Method for manufacturing an LNG tank and an LNG tank

Abstract

The present invention discloses a manufacturing method of an LNG tank and an LNG tank. The manufacturing method includes: Step S1, providing a positioning tooling which includes a positioning plate with positioning holes provided thereon. The tank body, support seat and platform of the LNG tank are respectively manufactured. When manufacturing the support seat, the support seat is assembled with the positioning tooling, and a first installation hole is reamed on the support seat according to the positioning holes. When manufacturing the platform, the platform is assembled with the positioning tooling, and a second installation hole is reamed on the platform according to the positioning holes; Step S2, installing the support seat on the positioning plate through fasteners, hoisting the positioning tooling and the tank body for assembly, and welding and fixing the support seat and the tank body; Step S3, removing the positioning tooling on the tank body; Step S4, hoisting the platform and the tank body for assembly, and connecting the first installation hole and the second installation hole through fasteners. This method can avoid long-time high-altitude hoisting operations, reduce the difficulty of opening holes on the platform, and has high operation efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of pressure vessel manufacturing, and particularly to a manufacturing method of an LNG tank and an LNG tank. Background Art

[0002] An LNG (liquefied natural gas) tank is a common pressure vessel equipment in marine equipment, which is used for storing and transporting liquefied natural gas. An existing LNG tank with a capacity of 1750 m 3 mainly includes a tank body, a support seat and a platform. Among them, the tank body is a pressure vessel, which is used to contain liquefied natural gas. The support seat is welded and installed on the tank body. The support seat is used to install the platform, and the platform is connected to the support seat by bolts. During the manufacturing process of the LNG tank, the support seat is pre-installed on the tank body, and then the fabricated platform is hoisted and installed with the support seat on the tank body. To ensure the position accuracy between the platform and the support seat to ensure the smooth connection of the bolts, a method of matching the holes of the platform and the support seat is usually adopted, that is, the platform and the support seat are hoisted and assembled, and then the corresponding positions on the platform are matched with the support seat to drill holes. Although this manufacturing method can ensure the alignment of the hole positions of the platform and the support seat and ensure the smooth connection of the bolts. However, this method requires the crane to be occupied for a long time, and the operators need to work at high altitude for a long time to drill holes, the difficulty of drilling holes is large, and the operation efficiency is low. Summary of the Invention

[0003] An object of an embodiment of the present invention is to provide a manufacturing method of an LNG tank, which can avoid long-term high-altitude hoisting operations, reduce the difficulty of opening holes on the platform, and has high operation efficiency.

[0004] Another object of an embodiment of the present invention is to provide an LNG tank, which can ensure the smooth installation of the platform and the tank body and is convenient for manufacturing.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] Provide a manufacturing method of an LNG tank, including the following steps:

[0007] Step S1, provide a positioning tooling, the positioning tooling includes a positioning plate, and positioning holes for passing fasteners are provided on the positioning plate. Respectively manufacture the tank body, the support seat and the platform of the LNG tank. When manufacturing the support seat, assemble the support seat with the positioning tooling, and drill first mounting holes on the support seat according to the positioning holes. When manufacturing the platform, assemble the platform with the positioning tooling, and drill second mounting holes on the platform according to the positioning holes;

[0008] Step S2, installing the support seat on the positioning plate through the fastener, hoisting the positioning tool and the tank body for assembly, and welding and fixing the support seat and the tank body;

[0009] Step S3, removing the positioning tool on the tank body;

[0010] Step S4, hoisting the platform and the tank body for assembly, and connecting the first mounting hole and the second mounting hole through the fastener.

[0011] Furthermore, the steps of making the platform are as follows:

[0012] Step S11, assembling the platform, and assembling the positioning tool on the platform;

[0013] Step S12, welding the platform;

[0014] Step S13: drilling the second mounting hole on the platform.

[0015] Furthermore, the manufacturing steps of the platform also include: step S14, pre-installing the fastener, and passing the fastener through the positioning plate and the second mounting hole.

[0016] Furthermore, a first reference line is provided on the positioning tool, and the platform is assembled using the first reference line as a positioning reference.

[0017] Furthermore, a second reference line is drawn on the tank body, and when the positioning tool and the tank body are assembled, the first reference line and the second reference line are aligned to achieve axial positioning between the positioning tool and the tank body, and the radial positioning between the positioning tool and the tank body is achieved by adjusting the angle between the positioning plate of the positioning tool and the horizontal direction.

