LNG double-wall pipe welding structure and welding method thereof

Abstract

The invention provides an LNG (Liquefied Natural Gas) double-wall pipe welding structure. The LNG double-wall pipe welding structure comprises a first group of double-wall pipes and a second group of double-wall pipes, the first group of double-wall pipes comprises a first inner pipe and a first outer pipe; the first outer pipe is sleeved outside the first inner pipe; the second group of double-wall pipes comprises a second inner pipe and a second outer pipe; the second inner pipe is sleeved with the second outer pipe, and the extending end of the first inner pipe and the extending end of the second inner pipe are welded after being in butt joint; the first half pipe and the second half pipe are buckled at the butt joint position of the first outer pipe and the second outer pipe, and the first half pipe, the second half pipe, the first outer pipe and the second outer pipe form a smooth tubular outer wall and then are welded. The integral structure of the first group of double-wall pipes and the integral structure of the second group of double-wall pipes are subjected to butt welding, so that the technical problem that an integral segmented welding structure and an integral segmented welding method are lacked in the prior art is solved.

Description

Technical field:

[0001] The invention relates to the field of welding, in particular to an LNG double-wall pipe welding structure and a welding method thereof. Background technology:

[0002] For the installation of LNG double-wall pipes, due to the special structure of double-wall pipes, it is necessary to complete the cutting of each pipe section in the workshop according to the design drawings, and then transport it to the site. According to the method of "first assemble a section of inner pipe, and then assemble the corresponding outer pipe", the installation construction is carried out in sections according to the designed welding points.

[0003] The installation process of double-wall pipes is complicated, and a lot of welding is required on site. Due to the complex construction environment on board, installation according to existing practices is not only inefficient, but also increases safety hazards in disguise due to the large amount of welding workload.

[0004] An LNG double-wall pipe welding structure is urgently needed to help solve the technical problem of lacking an integral segmented welding structure and welding method in the prior art. Summary of the invention:

[0005] In one embodiment, the present invention provides an LNG double-wall pipe welding structure, which is butt-welded by the overall structure of the first group of double-wall pipes and the second group of double-wall pipes, which helps to solve the technical problem of the lack of an overall segmented welding structure and welding method in the prior art.

[0006] The LNG double-wall pipe welding structure comprises a first group of double-wall pipes and a second group of double-wall pipes;

[0007] The first double set of double walls includes a first inner tube and a first outer tube;

[0008] The first outer tube is disposed outside the first inner tube and supported between the first outer tube and the first inner tube by a first annular support member, and the first inner tube extends out from one end of the first outer tube;

[0009] The second set of double-walled tubes includes a second inner tube and a second outer tube;

[0010] The second outer tube is sleeved outside the second inner tube and supported between the second outer tube and the second inner tube by a second annular support member, and the second inner tube extends out from one end of the second outer tube, and the extended end of the first inner tube and the extended end of the second inner tube are butt-jointed and then welded;

[0011] The first half tube and the second half tube are buckled at the joint of the first outer tube and the second outer tube, and are welded after forming a smooth tubular outer wall with the first outer tube and the second outer tube.

[0012] In one embodiment, the first half pipe and the second half pipe are 200 mm.

[0013] In one embodiment, the first supporting member supports and the second supporting member supports are multiple and are arranged at intervals along the length direction of the first group of double-walled tubes and the second group of double-walled tubes.

[0014] In one embodiment, the LNG double-wall pipe welding structure is arranged on an LNG ship, and the first inner pipe and the second inner pipe are used for LNG transportation.

[0015] In one embodiment, the present invention further provides a welding method for an LNG double-wall pipe welding structure. Based on the LNG double-wall pipe welding structure, the welding method for the LNG double-wall pipe welding structure includes:

[0016] The first inner tube and the second inner tube in the first group of double-wall tubes and the second group of double-wall tubes are butted and then welded;

[0017] The first half pipe and the second half pipe are spot welded and welded after centering.

