Method for controlling the folding accuracy of LNG ship B-type fuel tank arc-shaped sectional wall plate

Abstract

The present application relates to the technical field of shipbuilding, in particular to a LNG ship B type fuel tank arc segment wall plate closing precision control method, comprising the following steps: S100, small radius arc plate forming construction and precision control; S200, B type fuel tank body bottom layer assembly construction and precision control; the bottom layer is symmetrically arranged by two bottom segments with the center line of the fuel tank body; S300, B type fuel tank body middle layer assembly construction and precision control; the middle layer is symmetrically arranged by two middle segments with the center line of the fuel tank body. The segment closing precision control scheme of arc plate alignment can solve the technical difficulty that the closing butt joint error of the outer wall plate meets the horizontal B level weld quality in ISO 5817 standard without firework correction, and the construction risk of segment part scrap caused by unqualified closing precision is reduced to the greatest extent.

Description

Technical Field

[0001] This invention relates to the field of shipbuilding technology, specifically to a method for controlling the precision of closure of the arc-shaped segmented wall panels of the LNG carrier's Type B fuel tank. Background Technology

[0002] Currently, the misalignment of butt weld joints in marine Type B bulkheads must meet ISO 5817-B requirements, with a value of less than 3mm. When the corners of Type B fuel tanks use small-radius arc transitions (forming radius less than 1000mm), the misalignment of the arc-shaped bulkhead weld joints at the corners of the segmented closure ends is very likely to exceed the tolerance.

[0003] The B-type compartment structure is made of 9Ni steel, which is a low-temperature high-strength steel. Conventional hull forming processes have low forming precision and usually use large-radius forming to reduce the stiffness of the arc joint and facilitate assembly. However, in the actual construction process of 9Ni, conventional pyrotechnic straightening will cause the material to lose its low-temperature performance. It is strictly forbidden to use conventional pyrotechnic straightening to adjust the assembly precision of the weld joint. Misalignment and roundness of the weld joint at the joint may still occur. Usually, the arc plate parts are replaced locally according to the actual size of the arc plate. If necessary, the strength, fatigue and crack propagation of the compartment need to be recalculated.

[0004] Using small-radius corner arc-shaped wall panels for transition allows the arc panels to be separated from the flat wall panels and formed independently, reducing the size of the formed parts and increasing the overall volume of the B-type compartment, thus improving the space utilization rate of B-type compartments of the same size. However, the reduction in the radius of curvature increases the stiffness of the arc segment, reduces the amount of assembly straightening adjustment, and makes it extremely difficult to control the precision. The traditional network line segmented joining method is no longer suitable for the precision requirements of joining small-radius corner arc-shaped segmented wall panels in 9Ni box-type compartments.

[0005] The assembly of the B-type cabin sections with the aforementioned small-radius corner arc-shaped wall panels requires the use of professional methods and precision control methods. The arc-shaped panel precision control method, which combines network lines and arc-shaped wall panel assembly line positioning, can effectively position the arc-shaped panels at the closure end, avoid heat straightening, ensure assembly accuracy, improve closure welding quality, and reduce stress concentration and segment deformation of the B-type cabin structure caused by internal stress generated by mechanical straightening. Summary of the Invention

[0006] In view of the deficiencies of the prior art, the present invention provides a method for controlling the closure accuracy of the arc-shaped segmented wall panels of the LNG ship Type B fuel tank. The segmented closure accuracy control scheme using arc plate alignment can solve the technical difficulty of ensuring that the misalignment of the closure butt joint of the outer wall panel meets the level B weld quality of ISO 5817 standard without fire straightening, and minimize the construction risk of scrapping segmented parts due to unqualified closure accuracy.

[0007] To achieve the above objectives, the technical solution provided by this invention is a method for controlling the closing accuracy of the arc-shaped segmented wall panels of the LNG carrier's Type B fuel tank, characterized by the following steps:

[0008] S100, small radius arc plate forming construction and precision control;

[0009] S200 and Type B fuel tank bottom layer assembly construction and precision control; the bottom layer consists of two bottom sections symmetrically arranged around the centerline of the fuel tank;

[0010] S300 and Type B fuel tank intermediate layer assembly construction and precision control; the intermediate layer consists of two intermediate sections symmetrically arranged around the centerline of the fuel tank;

[0011] S400, Type B fuel tank top layer assembly construction and precision control; the top layer consists of two top sections symmetrically arranged around the centerline of the fuel tank;

[0012] S500, top layer, middle layer and bottom layer combined construction and precision control.

[0013] Furthermore, the small-radius arc plate forming and precision control described in step S100 specifically includes the following steps:

[0014] S110, Measurement is performed after the arc plate is fed;

[0015] S120, after measuring the arc plate, scribing is performed;

[0016] S130, the arc plate blank is formed and processed;

[0017] S140, Obtain the horizontal arc plate and the vertical arc plate;

[0018] S150, use conformal support brackets for transportation and storage.

[0019] Furthermore, the bottom layer assembly construction and precision control described in step S200 specifically includes the following steps:

[0020] S210. Drawing the baseline of the bottom section: Using a total station, draw the center line of the fuel tank, the center line of the horizontal arc plate, the R-stop line of the horizontal arc plate, the perpendicular point of the center line of the vertical arc plate, and the perpendicular point of the R-stop line of the vertical arc plate, and draw the bottom section of the vertical section of the baseline.