[0018] Furthermore, when assembling the positioning tool and the tank body, the position of the tank body is adjusted, and the first reference line and the second reference line are aligned in the vertical direction.

[0019] Furthermore, in step S3, after the positioning tool is removed, the LNG tank is surface treated.

[0020] Furthermore, the positioning tooling includes a plurality of positioning plates, and the plurality of positioning plates correspond one-to-one to the plurality of support seats.

[0021] Furthermore, the fastener is a bolt.

[0022] Also provided is an LNG tank manufactured by the above-mentioned manufacturing method of the LNG tank.

[0023] The beneficial effects of the present invention are as follows: By using the positioning tooling to cooperate with the support seat and the platform respectively, the first mounting hole is formed on the support seat by drilling with reference to the positioning holes of the positioning tooling, and the second mounting hole is formed on the platform by drilling with reference to the positioning holes of the positioning tooling. Then, the positioning tooling is assembled with the tank body, and the support seat is welded and fixed. This method enables the support seat on the tank body to cooperate with the platform, so that the platform can be quickly hoisted onto the tank body and assembled with the support seat smoothly. While ensuring the smooth installation of fasteners, since the platform can be welded, drilled and opened on the ground, it is beneficial to reduce the hoisting time during the installation of the platform, reduce high-altitude operations, and thus reduce the drilling difficulty of the platform and improve the operation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention will be further described in detail below with reference to the drawings and embodiments.

[0025] Figure 1 It is a schematic diagram of the LNG tank according to the embodiment of the present invention.

[0026] Figure 2 It is a top view of the tank body according to the embodiment of the present invention.

[0027] Figure 3 It is a schematic diagram of the platform according to the embodiment of the present invention.

[0028] Figure 4 It is a schematic diagram of the positioning tooling according to the embodiment of the present invention.

[0029] In the figure:

[0030] 1, tank body; 11, installation position; 12, second reference line; 2, support seat; 3, platform; 31, bottom plate; 32, second mounting hole; 33, fence; 34, avoidance hole; 4, positioning tooling; 41, first reference line; 42, frame; 43, positioning plate; 44, positioning hole; 5, pipe fitting. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] To make the technical problems solved, the technical solutions adopted and the technical effects achieved by the present invention clearer, the technical solutions of the embodiments of the present invention will be further described in detail below with reference to the drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present invention.

[0032] As Figures 1 to 4 shown, a manufacturing method of an LNG tank provided by the present invention is used to manufacture an LNG tank. In this embodiment, the capacity of the LNG tank is 1750 m 3, which includes a tank body 1, a support base 2 and a platform 3. Among them, the tank body 1 is a pressure vessel with a steel shell, presenting a hollow cylindrical structure, and the tank body 1 is used to contain liquefied natural gas. There are multiple support bases 2, and the multiple support bases 2 are arranged at intervals on the top surface of the tank body 1. The support base 2 is fixedly welded to the tank body 1, and the support base 2 is used to install the platform 3. The platform 3 is arranged horizontally, and the platform 3 includes a bottom plate 31 and a fence 33 arranged at the edge position of the bottom plate 31. The platform 3 is used to install control valves, pipelines, etc. of the LNG tank, so that operators can conduct inspections, valve control, etc. on the LNG tank through the platform 3. Second mounting holes 32 are provided on the bottom plate 31 of the platform 3. Correspondingly, first mounting holes are provided on the support base. The first mounting holes and the second mounting holes 32 are used to pass through fasteners, so that the platform 3 and the support base 2 are fixedly installed through the fasteners. In this embodiment, the fastener is a bolt.

[0033] The manufacturing method of the LNG tank includes the following steps:

[0034] Step S1: Provide a positioning tooling 4, and the positioning tooling 4 includes a frame 42 and multiple positioning plates 43 arranged on the frame 42. The multiple positioning plates 43 correspond to the multiple support bases 2 one by one. In this embodiment, the number of both the positioning plates 43 and the support bases 2 is eight. The eight positioning plates 43 are divided into two rows along the width direction (illustrated Y direction) of the frame 42, and four positioning plates 43 are distributed in each row. The four positioning plates 43 in each row are spaced apart along the length direction (illustrated X direction) of the frame 42. Positioning holes 44 for passing through fasteners are provided on the positioning plates 43.

