LNG module oversized tower equipment installation method

Abstract

The invention relates to the technical field of marine ship hoisting, in particular to an LNG module oversized tower equipment mounting method. The method comprises the following steps: S1, confirming a hoisting object, wherein the hoisting object comprises a tower body section, a lifting lug, a shaft lug and a tail lug; s2, confirming hoisting parameters, wherein the hoisting parameters comprise a weight gravity center, a hoisting point, a lifting lug parameter and a hoisting coefficient; s3, selecting a calculation method: analyzing by using a mechanical formula or a finite element; s4, step-by-step planning confirmation: installation is carried out step by step in a narrow space; and S5, sliding and jacking are controlled. According to the method, objects are confirmed in combination with a hoisting failure mode, parameters are defined, stress is checked by selecting a proper calculation method, and the defects of deformation, cracks and the like of a tower body, a lifting lug and the like due to stress problems are avoided; the gravity center of weight is accurately determined, hoisting points are reasonably set, lifting lug parameters and hoisting coefficients are selected, and sliding and jacking cooperative control is adopted, so that the heavy equipment stably moves in the horizontal direction and the vertical direction and is accurately in place.

Description

Technical Field

[0001] This invention relates to the field of marine vessel hoisting technology, specifically to a method for installing an ultra-large LNG module tower device. Background Technology

[0002] In the field of marine vessel hoisting technology, the installation of ultra-large LNG module tower equipment presents numerous challenges. This is especially true for towers with large length-to-diameter ratios and high tonnage, such as those involved in the novel hoisting method for a large, lightweight platform and its superstructure disclosed in Chinese Patent Publication No. CN117923296A. During hoisting, the cylinder cross-section experiences significant bending and shear stresses. If the combined stress exceeds the elastic deformation range, it will induce permanent plastic deformation, affecting the straightness of the equipment, reducing the tower's process performance, and posing serious safety hazards. Furthermore, excessive local stress is prone to occur at the welded joints between the lifting lugs and the cylinder, leading to localized deformation, micro-cracks, affecting the installation of internal components, and reducing localized corrosion resistance. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a safe, reliable, economical and efficient method for installing ultra-large LNG module tower equipment.

[0004] The technical solution adopted in this invention is as follows: A method for installing an ultra-large LNG module tower device includes the following steps: S1. Confirmation of the hoisting object: Based on the failure modes of tower hoisting, confirm the hoisting object, including the tower body section, lifting lugs, shaft lugs, and tail lugs; S2. Confirmation of lifting parameters: Clarify the lifting parameters, including weight center of gravity, lifting point, lifting lug parameters and lifting coefficient, to ensure the safety and efficiency of the lifting process; S3. Calculation method selection: Select the calculation method according to the situation, and use mechanical formulas or finite element analysis to check the combined stress of the tower section to ensure that the structural strength meets the standards. S4. Confirmation of phased planning: Based on the preliminary calculations, the ultra-large tower equipment is planned in phases, and it is installed step by step in narrow spaces to improve the controllability of the construction period; S5. Control of sliding and lifting: Within complex modules, heavy equipment is moved and its position adjusted gradually through the coordinated sliding and lifting, thus successfully completing the installation process.

[0005] This technical solution identifies the lifting target by combining tower hoisting failure modes, covering key parts such as the tower body cross-section, lifting lugs, shaft lugs, and tail lugs. It ensures a safe and efficient hoisting process by clearly defining lifting parameters such as the center of gravity, lifting points, lifting lug parameters, and lifting coefficients. It verifies the combined stress of the tower body cross-section using mechanical formulas or finite element analysis based on actual conditions, ensuring structural strength meets standards. It plans the ultra-large tower equipment in stages based on preliminary calculations, enabling step-by-step installation in confined spaces and improving project timeline controllability. By coordinating sliding and jacking within complex modules, it gradually moves and adjusts the position of heavy equipment, smoothly completing the installation process. This avoids problems such as permanent plastic deformation caused by excessive bending and shear stress on the cylinder cross-section due to excessive length-to-diameter ratio and large tonnage towers during hoisting, which can lead to combined stress levels exceeding elastic deformation range, affecting equipment straightness and process performance, and posing safety hazards. It also avoids excessive local stress at the weld between the lifting lug root and the cylinder, which can cause local deformation, induce microcracks, affect internal component installation, and reduce local corrosion resistance.

[0006] In addition, the LNG module ultra-large tower equipment installation method proposed above according to the present invention also has the following additional technical features: According to one embodiment of the present invention, the confirmation of the hoisting object in S1 specifically includes the following steps: S11. Combined stress check of tower body section: Based on the tower parameters and actual weight distribution, use the formulas in the "Mechanical Design Handbook" or PV Elite software to perform modeling and analysis, calculate the stress and bending moment distribution of each section of the tower body during the hoisting process, and ensure that the combined stress does not exceed the allowable stress of the material to prevent plastic deformation. S12. Lifting lug strength verification: In accordance with HG / T21574-2008 "Technical Requirements for Lifting Lugs and Engineering of Chemical Equipment", the lifting lugs are selected, and the sum of the tensile stress and bending stress borne by the pipe shaft is calculated and compared with the allowable tensile stress of the pipe shaft to ensure that the strength of the lifting lugs meets the lifting requirements. S13. Calculation of local stress in the lug: For lifting points using lugs, a detailed analysis is conducted on the relationship between the magnitude of the local stress in the lug and the magnitude of the load borne by the lifting point, the structural dimensions of the lug, and the length of the boom. S14. Calculation of tail lugs: Set 1 to 2 tail lugs on the anchor bolt seats of the skirt seat. According to the provisions of HG / T21574-2008, the strength of the skirt seat is calculated in combination with the tangential shear force and bending moment generated by the tail lugs inside the skirt seat.

[0007] This technical solution calculates the stress and bending moment distribution of each section of the tower body during the hoisting process by using formulas in the "Mechanical Design Manual" or PV Elite software to analyze the tower parameters and actual weight distribution. It completes the combined stress check of the tower body section to ensure that the combined stress does not exceed the allowable stress of the material and prevents the tower body from undergoing plastic deformation due to excessive stress. Based on HG / T21574-200(1) and "Technical Requirements for Lifting Lugs and Engineering of Chemical Equipment", it comprehensively considers the common failure modes of tower hoisting, selects the type of lifting lug, calculates the sum of tensile stress and bending stress borne by the pipe shaft, compares it with the allowable tensile stress of the pipe shaft, completes the strength check of the lifting lug, avoids defects such as plastic deformation and cracks in the lifting lug, and ensures that the strength of the lifting lug meets the hoisting requirements. For the hoisting point using the shaft lug form, it analyzes in detail the relationship between the local stress of the lifting lug and the load size, the structural size of the lifting lug, and the length of the boom, completes the local stress calculation of the shaft lug, further ensures the safety and reliability of the hoisting point during the hoisting process, and thus comprehensively and accurately confirms the hoisting object.

