom plate and a fall chain mounted on the top of the lifting column, and the hook of the fall chain is connected to the wall panel to lift the wall panel through the fall chain.

[0019] Preferably, in step five, after the assembly and welding of the top ring tank wall is completed, a hemming angle steel is installed on the top of the top ring tank wall, the butt weld of the hemming angle steel is staggered with the vertical seam of the wall panel, and the lap seam between the hemming angle steel and the wall panel is temporarily fixed by spot welding.

[0020] Preferably, in step seven, the inner expansion ring is 200 mm away from the lower opening of the top ring tank wall, and the inner expansion ring is composed of channel steel divided into 1 / 4 types, which are connected into a full circle by a 15-ton screw jack.

[0021] Preferably, in step eight, the welding of the large angle weld between the bottom tank wall and the tank bottom plate is first performed by simultaneously adopting the method of segmented back-welding or skip welding along the same direction inside and outside the tank, and a 100% magnetic powder or penetration inspection is performed after welding; then the filling and covering layers are segmentedly welded along the same direction by four angular submerged arc automatic welding machines symmetrically distributed; during the operation, the inside is welded first and then the outside.

[0022] Preferably, reinforcement support must be provided on the inner side of the bottom tank wall before welding, and the distance between two adjacent reinforcement support points is less than or equal to 1200 mm. The reinforcement support must be removed after the tank bottom shrinkage seam welding is completed.

[0023] In the present invention, the above steps can be used to weld the oil storage tank layer by layer with high precision, effectively reducing the requirements on the operation level of the welding workers, avoiding the high-altitude operation of the operators, and improving the safety of the construction. The laying welding of the tank bottom plate adopts the method of welding the middle plate first, and then welding the edge plates after the tank wall welding is completed and welded with the edge plates, and fixing them with temporary positioning plates and gantry fixtures is used to facilitate the control of deformation during welding.

[0024] The positioning assembly is used to measure the position and horizontality of each wall panel relative to the center of the tank bottom. It is used with a square ruler to measure the verticality of the wall panel installation. Each installed wall panel can be measured quickly, avoiding the disadvantage of the traditional measurement instrument that needs to be adjusted repeatedly for one measurement, and improving the measurement efficiency and accuracy. The adjustable positioning parts can not only limit the installation of the wall panel, but also adjust the position and angle of the wall panel installation. It is a dual purpose device, which reduces the use of auxiliary adjustment equipment, reduces the number of adjustment personnel, and reduces construction costs.

[0025] In this construction process, multiple fall chains are used for synchronous lifting, which is simple to operate and low in cost. The number of fall chains can be adjusted according to the size of the oil tank, and has good versatility. It avoids the drawbacks of oil leakage and difficulty in synchronous lifting control during hydraulic lifting, and is also easy to remove from the oil tank after disassembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the construction process of the present invention;

[0027] Figure 2 It is a cross-sectional schematic diagram of the basic structure of the present invention;

[0028] Figure 3 It is a top view schematic diagram of the edge plate structure of the present invention;

[0029] Figure 4 It is a top view schematic diagram of the middle plate structure of the present invention;

[0030] Figure 5 It is a top view schematic diagram of the wall panel structure of the present invention;

[0031] Figure 6 This is a schematic diagram of the laying state of the edge plate of the present invention;

[0032] Figure 7 This is an intention to show the working state of the positioning component of the present invention;

[0033] Figure 8 This is a schematic diagram of the lifting state of the lifting assembly of the present invention;

[0034] Fig. 9 It is a schematic diagram of the structure of the adjustable positioning member of the present invention;

[0035] In the figure: 1. foundation pile; 2. perlite concrete cushion layer; 3. asphalt sand insulation layer; 4. edge plate; 5. middle plate; 6. wall plate; 7. pad; 8. interval limit block; 9. gantry fixture; 10. inclined iron; 11. positioning assembly; 12. lifting assembly; 13. adjustable positioning piece; 14. square; 110. support column; 111. support seat; 112. level; 113. laser displacement sensor; 114. photosensitive element; 120. lifting column; 121. fall chain; 130. L-shaped support base plate; 131. adjusting bolt; 132. adjusting rod. DETAILED DESCRIPTION

