Simulated hoisting control method for ship LNG large storage tank

Abstract

The invention provides a simulation hoisting control method for a ship LNG large storage tank. The simulation hoisting control method comprises the following steps that S1, a small saddle assembly is manufactured; s2, saddle carrying line type simulation positioning, specifically comprising the following steps: S21, scanning data of a molded outer edge laminated wood line type of the LNG large-scale storage tank by adopting a three-dimensional scanner, and performing data analysis on the scanned laminated wood line type; s22, the saddles are assembled and positioned, the seven small assemblies of the fixed saddles are assembled into a fixed annular saddle, the seven small assemblies of the sliding saddles are assembled into a sliding annular saddle, and size precision control is conducted in the saddle positioning process in the assembling process; s23, saddle assemblies are welded and formed, and the seven small assemblies of the fixed saddle and the seven small assemblies of the sliding saddle are welded respectively; s24, the saddle line type is matched with the LNG tank body laminated wood in a simulation mode; and S3, the LNG large storage tank is hoisted. The epoxy clearance fitting degree of the saddle and the tank body laminated wood is ensured through three-dimensional scanning simulation and accurate process control, and the large storage tank is hoisted in place at a time.

Description

Technical Field

[0001] The invention belongs to the technical field of shipbuilding, and in particular relates to a simulated hoisting control method for a large LNG storage tank on a ship. Background Art

[0002] The installation and hoisting of traditional large LNG storage tanks need to wait until the large storage tanks are built and formed, and then the hull saddle structure is built according to the linear shape of the pressure-bearing wood outside the LNG storage tank. This production mode has a slow production rhythm, the linear accuracy of the saddle structure is difficult to control, and the data error is large. It is not convenient for the construction of the saddle structure of the series of ships, and the tire frame cannot be reused, which affects the subsequent fit with the linear shape of the pressure-bearing wood. In the epoxy thickness pouring stage, it is necessary to use two liftings and use the film pressing to collect data on the gap between the pressure-bearing wood of the storage tank and the saddle panel. The epoxy pouring process can only be entered when the film pressing thickness meets the gap of 5-40mm. This construction process has a small area, a harsh construction environment, wastes crane resources, and reduces production efficiency. If the film pressing gap cannot meet the epoxy pouring gap, the hull saddle structure linear shape will be reworked and corrected, which will cause greater waste.

[0003] How to ensure the linear fit accuracy between the hull saddle structure and the linear fit accuracy of the LNG tank pressure-bearing wood, improve the reuse rate of the saddle frame, and achieve a successful one-time lifting of the LNG tank, thereby improving production efficiency, shortening the dock cycle, and improving the working environment, is an urgent problem to be solved. Summary of the invention

[0004] In view of the above problems, the present invention provides a simulated hoisting control method for a large-scale LNG storage tank on a ship, so as to achieve a successful hoisting of a large-scale dual-fuel LNG storage tank in one go.

[0005] To achieve the above object, the present invention adopts the following technical solution: A simulated hoisting control method for a large LNG storage tank on a ship comprises the following steps: S1. Saddle group production; S2. Saddle carrying linear simulation positioning; S3. Lifting of large LNG storage tanks.

[0006] Furthermore, the step S1 specifically includes the following steps: S11. Saddle assembly division: the fixed saddle and the sliding saddle ring saddle assembly are divided into 7 small groups; S12. Saddle panel production. The saddle panels are divided into 7 small groups. During the surface processing stage of each saddle panel, the linear accuracy of the saddle panel is controlled within 2mm through cold pressing and sample linear control; S13. Saddle assembly production: 7 small groups of fixed saddles and 7 small groups of sliding saddles are produced on the fixed saddle frame and the sliding saddle frame respectively. Specifically, the saddle panels are first positioned, and each saddle panel is placed on the corresponding saddle frame to fit with the base surface of the saddle frame; secondly, the saddle is welded to the saddle panel with connecting brackets and T-profile webs. During the positioning and welding process, the dimensional accuracy of the connecting brackets, T-profile webs and saddle panel lines is tested and confirmed, and the accuracy is controlled within 3mm; all saddle frames are steel structure digital cutting template frames, which have high linear accuracy and strong structural stability; S14. After welding is completed, data detection is carried out on the control points according to the detection plan formulated by the precision control to ensure that the error between the precision data and the theoretical data is within 5mm.