[0021] S220, Bottom section reference arc plate mounting frame: Set up the horizontal arc plate mounting frame according to the position of the arc center line of the horizontal arc plate;

[0022] S230. Installation of the bottom section reference horizontal arc plate: After the bottom wall panel splicing and pressure beam construction are completed, install the bottom section horizontal arc plate, control the R-stop line of the horizontal arc plate to coincide with the ground line, hang the plumb bob on the upper edge of the horizontal arc plate, and use tools to adjust the placement of the horizontal arc plate so that the plumb bob is vertically coincident with the intersection of the R-stop line of the horizontal arc plate and the theoretical closing ground line of the bottom section on the ground line.

[0023] S240. Installation of the bottom section reference arch plate: After the bow sealing plate, stern sealing plate, side sealing plate and horizontal arch plate are assembled and welded, install the arch plate. Hang the plumb bob on the upper edge of the arch plate to control the arc center line and the R stop line of the arch plate to coincide with the bottom section ground line. Use a total station to control the congruence of the bottom section closure and the consistency of the diagonal length of the bottom section.

[0024] S250. Use a total station to measure the center line of the actual bottom segment closure, the arc center line of the vertical arc plate, and the R-stop line position data of the vertical arc plate.

[0025] Furthermore, the intermediate layer assembly and precision control described in step S300 specifically includes the following steps:

[0026] S310. Drawing of intermediate segment benchmark lines: Based on the actual data of the arc center line and R-stop line of the vertical arc plate measured at the closure of the bottom benchmark segment, the center line of the intermediate segment, the arc center line of the vertical arc plate, and the R-stop line of the vertical arc plate are drawn using a total station, and the segment group benchmark lines are divided based on this benchmark.

[0027] S320. Installation of intermediate segment reference arch plate: After the bow sealing plate, stern sealing plate and side sealing plate are assembled and welded, install the arch plate. The plumb bob is placed vertically on the upper and lower edges of the arch plate. Use tools to adjust the position of the arch plate and control the arc center line and the R-stop line of the arch plate to coincide with the ground line. The top of the plumb bob is perpendicular to the ground line plane. Use a total station to control the congruence of the upper and lower joints of the intermediate segment and the consistency of the diagonal length of the upper and lower joints of the intermediate segment.

[0028] S330. Use a total station to control the coplanarity of the upper closure joint of the intermediate segment and the consistency of the diagonal length of the upper closure joint.

[0029] S340. Use a total station to measure the actual center line of the closure joint of the intermediate segment, the arc center line of the vertical arc plate, and the R-stop line position data of the vertical arc plate.

[0030] Furthermore, the top layer assembly construction and precision control described in step S400 specifically includes the following steps:

[0031] S410. Drawing the benchmark ground line of the top section: Based on the center line of the closure of the middle section, the arc center line of the vertical arc plate and the R stop line data of the vertical arc plate, use a total station to set the ground line to determine the ground line of the vertical arc plate, the arc center line ground line of the horizontal arc plate, the R stop line ground line of the horizontal arc plate, and the theoretical closure ground line of the top section.

[0032] S420, Top section reference horizontal arc plate mounting frame: Install the horizontal arc plate mounting frame according to the position of the horizontal arc plate ground line;

[0033] S430, Top section reference sloping shoulder end plate installation jig: Install the sloping shoulder installation jig according to the position of the ground line;

[0034] S440. Installation of top section reference top sealing plate, sloping shoulder sealing plate and horizontal arc plate: Install the top sealing plate, sloping shoulder sealing plate and horizontal arc plate according to the construction method steps of the bottom section in step S200.

[0035] S450. Use a total station to measure the center line of the top section closure, the arc center line of the vertical arc plate, and the R-stop line position data of the vertical arc plate.

[0036] Furthermore, the construction and precision control of the top layer, middle layer, and bottom layer assembly described in step S500 specifically includes the following steps:

[0037] S510. Drawing the closure plot line: The bottom reference segment is hoisted onto the closure jig. The bottom reference segment is leveled using a crane. A total station is used to measure and make the horizontal grid line of the bottom reference segment parallel to the reference horizontal line. The total station is used to draw the bottom segment closure center line, the arc center line of the horizontal arc plate, the R-stop line of the horizontal arc plate, the perpendicular point of the arc center line of the vertical arc plate, and the perpendicular point of the R-stop line of the vertical arc plate according to the actual position of the bottom reference segment. These are used as the closure plot line of the segment assembly.

[0038] S520. Use a total station to measure the center line of the bottom section of the bottom reference segment, the arc center line of the vertical arc plate, and the R-stop line data of the vertical arc plate.

[0039] S530. Use a total station to measure the center line of the lower closure joint of the intermediate segment that merges with the bottom reference segment, the arc center line of the vertical arc plate, and the R-stop line of the vertical arc plate to ensure that the data are consistent.