[0018] In one embodiment, the LNG double-walled pipes on the ship are divided into multiple groups, and each group of the LNG double-walled pipes is welded after being spliced ​​end to end on site according to the above method. Description of the drawings:

[0019] Figure 1 This is a schematic diagram of a LNG double-wall pipe welding structure in one embodiment of the present invention;

[0020] Figure 2 This is a schematic diagram of the AA cross-section structure of another embodiment of the present invention;

[0021] Figure 3 The figure is a schematic flow chart of a welding method for a LNG double-wall pipe welding structure in another embodiment of the present invention.

[0022] Reference numerals:

[0023] The first set of double wall pipe 1

[0024] First inner tube 11

[0025] First outer tube 12

[0026] The first support member 13

[0027] The second support member 23

[0028] The second set of double wall pipe 2

[0029] Second inner tube 21

[0030] Second outer tube 22

[0031] First Half Pipe 3

[0032] Second Half Pipe 4 Specific implementation method:

[0033] The present invention uses a HALF-shaped short tube as a design method for on-site welding of an outer tube, so that a complete pipeline (including an inner tube and an outer tube) can be prefabricated in a workshop first, and after arriving on board, each complete set of pipelines is installed according to the design drawings, and then the pipeline is welded on-site according to the designed position of the HALF-shaped short tube, thereby improving installation efficiency and reducing safety hazards.

[0034] Figure 1 This is a schematic diagram of a LNG double-wall pipe welding structure in one embodiment of the present invention; Figure 2 This is a schematic diagram of the AA cross-section structure of another embodiment of the present invention; Figure 3 FIG. 2 is a flow chart of a welding method for a LNG double-wall pipe welding structure according to another embodiment of the present invention. Figures 1 to 3 As shown, in one embodiment, the present invention provides an LNG double-wall pipe welding structure, the LNG double-wall pipe welding structure comprises a first group of double-wall pipes 1 and a second group of double-wall pipes 2;

[0035] The first group of double-walled tubes includes a first inner tube 11 and a first outer tube 12;

[0036] The first outer tube 12 is sleeved outside the first inner tube 11 and is supported between the first outer tube 12 and the first inner tube 11 by a first annular support member 13, and the first inner tube 11 extends out from one end of the first outer tube 12;

[0037] The second group of double-walled tubes 2 includes a second inner tube 21 and a second outer tube 22;

[0038] The second outer tube 22 is sleeved outside the second inner tube 21 and supported between the second outer tube 22 and the second inner tube 21 by the annular second support member 23. The second inner tube 21 extends out from one end of the second outer tube 22. The extended end of the first inner tube 11 and the extended end of the second inner tube 21 are butt-jointed and then welded.

[0039] The first half tube 3 and the second half tube 4 are buckled at the joint of the first outer tube 12 and the second outer tube 22, and are welded after forming a smooth tubular outer wall with the first outer tube 12 and the second outer tube 22.

[0040] In one embodiment, the first half pipe 3 and the second half pipe 4 are 200 mm.

[0041] The invention consists of a 200MM long half-shaped half-tube 1 and a 200MM long half-shaped half-tube 2.

[0042] In one embodiment, the first support member 13 and the second support member 23 are multiple and are arranged at intervals along the length direction of the first group of double-walled tubes 1 and the second group of double-walled tubes 2 .

[0043] In one embodiment, the LNG double-wall pipe welding structure is arranged on an LNG ship, and the first inner pipe and the second inner pipe are used for LNG transportation.

[0044] In one embodiment, the present invention provides a welding method for an LNG double-wall pipe welding structure. Based on the LNG double-wall pipe welding structure, the welding method for the LNG double-wall pipe welding structure includes:

[0045] The first inner tube 11 and the second inner tube 21 in the first group of double-walled tubes 1 and the second group of double-walled tubes 2 are butt-jointed and then welded;

[0046] The first half pipe 3 and the second half pipe 4 are spot welded and welded after centering.

