A method for constructing a cryogenic pipe unit of an LNG carrier

Abstract

This invention discloses a method for constructing cryogenic pipe units for LNG carriers. The method involves fabricating a jig with equal-height jig columns, assembling the lower frame on the jig, installing unit columns between the jig columns on the lower frame, hoisting the lower frame onto a platform equipped with multiple lifting piers, adjusting the height of the lifting piers to ensure the lower surfaces of the lower frame are on the same horizontal plane, and installing outfitting within the lower frame. The upper frame is then assembled on the jig, and outfitting within the upper frame is installed. The assembled upper frame is hoisted onto the platform and joined with the lower frame to form a unit frame. Outfitting is then installed to align the outfitting within the lower and upper frames, ensuring the unit columns are staggered between the jig columns and the lower frame. This method requires only cutting jig columns of equal length, reducing construction difficulty, improving cutting efficiency, and enabling layered construction of unit frames, thus increasing jig utilization, shortening the production cycle, and saving production costs.

Description

Technical Field

[0001] This invention relates to the field of shipbuilding, and in particular to a method for constructing cryogenic pipe units for LNG carriers. Background Technology

[0002] The cryogenic piping on the deck of an LNG carrier is a core component of the LNG carrier's cryogenic system. The construction of cryogenic piping units is lengthy, complex, and requires extremely high precision. An LNG carrier's cryogenic piping unit consists of a unit frame and unit columns supporting the unit frame on the deck. In existing technologies, the lower surface of the unit frame is flat, but the deck height where the cryogenic piping unit is placed varies. Therefore, the height of the unit columns supporting the lower frame on the deck also varies. As described in Chinese invention patent application number 202210819537, "A Construction Method for a Large Cryogenic Piping Unit on the Deck of an LNG Carrier," the jig used to produce the cryogenic piping unit requires cutting jig columns of different heights to accommodate unit columns of varying heights and adjust the jig's flatness. This method results in low production efficiency, long production cycles, and high costs. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this application provides a method for constructing cryogenic pipe units for LNG carriers, thereby solving the technical problems of low production efficiency, long cycle time, and high cost in the construction of cryogenic pipe units for LNG carriers.

[0004] To achieve the objectives of the invention described above, the technical solution provided by this invention patent is as follows:

[0005] A method for constructing a cryogenic pipe unit for an LNG carrier specifically includes the following steps:

[0006] S1. Weld and manufacture the frame body at the construction site, and fix the frame body at the construction site;

[0007] S2. Weld the lower end faces of multiple frame uprights to the upper surface of the frame to form a frame, and set the distance between the upper end face of the frame uprights and the upper surface of the frame to be 0.5 to 0.8 meters.

[0008] S3. Complete the splicing of the lower frame of the unit frame on the jig, and install the unit columns between the jig columns on the lower frame.

[0009] S4. Hoist the assembled lower frame onto a platform equipped with multiple lifting blocks. Each frame column corresponds to one lifting block. Adjust the height of the lifting blocks so that the lower surface of the lower frame is on the same horizontal plane. Install the outfitting inside the lower frame.

[0010] S5. Complete the splicing of the upper frame of the unit frame on the jig, and install the outfitting inside the upper frame inside the upper frame.

[0011] S6. Hoist the assembled upper frame to the platform and join it with the lower frame to form a unit frame;

[0012] S7. Install the outfitting assembly that brings together the outfitting in the lower frame with the outfitting in the upper frame, thus completing the construction of the cryogenic pipe unit for the LNG ship.

[0013] In one implementation, S1 includes the following steps:

[0014] S11. Mark the transverse and longitudinal positioning lines of the formwork at the construction site.

[0015] S12. Based on the design dimensions of the lower frame, mark out the transverse auxiliary lines and longitudinal auxiliary lines on the construction site, which are parallel to the transverse frame positioning line and the longitudinal frame positioning line, respectively.

[0016] S13. Lay channel steel along the horizontal and vertical auxiliary lines on the construction site as the frame of the lower frame. Weld and fix the horizontal and vertical channel steel at the intersection. Weld and fix both the horizontal and vertical channel steel to the pre-embedded iron on the construction site.

[0017] In one implementation, both the channel steel and the jig column in step S13 are No. 20 channel steel.

[0018] In one implementation, the lateral and longitudinal distances between the support columns of the frame in step S2 are the same.

[0019] In one embodiment, the lateral and longitudinal distances between the support columns of the frame are both 1.5 meters.

[0020] In one embodiment, the distance between the upper end face of the support column and the upper surface of the support frame is 0.5 meters.

