Box ship LNG fuel system pipeline with self-repairing function

Abstract

The utility model relates to a box ship LNG (Liquefied Natural Gas) fuel system pipeline with a self-repairing function, which is applied to the field of box ship LNG fuel conveying, and comprises two LNG pipelines which are arranged in parallel, the two LNG pipelines are welded together, a positioning ring is fixedly sleeved outside the two LNG pipelines, the positioning ring is positioned at a welding seam of the two LNG pipelines, and the two LNG pipelines are welded together. The LNG pipeline on the right side is movably sleeved with a baffle ring and fixedly sleeved with an isolating ring, the left end of the baffle ring movably penetrates into an inner cavity of the positioning ring, the outer surface of the isolating ring is fixedly sleeved with a telescopic pipe, and the left end of the telescopic pipe and the left end of the isolating ring make contact with the baffle ring. And the telescopic pipe pushes the baffle ring to generate displacement, so that the baffle ring moves towards the interior of the positioning ring to shield the weld joint of the pipeline, so that the pipeline is self-repaired, LNG fuel is prevented from leaking, and meanwhile, the guide rod can be driven to generate displacement to extrude the pressure sensor.

Description

Technical Field

[0001] This utility model relates to an LNG fuel system pipeline, and more particularly to a container ship LNG fuel system pipeline with self-repairing function applied in the field of container ship LNG fuel transportation. Background Technology

[0002] Liquefied natural gas, or LNG for short, is mainly composed of methane. It is recognized as the cleanest fossil fuel on Earth. It is colorless, odorless, non-toxic, and non-corrosive. It has a high calorific value and produces very little air pollution after combustion. Therefore, LNG is a relatively advanced energy source. Its manufacturing process involves purifying the natural gas produced from the gas field, liquefying it through a series of cryogenic processes, and then transporting it via LNG pipelines or LNG carriers.

[0003] LNG (liquefied natural gas) fuel pipelines present unique hazards during use, primarily due to LNG's extremely low temperature (approximately -162°C), flammability (with methane as the main component), and phase change characteristics (the liquid to gas phase expands approximately 600 times in volume). The pipeline's interior remains in an extremely low temperature state for extended periods, making the welds between the two pipe sections prone to cracking, which can lead to LNG fuel leaks. Once LNG fuel leaks, the temperature difference between the inside and outside of the pipeline causes the LNG fuel to rapidly vaporize, forming a large amount of low-temperature natural gas vapor. If the flammable vapor cloud formed by the leak encounters an ignition source (such as an open flame, static spark, electrical equipment spark, high-temperature surface, lightning, etc.), it is highly susceptible to ignition, causing a fire.

[0004] The specification of Chinese Patent Publication No. CN218914123U discloses an LNG transmission pipeline. This utility model, through a first flange, a second flange, and other components, allows for quick assembly and disassembly of the transmission pipeline compared to conventional bolt fixing. It also prevents the pipeline from being difficult to disassemble due to bolt rust or stripping. Although this installation method does not require welding to connect the two pipelines, the sealing materials (such as gaskets and fillers) at the pipeline flanges, springs, and other connections may harden, shrink, or lose elasticity at low temperatures, leading to seal failure and leakage. Utility Model Content

[0005] The technical problem that this utility model aims to solve in view of the above-mentioned prior art is that the inside of the conveying pipeline is in an ultra-low temperature state for a long time, which makes the weld seam between the two pipelines prone to cracking. The leaked LNG fuel is prone to cause fire. Although the existing conveying pipeline avoids weld seam connection, the sealing material is also prone to sealing failure at low temperature.

[0006] To address the aforementioned problems, this utility model provides a container ship LNG fuel system pipeline with self-repairing function, comprising two parallel LNG pipelines welded together, with a positioning ring fixedly fitted around both pipelines at the weld seam. A retaining ring and an isolation ring are movably and fixedly fitted around the right-hand LNG pipeline, respectively. The left end of the retaining ring extends movably into the inner cavity of the positioning ring. A telescopic tube is fixedly fitted onto the outer surface of the isolation ring, with the left ends of both the telescopic tube and the isolation ring contacting the retaining ring. Multiple exhaust pipes are fixedly connected between the positioning ring and the telescopic tube. The LNG pipeline is externally fixed with flange plates, and an expansion joint is connected between the two flange plates. A positioning block is fixedly embedded in the upper end of the expansion joint. A partition is fixedly connected to the inner cavity of the positioning block. Magnetic blocks are provided at both the upper and lower ends of the partition. The two magnetic blocks attract each other, and a guide rod is fixedly connected to the ends of the two magnetic blocks that are far apart. Sliding grooves are carved at both the upper and lower ends of the positioning block. The lower guide rod moves through the adjacent sliding groove and is fixedly connected to a retaining ring. The upper guide rod moves through the adjacent sliding groove and is fixedly connected to a top rod. A mounting plate is fixedly connected to the upper end of the positioning block, and a pressure sensor is fixedly connected to the right end of the mounting plate.