[0040] S540. Closure of the bottom and middle sections: Positioning baffles are installed at the intersection of the upper closure opening of the reference bottom section and the arc center line of the vertical arc plate, and at the intersection of the upper closure opening of the reference bottom section and the R-stop line of the vertical arc plate. The middle section is hoisted and closed using a crane so that the lower closure opening of the vertical arc plate of the middle section contacts the positioning baffle. The section posture is adjusted by the crane to control the lower closure opening of the middle section to coincide with the upper closure opening of the reference bottom section. The horizontal grid line of the middle section is measured with a total station to make it parallel to the reference horizontal line. Positioning nails are welded, positioning code plates are installed, and closure welding is performed.

[0041] S550 and S540: When all segments in S550 and S540 are joined together, the joined segments are used as the reference segments. The total station is used to measure the center line of the joining point, the arc center line of the vertical arc plate, and the R-stop line position data of the vertical arc plate on the reference segments.

[0042] S560. After the top section is turned over by a crane to the storage area of ​​the closure section, use a total station to measure the center line of the lower closure opening of the top section, the arc center line of the vertical arc plate, and the R-stop line position data of the vertical arc plate to ensure that the data are consistent.

[0043] S570. Closure of the top section: Positioning baffles are installed at the intersection of the closure opening of the reference section and the arc center line of the vertical arc plate, and at the intersection of the closure opening of the reference section and the R-stop line of the vertical arc plate. The top section is hoisted and closed using a crane so that the lower closure surface of the vertical arc plate of the closure top section contacts the positioning baffles. The attitude of the top section is adjusted by the crane to control the lower closure opening of the top section to coincide with the upper closure opening of the reference section. The horizontal grid line of the top section is measured with a total station to make it parallel to the reference horizontal line. Positioning nails are welded, positioning code plates are installed, and closure welding is performed. The closure is then completed.

[0044] The beneficial effects of this invention are as follows: Precision control of segmented assembly is a key technical challenge in the construction of Type B cabins with small-radius, arc-shaped segmented wall panels. The segmented assembly precision control scheme using arc plate alignment solves the technical difficulty of ensuring that the misalignment of the butt joints of the outer wall panels meets the level B weld quality requirements of ISO 5817 without heat treatment, minimizing the construction risk of component scrapping due to substandard assembly precision. Compared to segmented assembly of approximately 20m in length, meeting the construction requirements for Type B cabin segmented assembly satisfies the standard requirements for arc plate straightness, wall panel flatness, and butt weld misalignment, significantly reducing the risk of workpiece or even segment scrapping due to misalignment of the arc plate.

[0045] 1. Decompose the key points of precision control for curved wall panels and flat wall panels, control the assembly of curved panels throughout the process, and set segmented construction site lines and assembly lines with the end of the curved panel as the reference, which is quite different from the traditional grid line setting.

[0046] 2. The precision of the parts used in the arc plate feeding process is strictly controlled, with particular emphasis on the marking precision of the arc center line and the R-stop line;

[0047] 3. Strict control of the form and position tolerances of the arc center line and the forming dimensions of the arc end of the arc plate during the forming process. Attached Figure Description

[0048] Figure 1 This is a schematic diagram of the B-type cabin segment structure in this invention;

[0049] Figure 2 This is a schematic diagram of the small-radius arc plate feeding accuracy control in this invention;

[0050] Figure 3 This is a schematic diagram illustrating the precision control of the small-radius arc plate after forming in this invention;

[0051] Figure 4 This is a schematic diagram of the bottom horizontal arc plate frame in this invention;

[0052] Figure 5 This is a schematic diagram of the installation accuracy control of the bottom horizontal arc plate in this invention;

[0053] Figure 6 This is a schematic diagram of the relevant ground sampling lines and accuracy control in the bottom section of this invention;

[0054] Figure 7 This is a schematic diagram of the relevant geodetic survey lines and accuracy control in the intermediate segment of this invention;

[0055] Figure 8 yes Figure 3 Side view;

[0056] Figure 9 This is a schematic diagram of the flat frame constructed in sections in this invention;

[0057] In the diagram: 100, Fuel tank; 110, Top section; 120, Middle section; 121, Diagonal of middle section; 122, Ground plot of the vertical arc plate of middle section; 123, Theoretical closure ground plot of middle section; 124, Surface applicability of the upper closure joint of middle section; 130, Bottom section; 131, Diagonal of bottom section; 132, Ground plot of the vertical arc plate of bottom section; 133, Theoretical closure ground plot of bottom section; 134, Surface applicability of the upper closure joint of bottom section.

[0058] 200. Side sealing plate,

[0059] 300. Small radius arc plate; 310. Arc center line; 320. R-stop line; 330. Arc plate feeding diagonal; 340. Arc plate length; 350. Arc plate width; 360. Horizontal arc plate; 361. Horizontal arc plate R-stop line layout line; 370. Vertical arc plate; 371. Vertical arc plate arc center line perpendicular point; 372. Vertical arc plate R-stop line perpendicular point.

[0060] 400. Spherical plate.

[0061] 500, Bow sealing plate,

[0062] 600. Stern sealing plate.

[0063] 700, bottom sealing plate,

[0064] 800. Template; 810. Arc plate segment fit.

[0065] 900. Flat tire frame; 910. Tire frame verticality.

