Pressure testing structure for airtight cabin of LNG transport ship

Abstract

The utility model relates to the field of ship construction, and provides a pressure testing structure for a closed cabin of an LNG (Liquefied Natural Gas) transport ship. Comprising a mounting hole in the bulkhead, a sealing rebounding device is mounted in the mounting hole and comprises an air inlet pipe and a rebounding assembly, the rebounding assembly comprises a sleeve, an elastic piece and a limiting screw plug, one end of the sleeve is arranged on the outer side of the air inlet pipe in a sleeving mode, the sleeve is connected with the air inlet pipe through threads, the elastic piece is mounted on the inner side of the sleeve, and the limiting screw plug is connected with the elastic piece. And the size of the elastic sheet corresponds to the cross section of the channel in the sleeve. The sealing springback device is installed on the cabin wall of the isolation cabin or the closed cabin, high-pressure gas can open the sealing springback device through pressure in the pressure measuring process and continuously introduce the high-pressure gas into the cabin, after ventilation is completed, the sealing springback device closes pressure maintaining under the action of the pressure in the cabin, and the air pressure change in the cabin is conveniently tested.

Description

Technical Field

[0001] The utility model relates to the field of shipbuilding, in particular to a closed cabin pressure test structure of an LNG transport ship. Background Art

[0002] As countries around the world pay more and more attention to carbon emissions, traditional fossil fuels will gradually be replaced by LNG, H2, NH3 and other fuels. As a stable fuel for medium- and long-term transition, the demand for LNG transport ships is also increasing. The liquid tanks of LNG ships include type A tanks, type B tanks, type C tanks, membrane tanks and other types. The liquid tanks are used to store low-temperature liquid LNG fuel and need to meet the requirements of complete airtightness.

[0003] During the construction of LNG carriers, the tanks need to be pressure tested to confirm air tightness, and annual pressure tests are required throughout the entire operational life cycle. How to apply pressure conveniently, quickly and safely has always been a matter of great concern to shipowners. Summary of the invention

[0004] In order to facilitate the pressure test of the closed cabin during the manufacturing and operation of the LNG carrier, the utility model provides a closed cabin pressure test structure of the LNG carrier suitable for various types of liquid tank tests.

[0005] The technical solution adopted by the utility model is:

[0006] A pressure test structure for a sealed compartment of an LNG carrier is installed on the outer side of a bulkhead of a sealed compartment of an LNG carrier, and comprises a mounting hole on the bulkhead connected to the interior of the sealed compartment, a sealing rebound device is installed in the mounting hole, an inner flange is installed in the mounting hole, the outer diameter of the inner flange corresponds to the inner diameter of the mounting hole, the inner flange is welded and fixed to the mounting hole, an outer flange is installed on the outer side of the inner flange, the outer flange and the inner flange are fixedly connected by a plurality of screws, a sealing rebound device is installed in the center holes of the inner and outer flanges, the sealing rebound device comprises an air inlet pipe and a rebound assembly, the outer diameter of the air inlet pipe corresponds to the inner diameter of the center hole of the outer flange The diameter corresponds to that of the air intake pipe, the air intake pipe passes through the center hole of the outer flange and is welded to the outer flange, the rebound assembly is installed at one end of the air intake pipe away from the inner flange, the rebound assembly comprises a sleeve, a spring piece and a limit screw plug, one end of the sleeve is sleeved on the outside of the air intake pipe, the sleeve and the air intake pipe are connected by a thread, the spring piece is installed on the inside of the sleeve, the size of the spring piece corresponds to the channel cross-section in the sleeve, the limit screw plug is installed at the other end of the sleeve, the limit screw plug cooperates with the internal thread of the inner wall of the sleeve through its external thread, the limit screw plug is a hollow structure, and when the spring piece is parallel to the radial cross-section of the sleeve, the limit screw plug limits the spring piece.

[0007] Furthermore, an isolation sleeve is installed on the outer side of the enclosed cabin bulkhead, one end of the isolation sleeve is welded and fixed to the outer side wall of the enclosed cabin bulkhead, the inner and outer flanges and the sealing rebound device are located inside the isolation sleeve, and a flange is provided at the other end of the isolation sleeve, and a cover plate is installed on the isolation sleeve through the flange, and the cover plate seals the isolation sleeve.

[0008] Furthermore, a threaded hole is provided at the center of the cover plate, the threaded hole is connected to the boosting device, and a test air compressor bolt is installed on the threaded hole.

[0009] Furthermore, the spring sheet is mounted on the inner wall of the sleeve via a torsion spring.

[0010] Furthermore, a sealing strip is installed on the outer ring of the spring piece, and the sealing strip is sealed with the inner wall of the sleeve.

[0011] Furthermore, a heat insulating pad is installed between the inner flange and the outer flange.