[0008] According to one embodiment of the present invention, in the strength check of the lifting lug in S12, for side-wall type lifting lugs, their characteristics of high installation position, easy installation of accessories, short boom, and low local stress need to be considered for comprehensive evaluation. In the local stress calculation of the shaft lug in S13, local stress calculation is not performed if the minimum thickness of the cylinder meets the standard requirements; however, when the thickness of the cylinder exceeds the specification requirements or the structural dimensions are modified, the lifting lug body and local stress need to be recalculated to ensure safety.

[0009] According to one embodiment of the present invention, the confirmation of the hoisting parameters in S2 specifically includes the following steps: S21. Determining the weight and center of gravity: Accurately measure the weight of the tower body and its accessories, and determine the overall center of gravity position; the center of gravity position is crucial for setting the lifting points and selecting the size of the lifting lug structure, and directly affects the balance and stability during the lifting process. S22. Lifting point setting: Based on the weight distribution and center of gravity, the lifting points should be set reasonably to optimize the bending moment distribution of the tower body section; the lifting points should be set at a higher position to facilitate the installation of the lower accessories, but the mechanical balance and safety during the lifting process should be comprehensively considered. S23. Selection of lifting lug parameters: including the type, extension length, and orientation of the lifting lug, which must be selected based on the specific location of the lifting point and the mechanical requirements during the lifting process; the extension length and orientation of the shaft lug must fully consider the local stress caused by it and the interference with the pre-welded parts. S24. Selection of Lifting Coefficient: Select an appropriate lifting coefficient based on the dynamic characteristics during the lifting process.

[0010] This technical solution provides crucial information for subsequent hoisting point setting and lug structure size selection by accurately measuring the weight of the tower body and its accessories and determining the overall center of gravity. The center of gravity directly affects the balance and stability of the hoisting process. By rationally setting the hoisting points based on weight distribution and center of gravity, the bending moment distribution of the tower body section is optimized from a gravity distribution perspective. Furthermore, the hoisting points are positioned at higher levels to facilitate the installation of lower accessories, while simultaneously considering mechanical balance and safety. Lug parameters are selected based on the specific location of the hoisting points and hoisting mechanics requirements. For lug types, the local stress caused by the extended length and interference with pre-welded components are fully considered. The orientation setting also takes into account the surrounding pre-welded component layout and the use of balance beams to avoid interference between the hoisting ropes and pre-welded components. Finally, an appropriate hoisting coefficient is selected based on the dynamic characteristics of the hoisting process. This considers various scenarios, including the absence of special regulations, engineering specifications, accurate weight calculations, and comprehensive safety risks, ensuring accurate and reliable calculation results and thus comprehensively confirming the hoisting parameters.

[0011] According to one embodiment of the present invention, in determining the center of gravity in S21, all accessories, including insulation layers, fireproof layers, ladders, platforms, and pipelines, are considered together to determine the overall center of gravity position based on the combined weight of the tower body and its accessories. In selecting the hoisting coefficient in S24, a coefficient of 1.65 is used when there are no specific requirements, and 2.0 is used when engineering specifications require it; a lower hoisting coefficient is selected when calculating the tower hoisting weight and comprehensively considering safety risks.

[0012] According to an embodiment of the present invention, the selection of the calculation method for S3 specifically includes the following steps: S31. Mechanical Formula: For towers with uniform diameter, uniform wall thickness, and no concentrated mass, mechanical formulas are used to check the combined stress. S32. Finite Element Analysis: For tower structures under complex working conditions, the finite element analysis method is used for simulation calculation; a precise finite element model is established using professional software, high-quality mesh elements are divided, and the stress distribution during the actual hoisting process is simulated.

[0013] This technical solution calculates the stress and bending moment distribution of each section by treating the weight as a uniformly distributed load and using the lifting positions of the shaft lugs and tail lugs as simple supports, based on the weight distribution of the tower body. This method is convenient for towers with uniform diameter, uniform wall thickness, and no concentrated mass, and can also be approximated for towers with varying diameters and non-uniform wall thicknesses. Furthermore, shear stress and bending stress are derived from the section modulus to calculate the combined stress of the section. Simultaneously, PV Elite modeling and simulation can be used to more realistically simulate the weight distribution, accurately determine the center of gravity and weight distribution, clearly present the ratio of combined stress to allowable stress at each section, identify the location of critical sections, and generally only calculate the combined stress under horizontal conditions, thus completing the combined stress check of the tower body sections. Referring to HG / T21574-2008 "Technical Requirements for Lifting Lugs and Engineering of Chemical Equipment," the diameter and thickness of commonly used shaft lugs are determined by comparing the sum of tensile and bending stresses borne by the shaft with the allowable tensile stress of the shaft. For side-wall type lifting lugs with many advantages, the same standard is used for calculation, thus completing the calculation of the lifting lug itself. Strength verification; by clarifying the direct relationship between the magnitude of local stress in the lifting lug and the load at the lifting point, the structural dimensions of the lifting lug, and the length of the boom, lifting lugs selected according to HG / T21574-2008 and whose minimum cylinder thickness meets the standard requirements do not need local stress calculation. However, lifting lugs with cylinder thickness exceeding the specification or with modified structural dimensions need to be recalculated. Local stress is calculated using the WRC107 announcement, thus completing the local stress calculation for the lifting lug; by selecting the tail lug according to HG / T21574-2008, when NB / T47041-2014 does not provide a calculation method for the tangential shear force and bending moment effect of the tail lug on the skirt seat, refer to Pressure Chapters 10-5 of the Vessel Design Manual (Fourth Edition) perform strength calculations for the skirt support. For large-diameter towers, considering the difference in skirt stiffness, a supporting steel beam is added at the bottom. Tensile or compressive stress is checked for the supporting steel beam under common support forms. The calculation method in this chapter is also followed to complete the calculation of the tail lug. By selecting appropriate calculation methods for towers with different structural conditions, mechanical formulas are used to check the combined stress for towers with equal diameter, equal wall thickness, and no concentrated mass. For towers with complex structural conditions, the finite element analysis method is used. A precise finite element model is established using professional software, high-quality mesh elements are divided, and the actual lifting stress distribution is simulated to complete the selection of the calculation method.