[0007] Furthermore, the step S2 specifically includes the following steps: S21. Scanning the outer edge laminated wood linear data of the formed large LNG storage tank using a 3D scanner, and performing data analysis on the scanned laminated wood linear data; S22 saddle assembly positioning, the fixed saddle seven small group assembly into a fixed annular saddle, the sliding saddle seven small group assembly into a sliding annular saddle, the saddle positioning process during the assembly process to control the dimensional accuracy; S23 saddle assembly welding forming, respectively welding the fixed saddle seven small groups and sliding saddle seven small groups stand; S24. Simulate and match the above saddle line shape with the laminated wood of the LNG tank.

[0008] Furthermore, the step S21 specifically includes the following steps: S211. After the installation of laminated wood for LNG tanks is completed, according to the placement of the LNG tanks, the outer surface of the tanks is scanned by using a scanner at the outer edge of the LNG tanks, and at the same time, the outer edge line shape of the laminated wood of the fixed saddle, the outer edge line shape of the pressure-bearing wood of the sliding saddle, and the flatness of the upper edge of the anti-floating block are collected in three dimensions and a model is generated; S212. Data processing is performed on the scanned LNG storage tank, and the line shape data of the laminated wood outer edge of the fixed saddle and the line shape data of the pressure-bearing wood outer edge of the sliding saddle are analyzed, and a line shape and spacing accuracy data table is formed to obtain the curvature line shape of the laminated wood outer shape of the two support seats of the LNG tank body.

[0009] Furthermore, the step S22 specifically includes the following steps: S221. Positioning in the front and rear direction: Based on the distance data between the fixed saddle and sliding saddle laminated wood of the LNG tank obtained by scanning and analysis, the saddle ribs corresponding to the HB01~HB03 sections of the double bottom of the hull are controlled for size positioning to ensure that the distance data between the double saddle bottom ribs of the hull and the laminated wood blocks of the two front and rear support seats of the LNG tank are consistent, and the hull structure welding shrinkage is taken into account; the corresponding saddle ribs are laid out on the inner bottom plate, and the saddle web is controlled to coincide with the double bottom ribs during the saddle assembly and positioning to ensure the front and rear dimensional accuracy; S222. Positioning in the left and right directions: Release the hull centerline on the double bottom HB01~HB03, release two saddle centerlines based on the hull centerline, and use a scanner to perform linear scanning on the saddle assembly based on the saddle centerline. Furthermore, the step S222 specifically includes the following steps: S2221. Positioning of the stern saddle: According to the curvature line shape of the laminated wood outer edge of the fixed saddle obtained by scanning the LNG tank, the annular saddle formed by assembling the seven assembled saddles is simulated and analyzed and positioned according to the line shape of the laminated wood block of the LNG tank, ensuring that the line shape of the saddle panel in the height direction and the width direction matches the line shape of the laminated wood block of the LNG tank fixed support seat during the positioning stage; S2222. Forward saddle positioning: Based on the curvature line shape of the outer edge of the laminated wood of the sliding saddle obtained by scanning the LNG tank, the annular saddle formed by assembling seven assembled saddles is simulated, analyzed and positioned according to the line shape of the laminated wood block of the LNG tank obtained, ensuring that the line shape of the saddle panel in the height direction and the width direction matches the line shape of the laminated wood block of the LNG tank sliding support seat during the positioning stage; S223. Anti-deformation: According to the curvature line of the outer edge of the two saddle laminated wood obtained by scanning the LNG storage tank, the positioning of the hull assembly saddle is guided by data, and a welding anti-deformation of 8~10mm is added on one side in the width direction. At the same time, shape-preserving support is added to ensure that the linear accuracy of the saddle after positioning and splicing and the linear accuracy error of the LNG tank laminated wood are within a controllable range.

