Tightness testing method for special compartment of dual-fuel container ship

Abstract

A tightness testing method for a special compartment of a dual-fuel container ship. The method comprises the following steps: S1, making a plan to perform a tightness test on a special compartment by zones; S2, according to the plan in S1, simulating the tightness test for the special compartment of a dual-fuel container ship, so as to determine whether the plan in S1 is feasible; S3, according to the plan in S1, performing the tightness test on the special compartment; and S4, restoring the special compartment. By means of the present invention, a tightness test for a special compartment of a dual-fuel container ship can be implemented by zones in advance without relying on the integrity of the overall compartment structure, and a containment system can be constructed in advance, thereby shortening the shipbuilding cycle.

Description

A Test Method for the Tightness of Special Compartments in Dual-Fuel Container Ships Technical Field

[0001] This invention relates to the field of shipbuilding, and in particular to a method for testing the tightness of special compartments in dual-fuel container ships. Background Technology

[0002] In the construction of dual-fuel container ships, the LNG tank is a key area, especially the construction of the containment system. In existing technologies, the LNG tank containment system construction typically begins only after the tightness test of a special compartment outside the LNG tank is completed. However, the tightness test of the special compartment must be conducted after the special compartment is fully constructed, as shown in the shaded area of ​​Figure 1. Special compartment 1 is a sealed space enclosed by the LNG tank's outer wall, bulkhead sections, outer plating, hatch coaming sections, room sections, and the main deck. During ship construction, the installation of hatch coaming and room sections often requires the completion of other work on the main deck before installation, resulting in a long installation cycle for the complete special compartment and delaying the construction of the LNG tank containment system. To facilitate the construction of the containment system and the access of materials and personnel, temporary process holes need to be opened on the side of the LNG tank. These temporary process holes are sealed during the tightness test of the special compartment and reopened after the tightness test is completed, resulting in repetitive work and low production efficiency. Summary of the Invention

[0003] To address the deficiencies in existing technologies, this application provides a special compartment tightness test method for dual-fuel container ships, thereby solving technical problems such as the impact of special compartment tightness tests on the construction of LNG tank containment systems.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0005] A method for testing the tightness of a special compartment in a dual-fuel container ship, wherein the special compartment is a sealed space enclosed by an LNG bulkhead and bulkhead sections, outer plating, hatch coaming sections, cabin sections, and a main deck. The main deck is located at the upper end of the bulkhead sections. The hatch coaming sections and cabin sections are adjacent to each other on the upper surface of the main deck. The main deck divides the special compartment into a lower compartment and an upper compartment. The lower compartment is the space excluding the piping area enclosed by the LNG bulkhead and bulkhead sections, outer plating, and the main deck. The upper compartment is the space enclosed by the hatch coaming section bulkhead, hatch coaming section top plate, cabin section bulkhead, and the main deck. Multiple weight-reduction holes are provided on the main deck between the lower and upper compartments. Multiple fuel-related compartments are provided in the lower compartment. The method for testing the tightness of the special compartment includes the following steps:

[0006] S1. The plan is to conduct tightness tests on special compartments in different areas, so that the lower compartments are tested before the upper compartments.

[0007] S2. Simulate the tightness test of the special compartment of the dual-fuel container ship in the simulation software according to the plan in S1 to determine whether the plan in S1 is feasible. If it is feasible, proceed to S3.

[0008] S3. Conduct a tightness test on the special compartment according to the plan of S1. After conducting a tightness test on the lower compartment, set a side process hole through the outer plate, the fifth fuel-related compartment wall and the LNG wall on the side.

[0009] S4. Restore the special compartments to connect the upper and lower compartments.

[0010] In one implementation, the zoned tightness test for special compartments described in S1 includes sequentially conducting tightness and strength tests on fuel-related compartments, conducting tightness tests on lower compartments, and conducting tightness tests on upper compartments.

[0011] In one implementation scheme, the specific steps of S1 are as follows: the plan is to first conduct leak tests and strength tests on multiple fuel-related compartments in the lower compartment in batches, and then conduct leak tests on the lower compartment and the upper compartment in sequence. Non-adjacent fuel-related compartments are considered to be in the same batch.