[0014] According to an embodiment of the present invention, the confirmation of the step-by-step planning in S4 specifically includes the following steps: S41, Modular Design: The ultra-large tower equipment is broken down into several modules, and the assembly and debugging of each module are completed in the manufacturing plant, reducing the workload and risks of on-site installation. S42. Installation sequence planning: Based on the equipment structure characteristics and site conditions, develop a detailed step-by-step installation sequence diagram, clearly defining the installation content, required tooling and equipment, personnel configuration and safety measures for each step, to ensure that the installation process proceeds in an orderly manner; S43. Operations in confined spaces: For the enclosed, crowded, and limited-capacity confined space environment of the LNG upper module, develop an operation plan, including equipment transportation route planning, temporary support structure setting, and selection and adjustment of installation tools, to ensure that the installation task is completed efficiently in the limited space.

[0015] According to an embodiment of the present invention, the control of sliding and lifting in step S5 specifically includes the following steps: S51. Sliding system installation: Install sliding rails and sliding devices to ensure that heavy equipment moves smoothly and steadily in the horizontal direction; S52. Lifting System Configuration: Select appropriate lifting equipment and configure it according to the weight of the equipment and the required lifting height; during the lifting process, the lifting speed and synchronization must be strictly controlled to ensure that the equipment rises smoothly in the vertical direction and avoids tilting or shaking; S53. Coordinated Control Strategy: Formulate a coordinated control strategy for sliding and jacking, and clarify the division of tasks and operation sequence for each stage.

[0016] This technical solution employs a modular design, rationally disassembling the ultra-large tower equipment into several modules. Assembly and commissioning of each module are completed centrally at the manufacturing plant, effectively reducing on-site installation workload and mitigating risks arising from environmental and space constraints. This lays a solid foundation for subsequent installation work and ensures strong control over the overall quality and performance of the equipment from the outset. By meticulously developing a detailed step-by-step installation sequence diagram based on the equipment's unique structural characteristics and actual site conditions, the installation process proceeds smoothly and systematically, with each stage closely linked to avoid confusion and errors, ensuring successful installation. Furthermore, considering the confined, crowded, and limited-capacity space of the LNG upper module, a comprehensive and detailed operational plan is tailored to fully account for on-site space limitations and equipment constraints in equipment transportation route planning. Size is carefully considered to ensure smooth transportation; temporary support structures are rationally designed to enhance the stability and safety of equipment in confined spaces; installation tools are carefully selected and adjusted to adapt to the needs of confined space operations, thereby ensuring efficient and accurate completion of installation tasks in narrow spaces. In the transportation and hoisting stage, the impact of the weight of the transport saddle is treated differently according to the size of the equipment. The weight of the transport saddle can be ignored for small equipment, while it needs to be given special consideration for large equipment under specific working conditions, and it is ensured that the equipment is kept horizontal throughout the hoisting process; in the on-site installation and hoisting stage, the installation time is reasonably arranged according to the installation accuracy requirements of the internal components. At the same time, considering the load-bearing capacity and local stress changes of the lifting lugs and tail lugs during the hoisting of the tower from horizontal to vertical, in order to simplify the calculation, only the two most demanding conditions of horizontal and vertical are checked, improving the calculation efficiency while ensuring safety.

[0017] Compared with the prior art, the present invention has the following advantages: (1) The overall hoisting is decomposed into sliding and jacking operations, which reduces the risk of collision between equipment and modules and the sensitivity to severe weather, making the installation process safer and more controllable; by using technologies such as synchronous hydraulic jacking, the equipment can be finely adjusted at the millimeter level and lifted and lowered smoothly and synchronously, ensuring accurate positioning, and the installation quality and precision far exceed those of traditional hoisting. (2) Reduce reliance on large floating cranes and usage time, thereby reducing direct costs; less affected by weather, with predictable construction period, reducing overall project delay risk and indirect costs; provide new solutions for installing ultra-large equipment in narrow spaces and complex structures, expand the design possibilities of LNG top-mounted modules, and promote technological progress in the industry; (3) Combine the failure mode of hoisting to identify the object, clarify the parameters, select the appropriate calculation method to check the stress, avoid the tower body, lifting lugs and other defects caused by stress problems, and fully ensure the safety of the hoisting process; accurately determine the weight center, reasonably set the hoisting point, select the lifting lug parameters and hoisting coefficient, and adopt the sliding and jacking coordinated control to make the heavy equipment move smoothly and accurately in the horizontal and vertical directions. Attached Figure Description

[0018] Figure 1 This is a hoisting diagram of the tower equipment of the present invention.

[0019] Figure 2 This is a diagram showing the distribution of force and bending moment in this invention.

[0020] Figure 3 This is a diagram of the variable diameter tower of the present invention.

[0021] Figure 4 This is the combined stress and allowable stress diagram of the present invention.

[0022] Figure 5 This is the shear force and bending moment diagram of the present invention.

[0023] Figure 6 These are diagrams of several commonly used support forms in this invention.

[0024] Figure 7 This is a diagram of the foundation treatment before hoisting of the present invention.

[0025] Figure 8 This is the finite element mesh diagram of the tower body of the present invention.

[0026] Figure 9 This is a stress distribution diagram of the bottom lifting lug in the horizontal state of the present invention.

[0027] Figure 10 This is a cloud map showing the deflection distribution of the horizontal lifting tower body according to the present invention.

[0028] Figure 11 This is a cloud diagram showing the stress distribution of the horizontal lifting cylinder of the present invention.

[0029] Figure 12 This is a cloud map showing the stress distribution of the axial lifting lug and surrounding area during horizontal lifting of the present invention.

[0030] Figure 13 This is a cloud diagram showing the stress distribution of the horizontal lifting skirt and end cap of the present invention.

[0031] Figure 14 This is one of the stress distribution cloud diagrams of the lifting lugs during vertical lifting according to the present invention.

[0032] Figure 15 This is a stress distribution cloud diagram of the end cap and part of the cylinder of the present invention.

[0033] Figure 16 This is a cloud map showing the distribution of the sag of the vertical lifting tower body according to the present invention.

[0034] Figure 17 These are before-and-after comparison images of the optimized top hanging lugs of this invention.

[0035] Figure 18 This is a stress distribution cloud map of the contact area between the top lifting lug and the wire rope in the vertical lifting process of this invention.

[0036] Figure 19 This is the second stress distribution cloud diagram of the end cap and part of the cylinder of this invention.

[0037] Figure 20 This is the second cloud map showing the distribution of the vertical sag of the lifting tower body according to the present invention.

[0038] Figure 21 This is one of the counterweight configuration diagrams of the present invention.

[0039] Figure 22 This is the second counterweight configuration diagram of the present invention.

[0040] Figure 23 This is a diagram showing the crane's travel route and final station position in this invention.

[0041] Figure 24 This is one of the track hoisting diagrams of this invention.

[0042] Figure 25 This is the second track hoisting diagram of the present invention.

[0043] Figure 26 This is the third track hoisting diagram of the present invention.