[0036] The present invention will be further described below in conjunction with the accompanying drawings:

[0037] like Figures 1 to 9 An assembling method of an assembled oil storage tank structure is shown, and the assembling method comprises the following steps:

[0038] Step 1, foundation construction, construct multiple foundation piles 1 at the bottom of the oil storage tank installation area, and lay a perlite concrete cushion layer 2 in the area, lay an asphalt sand insulation layer 3 on the top of the perlite concrete cushion layer 2, and set an orientation mark on the top of the asphalt sand insulation layer 3. The orientation mark includes 0°, 90°, 180° and 270° marks. When the perlite concrete cushion layer 2 is laid, the laying thickness of each layer is 100mm, and the layer thickness can be controlled by a stake. Each layer of the perlite concrete cushion layer 2 is compacted by vibration, tamping or compaction. In this embodiment, the thickness of the perlite concrete cushion layer 2 is 200mm. The asphalt in the asphalt sand insulation layer 3 should be selected according to the medium temperature in the oil tank. When the medium temperature in the oil tank is lower than 80°C, No. 60A (or No. 60B) road petroleum asphalt or No. 30A (or No. 30B) construction petroleum asphalt is used; the asphalt sand is mixed with 92% to 90% of medium and coarse sand and 8% to 10% of hot asphalt; in this embodiment, the thickness of the asphalt sand insulation layer 3 is 50 mm, and the slope is 120:1 from the center to the periphery.

[0039] Step 2: prefabricate the oil storage tank. The oil storage tank includes a tank bottom plate fixedly arranged on the top of the asphalt sand insulation layer 3, a tank wall plate sealed and fixedly arranged on the tank bottom plate, and a tank top plate fixedly arranged on the top of the tank wall plate. A plurality of accessories are arranged on the tank wall plate and the tank top plate, and the accessories include an oil inlet, an oil outlet, a manhole, a visual observation piece, etc.

[0040] The tank bottom plate is divided into multiple edge plates 4 and middle plates 5. One end of the edge plate 4 is arc-shaped. The minimum size of the edge plate 4 along the radius of the tank bottom is greater than or equal to 700mm. After the multiple edge plates 4 are spliced ​​circumferentially, they are adapted to the shape of the tank wall. The middle plate 5 is rectangular, and the width of the middle plate 5 is greater than or equal to 1000mm, and the length is greater than or equal to 2000mm. The distance between any adjacent welds on the tank bottom plate is greater than or equal to 200mm. When the edge plates 4 and middle plates 5 are made, the cutting lines and standard lines of each edge plate 4 and middle plate 5 need to be drawn on the steel plate, and each edge plate 4 and middle plate 5 is numbered and marked; the number mark is marked on the upper left of the steel plate with paint. When assembling, the installation position of the edge plate 4 and middle plate 5 can be quickly determined according to the number mark, thereby improving the assembly efficiency. The middle plate 5 is cut by a special semi-automatic cutting machine, and the edge plate 4 is cut manually or by a CNC cutting machine in the prefabrication yard, and polished after cutting. The size deviation of the edge plate 4 and the middle plate 5 must be within the preset range. The deviation of the edge plate 4 is controlled according to Table 1; the deviation of the middle plate 5 is controlled according to Table 2.

[0041] Table 1 Edge plate deviation

[0042]

[0043] Table 2 Middle plate deviation

[0044]

[0045] The tank wall is divided into multiple circles from top to bottom, and each circle of the tank wall is composed of multiple wall panels 6. When making the wall panels 6, the cutting line, standard line, and three-equal grouping lines of the board length of each wall panel 6 need to be marked on the steel plate, and the size and number are marked on the wall panels 6. The width of the wall panel 6 is greater than or equal to 1000mm, and the length is greater than or equal to 2000mm; the deviation of the wall panel 6 is controlled according to Table 3.