[0012] In one implementation scheme, in S2, the simulation software analyzes whether the stress and deformation of the dock piers under the special compartments set during the simulation process are within the allowable range to determine whether the plan in S1 is feasible. If the plan is feasible, proceed to S3. If the plan is not feasible, increase the number of dock piers in the areas with high stress on the dock piers until the plan is feasible.

[0013] In one implementation, spring units are used in S2 to simulate dock piers.

[0014] In one embodiment, the lower compartment is provided with six fuel-related compartments. The first, second, third, and fourth fuel-related compartments are located on one side of the LNG compartment, and the fifth and sixth fuel-related compartments are located on the other side of the LNG compartment. The first and second fuel-related compartments are adjacent to each other, the third and fourth fuel-related compartments are adjacent to each other, and the fifth and sixth fuel-related compartments are adjacent to each other.

[0015] In one implementation scheme, step S3 specifically includes: S31, injecting compressed air at a certain pressure into the second, third, and fifth fuel-related compartments, maintaining this pressure for a certain period of time, and judging the tightness of the second, third, and fifth fuel-related compartments by whether soapy water bubbles on the weld seam; then injecting compressed air at a certain pressure into the first, fourth, and sixth fuel-related compartments, maintaining this pressure for a certain period of time, and judging the tightness of the first, fourth, and sixth fuel-related compartments by whether soapy water bubbles on the weld seam, thus completing the fuel-related compartment tightness test;

[0016] S32. Inject fresh water into the second, third, and fifth fuel-related compartments until a certain water pressure is reached, maintain this water pressure for a certain period of time, and observe the deformation of the relevant structures of the second, third, and fifth fuel-related compartments; then inject fresh water into the first, fourth, and sixth fuel-related compartments until a certain water pressure is reached, maintain this water pressure for a certain period of time, and observe the deformation of the relevant structures of the first, fourth, and sixth fuel-related compartments to complete the fuel-related compartment strength test;

[0017] S33. A temporary sealing plate is used to seal the main deck's light-reducing holes, creating a sealed space in the lower compartment. One of the temporary sealing plates has two threaded through holes of different diameters. The smaller diameter threaded through hole is used to inject compressed air, and the larger diameter threaded through hole is used to connect a tee. Pressure gauges and U-tubes are installed at the other two ends of the tee, respectively. Compressed air of a certain pressure is injected into the lower compartment and maintained at this pressure for a certain period of time. The tightness of the lower compartment is judged by measuring whether soapy water bubbles on the relevant welds of the lower compartment. After the lower compartment tightness test is completed, a through-plate and fifth-stage sealing plate is installed on the side of the hull. The side process holes of the fuel-related compartment bulkheads and LNG bulkheads are used to transport the relevant materials of the containment system to the LNG tank. The construction of the containment system is carried out simultaneously with the installation of the hatch coaming section and room section on the main deck. When the hatch coaming section and room section are completed, the upper compartment, which is sealed by the hatch coaming section bulkhead, hatch coaming section top plate, room section bulkhead and the main deck with temporary sealing plates, is injected with compressed air of a certain pressure and maintained at this pressure for a certain period of time. The tightness of the upper compartment is judged by measuring whether soapy water bubbles on the relevant welds of the upper compartment.

[0018] In one implementation, step S4 specifically includes: removing the temporary sealing plate to connect the upper and lower compartments vertically, thus restoring the special compartment.

[0019] In one embodiment, step S4 further includes re-fixing multiple square steel bars across the main deck relief holes.