[0044] Figure 27 This is the manhole diagram of the present invention.

[0045] Figure 28 This is a diagram of the flange plate of the present invention.

[0046] Figure 29 This is a diagram of the device of the present invention.

[0047] Figure 30 This is one of the tank orientation diagrams of the present invention.

[0048] Figure 31 This is the second orientation diagram of the tank body of the present invention.

[0049] Figure 32 This is the third orientation diagram of the tank body of the present invention.

[0050] Figure 33 This is the fourth orientation diagram of the tank body of the present invention.

[0051] Figure 34 This is the fifth orientation diagram of the tank body of the present invention. Detailed Implementation

[0052] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0053] Example 1 like Figure 1 As shown in the figure, this embodiment provides a method for installing an ultra-large LNG module tower device, including the following steps: S1. Confirmation of the hoisting object: Taking into account the common failure modes of tower hoisting, in order to avoid defects such as plastic deformation and cracks, the tower hoisting calculation should at least consider the following four aspects: S11. Combined stress check of tower body section; S12. Strength check of lifting lugs; S13. Calculation of local stress of shaft lugs; S14. Calculation of tail lugs; S2. Confirmation of Lifting Parameters: The determination of lifting design parameters has a significant impact on the calculation results, and may even affect the thickness of the cylinder in the lifting section. Designers should pay attention to lifting calculations in the early stages of the design process to ensure the safety and economy of the equipment. S21. Determining the Center of Gravity: Tower cranes typically carry many external accessories, such as insulation layers, fireproof layers, ladders, platforms, pipelines, and various internal components. Whether these accessories have been installed before hoisting is a necessary condition that the designer must clarify before starting the hoisting design, as it directly determines the hoisting weight and the structural dimensions of the lifting lugs. After determining the weight distribution, the center of gravity location is found in the calculation results generated by SW6. The accuracy of this data will affect the weight distribution at the lifting lugs and tail lugs. S22. Lifting Point Setting: From the perspective of gravity distribution, appropriately adjusting the position of the lifting point relative to the center of gravity optimizes the bending moment of the tower shell section. However, in practical engineering applications, it is more common to set the lifting lugs at the highest possible position to facilitate the installation of lower accessories. Therefore, when encountering a situation with many installation accessories, the lifting points should be set reasonably to carry as many external accessories as possible. S23. Selection of Lifting Lug Parameters: Two common types of lifting lugs for tower crane lifting are sidewall lugs and shaft lugs. Sidewall lugs fit snugly against the cylinder wall, eliminating the issue of overhang length. When using shaft lugs, on the one hand, a longer overhang can cause significant local stress at the lug root, potentially increasing the cylinder thickness; on the other hand, it's necessary to avoid pre-welded components within the lifting range. The design must fully consider the advantages and disadvantages to select a reasonable overhang length. The orientation of the shaft lug needs to comprehensively consider the arrangement of pre-welded components around it. Distinguishing between lifting operations using a balance beam and other methods is crucial. See [link to relevant documentation]. Figure 1 The interference between the hoisting rope and the pre-welded parts during the hoisting process was fully considered and adjusted accordingly; S24. Selection of hoisting coefficient: (e.g., ...) Figure 1 As shown, since hoisting is a dynamic process, there may be accelerations in the X, Y, and Z directions, which are usually represented in hoisting calculations as hoisting coefficients. The choice of hoisting coefficient also has a direct impact on the calculation results. Common hoisting coefficients fall into three categories: a. When there are no special provisions, a hoisting coefficient of 1.65 is used; b. In actual engineering practice, engineering specifications may require a hoisting coefficient of 2.0. This value is based on the consideration that one lug may fail during hoisting, in which case the other lug will bear the weight of the entire equipment; c. If the hoisting weight of the tower is to be calculated accurately, and the safety risks during hoisting are taken into account, a lower hoisting coefficient is also selected for calculation. S3. Calculation Method Selection: Lifting calculations typically use conventional mechanical formulas, but finite element analysis is also used in special cases. This invention mainly discusses the calculation methods and steps using conventional mechanical formulas; 1) Combined stress check of tower body sections: Based on the weight distribution of the tower body, the weight of the tower body is treated as a uniformly distributed load, and the hoisting positions of the shaft lugs and tail lugs are treated as simply supported points. The stress and bending moment distribution of each section are calculated, see... Figure 2 Detailed calculation formulas can be derived by referring to the "Mechanical Design Handbook," or calculation tables can be created for calculation. This calculation method is simple and convenient for handling the gravity and bending moment distribution of towers with uniform diameter, uniform wall thickness, and no concentrated mass. This method is also used for approximate calculations of towers with varying diameters and non-uniform wall thicknesses, but its calculation accuracy will differ slightly from the actual situation. Then, based on the section modulus of each section, the shear stress and bending stress borne by each interface are derived, and then the combined stress of the section is calculated. In addition to the above methods, PV Elite modeling can also be used for simulation calculations. Its advantage is that it more realistically simulates the weight distribution, and the calculated center of gravity position and weight distribution are more accurate. Figure 3 Taking the equipment shown as an example, this is a variable-diameter tower with a total length of 67.45m. PV was used for modeling and analysis to obtain the shear force and bending moment distribution diagrams for each section, and the resulting shear stress and bending stress were superimposed. See... Figure 4 This allows for a clear view of the ratio between the combined stress and the allowable stress at each cross-section, thus enabling the identification of critical cross-section locations and targeted adjustments. Since the tower structure changes from horizontal to vertical during hoisting, theoretically, stress levels at various angles need to be calculated. However, the most demanding stress distribution actually occurs in the horizontal state; therefore, generally only the combined stress in the horizontal state is calculated. 2) Strength verification of the lifting lug itself: The selection or design of the lifting lug can refer to HG / T21574-2008 "Technical Requirements for Lifting Lugs and Engineering of Chemical Equipment". Taking the most commonly used shaft lug of tower equipment as an example, the selection of the shaft diameter and thickness is determined by comparing the sum of the tensile stress and bending stress borne by the shaft with the allowable tensile stress of the shaft. In addition, side-wall type lifting lugs have the advantages of high installation position, easy installation of accessories, short boom, and small local stress, and are also a common type of lifting lug in tower equipment design. The calculation method is also carried out in accordance with HG / T21574-2008. 3) Calculation of Local Stress in Lifting Lugs: The magnitude of local stress in lifting lugs is directly related to the load borne by the lifting point, the structural dimensions of the lifting lugs, and the length of the boom. The closer the lifting point is to the top, the greater the gravity load borne by the lifting lugs; the longer the boom, the greater the bending stress borne by the lifting lugs, and thus the greater the local stress. For lifting lugs selected according to HG / T21574-2008, local stress calculation is not performed if the minimum thickness of the cylinder meets the standard requirements. However, when the cylinder thickness exceeds the specification requirements or the structural dimensions of the lifting lugs are modified, the lifting lug body and local stress need to be recalculated. Local stress can be calculated using the WRC107 announcement. 4) Calculation of Tail Lugs: Tower equipment typically has 1-2 tail lugs on the skirt support anchor bolt seats. When the tower is too heavy to use a tail lug structure, a set of shaft lugs can also be installed on the skirt support or bottom cylinder. The selection of tail lugs follows the specifications in HG / T21574-2008. Since NB / T47041-2014 does not provide a calculation method for the tangential shear force and bending moment generated by the tail lugs on the interior of the skirt support during hoisting, see [link to relevant documentation]. Figure 5 At this point, refer to Chapter 10-5 of the Pressure Vessel Design Manual (Fourth Edition) for strength calculations of the skirt support. Additionally, when dealing with large-diameter towers, due to the poor stiffness of the skirt support, it is necessary to consider adding supporting steel beams at the bottom of the skirt support. Several commonly used support methods are listed below. Figure 6 When using these methods, it is necessary to check the tensile or compressive stress of the supporting steel beams. Detailed calculation methods can be found in this chapter. 5) The process of changing from a horizontal to a vertical position: Tower equipment hoisting is generally divided into two types: transport hoisting and on-site installation hoisting. The difference lies in whether the transport saddle or installation accessories are included during hoisting, which has a certain impact on the weight load distribution calculation. a. Transport hoisting: Before the equipment is shipped, the transport saddle is installed first, while internal components and external accessories are not installed. Theoretically, the weight of the transport saddle should be considered during the process of hoisting from the ground to the truck bed or from the dock to the cargo ship. However, in reality, the weight of the transport saddle used for many small pieces of equipment is very small and can be ignored in this process. But for large equipment, if the weight of the transport saddle is very large due to transportation reasons, and the combined stress of the cylinder is relatively critical, it is recommended to consider this type of hoisting. During this hoisting process, the equipment is always kept horizontal; b. On-site installation hoisting: The tower equipment needs to have external accessories, insulation, and fireproofing installed on-site; for internal components, if the installation accuracy is high, it is usually chosen to install them after the tower equipment is in place. During the hoisting process, the tower structure changes from a horizontal to an vertical position. Theoretically, at each hoisting angle, the load-bearing capacity, direction, and local stress magnitude and distribution of its lifting lugs and tail lugs will change, requiring individual verification. To simplify calculations, calculations are typically performed only for the two most demanding hoisting conditions: horizontal and vertical.