[0066] 1000, Arc plate jig; 1100, Outer plate jig gap;

[0067] 2000, coordinates. Detailed Implementation

[0068] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0069] like Figure 1-9 As shown, a method for controlling the closing accuracy of the 9Ni box-shaped arc-shaped segmented wall panels of the B-type fuel tank of an LNG carrier is described. The method includes the following steps:

[0070] S100, small radius arc plate 300 forming construction and precision control;

[0071] S200, Type B fuel tank bottom reference segmented layered assembly construction and precision control method; the bottom layer is composed of two bottom segments 130 symmetrically arranged with the center line of the fuel tank 100;

[0072] S300, Type B fuel tank body intermediate layer except for bottom segment 130 other segment assembly construction and precision control method; the intermediate layer is composed of two intermediate segments 120 symmetrically arranged with the center line of fuel tank body 100;

[0073] S400, Type B fuel tank top layer assembly construction and precision control; the top layer consists of two top sections 110 symmetrically arranged around the centerline of the fuel tank;

[0074] S500, top layer, middle layer and bottom layer segmented assembly construction method and precision control.

[0075] In one embodiment, the forming and precision control of the small-radius arc plate 300 (horizontal arc plate 360 ​​and vertical arc plate 370) in step S100 includes the following steps:

[0076] S110 and small radius arc plate 300 were measured after material feeding (see...). Figure 2 The overall dimensions of the feeding arc plate (length 340, width 350) are controlled within +1 to -2 mm, the difference between the feeding arc plate diagonals (330) is controlled within ≤2 mm, and the flatness of the plate is controlled within 3 mm / 2 m using a total station. Dimensions that do not meet the feeding accuracy requirements are ground until the accuracy requirements are met.

[0077] S120. After measuring the material for the arc plate, mark the lines (see...). Figure 2 Use a stainless steel signal pen or other tools to draw the arc center line 310 and the R stop line 320 (double-sided marking). The marking accuracy is controlled within ±2mm. Use tape to protect the markings at the end of the board.

[0078] S130. The arc plate blank is formed. During the forming process, the accuracy of the arc plate ends is controlled. After the forming process is completed, the accuracy of the formed arc surface is measured using template 800. The arc plate arc segment fit 810 is controlled within ±3mm, and the position deviation of the arc plate center line 310 and the R-stop line 320 is controlled within ±2mm. If the forming accuracy does not meet the accuracy requirements, it is corrected until the arc plate accuracy requirements are met (see...). Figure 3 );

[0079] S140, resulting in a horizontal arc plate 360 ​​and a vertical arc plate 370;

[0080] S150, Use conformal support brackets for transportation and storage.

[0081] In one embodiment, the bottom layer assembly construction and precision control in step S200 includes the following steps:

[0082] S210, drawing of the baseline of the bottom section;

[0083] S211. Use a total station to measure the level of the supporting piers for the flat tire. Adjust the height by adjusting the thickness of the stainless steel pads of each supporting pier so that the overall levelness of the tire tread is controlled within ±3mm.

[0084] S212. At the construction site of section 130 at the bottom, use a total station to set the ground line according to the ground line map of section 130 and the column spacing of the 900-meter-long flat frame (see...). Figure 6), determine the center line of the horizontal arc plate, the R-stop line of the horizontal arc plate 361, the theoretical closing line of the bottom section 133, and the vertical arc plate of the bottom section 132 (the figure is an example illustration, and in actual construction, a line drawing is required for each theoretical closing network line and assembly network line).

[0085] S220, Bottom section 130 reference arc plate mounting frame:

[0086] S221. Based on the location of all the ground lines of the horizontal arc plates in step S212 above (the arc center line ground line and the R-stop line ground line 361 of the horizontal arc plates), install the arc plate jig 1000, adjust the height of the jig, and ensure the verticality of the jig 910 and the gap between the outer plate jig 1100. Use a level to measure the levelness of the top of the arc plate jig 1000, and control it within ±3mm / 2m (see...). Figure 4 );

[0087] S222. Lay the bottom sealing plate 700 on the flat frame 900, complete the welding and install the T-shaped material and internal reinforcing structure;

[0088] S230, Installation of the Base Horizontal Plate of the Bottom Segment 130: Use a crane to install the horizontal arc plate 360. Use plumb bobs (3 in total) to hang on the top of the arc of the horizontal arc plate. The three plumb bobs are located at the two ends and the upper edge of the midpoint of the horizontal arc plate 360 ​​along its length. Use tools to adjust the horizontal position of the horizontal arc plate 360 ​​so that the difference between the arc end of the horizontal arc plate 360 ​​and the edge of the bottom sealing plate 700 is ≤2mm. The plumb bobs hanging on the arc end of the horizontal arc plate 360 ​​are perpendicularly aligned with the intersection of the R-stop line of the horizontal arc plate and the theoretical closing line 133 of the bottom segment on the ground. The deviation between the plumb bob top and the projection point on the ground meets the coordinate 2000. The plumb bob hanging on the upper edge of the midpoint of the horizontal arc plate 360 ​​is perpendicularly aligned with the R-stop line 361 of the horizontal arc plate on the ground. Add a mounting plate for fixation. Install and weld the horizontal arc plates 360 along the edge of the bottom sealing plate 700 in sequence as described above until the horizontal arc plates 360 are installed around the bottom sealing plate 700. Ensure that the gap between the arc end of the horizontal arc plate 360 ​​and the interface meets the gap requirements of the welding process. If it does not meet the requirements, use tools to adjust the horizontal position of the horizontal arc plate 360 ​​until the accuracy requirements are met. The installation of the horizontal arc plate 360 ​​is then complete.