[0035] Manufacture the tank body 1, the support base 2 and the platform 3 of the LNG tank respectively. The tank body 1 is made of metal plates. The metal plates are rolled and welded to form several barrel sections. The several barrel sections are spliced along the length direction of the tank body 1 into a cylindrical cylinder, and then heads are welded at both ends of the cylinder to form the sealed tank body 1. Finally, pipe fittings 5 are installed on the tank body 1. The pipe fittings 5 include pipe joints for connecting the inside and outside of the tank body 1, manhole assemblies for maintenance, and connecting pipes for other functions.

[0036] The support base 2 is welded by steel plates. The support base 2 serves to support the platform 3. The support base 2 has a mounting surface for abutting against the platform 3, and first mounting holes for passing through fasteners are provided on the mounting surface. When manufacturing the support base 2, the support base 2 is assembled with the positioning tooling 4, and the first mounting holes are drilled on the support base 2 according to the positioning holes 44 on the positioning plates 43. Since the first mounting holes and the positioning holes 44 on the positioning tooling 4 are cooperatively drilled, the positions and sizes of the first mounting holes are matched with the positioning holes 44 on the positioning tooling 4 to ensure that the fasteners can be smoothly passed through the first mounting holes and the positioning holes 44.

[0037] The platform 3 includes a bottom plate 31 and a fence 33. The bottom plate 31 is welded by section steel and steel plates, and the bottom plate 31 is integrally flat. The fence 33 is welded by section steel. The manufacturing steps of the platform 3 include:

[0038] Step S11: Assemble the bottom plate 31 and the fence 33 of the platform 3, and assemble the positioning tooling 4 on the side surface of the bottom plate 31 facing away from the fence 33. The positioning tooling 4 can be assembled with the bottom plate 31 by using a fixture or spot welding.

[0039] Step S12: Weld each component of the bottom plate 31 and the fence 33 to form the platform 3. Since the positioning tooling 4 is assembled with the platform 3, the positioning tooling 4 plays a role in fixing the platform 3 and prevents the platform 3 from deforming during welding.

[0040] Step S13: Drill a second mounting hole 32 on the bottom plate 31 of the platform 3 according to the positioning hole 44 of the positioning tooling 4. Since the second mounting hole 32 and the positioning hole 44 on the positioning tooling 4 are drilled in cooperation, the position and size of the second mounting hole 32 are matched with the positioning hole 44 on the positioning tooling 4 to ensure that the fastener can pass through the second mounting hole 32 and the positioning hole 44 smoothly.

[0041] Step S14: Pre-install the fastener, pass the fastener through the positioning hole 44 and the second mounting hole 32, that is, connect the positioning plate 43 of the positioning tooling 4 and the bottom plate 31 through the fastener. This method can verify the processing quality of the second mounting hole 32 on the platform 3. When the fastener cannot be connected, the second mounting hole 32 can be repaired. By pre-installing the fastener, it is ensured that the bolt connection between the platform 3 and the positioning tooling 4 can be carried out smoothly.

[0042] It can be understood that during the manufacturing process of the support base 2 and the platform 3, the support base 2 and the positioning tooling 4 are assembled together for drilling in cooperation to form the first mounting hole, and the platform 3 and the positioning tooling 4 are assembled together for drilling in cooperation to form the second mounting hole 32, so that the first mounting hole, the second mounting hole 32 and the positioning hole 44 are all matched with each other to ensure that the first mounting hole and the positioning hole 44 can be smoothly connected through the fastener, and the second mounting hole 32 and the positioning hole 44 can be smoothly connected through the fastener.

[0043] Step S2: Install the support base 2 on the positioning plate 43 of the positioning tooling 4 through fasteners, hoist the positioning tooling 4 for assembly with the tank body 1, and weld and fix the support base 2 to the tank body 1. It can be understood that the support base 2 and the positioning tooling 4 are assembled together, and after welding, the support base 2 on the tank body 1 and the positioning tooling 4 cooperate with each other. At the same time, since the positioning tooling 4 and the platform 3 cooperate with each other, the platform 3 and the support base 2 on the tank body 1 cooperate with each other, so that when the platform 3 is installed on the tank body 1, the second mounting hole 32 on the platform 3 can cooperate with the first mounting hole on the support base 2, and the platform 3 and the support base 2 can be smoothly connected through fasteners.