[0054] Example 2 Based on Example 1, this example provides an extractive distillation column with a nominal diameter of 4600mm, a column thickness of 20mm, a skirt wall thickness of 22mm, a column material of Q345R, a column height of 76720mm, a weight of 205t, and a lifting lug tube shaft material of Q235 with a tube shaft wall thickness of 20mm. Adhering to the principles of advanced technology, economic rationality, and safety and reliability, the overall lifting is completed by using two cranes in coordination, one at the front and one at the rear. Special hardening treatment of the foundation is required in the crane station area to meet the ground bearing capacity requirements of the cranes. For example... Figure 7 As shown; When hoisting the entire tower, a shaft-type lifting lug is installed at the top of the tower, and a tail lifting lug is installed at the bottom of the tower. Strength checks are required in both horizontal and vertical conditions. The existing solution is to install the shaft-type lifting lug 3200mm from the top of the tower and the tail lifting lug at the bottom. This paper will analyze whether this solution meets the strength requirements, and if so, propose a more reasonable solution.

[0055] Due to the difficulty in guaranteeing the mesh quality of finite element method (FEM) software, the tower mesh was generated using professional meshing software. The mesh uses hexahedral elements throughout, totaling 369,359 elements and 536,633 nodes, with all nodes having a one-to-one correspondence. Figure 8As shown. Considering that the main stress is concentrated at the root of the lifting lug during lifting, the mesh at the weld is refined to ensure that the mesh size and the actual weld width have an error of less than 1%. The closer to the lifting lug, the denser the weld mesh. Considering the tower height and diameter, the pipes and openings on the tower internals and cylinder are ignored. The model is symmetrical about the y-axis, but the mass of the accessories on the tower body needs to be considered.

[0056] The actual lifting process is accomplished through the interaction between the wire rope and the lifting lugs. A separate region needs to be defined when creating the finite element mesh. Since the bottom of the lifting lugs is subjected to bending moment, this region is placed as close as possible to the outer side of the lugs, and gravity is applied for both horizontal and vertical lifting. In the horizontal state, constraints in the xz directions are applied to the bottom of the lifting lugs at both ends, and the y-axis is fixed on the bottom center of the cylinder near the ground. In the vertical state, constraints in both the yz directions are applied to the bottom sides of the upper lifting lugs, and constraints in the xz directions are applied to the center of the top end cap of the cylinder. Because the reinforcing ring, lifting lugs, and cylinder are connected by welds, the reinforcing ring and cylinder are not actually connected. Therefore, the mesh nodes between the reinforcing ring and cylinder need to be separated, and the contact area between the reinforcing ring and cylinder needs to be defined.

[0057] In the original design, during horizontal lifting, the maximum stress occurs at the weld between the bottom lifting lug and the reinforcing plate, and this maximum stress exceeds the material's allowable stress, failing to meet the strength requirements. Figure 9 As shown. Therefore, the original solution does not meet the requirements and needs to be optimized.

[0058] Based on the strength analysis of the original scheme, two optimized schemes are considered.

[0059] Optimization Scheme 1: The tail lifting lug is optimized to a shaft-type lifting lug, while the top lifting lug remains located 3200mm from the top of the cylinder, and the bottom lifting lug's axis is 1000mm from the bottom of the tower. Optimization Scheme 2: To increase the welding area between the reinforcing ring and the cylinder, based on Optimization Scheme 1, six holes are drilled in the middle of the reinforcing ring of the top lifting lug. The finite element mesh remains entirely hexahedral, and the loads and applied boundaries are consistent with the above. The following results were obtained after calculation.