[0021] In one implementation, in step S2, after cutting the jig frame columns to the same length, the jig frame columns are welded to the upper surface of the jig frame body.

[0022] In one implementation, in step S2, the jig frame column is first welded to the upper surface of the jig frame body, and then the jig frame column is cut to the same length.

[0023] In one implementation, in step S2, a theodolite is used to select a horizontal line along the upper surface of the frame as the horizontal line of the frame, and the frame column is cut so that the vertical distance between the upper end face of the frame column and the horizontal line of the frame is 0.5 meters.

[0024] In one embodiment, the theodolite is a laser theodolite.

[0025] The method of the present invention has achieved the following positive and beneficial effects through practice:

[0026] The LNG carrier cryogenic pipe unit construction method of this invention involves fabricating a jig with equal-height jig columns, assembling the lower frame on the jig, installing unit columns between the jig columns on the lower frame, hoisting the lower frame onto a platform equipped with multiple lifting piers, adjusting the height of the lifting piers to ensure the lower surfaces of the lower frame are on the same horizontal plane, and installing outfitting within the lower frame. The upper frame is then assembled on the jig, and outfitting within the upper frame is installed. The assembled upper frame is hoisted onto the platform and joined with the lower frame to form a unit frame. Outfitting is then installed to allow the outfitting within the lower frame to align with the outfitting within the upper frame, ensuring the unit columns are staggered between the jig columns and the lower frame. This method requires only cutting jig columns of equal length, reducing construction difficulty, improving cutting efficiency, and enabling layered construction of unit frames, thus increasing jig utilization, shortening the production cycle, and saving production costs. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the construction method of the cryogenic pipe unit for LNG ships in the embodiments of this application;

[0028] Figure 2 This is a top view of the tire frame in an embodiment of this application;

[0029] Figure 3 yes Figure 2 Sectional view of AA;

[0030] Figure 4 yes Figure 2 BB section view;

[0031] Figure 5 This is a schematic diagram illustrating the assembly of the lower frame on the jig in an embodiment of this application;

[0032] Figure 6 This is a schematic diagram of a cryogenic tube unit formed by the lower frame and the upper frame being joined together in an embodiment of this application. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the invention is described below with reference to specific examples 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 techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0034] like Figure 1 As shown, a method for constructing a cryogenic pipe unit for an LNG carrier includes the following steps:

[0035] S1. Weld and manufacture the frame 11 at the construction site, and fix the frame 11 to the construction site;

[0036] S2, such as Figures 2 to 4 As shown, the lower end faces of multiple frame columns 12 are welded at equal intervals to the upper surface of the frame frame 11 to form a frame. The upper end faces of the frame columns 12 are set to be at the same distance from the upper surface of the frame frame 12. In order to allow space to place unit columns 21 of different heights in step S3, the distance between the upper end faces of the frame columns 12 and the upper surface of the frame frame 11 is 0.5 to 0.8 meters.

[0037] S3, such as Figure 5 As shown, the lower frame 22 of the unit frame 2 is assembled on the frame 1, and the unit column 21 is installed on the lower frame 22 between the frame columns 12.

[0038] S4. Hoist the assembled lower frame 22 to a platform with multiple lifting blocks. Each frame column 12 corresponds to one lifting block. Adjust the height of the lifting blocks so that the lower surface of the lower frame 22 is on the same horizontal plane. Install the outfitting inside the lower frame 22.

[0039] S5. Complete the splicing of the upper frame 23 on the jig 1, and install the outfitting inside the upper frame 23.

[0040] S6. Hoist the assembled upper frame 23 to the platform and join it with the lower frame 22 to form the unit frame 2;

[0041] S7, such as Figure 6 As shown, an outfitting assembly is installed to bring together the outfitting in the lower frame 22 and the outfitting in the upper frame 23, thus completing the construction of the cryogenic pipe unit 3 for the LNG ship.

[0042] Step S1 includes the following steps:

[0043] S11. Mark the transverse and longitudinal positioning lines of the formwork at the construction site. In this embodiment, the transverse positioning line is the center line of the formwork.

[0044] S12. Based on the design dimensions of the lower frame 22, mark out the transverse auxiliary lines and longitudinal auxiliary lines on the construction site, which are parallel to the transverse frame positioning line and the longitudinal frame positioning line, respectively.

[0045] S13. Lay channel steel along the horizontal and vertical auxiliary lines on the construction site as the frame of the lower frame 22. Weld and fix the horizontal and vertical channel steel at the intersection. Weld and fix both the horizontal and vertical channel steel to the pre-embedded iron on the construction site.