[0010] Furthermore, in the step S23, during the structural welding process between the hull saddle assembly, a scanner device is used to collect three-dimensional data of the welding process status data of the saddle assembly, and the scanned saddle line shape is matched with the line shape of the LNG tank laminated wood. The three-dimensional coordinate difference obtained by scanning is used to analyze the linear deviation value and gap situation of the linear shape of the saddle assembly of the ship and the linear shape of the LNG tank laminated wood in the three-dimensional space. If the matching accuracy error exceeds the error range, that is, the gap is less than 15mm or greater than 40mm, the linear error is adjusted by adjusting the welding sequence of the saddle joints to control the matching gap error within the standard range of 15~40mm.

[0011] Furthermore, the step S24 specifically includes the following steps: S241. Linear scanning of the saddle welding completion site, scanning data collection of the hull saddle through multiple stations, and forming a three-dimensional data model; S242. The scanned 3D model of the hull saddle and the overall model of the LNG tank are imported into the analysis software, and the four anti-floating blocks of the LNG tank are leveled, and the center of the LNG tank is overlapped with the center of the hull saddle to perform line comparison analysis; S243. Utilize the collision box principle of the simulated test box to calculate the gap matching between the saddle and the laminated wood of the LNG tank. At the same time, use the centerline tolerance and the horizontal tolerance of the anti-floating block to fine-tune the state of the LNG tank and control the matching gap error between the two within the standard range of 5~40mm. Record the centerline deviation value, the horizontal deviation value of the anti-floating block and the gap data to generate a report. At the same time, mark the tank and saddle to guide the subsequent precise adjustment of the LNG tank position.

[0012] Furthermore, the step S3 specifically includes the following steps: S31. Extend the center lines of the laminated wood of the fixed saddle and the sliding saddle of the LNG tank to the center lines of the bow and stern, and make marks; pre-stick target sheets on the four anti-floating panels of the LNG tank in advance to facilitate subsequent horizontal detection; S32. During the hoisting process of LNG storage tanks, the state of the LNG storage tanks shall be adjusted according to the simulated positioning state to ensure that the LNG tank body is positioned in the correct state, specifically: (1) When the LNG storage tank is located directly above the saddle, start to check the level of the four stop-floating point panels and adjust the LNG tank body to a simulated positioning level state; (2) Adjust the centerline of the LNG tank at the front and rear ends and the centerline of the saddle to be consistent with the centerline deviation value, anti-floating block horizontal deviation value and gap deviation value obtained in S243; S33. The LNG storage tank was successfully placed in place at one time, and the epoxy gap was controlled within the effective range.

[0013] Furthermore, in step S33, the effective range of the epoxy gap is within the standard range of 5 to 40 mm.

[0014] The simulated hoisting control method of the large-scale LNG storage tank for ships of the present invention is implemented through three-dimensional scanning simulation, and the construction efficiency of the saddle assembly, assembly, liquid tank hoisting, and each link is high, which reduces the secondary lifting and film pressing work of the tank body, ensures that the LNG tank body is in place at one time without rework, and greatly improves the work efficiency; through the three-dimensional scanning simulation implementation, the construction accuracy control of each link is effectively improved. In particular, before the LNG tank body hoisting process, the hoisting state is simulated in advance by three-dimensional scanning, and the optimal state of LNG tank body placement is formulated. During the LNG tank body hoisting process, adjustments are made according to the simulated state data, which can not only reduce the number of lifting times and cancel the film pressing process, but also effectively control the matching accuracy of the gap between the LNG tank body and the saddle. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the assembly division of the fixed saddle of the present invention; Figure 2 It is a schematic diagram of the assembly and division of the sliding saddle of the present invention; Figure 3 is a schematic diagram of three-dimensional measurement data of the saddle assembly manufacturing stage of the present invention; Figure 4 It is a schematic diagram of the curvature line of the laminated wood of the fixed saddle according to the present invention; Figure 5 It is a schematic diagram of the curvature line of the laminated wood appearance of the sliding saddle of the present invention; Figure 6 It is a schematic diagram of the gap matching between the saddle and the laminated wood of the LNG tank body described in the present invention. DETAILED DESCRIPTION

[0016] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0017] like Figure 1-Figure 6 As shown, a simulated hoisting control method for a large LNG storage tank on a ship comprises the following steps: S1. Saddle group production; S2. Saddle carrying linear simulation positioning; S3. Lifting of large LNG storage tanks.