[0060] 1) Optimization Solution 1: a. Calculation of deflection at the midpoint of the tower in a horizontal state: The deflection at the midpoint of the tower in a horizontal state is as follows: Figure 10 As shown (magnified 100 times). The results indicate that the deflection is greatest in the middle of the tower, with a maximum value of less than 60 mm, and the tower will not become unstable when lifted horizontally. b. Stress calculation at the midpoint of the tower under horizontal conditions: The stress calculation results at the midpoint of the tower under horizontal conditions are shown below. Figure 11 The maximum stress in the tower body occurs in the middle, and the maximum stress value is less than 50 MPa. The horizontal lifting tower body meets the strength requirements. c. Calculation of lug stress in horizontal state: through Figure 12 It was found that the maximum stress in both the top and bottom shaft-type lifting lugs occurred at the contact points between the lugs and the wire rope, exceeding the allowable stress. However, the stresses in the end caps connected to the top lifting lug and the skirt supports connected to the bottom lifting lug were both less than the material's allowable stress. This indicates that the lifting lugs need to be reinforced for the pipe shaft during horizontal lifting; increasing the wall thickness and adding more supports could be considered, but the overall tower structure still meets the strength requirements. Figure 13 It can be seen that the skirt is safe when lifted horizontally, and the maximum stress occurs at the weld where the lifting lug connects to the skirt; the end cap and part of the cylinder are safe when lifted horizontally, and the maximum stress occurs at the weld where the lifting lug connects to the cylinder. d. Stress calculation of the lifting lugs at the top of the tower body during vertical lifting: (e.g.) Figure 14 As shown, during vertical lifting, the maximum stress occurs at the connection between the top lifting lug and the wire rope. The stress at the root of the top lifting lug is less than the allowable stress of the material. The lifting lug meets the strength requirements throughout the lifting process, but the maximum stress at the contact point between the top lifting lug and the wire rope exceeds the allowable stress of the material, so the lifting lug cylinder must be reinforced. Figure 15 This indicates that the maximum stress during vertical lifting occurs in the area where the weld connects to the cylinder, and the maximum stress is less than 56 MPa, which is less than the allowable stress of the material, indicating that the tower body is safe during vertical lifting. e. Calculation of tower sag in vertical condition: Sag distribution cloud map as shown in the figure. Figure 16 As shown, the entire tower body sags by about 10mm during vertical lifting, indicating that the tower body is safe.

[0061] Optimization Option 2: Drill six 90mm diameter holes in the reinforcing ring of the top lug, with the center of each hole located in the middle of the reinforcing ring. Figure 17 As shown. Considering that the difference between optimization scheme 2 and optimization scheme 1 is very small during horizontal lifting, the calculation results under the vertical state are mainly introduced below; a. Stress calculation at the contact point between the top lifting lug and the wire rope under the vertical state: Figure 18 The display shows that the maximum stress at the point where the top lifting lug contacts the wire rope exceeds the allowable stress of the material, and the lifting lug cylinder must be reinforced. Figure 19 This indicates that the maximum stress during vertical lifting occurs in the area where the weld connects to the cylinder, and the maximum stress is less than 50 MPa, which is less than the allowable stress of the material, indicating that vertical lifting of the tower is safe; b. Calculation of tower sag in vertical state: Figure 20 This indicates that the entire tower body sags by less than 8mm during vertical lifting, indicating that the tower body is safe. The tower was successfully hoisted as a whole, but the solution provided by the construction party was not feasible. It is necessary to optimize the tail lifting lugs to be shaft-type lifting lugs that are consistent with the top lifting lugs.

[0062] The present invention has two optimization schemes. The following conclusions are drawn from the comparison of the two schemes: (1) Both optimization schemes are feasible. Compared with optimization scheme 1, optimization scheme 2 reduces local stress, but the reduction effect is not obvious. (2) Regardless of the optimization scheme, the shaft-type lifting lugs need to be reinforced. Consider increasing the wall thickness of the lifting lug tube shaft and setting reinforcing ribs, etc. For some towers that meet transportation requirements or towers that have special requirements that cannot be installed in sections, overall installation is required.

[0063] The main construction sequence is as follows: As can be seen from the above construction sequence, the construction sequence is basically the same as that of segmented installation, except that the "overall hoisting of equipment" omits all the assembly and welding processes in segmented hoisting. Correspondingly, the difficulty of hoisting is also significantly increased.