[0089] S240, bottom segment reference vertical arc plate 370 installation:

[0090] S241. After the bottom sealing plate 700 assembled in step S230 is assembled and welded with the bow sealing plate 500, stern sealing plate 600 and side sealing plate 200, the upright arc plate 370 is installed. The bow sealing plate 500, stern sealing plate 600, and side sealing plate 200 are assembled and welded together. After checking that the accuracy is correct, a crane is used to install the vertical arc plate 370. The placement of the vertical arc plate 370 is adjusted using tools so that the difference between the straight edge of the arc end of the vertical arc plate 370 and the edge of the upper closing plate of the bow sealing plate 500, stern sealing plate 600, and side sealing plate 200 is ≤2mm. A plumb bob is hung on the edge of the top arc plate of the vertical arc plate 370. The plumb bob is vertically aligned with the R-stop line perpendicular point 372 and the arc center line perpendicular point 371 of the vertical arc plate on the ground survey line. The deviation between the plumb bob tip and the projection point on the ground meets the coordinate requirement. A bracket is added for fixation. The vertical arc plate 370 is then welded to the bow sealing plate 500, stern sealing plate 600, and side sealing plate 200.

[0091] S242. Use a total station to measure the coherence of the upper closure joint 134 of the bottom section and the consistency of the length of the diagonal 131 of the bottom section. If the accuracy requirements are not met, grind the upper closure joint of the bottom section 130 until the accuracy requirements are met.

[0092] S250. Use a total station to measure the center line of the bottom section closure, the arc center line of the vertical arc plate 370, and the R-stop line position data of the vertical arc plate 370 as the construction benchmark for the intermediate section to be connected with it.

[0093] In one embodiment, step S300, intermediate layer assembly construction and precision control, includes the following steps:

[0094] S310, intermediate segment 120 benchmark plot drawing:

[0095] S311. Use a total station to measure the level of the supporting piers for the flat tire. Adjust the height by adjusting the thickness of the stainless steel pads of each supporting pier, so that the overall levelness of the tire tread is controlled within ±3mm.

[0096] S312. Based on the center line of the closure of the bottom segment 130, the arc center line of the vertical arc plate 370, and the R-stop line data of the vertical arc plate 370, use a total station to set up the ground plot line to determine the intermediate segment vertical arc plate ground plot line 122 and the intermediate segment theoretical closure ground plot line 123, with reference to the column spacing position of the construction flat frame.

[0097] S320, intermediate segment 120 reference vertical arc plate installation:

[0098] S321, the intermediate section 120 adopts vertical assembly. First, using the center line of the stern sealing plate 600 as a reference, the stern sealing plate 600 is lifted by a crane and vertically welded to the flat tire, with H-beam diagonal supports added; the bow sealing plate 500 and the side sealing plate 200 are successively lifted by a crane and welded to the flat tire, with H-beam diagonal supports added.

[0099] S322. Use a crane to install the vertical arc plate 370. Use tools to adjust the placement of the vertical arc plate 370 so that the difference in edge length between the upper and lower ends of the arc of the vertical arc plate 370 and the upper and lower closing lines of the bow sealing plate 500, stern sealing plate 600 and side sealing plate 200 is ≤2mm. Use a plumb bob to hang on the edge of the bottom plate of the arc of the vertical arc plate 370. The plumb bob should be perpendicular to the R-stop line plumb point 372 and the arc center line plumb point 371 of the vertical arc plate on the ground survey line. The deviation between the plumb bob top and the projection point on the ground should meet the same point coordinate. The bottom of the vertical arc plate 370 is spot welded to the sealing plate and H-beam diagonal supports are added.

[0100] S323. Use a plumb bob to hang on the top of the 370 arc of the vertical arc plate. The plumb bob is perpendicular to the center line of the arc plate on the ground line at point 371 and the R-stop line of the arc plate at point 372. The deviation between the plumb bob top and the projection point on the ground is consistent with the intersection coordinates.

[0101] S330. Use a total station to measure the coherence of the closure joint on the middle section 124 and the consistency of the length of the diagonal 121 of the middle section. If the accuracy requirements are not met, grind the closure joint on the middle section until the accuracy requirements are met.

[0102] S340. Use a total station to measure the center line of the intermediate segment closure, the arc center line of the vertical arc plate 370, and the R-stop line data of the vertical arc plate 370 as the construction benchmark for the top segment to be connected with it.

[0103] In one embodiment, the top layer assembly construction and precision control in step S400 includes the following steps:

[0104] S410, top section 110 benchmark plot drawing:

[0105] S411. Use a total station to measure the level of the supporting piers for the flat tire. Adjust the height by adjusting the thickness of the stainless steel pads of each supporting pier, so that the overall levelness of the tire tread is controlled within ±3mm.

[0106] S412. Based on the center line of the closure of the middle segment, the arc center line of the vertical arc plate 370, and the R-stop line data of the vertical arc plate 370, and with reference to the column spacing of the construction flat sheet, use a total station to set up the ground map lines to determine the arc center line ground map line of the vertical arc plate, the R-stop line ground map line of the vertical arc plate, the arc center line ground map line of the horizontal arc plate, the R-stop line ground map line of the horizontal arc plate 361, and the theoretical closure ground map line of the top segment.