[0018] The step S1 specifically includes the following steps: S11. Saddle assembly division: the fixed saddle and the sliding saddle ring saddle assembly are divided into 7 small groups; S12. Saddle panel production. The saddle panels are also divided into 7 small groups. During the surface processing stage of each saddle panel, the linear accuracy of the saddle panel is controlled within 2mm through cold pressing and sample linear control. S13. Saddle assembly production: 7 small groups of fixed saddles and 7 small groups of sliding saddles are produced on the fixed saddle frame and the sliding saddle frame respectively. Specifically, the saddle panels are first positioned, and each saddle panel is placed on the corresponding saddle frame to fit the base surface of the saddle frame; secondly, the saddle is welded to the saddle panel to connect the bracket and the T-profile web. During the positioning and welding process, the dimensional accuracy of the connecting bracket, the T-profile web and the saddle panel line is detected and confirmed, and the accuracy is controlled within 3mm; S14. After welding is completed, data detection is carried out on the control points according to the detection plan formulated by the precision control to ensure that the error between the precision data and the theoretical data is within 5mm.

[0019] The step S2 specifically includes the following steps: S21. Scanning the outer edge laminated wood linear data of the formed large LNG storage tank using a 3D scanner, and performing data analysis on the scanned laminated wood linear data; S22 saddle assembly positioning, the fixed saddle seven small group assembly into a fixed annular saddle, the sliding saddle seven small group assembly into a sliding annular saddle, the saddle positioning process during the assembly process to control the dimensional accuracy; S23. The saddle assembly is welded and formed, and the seven small groups of the fixed saddle and the seven small groups of the sliding saddle are welded respectively; in the structural welding process between the hull saddle assemblies, a scanner device is used to collect three-dimensional data of the welding process status data of the saddle assembly, and the scanned saddle line shape is matched with the line shape of the LNG tank laminated wood. The line shape deviation value and gap situation of the line shape of the ship saddle assembly and the line shape of the LNG tank laminated wood in three-dimensional space are analyzed by the three-dimensional coordinate difference obtained by scanning. If the matching accuracy error exceeds the error range, that is, the gap is less than 15mm or greater than 40mm, the line shape error is adjusted by adjusting the welding sequence of the saddle joint to control the matching gap error within the standard range of 15~40mm; S24. The saddle line shape is matched with the LNG tank laminated wood simulation, specifically comprising the following steps: S241. Linear scanning of the saddle welding completion site, scanning data collection of the hull saddle through multiple stations, and forming a three-dimensional data model; S242. The scanned 3D model of the hull saddle and the overall model of the LNG tank are imported into the analysis software, and the four anti-floating blocks of the LNG tank are leveled, and the center of the LNG tank is overlapped with the center of the hull saddle to perform line comparison analysis; S243. Utilize the collision box principle of the simulated test box to calculate the gap matching between the saddle and the laminated wood of the LNG tank. At the same time, use the centerline tolerance and the horizontal tolerance of the anti-floating block to fine-tune the state of the LNG tank and control the matching gap error between the two within the standard range of 5~40mm. Record the centerline deviation value, the horizontal deviation value of the anti-floating block and the gap data to generate a report. At the same time, mark the tank and saddle to guide the subsequent precise adjustment of the LNG tank position.

[0020] The step S21 specifically includes the following steps: S211. After the installation of laminated wood for LNG tanks is completed, according to the placement of the LNG tanks, the outer surface of the tanks is scanned by using a scanner at the outer edge of the LNG tanks, and at the same time, the outer edge line shape of the laminated wood of the fixed saddle, the outer edge line shape of the pressure-bearing wood of the sliding saddle, and the flatness of the upper edge of the anti-floating block are collected in three dimensions and a model is generated; S212. Data processing is performed on the scanned LNG storage tank, and the line shape data of the laminated wood outer edge of the fixed saddle and the line shape data of the pressure-bearing wood outer edge of the sliding saddle are analyzed, and a line shape and spacing accuracy data table is formed to obtain the curvature line shape of the laminated wood outer shape of the two support seats of the LNG tank body.