[0064] Therefore, taking a 37-meter-high demethanizer tower as an example, the same construction process as in the segmented installation of the tower will not be repeated; only the "overall equipment hoisting" method will be described. During the lifting and turning stages, two cranes work together, serving as the main crane and the tail crane respectively. During lifting, both cranes lift their hooks simultaneously. During turning, the main crane lifts its hook, while the tail crane moves towards the main crane. After the demethanizer tower is completely vertical, the tail crane is removed from the trench. The main crane swings the demethanizer tower above the installation position and then lowers its hook. Since the equipment penetrates three decks, the hoisting path needs to be designed, including: removing collision objects along the installation path; using slings to limit the lateral sway of the equipment before it passes through the decks; using guide blocks to protect the equipment during deck penetration and using thrust blocks to adjust the equipment's orientation; restoring collision objects after installation; and leveling the equipment after hoisting. (1) Selection of main hoist: 1) Determination of total hoisting load: The total hoisting load should be the sum of the equipment hoisting weight and the weight of the lifting equipment. It can be calculated by the following formula: Q=Ka*Kd*(Q equipment+Q lifting equipment); where Q is the hoisting weight, Ka is the safety factor, Kd is the dynamic amplification factor, Q equipment is the weight of the equipment at the hoisting point, and Q lifting equipment is the weight of the lifting slings used; the total weight of the demethanizer tower equipment is 451.1 tons. Before the equipment is turned over, it is decomposed according to the center of gravity position, and the equipment weight at the main hoisting point is 266 tons. The weight of the hook used is 22 tons, and the total weight of the slings used is 15.42 tons. The safety factor and the dynamic amplification factor are both selected as 1.05%. According to the above formula, the total hoisting weight before the equipment is turned over is 331.9 tons; after the equipment is turned over, it is decomposed according to the center of gravity position, and the equipment weight at the main hoisting point is 451.1 tons. The hook used weighs 22 tons, and the total weight of the slings used is 15.42 tons. The safety factor and dynamic amplification factor are both 1.05%. According to the above formula, the total lifting weight after the equipment is overturned is 535.5 tons. 2) Crane and counterweight selection: Based on the above calculations, a crane with a lifting weight greater than 535.5 tons should be selected. Finally, a crawler crane of model CC8800-1 was selected. During the previous lifting scheme design, the crane's position was calculated, determining that the crane should have two slewing radii: 14 meters and 22 meters respectively. By checking the crane's curve, the counterweight configuration of the crane was determined as follows: Figure 21 As shown; (2) Selection of tailing crane: 1) Determination of total lifting load: The total lifting load should be the sum of the lifting weight of the equipment and the weight of the lifting gear. It can be calculated by the following formula: Q=Ka*Kd*(Q equipment+Q lifting gear); where Q is the lifting weight, Ka is the safety factor, Kd is the dynamic amplification factor, Q equipment is the weight of the equipment at the lifting point, and Q lifting gear is the weight of the lifting slings used; the total weight of the demethanizer tower equipment is 451.1 tons. Before the equipment is turned over, it is decomposed according to the center of gravity position, and the weight of the equipment at the tailing crane is 185.1 tons. The weight of the hook used is 11.4 tons, and the total weight of the slings used is 4.92 tons. The safety factor and the dynamic amplification factor are both selected as 1.05%. According to the above formula, the total lifting weight before the equipment is turned over is 221.2 tons; 2) Selection of crane and its counterweight: According to the above calculation results, a crawler crane with a lifting weight greater than 221.2 tons should be selected. The final selected crawler crane model is Manitowoc18000. During the initial lifting scheme design, calculations of the crane's position determined that its slewing radius should be 18 meters. By consulting the crane's profile, the appropriate counterweight configuration was determined. Figure 22 ; (3) Walking route: Figure 23When designing the travel route, the feasibility of the route should be fully considered, including whether there are obstacles along the way, whether there will be collisions at the turns, whether the ground bearing capacity of the route meets the requirements, and whether steel plates need to be laid. Precautions during transportation: 1) Clear the transportation path before hoisting; 2) Take necessary protection for the equipment during transportation; 3) Keep the equipment 100mm off the ground during transportation; 4) Clear a passage between the module and slide rail No. 2 to allow the 750T crane to leave; 5) Lay 20mm thick steel plates for the 1600T crawler hoist. (4) Equipment Turning: 1) After the equipment is transported to the side of the module, it is temporarily placed on the pre-arranged frame structure. Then the 1600T crawler crane is unhooked and moves from a position 14 meters away from the equipment to a position 22 meters away from the equipment. A 340-ton counterweight is added and the climbing pole angle is adjusted. Then, together with the 750T crane, it is lifted again to lift the equipment horizontally more than 3 meters off the ground; 2) The 1600T crawler crane slowly lifts the hook, while the 750T crane moves towards the 1600T crawler crane. The angle of the sling at the 750T crane is controlled, and finally the equipment is changed from a horizontal position to a vertical position. The weight of the equipment is completely borne by the 1600T crawler crane. Figure 24 As shown; 3) The 1600T crawler crane lowers the hook, lowering the bottom of the equipment to about half a meter above the ground, attaching the tow rope, and then the 750T crane releases the hook; 4) The 1600T crawler crane raises the hook, lifting the equipment to a height more than 2 meters above the top deck of the module, and then slowly rotates the crane to position the equipment directly above its installation location on the module, as shown. Figure 25 As shown; 5) After placing the equipment above the module, further adjust the horizontal position of the equipment so that the center of the equipment coincides with the final positioning position, as shown. Figure 26 As shown; (5) Equipment hoisting: 1) Preparatory work: ① Before hoisting the equipment, the actual dimensions of the equipment and module structure should be measured, including: the actual dimensions of the guides and their distance from the center of the equipment; the actual dimensions of the manholes and their distance from the center of the equipment; the actual structural dimensions of the equipment installation location; and the actual dimensions of the support rings; ② After obtaining the actual dimensions, design calculations should be performed on the process of the equipment passing through the deck, and based on the calculation results, protruding parts that will cause collisions during installation should be temporarily removed; the parts that need to be removed from the equipment include two guides and one manhole, such as Figure 27 As shown: The specific procedure for removing the manhole is as follows: First, release the nitrogen gas stored for protection inside the tower, then remove the manhole cover, and finally protect the equipment flange sealing surface with a wooden board and rubber sheet; the structural parts that need to be cut off include the flange plates of three five-story structural beams, such as... Figure 28 As shown: 2) Equipment position adjustment: Figure 29After the equipment is hoisted directly above the installation position, its verticality should be measured. If the verticality does not meet the requirements, manually adjust the equipment's verticality using a hand-operated hoist; rotate the equipment by pulling the index rope to turn it to the correct orientation; adjust the crane hook to align the equipment with the support hole; before entering the support ring, the tank's orientation should be checked one last time. Figure 30 As shown; 3) The bottom of the equipment passes through five support rings: Slowly lower the crane hook, stopping when the equipment manhole is 400 mm above the support rings; Prepare slings above the equipment guide. Prioritize preparing these slings before hoisting the equipment; Weld temporary lifting lugs (which can be replaced by the surrounding columns) to the four corners of the equipment; Connect the slings using a hand chain hoist; Adjust the hand chain hoist to keep it taut to prevent the equipment from swaying, such as... Figure 31 and Figure 32 As shown; 4) The manhole and guides pass through the support ring; slowly lower the hook while adjusting the hoisting rope using a hand chain hoist. The manhole first passes through the support ring and the cutting hole in the north I-beam; when the four guides approach the support ring, slowly lower the hook; stop and slightly rotate the equipment using the hand chain hoist so that the guides on the equipment contact the temporary thrust block on the structure; slowly lower the hook through the structural support ring, as shown. Figure 33 As shown; 5) Manhole and guide through the fifth layer: When the guide is about to pass through the fifth-layer structural beam, the worker should use a tail rope on the fourth layer to restrain the tank and prevent violent swinging; when the manhole and guide pass through the fifth layer, release the adjusting rope; lower the hook until the manhole is close to the fourth-layer structural beam; 6) Use flame cutting to remove the temporary thrust block on the fifth layer. Finally, position the pad and spot weld it; 7) Manhole and guide through the fourth-layer structural beam: Slowly lower the hook to allow the manhole to enter the fourth-layer structural hole; slowly lower the hook to allow the guide to enter the structural beam; 8) Weld temporary rotation limit blocks on the fifth layer: When the equipment base is 100 mm above the equipment support ring, stop; weld the temporary rotation limit blocks to the fifth-layer structural beam next to the equipment base to correct the equipment orientation; for precise positioning, a series of temporary limit blocks should be welded at the edge of the structural support; lower the hook to place the equipment base on the structural support; take care to protect the tank during welding, such as Figure 34 As shown; 9) Leveling, adding adjusting shims and welding; 10) Resetting the manhole cover: After hoisting, reinstall the manhole cover, and have qualified personnel manage the flanges; 11) Refill the equipment with nitrogen for protection; 12) Weld the two guides back to the tank body, and then touch up the paint.

[0065] Although the present invention has been described in detail with reference to the accompanying drawings and preferred embodiments, the invention is not limited thereto. Various equivalent modifications or substitutions can be made to the embodiments of the invention by those skilled in the art without departing from the spirit and essence of the invention, and such modifications or substitutions should all be within the scope of the invention. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the invention should also be covered within the protection scope of the invention. Therefore, the protection scope of the invention should be determined by the scope of the claims.