[0020] Compared with the prior art, this application has at least the following beneficial effects:

[0021] This application, taking into account the structural characteristics of the hull, allows for the zonal tightness testing of special compartments. This enables the early implementation of tightness testing for special compartments that affect the construction of the containment system, laying the foundation for early construction of the containment system and avoiding the need for repeated opening of temporary process holes. By temporarily sealing the main deck's relief holes with sealing plates, the tightness testing of the upper and lower areas of special compartments can be universally applied. This invention enables the zonal early implementation of tightness testing for special compartments on dual-fuel container ships, independent of the integrity of the overall compartment structure, allowing for early construction of the containment system, avoiding repetitive work, improving efficiency, and shortening the shipbuilding cycle. Attached Figure Description

[0022] Figure 1 is a structural schematic diagram of the special compartment in an embodiment of this application;

[0023] Figure 2 is a top view of a special compartment in an embodiment of this application;

[0024] Figure 3 is a cross-sectional schematic diagram of the special compartment along rib 233 in an embodiment of this application;

[0025] Figure 4 is a cross-sectional schematic diagram of the special compartment along rib 249 in an embodiment of this application;

[0026] Figure 5 is a top view of a portion of the main deck in an embodiment of this application;

[0027] Figure 6 is a flowchart illustrating the method for testing the tightness of special compartments in dual-fuel container ships according to an embodiment of this application.

[0028] Reference numerals: 1. Special compartment; 101. Lower compartment; 11. First fuel-related compartment; 12. Second fuel-related compartment; 13. Third fuel-related compartment; 14. Fourth fuel-related compartment; 15. Fifth fuel-related compartment; 16. Sixth fuel-related compartment; 102. Upper compartment; 2. Main deck; 201. Lightening hole; 202. Square steel; 3. LNG bulkhead; 4. Compartment section bulkhead; 5. Outer plating; 6. Hatch coaming section; 601. Hatch coaming section bulkhead plate; 602. Hatch coaming section top plate; 7. Room section; 701. Room section bulkhead; 8. Piping area; 9. Side process hole. Detailed Implementation

[0029] 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.

[0030] 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.

[0031] It should be understood that although the terms first, second, third, etc., may be used in this disclosure to describe various information, such information should not be limited to these terms and should not be construed as indicating or implying relative importance. These terms are used only to distinguish information of the same type from one another. For example, without departing from the scope of this disclosure, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."

[0032] In the description of this invention, unless otherwise specified and limited, it should be noted that the terms "installation", "connection" and "linking" should be interpreted broadly. For example, they can refer to mechanical connection or internal connection between two components. They can be direct connection or indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[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 discloses a method for testing the tightness of a special compartment in a dual-fuel container ship. As shown in Figures 1-4, the special compartment 1 is a sealed space enclosed by an LNG bulkhead 3, a bulkhead section 4, an outer plating 5, a hatch coaming section 6, a room section 7, and a main deck 2. The main deck 2 is located at the upper end of the bulkhead section 4. The hatch coaming section 6 and the room section 7 are adjacent to each other on the upper surface of the main deck 2. The main deck 2 divides the special compartment 1 into a lower compartment 101 and an upper compartment 102. The lower compartment 101 is composed of an LNG bulkhead section 3, a bulkhead section 4, an outer plating 5, a hatch coaming section 6, a room section 7, and a main deck 2. The space excluding the pipework area is enclosed by bulkhead 3, compartment section bulkhead 4, outer plating 5, and main deck 2. Upper compartment 102 is the space enclosed by hatch coaming section bulkhead 601, hatch coaming section top plate 602, room section bulkhead 701, and main deck 2, as shown in Figure 5. Multiple weight-reducing holes 201 are provided on the main deck 2 between lower compartment 101 and upper compartment 102. Multiple fuel-related compartments are located within lower compartment 101. The special compartment tightness test method includes the following steps:

[0035] S1. The plan is to conduct tightness tests on special compartments in different areas, so that the lower compartment 101 is tested before the upper compartment 102.

[0036] In this embodiment, the tightness test of special compartments by region includes conducting tightness and strength tests on fuel-related compartments in sequence, conducting tightness tests on lower compartment 101, and conducting tightness tests on upper compartment 102.

[0037] S2. Simulate the tightness test of the special compartment of the dual-fuel container ship in the simulation software according to the plan in S1 to determine whether the plan in S1 is feasible. If it is feasible, proceed to S3.