[0107] S420, Top Segment 110 Reference Horizontal Arc Plate Installation Frame: Install the horizontal arc plate 360 ​​frame according to the position of the horizontal arc plate ground line (the arc center line ground line and the R stop line ground line of the horizontal arc plate), adjust the height of the frame, ensure the verticality of the frame and the gap between the outer plate frame, and use a level to measure the horizontality of the horizontal arc plate 360 ​​installation frame at the top of the frame, and control it within ±3mm / 2m;

[0108] S430. Install the sloping shoulder mounting frame according to the location of the ground line: Install the sloping shoulder mounting frame according to the location of the ground line; adjust the height of the sloping shoulder mounting plate to ensure the straightness of the frame and use a level to measure the horizontality of the top of the frame, controlling it within ±3mm / 2m;

[0109] S440, Top section reference top sealing plate, sloping shoulder sealing plate and horizontal arc plate 360 ​​installation: Install the top sealing plate, sloping shoulder sealing plate and horizontal arc plate 360 ​​according to the construction method of bottom section 130 in step S200;

[0110] After the spherical plate 400 and horizontal arc plate 360 ​​at the top corner of the S441 and B-type cabin are installed and welded, the bow sealing plate 500, stern sealing plate 600 and side sealing plate 200 are assembled and welded. After checking that the accuracy is correct, a crane is used to install the vertical arc plate 370. The placement position of the vertical arc plate 370 is adjusted with tools so that the difference between the straight edge of the arc end of the vertical arc plate 370 and the edge of the closing plate of the bow sealing plate 500, stern sealing plate 600 and side sealing plate 200 is ≤2mm. A plumb bob is hung on the edge of the arc top plate of the vertical arc plate 370. The plumb bob is vertically aligned with the R-stop line perpendicular point 372 and the arc center line perpendicular point 371 of the vertical arc plate on the ground line. The deviation between the plumb bob tip and the projection point on the ground meets the coordinate requirement. The clamp plate is added for fixation. The vertical arc plate is then welded to the bow sealing plate 500, stern sealing plate 600 and side sealing plate 200.

[0111] S442. Use a total station to control the congruence of the top section's upper closure joint and the consistency of the top section's diagonal length. If the accuracy requirements are not met, grind the top section's upper closure joint until the accuracy requirements are met.

[0112] S450. Use a total station to measure the center line of the closure of the top section, the center line of the arc of the vertical arc plate, and the R-stop line position data of the vertical arc plate.

[0113] In one embodiment, the construction and precision control of the merging of the top layer, middle layer, and bottom layer in step S500 includes the following steps:

[0114] S510, Drawing of fused ground profile:

[0115] S511. Use a total station to measure the level of the closure flat tire support blocks. Adjust the height by adjusting the thickness of the pad of each support block so that the overall levelness of the tire tread is controlled within ±3mm.

[0116] S512. The two bottom sections 130 are hoisted onto the merging jig. The crane is used to adjust the bottom section 130 to be level. A total station is used to measure to make the horizontal grid line of the bottom section parallel to the reference horizontal line. The gap between the supporting pier and the bottom section is eliminated by using stainless steel pads. The center line of the bottom section merging, the R-stop line of the horizontal arc plate 360, the vertical arc center line perpendicular point 371 of the vertical arc plate, and the vertical arc line perpendicular point 372 of the vertical arc plate are marked with the actual position of the bottom section. These are used as the ground template for the merging of the two bottom sections.

[0117] S520. Use a total station to re-measure the center line of the bottom section closure, the arc center line of the vertical arc plate 370, the R stop line position data of the vertical arc plate 370, and the coplanarity of the bottom section closure. If the coplanarity does not meet the accuracy requirements due to hoisting deformation, the top closure of the bottom section is ground until the accuracy requirements are met.

[0118] S530. Use a total station to re-inspect the center line of the lower closure opening of the intermediate segment 120 (there are two intermediate segments, and the storage area for the closure segments) that are joined together with the bottom segment, the arc center line of the vertical arc plate 370, the R-stop line position data of the vertical arc plate 370, and the coplanarity of the closure opening of the intermediate segment. If permanent deformation occurs during hoisting and transportation, grind the lower closure opening of the closure intermediate segment (set the end compensation amount when feeding the material). After grinding, use a total station again to measure the center line of the lower closure opening of the intermediate segment, the arc center line of the vertical arc plate 370, and the R-stop line position data of the vertical arc plate 370 until the data are consistent.

[0119] The junction of the side sealing plate 200 of the bottom section 130 with the bow sealing plate 500 and the stern sealing plate 600 forms the upper closure opening of the bottom section. Positioning baffles are installed at the intersection of the arc center line of the vertical arc plate 370 and the intersection of the upper closure opening of the bottom section with the R stop line of the vertical arc plate 370. Two intermediate sections 130 are hoisted by cranes so that the lower closure opening of the vertical arc plate of the closed intermediate section contacts the positioning baffle. The section attitude is adjusted by crane to control the lower closure opening of the intermediate section to coincide with the upper closure opening of the bottom section. A total station is used for measurement, and the horizontal grid line of the intermediate section is adjusted by crane to be parallel to the reference horizontal line. Positioning nails are then welded. The flatness of the sealing plate at the closure opening is measured by total station. The flatness is adjusted to ≤8mm / m using tools. Positioning plates are then installed and the sections are welded together.