Claims

1. A method for installing an ultra-large LNG module tower device, characterized in that, Includes the following steps: S1. Confirmation of the hoisting object: Based on the failure modes of tower hoisting, confirm the hoisting object, including the tower body section, lifting lugs, shaft lugs, and tail lugs; S2. Confirmation of lifting parameters: Clarify the lifting parameters, including weight center of gravity, lifting point, lifting lug parameters and lifting coefficient, to ensure the safety and efficiency of the lifting process; S3. Calculation method selection: Select the calculation method according to the situation, and use mechanical formulas or finite element analysis to check the combined stress of the tower section to ensure that the structural strength meets the standards. S4. Confirmation of phased planning: Based on the preliminary calculations, the ultra-large tower equipment is planned in phases, and it is installed step by step in narrow spaces to improve the controllability of the construction period; S5. Control of sliding and lifting: Within complex modules, heavy equipment is moved and its position adjusted gradually through the coordinated sliding and lifting, thus successfully completing the installation process.

2. The installation method for the ultra-large LNG module tower equipment as described in claim 1, characterized in that, The confirmation of the hoisting object in S1 specifically includes the following steps: S11. Combined stress check of tower body section: Based on the tower parameters and actual weight distribution, use the formulas in the "Mechanical Design Handbook" or PV Elite software to perform modeling and analysis, calculate the stress and bending moment distribution of each section of the tower body during the hoisting process, and ensure that the combined stress does not exceed the allowable stress of the material to prevent plastic deformation. S12. Lifting lug strength verification: In accordance with HG / T21574-2008 "Technical Requirements for Lifting Lugs and Engineering of Chemical Equipment", the lifting lugs are selected, and the sum of the tensile stress and bending stress borne by the pipe shaft is calculated and compared with the allowable tensile stress of the pipe shaft to ensure that the strength of the lifting lugs meets the lifting requirements. S13. Calculation of local stress in the lug: For lifting points using lugs, a detailed analysis is conducted on the relationship between the magnitude of the local stress in the lug and the magnitude of the load borne by the lifting point, the structural dimensions of the lug, and the length of the boom. S14. Calculation of tail lugs: Set 1 to 2 tail lugs on the anchor bolt seats of the skirt seat. According to the provisions of HG / T21574-2008, the strength of the skirt seat is calculated in combination with the tangential shear force and bending moment generated by the tail lugs inside the skirt seat.

3. The installation method for the ultra-large LNG module tower equipment as described in claim 2, characterized in that, In the strength check of the lifting lug in S12, for the side wall type lifting lug, its characteristics of high installation position, easy installation of accessories, short boom and small local stress need to be considered for comprehensive evaluation.

4. The installation method for the ultra-large LNG module tower equipment as described in claim 2, characterized in that, In the calculation of local stress of the lug in S13, if the minimum thickness of the cylinder meets the standard requirements, no local stress calculation is performed; however, when the thickness of the cylinder exceeds the specification requirements or the structural dimensions are modified, the lug body and local stress must be recalculated to ensure safety.

5. The installation method for the ultra-large LNG module tower equipment as described in claim 1, characterized in that, The confirmation of the hoisting parameters for S2 specifically includes the following steps: S21. Determining the weight and center of gravity: Accurately measure the weight of the tower body and its accessories, and determine the overall center of gravity position; the center of gravity position is crucial for setting the lifting points and selecting the size of the lifting lug structure, and directly affects the balance and stability during the lifting process. S22. Lifting point setting: Based on the weight distribution and center of gravity, the lifting points should be set reasonably to optimize the bending moment distribution of the tower body section; the lifting points should be set at a higher position to facilitate the installation of the lower accessories, but the mechanical balance and safety during the lifting process should be comprehensively considered. S23. Selection of lifting lug parameters: including the type, extension length, and orientation of the lifting lug, which must be selected based on the specific location of the lifting point and the mechanical requirements during the lifting process; the extension length and orientation of the shaft lug must fully consider the local stress caused by it and the interference with the pre-welded parts. S24. Selection of Lifting Coefficient: Select an appropriate lifting coefficient based on the dynamic characteristics during the lifting process.

6. The installation method for the ultra-large LNG module tower equipment as described in claim 5, characterized in that, In determining the center of gravity in S21, the overall center of gravity is determined by taking into account the weight of all accessories, including insulation layer, fireproof layer, ladder, platform, and pipelines, as well as the weight of the tower body and its accessories.

7. The installation method for the ultra-large LNG module tower equipment as described in claim 5, characterized in that, In selecting the lifting coefficient for S24, 1.65 is used when there are no standard requirements, and 2.0 is used when there are engineering standards requirements; when calculating the lifting weight of the tower and comprehensively considering safety risks, a lower lifting coefficient is selected.

8. The installation method for the ultra-large LNG module tower equipment as described in claim 1, characterized in that, The selection of the calculation method for S3 specifically includes the following steps: S31. Mechanical Formula: For towers with uniform diameter, uniform wall thickness, and no concentrated mass, mechanical formulas are used to check the combined stress. S32. Finite Element Analysis: For tower structures under complex working conditions, the finite element analysis method is used for simulation calculation; a precise finite element model is established using professional software, high-quality mesh elements are divided, and the stress distribution during the actual hoisting process is simulated.

9. The installation method for the ultra-large LNG module tower equipment as described in claim 1, characterized in that, The confirmation of the step-by-step planning in S4 specifically includes the following steps: S41, Modular Design: The ultra-large tower equipment is broken down into several modules, and the assembly and debugging of each module are completed in the manufacturing plant, reducing the workload and risks of on-site installation. S42. Installation sequence planning: Based on the equipment structure characteristics and site conditions, develop a detailed step-by-step installation sequence diagram, clearly defining the installation content, required tooling and equipment, personnel configuration and safety measures for each step, to ensure that the installation process proceeds in an orderly manner; S43. Operations in confined spaces: For the enclosed, crowded, and limited-capacity confined space environment of the LNG upper module, develop an operation plan, including equipment transportation route planning, temporary support structure setting, and selection and adjustment of installation tools, to ensure that the installation task is completed efficiently in the limited space.

10. The installation method for the ultra-large LNG module tower equipment as described in claim 1, characterized in that, The control of the sliding and lifting of S5 specifically includes the following steps: S51. Sliding system installation: Install sliding rails and sliding devices to ensure that heavy equipment moves smoothly and steadily in the horizontal direction; S52. Lifting System Configuration: Select appropriate lifting equipment and configure it according to the weight of the equipment and the required lifting height; during the lifting process, the lifting speed and synchronization must be strictly controlled to ensure that the equipment rises smoothly in the vertical direction and avoids tilting or shaking; S53. Coordinated Control Strategy: Formulate a coordinated control strategy for sliding and jacking, and clarify the division of tasks and operation sequence for each stage.

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