[0046] Table 3 Wallboard deviation

[0047]

[0048]

[0049] A plate should be reserved for each circle of wall panel 6 as a sealing plate. One side of the sealing plate should be extended by more than 200mm. After the size of the longitudinal seam of the whole circle of plates is determined (using a ruler to measure the outer circumference), the excess plate length can be cut off. After the wall panel 6 is cut, the bevel is processed with a planer, an angle grinding wheel or a special semi-automatic cutting machine according to the bevel type required by the welding plan. When the wall panel 6 is rolled with a rolling machine, the length of the pressure head shall not be less than 300mm, and the outer part of the rolling bed shall be supported by a bracket. After the wall panel 6 is rolled into shape, it is immediately placed on the platform and checked with a template. The curved wall panel 6 is checked with a 2-meter curved template in the horizontal direction, and the gap shall not be greater than 4mm; the vertical direction is checked with a straight template with a length of not less than 1 meter, and the gap shall not be greater than 1mm. After the wall panel 6 is qualified, it is placed on a special transport jig that matches the curvature of the wall panel 6 for stacking, transportation and lifting to effectively prevent deformation.

[0050] The tank top plate consists of multiple melon peel plates and reinforcing ribs fixed on the inner wall of the melon peel plates. The melon peel plates are cut and integrally formed using an arch forming mold. After the reinforcing ribs are pressed into an arc, they are checked with an arc sample, and the gap shall not be greater than 2mm.

[0051] Step 3: Assemble the tank bottom plate. Before laying the tank bottom plate, the lower surface of the tank bottom plate should be coated with anti-corrosion paint, and the edge of each tank bottom plate within 50mm shall not be painted. Before laying the tank bottom plate, the outer contour line of the edge plate 4, the cross center line and the division line of the edge plate 4 weld are drawn on the surface of the asphalt sand insulation layer 3, and the division value is marked on the ring beam with red paint. Theodolite and tape measure are used for measurement.

[0052] First, a pad 7 is laid on the foundation. After the pad 7 is laid into a circle, the edge plate 4 is laid on the pad 7. When laying, the interval between two adjacent edge plates 4 is adjusted using a spacing limiter 8 so that the interval between the two adjacent edge plates 4 is consistent, and the horizontality of the edge plate 4 is adjusted using an inclined iron 10. After the adjustment of the entire circle of edge plates 4 is completed, the gantry fixture 9 is used to fix them.

[0053] Then lay the middle plate 5, which is laid piece by piece from the center of the tank bottom to both ends. After the middle row is laid, it is laid row by row on both sides based on the middle row. Each row of middle plates 5 is laid from the middle to both sides in sequence. After the tank bottom plate is laid as a whole, the joints of two adjacent middle plates 5 are welded. The lap welds of the edge plate 4 and the middle plate 5 are used as contraction seams and are not welded for the time being. The tank bottom welds must be vacuum tested according to the design and construction specifications.

[0054] Step 4, installation of auxiliary equipment, installation of positioning assembly 11 at the center of the tank bottom, positioning assembly 11 is used to measure the position and horizontality of each wall panel 6 relative to the center of the tank bottom. Positioning assembly 11 is fixedly installed on the support column 110 at the center of the tank bottom plate and the support seat 111 rotatably arranged on the outer wall of the support column 110 through a bearing, and a level 112 and a laser displacement sensor 113 are fixedly installed on the support seat 111 through fasteners, and two photosensitive elements 114 are horizontally arranged on the inner side of each wall panel 6, and the photosensitive elements 114 are used to receive the optical signals of the level 112 and the laser displacement sensor 113 and convert them into electrical signals, and transmit the electrical signals to the controller, and display them through the display on the controller, thereby improving the accuracy and efficiency of measurement and avoiding the tedious process of repeated installation and adjustment of the traditional theodolite. In this embodiment, the support base 111 is a liftable structure, specifically including a support base and an electric slide installed on the support base. The receiving level 112 and the laser displacement sensor 113 are installed on the electric slide. The height of the receiving level 112 and the laser displacement sensor 113 is controlled by controlling the electric slide, thereby increasing the measurement range and enabling rapid measurement.