[0021] Furthermore, the step S22 specifically includes the following steps: S221. Positioning in the front and rear direction: Based on the distance data between the fixed saddle and sliding saddle laminated wood of the LNG tank obtained by scanning and analysis, the saddle ribs corresponding to the HB01~HB03 sections of the double bottom of the hull are controlled for size positioning to ensure that the distance data between the double saddle bottom ribs of the hull and the laminated wood blocks of the two front and rear support seats of the LNG tank are consistent, and the hull structure welding shrinkage is taken into account; the corresponding saddle ribs are laid out on the inner bottom plate, and the saddle web is controlled to coincide with the double bottom ribs during the saddle assembly and positioning to ensure the front and rear dimensional accuracy; S222. Positioning in the left and right directions: Release the hull centerline on the double bottom HB01~HB03, release two saddle centerlines based on the hull centerline, and use a scanner to perform linear scanning on the saddle assembly based on the saddle centerline. Furthermore, the step S222 specifically includes the following steps: S2221. Positioning of the stern saddle: According to the curvature line shape of the laminated wood outer edge of the fixed saddle obtained by scanning the LNG tank, the annular saddle formed by assembling the seven assembled saddles is simulated and analyzed and positioned according to the line shape of the laminated wood block of the LNG tank, ensuring that the line shape of the saddle panel in the height direction and the width direction matches the line shape of the laminated wood block of the LNG tank fixed support seat during the positioning stage; S2222. Forward saddle positioning: Based on the curvature line shape of the outer edge of the laminated wood of the sliding saddle obtained by scanning the LNG tank, the annular saddle formed by assembling seven assembled saddles is simulated, analyzed and positioned according to the line shape of the laminated wood block of the LNG tank obtained, ensuring that the line shape of the saddle panel in the height direction and the width direction matches the line shape of the laminated wood block of the LNG tank sliding support seat during the positioning stage; S223. Anti-deformation: According to the curvature line of the outer edge of the two saddle laminated wood obtained by scanning the LNG storage tank, the positioning of the hull assembly saddle is guided by data, and a welding anti-deformation of 8~10mm is added on one side in the width direction. At the same time, shape-preserving support is added to ensure that the linear accuracy of the saddle after positioning and splicing and the linear accuracy error of the LNG tank laminated wood are within a controllable range.

[0022] The step S3 specifically comprises the following steps: S31. Pop out the bow centerline and stern centerline of the laminated wood of the fixed saddle and the sliding saddle of the LNG tank and mark them; pre-stick target sheets on the four anti-floating panels of the LNG tank in advance to facilitate subsequent horizontal detection; S32. During the hoisting process of LNG storage tanks, the state of the LNG storage tanks shall be adjusted according to the simulated positioning state to ensure that the LNG tank body is positioned in the correct state, specifically: (1) When the LNG storage tank is located directly above the saddle, start to check the level of the four stop-floating point panels and adjust the LNG tank body to a simulated positioning level state; (2) Adjust the centerline of the LNG tank at the front and rear ends and the centerline of the saddle to be consistent with the centerline deviation value, anti-floating block horizontal deviation value and gap deviation value obtained in S243; S33. The LNG storage tank is successfully placed in place at one time, and the epoxy gap is controlled within the standard range of 5~40mm.

[0023] Those skilled in the art should understand that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A simulated hoisting control method for a large LNG storage tank on a ship, characterized in that: The following steps are involved: S1. Saddle group production; S2. Saddle carrying linear simulation positioning; S3. Lifting of large LNG storage tanks.