[0012] Furthermore, a filter is installed at one end of the air inlet pipe close to the sleeve, and the filter is squeezed between the air inlet pipe and the sleeve.

[0013] After adopting the above technical scheme, the beneficial effects of the utility model are:

[0014] By installing a sealing rebound device on the bulkhead of an isolation cabin or a closed cabin, during the pressure measurement process, high-pressure gas can open the sealing rebound device through pressure and continue to pass high-pressure gas into the cabin. After the ventilation is completed, the sealing rebound device is closed and the pressure is maintained under the action of the cabin pressure, which is convenient for testing the air pressure changes in the cabin.

[0015] By installing an additional isolation sleeve on the outside of the sealing rebound device, a two-layer isolation space is formed at the most convenient position outside the LNG tank, and the back pressure rebound sealing device is sealed. The dustproof effect is very good, and it can be installed and tested very conveniently. It can be very easily disassembled for cleaning, debugging and other work in the later stage. After the relevant construction, the protection device can be directly reset to continue to play the role of protection and isolation. It effectively avoids trampling, grinding, and external force impact that may occur during navigation, ensuring the integrity of the back pressure rebound sealing device during the entire construction process and ensuring the safety of the ship. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the utility model.

[0017] Figure 2 This is a partial enlarged view.

[0018] In the figure: bulkhead 1, inner flange 2, outer flange 3, thermal insulation pad 4, air inlet pipe 5, filter screen 6, sleeve 7, spring piece 8, limit screw plug 9, isolation sleeve 10, cover plate 11, test air compressor bolt 12. DETAILED DESCRIPTION

[0019] The specific implementation of the utility model is further described in detail below with reference to the accompanying drawings:

[0020] like Figure 1 As shown, a closed compartment pressure test structure of an LNG carrier is installed on the outside of the closed compartment bulkhead 1 of the LNG carrier, and mainly consists of two parts: a sealing rebound device and an isolation device. It is used for testing the air tightness of the closed compartment of the LNG carrier.

[0021] The sealing rebound device is installed on the outside of the closed cabin bulkhead 1 through the inner flange 2 and the outer flange 3. A mounting hole connected to the inside of the closed cabin is processed on the bulkhead. The size of the inner flange 2 corresponds to the mounting hole. The inner flange 2 is installed in the mounting hole. The edges on both sides of the inner flange 2 are fully welded to the mounting hole to form a seal to ensure air tightness. The outer side of the inner flange 2 is flush with the outer side of the bulkhead. The size of the outer flange 3 corresponds to that of the inner flange 2, and a circle of screws is used to form a fixed installation. A low-temperature resistant heat insulation pad 4 is installed between the inner and outer flanges. PTFE material is generally selected to prevent the low temperature in the isolation cabin from being transmitted to the outside.

[0022] The sealing rebound device is installed in the center hole of the outer flange 3. The sealing rebound device consists of an air intake pipe 5 and a rebound component. The air intake pipe 5 is used to inflate the airtight cabin. The outer diameter of the air intake pipe 5 corresponds to the inner diameter of the center hole of the outer flange 3. One end of the air intake pipe 5 is inserted into the center hole of the outer flange 3 and is welded and fixed to the outer flange 3 to ensure air tightness. It is used to filter impurities in the gas to avoid contamination in the airtight cabin. The rebound component is installed at the other end of the air intake pipe 5 for sealing after inflation. A filter screen 6 is installed between the air intake pipe 5 and the rebound component.

[0023] The rebound assembly is composed of a sleeve 7, a spring piece 8 and a limit screw plug 9. One end of the sleeve 7 is sleeved on the outside of the air inlet pipe 5. The sleeve 7 and the air inlet pipe 5 are fixedly connected by means of internal and external threads. The spring piece 8 is installed on the inside of the sleeve 7. The spring piece 8 can be a circular spring piece that can be elastically deformed after stamping and bending, or it can be installed on the inner wall of the sleeve 7 through a torsion spring. The size of the spring piece corresponds to the channel section in the sleeve, and a sealing strip is installed on the outer ring of the spring piece. Under normal pressure, the spring piece 8 is in an open state facing the airtight cabin. When the airtight cabin is filled with high-pressure gas, the pressure in the airtight cabin pushes the spring piece 8 to reset it to be parallel to the radial section of the sleeve 7. At this time, the sealing strip of the spring piece is sealed with the inner wall of the sleeve 7 to seal the sleeve 7 and prevent the gas in the airtight cabin from leaking out.

[0024] The limit screw plug 9 limits the position of the spring piece 8 to prevent the spring piece 8 from flipping over or elastically deforming to cause sealing failure. The limit screw plug 9 is installed at the other end of the sleeve 7. The limit screw plug 9 cooperates with the internal thread of the inner wall of the sleeve 7 through its external thread. The limit screw plug 9 is a hollow structure and can be ventilated. When the spring piece 8 is parallel to the radial section of the sleeve 7, the end face of the limit screw plug 9 limits the position of the spring piece 8.