[0038] S3. Conduct a tightness test on the special compartment according to the plan of S1. After the tightness test is conducted on the lower compartment 101, a side process hole is set on the side to penetrate the outer plate 5, the bulkhead of the fifth fuel-related compartment 15 and the LNG bulkhead 3 so that the construction of the enclosure system can be carried out at the same time when the tightness test is conducted on the upper compartment 102.

[0039] S4. Restore the special compartments to connect the upper compartment 102 and the lower compartment 101.

[0040] The specific steps for S1 are as follows: First, multiple fuel-related compartments within the lower compartment 101 will undergo leak testing and strength testing in batches. Then, leak testing will be conducted sequentially on the lower compartment 101 and the upper compartment 102. Non-adjacent fuel-related compartments will be considered part of the same batch. Testing the fuel-related compartments in batches can accelerate the testing process and avoid excessive load on the dock piers. Furthermore, classifying non-adjacent fuel-related compartments as part of the same batch allows for a more accurate assessment of the strength test results.

[0041] In this embodiment, the lower compartment 101 is equipped with six fuel-related compartments, as shown in Figures 2-4. The first fuel-related compartment 11, the second fuel-related compartment 12, the third fuel-related compartment 13, and the fourth fuel-related compartment 14 are located on one side of the LNG compartment, and the fifth fuel-related compartment 15 and the sixth fuel-related compartment 16 are located on the other side of the LNG compartment. The first fuel-related compartment 11 and the second fuel-related compartment 12 are adjacent, the third fuel-related compartment 13 and the fourth fuel-related compartment 14 are adjacent, and the fifth fuel-related compartment 15 and the sixth fuel-related compartment 16 are adjacent. In step S1, it is planned to first conduct a tightness test on the second fuel-related compartment 12, the third fuel-related compartment 13, and the fifth fuel-related compartment 15 simultaneously, and then conduct a tightness test on the first fuel-related compartment 11, the fourth fuel-related compartment 14, and the sixth fuel-related compartment 16 simultaneously; after the tightness test is passed, a strength test will be conducted on the second fuel-related compartment 12, the third fuel-related compartment 13, and the fifth fuel-related compartment 15 simultaneously, and then conduct a strength test on the first fuel-related compartment 11, the fourth fuel-related compartment 14, and the sixth fuel-related compartment 16 simultaneously.

[0042] In S2, the simulation software analyzes whether the stress and deformation of the dock piers set under the special compartments during the simulation are within the allowable range to determine whether the plan in S1 is feasible. If the plan is not feasible, the number of dock piers is increased in areas with high stress until the stress and deformation of the dock piers are within the allowable range. To facilitate the demonstration of the stress and deformation of the dock piers in the simulation software, spring units are used to simulate the dock piers in this embodiment.

[0043] Step S3 specifically includes: S31, injecting compressed air at a certain pressure into the second fuel-related compartment 12, the third fuel-related compartment 13, and the fifth fuel-related compartment 15, and maintaining this pressure for a certain period of time, and judging the tightness of the second fuel-related compartment 12, the third fuel-related compartment 13, and the fifth fuel-related compartment 15 by whether soapy water bubbles on the weld seam; then injecting compressed air at a certain pressure into the first fuel-related compartment 11, the fourth fuel-related compartment 14, and the sixth fuel-related compartment 16, and maintaining this pressure for a certain period of time, and judging the tightness of the first fuel-related compartment 11, the fourth fuel-related compartment 14, and the sixth fuel-related compartment 16 by whether soapy water bubbles on the weld seam, thus completing the fuel-related compartment tightness test;

[0044] S32. Inject fresh water into the second fuel-related compartment 12, the third fuel-related compartment 13, and the fifth fuel-related compartment 15 until a certain water pressure is reached. Maintain this water pressure for a certain period of time and observe the deformation of the relevant structures of the second fuel-related compartment 12, the third fuel-related compartment 13, and the fifth fuel-related compartment 15. Then, inject fresh water into the first fuel-related compartment 11, the fourth fuel-related compartment 14, and the sixth fuel-related compartment 16 until a certain water pressure is reached. Maintain this water pressure for a certain period of time and observe the deformation of the relevant structures of the first fuel-related compartment 11, the fourth fuel-related compartment 14, and the sixth fuel-related compartment 16 to complete the fuel-related compartment strength test.