[0044] Step S3: Remove the positioning tooling 4 from the tank body 1. The positioning tooling 4 plays a role in positioning the support base 2 during the installation process of the support base 2, so that the relative position between the support base 2 and the tank body 1 matches the relative position of the second mounting hole 32 on the platform 3. Therefore, after the support base 2 is installed, the positioning tooling 4 is removed.

[0045] After removing the positioning tooling 4, perform surface treatment on the LNG tank. It can be understood that the outer surface of the tank body 1 needs to be subjected to insulation, anti-corrosion, heat preservation treatment, etc. Performing surface treatment on the LNG tank after welding the support base 2 can ensure that the weld of the support base 2 is also subjected to surface treatment, ensuring the surface treatment quality of the LNG tank.

[0046] Step S4: Hoist the platform 3 for assembly with the tank body 1, and connect the first mounting hole and the second mounting hole 32 through fasteners. Since both the support base 2 and the platform 3 are drilled with holes based on the positioning holes 44 on the positioning tooling 4, when the platform 3 is installed on the tank body 1, the first mounting hole on the support base 2 can be directly opposite to the second mounting hole 32 on the platform 3, facilitating the smooth installation of the fasteners.

[0047] Optionally, as shown in Figure 4 a first reference line 41 is provided on the positioning tooling 4. When manufacturing the platform 3, each component on the platform 3 is assembled with the first reference line 41 as the positioning reference, which is beneficial to ensuring the cooperation between the platform 3 and the positioning tooling 4.

[0048] When manufacturing the platform 3, after the platform 3 is welded, a relief hole 34 is drilled on the bottom plate 31 with the first reference line 41 on the positioning tooling 4 as the positioning reference. The relief hole 34 is used to avoid the pipe fittings 5 on the tank body 1, so that when the platform 3 is installed on the tank body 1, the pipe fittings 5 can pass through the relief hole 34 smoothly.

[0049] Optionally, a second reference line 12 is marked on the tank body 1, and the second reference line 12 is located on the outer surface of the tank body 1. When assembling and positioning the tooling 4 with the tank body 1, axial positioning between the positioning tooling 4 and the tank body 1 is achieved by aligning the first reference line 41 with the second reference line 12. Radial positioning between the positioning tooling 4 and the tank body 1 is achieved by adjusting the angle between the positioning plate 43 of the positioning tooling 4 and the horizontal direction. It can be understood that by respectively setting the first reference line 41 on the positioning tooling 4 and the second reference line 12 on the tank body 1, it is convenient to perform positioning when installing the support seat 2, so that the installation position of the support seat 2 meets the design requirements. Specifically, there are two first reference lines 41, and the two first reference lines 41 are perpendicular to each other. The two first reference lines 41 extend along the length direction and the width direction of the positioning tooling 4 respectively. Similarly, there are two second reference lines 12, and the two second reference lines 12 extend along the axial direction and the radial direction of the tank body 1 respectively.

[0050] For the convenience of assembling the positioning tooling 4 with the tank body 1, during the assembly operation, the position of the tank body 1 is adjusted so that the first reference line 41 is aligned with the second reference line 12 in the vertical direction. It can be understood that the position of the tank body 1 is adjusted so that the second reference line 12 extending along the axial direction of the tank body 1 is located at the top of the tank body 1. Then the positioning tooling 4 is hoisted to the top of the tank body 1, and tools such as a laser positioning device and a plumb line can be used to quickly position the positioning tooling 4 to achieve alignment of the first reference line 41 with the second reference line 12 in the vertical direction. In this state, the positioning plate 43 on the positioning tooling 4 is in a horizontal state, so that the horizontal position of the positioning tooling 4 can be quickly measured by a level, and then the positioning of the positioning tooling 4 is completed. Assembling the positioning tooling 4 at the top of the tank body 1 has the characteristics of convenient hoisting and measurement compared with assembling in other directions of the tank body 1, which is beneficial to reducing the hoisting time of the positioning tooling 4.

[0051] Optionally, a plurality of installation positions 11 are also marked on the tank body 1, and the plurality of installation positions 11 correspond to the plurality of support seats 2 one by one, so as to facilitate quick assembly when installing the support seats 2.