[0120] S550. Use a total station to re-measure the center line of the closure joint on the middle section, the arc center line of the vertical arc plate, the R-stop line data of the vertical arc plate, and the coplanarity of the closure joint on the middle section. If the coplanarity does not meet the accuracy requirements due to the deformation of the closure assembly, the closure joint on the middle section shall be ground until the accuracy requirements are met.

[0121] After S560 and top section 110 (two sections) are turned over by crane to the storage area for the assembled sections, the center line of the lower closure of the top section, the arc center line of the vertical arc plate 370, the R-stop line position data of the vertical arc plate 370, and the coplanarity of the top section closure are measured using a total station to ensure data consistency. If permanent deformation occurs during hoisting and transportation, the lower closure of the top section is ground (with end compensation set during material feeding). After grinding, the center line of the lower closure of the top section, the arc center line of the vertical arc plate 370, and the R-stop line position data of the vertical arc plate 370 are measured again using a total station until the data are consistent.

[0122] S570 and the closing of the top section 110: The junction of the side sealing plate 200 of the middle section 120 with the bow sealing plate 500 and the stern sealing plate 600 forms the upper closing opening of the middle section. Positioning baffles are installed at the intersection of the arc center line of the vertical arc plate 370 and the intersection of the upper closing opening of the middle section and the R stop line of the vertical arc plate 370. The top section 110 (two sections) is lifted by a crane so that the lower closing opening of the vertical arc plate of the closing top section contacts the positioning baffle. The section attitude is adjusted by the crane to control the lower closing opening of the top section to coincide with the upper closing opening of the middle section. The horizontal grid line of the top section is measured to be parallel to the reference horizontal line, and positioning nails are welded. The flatness of the sealing plate at the closing opening is measured by a total station. The flatness is adjusted to ≤8mm / m using tools, and positioning code plates are installed. The section is then welded together, and the section closing is completed.

[0123] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0124] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0125] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0126] In this invention, unless otherwise explicitly specified and limited, "above" or "below" a second feature can mean that the first and second features are in direct contact, or that they are in indirect contact through an intermediate medium. Furthermore, "above," "over," and "on top" of a second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" a second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature. It should be noted that when an element is referred to as "fixed to" or "set on" another element, it can be directly on the other element or there may be an intermediate element present. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element present. The terms "vertical," "horizontal," "above," "below," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible embodiments.

Claims

1. A method for controlling the closing accuracy of the arc-shaped segmented wall panels of the LNG carrier's Type B fuel tank, characterized in that: Includes the following steps S100, small radius arc plate forming construction and precision control; specifically including S110, Measurement is performed after the arc plate is fed; S120, after measuring the arc plate, scribing is performed; S130, the arc plate blank is formed and processed; S140, Obtain the horizontal arc plate and the vertical arc plate; S150, Use conformal support racks for transportation and storage; S200 and Type B fuel tank bottom layer assembly construction and precision control; the bottom layer consists of two bottom sections symmetrically arranged around the centerline of the fuel tank; specifically including... S210. Drawing the baseline of the bottom section: Using a total station, draw the center line of the fuel tank, the center line of the horizontal arc plate, the R-stop line of the horizontal arc plate, the perpendicular point of the center line of the vertical arc plate, and the perpendicular point of the R-stop line of the vertical arc plate, and draw the bottom section of the vertical section of the baseline. S220, Bottom section reference arc plate mounting frame: Set up the horizontal arc plate mounting frame according to the position of the arc center line of the horizontal arc plate; S230. Installation of the bottom section reference horizontal arc plate: After the bottom wall panel splicing and pressure beam construction are completed, install the bottom section horizontal arc plate, control the R-stop line of the horizontal arc plate to coincide with the ground line, hang the plumb bob on the upper edge of the horizontal arc plate, and use tools to adjust the placement of the horizontal arc plate so that the plumb bob is vertically coincident with the intersection of the R-stop line of the horizontal arc plate and the theoretical closing ground line of the bottom section on the ground line. S240. Installation of the bottom section reference arch plate: After the bow sealing plate, stern sealing plate, side sealing plate and horizontal arch plate are assembled and welded, install the arch plate. Hang the plumb bob on the upper edge of the arch plate to control the arc center line and the R stop line of the arch plate to coincide with the bottom section ground line. Use a total station to control the congruence of the bottom section closure and the consistency of the diagonal length of the bottom section. S250. Use a total station to measure the actual center line of the bottom section closure, the arc center line of the vertical arc plate, and the R-stop line position data of the vertical arc plate. S300 and Type B fuel tank intermediate layer assembly construction and precision control; the intermediate layer consists of two intermediate sections symmetrically arranged around the centerline of the fuel tank; S400, Type B fuel tank top layer assembly construction and precision control; the top layer consists of two top sections symmetrically arranged around the centerline of the fuel tank; S500, top layer, middle layer and bottom layer combined construction and precision control.