[0047] The present invention is to adjust the outer tubes on both sides to the half-shaped half-tube length on site and then perform on-site butt welding to complete the pipeline installation. After the on-site butt welding of the inner tube is completed, the outer tubes on both sides are adjusted to the half-shaped short tube length, the half-tube 1 and the half-tube 2 are positioned between the outer tubes on both sides, spot welded and centered, and then welded to complete the on-site installation of the outer tubes.

[0048] In one embodiment, the LNG double-walled pipes on the ship are divided into multiple groups, and each group of the LNG double-walled pipes is welded after being spliced ​​end to end on site according to the above method.

[0049] Beneficial effects:

[0050] The present invention utilizes a small number of HALF-shaped short pipes to divide the complete pipeline into several groups. After each group of pipelines is prefabricated in a workshop, each group of pipelines is installed and spliced ​​on site, which can greatly reduce the amount of on-site splicing. Most of the on-site splicing work is prefabricated in the workshop in advance, thereby improving installation efficiency and reducing safety hazards.

[0051] It can greatly improve the on-site installation efficiency and safety of LNG double-wall pipes and effectively reduce safety hazards.

[0052] The installation process has been optimized to achieve the goal of reducing costs and increasing efficiency, thereby improving economic benefits.

[0053] Simplify the installation process and save the cost of ship construction;

[0054] It solved the originally complicated installation process of LNG double-wall pipes and improved the overall technical level;

[0055] Most of the pipe sections are manufactured in the workshop, which reduces the impact of complex environment on the manufacturing quality;

[0056] It is suitable for the production and installation of LNG double-wall pipes and can be widely used in ship design and construction to improve economic benefits.

Claims

1. A LNG double-wall pipe welding structure, characterized in that: The LNG double-wall pipe welding structure comprises: A first group of double-walled tubes (1), the first group of double-walled tubes comprising a first inner tube (11) and a first outer tube (12); The first outer tube (12) is sheathed outside the first inner tube (11) and supported between the first outer tube (12) and the first inner tube (11) by a first annular support member (13), and the first inner tube (11) extends out from one end of the first outer tube (12); A second group of double-walled tubes (2), the second group of double-walled tubes (2) comprising a second inner tube (21) and a second outer tube (22); The second outer tube (22) is sleeved outside the second inner tube (21) and supported between the second outer tube (22) and the second inner tube (21) by a second annular support member (23), and the second inner tube (21) extends out from one end of the second outer tube (22), and the extended end of the first inner tube (11) and the extended end of the second inner tube (21) are butt-jointed and then welded; A first half tube (3) and a second half tube (4); the first half tube (3) and the second half tube (4) are buckled at the joint of the first outer tube (12) and the second outer tube (22), and are welded after forming a smooth tubular outer wall with the first outer tube (12) and the second outer tube (22).

2. The LNG double-wall pipe welding structure according to claim 1 is characterized in that: The first half pipe (3) and the second half pipe (4) are 200 mm.

3. The LNG double-wall pipe welding structure according to claim 2 is characterized in that: The first supporting member (13) and the second supporting member (23) are multiple and are arranged at intervals along the length direction of the first group of double-walled tubes (1) and the second group of double-walled tubes (2).

4. The LNG double-wall pipe welding structure according to claim 3 is characterized in that: The LNG double-wall pipe welding structure is arranged on an LNG ship, and the first inner pipe and the second inner pipe are used for LNG transportation.

5. A welding method for a LNG double-wall pipe welding structure, characterized in that: Based on the LNG double-wall pipe welding structure according to any one of claims 1 to 4, the welding method of the LNG double-wall pipe welding structure includes: The first inner tube (11) and the second inner tube (21) in the first group of double-walled tubes (1) and the second group of double-walled tubes (2) are butt-jointed and then welded; The first half pipe (3) and the second half pipe (4) are spot welded and welded after centering.

6. The welding method of the LNG double-wall pipe welding structure according to claim 5 is characterized in that: The LNG double-walled pipes on the ship are divided into multiple groups, and each group of the LNG double-walled pipes is welded after being spliced ​​end to end on site according to the above method.

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