[0007] In the aforementioned container ship LNG fuel system pipeline with self-repair function, the expansion and vaporization of LNG fuel drives the deformation and extension of the telescopic pipe, which in turn pushes the retaining ring to move inward toward the positioning ring, thus shielding the weld seam of the pipeline and performing self-repair to prevent LNG fuel leakage. At the same time, it can also drive the guide rod to move, squeezing the pressure sensor and warning the staff.

[0008] As a further improvement to this application, multiple exhaust pipes are arranged in a ring array around the LNG pipeline, with the positioning ring, telescopic pipe and exhaust pipe connected together.

[0009] As a further improvement of this application, the outer ring surface of the retaining ring is slidably connected to the inner ring surface of the positioning ring, and the inner ring surface of the retaining ring is in contact with the outer surface of the LNG pipeline.

[0010] As a further improvement of this application, the width of the retaining ring is greater than the distance between the weld seam of the retaining ring and the two LNG pipelines. The right end of the lower guide rod is on the same horizontal plane as the right end of the retaining ring. When the left end of the lower guide rod contacts the right end of the positioning ring, the top rod contacts the pressure sensor.

[0011] As another improvement of this application, the longitudinal section of the isolation ring is L-shaped, and the telescopic tube is made of low-temperature resistant metal material.

[0012] As another improvement of this application, a gas concentration detector is installed on the left end of the positioning ring, and multiple heating rods are fixedly connected to the outer surface of the positioning ring. The pressure sensor, the gas concentration detector and the heating rods are all connected to the signal of an external controller.

[0013] In summary, in practical applications, if a crack occurs at the weld joint of two LNG pipelines and LNG fuel leaks, the LNG fuel will enter the positioning ring. The temperature difference between the inside and outside of the LNG pipeline will cause the LNG fuel to vaporize. The vaporized gas will then enter the telescopic pipe through the exhaust pipe, causing the telescopic pipe to deform and expand. This will push the retaining ring towards the inside of the positioning ring until the guide rod below contacts the positioning ring. At this point, the retaining ring will completely cover the weld joint of the two LNG pipelines, thus achieving a self-repairing function and effectively preventing LNG fuel leakage. Attached Figure Description

[0014] Figure 1 This is a three-dimensional structural diagram of the first embodiment of this application;

[0015] Figure 2 This is a structural cross-sectional view of the first embodiment of this application;

[0016] Figure 3 This is a schematic diagram of the LNG pipeline structure according to the first embodiment of this application;

[0017] Figure 4 This is a schematic diagram of the positioning ring structure according to the first embodiment of this application;

[0018] Figure 5 This is a schematic diagram of the retaining ring structure according to the first embodiment of this application;

[0019] Figure 6 This is a schematic diagram of the expansion joint structure according to the first embodiment of this application;

[0020] Figure 7 This is a schematic diagram of the positioning block structure according to the first embodiment of this application;

[0021] Figure 8 This is a schematic diagram of the movement of the retaining ring according to the first embodiment of this application;

[0022] Figure 9 This is a schematic diagram of the structure of the second embodiment of this application.

[0023] Explanation of the labels in the diagram:

[0024] 1 LNG pipeline, 2 positioning ring, 3 retaining ring, 4 isolation ring, 5 telescopic pipe, 6 exhaust pipe, 7 flange plate, 8 expansion joint, 9 positioning block, 10 partition plate, 11 magnetic block, 12 guide rod, 13 slide groove, 14 top rod, 15 mounting plate, 16 pressure sensor, 17 gas concentration detector, 18 heating rod. Detailed Implementation

[0025] The two embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0026] First implementation method:

[0027] Figures 1-5 The diagram shows a container ship LNG fuel system pipeline with self-repairing function, comprising two parallel LNG pipelines 1, welded together, and both LNG pipelines 1 are jointly and fixedly fitted with a positioning ring 2. The positioning ring 2 is mainly a leakage gas collection chamber, located at the weld seam of the two LNG pipelines 1. A retaining ring 3 and an isolation ring 4 are respectively movably and fixedly fitted on the right LNG pipeline 1. The retaining ring 3 is a crack shielding actuator, shielding the weld seam of the two LNG pipelines 1. The isolation ring 4 has an L-shaped longitudinal section. The telescopic pipe 5 is made of a low-temperature resistant metal material. The gas produced after LNG fuel is vaporized generates a large pressure, causing the telescopic tube 5 to deform and expand, thereby pushing the retaining ring 3 toward the interior of the positioning ring 2. The left end of the retaining ring 3 moves through the inner cavity of the positioning ring 2. The telescopic tube 5 is fixedly sleeved on the outer surface of the isolation ring 4. The left ends of both the telescopic tube 5 and the isolation ring 4 are in contact with the retaining ring 3. Multiple exhaust pipes 6 are fixedly connected between the positioning ring 2 and the telescopic tube 5. The multiple exhaust pipes 6 are arranged in a ring array around the LNG pipeline 1. The positioning ring 2, the telescopic tube 5 and the exhaust pipes 6 are connected. After the LNG fuel is vaporized, it enters the telescopic tube 5 through the multiple exhaust pipes 6.