[0055] A lifting assembly 12 is installed on the bottom of the tank and on the inner side of the tank wall. The lifting assembly 12 is used to lift the assembled tank wall. The lifting assembly 12 includes a lifting column 120 fixedly installed on the tank bottom plate and a fall chain 121 installed on the top of the lifting column 120. The hook at the bottom of the fall chain 121 is connected to the wall panel 6, and the wall panel is lifted synchronously as a whole through the fall chain 121. The fall chain 121 is selected for manual lifting operations, which is simple to operate. The number of fall chains 121 can be adaptively adjusted according to the size of the oil storage tank, and the versatility is good. It avoids the drawbacks of oil leakage and difficulty in synchronous lifting control during hydraulic lifting, and is also convenient for removal from the oil storage tank after disassembly.

[0056] Step five, assembling the top ring tank wall. Through the positioning of the positioning component 11, draw the inner circumference and outer circumference of the top ring tank wall on the tank bottom plate. Place several adjustable positioning parts 13 at intervals along the inner side of the inner circumference. Assemble the wall panels 6 according to the number marks and corresponding orientation marks. During assembly, use the positioning component 11 and the square ruler 14 to detect the installation position, horizontality and verticality of the wall panels 6. When the verticality, curvature and circumference of the entire circle of the tank wall meet the requirements, spot weld the vertical seams of the two adjacent wall panels 6, leaving a vertical seam as a vertical shrinkage seam. After the spot welding is completed, weld the vertical seams as a whole, and finally weld the vertical shrinkage seam.

[0057] The allowable horizontal deviation of the upper edges of two adjacent wall panels is ≤2mm; the allowable horizontal deviation of any two points on the entire circumference is ≤6mm; the allowable vertical deviation of the wall panels is ≤3mm; the allowable deviation of the misalignment of the vertical welds of the wall panels is ≤1mm.

[0058] The adjustable positioning member 13 includes an L-shaped support base plate 130 fixedly mounted on the tank bottom plate and two adjusting bolts 131 adjustable by threads on the L-shaped support base plate 130. The two adjusting bolts 131 are pressed against the inner wall of the wall plate 6. The position and angle of the wall plate 6 are adjusted by the two adjusting bolts 131. It also includes an adjusting rod 132 hingedly mounted between the wall plate 6 and the tank bottom plate. The operator adjusts the verticality of the wall plate 6 by adjusting the length of the adjusting rod 132. The adjustment is simple and convenient. The position and angle can be adjusted, and the posture of the wall plate 6 can be maintained after adjustment, which is convenient for subsequent welding operations. The adjusting rod 132 includes a screw and a sleeve that are adjustable by threads. One end of the screw is mounted on the tank bottom plate through a hinged support, and one end of the sleeve is mounted on the inner wall of the wall plate 6 through a hinged support. The length of the adjusting rod 132 is adjusted by rotating the screw and the sleeve to achieve the verticality adjustment of the wall plate 6. The L-shaped support base plate 130 is trapezoidal in top view.

[0059] After the assembly and welding of the top ring tank wall is completed, the edge angle steel is installed on the top of the top ring tank wall. The butt weld of the edge angle steel is staggered with the vertical seam of the wall plate 6, and the distance is more than 200mm; the lap joint of the edge angle steel and the wall plate 6 is temporarily fixed by spot welding. The edge angle steel is 16mm higher than the top of the wall plate, and the local allowable deviation of the higher than the wall plate is ≤4mm; the edge angle steel is close to the wall plate, and the gap is not more than 2mm; when welding, the butt weld of the edge angle steel is welded first. To prevent deformation, the internal lap weld is first welded, and the external continuous weld is finally welded. The lap weld is welded after the tank top plate is welded.

[0060] Step six, top assembly, first assemble two melon peel boards in an axially symmetrical position, adjust them evenly and then weld them, then assemble other melon peel boards, and adjust the overlap width to 60mm; when installing the melon peel boards, set their central support members on the top of the support column 110, and reserve a mounting flange on the top of the support column 110. The center position of the top can be quickly determined according to the position of the support column 110, which has a high splicing efficiency.