2. The method for simulating the lifting and controlling of a large LNG storage tank on a ship according to claim 1, characterized in that: The step S1 specifically includes the following steps: S11. Saddle assembly division: the fixed saddle and the sliding saddle ring saddle assembly are divided into 7 groups; S12. Saddle panel production: The saddle panels are divided into 7 small groups. During the surface processing stage of each saddle panel, the linear accuracy of the saddle panel is controlled within 2mm through cold pressing and sample linear control; S13. Saddle assembly production: 7 small groups of fixed saddles and 7 small groups of sliding saddles are produced on the fixed saddle frame and the sliding saddle frame respectively. Specifically, the saddle panels are first positioned, and each saddle panel is placed on the corresponding saddle frame to fit the base surface of the saddle frame; secondly, the saddle is welded to the saddle panel to connect the bracket and the T-profile web. During the positioning and welding process, the dimensional accuracy of the connecting bracket, the T-profile web and the saddle panel line is detected and confirmed, and the accuracy is controlled within 3mm; S14. After welding is completed, data detection is carried out on the control points according to the detection plan formulated by the precision control to ensure that the error between the precision data and the theoretical data is within 5mm.

3. The method for simulating the lifting and controlling of a large LNG storage tank on a ship according to claim 1, characterized in that: The step S2 specifically includes the following steps: S21. Scanning the outer edge laminated wood linear data of the formed large LNG storage tank using a 3D scanner, and performing data analysis on the scanned laminated wood linear data; S22 saddle assembly positioning, the fixed saddle seven small group assembly into a fixed annular saddle, the sliding saddle seven small group assembly into a sliding annular saddle, the saddle positioning process during the assembly process to control the dimensional accuracy; S23 saddle assembly welding forming, respectively welding seven small groups of fixed saddle standing and seven small groups of sliding saddle standing; S24. Simulate and match the above saddle line shape with the laminated wood of the LNG tank.

4. The method for simulating the lifting and controlling of a large LNG storage tank on a ship according to claim 3, characterized in that: The step S21 specifically includes the following steps: S211. After the installation of laminated wood for LNG tanks is completed, according to the placement of the LNG tanks, the outer surface of the tanks is scanned by using a scanner at the outer edge of the LNG tanks, and at the same time, the outer edge line shape of the laminated wood of the fixed saddle, the outer edge line shape of the pressure-bearing wood of the sliding saddle, and the flatness of the upper edge of the anti-floating block are collected in three dimensions and a model is generated; S212. Data processing is performed on the scanned LNG storage tank, and the line shape data of the laminated wood outer edge of the fixed saddle and the line shape data of the pressure-bearing wood outer edge of the sliding saddle are analyzed, and a line shape and spacing accuracy data table is formed to obtain the curvature line shape of the laminated wood outer shape of the two support seats of the LNG tank body.

5. The method for simulating the lifting and controlling of a large LNG storage tank on a ship according to claim 4, characterized in that: The step S22 specifically includes the following steps: S221. Positioning in the front and rear direction: Based on the distance data between the fixed saddle and sliding saddle laminated wood of the LNG tank obtained by scanning and analysis, the saddle ribs corresponding to the HB01~HB03 sections of the double bottom of the hull are controlled for size positioning to ensure that the distance data between the double saddle bottom ribs of the hull and the laminated wood blocks of the two front and rear support seats of the LNG tank are consistent, and the hull structure welding shrinkage is taken into account; the corresponding saddle ribs are laid out on the inner bottom plate, and the saddle web is controlled to coincide with the double bottom ribs during the saddle assembly and positioning to ensure the front and rear dimensional accuracy; S222. Positioning in left and right directions: Release the hull centerline on the double bottom HB01~HB03, release two saddle centerlines based on the hull centerline, and use a scanner to perform linear scanning on the saddle assembly based on the saddle centerline.