[0052] The beneficial effect of this embodiment is that by using the positioning tooling 4 to cooperate with the support seat 2 and the platform 3 respectively, a first installation hole is formed on the support seat 2 by the method of drilling with the positioning hole 44 of the positioning tooling 4, a second installation hole 32 is formed on the platform 3 by the method of drilling with the positioning hole 44 of the positioning tooling 4, and the positioning tooling 4 is assembled with the tank body 1 to weld and fix the support seat 2. This method enables the support seat 2 on the tank body 1 to cooperate with the platform 3, so that the platform 3 can be quickly hoisted onto the tank body 1 and smoothly assembled with the support seat 2. While ensuring the smooth installation of fasteners, since the platform 3 can be welded and drilled on the ground, it is beneficial to reduce the hoisting time during the installation of the platform 3, reduce high-altitude operations, and thus reduce the drilling difficulty of the platform 3 and improve the operation efficiency.

[0053] Referring to Figures 1 to 3 as shown, an LNG tank is also provided. The LNG tank is made by the manufacturing method of the above-mentioned LNG tank, and it includes a tank body 1, a support seat 2 and a platform 3. By using a positioning tooling 4 to cooperate with the support seat 2 and the platform 3 respectively for manufacturing, a first installation hole is formed on the support seat 2 by means of drilling in cooperation with the positioning hole 44 of the positioning tooling 4, and a second installation hole 32 is formed on the platform 3 by means of drilling in cooperation with the positioning hole 44 of the positioning tooling 4, and the positioning tooling 4 is assembled with the tank body 1 for welding and fixing the support seat 2. It can ensure the smooth installation of the platform 3 and the tank body 1, and has the characteristics of convenient manufacturing.

[0054] The above content is only a preferred embodiment of the present invention. For those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. The content of this specification should not be construed as a limitation to the present invention.

Claims

1. A manufacturing method of an LNG tank, characterized in that, It includes the following steps: Step S1: Provide a positioning tooling. The positioning tooling includes a positioning plate, and positioning holes for passing fasteners are provided on the positioning plate. The tank body, support seat and platform of the LNG tank are respectively manufactured. When manufacturing the support seat, assemble the support seat with the positioning tooling, and drill first mounting holes on the support seat according to the positioning holes. When manufacturing the platform, assemble the platform with the positioning tooling, and drill second mounting holes on the platform according to the positioning holes; Step S2: Install the support seat on the positioning plate through the fasteners, hoist the positioning tooling and assemble it with the tank body, and weld and fix the support seat and the tank body; Step S3: Remove the positioning tooling from the tank body; Step S4: Hoist the platform and assemble it with the tank body, and connect the first mounting hole and the second mounting hole through the fasteners; The positioning tooling includes a plurality of the positioning plates, and the plurality of positioning plates correspond to the plurality of support seats one by one; The manufacturing steps of the platform are as follows: Step S11: Assemble the bottom plate and railing of the platform, and assemble the positioning tooling on the platform; Step S12: Weld the platform; Step S13: Drill the second mounting holes on the bottom plate of the platform according to the positioning holes of the positioning tooling; A first reference line is provided on the positioning tooling, and the platform is assembled with the first reference line as the positioning reference; Draw a second reference line on the tank body. When assembling the positioning tooling and the tank body, align the first reference line and the second reference line to achieve axial positioning between the positioning tooling and the tank body, and adjust the angle between the positioning plate of the positioning tooling and the horizontal direction to achieve radial positioning between the positioning tooling and the tank body; When assembling the positioning tooling and the tank body, adjust the position of the tank body and align the first reference line and the second reference line in the vertical direction.

2. The manufacturing method of the LNG tank according to claim 1, wherein, The manufacturing steps of the platform further include: Step S14: Pre-install the fasteners, and pass the fasteners through the positioning plate and the second mounting holes.

3. The manufacturing method of the LNG tank according to claim 1, characterized in that, In Step S3, after removing the positioning tooling, perform surface treatment on the LNG tank.

4. The manufacturing method of the LNG tank according to claim 1, characterized in that, The fastener is a bolt.

5. An LNG tank, characterized in that, Manufactured by the manufacturing method of the LNG tank according to any one of claims 1 to 4.

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