[0028] Figure 1 , Figure 2 , Figure 6 and Figure 7The diagram shows that: LNG pipeline 1 is externally fixedly connected to flange plate 7, and an expansion joint 8 is connected between the two flange plates 7. The expansion joint 8 can absorb thermal expansion and contraction displacement, thereby effectively improving the stability of the two LNG pipelines 1 during use. A positioning block 9 is fixedly embedded in the upper end of the expansion joint 8, and a partition plate 10 is fixedly connected to the inner cavity of the positioning block 9. The partition plate 10 keeps the expansion joint 8 in a sealed state. Magnetic blocks 11 are provided at both the upper and lower ends of the partition plate 10. The two magnetic blocks 11 attract each other. When the lower magnetic block 11 moves, the upper magnetic block 11 that is attracted to it also moves. Guide rods 12 are fixedly connected to the ends of the two magnetic blocks 11 that are far apart. Sliding grooves 13 are carved at both the upper and lower ends of the positioning block 9. The lower guide rod 12 moves through the adjacent sliding groove 13 and is fixedly connected to the retaining ring 3. Next, the upper guide rod 12 moves through the adjacent slide 13 and is fixedly connected to the top rod 14. The upper end of the positioning block 9 is fixedly connected to the mounting plate 15, and the right end of the mounting plate 15 is fixedly connected to the pressure sensor 16. Those skilled in the art can select a suitable model of pressure sensor 16 according to actual needs, such as LP-9026wt. When the retaining ring 3 moves, the lower guide rod 12 moves with the retaining ring 3, causing the lower magnetic block 11 to move to the left. The two magnetic blocks 11 attract each other, causing the upper magnetic block 11 and the guide rod 12 to move synchronously. After the retaining ring 3 completely blocks the weld seams of the two LNG pipes 1, the top rod 14 also comes into contact with the pressure sensor 16, thereby transmitting the signal to the external controller to alert the staff.

[0029] Figure 8 The diagram shows that the outer ring surface of the retaining ring 3 is slidably connected to the inner ring surface of the positioning ring 2, and the inner ring surface of the retaining ring 3 is in contact with the outer surface of the LNG pipeline 1. The width of the retaining ring 3 is greater than the distance between the weld seams of the retaining ring 3 and the two LNG pipelines 1. The right end of the lower guide rod 12 is at the same horizontal plane as the right end of the retaining ring 3. When the left end of the lower guide rod 12 contacts the right end of the positioning ring 2, the top rod 14 contacts the pressure sensor 16, the telescopic tube 5 deforms and expands, pushing the retaining ring 3 toward the inside of the positioning ring 2. The lower guide rod 12 moves with the movement of the retaining ring 3, driving the two magnetic blocks 11 to move, so that the top rod 14 moves until it squeezes the pressure sensor 16, thereby triggering the pressure sensor 16. The black arrows in the figure indicate the moving direction of the retaining ring 3 and the guide rod 12, and the gray dashed arrows indicate the gas flow direction after the LNG fuel is vaporized.

[0030] When LNG fuel is transported using LNG pipeline 1, if a crack occurs at the weld between the two LNG pipelines 1, LNG fuel will leak out. At this time, the LNG fuel will enter the positioning ring 2. The temperature difference between the inside and outside of LNG pipeline 1 will cause the LNG fuel to vaporize. The vaporized gas will enter the telescopic pipe 5 through the exhaust pipe 6, causing the telescopic pipe 5 to deform and expand. This will push the retaining ring 3 towards the inside of the positioning ring 2 until the guide rod 12 below contacts the positioning ring 2. At this time, the retaining ring 3 will completely cover the weld between the two LNG pipelines 1, thus achieving a self-repairing function and effectively preventing LNG fuel leakage.

[0031] Second implementation method:

[0032] This embodiment adds a gas concentration detector 17 and a heating rod 18 to the first embodiment, while the rest remains the same as the first embodiment.