[0025] The isolation device is installed on the outside of the sealing and rebounding device and seals the sealing and rebounding device. The isolation device consists of an isolation sleeve 10 and a cover plate 11. One end of the isolation sleeve 10 is welded and fixed to the outer wall of the closed cabin bulkhead 1 to ensure air tightness, and the inner and outer flanges and the sealing and rebounding device are located within the range covered by the isolation sleeve 10. A flange is provided at the other end of the isolation sleeve 10, and the cover plate 11 is fixed and installed with the flange by multiple bolts. A sealing ring is installed between the cover plate 11 and the flange, and the cover plate 11 seals the isolation sleeve 10. A threaded hole is provided in the center of the cover plate 11, and a test air compressor bolt 12 is installed on the threaded hole. When testing is required, the test air compressor bolt 12 is unscrewed, and the threaded hole can be directly threadedly connected to the pipeline of the booster device and used as an inflation port. High-pressure gas enters the sealing and rebounding device through the isolation device, and the shrapnel 8 is pushed away by the high-pressure gas and the high-pressure gas is filled into the closed cabin. When the pressure is completed, the booster device stops working, and the high pressure in the closed cabin pushes the shrapnel 8 back and seals the channel of the sealing and rebounding device. After maintaining the pressure for a period of time, the closed cabin pressure test is completed by observing the pressure changes in the closed cabin.

[0026] During the construction and operation of LNG ships, the isolation device serves as a protective device to form secondary isolation, preventing external dust and other substances from entering the isolation compartment, while protecting the sealing rebound device from damage such as collision.

Claims

1. A pressure test structure for a closed compartment of an LNG carrier, installed on the outer side of the bulkhead of a closed compartment of an LNG carrier, comprising a mounting hole on the bulkhead connected to the interior of the closed compartment, a sealing rebound device being installed in the mounting hole, characterized in that: An inner flange is installed in the mounting hole, the outer diameter of the inner flange corresponds to the inner diameter of the mounting hole, the inner flange is welded and fixed to the mounting hole, an outer flange is installed on the outer side of the inner flange, the outer flange and the inner flange are fixedly connected by a plurality of screws, a sealing rebound device is installed in the center holes of the inner and outer flanges, the sealing rebound device includes an intake pipe and a rebound assembly, the outer diameter of the intake pipe corresponds to the inner diameter of the center hole of the outer flange, the intake pipe passes through the center hole of the outer flange and is welded and fixed to the outer flange, the rebound assembly The component is installed at one end of the intake pipe away from the inner flange. The rebound component includes a sleeve, a spring and a limit screw plug. One end of the sleeve is sleeved on the outside of the intake pipe. The sleeve and the intake pipe are connected by a thread. The spring is installed on the inside of the sleeve. The size of the spring corresponds to the channel cross-section in the sleeve. The limit screw plug is installed at the other end of the sleeve. The limit screw plug cooperates with the internal thread of the inner wall of the sleeve through its external thread. The limit screw plug is a hollow structure. When the spring is parallel to the radial cross-section of the sleeve, the limit screw plug limits the spring.

2. The LNG carrier closed tank pressure test structure according to claim 1, characterized in that: An isolation sleeve is installed on the outside of the enclosed cabin bulkhead, one end of the isolation sleeve is welded and fixed to the outer side wall of the enclosed cabin bulkhead, the inner and outer flanges and the sealing rebound device are located in the isolation sleeve, the other end of the isolation sleeve is provided with a flange, and a cover plate is installed on the isolation sleeve through the flange, and the cover plate seals the isolation sleeve.

3. The LNG carrier closed tank pressure test structure according to claim 2, characterized in that: A threaded hole is provided at the center of the cover plate, the threaded hole is connected to the boosting device, and a test air compressor bolt is installed on the threaded hole.

4. The LNG carrier closed tank pressure test structure according to claim 1, characterized in that: The spring sheet is installed on the inner wall of the sleeve through a torsion spring.

5. The LNG carrier closed tank pressure test structure according to claim 4, characterized in that: The outer ring of the spring piece is provided with a sealing strip, and the sealing strip is in sealing cooperation with the inner wall of the sleeve.

6. The LNG carrier closed tank pressure test structure according to claim 1, characterized in that: A heat insulation pad is installed between the inner flange and the outer flange.

7. The LNG carrier closed tank pressure test structure according to claim 1, characterized in that: A filter screen is installed at one end of the air inlet pipe close to the sleeve, and the filter screen is squeezed between the air inlet pipe and the sleeve.

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