[0061] After the melon skin panels are assembled, they are welded by step-back welding, followed by welding the intermittent welds on the inner side of the vault and the connecting welds of the ribs; finally, the edge angle steel and the top hole opening machine accessories are installed. The overlap width of two adjacent melon skin panels is 60mm, with an allowable deviation of ±5mm.

[0062] Step seven, assemble the remaining tank walls, install the inner expansion ring on the inner side of the top ring tank wall, the inner expansion ring is fixed on the inner side of the wall plate 6 with a gantry plate; the inner expansion ring is 200mm away from the lower opening of the top ring tank wall, the inner expansion ring is composed of channel steel divided into 1 / 4 types, and is connected into a complete circle with a 15-ton screw jack.

[0063] Install the secondary top ring tank wall on the outside of the top ring tank wall according to the corresponding position, leaving a gap; connect the inner expansion ring with the lifting assembly, lift the top ring tank wall to above the position of the two ring tank wall assembly through the lifting assembly, assemble the secondary top ring tank wall according to step three, after the secondary top ring tank wall is welded, splice the top ring tank wall and the secondary top ring tank wall through the lifting assembly, detect the position and posture of the top ring tank wall and the secondary top ring tank wall through the positioning assembly 10, adjust them manually, and fix them by spot welding after the position and posture of the two are qualified. The shape and size of the tank wall are checked. After passing the inspection, the annular welds of the top ring tank wall and the secondary top ring tank wall are welded; the third and fourth rings of tank walls from top to bottom are lifted, assembled and installed according to the above operations until the bottom tank wall is assembled; the longitudinal welds of each ring wall plate should be staggered in the same direction, and the spacing should be 1 / 3 of the plate length, and must not be less than 500mm; the edge angle of the vertical seam is checked with a 1m long arc template, and the edge angle is ≤10mm; the local concave and convex deformation of the tank wall is ≤13mm.

[0064] The welding of the tank wall circumferential seam must be carried out after the longitudinal seams of the upper and lower wall panels are completely welded, and the 300mm range on both sides of the T-joint should be avoided as the arc starting and arc ending points. Manual arc welding is used for the welding of the wall panel circumferential seam, and manual arc welding is used for the repair of the weld. First weld the outer weld of the circumferential seam, then weld the inner weld. The inner weld is cleaned with an automatic carbon arc air planer and polished with a grinding wheel before welding. After the longitudinal and circumferential seams of the tank wall are welded and passed the inspection, all longitudinal and circumferential seams on the inner side of the tank wall should be polished to be flush with the parent material, and no excess weld height should be left.

[0065] Step 8: Assemble the bottom tank wall and the tank bottom plate. After the bottom tank wall is installed, open the tank body, install the pipe and the tank top plate. Spot weld the bottom tank wall and the tank bottom plate first, and then perform full welding after measuring the size and shape of the tank body. After welding, weld the shrinkage seams between the edge plate 4 and the middle plate 5 and between the edge plate 5 and the edge plate 5. Temporary welding is performed between the middle plate 5 and the edge plate 4 through a temporary positioning plate to control the welding deformation. After welding, perform a vacuum inspection. The distance between the longitudinal weld of the bottom ring wall plate and the butt weld of the tank bottom edge plate shall not be less than 200mm.

[0066] For the welding of the large angle weld between the bottom tank wall and the tank bottom plate, firstly, the welding is carried out in the same direction inside and outside the tank by means of segmented back welding or skip welding. After welding, a 100% magnetic powder or penetration inspection is carried out. Then, the filling and covering layers are symmetrically distributed and segmentedly welded in the same direction by four angular submerged arc automatic welding machines. During the operation, the inside is welded first and then the outside. Before welding, the inside of the bottom tank wall must be reinforced and supported. The distance between two adjacent reinforcement support points is less than or equal to 1200mm. The reinforcement support must be removed after the tank bottom shrinkage seam is welded. The weld surface of the large angle weld should ensure a smooth transition, and the inner weld should be concave, otherwise it should be ground with a grinding wheel.