[0033] Figure 9 As shown: A gas concentration detector 17 is installed on the left end of the positioning ring 2. Those skilled in the art can select a suitable model of gas concentration detector 17 according to actual needs, such as FGD2-C-CO. Multiple heating rods 18 are fixedly connected to the outer surface of the positioning ring 2. Those skilled in the art can select a suitable model of heating rod 18 according to actual needs, such as Q10X80. The pressure sensor 16, gas concentration detector 17 and heating rods 18 are all connected to the signal of an external controller.

[0034] Even with good insulation, the temperature of the outer surface of the pipeline is still much lower than the ambient temperature. When a crack appears at the weld of LNG pipeline 1, the gas concentration detector 17 detects methane gas inside the positioning ring 2 and can activate the heating rod 18 to heat the positioning ring 2, thereby increasing the temperature difference between the inside and outside of LNG pipeline 1, which in turn promotes the gasification speed of LNG fuel and allows the gas to enter the telescopic pipe 5 more quickly, effectively improving the response speed.

[0035] This implementation method is optional and not necessary. In specific implementation, the first or second implementation method can be used according to actual needs.

[0036] In light of current practical needs, the above-described embodiments adopted in this application are not limited to these. Any changes made within the scope of knowledge possessed by those skilled in the art without departing from the concept of this application still fall within the protection scope of this utility model.

Claims

1. A container ship LNG fuel system pipeline with self-repair function, comprising two parallel LNG pipelines (1), characterized in that: Two LNG pipelines (1) are welded together, and a positioning ring (2) is fixedly fitted on the outside of both LNG pipelines (1). The positioning ring (2) is located at the weld of the two LNG pipelines (1). A retaining ring (3) and an isolation ring (4) are movably fitted and fixedly fitted on the outside of the LNG pipeline (1) on the right side. The left end of the retaining ring (3) movably penetrates into the inner cavity of the positioning ring (2). A telescopic tube (5) is fixedly fitted on the outer surface of the isolation ring (4). The left ends of the telescopic tube (5) and the isolation ring (4) are in contact with the retaining ring (3). Multiple exhaust pipes (6) are fixedly connected between the positioning ring (2) and the telescopic tube (5). The LNG pipeline (1) is fixedly connected to a flange plate (7), and an expansion joint (8) is connected between the two flange plates (7). A positioning block (9) is fixedly embedded in the upper end of the expansion joint (8). A partition plate (10) is fixedly connected to the inner cavity of the positioning block (9). A magnetic block (11) is provided at both the upper and lower ends of the partition plate (10). The two magnetic blocks (11) attract each other, and a guide rod (12) is fixedly connected to the ends of the two magnetic blocks (11) that are far apart. A sliding groove (13) is chiseled at both the upper and lower ends of the positioning block (9). The lower guide rod (12) moves through the adjacent sliding groove (13) and is fixedly connected to the retaining ring (3). The upper guide rod (12) moves through the adjacent sliding groove (13) and is fixedly connected to the top rod (14). An installation plate (15) is fixedly connected to the upper end of the positioning block (9). A pressure sensor (16) is fixedly connected to the right end of the installation plate (15).

2. A container ship LNG fuel system pipeline with self-repairing function according to claim 1, characterized in that: Multiple exhaust pipes (6) are arranged in a ring array around the LNG pipeline (1), and the positioning ring (2), telescopic pipe (5) and exhaust pipes (6) are connected.

3. A container ship LNG fuel system pipeline with self-repairing function according to claim 1, characterized in that: The outer ring surface of the retaining ring (3) is slidably connected to the inner ring surface of the positioning ring (2), and the inner ring surface of the retaining ring (3) is in contact with the outer surface of the LNG pipeline (1).

4. A container ship LNG fuel system pipeline with self-repairing function according to claim 3, characterized in that: The width of the retaining ring (3) is greater than the distance between the retaining ring (3) and the weld seam of the two LNG pipes (1). The right end of the lower guide rod (12) is on the same horizontal plane as the right end of the retaining ring (3). When the left end of the lower guide rod (12) contacts the right end of the positioning ring (2), the top rod (14) contacts the pressure sensor (16).

5. A container ship LNG fuel system pipeline with self-repairing function according to claim 1, characterized in that: The longitudinal section of the isolation ring (4) is L-shaped, and the telescopic tube (5) is made of low-temperature resistant metal material.

6. A container ship LNG fuel system pipeline with self-repairing function according to claim 1, characterized in that: A gas concentration detector (17) is installed on the left end of the positioning ring (2), and multiple heating rods (18) are fixedly connected to the outer surface of the positioning ring (2). The pressure sensor (16), the gas concentration detector (17) and the heating rods (18) are all connected to the signal of the external controller.

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