[0045] S33. A temporary sealing plate is used to seal the main deck light-relief hole 201, creating a sealed space for the lower compartment 101. One of the temporary sealing plates has two threaded through holes of different diameters. The smaller diameter threaded through hole is used to inject compressed air, and the larger diameter threaded through hole is used to connect a tee. Pressure gauges and U-tubes are installed on the other two ends of the tee, respectively. Compressed air of a certain pressure is injected into the lower compartment 101 and maintained at this pressure for a certain period of time. The tightness of the lower compartment 101 is judged by whether soapy water bubbles on the relevant welds of the lower compartment 101. After the tightness test of the lower compartment 101 is completed, a through-plate 5 and the fifth fuel-related compartment 1 are installed on the side. 5. The side process holes 9 of the bulkhead and LNG bulkhead 3 are used to transport the relevant materials of the containment system to the LNG tank. The construction of the containment system is carried out simultaneously with the installation of the hatch coaming section 6 and the room section 7 on the main deck 2. When the hatch coaming section 6 and the room section 7 are completed, the upper compartment 102, which is sealed by the hatch coaming section bulkhead 601, the hatch coaming section top plate 602, the room section bulkhead 701 and the main deck 2 with temporary sealing plates, is injected with compressed air of a certain pressure and maintained at this pressure for a certain period of time. The tightness of the upper compartment 102 is judged by whether soapy water bubbles on the relevant welds of the upper compartment 102.

[0046] Step S4 specifically includes: removing the temporary sealing plate to connect the upper compartment 102 and the lower compartment 101 vertically, restoring the special compartment. Step S4 also includes fixing multiple square steel bars 202 across the main deck relief hole 201 to prevent workers from falling into the lower compartment 101 through the main deck relief hole, thereby improving construction safety.

[0047] 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 testing the tightness of special compartments in a dual-fuel container ship, characterized in that, The special compartment is a sealed space enclosed by LNG bulkheads and bulkhead sections, outer plating, hatch coaming sections, room sections, and the main deck. The main deck is located at the upper end of the bulkhead section. The hatch coaming section and room section are adjacent to each other on the upper surface of the main deck. The main deck divides the special compartment into a lower compartment and an upper compartment. The lower compartment is the space excluding the pipework area enclosed by LNG bulkheads and bulkhead sections, outer plating, and the main deck. The upper compartment is the space enclosed by the hatch coaming section bulkhead, hatch coaming section top plate, room section bulkhead, and the main deck. Multiple weight-reducing holes are provided on the main deck between the lower and upper compartments. Multiple fuel-related compartments are located in the lower compartment. The special compartment tightness test method includes the following steps: S1. The plan is to conduct tightness tests on special compartments in different areas, so that the lower compartments are tested before the upper compartments. S2. Simulate the tightness test of the special compartment of the dual-fuel container ship in the simulation software according to the plan in S1 to determine whether the plan in S1 is feasible. If it is feasible, proceed to S3. S3. Conduct a tightness test on the special compartment according to the plan of S1. After conducting a tightness test on the lower compartment, set a side process hole through the outer plate, the fifth fuel-related compartment wall and the LNG wall on the side. S4. Restore the special compartments to connect the upper and lower compartments.

2. The method for testing the tightness of special compartments in dual-fuel container ships according to claim 1, characterized in that, The zonal tightness test for special compartments described in S1 includes sequentially conducting tightness and strength tests on fuel-related compartments, conducting tightness tests on lower compartments, and conducting tightness tests on upper compartments.

3. The method for testing the tightness of special compartments in a dual-fuel container ship according to claim 2, characterized in that, The specific steps for S1 are as follows: First, multiple fuel-related compartments in the lower compartment will be tested for tightness and strength in batches. Then, the lower compartment and the upper compartment will be tested for tightness in sequence. Non-adjacent fuel-related compartments will be in the same batch.