[0067] The above embodiments are only some illustrations of the concept and implementation of the present invention, and are not intended to limit the same. Under the concept of the present invention, technical solutions that have not been substantially changed are still within the scope of protection.

Claims

1. A method for assembling an assembled oil storage tank structure, characterized in that: The assembling method comprises the following steps: Step 1: foundation construction: construct multiple foundation piles at the bottom of the oil storage tank installation area, lay a perlite concrete cushion layer in the area, lay an asphalt sand insulation layer on top of the perlite concrete cushion layer; set position marks on the asphalt sand insulation layer; Step 2: prefabricate the oil storage tank, divide the tank bottom plate into multiple edge plates and middle plates; the tank wall is composed of multiple wall panels, and the cutting line, standard line, and three-equal grouping lines of the plate length of each wall panel are marked on the steel plate, and the size and number are marked on the wall panel; the tank top plate includes multiple melon skin plates and reinforcing ribs fixed on the inner wall of the melon skin plates. After the melon skin plates are cut, they are integrally formed using an arch forming mold; Step 3: Assemble the tank bottom plate. First, lay the pad on the foundation. After the pad is laid into a circle, lay the edge plate on the pad. When laying, use the spacing limit block to adjust the interval between two adjacent edge plates. After the overall adjustment is completed, use the gantry clamp to fix it; then lay the middle plate. The middle plates are laid piece by piece from the center of the tank bottom to both ends. After the middle row is laid, the middle row is used as the basis to lay rows on both sides. Each row of middle plates is laid from the middle to both sides in sequence; after the overall laying of the tank bottom plate is completed, the joint seams of the two adjacent middle plates are welded; the lap welds between the edge plate and the middle plate are used as contraction seams and are not welded for the time being; Step 4: Installation of auxiliary equipment: Install a positioning assembly at the center of the tank bottom. The positioning assembly is used to measure the position and horizontality of each wall panel relative to the center of the tank bottom; install a lifting assembly on the tank bottom and inside the tank wall. The lifting assembly is used to lift the assembled tank wall; the positioning assembly includes a support column fixedly installed at the center of the tank bottom plate and a support seat rotatably arranged on the support column. A level and a laser displacement sensor are fixedly installed on the support seat. Two photosensitive elements are horizontally arranged on the inside of each wall panel. The photosensitive elements are used to receive light signals from the level and the laser displacement sensor and convert them into electrical signals; Step 5, assembling the top ring tank wall, through the positioning of the positioning component, draw the inner circumference line and the outer circumference line of the top ring tank wall on the tank bottom plate, and place several adjustable positioning parts along the inner side of the inner circumference. The wall panels are assembled according to the number marks and corresponding orientation marks. During assembly, the positioning component and the square ruler are used to detect the installation position, horizontality and verticality of the wall panels. When the verticality, arc and circumference of the entire circle of the tank wall meet the requirements, the vertical seams of the two adjacent wall panels are spot welded, leaving a vertical seam as a vertical contraction seam. After the spot welding is completed, the vertical seams are welded as a whole, and finally the vertical contraction seams are welded; the adjustable positioning parts include an L-shaped support bottom plate fixedly mounted on the tank bottom plate and two adjusting bolts adjustably mounted on the L-shaped support bottom plate, and also include an adjusting rod hingedly mounted between the wall panel and the tank bottom plate, and the verticality of the wall panel is adjusted by adjusting the length of the adjusting rod; Step 6: Roof assembly: first assemble two melon skin boards at the axially symmetrical position, adjust them evenly and then weld them, then assemble other melon skin boards and adjust the overlap width to 60mm; after the melon skin boards are assembled, they are welded by step-back welding, and then the intermittent welds on the inner side of the arch and the connecting welds of the ribs are welded; finally, the hemming angle steel is welded and the roof opening machine accessories are installed; Step seven, assemble the remaining tank walls, install the inner expansion ring on the inner side of the top ring tank wall, and use the gantry plate to fix the inner expansion ring on the inner side of the wall plate; install the secondary top ring tank wall on the outer side of the top ring tank wall according to the corresponding position, and reserve a live opening; connect the inner expansion ring with the lifting assembly, lift the top ring tank wall to above the assembly position of the two rings of tank walls through the lifting assembly, and assemble the secondary top ring tank wall according to the method of step three. After the welding of the secondary top ring tank wall is completed, the top ring tank wall and the secondary top ring tank wall are spliced ​​by the lifting assembly, and the position and posture of the two are adjusted and then spot welded and fixed. The tank wall is checked for shape and size. After the inspection is qualified, the annular weld of the top ring tank wall and the secondary top ring tank wall is welded; the third and fourth rings of tank walls from top to bottom are lifted and assembled and installed according to the above operations until the bottom tank wall is assembled; Step eight, assemble the bottom tank wall and the tank bottom plate. After the installation of the bottom tank wall is completed, construct the tank body opening, pipe connection and top plate installation; first spot weld the bottom tank wall and the tank bottom plate, measure the size and shape of the tank body and then perform full welding; after welding, weld the shrinkage seams between the edge plate and the middle plate and between the edge plates; after welding, perform vacuum inspection.