6. The method for simulating the lifting and controlling of a large LNG storage tank on a ship according to claim 5, characterized in that: The step S222 specifically includes the following steps: S2221. Positioning of the stern saddle: According to the curvature line shape of the laminated wood outer edge of the fixed saddle obtained by scanning the LNG tank, the annular saddle formed by assembling the seven assembled saddles is simulated and analyzed and positioned according to the line shape of the laminated wood block of the LNG tank, ensuring that the line shape of the saddle panel in the height direction and the width direction matches the line shape of the laminated wood block of the LNG tank fixed support seat during the positioning stage; S2222. Forward saddle positioning: Based on the curvature line shape of the outer edge of the laminated wood of the sliding saddle obtained by scanning the LNG tank, the annular saddle formed by assembling seven assembled saddles is simulated, analyzed and positioned according to the line shape of the laminated wood block of the LNG tank obtained, ensuring that the line shape of the saddle panel in the height direction and the width direction matches the line shape of the laminated wood block of the LNG tank sliding support seat during the positioning stage; S223. Anti-deformation: According to the curvature line of the outer edge of the two saddle laminated wood obtained by scanning the LNG storage tank, the positioning of the hull assembly saddle is guided by data, and a welding anti-deformation of 8~10mm is added on one side in the width direction. At the same time, shape-preserving support is added to ensure that the linear accuracy of the saddle after positioning and splicing and the linear accuracy error of the LNG tank laminated wood are within a controllable range.

7. The method for controlling the simulated hoisting of a large LNG storage tank on a ship according to claim 6, characterized in that: In the step S23, during the structural welding process between the hull saddle assembly, a scanner device is used to collect three-dimensional data of the welding process status data of the saddle assembly, and the scanned saddle line shape is matched with the line shape of the LNG tank laminated wood. The three-dimensional coordinate difference obtained by scanning is used to analyze the linear deviation value and gap situation of the linear shape of the ship's saddle assembly and the linear shape of the LNG tank laminated wood in three-dimensional space. If the matching accuracy error exceeds the error range, that is, the gap is less than 15mm or greater than 40mm, the linear error is adjusted by adjusting the welding sequence of the saddle joints to control the matching gap error within the standard range of 15~40mm.

8. The method for simulating the lifting and controlling of a large LNG storage tank on a ship according to claim 7, characterized in that: The step S24 specifically includes the following steps: S241. Linear scanning of the saddle welding completion site, scanning data collection of the hull saddle through multiple stations, and forming a three-dimensional data model; S242. The scanned 3D model of the hull saddle and the overall model of the LNG tank are imported into the analysis software, and the four anti-floating blocks of the LNG tank are leveled, and the center of the LNG tank is overlapped with the center of the hull saddle to perform line comparison analysis; S243. Utilize the collision box principle of the simulated test box to calculate the gap matching between the saddle and the laminated wood of the LNG tank. At the same time, use the centerline tolerance and the horizontal tolerance of the anti-floating block to fine-tune the state of the LNG tank and control the matching gap error between the two within the standard range of 5~40mm. Record the centerline deviation value, the horizontal deviation value of the anti-floating block and the gap deviation value data to generate a report. At the same time, mark the tank and saddle to guide the subsequent precise adjustment of the LNG tank position.

9. The method for controlling the simulated hoisting of a large LNG storage tank on a ship according to claim 8, characterized in that: The step S3 specifically comprises the following steps: S31. Pop out the bow centerline and stern centerline of the laminated wood of the fixed saddle and the sliding saddle of the LNG tank and mark them; pre-stick target sheets on the four anti-floating panels of the LNG tank in advance to facilitate subsequent horizontal detection; S32. During the hoisting process of LNG storage tanks, the state of the LNG storage tanks shall be adjusted according to the simulated positioning state to ensure that the LNG tank body is positioned in the correct state, specifically: (1) When the LNG storage tank is located directly above the saddle, start to check the level of the four stop-floating point panels and adjust the LNG tank body to a simulated positioning level state; (2) Adjust the fore-aft centerline of the LNG storage tank and the saddle centerline to be consistent with the centerline deviation value, stop block horizontal deviation value and gap deviation value obtained in S243; S33. The LNG storage tank was successfully placed in place at one time, and the epoxy gap was controlled within the effective range.

10. The method for simulating the lifting and controlling of a large LNG storage tank on a ship according to claim 9, characterized in that: In step S33, the effective range of the epoxy gap is within the standard range of 5 to 40 mm.

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