A method for constructing key sections of an LNG carrier

Abstract

This invention discloses a method for constructing key nodes of LNG carrier sections, comprising the following steps: fabricating a jig; marking and punching points on the circular template of the jig; hoisting the inner longitudinal wall panel onto the horizontal jig and aligning its edge with the punched points on the circular template; then hoisting the diagonal side panel onto the circular jig and connecting it to the inner longitudinal wall panel; spot welding the diagonal side panel to the circular template; welding the butt joint between the diagonal side panel and the inner longitudinal wall panel using a fully automatic welding machine; installing multiple support plates on the free edge of the diagonal side panel; successively installing other components on the section; and removing the support plates after installation. This invention, by fabricating a dedicated jig and using support plates to further fix the edge of the diagonal side panel, ensures that the overall deformation during the splicing of the inner longitudinal wall panel and diagonal side panel and subsequent hoisting is controllable.

Description

Technical Field

[0001] This invention relates to the field of shipbuilding technology, and in particular to a method for constructing key sections of an LNG carrier. Background Technology

[0002] As is well known, LNG carriers are one of the three crown jewels of the shipbuilding industry, renowned for transporting cryogenic liquefied natural gas. Compared to other conventional main ship types, LNG carriers have several critical structural nodes, which are also the most demanding parts of the entire ship's construction. Through the construction of a series of LNG carriers, the connection between the diagonal side plates and the inner longitudinal wall plates is now achieved using curved plates instead of the original three-plate alignment structure, reducing construction difficulty. However, controlling the deformation at the splicing of the curved plates and the inner longitudinal wall plates remains a significant factor affecting the construction quality of this critical node. Summary of the Invention

[0003] In view of this, the present invention provides a method for constructing key nodes of LNG ship sections. This method can reduce welding deformation at key nodes of LNG ship during construction, thereby ensuring that the construction quality of these key nodes meets the requirements, avoiding unnecessary rework, and helping to improve the construction quality of LNG ship.

[0004] A method for constructing key sections of an LNG carrier includes the following steps:

[0005] S1, Making the tire frame;

[0006] Specifically, first, a horizontal jig is made and placed on the ground; then, according to the length of the inner oblique side plate, multiple rotating templates are fixed on one side of the horizontal jig, with the corners of the rotating templates facing the ground; then, a side tie bar is set along the length of the inner oblique side plate, so that the side tie bar is connected to the ends of all the rotating templates to form a rotating jig, and the upper edge of the side tie bar is flush with the upper edge of the lower folded edge of the rotating template;

[0007] S2, tap out the punch point at a position 150mm away from the center of the arc of the rotating template;

[0008] S3, hoist the inner longitudinal wall plate onto the horizontal jig and align its edge with the punch point on the rotating template, then hoist the oblique side plate onto the rotating jig and align its edge with the punch point to connect with the inner longitudinal wall plate.

[0009] S4. Spot weld the oblique side plate to the round template and use a fully automatic welding machine to weld the butt joint between the oblique side plate and the inner longitudinal wall plate.

[0010] S5, Install multiple support plates on the free edge of the diagonal plate. One end of the support plate is clamped on the free edge of the diagonal plate and welded to the diagonal plate, and the other end is welded to the edge tie rod.

[0011] S6, install other components on the segment one after another, and remove the mast after installation.

[0012] Preferably, the specific steps for making the horizontal frame in step S1 are as follows: multiple horizontal tie bars and multiple vertical tie bars are fixed together in an interlaced manner to form the frame support frame of the horizontal frame; then, a column is vertically fixed at each intersection of the horizontal tie bars and the vertical tie bars, and the column is supported on the ground.

[0013] Preferably, the circular template is vertically fixed on the longitudinal tie rod, and the upper edge of the folded edge of the end of the template that is welded to the longitudinal tie rod is flush with the upper surface of the longitudinal tie rod.

[0014] Preferably, the spacing between two adjacent rotating templates is 3000-3500mm, and the spacing between two adjacent transverse tie rods and two adjacent longitudinal tie rods is 1000-1500mm.

[0015] Preferably, the distance between the outermost circular template and the end of the oblique plate is 500-1000mm.

[0016] Preferably, the rounding template is a folded plate with its two folded edges transitioning through a circular arc.

[0017] Preferably, the edge tie is made of angle steel, and its bends face upwards.