2. The method for assembling an assembled oil storage tank structure according to claim 1, characterized in that: The cutting lines and standard lines of each edge plate and middle plate are drawn on the steel plate, and each edge plate and middle plate is numbered and marked; one end of the edge plate is arc-shaped, and the minimum dimension of the edge plate along the radius of the tank bottom is greater than or equal to 700mm; the middle plate is rectangular, and the width of the middle plate is greater than or equal to 1000mm, and the length is greater than or equal to 2000mm.

3. The method for assembling an assembled oil storage tank structure according to claim 1 or 2, characterized in that: In the step three, the middle plate and the edge plate are temporarily welded via a temporary positioning plate to control the welding deformation.

4. The method for assembling an assembled oil storage tank structure according to claim 1, characterized in that: In the step three, before the tank bottom plate is laid, an anti-corrosion coating should be applied to the lower surface of the tank bottom plate, and the area within 50 mm of the edge of each tank bottom plate shall not be painted.

5. The method for assembling an assembled oil storage tank structure according to claim 1 or 4, characterized in that: In step 4, the lifting assembly includes a lifting column fixedly mounted on the tank bottom plate and a fall chain mounted on the top of the lifting column, and the hook of the fall chain is connected to the wall panel to lift the wall panel through the fall chain.

6. The method for assembling an assembled oil storage tank structure according to claim 1, characterized in that: In step five, after the top ring tank wall is assembled and welded, an edge angle steel is installed on the top of the top ring tank wall. The butt weld of the edge angle steel is staggered with the vertical seam of the wall panel, and the lap seam between the edge angle steel and the wall panel is temporarily fixed by spot welding.

7. The method for assembling an assembled oil storage tank structure according to claim 1, characterized in that: In step seven, the inner expansion ring is 200 mm away from the lower opening of the top ring tank wall. The inner expansion ring is composed of channel steel divided into 1 / 4 types and connected into a complete circle by a 15-ton screw jack.

8. The method for assembling an assembled oil storage tank structure according to claim 1, characterized in that: In the step eight, the welding of the large angle weld between the bottom tank wall and the tank bottom plate is first performed by simultaneously using the segmented back-welding or skip welding method along the same direction inside and outside the tank, and a 100% magnetic powder or penetration inspection is performed after welding; then the filling and covering layers are symmetrically distributed and segmentedly welded along the same direction by four angular submerged arc automatic welding machines; during the operation, the inside is welded first and then the outside.

9. The method for assembling an assembled oil storage tank structure according to claim 8, characterized in that: Before welding, reinforcement support must be provided on the inner side of the bottom tank wall. The distance between two adjacent reinforcement support points should be less than or equal to 1200mm. The reinforcement support must be removed after the tank bottom shrinkage seam welding is completed.

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