4. The method for testing the tightness of special compartments in a dual-fuel container ship according to claim 3, characterized in that, In S2, the simulation software analyzes whether the stress and deformation of the dock piers under the special compartments are within the allowable range during the simulation process to determine whether the plan in S1 is feasible. If the plan is feasible, proceed to S3. If the plan is not feasible, increase the number of dock piers in areas with high stress on the dock piers until the plan is feasible.

5. The method for testing the tightness of special compartments in a dual-fuel container ship according to claim 4, characterized in that, Spring units are used to simulate dock piers in S2.

6. The method for testing the tightness of special compartments in a dual-fuel container ship according to claim 3, characterized in that, The lower compartment is equipped with six fuel-related compartments. The first, second, third, and fourth fuel-related compartments are located on one side of the LNG compartment, and the fifth and sixth fuel-related compartments are located on the other side of the LNG compartment. The first and second fuel-related compartments are adjacent to each other, the third and fourth fuel-related compartments are adjacent to each other, and the fifth and sixth fuel-related compartments are adjacent to each other.

7. The method for testing the tightness of special compartments in a dual-fuel container ship according to claim 6, characterized in that, Step S3 specifically includes: S31, injecting compressed air at a certain pressure into the second, third, and fifth fuel-related compartments, maintaining this pressure for a certain period of time, and judging the tightness of the second, third, and fifth fuel-related compartments by whether soapy water bubbles on the weld seam; then injecting compressed air at a certain pressure into the first, fourth, and sixth fuel-related compartments, maintaining this pressure for a certain period of time, and judging the tightness of the first, fourth, and sixth fuel-related compartments by whether soapy water bubbles on the weld seam, thus completing the fuel-related compartment tightness test; S32. Inject fresh water into the second, third, and fifth fuel-related compartments until a certain water pressure is reached, maintain this water pressure for a certain period of time, and observe the deformation of the relevant structures of the second, third, and fifth fuel-related compartments; then inject fresh water into the first, fourth, and sixth fuel-related compartments until a certain water pressure is reached, maintain this water pressure for a certain period of time, and observe the deformation of the relevant structures of the first, fourth, and sixth fuel-related compartments to complete the fuel-related compartment strength test; S33. A temporary sealing plate is used to seal the main deck's light-reducing holes, creating a sealed space in the lower compartment. One of the temporary sealing plates has two threaded through holes of different diameters. The smaller diameter threaded through hole is used to inject compressed air, and the larger diameter threaded through hole is used to connect a tee. Pressure gauges and U-tubes are installed at the other two ends of the tee, respectively. Compressed air of a certain pressure is injected into the lower compartment and maintained at this pressure for a certain period of time. The tightness of the lower compartment is judged by whether soapy water bubbles on the relevant welds of the lower compartment. After the lower compartment tightness test is completed, a through-plate and fifth-stage sealing plate is installed on the side of the hull. The side process holes of the fuel-related compartment bulkheads and LNG bulkheads are used to transport the relevant materials of the containment system to the LNG tank. The construction of the containment system is carried out simultaneously with the installation of the hatch coaming section and room section on the main deck. When the hatch coaming section and room section are completed, the upper compartment, which is sealed by the hatch coaming section bulkhead, hatch coaming section top plate, room section bulkhead and the main deck with temporary sealing plates, is injected with compressed air of a certain pressure and maintained at this pressure for a certain period of time. The tightness of the upper compartment is judged by whether soapy water bubbles on the relevant welds of the upper compartment.

8. The method for testing the tightness of special compartments in a dual-fuel container ship according to claim 7, characterized in that, Step S4 specifically includes: removing the temporary sealing panels to connect the upper and lower compartments vertically, thus restoring the special compartment.

9. The method for testing the tightness of special compartments in a dual-fuel container ship according to claim 8, characterized in that, Step S4 also includes fixing multiple square steel bars across the main deck relief holes.

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