[0018] The beneficial effects of this invention are:

[0019] This invention utilizes a specialized jig, along with a support plate to further secure the edges of the diagonal side panels, ensuring controllable overall deformation during the splicing of the inner longitudinal wall panels and diagonal side panels, as well as subsequent hoisting. By flexibly adjusting the number and placement of the rotating templates according to the length of the diagonal side panels, labor waste in jig fabrication is reduced while ensuring controllable deformation. Furthermore, the innovative use of all-position welding machines and submerged arc welding machines to fill the cover surface replaces the original manual welding method, improving welding efficiency and quality, and guaranteeing the construction quality of key nodes. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram showing the inner longitudinal wall panel and the diagonal side panel suspended on the jig.

[0022] Figure 2 This is a schematic diagram of the tire frame structure.

[0023] Figure 3 This is a schematic diagram of the rotating template.

[0024] Figure 4 This is a schematic diagram of the structure of the horse board.

[0025] The meanings of the labels in the diagram are as follows:

[0026] 1 is the horizontal frame, 11 is the transverse tie rod, 12 is the longitudinal tie rod, and 13 is the upright.

[0027] 2 is the rotary mold frame, 21 is the rotary template, and 22 is the edge tie rod;

[0028] 3 represents the diagonal radical;

[0029] 4 is the inner longitudinal wall panel;

[0030] 5 represents the horse board. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the invention is described below with reference to specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0032] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. The singular forms “a,” “the,” and “the” as used in this disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

[0033] To better understand the technical solution of the present invention, the present invention will be described in detail below with reference to the accompanying drawings.

[0034] This invention provides a method for constructing key nodes of LNG ship sections, specifically including the following steps:

[0035] S1, Making the tire frame.

[0036] The jig includes a horizontal jig and a circular jig that is arranged along the length of the diagonal plate on one side of the horizontal jig.

[0037] The horizontal frame 1 includes multiple horizontal tie bars 11 and longitudinal tie bars 12 that are interwoven, and a column 13 that is vertically fixed at the intersection of the horizontal tie bars 11 and the longitudinal tie bars 12. The column 13 is supported on the ground.

[0038] The rotating jig 2 includes multiple rotating templates 21 and a side tie rod 22. The multiple rotating templates 21 are fixed at equal intervals along the length of the inner oblique side plate 3 on one side of the horizontal jig 1. The side tie rod 22 is arranged along the length of the inner oblique side plate 3 and fixed to the ends of all the rotating templates 21. That is, the rotating templates 21 are vertically fixed on the longitudinal tie rod 12, and the upper edge of the folded edge of the end of the template 21 that is welded to the longitudinal tie rod 12 is flush with the upper surface of the longitudinal tie rod 12.

[0039] The number of the rotating templates 21 is determined by the arrangement position and the length of the oblique plate 3, and the spacing between two adjacent rotating templates 21 is 3000-3500mm. After the oblique plate 3 is mounted on the jig, the distance between the outermost rotating template and the end of the oblique plate should be 500-1000mm. In this embodiment, three rotating templates 21 are provided, and the spacing between two adjacent rotating templates 21 is 3000-3500mm, so as to ensure that the deformation of the oblique plate 3 is controllable when welding heat input at this location.

[0040] The circular template 21 is a folded plate with its two folded edges transitioning through a circular arc. The length of the folded edges is slightly greater than the length of the diagonal plate. In this embodiment, the included angle between the two folded edges is 135°, and the two folded edges transition through a circular arc of R150mm.

[0041] In this embodiment, the horizontal tie rod 11, the vertical tie rod 12, the column 13 and the edge tie rod 22 are all made of 150*150 angle steel, and the opening of the bend of the edge tie rod 22 faces upward.

[0042] Specifically, the steps for making the jig are as follows:

[0043] First, construct the horizontal jig 1: fix multiple transverse tie rods 11 and multiple longitudinal tie rods 12 together in a crisscross pattern to form the jig support frame of the horizontal jig 1; then, vertically fix a column 13 at each intersection of the transverse tie rods 11 and the longitudinal tie rods 12, with the column 13 supporting the ground; the spacing between two adjacent transverse tie rods 11 and two adjacent longitudinal tie rods 12 is 1000-1500mm, providing workers with construction space while ensuring the strength of the jig;

[0044] Then, make the rotating frame 2: fix multiple rotating templates 21 on one side of the horizontal frame 1 according to the length of the inner oblique side plate 3. The corner of the rotating template 21 faces the ground. Then set a side tie bar 22 along the length of the inner oblique side plate 3 so that the side tie bar 22 is connected to the ends of all the rotating templates 21 to form the rotating frame 2. The upper edge of the side tie bar 22 is flush with the upper edge of the lower folded edge of the rotating template 21.