[0046] To save production costs, the channel steel and the jig column 12 in step S13 are both No. 20 channel steel.

[0047] like Figures 2 to 4 As shown, in order to make the frame 1 more suitable for splicing the unit frame 2, the horizontal and vertical distances between the frame columns 12 are set to be the same. In this embodiment, the horizontal and vertical distances between the frame columns 12 are both 1.5 meters.

[0048] In step S2, you can choose to cut the jig frame column 12 to the same length and then weld the jig frame column 12 to the upper surface of the jig frame 11, or you can first weld the jig frame column 12 to the upper surface of the jig frame 11 and then cut the jig frame column 12 to the same length.

[0049] In step S2, to accurately cut the frame column 12, a theodolite is used to select a horizontal line along the upper surface of the frame 11 as the frame horizontal line, and the frame column 12 is cut so that the vertical distance between the upper end face of the frame column 12 and the frame horizontal line is 0.5 meters. In this embodiment, the theodolite is a laser theodolite.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. A method for constructing a cryogenic pipe unit for an LNG carrier, characterized in that, Specifically, the following steps are included: S1. Weld and manufacture the frame body at the construction site, and fix the frame body at the construction site; S2. Weld the lower end faces of multiple frame uprights to the upper surface of the frame to form a frame, and set the distance between the upper end face of the frame uprights and the upper surface of the frame to be 0.5~0.8 meters. S3. Complete the splicing of the lower frame of the unit frame on the jig, and install the unit columns between the jig columns on the lower frame. S4. Hoist the assembled lower frame onto a platform equipped with multiple lifting blocks. Each frame column corresponds to one lifting block. Adjust the height of the lifting blocks so that the lower surface of the lower frame is on the same horizontal plane. Install the outfitting inside the lower frame. S5. Complete the splicing of the upper frame of the unit frame on the jig, and install the outfitting inside the upper frame inside the upper frame. S6. Hoist the assembled upper frame to the platform and join it with the lower frame to form a unit frame; S7. Install the outfitting assembly that brings together the outfitting in the lower frame with the outfitting in the upper frame, thus completing the construction of the cryogenic pipe unit for the LNG ship.

2. The method for constructing a cryogenic pipe unit for an LNG carrier according to claim 1, characterized in that, S1 includes the following steps: S11. Mark the transverse and longitudinal positioning lines of the formwork at the construction site. S12. Based on the design dimensions of the lower frame, mark out the transverse auxiliary lines and longitudinal auxiliary lines on the construction site, which are parallel to the transverse frame positioning line and the longitudinal frame positioning line, respectively. S13. Lay channel steel along the horizontal and vertical auxiliary lines on the construction site as the frame of the lower frame. Weld and fix the horizontal and vertical channel steel at the intersection. Weld and fix both the horizontal and vertical channel steel to the pre-embedded iron on the construction site.

3. The method for constructing a cryogenic pipe unit for an LNG carrier according to claim 2, characterized in that, The channel steel and the support column of the jig in step S13 are both No. 20 channel steel.

4. The method for constructing a cryogenic pipe unit for an LNG carrier according to claim 1, characterized in that, In step S2, the lateral and longitudinal distances between the support columns of the frame are the same.

5. A method for constructing a cryogenic pipe unit for an LNG carrier according to claim 4, characterized in that, The lateral and longitudinal distances between the support columns of the frame are both 1.5 meters.

6. The method for constructing a cryogenic pipe unit for an LNG carrier according to claim 1, characterized in that, The distance between the upper end of the support column and the upper surface of the frame is 0.5 meters.

7. A method for constructing a cryogenic pipe unit for an LNG carrier according to claim 1, characterized in that, In step S2, after cutting the jig frame columns to the same length, the jig frame columns are welded to the upper surface of the jig frame body.

8. A method for constructing a cryogenic pipe unit for an LNG carrier according to claim 1, characterized in that, In step S2, the jig frame columns are first welded to the upper surface of the jig frame body, and then the jig frame columns are cut to the same length.

9. A method for constructing a cryogenic pipe unit for an LNG carrier according to claim 8, characterized in that, In step S2, a theodolite is used to select a horizontal line along the upper surface of the frame as the horizontal line of the frame, and the frame columns are cut so that the vertical distance between the upper end of the frame column and the horizontal line of the frame is 0.5 meters.

10. A method for constructing a cryogenic pipe unit for an LNG carrier according to claim 9, characterized in that, The theodolite is a laser theodolite.

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