2. The method for controlling the closing accuracy of the arc-shaped segmented wall panel of the LNG ship type B fuel tank according to claim 1, characterized in that: The intermediate layer assembly and precision control described in step S300 include the following specific steps: S310. Drawing of intermediate segment reference lines: Based on the actual data of the arc center line and R-stop line of the vertical arc plate measured at the closure of the bottom segment, the center line of the intermediate segment, the arc center line of the vertical arc plate and the R-stop line of the vertical arc plate are drawn using a total station, and the segment group vertical reference lines are divided based on this reference. S320. Installation of intermediate segment reference arch plate: After the bow sealing plate, stern sealing plate and side sealing plate are assembled and welded, install the arch plate. The plumb bob is placed vertically on the upper and lower edges of the arch plate. Use tools to adjust the position of the arch plate and control the arc center line and the R-stop line of the arch plate to coincide with the ground line. The top of the plumb bob is perpendicular to the ground line plane. Use a total station to control the congruence of the upper and lower joints of the intermediate segment and the consistency of the diagonal length of the upper and lower joints of the intermediate segment. S330. Use a total station to control the coplanarity of the upper closure joint of the intermediate segment and the consistency of the diagonal length of the upper closure joint. S340. Use a total station to measure the actual center line of the closure joint of the intermediate segment, the arc center line of the vertical arc plate, and the R-stop line position data of the vertical arc plate.

3. The method for controlling the closing accuracy of the arc-shaped segmented wall panel of the LNG ship type B fuel tank according to claim 1, characterized in that: The top layer assembly construction and precision control described in step S400 include the following specific steps: S410. Drawing the benchmark ground line of the top section: Based on the center line of the closure of the middle section, the arc center line of the vertical arc plate and the R stop line data of the vertical arc plate, use a total station to set the ground line to determine the ground line of the vertical arc plate, the arc center line ground line of the horizontal arc plate, the R stop line ground line of the horizontal arc plate, and the theoretical closure ground line of the top section. S420, Top section reference horizontal arc plate mounting frame: Install the horizontal arc plate mounting frame according to the position of the horizontal arc plate ground line; S430, Top section reference sloping shoulder end plate installation jig: Install the sloping shoulder installation jig according to the position of the ground line; S440. Installation of top section reference top sealing plate, sloping shoulder sealing plate and horizontal arc plate: Install the top sealing plate, sloping shoulder sealing plate and horizontal arc plate according to the construction method steps of the bottom section in step S200. S450. Use a total station to measure the center line of the top section closure, the arc center line of the vertical arc plate, and the R-stop line position data of the vertical arc plate.

4. The method for controlling the closing accuracy of the arc-shaped segmented wall panel of the LNG ship type B fuel tank according to claim 1, characterized in that: The construction and precision control of the top layer, middle layer, and bottom layer assembly described in step S500 include the following specific steps: S510. Drawing the closure plot line: The bottom section is hoisted onto the closure jig. The crane is used to adjust the bottom section to be level. A total station is used to measure so that the horizontal grid line of the bottom section is parallel to the reference horizontal line. The total station is used to draw the closure center line of the bottom section, the arc center line of the horizontal arc plate, the R-stop line of the horizontal arc plate, the perpendicular point of the arc center line of the vertical arc plate, and the perpendicular point of the R-stop line of the vertical arc plate according to the actual position of the bottom section. These are used as the closure plot line of the section assembly. S520. Use a total station to measure the center line of the bottom section's closure, the arc center line of the vertical arc plate, and the R-stop line data of the vertical arc plate. S530. Use a total station to measure the center line of the lower closure joint of the intermediate segment that merges with the bottom segment, the arc center line of the vertical arc plate, and the R-stop line of the vertical arc plate to ensure that the data are consistent. S540. Closure of the bottom and middle sections: Positioning baffles are installed at the intersection of the upper closure opening of the bottom section and the arc center line of the vertical arc plate, and at the intersection of the upper closure opening of the bottom section and the R-stop line of the vertical arc plate. The middle section is hoisted and closed using a crane so that the lower closure opening of the vertical arc plate of the middle section contacts the positioning baffle. The section posture is adjusted by the crane to control the lower closure opening of the middle section to coincide with the upper closure opening of the bottom section. The horizontal grid line of the middle section is measured with a total station to make it parallel to the reference horizontal line. Positioning nails are welded, positioning code plates are installed, and the closure welding is performed. S550 and S540: When all segments in S550 and S540 are joined together, the joined segments are used as the reference segments. The total station is used to measure the center line of the joining point, the arc center line of the vertical arc plate, and the R-stop line position data of the vertical arc plate on the reference segments. S560. After the top section is turned over by a crane to the storage area of ​​the closure section, use a total station to measure the center line of the lower closure opening of the top section, the arc center line of the vertical arc plate, and the R-stop line position data of the vertical arc plate to ensure that the data are consistent. S570. Closure of the top section: Positioning baffles are installed at the intersection of the closure opening of the reference section and the arc center line of the vertical arc plate, and at the intersection of the closure opening of the reference section and the R-stop line of the vertical arc plate. The top section is hoisted and closed using a crane so that the lower closure surface of the vertical arc plate of the closure top section contacts the positioning baffles. The attitude of the top section is adjusted by the crane to control the lower closure opening of the top section to coincide with the upper closure opening of the reference section. The horizontal grid line of the top section is measured with a total station to make it parallel to the reference horizontal line. Positioning nails are welded, positioning code plates are installed, and closure welding is performed. The closure is then completed.

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