[0045] S2, a punch mark is made at a position 150mm away from the center of the arc of the rotating template 21. The punch mark serves as the positioning reference point for the inner longitudinal wall plate 4 during assembly.

[0046] S3, hoist the inner longitudinal wall plate 4 onto the horizontal jig 1 and slowly adjust its position using a hand-operated hoist so that its edge is aligned with the punch point on the rotating template 21. Then hoist the oblique side plate 3 onto the rotating jig 2 and align its edge with the punch point so that it can be connected with the inner longitudinal wall plate 4. The gap between the inner longitudinal wall plate 4 and the oblique side plate 3 is controlled within 2mm.

[0047] S4. Spot weld the oblique side plate 3 to the round template 21. Use an all-position welding machine and a submerged arc automatic welding machine to weld the butt joint between the oblique side plate 3 and the inner longitudinal wall plate 4. After welding, check the straightness of the butt joint surface.

[0048] S5, multiple support plates 5 are installed on the free side of the diagonal plate 3. One end of the support plate 5 is stuck on the free side of the diagonal plate 3 and welded to the diagonal plate 3, and the other end is welded to the edge tie strip 22.

[0049] S6, install other components on the segment one after another, and remove the mast 5 after installation is completed.

[0050] It should be understood that the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A method for constructing key sections of an LNG carrier, characterized in that, Specifically, the following steps are included: S1, Making the tire frame; Specifically, first, a horizontal jig is made and placed on the ground; then, according to the length of the diagonal plate, multiple rotating templates are fixed on one side of the horizontal jig, with the corners of the rotating templates facing the ground. Then, a side tie bar is set along the length of the diagonal plate, so that the side tie bar is connected to the ends of all the rotating templates to form a rotating jig. The upper edge of the side tie bar is flush with the upper edge of the lower folded edge of the rotating template. The circular template is a folded plate with its two folded edges transitioned by a circular arc. S2, tap out the punch point at a position 150mm away from the midpoint of the arc of the rotating template; S3, hoist the inner longitudinal wall plate onto the horizontal jig and align its edge with the punch point on the rotating template, then hoist the oblique side plate onto the rotating jig and align its edge with the punch point to connect with the inner longitudinal wall plate. S4. Spot weld the oblique side plate to the round template and use a fully automatic welding machine to weld the butt joint between the oblique side plate and the inner longitudinal wall plate. S5, Install multiple support plates on the free edge of the diagonal plate. One end of the support plate is clamped on the free edge of the diagonal plate and welded to the diagonal plate, and the other end is welded to the edge tie rod. S6, install other components on the segment one after another, and remove the mast after installation.

2. The method for constructing key nodes of LNG ship sections according to claim 1, characterized in that, The specific steps for making the horizontal jig in step S1 are as follows: multiple horizontal tie rods and multiple vertical tie rods are fixed together in an interlaced manner to form the jig support frame of the horizontal jig; then, a column is vertically fixed at each intersection of the horizontal tie rods and the vertical tie rods, and the column is supported on the ground.

3. The method for constructing key nodes of LNG ship sections according to claim 2, characterized in that, The circular template is vertically fixed on the longitudinal tie rod, and the upper edge of the folded edge of the end that is welded to the longitudinal tie rod is flush with the upper surface of the longitudinal tie rod.

4. The method for constructing key nodes of LNG ship sections according to claim 2, characterized in that, The spacing between two adjacent circular templates is 3000-3500mm, and the spacing between two adjacent horizontal tie rods and two adjacent vertical tie rods is 1000-1500mm.

5. The method for constructing key nodes of LNG ship sections according to claim 1, 3, or 4, characterized in that, The distance between the outermost circular template and the end of the oblique plate is 500-1000mm.

6. The method for constructing key nodes of LNG ship sections according to claim 1, characterized in that, The edge tie is made of angle steel, and its bends face upwards.

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